Scholars@Duke
Angel V Peterchev

Angel V Peterchev

Professor in Psychiatry and Behavioral Sciences
Psychiatry & Behavioral Sciences, Behavioral Medicine & Neurosciences
angel.peterchev@duke.edu
40 Duke Medicine Circle, Box 3620 DUMC, Durham, NC 27710

Selected Publications

Reduced auditory perception and brain response with quiet TMS coil.

Journal Article Brain Stimul · October 10, 2024 BACKGROUND: Electromagnetic forces in transcranial magnetic stimulation (TMS) coils generate a loud clicking sound that produces confounding auditory activation and is potentially hazardous to hearing. To reduce this noise while maintaining stimulation eff ... Full text Link to item Cite

A semi-automated pipeline for finite element modeling of electric field induced in nonhuman primates by transcranial magnetic stimulation.

Journal Article J Neurosci Methods · August 2024 BACKGROUND: Transcranial magnetic stimulation (TMS) is used to treat a range of brain disorders by inducing an electric field (E-field) in the brain. However, the precise neural effects of TMS are not well understood. Nonhuman primates (NHPs) are used to m ... Full text Link to item Cite

Scalp surface estimation and head registration using sparse sampling and 3D statistical models.

Journal Article Comput Biol Med · August 2024 Registering the head and estimating the scalp surface are important for various biomedical procedures, including those using neuronavigation to localize brain stimulation or recording. However, neuronavigation systems rely on manually-identified fiducial h ... Full text Link to item Cite

Abnormalities of cortical stimulation strength-duration time constant in amyotrophic lateral sclerosis.

Journal Article Clin Neurophysiol · August 2024 OBJECTIVES: Strength-duration time constant (SDTC) may now be determined for cortical motor neurones, with activity mediated by transient Na+ conductances. The present study determined whether cortical SDTC is abnormal and linked to the pathogenesis of amy ... Full text Link to item Cite

Quasistatic approximation in neuromodulation.

Journal Article J Neural Eng · July 24, 2024 We define and explain the quasistatic approximation (QSA) as applied to field modeling for electrical and magnetic stimulation. Neuromodulation analysis pipelines include discrete stages, and QSA is applied specifically when calculating the electric and ma ... Full text Link to item Cite

A Rapidly Reconfigurable DC Battery for Increasing Flexibility and Efficiency of Electric Vehicle Drive Trains

Journal Article IEEE Transactions on Transportation Electrification · June 1, 2024 Traditional electric vehicle (EV) battery drive trains comprise hard-wired batteries forming a fixed high-voltage dc link and a main inverter. This article proposes a novel topology to break hard-wired batteries into smaller subunits interfaced by low-volt ... Full text Cite

Quasistatic approximation in neuromodulation.

Journal Article ArXiv · April 23, 2024 We define and explain the quasistatic approximation (QSA) as applied to field modeling for electrical and magnetic stimulation. Neuromodulation analysis pipelines include discrete stages, and QSA is applied specifically when calculating the electric and ma ... Link to item Cite

Amplitude-determined seizure-threshold, electric field modeling, and electroconvulsive therapy antidepressant and cognitive outcomes.

Journal Article Neuropsychopharmacology · March 2024 Electroconvulsive therapy (ECT) pulse amplitude, which dictates the induced electric field (E-field) magnitude in the brain, is presently fixed at 800 or 900 milliamperes (mA) without clinical or scientific rationale. We have previously demonstrated that i ... Full text Link to item Cite

Modulation-Enhanced Nearest-Level Quantization for a Wide Output Bandwidth.

Journal Article IEEE Trans Power Electron · March 2024 Multilevel converters have enabled various applications that are not possible with conventional two-level converters. Many of these applications, however, need a high output bandwidth, often approaching the switching rate limit of the transistors, with hig ... Full text Link to item Cite

Transcranial magnetic stimulation input-output curve slope differences suggest variation in recruitment across muscle representations in primary motor cortex.

Journal Article Front Hum Neurosci · 2024 Measurement of the input-output (IO) curves of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) can be used to assess corticospinal excitability and motor recruitment. While IO curves have been used to study disease and ph ... Full text Link to item Cite

Frequency-Dependent Impedance Variation in Multilevel Converters with Parallel Connectivity

Conference Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC · January 1, 2024 Multilevel converters with parallel connectivity, known for their flexibility and scalability, are extensively applied across diverse fields. Earlier studies presumed an ideal inverse relationship between the output impedance and the number of paralleled m ... Full text Cite

Overshoot Dynamics in Parallel Connectivity Enabled Multilevel Converters: Generalized Analytic Expression and Impact Analysis

Conference Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC · January 1, 2024 Multilevel converters are indispensable in power transmission and motor drivetrains, offering enhanced scalability and flexibility through parallel connectivity. This advancement offers beneficial features like sensorless voltage balancing and reduced impe ... Full text Cite

DC-to-5-MHz Wide-Output-Bandwidth High-Power High-Fidelity Converter

Journal Article IEEE Transactions on Industrial Electronics · January 1, 2024 Advances in power electronics have made it possible to achieve high-power levels, e.g., reaching GW in grids, or alternatively high output bandwidths, e.g., beyond MHz in communications. Achieving both simultaneously, however, remains challenging. Various ... Full text Cite

Analytical Model and Planar Magnetic Solution for Parallelization Surges in Switched-Capacitor and Series/Parallel Multilevel Circuits

Journal Article IEEE Transactions on Industrial Electronics · January 1, 2024 Cascaded multilevel converters are pivotal in various applications, including offshore wind energy, power transmission, large drives, or reconfigurable battery systems. Enabling parallel connectivity in these converters enhances their scalability and flexi ... Full text Cite

Automatic Neurocranial Landmarks Detection from Visible Facial Landmarks Leveraging 3D Head Priors.

Conference Clin Image Based Proced Fairness AI Med Imaging Ethical Philos Issues Med Imaging (2023) · October 2023 The localization and tracking of neurocranial landmarks is essential in modern medical procedures, e.g., transcranial magnetic stimulation (TMS). However, state-of-the-art treatments still rely on the manual identification of head targets and require setti ... Full text Link to item Cite

Data from: A semi-automated pipeline for finite element modeling of induced electric field in nonhuman primates by transcranial magnetic stimulation

Dataset · September 27, 2023 Background Transcranial magnetic stimulation (TMS) is used to treat a range of brain disorders by inducing an electric field (E-field) in the brain. However, the precise neural effects of TMS are not well understood. Nonhuman primates (NHPs) are increasing ... Full text Cite

Three novel methods for determining motor threshold with transcranial magnetic stimulation outperform conventional procedures.

Journal Article J Neural Eng · September 13, 2023 Objective. Thresholding of neural responses is central to many applications of transcranial magnetic stimulation (TMS), but the stochastic aspect of neuronal activity and motor evoked potentials (MEPs) challenges thresholding techniques. We analyzed existi ... Full text Link to item Cite

Transcranial magnetic stimulation: the road to clinical therapy for dystonia

Journal Article Dystonia · August 16, 2023 Despite many research studies, transcranial magnetic stimulation (TMS) is not yet an FDA-approved clinical therapy for dystonia patients. This review describes the four major challenges that have historically hindered the clinical translation of TM ... Full text Open Access Cite

Rapid estimation of cortical neuron activation thresholds by transcranial magnetic stimulation using convolutional neural networks.

