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Ramon C, Doud A, Holmes MD. Decrease in phase slip rates and phase cone structures during seizure evolution and epileptogenic activities derived from microgrid ECoG data. CURRENT RESEARCH IN NEUROBIOLOGY 2024; 6:100126. [PMID: 38616959 PMCID: PMC11015059 DOI: 10.1016/j.crneur.2024.100126] [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] [Received: 05/18/2023] [Revised: 12/25/2023] [Accepted: 02/03/2024] [Indexed: 04/16/2024] Open
Abstract
Sudden phase changes are related to cortical phase transitions, which likely change in frequency and spatial distribution as epileptogenic activity evolves. A 100 s long section of micro-ECoG data obtained before and during a seizure was selected and analyzed. In addition, nine other short-duration epileptic events were also examined. The data was collected at 420 Hz, imported into MATLAB, downsampled to 200 Hz, and filtered in the 1-50 Hz band. The Hilbert transform was applied to compute the analytic phase, which was then unwrapped, and detrended to look for sudden phase changes. The phase slip rate (counts/s) and its acceleration (counts/s2) were computed with a stepping window of 1-s duration and with a step size of 5 ms. The analysis was performed for theta (3-7 Hz), alpha (7-12 Hz), and beta (12-30 Hz) bands. The phase slip rate on all electrodes in the theta band decreased while it increased for the alpha and beta bands during the seizure period. Similar patterns were observed for isolated epileptogenic events. Spatiotemporal contour plots of the phase slip rates were also constructed using a montage layout of 8 × 8 electrode positions. These plots exhibited dynamic and oscillatory formation of phase cone-like structures which were higher in the theta band and lower in the alpha and beta bands during the seizure period and epileptogenic events. These results indicate that the formation of phase cones might be an excellent biomarker to study the evolution of a seizure and also the cortical dynamics of isolated epileptogenic events.
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Affiliation(s)
- Ceon Ramon
- Department of Electrical & Computer Engineering, University of Washington, Seattle, WA, 98195, USA
- Regional Epilepsy Center, Harborview Medical Center, Department of Neurology, University of Washington, Seattle, WA, 98195, USA
| | - Alexander Doud
- Providence Spokane Neuroscience Institute, 105 West 8th Avenue, Spokane, WA, 99204, USA
| | - Mark D. Holmes
- Regional Epilepsy Center, Harborview Medical Center, Department of Neurology, University of Washington, Seattle, WA, 98195, USA
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2
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Tringides CM, Mooney DJ. Materials for Implantable Surface Electrode Arrays: Current Status and Future Directions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107207. [PMID: 34716730 DOI: 10.1002/adma.202107207] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Surface electrode arrays are mainly fabricated from rigid or elastic materials, and precisely manipulated ductile metal films, which offer limited stretchability. However, the living tissues to which they are applied are nonlinear viscoelastic materials, which can undergo significant mechanical deformation in dynamic biological environments. Further, the same arrays and compositions are often repurposed for vastly different tissues rather than optimizing the materials and mechanical properties of the implant for the target application. By first characterizing the desired biological environment, and then designing a technology for a particular organ, surface electrode arrays may be more conformable, and offer better interfaces to tissues while causing less damage. Here, the various materials used in each component of a surface electrode array are first reviewed, and then electrically active implants in three specific biological systems, the nervous system, the muscular system, and skin, are described. Finally, the fabrication of next-generation surface arrays that overcome current limitations is discussed.
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Affiliation(s)
- Christina M Tringides
- Harvard Program in Biophysics, Harvard University, Cambridge, MA, 02138, USA
- Harvard-MIT Division in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
| | - David J Mooney
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
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3
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Sethia M, Sahin M. The size of via holes influence the amplitude and selectivity of neural signals in Micro-ECoG arrays. BMC Biomed Eng 2022; 4:3. [PMID: 35313997 PMCID: PMC8935835 DOI: 10.1186/s42490-022-00060-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 03/07/2022] [Indexed: 11/11/2022] Open
Abstract
Background Electrocorticography (ECoG) arrays are commonly used to record the brain activity both in animal and human subjects. There is a lack of guidelines in the literature as to how the array geometry, particularly the via holes in the substrate, affects the recorded signals. A finite element (FE) model was developed to simulate the electric field generated by neurons located at different depths in the rat brain cortex and a micro ECoG array (μECoG) was placed on the pia surface for recording the neural signal. The array design chosen was a typical array of 8 × 8 circular (100 μm in diam.) contacts with 500 μm pitch. The size of the via holes between the recording contacts was varied to see the effect. Results The results showed that recorded signal amplitudes were reduced if the substrate was smaller than about four times the depth of the neuron in the gray matter. The signal amplitude profiles had dips around the via holes and the amplitudes were also lower at the contact sites as compared to the design without the holes; an effect that increased with the hole size. Another noteworthy result is that the spatial selectivity of the multi-contact recordings could be improved or reduced by the selection of the via hole sizes, and the effect depended on the distance between the neuron pair targeted for selective recording and its depth. Conclusions The results suggest that the via-hole size clearly affects the recorded neural signal amplitudes and it can be leveraged as a parameter to reduce the inter-channel correlation and thus maximize the information content of neural signals with μECoG arrays.
