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Dalrymple AN, Fisher LE, Weber DJ. A preliminary study exploring the effects of transcutaneous spinal cord stimulation on spinal excitability and phantom limb pain in people with a transtibial amputation. J Neural Eng 2024; 21:046058. [PMID: 39094627 DOI: 10.1088/1741-2552/ad6a8d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 08/02/2024] [Indexed: 08/04/2024]
Abstract
Objective. Phantom limb pain (PLP) is debilitating and affects over 70% of people with lower-limb amputation. Other neuropathic pain conditions correspond with increased spinal excitability, which can be measured using reflexes andF-waves. Spinal cord neuromodulation can be used to reduce neuropathic pain in a variety of conditions and may affect spinal excitability, but has not been extensively used for treating PLP. Here, we propose using a non-invasive neuromodulation method, transcutaneous spinal cord stimulation (tSCS), to reduce PLP and modulate spinal excitability after transtibial amputation.Approach. We recruited three participants, two males (5- and 9-years post-amputation, traumatic and alcohol-induced neuropathy) and one female (3 months post-amputation, diabetic neuropathy) for this 5 d study. We measured pain using the McGill Pain Questionnaire (MPQ), visual analog scale (VAS), and pain pressure threshold (PPT) test. We measured spinal reflex and motoneuron excitability using posterior root-muscle (PRM) reflexes andF-waves, respectively. We delivered tSCS for 30 min d-1for 5 d.Main Results. After 5 d of tSCS, MPQ scores decreased by clinically-meaningful amounts for all participants from 34.0 ± 7.0-18.3 ± 6.8; however, there were no clinically-significant decreases in VAS scores. Two participants had increased PPTs across the residual limb (Day 1: 5.4 ± 1.6 lbf; Day 5: 11.4 ± 1.0 lbf).F-waves had normal latencies but small amplitudes. PRM reflexes had high thresholds (59.5 ± 6.1μC) and low amplitudes, suggesting that in PLP, the spinal cord is hypoexcitable. After 5 d of tSCS, reflex thresholds decreased significantly (38.6 ± 12.2μC;p< 0.001).Significance. These preliminary results in this non-placebo-controlled study suggest that, overall, limb amputation and PLP may be associated with reduced spinal excitability and tSCS can increase spinal excitability and reduce PLP.
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Affiliation(s)
- Ashley N Dalrymple
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
- NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America
- Department of Physical Medicine & Rehabilitation, University of Utah, Salt Lake City, UT, United States of America
- NERVES Lab, University of Utah, Salt Lake City, UT, United States of America
| | - Lee E Fisher
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Douglas J Weber
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
- NeuroMechatronics Lab, Carnegie Mellon University, Pittsburgh, PA, United States of America
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA, United States of America
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2
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Pitkin M, Park H, Frossard L, Klishko AN, Prilutsky BI. Transforming the Anthropomorphic Passive Free-Flow Foot Prosthesis Into a Powered Foot Prosthesis With Intuitive Control and Sensation (Bionic FFF). Mil Med 2024; 189:439-447. [PMID: 39160882 DOI: 10.1093/milmed/usae149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/19/2024] [Accepted: 03/15/2024] [Indexed: 08/21/2024] Open
Abstract
INTRODUCTION Approximately 89% of all service members with amputations do not return to duty. Restoring intuitive neural control with somatosensory sensation is a key to improving the safety and efficacy of prosthetic locomotion. However, natural somatosensory feedback from lower-limb prostheses has not yet been incorporated into any commercial prostheses. MATERIALS AND METHODS We developed a neuroprosthesis with intuitive bidirectional control and somatosensation and evoking phase-dependent locomotor reflexes, we aspire to significantly improve the prosthetic rehabilitation and long-term functional outcomes of U.S. amputees. We implanted the skin and bone integrated pylon with peripheral neural interface pylon into the cat distal tibia, electromyographic electrodes into the residual gastrocnemius muscle, and nerve cuff electrodes on the distal tibial and sciatic nerves. Results. The bidirectional neural interface that was developed was integrated into the existing passive Free-Flow Foot and Ankle prosthesis, WillowWood, Mount Sterling, OH. The Free-Flow Foot was chosen because it had the highest Index of Anthropomorphicity among lower-limb prostheses and was the first anthropomorphic prosthesis brought to market. Conclusion. The cats walked on a treadmill with no cutaneous feedback from the foot in the control condition and with their residual distal tibial nerve stimulated during the stance phase of walking.
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Affiliation(s)
- Mark Pitkin
- Poly-Orth International, Sharon, MA 02067, USA
- Tufts University School of Medicine, Boston, MA 02111, USA
| | - Hangue Park
- Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
- Biomedical Engineering, Sungkyunkwan University, Suwon 16419, South Korea
- Intelligent Prevision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, South Korea
| | - Laurent Frossard
- Griffith University, Griffith Centre of Biomedical and Rehabilitation Engineering (GCORE), Southport, QLD 4215, Australia
- YourResearchProject Ptd Ltd, Brisbane, QLD 4065, Australia
| | - Alexander N Klishko
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
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3
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Song H, Hsieh TH, Yeon SH, Shu T, Nawrot M, Landis CF, Friedman GN, Israel EA, Gutierrez-Arango S, Carty MJ, Freed LE, Herr HM. Continuous neural control of a bionic limb restores biomimetic gait after amputation. Nat Med 2024; 30:2010-2019. [PMID: 38951635 PMCID: PMC11271427 DOI: 10.1038/s41591-024-02994-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 04/11/2024] [Indexed: 07/03/2024]
Abstract
For centuries scientists and technologists have sought artificial leg replacements that fully capture the versatility of their intact biological counterparts. However, biological gait requires coordinated volitional and reflexive motor control by complex afferent and efferent neural interplay, making its neuroprosthetic emulation challenging after limb amputation. Here we hypothesize that continuous neural control of a bionic limb can restore biomimetic gait after below-knee amputation when residual muscle afferents are augmented. To test this hypothesis, we present a neuroprosthetic interface consisting of surgically connected, agonist-antagonist muscles including muscle-sensing electrodes. In a cohort of seven leg amputees, the interface is shown to augment residual muscle afferents by 18% of biologically intact values. Compared with a matched amputee cohort without the afferent augmentation, the maximum neuroprosthetic walking speed is increased by 41%, enabling equivalent peak speeds to persons without leg amputation. Further, this level of afferent augmentation enables biomimetic adaptation to various walking speeds and real-world environments, including slopes, stairs and obstructed pathways. Our results suggest that even a small augmentation of residual muscle afferents restores biomimetic gait under continuous neuromodulation in individuals with leg amputation.
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Affiliation(s)
- Hyungeun Song
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tsung-Han Hsieh
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Seong Ho Yeon
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tony Shu
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Michael Nawrot
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Mechanical Engineering Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Christian F Landis
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Gabriel N Friedman
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Erica A Israel
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Samantha Gutierrez-Arango
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew J Carty
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Division of Plastic and Reconstructive Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Lisa E Freed
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Hugh M Herr
- K. Lisa Yang Center for Bionics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
- McGovern Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
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4
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Katic Secerovic N, Balaguer JM, Gorskii O, Pavlova N, Liang L, Ho J, Grigsby E, Gerszten PC, Karal-Ogly D, Bulgin D, Orlov S, Pirondini E, Musienko P, Raspopovic S, Capogrosso M. Neural population dynamics reveals disruption of spinal circuits' responses to proprioceptive input during electrical stimulation of sensory afferents. Cell Rep 2024; 43:113695. [PMID: 38245870 PMCID: PMC10962447 DOI: 10.1016/j.celrep.2024.113695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 11/08/2023] [Accepted: 01/06/2024] [Indexed: 01/23/2024] Open
Abstract
While neurostimulation technologies are rapidly approaching clinical applications for sensorimotor disorders, the impact of electrical stimulation on network dynamics is still unknown. Given the high degree of shared processing in neural structures, it is critical to understand if neurostimulation affects functions that are related to, but not targeted by, the intervention. Here, we approach this question by studying the effects of electrical stimulation of cutaneous afferents on unrelated processing of proprioceptive inputs. We recorded intraspinal neural activity in four monkeys while generating proprioceptive inputs from the radial nerve. We then applied continuous stimulation to the radial nerve cutaneous branch and quantified the impact of the stimulation on spinal processing of proprioceptive inputs via neural population dynamics. Proprioceptive pulses consistently produce neural trajectories that are disrupted by concurrent cutaneous stimulation. This disruption propagates to the somatosensory cortex, suggesting that electrical stimulation can perturb natural information processing across the neural axis.
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Affiliation(s)
- Natalija Katic Secerovic
- School of Electrical Engineering, University of Belgrade, 11000 Belgrade, Serbia; The Mihajlo Pupin Institute, University of Belgrade, 11060 Belgrade, Serbia; Laboratory for Neuroengineering, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland
| | - Josep-Maria Balaguer
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Oleg Gorskii
- Institute of Translational Biomedicine, Saint-Petersburg State University, 199034 Saint-Petersburg, Russia; Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 Saint-Petersburg, Russia; National University of Science and Technology "MISIS," 4 Leninskiy Pr., 119049 Moscow, Russia
| | - Natalia Pavlova
- Institute of Translational Biomedicine, Saint-Petersburg State University, 199034 Saint-Petersburg, Russia
| | - Lucy Liang
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Jonathan Ho
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Erinn Grigsby
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Peter C Gerszten
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Dzhina Karal-Ogly
- National Research Centre "Kurchatov Institute," 123098 Moscow, Russia
| | - Dmitry Bulgin
- National Research Centre "Kurchatov Institute," 123098 Moscow, Russia; Sirius University of Science and Technology, 354340 Sochi, Russia
| | - Sergei Orlov
- National Research Centre "Kurchatov Institute," 123098 Moscow, Russia
| | - Elvira Pirondini
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Pavel Musienko
- Institute of Translational Biomedicine, Saint-Petersburg State University, 199034 Saint-Petersburg, Russia; Sirius University of Science and Technology, 354340 Sochi, Russia; Life Improvement by Future Technologies Center "LIFT," 143025 Moscow, Russia
| | - Stanisa Raspopovic
- Laboratory for Neuroengineering, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland.
| | - Marco Capogrosso
- Rehab and Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neural Basis of Cognition, Pittsburgh, PA, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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5
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Taghlabi KM, Cruz-Garza JG, Hassan T, Potnis O, Bhenderu LS, Guerrero JR, Whitehead RE, Wu Y, Luan L, Xie C, Robinson JT, Faraji AH. Clinical outcomes of peripheral nerve interfaces for rehabilitation in paralysis and amputation: a literature review. J Neural Eng 2024; 21:011001. [PMID: 38237175 DOI: 10.1088/1741-2552/ad200f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 01/18/2024] [Indexed: 02/02/2024]
Abstract
Peripheral nerve interfaces (PNIs) are electrical systems designed to integrate with peripheral nerves in patients, such as following central nervous system (CNS) injuries to augment or replace CNS control and restore function. We review the literature for clinical trials and studies containing clinical outcome measures to explore the utility of human applications of PNIs. We discuss the various types of electrodes currently used for PNI systems and their functionalities and limitations. We discuss important design characteristics of PNI systems, including biocompatibility, resolution and specificity, efficacy, and longevity, to highlight their importance in the current and future development of PNIs. The clinical outcomes of PNI systems are also discussed. Finally, we review relevant PNI clinical trials that were conducted, up to the present date, to restore the sensory and motor function of upper or lower limbs in amputees, spinal cord injury patients, or intact individuals and describe their significant findings. This review highlights the current progress in the field of PNIs and serves as a foundation for future development and application of PNI systems.
