Download or read book Implantable Neural Recording Front Ends for Closed Loop Neuromodulation Systems written by Hariprasad Chandrakumar and published by . This book was released on 2018 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of neuromodulation is to alter neural activity through targeted delivery of a stimulus to specific sites in the body. A prominent example of neuromodulation is deep brain stimulation (DBS), which has proved effective in mitigating the effects of certain neurological conditions. However, existing neuromodulation treatments lack real-time feedback (simultaneous sensing) to adapt stimulation parameters in response to brain dynamics. Hence, neuroscientists and clinicians aim to perform closed-loop neuromodulation, where stimulation can be optimally controlled in real time for better treatment outcomes. In recent years, the community has emphasized closed-loop neuromodulation as a highly desirable tool for administering therapy in patients suffering from drug-resistant neurological ailments. A miniaturized autonomous implant would be instrumental in ensuring that neuromodulation achieves its full potential. A key requirement for any closed-loop neuromodulation system is the ability to record neural signals while concurrently performing stimulation. However, neural stimulation generates large differential and common-mode artifacts at the recording sites, which easily saturate existing implantable recording front-ends due to their limited linear input range. To observe the neural response during stimulation, the front-end must faithfully digitize neural signals in the presence of large stimulation artifacts. The front-end must also satisfy strict constraints on power consumption, noise and input impedance, while achieving a small form-factor. State-of-the-art neural recording front-ends do not meet these requirements. This work presents a recording front-end that can digitize neural signals in the presence of 200mVpp differential artifacts and 700mVpp common-mode artifacts. The front-end consists of a chopper amplifier and a 15.2b-ENOB continuous-time delta-sigma ADC. In the design of the chopper amplifier, new techniques have been proposed that introduce immunity to common-mode interference, increase the DC input impedance (Zin) of the chopper amplifier to 1.5G , and enable the realization of large resistances (90G ) on-chip in a small area for filtering electrode offsets. In the design of the delta-sigma ADC, a modified loop-filter is used along with new linearization techniques to significantly reduce power consumption in the ADC. These techniques enable our recording front-end to achieve a dynamic range of 90dB (14b ENOB) in 1Hz - 200Hz, and 81dB (12.7b ENOB) in 1Hz - 5kHz. Implemented in a 40nm CMOS process, the prototype occupies an area of 0.113mm2/channel, consumes 7.3i W from a 1.2V supply, and can digitize neural signals from 1Hz to 5kHz. The input-referred noise is 1.8i Vrms (1Hz - 200Hz) and 6.35i Vrms (1Hz - 5kHz). The total harmonic distortion for a 200mVpp input at 1kHz is 81dB. Compared to state-of-the-art neural recording front-ends, this work improves Zin by 24.2x (for chopped front-ends), the linear-input range by 2x, the signal bandwidth (BW) by 10x, the dynamic range by 12.6dB, and tolerance to common-mode interferers by 6.5x, while maintaining comparable power and noise performance. The ADC alone consumes 4.5i W, has Zin of 20M , BW of 5kHz, and achieves a peak SNDR of 93.5dB for a 1.77Vpp differential input at 1kHz. The ADC's Schreier FOM (using SNDR) is 184dB, which is 6dB higher than the state-of-the-art in high-resolution ADCs.