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Li X, Song Y, Xiao G, He E, Xie J, Dai Y, Xing Y, Wang Y, Wang Y, Xu S, Wang M, Tao TH, Cai X. PDMS-Parylene Hybrid, Flexible Micro-ECoG Electrode Array for Spatiotemporal Mapping of Epileptic Electrophysiological Activity from Multicortical Brain Regions. ACS APPLIED BIO MATERIALS 2021; 4:8013-8022. [PMID: 35006782 DOI: 10.1021/acsabm.1c00923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Epilepsy detection and focus location are urgent issues that need to be solved in epilepsy research. A cortex conformable and fine spatial accuracy electrocorticogram (ECoG) sensor array, especially for real-time detection of multicortical functional regions and delineating epileptic focus remains a challenge. Here, we fabricated a polydimethylsiloxane (PDMS)-parylene hybrid, flexible micro-ECoG electrode array. The multiwalled carbon nanotubes (MWCNTs)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) nanocomposite-modified electrode interface significantly improved the sensing performance with low impedance (20.68 ± 6.65 kΩ), stable phase offset, and high sensitivity. The electrophysiological activities of multicortical brain regions (somatosensory cortex, parietal association cortex, and visual cortex) were simultaneously monitored during normal and epileptic statuses. The epileptic ECoG activities spread spatiotemporally from the starting point toward the adjacent cortex. Significant variations of the waveform, power, and frequency band were observed. The ECoG potential (123 ± 23 μV) at normal status was prominently up to 417 ± 87 μV at the spike wave stage. Besides, the power for epileptic activity (11.049 ± 4.513 μW) was 10 times higher than that (1.092 ± 0.369 μW) for normal activity. In addition, the theta frequency band was found to be a characteristic frequency band of epileptic signals. These joint analysis results of multicortical regions indicated that the active micron-scale region on the parietal association cortex was more likely to be the epileptogenic focus. Cortical mapping with high spatial detail provides the accurate delineation of lesions. The flexible micro-ECoG electrode array is a powerful tool for constructing a spatiotemporal map of the cortex. It provides a technical platform for epileptic focus location, biomedical diagnosis, and brain-computer interaction.
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Affiliation(s)
- Xinrong Li
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yilin Song
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Guihua Xiao
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Enhui He
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jingyu Xie
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yuchuan Dai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yu Xing
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yun Wang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yiding Wang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shengwei Xu
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Mixia Wang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Tiger H Tao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, P. R. China
| | - Xinxia Cai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Viaro R, Maggiolini E, Farina E, Canto R, Iriki A, D'Ausilio A, Fadiga L. Neurons of rat motor cortex become active during both grasping execution and grasping observation. Curr Biol 2021; 31:4405-4412.e4. [PMID: 34433079 DOI: 10.1016/j.cub.2021.07.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/02/2021] [Accepted: 07/23/2021] [Indexed: 11/25/2022]
Abstract
In non-human primates, a subset of frontoparietal neurons (mirror neurons) respond both when an individual executes an action and when it observes another individual performing a similar action.1-8 Mirror neurons constitute an observation and execution matching system likely involved in others' actions processing3,5,9 and in a large set of complex cognitive functions.10,11 Here, we show that the forelimb motor cortex of rats contains neurons presenting mirror properties analogous to those observed in macaques. We provide this evidence by event-related potentials acquired by microelectrocorticography and intracortical single-neuron activity, recorded from the same cortical region during grasping execution and observation. Mirror responses are highly specific, because grasping-related neurons do not respond to the observation of either grooming actions or graspable food alone. These results demonstrate that mirror neurons are present already in species phylogenetically distant from primates, suggesting for them a fundamental, albeit basic, role not necessarily related to higher cognitive functions. Moreover, because murine models have long been valued for their superior experimental accessibility and rapid life cycle, the present finding opens an avenue to new empirical studies tackling questions such as the innate or acquired origin of sensorimotor representations and the effects of social and environmental deprivation on sensorimotor development and recovery.
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Affiliation(s)
- Riccardo Viaro
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, 44121 Ferrara, Italy; Center for Translational Neurophysiology, Istituto Italiano di Tecnologia, 44121 Ferrara, Italy
| | - Emma Maggiolini
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, 44121 Ferrara, Italy
| | - Emanuele Farina
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, 44121 Ferrara, Italy
| | - Rosario Canto
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, 44121 Ferrara, Italy
| | - Atsushi Iriki
- Laboratory for Symbolic Cognitive Development, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Alessandro D'Ausilio
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, 44121 Ferrara, Italy; Center for Translational Neurophysiology, Istituto Italiano di Tecnologia, 44121 Ferrara, Italy
| | - Luciano Fadiga
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, 44121 Ferrara, Italy; Center for Translational Neurophysiology, Istituto Italiano di Tecnologia, 44121 Ferrara, Italy.
