Download or read book Simulation of the excitation of human lower spinal cord structures with surface electrodes 3D finite element analysis and nerve fiber modeling written by and published by Josef Ladenbauer. This book was released on 2008 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computer simulation of electrically stimulated nerve fibers in the human spinal cord written by and published by Simon Danner. This book was released on 2010 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Three Dimensional Anatomically Accurate Finite Element Model for Nerve Fiber Activation Simulation Coupling written by Shaina Ann Fischer and published by . This book was released on 2015 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Improved knowledge of human nerve function and recruitment would enable innovation in the Biomedical Engineering field. Better understanding holds the potential for greater integration between devices and the nervous system as well as the ability to develop therapeutic devices to treat conditions affecting the nervous system. This work presents a three-dimensional volume conductor model of the human arm for coupling with code describing nerve membrane characteristics. The model utilizes an inhomogeneous medium composed of bone, muscle, skin, nerve, artery, and vein. Dielectric properties of each tissue were collected from the literature and applied to corresponding material subdomains. Both a fully anatomical version and a simplified version are presented. The computational model for this study was developed in COMSOL and formatted to be coupled with SPICE netlist code. Limitations to this model due to computational power as well as future work are discussed. The final model incorporated both anatomically correct geometries and simplified geometries to enhance computational power. A stationary study was performed implementing a boundary current source through the surface of a conventionally placed electrode. Results from the volume conductor study are presented and validated through previous studies.
Download or read book Models and Simulations of the Electric Field in Deep Brain Stimulation written by Fabiola Alonso and published by Linköping University Electronic Press. This book was released on 2018-09-10 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deep brain stimulation (DBS) is an established surgical therapy for movement disorders such as Parkinson’s disease (PD) and essential tremor (ET). A thin electrode is implanted in a predefined area of the brain with the use of stereotactic neurosurgery. In the last few years new DBS electrodes and systems have been developed with possibilities for using more parameters for control of the stimulation volume. In this thesis, simulations using the finite element method (FEM) have been developed and used for investigation of the electric field (EF) extension around different types of DBS lead designs (symmetric, steering) and stimulation modes (voltage, current). The electrode surrounding was represented either with a homogeneous model or a patient-specific model based on individual preoperative magnetic resonance imaging (MRI). The EF was visualized and compared for different lead designs and operating modes. In Paper I, the EF was quantitatively investigated around two lead designs (3389 and 6148) simulated to operate in voltage and current mode under acute and chronic time points following implantation.Simulations showed a major impact on the EF extension between postoperative time points which may explain the clinical decisions to change the stimulation amplitude weeks after implantation. In Paper II, the simulations were expanded to include two leads having steering function (6180, Surestim1) and patient-specific FEM simulations in the zona incerta. It was found that both the heterogeneity of the tissue and the operating mode, influence the EF distribution and that equivalent contact configurations of the leads result in similar EF. The steering mode presented larger volumes in current mode when using equivalent amplitudes. Simulations comparing DBS and intraoperative stimulation test using a microelectrode recording (MER) system (Paper III), showed that several parallel MER leads and the presence of the non-active DBS contacts influence the EF distribution and that the DBS EF volume can cover, but also extend to, other anatomical areas. Paper IV introduces a method for an objective exploitation of intraoperative stimulation test data in order to identify the optimal implant position in the thalamus of the chronic DBS lead. Patient-specific EF simulations were related to the anatomy with the help of brain atlases and the clinical effects which were quantified by accelerometers. The first results indicate that the good clinical effect in ET is due to several structures around the ventral intermediate nucleus of the thalamus.