Download or read book Analog Front End Research Applied in Implantable Neural Recording System On a Chip written by 戴維頡 and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multi Channel High Dynamic Range Implantable VCO Based Neural Sensing System written by Wenlong Jiang and published by . This book was released on 2017 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neuromodulation is the alternation of nerve activity through targeted delivery of a stimulus, such as electrical stimulation, to specific sites in the body. Deep brain stimulation (DBS) is a commonly-used neuromodulation treatment for neurological ailments when traditional methods, such as surgery, medication or psychotherapy, fail. DBS is performed by sending controlled electrical pulses into the brain to evoke the desired response. However, existing DBS systems can only administer open-loop stimulation over a limited number of channels. Future neuromodulation systems require a multi-channel closed-loop platform that can provide high spatial precision, and automatically adjust stimulation parameters based on feedback from recorded neural signals. This multi-channel, closed-loop system poses new challenges for brain-sensing circuit and system design. To enable closed-loop operation, the sensing circuit needs to work with concurrent stimulation. Therefore, it needs to provide a large input range to prevent saturation under stimulation artifacts. In addition, the sensing circuit should simultaneously meet device/patient safety constraints. Current state-of-the-art neural sensing circuits, however, do not meet these requirements. This work presents an implantable VCO-based neural-sensing front-end design intended for multi-channel, closed-loop neuromodulation applications. Specifically, it converts the input voltage into the phase domain, and performs direct digitization without any voltage-domain amplification, thus preventing saturation. The phase-domain processing allows a large input range that can comprise both stimulation artifacts and the neural signals. Four techniques have been implemented to overcome design challenges: (1) in the high-pass filter, we utilize a multi-rate duty-cycled resistor as a reliable solution to attenuate electrode-offsets; (2) inside of the VCO, chopping is applied to lower circuit noise; (3) at the analog-digital interface, we employ a new glitch-free quantizer; and (4) after digitization, circuit linearity is restored through the digital non-linearity correction. With these techniques, the design achieves 10x linear range and 2-3 bit ENOB improvement over prior-art with comparable power and noise performance. This work also presents a 32/64-channel sensing chip based on the proposed front-end design. The chip is assembled on a miniaturized PCB to achieve a fully integrated neuromodulation system. Sensing performance and function under concurrent stimulation have been verified in bench-top and in-vitro environments. This allows further development of a complete multi-channel closed-loop neuromodulation implant.
Download or read book Closed Loop Systems for Next Generation Neuroprostheses written by Timothée Levi and published by Frontiers Media SA. This book was released on 2018-04-26 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Millions of people worldwide are affected by neurological disorders which disrupt the connections within the brain and between brain and body causing impairments of primary functions and paralysis. Such a number is likely to increase in the next years and current assistive technology is yet limited. A possible response to such disabilities, offered by the neuroscience community, is given by Brain-Machine Interfaces (BMIs) and neuroprostheses. The latter field of research is highly multidisciplinary, since it involves very different and disperse scientific communities, making it fundamental to create connections and to join research efforts. Indeed, the design and development of neuroprosthetic devices span/involve different research topics such as: interfacing of neural systems at different levels of architectural complexity (from in vitro neuronal ensembles to human brain), bio-artificial interfaces for stimulation (e.g. micro-stimulation, DBS: Deep Brain Stimulation) and recording (e.g. EMG: Electromyography, EEG: Electroencephalography, LFP: Local Field Potential), innovative signal processing tools for coding and decoding of neural activity, biomimetic artificial Spiking Neural Networks (SNN) and neural network modeling. In order to develop functional communication with the nervous system and to create a new generation of neuroprostheses, the study of closed-loop systems is mandatory. It has been widely recognized that closed-loop neuroprosthetic systems achieve more favorable outcomes for users then equivalent open-loop devices. Improvements in task performance, usability, and embodiment have all been reported in systems utilizing some form of feedback. The bi-directional communication between living neurons and artificial devices is the main final goal of those studies. However, closed-loop systems are still uncommon in the literature, mostly due to requirement of multidisciplinary effort. Therefore, through eBook on closed-loop systems for next-generation neuroprostheses, we encourage an active discussion among neurobiologists, electrophysiologists, bioengineers, computational neuroscientists and neuromorphic engineers. This eBook aims to facilitate this process by ordering the 25 contributions of this research in which we highlighted in three different parts: (A) Optimization of different blocks composing the closed-loop system, (B) Systems for neuromodulation based on DBS, EMG and SNN and (C) Closed-loop BMIs for rehabilitation.
Download or read book Microelectronic Implants for Central and Peripheral Nervous System Overview of Circuit and System Technology written by Morris (Ming-Dou) Ker and published by Frontiers Media SA. This book was released on 2022-01-11 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professor Ker is on the Board of Amazingneuron. The Other Topic Editors Declare no Competing Interests With Regards to the Research Topic Theme.