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Affiliation(s)
- Khaled M Taghlabi
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
| | - Jesus G Cruz-Garza
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
| | - Taimur Hassan
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- School of Medicine, Texas A&M University, Bryan, TX 77807, United States of America
| | - Ojas Potnis
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- School of Engineering Medicine, Texas A&M University, Houston, TX 77030, United States of America
| | - Lokeshwar S Bhenderu
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- School of Medicine, Texas A&M University, Bryan, TX 77807, United States of America
| | - Jaime R Guerrero
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
| | - Rachael E Whitehead
- Department of Academic Affairs, Houston Methodist Academic Institute, Houston, TX 77030, United States of America
| | - Yu Wu
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Lan Luan
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Chong Xie
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Jacob T Robinson
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Amir H Faraji
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America
- Center for Neural Systems Restoration, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Clinical Innovations Laboratory, Houston Methodist Research Institute, Houston, TX 77030, United States of America
- Rice Neuroengineering Initiative, Rice University, Houston, TX 77005, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
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6
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Donati E, Valle G. Neuromorphic hardware for somatosensory neuroprostheses. Nat Commun 2024; 15:556. [PMID: 38228580 PMCID: PMC10791662 DOI: 10.1038/s41467-024-44723-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/03/2024] [Indexed: 01/18/2024] Open
Abstract
In individuals with sensory-motor impairments, missing limb functions can be restored using neuroprosthetic devices that directly interface with the nervous system. However, restoring the natural tactile experience through electrical neural stimulation requires complex encoding strategies. Indeed, they are presently limited in effectively conveying or restoring tactile sensations by bandwidth constraints. Neuromorphic technology, which mimics the natural behavior of neurons and synapses, holds promise for replicating the encoding of natural touch, potentially informing neurostimulation design. In this perspective, we propose that incorporating neuromorphic technologies into neuroprostheses could be an effective approach for developing more natural human-machine interfaces, potentially leading to advancements in device performance, acceptability, and embeddability. We also highlight ongoing challenges and the required actions to facilitate the future integration of these advanced technologies.
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Affiliation(s)
- Elisa Donati
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland.
| | - Giacomo Valle
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA.
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7
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Barberi F, Anselmino E, Mazzoni A, Goldfarb M, Micera S. Toward the Development of User-Centered Neurointegrated Lower Limb Prostheses. IEEE Rev Biomed Eng 2024; 17:212-228. [PMID: 37639425 DOI: 10.1109/rbme.2023.3309328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The last few years witnessed radical improvements in lower-limb prostheses. Researchers have presented innovative solutions to overcome the limits of the first generation of prostheses, refining specific aspects which could be implemented in future prostheses designs. Each aspect of lower-limb prostheses has been upgraded, but despite these advances, a number of deficiencies remain and the most capable limb prostheses fall far short of the capabilities of the healthy limb. This article describes the current state of prosthesis technology; identifies a number of deficiencies across the spectrum of lower limb prosthetic components with respect to users' needs; and discusses research opportunities in design and control that would substantially improve functionality concerning each deficiency. In doing so, the authors present a roadmap of patients related issues that should be addressed in order to fulfill the vision of a next-generation, neurally-integrated, highly-functional lower limb prosthesis.
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8
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Manoharan S, Park H. Characterization of perception by transcutaneous electrical Stimulation in terms of tingling intensity and temporal dynamics. Biomed Eng Lett 2024; 14:35-44. [PMID: 38186955 PMCID: PMC10770012 DOI: 10.1007/s13534-023-00308-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/12/2023] [Accepted: 07/28/2023] [Indexed: 01/09/2024] Open
Abstract
Electrotactile feedback is a cost-effective and versatile method to provide new information or to augment intrinsic tactile feedback. As tactile feedback provides critical information for human-environment interaction, electrotactile feedback, accordingly, has many purposes to improve the quality of human-environment interaction in both direct and remote settings. However, electrotactile feedback overlays tingling sensation on top of the natural tactile feedback. To better characterize electrotactile feedback and understand the origin of the tingling sensation, a need arises to characterize the human perception of electrotactile feedback qualitatively and quantitatively, while varying the key stimulation parameters, namely amplitude and frequency. This study consists of two experiments. In the first experiment, the voltage for each subject was characterized by setting perception and discomfort thresholds. In the second experiment, subjects received electrical stimulation in 9 different combinations of voltages and frequencies. On delivering stimulation with each parameter combination, subjects reported their perception in two comparative scales-pressure vs. tingling and constant vs. pulsing. Subjects also reported the location of perception for stimulation with every parameter combination. More tingling and less pressure was reported as frequency increased, while the tingling-pressure percept was not affected by the amplitude change. Additionally, less pulsing and more constant was reported as frequency increased, while the pulsing-constant percept was not affected by the amplitude change. Concurrently, the normalized level of voltage thresholds was decreased as frequency increased. Dependency of tingling-pressure percept on stimulation frequency suggests that incongruency between the stimulation frequency and the natural firing rate of the sensory neuron would be an important factor of the tingling sensation. This study is a steppingstone to further demystify the origin of the tingling percept caused by electrical stimulation, thus broadening the use of transcutaneous electrical stimulation as a way of providing tactile cue or augmentation.
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Affiliation(s)
- Stefan Manoharan
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX USA
| | - Hangue Park
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX USA
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, South Korea
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9
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Nanivadekar AC, Bose R, Petersen BA, Okorokova EV, Sarma D, Madonna TJ, Barra B, Farooqui J, Dalrymple AN, Levy I, Helm ER, Miele VJ, Boninger ML, Capogrosso M, Bensmaia SJ, Weber DJ, Fisher LE. Restoration of sensory feedback from the foot and reduction of phantom limb pain via closed-loop spinal cord stimulation. Nat Biomed Eng 2023:10.1038/s41551-023-01153-8. [PMID: 38097809 DOI: 10.1038/s41551-023-01153-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/27/2023] [Indexed: 12/30/2023]
Abstract
Restoring somatosensory feedback in individuals with lower-limb amputations would reduce the risk of falls and alleviate phantom limb pain. Here we show, in three individuals with transtibial amputation (one traumatic and two owing to diabetic peripheral neuropathy), that sensations from the missing foot, with control over their location and intensity, can be evoked via lateral lumbosacral spinal cord stimulation with commercially available electrodes and by modulating the intensity of stimulation in real time on the basis of signals from a wireless pressure-sensitive shoe insole. The restored somatosensation via closed-loop stimulation improved balance control (with a 19-point improvement in the composite score of the Sensory Organization Test in one individual) and gait stability (with a 5-point improvement in the Functional Gait Assessment in one individual). And over the implantation period of the stimulation leads, the three individuals experienced a clinically meaningful decrease in phantom limb pain (with an average reduction of nearly 70% on a visual analogue scale). Our findings support the further clinical assessment of lower-limb neuroprostheses providing somatosensory feedback.
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Affiliation(s)
- Ameya C Nanivadekar
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Rohit Bose
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Bailey A Petersen
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Elizaveta V Okorokova
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA
| | - Devapratim Sarma
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Tyler J Madonna
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Beatrice Barra
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neuroscience and Movement Science, University of Fribourg, Fribourg, Switzerland
| | - Juhi Farooqui
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
| | - Ashley N Dalrymple
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
- Department of Physical Medicine and Rehabilitation, University of Utah, Salt Lake City, UT, USA
| | - Isaiah Levy
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Eric R Helm
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Vincent J Miele
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael L Boninger
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA
| | - Marco Capogrosso
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sliman J Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA
| | - Douglas J Weber
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Lee E Fisher
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA.
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA.
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10
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Pan L, Ren Z, Zhu K, Li J. Eliciting tactile sensations in the hand through non-invasive proximal nerve stimulation: a feasibility study. Med Biol Eng Comput 2023; 61:3225-3232. [PMID: 37721698 DOI: 10.1007/s11517-023-02923-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
Recently, non-invasive proximal nerve stimulation has been widely investigated to restore tactile sensations. It has been demonstrated that tactile sensations in the hand could be elicited by nerve stimulation on the upper arm. However, it is still unknown whether tactile sensations could be elicited by stimulation at a proximal location close to the neck. In this study, non-invasive proximal nerve stimulation tests were performed to elicit tactile sensations in the hand of subjects. Six Ag/AgCl gel electrodes (2 × 3) were placed on the supraclavicular fossa where the proximal parts of the brachial plexus nerves were located. Then, fifteen potential electrode pairs were tested to explore whether tactile sensations could be elicited by non-invasive proximal nerve stimulation. Eight able-bodied subjects (male) were recruited to participate in the test. The stimulated sensation regions in the hand and the sensory intensity were reported and recorded during the experiment. The results demonstrated that the tactile sensations in various regions in the hand could be elicited through non-invasive nerve stimulation at the proximal location close to the neck.
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Affiliation(s)
- Lizhi Pan
- The Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin, 300350, China
| | - Zhihao Ren
- The Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin, 300350, China
| | - Kun Zhu
- The Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin, 300350, China
| | - Jianmin Li
- The Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin, 300350, China.
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11
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Kim D, Triolo R, Charkhkar H. Plantar somatosensory restoration enhances gait, speed perception, and motor adaptation. Sci Robot 2023; 8:eadf8997. [PMID: 37820003 DOI: 10.1126/scirobotics.adf8997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
Lower limb loss is a major insult to the body's nervous and musculoskeletal systems. Despite technological advances in prosthesis design, artificial limbs are not yet integrated into the body's physiological systems. Therefore, lower limb amputees (LLAs) experience lower balance confidence, higher fear of falls, and impaired gait compared with their able-bodied peers (ABs). Previous studies have demonstrated that restored sensations perceived as originating directly from the missing limb via neural interfaces improve balance and performance in certain ambulatory tasks; however, the effects of such evoked sensations on neural circuitries involved in the locomotor activity are not well understood. In this work, we investigated the effects of plantar sensation elicited by peripheral nerve stimulation delivered by multicontact nerve cuff electrodes on gait symmetry and stability, speed perception, and motor adaptation. We found that restored plantar sensation increased stance time and propulsive force on the prosthetic side, improved gait symmetry, and yielded an enhanced perception of prosthetic limb movement. Our results show that the locomotor adaptation among LLAs with plantar sensation became similar to that of ABs. These findings suggest that our peripheral nerve-based approach to elicit plantar sensation directly affects central nervous pathways involved in locomotion and motor adaptation during walking. Our neuroprosthesis provided a unique model to investigate the role of somatosensation in the lower limb during walking and its effects on perceptual recalibration after a locomotor adaptation task. Furthermore, we demonstrated how plantar sensation in LLAs could effectively increase mobility, improve walking dynamics, and possibly reduce fall risks.
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Affiliation(s)
- Daekyoo Kim
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA
- Department of Physical Education, Korea University, Seoul 02841, Korea
| | - Ronald Triolo
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA
| | - Hamid Charkhkar
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA
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12
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Borda L, Gozzi N, Preatoni G, Valle G, Raspopovic S. Automated calibration of somatosensory stimulation using reinforcement learning. J Neuroeng Rehabil 2023; 20:131. [PMID: 37752607 PMCID: PMC10523674 DOI: 10.1186/s12984-023-01246-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 09/13/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND The identification of the electrical stimulation parameters for neuromodulation is a subject-specific and time-consuming procedure that presently mostly relies on the expertise of the user (e.g., clinician, experimenter, bioengineer). Since the parameters of stimulation change over time (due to displacement of electrodes, skin status, etc.), patients undergo recurrent, long calibration sessions, along with visits to the clinics, which are inefficient and expensive. To address this issue, we developed an automatized calibration system based on reinforcement learning (RL) allowing for accurate and efficient identification of the peripheral nerve stimulation parameters for somatosensory neuroprostheses. METHODS We developed an RL algorithm to automatically select neurostimulation parameters for restoring sensory feedback with transcutaneous electrical nerve stimulation (TENS). First, the algorithm was trained offline on a dataset comprising 49 subjects. Then, the neurostimulation was then integrated with a graphical user interface (GUI) to create an intuitive AI-based mapping platform enabling the user to autonomously perform the sensation characterization procedure. We assessed the algorithm against the performance of both experienced and naïve and of a brute force algorithm (BFA), on 15 nerves from five subjects. Then, we validated the AI-based platform on six neuropathic nerves affected by distal sensory loss. RESULTS Our automatized approach demonstrated the ability to find the optimal values of neurostimulation achieving reliable and comfortable elicited sensations. When compared to alternatives, RL outperformed the naïve and BFA, significantly decreasing the time for mapping and the number of delivered stimulation trains, while improving the overall quality. Furthermore, the RL algorithm showed performance comparable to trained experimenters. Finally, we exploited it successfully for eliciting sensory feedback in neuropathic patients. CONCLUSIONS Our findings demonstrated that the AI-based platform based on a RL algorithm can automatically and efficiently calibrate parameters for somatosensory nerve stimulation. This holds promise to avoid experts' employment in similar scenarios, thanks to the merging between AI and neurotech. Our RL algorithm has the potential to be used in other neuromodulation fields requiring a mapping process of the stimulation parameters. TRIAL REGISTRATION ClinicalTrial.gov (Identifier: NCT04217005).
