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Huang Y, Yao K, Zhang Q, Huang X, Chen Z, Zhou Y, Yu X. Bioelectronics for electrical stimulation: materials, devices and biomedical applications. Chem Soc Rev 2024; 53:8632-8712. [PMID: 39132912 DOI: 10.1039/d4cs00413b] [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: 08/13/2024]
Abstract
Bioelectronics is a hot research topic, yet an important tool, as it facilitates the creation of advanced medical devices that interact with biological systems to effectively diagnose, monitor and treat a broad spectrum of health conditions. Electrical stimulation (ES) is a pivotal technique in bioelectronics, offering a precise, non-pharmacological means to modulate and control biological processes across molecular, cellular, tissue, and organ levels. This method holds the potential to restore or enhance physiological functions compromised by diseases or injuries by integrating sophisticated electrical signals, device interfaces, and designs tailored to specific biological mechanisms. This review explains the mechanisms by which ES influences cellular behaviors, introduces the essential stimulation principles, discusses the performance requirements for optimal ES systems, and highlights the representative applications. From this review, we can realize the potential of ES based bioelectronics in therapy, regenerative medicine and rehabilitation engineering technologies, ranging from tissue engineering to neurological technologies, and the modulation of cardiovascular and cognitive functions. This review underscores the versatility of ES in various biomedical contexts and emphasizes the need to adapt to complex biological and clinical landscapes it addresses.
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Affiliation(s)
- Ya Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Kuanming Yao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Qiang Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Xingcan Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Zhenlin Chen
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Yu Zhou
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
| | - Xinge Yu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
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2
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Jiang Z, Zhu M, Chen X. Interfacing Neuron-Motor Pathways with Stretchable and Biocompatible Electrode Arrays. Acc Chem Res 2024; 57:2255-2266. [PMID: 39023124 DOI: 10.1021/acs.accounts.4c00215] [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: 07/20/2024]
Abstract
ConspectusIn the field of neuroscience, understanding the complex interactions within the intricate neuron-motor system depends crucially on the use of high-density, physiological multiple electrode arrays (MEAs). In the neuron-motor system, the transmission of biological signals primarily occurs through electrical and chemical signaling. Taking neurons for instance, when a neuron receives external stimuli, it generates an electrical signal known as the action potential. This action potential propagates along the neuron's axon and is transmitted to other neurons via synapses. At the synapse, chemical signals (neurotransmitters) are released, allowing the electrical signal to traverse the synaptic gap and influence the next neuron. MEAs can provide unparalleled insights into neural signal patterns when interfacing with the nerve systems through their excellent spatiotemporal resolution. However, the inherent differences in mechanical and chemical properties between these artificial devices and biological tissues can lead to serious complications after chronic implantation, such as body rejection, infection, tissue damage, or device malfunction. A promising strategy to enhance MEAs' biocompatibility involves minimizing their thickness, which aligns their bending stiffness with that of surrounding tissues, thereby minimizing damage over time. However, this solution has its limits; the resulting ultrathin devices, typically based on plastic films, lack the necessary stretchability, restricting their use to organs that neither stretch nor grow.For practical deployments, devices must exhibit certain levels of stretchability (ranging from 20 to 70%), tailored to the specific requirements of the target organs. In this Account, we outline recent advancements in developing stretchable MEAs that balance stretchability with sufficient electrical conductivity for effective use in physiological research, acting as sensors and stimulators. By concentrating on the neuron-motor pathways, we summarize how the stretchable MEAs meet various application needs and examine their effectiveness. We distinguish between on-skin and implantable uses, given their vastly different requirements. Within each application scope, we highlight cutting-edge technologies, evaluating their strengths and shortcomings. Recognizing that most current devices rely on elastic films with a Young's modulus value between ∼0.5 and 5 MPa, we delve into the potential for softer MEAs, particularly those using multifunctional hydrogels for an optimizing tissue-device interface and address the challenges in adapting such hydrogel-based MEAs for chronic implants. Additionally, transitioning soft MEAs from lab to fab involves connecting them to a rigid adapter and external machinery, highlighting a critical challenge at the soft-rigid interface due to strain concentration, especially in chronic studies subject to unforeseen mechanical strains. We discuss innovative solutions to this integration challenge, being optimistic that the development of durable, biocompatible, stretchable MEAs will significantly advance neuroscience and related fields.
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Affiliation(s)
- Zhi Jiang
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- School of Integrated Circuits, Harbin Institute of Technology (Shen Zhen), Shenzhen 518055, China
| | - Ming Zhu
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Xiaodong Chen
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
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3
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Romeni S, Toni L, Artoni F, Micera S. Decoding electroencephalographic responses to visual stimuli compatible with electrical stimulation. APL Bioeng 2024; 8:026123. [PMID: 38894958 PMCID: PMC11184972 DOI: 10.1063/5.0195680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
Electrical stimulation of the visual nervous system could improve the quality of life of patients affected by acquired blindness by restoring some visual sensations, but requires careful optimization of stimulation parameters to produce useful perceptions. Neural correlates of elicited perceptions could be used for fast automatic optimization, with electroencephalography as a natural choice as it can be acquired non-invasively. Nonetheless, its low signal-to-noise ratio may hinder discrimination of similar visual patterns, preventing its use in the optimization of electrical stimulation. Our work investigates for the first time the discriminability of the electroencephalographic responses to visual stimuli compatible with electrical stimulation, employing a newly acquired dataset whose stimuli encompass the concurrent variation of several features, while neuroscience research tends to study the neural correlates of single visual features. We then performed above-chance single-trial decoding of multiple features of our newly crafted visual stimuli using relatively simple machine learning algorithms. A decoding scheme employing the information from multiple stimulus presentations was implemented, substantially improving our decoding performance, suggesting that such methods should be used systematically in future applications. The significance of the present work relies in the determination of which visual features can be decoded from electroencephalographic responses to electrical stimulation-compatible stimuli and at which granularity they can be discriminated. Our methods pave the way to using electroencephalographic correlates to optimize electrical stimulation parameters, thus increasing the effectiveness of current visual neuroprostheses.
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Affiliation(s)
| | | | - Fiorenzo Artoni
- Department of Clinical Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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4
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Wang K, Ren S, Jia Y, Yan X. An Ultrasensitive Biomimetic Optic Afferent Nervous System with Circadian Learnability. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2309489. [PMID: 38468430 DOI: 10.1002/advs.202309489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/04/2024] [Indexed: 03/13/2024]
Abstract
The optic afferent nervous system (OANS) plays a significant role in generating vision and circadian behaviors based on light detection and signals from the endocrine system. However, the bionic simulation of this photochemically mediated behavior is still a challenge for neuromorphic devices. Herein, stimuli of neurotransmitters at ultralow concentrations and illumination are coupled to artificial synapses with the aid of biofunctionalized heterojunction and tunneling to successfully simulate a circadian neural response. Furthermore, the mechanisms underlying the photosensitive synaptic current in response to stimuli are described. Interestingly, this OANS is demonstrated to be capable of mimicking normal and abnormal circadian learnability by combining the measured synaptic current with a three-layer spike neural network. Strong theoretical and experimental evidence, as well as applications, are provided for the proposed biomimetic OANS to demonstrate that it can reproduce biological circadian behavior, thus establishing it as a promising candidate for future neuromorphic intelligent robots.