Download or read book Spinal Cord Stimulation written by Paul Kreis and published by Oxford University Press. This book was released on 2009-06-03 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spinal cord stimulators (SCS) are implantable medical devices used to treat chronic pain of neurologic origin, such as sciatica, intractable back pain, and diabetic. The device generates an electric pulse near the spinal cord's dorsal surface, providing a parasthesia sensation that alters the perception of pain by the patient, and is typically used in conjunction with conventional medical management. Spinal cord stimulators (SCS) are implantable medical devices used to treat chronic pain of neurologic origin, such as sciatica, intractable back pain, and diabetic. The device generates an electric pulse near the spinal cord's dorsal surface, providing a parasthesia sensation that alters the perception of pain by the patient, and is typically used in conjunction with conventional medical management.
Download or read book Electrical Nerve Stimulation written by Frank Rattay and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional electrical stimulation is the most important application in the field of clinical treatment with currents or magnetism. This technique artificially generates neural activity in order to overcome lost functions of the paralized, incontinent or sensory handicapped patient. Electricity and magnetism is also used in many cases, e.g., to stimulate bone growth or wound healing. Nevertheless, the basic mechanism of the artificial excitation of nerve and muscle fibers has become known only in the last few years. Although many textbooks are concerned with the natural excitation process there is a lack of information on the influence of an applied electrical or magnetic field. This book, written for students and biomedical engineers, should close the gap and, furthermore, it should stimulate the design of new instrumentation using optimal strategies.
Download or read book Biomechanics of the Spine written by Navid Soltani and published by LAP Lambert Academic Publishing. This book was released on 2014-02 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: To achieve a new method for predicting the result of disc replacement or to predict biomechanics of lumbar (or any other skeletal segment) by finite element model analysis, its necessary to follow an organized procedure including 3D bone model, meshing the proposed model, designing an artificial implant and simulation of loading condition. In this study we try to explain the whole procedure step by step from importing the CT image to analysis of lumbar section with designed implant. First it's explained how the 3D model can be made based on the CT image using MIMICS software and some details related to simulation of the skeletal model by this software will be released. Second part shows the tutorial method for importing proposed model in ABAQUS software and how it can be analyzed. This step by step tutorial is helpful in lumbar biomechanics and creating human body skeletal model. Also it is useful to achieve a perfect procedure for creating and analyzing lumbar disc implant.
Download or read book Cumulated Index Medicus written by and published by . This book was released on 1998 with total page 1848 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Element Simulation of the Healthy and Degenerated Lumbar Spine Interplay Between Muscle Activity and Intervertebral Disc Multiphysics written by Themis Toumanidou and published by . This book was released on 2017 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The human spine provides mechanical support to the trunk while it protects the spinal cord and nerves from the external loads transferred during daily activities. Such loads are largely controlled by the spine muscles and influence the biophysical regulation of the intervertebral discs (IVD). Numerical models have been important tools for the translation of the external forces into internal loads that otherwise cannot be easily measured directly. This PhD thesis used the predictive ability of constitutive equations to reflect the mechanical properties of the lumbar IVD and muscles and explore the IVD-muscle interplay on the healthy and degenerated spine. A review of the state-of-the-art reported for the estimation of spine loads was performed, and the Hill¿s mus cle model and the poro-hyperelastic formulations used for IVD modeling were particularly detailed. A new constitutive equation assembly was proposed involving one active parameter controlled via strain-based criteria, and four passive parameters. For the latters, literature-based values were initially defined, and a parametric study was designed for the active parameter by proposing stretch-related activation thresholds. An optimization scheme was then developed to define a full set of calibrated values per fascicle using force estimations from a reported rigid body model based on measured kinematics of the vertebrae. To test the robustness of the method, a generic L3-S1 finite element (FE) model was developed that included 46 muscle fascicles