Journal Article Neuroimage · July 15, 2023 BACKGROUND: Transcranial magnetic stimulation (TMS) can modulate neural activity by evoking action potentials in cortical neurons. TMS neural activation can be predicted by coupling subject-specific head models of the TMS-induced electric field (E-field) t ... Full text Link to item Cite

Optimized monophasic pulses with equivalent electric field for rapid-rate transcranial magnetic stimulation.

Journal Article J Neural Eng · June 6, 2023 Objective.Transcranial magnetic stimulation (TMS) with monophasic pulses achieves greater changes in neuronal excitability but requires higher energy and generates more coil heating than TMS with biphasic pulses, and this limits the use of monophasic pulse ... Full text Link to item Cite

Dependence of cortical neuronal strength-duration properties on TMS pulse shape.

Journal Article Clin Neurophysiol · June 2023 OBJECTIVE: The aim of present study was to explore the effects of different combinations of transcranial magnetic stimulation (TMS) pulse width and pulse shape on cortical strength-duration time constant (SDTC) and rheobase measurements. METHODS: Resting m ... Full text Link to item Cite

Electroconvulsive Therapy: Mechanisms of Action, Clinical Considerations, and Future Directions.

Journal Article Harv Rev Psychiatry · May 2023 LEARNING OBJECTIVES: • Outline and discuss the fundamental physiologic, cellular, and molecular mechanisms of ECT to devise strategies to optimize therapeutic outcomes• Summarize the overview of ECT, its efficacy in treating depression, the known effects o ... Full text Link to item Cite

Responses of model cortical neurons to temporal interference stimulation and related transcranial alternating current stimulation modalities.

Journal Article J Neural Eng · January 3, 2023 Objective.Temporal interference stimulation (TIS) was proposed as a non-invasive, focal, and steerable deep brain stimulation method. However, the mechanisms underlying experimentally-observed suprathreshold TIS effects are unknown, and prior simulation st ... Full text Link to item Cite

Multi-scale model of axonal and dendritic polarization by transcranial direct current stimulation in realistic head geometry.

Journal Article Brain Stimul · 2023 BACKGROUND: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation modality that can alter cortical excitability. However, it remains unclear how the subcellular elements of different neuron types are polarized by specific elect ... Full text Link to item Cite

Modular pulse synthesizer for transcranial magnetic stimulation with fully adjustable pulse shape and sequence.

Journal Article J Neural Eng · November 23, 2022 The temporal shape of a pulse in transcranial magnetic stimulation (TMS) influences which neuron populations are activated preferentially as well as the strength and even direction of neuromodulation effects. Furthermore, various pulse shapes differ in the ... Full text Link to item Cite

Detection of motor-evoked potentials below the noise floor: rethinking the motor stimulation threshold.

Journal Article J Neural Eng · October 21, 2022 Objective. Motor-evoked potentials (MEPs) are among the most prominent responses to brain stimulation, such as supra-threshold transcranial magnetic stimulation and electrical stimulation. Understanding of the neurophysiology and the determination of the l ... Full text Link to item Cite

Data from: Optimized Monophasic Pulses with Equivalent Electric Field for Rapid-Rate Transcranial Magnetic Stimulation

Dataset · September 14, 2022 Objective. Transcranial magnetic stimulation (TMS) with monophasic pulses achieves greater changes in neuronal excitability but requires higher energy and generates more coil heating than TMS with biphasic pulses, and this limits the use of monophasic puls ... Full text Cite

Subsecond multichannel magnetic control of select neural circuits in freely moving flies.

Journal Article Nat Mater · August 2022 Precisely timed activation of genetically targeted cells is a powerful tool for the study of neural circuits and control of cell-based therapies. Magnetic control of cell activity, or 'magnetogenetics', using magnetic nanoparticle heating of temperature-se ... Full text Link to item Cite

Transcranial magnetic stimulation of the brain: What is stimulated? - A consensus and critical position paper.

Journal Article Clin Neurophysiol · August 2022 Transcranial (electro)magnetic stimulation (TMS) is currently the method of choice to non-invasively induce neural activity in the human brain. A single transcranial stimulus induces a time-varying electric field in the brain that may evoke action potentia ... Full text Link to item Cite

A wireless millimetric magnetoelectric implant for the endovascular stimulation of peripheral nerves.

Journal Article Nat Biomed Eng · June 2022 Implantable bioelectronic devices for the simulation of peripheral nerves could be used to treat disorders that are resistant to traditional pharmacological therapies. However, for many nerve targets, this requires invasive surgeries and the implantation o ... Full text Link to item Cite

Isolating two sources of variability of subcortical stimulation to quantify fluctuations of corticospinal tract excitability.

Journal Article Clin Neurophysiol · June 2022 OBJECTIVE: Investigate the variability previously found with cortical stimulation and handheld transcranial magnetic stimulation (TMS) coils, criticized for its high potential of coil position fluctuations, bypassing the cortex using deep brain electrical ... Full text Link to item Cite

Characterizing the short-latency evoked response to intracortical microstimulation across a multi-electrode array.

Journal Article J Neural Eng · April 20, 2022 Objective.Persons with tetraplegia can use brain-machine interfaces to make visually guided reaches with robotic arms. Without somatosensory feedback, these movements will likely be slow and imprecise, like those of persons who retain movement but have los ... Full text Link to item Cite

Using diffusion tensor imaging to effectively target TMS to deep brain structures

Conference NeuroImage · April 1, 2022 TMS has become a powerful tool to explore cortical function, and in parallel has proven promising in the development of therapies for various psychiatric and neurological disorders. Unfortunately, much of the inference of the direct effects of TMS has been ... Full text Cite

Using diffusion tensor imaging to effectively target TMS to deep brain structures.

Journal Article Neuroimage · April 1, 2022 TMS has become a powerful tool to explore cortical function, and in parallel has proven promising in the development of therapies for various psychiatric and neurological disorders. Unfortunately, much of the inference of the direct effects of TMS has been ... Full text Link to item Cite

TAP: targeting and analysis pipeline for optimization and verification of coil placement in transcranial magnetic stimulation.

Journal Article Journal of neural engineering · April 2022 Objective.Transcranial magnetic stimulation (TMS) can modulate brain function via an electric field (E-field) induced in a brain region of interest (ROI). The ROI E-field can be computationally maximized and set to match a specific reference using i ... Full text Cite

Multichannel power electronics and magnetic nanoparticles for selective thermal magnetogenetics.

Journal Article J Neural Eng · March 29, 2022 Objective.We present a combination of a power electronics system and magnetic nanoparticles that enable frequency-multiplexed magnetothermal-neurostimulation with rapid channel switching between three independent channels spanning a wide frequency range.Ap ... Full text Link to item Cite

Modular multilevel TMS device with wide output range and ultrabrief pulse capability for sound reduction.

Journal Article J Neural Eng · March 17, 2022 Objective.This article presents a novel transcranial magnetic stimulation (TMS) pulse generator with a wide range of pulse shape, amplitude, and width.Approach.Based on a modular multilevel TMS (MM-TMS) topology we had proposed previously, we realized the ... Full text Link to item Cite

Asymmetrical Modular Multilevel Converter with Sensorless Voltage Control for High-Quality Output

Conference IECON Proceedings (Industrial Electronics Conference) · January 1, 2022 The paper proposes an Asymmetrical Modular Multilevel Converter (AMMC) suitable for low/medium-voltage dc-ac conversions with very high output quality. The modules' dc-links of the AMMC are charged to a binary exponential sequence to produce a large number ... Full text Cite

Network-based rTMS to modulate working memory: The difficult choice of effective parameters for online interventions.

Journal Article Brain Behav · November 2021 BACKGROUND: Online repetitive transcranialmagnetic stimulation (rTMS) has been shown to modulate working memory (WM) performance in a site-specific manner, with behavioral improvements due to stimulation of the dorsolateral prefrontal cortex (DLPFC), and i ... Full text Link to item Cite

A high-frequency pulsating dc link for electric vehicle drives with reduced losses

Journal Article IEEE Industrial Electronics Society (IECON) · November 1, 2021 This paper proposes a motor drive suitable for electric vehicles (EVs) with notably reduced losses as compared to conventional drives. The proposed drive feeds the dc-link with a dynamically reconfigurable battery formed by cascaded half-bridges containing ... Open Access Cite

Double-Containment Coil With Enhanced Winding Mounting for Transcranial Magnetic Stimulation With Reduced Acoustic Noise.

Journal Article IEEE Trans Biomed Eng · July 2021 OBJECTIVE: This work aims to reduce the acoustic noise level of transcranial magnetic stimulation (TMS) coils. TMS requires high currents (several thousand amperes) to be pulsed through the coil, which generates a loud acoustic impulse whose peak sound pre ... Full text Link to item Cite

Transcranial alternating current stimulation entrains alpha oscillations by preferential phase synchronization of fast-spiking cortical neurons to stimulation waveform.

Journal Article Nat Commun · May 25, 2021 Computational modeling and human studies suggest that transcranial alternating current stimulation (tACS) modulates alpha oscillations by entrainment. Yet, a direct examination of how tACS interacts with neuronal spiking activity that gives rise to the alp ... Full text Link to item Cite

Effect of Experimental Manipulation of the Orbitofrontal Cortex on Short-Term Markers of Compulsive Behavior: A Theta Burst Stimulation Study.

Journal Article Am J Psychiatry · May 1, 2021 OBJECTIVE: Compulsive behaviors are a core feature of obsessive-compulsive spectrum disorders but appear across a broad spectrum of psychological conditions. It is thought that compulsions reflect a failure to override habitual behaviors "stamped in" throu ... Full text Link to item Cite

Modular Multilevel Series/Parallel Converter for Bipolar DC Distribution and Transmission

Journal Article IEEE Journal of Emerging and Selected Topics in Power Electronics · April 1, 2021 This article proposes a novel bipolar-type dc system suitable for both distribution and transmission systems based on modular multilevel series/parallel converters (MMSPCs). The system features decoupled operations of each pole of the bipolar system, being ... Full text Open Access Cite

Fast computational optimization of TMS coil placement for individualized electric field targeting.

Journal Article Neuroimage · March 2021 BACKGROUND: During transcranial magnetic stimulation (TMS) a coil placed on the scalp is used to non-invasively modulate activity of targeted brain networks via a magnetically induced electric field (E-field). Ideally, the E-field induced during TMS is con ... Full text Link to item Cite

The oxford handbook of transcranial stimulation: Second edition

Book · February 10, 2021 Transcranial stimulation encompasses noninvasive methods that transmit physical fields-such as magnetic, electric, ultrasound, and light-to the brain to modulate its function. The most widespread approach, transcranial magnetic stimulation (TMS), has emerg ... Full text Cite

Transcranial magnetic stimulation coils

Chapter · February 10, 2021 Many different types of TMS coils have been proposed and implemented, but all share certain common features. The induced electric field is always maximum in the superficial parts of the brain, nearest the coil, and attenuates toward the center of the head. ... Full text Cite

TMS pulse waveform and direction

Chapter · February 10, 2021 The pulse waveform and current direction contribute to the specific effects of transcranial magnetic stimulation (TMS). For single pulse TMS these factors have been shown to influence, for example, motor threshold and recruitment curve, motor-evoked potent ... Full text Cite

Transcranial magnetic stimulators

Chapter · February 10, 2021 Transcranial magnetic stimulators are used for clinical diagnostic and therapeutic applications as well as in support of research. Consequently, a number of stimulator types and design variations have been developed to serve these purposes each having uniq ... Full text Cite

Physics, biophysics, and technology

Chapter · February 10, 2021 Cite

Transcranial electrical stimulation devices

Chapter · February 10, 2021 Transcranial electrical stimulation (tES) devices apply electrical waveforms through electrodes placed on the scalp to modulate brain function. This chapter describes the principles, types, and components of tES devices as well as practical considerations ... Full text Cite

Physics and biophysics fundamentals of transcranial stimulation

Chapter · February 10, 2021 Transcranial stimulation induces or modulates neural activity in the brain through basic physical and biophysical processes. Transcranial electrical stimulation and transcranial magnetic stimulation impose an exogenous electric field in the brain that is d ... Full text Cite

A Reduced Series/Parallel Module for Cascade Multilevel Static Compensators Supporting Sensorless Balancing

Journal Article IEEE Transactions on Industrial Electronics · January 1, 2021 Cascaded multilevel converters have been gaining popularity in static compensators (STATCOMs) owing to their excellent modularity, output quality, and fault tolerance. However, cascaded multilevel converters require a large number of galvanically isolated ... Full text Open Access Cite

Rapid, Dose-Dependent Enhancement of Cerebral Blood Flow by transcranial AC Stimulation in Mouse.

Journal Article Brain Stimul · 2021 BACKGROUND: Transcranial electrical stimulation at an appropriate dose may demonstrate intracranial effects, including neuronal stimulation and cerebral blood flow responses. OBJECTIVE: We performed in vivo experiments on mouse cortex using transcranial al ... Full text Link to item Cite

Safety and recommendations for TMS use in healthy subjects and patient populations, with updates on training, ethical and regulatory issues: Expert Guidelines.

Journal Article Clin Neurophysiol · January 2021 This article is based on a consensus conference, promoted and supported by the International Federation of Clinical Neurophysiology (IFCN), which took place in Siena (Italy) in October 2018. The meeting intended to update the ten-year-old safety guidelines ... Full text Link to item Cite

TAP: Targeting and analysis pipeline for optimization and verification of coil placement in transcranial magnetic stimulation

Journal Article · 2021 Objective Transcranial magnetic stimulation (TMS) can modulate brain function via an electric field (E-field) induced in a brain region of interest (ROI). The ROI E-field can be computationally maximized and set to match a specific reference using ... Full text Cite

High Bandwidth Power Electronics and Magnetic Nanoparticles for Multichannel Magnetogenetic Neurostimulation

Journal Article · 2021 Objective We present a power electronic system and magnetic nanoparticles for multiplexed magnetogenetic neurostimulation with three channels spanning a wide frequency range and rapid channel switching capability. This enables selective heating of ... Full text Cite

Modular multilevel TMS device with wide output range and ultrabrief pulse capability for sound reduction

Journal Article · 2021 Objective This article presents a novel transcranial magnetic stimulation (TMS) pulse generator with a wide range of pulse shape, amplitude, and width. Approach Based on a modular multilevel TMS (MM-TMS) topology we had proposed previousl ... Full text Cite

Effect of Pulse Duration and Direction on Plasticity Induced by 5 Hz Repetitive Transcranial Magnetic Stimulation in Correlation With Neuronal Depolarization.