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Affiliation(s)
- Kaiyang Wang
- College of Electronic Information and Optical Engineering, Nankai University, Tianjin, 300071, P. R. China
| | - Shuhui Ren
- College of Electronic Information and Optical Engineering, Nankai University, Tianjin, 300071, P. R. China
| | - Yunfang Jia
- College of Electronic Information and Optical Engineering, Nankai University, Tianjin, 300071, P. R. China
| | - Xiaobing Yan
- Key Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei Province, College of Electron and Information Engineering, Hebei University, Baoding, 071002, P. R. China
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Lu G, Gong C, Sun Y, Qian X, Rajendran Nair DS, Li R, Zeng Y, Ji J, Zhang J, Kang H, Jiang L, Chen J, Chang CF, Thomas BB, Humayun MS, Zhou Q. Noninvasive imaging-guided ultrasonic neurostimulation with arbitrary 2D patterns and its application for high-quality vision restoration. Nat Commun 2024; 15:4481. [PMID: 38802397 PMCID: PMC11130148 DOI: 10.1038/s41467-024-48683-6] [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: 01/03/2024] [Accepted: 05/09/2024] [Indexed: 05/29/2024] Open
Abstract
Retinal degeneration, a leading cause of irreversible low vision and blindness globally, can be partially addressed by retina prostheses which stimulate remaining neurons in the retina. However, existing electrode-based treatments are invasive, posing substantial risks to patients and healthcare providers. Here, we introduce a completely noninvasive ultrasonic retina prosthesis, featuring a customized ultrasound two-dimensional array which allows for simultaneous imaging and stimulation. With synchronous three-dimensional imaging guidance and auto-alignment technology, ultrasonic retina prosthesis can generate programmed ultrasound waves to dynamically and precisely form arbitrary wave patterns on the retina. Neuron responses in the brain's visual center mirrored these patterns, evidencing successful artificial vision creation, which was further corroborated in behavior experiments. Quantitative analysis of the spatial-temporal resolution and field of view demonstrated advanced performance of ultrasonic retina prosthesis and elucidated the biophysical mechanism of retinal stimulation. As a noninvasive blindness prosthesis, ultrasonic retina prosthesis could lead to a more effective, widely acceptable treatment for blind patients. Its real-time imaging-guided stimulation strategy with a single ultrasound array, could also benefit ultrasound neurostimulation in other diseases.
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Affiliation(s)
- Gengxi Lu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Chen Gong
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Yizhe Sun
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Xuejun Qian
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Deepthi S Rajendran Nair
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Runze Li
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Yushun Zeng
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Jie Ji
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Junhang Zhang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Haochen Kang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Laiming Jiang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Jiawen Chen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Chi-Feng Chang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Biju B Thomas
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Mark S Humayun
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA.
- Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA, USA.
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Li P, Zhang J, Hayashi H, Yue J, Li W, Yang C, Sun C, Shi J, Huberman-Shlaes J, Hibino N, Tian B. Monolithic silicon for high spatiotemporal translational photostimulation. Nature 2024; 626:990-998. [PMID: 38383782 DOI: 10.1038/s41586-024-07016-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 01/02/2024] [Indexed: 02/23/2024]
Abstract
Electrode-based electrical stimulation underpins several clinical bioelectronic devices, including deep-brain stimulators1,2 and cardiac pacemakers3. However, leadless multisite stimulation is constrained by the technical difficulties and spatial-access limitations of electrode arrays. Optogenetics offers optically controlled random access with high spatiotemporal capabilities, but clinical translation poses challenges4-6. Here we show tunable spatiotemporal photostimulation of cardiac systems using a non-genetic platform based on semiconductor-enabled biomodulation interfaces. Through spatiotemporal profiling of photoelectrochemical currents, we assess the magnitude, precision, accuracy and resolution of photostimulation in four leadless silicon-based monolithic photoelectrochemical devices. We demonstrate the optoelectronic capabilities of the devices through optical overdrive pacing of cultured cardiomyocytes (CMs) targeting several regions and spatial extents, isolated rat hearts in a Langendorff apparatus, in vivo rat hearts in an ischaemia model and an in vivo mouse heart model with transthoracic optical pacing. We also perform the first, to our knowledge, optical override pacing and multisite pacing of a pig heart in vivo. Our systems are readily adaptable for minimally invasive clinical procedures using our custom endoscopic delivery device, with which we demonstrate closed-thoracic operations and endoscopic optical stimulation. Our results indicate the clinical potential of the leadless, lightweight and multisite photostimulation platform as a pacemaker in cardiac resynchronization therapy (CRT), in which lead-placement complications are common.
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Affiliation(s)
- Pengju Li
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL, USA
| | - Jing Zhang
- The James Franck Institute, The University of Chicago, Chicago, IL, USA
| | - Hidenori Hayashi
- Section of Cardiac Surgery, Department of Surgery, The University of Chicago, Chicago, IL, USA
| | - Jiping Yue
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Wen Li
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Chuanwang Yang
- The James Franck Institute, The University of Chicago, Chicago, IL, USA
| | - Changxu Sun
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL, USA
| | - Jiuyun Shi
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | | | - Narutoshi Hibino
- Section of Cardiac Surgery, Department of Surgery, The University of Chicago, Chicago, IL, USA.
| | - Bozhi Tian
- The James Franck Institute, The University of Chicago, Chicago, IL, USA.
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA.
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7
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Leong F, Rahmani B, Psaltis D, Moser C, Ghezzi D. An actor-model framework for visual sensory encoding. Nat Commun 2024; 15:808. [PMID: 38280912 PMCID: PMC10821921 DOI: 10.1038/s41467-024-45105-5] [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: 08/17/2023] [Accepted: 01/15/2024] [Indexed: 01/29/2024] Open
Abstract
A fundamental challenge in neuroengineering is determining a proper artificial input to a sensory system that yields the desired perception. In neuroprosthetics, this process is known as artificial sensory encoding, and it holds a crucial role in prosthetic devices restoring sensory perception in individuals with disabilities. For example, in visual prostheses, one key aspect of artificial image encoding is to downsample images captured by a camera to a size matching the number of inputs and resolution of the prosthesis. Here, we show that downsampling an image using the inherent computation of the retinal network yields better performance compared to learning-free downsampling methods. We have validated a learning-based approach (actor-model framework) that exploits the signal transformation from photoreceptors to retinal ganglion cells measured in explanted mouse retinas. The actor-model framework generates downsampled images eliciting a neuronal response in-silico and ex-vivo with higher neuronal reliability than the one produced by a learning-free approach. During the learning process, the actor network learns to optimize contrast and the kernel's weights. This methodological approach might guide future artificial image encoding strategies for visual prostheses. Ultimately, this framework could be applicable for encoding strategies in other sensory prostheses such as cochlear or limb.
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Affiliation(s)
- Franklin Leong
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Babak Rahmani
- Laboratory of Applied Photonics Devices, Institute of Electrical and Micro Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Microsoft Research, Cambridge, UK
| | - Demetri Psaltis
- Optics Laboratory, Institute of Electrical and Micro Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Christophe Moser
- Laboratory of Applied Photonics Devices, Institute of Electrical and Micro Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Diego Ghezzi
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland.
- Ophthalmic and Neural Technologies Laboratory, Department of Ophthalmology, University of Lausanne, Hôpital ophtalmique Jules-Gonin, Fondation Asile des Aveugles, Lausanne, Switzerland.
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Artoni F, Cometa A, Dalise S, Azzollini V, Micera S, Chisari C. Cortico-muscular connectivity is modulated by passive and active Lokomat-assisted Gait. Sci Rep 2023; 13:21618. [PMID: 38062035 PMCID: PMC10703891 DOI: 10.1038/s41598-023-48072-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
The effects of robotic-assisted gait (RAG) training, besides conventional therapy, on neuroplasticity mechanisms and cortical integration in locomotion are still uncertain. To advance our knowledge on the matter, we determined the involvement of motor cortical areas in the control of muscle activity in healthy subjects, during RAG with Lokomat, both with maximal guidance force (100 GF-passive RAG) and without guidance force (0 GF-active RAG) as customary in rehabilitation treatments. We applied a novel cortico-muscular connectivity estimation procedure, based on Partial Directed Coherence, to jointly study source localized EEG and EMG activity during rest (standing) and active/passive RAG. We found greater cortico-cortical connectivity, with higher path length and tendency toward segregation during rest than in both RAG conditions, for all frequency bands except for delta. We also found higher cortico-muscular connectivity in distal muscles during swing (0 GF), and stance (100 GF), highlighting the importance of direct supraspinal control to maintain balance, even when gait is supported by a robotic exoskeleton. Source-localized connectivity shows that this control is driven mainly by the parietal and frontal lobes. The involvement of many cortical areas also in passive RAG (100 GF) justifies the use of the 100 GF RAG training for neurorehabilitation, with the aim of enhancing cortical-muscle connections and driving neural plasticity in neurological patients.
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Affiliation(s)
- Fiorenzo Artoni
- Department of Clinical Neurosciences, University of Genève, Faculty of Medicine, 1211, Geneva, Switzerland.