and all passive issues. Simulation of forward flexion showed that the predicted muscle forces increased in caudal direction. The intradiscal pressure (IDP) predictions correlated with previous in vivo measurements showing the ability of the model to capture realistic internal loads. To simulate standing, the gravity loads were defined by considering the heterogeneous distribution of body volumes along the trunk. This simulation was also coupled to a previous 8-hour free IVD swelling to mimic the overnight disc hydration. Disc swelling led to muscle activation and force distributions that seemed particularly appropriate to counterbalance the gravity loads, pointing out the likely existence of a functional balance between stretch-induced muscle activation and IVD multiphysics. A geometrical extension was then performed to incorporate all relevant tissues of the full lumbar spine including in total 96 fascicles. The effect of previous rest (PR) and muscle presence (MS) on internal loads was explored in standing and lying. Muscle force predictions in standing showed that with PR, the total loads transferred were altered from compressive to tensile. Overnight, the computed IDP increase reproduced previous in vivo data. Both PR and MS affected the vertebrae motion particularly between L1-L2. When degenerated discs properties were used, a general IDP decrease and up to 14 times higher activation was predicted in standing with PR.At last, the previous workflow was repeated using a patient L1-S1 FE model with patient-specific (P-SP) and condition-depended material properties. In standing, asymmetric fascicle activation with increased shortening at the left side and lateral bending was predicted. The decreased swelling capacity of the degenerated discs was associated to an increased muscle activation needed to balance the gravity loads that tended to flex forward the trunk. Comparisons of the IDP results in both models with healthy discs showed that introducing P-SP geometries gave better correlations with in vivo data. Given the difficulties to evaluate the predicted muscle forces experimentally, such outcome further contributed to the validation of the method. Despite its limitations, this approach allowed to explicitly and rationally explore the interactions between muscle function and passive tissue biomechanics in the lumbar spine. The information provided could help clinical decision for patients whom source of back pain is unclear.
Download or read book Index to IEEE Publications written by Institute of Electrical and Electronics Engineers and published by . This book was released on 1989 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues for 1973- cover the entire IEEE technical literature.
Download or read book Brain and Human Body Modeling 2020 written by Sergey N. Makarov and published by Springer Nature. This book was released on 2021 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 41st Annual International Conference of the IEEE EMBS, took place between July 23 and 27, 2019, in Berlin, Germany. The focus was on "Biomedical engineering ranging from wellness to intensive care." This conference provided an opportunity for researchers from academia and industry to discuss a variety of topics relevant to EMBS and hosted the 4th Annual Invited Session on Computational Human Models. At this session, a bevy of research related to the development of human phantoms was presented, together with a substantial variety of practical applications explored through simulation.
Download or read book Spinal Cord Monitoring and Electrodiagnosis written by Koki Shimoji and published by Springer. This book was released on 2011-12-13 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The spinal cord has a characteristic structure and functions that are distinct from those of the brain. Its functions are tremendously important since it modulates the peripheral sensory inputs to the dorsal horn, and it gives rise to the ascending pathways transmitting peripheral afferent inputs to the brain, and conveys the descending pathways from the brain both to the lower motor neurons, the final common pathway, and to dorsal horn sensory neurons. In spite of these vital functions, the spinal cord constitutes only a small percent age of the mass of the human central nervous system and is located far from the skin surface, which has obstructed the recording of its electrical activity. Recently, however, important advances have been made in several recording techniques, including epidural recording or averaging methods, allowing both sensory and motor evoked spinal cord potentials in man to be recorded. This volume is based on the papers presented at the Fourth International Symposium on Spinal Cord Monitoring and Electrodiagnosis. Each of these international symposia has brought together many of the specialists involved in this research, with an important increase in the number of participants since the first symposium was held in Toyko in 1981. At the past symposia several attempts were made to standardize data, techniques, and clinical applications and to integrate the new findings into patient care.