Journal Article Front Neurosci · 2021 Introduction: High frequency repetitive transcranial magnetic stimulation applied to the motor cortex causes an increase in the amplitude of motor evoked potentials (MEPs) that persists after stimulation. Here, we focus on the aftereffects generated by hig ... Full text Link to item Cite

Modulation and Control of Series/Parallel Module for Ripple-Current Reduction in Star-Configured Split-Battery Applications

Journal Article IEEE Transactions on Power Electronics · December 1, 2020 Split-battery converters based on cascaded H-bridges (CHBs) are gaining popularity due to their excellent physical modularity. During operation, however, the batteries experience substantial current ripple. Conventional ripple-current reduction methods rel ... Full text Open Access Cite

Intensity- and timing-dependent modulation of motion perception with transcranial magnetic stimulation of visual cortex.

Journal Article Neuropsychologia · October 2020 Despite the widespread use of transcranial magnetic stimulation (TMS) in research and clinical care, the dose-response relations and neurophysiological correlates of modulatory effects remain relatively unexplored. To fill this gap, we studied modulation o ... Full text Open Access Link to item Cite

Older adults benefit from more widespread brain network integration during working memory.

Journal Article Neuroimage · September 2020 Neuroimaging evidence suggests that the aging brain relies on a more distributed set of cortical regions than younger adults in order to maintain successful levels of performance during demanding cognitive tasks. However, it remains unclear how task demand ... Full text Open Access Link to item Cite

Structural Controllability Predicts Functional Patterns and Brain Stimulation Benefits Associated with Working Memory.

Journal Article J Neurosci · August 26, 2020 The brain is an inherently dynamic system, and much work has focused on the ability to modify neural activity through both local perturbations and changes in the function of global network ensembles. Network controllability is a recent concept in network n ... Full text Link to item Cite

Application of long-interval paired-pulse transcranial magnetic stimulation to motion-sensitive visual cortex does not lead to changes in motion discrimination.

Journal Article Neurosci Lett · June 21, 2020 The perception of visual motion is dependent on a set of occipitotemporal regions that are readily accessible to neuromodulation. The current study tested if paired-pulse Transcranial Magnetic Stimulation (ppTMS) could modulate motion perception by stimula ... Full text Open Access Link to item Cite

Site-Specific Effects of Online rTMS during a Working Memory Task in Healthy Older Adults.

Journal Article Brain Sci · April 27, 2020 The process of manipulating information within working memory is central to many cognitive functions, but also declines rapidly in old age. Improving this process could markedly enhance the health-span in older adults. The current pre-registered, randomize ... Full text Open Access Link to item Cite

Simulation of transcranial magnetic stimulation in head model with morphologically-realistic cortical neurons.

Journal Article Brain Stimul · 2020 BACKGROUND: Transcranial magnetic stimulation (TMS) enables non-invasive modulation of brain activity with both clinical and research applications, but fundamental questions remain about the neural types and elements TMS activates and how stimulation param ... Full text Link to item Cite

Conditions for numerically accurate TMS electric field simulation.

Journal Article Brain Stimul · 2020 BACKGROUND: Computational simulations of the E-field induced by transcranial magnetic stimulation (TMS) are increasingly used to understand its mechanisms and to inform its administration. However, characterization of the accuracy of the simulation methods ... Full text Link to item Cite

Sound comparison of seven TMS coils at matched stimulation strength.

Journal Article Brain Stimul · 2020 BACKGROUND: Accurate data on the sound emitted by transcranial magnetic stimulation (TMS) coils is lacking. METHODS: We recorded the sound waveforms of seven coils with high bandwidth. We estimated the neural stimulation strength by measuring the induced e ... Full text Link to item Cite

Dose-dependent enhancement of motion direction discrimination with transcranial magnetic stimulation of visual cortex

Journal Article · 2020 Despite the widespread use of transcranial magnetic stimulation (TMS) in research and clinical care, the underlying mechanisms-of-actions that mediate modulatory effects remain poorly understood. To fill this gap, we studied dose–response functions of TMS ... Full text Cite

Fast computational optimization of TMS coil placement for individualized electric field targeting

Journal Article · 2020 Background During transcranial magnetic stimulation (TMS) a coil placed on the scalp is used to non-invasively modulate activity of targeted brain networks via a magnetically induced electric field (E-field). Ideally, the E-field induced during TM ... Full text Cite

Transcranial Magnetic Stimulation: Principles and Applications

Chapter · January 1, 2020 Transcranial magnetic stimulation (TMS) is a noninvasive method for focal brain stimulation, with applications in research, diagnostics, and treatment. In basic research, TMS can help establish a causal link between a brain circuit and a behavior. Clinical ... Full text Cite

Erratum to: "Optimal Estimation of Neural Recruitment Curves Using Fisher Information: Application to Transcranial Magnetic Stimulation".

Journal Article IEEE Trans Neural Syst Rehabil Eng · November 2019 This erratum provides the link to the software implementation of the algorithm and the examples presented in [1], which was omitted by mistake in the published version of the manuscript. The algorithm was implemented in Matlab and is available online on Co ... Full text Link to item Cite

A Modular Multilevel Series/Parallel Converter for a Wide Frequency Range Operation

Journal Article IEEE Transactions on Power Electronics · October 1, 2019 When providing ac output, modular multilevel converters (MMCs) experience power fluctuation in the phase arms. The power fluctuation causes voltage ripple on the module capacitors, which grows with the output power and inversely to the output frequency. Th ... Full text Open Access Cite

Different parallel connections generated by the Modular Multilevel Series/Parallel Converter: An overview

Conference IECON Proceedings (Industrial Electronics Conference) · October 1, 2019 The Modular Multilevel Series Parallel Converter (MMSPC) not only allows dynamic interconnection among the modules in series connection, like the traditional Modular Multilevel Converter (MMC), but also in parallel connection. This extra switching state am ... Full text Cite

Accuracy of robotic coil positioning during transcranial magnetic stimulation.

Journal Article J Neural Eng · September 17, 2019 OBJECTIVE: Robotic positioning systems for transcranial magnetic stimulation (TMS) promise improved accuracy and stability of coil placement, but there is limited data on their performance. Investigate the usability, accuracy, and limitations of robotic co ... Full text Link to item Cite

Module implementation and modulation strategy for sensorless balancing in modular multilevel converters

Journal Article IEEE Transactions on Power Electronics · September 1, 2019 Modules with series and parallel connectivity add new features and operation modes to modular multilevel converters (MMCs). Compared to full-and half-bridges, the series/parallel modules allow sensorless module balancing and reduce conduction loss with the ... Full text Cite

Concept of a distributed photovoltaic multilevel inverter with cascaded double H-bridge topology

Journal Article International Journal of Electrical Power and Energy Systems · September 1, 2019 This paper presents proof-of-concept of a novel photovoltaic (PV) inverter with integrated short-term storage, based on the modular cascaded double H-bridge (CHB 2 ) topology, and a new look-up table control approach. This topology combines and extends the ... Full text Cite

Erratum to ‘Electroconvulsive stimulation increases astrocyte marker GFAP in mouse hippocampus regardless of chronic social defeat stress’ (Brain Stimulation (2019) 12(2) (543), (S1935861X18312105), (10.1016/j.brs.2018.12.791))