Download or read book A Modular Neural Interface for Massively Parallel Recording and Control written by Christian T. Wentz and published by . This book was released on 2010 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: The closed-loop Brain-Machine Interface (BMI) has long been a dream for clinicians and neuroscience researchers alike - that is, the ability to extract meaningful information from the brain, perform computation on this information, and selectively perturb neural dynamics in the brain for therapeutic benefit to the patient. Such systems have immediate application to treatment of paralysis, epilepsy and the amputated, and the potential for treatment of higher order cognitive dysfunction. Despite the promise of the BMI concept, the technology for bidirectional communication with the brain at sufficiently large scale to be truly therapeutically useful is lacking. Current state-of-the-art neuromodulation systems deliver open loop, 16-channel patterned electrical stimulation incapable of precisely targeting small numbers of neurons. Large-scale neural recording systems are limited to 16-128 electrodes, at the cost of several thousand dollars per channel. The ability to record from the awake behaving animal - let alone precisely modulate neural network dynamics in closed-loop fashion- presents a substantial challenge today. In this thesis, I present decoupled design solutions for three critical subcomponents of the closed-loop BMI - (i) a highly miniature, wirelessly powered and wirelessly controlled implantable optogenetic neuromodulation system capable of selective neural network control with single neural subtype- and millisecond-timescale precision, (ii) a prototype, highly parallel and scalable bio-potential recording system for simultaneous monitoring of many thousands of electrodes, and (iii) a space- and energy-efficient battery charger for biomedical applications. In aggregate, these systems overcome many of the fundamental architectural problems seen in the research and clinical environment today, potentially enabling a new class of neuromodulation system capable of treatment of higher-order cognitive dysfunction. In the research setting, these systems may be scaled to enable whole-brain recording, potentially yielding insights into large-scale neural network dynamics underlying disease and cognition.
Download or read book Micro and Nanoelectronics Devices Circuits and Systems written by Trupti Ranjan Lenka and published by Springer Nature. This book was released on 2023-10-04 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents select proceedings of the International Conference on Micro and Nanoelectronics Devices, Circuits and Systems (MNDCS-2023). The book includes cutting-edge research papers in the emerging fields of micro and nanoelectronics devices, circuits, and systems from experts working in these fields over the last decade. The book is a unique collection of chapters from different areas with a common theme and is immensely useful to academic researchers and practitioners in the industry who work in this field.
Download or read book Closing the Loop on Neuromodulation for Neurological Diseases written by Doris D. Wang and published by Frontiers Media SA. This book was released on 2022-05-27 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bioelectronic Medicine written by Valentin A. Pavlov and published by Perspectives Cshl. This book was released on 2019 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Cold Spring Harbor perspectives in medicine."
Download or read book Energy efficient DSP Solutions for Simultaneous Neural Recording and Stimulation written by Sina Basir-Kazeruni and published by . This book was released on 2017 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: An increased interest in the investigation of the inner workings of the brain, together with recent technological advancements have been great catalysts for the development of neural stimulation and signal recording systems. These neural interfaces have enabled a better understanding of underlying neurological diseases, and provide promising therapeutic interventions for various neurological disorders. As discoveries and technological advancements continue, new challenges and opportunities emerge. One of the major challenges is the development of small, portable, and power-efficient closed-loop neuromodulation systems. The ability to simultaneously stimulate and record is a key capability required in enabling such systems. A closed-loop neuromodulation system is comprised of mainly four elements: (a) Stimulator: an energy-efficient and flexible stimulation engine, (b) Sensing: Low-power, high dynamic-range analog front-ends, (c) Digital Signal Processing (DSP): energy-/area-efficient digital signal processing units, and (d) Wireless transfer: an energy-efficient wireless power and data transfer unit. In summary, efficient and concurrent stimulation, sensing, processing, and transfer of neural signals are required. Design efforts are in full effect to realize leading edge stimulation, sensing, and wireless transfer technologies; however, one common difficulty in realizing concurrent stimulation and recording of neural signals is the presence of stimulation artifacts observed at the sensing end. Existing solutions (e.g., blanking the recording channel during stimulation or self-cancelling stimulation electrodes) have not answered all the challenges and lack the ability of continuous signal recording during the stimulation phase, thus rendering a critical portion of the data unusable. In this work we propose an energy-efficient, implantable, real-time Adaptive Stimulation Artifact Rejection (ASAR) engine, capable of adaptively removing stimulation artifact for varying stimulation characteristics at multiple sites. Additionally, a blind artifact template detection technique is introduced, which in combination with the proposed ASAR algorithm, eliminates the need for any prior knowledge of the temporal and structural characteristics of the stimulation pulse; this technique also enables us to effectively battle the non-linear mapping of brain tissue, and non-idealities of electrode interfaces, with linear filtering. Two engines, implemented in 40nm CMOS, achieve convergence of