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Affiliation(s)
- Luigi Borda
- Laboratory for Neuroengineering, Department of Health Science and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092, Zurich, Switzerland
| | - Noemi Gozzi
- Laboratory for Neuroengineering, Department of Health Science and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092, Zurich, Switzerland
| | - Greta Preatoni
- Laboratory for Neuroengineering, Department of Health Science and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092, Zurich, Switzerland
| | - Giacomo Valle
- Laboratory for Neuroengineering, Department of Health Science and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092, Zurich, Switzerland
| | - Stanisa Raspopovic
- Laboratory for Neuroengineering, Department of Health Science and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092, Zurich, Switzerland.
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13
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Li S, Triolo RJ, Charkhkar H. Neural sensory stimulation does not interfere with the H-reflex in individuals with lower limb amputation. Front Neurosci 2023; 17:1276308. [PMID: 37817801 PMCID: PMC10560717 DOI: 10.3389/fnins.2023.1276308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 09/12/2023] [Indexed: 10/12/2023] Open
Abstract
Introduction Individuals with lower limb loss experience an increased risk of falls partly due to the lack of sensory feedback from their missing foot. It is possible to restore plantar sensation perceived as originating from the missing foot by directly interfacing with the peripheral nerves remaining in the residual limb, which in turn has shown promise in improving gait and balance. However, it is yet unclear how these electrically elicited plantar sensation are integrated into the body's natural sensorimotor control reflexes. Historically, the H-reflex has been used as a model for investigating sensorimotor control. Within the spinal cord, an array of inputs, including plantar cutaneous sensation, are integrated to produce inhibitory and excitatory effects on the H-reflex. Methods In this study, we characterized the interplay between electrically elicited plantar sensations and this intrinsic reflex mechanism. Participants adopted postures mimicking specific phases of the gait cycle. During each posture, we electrically elicited plantar sensation, and subsequently the H-reflex was evoked both in the presence and absence of these sensations. Results Our findings indicated that electrically elicited plantar sensations did not significantly alter the H-reflex excitability across any of the adopted postures. Conclusion This suggests that individuals with lower limb loss can directly benefit from electrically elicited plantar sensation during walking without disrupting the existing sensory signaling pathways that modulate reflex responses.
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Affiliation(s)
- Suzhou Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Louis Stokes Cleveland Veteran Affairs Medical Center, Cleveland, OH, United States
| | - Ronald J. Triolo
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Louis Stokes Cleveland Veteran Affairs Medical Center, Cleveland, OH, United States
| | - Hamid Charkhkar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Louis Stokes Cleveland Veteran Affairs Medical Center, Cleveland, OH, United States
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14
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Sun H, He C, Vujaklija I. Design trends in actuated lower-limb prosthetic systems: a narrative review. Expert Rev Med Devices 2023; 20:1157-1172. [PMID: 37925668 DOI: 10.1080/17434440.2023.2279999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 11/02/2023] [Indexed: 11/07/2023]
Abstract
INTRODUCTION Actuated lower limb prostheses, including powered (active) and semi-active (quasi-passive) joints, are endowed with controllable power and/or impedance, which can be advantageous to limb impairment individuals by improving locomotion mechanics and reducing the overall metabolic cost of ambulation. However, an increasing number of commercial and research-focused options have made navigating this field a daunting task for users, researchers, clinicians, and professionals. AREAS COVERED The present paper provides an overview of the latest trends and developments in the field of actuated lower-limb prostheses and corresponding technologies. Following a gentle summary of essential gait features, we introduce and compare various actuated prosthetic solutions in academia and the market designed to provide assistance at different levels of impairments. Correspondingly, we offer insights into the latest developments of sockets and suspension systems, before finally discussing the established and emerging trends in surgical approaches aimed at improving prosthetic experience through enhanced physical and neural interfaces. EXPERT OPINION The ongoing challenges and future research opportunities in the field are summarized for exploring potential avenues for development of next generation of actuated lower limb prostheses. In our opinions, a closer multidisciplinary integration can be found in the field of actuated lower-limb prostheses in the future.
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Affiliation(s)
- Haoran Sun
- School of Mechanical Engineering, Southwest Jiaotong University, Chengdu, P.R. China
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
| | - Chaoming He
- School of Mechanical Engineering, Southwest Jiaotong University, Chengdu, P.R. China
| | - Ivan Vujaklija
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
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15
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Symbiotic electroneural and musculoskeletal framework to encode proprioception via neurostimulation: ProprioStim. iScience 2023; 26:106248. [PMID: 36923003 PMCID: PMC10009292 DOI: 10.1016/j.isci.2023.106248] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/23/2022] [Accepted: 02/16/2023] [Indexed: 02/23/2023] Open
Abstract
Peripheral nerve stimulation in amputees achieved the restoration of touch, but not proprioception, which is critical in locomotion. A plausible reason is the lack of means to artificially replicate the complex activity of proprioceptors. To uncover this, we coupled neuromuscular models from ten subjects and nerve histologies from two implanted amputees to develop ProprioStim: a framework to encode proprioception by electrical evoking neural activity in close agreement with natural proprioceptive activity. We demonstrated its feasibility through non-invasive stimulation on seven healthy subjects comparing it with standard linear charge encoding. Results showed that ProprioStim multichannel stimulation was felt more natural, and hold promises for increasing accuracy in knee angle tracking, especially in future implantable solutions. Additionally, we quantified the importance of realistic 3D-nerve models against extruded models previously adopted for further design and validation of novel neurostimulation encoding strategies. ProprioStim provides clear guidelines for the development of neurostimulation policies restoring natural proprioception.
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16
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Schmitt MS, Wright JD, Triolo RJ, Charkhkar H, Graczyk EL. The experience of sensorimotor integration of a lower limb sensory neuroprosthesis: A qualitative case study. Front Hum Neurosci 2023; 16:1074033. [PMID: 36712150 PMCID: PMC9874950 DOI: 10.3389/fnhum.2022.1074033] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 12/13/2022] [Indexed: 01/12/2023] Open
Abstract
Introduction Lower limb prosthesis users often struggle to navigate uneven terrain or ambulate in low light conditions where it can be challenging to rely on visual cues for balance and walking. Sensory feedback about foot-floor interactions may allow users to reduce reliance on secondary sensory cues and improve confidence and speed when navigating difficult terrain. Our group has developed a Sensory Neuroprosthesis (SNP) to restore sensation to people with lower limb amputation by pairing electrical stimulation of nerves in the residual limb applied via implanted neurotechnology with pressure sensors in the insole of a standard prosthesis. Stimulation applied to the nerves evoked sensations perceived as originating on the missing leg and foot. Methods This qualitative case study reports on the experiences of a 68-year-old with a unilateral trans-tibial amputation who autonomously used the SNP at home for 31 weeks. Interview data collected throughout the study period was analyzed using a grounded theory approach with constant comparative methods to understand his experience with this novel technology and its impacts on his daily life. Results A conceptual model was developed that explained the experience of integrating SNP-provided sensory feedback into his body and motor plans. The model described the requirements of integration, which were a combination of a low level of mental focus and low stimulation levels. While higher levels of stimulation and focus could result in distinct sensory percepts and various phantom limb experiences, optimal integration was associated with SNP-evoked sensation that was not readily perceivable. Successful sensorimotor integration of the SNP resulted in improvements to locomotion, a return to a more normal state, an enhancement of perceived prosthesis utility, and a positive outlook on the experience. Discussion These outcomes emerged over the course of the nearly 8 month study, suggesting that findings from long-term home studies of SNPs may differ from those of short-term in-laboratory tests. Our findings on the experience of sensorimotor integration of the SNP have implications for the optimal training of SNP users and the future deployment of clinical SNP systems for long-term home use.
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Affiliation(s)
- Melissa S. Schmitt
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States,Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, OH, United States
| | - John D. Wright
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Ronald J. Triolo
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Hamid Charkhkar
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Emily L. Graczyk
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States,*Correspondence: Emily L. Graczyk,
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17
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Gupta A, Vardalakis N, Wagner FB. Neuroprosthetics: from sensorimotor to cognitive disorders. Commun Biol 2023; 6:14. [PMID: 36609559 PMCID: PMC9823108 DOI: 10.1038/s42003-022-04390-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 12/19/2022] [Indexed: 01/07/2023] Open
Abstract
Neuroprosthetics is a multidisciplinary field at the interface between neurosciences and biomedical engineering, which aims at replacing or modulating parts of the nervous system that get disrupted in neurological disorders or after injury. Although neuroprostheses have steadily evolved over the past 60 years in the field of sensory and motor disorders, their application to higher-order cognitive functions is still at a relatively preliminary stage. Nevertheless, a recent series of proof-of-concept studies suggest that electrical neuromodulation strategies might also be useful in alleviating some cognitive and memory deficits, in particular in the context of dementia. Here, we review the evolution of neuroprosthetics from sensorimotor to cognitive disorders, highlighting important common principles such as the need for neuroprosthetic systems that enable multisite bidirectional interactions with the nervous system.
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Affiliation(s)
- Ankur Gupta
- grid.462010.1Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | | | - Fabien B. Wagner
- grid.462010.1Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
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18
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Park H, Klishko AN, Oh K, Zhang C, Grenga G, Herrin KR, Dalton JF, Kistenberg RS, Lemay MA, Pitkin M, DeWeerth SP, Prilutsky BI. Electrical Stimulation of Distal Tibial Nerve During Stance Phase of Walking May Reverse Effects of Unilateral Paw Pad Anesthesia in the Cat. Motor Control 2023; 27:71-95. [PMID: 36316008 PMCID: PMC9772080 DOI: 10.1123/mc.2022-0096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/18/2022] [Accepted: 09/20/2022] [Indexed: 11/11/2022]
Abstract
Cutaneous feedback from feet is involved in regulation of muscle activity during locomotion, and the lack of this feedback results in motor deficits. We tested the hypothesis that locomotor changes caused by local unilateral anesthesia of paw pads in the cat could be reduced/reversed by electrical stimulation of cutaneous and proprioceptive afferents in the distal tibial nerve during stance. Several split-belt conditions were investigated in four adult female cats. In addition, we investigated the effects of similar distal tibial nerve stimulation on overground walking of one male cat that had a transtibial, bone-anchored prosthesis for 29 months and, thus, had no cutaneous/proprioceptive feedback from the foot. In all treadmill conditions, cats walked with intact cutaneous feedback (control), with right fore- and hindpaw pads anesthetized by lidocaine injections, and with a combination of anesthesia and electrical stimulation of the ipsilateral distal tibial nerve during the stance phase at 1.2× threshold of afferent activation. Electrical stimulation of the distal tibial nerve during the stance phase of walking with anesthetized ipsilateral paw pads reversed or significantly reduced the effects of paw pad anesthesia on several kinematic variables, including lateral center of mass shift, cycle and swing durations, and duty factor. We also found that stimulation of the residual distal tibial nerve in the prosthetic hindlimb often had different effects on kinematics compared with stimulation of the intact hindlimb with paw anesthetized. We suggest that stimulation of cutaneous and proprioceptive afferents in the distal tibial nerve provides functionally meaningful motion-dependent sensory feedback, and stimulation responses depend on limb conditions.
