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Yan T, Suzuki K, Kameda S, Maeda M, Mihara T, Hirata M. Chronic subdural electrocorticography in nonhuman primates by an implantable wireless device for brain-machine interfaces. Front Neurosci 2023; 17:1260675. [PMID: 37841689 PMCID: PMC10568031 DOI: 10.3389/fnins.2023.1260675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/12/2023] [Indexed: 10/17/2023] Open
Abstract
Background Subdural electrocorticography (ECoG) signals have been proposed as a stable, good-quality source for brain-machine interfaces (BMIs), with a higher spatial and temporal resolution than electroencephalography (EEG). However, long-term implantation may lead to chronic inflammatory reactions and connective tissue encapsulation, resulting in a decline in signal recording quality. However, no study has reported the effects of the surrounding tissue on signal recording and device functionality thus far. Methods In this study, we implanted a wireless recording device with a customized 32-electrode-ECoG array subdurally in two nonhuman primates for 15 months. We evaluated the neural activities recorded from and wirelessly transmitted to the devices and the chronic tissue reactions around the electrodes. In addition, we measured the gain factor of the newly formed ventral fibrous tissue in vivo. Results Time-frequency analyses of the acute and chronic phases showed similar signal features. The average root mean square voltage and power spectral density showed relatively stable signal quality after chronic implantation. Histological examination revealed thickening of the reactive tissue around the electrode array; however, no evident inflammation in the cortex. From gain factor analysis, we found that tissue proliferation under electrodes reduced the amplitude power of signals. Conclusion This study suggests that subdural ECoG may provide chronic signal recordings for future clinical applications and neuroscience research. This study also highlights the need to reduce proliferation of reactive tissue ventral to the electrodes to enhance long-term stability.
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Affiliation(s)
- Tianfang Yan
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita, Japan
| | | | - Seiji Kameda
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita, Japan
| | - Masashi Maeda
- Candidate Discovery Science Labs, Astellas Pharma Inc., Tokyo, Japan
| | - Takuma Mihara
- Candidate Discovery Science Labs, Astellas Pharma Inc., Tokyo, Japan
| | - Masayuki Hirata
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita, Japan
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Japan
- Global Center for Medical Engineering and Informatics, Osaka University, Suita, Japan
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Fekete Z, Zátonyi A, Kaszás A, Madarász M, Slézia A. Transparent neural interfaces: challenges and solutions of microengineered multimodal implants designed to measure intact neuronal populations using high-resolution electrophysiology and microscopy simultaneously. MICROSYSTEMS & NANOENGINEERING 2023; 9:66. [PMID: 37213820 PMCID: PMC10195795 DOI: 10.1038/s41378-023-00519-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 02/03/2023] [Accepted: 03/01/2023] [Indexed: 05/23/2023]
Abstract
The aim of this review is to present a comprehensive overview of the feasibility of using transparent neural interfaces in multimodal in vivo experiments on the central nervous system. Multimodal electrophysiological and neuroimaging approaches hold great potential for revealing the anatomical and functional connectivity of neuronal ensembles in the intact brain. Multimodal approaches are less time-consuming and require fewer experimental animals as researchers obtain denser, complex data during the combined experiments. Creating devices that provide high-resolution, artifact-free neural recordings while facilitating the interrogation or stimulation of underlying anatomical features is currently one of the greatest challenges in the field of neuroengineering. There are numerous articles highlighting the trade-offs between the design and development of transparent neural interfaces; however, a comprehensive overview of the efforts in material science and technology has not been reported. Our present work fills this gap in knowledge by introducing the latest micro- and nanoengineered solutions for fabricating substrate and conductive components. Here, the limitations and improvements in electrical, optical, and mechanical properties, the stability and longevity of the integrated features, and biocompatibility during in vivo use are discussed.
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Affiliation(s)
- Z. Fekete
- Research Group for Implantable Microsystems, Faculty of Information Technology & Bionics, Pázmány Péter Catholic University, Budapest, Hungary
- Institute of Cognitive Neuroscience & Psychology, Eotvos Lorand Research Network, Budapest, Hungary
| | - A. Zátonyi
- Research Group for Implantable Microsystems, Faculty of Information Technology & Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - A. Kaszás
- Mines Saint-Etienne, Centre CMP, Département BEL, F - 13541 Gardanne, France
- Institut de Neurosciences de la Timone, CNRS UMR 7289 & Aix-Marseille Université, 13005 Marseille, France
| | - M. Madarász
- János Szentágothai PhD Program of Semmelweis University, Budapest, Hungary
- BrainVision Center, Budapest, Hungary
| | - A. Slézia
- Institut de Neurosciences de la Timone, CNRS UMR 7289 & Aix-Marseille Université, 13005 Marseille, France
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Zhang F, Zhang L, Xia J, Zhao W, Dong S, Ye Z, Pan G, Luo J, Zhang S. Multimodal Electrocorticogram Active Electrode Array Based on Zinc Oxide-Thin Film Transistors. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2204467. [PMID: 36403238 PMCID: PMC9839861 DOI: 10.1002/advs.202204467] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Active electrocorticogram (ECoG) electrodes can amplify weak electrophysiological signals and improve anti-interference ability; however, traditional active electrodes are opaque and cannot realize photoelectric collaborative observation. In this study, an active and fully transparent ECoG array based on zinc oxide thin-film transistors (ZnO TFTs) is developed as a local neural signal amplifier for electrophysiological monitoring. The transparency of the proposed ECoG array is up to 85%, which is superior to that of the previously reported active electrode arrays. Various electrical characterizations have demonstrated its ability to record electrophysiological signals with a higher signal-to-noise ratio of 19.9 dB compared to the Au grid (13.2 dB). The high transparency of the ZnO-TFT electrode array allows the concurrent collection of high-quality electrophysiological signals (32.2 dB) under direct optical stimulation of the optogenetic mice brain. The ECoG array can also work under 7-Tesla magnetic resonance imaging to record local brain signals without affecting brain tissue imaging. As the most transparent active ECoG array to date, it provides a powerful multimodal tool for brain observation, including recording brain activity under synchronized optical modulation and 7-Tesla magnetic resonance imaging.
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Affiliation(s)
- Fan Zhang
- Key Laboratory of Biomedical Engineering of Ministry of EducationQiushi Academy for Advanced StudiesZhejiang Provincial Key Laboratory of Cardio‐Cerebral Vascular Detection Technology and Medicinal Effectiveness AppraisalZhejiang University38 Zheda RoadHangzhou310027China
| | - Luxi Zhang
- College of Information Science and Electronic EngineeringFrontier Center of Brain Science and Brain‐machine IntegrationCancer CenterZhejiang University38 Zheda RoadHangzhou310027China
| | - Jie Xia
- College of Information Science and Electronic EngineeringZhejiang University38 Zheda RoadHangzhou310027China
| | - Wanpeng Zhao
- College of Information Science and Electronic EngineeringZhejiang University38 Zheda RoadHangzhou310027China
| | - Shurong Dong
- College of Information Science and Electronic EngineeringFrontier Center of Brain Science and Brain‐machine IntegrationCancer CenterZhejiang University38 Zheda RoadHangzhou310027China
| | - Zhi Ye
- College of Information Science and Electronic EngineeringZhejiang University38 Zheda RoadHangzhou310027China
| | - Gang Pan
- College of Computer Science and TechnologyZhejiang University38 Zheda RoadHangzhou310027China
| | - Jikui Luo
- College of Information Science and Electronic EngineeringZhejiang University38 Zheda RoadHangzhou310027China
| | - Shaomin Zhang
- Key Laboratory of Biomedical Engineering of Ministry of EducationQiushi Academy for Advanced StudiesZhejiang Provincial Key Laboratory of Cardio‐Cerebral Vascular Detection Technology and Medicinal Effectiveness AppraisalZhejiang University38 Zheda RoadHangzhou310027China
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Large-scale multimodal surface neural interfaces for primates. iScience 2022; 26:105866. [PMID: 36647381 PMCID: PMC9840154 DOI: 10.1016/j.isci.2022.105866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Deciphering the function of neural circuits can help with the understanding of brain function and treating neurological disorders. Progress toward this goal relies on the development of chronically stable neural interfaces capable of recording and modulating neural circuits with high spatial and temporal precision across large areas of the brain. Advanced innovations in designing high-density neural interfaces for small animal models have enabled breakthrough discoveries in neuroscience research. Developing similar neurotechnology for larger animal models such as nonhuman primates (NHPs) is critical to gain significant insights for translation to humans, yet still it remains elusive due to the challenges in design, fabrication, and system-level integration of such devices. This review focuses on implantable surface neural interfaces with electrical and optical functionalities with emphasis on the required technological features to realize scalable multimodal and chronically stable implants to address the unique challenges associated with nonhuman primate studies.
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Witham NS, Reiche CF, Odell T, Barth K, Chiang CH, Wang C, Dubey A, Wingel K, Devore S, Friedman D, Pesaran B, Viventi J, Solzbacher F. Flexural bending to approximate cortical forces exerted by electrocorticography (ECoG) arrays. J Neural Eng 2022; 19:10.1088/1741-2552/ac8452. [PMID: 35882223 PMCID: PMC10002477 DOI: 10.1088/1741-2552/ac8452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 07/26/2022] [Indexed: 11/11/2022]
Abstract
Objective.The force that an electrocorticography (ECoG) array exerts on the brain manifests when it bends to match the curvature of the skull and cerebral cortex. This force can negatively impact both short-term and long-term patient outcomes. Here we provide a mechanical characterization of a novel liquid crystal polymer (LCP) ECoG array prototype to demonstrate that its thinner geometry reduces the force potentially applied to the cortex of the brain.Approach.We built a low-force flexural testing machine to measure ECoG array bending forces, calculate their effective flexural moduli, and approximate the maximum force they could exerted on the human brain.Main results.The LCP ECoG prototype was found to have a maximal force less than 20% that of any commercially available ECoG arrays that were tested. However, as a material, LCP was measured to be as much as 24× more rigid than silicone, which is traditionally used in ECoG arrays. This suggests that the lower maximal force resulted from the prototype's thinner profile (2.9×-3.25×).Significance.While decreasing material stiffness can lower the force an ECoG array exhibits, our LCP ECoG array prototype demonstrated that flexible circuit manufacturing techniques can also lower these forces by decreasing ECoG array thickness. Flexural tests of ECoG arrays are necessary to accurately assess these forces, as material properties for polymers and laminates are often scale dependent. As the polymers used are anisotropic, elastic modulus cannot be used to predict ECoG flexural behavior. Accounting for these factors, we used our four-point flexure testing procedure to quantify the forces exerted on the brain by ECoG array bending. With this experimental method, ECoG arrays can be designed to minimize force exerted on the brain, potentially improving both acute and chronic clinical utility.