Download or read book Implantable Neural Prostheses 1 written by David Zhou and published by Springer Science & Business Media. This book was released on 2009-06-10 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant progress has been made in the development of neural prostheses to restore human functions and improve the quality of human life. Biomedical engineers and neuroscientists around the world are working to improve design and performance of existing devices and to develop novel devices for artificial vision, artificial limbs, and brain–machine interfaces. This book, Implantable Neural Prostheses 1: Devices and Applications,ispart one of a two-book series and describes state-of-the-art advances in techniques associated with implantable neural prosthetic devices and their applications. Devices covered include sensory prosthetic devices, such as visual implants, cochlear implants, auditory midbrain implants, and spinal cord stimulators. Motor prosthetic devices, such as deep brain stimulators, Bion microstimu- tors, the brain control and sensing interface, and cardiac electro-stimulation devices are also included. Progress in magnetic stimulation that may offer a non-invasive approach to prosthetic devices is introduced. Regulatory approval of implantable medical devices in the United States and Europe is also discussed.
Download or read book The Circuitry of the Human Spinal Cord written by Emmanuel Pierrot-Deseilligny and published by Cambridge University Press. This book was released on 2005-06-08 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of human movement have proliferated in recent years, and there have been many studies of spinal pathways in humans, their role in movement, and their dysfunction in neurological disorders. This comprehensive reference surveys the literature related to the control of spinal cord circuits in human subjects, showing how they can be studied, their role in normal movement, and how they malfunction in disease states. Chapters are highly illustrated and consistently organised, reviewing, for each pathway, the experimental background, methodology, organisation and control, role during motor tasks, and changes in patients with CNS lesions. Each chapter concludes with a helpful resume that can be used independently of the main text to provide practical guidance for clinical studies. This will be essential reading for research workers and clinicians involved in the study, treatment and rehabilitation of movement disorders.
Download or read book Brain and Human Body Modeling written by Sergey Makarov and published by Springer Nature. This book was released on 2019-08-27 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book describes modern applications of computational human modeling with specific emphasis in the areas of neurology and neuroelectromagnetics, depression and cancer treatments, radio-frequency studies and wireless communications. Special consideration is also given to the use of human modeling to the computational assessment of relevant regulatory and safety requirements. Readers working on applications that may expose human subjects to electromagnetic radiation will benefit from this book’s coverage of the latest developments in computational modelling and human phantom development to assess a given technology’s safety and efficacy in a timely manner. Describes construction and application of computational human models including anatomically detailed and subject specific models; Explains new practices in computational human modeling for neuroelectromagnetics, electromagnetic safety, and exposure evaluations; Includes a survey of modern applications for which computational human models are critical; Describes cellular-level interactions between the human body and electromagnetic fields.
Download or read book Computational Neurostimulation written by and published by Elsevier. This book was released on 2015-11-16 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Neurostimulation, the latest volume in the Progress in Brain Research series provides an introduction to a nascent field with contributions from leading researchers. In addition, it addresses a very timely and relevant issue which has long been known to require more treatment. - Part of a well-established international series that examines major areas of basic and clinical research within neuroscience, as well as emerging subfields - Provides an introduction to a nascent field with contributions from leading researchers
Download or read book Converging Technologies for Improving Human Performance written by Mihail C. Roco and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: M. C. Roco and W.S. Bainbridge In the early decades of the 21st century, concentrated efforts can unify science based on the unity of nature, thereby advancing the combination of nanotechnology, biotechnology, information technology, and new technologies based in cognitive science. With proper attention to ethical issues and societal needs, converging in human abilities, societal technologies could achieve a tremendous improvement outcomes, the nation's productivity, and the quality of life. This is a broad, cross cutting, emerging and timely opportunity of interest to individuals, society and humanity in the long term. The phrase "convergent technologies" refers to the synergistic combination of four major "NBIC" (nano-bio-info-cogno) provinces of science and technology, each of which is currently progressing at a rapid rate: (a) nanoscience and nanotechnology; (b) biotechnology and biomedicine, including genetic engineering; (c) information technology, including advanced computing and communications; (d) cognitive science, including cognitive neuroscience. Timely and Broad Opportunity. Convergence of diverse technologies is based on material unity at the nanoscale and on technology integration from that scale.