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Affiliation(s)
- Hangue Park
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA,USA
- Department of Electrical & Computer Engineering, Texas A&M University, College Station, TX,USA
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon,South Korea
| | - Alexander N Klishko
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA,USA
| | - Kyunggeune Oh
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA,USA
- Department of Neuroscience and Kennedy Krieger Institute, The Johns Hopkins University School of Medicine, Baltimore, MD,USA
| | - Celina Zhang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA,USA
| | - Gina Grenga
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA,USA
| | - Kinsey R Herrin
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA,USA
| | | | - Robert S Kistenberg
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA,USA
| | | | - Mark Pitkin
- Tufts University School of Medicine, Boston, MA,USA
- Poly-Orth International, Sharon, MA,USA
| | - Stephen P DeWeerth
- School of Electrical and Computer Engineering and Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA,USA
- Departments of Bioengineering and of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA,USA
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA,USA
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19
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Valle G. Peripheral neurostimulation for encoding artificial somatosensations. Eur J Neurosci 2022; 56:5888-5901. [PMID: 36097134 PMCID: PMC9826263 DOI: 10.1111/ejn.15822] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/08/2022] [Accepted: 09/08/2022] [Indexed: 01/11/2023]
Abstract
The direct neural stimulation of peripheral or central nervous systems has been shown as an effective tool to treat neurological conditions. The electrical activation of the nervous sensory pathway can be adopted to restore the artificial sense of touch and proprioception in people suffering from sensory-motor disorders. The modulation of the neural stimulation parameters has a direct effect on the electrically induced sensations, both when targeting the somatosensory cortex and the peripheral somatic nerves. The properties of the artificial sensations perceived, as their location, quality and intensity are strongly dependent on the direct modulation of pulse width, amplitude and frequency of the neural stimulation. Different sensory encoding schemes have been tested in patients showing distinct effects and outcomes according to their impact on the neural activation. Here, I reported the most adopted neural stimulation strategies to artificially encode somatosensation into the peripheral nervous system. The real-time implementation of these strategies in bionic devices is crucial to exploit the artificial sensory feedback in prosthetics. Thus, neural stimulation becomes a tool to directly communicate with the human nervous system. Given the importance of adding artificial sensory information to neuroprosthetic devices to improve their control and functionality, the choice of an optimal neural stimulation paradigm could increase the impact of prosthetic devices on the quality of life of people with sensorimotor disabilities.
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Affiliation(s)
- Giacomo Valle
- Laboratory for Neuroengineering, Department of Health Sciences and TechnologyInstitute for Robotics and Intelligent Systems, ETH ZürichZürichSwitzerland
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20
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Cognitive benefits of using non-invasive compared to implantable neural feedback. Sci Rep 2022; 12:16696. [PMID: 36202893 PMCID: PMC9537330 DOI: 10.1038/s41598-022-21057-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/22/2022] [Indexed: 11/26/2022] Open
Abstract
A non-optimal prosthesis integration into an amputee’s body schema suggests some important functional and health consequences after lower limb amputation. These include low perception of a prosthesis as a part of the body, experiencing it as heavier than the natural limb, and cognitively exhausting use for users. Invasive approaches, exploiting the surgical implantation of electrodes in residual nerves, improved prosthesis integration by restoring natural and somatotopic sensory feedback in transfemoral amputees. A non-invasive alternative that avoids surgery would reduce costs and shorten certification time, significantly increasing the adoption of such systems. To explore this possibility, we compared results from a non-invasive, electro-cutaneous stimulation system to outcomes observed with the use of implants in above the knee amputees. This non-invasive solution was tested in transfemoral amputees through evaluation of their ability to perceive and recognize touch intensity and locations, or movements of a prosthesis, and its cognitive integration (through dual task performance and perceived prosthesis weight). While this managed to evoke the perception of different locations on the artificial foot, and closures of the leg, it was less performant than invasive solutions. Non-invasive stimulation induced similar improvements in dual motor and cognitive tasks compared to neural feedback. On the other hand, results demonstrate that remapped, evoked sensations are less informative and intuitive than the neural evoked somatotopic sensations. The device therefore fails to improve prosthesis embodiment together with its associated weight perception. This preliminary evaluation meaningfully highlights the drawbacks of non-invasive systems, but also demonstrates benefits when performing multiple tasks at once. Importantly, the improved dual task performance is consistent with invasive devices, taking steps towards the expedited development of a certified device for widespread use.
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21
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Sadeghi A, Afshari E, Hashemi M, Kaplan D, Mozafari M. Brainy Biomaterials: Latest Advances in Smart Biomaterials to Develop the Next Generation of Neural Interfaces. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2022. [DOI: 10.1016/j.cobme.2022.100420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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22
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Valle G, Aiello G, Ciotti F, Cvancara P, Martinovic T, Kravic T, Navarro X, Stieglitz T, Bumbasirevic M, Raspopovic S. Multifaceted understanding of human nerve implants to design optimized electrodes for bioelectronics. Biomaterials 2022; 291:121874. [DOI: 10.1016/j.biomaterials.2022.121874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 10/23/2022] [Indexed: 11/24/2022]
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23
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Gonzalez M, Bismuth A, Lee C, Chestek CA, Gates DH. Artificial referred sensation in upper and lower limb prosthesis users: a systematic review. J Neural Eng 2022; 19:10.1088/1741-2552/ac8c38. [PMID: 36001115 PMCID: PMC9514130 DOI: 10.1088/1741-2552/ac8c38] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/23/2022] [Indexed: 11/12/2022]
Abstract
Objective.Electrical stimulation can induce sensation in the phantom limb of individuals with amputation. It is difficult to generalize existing findings as there are many approaches to delivering stimulation and to assessing the characteristics and benefits of sensation. Therefore, the goal of this systematic review was to explore the stimulation parameters that effectively elicited referred sensation, the qualities of elicited sensation, and how the utility of referred sensation was assessed.Approach.We searched PubMed, Web of Science, and Engineering Village through January of 2022 to identify relevant papers. We included papers which electrically induced referred sensation in individuals with limb loss and excluded papers that did not contain stimulation parameters or outcome measures pertaining to stimulation. We extracted information on participant demographics, stimulation approaches, and participant outcomes.Main results.After applying exclusion criteria, 49 papers were included covering nine stimulation methods. Amplitude was the most commonly adjusted parameter (n= 25), followed by frequency (n= 22), and pulse width (n= 15). Of the 63 reports of sensation quality, most reported feelings of pressure (n= 52), paresthesia (n= 48), or vibration (n= 40) while less than half (n= 29) reported a sense of position or movement. Most papers evaluated the functional benefits of sensation (n= 33) using force matching or object identification tasks, while fewer papers quantified subjective measures (n= 16) such as pain or embodiment. Only 15 studies (36%) observed percept intensity, quality, or location over multiple sessions.Significance.Most studies that measured functional performance demonstrated some benefit to providing participants with sensory feedback. However, few studies could experimentally manipulate sensation location or quality. Direct comparisons between studies were limited by variability in methodologies and outcome measures. As such, we offer recommendations to aid in more standardized reporting for future research.
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Affiliation(s)
- Michael Gonzalez
- Department of Robotics, University of Michigan, Ann Arbor, MI, United States of America
| | - Alex Bismuth
- School of Kinesiology, University of Michigan, Ann Arbor, MI, United States of America
| | - Christina Lee
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
| | - Deanna H Gates
- School of Kinesiology, University of Michigan, Ann Arbor, MI, United States of America
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Manoharan S, Oh S, Jiang B, Patton JL, Park H. Electro-prosthetic E-skin Successfully Delivers Finger Aperture Distance by Electro-Prosthetic Proprioception (EPP). ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2022; 2022:4196-4199. [PMID: 36086470 DOI: 10.1109/embc48229.2022.9871592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Electronic skin (E-skin) is an emerging wearable device typically used to mimic the function of the human skin, mainly by replicating the role of tactile sensory receptors in the skin. This study showed an interesting modification of the E-skin, called an electro-prosthetic E-skin, which adds the functionality of distance sensing and stimulation of the palmar digital nerve. The electro-prosthetic E-skin operates as a closed loop to deliver the finger aperture distance information to the nervous system. This E-skin was implemented as an additional layer mounted to the original human skin, to be worn on the fingertip with a thin silicone substrate. The E-skin was designed to be mounted onto the index fingertip, to deliver the distance information between the fingertips and to enhance the finger aperture distance control. In this study, we demonstrated that electro-prosthetic proprioception (EPP), implemented with the electro-prosthetic E-skin, successfully delivered the distance information between the fingertips and enhanced the finger aperture distance control accuracy. Clinical Relevance- Presented electro-prosthetic E-skin delivering finger aperture distance via electro-prosthetic proprioception (EPP) will enhance accuracy of the finger aperture distance control. This technology can be applied to the neurosurgery to minimize unforced errors caused by the limited human control accuracy over the fingertip.
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In vivo closed-loop control of a locust's leg using nerve stimulation. Sci Rep 2022; 12:10864. [PMID: 35760828 PMCID: PMC9237135 DOI: 10.1038/s41598-022-13679-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 05/10/2022] [Indexed: 01/17/2023] Open
Abstract
Activity of an innervated tissue can be modulated based on an acquired biomarker through feedback loops. How to convert this biomarker into a meaningful stimulation pattern is still a topic of intensive research. In this article, we present a simple closed-loop mechanism to control the mean angle of a locust’s leg in real time by modulating the frequency of the stimulation on its extensor motor nerve. The nerve is interfaced with a custom-designed cuff electrode and the feedback loop is implemented online with a proportional control algorithm, which runs solely on a microcontroller without the need of an external computer. The results show that the system can be controlled with a single-input, single-output feedback loop. The model described in this article can serve as a primer for young researchers to learn about neural control in biological systems before applying these concepts in advanced systems. We expect that the approach can be advanced to achieve control over more complex movements by increasing the number of recorded biomarkers and selective stimulation units.
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26
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Fogel HP, Winfree CJ. What’s New in Peripheral Nerve Stimulation. Neurosurg Clin N Am 2022; 33:323-330. [DOI: 10.1016/j.nec.2022.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Basla C, Chee L, Valle G, Raspopovic S. A non-invasive wearable sensory leg neuroprosthesis: mechanical, electrical and functional validation. J Neural Eng 2021; 19. [PMID: 34915454 DOI: 10.1088/1741-2552/ac43f8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 12/16/2021] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Lower limb amputees suffer from a variety of functional deficits related to the absence of sensory communication between the central nervous system and the lost extremity. Indeed, they experience high risk of falls, asymmetric walking and balance, and low prosthesis embodiment, that significantly decrease their quality of life. Presently, there are no commercially available devices able to provide sensory feedback to leg amputees. Recently, some invasive solutions (i.e. requiring a surgery) have been proposed by different research groups, however a non-invasive effective alternative exploitable in everyday life is still missing. APPROACH To address this need we developed and tested a lightweight, non-invasive, wearable technology (NeuroLegs) providing sensory (i.e. knee angle joint and tactile) feedback to the users through electro-cutaneous stimulation. A user-friendly GUI and mobile App have been developed to easily calibrate and control the system. Standard mechanical and electrical tests were performed to assess the safety and reliability of the technology. MAIN RESULTS No mechanical failures, stable communication among system parts and a long-lasting battery (>23h) were demonstrated. The NeuroLegs system was then verified in terms of accuracy in measuring relevant gait parameters in healthy participants. A high temporal reliability was found when detecting stride features (important for the real-time configuration) with a correct match to the walking cadence, in all assessed walking conditions. The effectiveness of the NeuroLegs system at improving walking of three transfemoral amputees was then verified in movement laboratory tests. Increased temporal gait symmetry and augmented confidence were found. Stepping outside from the lab, Neurolegs was successfully exploited by a transfemoral amputee in CYBATHLON Global Edition 2020 in several challenging situations related to daily-living activities. SIGNIFICANCE Our results demonstrate that the NeuroLegs system provides the user with useful sensory information that can be successfully exploited in different walking conditions of daily life.
