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Patel PR, Welle EJ, Letner JG, Shen H, Bullard AJ, Caldwell CM, Vega-Medina A, Richie JM, Thayer HE, Patil PG, Cai D, Chestek CA. Utah array characterization and histological analysis of a multi-year implant in non-human primate motor and sensory cortices. J Neural Eng 2023; 20:10.1088/1741-2552/acab86. [PMID: 36595323 PMCID: PMC9954796 DOI: 10.1088/1741-2552/acab86] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/14/2022] [Indexed: 12/15/2022]
Abstract
Objective.The Utah array is widely used in both clinical studies and neuroscience. It has a strong track record of safety. However, it is also known that implanted electrodes promote the formation of scar tissue in the immediate vicinity of the electrodes, which may negatively impact the ability to record neural waveforms. This scarring response has been primarily studied in rodents, which may have a very different response than primate brain.Approach.Here, we present a rare nonhuman primate histological dataset (n= 1 rhesus macaque) obtained 848 and 590 d after implantation in two brain hemispheres. For 2 of 4 arrays that remained within the cortex, NeuN was used to stain for neuron somata at three different depths along the shanks. Images were filtered and denoised, with neurons then counted in the vicinity of the arrays as well as a nearby section of control tissue. Additionally, 3 of 4 arrays were imaged with a scanning electrode microscope to evaluate any materials damage that might be present.Main results.Overall, we found a 63% percent reduction in the number of neurons surrounding the electrode shanks compared to control areas. In terms of materials, the arrays remained largely intact with metal and Parylene C present, though tip breakage and cracks were observed on many electrodes.Significance.Overall, these results suggest that the tissue response in the nonhuman primate brain shows similar neuron loss to previous studies using rodents. Electrode improvements, for example using smaller or softer probes, may therefore substantially improve the tissue response and potentially improve the neuronal recording yield in primate cortex.
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Affiliation(s)
- Paras R. Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Elissa J. Welle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Joseph G. Letner
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Hao Shen
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Autumn J. Bullard
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Ciara M. Caldwell
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Alexis Vega-Medina
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48019, United States of America,Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, United States of America
| | - Julianna M. Richie
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Hope E. Thayer
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Parag G. Patil
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America,Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI 48109, United States of America,Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, United States of America,Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, United States of America
| | - Dawen Cai
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, United States of America,Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, United States of America,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48019, United States of America
| | - Cynthia A. Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America,Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, United States of America,Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, United States of America,Robotics Program, University of Michigan, Ann Arbor, MI 48109, United States of America, Corresponding author:
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2
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Yan D, Jiman AA, Bottorff EC, Patel PR, Meli D, Welle EJ, Ratze DC, Havton LA, Chestek CA, Kemp SWP, Bruns TM, Yoon E, Seymour JP. Ultraflexible and Stretchable Intrafascicular Peripheral Nerve Recording Device with Axon-Dimension, Cuff-Less Microneedle Electrode Array. Small 2022; 18:e2200311. [PMID: 35491522 PMCID: PMC9167574 DOI: 10.1002/smll.202200311] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/08/2022] [Indexed: 05/03/2023]
Abstract
Peripheral nerve mapping tools with higher spatial resolution are needed to advance systems neuroscience, and potentially provide a closed-loop biomarker in neuromodulation applications. Two critical challenges of microscale neural interfaces are 1) how to apply them to small peripheral nerves, and 2) how to minimize chronic reactivity. A flexible microneedle nerve array (MINA) is developed, which is the first high-density penetrating electrode array made with axon-sized silicon microneedles embedded in low-modulus thin silicone. The design, fabrication, acute recording, and chronic reactivity to an implanted MINA, are presented. Distinctive units are identified in the rat peroneal nerve. The authors also demonstrate a long-term, cuff-free, and suture-free fixation manner using rose bengal as a light-activated adhesive for two time-points. The tissue response is investigated at 1-week and 6-week time-points, including two sham groups and two MINA-implanted groups. These conditions are quantified in the left vagus nerve of rats using histomorphometry. Micro computed tomography (micro-CT) is added to visualize and quantify tissue encapsulation around the implant. MINA demonstrates a reduction in encapsulation thickness over previously quantified interfascicular methods. Future challenges include techniques for precise insertion of the microneedle electrodes and demonstrating long-term recording.