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Affiliation(s)
- Nicholas S Witham
- The University of Utah, Salt Lake City, UT, United States of America
| | | | - Thomas Odell
- The University of Utah, Salt Lake City, UT, United States of America
| | - Katrina Barth
- Duke University, Durham, NC, United States of America
| | | | - Charles Wang
- Duke University, Durham, NC, United States of America
| | - Agrita Dubey
- New York University Grossman School of Medicine, New York City, NY, United States of America
| | - Katie Wingel
- New York University Grossman School of Medicine, New York City, NY, United States of America
| | - Sasha Devore
- New York University Grossman School of Medicine, New York City, NY, United States of America
| | - Daniel Friedman
- New York University Grossman School of Medicine, New York City, NY, United States of America
| | - Bijan Pesaran
- New York University, New York City, NY, United States of America
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Amini S, Seche W, May N, Choi H, Tavousi P, Shahbazmohamadi S. Femtosecond laser hierarchical surface restructuring for next generation neural interfacing electrodes and microelectrode arrays. Sci Rep 2022; 12:13966. [PMID: 35978090 PMCID: PMC9385846 DOI: 10.1038/s41598-022-18161-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022] Open
Abstract
Long-term implantable neural interfacing devices are able to diagnose, monitor, and treat many cardiac, neurological, retinal and hearing disorders through nerve stimulation, as well as sensing and recording electrical signals to and from neural tissue. To improve specificity, functionality, and performance of these devices, the electrodes and microelectrode arrays-that are the basis of most emerging devices-must be further miniaturized and must possess exceptional electrochemical performance and charge exchange characteristics with neural tissue. In this report, we show for the first time that the electrochemical performance of femtosecond-laser hierarchically-restructured electrodes can be tuned to yield unprecedented performance values that significantly exceed those reported in the literature, e.g. charge storage capacity and specific capacitance were shown to have improved by two orders of magnitude and over 700-fold, respectively, compared to un-restructured electrodes. Additionally, correlation amongst laser parameters, electrochemical performance and surface parameters of the electrodes was established, and while performance metrics exhibit a relatively consistent increasing behavior with laser parameters, surface parameters tend to follow a less predictable trend negating a direct relationship between these surface parameters and performance. To answer the question of what drives such performance and tunability, and whether the widely adopted reasoning of increased surface area and roughening of the electrodes are the key contributors to the observed increase in performance, cross-sectional analysis of the electrodes using focused ion beam shows, for the first time, the existence of subsurface features that may have contributed to the observed electrochemical performance enhancements. This report is the first time that such performance enhancement and tunability are reported for femtosecond-laser hierarchically-restructured electrodes for neural interfacing applications.
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Affiliation(s)
- Shahram Amini
- Research and Development, Pulse Technologies Inc., Quakertown, PA, 18951, USA. .,Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA.
| | - Wesley Seche
- Research and Development, Pulse Technologies Inc., Quakertown, PA, 18951, USA
| | - Nicholas May
- Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA
| | - Hongbin Choi
- Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA
| | - Pouya Tavousi
- UConn Tech Park, University of Connecticut, Storrs, CT, 06269, USA
| | - Sina Shahbazmohamadi
- Biomedical Engineering Department, University of Connecticut, Storrs, CT, 06269, USA
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Jahanbekam A, Baumann J, Nass RD, Bauckhage C, Hill H, Elger CE, Surges R. Performance of ECG-based seizure detection algorithms strongly depends on training and test conditions. Epilepsia Open 2021; 6:597-606. [PMID: 34250754 PMCID: PMC8408591 DOI: 10.1002/epi4.12520] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 07/02/2021] [Accepted: 07/06/2021] [Indexed: 11/11/2022] Open
Abstract
Objective To identify non‐EEG‐based signals and algorithms for detection of motor and non‐motor seizures in people lying in bed during video‐EEG (VEEG) monitoring and to test whether these algorithms work in freely moving people during mobile EEG recordings. Methods Data of three groups of adult people with epilepsy (PwE) were analyzed. Group 1 underwent VEEG with additional devices (accelerometry, ECG, electrodermal activity); group 2 underwent VEEG; and group 3 underwent mobile EEG recordings both including one‐lead ECG. All seizure types were analyzed. Feature extraction and machine‐learning techniques were applied to develop seizure detection algorithms. Performance was expressed as sensitivity, precision, F1 score, and false positives per 24 hours. Results The algorithms were developed in group 1 (35 PwE, 33 seizures) and achieved best results (F1 score 56%, sensitivity 67%, precision 45%, false positives 0.7/24 hours) when ECG features alone were used, with no improvement by including accelerometry and electrodermal activity. In group 2 (97 PwE, 255 seizures), this ECG‐based algorithm largely achieved the same performance (F1 score 51%, sensitivity 39%, precision 73%, false positives 0.4/24 hours). In group 3 (30 PwE, 51 seizures), the same ECG‐based algorithm failed to meet up with the performance in groups 1 and 2 (F1 score 27%, sensitivity 31%, precision 23%, false positives 1.2/24 hours). ECG‐based algorithms were also separately trained on data of groups 2 and 3 and tested on the data of the other groups, yielding maximal F1 scores between 8% and 26%. Significance Our results suggest that algorithms based on ECG features alone can provide clinically meaningful performance for automatic detection of all seizure types. Our study also underscores that the circumstances under which such algorithms were developed, and the selection of the training and test data sets need to be considered and limit the application of such systems to unseen patient groups behaving in different conditions.
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Affiliation(s)
| | - Jan Baumann
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Robert D Nass
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Christian Bauckhage
- Fraunhofer-Institut für Intelligente Analyse- und Informationssysteme IAIS, Sankt Augustin, Germany
| | - Holger Hill
- Mental mHealth Lab, Institut für Sport und Sportwissenschaft, Karlsruher Institut für Technologie, Karlsruhe, Germany
| | | | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
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Cai L, Gutruf P. Soft, Wireless and subdermally implantable recording and neuromodulation tools. J Neural Eng 2021; 18. [PMID: 33607646 DOI: 10.1088/1741-2552/abe805] [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: 04/19/2020] [Accepted: 02/19/2021] [Indexed: 12/14/2022]
Abstract
Progress in understanding neuronal interaction and circuit behavior of the central and peripheral nervous system strongly relies on the advancement of tools that record and stimulate with high fidelity and specificity. Currently, devices used in exploratory research predominantly utilize cables or tethers to provide pathways for power supply, data communication, stimulus delivery and recording, which constrains the scope and use of such devices. In particular, the tethered connection, mechanical mismatch to surrounding soft tissues and bones frustrate the interface leading to irritation and limitation of motion of the subject, which in the case of fundamental and preclinical studies, impacts naturalistic behaviors of animals and precludes the use in experiments involving social interaction and ethologically relevant three-dimensional environments, limiting the use of current tools to mostly rodents and exclude species such as birds and fish. This review explores the current state-of-the-art in wireless, subdermally implantable tools that quantitively expand capabilities in analysis and perturbation of the central and peripheral nervous system by removing tethers and externalized features of implantable neuromodulation and recording tools. Specifically, the review explores power harvesting strategies, wireless communication schemes, and soft materials and mechanics that enable the creation of such devices and discuss their capabilities in the context of freely-behaving subjects. Highlights of this class of devices includes wireless battery-free and fully implantable operation with capabilities in cell specific recording, multimodal neural stimulation and electrical, optogenetic and pharmacological neuromodulation capabilities. We conclude with discussion on translation of such technologies which promises routes towards broad dissemination.
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Affiliation(s)
- Le Cai
- Biomedical Engineering, University of Arizona, 1230 N Cherry Ave., Tucson, Arizona, 85719, UNITED STATES
| | - Philipp Gutruf
- Biomedical Engineering, University of Arizona, 1230 N Cherry Ave., Tucson, Arizona, 85719, UNITED STATES
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Yan T, Kameda S, Suzuki K, Kaiju T, Inoue M, Suzuki T, Hirata M. Minimal Tissue Reaction after Chronic Subdural Electrode Implantation for Fully Implantable Brain-Machine Interfaces. SENSORS 2020; 21:s21010178. [PMID: 33383864 PMCID: PMC7795822 DOI: 10.3390/s21010178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/12/2020] [Accepted: 12/25/2020] [Indexed: 11/16/2022]
Abstract
There is a growing interest in the use of electrocorticographic (ECoG) signals in brain–machine interfaces (BMIs). However, there is still a lack of studies involving the long-term evaluation of the tissue response related to electrode implantation. Here, we investigated biocompatibility, including chronic tissue response to subdural electrodes and a fully implantable wireless BMI device. We implanted a half-sized fully implantable device with subdural electrodes in six beagles for 6 months. Histological analysis of the surrounding tissues, including the dural membrane and cortices, was performed to evaluate the effects of chronic implantation. Our results showed no adverse events, including infectious signs, throughout the 6-month implantation period. Thick connective tissue proliferation was found in the surrounding tissues in the epidural space and subcutaneous space. Quantitative measures of subdural reactive tissues showed minimal encapsulation between the electrodes and the underlying cortex. Immunohistochemical evaluation showed no significant difference in the cell densities of neurons, astrocytes, and microglia between the implanted sites and contralateral sites. In conclusion, we established a beagle model to evaluate cortical implantable devices. We confirmed that a fully implantable wireless device and subdural electrodes could be stably maintained with sufficient biocompatibility in vivo.
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Affiliation(s)
- Tianfang Yan
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (T.Y.); (S.K.)
| | - Seiji Kameda
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (T.Y.); (S.K.)
- Global Center for Medical Engineering and Informatics, Osaka University, Suita 565-0871, Japan
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
| | - Katsuyoshi Suzuki
- Ogino Memorial Laboratory, Nihon Kohden Corporation, Tokorozawa 359-0037, Japan;
| | - Taro Kaiju
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita 565-0871, Japan; (T.K.); (M.I.); (T.S.)
| | - Masato Inoue
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita 565-0871, Japan; (T.K.); (M.I.); (T.S.)
| | - Takafumi Suzuki
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita 565-0871, Japan; (T.K.); (M.I.); (T.S.)
| | - Masayuki Hirata
- Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (T.Y.); (S.K.)
