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Lambrecht JM, Cady SR, Peterson EJ, Dunning JL, Dinsmoor DA, Pape F, Graczyk EL, Tyler DJ. A distributed, high-channel-count, implanted bidirectional system for restoration of somatosensation and myoelectric control. J Neural Eng 2024; 21:036049. [PMID: 38861967 DOI: 10.1088/1741-2552/ad56c9] [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: 01/31/2024] [Accepted: 06/11/2024] [Indexed: 06/13/2024]
Abstract
Objective. We intend to chronically restore somatosensation and provide high-fidelity myoelectric control for those with limb loss via a novel, distributed, high-channel-count, implanted system.Approach.We have developed the implanted Somatosensory Electrical Neurostimulation and Sensing (iSens®) system to support peripheral nerve stimulation through up to 64, 96, or 128 electrode contacts with myoelectric recording from 16, 8, or 0 bipolar sites, respectively. The rechargeable central device has Bluetooth® wireless telemetry to communicate to external devices and wired connections for up to four implanted satellite stimulation or recording devices. We characterized the stimulation, recording, battery runtime, and wireless performance and completed safety testing to support its use in human trials.Results.The stimulator operates as expected across a range of parameters and can schedule multiple asynchronous, interleaved pulse trains subject to total charge delivery limits. Recorded signals in saline show negligible stimulus artifact when 10 cm from a 1 mA stimulating source. The wireless telemetry range exceeds 1 m (direction and orientation dependent) in a saline torso phantom. The bandwidth supports 100 Hz bidirectional update rates of stimulation commands and data features or streaming select full bandwidth myoelectric signals. Preliminary first-in-human data validates the bench testing result.Significance.We developed, tested, and clinically implemented an advanced, modular, fully implanted peripheral stimulation and sensing system for somatosensory restoration and myoelectric control. The modularity in electrode type and number, including distributed sensing and stimulation, supports a wide variety of applications; iSens® is a flexible platform to bring peripheral neuromodulation applications to clinical reality. ClinicalTrials.gov ID NCT04430218.
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Affiliation(s)
- Joris M Lambrecht
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States of America
| | - Sedona R Cady
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States of America
| | | | - Jeremy L Dunning
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States of America
| | | | - Forrest Pape
- Medtronic plc, Minneapolis, MN, United States of America
| | - Emily L Graczyk
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States of America
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States of America
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Ding K, Rakhshan M, Paredes-Acuña N, Cheng G, Thakor NV. Sensory integration for neuroprostheses: from functional benefits to neural correlates. Med Biol Eng Comput 2024:10.1007/s11517-024-03118-8. [PMID: 38760597 DOI: 10.1007/s11517-024-03118-8] [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: 04/21/2023] [Accepted: 04/19/2024] [Indexed: 05/19/2024]
Abstract
In the field of sensory neuroprostheses, one ultimate goal is for individuals to perceive artificial somatosensory information and use the prosthesis with high complexity that resembles an intact system. To this end, research has shown that stimulation-elicited somatosensory information improves prosthesis perception and task performance. While studies strive to achieve sensory integration, a crucial phenomenon that entails naturalistic interaction with the environment, this topic has not been commensurately reviewed. Therefore, here we present a perspective for understanding sensory integration in neuroprostheses. First, we review the engineering aspects and functional outcomes in sensory neuroprosthesis studies. In this context, we summarize studies that have suggested sensory integration. We focus on how they have used stimulation-elicited percepts to maximize and improve the reliability of somatosensory information. Next, we review studies that have suggested multisensory integration. These works have demonstrated that congruent and simultaneous multisensory inputs provided cognitive benefits such that an individual experiences a greater sense of authority over prosthesis movements (i.e., agency) and perceives the prosthesis as part of their own (i.e., ownership). Thereafter, we present the theoretical and neuroscience framework of sensory integration. We investigate how behavioral models and neural recordings have been applied in the context of sensory integration. Sensory integration models developed from intact-limb individuals have led the way to sensory neuroprosthesis studies to demonstrate multisensory integration. Neural recordings have been used to show how multisensory inputs are processed across cortical areas. Lastly, we discuss some ongoing research and challenges in achieving and understanding sensory integration in sensory neuroprostheses. Resolving these challenges would help to develop future strategies to improve the sensory feedback of a neuroprosthetic system.