Journal Article Brain Stimulation · September 1, 2019 The title of this abstract was incorrectly published as ‘Electroconvulsive stimulation increases astrocytes in mice subjected to chronic social defeat stress’. The correct title is above. The Publisher apologises for this error. ... Full text Cite

Online switch open-circuit fault diagnosis using reconfigurable scheduler for modular multilevel converter with parallel connectivity

Conference 2019 21st European Conference on Power Electronics and Applications, EPE 2019 ECCE Europe · September 1, 2019 The modular multilevel series-parallel converter (MMSPC) was shown to provide advantages in several industrial applications, but the many individual switches may challenge its reliability. This paper proposes an effective fault diagnosis method (FDM) based ... Full text Cite

Closed-loop predictively optimizing control for modular multilevel converter with parallel connectivity

Conference 2019 21st European Conference on Power Electronics and Applications, EPE 2019 ECCE Europe · September 1, 2019 This paper adopts the bilinear modeling method to design a coherent model for modular multilevel converters with parallel connectivity and proposes an optimized closed-loop control combining proportional resonant (PR) control, nearest level modulation, and ... Full text Cite

Current Injection Methods for Ripple-Current Suppression in Delta-Configured Split-Battery Energy Storage

Journal Article IEEE Transactions on Power Electronics · August 1, 2019 Cascaded H-bridge (CHB) converters are receiving growing attention in battery energy storage systems (BESS) due to their modularity and flexibility. However, direct generation of ac output in CHB-BESSs incurs large second-order current ripple in the batter ... Full text Cite

Statistical Model of Motor-Evoked Potentials.

Journal Article IEEE Trans Neural Syst Rehabil Eng · August 2019 Motor-evoked potentials (MEPs) are widely used for biomarkers and dose individualization in transcranial stimulation. The large variability of MEPs requires sophisticated methods of analysis to extract information fast and correctly. Development and testin ... Full text Link to item Cite

Optimal Estimation of Neural Recruitment Curves Using Fisher Information: Application to Transcranial Magnetic Stimulation.

Journal Article IEEE Trans Neural Syst Rehabil Eng · June 2019 This paper presents a novel method for fast and optimal determination of recruitment (input-output, IO) curve parameters in neural stimulation. A sequential parameter estimation (SPE) method was developed based on the Fisher information matrix (FIM), with ... Full text Link to item Cite

Modular Multilevel Series/Parallel Converter with Switched-Inductor Energy Transfer between Modules

Journal Article IEEE Transactions on Power Electronics · May 1, 2019 This paper presents a modular multilevel series/parallel converter (MMSPC) with intermodule switched-inductor power transfer. The switched-inductor voltage conversion feature allows controllable and efficient transfer of energy between modules with nonnegl ... Full text Cite

Relative abundance of Akkermansia spp. and other bacterial phylotypes correlates with anxiety- and depressive-like behavior following social defeat in mice.

Journal Article Sci Rep · March 1, 2019 As discussion of stress and stress-related disorders rapidly extends beyond the brain, gut microbiota have emerged as a promising contributor to individual differences in the risk of illness, disease course, and treatment response. Here, we employed chroni ... Full text Link to item Cite

Online repetitive transcranial magnetic stimulation during working memory in younger and older adults: A randomized within-subject comparison.

Journal Article PLoS One · 2019 Working memory is the ability to perform mental operations on information that is stored in a flexible, limited capacity buffer. The ability to manipulate information in working memory is central to many aspects of human cognition, but also declines with h ... Full text Open Access Link to item Cite

Transcranial electrical stimulation nomenclature.

Journal Article Brain Stimul · 2019 Transcranial electrical stimulation (tES) aims to alter brain function non-invasively by applying current to electrodes on the scalp. Decades of research and technological advancement are associated with a growing diversity of tES methods and the associate ... Full text Link to item Cite

Accuracy of robotic coil positioning during transcranial magnetic stimulation

Journal Article · 2019 Objective Robotic positioning systems for transcranial magnetic stimulation (TMS) promise improved accuracy and stability of coil placement, but there is limited data on their performance. This text investigates the usability, accuracy, and limita ... Full text Cite

Sound comparison of seven TMS coils at matched stimulation strength

Journal Article · 2019 Background Accurate data on the sound emitted by transcranial magnetic stimulation (TMS) coils is lacking. Methods We recorded the sound waveforms of seven coils with high bandwidth. We estimated the neural stimulation strength by measuri ... Full text Cite

Transcranial Alternating Current Stimulation (tACS) Entrains Alpha Oscillations by Preferential Phase Synchronization of Fast-Spiking Cortical Neurons to Stimulation Waveform

Journal Article · 2019 Summary Modeling studies predict that transcranial alternating current stimulation (tACS) entrains brain oscillations, yet direct examination has been lacking or potentially contaminated by stimulation artefact. Here we first demonstrate how the p ... Full text Cite

Structural controllability predicts functional patterns and brain stimulation benefits associated with working memory

Journal Article · 2019 Summary The brain is an inherently dynamic system, and much work has focused on the ability to modify neural activity through both local perturbations and changes in the function of global network ensembles. Network controllability is a recent con ... Full text Cite

Complementary topology of maintenance and manipulation brain networks in working memory.

Journal Article Sci Rep · December 13, 2018 Working memory (WM) is assumed to consist of a process that sustains memory representations in an active state (maintenance) and a process that operates on these activated representations (manipulation). We examined evidence for two distinct, concurrent co ... Full text Open Access Link to item Cite

Biophysically realistic neuron models for simulation of cortical stimulation.

Journal Article J Neural Eng · December 2018 OBJECTIVE: We implemented computational models of human and rat cortical neurons for simulating the neural response to cortical stimulation with electromagnetic fields. APPROACH: We adapted model neurons from the library of Blue Brain models to reflect bio ... Full text Link to item Cite

Electric field measurement of two commercial active/sham coils for transcranial magnetic stimulation.

Journal Article J Neural Eng · October 2018 OBJECTIVE: Sham TMS coils isolate the ancillary effects of their active counterparts but typically induce low-strength electric fields (E-fields) in the brain, which could be biologically active. We measured the E-fields induced by two pairs of commonly-us ... Full text Link to item Cite

Design of transcranial magnetic stimulation coils with optimal trade-off between depth, focality, and energy.

Journal Article J Neural Eng · August 2018 OBJECTIVE: Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique used for research and clinical applications. Existent TMS coils are limited in their precision of spatial targeting (focality), especially for deeper targets. T ... Full text Link to item Cite

Coupling Magnetically Induced Electric Fields to Neurons: Longitudinal and Transverse Activation.

Journal Article Biophys J · July 3, 2018 We present a theory and computational models to couple the electric field induced by magnetic stimulation to neuronal membranes. Based on the characteristics of magnetically induced electric fields and the modified cable equation that we developed previous ... Full text Link to item Cite

Noninvasive Detection of Motor-Evoked Potentials in Response to Brain Stimulation Below the Noise Floor-How Weak Can a Stimulus Be and Still Stimulate.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · July 2018 Motor-evoked potentials (MEP) are one of the most important responses to brain stimulation, such as supra-threshold transcranial magnetic stimulation (TMS) and electrical stimulation. The understanding of the neurophysiology and the determination of the lo ... Full text Open Access Link to item Cite

Field Distribution of Transcranial Static Magnetic Stimulation in Realistic Human Head Model.