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6
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Sellers KK, Chung JE, Zhou J, Triplett MG, Dawes HE, Haque R, Chang EF. Thin-film microfabrication and intraoperative testing of µECoG and iEEG depth arrays for sense and stimulation. J Neural Eng 2021; 18:10.1088/1741-2552/ac1984. [PMID: 34330113 PMCID: PMC10495194 DOI: 10.1088/1741-2552/ac1984] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 07/30/2021] [Indexed: 11/11/2022]
Abstract
Objective.Intracranial neural recordings and electrical stimulation are tools used in an increasing range of applications, including intraoperative clinical mapping and monitoring, therapeutic neuromodulation, and brain computer interface control and feedback. However, many of these applications suffer from a lack of spatial specificity and localization, both in terms of sensed neural signal and applied stimulation. This stems from limited manufacturing processes of commercial-off-the-shelf (COTS) arrays unable to accommodate increased channel density, higher channel count, and smaller contact size.Approach.Here, we describe a manufacturing and assembly approach using thin-film microfabrication for 32-channel high density subdural micro-electrocorticography (µECoG) surface arrays (contacts 1.2 mm diameter, 2 mm pitch) and intracranial electroencephalography (iEEG) depth arrays (contacts 0.5 mm × 1.5 mm, pitch 0.8 mm × 2.5 mm). Crucially, we tackle the translational hurdle and test these arrays during intraoperative studies conducted in four humans under regulatory approval.Main results.We demonstrate that the higher-density contacts provide additional unique information across the recording span compared to the density of COTS arrays which typically have electrode pitch of 8 mm or greater; 4 mm in case of specially ordered arrays. Our intracranial stimulation study results reveal that refined spatial targeting of stimulation elicits evoked potentials with differing spatial spread.Significance.Thin-film,μECoG and iEEG depth arrays offer a promising substrate for advancing a number of clinical and research applications reliant on high-resolution neural sensing and intracranial stimulation.
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Affiliation(s)
- Kristin K Sellers
- Department of Neurological Surgery, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, United States of America
- These authors contributed equally
| | - Jason E Chung
- Department of Neurological Surgery, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, United States of America
- These authors contributed equally
| | - Jenny Zhou
- Lawrence Livermore National Laboratories, Livermore, CA, United States of America
| | - Michael G Triplett
- Lawrence Livermore National Laboratories, Livermore, CA, United States of America
| | - Heather E Dawes
- Department of Neurological Surgery, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, United States of America
| | - Razi Haque
- Lawrence Livermore National Laboratories, Livermore, CA, United States of America
| | - Edward F Chang
- Department of Neurological Surgery, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, United States of America
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7
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Miller KJ, Hermes D, Staff NP. The current state of electrocorticography-based brain-computer interfaces. Neurosurg Focus 2021; 49:E2. [PMID: 32610290 DOI: 10.3171/2020.4.focus20185] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 04/20/2020] [Indexed: 11/06/2022]
Abstract
Brain-computer interfaces (BCIs) provide a way for the brain to interface directly with a computer. Many different brain signals can be used to control a device, varying in ease of recording, reliability, stability, temporal and spatial resolution, and noise. Electrocorticography (ECoG) electrodes provide a highly reliable signal from the human brain surface, and these signals have been used to decode movements, vision, and speech. ECoG-based BCIs are being developed to provide increased options for treatment and assistive devices for patients who have functional limitations. Decoding ECoG signals in real time provides direct feedback to the patient and can be used to control a cursor on a computer or an exoskeleton. In this review, the authors describe the current state of ECoG-based BCIs that are approaching clinical viability for restoring lost communication and motor function in patients with amyotrophic lateral sclerosis or tetraplegia. These studies provide a proof of principle and the possibility that ECoG-based BCI technology may also be useful in the future for assisting in the cortical rehabilitation of patients who have suffered a stroke.
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Affiliation(s)
- Kai J Miller
- Departments of1Neurosurgery.,2Physiology & Biomedical Engineering, and
| | - Dora Hermes
- 2Physiology & Biomedical Engineering, and.,3Neurology, Mayo Clinic, Rochester, Minnesota
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8
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Kaiju T, Inoue M, Hirata M, Suzuki T. High-density mapping of primate digit representations with a 1152-channel µECoG array. J Neural Eng 2021; 18. [PMID: 33530064 DOI: 10.1088/1741-2552/abe245] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/02/2021] [Indexed: 12/11/2022]
Abstract
Objective.Advances in brain-machine interfaces (BMIs) are expected to support patients with movement disorders. Electrocorticogram (ECoG) measures electrophysiological activities over a large area using a low-invasive flexible sheet placed on the cortex. ECoG has been considered as a feasible signal source of the clinical BMI device. To capture neural activities more precisely, the feasibility of higher-density arrays has been investigated. However, currently, the number of electrodes is limited to approximately 300 due to wiring difficulties, device size, and system costs.Approach.We developed a high-density recording system with a large coverage (14 × 7 mm2) and using 1152 electrodes by directly integrating dedicated flexible arrays with the neural-recording application-specific integrated circuits and their interposers.Main results.Comparative experiments with a 128-channel array demonstrated that the proposed device could delineate the entire digit representation of a nonhuman primate. Subsampling analysis revealed that higher-amplitude signals can be measured using higher-density arrays.Significance.We expect that the proposed system that simultaneously establishes large-scale sampling, high temporal-precision of electrophysiology, and high spatial resolution comparable to optical imaging will be suitable for next-generation brain-sensing technology.
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Affiliation(s)
- Taro Kaiju
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan
| | - Masato Inoue
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan.,Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masayuki Hirata
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan.,Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Osaka, Japan
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9
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Trumpis M, Chiang CH, Orsborn AL, Bent B, Li J, Rogers JA, Pesaran B, Cogan G, Viventi J. Sufficient sampling for kriging prediction of cortical potential in rat, monkey, and human µECoG. J Neural Eng 2021; 18. [PMID: 33326943 DOI: 10.1088/1741-2552/abd460] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 12/16/2020] [Indexed: 12/22/2022]
Abstract
Objective. Large channel count surface-based electrophysiology arrays (e.g. µECoG) are high-throughput neural interfaces with good chronic stability. Electrode spacing remains ad hoc due to redundancy and nonstationarity of field dynamics. Here, we establish a criterion for electrode spacing based on the expected accuracy of predicting unsampled field potential from sampled sites.Approach. We applied spatial covariance modeling and field prediction techniques based on geospatial kriging to quantify sufficient sampling for thousands of 500 ms µECoG snapshots in human, monkey, and rat. We calculated a probably approximately correct (PAC) spacing based on kriging that would be required to predict µECoG fields at≤10% error for most cases (95% of observations).Main results. Kriging theory accurately explained the competing effects of electrode density and noise on predicting field potential. Across five frequency bands from 4-7 to 75-300 Hz, PAC spacing was sub-millimeter for auditory cortex in anesthetized and awake rats, and posterior superior temporal gyrus in anesthetized human. At 75-300 Hz, sub-millimeter PAC spacing was required in all species and cortical areas.Significance. PAC spacing accounted for the effect of signal-to-noise on prediction quality and was sensitive to the full distribution of non-stationary covariance states. Our results show that µECoG arrays should sample at sub-millimeter resolution for applications in diverse cortical areas and for noise resilience.
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Affiliation(s)
- Michael Trumpis
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America
| | - Chia-Han Chiang
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America
| | - Amy L Orsborn
- Center for Neural Science, New York University, New York, NY 10003, United States of America.,Department of Electrical & Computer Engineering, University of Washington, Seattle, WA 98195, United States of America.,Department of Bioengineering, University of Washington, Seattle, Washington 98105, United States of America.,Washington National Primate Research Center, Seattle, Washington 98195, United States of America
| | - Brinnae Bent
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America
| | - Jinghua Li
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, United States of America.,Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, United States of America.,Chronic Brain Injury Program, The Ohio State University, Columbus, OH 43210, United States of America
| | - John A Rogers
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, United States of America.,Simpson Querrey Institute, Northwestern University, Chicago, IL 60611, United States of America.,Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, United States of America.,Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, United States of America
| | - Bijan Pesaran
- Center for Neural Science, New York University, New York, NY 10003, United States of America
| | - Gregory Cogan
- Department of Neurosurgery, Duke School of Medicine, Durham, NC 27710, United States of America.,Department of Psychology and Neuroscience, Duke University, Durham, NC 27708, United States of America.,Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, United States of America.,Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC 27710, United States of America
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America.,Department of Neurosurgery, Duke School of Medicine, Durham, NC 27710, United States of America.,Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC 27710, United States of America.,Department of Neurobiology, Duke School of Medicine, Durham, NC 27710, United States of America
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10
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Conformable polyimide-based μECoGs: Bringing the electrodes closer to the signal source. Biomaterials 2020; 255:120178. [PMID: 32569863 DOI: 10.1016/j.biomaterials.2020.120178] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 02/07/2023]
Abstract
Structural biocompatibility is a fundamental requirement for chronically stable bioelectronic devices. Newest neurotechnologies are increasingly focused on minimizing the foreign body response through the development of devices that match the mechanical properties of the implanted tissue and mimic its surface composition, often compromising on their robustness. In this study, an analytical approach is proposed to determine the threshold of conformability for polyimide-based electrocorticography devices. A finite element model was used to quantify the depression of the cortex following the application of devices mechanically above or below conformability threshold. Findings were validated in vivo on rat animal models. Impedance measurements were performed for 40 days after implantation to monitor the status of the biotic/abiotic interface with both conformable and non-conformable implants. Multi-unit activity was then recorded for 12 weeks after implantation using the most compliant device type. It can therefore be concluded that conformability is an essential prerequisite for steady and reliable implants which does not only depend on the Young's modulus of the device material: it strongly relies on the relation between tissue curvature at the implantation site and corresponding device's thickness and geometry, which eventually define the moment of inertia and the interactions at the material-tissue interface.
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11
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Eickenscheidt M, Schäfer P, Baslan Y, Schwarz C, Stieglitz T. Highly Porous Platinum Electrodes for Dry Ear-EEG Measurements. SENSORS 2020; 20:s20113176. [PMID: 32503211 PMCID: PMC7309044 DOI: 10.3390/s20113176] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/18/2020] [Accepted: 06/01/2020] [Indexed: 11/29/2022]
Abstract
The interest in dry electroencephalography (EEG) electrodes has increased in recent years, especially as everyday suitability earplugs for measuring drowsiness or focus of auditory attention. However, the challenge is still the need for a good electrode material, which is reliable and can be easily processed for highly personalized applications. Laser processing, as used here, is a fast and very precise method to produce personalized electrode configurations that meet the high requirements of in-ear EEG electrodes. The arrangement of the electrodes on the flexible and compressible mats allows an exact alignment to the ear mold and contributes to high wearing comfort, as no edges or metal protrusions are present. For better transmission properties, an adapted coating process for surface enlargement of platinum electrodes is used, which can be controlled precisely. The resulting porous platinum-copper alloy is chemically very stable, shows no exposed copper residues, and enlarges the effective surface area by 40. In a proof-of-principle experiment, these porous platinum electrodes could be used to measure the Berger effect in a dry state using just one ear of a test person. Their signal-to-noise ratio and the frequency transfer function is comparable to gel-based silver/silver chloride electrodes.