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Affiliation(s)
- Keqin Ding
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
| | - Mohsen Rakhshan
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, FL, 32816, USA
- Disability, Aging, and Technology Cluster, University of Central Florida, Orlando, FL, 32816, USA
| | - Natalia Paredes-Acuña
- Institute for Cognitive Systems, School of Computation, Information and Technology, Technical University of Munich, 80333, Munich, Germany
| | - Gordon Cheng
- Institute for Cognitive Systems, School of Computation, Information and Technology, Technical University of Munich, 80333, Munich, Germany
| | - Nitish V Thakor
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA
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Ghiami Rad A, Shahbazi B. A systematic investigation of sensorimotor mechanisms with intelligent prostheses in patients with ankle amputation while walking. J Mech Behav Biomed Mater 2024; 151:106357. [PMID: 38181570 DOI: 10.1016/j.jmbbm.2023.106357] [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: 09/21/2023] [Accepted: 12/25/2023] [Indexed: 01/07/2024]
Abstract
It is thought that creating sensorimotor feedback in people with ankle joint amputation can affect motor biomechanics during gait, but there is little evidence or previous research. This study e aim ed to investigate the sensorimotor mechanism of smart prostheses in with ankle amputations while walking. Search in Google Scholar, Scopus, PubMed and Medline databases between April 2017 and February 2023, in addition to a detailed review in specialized clinical and engineering databases, 29 articles were selected based on the inclusion and exclusion criteria. Trials that mainly include; Proprioception, walking process in movement disorders, ankle amputation were included. Qualitative assessments of selected trials using PEDro' scale was used. The review of studies showed that the use of pressure sensors, neural stimulation through encoded algorithms can provide continuous tactile and positional information of the artificial leg in the direction of neural stimulation throughout the entire walking cycle. These findings indicate that restoration of intraneuronal sensory feedback leads to functional and cognitive benefits. With these definitions, different companies and research centers are trying to improve the mechanics of walking, however, movement strategies are unknown despite little research in creating sense and movement in the use of smart prostheses.
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Affiliation(s)
- Amir Ghiami Rad
- Movement Biomechanics, Department of Movement Behavior, Faculty of Sports Sciences, University Of Tabriz, Tabriz, Iran.
| | - Behnam Shahbazi
- Movement Biomechanics, Department of Sports Biomechanics, Faculty of Sports Sciences, Bu- Ali Sina University, Hamadan, Iran.
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Fisher LE, Gaunt RA, Huang H. Sensory Restoration for Improved Motor Control of Prostheses. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2023; 28:100498. [PMID: 37860289 PMCID: PMC10583965 DOI: 10.1016/j.cobme.2023.100498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Somatosensory neuroprostheses are devices with the potential to restore the senses of touch and movement from prosthetic limbs for people with limb amputation or paralysis. By electrically stimulating the peripheral or central nervous system, these devices evoke sensations that appear to emanate from the missing or insensate limb, and when paired with sensors on the prosthesis, they can improve the functionality and embodiment of the prosthesis. There have been major advances in the design of these systems over the past decade, although several important steps remain before they can achieve widespread clinical adoption outside the lab setting. Here, we provide a brief overview of somatosensory neuroprostheses and explores these hurdles and potential next steps towards clinical translation.