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Affiliation(s)
- Chiara Basla
- ETH Zurich, Tannenstrasse 1, Zurich, Zürich, 8092, SWITZERLAND
| | - Lauren Chee
- ETH Zurich, Tannenstrasse 1, Zurich, Zürich, 8092, SWITZERLAND
| | - Giacomo Valle
- ETH Zürich, Tannenstrasse 1, Zurich, 8092, SWITZERLAND
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28
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Liu J, Grayden DB, Keast JR, John SE. Computational Modeling of an Endovascular Peripheral Nerve Interface. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:5966-5969. [PMID: 34892477 DOI: 10.1109/embc46164.2021.9630085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Implantable neuromodulation devices that interface with the peripheral nervous system are a promising approach to restore functions lost to nerve damage. Existing nerve stimulation electrodes require direct contact with the target nerve and are associated with mechanical nerve damage and fibrous tissue encapsulation. Endovascularly delivered electrode arrays may provide a less invasive solution. Using a hybrid tissue conductor-neuron model and computational simulations, this study demonstrates the feasibility of delivering electrical stimulation of a peripheral nerve from a blood vessel in the vicinity of the target and predicts that the stimulation intensity required strongly depends on nerve-vessel distance and relative orientation, which are important factors to consider when screening candidate blood vessels for electrode implantation.
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29
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Chandra NS, McCarron WM, Yan Y, Ruiz LC, Sallinger EG, Birenbaum NK, Burton H, Green L, Moran DW, Ray WZ, MacEwan MR. Sensory Percepts Elicited by Chronic Macro-Sieve Electrode Stimulation of the Rat Sciatic Nerve. Front Neurosci 2021; 15:758427. [PMID: 34690689 PMCID: PMC8530229 DOI: 10.3389/fnins.2021.758427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/17/2021] [Indexed: 11/30/2022] Open
Abstract
Objective: Intuitive control of conventional prostheses is hampered by their inability to provide the real-time tactile and proprioceptive feedback of natural sensory pathways. The macro-sieve electrode (MSE) is a candidate interface to amputees’ truncated peripheral nerves for introducing sensory feedback from external sensors to facilitate prosthetic control. Its unique geometry enables selective control of the complete nerve cross-section by current steering. Unlike previously studied interfaces that target intact nerve, the MSE’s implantation requires transection and subsequent regeneration of the target nerve. Therefore, a key determinant of the MSE’s suitability for this task is whether it can elicit sensory percepts at low current levels in the face of altered morphology and caliber distribution inherent to axon regeneration. The present in vivo study describes a combined rat sciatic nerve and behavioral model developed to answer this question. Approach: Rats learned a go/no-go detection task using auditory stimuli and then underwent surgery to implant the MSE in the sciatic nerve. After healing, they were trained with monopolar electrical stimuli with one multi-channel and eight single-channel stimulus configurations. Psychometric curves derived by the method of constant stimuli (MCS) were used to calculate 50% detection thresholds and associated psychometric slopes. Thresholds and slopes were calculated at two time points 3 weeks apart. Main Results: For the multi-channel stimulus configuration, the average current required for stimulus detection was 19.37 μA (3.87 nC) per channel. Single-channel thresholds for leads located near the nerve’s center were, on average, half those of leads located near the periphery (54.92 μA vs. 110.71 μA, or 10.98 nC vs. 22.14 nC). Longitudinally, 3 of 5 leads’ thresholds decreased or remained stable over the 3-week span. The remaining two leads’ thresholds increased by 70–74%, possibly due to scarring or device failure. Significance: This work represents an important first step in establishing the MSE’s viability as a sensory feedback interface. It further lays the groundwork for future experiments that will extend this model to the study of other devices, stimulus parameters, and task paradigms.
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Affiliation(s)
- Nikhil S Chandra
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Weston M McCarron
- Department of Neurosurgery, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Ying Yan
- Department of Neurosurgery, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Luis C Ruiz
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Eric G Sallinger
- Department of Biology, Washington University in St. Louis, St. Louis, MO, United States
| | - Nathan K Birenbaum
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Harold Burton
- Department of Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Leonard Green
- Department of Psychological & Brain Sciences, Washington University in St. Louis, St. Louis, MO, United States
| | - Daniel W Moran
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Wilson Z Ray
- Department of Neurosurgery, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Matthew R MacEwan
- Department of Neurosurgery, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
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30
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Shokur S, Mazzoni A, Schiavone G, Weber DJ, Micera S. A modular strategy for next-generation upper-limb sensory-motor neuroprostheses. MED 2021; 2:912-937. [DOI: 10.1016/j.medj.2021.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 04/28/2021] [Accepted: 05/10/2021] [Indexed: 02/06/2023]
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31
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Fleming A, Stafford N, Huang S, Hu X, Ferris DP, Huang H(H. Myoelectric control of robotic lower limb prostheses: a review of electromyography interfaces, control paradigms, challenges and future directions. J Neural Eng 2021; 18:10.1088/1741-2552/ac1176. [PMID: 34229307 PMCID: PMC8694273 DOI: 10.1088/1741-2552/ac1176] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 07/06/2021] [Indexed: 11/16/2022]
Abstract
Objective.Advanced robotic lower limb prostheses are mainly controlled autonomously. Although the existing control can assist cyclic movements during locomotion of amputee users, the function of these modern devices is still limited due to the lack of neuromuscular control (i.e. control based on human efferent neural signals from the central nervous system to peripheral muscles for movement production). Neuromuscular control signals can be recorded from muscles, called electromyographic (EMG) or myoelectric signals. In fact, using EMG signals for robotic lower limb prostheses control has been an emerging research topic in the field for the past decade to address novel prosthesis functionality and adaptability to different environments and task contexts. The objective of this paper is to review robotic lower limb Prosthesis control via EMG signals recorded from residual muscles in individuals with lower limb amputations.Approach.We performed a literature review on surgical techniques for enhanced EMG interfaces, EMG sensors, decoding algorithms, and control paradigms for robotic lower limb prostheses.Main results.This review highlights the promise of EMG control for enabling new functionalities in robotic lower limb prostheses, as well as the existing challenges, knowledge gaps, and opportunities on this research topic from human motor control and clinical practice perspectives.Significance.This review may guide the future collaborations among researchers in neuromechanics, neural engineering, assistive technologies, and amputee clinics in order to build and translate true bionic lower limbs to individuals with lower limb amputations for improved motor function.
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Affiliation(s)
- Aaron Fleming
- Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695, United States of America
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America
- Equal contribution as the first author
| | - Nicole Stafford
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, United States of America
- Equal contribution as the first author
| | - Stephanie Huang
- Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695, United States of America
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America
| | - Xiaogang Hu
- Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695, United States of America
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America
| | - Daniel P Ferris
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, United States of America
| | - He (Helen) Huang
- Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695, United States of America
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America
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32
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Karczewski AM, Dingle AM, Poore SO. The Need to Work Arm in Arm: Calling for Collaboration in Delivering Neuroprosthetic Limb Replacements. Front Neurorobot 2021; 15:711028. [PMID: 34366820 PMCID: PMC8334559 DOI: 10.3389/fnbot.2021.711028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 06/22/2021] [Indexed: 11/21/2022] Open
Abstract
Over the last few decades there has been a push to enhance the use of advanced prosthetics within the fields of biomedical engineering, neuroscience, and surgery. Through the development of peripheral neural interfaces and invasive electrodes, an individual's own nervous system can be used to control a prosthesis. With novel improvements in neural recording and signal decoding, this intimate communication has paved the way for bidirectional and intuitive control of prostheses. While various collaborations between engineers and surgeons have led to considerable success with motor control and pain management, it has been significantly more challenging to restore sensation. Many of the existing peripheral neural interfaces have demonstrated success in one of these modalities; however, none are currently able to fully restore limb function. Though this is in part due to the complexity of the human somatosensory system and stability of bioelectronics, the fragmentary and as-yet uncoordinated nature of the neuroprosthetic industry further complicates this advancement. In this review, we provide a comprehensive overview of the current field of neuroprosthetics and explore potential strategies to address its unique challenges. These include exploration of electrodes, surgical techniques, control methods, and prosthetic technology. Additionally, we propose a new approach to optimizing prosthetic limb function and facilitating clinical application by capitalizing on available resources. It is incumbent upon academia and industry to encourage collaboration and utilization of different peripheral neural interfaces in combination with each other to create versatile limbs that not only improve function but quality of life. Despite the rapidly evolving technology, if the field continues to work in divided "silos," we will delay achieving the critical, valuable outcome: creating a prosthetic limb that is right for the patient and positively affects their life.
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Affiliation(s)
| | - Aaron M. Dingle
- Division of Plastic Surgery, Department of Surgery, University of Wisconsin–Madison, Madison, WI, United States
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33
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Raspopovic S, Valle G, Petrini FM. Sensory feedback for limb prostheses in amputees. NATURE MATERIALS 2021; 20:925-939. [PMID: 33859381 DOI: 10.1038/s41563-021-00966-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Commercial prosthetic devices currently do not provide natural sensory information on the interaction with objects or movements. The subsequent disadvantages include unphysiological walking with a prosthetic leg and difficulty in controlling the force exerted with a prosthetic hand, thus creating health issues. Restoring natural sensory feedback from the prosthesis to amputees is an unmet clinical need. An optimal device should be able to elicit natural sensations of touch or proprioception, by delivering the complex signals to the nervous system that would be produced by skin, muscles and joints receptors. This Review covers the various neurotechnological approaches that have been proposed for the development of the optimal sensory feedback restoration device for arm and leg amputees.
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Affiliation(s)
- Stanisa Raspopovic
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, Zurich, Switzerland.
| | - Giacomo Valle
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, Zurich, Switzerland
| | - Francesco Maria Petrini
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, Zurich, Switzerland
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34
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Current Stimulation of the Midbrain Nucleus in Pigeons for Avian Flight Control. MICROMACHINES 2021; 12:mi12070788. [PMID: 34209448 PMCID: PMC8305299 DOI: 10.3390/mi12070788] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/18/2021] [Accepted: 06/28/2021] [Indexed: 11/17/2022]
Abstract
A number of research attempts to understand and modulate sensory and motor skills that are beyond the capability of humans have been underway. They have mainly been expounded in rodent models, where numerous reports of controlling movement to reach target locations by brain stimulation have been achieved. However, in the case of birds, although basic research on movement control has been conducted, the brain nuclei that are triggering these movements have yet to be established. In order to fully control flight navigation in birds, the basic central nervous system involved in flight behavior should be understood comprehensively, and functional maps of the birds’ brains to study the possibility of flight control need to be clarified. Here, we established a stable stereotactic surgery to implant multi-wire electrode arrays and electrically stimulated several nuclei of the pigeon’s brain. A multi-channel electrode array and a wireless stimulation system were implanted in thirteen pigeons. The pigeons’ flight trajectories on electrical stimulation of the cerebral nuclei were monitored and analyzed by a 3D motion tracking program to evaluate the behavioral change, and the exact stimulation site in the brain was confirmed by the postmortem histological examination. Among them, five pigeons were able to induce right and left body turns by stimulating the nuclei of the tractus occipito-mesencephalicus (OM), nucleus taeniae (TN), or nucleus rotundus (RT); the nuclei of tractus septo-mesencephalicus (TSM) or archistriatum ventrale (AV) were stimulated to induce flight aviation for flapping and take-off with five pigeons.
