Download or read book Development and Evaluation of Micro electrocorticography Arrays for Neural Interfacing Applications written by and published by . This book was released on 2016 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neural interfaces have great promise for both electrophysiological research and therapeutic applications. Whether for the study of neural circuitry or for neural prosthetic or other therapeutic applications, micro-electrocorticography (micro-ECoG) arrays have proven extremely useful as neural interfacing devices. These devices strike a balance between invasiveness and signal resolution, an important step towards eventual human application. The objective of this research was to make design improvements to micro-ECoG devices to enhance both biocompatibility and device functionality. To best evaluate the effectiveness of these improvements, a cranial window imaging method for in vivo monitoring of the longitudinal tissue response post device implant was developed. Employment of this method provided valuable insight into the way tissue grows around micro-ECoG arrays after epidural implantation, spurring a study of the effects of substrate geometry on the meningeal tissue response. The results of the substrate footprint comparison suggest that a more open substrate geometry provides an easy path for the tissue to grow around to the top side of the device, whereas a solid device substrate encourages the tissue to thicken beneath the device, between the electrode sites and the brain. The formation of thick scar tissue between the recording electrode sites and the neural tissue is disadvantageous for long-term recorded signal quality, and thus future micro-ECoG device designs should incorporate open-architecture substrates for enhanced longitudinal in vivo function. In addition to investigating improvements for long-term device reliability, it was also desired to enhance the functionality of micro-ECoG devices for neural electrophysiology research applications. To achieve this goal, a completely transparent graphene-based device was fabricated for use with the cranial window imaging method and optogenetic techniques. The use of graphene as the conductive material provided the transparency necessary to image tissues directly below the micro-ECoG electrode sites, and to transmit light through the electrode sites to underlying neural tissue, for optical stimulation of neural cells. The flexibility and broad-spectrum transparency of graphene make it an ideal choice for thin-film, flexible electronic devices.

Download or read book Development of Thin Film Polymer Flexible Microelectrode Arrays for Neural Interface Applications written by Jiwan Kim and published by . This book was released on 2008 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Intra cortical Microelectrode Arrays for Neuro interfacing written by Salam Ramy Gabran and published by . This book was released on 2012 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neuro-engineering is an emerging multi-disciplinary domain which investigates the electrophysiological activities of the nervous system. It provides procedures and techniques to explore, analyze and characterize the functions of the different components comprising the nervous system. Neuro-engineering is not limited to research applications; it is employed in developing unconventional therapeutic techniques for treating different neurological disorders and restoring lost sensory or motor functions. Microelectrodes are principal elements in functional electric stimulation (FES) systems used in electrophysiological procedures. They are used in establishing an interface with the individual neurons or in clusters to record activities and communications, as well as modulate neuron behaviour through stimulation. Microelectrode technologies progressed through several modifications and innovations to improve their functionality and usability. However, conventional electrode technologies are open to further development, and advancement in microelectrodes technology will progressively meliorate the neuro-interfacing and electrotherapeutic techniques. This research introduced design methodology and fabrication processes for intra-cortical microelectrodes capable of befitting a wide range of design requirements and applications. The design process was employed in developing and implementing an ensemble of intra-cortical microelectrodes customized for different neuro-interfacing applications. The proposed designs presented several innovations and novelties. The research addressed practical considerations including assembly and interconnection to external circuitry. The research was concluded by exhibiting the Waterloo Array which is a high channel count flexible 3-D neuro-interfacing array. Finally, the dissertation was concluded by demonstrating the characterization, in vitro and acute in vivo testing results of the Waterloo Array. The implemented electrodes were tested and benchmarked against commercial equivalents and the results manifested improvement in the electrode performance compared to conventional electrodes. Electrode testing and evaluation were conducted in the Krembil Neuroscience Centre Research Lab (Toronto Western Hospital), and the Neurosciences & Mental Health Research Institute (the Sick Kids hospital). The research results and outcomes are currently being employed in developing chronic intra-cortical and electrocorticography (ECoG) electrode arrays for the epilepsy research and rodents nervous system investigations. The introduced electrode technologies will be used to develop customized designs for the clinical research labs collaborating with CIRFE Lab.