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Affiliation(s)
- Lee E. Fisher
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Physical Medicine & Rehabilitation, 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 15213, USA
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Robert A. Gaunt
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Physical Medicine & Rehabilitation, 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 15213, USA
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - He Huang
- UNC/NC State Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695, USA
- UNC/NC State Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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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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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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Valette R, Gonzalez-Vargas J, Dosen S. The impact of walking on the perception of multichannel electrotactile stimulation in individuals with lower-limb amputation and able-bodied participants. J Neuroeng Rehabil 2023; 20:108. [PMID: 37592336 PMCID: PMC10436512 DOI: 10.1186/s12984-023-01234-4] [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: 03/20/2023] [Accepted: 08/09/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND One of the drawbacks of lower-limb prostheses is that they do not provide explicit somatosensory feedback to their users. Electrotactile stimulation is an attractive technology to restore such feedback because it enables compact solutions with multiple stimulation points. This allows stimulating a larger skin area to provide more information concurrently and modulate parameters spatially as well as in amplitude. However, for effective use, electrotactile stimulation needs to be calibrated and it would be convenient to perform this procedure while the subject is seated. However, amplitude and spatial perception can be affected by motion and/or physical coupling between the residual limb and the socket. In the present study, we therefore evaluated and compared the psychometric properties of multichannel electrotactile stimulation applied to the thigh/residual limb during sitting versus walking. METHODS The comprehensive assessment included the measurement of the sensation and discomfort thresholds (ST & DT), just noticeable difference (JND), number of distinct intervals (NDI), two-point discrimination threshold (2PD), and spatial discrimination performance (SD). The experiment involved 11 able-bodied participants (4 females and 7 males; 29.2 ± 3.8 years), 3 participants with transtibial amputation, and 3 participants with transfemoral amputation. RESULTS In able-bodied participants, the results were consistent for all the measured parameters, and they indicated that both amplitude and spatial perception became worse during walking. More specifically, ST and DT increased significantly during walking vs. sitting (2.90 ± 0.82 mA vs. 2.00 ± 0.52 mA; p < 0.001 for ST and 7.74 ± 0.84 mA vs. 7.21 ± 1.30 mA; p < 0.05 for DT) and likewise for the JND (22.47 ± 12.21% vs. 11.82 ± 5.07%; p < 0.01), while the NDI became lower (6.46 ± 3.47 vs. 11.27 ± 5.18 intervals; p < 0.01). Regarding spatial perception, 2PD was higher during walking (69.78 ± 17.66 mm vs. 57.85 ± 14.87 mm; p < 0.001), while the performance of SD was significantly lower (56.70 ± 10.02% vs. 64.55 ± 9.44%; p < 0.01). For participants with lower-limb amputation, the ST, DT, and performance in the SD assessment followed the trends observed in the able-bodied population. The results for 2PD and JND were however different and subject-specific. CONCLUSION The conducted evaluation demonstrates that electrotactile feedback should be calibrated in the conditions in which it will be used (e.g., during walking). The calibration during sitting, while more convenient, might lead to an overly optimistic (or in some cases pessimistic) estimate of sensitivity. In addition, the results underline that calibration is particularly important in people affected by lower-limb loss to capture the substantial variability in the conditions of the residual limb and prosthesis setup. These insights are important for the implementation of artificial sensory feedback in lower-limb prosthetics applications.
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Affiliation(s)
- Romain Valette
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | | | - Strahinja Dosen
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
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Osborn LE, Venkatasubramanian R, Himmtann M, Moran CW, Pierce JM, Gajendiran P, Wormley JM, Ung RJ, Nguyen HH, Crego ACG, Fifer MS, Armiger RS. Evoking natural thermal perceptions using a thin-film thermoelectric device with high cooling power density and speed. Nat Biomed Eng 2023:10.1038/s41551-023-01070-w. [PMID: 37500749 DOI: 10.1038/s41551-023-01070-w] [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: 03/15/2021] [Accepted: 06/26/2023] [Indexed: 07/29/2023]
Abstract
Multimodal sensory feedback from upper-limb prostheses can increase their function and usability. Here we show that intuitive thermal perceptions during cold-object grasping with a prosthesis can be restored in a phantom hand through targeted nerve stimulation via a wearable thin-film thermoelectric device with high cooling power density and speed. We found that specific regions of the residual limb, when thermally stimulated, elicited thermal sensations in the phantom hand that remained stable beyond 48 weeks. We also found stimulation sites that selectively elicited sensations of temperature, touch or both, depending on whether the stimulation was thermal or mechanical. In closed-loop functional tasks involving the identification of cold objects by amputees and by non-amputee participants, and compared with traditional bulk thermoelectric devices, the wearable thin-film device reliably elicited cooling sensations that were up to 8 times faster and up to 3 times greater in intensity while using half the energy and 1/600th the mass of active thermoelectric material. Wearable thin-film thermoelectric devices may allow for the non-invasive restoration of thermal perceptions during touch.