- Global Center for Medical Engineering and Informatics, Osaka University, Suita 565-0871, Japan
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
- Correspondence:
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Pavone L, Moyanova S, Mastroiacovo F, Fazi L, Busceti C, Gaglione A, Martinello K, Fucile S, Bucci D, Prioriello A, Nicoletti F, Fornai F, Morales P, Senesi R. Chronic neural interfacing with cerebral cortex using single-walled carbon nanotube-polymer grids. J Neural Eng 2020; 17:036032. [PMID: 32485702 DOI: 10.1088/1741-2552/ab98db] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The development of electrode arrays able to reliably record brain electrical activity is a critical issue in brain machine interface (BMI) technology. In the present study we undertook a comprehensive physico-chemical, physiological, histological and immunohistochemical characterization of new single-walled carbon nanotubes (SWCNT)-based electrode arrays grafted onto medium-density polyethylene (MD-PE) films. APPROACH The long-term electrical stability, flexibility, and biocompatibility of the SWCNT arrays were investigated in vivo in laboratory rats by two-months recording and analysis of subdural electrocorticogram (ECoG). Ex-vivo characterization of a thin flexible and single probe SWCNT/polymer electrode is also provided. MAIN RESULTS The SWCNT arrays were able to capture high quality and very stable ECoG signals across 8 weeks. The histological and immunohistochemical analyses demonstrated that SWCNT arrays show promising biocompatibility properties and may be used in chronic conditions. The SWCNT-based arrays are flexible and stretchable, providing low electrode-tissue impedance, and, therefore, high compliance with the irregular topography of the cortical surface. Finally, reliable evoked synaptic local field potentials in rat brain slices were recorded using a special SWCNT-polymer-based flexible electrode. SIGNIFICANCE The results demonstrate that the SWCNT arrays grafted in MD-PE are suitable for manufacturing flexible devices for subdural ECoG recording and might represent promising candidates for long-term neural implants for epilepsy monitoring or neuroprosthetic BMI.
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Affiliation(s)
- Luigi Pavone
- Department of Life and Health 'V. Tiberio', University of Molise, Campobasso, Italy. IRCCS Neuromed, Via Atinense 18, 86077, Pozzilli (IS), Italy. These authors contributed equally. Author to whom any correspondence should be addressed
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Taccola G, Barber S, Horner PJ, Bazo HAC, Sayenko D. Complications of epidural spinal stimulation: lessons from the past and alternatives for the future. Spinal Cord 2020; 58:1049-1059. [DOI: 10.1038/s41393-020-0505-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 02/06/2023]
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Baek DH, Ahn S, Kim HS, Kim DW. Fabrication of Donut-Type Neural Electrode for Visual Information as Well as Surface Electrical Stimulation. J Med Biol Eng 2020. [DOI: 10.1007/s40846-020-00540-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Araki T, Uemura T, Yoshimoto S, Takemoto A, Noda Y, Izumi S, Sekitani T. Wireless Monitoring Using a Stretchable and Transparent Sensor Sheet Containing Metal Nanowires. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1902684. [PMID: 31782576 DOI: 10.1002/adma.201902684] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/02/2019] [Indexed: 05/24/2023]
Abstract
Mechanically and visually imperceptible sensor sheets integrated with lightweight wireless loggers are employed in ultimate flexible hybrid electronics (FHE) to reduce vital stress/nervousness and monitor natural biosignal responses. The key technologies and applications for conceptual sensor system fabrication are reported, as exemplified by the use of a stretchable sensor sheet completely conforming to an individual's body surface to realize a low-noise wireless monitoring system (<1 µV) that can be attached to the human forehead for recording electroencephalograms. The above system can discriminate between Alzheimer's disease and the healthy state, thus offering a rapid in-home brain diagnosis possibility. Moreover, the introduction of metal nanowires to improve the transparency of the biocompatible sensor sheet allows one to wirelessly acquire electrocorticograms of nonhuman primates and simultaneously offers optogenetic stimulation such as toward-the-brain-machine interface under free movement. Also discussed are effective methods of improving electrical reliability, biocompatibility, miniaturization, etc., for metal nanowire based tracks and exploring the use of an organic amplifier as an important component to realize a flexible active probe with a high signal-to-noise ratio. Overall, ultimate FHE technologies are demonstrated to achieve efficient closed-loop systems for healthcare management, medical diagnostics, and preclinical studies in neuroscience and neuroengineering.
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Affiliation(s)
- Teppei Araki
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), Suita, Osaka, 565-0871, Japan
- Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Takafumi Uemura
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), Suita, Osaka, 565-0871, Japan
| | - Shusuke Yoshimoto
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
| | - Ashuya Takemoto
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), Suita, Osaka, 565-0871, Japan
- Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yuki Noda
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Artificial Intelligence Research Center, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
| | - Shintaro Izumi
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
| | - Tsuyoshi Sekitani
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), Suita, Osaka, 565-0871, Japan
- Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
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14
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Meningeal Lymphangiogenesis and Enhanced Glymphatic Activity in Mice with Chronically Implanted EEG Electrodes. J Neurosci 2020; 40:2371-2380. [PMID: 32047056 DOI: 10.1523/jneurosci.2223-19.2020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 12/27/2019] [Accepted: 01/22/2020] [Indexed: 12/26/2022] Open
Abstract
Chronic electroencephalography (EEG) is a widely used tool for monitoring cortical electrical activity in experimental animals. Although chronic implants allow for high-quality, long-term recordings in preclinical studies, the electrodes are foreign objects and might therefore be expected to induce a local inflammatory response. We here analyzed the effects of chronic cranial electrode implantation on glymphatic fluid transport and in provoking structural changes in the meninges and cerebral cortex of male and female mice. Immunohistochemical analysis of brain tissue and dura revealed reactive gliosis in the cortex underlying the electrodes and extensive meningeal lymphangiogenesis in the surrounding dura. Meningeal lymphangiogenesis was also evident in mice prepared with the commonly used chronic cranial window. Glymphatic influx of a CSF tracer was significantly enhanced at 30 d postsurgery in both awake and ketamine-xylazine anesthetized mice with electrodes, supporting the concept that glymphatic influx and intracranial lymphatic drainage are interconnected. Altogether, the experimental results provide clear evidence that chronic implantation of EEG electrodes is associated with significant changes in the brain's fluid transport system. Future studies involving EEG recordings and chronic cranial windows must consider the physiological consequences of cranial implants, which include glial scarring, meningeal lymphangiogenesis, and increased glymphatic activity.SIGNIFICANCE STATEMENT This study shows that implantation of extradural electrodes provokes meningeal lymphangiogenesis, enhanced glymphatic influx of CSF, and reactive gliosis. The analysis based on CSF tracer injection in combination with immunohistochemistry showed that chronically implanted electroencephalography electrodes were surrounded by lymphatic sprouts originating from lymphatic vasculature along the dural sinuses and the middle meningeal artery. Likewise, chronic cranial windows provoked lymphatic sprouting. Tracer influx assessed in coronal slices was increased in agreement with previous reports identifying a close association between glymphatic activity and the meningeal lymphatic vasculature. Lymphangiogenesis in the meninges and altered glymphatic fluid transport after electrode implantation have not previously been described and adds new insights to the foreign body response of the CNS.
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15
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Yang W, Gong Y, Li W. A Review: Electrode and Packaging Materials for Neurophysiology Recording Implants. Front Bioeng Biotechnol 2020; 8:622923. [PMID: 33585422 PMCID: PMC7873964 DOI: 10.3389/fbioe.2020.622923] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/10/2020] [Indexed: 01/28/2023] Open
Abstract
To date, a wide variety of neural tissue implants have been developed for neurophysiology recording from living tissues. An ideal neural implant should minimize the damage to the tissue and perform reliably and accurately for long periods of time. Therefore, the materials utilized to fabricate the neural recording implants become a critical factor. The materials of these devices could be classified into two broad categories: electrode materials as well as packaging and substrate materials. In this review, inorganic (metals and semiconductors), organic (conducting polymers), and carbon-based (graphene and carbon nanostructures) electrode materials are reviewed individually in terms of various neural recording devices that are reported in recent years. Properties of these materials, including electrical properties, mechanical properties, stability, biodegradability/bioresorbability, biocompatibility, and optical properties, and their critical importance to neural recording quality and device capabilities, are discussed. For the packaging and substrate materials, different material properties are desired for the chronic implantation of devices in the complex environment of the body, such as biocompatibility and moisture and gas hermeticity. This review summarizes common solid and soft packaging materials used in a variety of neural interface electrode designs, as well as their packaging performances. Besides, several biopolymers typically applied over the electrode package to reinforce the mechanical rigidity of devices during insertion, or to reduce the immune response and inflammation at the device-tissue interfaces are highlighted. Finally, a benchmark analysis of the discussed materials and an outlook of the future research trends are concluded.
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Affiliation(s)
- Weiyang Yang
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Yan Gong
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Wen Li
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
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16
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Torres-Martinez N, Ratel D, Crétallaz C, Gaude C, Maubert S, Divoux JL, Henry C, Guiraud D, Sauter-Starace F. Reliability of parylene-based multi-electrode arrays chronically implanted in adult rat brains, and evidence of electrical stimulation on contact impedance. J Neural Eng 2019; 16:066047. [PMID: 31374559 DOI: 10.1088/1741-2552/ab3836] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The goal of this study was to evaluate the long-term behavior of the surface electrode through electrochemical characterization and follow-up of implanted parylene/platinum microelectrodes. APPROACH To this aim, we designed and manufactured specific planar electrodes for cortical implantation for a rat model. This work was included in the INTENSE® project, one of the goals of which was to prove the feasibility of selective neural recording or stimulation with cuff electrodes around the vagus nerve. MAIN RESULTS After a 12-week implantation in a rat model, we can report that these microelectrodes have withstood in vivo use. Regarding the biocompatibility of the electrodes (materials and manufacturing process), no adverse effect was reported. Indeed, after the three-month implantation, we characterized limited tissue reaction beneath the electrodes and showed an increase and a stabilization of their impedance. Interestingly, the follow-up of the electrochemical impedance combined with electrical stimulation highlighted a drop in the impedance up to 60% at 1 kHz after ten minutes of electrical stimulation at 110 Hz. SIGNIFICANCE This study gives evidence of the biocompatibility of the parylene platinum contact array designed for the project and confirms the effect of stimulation on the contact impedance.
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17
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Bent B, Williams AJ, Bolick R, Chiang CH, Trumpis M, Viventi J. 3D Printed Cranial Window System for Chronic μECoG Recording. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2019; 2018:4591-4594. [PMID: 30441374 DOI: 10.1109/embc.2018.8513117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Chronic studies of flexible μECoG electrodes and the electrode-brain interface have been limited by the inability to assess tissue response over time. The electrophysiological system presented here combines epidural microelectrocorticographic (μECoG) recording capabilities with the ability to visualize tissue response over time through light microscopy and optical coherence tomography (OCT). With the ability to interchange both the electrode and the electronics, and a flushing port for injection of flushing saline and/or drugs, this 3D printed system has future applications in chronic electrophysiology, optogenetics, and advanced imaging methods.