Download or read book High Density Integrated Electrocortical Neural Interfaces written by Sohmyung Ha and published by Academic Press. This book was released on 2019-08-03 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-Density Integrated Electrocortical Neural Interfaces provides a basic understanding, design strategies and implementation applications for electrocortical neural interfaces with a focus on integrated circuit design technologies. A wide variety of topics associated with the design and application of electrocortical neural implants are covered in this book. Written by leading experts in the field— Dr. Sohmyung Ha, Dr. Chul Kim, Dr. Patrick P. Mercier and Dr. Gert Cauwenberghs —the book discusses basic principles and practical design strategies of electrocorticography, electrode interfaces, signal acquisition, power delivery, data communication, and stimulation. In addition, an overview and critical review of the state-of-the-art research is included. These methodologies present a path towards the development of minimally invasive brain-computer interfaces capable of resolving microscale neural activity with wide-ranging coverage across the cortical surface. - Written by leading researchers in electrocorticography in brain-computer interfaces - Offers a unique focus on neural interface circuit design, from electrode to interface, circuit, powering, communication and encapsulation - Covers the newest ECoG interface systems and electrode interfaces for ECoG and biopotential sensing

Download or read book Neural Interface Engineering for Electrophysiology Application written by Hyungsoo Kim and published by . This book was released on 2018 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: The brain is a wondrous and complex organ, a biological machine forged by the evolutionary forces of nature. The human brain contains 100 billion neurons and each neuron is connected by synapses to several thousand other neurons. Connected neurons work together to produce perceptions and sensations, memories and emotions, physical movements and abstract constructs. The neurons communicate by means of electricity that passes along and across their cellular membrane. Much of what is known about brain physiology is through the measurement of this electrical activity, either with relatively large electrodes placed on the scalp or tiny microelectrodes inserted into the brain tissue itself. At the finer end of this scale, scientists have discovered much about the way individual neurons extract sensory information, adapt their behavior to form a memory, and convey signals to other regions of the brain. However, it has long been recognized that the brain operates on a global scale, through the collective behavior and interaction of its neural units1. Information is processed in several regions of the brain simultaneously, and the activity of neighboring neurons can be quite different from one another. By one analogy, the attempt to assess brain function by observing a single neuron is like looking at the output of one transistor to learn how a computer works. Thus, the recording of many neurons simultaneously is necessary to truly reveal the mechanisms of the brain2. In recent decades, a variety of recording techniques have been developed for a neural interface such as electroencephalography (EEG), magneto-encephalography (MEG), electrocorticography (ECOG), local field potential (LFP) recordings, micro-electrode array (MEA) and peripheral nerve interfaces (PNIs) to the micron-level precision required for multi-neuron recording. Their small size allows many recording channels to be placed onto one device. One of the goals of neural interface research is to create a seamless connection between the nervous system and the neuroprostheses either by stimulating or by recording from neural tissue to restore or substitute function for individuals with neurological deficits or disabilities. Hence, significant amount of scientific and technological efforts have been devoted to develop neural interfaces that link the nervous system with robotic prosthetic devices. The creation of a novel neural interface is essential for developing the full potential of advanced prosthesis technology required to replace lost limbs. Additionally, meticulous studies of a single neuron and between neurons utilizing the neural interface technology should be made to elucidate fundamental biological phenomena such as cellular processes and heterogeneities. Particularly, an electrophysiological study of neural networks can provide knowledge to unravel the functions of brain. When fundamental research about molecular and cellular mechanisms of a single neuron and electrophysiological studies using neural interfaces on both the central and peripheral nervous systems are done together, it has a synergistic effect on neural interface technology. The research and methodologies described in this dissertation stem from our research group's efforts to optimize the design and expand the applications of neural interfaces. The dissertation is organized into four chapters. Chapter 1 is a review of neural interface technology and study of neural signal detection. This chapter provides a foundation for Chapter 2 and 3. Chapter 2 is a study of a neural interface as cellular level research. We present an advanced single-neuronal cell culture and monitoring platform using a fully transparent microfluidic dielectrophoresis (DEP) device for unabated monitoring of neuronal cell development and function. The device is mounted inside a sealed incubation chamber to ensure improved homeostatic conditions and reduced contamination risk. Consequently, we successfully trap and culture single neurons on a desired location and monitor their growth process over a week. Chapter 3 deals with the specific application of PNIs to the sciatic nerve of a rat as a nervous system-level research. We developed novel devices, "cuff and sieve electrodes" (CASE), that integrate microfabricated cuff and sieve electrodes capable of broad (via cuff) and precise (via sieve) selectivity to increase the strengths and simultaneously decrease the weaknesses of traditional electrode designs. We performed terminal device implantations in a rat sciatic transection and repair model to test the capacity of the CASE interface. The sciatic nerve was stimulated by the sieve portion of the CASE electrode and somatosensory evoked potentials were recorded from the somatosensory cortex via micro-eletrocorticography. The ability to elicit cortical responses from sciatic nerve stimulation demonstrates the proof of concept for both the implantation and chronic monitoring of CASE interfaces for innovative prosthetic control. Lastly, in Chapter 4, I will identify areas in which further investigation is needed and propose future directions of both cellular and system-level neural interface.

Download or read book Thin film Neural Interfaces for Brain computer Interface and Electroretinography Applications written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: THIN-FILM NEURAL INTERFACES FOR BRAIN-COMPUTER INTERFACE AND ELECTRORETINOGRAPHY APPLICATIONS Sanitta Thongpang Under the supervision of Associate Professor Justin C. Williams At the University of Wisconsin-Madison The brain, and more precisely the central nervous system (CNS), is an extremely complex organ responsible for controlling essential sensorimotor functions of the human body. These functions rely on nerves running all-throughout the organism, transporting the sensory information from the body towards the CNS and the motor information from the CNS to the muscles. However, when severed, these functions can be durably lost, provoking paralysis and significant loss of quality of life. Neuroprosthesis is a promising approach to allow the patient to regain some of the quality of life lost through the control of a computer directly from measuring brain activity. Unfortunately, current methods are either too invasive, risk a decrease of performance over time and require extreme precision to place (i.e. single-unit electrode) or non-invasive but imprecise and limited (e.g. electroencephalogram). Electrocorticogram interfaces (ECoG and micro-ECoG) have been developed to measure brain activity as close as possible to the neurons while minimizing invasivity and long-term effects. These are placed on between the cortex and the cranium and allow good improvements in signal quality and spatial resolution. Here, I present the improved electrode designs and fabrication methods for reliable micro-ECoG electrode arrays using flexible insulating materials such as polyimide and parylene C. Furthermore, we characterize the long-term effect of chronic implantation of the device both on the electrical and material properties as well as the biological response of the brain of the micro-ECoG arrays. In addition, leveraging recent developments in optogenetics, two-way neural interface devices were developed. By integrating these methods with cranial window imaging techniques, I demonstrated that very powerful tools for optimizing micro-ECoG electrode arrays, as well as answering fundamental biological question on the function of the brain, can be developed. Finally, the flexible thin-film bio-MEMS fabrication methods demonstrated were readily expanded to many other applications such as electroretinogram (ERG) recording.

Download or read book Silicon Integrated High density Electrocortical and Retinal Neural Interfaces written by Sohmyung Ha and published by . This book was released on 2016 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent interest and initiatives in brain research have driven a worldwide effort towards developing implantable neural interface systems with high spatiotemporal resolution and spatial coverage extending to the whole brain. Electrocorticography (ECoG) promises a minimally invasive, chronically implantable neural interface with resolution and spatial coverage capabilities that, when appropriately scaled, meet the needs of recently proposed brain initiatives. Current ECoG technologies, however, typically rely on cm-sized electrodes and wired operation, severely limiting their resolution and long-term use. The work presented here has advanced micro-electrocorticography (uECoG) technologies for wireless high-density cortical neural interfaces in two main directions: flexible active uECoG arrays; and modular fully integrated uECoG systems. This dissertation presents a systematic design methodology which addresses unique design challenges posed by the extreme densities, form factors and power budgets of these fully implantable neural interface systems, with experimental validation of their performance for neural signal acquisition, stimulation, and wireless powering and data communication. Notable innovations include 1) first demonstration of simultaneous wireless power and data telemetry at 6.78 Mbps data rate over a single 13.56 MHz inductive link; 2) integrated recording from a flexible active electrode ECoG array with 85 dB dynamic range at 7.7 nJ energy per 16-b sample; and 3) the first fully integrated and encapsulated wireless neural-interface-on-chip microsystem for non-contact neural sensing and energy-replenishing adiabatic stimulation delivering 145 uA current at 6 V compliance within 2.25 mm3 volume. In addition, the work presented here on advancing the resolution and coverage of neural interfaces extends further from the cortex to the retina. Despite considerable advances in retinal prostheses over the last two decades, the resolution of restored vision has remained severely limited, well below the 20/200 acuity threshold of blindness. Towards drastic improvements in spatial resolution, this dissertation presents a scalable architecture for retinal prostheses in which each stimulation electrode is directly activated by incident light and powered by a common voltage pulse transferred over a single wireless inductive link. The hybrid optical addressability and electronic powering scheme provides for separate spatial and temporal control over stimulation, and further provides optoelectronic gain for substantially lower light intensity thresholds than other optically addressed retinal prostheses using passive microphotodiode arrays. The architecture permits the use of high-density electrode arrays with ultra-high photosensitive silicon nanowires, obviating the need for excessive wiring and high-throughput data telemetry. Instead, the single inductive link drives the entire array of electrodes through two wires and provides external control over waveform parameters for the common voltage stimulation. A complete system comprising inductive telemetry link, stimulation pulse demodulator, charge-balancing series capacitor, and nanowire-based electrode device is integrated and validated ex vivo on rat retina tissue. Measurements demonstrate control over retinal neural activity both by light and electrical bias, validating the feasibility of the proposed architecture and its system components as an important first step towards a high-resolution optically addressed retinal prosthesis.

Download or read book Mechanistic Electrochemical Characterization of Novel Microelectrode Arrays and Their Application in Mapping Brain Activity Across Species and Humans written by Mehran Ganji and published by . This book was released on 2019 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrocorticography (ECoG) arrays are used in clinical mapping for neurosurgical resection and hold the promise for less damaging brain-machine interfaces. Current clinical ECoG electrodes face physical limits to the number of contact sites, spatial resolution (centimeter scale), and contact diameter (millimeter scale), and thus cannot resolve the dynamically changing neural activity over sub-millimeter scales . In addition to these practical limitations, current clinical electrode arrays are constrained to non-conformal electrode-carriers/substrates and to less-optimal metal electrochemical interfaces. Increasing the flexibility of clinical electrodes may lead to higher signal-to-noise ratios as well as higher spatial specificity and this also requires overcoming substantial physical barriers due to the compromised metal electrochemical interface properties. The objectives of this thesis, described in seven chapters, are to develop high performance, safe, and durable neural electrode interfaces to yield stable, high signal-to-noise ratio cortical recordings in animal models as well as in humans. In the second chapter, we demonstrate that sterilization of PEDOT:PSS electrophysiology devices can be performed using an autoclave. We find that autoclaving is a viable sterilization method, leaving morphology unaltered and causing only minor changes in electrical properties. These results pave the way for the widespread utilization of PEDOT:PSS electrophysiology devices in the clinic. In the third chapter, we translate the use of robust PEDOT:PSS microelectrode arrays for safe intraoperative monitoring of the human brain. PEDOT:PSS micro-electrodes measured significant differential neural modulation under various clinically relevant conditions. We report the first evoked (stimulus-locked) cognitive activity with changes in amplitude across pial surface distances as small as 400 [mu]m, potentially enabling basic neurophysiology studies at the scale of neural micro-circuitry. In the fourth and fifth chapters, we present the first systematic study of scaling effects on the electrochemical properties of Pt and Au metallic and PEDOT:PSS organic electrodes from neural recording and stimulation perspectives. PEDOT:PSS coating reduced the impedances of metallic electrodes by up to 18X. The overall reduced noise of the PEDOT:PSS microelectrodes enable a lower noise floor for recording action-potentials with high fidelity. We observed a substantial enhancement in charge injection capacity up to 9.5X for PEDOT:PSS microelectrodes compared to metal ones and 88% lower required power for injecting the same charge density. These results permit quantitative optimization of contact material and diameter for different ECoG applications. In the sixth chapter, We report an effective method of mechanically anchoring the PEDOT within the Au nanorod (Au-nr) structure and demonstrate that it provides enhanced adhesion and overall PEDOT layer stability under various electrochemical (charge injection) and In vivo stability tests. In the seventh chapter, we report the fabrication of pure Pt nanorods (PtNRs) by utilizing low-temperature selective dealloying to develop scalable and biocompatible 1D platinum nanorod (PtNR) arrays that exhibit superb electrochemical properties at various length scales for high-performance neurotechnologies. PtNR arrays record brain activity with cellular resolution from the cortical surfaces in birds, mice, and non-human primates; demonstrating the PtNR microelectrode system as a robust system for high performance and stable neural electrode interfaces.

Download or read book The Relationship Between Micro electrocorticography and Intracortical Signals written by and published by . This book was released on 2014 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neural interfaces record and modulate brain signals, and they are applicable to neuroprosthesis and neuroscience research. Electrode arrays that reside on the surface of the brain are less invasive than those that penetrate into the cortex. However, micro-electrocorticography (micro-ECoG) signals recorded from the cortical surface have different spatial and spectral properties than those recorded intracortically. We studied the relationship between signals recorded from the surface of the brain and intracortical neural activity. To accomplish this, we integrated electrode array technology, optogenetics, and in vivo imaging. Four original studies were conducted. First, we analyzed simultaneously recorded action potentials (spikes) and micro-ECoG signals for spectral coherence. We observed the effect of pharmacological and stimulus manipulations on this relationship. Spikes became more strongly phase locked under an alpha-2 agonist, dexmedetomidine. Second, we integrated optogenetics and micro-ECoG by utilizing a cranial window in Thy1-Channelrhodopsin-2 (ChR2) mice. Pyramidal neurons were driven at known locations in the cortex while recording micro-ECoG signals. Spatial, temporal and spectral aspects of this bidirectional interface were investigated. Third, we used micro-ECoG recordings to map the sensory cortex of Thy1-ChR2 mice using optogenetic stimuli delivered to the limbs, through the skin. We compared sensory evoked potentials (SEPs) due to optogenetic and electrical stimulation of the periphery. Optogenetic stimulation evoked alpha fibers in these mice. Last, we investigated the response of hemodynamic and intrinsic optical signals imaged at the cortical surface to optogenetic stimulation. We used a custom microscope with a microprojector to apply spatio-temporal patterns of light to the cortex. We found that arteries dilate rapidly in response. These approaches could be further applied to study electrocorticography, epilepsy, brain-computer interfaces, and neurovascul

Download or read book Electrocorticography on the Micron Scale written by John Hermiz and published by . This book was released on 2018 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrocorticography on the micron scale (micro-ECoG) is an emerging neural sensing modality that provides a high-resolution view of the brain. Micron scale electrodes measure electrical potential propagated to the brain surface from local and distant current sources. Moreover, electrodes spatially sample the surface of the brain at the micron scale over potentially large regions providing both high resolution and large coverage. Micro-ECoG can be likened to HD monitors, whereas classical ECoG grids are more like Hex LED displays. In this dissertation, I demonstrate the value of micro-ECoG both in animal model and in humans. I developed a suite of neural acquisition tools (NACQ), which was used to record from human subjects intraoperatively and in the epilepsy monitoring unit for research purposes. These tools provide an affordable alternative to commercial systems and a safer alternative to existing open source systems. I demonstrate that micro-ECoG electrode can sense physiologically relevant features, including single unit activity in songbird. These physiological features measured from micro-ECoG are compared to gold standard probes including penetrating laminar silicon shanks in songbird and clinical ECoG strips in human. Finally, I explored theoretical and empirical instances in which a high density grid of electrodes outperforms sub-sampled lower density grids in discrete neural state estimation. Empirically, I show that when controlling for area and selecting task informative sub-regions of the complete grid, we observed a consistent increase in mean binary classification accuracy with higher grid density; in particular, 400 [mu]m pitch grids outperforming spatially sub-sampled lower density grids up to 23%. Micro-ECoG is a promising neural sensing modality that may lead to new neuroscientific discoveries and neuroengineering achievements. For example, it may uncover novel neural dynamics from cortical columns or intricate cortical wave patterns important from neural information processing. Micro-ECoG may lead to the development of a high-bandwidth brain machine interface that not only restores abilities of disabled individuals, but augments and enhances abilities of able-bodied people. Neuroscientists and neurotechnologists are poised to make major advances in neuroscience and neuroengineering with the advent of micro-ECoG.

Download or read book Neural Microelectrodes Design and Applications written by Stuart Cogan and published by . This book was released on 2019 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neural electrodes enable the recording and stimulation of bioelectrical activity in the nervous system. This technology provides neuroscientists with the means to probe the functionality of neural circuitry in both health and disease. In addition, neural electrodes can deliver therapeutic stimulation for the relief of debilitating symptoms associated with neurological disorders such as Parkinson's disease and may serve as the basis for the restoration of sensory perception through peripheral nerve and brain regions after disease or injury. Lastly, microscale neural electrodes recording signals associated with volitional movement in paralyzed individuals can be decoded for controlling external devices and prosthetic limbs or driving the stimulation of paralyzed muscles for functional movements. In spite of the promise of neural electrodes for a range of applications, chronic performance remains a goal for long-term basic science studies, as well as clinical applications. New perspectives and opportunities from fields including tissue biomechanics, materials science, and biological mechanisms of inflammation and neurodegeneration are critical to advances in neural electrode technology. This Special Issue will address the state-of-the-art knowledge and emerging opportunities for the development and demonstration of advanced neural electrodes.

Download or read book Development and Analysis of Sub Millimeter Electrocorticography written by Nicholas Gregory Rogers and published by . This book was released on 2019 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work summarized in this thesis focuses on the recording and analysis of data from micro-ECoG arrays implanted in vivo. The electrode arrays with diameters on the order of tens of microns and grid pitches on the order of hundreds of microns are recording from the surface of the brain at a novel scale. The research summarized in this work is aimed at the successful implantation and recording of these arrays and subsequent analysis of the properties of the electric potentials on the brain surface as measured at this considerably smaller than usual scale.

Download or read book Development and Modelling of a Versatile Active Micro electrode Array for High Density In vivo and In vitro Neural Signal Investigation written by Richard Ian Curry and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The electrophysiological observation of neurological cells has allowed much knowledge to be gathered regarding how living organisms are believed to acquire and process sensation. Although much has been learned about neurons in isolation, there is much more to be discovered in how these neurons communicate within large networks. The challenges of measuring neurological networks at the scale, density and chronic level of non invasiveness required to observe neurological processing and decision making are manifold, however methods have been suggested that have allowed small scale networks to be observed using arrays of micro-fabricated electrodes. These arrays transduce ionic perturbations local to the cell membrane in the extracellular fluid into small electrical signals within the metal that may be measured. A device was designed for optimal electrical matching to the electrode interface and maximal signal preservation of the received extracellular neural signals. Design parameters were developed from electrophysiological computer simulations and experimentally obtained empirical models of the electrode-electrolyte interface. From this information, a novel interface based signal filtering method was developed that enabled high density amplifier interface circuitry to be realised. A novel prototype monolithic active electrode was developed using CMOS microfabrication technology. The device uses the top metallization of a selected process to form the electrode substrate and compact amplification circuitry fabricated directly beneath the electrode to amplify and separate the neural signal from the baseline offsets and noise of the electrode interface. The signal is then buffered for high speed sampling and switched signal routing. Prototype 16 and 256 active electrode array with custom support circuitry is presented at the layout stage for a 20?m diameter 100?m pitch electrode array. Each device consumes 26.4?W of power and contributes 4.509?V (rms) of noise to the received signal over a controlled bandwidth of 10 Hz - 5 kHz. The research has provided a fundamental insight into the challenges of high density neural network observation, both in the passive and the active manner. The thesis concludes that power consumption is the fundamental limiting factor of high density integrated MEA circuitry; low power dissipation being crucial for the existence of the surface adhered cells under measurement. With transistor sizing, noise and signal slewing each being inversely proportional to the dc supply current and the large power requirements of desirable ancillary circuitry such as analogue-to-digital converters, a situation of compromise is approached that must be carefully considered for specific application design.

Download or read book Brain Computer Interface Research written by Christoph Guger and published by Springer. This book was released on 2017-04-29 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the prize-winning brain-computer-interface (BCI) projects honored in the community's most prestigious annual award. BCIs enable people to communicate and control their limbs and/or environment using thought processes alone. Research in this field continues to develop and expand rapidly, with many new ideas, research groups, and improved technologies having emerged in recent years. The chapters in this volume feature the newest developments from many of the best labs worldwide. They present both non-invasive systems (based on the EEG) and intracortical methods (based on spikes or ECoG), and numerous innovative applications that will benefit new user groups

Download or read book Neural Interface Frontiers and Applications written by Xiaoxiang Zheng and published by Springer Nature. This book was released on 2019-11-15 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the frontiers of neural interface technology, including hardware, software, neural decoding and encoding, control systems, and system integration. It also discusses applications for neuroprosthetics, neural diseases and neurorobotics, and the toolkits for basic neuroscience. A neural interface establishes a direct communication channel with the central or peripheral nervous system (CNS or PNS), and enables the nervous system to interact directly with the external devices. Recent advances in neuroscience and engineering are speeding up neural interface technology, paving the way for assisting, augmenting, repairing or restoring sensorimotor and other cognitive functions impaired due to neurological disease or trauma, and so improving the quality of life of those affected. Neural interfaces are now being explored in applications as diverse as rehabilitation, accessibility, gaming, education, recreation, robotics and human enhancement. Neural interfaces also represent a powerful tool to address fundamental questions in neuroscience. Recent decades have witnessed tremendous advances in the field, with a huge impact not only in the development of neuroprosthetics, but also in our basic understanding of brain function. Neural interface technology can be seen as a bridge across the traditional engineering and basic neuroscience. This book provides researchers, graduate and upper undergraduate students from a wide range of disciplines with a cutting-edge and comprehensive summary of neural interface engineering research.

Download or read book Brain Computer Interfaces written by Jonathan Wolpaw and published by Oxford University Press. This book was released on 2012-01-24 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: A recognizable surge in the field of Brain Computer Interface (BCI) research and development has emerged in the past two decades. This book is intended to provide an introduction to and summary of essentially all major aspects of BCI research and development. Its goal is to be a comprehensive, balanced, and coordinated presentation of the field's key principles, current practice, and future prospects.

Download or read book SiC based Miniaturized Devices written by Stephen Edward Saddow and published by MDPI. This book was released on 2020-06-18 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: MEMS devices are found in many of today’s electronic devices and systems, from air-bag sensors in cars to smart phones, embedded systems, etc. Increasingly, the reduction in dimensions has led to nanometer-scale devices, called NEMS. The plethora of applications on the commercial market speaks for itself, and especially for the highly precise manufacturing of silicon-based MEMS and NEMS. While this is a tremendous achievement, silicon as a material has some drawbacks, mainly in the area of mechanical fatigue and thermal properties. Silicon carbide (SiC), a well-known wide-bandgap semiconductor whose adoption in commercial products is experiening exponential growth, especially in the power electronics arena. While SiC MEMS have been around for decades, in this Special Issue we seek to capture both an overview of the devices that have been demonstrated to date, as well as bring new technologies and progress in the MEMS processing area to the forefront. Thus, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on: (1) novel designs, fabrication, control, and modeling of SiC MEMS and NEMS based on all kinds of actuation mechanisms; and (2) new developments in applying SiC MEMS and NEMS in consumer electronics, optical communications, industry, medicine, agriculture, space, and defense.