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Affiliation(s)
- Luke E Osborn
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA.
| | | | - Meiyong Himmtann
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Courtney W Moran
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Jonathan M Pierce
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Priya Gajendiran
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Jared M Wormley
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Richard J Ung
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Harrison H Nguyen
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Adam C G Crego
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Matthew S Fifer
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Robert S Armiger
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
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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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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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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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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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Osborn LE, Moran C, Dodd LD, Sutton E, Norena Acosta N, Wormley J, Pyles CO, Gordge KD, Nordstrom M, Butkus J, Forsberg JA, Pasquina P, Fifer MS, Armiger RS. Monitoring at-home prosthesis control improvements through real-time data logging. J Neural Eng 2022; 19. [PMID: 35523131 DOI: 10.1088/1741-2552/ac6d7b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 05/06/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Validating the ability for advanced prostheses to improve function beyond the laboratory remains a critical step in enabling long-term benefits for prosthetic limb users. APPROACH A nine week take-home case study was completed with a single participant with upper limb amputation and osseointegration (OI) to better understand how an advanced prosthesis is used during daily activities. The participant was already an expert prosthesis user and used the Modular Prosthetic Limb (MPL) at home during the study. The MPL was controlled using wireless electromyography (EMG) pattern recognition-based movement decoding. Clinical assessments were performed before and after the take-home portion of the study. Data was recorded using an onboard data log in order to measure daily prosthesis usage, sensor data, and EMG data. MAIN RESULT The participant's continuous prosthesis usage steadily increased (p = 0.04, max = 5.5 hr) over time and over 30% of the total time was spent actively controlling the prosthesis. The duration of prosthesis usage after each pattern recognition training session also increased over time (p = 0.04), resulting in up to 5.4 hr of usage before retraining the movement decoding algorithm. Pattern recognition control accuracy improved (1.2% per week, p < 0.001) with a maximum number of 10 classes trained at once and the transitions between different degrees of freedom increased as the study progressed, indicating smooth and efficient control of the advanced prosthesis. Variability of decoding accuracy also decreased with prosthesis usage (p < 0.001) and 30% of the time was spent performing a prosthesis movement. During clinical evaluations, Box and Blocks and the Assessment of the Capacity for Myoelectric Control (ACMC) scores increased by 43% and 6.2%, respectively, demonstrating prosthesis functionality and the NASA Task Load Index (NASA-TLX) scores decreased, on average, by 25% across assessments, indicating reduced cognitive workload while using the MPL, over the nine week study. SIGNIFICANCE In this case study, we demonstrate that an onboard system to monitor prosthesis usage enables better understanding of how prostheses are incorporated into daily life. That knowledge can support the long-term goal of completely restoring independence and quality of life to individuals living with upper limb amputation.
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Affiliation(s)
- Luke E Osborn
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Courtney Moran
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Lauren D Dodd
- Henry M Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Dr, Bethesda, Maryland, 20817, UNITED STATES
| | - Erin Sutton
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Nicolas Norena Acosta
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Jared Wormley
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Connor O Pyles
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Kelles D Gordge
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Michelle Nordstrom
- Department of Rehabilitation, Walter Reed National Military Medical Center, 4494 Palmer Rd N, Bethesda, 20889, UNITED STATES
| | - Josef Butkus
- Department of Rehabilitation, Walter Reed National Military Medical Center, 4494 Palmer Rd N, Bethesda, 20889, UNITED STATES
| | - Jonathan A Forsberg
- Department of Orthopaedic Surgery, Johns Hopkins Medicine, 1800 Orleans St, Baltimore, Maryland, 21287, UNITED STATES
| | - Paul Pasquina
- Department of Rehabilitation, Walter Reed National Military Medical Center, 4494 Palmer Rd N, Bethesda, Maryland, 20814, UNITED STATES
| | - Matthew S Fifer
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
| | - Robert S Armiger
- Research & Exploratory Development, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, Maryland, 20723, UNITED STATES
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Abstract
When animals walk overground, mechanical stimuli activate various receptors located in muscles, joints, and skin. Afferents from these mechanoreceptors project to neuronal networks controlling locomotion in the spinal cord and brain. The dynamic interactions between the control systems at different levels of the neuraxis ensure that locomotion adjusts to its environment and meets task demands. In this article, we describe and discuss the essential contribution of somatosensory feedback to locomotion. We start with a discussion of how biomechanical properties of the body affect somatosensory feedback. We follow with the different types of mechanoreceptors and somatosensory afferents and their activity during locomotion. We then describe central projections to locomotor networks and the modulation of somatosensory feedback during locomotion and its mechanisms. We then discuss experimental approaches and animal models used to investigate the control of locomotion by somatosensory feedback before providing an overview of the different functional roles of somatosensory feedback for locomotion. Lastly, we briefly describe the role of somatosensory feedback in the recovery of locomotion after neurological injury. We highlight the fact that somatosensory feedback is an essential component of a highly integrated system for locomotor control. © 2021 American Physiological Society. Compr Physiol 11:1-71, 2021.