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18
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Brodnick SK, Ness JP, Richner TJ, Thongpang S, Novello J, Hayat M, Cheng KP, Krugner-Higby L, Suminski AJ, Ludwig KA, Williams JC. μECoG Recordings Through a Thinned Skull. Front Neurosci 2019; 13:1017. [PMID: 31632232 PMCID: PMC6779785 DOI: 10.3389/fnins.2019.01017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 09/06/2019] [Indexed: 12/12/2022] Open
Abstract
The studies described in this paper for the first time characterize the acute and chronic performance of optically transparent thin-film micro-electrocorticography (μECoG) grids implanted on a thinned skull as both an electrophysiological complement to existing thinned skull preparation for optical recordings/manipulations, and a less invasive alternative to epidural or subdurally placed μECoG arrays. In a longitudinal chronic study, μECoG grids placed on top of a thinned skull maintain impedances comparable to epidurally placed μECoG grids that are stable for periods of at least 1 month. Optogenetic activation of cortex is also reliably demonstrated through the optically transparent μECoG grids acutely placed on the thinned skull. Finally, spatially distinct electrophysiological recordings were evident on μECoG electrodes placed on a thinned skull separated by 500–750 μm, as assessed by stimulation evoked responses using optogenetic activation of cortex as well as invasive and epidermal stimulation of the sciatic and median nerve at chronic time points. Neural signals were collected through a thinned skull in mice and rats, demonstrating potential utility in neuroscience research applications such as in vivo imaging and optogenetics.
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Affiliation(s)
- Sarah K Brodnick
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Jared P Ness
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Thomas J Richner
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Sanitta Thongpang
- Department of Biomedical Engineering, Mahidol University, Salaya, Thailand
| | - Joseph Novello
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Mohammed Hayat
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Kevin P Cheng
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States
| | - Lisa Krugner-Higby
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Aaron J Suminski
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States.,Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, United States
| | - Kip A Ludwig
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States.,Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, United States
| | - Justin C Williams
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States.,Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, United States
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19
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Lee WR, Im C, Park HY, Seo JM, Kim JM. Fabrication of Convex PDMS-Parylene Microstructures for Conformal Contact of Planar Micro-Electrode Array. Polymers (Basel) 2019; 11:polym11091436. [PMID: 31480664 PMCID: PMC6780241 DOI: 10.3390/polym11091436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/23/2019] [Accepted: 08/27/2019] [Indexed: 11/16/2022] Open
Abstract
Polymer-based micro-electrode arrays (MEAs) are gaining attention as an essential technology to understand brain connectivity and function in the field of neuroscience. However, polymer based MEAs may have several challenges such as difficulty in performing the etching process, difficulty of micro-pattern generation through the photolithography process, weak metal adhesion due to low surface energy, and air pocket entrapment over the electrode site. In order to compensate for the challenges, this paper proposes a novel MEA fabrication process that is performed sequentially with (1) silicon mold preparation; (2) PDMS replica molding, and (3) metal patterning and parylene insulation. The MEA fabricated through this process possesses four arms with electrode sites on the convex microstructures protruding about 20 μm from the outermost layer surface. The validity of the convex microstructure implementation is demonstrated through theoretical background. The electrochemical impedance magnitude is 204.4 ± 68.1 kΩ at 1 kHz. The feasibility of the MEA with convex microstructures was confirmed by identifying the oscillation in the beta frequency band (13–30 Hz) in the electrocorticography signal of a rat olfactory bulb during respiration. These results suggest that the MEA with convex microstructures is promising for applying to various neural recording and stimulation studies.
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Affiliation(s)
- Woo Ram Lee
- Dental Life Science Research Institute, Seoul National University Dental Hospital, Seoul 03080, Korea
- Department of Electrical and Computer Engineering, and Institute of Engineering, Seoul National University, Seoul 08826, Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul 08826, Korea
| | - Changkyun Im
- Dental Life Science Research Institute, Seoul National University Dental Hospital, Seoul 03080, Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul 08826, Korea
- Dental Research Institute, Seoul National University School of Dentistry, Seoul 03080, Korea
| | - Hae-Yong Park
- Department of Physiology, College of Medicine, Hallym University, Chuncheon 24252, Korea
| | - Jong-Mo Seo
- Department of Electrical and Computer Engineering, and Institute of Engineering, Seoul National University, Seoul 08826, Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul 08826, Korea
| | - Jun-Min Kim
- Dental Life Science Research Institute, Seoul National University Dental Hospital, Seoul 03080, Korea.
- Inter-university Semiconductor Research Center, Seoul National University, Seoul 08826, Korea.
- Department of Electronic Communication Engineering, Gyeonggi University of Science Technology, Siheung 15073, Korea.
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20
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Betzel RF, Medaglia JD, Kahn AE, Soffer J, Schonhaut DR, Bassett DS. Structural, geometric and genetic factors predict interregional brain connectivity patterns probed by electrocorticography. Nat Biomed Eng 2019; 3:902-916. [DOI: 10.1038/s41551-019-0404-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 04/15/2019] [Indexed: 01/05/2023]
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21
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Araki T, Yoshida F, Uemura T, Noda Y, Yoshimoto S, Kaiju T, Suzuki T, Hamanaka H, Baba K, Hayakawa H, Yabumoto T, Mochizuki H, Kobayashi S, Tanaka M, Hirata M, Sekitani T. Long-Term Implantable, Flexible, and Transparent Neural Interface Based on Ag/Au Core-Shell Nanowires. Adv Healthc Mater 2019; 8:e1900130. [PMID: 30946540 DOI: 10.1002/adhm.201900130] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/11/2019] [Indexed: 12/11/2022]
Abstract
Neural interfaces enabling light transmittance rely on optogenetics to control and monitor specific neural activity, thereby facilitating deeper understanding of intractable diseases. This study reports the material strategy underlying an optogenetic neural interface comprising stretchable and transparent conductive tracks and capable of demonstrating high biocompatibility after long-term (5-month) implantation. Ag/Au core-shell nanowires contribute toward improving track performance in terms of stretchability (<60% strain), transparency (<83%), and electrical resistance (15 Ω sq-1 ). The neural interface integrated with gel-coated exterior microelectrodes preserves low impedance (1.1-3.2 Ω cm2 ) in a saline solution over the evaluated 5-month period. Besides the use of efficient conductive materials, surface treatment using antithrombogenic polymer tends to prevent the growth of granulation tissue, thereby facilitating clear monitoring of electrocorticograms (ECoG) in a rodent during chronic implantation. The flexible and transparent neural interface pathologically exhibits noncytotoxicity and low inflammatory response while efficiently recording evoked ECoG in a nonhuman primate via optogenetic stimulation. The proposed highly reliable interface can be employed in multifaceted approaches for translational research based on chronic implants.
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Affiliation(s)
- Teppei Araki
- Institute of Scientific and Industrial Research (ISIR) Osaka University Mihogaoka 8‐1 Ibaraki Osaka 567‐0047 Japan
| | - Fumiaki Yoshida
- Endowed Research Department of Clinical Neuroengineering Global Center for Medical Engineering and Informatics Osaka University 2‐2 Yamadaoka Suita Osaka 565‐0871 Japan
- Center for Information and Neural Networks National Institute of Information and Communications Technology (NICT) and Osaka University 1‐4 Yamadaoka Suita Osaka 565‐0871 Japan
- Department of Neurosurgery Graduate School of Medical Sciences Kyushu University 3‐1‐1, Maidashi, Higashi‐ku Fukuoka 812‐8582 Japan
- Japan Science and Technology Agency Precursory Research for Embryonic Science and Technology (PRESTO) 4‐1‐8 Honcho Kawaguchi Saitama 332‐0012 Japan
| | - Takafumi Uemura
- Institute of Scientific and Industrial Research (ISIR) Osaka University Mihogaoka 8‐1 Ibaraki Osaka 567‐0047 Japan
| | - Yuki Noda
- Institute of Scientific and Industrial Research (ISIR) Osaka University Mihogaoka 8‐1 Ibaraki Osaka 567‐0047 Japan
| | - Shusuke Yoshimoto
- Institute of Scientific and Industrial Research (ISIR) Osaka University Mihogaoka 8‐1 Ibaraki Osaka 567‐0047 Japan
| | - Taro Kaiju
- Center for Information and Neural Networks National Institute of Information and Communications Technology (NICT) and Osaka University 1‐4 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Takafumi Suzuki
- Center for Information and Neural Networks National Institute of Information and Communications Technology (NICT) and Osaka University 1‐4 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Hiroki Hamanaka
- Endowed Research Department of Clinical Neuroengineering Global Center for Medical Engineering and Informatics Osaka University 2‐2 Yamadaoka Suita Osaka 565‐0871 Japan
- Center for Information and Neural Networks National Institute of Information and Communications Technology (NICT) and Osaka University 1‐4 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Kousuke Baba
- Department of Neurology Graduate School of Medicine Osaka University 2‐2 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Hideki Hayakawa
- Department of Neurology Graduate School of Medicine Osaka University 2‐2 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Taiki Yabumoto
- Department of Neurology Graduate School of Medicine Osaka University 2‐2 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Hideki Mochizuki
- Department of Neurology Graduate School of Medicine Osaka University 2‐2 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Shingo Kobayashi
- Institute for Materials Chemistry and Engineering (IMCE) Kyushu University 744 Motooka, Nishi‐ku Fukuoka 819‐0395 Japan
| | - Masaru Tanaka
- Institute for Materials Chemistry and Engineering (IMCE) Kyushu University 744 Motooka, Nishi‐ku Fukuoka 819‐0395 Japan
| | - Masayuki Hirata
- Endowed Research Department of Clinical Neuroengineering Global Center for Medical Engineering and Informatics Osaka University 2‐2 Yamadaoka Suita Osaka 565‐0871 Japan
- Center for Information and Neural Networks National Institute of Information and Communications Technology (NICT) and Osaka University 1‐4 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Tsuyoshi Sekitani
- Institute of Scientific and Industrial Research (ISIR) Osaka University Mihogaoka 8‐1 Ibaraki Osaka 567‐0047 Japan
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22
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Eles JR, Vazquez AL, Kozai TDY, Cui XT. Meningeal inflammatory response and fibrous tissue remodeling around intracortical implants: An in vivo two-photon imaging study. Biomaterials 2018; 195:111-123. [PMID: 30634095 DOI: 10.1016/j.biomaterials.2018.12.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 12/15/2018] [Accepted: 12/28/2018] [Indexed: 12/21/2022]
Abstract
Meningeal inflammation and encapsulation of neural electrode arrays is a leading cause of device failure, yet little is known about how it develops over time or what triggers it. This work characterizes the dynamic changes of meningeal inflammatory cells and collagen-I in order to understand the meningeal tissue response to neural electrode implantation. We use in vivo two-photon microscopy of CX3CR1-GFP mice over the first month after electrode implantation to quantify changes in inflammatory cell behavior as well as meningeal collagen-I remodeling. We define a migratory window during the first day after electrode implantation hallmarked by robust inflammatory cell migration along electrodes in the meninges as well as cell trafficking through meningeal venules. This migratory window attenuates by 2 days post-implant, but over the next month, the meningeal collagen-I remodels to conform to the surface of the electrode and thickens. This work shows that there are distinct time courses for initial meningeal inflammatory cell infiltration and meningeal collagen-I remodeling. This may indicate a therapeutic window early after implantation for modulation and mitigation of meningeal inflammation.