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Affiliation(s)
- Dongxiao Yan
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ahmad A Jiman
- Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Elizabeth C Bottorff
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Paras R Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Dilara Meli
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Elissa J Welle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - David C Ratze
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Leif A Havton
- Departments of Neurology and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- James J Peters Veterans Affairs Medical Center, Bronx, NY, 10468, USA
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Stephen W P Kemp
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Section of Plastic Surgery, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Tim M Bruns
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Euisik Yoon
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Center for Nanomedicine, Institute for Basic Science (IBS) and Graduate Program of Nano Biomedical Engineering (Nano BME), Advanced Science Institute, Yonsei University, Seoul, South Korea
| | - John P Seymour
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Neurosurgery, UTHealth, Houston, TX, 77030, USA
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, 77030, USA
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3
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Richie JM, Patel PR, Welle EJ, Dong T, Chen L, Shih AJ, Chestek CA. Open-source Toolkit: Benchtop Carbon Fiber Microelectrode Array for Nerve Recording. J Vis Exp 2021:10.3791/63099. [PMID: 34779441 PMCID: PMC10771276 DOI: 10.3791/63099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Conventional peripheral nerve probes are primarily fabricated in a cleanroom, requiring the use of multiple expensive and highly specialized tools. This paper presents a cleanroom "light" fabrication process of carbon fiber neural electrode arrays that can be learned quickly by an inexperienced cleanroom user. This carbon fiber electrode array fabrication process requires just one cleanroom tool, a Parylene C deposition machine, that can be learned quickly or outsourced to a commercial processing facility at marginal cost. This fabrication process also includes hand-populating printed circuit boards, insulation, and tip optimization. The three different tip optimizations explored here (Nd:YAG laser, blowtorch, and UV laser) result in a range of tip geometries and 1 kHz impedances, with blowtorched fibers resulting in the lowest impedance. While previous experiments have proven laser and blowtorch electrode efficacy, this paper also shows that UV laser-cut fibers can record neural signals in vivo. Existing carbon fiber arrays either do not have individuated electrodes in favor of bundles or require cleanroom fabricated guides for population and insulation. The proposed arrays use only tools that can be used at a benchtop for fiber population. This carbon fiber electrode array fabrication process allows for quick customization of bulk array fabrication at a reduced price compared to commercially available probes.
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Affiliation(s)
- Julianna M Richie
- Department of Biomedical Engineering, University of Michigan, Ann Arbor
| | - Paras R Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor
| | - Elissa J Welle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor
| | - Tianshu Dong
- Department of Mechanical Engineering, University of Michigan, Ann Arbor
| | - Lei Chen
- Department of Mechanical Engineering, University of Massachusetts Lowell
| | - Albert J Shih
- Department of Mechanical Engineering, University of Michigan, Ann Arbor
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor; Neuroscience Graduate Program, University of Michigan, Ann Arbor; Robotics Graduate Program, University of Michigan, Ann Arbor;
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Valle ED, Welle EJ, Chestek CA, Weiland JD. Compositional and morphological properties of platinum-iridium electrodeposited on carbon fiber microelectrodes. J Neural Eng 2021; 18:10.1088/1741-2552/ac20bb. [PMID: 34428753 PMCID: PMC10756281 DOI: 10.1088/1741-2552/ac20bb] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 08/24/2021] [Indexed: 11/12/2022]
Abstract
Objective. Neural interfaces based on carbon fiber (CF) electrodes have demonstrated key positive attributes such as minimal foreign body response and mechanical strength to self-insert in brain tissue. However, carbon does not form a low impedance electrode interface with neural tissue. Electrodeposited platinum iridium (PtIr) has been used to improve electrode interface properties for metallic bioelectrodes.Approach. In this study, a PtIr electrodeposition process has been performed on CF microelectrode arrays to improve the interfacial properties of these arrays. We study the film morphology and composition as well as electrode durability and impedance.Results. A PtIr coating with a composition of 70% Pt, 30% Ir and a thickness of ∼400 nm was observed. Pt and Ir were evenly distributed within the film. Impedance was decreased by 89% @ 1 kHz. Accelerated soak testing in a heated (T= 50∘C) saline solution showed impedance increase (@ 1 kHz) of ∼12% after 36 days (89 equivalent) of soaking.
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Affiliation(s)
- Elena della Valle
- Biomedical Engineering Department, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Elissa J Welle
- Biomedical Engineering Department, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Cynthia A Chestek
- Biomedical Engineering Department, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - James D Weiland
- Biomedical Engineering Department, University of Michigan, Ann Arbor, MI, United States of America
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
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5
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Ravagli E, Mastitskaya S, Thompson N, Welle EJ, Chestek CA, Aristovich K, Holder D. Fascicle localisation within peripheral nerves through evoked activity recordings: A comparison between electrical impedance tomography and multi-electrode arrays. J Neurosci Methods 2021; 358:109140. [PMID: 33774053 PMCID: PMC8249910 DOI: 10.1016/j.jneumeth.2021.109140] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 03/07/2021] [Accepted: 03/12/2021] [Indexed: 01/25/2023]
Abstract
BACKGROUND The lack of understanding of fascicular organisation in peripheral nerves limits the potential of vagus nerve stimulation therapy. Two promising methods may be employed to identify the functional anatomy of fascicles within the nerve: fast neural electrical impedance tomography (EIT), and penetrating multi-electrode arrays (MEA). These could provide a means to image the compound action potential within fascicles in the nerve. NEW METHOD We compared the ability to localise fascicle activity between silicon shanks (SS) and carbon fibre (CF) multi-electrode arrays and fast neural EIT, with micro-computed tomography (MicroCT) as an independent reference. Fast neural EIT in peripheral nerves was only recently developed and MEA technology has been used only sparingly in nerves and not for source localisation. Assessment was performed in rat sciatic nerves while evoking neural activity in the tibial and peroneal fascicles. RESULTS Recorded compound action potentials were larger with CF compared to SS (∼700 μV vs ∼300 μV); however, background noise was greater (6.3 μV vs 1.7 μV) leading to lower SNR. Maximum spatial discrimination between Centres-of-Mass of fascicular activity was achieved by fast neural EIT (402 ± 30 μm) and CF MEA (414 ± 123 μm), with no statistical difference between MicroCT (625 ± 17 μm) and CF (p > 0.05) and between CF and EIT (p > 0.05). Compared to CF MEAs, SS MEAs had a lower discrimination power (103 ± 51 μm, p < 0.05). COMPARISON WITH EXISTING METHODS EIT and CF MEAs showed localisation power closest to MicroCT. Silicon MEAs adopted in this study failed to discriminate fascicle location. Re-design of probe geometry may improve results. CONCLUSIONS Nerve EIT is an accurate tool for assessment of fascicular position within nerves. Accuracy of EIT and CF MEA is similar to the reference method. We give technical recommendations for performing multi-electrode recordings in nerves.
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Affiliation(s)
- Enrico Ravagli
- Medical Physics and Biomedical Engineering, University College London, UK.
| | | | - Nicole Thompson
- Medical Physics and Biomedical Engineering, University College London, UK
| | - Elissa J Welle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Kirill Aristovich
- Medical Physics and Biomedical Engineering, University College London, UK
| | - David Holder
- Medical Physics and Biomedical Engineering, University College London, UK
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6
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Welle EJ, Woods JE, Jiman AA, Richie JM, Bottorff EC, Ouyang Z, Seymour JP, Patel PR, Bruns TM, Chestek CA. Sharpened and Mechanically Durable Carbon Fiber Electrode Arrays for Neural Recording. IEEE Trans Neural Syst Rehabil Eng 2021; 29:993-1003. [PMID: 34014825 PMCID: PMC8459724 DOI: 10.1109/tnsre.2021.3082056] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Bioelectric medicine treatments target disorders of the nervous system unresponsive to pharmacological methods. While current stimulation paradigms effectively treat many disorders, the underlying mechanisms are relatively unknown, and current neuroscience recording electrodes are often limited in their specificity to gross averages across many neurons or axons. Here, we develop a novel, durable carbon fiber electrode array adaptable to many neural structures for precise neural recording. Carbon fibers ( [Formula: see text] diameter) were sharpened using a reproducible blowtorchmethod that uses the reflection of fibers against the surface of a water bath. The arrays were developed by partially embedding carbon fibers in medical-grade silicone to improve durability. We recorded acute spontaneous electrophysiology from the rat cervical vagus nerve (CVN), feline dorsal root ganglia (DRG), and rat brain. Blowtorching resulted in fibers of 72.3 ± 33.5-degree tip angle with [Formula: see text] exposed carbon. Observable neural clusters were recorded using sharpened carbon fiber electrodes fromrat CVN ( [Formula: see text]), feline DRG ( [Formula: see text]), and rat brain ( [Formula: see text]). Recordings from the feline DRG included physiologically relevant signals from increased bladder pressure and cutaneous brushing. These results suggest that this carbon fiber array is a uniquely durable and adaptable neural recordingdevice. In the future, this device may be useful as a bioelectric medicine tool for diagnosis and closed-loop neural control of therapeutic treatments and monitoring systems.
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Patel PR, Popov P, Caldwell CM, Welle EJ, Egert D, Pettibone JR, Roossien DH, Becker JB, Berke JD, Chestek CA, Cai D. High density carbon fiber arrays for chronic electrophysiology, fast scan cyclic voltammetry, and correlative anatomy. J Neural Eng 2020; 17:056029. [PMID: 33055366 DOI: 10.1088/1741-2552/abb1f6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Multimodal measurements at the neuronal level allow for detailed insight into local circuit function. However, most behavioral studies focus on one or two modalities and are generally limited by the available technology. APPROACH Here, we show a combined approach of electrophysiology recordings, chemical sensing, and histological localization of the electrode tips within tissue. The key enabling technology is the underlying use of carbon fiber electrodes, which are small, electrically conductive, and sensitive to dopamine. The carbon fibers were functionalized by coating with Parylene C, a thin insulator with a high dielectric constant, coupled with selective re-exposure of the carbon surface using laser ablation. MAIN RESULTS We demonstrate the use of this technology by implanting 16 channel arrays in the rat nucleus accumbens. Chronic electrophysiology and dopamine signals were detected 1 month post implant. Additionally, electrodes were left in the tissue, sliced in place during histology, and showed minimal tissue damage. SIGNIFICANCE Our results validate our new technology and methods, which will enable a more comprehensive circuit level understanding of the brain.
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Affiliation(s)
- Paras R Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
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8
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Jiman AA, Ratze DC, Welle EJ, Patel PR, Richie JM, Bottorff EC, Seymour JP, Chestek CA, Bruns TM. Multi-channel intraneural vagus nerve recordings with a novel high-density carbon fiber microelectrode array. Sci Rep 2020; 10:15501. [PMID: 32968177 PMCID: PMC7511947 DOI: 10.1038/s41598-020-72512-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/27/2020] [Indexed: 01/03/2023] Open
Abstract
Autonomic nerves convey essential neural signals that regulate vital body functions. Recording clearly distinctive physiological neural signals from autonomic nerves will help develop new treatments for restoring regulatory functions. However, this is very challenging due to the small nature of autonomic nerves and the low-amplitude signals from their small axons. We developed a multi-channel, high-density, intraneural carbon fiber microelectrode array (CFMA) with ultra-small electrodes (8-9 µm in diameter, 150-250 µm in length) for recording physiological action potentials from small autonomic nerves. In this study, we inserted CFMA with up to 16 recording carbon fibers in the cervical vagus nerve of 22 isoflurane-anesthetized rats. We recorded action potentials with peak-to-peak amplitudes of 15.1-91.7 µV and signal-to-noise ratios of 2.0-8.3 on multiple carbon fibers per experiment, determined conduction velocities of some vagal signals in the afferent (0.7-4.4 m/s) and efferent (0.7-8.8 m/s) directions, and monitored firing rate changes in breathing and blood glucose modulated conditions. Overall, these experiments demonstrated that CFMA is a novel interface for in-vivo intraneural action potential recordings. This work is considerable progress towards the comprehensive understanding of physiological neural signaling in vital regulatory functions controlled by autonomic nerves.
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Affiliation(s)
- Ahmad A Jiman
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah, Saudi Arabia
| | - David C Ratze
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Elissa J Welle
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Paras R Patel
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Julianna M Richie
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Elizabeth C Bottorff
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - John P Seymour
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
- Department of Neurosurgery, University of Texas Health Science Center, Houston, TX, USA
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Tim M Bruns
- Department of Biomedical Engineering, University of Michigan, NCRC - B10 - A-169, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA.
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA.
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Nason SR, Vaskov AK, Willsey MS, Welle EJ, An H, Vu PP, Bullard AJ, Nu CS, Kao JC, Shenoy KV, Jang T, Kim HS, Blaauw D, Patil PG, Chestek CA. A low-power band of neuronal spiking activity dominated by local single units improves the performance of brain-machine interfaces. Nat Biomed Eng 2020; 4:973-983. [PMID: 32719512 DOI: 10.1038/s41551-020-0591-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 06/24/2020] [Indexed: 12/18/2022]
Abstract
The large power requirement of current brain-machine interfaces is a major hindrance to their clinical translation. In basic behavioural tasks, the downsampled magnitude of the 300-1,000 Hz band of spiking activity can predict movement similarly to the threshold crossing rate (TCR) at 30 kilo-samples per second. However, the relationship between such a spiking-band power (SBP) and neural activity remains unclear, as does the capability of using the SBP to decode complicated behaviour. By using simulations of recordings of neural activity, here we show that the SBP is dominated by local single-unit spikes with spatial specificity comparable to or better than that of the TCR, and that the SBP correlates better with the firing rates of lower signal-to-noise-ratio units than the TCR. With non-human primates, in an online task involving the one-dimensional decoding of the movement of finger groups and in an offline two-dimensional cursor-control task, the SBP performed equally well or better than the TCR. The SBP may enhance the decoding performance of neural interfaces while enabling substantial cuts in power consumption.
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Affiliation(s)
- Samuel R Nason
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Alex K Vaskov
- Robotics Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Matthew S Willsey
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.,Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Elissa J Welle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Hyochan An
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Philip P Vu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Autumn J Bullard
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Chrono S Nu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Jonathan C Kao
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, USA.,Neurosciences Program, University of California, Los Angeles, Los Angeles, CA, USA
| | - Krishna V Shenoy
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA.,Department of Bioengineering, Stanford University, Stanford, CA, USA.,Department of Neurobiology, Stanford University, Stanford, CA, USA.,The Bio-X Program, Stanford University, Stanford, CA, USA.,Wu Tsai Neuroscience Institute, Stanford University, Stanford, CA, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Taekwang Jang
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA.,Department of Information Technology and Electrical Engineering, ETH Zürich, Zürich, Switzerland
| | - Hun-Seok Kim
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - David Blaauw
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Parag G Patil
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.,Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA. .,Robotics Graduate Program, University of Michigan, Ann Arbor, MI, USA. .,Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA. .,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA.
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Welle EJ, Patel PR, Woods JE, Petrossians A, della Valle E, Vega-Medina A, Richie JM, Cai D, Weiland JD, Chestek CA. Ultra-small carbon fiber electrode recording site optimization and improved in vivo chronic recording yield. J Neural Eng 2020; 17:026037. [PMID: 32209743 PMCID: PMC10771280 DOI: 10.1088/1741-2552/ab8343] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Carbon fiber electrodes may enable better long-term brain implants, minimizing the tissue response commonly seen with silicon-based electrodes. The small diameter fiber may enable high-channel count brain-machine interfaces capable of reproducing dexterous movements. Past carbon fiber electrodes exhibited both high fidelity single unit recordings and a healthy neuronal population immediately adjacent to the recording site. However, the recording yield of our carbon fiber arrays chronically implanted in the brain typically hovered around 30%, for previously unknown reasons. In this paper we investigated fabrication process modifications aimed at increasing recording yield and longevity. APPROACH We tested a new cutting method using a 532nm laser against traditional scissor methods for the creation of the electrode recording site. We verified the efficacy of improved recording sites with impedance measurements and in vivo array recording yield. Additionally, we tested potentially longer-lasting coating alternatives to PEDOT:pTS, including PtIr and oxygen plasma etching. New coatings were evaluated with accelerated soak testing and acute recording. MAIN RESULTS We found that the laser created a consistent, sustainable 257 ± 13.8 µm2 electrode with low 1 kHz impedance (19 ± 4 kΩ with PEDOT:pTS) and low fiber-to-fiber variability. The PEDOT:pTS coated laser cut fibers were found to have high recording yield in acute (97% > 100 µV pp , N = 34 fibers) and chronic (84% > 100 µV pp , day 7; 71% > 100 µV pp , day 63, N = 45 fibers) settings. The laser cut recording sites were good platforms for the PtIr coating and oxygen plasma etching, slowing the increase in 1 kHz impedance compared to PEDOT:pTS in an accelerated soak test. SIGNIFICANCE We have found that laser cut carbon fibers have a high recording yield that can be maintained for over two months in vivo and that alternative coatings perform better than PEDOT:pTS in accelerated aging tests. This work provides evidence to support carbon fiber arrays as a viable approach to high-density, clinically-feasible brain-machine interfaces.
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Affiliation(s)
- Elissa J Welle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
| | - Paras R Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
| | - Joshua E Woods
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
| | | | - Elena della Valle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
| | - Alexis Vega-Medina
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States of America
| | - Julianna M Richie
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
| | - Dawen Cai
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States of America
- Biophysics, University of Michigan, Ann Arbor, MI, United States of America
| | - James D Weiland
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Platinum Group Coatings, Pasadena, CA, United States of America
- Robotics Graduate Program, University of Michigan, Ann Arbor, MI, United States of America
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States of America
- Robotics Graduate Program, University of Michigan, Ann Arbor, MI, United States of America
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Jiman AA, Ratze DC, Welle EJ, Patel PR, Bottorff EC, Richie JM, Seymour JP, Chestek CA, Bruns TM. SPARC: Acute Glucose Regulation Recordings from the Rat Vagus Nerve Using Carbon Fiber Microelectrode Arrays. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.06641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | | | - John P. Seymour
- University of Michigan
- University of Texas Health Science Center
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