Download or read book Towards Closed Loop Neuromodulation with Wireless Biomimetic Circuits and Systems written by Po-Min Wang and published by . This book was released on 2019 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional functional electrical stimulation for neuromodulation delivers regular and periodic electrical pulses in an open-loop fashion. However, with advances in neuroscience, emerging applications require an electrical stimulation delivered in a non-conventional form. For example, electroceuticals and brain-machine interface (BMI) need a closed-loop modulation scheme such that the stimulation protocol can be dynamically adjusted in response to the subject's physiological state. Furthermore, it has been recently shown that a stimulation pattern that mimics the biological signal (i.e. biomimetic stimulation) outperforms periodic pulses in some applications including retina stimulation to regain eyesight and spinal cord stimulation to restore motor function. Despite increasing interests in closed-loop neuromodulation and biomimetic stimulation, existing implantable neuromodulation devices have limited capability in supporting those sophisticated stimulation schemes. We have developed two wireless biomimetic systems--an implantable stimulation and recording system and a biomimetic stimulation system, aiming to support closed-loop neuromodulation and biomimetic stimulation. In this dissertation, system design and circuit implementation of both systems are presented. Both systems were validated in bench-top tests and in-vivo experiments. The implantable system was used to conduct intestinal stimulation that facilitated the intestinal transit in chronic porcine experiments. The implant is an order lighter and 7.7 times smaller than commercialized GI stimulators, and the delivered electrical charge is smaller than most existing protocols, thus safer and more energy-efficient. The system was also used to conduct acute epidural stimulation in rat models and selectively activate desired muscles through targeting different motor neurons, laying the foundation for the future development of the control algorithms for closed-loop epidural stimulation. On the other hand, the biomimetic stimulation system was also validated in acute experiments using spinally transected rats. The system that delivered a protocol mimicking electromyography (EMG) signal lowered the excitation threshold of the spinal network, showing its potential of accelerating the rate of functional recovery after spinal cord injury. The development of these two biomimetic systems along with the future implementation of the closed-loop control algorithm using the in-vivo data acquired by both systems will make an implantable device that supports closed-loop biomimetic stimulation a reality.
Download or read book Design and Verification of a Closed loop ready High channel count Neuromodulation Unit written by Vahagn Hokhikyan and published by . This book was released on 2017 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: According to a report by the World Health Organization (WHO), neuropsychiatric disorders affect about one billion people worldwide and are the leading cause of disability in the U.S.. To address this global epidemic, neuroscientific initiatives are being developed globally. Deep brain stimulation (DBS) has been successful alternate treatment modality for some neuropsychiatric disorders (Parkinson's disease, essential tremor, dystonia, and obsessive-compulsive disorder) when traditional treatment options failed (resection, medication, and psychotherapy). According to one long term study targeting Parkinson's disease, patients' motor function and daily activity-scores improve about 50% while off medication and receiving only DBS therapy. This therapy is delivered through large electrodes in the form of fixed-frequency rectangular stimulation pulses in an always-on, open-loop fashion - ignoring the disease state, medication status, or side effects. In this work, we present a more advanced neural implant which, while being backward compatible with traditional DBS therapy, 1) is capable of sensing neural signals while delivering stimulation, 2) has high-channel-count, and 3) can generate non-rectangular stimulation waveforms. These key features are enabled by our custom-designed neural sensing and stimulation integrated circuits (ICs), which along with a few passive components, a miniature printed circuit board, and our user-friendly graphical interface comprise a capable neuromodulation system. Our sensing IC's ability to capture neural signals and stimulation artifacts without saturation at implant-level power is unique. Sampled local field potential (LFP) signals can be used to close the knowledge gap about the disease biomarkers and be fed into closed-loop algorithms for automatic tuning of stimulation parameters based on the disease state. The resulting autonomy will reduce or eliminate the need for periodic clinical visits for re-adjusting stimulation parameters to ameliorate neural network's habituation effects. Our high-channel-count stimulation IC, when paired with high-density probes, will substantially increase the spatial resolution of DBS, which can improve the therapeutic index and potentially result in lower power consumption for achieving the same therapeutic benefits. Also, the ability of our stimulation IC to generate custom, non-rectangular waveforms can lead to increased implant battery life, as some non-rectangular waveforms seem to be more energy efficient. We believe that the proposed system has the potential to improve the quality of patient care and to further our understanding of neuropsychiatric disorders, and we hope that it will soon find an increased use in various clinical and research environments.