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35
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Valle G, Saliji A, Fogle E, Cimolato A, Petrini FM, Raspopovic S. Mechanisms of neuro-robotic prosthesis operation in leg amputees. SCIENCE ADVANCES 2021; 7:7/17/eabd8354. [PMID: 33883127 PMCID: PMC8059925 DOI: 10.1126/sciadv.abd8354] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 03/05/2021] [Indexed: 05/31/2023]
Abstract
Above-knee amputees suffer the lack of sensory information, even while using most advanced prostheses. Restoring intraneural sensory feedback results in functional and cognitive benefits. It is unknown how this artificial feedback, restored through a neuro-robotic leg, influences users' sensorimotor strategies and its implications for future wearable robotics. To unveil these mechanisms, we measured gait markers of a sensorized neuroprosthesis in two leg amputees during motor tasks of different difficulty. Novel sensorimotor strategies were intuitively promoted, allowing for a higher walking speed in both tasks. We objectively quantified the augmented prosthesis' confidence and observed the reshaping of the legs' kinematics toward a more physiological gait. In a possible scenario of a leg amputee driving a conventional car, we showed a finer pressure estimation from the prosthesis. Users exploited different features of the neural stimulation during tasks, suggesting that a simple prosthesis sensorization could be effective for future neuro-robotic prostheses.
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Affiliation(s)
- Giacomo Valle
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland
| | - Albulena Saliji
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland
| | - Ezra Fogle
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland
| | - Andrea Cimolato
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland
| | - Francesco M Petrini
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland
- SensArs Neuroprosthetics, Saint-Sulpice CH-1025, Switzerland
| | - Stanisa Raspopovic
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland.
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Abstract
Peripheral nerve interfaces (PNIs) record and/or modulate neural activity of nerves, which are responsible for conducting sensory-motor information to and from the central nervous system, and for regulating the activity of inner organs. PNIs are used both in neuroscience research and in therapeutical applications such as precise closed-loop control of neuroprosthetic limbs, treatment of neuropathic pain and restoration of vital functions (e.g. breathing and bladder management). Implantable interfaces represent an attractive solution to directly access peripheral nerves and provide enhanced selectivity both in recording and in stimulation, compared to their non-invasive counterparts. Nevertheless, the long-term functionality of implantable PNIs is limited by tissue damage, which occurs at the implant-tissue interface, and is thus highly dependent on material properties, biocompatibility and implant design. Current research focuses on the development of mechanically compliant PNIs, which adapt to the anatomy and dynamic movements of nerves in the body thereby limiting foreign body response. In this paper, we review recent progress in the development of flexible and implantable PNIs, highlighting promising solutions related to materials selection and their associated fabrication methods, and integrated functions. We report on the variety of available interface designs (intraneural, extraneural and regenerative) and different modulation techniques (electrical, optical, chemical) emphasizing the main challenges associated with integrating such systems on compliant substrates.
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Affiliation(s)
- Valentina Paggi
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland. Equally contributing authors
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37
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Earley EJ, Johnson RE, Sensinger JW, Hargrove LJ. Joint speed feedback improves myoelectric prosthesis adaptation after perturbed reaches in non amputees. Sci Rep 2021; 11:5158. [PMID: 33664421 PMCID: PMC7970849 DOI: 10.1038/s41598-021-84795-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/17/2021] [Indexed: 01/31/2023] Open
Abstract
Accurate control of human limbs involves both feedforward and feedback signals. For prosthetic arms, feedforward control is commonly accomplished by recording myoelectric signals from the residual limb to predict the user's intent, but augmented feedback signals are not explicitly provided in commercial devices. Previous studies have demonstrated inconsistent results when artificial feedback was provided in the presence of vision; some studies showed benefits, while others did not. We hypothesized that negligible benefits in past studies may have been due to artificial feedback with low precision compared to vision, which results in heavy reliance on vision during reaching tasks. Furthermore, we anticipated more reliable benefits from artificial feedback when providing information that vision estimates with high uncertainty (e.g. joint speed). In this study, we test an artificial sensory feedback system providing joint speed information and how it impacts performance and adaptation during a hybrid positional-and-myoelectric ballistic reaching task. We found that overall reaching errors were reduced after perturbed control, but did not significantly improve steady-state reaches. Furthermore, we found that feedback about the joint speed of the myoelectric prosthesis control improved the adaptation rate of biological limb movements, which may have resulted from high prosthesis control noise and strategic overreaching with the positional control and underreaching with the myoelectric control. These results provide insights into the relevant factors influencing the improvements conferred by artificial sensory feedback.
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Affiliation(s)
- Eric J Earley
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, USA.
- Center for Bionic Medicine, Shirley Ryan AbilityLab, Chicago, IL, USA.
| | - Reva E Johnson
- Department of Mechanical Engineering and Bioengineering, Valparaiso University, Valparaiso, IN, USA
| | - Jonathon W Sensinger
- Institute of Biomedical Engineering, University of New Brunswick, Fredericton, NB, Canada
- Department of Electrical and Computer Engineering, University of New Brunswick, Fredericton, NB, Canada
| | - Levi J Hargrove
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, USA
- Center for Bionic Medicine, Shirley Ryan AbilityLab, Chicago, IL, USA
- Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA
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Shell CE, Christie BP, Marasco PD, Charkhkar H, Triolo RJ. Lower-Limb Amputees Adjust Quiet Stance in Response to Manipulations of Plantar Sensation. Front Neurosci 2021; 15:611926. [PMID: 33679300 PMCID: PMC7930749 DOI: 10.3389/fnins.2021.611926] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/25/2021] [Indexed: 01/13/2023] Open
Abstract
Interfering with or temporarily eliminating foot-sole tactile sensations causes postural adjustments. Furthermore, individuals with impaired or missing foot-sole sensation, such as lower-limb amputees, exhibit greater postural instability than those with intact sensation. Our group has developed a method of providing tactile feedback sensations projected to the missing foot of lower-limb amputees via electrical peripheral nerve stimulation (PNS) using implanted nerve cuff electrodes. As a step toward effective implementation of the system in rehabilitation and everyday use, we compared postural adjustments made in response to tactile sensations on the missing foot elicited by our system, vibration on the intact foot-sole, and a control condition in which no additional sensory input was applied. Three transtibial amputees with at least a year of experience with tactile sensations provided by our PNS system participated in the study. Participants stood quietly with their eyes closed on their everyday prosthesis while electrically elicited, vibratory, or no additional sensory input was administered for 20 s. Early and steady-state postural adjustments were quantified by center of pressure location, path length, and average angle over the course of each trial. Electrically elicited tactile sensations and vibration both caused shifts in center of pressure location compared to the control condition. Initial (first 3 s) shifts in center of pressure location with electrically elicited or vibratory sensory inputs often differed from shifts measured over the full 20 s trial. Over the full trial, participants generally shifted toward the foot receiving additional sensory input, regardless of stimulation type. Similarities between responses to electrically elicited tactile sensations projected to the missing foot and responses to vibration in analogous regions on the intact foot suggest that the motor control system treats electrically elicited tactile inputs similarly to native tactile inputs. The ability of electrically elicited tactile inputs to cause postural adjustments suggests that these inputs are incorporated into sensorimotor control, despite arising from artificial nerve stimulation. These results are encouraging for application of neural stimulation in restoring missing sensory feedback after limb loss and suggest PNS could provide an alternate method to perturb foot-sole tactile information for investigating integration of tactile feedback with other sensory modalities.
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Affiliation(s)
- Courtney E Shell
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
| | - Breanne P Christie
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States
| | - Paul D Marasco
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
| | - Hamid Charkhkar
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Ronald J Triolo
- Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
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Chandrasekaran S, Nanivadekar AC, McKernan G, Helm ER, Boninger ML, Collinger JL, Gaunt RA, Fisher LE. Sensory restoration by epidural stimulation of the lateral spinal cord in upper-limb amputees. eLife 2020; 9:54349. [PMID: 32691733 PMCID: PMC7373432 DOI: 10.7554/elife.54349] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/21/2020] [Indexed: 12/14/2022] Open
Abstract
Restoring somatosensory feedback to people with limb amputations is crucial to improve prosthetic control. Multiple studies have demonstrated that peripheral nerve stimulation and targeted reinnervation can provide somatotopically relevant sensory feedback. While effective, the surgical procedures required for these techniques remain a major barrier to translatability. Here, we demonstrate in four people with upper-limb amputation that epidural spinal cord stimulation (SCS), a common clinical technique to treat pain, evoked somatosensory percepts that were perceived as emanating from the missing arm and hand. Over up to 29 days, stimulation evoked sensory percepts in consistent locations in the missing hand regardless of time since amputation or level of amputation. Evoked sensations were occasionally described as naturalistic (e.g. touch or pressure), but were often paresthesias. Increasing stimulus amplitude increased the perceived intensity linearly, without increasing area of the sensations. These results demonstrate the potential of SCS as a tool to restore somatosensation after amputations. Even some of the most advanced prosthetic arms lack an important feature: the ability to relay information about touch or pressure to the wearer. In fact, many people prefer to use simpler prostheses whose cables and harnesses pass on information about tension. However, recent studies suggest that electrical stimulation might give prosthesis users more sensation and better control. After an amputation, the nerves that used to deliver sensory information from the hand still exist above the injury. Stimulating these nerves can help to recreate sensations in the missing limb and improve the control of the prosthesis. Still, this stimulation requires complicated surgical interventions to implant electrodes in or around the nerves. Spinal cord stimulation – a technique where a small electrical device is inserted near the spinal cord to stimulate nerves – may be an easier alternative. This approach only requires a simple outpatient procedure, and it is routinely used to treat chronic pain conditions. Now, Chandrasekaran, Nanivadekar et al. show that spinal cord stimulation can produce the feeling of sensations in a person’s missing hand or arm. In the experiments, four people who had an arm amputation underwent spinal cord stimulation over 29 days. During the stimulation, the participants reported feeling electrical buzzing, vibration, or pressure in their missing limb. Changing the strength of the electric signals delivered to the spinal cord altered the intensity of these sensations. The experiments are a step toward developing better prosthetics that restore some sensation. Further studies are now needed to determine whether spinal cord stimulation would allow people to perform sensory tasks with a prosthetic, for example handling an object that they cannot see.
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Affiliation(s)
- Santosh Chandrasekaran
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, United States.,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, United States.,Center for Neural Basis of Cognition, Pittsburgh, United States
| | - Ameya C Nanivadekar
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, United States.,Center for Neural Basis of Cognition, Pittsburgh, United States.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, United States
| | - Gina McKernan
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, United States.,Human Engineering Research Labs, VA Center of Excellence, Department of Veteran Affairs, Pittsburgh, United States
| | - Eric R Helm
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, United States
| | - Michael L Boninger
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, United States.,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, United States.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, United States.,Human Engineering Research Labs, VA Center of Excellence, Department of Veteran Affairs, Pittsburgh, United States.,University of Pittsburgh Clinical Translational Science Institute, Pittsburgh, United States
| | - Jennifer L Collinger
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, United States.,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, United States.,Center for Neural Basis of Cognition, Pittsburgh, United States.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, United States.,Human Engineering Research Labs, VA Center of Excellence, Department of Veteran Affairs, Pittsburgh, United States
| | - Robert A Gaunt
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, United States.,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, United States.,Center for Neural Basis of Cognition, Pittsburgh, United States.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, United States
| | - Lee E Fisher
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, United States.,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, United States.,Center for Neural Basis of Cognition, Pittsburgh, United States.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, United States
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Čvančara P, Boretius T, López-Álvarez VM, Maciejasz P, Andreu D, Raspopovic S, Petrini F, Micera S, Granata G, Fernandez E, Rossini PM, Yoshida K, Jensen W, Divoux JL, Guiraud D, Navarro X, Stieglitz T. Stability of flexible thin-film metallization stimulation electrodes: analysis of explants after first-in-human study and improvement of in vivo performance. J Neural Eng 2020; 17:046006. [PMID: 32512544 DOI: 10.1088/1741-2552/ab9a9a] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Micro-fabricated neural interfaces based on polyimide (PI) are achieving increasing importance in translational research. The ability to produce well-defined micro-structures with properties that include chemical inertness, mechanical flexibility and low water uptake are key advantages for these devices. APPROACH This paper reports the development of the transverse intrafascicular multichannel electrode (TIME) used to deliver intraneural sensory feedback to an upper-limb amputee in combination with a sensorized hand prosthesis. A failure mode analysis on the explanted devices was performed after a first-in-human study limited to 30 d. MAIN RESULTS About 90% of the stimulation contact sites of the TIMEs maintained electrical functionality and stability during the full implant period. However, optical analysis post-explantation revealed that 62.5% of the stimulation contacts showed signs of delamination at the metallization-PI interface. Such damage likely occurred due to handling during explantation and subsequent analysis, since a significant change in impedance was not observed in vivo. Nevertheless, whereas device integrity is mandatory for long-term functionality in chronic implantation, measures to increase the bonding strength of the metallization-PI interface deserve further investigation. We report here that silicon carbide (SiC) is an effective adhesion-promoting layer resisting heavy electrical stimulation conditions within a rodent animal trial. Optical analysis of the new electrodes revealed that the metallization remained unaltered after delivering over 14 million pulses in vivo without signs of delamination at the metallization-PI interface. SIGNIFICANCE Failure mode analysis guided implant stability optimization. Reliable adhesion of thin-film metallization to substrate has been proven using SiC, improving the potential transfer of micro-fabricated neural electrodes for chronic clinical applications. (Document number of Ethical Committee: P/905/CE/2012; Date of approval: 2012-10-04).