- Ago Neurotechnologies Sàrl, 1201, Geneva, Switzerland.
| | - Andrea Cometa
- The BioRobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56025, Pontedera, Italy
- University School for Advanced Studies IUSS Pavia, 27100, Pavia, Italy
| | - Stefania Dalise
- Unit of Neurorehabilitation, Pisa University Hospital, Pisa, Italy
| | - Valentina Azzollini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Silvestro Micera
- The BioRobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56025, Pontedera, Italy
- Translational Neural Engineering Laboratory (TNE), École Polytechnique Fédérale de Lausanne, Campus Biotech, Geneva, Switzerland
| | - Carmelo Chisari
- Unit of Neurorehabilitation, Pisa University Hospital, Pisa, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
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Buonfiglio F, Böhm EW, Pfeiffer N, Gericke A. Oxidative Stress: A Suitable Therapeutic Target for Optic Nerve Diseases? Antioxidants (Basel) 2023; 12:1465. [PMID: 37508003 PMCID: PMC10376185 DOI: 10.3390/antiox12071465] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Optic nerve disorders encompass a wide spectrum of conditions characterized by the loss of retinal ganglion cells (RGCs) and subsequent degeneration of the optic nerve. The etiology of these disorders can vary significantly, but emerging research highlights the crucial role of oxidative stress, an imbalance in the redox status characterized by an excess of reactive oxygen species (ROS), in driving cell death through apoptosis, autophagy, and inflammation. This review provides an overview of ROS-related processes underlying four extensively studied optic nerve diseases: glaucoma, Leber's hereditary optic neuropathy (LHON), anterior ischemic optic neuropathy (AION), and optic neuritis (ON). Furthermore, we present preclinical findings on antioxidants, with the objective of evaluating the potential therapeutic benefits of targeting oxidative stress in the treatment of optic neuropathies.
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Affiliation(s)
- Francesco Buonfiglio
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (E.W.B.); (N.P.)
| | | | | | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (E.W.B.); (N.P.)
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Ye Z, Hang Chan LL. Effect of the Aperiodic Electrical Stimulation on the Visual Cortical Neuronal Response . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083157 DOI: 10.1109/embc40787.2023.10341193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
In patients with retinal degenerative illnesses such as retinitis pigmentosa and age-related macular degeneration, retinal prosthesis shows the potential to restore partial vision. The natural stimuli are the aperiodic events distributed across a short time span. However, most studies commonly used periodic stimulation. Even though some in vitro studies explored the effect of aperiodic retinal stimulation on the retina ganglion cells' membrane potential, it still needs to understand how the aperiodic electrical stimulation on the retina affects the response in visual cortex. This study investigated how aperiodic retinal stimulation affects the electrically evoked cortical response compared with periodic stimulation in Sprague Dawley (SD) rats. We found that the aperiodic retinal stimulation evoked a significantly higher spike rate than the periodic pattern, especially at high frequencies (10 and 20 Hz). The spike rates showed a more significant difference between the periodic and 10% noise stimulation (P = 0.0013 at 20 Hz, two-tailed paired t-test) at 20 Hz stimulation. Regarding the temporal precision of responses, the responses to aperiodic stimulation showed higher temporal precision compared to periodic stimulation. The response to some stimulation pulse numbers under 10 and 20 Hz 50% noise and Poisson pattern stimulation was higher than the response to the first pulse. However, at the same frequency, the response to some stimulation pulse numbers under periodic stimulation was lower than the response to the first pulse. These findings raised a possible way to increase the response level and the temporal precision of the electrically evoked response.Clinical Relevance- This suggests that using aperiodic stimulation in retinal prostheses can increase electrically evoked response levels and temporal precision.
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Hiendlmeier L, Zurita F, Vogel J, Del Duca F, Al Boustani G, Peng H, Kopic I, Nikić M, F Teshima T, Wolfrum B. 4D-Printed Soft and Stretchable Self-Folding Cuff Electrodes for Small-Nerve Interfacing. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2210206. [PMID: 36594106 DOI: 10.1002/adma.202210206] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Peripheral nerve interfacing (PNI) has a high clinical potential for treating various diseases, such as obesity or diabetes. However, currently existing electrodes present challenges to the interfacing procedure, which limit their clinical application, in particular, when targeting small peripheral nerves (<200 µm). To improve the electrode handling and implantation, a nerve interface that can fold itself to a cuff around a small nerve, triggered by the body moisture during insertion, is fabricated. This folding is achieved by printing a bilayer of a flexible polyurethane printing resin and a highly swelling sodium acrylate hydrogel using photopolymerization. When immersed in an aqueous liquid, the hydrogel swells and folds the electrode softly around the nerve. Furthermore, the electrodes are robust, can be stretched (>20%), and bent to facilitate the implantation due to the use of soft and stretchable printing resins as substrates and a microcracked gold film as conductive layer. The straightforward implantation and extraction of the electrode as well as stimulation and recording capabilities on a small peripheral nerve in vivo are demonstrated. It is believed that such simple and robust to use self-folding electrodes will pave the way for bringing PNI to a broader clinical application.
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Affiliation(s)
- Lukas Hiendlmeier
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
- Medical & Health Informatics Laboratories, NTT Research Incorporated, 940 Stewart Dr, Sunnyvale, CA, 94085, USA
| | - Francisco Zurita
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
- Medical & Health Informatics Laboratories, NTT Research Incorporated, 940 Stewart Dr, Sunnyvale, CA, 94085, USA
| | - Jonas Vogel
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
| | - Fulvia Del Duca
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
- Medical & Health Informatics Laboratories, NTT Research Incorporated, 940 Stewart Dr, Sunnyvale, CA, 94085, USA
| | - George Al Boustani
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
- Medical & Health Informatics Laboratories, NTT Research Incorporated, 940 Stewart Dr, Sunnyvale, CA, 94085, USA
| | - Hu Peng
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
| | - Inola Kopic
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
| | - Marta Nikić
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
| | - Tetsuhiko F Teshima
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
- Medical & Health Informatics Laboratories, NTT Research Incorporated, 940 Stewart Dr, Sunnyvale, CA, 94085, USA
| | - Bernhard Wolfrum
- Neuroelectronics, Munich Institute of Biomedical Engineering, School of Computation, Informatics and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany
- Medical & Health Informatics Laboratories, NTT Research Incorporated, 940 Stewart Dr, Sunnyvale, CA, 94085, USA
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12
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Borda E, Medagoda DI, Airaghi Leccardi MJI, Zollinger EG, Ghezzi D. Conformable neural interface based on off-stoichiometry thiol-ene-epoxy thermosets. Biomaterials 2023; 293:121979. [PMID: 36586146 DOI: 10.1016/j.biomaterials.2022.121979] [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: 06/03/2022] [Revised: 11/29/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022]
Abstract
Off-stoichiometry thiol-ene-epoxy (OSTE+) thermosets show low permeability to gases and little absorption of dissolved molecules, allow direct low-temperature dry bonding without surface treatments, have a low Young's modulus, and can be manufactured via UV polymerisation. For these reasons, OSTE+ thermosets have recently gained attention for the rapid prototyping of microfluidic chips. Moreover, their compatibility with standard clean-room processes and outstanding mechanical properties make OSTE+ an excellent candidate as a novel material for neural implants. Here we exploit OSTE+ to manufacture a conformable multilayer micro-electrocorticography array with 16 platinum electrodes coated with platinum black. The mechanical properties allow conformability to curved surfaces such as the brain. The low permeability and strong adhesion between layers improve the stability of the device. Acute experiments in mice show the multimodal capacity of the array to record and stimulate the neural tissue by smoothly conforming to the mouse cortex. Devices are not cytotoxic, and immunohistochemistry stainings reveal only modest foreign body reaction after two and six weeks of chronic implantation. This work introduces OSTE+ as a promising material for implantable neural interfaces.
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Affiliation(s)
- Eleonora Borda
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
| | - Danashi Imani Medagoda
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
| | - Marta Jole Ildelfonsa Airaghi Leccardi
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
| | - Elodie Geneviève Zollinger
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
| | - Diego Ghezzi
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Switzerland.