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 210 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 Handbook of Biomedical Telemetry written by Konstantina S. Nikita and published by John Wiley & Sons. This book was released on 2014-08-25 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: A must-have compendium on biomedical telemetry for all biomedical professional engineers, researchers, and graduate students in the field Handbook of Biomedical Telemetry describes the main components of a typical biomedical telemetry system, as well as its technical challenges. Written by a diverse group of experts in the field, it is filled with overviews, highly-detailed scientific analyses, and example applications of biomedical telemetry. The book also addresses technologies for biomedical sensing and design of biomedical telemetry devices with special emphasis on powering/integration issues and materials for biomedical telemetry applications. Handbook of Biomedical Telemetry: Describes the main components of a typical biomedical telemetry system, along with the technical challenges Discusses issues of spectrum regulations, standards, and interoperability—while major technical challenges related to advanced materials, miniaturization, and biocompatibility issues are also included Covers body area electromagnetics, inductive coupling, antennas for biomedical telemetry, intra-body communications, non-RF communication links for biomedical telemetry (optical biotelemetry), as well as safety issues, human phantoms, and exposure assessment to high-frequency biotelemetry fields Presents biosensor network topologies and standards; context-aware sensing and multi-sensor fusion; security and privacy issues in biomedical telemetry; and the connection between biomedical telemetry and telemedicine Introduces clinical applications of Body Sensor Networks (BSNs) in addition to selected examples of wearable, implantable, ingestible devices, stimulator and integrated mobile healthcare system paradigms for monitoring and therapeutic intervention Covering biomedical telemetry devices, biosensor network topologies and standards, clinical applications, wearable and implantable devices, and the effects on the mobile healthcare system, this compendium is a must-have for professional engineers, researchers, and graduate students.
Download or read book Principles and Technologies for Electromagnetic Energy Based Therapies written by Punit Prakash and published by Academic Press. This book was released on 2021-12-02 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles and Technologies for Electromagnetic Energy Based Therapies covers the theoretical foundations of electromagnetic-energy based therapies, principles for design of practical devices and systems, techniques for in vitro and in vivo testing of devices, and clinical application examples of contemporary therapies employing non-ionizing electromagnetic energy. The book provides in-depth coverage of: pulsed electric fields, radiofrequency heating systems, tumor treating fields, and microwave heating technology. Devices and systems for electrical stimulation of neural and cardiac issue are covered as well. Lastly, the book describes and discusses issues that are relevant to engineers who develop and translate these technologies to clinical applications. Readers can access information on incorporation of preclinical testing, clinical studies and IP protection in this book, along with in-depth technical background for engineers on electromagnetic phenomena within the human body and selected therapies. It covers both engineering and biological/medical materials and gives a full perspective on electromagnetics therapies. Unique features include content on tumor treating fields and the development and translation of biomedical devices. Provides in-depth technical background on electromagnetic energy-based therapies, along with real world examples on how to design devices and systems for delivering electromagnetic energy-based therapies Includes guidance on issues that are relevant for translating the technology to the market, such as intellectual property, regulatory issues, and preclinical testing Companion site includes COMSOL models, MATLAB code, and lab protocols
Download or read book Electrocorticographic Brain Computer Interfaces written by Mikhail Lebedev and published by Frontiers Media SA. This book was released on 2022-02-22 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topic Editor Christoph Guger is the CEO of Guger Technologies. All other topic editors declare no competing interests with regards to the Research Topic subject.
Download or read book Deep brain stimulation think tank Updates in neurotechnology and neuromodulation volume III written by Michael S. Okun and published by Frontiers Media SA. This book was released on 2023-02-02 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:
