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Yan D, Ruiz JRL, Hsieh ML, Jeong D, Vöröslakos M, Lanzio V, Warner EV, Ko E, Tian Y, Patel PR, ElBidweihy H, Smith CS, Lee JH, Cheon J, Buzsáki G, Yoon E. Self-Assembled Origami Neural Probes for Scalable, Multifunctional, Three-Dimensional Neural Interface. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.591141. [PMID: 38712092 PMCID: PMC11071508 DOI: 10.1101/2024.04.25.591141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Flexible intracortical neural probes have drawn attention for their enhanced longevity in high-resolution neural recordings due to reduced tissue reaction. However, the conventional monolithic fabrication approach has met significant challenges in: (i) scaling the number of recording sites for electrophysiology; (ii) integrating of other physiological sensing and modulation; and (iii) configuring into three-dimensional (3D) shapes for multi-sided electrode arrays. We report an innovative self-assembly technology that allows for implementing flexible origami neural probes as an effective alternative to overcome these challenges. By using magnetic-field-assisted hybrid self-assembly, multiple probes with various modalities can be stacked on top of each other with precise alignment. Using this approach, we demonstrated a multifunctional device with scalable high-density recording sites, dopamine sensors and a temperature sensor integrated on a single flexible probe. Simultaneous large-scale, high-spatial-resolution electrophysiology was demonstrated along with local temperature sensing and dopamine concentration monitoring. A high-density 3D origami probe was assembled by wrapping planar probes around a thin fiber in a diameter of 80∼105 μm using optimal foldable design and capillary force. Directional optogenetic modulation could be achieved with illumination from the neuron-sized micro-LEDs (μLEDs) integrated on the surface of 3D origami probes. We could identify angular heterogeneous single-unit signals and neural connectivity 360° surrounding the probe. The probe longevity was validated by chronic recordings of 64-channel stacked probes in behaving mice for up to 140 days. With the modular, customizable assembly technologies presented, we demonstrated a novel and highly flexible solution to accommodate multifunctional integration, channel scaling, and 3D array configuration.
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Muceli S, Poppendieck W, Holobar A, Gandevia S, Liebetanz D, Farina D. Blind identification of the spinal cord output in humans with high-density electrode arrays implanted in muscles. SCIENCE ADVANCES 2022; 8:eabo5040. [PMID: 36383647 PMCID: PMC9668292 DOI: 10.1126/sciadv.abo5040] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Invasive electromyography opened a new window to explore motoneuron behavior in vivo. However, the technique is limited by the small fraction of active motoneurons that can be concurrently detected, precluding a population analysis in natural tasks. Here, we developed a high-density intramuscular electrode for in vivo human recordings along with a fully automatic methodology that could detect the discharges of action potentials of up to 67 concurrently active motoneurons with 99% accuracy. These data revealed that motoneurons of the same pool receive common synaptic input at frequencies up to 75 Hz and that late-recruited motoneurons inhibit the discharges of those recruited earlier. These results constitute an important step in the population coding analysis of the human motor system in vivo.
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Affiliation(s)
- Silvia Muceli
- Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | | | - Aleš Holobar
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
| | - Simon Gandevia
- Neuroscience Research Australia and University of New South Wales, Randwick, Sydney, New South Wales, Australia
| | - David Liebetanz
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, UK
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Becerra-Fajardo L, Krob MO, Minguillon J, Rodrigues C, Welsch C, Tudela-Pi M, Comerma A, Oliveira Barroso F, Schneider A, Ivorra A. Floating EMG sensors and stimulators wirelessly powered and operated by volume conduction for networked neuroprosthetics. J Neuroeng Rehabil 2022; 19:57. [PMID: 35672857 PMCID: PMC9171952 DOI: 10.1186/s12984-022-01033-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/19/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Implantable neuroprostheses consisting of a central electronic unit wired to electrodes benefit thousands of patients worldwide. However, they present limitations that restrict their use. Those limitations, which are more adverse in motor neuroprostheses, mostly arise from their bulkiness and the need to perform complex surgical implantation procedures. Alternatively, it has been proposed the development of distributed networks of intramuscular wireless microsensors and microstimulators that communicate with external systems for analyzing neuromuscular activity and performing stimulation or controlling external devices. This paradigm requires the development of miniaturized implants that can be wirelessly powered and operated by an external system. To accomplish this, we propose a wireless power transfer (WPT) and communications approach based on volume conduction of innocuous high frequency (HF) current bursts. The currents are applied through external textile electrodes and are collected by the wireless devices through two electrodes for powering and bidirectional digital communications. As these devices do not require bulky components for obtaining power, they may have a flexible threadlike conformation, facilitating deep implantation by injection. METHODS We report the design and evaluation of advanced prototypes based on the above approach. The system consists of an external unit, floating semi-implantable devices for sensing and stimulation, and a bidirectional communications protocol. The devices are intended for their future use in acute human trials to demonstrate the distributed paradigm. The technology is assayed in vitro using an agar phantom, and in vivo in hindlimbs of anesthetized rabbits. RESULTS The semi-implantable devices were able to power and bidirectionally communicate with the external unit. Using 13 commands modulated in innocuous 3 MHz HF current bursts, the external unit configured the sensing and stimulation parameters, and controlled their execution. Raw EMG was successfully acquired by the wireless devices at 1 ksps. CONCLUSIONS The demonstrated approach overcomes key limitations of existing neuroprostheses, paving the way to the development of distributed flexible threadlike sensors and stimulators. To the best of our knowledge, these devices are the first based on WPT by volume conduction that can work as EMG sensors and as electrical stimulators in a network of wireless devices.
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Affiliation(s)
- Laura Becerra-Fajardo
- Department of Information and Communications Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain.
| | - Marc Oliver Krob
- Fraunhofer Institute for Biomedical Engineering IBMT, 66280, Sulzbach, Germany
| | - Jesus Minguillon
- Department of Information and Communications Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
- Research Centre for Information and Communications Technologies, University of Granada, 18014, Granada, Spain
- Department of Signal Theory, Telematics and Communications, University of Granada, 18014, Granada, Spain
| | - Camila Rodrigues
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), 28002, Madrid, Spain
- Electronics, Automation and Communications Department, ICAI School of Engineering, Comillas Pontifical University, 28015, Madrid, Spain
| | - Christine Welsch
- Fraunhofer Institute for Biomedical Engineering IBMT, 66280, Sulzbach, Germany
| | - Marc Tudela-Pi
- Department of Information and Communications Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
| | - Albert Comerma
- Department of Information and Communications Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
| | - Filipe Oliveira Barroso
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), 28002, Madrid, Spain
| | - Andreas Schneider
- Fraunhofer Institute for Biomedical Engineering IBMT, 66280, Sulzbach, Germany
| | - Antoni Ivorra
- Department of Information and Communications Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
- Serra Húnter Fellow Programme, Universitat Pompeu Fabra, 08018, Barcelona, Spain
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Jung D, Song K, Ju H, Park H, Han JH, Kim N, Kim J, Lee J. Sustainably Powered, Multifunctional Flexible Feedback Implant by the Bifacial Design and Si Photovoltaics. Adv Healthc Mater 2021; 10:e2001480. [PMID: 33200555 DOI: 10.1002/adhm.202001480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/05/2020] [Indexed: 11/08/2022]
Abstract
Advanced design and integration of functioning devices with secured power is of interest for many applications that require complicated, sophisticated, or multifunctional processes in confined environments such as in human bodies. Here, strategies for design and realization are introduced for multifunctional feedback implants with the bifacial design and silicon (Si) photovoltaics in flexible forms. The approaches provide efficient design spaces for flexible Si photovoltaics facing up for sustainable powering and multiple electronic components for feedback functions facing down for sensing, processing, and stimulating in human bodies. The computational and experimental results including in vivo assessments ensure feasibility of the approaches by demonstrating feedback multifunctions, power-harvesting in milliwatts, and mechanical compatibility for operations in live tissues. This work should useful for wide range of applications that require sustainable power and advanced multifunctions.
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Affiliation(s)
- Dongwuk Jung
- School of Mechanical Engineering Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
| | - Kwangsun Song
- School of Mechanical Engineering Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
| | - Hunpyo Ju
- School of Mechanical Engineering Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
| | - Hyeongoh Park
- School of Mechanical Engineering Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
| | - Jung Hyun Han
- School of Life Sciences Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
| | - Namyun Kim
- School of Mechanical Engineering Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
| | - Juho Kim
- School of Mechanical Engineering Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
| | - Jongho Lee
- School of Mechanical Engineering Gwangju Institute of Science and Technology (GIST) 123 Cheomdangwagi‐ro, Buk‐gu Gwangju 61005 Republic of Korea
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Kim C, Jeong J, Kim SJ. Recent Progress on Non-Conventional Microfabricated Probes for the Chronic Recording of Cortical Neural Activity. SENSORS (BASEL, SWITZERLAND) 2019; 19:E1069. [PMID: 30832357 PMCID: PMC6427797 DOI: 10.3390/s19051069] [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] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 02/06/2023]
Abstract
Microfabrication technology for cortical interfaces has advanced rapidly over the past few decades for electrophysiological studies and neuroprosthetic devices offering the precise recording and stimulation of neural activity in the cortex. While various cortical microelectrode arrays have been extensively and successfully demonstrated in animal and clinical studies, there remains room for further improvement of the probe structure, materials, and fabrication technology, particularly for high-fidelity recording in chronic implantation. A variety of non-conventional probes featuring unique characteristics in their designs, materials and fabrication methods have been proposed to address the limitations of the conventional standard shank-type ("Utah-" or "Michigan-" type) devices. Such non-conventional probes include multi-sided arrays to avoid shielding and increase recording volumes, mesh- or thread-like arrays for minimized glial scarring and immune response, tube-type or cylindrical probes for three-dimensional (3D) recording and multi-modality, folded arrays for high conformability and 3D recording, self-softening or self-deployable probes for minimized tissue damage and extensions of the recording sites beyond gliosis, nanostructured probes to reduce the immune response, and cone-shaped electrodes for promoting tissue ingrowth and long-term recording stability. Herein, the recent progress with reference to the many different types of non-conventional arrays is reviewed while highlighting the challenges to be addressed and the microfabrication techniques necessary to implement such features.
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Affiliation(s)
- Chaebin Kim
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea.
| | - Joonsoo Jeong
- Department of Biomedical Engineering, School of Medicine, Pusan National University, Yangsan 50612, Korea.
| | - Sung June Kim
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea.
- Institute on Aging, College of Medicine, Seoul National University, Seoul 08826, Korea.
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Muceli S, Poppendieck W, Hoffmann KP, Dosen S, Benito-León J, Barroso FO, Pons JL, Farina D. A thin-film multichannel electrode for muscle recording and stimulation in neuroprosthetics applications. J Neural Eng 2019; 16:026035. [PMID: 30721892 DOI: 10.1088/1741-2552/ab047a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE We propose, design and test a novel thin-film multichannel electrode that can be used for both recording from and stimulating a muscle in acute implants. APPROACH The system is built on a substrate of polyimide and contains 12 recording and three stimulation sites made of platinum. The structure is 420 µm wide, 20 µm thick and embeds the recording and stimulation contacts on the two sides of the polyimide over an approximate length of 2 cm. We show representative applications in healthy individuals as well as tremor patients. The designed system was tested by a psychometric characterization of the stimulation contacts in six tremor patients and three healthy individuals determining the perception threshold and current limit as well as the success rate in discriminating elicited sensations (electrotactile feedback). Also, we investigated the possibility of using the intramuscular electrode for reducing tremor in one patient by electrical stimulation delivered with timing based on the electromyographic activity recorded with the same electrode. MAIN RESULTS In the tremor patients, the current corresponding to the perception threshold and the current limit were 0.7 ± 0.2 and 1.4 ± 0.7 mA for the wrist flexor muscles and 0.4 ± 0.2 and 1.5 ± 0.7 mA for the extensors. In one patient, closed-loop stimulation resulted in a decrease of the tremor power >50%. In healthy individuals the perception threshold and current limits were 0.9 ± 0.6 and 2.1 ± 0.6 mA for the extensor carpi radialis muscle. The subjects could distinguish four or six stimulation patterns (two or three stimulation sites × two stimulation current amplitudes) with true positive rate >80% (two subjects) and >60% (one subject), respectively. SIGNIFICANCE The proposed electrode provides a compact multichannel interface for recording electromyogram and delivering electrical stimulation in applications such as neuroprostheses for tremor suppression and closed-loop myoelectric prostheses.
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Affiliation(s)
- Silvia Muceli
- Department of Bioengineering, Imperial College London, London, United Kingdom
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Jiang D, Demosthenous A. A Multichannel High-Frequency Power-Isolated Neural Stimulator With Crosstalk Reduction. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2018; 12:940-953. [PMID: 29993559 DOI: 10.1109/tbcas.2018.2832541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In neuroprostheses applications requiring simultaneous stimulations on a multielectrode array, electric crosstalk, the spatial interaction between electric fields from various electrodes is a major limitation to the performance of multichannel stimulation. This paper presents a multichannel stimulator design that combines high-frequency current stimulation (using biphasic charge-balanced chopped pulse profile) with a switched-capacitor power isolation method. The approach minimizes crosstalk and is particularly suitable for fully integrated realization. A stimulator fabricated in a 0.6 μm CMOS high-voltage technology is presented. It is used to implement a multichannel, high-frequency, power-isolated stimulator. Crosstalk reduction is demonstrated with electrodes in physiological media while the efficacy of the high-frequency stimulator chip is proven in vivo. The stimulator provides fully independent operation on multiple channels and full flexibility in the design of neural modulation protocols.
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Westerhausen M, Martin T, Kappel M, Hofmann B. Stress testing of electrically active FlexMEAs with simultaneous electrical recording in fluidic environment: Introduction of a new measurement setup. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:025003. [PMID: 29495819 DOI: 10.1063/1.4999822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We present a measurement setup consisting of two fluid-filled pressure chambers to mimic the mechanical stress likely to that of small body movements on biomedical flexible micro-electrode arrays for the analysis of various degradation mechanisms. Our main goal was the simulation of micro-motions in fluid conditions, while maintaining an electric access to the device. These micro-motions would be likely to those occurring in the human body caused by the intracranial pressure in magnitudes of 7-25 mmHg, which translates to a fluid pressure of 9-33 mbar. Furthermore, severe mechanical stress can be administered to the samples under the previously mentioned environment. Therefore, a flexible, polyimide-based sample with various metal test structures was fabricated and analyzed in the presented measurement setup. A comparison of the elongation of the sample's surface as a function of the applied hydrostatic pressure is given with computer simulations.
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Affiliation(s)
- Markus Westerhausen
- Eberhard Karls University, Auf der Morgenstelle 10, 72076 Tuebingen, Germany
| | - Tanja Martin
- Eberhard Karls University, Auf der Morgenstelle 10, 72076 Tuebingen, Germany
| | - Marcel Kappel
- Eberhard Karls University, Auf der Morgenstelle 10, 72076 Tuebingen, Germany
| | - Boris Hofmann
- Eberhard Karls University, Auf der Morgenstelle 10, 72076 Tuebingen, Germany
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Nguyen TAK, DiGiovanna J, Cavuscens S, Ranieri M, Guinand N, van de Berg R, Carpaneto J, Kingma H, Guyot JP, Micera S, Fornos AP. Characterization of pulse amplitude and pulse rate modulation for a human vestibular implant during acute electrical stimulation. J Neural Eng 2016; 13:046023. [DOI: 10.1088/1741-2560/13/4/046023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Muceli S, Poppendieck W, Negro F, Yoshida K, Hoffmann KP, Butler JE, Gandevia SC, Farina D. Accurate and representative decoding of the neural drive to muscles in humans with multi-channel intramuscular thin-film electrodes. J Physiol 2016; 593:3789-804. [PMID: 26174910 DOI: 10.1113/jp270902] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/13/2015] [Indexed: 12/21/2022] Open
Abstract
Intramuscular electrodes developed over the past 80 years can record the concurrent activity of only a few motor units active during a muscle contraction. We designed, produced and tested a novel multi-channel intramuscular wire electrode that allows in vivo concurrent recordings of a substantially greater number of motor units than with conventional methods. The electrode has been extensively tested in deep and superficial human muscles. The performed tests indicate the applicability of the proposed technology in a variety of conditions. The electrode represents an important novel technology that opens new avenues in the study of the neural control of muscles in humans. We describe the design, fabrication and testing of a novel multi-channel thin-film electrode for detection of the output of motoneurones in vivo and in humans, through muscle signals. The structure includes a linear array of 16 detection sites that can sample intramuscular electromyographic activity from the entire muscle cross-section. The structure was tested in two superficial muscles (the abductor digiti minimi (ADM) and the tibialis anterior (TA)) and a deep muscle (the genioglossus (GG)) during contractions at various forces. Moreover, surface electromyogram (EMG) signals were concurrently detected from the TA muscle with a grid of 64 electrodes. Surface and intramuscular signals were decomposed into the constituent motor unit (MU) action potential trains. With the intramuscular electrode, up to 31 MUs were identified from the ADM muscle during an isometric contraction at 15% of the maximal force (MVC) and 50 MUs were identified for a 30% MVC contraction of TA. The new electrode detects different sources from a surface EMG system, as only one MU spike train was found to be common in the decomposition of the intramuscular and surface signals acquired from the TA. The system also allowed access to the GG muscle, which cannot be analysed with surface EMG, with successful identification of MU activity. With respect to classic detection systems, the presented thin-film structure enables recording from large populations of active MUs of deep and superficial muscles and thus can provide a faithful representation of the neural drive sent to a muscle.
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Affiliation(s)
- Silvia Muceli
- Department of Neurorehabilitation Engineering, Bernstein Focus Neurotechnology Göttingen, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University, 37075, Göttingen, Germany
| | - Wigand Poppendieck
- Department of Medical Engineering and Neuroprosthetics, Fraunhofer Institute for Biomedical Engineering, 66386, St Ingbert, Germany
| | - Francesco Negro
- Department of Neurorehabilitation Engineering, Bernstein Focus Neurotechnology Göttingen, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University, 37075, Göttingen, Germany
| | - Ken Yoshida
- Biomedical Engineering Department, Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN, 46202-5160, USA
| | - Klaus P Hoffmann
- Department of Medical Engineering and Neuroprosthetics, Fraunhofer Institute for Biomedical Engineering, 66386, St Ingbert, Germany
| | - Jane E Butler
- Neuroscience Research Australia, Barker St, Randwick and University of New South Wales, Sydney, NSW, 2031, Australia
| | - Simon C Gandevia
- Neuroscience Research Australia, Barker St, Randwick and University of New South Wales, Sydney, NSW, 2031, Australia
| | - Dario Farina
- Department of Neurorehabilitation Engineering, Bernstein Focus Neurotechnology Göttingen, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University, 37075, Göttingen, Germany
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Stienen PJ, Venzi M, Poppendieck W, Hoffmann KP, Åberg E. Precaution for volume conduction in rodent cortical electroencephalography using high-density polyimide-based microelectrode arrays on the skull. J Neurophysiol 2016; 115:1970-7. [PMID: 26864767 DOI: 10.1152/jn.00932.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/09/2016] [Indexed: 12/20/2022] Open
Abstract
In humans, significant progress has been made to link spatial changes in electroencephalographic (EEG) spectral density, connectivity strength, and phase-amplitude modulation to neurological, physiological, and psychological correlates. In contrast, standard rodent EEG techniques employ only few electrodes, which results in poor spatial resolution. Recently, a technique was developed to overcome this limitation in mice. This technique was based on a polyimide-based microelectrode (PBM) array applied on the mouse skull, maintaining a significant number of electrodes with consistent contact, electrode impedance, and mechanical stability. The present study built on this technique by extending it to rats. Therefore, a similar PBM array, but adapted to rats, was designed and fabricated. In addition, this array was connected to a wireless EEG headstage, allowing recording in untethered, freely moving rats. The advantage of a high-density array relies on the assumption that the signal recorded from the different electrodes is generated from distinct sources, i.e., not volume-conducted. Therefore, the utility and validity of the array were evaluated by determining the level of synchrony between channels due to true synchrony or volume conduction during basal vigilance states and following a subanesthetic dose of ketamine. Although the PBM array allowed recording with high signal quality, under both drug and drug-free conditions, high synchronization existed due to volume conduction between the electrodes even in the higher spectral frequency range. Discrimination existed only between frontally and centrally/distally grouped electrode pairs. Therefore, caution should be used in interpreting spatial data obtained from high-density PBM arrays in rodents.
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Affiliation(s)
- P J Stienen
- AstraZeneca Research and Development, Innovative Medicines and Early Development, Personalized Healthcare and Biomarkers, AstraZeneca Translational Science Centre at Science for Life Laboratory, Solna, Sweden; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; and
| | - M Venzi
- AstraZeneca Research and Development, Innovative Medicines and Early Development, Personalized Healthcare and Biomarkers, AstraZeneca Translational Science Centre at Science for Life Laboratory, Solna, Sweden; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; and
| | - W Poppendieck
- Department of Medical Engineering and Neuroprosthetics, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany
| | - K P Hoffmann
- Department of Medical Engineering and Neuroprosthetics, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany
| | - E Åberg
- AstraZeneca Research and Development, Innovative Medicines and Early Development, Personalized Healthcare and Biomarkers, AstraZeneca Translational Science Centre at Science for Life Laboratory, Solna, Sweden; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; and
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Márton G, Orbán G, Kiss M, Fiáth R, Pongrácz A, Ulbert I. A Multimodal, SU-8 - Platinum - Polyimide Microelectrode Array for Chronic In Vivo Neurophysiology. PLoS One 2015; 10:e0145307. [PMID: 26683306 PMCID: PMC4684315 DOI: 10.1371/journal.pone.0145307] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/02/2015] [Indexed: 11/18/2022] Open
Abstract
Utilization of polymers as insulator and bulk materials of microelectrode arrays (MEAs) makes the realization of flexible, biocompatible sensors possible, which are suitable for various neurophysiological experiments such as in vivo detection of local field potential changes on the surface of the neocortex or unit activities within the brain tissue. In this paper the microfabrication of a novel, all-flexible, polymer-based MEA is presented. The device consists of a three dimensional sensor configuration with an implantable depth electrode array and brain surface electrodes, allowing the recording of electrocorticographic (ECoG) signals with laminar ones, simultaneously. In vivo recordings were performed in anesthetized rat brain to test the functionality of the device under both acute and chronic conditions. The ECoG electrodes recorded slow-wave thalamocortical oscillations, while the implanted component provided high quality depth recordings. The implants remained viable for detecting action potentials of individual neurons for at least 15 weeks.
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Affiliation(s)
- Gergely Márton
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, building Q2, H-1117, Budapest, Hungary
- Department of Microtechnology, Institute for Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, Konkoly Thege M. út. 29–33, H-1121, Budapest, Hungary
- School of Ph.D. Studies, Semmelweis University, Ü llői út 26, H – 1085, Budapest, Hungary
- * E-mail:
| | - Gábor Orbán
- Department of Electron Devices, Budapest University of Technology and Economics, Magyar tudósok körútja 2, building Q, H-1117, Budapest, Hungary
| | - Marcell Kiss
- Department of Microtechnology, Institute for Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, Konkoly Thege M. út. 29–33, H-1121, Budapest, Hungary
- Department of Electron Devices, Budapest University of Technology and Economics, Magyar tudósok körútja 2, building Q, H-1117, Budapest, Hungary
| | - Richárd Fiáth
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, building Q2, H-1117, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter utca 50/a, H-1083, Budapest, Hungary
| | - Anita Pongrácz
- Department of Microtechnology, Institute for Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, Konkoly Thege M. út. 29–33, H-1121, Budapest, Hungary
| | - István Ulbert
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, building Q2, H-1117, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter utca 50/a, H-1083, Budapest, Hungary
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Poppendieck W, Muceli S, Dideriksen J, Rocon E, Pons JL, Farina D, Hoffmann KP. A new generation of double-sided intramuscular electrodes for multi-channel recording and stimulation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2015:7135-7138. [PMID: 26737937 DOI: 10.1109/embc.2015.7320037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this work, a new generation of intramuscular multi-channel electrode for EMG recording and muscle stimulation is presented. The electrode is based on double-sided polyimide microtechnology, and features electrode contacts on both sides of a thin polyimide filament. The structure is attached to a cannula, allowing insertion and application of the electrode system similar to conventional intramuscular wire electrodes. In the presented design, the electrode has 12 small recording sites on one side of the structure, and 3 large stimulation sites on the other side. Applications of the system include diagnosis and treatment of tremor. To this end, the electrode has been successfully tested in tremor patients. In the future, the concept will be extended to other fields of application including intraneural electrodes.
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