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13
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Grani F, Soto-Sánchez C, Fimia A, Fernández E. Toward a personalized closed-loop stimulation of the visual cortex: Advances and challenges. Front Cell Neurosci 2022; 16:1034270. [PMID: 36582211 PMCID: PMC9792612 DOI: 10.3389/fncel.2022.1034270] [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: 09/01/2022] [Accepted: 11/24/2022] [Indexed: 12/15/2022] Open
Abstract
Current cortical visual prosthesis approaches are primarily unidirectional and do not consider the feed-back circuits that exist in just about every part of the nervous system. Herein, we provide a brief overview of some recent developments for better controlling brain stimulation and present preliminary human data indicating that closed-loop strategies could considerably enhance the effectiveness, safety, and long-term stability of visual cortex stimulation. We propose that the development of improved closed-loop strategies may help to enhance our capacity to communicate with the brain.
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Affiliation(s)
- Fabrizio Grani
- Institute of Bioengineering, Universidad Miguel Hernández de Elche, Elche, Spain
| | - Cristina Soto-Sánchez
- Institute of Bioengineering, Universidad Miguel Hernández de Elche, Elche, Spain,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Antonio Fimia
- Departamento de Ciencia de Materiales, Óptica y Tecnología Electrónica, Universidad Miguel Hernández de Elche, Elche, Spain
| | - Eduardo Fernández
- Institute of Bioengineering, Universidad Miguel Hernández de Elche, Elche, Spain,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain,*Correspondence: Eduardo Fernández,
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14
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Lu G, Qian X, Gong C, Ji J, Thomas BB, Humayun MS, Zhou Q. Ultrasound Retinal Stimulation: A Mini-Review of Recent Developments. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:3224-3231. [PMID: 36343006 PMCID: PMC10424795 DOI: 10.1109/tuffc.2022.3220568] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Ultrasound neuromodulation is an emerging technology. A significant amount of effort has been devoted to investigating the feasibility of noninvasive ultrasound retinal stimulation. Recent studies have shown that ultrasound can activate neurons in healthy and degenerated retinas. Specifically, high-frequency ultrasound can evoke localized neuron responses and generate patterns in visual circuits. In this review, we recapitulate pilot studies on ultrasound retinal stimulation, compare it with other neuromodulation technologies, and discuss its advantages and limitations. An overview of the opportunities and challenges to develop a noninvasive retinal prosthesis using high-frequency ultrasound is also provided.
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15
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Caravaca-Rodriguez D, Gaytan SP, Suaning GJ, Barriga-Rivera A. Implications of Neural Plasticity in Retinal Prosthesis. Invest Ophthalmol Vis Sci 2022; 63:11. [PMID: 36251317 DOI: 10.1167/iovs.63.11.11] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Retinal degenerative diseases such as retinitis pigmentosa cause a progressive loss of photoreceptors that eventually prevents the affected person from perceiving visual sensations. The absence of a visual input produces a neural rewiring cascade that propagates along the visual system. This remodeling occurs first within the retina. Then, subsequent neuroplastic changes take place at higher visual centers in the brain, produced by either the abnormal neural encoding of the visual inputs delivered by the diseased retina or as the result of an adaptation to visual deprivation. While retinal implants can activate the surviving retinal neurons by delivering electric current, the unselective activation patterns of the different neural populations that exist in the retinal layers differ substantially from those in physiologic vision. Therefore, artificially induced neural patterns are being delivered to a brain that has already undergone important neural reconnections. Whether or not the modulation of this neural rewiring can improve the performance for retinal prostheses remains a critical question whose answer may be the enabler of improved functional artificial vision and more personalized neurorehabilitation strategies.
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Affiliation(s)
- Daniel Caravaca-Rodriguez
- Department of Applied Physics III, Technical School of Engineering, Universidad de Sevilla, Sevilla, Spain
| | - Susana P Gaytan
- Department of Physiology, Universidad de Sevilla, Sevilla, Spain
| | - Gregg J Suaning
- School of Biomedical Engineering, University of Sydney, Sydney, Australia
| | - Alejandro Barriga-Rivera
- Department of Applied Physics III, Technical School of Engineering, Universidad de Sevilla, Sevilla, Spain.,School of Biomedical Engineering, University of Sydney, Sydney, Australia
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16
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Huang Y, Cui Y, Deng H, Wang J, Hong R, Hu S, Hou H, Dong Y, Wang H, Chen J, Li L, Xie Y, Sun P, Fu X, Yin L, Xiong W, Shi SH, Luo M, Wang S, Li X, Sheng X. Bioresorbable thin-film silicon diodes for the optoelectronic excitation and inhibition of neural activities. Nat Biomed Eng 2022; 7:486-498. [PMID: 36065014 DOI: 10.1038/s41551-022-00931-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 07/25/2022] [Indexed: 11/09/2022]
Abstract
Neural activities can be modulated by leveraging light-responsive nanomaterials as interfaces for exerting photothermal, photoelectrochemical or photocapacitive effects on neurons or neural tissues. Here we show that bioresorbable thin-film monocrystalline silicon pn diodes can be used to optoelectronically excite or inhibit neural activities by establishing polarity-dependent positive or negative photovoltages at the semiconductor/solution interface. Under laser illumination, the silicon-diode optoelectronic interfaces allowed for the deterministic depolarization or hyperpolarization of cultured neurons as well as the upregulated or downregulated intracellular calcium dynamics. The optoelectronic interfaces can also be mounted on nerve tissue to activate or silence neural activities in peripheral and central nervous tissues, as we show in mice with exposed sciatic nerves and somatosensory cortices. Bioresorbable silicon-based optoelectronic thin films that selectively excite or inhibit neural tissue may find advantageous biomedical applicability.
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Affiliation(s)
- Yunxiang Huang
- Department of Electronic Engineering, Beijing National Research Center for Information Science and Technology, Institute for Precision Medicine, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China.,School of Materials Science and Engineering, The Key Laboratory of Advanced Materials of Ministry of Education, State Key Laboratory of New Ceramics and Fine Processing, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Yuting Cui
- Chinese Institute for Brain Research, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Hanjie Deng
- CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Jingjing Wang
- CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Rongqi Hong
- CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Shuhan Hu
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China
| | - Hanqing Hou
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuanrui Dong
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing, China
| | - Huachun Wang
- Department of Electronic Engineering, Beijing National Research Center for Information Science and Technology, Institute for Precision Medicine, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Junyu Chen
- Department of Electronic Engineering, Beijing National Research Center for Information Science and Technology, Institute for Precision Medicine, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Lizhu Li
- Department of Electronic Engineering, Beijing National Research Center for Information Science and Technology, Institute for Precision Medicine, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Yang Xie
- Department of Electronic Engineering, Beijing National Research Center for Information Science and Technology, Institute for Precision Medicine, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Pengcheng Sun
- School of Materials Science and Engineering, The Key Laboratory of Advanced Materials of Ministry of Education, State Key Laboratory of New Ceramics and Fine Processing, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Xin Fu
- School of Materials Science and Engineering, The Key Laboratory of Advanced Materials of Ministry of Education, State Key Laboratory of New Ceramics and Fine Processing, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Lan Yin
- School of Materials Science and Engineering, The Key Laboratory of Advanced Materials of Ministry of Education, State Key Laboratory of New Ceramics and Fine Processing, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Wei Xiong
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China
| | - Song-Hai Shi
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China
| | - Minmin Luo
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China.,Chinese Institute for Brain Research, Beijing, China.,National Institute of Biological Sciences, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China
| | - Shirong Wang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing, China.
| | - Xiaojian Li
- CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.
| | - Xing Sheng
- Department of Electronic Engineering, Beijing National Research Center for Information Science and Technology, Institute for Precision Medicine, Center for Flexible Electronics Technology, Tsinghua University, Beijing, China. .,IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China.
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17
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Kim S, Roh H, Im M. Artificial Visual Information Produced by Retinal Prostheses. Front Cell Neurosci 2022; 16:911754. [PMID: 35734216 PMCID: PMC9208577 DOI: 10.3389/fncel.2022.911754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/18/2022] [Indexed: 11/18/2022] Open
Abstract
Numerous retinal prosthetic systems have demonstrated somewhat useful vision can be restored to individuals who had lost their sight due to outer retinal degenerative diseases. Earlier prosthetic studies have mostly focused on the confinement of electrical stimulation for improved spatial resolution and/or the biased stimulation of specific retinal ganglion cell (RGC) types for selective activation of retinal ON/OFF pathway for enhanced visual percepts. To better replicate normal vision, it would be also crucial to consider information transmission by spiking activities arising in the RGC population since an incredible amount of visual information is transferred from the eye to the brain. In previous studies, however, it has not been well explored how much artificial visual information is created in response to electrical stimuli delivered by microelectrodes. In the present work, we discuss the importance of the neural information for high-quality artificial vision. First, we summarize the previous literatures which have computed information transmission rates from spiking activities of RGCs in response to visual stimuli. Second, we exemplify a couple of studies which computed the neural information from electrically evoked responses. Third, we briefly introduce how information rates can be computed in the representative two ways - direct method and reconstruction method. Fourth, we introduce in silico approaches modeling artificial retinal neural networks to explore the relationship between amount of information and the spiking patterns. Lastly, we conclude our review with clinical implications to emphasize the necessity of considering visual information transmission for further improvement of retinal prosthetics.
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Affiliation(s)
- Sein Kim
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
| | - Hyeonhee Roh
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, South Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, South Korea
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18
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Borda E, Gaillet V, Airaghi Leccardi MJI, Zollinger EG, Moreira RC, Ghezzi D. Three-dimensional multilayer concentric bipolar electrodes restrict spatial activation in optic nerve stimulation. J Neural Eng 2022; 19. [PMID: 35523152 DOI: 10.1088/1741-2552/ac6d7e] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 05/06/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Intraneural nerve interfaces often operate in a monopolar configuration with a common and distant ground electrode. This configuration leads to a wide spreading of the electric field. Therefore, this approach is suboptimal for intraneural nerve interfaces when selective stimulation is required. APPROACH We designed a multilayer electrode array embedding three-dimensional concentric bipolar electrodes. First, we validated the higher stimulation selectivity of this new electrode array compared to classical monopolar stimulation using simulations. Next, we compared them in-vivo by intraneural stimulation of the rabbit optic nerve and recording evoked potentials in the primary visual cortex. MAIN RESULTS Simulations showed that three-dimensional concentric bipolar electrodes provide a high localisation of the electric field in the tissue so that electrodes are electrically independent even for high electrode density. Experiments in-vivo highlighted that this configuration restricts spatial activation in the visual cortex due to the fewer fibres activated by the electric stimulus in the nerve. SIGNIFICANCE Highly focused electric stimulation is crucial to achieving high selectivity in fibre activation. The multilayer array embedding three-dimensional concentric bipolar electrodes improves selectivity in optic nerve stimulation. This approach is suitable for other neural applications, including bioelectronic medicine.
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Affiliation(s)
- Eleonora Borda
- Medtronic Chair in Neuroengineering, Ecole Polytechnique Federale de Lausanne, EPFL STI IBI LNE, Geneva, 1012, SWITZERLAND
| | - Vivien Gaillet
- Medtronic Chair in Neuroengineering, Ecole Polytechnique Federale de Lausanne, EPFL STI IBI LNE, Geneva, 1012, SWITZERLAND
| | | | - Elodie Geneviève Zollinger
- Medtronic Chair in Neuroengineering, Ecole Polytechnique Federale de Lausanne, EPFL STI IBI LNE, Geneva, 1012, SWITZERLAND
| | | | - Diego Ghezzi
- École Polytechnique Fédérale de Lausanne, Chemin des Mines 9, Geneva, 1202, SWITZERLAND
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19
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Thorn JT, Chenais NAL, Hinrichs S, Chatelain M, Ghezzi D. Virtual reality validation of naturalistic modulation strategies to counteract fading in retinal stimulation. J Neural Eng 2022; 19. [PMID: 35240583 DOI: 10.1088/1741-2552/ac5a5c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/03/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Temporal resolution is a key challenge in artificial vision. Several prosthetic approaches are limited by the perceptual fading of evoked phosphenes upon repeated stimulation from the same electrode. Therefore, implanted patients are forced to perform active scanning, via head movements, to refresh the visual field viewed by the camera. However, active scanning is a draining task, and it is crucial to find compensatory strategies to reduce it. APPROACH To address this question, we implemented perceptual fading in simulated prosthetic vision using virtual reality. Then, we quantified the effect of fading on two indicators: the time to complete a reading task and the head rotation during the task. We also tested if stimulation strategies previously proposed to increase the persistence of responses in retinal ganglion cells to electrical stimulation could improve these indicators. MAIN RESULTS This study shows that stimulation strategies based on interrupted pulse trains and randomisation of the pulse duration allows significant reduction of both the time to complete the task and the head rotation during the task. SIGNIFICANCE The stimulation strategy used in retinal implants is crucial to counteract perceptual fading and to reduce active head scanning during prosthetic vision. In turn, less active scanning might improve the patient's comfort in artificial vision.
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Affiliation(s)
- Jacob Thomas Thorn
- Neuroengineering, EPFL STI, Chemin des Mines 9, Geneva, 1202, SWITZERLAND
| | | | - Sandrine Hinrichs
- École Polytechnique Fédérale de Lausanne, Chemin des Mines 9, Geneva, 1202, SWITZERLAND
| | - Marion Chatelain
- École Polytechnique Fédérale de Lausanne, Chemin des Mines 9, Geneva, 1202, SWITZERLAND
| | - Diego Ghezzi
- Medtronic Chair in Neuroengineering, Ecole Polytechnique Federale de Lausanne, EPFL STI IBI LNE, Lausanne, 1015, SWITZERLAND
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20
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Qian X, Lu G, Thomas BB, Li R, Chen X, Shung KK, Humayun M, Zhou Q. Noninvasive Ultrasound Retinal Stimulation for Vision Restoration at High Spatiotemporal Resolution. BME FRONTIERS 2022; 2022:9829316. [PMID: 37850175 PMCID: PMC10521738 DOI: 10.34133/2022/9829316] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/05/2022] [Indexed: 10/19/2023] Open
Abstract
Objective. Retinal degeneration involving progressive deterioration and loss of function of photoreceptors is a major cause of permanent vision loss worldwide. Strategies to treat these incurable conditions incorporate retinal prostheses via electrically stimulating surviving retinal neurons with implanted devices in the eye, optogenetic therapy, and sonogenetic therapy. Existing challenges of these strategies include invasive manner, complex implantation surgeries, and risky gene therapy. Methods and Results. Here, we show that direct ultrasound stimulation on the retina can evoke neuron activities from the visual centers including the superior colliculus and the primary visual cortex (V1), in either normal-sighted or retinal degenerated blind rats in vivo. The neuron activities induced by the customized spherically focused 3.1 MHz ultrasound transducer have shown both good spatial resolution of 250 μm and temporal resolution of 5 Hz in the rat visual centers. An additional customized 4.4 MHz helical transducer was further implemented to generate a static stimulation pattern of letter forms. Conclusion. Our findings demonstrate that ultrasound stimulation of the retina in vivo is a safe and effective approach with high spatiotemporal resolution, indicating a promising future of ultrasound stimulation as a novel and noninvasive visual prosthesis for translational applications in blind patients.
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Affiliation(s)
- Xuejun Qian
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Gengxi Lu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B. Thomas
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Runze Li
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
| | - Xiaoyang Chen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - K. Kirk Shung
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Mark Humayun
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA
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21
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Cho Y, Park S, Lee J, Yu KJ. Emerging Materials and Technologies with Applications in Flexible Neural Implants: A Comprehensive Review of Current Issues with Neural Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005786. [PMID: 34050691 DOI: 10.1002/adma.202005786] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/29/2020] [Indexed: 05/27/2023]
Abstract
Neuroscience is an essential field of investigation that reveals the identity of human beings, with a comprehensive understanding of advanced mental activities, through the study of neurobiological structures and functions. Fully understanding the neurotransmission system that allows for connectivity among neuronal circuits has paved the way for the development of treatments for neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and depression. The field of flexible implants has attracted increasing interest mainly to overcome the mechanical mismatch between rigid electrode materials and soft neural tissues, enabling precise measurements of neural signals from conformal contact. Here, the current issues of flexible neural implants (chronic device failure, non-bioresorbable electronics, low-density electrode arrays, among others are summarized) by presenting material candidates and designs to address each challenge. Furthermore, the latest investigations associated with the aforementioned issues are also introduced, including suggestions for ideal neural implants. In terms of the future direction of these advances, designing flexible devices would provide new opportunities for the study of brain-machine interfaces or brain-computer interfaces as part of locomotion through brain signals, and for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Younguk Cho
- School of Electrical Engineering, Yonsei University, Seoul, 03722, Korea
| | - Sanghoon Park
- School of Electrical Engineering, Yonsei University, Seoul, 03722, Korea
| | - Juyoung Lee
- School of Electrical Engineering, Yonsei University, Seoul, 03722, Korea
| | - Ki Jun Yu
- School of Electrical Engineering, YU-KIST Institute, Yonsei University, Seoul, 03722, Korea
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22
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Mohana Devi S, Abishek Kumar B, Mahalaxmi I, Balachandar V. Leber's hereditary optic neuropathy: Current approaches and future perspectives on Mesenchymal stem cell-mediated rescue. Mitochondrion 2021; 60:201-218. [PMID: 34454075 DOI: 10.1016/j.mito.2021.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/03/2021] [Accepted: 08/23/2021] [Indexed: 12/19/2022]
Abstract
Leber's Hereditary Optic Neuropathy (LHON) is an inherited optic nerve disorder. It is a mitochondrially inherited disease due to point mutation in the MT-ND1, MT-ND4, and MT-ND6 genes of mitochondrial DNA (mtDNA) coding for complex I subunit proteins. These mutations affect the assembly of the mitochondrial complex I and hence the electron transport chain leading to mitochondrial dysfunction and oxidative damage. Optic nerve cells like retinal ganglion cells (RGCs) are more sensitive to mitochondrial loss and oxidative damage which results in the progressive degeneration of RGCs at the axonal region of the optic nerve leading to bilateral vision loss. Currently, gene therapy using Adeno-associated viral vector (AAV) is widely studied for the therapeutics application in LHON. Our review highlights the application of cell-based therapy for LHON. Mesenchymal stem cells (MSCs) are known to rescue cells from the pre-apoptotic stage by transferring healthy mitochondria through tunneling nanotubes (TNT) for cellular oxidative function. Empowering the transfer of healthy mitochondria using MSCs may replace the mitochondria with pathogenic mutation and possibly benefit the cells from progressive damage. This review discusses the ongoing research in LHON and mitochondrial transfer mechanisms to explore its scope in inherited optic neuropathy.
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Affiliation(s)
- Subramaniam Mohana Devi
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India.
| | - B Abishek Kumar
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | - Iyer Mahalaxmi
- Livestock Farming and Bioresource Technology, Tamil Nadu, India
| | - Vellingiri Balachandar
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, India
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23
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Vallone F, Ottaviani MM, Dedola F, Cutrone A, Romeni S, Panarese AM, Bernini F, Cracchiolo M, Strauss I, Gabisonia K, Gorgodze N, Mazzoni A, Recchia FA, Micera S. Simultaneous decoding of cardiovascular and respiratory functional changes from pig intraneural vagus nerve signals. J Neural Eng 2021; 18. [PMID: 34153949 DOI: 10.1088/1741-2552/ac0d42] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 06/21/2021] [Indexed: 12/15/2022]
Abstract
Objective. Bioelectronic medicine is opening new perspectives for the treatment of some major chronic diseases through the physical modulation of autonomic nervous system activity. Being the main peripheral route for electrical signals between central nervous system and visceral organs, the vagus nerve (VN) is one of the most promising targets. Closed-loop VN stimulation (VNS) would be crucial to increase effectiveness of this approach. Therefore, the extrapolation of useful physiological information from VN electrical activity would represent an invaluable source for single-target applications. Here, we present an advanced decoding algorithm novel to VN studies and properly detecting different functional changes from VN signals.Approach. VN signals were recorded using intraneural electrodes in anaesthetized pigs during cardiovascular and respiratory challenges mimicking increases in arterial blood pressure, tidal volume and respiratory rate. We developed a decoding algorithm that combines discrete wavelet transformation, principal component analysis, and ensemble learning made of classification trees.Main results. The new decoding algorithm robustly achieved high accuracy levels in identifying different functional changes and discriminating among them. Interestingly our findings suggest that electrodes positioning plays an important role on decoding performances. We also introduced a new index for the characterization of recording and decoding performance of neural interfaces. Finally, by combining an anatomically validated hybrid neural model and discrimination analysis, we provided new evidence suggesting a functional topographical organization of VN fascicles.Significance. This study represents an important step towards the comprehension of VN signaling, paving the way for the development of effective closed-loop VNS systems.
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Affiliation(s)
- Fabio Vallone
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Matteo Maria Ottaviani
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy.,Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Francesca Dedola
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Annarita Cutrone
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Simone Romeni
- Bertarelli Foundation Chair in Translational Neural Engineering, Center for Neuroprosthetics and Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Adele Macrí Panarese
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Fabio Bernini
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Marina Cracchiolo
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Ivo Strauss
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Khatia Gabisonia
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.,Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | - Nikoloz Gorgodze
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.,Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | - Alberto Mazzoni
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Fabio A Recchia
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.,Fondazione Toscana Gabriele Monasterio, Pisa, Italy.,Department of Physiology, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| | - Silvestro Micera
- The BioRobotics Institute and Department of Excellence in Robotics and Artificial Intelligence, Scuola Superiore Sant'Anna, Pisa, Italy.,Bertarelli Foundation Chair in Translational Neural Engineering, Center for Neuroprosthetics and Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
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24
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Moleirinho S, Whalen AJ, Fried SI, Pezaris JS. The impact of synchronous versus asynchronous electrical stimulation in artificial vision. J Neural Eng 2021; 18. [PMID: 33900206 DOI: 10.1088/1741-2552/abecf1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 03/09/2021] [Indexed: 11/12/2022]
Abstract
Visual prosthesis devices designed to restore sight to the blind have been under development in the laboratory for several decades. Clinical translation continues to be challenging, due in part to gaps in our understanding of critical parameters such as how phosphenes, the electrically-generated pixels of artificial vision, can be combined to form images. In this review we explore the effects that synchronous and asynchronous electrical stimulation across multiple electrodes have in evoking phosphenes. Understanding how electrical patterns influence phosphene generation to control object binding and perception of visual form is fundamental to creation of a clinically successful prosthesis.
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Affiliation(s)
- Susana Moleirinho
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, United States of America.,Department of Neurosurgery, Harvard Medical School, Boston, MA, United States of America
| | - Andrew J Whalen
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, United States of America.,Department of Neurosurgery, Harvard Medical School, Boston, MA, United States of America
| | - Shelley I Fried
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, United States of America.,Department of Neurosurgery, Harvard Medical School, Boston, MA, United States of America.,Boston VA Healthcare System, Boston, MA, United States of America
| | - John S Pezaris
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, United States of America.,Department of Neurosurgery, Harvard Medical School, Boston, MA, United States of America
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25
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Gaillet V, Borda E, Zollinger EG, Ghezzi D. A machine-learning algorithm correctly classifies cortical evoked potentials from both visual stimulation and electrical stimulation of the optic nerve. J Neural Eng 2021; 18. [PMID: 33823498 DOI: 10.1088/1741-2552/abf523] [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: 01/07/2021] [Accepted: 04/06/2021] [Indexed: 11/12/2022]
Abstract
Objective. Optic nerve's intraneural stimulation is an emerging neuroprosthetic approach to provide artificial vision to totally blind patients. An open question is the possibility to evoke individual non-overlapping phosphenes via selective intraneural optic nerve stimulation. To begin answering this question, first, we aim at showing in preclinical experiments with animals that each intraneural electrode could evoke a distinguishable activity pattern in the primary visual cortex.Approach. We performed both patterned visual stimulation and patterned electrical stimulation in healthy rabbits while recording evoked cortical activity with an electrocorticogram array in the primary visual cortex. Electrical stimulation was delivered to the optic nerve with the intraneural array OpticSELINE. We used a support vector machine algorithm paired to a linear regression model to classify cortical responses originating from visual stimuli located in different portions of the visual field and electrical stimuli from the different electrodes of the OpticSELINE.Main results. Cortical activity induced by visual and electrical stimulation could be classified with nearly 100% accuracy relative to the specific location in the visual field or electrode in the array from which it originated. For visual stimulation, the accuracy increased with the separation of the stimuli and reached 100% for separation higher than 7°. For electrical stimulation, at low current amplitudes, the accuracy increased with the distance between electrodes, while at higher current amplitudes, the accuracy was nearly 100% already for the shortest separation.Significance. Optic nerve's intraneural stimulation with the OpticSELINE induced discernible cortical activity patterns. These results represent a necessary condition for an optic nerve prosthesis to deliver vision with non-overlapping phosphene. However, clinical investigations will be required to assess the translation of these results into perceptual phenomena.
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Affiliation(s)
- Vivien Gaillet
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique fédérale de Lausanne, Geneva 1202, Switzerland
| | - Eleonora Borda
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique fédérale de Lausanne, Geneva 1202, Switzerland
| | - Elodie Geneviève Zollinger
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique fédérale de Lausanne, Geneva 1202, Switzerland
| | - Diego Ghezzi
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique fédérale de Lausanne, Geneva 1202, Switzerland
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26
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Sperry ZJ, Na K, Jun J, Madden LR, Socha A, Yoon E, Seymour JP, Bruns TM. High-density neural recordings from feline sacral dorsal root ganglia with thin-film array. J Neural Eng 2021; 18. [PMID: 33545709 DOI: 10.1088/1741-2552/abe398] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 02/05/2021] [Indexed: 12/26/2022]
Abstract
Objective. Dorsal root ganglia (DRG) are promising sites for recording sensory activity. Current technologies for DRG recording are stiff and typically do not have sufficient site density for high-fidelity neural data techniques.Approach. In acute experiments, we demonstrate single-unit neural recordings in sacral DRG of anesthetized felines using a 4.5µm thick, high-density flexible polyimide microelectrode array with 60 sites and 30-40µm site spacing. We delivered arrays into DRG with ultrananocrystalline diamond shuttles designed for high stiffness affording a smaller footprint. We recorded neural activity during sensory activation, including cutaneous brushing and bladder filling, as well as during electrical stimulation of the pudendal nerve and anal sphincter. We used specialized neural signal analysis software to sort densely packed neural signals.Main results. We successfully delivered arrays in five of six experiments and recorded single-unit sensory activity in four experiments. The median neural signal amplitude was 55μV peak-to-peak and the maximum unique units recorded at one array position was 260, with 157 driven by sensory or electrical stimulation. In one experiment, we used the neural analysis software to track eight sorted single units as the array was retracted ∼500μm.Significance. This study is the first demonstration of ultrathin, flexible, high-density electronics delivered into DRG, with capabilities for recording and tracking sensory information that are a significant improvement over conventional DRG interfaces.
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Affiliation(s)
- Zachariah J Sperry
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Kyounghwan Na
- Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
| | - James Jun
- Flatiron Institute, Simons Foundation, New York City, NY, United States of America
| | - Lauren R Madden
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Alec Socha
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
| | - Eusik Yoon
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America.,Center for Nanomedicine, Institute for Basic Science (IBS) and Graduate Program of Nano Biomedical Engineering (NanoBME), Advanced Science Institute, Yonsei University, Seoul, Republic of Korea
| | - John P Seymour
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America.,University of Texas Health Science Center, Department of Neurosurgery, Houston, TX, United States of America.,Department of Electrical and Computer Engineering, Rice University, Houston, TX, United States of America
| | - Tim M Bruns
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
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27
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Abbasi B, Rizzo JF. Advances in Neuroscience, Not Devices, Will Determine the Effectiveness of Visual Prostheses. Semin Ophthalmol 2021; 36:168-175. [PMID: 33734937 DOI: 10.1080/08820538.2021.1887902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Background: Innovations in engineering and neuroscience have enabled the development of sophisticated visual prosthetic devices. In clinical trials, these devices have provided visual acuities as high as 20/460, enabled coarse navigation, and even allowed for reading of short words. However, long-term commercial viability arguably rests on attaining even better vision and more definitive improvements in tasks of daily living and quality of life. Purpose: Here we review technological and biological obstacles in the implementation of visual prosthetics. Conclusions: Research in the visual prosthetic field has tackled significant technical challenges, including biocompatibility, signal spread through neural tissue, and inadvertent activation of passing axons; however, significant gaps in knowledge remain in the realm of neuroscience, including the neural code of vision and visual plasticity. We assert that further optimization of prosthetic devices alone will not provide markedly improved visual outcomes without significant advances in our understanding of neuroscience.
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Affiliation(s)
- Bardia Abbasi
- Neuro-Ophthalmology Service, Department of Ophthalmology, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA
| | - Joseph F Rizzo
- Neuro-Ophthalmology Service, Department of Ophthalmology, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA
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28
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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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29
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Fang Y, Meng L, Prominski A, Schaumann E, Seebald M, Tian B. Recent advances in bioelectronics chemistry. Chem Soc Rev 2020; 49:7978-8035. [PMID: 32672777 PMCID: PMC7674226 DOI: 10.1039/d0cs00333f] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Research in bioelectronics is highly interdisciplinary, with many new developments being based on techniques from across the physical and life sciences. Advances in our understanding of the fundamental chemistry underlying the materials used in bioelectronic applications have been a crucial component of many recent discoveries. In this review, we highlight ways in which a chemistry-oriented perspective may facilitate novel and deep insights into both the fundamental scientific understanding and the design of materials, which can in turn tune the functionality and biocompatibility of bioelectronic devices. We provide an in-depth examination of several developments in the field, organized by the chemical properties of the materials. We conclude by surveying how some of the latest major topics of chemical research may be further integrated with bioelectronics.
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Affiliation(s)
- Yin Fang
- The James Franck Institute, University of Chicago, Chicago, IL 60637, USA
| | - Lingyuan Meng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | | | - Erik Schaumann
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
| | - Matthew Seebald
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
| | - Bozhi Tian
- The James Franck Institute, University of Chicago, Chicago, IL 60637, USA
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
- The Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA
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30
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Strauss I, Niederhoffer T, Giannotti A, Panarese AM, Bernini F, Gabisonia K, Ottaviani MM, Petrini FM, Recchia FA, Raspopovic S, Micera S. Q-PINE: A quick to implant peripheral intraneural electrode. J Neural Eng 2020; 17. [DOI: 10.1088/1741-2552/abc52a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/27/2020] [Indexed: 11/11/2022]
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31
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Song X, Guo T, Shivdasani MN, Dokos S, Lovell NH, Li X, Qiu S, Li T, Zheng S, Li L. Creation of virtual channels in the retina using synchronous and asynchronous stimulation - a modelling study. J Neural Eng 2020; 17. [PMID: 33086210 DOI: 10.1088/1741-2552/abc3a9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 10/21/2020] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Implantable retinal prostheses aim to provide artificial vision to those suffering from retinal degenerative diseases by electrically stimulating the remaining retinal neurons using a multi-electrode array. The spatial resolution of these devices can be improved by creation of so-called virtual channels (VCs) that are commonly achieved through synchronized stimulation of multiple electrodes. It is largely unclear though if VCs can be created using asynchronous stimulation, which was the primary aim of this study. APPROACH A computational model of multi-layered retina and epi-retinal dual-electrode stimulation was developed to simulate the neural activity of populations of retinal ganglion cells (RGCs) using the VC strategy under both synchronous and asynchronous stimulation conditions. MAIN RESULTS Our simulation suggests that VCs can be created using asynchronous stimulation. VC performance under both synchronous and asynchronous stimulation conditions can be improved by optimizing stimulation parameters such as current intensity, current ratio (α) between two electrodes, electrode spacing and the stimulation waveform. In particular, two VC performance measures; (1) linear displacement of the centroid of RGC activation, and (2) the RGC activation size consistency as a function of different current ratios α, have comparable performance under asynchronous and synchronous stimulation with appropriately selected stimulation parameters. SIGNIFICANCE Our findings support the possibility of creating VCs in the retina under both synchronous and asynchronous stimulation conditions. The results provide theoretical evidence for future retinal prosthesis designs with higher spatial resolution and power efficiency whilst reducing the number of current sources required to achieve these outcomes.
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Affiliation(s)
- Xiaoyu Song
- , Shanghai Jiao Tong University, Shanghai, 200240, CHINA
| | - Tianruo Guo
- GSBME, UNSW, Sydney, New South Wales, 2052, AUSTRALIA
| | - Mohit N Shivdasani
- Graduate School of Biomedical Engineering, University of New South Wales, Lower Ground, Samuels Building (F25), Kensington, New South Wales, AUSTRALIA
| | - Socrates Dokos
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney 2052, New South Wales, Sydney, New South Wales, 2052, AUSTRALIA
| | - Nigel H Lovell
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Sydney, 2052, AUSTRALIA
| | - Xinxin Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, CHINA
| | - Shirong Qiu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, CHINA
| | - Tong Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, CHINA
| | - Shiwei Zheng
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, CHINA
| | - Liming Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, Shanghai, CHINA
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32
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Tutorial: a computational framework for the design and optimization of peripheral neural interfaces. Nat Protoc 2020; 15:3129-3153. [DOI: 10.1038/s41596-020-0377-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 06/15/2020] [Indexed: 01/05/2023]
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33
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Srivastava SB, Melikov R, Yildiz E, Han M, Sahin A, Nizamoglu S. Efficient photocapacitors via ternary hybrid photovoltaic optimization for photostimulation of neurons. BIOMEDICAL OPTICS EXPRESS 2020; 11:5237-5248. [PMID: 33014611 PMCID: PMC7510852 DOI: 10.1364/boe.396068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/16/2020] [Accepted: 08/03/2020] [Indexed: 05/31/2023]
Abstract
Optoelectronic photoelectrodes based on capacitive charge-transfer offer an attractive route to develop safe and effective neuromodulators. Here, we demonstrate efficient optoelectronic photoelectrodes that are based on the incorporation of quantum dots (QDs) into poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl-C61-butyric acid methyl ester (PCBM) bulk heterojunction. We control the performance of the photoelectrode by the blend ratio, thickness, and nanomorphology of the ternary bulk heterojunction. The optimization led to a photocapacitor that has a photovoltage of 450 mV under a light intensity level of 20 mW.cm-2 and a responsivity of 99 mA/W corresponding to the most light-sensitive organic photoelectrode reported to date. The photocapacitor can facilitate action potential generation by hippocampal neurons via burst waveforms at an intensity level of 20 mW.cm-2. Therefore, the results point to an alternative direction in the engineering of safe and ultra-light-sensitive neural interfaces.
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Affiliation(s)
| | - Rustamzhon Melikov
- Department of Electrical and Electronics Engineering, Koc University, Istanbul 34450, Turkey
| | - Erdost Yildiz
- Koc University Research Center for Translational Medicine, Koc University, Istanbul 34450, Turkey
| | - Mertcan Han
- Department of Electrical and Electronics Engineering, Koc University, Istanbul 34450, Turkey
| | - Afsun Sahin
- Koc University Research Center for Translational Medicine, Koc University, Istanbul 34450, Turkey
- Department of Ophthalmology, Medical School, Koc University, Istanbul 34450, Turkey
| | - Sedat Nizamoglu
- Department of Electrical and Electronics Engineering, Koc University, Istanbul 34450, Turkey
- Graduate School of Biomedical Sciences and Engineering, Koc University, Istanbul 34450, Turkey
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34
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Fernández E, Alfaro A, González-López P. Toward Long-Term Communication With the Brain in the Blind by Intracortical Stimulation: Challenges and Future Prospects. Front Neurosci 2020; 14:681. [PMID: 32848535 PMCID: PMC7431631 DOI: 10.3389/fnins.2020.00681] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 06/03/2020] [Indexed: 11/15/2022] Open
Abstract
The restoration of a useful visual sense in a profoundly blind person by direct electrical stimulation of the visual cortex has been a subject of study for many years. However, the field of cortically based sight restoration has made few advances in the last few decades, and many problems remain. In this context, the scientific and technological problems associated with safe and effective communication with the brain are very complex, and there are still many unresolved issues delaying its development. In this work, we review some of the biological and technical issues that still remain to be solved, including long-term biotolerability, the number of electrodes required to provide useful vision, and the delivery of information to the implants. Furthermore, we emphasize the possible role of the neuroplastic changes that follow vision loss in the success of this approach. We propose that increased collaborations among clinicians, basic researchers, and neural engineers will enhance our ability to send meaningful information to the brain and restore a limited but useful sense of vision to many blind individuals.
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Affiliation(s)
- Eduardo Fernández
- Institute of Bioengineering, Universidad Miguel Hernández, Elche, Spain
- Center for Biomedical Research in the Network in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Arantxa Alfaro
- Center for Biomedical Research in the Network in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
- Hospital Vega Baja, Orihuela, Spain
| | - Pablo González-López
- Institute of Bioengineering, Universidad Miguel Hernández, Elche, Spain
- Hospital General Universitario de Alicante, Alicante, Spain
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35
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Shim S, Eom K, Jeong J, Kim SJ. Retinal Prosthetic Approaches to Enhance Visual Perception for Blind Patients. MICROMACHINES 2020; 11:E535. [PMID: 32456341 PMCID: PMC7281011 DOI: 10.3390/mi11050535] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022]
Abstract
Retinal prostheses are implantable devices that aim to restore the vision of blind patients suffering from retinal degeneration, mainly by artificially stimulating the remaining retinal neurons. Some retinal prostheses have successfully reached the stage of clinical trials; however, these devices can only restore vision partially and remain insufficient to enable patients to conduct everyday life independently. The visual acuity of the artificial vision is limited by various factors from both engineering and physiological perspectives. To overcome those issues and further enhance the visual resolution of retinal prostheses, a variety of retinal prosthetic approaches have been proposed, based on optimization of the geometries of electrode arrays and stimulation pulse parameters. Other retinal stimulation modalities such as optics, ultrasound, and magnetics have also been utilized to address the limitations in conventional electrical stimulation. Although none of these approaches have been clinically proven to fully restore the function of a degenerated retina, the extensive efforts made in this field have demonstrated a series of encouraging findings for the next generation of retinal prostheses, and these could potentially enhance the visual acuity of retinal prostheses. In this article, a comprehensive and up-to-date overview of retinal prosthetic strategies is provided, with a specific focus on a quantitative assessment of visual acuity results from various retinal stimulation technologies. The aim is to highlight future directions toward high-resolution retinal prostheses.
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Affiliation(s)
- Shinyong Shim
- Department of Electrical and Computer Engineering, College of Engineering, Seoul National University, Seoul 08826, Korea;
- Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul 08826, Korea
| | - Kyungsik Eom
- Department of Electronics Engineering, College of Engineering, Pusan National University, Busan 46241, Korea
| | - Joonsoo Jeong
- School of Biomedical Convergence Engineering, College of Information and Biomedical Engineering, Pusan National University, Yangsan 50612, Korea
| | - Sung June Kim
- Department of Electrical and Computer Engineering, College of Engineering, Seoul National University, Seoul 08826, Korea;
- Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul 08826, Korea
- Institute on Aging, College of Medicine, Seoul National University, Seoul 08826, Korea
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36
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Abstract
Developments of new strategies to restore vision and improving on current strategies by harnessing new advancements in material and electrical sciences, and biological and genetic-based technologies are of upmost health priorities around the world. Federal and private entities are spending billions of dollars on visual prosthetics technologies. This review describes the most current and state-of-the-art bioengineering technologies to restore vision. This includes a thorough description of traditional electrode-based visual prosthetics that have improved substantially since early prototypes. Recent advances in molecular and synthetic biology have transformed vision-assisted technologies; For example, optogenetic technologies that introduce light-responsive proteins offer excellent resolution but cortical applications are restricted by fiber implantation and tissue damage. Other stimulation modalities, such as magnetic fields, have been explored to achieve non-invasive neuromodulation. Miniature magnetic coils are currently being developed to activate select groups of neurons. Magnetically-responsive nanoparticles or exogenous proteins can significantly enhance the coupling between external electromagnetic devices and any neurons affiliated with these modifications. The need to minimize cytotoxic effects for nanoparticle-based therapies will likely restrict the number of usable materials. Nevertheless, advances in identifying and utilizing proteins that respond to magnetic fields may lead to non-invasive, cell-specific stimulation and may overcome many of the limitations that currently exist with other methods. Finally, sensory substitution systems also serve as viable visual prostheses by converting visual input to auditory and somatosensory stimuli. This review also discusses major challenges in the field and offers bioengineering strategies to overcome those.
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Affiliation(s)
- Alexander Farnum
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI, United States
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Galit Pelled
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI, United States
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
- Department of Radiology, College of Human Medicine, Michigan State University, East Lansing, MI, United States
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