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Affiliation(s)
- Paul Čvančara
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering - IMTEK, Albert-Ludwig-University Freiburg, Freiburg, Germany. Author to whom any correspondence should be addressed
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Christie BP, Charkhkar H, Shell CE, Burant CJ, Tyler DJ, Triolo RJ. Ambulatory searching task reveals importance of somatosensation for lower-limb amputees. Sci Rep 2020; 10:10216. [PMID: 32576891 PMCID: PMC7311393 DOI: 10.1038/s41598-020-67032-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/02/2020] [Indexed: 01/29/2023] Open
Abstract
The contribution of somatosensation to locomotor deficits in below-knee amputees (BKAs) has not been fully explored. Unilateral disruption of plantar sensation causes able-bodied individuals to adopt locomotor characteristics that resemble those of unilateral BKAs, suggesting that restoring somatosensation may improve locomotion for amputees. In prior studies, we demonstrated that electrically stimulating the residual nerves of amputees elicited somatosensory percepts that were felt as occurring in the missing foot. Subsequently, we developed a sensory neuroprosthesis that modulated stimulation-evoked sensation in response to interactions between the prosthesis and the environment. To characterize the impact of the sensory neuroprosthesis on locomotion, we created a novel ambulatory searching task. The task involved walking on a horizontal ladder while blindfolded, which engaged plantar sensation while minimizing visual compensation. We first compared the performance of six BKAs to 14 able-bodied controls. Able-bodied individuals demonstrated higher foot placement accuracy than BKAs, indicating that the ladder test was sensitive enough to detect locomotor deficits. When three of the original six BKAs used the sensory neuroprosthesis, the tradeoff between speed and accuracy significantly improved for two of them. This study advanced our understanding of how cutaneous plantar sensation can be used to acquire action-related information during challenging locomotor tasks.
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Affiliation(s)
- Breanne P Christie
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA. .,Louis Stokes Cleveland Deptartment of Veterans Affairs Medical Center, Cleveland, OH, USA.
| | - Hamid Charkhkar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Louis Stokes Cleveland Deptartment of Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Courtney E Shell
- Louis Stokes Cleveland Deptartment of Veterans Affairs Medical Center, Cleveland, OH, USA.,Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Christopher J Burant
- Louis Stokes Cleveland Deptartment of Veterans Affairs Medical Center, Cleveland, OH, USA.,School of Nursing, Case Western Reserve University, Cleveland, OH, USA
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Louis Stokes Cleveland Deptartment of Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Ronald J Triolo
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Louis Stokes Cleveland Deptartment of Veterans Affairs Medical Center, Cleveland, OH, USA
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Pan L, Vargas L, Fleming A, Hu X, Zhu Y, Huang HH. Evoking haptic sensations in the foot through high-density transcutaneous electrical nerve stimulations. J Neural Eng 2020; 17:036020. [PMID: 32348977 DOI: 10.1088/1741-2552/ab8e8d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Evoking haptic sensation on upper limb amputees via peripheral nerve stimulation has been investigated intensively in the past decade, but related studies involving lower limb amputees are limited. This study aimed to evaluate the feasibility of using non-invasive transcutaneous electrical nerve stimulation to evoke haptic sensation along the phantom limb of the amputated foot of transtibial amputees. APPROACH A high-density electrode grid (4 × 4) was placed over the skin surface above the distal branching of the sciatic, tibial, and common peroneal nerves. We hypothesized that electrical stimulation delivered to distinct electrode pairs created unique electric fields, which can activate selective sets of sensory axons innervating different skin regions of the foot. Five transtibial amputee subjects (three unilateral and two bilateral) and one able-bodied subject were tested by scanning all possible electrode pair combinations. MAIN RESULTS All subjects reported various haptic percepts at distinct regions along the foot with each corresponding to specific electrode pairs. These results demonstrated the capability of our non-invasive nerve stimulation method to evoke haptic sensations in the foot of transtibial amputees and the able-bodied subject. SIGNIFICANCE The outcomes contribute important knowledge and evidence regarding missing tactile sensation in the foot of lower limb amputees and might also facilitate future development of strategies to manage phantom pain and enhance embodiment of prosthetic legs in the future.
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Affiliation(s)
- Lizhi Pan
- Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, Tianjin, People's Republic of China
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Charkhkar H, Christie BP, Triolo RJ. Sensory neuroprosthesis improves postural stability during Sensory Organization Test in lower-limb amputees. Sci Rep 2020; 10:6984. [PMID: 32332861 PMCID: PMC7181811 DOI: 10.1038/s41598-020-63936-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/08/2020] [Indexed: 12/26/2022] Open
Abstract
To maintain postural stability, unilateral lower-limb amputees (LLAs) heavily rely on visual and vestibular inputs, and somatosensory cues from their intact leg to compensate for missing somatosensory information from the amputated limb. When any of these resources are compromised, LLAs exhibit poor balance control compared to able-bodied individuals. We hypothesized that restoring somatosensation related to the missing limb via direct activation of the sensory nerves in the residuum would improve the standing stability of LLAs. We developed a closed-loop sensory neuroprosthesis utilizing non-penetrating multi-contact cuff electrodes implanted around the residual nerves to elicit perceptions of the location and intensity of plantar pressures under the prosthetic feet of two transtibial amputees. Effects of the sensory neuroprosthesis on balance were quantified with the Sensory Organization Test and other posturographic measures of sway. In both participants, the sensory neuroprosthesis improved equilibrium and sway when somatosensation from the intact leg and visual inputs were perturbed simultaneously. One participant also showed improvement with the sensory neuroprosthesis whenever somatosensation in the intact leg was compromised via perturbations of the platform. These observations suggest the sensory feedback elicited by neural stimulation can significantly improve the standing stability of LLAs, particularly when other sensory inputs are depleted or otherwise compromised.
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Affiliation(s)
- Hamid Charkhkar
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA. .,Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH, 44106, USA.
| | - Breanne P Christie
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.,Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH, 44106, USA
| | - Ronald J Triolo
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.,Louis Stokes Cleveland Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH, 44106, USA
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Yildiz KA, Shin AY, Kaufman KR. Interfaces with the peripheral nervous system for the control of a neuroprosthetic limb: a review. J Neuroeng Rehabil 2020; 17:43. [PMID: 32151268 PMCID: PMC7063740 DOI: 10.1186/s12984-020-00667-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 02/17/2020] [Indexed: 12/22/2022] Open
Abstract
The field of prosthetics has been evolving and advancing over the past decade, as patients with missing extremities are expecting to control their prostheses in as normal a way as possible. Scientists have attempted to satisfy this expectation by designing a connection between the nervous system of the patient and the prosthetic limb, creating the field of neuroprosthetics. In this paper, we broadly review the techniques used to bridge the patient's peripheral nervous system to a prosthetic limb. First, we describe the electrical methods including myoelectric systems, surgical innovations and the role of nerve electrodes. We then describe non-electrical methods used alone or in combination with electrical methods. Design concerns from an engineering point of view are explored, and novel improvements to obtain a more stable interface are described. Finally, a critique of the methods with respect to their long-term impacts is provided. In this review, nerve electrodes are found to be one of the most promising interfaces in the future for intuitive user control. Clinical trials with larger patient populations, and for longer periods of time for certain interfaces, will help to evaluate the clinical application of nerve electrodes.
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Affiliation(s)
- Kadir A Yildiz
- Motion Analysis Laboratory, Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Alexander Y Shin
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Kenton R Kaufman
- Motion Analysis Laboratory, Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA.
- Motion Analysis Laboratory, W. Hall Wendel, Jr., Musculoskeletal Research, 200 First Street SW, Rochester, MN, 55905, USA.
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Zelechowski M, Valle G, Raspopovic S. A computational model to design neural interfaces for lower-limb sensory neuroprostheses. J Neuroeng Rehabil 2020; 17:24. [PMID: 32075654 PMCID: PMC7029520 DOI: 10.1186/s12984-020-00657-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 02/13/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Leg amputees suffer the lack of sensory feedback from a prosthesis, which is connected to their low confidence during walking, falls and low mobility. Electrical peripheral nerve stimulation (ePNS) of upper-limb amputee's residual nerves has shown the ability to restore the sensations from the missing limb via intraneural (TIME) and epineural (FINE) neural interfaces. Physiologically plausible stimulation protocols targeting lower limb sciatic nerve hold promise to induce sensory feedback restoration that should facilitate close-to-natural sensorimotor integration and therefore walking corrections. The sciatic nerve, innervating the foot and lower leg, has very different dimensions in respect to upper-limb nerves. Therefore, there is a need to develop a computational model of its behavior in response to the ePNS. METHODS We employed a hybrid FEM-NEURON model framework for the development of anatomically correct sciatic nerve model. Based on histological images of two distinct sciatic nerve cross-sections, we reconstructed accurate FEM models for testing neural interfaces. Two different electrode types (based on TIME and FINE) with multiple active sites configurations were tested and evaluated for efficiency (selective recruitment of fascicles). We also investigated different policies of stimulation (monopolar and bipolar), as well as the optimal number of implants. Additionally, we optimized the existing simulation framework significantly reducing the computational load. RESULTS The main findings achieved through our modelling study include electrode manufacturing and surgical placement indications, together with beneficial stimulation policy of use. It results that TIME electrodes with 20 active sites are optimal for lower limb and the same number has been obtained for FINE electrodes. To interface the huge sciatic nerve, model indicates that 3 TIMEs is the optimal number of surgically implanted electrodes. Through the bipolar policy of stimulation, all studied configurations were gaining in the efficiency. Also, an indication for the optimized computation is given, which decreased the computation time by 80%. CONCLUSIONS This computational model suggests the optimal interfaces to use in human subjects with lower limb amputation, their surgical placement and beneficial bipolar policy of stimulation. It will potentially enable the clinical translation of the sensory neuroprosthetics towards the lower limb applications.
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Affiliation(s)
- Marek Zelechowski
- Center for medical Image Analysis & Navigation, Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Giacomo Valle
- Neuroengineering Lab, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH, Zürich, Switzerland
| | - Stanisa Raspopovic
- Neuroengineering Lab, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH, Zürich, Switzerland.