Journal Article Neuromodulation · June 2018 OBJECTIVE: The objective of this work was to characterize the magnetic field (B-field) that arises in a human brain model from the application of transcranial static magnetic field stimulation (tSMS). MATERIALS AND METHODS: The spatial distribution of the ... Full text Link to item Cite

Redesigning existing transcranial magnetic stimulation coils to reduce energy: application to low field magnetic stimulation.

Journal Article J Neural Eng · June 2018 OBJECTIVE: To present a systematic framework and exemplar for the development of a compact and energy-efficient coil that replicates the electric field (E-field) distribution induced by an existing transcranial magnetic stimulation coil. APPROACH: The E-fi ... Full text Link to item Cite

Modified cable equation incorporating transverse polarization of neuronal membranes for accurate coupling of electric fields.

Journal Article J Neural Eng · April 2018 OBJECTIVE: We present a theory and computational methods to incorporate transverse polarization of neuronal membranes into the cable equation to account for the secondary electric field generated by the membrane in response to transverse electric fields. T ... Full text Link to item Cite

International randomized-controlled trial of transcranial Direct Current Stimulation in depression.

Journal Article Brain Stimul · 2018 BACKGROUND: Evidence suggests that transcranial Direct Current Stimulation (tDCS) has antidepressant effects in unipolar depression, but there is limited information for patients with bipolar depression. Additionally, prior research suggests that brain der ... Full text Link to item Cite

Comparative evaluation of a new magnetic bead-based DNA extraction method from fecal samples for downstream next-generation 16S rRNA gene sequencing.

Journal Article PLoS One · 2018 We are colonized by a vast population of genetically diverse microbes, the majority of which are unculturable bacteria that reside within the gastrointestinal tract. As affordable, advanced next-generation sequencing technologies become more widely availab ... Full text Link to item Cite

Simulation of transcranial magnetic stimulation in head model with morphologically-realistic cortical neurons

Journal Article · 2018 Transcranial magnetic stimulation (TMS) enables non-invasive modulation of brain activity with both clinical and research applications, but fundamental questions remain about the neural types and elements it activates and how stimulation parameters affect ... Full text Cite

Coupling magnetically induced electric fields to neurons: longitudinal and transverse activation

Journal Article · 2018 ABSTRACT We present a theory and computational models to couple the electric field induced by magnetic stimulation to neuronal membranes. The response of neuronal membranes to induced electric fields is examined under different time scales, and th ... Full text Cite

A systematic study of repetitive transcranial magnetic stimulation to enhance working memory manipulation abilities

Journal Article · 2018 A core element of human working memory (WM) is the ability to perform mental operations on information that is stored in a flexible, limited capacity buffer. Given the profound importance of such WM manipulation (WM-M) abilities, there is a concerted effor ... Full text Cite

Biophysically Realistic Neuron Models for Simulation of Cortical Stimulation

Journal Article · 2018 1. Objective We implemented computational models of human and rat cortical neurons for simulating the neural response to cortical stimulation with electromagnetic fields. Approach We adapted model neurons from the library of Blue Brain mo ... Full text Cite

Ripple current suppression methods for star-configured modular multilevel converters

Conference Proceedings IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society · December 15, 2017 The star-configured modular multilevel converter is a promising topology for grid-connected storage as well as power-quality applications and motor drives. During operation, the ac output power generates substantial current pulsation at twice the output fr ... Full text Cite

Submodule short-circuit fault diagnosis based on wavelet transform and support vector machines for modular multilevel converter with series and parallel connectivity

Conference Proceedings IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society · December 15, 2017 The modular multilevel converter with series and parallel connectivity was shown to provide advantages in several industrial applications. Its reliability largely depends on the absence of failures in the power semiconductors. We propose and analyze a faul ... Full text Cite

Predictive control of modular multilevel series/parallel converter for battery systems

Conference 2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017 · November 3, 2017 This paper presents a multi-step predictive control framework for modular multilevel converters with series/parallel connectivity - a more generalized topology of the H-bridge-based modular multilevel converters. The controller coordinates a wide range of ... Full text Cite

Distributed balancing control for modular multilevel series/parallel converter with capability of sensorless operation

Conference 2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017 · November 3, 2017 Modular multilevel converters (MMC) have many advantages owing to their power-stage modularity. However, this modularity does not extend directly to the control. Particularly, the balancing control usually requires central coordination and increases in com ... Full text Cite

Control of Modular Multilevel Converter with Parallel Connectivity-Application to Battery Systems

Journal Article IEEE Transactions on Power Electronics · November 1, 2017 This paper presents a multiobjective real-time controller for a modular multilevel converter capable of parallel module connectivity, the so-called modular multilevel series parallel converter (MMSPC). The MMSPC topology allows the batteries to be dynamica ... Full text Cite

Photovoltaic multilevel inverter with distributed maximum power point tracking and dynamic circuit reconfiguration

Conference 2017 IEEE 3rd International Future Energy Electronics Conference and ECCE Asia, IFEEC - ECCE Asia 2017 · July 25, 2017 This work will present a novel photovoltaic (PV) inverter with integrated short-term storage. The topology combines advantages of microinverter topologies, such as module-specific maximum-power-point tracking, failure-tolerance, safety due to limited volta ... Full text Cite

Minimum Electric Field Exposure for Seizure Induction with Electroconvulsive Therapy and Magnetic Seizure Therapy.

Journal Article Neuropsychopharmacology · May 2017 Lowering and individualizing the current amplitude in electroconvulsive therapy (ECT) has been proposed as a means to produce stimulation closer to the neural activation threshold and more focal seizure induction, which could potentially reduce cognitive s ... Full text Link to item Cite

Transcranial electric stimulation seen from within the brain.

Journal Article Elife · March 28, 2017 Computer models can make transcranial electric stimulation a better tool for research and therapy. ... Full text Link to item Cite

Pulse Width Affects Scalp Sensation of Transcranial Magnetic Stimulation.

Journal Article Brain Stimul · 2017 BACKGROUND: Scalp sensation and pain comprise the most common side effect of transcranial magnetic stimulation (TMS), which can reduce tolerability and complicate experimental blinding. OBJECTIVE: We explored whether changing the width of single TMS pulses ... Full text Link to item Cite

Comparison of electric field strength and spatial distribution of electroconvulsive therapy and magnetic seizure therapy in a realistic human head model.

Journal Article Eur Psychiatry · August 2016 BACKGROUND: This study examines the strength and spatial distribution of the electric field induced in the brain by electroconvulsive therapy (ECT) and magnetic seizure therapy (MST). METHODS: The electric field induced by standard (bilateral, right unilat ... Full text Link to item Cite

Sensorless scheduling of the modular multilevel series-parallel converter: Enabling a flexible, efficient, modular battery

Conference Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC · May 10, 2016 We present a control approach for the modular multilevel converter (MMC) with series and parallel module connectivity (MMSPC) that provides natural module balancing, reduced conduction losses, and enhanced robustness afforded by the parallel mode. In conve ... Full text Cite

Effect of coil orientation on strength-duration time constant and I-wave activation with controllable pulse parameter transcranial magnetic stimulation.