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Affiliation(s)
- Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Quebec, Canada
| | - Turgay Akay
- Department of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
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Koppaka S, Hess-Dunning A, Tyler DJ. Directed stimulation with interfascicular interfaces for peripheral nerve stimulation. J Neural Eng 2021; 18. [PMID: 34706351 DOI: 10.1088/1741-2552/ac33e8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 10/27/2021] [Indexed: 01/10/2023]
Abstract
Objective.Computational models have shown that directional electrical contacts placed within the epineurium, between the fascicles, and not penetrating the perineurium, can achieve selectivity levels similar to point source contacts placed within the fascicle. The objective of this study is to test, in a murine model, the hypothesis that directed interfascicular contacts are selective.Approach.Multiple interfascicular electrodes with directional contacts, exposed on a single face, were implanted in the sciatic nerves of 32 rabbits. Fine-wire intramuscular wire electrodes were implanted to measure electromyographic (EMG) activity from medial and lateral gastrocnemius, soleus, and tibialis anterior muscles.Main results.The recruitment data demonstrated that directed interfascicular interfaces, which do not penetrate the perineurium, selectively activate different axon populations.Significance.Interfascicular interfaces that are inside the nerve, but do not penetrate the perineurium are an alternative to intrafascicular interfaces and may offer additional selectivity compared to extraneural approaches.
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Affiliation(s)
- Smruta Koppaka
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America.,Louis Stokes Cleveland VA Medical Center, Rehabilitation R&D, Cleveland, OH, United States of America.,Advanced Platform Technology (APT) Center, Cleveland, OH, United States of America
| | - Allison Hess-Dunning
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America.,Louis Stokes Cleveland VA Medical Center, Rehabilitation R&D, Cleveland, OH, United States of America.,Advanced Platform Technology (APT) Center, Cleveland, OH, United States of America
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America.,Louis Stokes Cleveland VA Medical Center, Rehabilitation R&D, Cleveland, OH, United States of America.,Advanced Platform Technology (APT) Center, Cleveland, OH, United States of America
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Osborn LE, Christie BP, McMullen DP, Nickl RW, Thompson MC, Pawar AS, Thomas TM, Alejandro Anaya M, Crone NE, Wester BA, Bensmaia SJ, Celnik PA, Cantarero GL, Tenore FV, Fifer MS. Intracortical microstimulation of somatosensory cortex enables object identification through perceived sensations. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:6259-6262. [PMID: 34892544 DOI: 10.1109/embc46164.2021.9630450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Advances in brain-machine interfaces have helped restore function and independence for individuals with sensorimotor deficits; however, providing efficient and effective sensory feedback remains challenging. Intracortical microstimulation (ICMS) of sensorimotor brain regions is a promising technique for providing bioinspired sensory feedback. In a human participant with chronically-implanted microelectrode arrays, we provided ICMS to the primary somatosensory cortex to generate tactile percepts in his hand. In a 3-choice object identification task, the participant identified virtual objects using tactile sensory feedback and no visual information. We evaluated three different stimulation paradigms, each with a different weighting of the grip force and its derivative, to explore the potential benefits of a more bioinspired stimulation strategy. In all paradigms, the participant's ability to identify the objects was above-chance, with object identification accuracy reaching 80% correct when using only sustained grip force feedback and 76.7% when using equal weighting of both sustained grip force and its derivative. These results demonstrate that bioinspired ICMS can provide sensory feedback that is functionally beneficial in sensorimotor tasks. Designing more efficient stimulation paradigms is important because it will allow us to 1) provide safer stimulation delivery methods that reduce overall injected charge without sacrificing function and 2) more effectively transmit sensory information to promote intuitive integration and usage by the human body.
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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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