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Affiliation(s)
- J R Eles
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States
| | - A L Vazquez
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; Radiology, University of Pittsburgh, United States
| | - T D Y Kozai
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States; NeuroTech Center of the University of Pittsburgh Brain Institute, United States; Center for Neuroscience, University of Pittsburgh, United States
| | - X T Cui
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States.
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23
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Choi JR, Kim SM, Ryu RH, Kim SP, Sohn JW. Implantable Neural Probes for Brain-Machine Interfaces - Current Developments and Future Prospects. Exp Neurobiol 2018; 27:453-471. [PMID: 30636899 PMCID: PMC6318554 DOI: 10.5607/en.2018.27.6.453] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 12/14/2022] Open
Abstract
A Brain-Machine interface (BMI) allows for direct communication between the brain and machines. Neural probes for recording neural signals are among the essential components of a BMI system. In this report, we review research regarding implantable neural probes and their applications to BMIs. We first discuss conventional neural probes such as the tetrode, Utah array, Michigan probe, and electroencephalography (ECoG), following which we cover advancements in next-generation neural probes. These next-generation probes are associated with improvements in electrical properties, mechanical durability, biocompatibility, and offer a high degree of freedom in practical settings. Specifically, we focus on three key topics: (1) novel implantable neural probes that decrease the level of invasiveness without sacrificing performance, (2) multi-modal neural probes that measure both electrical and optical signals, (3) and neural probes developed using advanced materials. Because safety and precision are critical for practical applications of BMI systems, future studies should aim to enhance these properties when developing next-generation neural probes.
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Affiliation(s)
- Jong-Ryul Choi
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation (DGMIF), Daegu 41061, Korea
| | - Seong-Min Kim
- Department of Medical Science, College of Medicine, Catholic Kwandong University, Gangneung 25601, Korea.,Biomedical Research Institute, Catholic Kwandong University International St. Mary's Hospital, Incheon 21711, Korea
| | - Rae-Hyung Ryu
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation (DGMIF), Daegu 41061, Korea
| | - Sung-Phil Kim
- Department of Human Factors Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Jeong-Woo Sohn
- Department of Medical Science, College of Medicine, Catholic Kwandong University, Gangneung 25601, Korea.,Biomedical Research Institute, Catholic Kwandong University International St. Mary's Hospital, Incheon 21711, Korea
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24
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Vomero M, Zucchini E, Delfino E, Gueli C, Mondragon NC, Carli S, Fadiga L, Stieglitz T. Glassy Carbon Electrocorticography Electrodes on Ultra-Thin and Finger-Like Polyimide Substrate: Performance Evaluation Based on Different Electrode Diameters. MATERIALS 2018; 11:ma11122486. [PMID: 30544545 PMCID: PMC6316905 DOI: 10.3390/ma11122486] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/03/2018] [Accepted: 12/05/2018] [Indexed: 02/07/2023]
Abstract
Glassy carbon (GC) has high potential to serve as a biomaterial in neural applications because it is biocompatible, electrochemically inert and can be incorporated in polyimide-based implantable devices. Miniaturization and applicability of GC is, however, thought to be partially limited by its electrical conductivity. For this study, ultra-conformable polyimide-based electrocorticography (ECoG) devices with different-diameter GC electrodes were fabricated and tested in vitro and in rat models. For achieving conformability to the rat brain, polyimide was patterned in a finger-like shape and its thickness was set to 8 µm. To investigate different electrode sizes, each ECoG device was assigned electrodes with diameters of 50, 100, 200 and 300 µm. They were electrochemically characterized and subjected to 10 million biphasic pulses—for achieving a steady-state—and to X-ray photoelectron spectroscopy, for examining their elemental composition. The electrodes were then implanted epidurally to evaluate the ability of each diameter to detect neural activity. Results show that their performance at low frequencies (up to 300 Hz) depends on the distance from the signal source rather than on the electrode diameter, while at high frequencies (above 200 Hz) small electrodes have higher background noises than large ones, unless they are coated with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS).
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Affiliation(s)
- Maria Vomero
- Institute of Microsystem Technology (IMTEK), Laboratory for Biomedical Microtechnology, Georges-Koehler-Allee 102, D-79110 Freiburg, Germany.
- Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Georges-Koehler-Allee 80, 79110 Freiburg, Germany.
| | - Elena Zucchini
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia (IIT), Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.
- Section of Human Physiology University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.
| | - Emanuela Delfino
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia (IIT), Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.
- Section of Human Physiology University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.
| | - Calogero Gueli
- Institute of Microsystem Technology (IMTEK), Laboratory for Biomedical Microtechnology, Georges-Koehler-Allee 102, D-79110 Freiburg, Germany.
| | - Norma Carolina Mondragon
- Institute of Microsystem Technology (IMTEK), Laboratory for Biomedical Microtechnology, Georges-Koehler-Allee 102, D-79110 Freiburg, Germany.
| | - Stefano Carli
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia (IIT), Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.
| | - Luciano Fadiga
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia (IIT), Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.
- Section of Human Physiology University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.
| | - Thomas Stieglitz
- Institute of Microsystem Technology (IMTEK), Laboratory for Biomedical Microtechnology, Georges-Koehler-Allee 102, D-79110 Freiburg, Germany.
- Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Georges-Koehler-Allee 80, 79110 Freiburg, Germany.
- Bernstein Center Freiburg, University of Freiburg, Hansastrasse 9a, 79104 Freiburg, Germany.
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Woods V, Trumpis M, Bent B, Palopoli-Trojani K, Chiang CH, Wang C, Yu C, Insanally MN, Froemke RC, Viventi J. Long-term recording reliability of liquid crystal polymer µECoG arrays. J Neural Eng 2018; 15:066024. [PMID: 30246690 PMCID: PMC6342453 DOI: 10.1088/1741-2552/aae39d] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The clinical use of microsignals recorded over broad cortical regions is largely limited by the chronic reliability of the implanted interfaces. APPROACH We evaluated the chronic reliability of novel 61-channel micro-electrocorticographic (µECoG) arrays in rats chronically implanted for over one year and using accelerated aging. Devices were encapsulated with polyimide (PI) or liquid crystal polymer (LCP), and fabricated using commercial manufacturing processes. In vitro failure modes and predicted lifetimes were determined from accelerated soak testing. Successful designs were implanted epidurally over the rodent auditory cortex. Trends in baseline signal level, evoked responses and decoding performance were reported for over one year of implantation. MAIN RESULTS Devices fabricated with LCP consistently had longer in vitro lifetimes than PI encapsulation. Our accelerated aging results predicted device integrity beyond 3.4 years. Five implanted arrays showed stable performance over the entire implantation period (247-435 d). Our regression analysis showed that impedance predicted signal quality and information content only in the first 31 d of recordings and had little predictive value in the chronic phase (>31 d). In the chronic phase, site impedances slightly decreased yet decoding performance became statistically uncorrelated with impedance. We also employed an improved statistical model of spatial variation to measure sensitivity to locally varying fields, which is typically concealed in standard signal power calculations. SIGNIFICANCE These findings show that µECoG arrays can reliably perform in chronic applications in vivo for over one year, which facilitates the development of a high-density, clinically viable interface.
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Affiliation(s)
- Virginia Woods
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
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Renz AF, Reichmuth AM, Stauffer F, Thompson-Steckel G, Vörös J. A guide towards long-term functional electrodes interfacing neuronal tissue. J Neural Eng 2018; 15:061001. [DOI: 10.1088/1741-2552/aae0c2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Graphitic Carbon Electrodes on Flexible Substrate for Neural Applications Entirely Fabricated Using Infrared Nanosecond Laser Technology. Sci Rep 2018; 8:14749. [PMID: 30283015 PMCID: PMC6170440 DOI: 10.1038/s41598-018-33083-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 09/20/2018] [Indexed: 11/08/2022] Open
Abstract
Neural interfaces for neuroscientific research are nowadays mainly manufactured using standard microsystems engineering technologies which are incompatible with the integration of carbon as electrode material. In this work, we investigate a new method to fabricate graphitic carbon electrode arrays on flexible substrates. The devices were manufactured using infrared nanosecond laser technology for both patterning all components and carbonizing the electrode sites. Two laser pulse repetition frequencies were used for carbonization with the aim of finding the optimum. Prototypes of the devices were evaluated in vitro in 30 mM hydrogen peroxide to mimic the post-surgery oxidative environment. The electrodes were subjected to 10 million biphasic pulses (39.5 μC/cm2) to measure their stability under electrical stress. Their biosensing capabilities were evaluated in different concentrations of dopamine in phosphate buffered saline solution. Raman spectroscopy and x-ray photoelectron spectroscopy analysis show that the atomic percentage of graphitic carbon in the manufactured electrodes reaches the remarkable value of 75%. Results prove that the infrared nanosecond laser yields activated graphite electrodes that are conductive, non-cytotoxic and electrochemically inert. Their comprehensive assessment indicates that our laser-induced carbon electrodes are suitable for future transfer into in vivo studies, including neural recordings, stimulation and neurotransmitters detection.
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Chronically Implanted Intracranial Electrodes: Tissue Reaction and Electrical Changes. MICROMACHINES 2018; 9:mi9090430. [PMID: 30424363 PMCID: PMC6187588 DOI: 10.3390/mi9090430] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/13/2018] [Accepted: 08/22/2018] [Indexed: 12/28/2022]
Abstract
The brain-electrode interface is arguably one of the most important areas of study in neuroscience today. A stronger foundation in this topic will allow us to probe the architecture of the brain in unprecedented functional detail and augment our ability to intervene in disease states. Over many years, significant progress has been made in this field, but some obstacles have remained elusive—notably preventing glial encapsulation and electrode degradation. In this review, we discuss the tissue response to electrode implantation on acute and chronic timescales, the electrical changes that occur in electrode systems over time, and strategies that are being investigated in order to minimize the tissue response to implantation and maximize functional electrode longevity. We also highlight the current and future clinical applications and relevance of electrode technology.