Journal Article Clin Neurophysiol · January 2016 OBJECTIVE: To compare the strength-duration (S-D) time constants of motor cortex structures activated by current pulses oriented posterior-anterior (PA) or anterior-posterior (AP) across the central sulcus. METHODS: Motor threshold and input-output curve, ... Full text Link to item Cite

Enhancement of Neuromodulation with Novel Pulse Shapes Generated by Controllable Pulse Parameter Transcranial Magnetic Stimulation.

Journal Article Brain Stimul · 2016 BACKGROUND: Standard repetitive transcranial magnetic stimulation (rTMS) devices generate bidirectional biphasic sinusoidal pulses that are energy efficient, but may be less effective than monophasic pulses that induce a more unidirectional electric field. ... Full text Link to item Cite

Subject-Specific Multiscale Modeling to Investigate Effects of Transcranial Magnetic Stimulation.

Journal Article Neuromodulation · December 2015 OBJECTIVE: Transcranial magnetic stimulation (TMS) is an effective intervention in noninvasive neuromodulation used to treat a number of neurophysiological disorders. Predicting the spatial extent to which neural tissue is affected by TMS remains a challen ... Full text Link to item Cite

Transcranial direct current stimulation (tDCS) of frontal cortex decreases performance on the WAIS-IV intelligence test.

Journal Article Behav Brain Res · September 1, 2015 Transcranial direct current stimulation (tDCS) modulates excitability of motor cortex. However, there is conflicting evidence about the efficacy of this non-invasive brain stimulation modality to modulate performance on cognitive tasks. Previous work has t ... Full text Link to item Cite

Electric Field Model of Transcranial Electric Stimulation in Nonhuman Primates: Correspondence to Individual Motor Threshold.

Journal Article IEEE Trans Biomed Eng · September 2015 OBJECTIVE: To develop a pipeline for realistic head models of nonhuman primates (NHPs) for simulations of noninvasive brain stimulation, and use these models together with empirical threshold measurements to demonstrate that the models capture individual a ... Full text Link to item Cite

Individualized Low-Amplitude Seizure Therapy: Minimizing Current for Electroconvulsive Therapy and Magnetic Seizure Therapy.

Journal Article Neuropsychopharmacology · August 2015 Electroconvulsive therapy (ECT) at conventional current amplitudes (800-900 mA) is highly effective but carries the risk of cognitive side effects. Lowering and individualizing the current amplitude may reduce side effects by virtue of a less intense and m ... Full text Link to item Cite

Modular multilevel converter with series and parallel module connectivity: Topology and control

Journal Article IEEE Transactions on Power Electronics · January 1, 2015 This paper introduces a novel modular multilevel series/parallel converter that allows switching modules dynamically not only in series, as in the traditional modular multilevel converter (M2C), but also in parallel. As in M2C, the semiconductor voltages d ... Full text Cite

Effect of anatomical variability on electric field characteristics of electroconvulsive therapy and magnetic seizure therapy: a parametric modeling study.

Journal Article IEEE Trans Neural Syst Rehabil Eng · January 2015 Electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) are conventionally applied with a fixed stimulus current amplitude, which may result in differences in the neural stimulation strength and focality across patients due to interindividual an ... Full text Link to item Cite

Quiet transcranial magnetic stimulation: Status and future directions.

Conference Annu Int Conf IEEE Eng Med Biol Soc · 2015 A significant limitation of transcranial magnetic stimulation (TMS) is that the magnetic pulse delivery is associated with a loud clicking sound as high as 140 dB resulting from electromagnetic forces. The loud noise significantly impedes both basic resear ... Full text Link to item Cite

Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping.

Journal Article J Neural Eng · October 2014 Featured Publication OBJECTIVE: This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. APPROACH: We present a third generation controllable pulse parameter device (cTMS ... Full text Link to item Cite

Simultaneous transcranial magnetic stimulation and single-neuron recording in alert non-human primates.

Journal Article Nat Neurosci · August 2014 Featured Publication Transcranial magnetic stimulation (TMS) is a widely used, noninvasive method for stimulating nervous tissue, yet its mechanisms of effect are poorly understood. Here we report new methods for studying the influence of TMS on single neurons in the brain of ... Full text Open Access Link to item Cite

Magnetic field strength and reproducibility of neodymium magnets useful for transcranial static magnetic field stimulation of the human cortex.

Journal Article Neuromodulation · July 2014 OBJECTIVE: The application of transcranial static magnetic field stimulation (tSMS) in humans reduces the excitability of the motor cortex for a few minutes after the end of stimulation. However, when tSMS is applied in humans, the cortex is at least 2 cm ... Full text Link to item Cite

Coil design considerations for deep transcranial magnetic stimulation.

Journal Article Clin Neurophysiol · June 2014 OBJECTIVES: To explore the field characteristics and design tradeoffs of coils for deep transcranial magnetic stimulation (dTMS). METHODS: We simulated parametrically two dTMS coil designs on a spherical head model using the finite element method, and comp ... Full text Link to item Cite

Coil design considerations for deep transcranial magnetic stimulation

Journal Article Clinical Neurophysiology · 2014 Cite

A novel model incorporating two variability sources for describing motor evoked potentials.

Journal Article Brain Stimul · 2014 OBJECTIVE: Motor evoked potentials (MEPs) play a pivotal role in transcranial magnetic stimulation (TMS), e.g., for determining the motor threshold and probing cortical excitability. Sampled across the range of stimulation strengths, MEPs outline an input- ... Full text Link to item Cite

Simultaneous transcranial magnetic stimulation and single-neuron recording in alert non-human primates

Journal Article Nature Neuroscience · January 1, 2014 Transcranial magnetic stimulation (TMS) is a widely used, noninvasive method for stimulating nervous tissue, yet its mechanisms of effect are poorly understood. Here we report new methods for studying the influence of TMS on single neurons in the brain of ... Full text Cite

Stimulation strength and focality of electroconvulsive therapy and magnetic seizure therapy in a realistic head model.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2014 This study examines the characteristics of the electric field (E-field) induced in the brain by electroconvulsive therapy (ECT) and magnetic seizure therapy (MST). The electric field induced by five ECT electrode configurations (bilateral, bifrontal, right ... Full text Link to item Cite

Transcranial Magnetic Stimulation Device with Reduced Acoustic Noise

Journal Article IEEE Magnetics Letters · January 1, 2014 Transcranial magnetic stimulation (TMS) is widely used for noninvasive activation of neurons in the brain for research and clinical applications. The strong, brief magnetic pulse generated in TMS is associated with a loud (>100 dB) clicking sound that can ... Full text Cite

Modeling transcranial electric stimulation in mouse: a high resolution finite element study.

Conference Annu Int Conf IEEE Eng Med Biol Soc · 2014 Mouse models are widely used in studies of various forms of transcranial electric stimulation (TES). However, there is limited knowledge of the electric field distribution induced by TES in mice, and computational models to estimate this distribution are l ... Full text Link to item Cite

Approximating transcranial magnetic stimulation with electric stimulation in mouse: a simulation study.

Conference Annu Int Conf IEEE Eng Med Biol Soc · 2014 Rodent models are valuable for preclinical examination of novel therapeutic techniques, including transcranial magnetic stimulation (TMS). However, comparison of TMS effects in rodents and humans is confounded by inaccurate scaling of the spatial extent of ... Full text Link to item Cite

Controlling stimulation strength and focality in electroconvulsive therapy via current amplitude and electrode size and spacing: comparison with magnetic seizure therapy.