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Wolf EJ, Cruz TH, Emondi AA, Langhals NB, Naufel S, Peng GCY, Schulz BW, Wolfson M. Advanced technologies for intuitive control and sensation of prosthetics. Biomed Eng Lett 2020; 10:119-128. [PMID: 32175133 PMCID: PMC7046895 DOI: 10.1007/s13534-019-00127-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/31/2019] [Indexed: 02/06/2023] Open
Abstract
The Department of Defense, Department of Veterans Affairs and National Institutes of Health have invested significantly in advancing prosthetic technologies over the past 25 years, with the overall intent to improve the function, participation and quality of life of Service Members, Veterans, and all United States Citizens living with limb loss. These investments have contributed to substantial advancements in the control and sensory perception of prosthetic devices over the past decade. While control of motorized prosthetic devices through the use of electromyography has been widely available since the 1980s, this technology is not intuitive. Additionally, these systems do not provide stimulation for sensory perception. Recent research has made significant advancement not only in the intuitive use of electromyography for control but also in the ability to provide relevant meaningful perceptions through various stimulation approaches. While much of this previous work has traditionally focused on those with upper extremity amputation, new developments include advanced bidirectional neuroprostheses that are applicable to both the upper and lower limb amputation. The goal of this review is to examine the state-of-the-science in the areas of intuitive control and sensation of prosthetic devices and to discuss areas of exploration for the future. Current research and development efforts in external systems, implanted systems, surgical approaches, and regenerative approaches will be explored.
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Affiliation(s)
- Erik J. Wolf
- Clinical and Rehabilitative Medicine Research Program, US Army Medical Research and Development Command, Fort Detrick, MD 21702 USA
| | - Theresa H. Cruz
- National Institute of Child Health and Human Development, National Institute of Health, Bethesda, MD 20817 USA
| | - Alfred A. Emondi
- Defense Advanced Research Projects Agency, Arlington, VA 22203 USA
| | - Nicholas B. Langhals
- National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD 20892 USA
| | | | - Grace C. Y. Peng
- National Institute of Biomedical Imaging and Bioengineering, National Institute of Health, Bethesda, MD 20817 USA
| | - Brian W. Schulz
- VA Office of Research and Development, Washington, DC 20002 USA
| | - Michael Wolfson
- National Institute of Biomedical Imaging and Bioengineering, National Institute of Health, Bethesda, MD 20817 USA
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Kiele P, Braig D, Weis J, Baslan Y, Pasluosta C, Stieglitz T. Neural Implants Without Electronics: A Proof-of-Concept Study on a Human Skin Model. IEEE OPEN JOURNAL OF ENGINEERING IN MEDICINE AND BIOLOGY 2020; 1:91-97. [PMID: 35402961 PMCID: PMC8975271 DOI: 10.1109/ojemb.2020.2981254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/16/2020] [Accepted: 03/10/2020] [Indexed: 11/25/2022] Open
Abstract
Objective: Chronic neural implants require energy and signal supply. The objective of this work was to evaluate a multichannel transcutaneous coupling approach in an ex vivo split-concept study, which minimizes the invasiveness of such an implant by externalizing the processing electronics. Methods: Herein, the experimental work focused on the transcutaneous energy and signal transmission. The performance was discussed with widely evaluated concepts of neural interfaces in the literature. Results: The performance of the transcutaneous coupling approach increased with higher channel count and higher electrode pitches. Electrical crosstalk among channels was present, but acceptable for the stimulation of peripheral nerves. Conclusions: Transcutaneous coupling with extracorporeal transmitting arrays and subcutaneous counterparts provide a promising alternative to the inductive concept particularly when a fully integration of the system in a prosthetic shaft is intended. The relocation of the electronics can potentially prevent pressure sores, improve accessibility for maintenance and increase lifetime of the implant.
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Affiliation(s)
- Patrick Kiele
- Laboratory of Biomedical MicrotechnologyDepartment of Microsystems Engineering-IMTEKUniversity of Freiburg 79110 Freiburg Germany
| | - David Braig
- Department of Plastic and Hand Surgery, Medical Center-University of FreiburgFaculty of MedicineUniversity of Freiburg 79106 Freiburg Germany
- Division of HandPlastic and Aesthetic SurgeryUniversity Hospital 80336 LMU Munich Germany
| | - Jakob Weis
- Division of HandPlastic and Aesthetic SurgeryUniversity Hospital 80336 LMU Munich Germany
| | - Yara Baslan
- Laboratory of Biomedical MicrotechnologyDepartment of Microsystems Engineering-IMTEKUniversity of Freiburg 79110 Freiburg Germany
| | - Cristian Pasluosta
- Laboratory of Biomedical MicrotechnologyDepartment of Microsystems Engineering-IMTEKUniversity of Freiburg 79110 Freiburg Germany
| | - Thomas Stieglitz
- Laboratory of Biomedical MicrotechnologyDepartment of Microsystems Engineering-IMTEKUniversity of Freiburg 79110 Freiburg Germany
- Bernstein Center FreiburgUniversity of Freiburg 79098 Freiburg Germany
- BrainLinks-BrainToolsUniversity of Freiburg 79110 Freiburg Germany
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Urbin M, Liu M, Bottorff EC, Gaunt RA, Fisher LE, Weber DJ. Hindlimb motor responses evoked by microstimulation of the lumbar dorsal root ganglia during quiet standing. J Neural Eng 2019; 17:016019. [PMID: 31597128 PMCID: PMC10321059 DOI: 10.1088/1741-2552/ab4c6c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Somatosensory afferent pathways have been a target for neural prostheses that seek to restore sensory feedback from amputated limbs and to recruit muscles paralyzed by neurological injury. These pathways supply inputs to spinal reflex circuits that are necessary for coordinating muscle activity in the lower limb. The dorsal root ganglia (DRG) is a potential site for accessing sensory neurons because DRG microstimulation selectively recruits major nerve branches of the cat hindlimb. Previous DRG microstimulation experiments have been performed in anesthetized animals, but effects on muscle recruitment and behavior in awake animals have not been examined. OBJECTIVE The objective of the current study was to measure the effects of DRG microstimulation on evoking changes in hindlimb muscle activity during quiet standing. APPROACH In this study, 32-channel penetrating microelectrode arrays were implanted chronically in the left L6 and L7 DRG of four cats. During each week of testing, one DRG electrode was selected to deliver microstimulation pulse-trains during quiet standing. Electromyographic (EMG) signals were recorded from intramuscular electrodes in ten hindlimb muscles, and ground-reaction forces (GRF) were measured under the foot of the implanted limb. MAIN RESULTS DRG Microstimulation evoked a mix of excitatory and inhibitory responses across muscles. Response rates were highest when microstimulation was applied on the L7 array, producing more excitatory than inhibitory responses. Response rates for the L6 array were lower, and the composition of responses was more evenly balanced between excitation and inhibition. On approximately one third of testing weeks, microstimulation induced a transient unloading of the hindlimb as indicated by a decrease in GRF. Reciprocal inhibition at the knee was a prevalent response pattern across testing days which contributed to the unloading force on this subset of testing weeks. SIGNIFICANCE Results show that single-channel microstimulation in the lumbar DRG evokes stereotyped patterns of muscle recruitment in awake animals, demonstrating that even limited sensory input can elicit hindlimb behavior. These findings imply that DRG microstimulation may have utility in neural prosthetic applications aimed at restoring somatosensory feedback and promoting motor function after neurological injury.
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Affiliation(s)
- M.A. Urbin
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA, 15213
- VA Pittsburgh Healthcare System, Pittsburgh, PA, USA, 15213
| | - Monica Liu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA, 15213
| | | | - Robert A. Gaunt
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA, 15213
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA, 15213
| | - Lee E. Fisher
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA, 15213
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA, 15213
| | - Douglas J. Weber
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA, 15213
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA, 15213
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King KW, Cusack WF, Nanivadekar AC, Ayers CA, Urbin MA, Gaunt RA, Fisher LE, Weber DJ. DRG microstimulation evokes postural responses in awake, standing felines. J Neural Eng 2019; 17:016014. [PMID: 31648208 PMCID: PMC9124048 DOI: 10.1088/1741-2552/ab50f4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Objective. We have demonstrated previously that microstimulation in the dorsal root ganglia (DRG) can selectively evoke activity in primary afferent neurons in anesthetized cats. This study describes the results of experiments focused on characterizing the postural effects of DRG microstimulation in awake cats during quiet standing. Approach. To understand the parameters of stimulation that can affect these postural shifts, we measured changes in ground reaction forces (GRF) while varying stimulation location and amplitude. Four animals were chronically implanted at the L6 and L7 DRG with penetrating multichannel microelectrode arrays. During each week of testing, we identified electrode channels that recruited primary afferent neurons with fast (80–120 m s−1) and medium (30–75 m s−1) conduction velocities, and selected one channel to deliver current-controlled biphasic stimulation trains during quiet standing. Main results. Postural responses were identified by changes in GRFs and were characterized based on their magnitude and latency. During DRG microstimulation, animals did not exhibit obvious signs of distress or discomfort, which could be indicative of pain or aversion to a noxious sensation. Across 56 total weeks, 13 electrode channels evoked behavioral responses, as detected by a significant change in GRF. Stimulation amplitude modulated the magnitude of the GRF responses for these 13 channels (p < 0.001). It was not possible to predict whether or not an electrode would drive a behavioral response based on information including conduction velocity, recruitment threshold, or the DRG in which it resided. Significance. The distinct and repeatable effects on the postural response to low amplitude (<40 μA) DRG microstimulation support that this technique may be an effective way to restore somatosensory feedback after neurological injuries such as amputation.
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Affiliation(s)
- Kevin W King
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, United States of America. Center for Neural Basis of Cognition, Pittsburgh, PA 15213, United States of America. Rehabilitation Neural Engineering Laboratories, 3520 Fifth Avenue, Suite 300, Pittsburgh, PA 15213, United States of America. KWK and WFC contributed equally to this work. LEF and DJW contributed equally to this work
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50
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Nanivadekar AC, Ayers CA, Gaunt RA, Weber DJ, Fisher LE. Selectivity of afferent microstimulation at the DRG using epineural and penetrating electrode arrays. J Neural Eng 2019; 17:016011. [PMID: 31577993 PMCID: PMC9131467 DOI: 10.1088/1741-2552/ab4a24] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE We have shown previously that microstimulation of the lumbar dorsal root ganglia (L5-L7 DRG) using penetrating microelectrodes, selectively recruits distal branches of the sciatic and femoral nerves in an acute preparation. However, a variety of challenges limit the clinical translatability of DRG microstimulation via penetrating electrodes. For clinical translation of a DRG somatosensory neural interface, electrodes placed on the epineural surface of the DRG may be a viable path forward. The goal of this study was to evaluate the recruitment properties of epineural electrodes and compare their performance with that of penetrating electrodes. Here, we compare the number of selectively recruited distal nerve branches and the threshold stimulus intensities between penetrating and epineural electrode arrays. APPROACH Antidromically propagating action potentials were recorded from multiple distal branches of the femoral and sciatic nerves in response to epineural stimulation on 11 ganglia in four cats to quantify the selectivity of DRG stimulation. Compound action potentials (CAPs) were recorded using nerve cuff electrodes implanted around up to nine distal branches of the femoral and sciatic nerve trunks. We also tested stimulation selectivity with penetrating microelectrode arrays implanted into ten ganglia in four cats. A binary search was carried out to identify the minimum stimulus intensity that evoked a response at any of the distal cuffs, as well as whether the threshold response selectively occurred in only a single distal nerve branch. MAIN RESULTS Stimulation evoked activity in just a single peripheral nerve through 67% of epineural electrodes (35/52) and through 79% of the penetrating microelectrodes (240/308). The recruitment threshold (median = 9.67 nC/phase) and dynamic range of epineural stimulation (median = 1.01 nC/phase) were significantly higher than penetrating stimulation (0.90 nC/phase and 0.36 nC/phase, respectively). However, the pattern of peripheral nerves recruited for each DRG were similar for stimulation through epineural and penetrating electrodes. SIGNIFICANCE Despite higher recruitment thresholds, epineural stimulation provides comparable selectivity and superior dynamic range to penetrating electrodes. These results suggest that it may be possible to achieve a highly selective neural interface with the DRG without penetrating the epineurium.
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Affiliation(s)
- Ameya C Nanivadekar
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, United States of America. Rehabilitation Neural Engineering Laboratories, 3520 Fifth Avenue, Suite 300, Pittsburgh, PA 15213, United States of America. Center for Neural Basis of Cognition, Pittsburgh, PA 15213, United States of America
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