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Zátonyi A, Fedor F, Borhegyi Z, Fekete Z. In vitro and in vivo stability of black-platinum coatings on flexible, polymer microECoG arrays. J Neural Eng 2018; 15:054003. [DOI: 10.1088/1741-2552/aacf71] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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A convex-shaped, PDMS-parylene hybrid multichannel ECoG-electrode array. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:1093-1096. [PMID: 29060065 DOI: 10.1109/embc.2017.8037018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Long-term electrode implant is a challenge for successful brain-computer interfaces (BCIs). It is well known that electrocorticography (ECoG) using flexible planar electrodes is more suitable for long-term implants than intracortical neural recordings using penetrative electrodes. In this study, we propose a convex-shaped, PDMS-parylene hybrid multi-electrode array for long-term stable ECoG recording on the brain or the spinal cord. The electrode array consists of 10 gold recording sites which show impedance values between 50 and 70 kOhm at 1 kHz with a diameter of 100 μm. It is designed like octopus's leg to tightly adhere to the ellipsoidal brain. To assess its performance, epidural ECoG recordings were performed from the main olfactory bulb (MOB) of an anesthetized rat during odor stimulation. The odor-evoked response was shown with an increase of the power in the beta band.
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Bentler C, Stieglitz T. Building wireless implantable neural interfaces within weeks for neuroscientists. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:1078-1081. [PMID: 29060061 DOI: 10.1109/embc.2017.8037014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The variety of "`ready-to-use'" implantable recording and stimulation systems commercially available for neuroscience is very limited and fabrication of custom made implants is commonly considered expensive and time consuming. We present a circuit design that allows cost efficient and fast translation of available components into fully wireless implants. As demonstration fully wireless implantable bidirectional neural interfaces are presented which are made of commercial off-the-shelf components (COTS) only. It is demonstrated that they are competitive to currently available state-of-the-art systems regarding size and performance.
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Heers M, Helias M, Hedrich T, Dümpelmann M, Schulze-Bonhage A, Ball T. Spectral bandwidth of interictal fast epileptic activity characterizes the seizure onset zone. NEUROIMAGE-CLINICAL 2017. [PMID: 29527491 PMCID: PMC5842664 DOI: 10.1016/j.nicl.2017.11.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The foremost aim of presurgical epilepsy evaluation is the delineation of the seizure onset zone (SOZ). There is increasing evidence that fast epileptic activity (FEA, 14–250 Hz) occurring interictally, i.e. between seizures, is predominantly localized within the SOZ. Currently it is unknown, which frequency band of FEA performs best in identifying the SOZ, although prior studies suggest highest concordance of spectral changes with the SOZ for high frequency changes. We suspected that FEA reflects dampened oscillations in local cortical excitatory-inhibitory neural networks, and that interictal FEA in the SOZ is a consequence of reduced oscillatory damping. We therefore predict a narrowing of the spectral bandwidth alongside increased amplitudes of spectral peaks during interictal FEA events. To test this hypothesis, we evaluated spectral changes during interictal FEA in invasive EEG (iEEG) recordings of 13 patients with focal epilepsy. In relative spectra of beta and gamma band changes (14–250 Hz) during FEA, we found that spectral peaks within the SOZ indeed were significantly more narrow-banded and their power changes were significantly higher than outside the SOZ. In contrast, the peak frequency did not differ within and outside the SOZ. Our results show that bandwidth and power changes of spectral modulations during FEA both help localizing the SOZ. We propose the spectral bandwidth as new source of information for the evaluation of EEG data. Invasive EEG spectral bandwidth changes differ in and outside seizure onset zone. Peak frequency of invasive EEG spectral changes was not informative. Model of dampened oscillator explains the observed spectral bandwidth changes. Spectral bandwidth changes are a novel diagnostic feature.
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Affiliation(s)
- Marcel Heers
- Epilepsy Center, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Translational Neurotechnology Lab, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Germany.
| | - Moritz Helias
- Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulations (IAS-6), Jülich Research Centre and JARA, Jülich, Germany
| | - Tanguy Hedrich
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada
| | - Matthias Dümpelmann
- Epilepsy Center, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Germany
| | - Andreas Schulze-Bonhage
- Epilepsy Center, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Germany
| | - Tonio Ball
- Epilepsy Center, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Translational Neurotechnology Lab, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Germany
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Ung H, Baldassano SN, Bink H, Krieger AM, Williams S, Vitale F, Wu C, Freestone D, Nurse E, Leyde K, Davis KA, Cook M, Litt B. Intracranial EEG fluctuates over months after implanting electrodes in human brain. J Neural Eng 2017; 14:056011. [PMID: 28862995 PMCID: PMC5860812 DOI: 10.1088/1741-2552/aa7f40] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Implanting subdural and penetrating electrodes in the brain causes acute trauma and inflammation that affect intracranial electroencephalographic (iEEG) recordings. This behavior and its potential impact on clinical decision-making and algorithms for implanted devices have not been assessed in detail. In this study we aim to characterize the temporal and spatial variability of continuous, prolonged human iEEG recordings. APPROACH Intracranial electroencephalography from 15 patients with drug-refractory epilepsy, each implanted with 16 subdural electrodes and continuously monitored for an average of 18 months, was included in this study. Time and spectral domain features were computed each day for each channel for the duration of each patient's recording. Metrics to capture post-implantation feature changes and inflexion points were computed on group and individual levels. A linear mixed model was used to characterize transient group-level changes in feature values post-implantation and independent linear models were used to describe individual variability. MAIN RESULTS A significant decline in features important to seizure detection and prediction algorithms (mean line length, energy, and half-wave), as well as mean power in the Berger and high gamma bands, was observed in many patients over 100 d following implantation. In addition, spatial variability across electrodes declines post-implantation following a similar timeframe. All selected features decreased by 14-50% in the initial 75 d of recording on the group level, and at least one feature demonstrated this pattern in 13 of the 15 patients. Our findings indicate that iEEG signal features demonstrate increased variability following implantation, most notably in the weeks immediately post-implant. SIGNIFICANCE These findings suggest that conclusions drawn from iEEG, both clinically and for research, should account for spatiotemporal signal variability and that properly assessing the iEEG in patients, depending upon the application, may require extended monitoring.
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Affiliation(s)
- Hoameng Ung
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia PA, USA
| | - Steven N. Baldassano
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia PA, USA
| | - Hank Bink
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia PA, USA
| | - Abba M Krieger
- Department of Statistics, University of Pennsylvania, Philadelphia, PA, USA
| | - Shawniqua Williams
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia PA, USA
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Flavia Vitale
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia PA, USA
| | - Chengyuan Wu
- Department of Neurosurgery, Thomas Jefferson University Hospitals, Philadelphia, PA, USA
| | - Dean Freestone
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Victoria, Australia
| | - Ewan Nurse
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Victoria, Australia
- Department of Biomedical Engineering, University of Melbourne, Victoria, Australia
| | - Kent Leyde
- Cascade Medical Devices, Seattle, Washington
| | - Kathryn A Davis
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia PA, USA
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Mark Cook
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Victoria, Australia
| | - Brian Litt
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia PA, USA
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
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Abstract
Polyimide based shaft electrodes were coated with a bioresorbable layer to stiffen them for intracortical insertion and to reduce the mechanical mismatch between the target tissue and the implanted device after degradation of the coating. Molten saccharose was used as coating material. In a proof-of-concept study, the electrodes were implanted into the cortex of Wistar rats and the insertion forces during implantation were recorded. Electrochemical impedance spectroscopy was performed immediately after implantation and up to 13 weeks after implantation to monitor the tissue response to the implanted electrodes. The recorded spectra were modeled with an equivalent circuit to differentiate the influence of the single components. In one rat, a peak in the encapsulation resistance was observable after two weeks of implantation, indicating the peak of the acute inflammatory response. In another rat, the lowest resistances were observed after four weeks, indicating the termination of the acute inflammatory response. Multiunit activity was recorded with an adequate signal to noise ratio to allow spike sorting. Histology was performed after 7, 45 and 201 days of implantation. The results showed the highest tissue reaction after 45 days and confirmed impedance data that acute inflammatory reactions terminate over time.
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Kohler F, Gkogkidis CA, Bentler C, Wang X, Gierthmuehlen M, Fischer J, Stolle C, Reindl LM, Rickert J, Stieglitz T, Ball T, Schuettler M. Closed-loop interaction with the cerebral cortex: a review of wireless implant technology. BRAIN-COMPUTER INTERFACES 2017. [DOI: 10.1080/2326263x.2017.1338011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Fabian Kohler
- CorTec GmbH, Freiburg, Germany
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering, Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | - C. Alexis Gkogkidis
- Translational Neurotechnology Lab, Department of Neurosurgery, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering, Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | - Christian Bentler
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering, Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | - Xi Wang
- Translational Neurotechnology Lab, Department of Neurosurgery, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering, Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | - Mortimer Gierthmuehlen
- Translational Neurotechnology Lab, Department of Neurosurgery, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | | | - Leonhard M. Reindl
- Laboratory for Electrical Instrumentation, Department of Microsystems Engineering, Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | | | - Thomas Stieglitz
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering, Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | - Tonio Ball
- Translational Neurotechnology Lab, Department of Neurosurgery, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Kuwabara M, Tashiro H, Terasawa Y, Osawa K, Tokuda T, Ohta J, Fujikado T. Development of Chronic Implantable Electrodes for Long-term Visual Evoked Potential Recording in Rabbits. ADVANCED BIOMEDICAL ENGINEERING 2017. [DOI: 10.14326/abe.6.59] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Mariko Kuwabara
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University
| | - Hiroyuki Tashiro
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University
- Graduate School of Materials Science, Nara Institute of Science & Technology
| | - Yasuo Terasawa
- Vision Institute, Nidek Co., Ltd
- Graduate School of Materials Science, Nara Institute of Science & Technology
| | | | - Takashi Tokuda
- Graduate School of Materials Science, Nara Institute of Science & Technology
| | - Jun Ohta
- Graduate School of Materials Science, Nara Institute of Science & Technology
| | - Takashi Fujikado
- Applied Visual Science, Osaka University Graduate School of Medicine
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Use of Objective Neurocognitive Measures to Assess the Psychological States that Influence Return to Sport Following Injury. Sports Med 2016; 46:299-303. [PMID: 26604099 DOI: 10.1007/s40279-015-0435-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
There is growing interest in the effects of psychological states on human performance, especially with those who have suffered debilitating injury and are attempting to return to sport (RTS). Current research methods measure psychological states through validated questionnaires; however, these outcomes only allow for subjective assessment and may be unintentionally biased. Application of objective neurocognitive measures correlated with psychological states will advance understanding of injury outcomes by identifying human behavior and avoiding vague assumptions from subjective measures.