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Affiliation(s)
- Max Eickenscheidt
- Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg, 79110 Freiburg, Germany; (Y.B.); (T.S.)
- Correspondence: ; Tel.: +49-761-20367636
| | - Patrick Schäfer
- Systems Neuroscience & Neurotechnology Unit, Mindscan Lab, Saarland University of Applied Sciences, 66117 Saarbrücken, Germany;
| | - Yara Baslan
- Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg, 79110 Freiburg, Germany; (Y.B.); (T.S.)
| | | | - Thomas Stieglitz
- Laboratory for Biomedical Microtechnology, IMTEK, University of Freiburg, 79110 Freiburg, Germany; (Y.B.); (T.S.)
- BrainLinks-BrainTools, University of Freiburg, 79110 Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, 79104 Freiburg, Germany
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12
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A 3D-CNT micro-electrode array for zebrafish ECG study including directionality measurement and drug test. Biocybern Biomed Eng 2020. [DOI: 10.1016/j.bbe.2020.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Behncke J, Kern M, Ruescher J, Schulze-Bonhage A, Ball T. Probabilistic neuroanatomical assignment of intracranial electrodes using the ELAS toolbox. J Neurosci Methods 2019; 327:108396. [DOI: 10.1016/j.jneumeth.2019.108396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/18/2019] [Accepted: 08/06/2019] [Indexed: 10/26/2022]
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14
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Oribe S, Yoshida S, Kusama S, Osawa SI, Nakagawa A, Iwasaki M, Tominaga T, Nishizawa M. Hydrogel-Based Organic Subdural Electrode with High Conformability to Brain Surface. Sci Rep 2019; 9:13379. [PMID: 31527626 PMCID: PMC6746719 DOI: 10.1038/s41598-019-49772-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/28/2019] [Indexed: 11/16/2022] Open
Abstract
A totally soft organic subdural electrode has been developed by embedding an array of poly(3,4-ethylenedioxythiophene)-modified carbon fabric (PEDOT-CF) into the polyvinyl alcohol (PVA) hydrogel substrate. The mesh structure of the stretchable PEDOT-CF allowed stable structural integration with the PVA substrate. The electrode performance for monitoring electrocorticography (ECoG) was evaluated in saline solution, on ex vivo brains, and in vivo animal experiments using rats and porcines. It was demonstrated that the large double-layer capacitance of the PEDOT-CF brings low impedance at the frequency of brain wave including epileptic seizures, and PVA hydrogel substrate minimized the contact impedance on the brain. The most important unique feature of the hydrogel-based ECoG electrode was its shape conformability to enable tight adhesion even to curved, grooved surface of brains by just being placed. In addition, since the hydrogel-based electrode is totally organic, the simultaneous ECoG-fMRI measurements could be conducted without image artifacts, avoiding problems induced by conventional metallic electrodes.
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Affiliation(s)
- Shuntaro Oribe
- Department of Neurosurgery, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Shotaro Yoshida
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-Aoba, Aoba-ku, Sendai, 980-8579, Japan
| | - Shinya Kusama
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-Aoba, Aoba-ku, Sendai, 980-8579, Japan
| | - Shin-Ichiro Osawa
- Department of Neurosurgery, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Atsuhiro Nakagawa
- Department of Neurosurgery, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawahigashi-cho, Kodaira-shi, Tokyo, 187-8551, Japan
| | - Teiji Tominaga
- Department of Neurosurgery, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Matsuhiko Nishizawa
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-Aoba, Aoba-ku, Sendai, 980-8579, Japan.
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15
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Fischer B, Schander A, Kreiter AK, Lang W, Wegener D. Visual epidural field potentials possess high functional specificity in single trials. J Neurophysiol 2019; 122:1634-1648. [PMID: 31412218 DOI: 10.1152/jn.00510.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recordings of epidural field potentials (EFPs) allow neuronal activity to be acquired over a large region of cortical tissue with minimal invasiveness. Because electrodes are placed on top of the dura and do not enter the neuronal tissue, EFPs offer intriguing options for both clinical and basic science research. On the other hand, EFPs represent the integrated activity of larger neuronal populations and possess a higher trial-by-trial variability and a reduced signal-to-noise ratio due the additional barrier of the dura. It is thus unclear whether and to what extent EFPs have sufficient spatial selectivity to allow for conclusions about the underlying functional cortical architecture, and whether single EFP trials provide enough information on the short timescales relevant for many clinical and basic neuroscience purposes. We used the high spatial resolution of primary visual cortex to address these issues and investigated the extent to which very short EFP traces allow reliable decoding of spatial information. We briefly presented different visual objects at one of nine closely adjacent locations and recorded neuronal activity with a high-density epidural multielectrode array in three macaque monkeys. With the use of receiver operating characteristics (ROC) to identify the most informative data, machine-learning algorithms provided close-to-perfect classification rates for all 27 stimulus conditions. A binary classifier applying a simple max function on ROC-selected data further showed that single trials might be classified with 100% performance even without advanced offline classifiers. Thus, although highly variable, EFPs constitute an extremely valuable source of information and offer new perspectives for minimally invasive recording of large-scale networks.NEW & NOTEWORTHY Epidural field potential (EFP) recordings provide a minimally invasive approach to investigate large-scale neural networks, but little is known about whether they possess the required specificity for basic and clinical neuroscience. By making use of the spatial selectivity of primary visual cortex, we show that single-trial information can be decoded with close-to-perfect performance, even without using advanced classifiers and based on very few data. This labels EFPs as a highly attractive and widely usable signal.
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Affiliation(s)
- Benjamin Fischer
- Brain Research Institute, Center for Cognitive Sciences, University of Bremen, Bremen, Germany
| | - Andreas Schander
- Institute for Microsensors, -Actuators, and -Systems, University of Bremen, Bremen, Germany
| | - Andreas K Kreiter
- Brain Research Institute, Center for Cognitive Sciences, University of Bremen, Bremen, Germany
| | - Walter Lang
- Institute for Microsensors, -Actuators, and -Systems, University of Bremen, Bremen, Germany
| | - Detlef Wegener
- Brain Research Institute, Center for Cognitive Sciences, University of Bremen, Bremen, Germany
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16
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Caldwell DJ, Ojemann JG, Rao RPN. Direct Electrical Stimulation in Electrocorticographic Brain-Computer Interfaces: Enabling Technologies for Input to Cortex. Front Neurosci 2019; 13:804. [PMID: 31440127 PMCID: PMC6692891 DOI: 10.3389/fnins.2019.00804] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 07/18/2019] [Indexed: 12/22/2022] Open
Abstract
Electrocorticographic brain computer interfaces (ECoG-BCIs) offer tremendous opportunities for restoring function in individuals suffering from neurological damage and for advancing basic neuroscience knowledge. ECoG electrodes are already commonly used clinically for monitoring epilepsy and have greater spatial specificity in recording neuronal activity than techniques such as electroencephalography (EEG). Much work to date in the field has focused on using ECoG signals recorded from cortex as control outputs for driving end effectors. An equally important but less explored application of an ECoG-BCI is directing input into cortex using ECoG electrodes for direct electrical stimulation (DES). Combining DES with ECoG recording enables a truly bidirectional BCI, where information is both read from and written to the brain. We discuss the advantages and opportunities, as well as the barriers and challenges presented by using DES in an ECoG-BCI. In this article, we review ECoG electrodes, the physics and physiology of DES, and the use of electrical stimulation of the brain for the clinical treatment of disorders such as epilepsy and Parkinson’s disease. We briefly discuss some of the translational, regulatory, financial, and ethical concerns regarding ECoG-BCIs. Next, we describe the use of ECoG-based DES for providing sensory feedback and for probing and modifying cortical connectivity. We explore future directions, which may draw on invasive animal studies with penetrating and surface electrodes as well as non-invasive stimulation methods such as transcranial magnetic stimulation (TMS). We conclude by describing enabling technologies, such as smaller ECoG electrodes for more precise targeting of cortical areas, signal processing strategies for simultaneous stimulation and recording, and computational modeling and algorithms for tailoring stimulation to each individual brain.
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Affiliation(s)
- David J Caldwell
- Department of Bioengineering, University of Washington, Seattle, WA, United States.,Medical Scientist Training Program, University of Washington, Seattle, WA, United States.,Center for Neurotechnology, University of Washington, Seattle, WA, United States
| | - Jeffrey G Ojemann
- Center for Neurotechnology, University of Washington, Seattle, WA, United States.,Department of Neurological Surgery, University of Washington, Seattle, WA, United States
| | - Rajesh P N Rao
- Department of Bioengineering, University of Washington, Seattle, WA, United States.,Center for Neurotechnology, University of Washington, Seattle, WA, United States.,Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, United States
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17
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Kern M, Bert S, Glanz O, Schulze-Bonhage A, Ball T. Human motor cortex relies on sparse and action-specific activation during laughing, smiling and speech production. Commun Biol 2019; 2:118. [PMID: 30937400 PMCID: PMC6435746 DOI: 10.1038/s42003-019-0360-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 02/05/2019] [Indexed: 11/09/2022] Open
Abstract
Smiling, laughing, and overt speech production are fundamental to human everyday communication. However, little is known about how the human brain achieves the highly accurate and differentiated control of such orofacial movement during natural conditions. Here, we utilized the high spatiotemporal resolution of subdural recordings to elucidate how human motor cortex is functionally engaged during control of real-life orofacial motor behaviour. For each investigated movement class-lip licking, speech production, laughing and smiling-our findings reveal a characteristic brain activity pattern within the mouth motor cortex with both spatial segregation and overlap between classes. Our findings thus show that motor cortex relies on sparse and action-specific activation during real-life orofacial behaviour, apparently organized in distinct but overlapping subareas that control different types of natural orofacial movements.
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Affiliation(s)
- Markus Kern
- Medical AI Lab, Department of Neurosurgery, Medical Center – University of Freiburg, Freiburg, 79106 Germany
- Neurobiology and Biophysics, Faculty of Biology, University of Freiburg, Freiburg, 79104 Germany
- Epilepsy Center, Department of Neurosurgery, Medical Center – University of Freiburg, Freiburg, 79106 Germany
- BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, 79110 Germany
| | - Sina Bert
- Neurobiology and Biophysics, Faculty of Biology, University of Freiburg, Freiburg, 79104 Germany
- Epilepsy Center, Department of Neurosurgery, Medical Center – University of Freiburg, Freiburg, 79106 Germany
- BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, 79110 Germany
| | - Olga Glanz
- Medical AI Lab, Department of Neurosurgery, Medical Center – University of Freiburg, Freiburg, 79106 Germany
- Epilepsy Center, Department of Neurosurgery, Medical Center – University of Freiburg, Freiburg, 79106 Germany
- BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, 79110 Germany
- Hermann Paul School Linguistics, University of Freiburg, Freiburg, 79085 Germany
- GRK 1624, University of Freiburg, Freiburg, 79098 Germany
| | - Andreas Schulze-Bonhage
- Epilepsy Center, Department of Neurosurgery, Medical Center – University of Freiburg, Freiburg, 79106 Germany
| | - Tonio Ball
- Medical AI Lab, Department of Neurosurgery, Medical Center – University of Freiburg, Freiburg, 79106 Germany
- BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, 79110 Germany
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18
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Correlation Structure in Micro-ECoG Recordings is Described by Spatially Coherent Components. PLoS Comput Biol 2019; 15:e1006769. [PMID: 30742605 PMCID: PMC6386410 DOI: 10.1371/journal.pcbi.1006769] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 02/22/2019] [Accepted: 01/03/2019] [Indexed: 01/17/2023] Open
Abstract
Electrocorticography (ECoG) is becoming more prevalent due to improvements in fabrication and recording technology as well as its ease of implantation compared to intracortical electrophysiology, larger cortical coverage, and potential advantages for use in long term chronic implantation. Given the flexibility in the design of ECoG grids, which is only increasing, it remains an open question what geometry of the electrodes is optimal for an application. Conductive polymer, PEDOT:PSS, coated microelectrodes have an advantage that they can be made very small without losing low impedance. This makes them suitable for evaluating the required granularity of ECoG recording in humans and experimental animals. We used two-dimensional (2D) micro-ECoG grids to record intra-operatively in humans and during acute implantations in mouse with separation distance between neighboring electrodes (i.e., pitch) of 0.4 mm and 0.2/0.25 mm respectively. To assess the spatial properties of the signals, we used the average correlation between electrodes as a function of the pitch. In agreement with prior studies, we find a strong frequency dependence in the spatial scale of correlation. By applying independent component analysis (ICA), we find that the spatial pattern of correlation is largely due to contributions from multiple spatially extended, time-locked sources present at any given time. Our analysis indicates the presence of spatially structured activity down to the sub-millimeter spatial scale in ECoG despite the effects of volume conduction, justifying the use of dense micro-ECoG grids. Electrocorticography (ECoG) is a type of electrophysiological monitoring that uses electrodes placed directly on the exposed surface of the brain. ECoG is a promising technique for studying the brain, and EcoG signals can be used to control brain-computer interfaces. Advances have made it possible to record simultaneously with an increasing number of smaller, and more closely spaced electrodes. However, a property of electrical recording from outside the brain is that common signals appear on different electrodes at different locations, and this affects decisions about how to best distribute a limited number of electrodes to maximize the information that can be gathered. Large spacing of electrodes around one centimeter apart on the brain’s surface has proven useful for clinical and research use, but how much benefit there is to recording from more locations in a smaller area remains to be answered. We found that we can explain the commonality between the different locations as the combination of different patterns of brain activity that are present at multiple electrode locations, and that signals recorded from very closely spaced electrodes, around a millimeter or less apart, are able to identify patterns that are at this small scale.
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19
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Guler S, Dannhauer M, Roig-Solvas B, Gkogkidis A, Macleod R, Ball T, Ojemann JG, Brooks DH. Computationally optimized ECoG stimulation with local safety constraints. Neuroimage 2018; 173:35-48. [PMID: 29427847 PMCID: PMC5911187 DOI: 10.1016/j.neuroimage.2018.01.088] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 01/03/2018] [Accepted: 01/31/2018] [Indexed: 12/22/2022] Open
Abstract
Direct stimulation of the cortical surface is used clinically for cortical mapping and modulation of local activity. Future applications of cortical modulation and brain-computer interfaces may also use cortical stimulation methods. One common method to deliver current is through electrocorticography (ECoG) stimulation in which a dense array of electrodes are placed subdurally or epidurally to stimulate the cortex. However, proximity to cortical tissue limits the amount of current that can be delivered safely. It may be desirable to deliver higher current to a specific local region of interest (ROI) while limiting current to other local areas more stringently than is guaranteed by global safety limits. Two commonly used global safety constraints bound the total injected current and individual electrode currents. However, these two sets of constraints may not be sufficient to prevent high current density locally (hot-spots). In this work, we propose an efficient approach that prevents current density hot-spots in the entire brain while optimizing ECoG stimulus patterns for targeted stimulation. Specifically, we maximize the current along a particular desired directional field in the ROI while respecting three safety constraints: one on the total injected current, one on individual electrode currents, and the third on the local current density magnitude in the brain. This third set of constraints creates a computational barrier due to the huge number of constraints needed to bound the current density at every point in the entire brain. We overcome this barrier by adopting an efficient two-step approach. In the first step, the proposed method identifies the safe brain region, which cannot contain any hot-spots solely based on the global bounds on total injected current and individual electrode currents. In the second step, the proposed algorithm iteratively adjusts the stimulus pattern to arrive at a solution that exhibits no hot-spots in the remaining brain. We report on simulations on a realistic finite element (FE) head model with five anatomical ROIs and two desired directional fields. We also report on the effect of ROI depth and desired directional field on the focality of the stimulation. Finally, we provide an analysis of optimization runtime as a function of different safety and modeling parameters. Our results suggest that optimized stimulus patterns tend to differ from those used in clinical practice.
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Affiliation(s)
- Seyhmus Guler
- Computational Radiology Laboratory (CRL), Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Moritz Dannhauer
- Center for Integrative Biomedical Computing (CIBC), University of Utah, Salt Lake City, UT, USA; Scientific Computing Institute (SCI), University of Utah, Salt Lake City, UT, USA
| | - Biel Roig-Solvas
- SPIRAL Group, Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, USA
| | - Alexis Gkogkidis
- Intracranial EEG and Brain Imaging Lab, Epilepsy Center, University Hospital Freiburg, Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence and Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Rob Macleod
- Center for Integrative Biomedical Computing (CIBC), University of Utah, Salt Lake City, UT, USA; Scientific Computing Institute (SCI), University of Utah, Salt Lake City, UT, USA
| | - Tonio Ball
- Intracranial EEG and Brain Imaging Lab, Epilepsy Center, University Hospital Freiburg, Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence and Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Jeffrey G Ojemann
- Department of Neurological Surgery and the Center for Sensorimotor Neural Engineering, University of Washington, Seattle, WA, USA
| | - Dana H Brooks
- Center for Integrative Biomedical Computing (CIBC), University of Utah, Salt Lake City, UT, USA; SPIRAL Group, Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, USA
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20
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John SE, Opie NL, Wong YT, Rind GS, Ronayne SM, Gerboni G, Bauquier SH, O'Brien TJ, May CN, Grayden DB, Oxley TJ. Signal quality of simultaneously recorded endovascular, subdural and epidural signals are comparable. Sci Rep 2018; 8:8427. [PMID: 29849104 PMCID: PMC5976775 DOI: 10.1038/s41598-018-26457-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 05/10/2018] [Indexed: 02/07/2023] Open
Abstract
Recent work has demonstrated the feasibility of minimally-invasive implantation of electrodes into a cortical blood vessel. However, the effect of the dura and blood vessel on recording signal quality is not understood and may be a critical factor impacting implementation of a closed-loop endovascular neuromodulation system. The present work compares the performance and recording signal quality of a minimally-invasive endovascular neural interface with conventional subdural and epidural interfaces. We compared bandwidth, signal-to-noise ratio, and spatial resolution of recorded cortical signals using subdural, epidural and endovascular arrays four weeks after implantation in sheep. We show that the quality of the signals (bandwidth and signal-to-noise ratio) of the endovascular neural interface is not significantly different from conventional neural sensors. However, the spatial resolution depends on the array location and the frequency of recording. We also show that there is a direct correlation between the signal-noise-ratio and classification accuracy, and that decoding accuracy is comparable between electrode arrays. These results support the consideration for use of an endovascular neural interface in a clinical trial of a novel closed-loop neuromodulation technology.
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Affiliation(s)
- Sam E John
- Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia. .,Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, (RMH), The University of Melbourne, Parkville, Australia. .,Florey Institute of Neuroscience and Mental Health, Parkville, Australia. .,SmartStent Pty Ltd, Parkville, Australia.
| | - Nicholas L Opie
- Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, (RMH), The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, Australia.,SmartStent Pty Ltd, Parkville, Australia
| | - Yan T Wong
- Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia.,Department of Physiology and Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Australia
| | - Gil S Rind
- Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, (RMH), The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, Australia.,SmartStent Pty Ltd, Parkville, Australia
| | - Stephen M Ronayne
- Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, (RMH), The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, Australia.,SmartStent Pty Ltd, Parkville, Australia
| | - Giulia Gerboni
- Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia.,Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, (RMH), The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Sebastien H Bauquier
- Department of Veterinary Science, The University of Melbourne, Werribee, Australia
| | - Terence J O'Brien
- Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, (RMH), The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Clive N May
- Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - David B Grayden
- Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia.,Centre for Neural Engineering, The University of Melbourne, Carlton, Australia
| | - Thomas J Oxley
- Vascular Bionics Laboratory, Department of Medicine, Royal Melbourne Hospital, (RMH), The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, Australia.,SmartStent Pty Ltd, Parkville, Australia
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21
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Thukral A, Ershad F, Enan N, Rao Z, Yu C. Soft Ultrathin Silicon Electronics for Soft Neural Interfaces: A Review of Recent Advances of Soft Neural Interfaces Based on Ultrathin Silicon. IEEE NANOTECHNOLOGY MAGAZINE 2018. [DOI: 10.1109/mnano.2017.2781290] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anish Thukral
- Mechanical Engineering, University of Houston, Houston, Texas United States
| | - Faheem Ershad
- Biomedical Engineering, University of Houston, Houston, Texas United States
| | - Nada Enan
- Biomedical Engineering, University of Houston, Houston, Texas United States
| | - Zhoulyu Rao
- Materials Science and Engineering, University of Houston, Houston, Texas United States
| | - Cunjiang Yu
- Mechanical Engineering, University of Houston, Houston, Texas United States
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