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Bechtold C, de Miranda RL, Chluba C, Quandt E. Fabrication of self-expandable NiTi thin film devices with micro-electrode array for bioelectric sensing, stimulation and ablation. Biomed Microdevices 2016; 18:106. [PMID: 27830452 DOI: 10.1007/s10544-016-0131-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Self-expandable medical devices provide mechanical functionality at a specific location of the human body and are viable for minimal invasive procedures. Besides radiopaque markers and drug-eluting coatings, next generation self-expandable devices can be equipped with additional functionality, such as conductive and flexible electrodes, which enables chronic recording of bioelectrical signals, stimulating or ablating tissue. This promises new therapeutic options in various medical fields, among them in particular neuromodulation (e.g. deep brain stimulation), BioMEMS, radio frequency ablation, mapping or denervation. However, the fabrication of such multi-functional devices is challenging. For this study we have realized a 35 μm thick, superelastic NiTi thin film stent structure with six isolated electrodes on the outer circumference, each electrode connected to a contact pad at the end of the stent structure, using magnetron sputtering, UV lithography and wet chemical etching. Mechanical and electrical properties of the device during typical loading conditions, i.e. crimping, simulated pulsatile and electrochemical testing, were characterized and reveal promising results. For the fabrication of future multifunctional, minimal invasive medical devices, such as electroceuticals or other intelligent implants, NiTi thin film technology is therefore a versatile alternative to conventional fabrication routes.
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Affiliation(s)
| | | | - Christoph Chluba
- Acquandas GmbH, Kaiserstrasse 2, 24143, Kiel, Germany.,Institute for Materials Science, Faculty of Engineering, University of Kiel, Kaiserstrasse 2, 24143, Kiel, Germany
| | - Eckhard Quandt
- Institute for Materials Science, Faculty of Engineering, University of Kiel, Kaiserstrasse 2, 24143, Kiel, Germany
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Opie NL, Rind GS, John SE, Ronayne SM, Grayden DB, Burkitt AN, May CN, O'Brien TJ, Oxley TJ. Feasibility of a chronic, minimally invasive endovascular neural interface. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2016:4455-4458. [PMID: 28269267 DOI: 10.1109/embc.2016.7591716] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Development of a neural interface that can be implanted without risky, open brain surgery will increase the safety and viability of chronic neural recording arrays. We have developed a minimally invasive surgical procedure and an endovascular electrode-array that can be delivered to overlie the cortex through blood vessels. Here, we describe feasibility of the endovascular interface through electrode viability, recording potential and safety. Electrochemical impedance spectroscopy demonstrated that electrode impedance was stable over 91 days and low frequency phase could be used to infer electrode incorporation into the vessel wall. Baseline neural recording were used to identify the maximum bandwidth of the neural interface, which remained stable around 193 Hz for six months. Cross-sectional areas of the implanted vessels were non-destructively measured using the Australian Synchrotron. There was no case of occlusion observed in any of the implanted animals. This work demonstrates the feasibility of an endovascular neural interface to safely and efficaciously record neural information over a chronic time course.
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Opie NL, John SE, Rind GS, Ronayne SM, Grayden DB, Burkitt AN, May CN, O'Brien TJ, Oxley TJ. Chronic impedance spectroscopy of an endovascular stent-electrode array. J Neural Eng 2016; 13:046020. [PMID: 27378157 DOI: 10.1088/1741-2560/13/4/046020] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Recently, we reported a minimally invasive stent-electrode array capable of recording neural signals from within a blood vessel. We now investigate the use of electrochemical impedance spectroscopy (EIS) measurements to infer changes occurring to the electrode-tissue interface from devices implanted in a cohort of sheep for up to 190 days. APPROACH In a cohort of 15 sheep, endovascular stent-electrode arrays were implanted in the superior sagittal sinus overlying the motor cortex for up to 190 days. EIS was performed routinely to quantify viable electrodes for up to 91 days. An equivalent circuit model (ECM) was developed from the in vivo measurements to characterize the electrode-tissue interface changes occurring to the electrodes chronically implanted within a blood vessel. Post-mortem histological assessment of stent and electrode incorporation into the wall of the cortical vessels was compared to the electrical impedance measurements. MAIN RESULTS EIS could be used to infer electrode viability and was consistent with x-ray analysis performed in vivo, and post-mortem evaluation. Viable electrodes exhibited consistent 1 kHz impedances across the 91 day measurement period, with the peak resistance frequency for the acquired data also stable over time. There was a significant change in 100 Hz phase angles, increasing from -67.8° ± 8.8° at day 0 to -43.8° ± 0.8° at day 91, which was observed to stabilize after eight days. ECM's modeled to the data suggested this change was due to an increase in the capacitance of the electrode-tissue interface. This was supported by histological assessment with >85% of the implanted stent struts covered with neointima and incorporated into the blood vessel within two weeks. CONCLUSION This work demonstrated that EIS could be used to determine the viability of electrode implanted chronically within a blood vessel. Impedance measurements alone were not observed to be a useful predictor of alterations occurring at the electrode tissue interface. However, measurement of 100 Hz phase angles was in good agreement with the capacitive changes predicted by the ECM and consistent with suggestions that this represents protein absorption on the electrode surface. 100 Hz phase angles stabilized after 8 days, consistent with histologically assessed samples. SIGNIFICANCE These findings demonstrate the potential application of this technology for use as a chronic neural recording system and indicate the importance of conducting EIS as a measure to identify viable electrodes and changes occurring at the electrode-tissue interface.
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Affiliation(s)
- Nicholas L Opie
- Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria, 3010, Australia. The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia. The Department of Electrical and Electronic Engineering, The University of Melbourne, Victoria, 3052, Australia
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Guiraud D, Andreu D, Bonnet S, Carrault G, Couderc P, Hagège A, Henry C, Hernandez A, Karam N, Le Rolle V, Mabo P, Maciejasz P, Malbert CH, Marijon E, Maubert S, Picq C, Rossel O, Bonnet JL. Vagus nerve stimulation: state of the art of stimulation and recording strategies to address autonomic function neuromodulation. J Neural Eng 2016; 13:041002. [PMID: 27351347 DOI: 10.1088/1741-2560/13/4/041002] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Neural signals along the vagus nerve (VN) drive many somatic and autonomic functions. The clinical interest of VN stimulation (VNS) is thus potentially huge and has already been demonstrated in epilepsy. However, side effects are often elicited, in addition to the targeted neuromodulation. APPROACH This review examines the state of the art of VNS applied to two emerging modulations of autonomic function: heart failure and obesity, especially morbid obesity. MAIN RESULTS We report that VNS may benefit from improved stimulation delivery using very advanced technologies. However, most of the results from fundamental animal studies still need to be demonstrated in humans.
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Affiliation(s)
- David Guiraud
- Inria, DEMAR, Montpellier, France. University of Montpellier, DEMAR, Montpellier, France
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Degenhart AD, Eles J, Dum R, Mischel JL, Smalianchuk I, Endler B, Ashmore RC, Tyler-Kabara EC, Hatsopoulos NG, Wang W, Batista AP, Cui XT. Histological evaluation of a chronically-implanted electrocorticographic electrode grid in a non-human primate. J Neural Eng 2016; 13:046019. [PMID: 27351722 DOI: 10.1088/1741-2560/13/4/046019] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Electrocorticography (ECoG), used as a neural recording modality for brain-machine interfaces (BMIs), potentially allows for field potentials to be recorded from the surface of the cerebral cortex for long durations without suffering the host-tissue reaction to the extent that it is common with intracortical microelectrodes. Though the stability of signals obtained from chronically implanted ECoG electrodes has begun receiving attention, to date little work has characterized the effects of long-term implantation of ECoG electrodes on underlying cortical tissue. APPROACH We implanted and recorded from a high-density ECoG electrode grid subdurally over cortical motor areas of a Rhesus macaque for 666 d. MAIN RESULTS Histological analysis revealed minimal damage to the cortex underneath the implant, though the grid itself was encapsulated in collagenous tissue. We observed macrophages and foreign body giant cells at the tissue-array interface, indicative of a stereotypical foreign body response. Despite this encapsulation, cortical modulation during reaching movements was observed more than 18 months post-implantation. SIGNIFICANCE These results suggest that ECoG may provide a means by which stable chronic cortical recordings can be obtained with comparatively little tissue damage, facilitating the development of clinically viable BMI systems.
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Affiliation(s)
- Alan D Degenhart
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. Center for the Neural Basis of Cognition, Pittsburgh, PA, USA. Systems Neuroscience Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Insanally M, Trumpis M, Wang C, Chiang CH, Woods V, Palopoli-Trojani K, Bossi S, Froemke RC, Viventi J. A low-cost, multiplexed μECoG system for high-density recordings in freely moving rodents. J Neural Eng 2016; 13:026030-26030. [PMID: 26975462 DOI: 10.1088/1741-2560/13/2/026030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely moving rats. APPROACH Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections. We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely moving awake animals. MAIN RESULTS We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (SNR) (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ∼10 s by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. SIGNIFICANCE This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision-making in rodents, particularly over the entire time course of behavioral training and learning.
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Affiliation(s)
- Michele Insanally
- Skirball Institute for Biomolecular Medicine, Neuroscience Institute, Departments of Otolaryngology, Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.,Center for Neural Science, New York University, New York, NY, USA
| | - Michael Trumpis
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Charles Wang
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Chia-Han Chiang
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Virginia Woods
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | | | - Silvia Bossi
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.,Robotics Laboratory, C.R. Casaccia, ENEA, V. Anguillarese, 301, 00123 S. Maria di Galeria, Roma, Italy.,BioRobotics Institute, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56025 Pontedera, Italy
| | - Robert C Froemke
- Skirball Institute for Biomolecular Medicine, Neuroscience Institute, Departments of Otolaryngology, Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.,Center for Neural Science, New York University, New York, NY, USA
| | - Jonathan Viventi
- Polytechnic Institute of New York University, Department of Electrical and Computer Engineering, New York, NY, USA.,Department of Biomedical Engineering, Duke University, Durham, NC, USA
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Minimally invasive endovascular stent-electrode array for high-fidelity, chronic recordings of cortical neural activity. Nat Biotechnol 2016; 34:320-7. [PMID: 26854476 DOI: 10.1038/nbt.3428] [Citation(s) in RCA: 152] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 11/09/2015] [Indexed: 12/18/2022]
Abstract
High-fidelity intracranial electrode arrays for recording and stimulating brain activity have facilitated major advances in the treatment of neurological conditions over the past decade. Traditional arrays require direct implantation into the brain via open craniotomy, which can lead to inflammatory tissue responses, necessitating development of minimally invasive approaches that avoid brain trauma. Here we demonstrate the feasibility of chronically recording brain activity from within a vein using a passive stent-electrode recording array (stentrode). We achieved implantation into a superficial cortical vein overlying the motor cortex via catheter angiography and demonstrate neural recordings in freely moving sheep for up to 190 d. Spectral content and bandwidth of vascular electrocorticography were comparable to those of recordings from epidural surface arrays. Venous internal lumen patency was maintained for the duration of implantation. Stentrodes may have wide ranging applications as a neural interface for treatment of a range of neurological conditions.
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46
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Adewole DO, Serruya MD, Harris JP, Burrell JC, Petrov D, Chen HI, Wolf JA, Cullen DK. The Evolution of Neuroprosthetic Interfaces. Crit Rev Biomed Eng 2016; 44:123-52. [PMID: 27652455 PMCID: PMC5541680 DOI: 10.1615/critrevbiomedeng.2016017198] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The ideal neuroprosthetic interface permits high-quality neural recording and stimulation of the nervous system while reliably providing clinical benefits over chronic periods. Although current technologies have made notable strides in this direction, significant improvements must be made to better achieve these design goals and satisfy clinical needs. This article provides an overview of the state of neuroprosthetic interfaces, starting with the design and placement of these interfaces before exploring the stimulation and recording platforms yielded from contemporary research. Finally, we outline emerging research trends in an effort to explore the potential next generation of neuroprosthetic interfaces.
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Affiliation(s)
- Dayo O. Adewole
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Penn Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Mijail D. Serruya
- Department of Neurology, Jefferson University, Philadelphia, PA, USA
| | - James P. Harris
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - Justin C. Burrell
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - Dmitriy Petrov
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - H. Isaac Chen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
- Penn Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - John A. Wolf
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - D. Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
- Penn Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
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Ledochowitsch P, Yazdan-Shahmorad A, Bouchard KE, Diaz-Botia C, Hanson TL, He JW, Seybold BA, Olivero E, Phillips EAK, Blanche TJ, Schreiner CE, Hasenstaub A, Chang EF, Sabes PN, Maharbiz MM. Strategies for optical control and simultaneous electrical readout of extended cortical circuits. J Neurosci Methods 2015; 256:220-31. [PMID: 26296286 DOI: 10.1016/j.jneumeth.2015.07.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 07/27/2015] [Accepted: 07/27/2015] [Indexed: 01/06/2023]
Abstract
BACKGROUND To dissect the intricate workings of neural circuits, it is essential to gain precise control over subsets of neurons while retaining the ability to monitor larger-scale circuit dynamics. This requires the ability to both evoke and record neural activity simultaneously with high spatial and temporal resolution. NEW METHOD In this paper we present approaches that address this need by combining micro-electrocorticography (μECoG) with optogenetics in ways that avoid photovoltaic artifacts. RESULTS We demonstrate that variations of this approach are broadly applicable across three commonly studied mammalian species - mouse, rat, and macaque monkey - and that the recorded μECoG signal shows complex spectral and spatio-temporal patterns in response to optical stimulation. COMPARISON WITH EXISTING METHODS While optogenetics provides the ability to excite or inhibit neural subpopulations in a targeted fashion, large-scale recording of resulting neural activity remains challenging. Recent advances in optical physiology, such as genetically encoded Ca(2+) indicators, are promising but currently do not allow simultaneous recordings from extended cortical areas due to limitations in optical imaging hardware. CONCLUSIONS We demonstrate techniques for the large-scale simultaneous interrogation of cortical circuits in three commonly used mammalian species.
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Affiliation(s)
- P Ledochowitsch
- The UC Berkeley-UCSF Graduate Program in Bioengineering, Berkeley, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States.
| | - A Yazdan-Shahmorad
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - K E Bouchard
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; LBNL, Life Sciences and Computational Research Divisions, Berkeley, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - C Diaz-Botia
- The UC Berkeley-UCSF Graduate Program in Bioengineering, Berkeley, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - T L Hanson
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - J-W He
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - B A Seybold
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - E Olivero
- Department of Electrical Engineering and Computer Science, Berkeley, CA, United States
| | - E A K Phillips
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States
| | - T J Blanche
- UC Berkeley-Redwood Center for Theoretical Neuroscience, Berkeley, CA, United States
| | - C E Schreiner
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - A Hasenstaub
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States
| | - E F Chang
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - P N Sabes
- UCSF Center for Integrative Neuroscience, San Francisco, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
| | - M M Maharbiz
- Department of Electrical Engineering and Computer Science, Berkeley, CA, United States; The Center for Neural Engineering and Prostheses (CNEP), United States
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48
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Ceyssens F, Puers R. Insulation lifetime improvement of polyimide thin film neural implants. J Neural Eng 2015; 12:054001. [DOI: 10.1088/1741-2560/12/5/054001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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49
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Salam MT, Gélinas S, Desgent S, Duss S, Bernier Turmel F, Carmant L, Sawan M, Nguyen DK. Subdural porous and notched mini-grid electrodes for wireless intracranial electroencephalographic recordings. J Multidiscip Healthc 2014; 7:573-86. [PMID: 25525368 PMCID: PMC4266360 DOI: 10.2147/jmdh.s64269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Intracranial electroencephalography (EEG) studies are widely used in the presurgical evaluation of drug-refractory patients with partial epilepsy. Because chronic implantation of intracranial electrodes carries a risk of infection, hemorrhage, and edema, it is best to limit the number of electrodes used without compromising the ability to localize the epileptogenic zone (EZ). There is always a risk that an intracranial study may fail to identify the EZ because of suboptimal coverage. We present a new subdural electrode design that will allow better sampling of suspected areas of epileptogenicity with lower risk to patients. METHOD Impedance of the proposed electrodes was characterized in vitro using electrochemical impedance spectroscopy. The appearance of the novel electrodes on magnetic resonance imaging (MRI) was tested by placing the electrodes into a gel solution (0.9% NaCl with 14 g gelatin). In vivo neural recordings were performed in male Sprague Dawley rats. Performance comparisons were made using microelectrode recordings from rat cortex and subdural/depth recordings from epileptic patients. Histological examinations of rat brain after 3-week icEEG intracerebral electroencephalography (icEEG) recordings were performed. RESULTS The in vitro results showed minimum impedances for optimum choice of pure gold materials for electrode contacts and wire. Different attributes of the new electrodes were identified on MRI. The results of in vivo recordings demonstrated signal stability, 50% noise reduction, and up to 6 dB signal-to-noise ratio (SNR) improvement as compared to commercial electrodes. The wireless icEEG recording system demonstrated on average a 2% normalized root-mean-square (RMS) deviation. Following the long-term icEEG recording, brain histological results showed no abnormal tissue reaction in the underlying cortex. CONCLUSION The proposed subdural electrode system features attributes that could potentially translate into better icEEG recordings and allow sampling of large of areas of epileptogenicity at lower risk to patients. Further validation for use in humans is required.
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Affiliation(s)
| | - Sébastien Gélinas
- Polystim Neurotechnologies Laboratory, Polytechnique Montréal, QC, Canada
| | - Sébastien Desgent
- Research Center, Sainte-Justine University Hospital Center (CHU Sainte-Justine), Université de Montréal, QC, Canada
| | - Sandra Duss
- Research Center, Sainte-Justine University Hospital Center (CHU Sainte-Justine), Université de Montréal, QC, Canada
| | - Félix Bernier Turmel
- Polystim Neurotechnologies Laboratory, Polytechnique Montréal, QC, Canada ; Neurology Service, Department of Medicine, Notre-Dame Hospital, Centre Hospitalier de l'Université de Montréal (CHUM), QC, Canada
| | - Lionel Carmant
- Research Center, Sainte-Justine University Hospital Center (CHU Sainte-Justine), Université de Montréal, QC, Canada
| | - Mohamad Sawan
- Polystim Neurotechnologies Laboratory, Polytechnique Montréal, QC, Canada
| | - Dang Khoa Nguyen
- Neurology Service, Department of Medicine, Notre-Dame Hospital, Centre Hospitalier de l'Université de Montréal (CHUM), QC, Canada
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50
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Park DW, Schendel AA, Mikael S, Brodnick SK, Richner TJ, Ness JP, Hayat MR, Atry F, Frye ST, Pashaie R, Thongpang S, Ma Z, Williams JC. Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications. Nat Commun 2014; 5:5258. [PMID: 25327513 PMCID: PMC4218963 DOI: 10.1038/ncomms6258] [Citation(s) in RCA: 254] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 09/12/2014] [Indexed: 01/06/2023] Open
Abstract
Neural micro-electrode arrays that are transparent over a broad wavelength spectrum from ultraviolet to infrared could allow for simultaneous electrophysiology and optical imaging, as well as optogenetic modulation of the underlying brain tissue. The long-term biocompatibility and reliability of neural micro-electrodes also require their mechanical flexibility and compliance with soft tissues. Here we present a graphene-based, carbon-layered electrode array (CLEAR) device, which can be implanted on the brain surface in rodents for high-resolution neurophysiological recording. We characterize optical transparency of the device at >90% transmission over the ultraviolet to infrared spectrum and demonstrate its utility through optical interface experiments that use this broad spectrum transparency. These include optogenetic activation of focal cortical areas directly beneath electrodes, in vivo imaging of the cortical vasculature via fluorescence microscopy and 3D optical coherence tomography. This study demonstrates an array of interfacing abilities of the CLEAR device and its utility for neural applications. Monitoring neuronal activity in the rodent in vivo brain is commonly done using micro-electrode arrays but these devices are not normally compatible with optical technologies. Here the authors design a transparent and flexible electrode array based on graphene that allows them to combine electrophysiological recordings with optogenetic and imaging experiments.
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Affiliation(s)
- Dong-Wook Park
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Amelia A Schendel
- Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Solomon Mikael
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Sarah K Brodnick
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Thomas J Richner
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Jared P Ness
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Mohammed R Hayat
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Farid Atry
- Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA
| | - Seth T Frye
- Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA
| | - Ramin Pashaie
- Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA
| | - Sanitta Thongpang
- Department of Biomedical Engineering, Mahidol University, Bangkok 73170, Thailand
| | - Zhenqiang Ma
- 1] Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA [2] Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Justin C Williams
- 1] Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA [2] Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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