Journal Article J ECT · December 2013 OBJECTIVES: Understanding the relationship between the stimulus parameters of electroconvulsive therapy (ECT) and the electric field characteristics could guide studies on improving risk/benefit ratio. We aimed to determine the effect of current amplitude ... Full text Link to item Cite

Static magnetic field modulates excitatory activity in layer II/III pyramidal neurons of the rat motor cortex

Conference International IEEE/EMBS Conference on Neural Engineering, NER · December 1, 2013 Recent studies revealed that transcranial stimulation with static magnetic field (SMF) at 0.1-0.15 T results in reduction of neural excitability in the human motor cortex. We explore the mechanisms of this phenomenon with patch-clamp recording in rat brain ... Full text Cite

Topography of seizures induced by electroconvulsive therapy and magnetic seizure therapy

Conference International IEEE/EMBS Conference on Neural Engineering, NER · December 1, 2013 We present the first topographical characterization of seizures induced by ultrabrief pulse width right unilateral electroconvulsive therapy (ECT) and magnetic seizure therapy (MST). Topographical electroencephalogram (EEG) was acquired during treatments i ... Full text Cite

Controllable pulse parameter transcranial magnetic stimulator with enhanced pulse shaping

Conference International IEEE/EMBS Conference on Neural Engineering, NER · December 1, 2013 Commercially available transcranial magnetic stimulation (TMS) devices provide very limited control over the pulse parameters. We present a third generation controllable pulse parameter device (cTMS3) that uses a novel full-bridge circuit topology with two ... Full text Cite

Anatomical variability predicts individual differences in transcranial electric stimulation motor threshold.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2013 We have proposed that the current amplitude in electroconvulsive therapy (ECT) be lowered to produce stimulation closer to the neural activation threshold and individualized to account for anatomical variability across patients. A novel approach to individ ... Cite

Controlling Stimulation Strength and Focality in Electroconvulsive Therapy via Current Amplitude and Electrode Size and Spacing: Comparison With Magnetic Seizure Therapy.

Journal Article J ECT · November 7, 2013 Understanding the relationship between the stimulus parameters of electroconvulsive therapy (ECT) and the electric field characteristics could guide studies on improving risk/benefit ratio. We aimed to determine the effect of current amplitude and electrod ... Full text Link to item Cite

Pulse width dependence of motor threshold and input-output curve characterized with controllable pulse parameter transcranial magnetic stimulation.

Journal Article Clin Neurophysiol · July 2013 Featured Publication OBJECTIVE: To demonstrate the use of a novel controllable pulse parameter TMS (cTMS) device to characterize human corticospinal tract physiology. METHODS: Motor threshold and input-output (IO) curve of right first dorsal interosseus were determined in 26 a ... Full text Link to item Cite

Extended remediation of sleep deprived-induced working memory deficits using fMRI-guided transcranial magnetic stimulation.

Journal Article Sleep · June 1, 2013 STUDY OBJECTIVES: We attempted to prevent the development of working memory (WM) impairments caused by sleep deprivation using fMRI-guided repetitive transcranial magnetic stimulation (rTMS). Novel aspects of our fMRI-guided rTMS paradigm included the use ... Full text Link to item Cite

Electric field depth-focality tradeoff in transcranial magnetic stimulation: simulation comparison of 50 coil designs.

Journal Article Brain Stimul · January 2013 Featured Publication BACKGROUND: Various transcranial magnetic stimulation (TMS) coil designs are available or have been proposed. However, key coil characteristics such as electric field focality and attenuation in depth have not been adequately compared. Knowledge of the coi ... Full text Link to item Cite

A 2.5D integrated voltage regulator using coupled-magnetic-core inductors on silicon interposer

Journal Article IEEE Journal of Solid-State Circuits · January 1, 2013 An integrated voltage regulator (IVR) is presented that uses custom fabricated thin-film magnetic power inductors. The inductors are fabricated on a silicon interposer and integrated with a multi-phase buck converter IC by 2.5D chip stacking. Several induc ... Full text Cite

Analysis and optimization of pulse dynamics for magnetic stimulation.

Journal Article PLoS One · 2013 Featured Publication Magnetic stimulation is a standard tool in brain research and has found important clinical applications in neurology, psychiatry, and rehabilitation. Whereas coil designs and the spatial field properties have been intensively studied in the literature, the ... Full text Link to item Cite

Electric field characteristics of electroconvulsive therapy with individualized current amplitude: a preclinical study.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2013 This study examines the characteristics of the electric field induced in the brain by electroconvulsive therapy (ECT) with individualized current amplitude. The electric field induced by bilateral (BL), bifrontal (BF), right unilateral (RUL), and frontomed ... Full text Link to item Cite

Anatomical variability predicts individual differences in transcranial electric stimulation motor threshold.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2013 We have proposed that the current amplitude in electroconvulsive therapy (ECT) be lowered to produce stimulation closer to the neural activation threshold and individualized to account for anatomical variability across patients. A novel approach to individ ... Full text Link to item Cite

Transcranial electric and magnetic stimulation: technique and paradigms.

Journal Article Handb Clin Neurol · 2013 Transcranial electrical and magnetic stimulation techniques encompass a broad physical variety of stimuli, ranging from static magnetic fields or direct current stimulation to pulsed magnetic or alternating current stimulation with an almost infinite numbe ... Full text Link to item Cite

Optimization of magnetic neurostimulation waveforms for minimum power loss.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2012 Magnetic stimulation is a key tool in experimental brain research and several clinical applications. Whereas coil designs and the spatial field properties have been intensively studied in the literature, the temporal dynamics of the field has received litt ... Cite

A model of variability in brain stimulation evoked responses.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2012 The input-output (IO) curve of cortical neuron populations is a key measure of neural excitability and is related to other response measures including the motor threshold which is widely used for individualization of neurostimulation techniques, such as tr ... Cite

Stimulation strength and focality of electroconvulsive therapy with individualized current amplitude: a preclinical study.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2012 This study investigates the stimulation strength and focality of electroconvulsive therapy (ECT) with individualized current amplitude in a nonhuman primate (NHP) model. We generated an anatomically realistic finite element model of a NHP head incorporatin ... Cite

Fundamentals of transcranial electric and magnetic stimulation dose: definition, selection, and reporting practices.

Journal Article Brain Stimul · October 2012 Featured Publication BACKGROUND: The growing use of transcranial electric and magnetic (EM) brain stimulation in basic research and in clinical applications necessitates a clear understanding of what constitutes the dose of EM stimulation and how it should be reported. METHODS ... Full text Link to item Cite

A switched-inductor integrated voltage regulator with nonlinear feedback and network-on-chip load in 45 nm SOI

Journal Article IEEE Journal of Solid-State Circuits · June 13, 2012 A four-phase integrated buck converter in 45 nm silicon-on-insulator (SOI) technology is presented. The controller uses unlatched pulse-width modulation (PWM) with nonlinear gain to provide both stable small-signal dynamics and fast response (∼ 700 ps) to ... Full text Cite

A 2.5D integrated voltage regulator using coupled-magnetic-core inductors on silicon interposer delivering 10.8A/mm 2

Journal Article Digest of Technical Papers - IEEE International Solid-State Circuits Conference · May 11, 2012 Energy consumption is a dominant constraint on the performance of modern microprocessors and systems-on-chip. Dynamic voltage and frequency scaling (DVFS) is a promising technique for performing "on-the-fly" energy-performance optimization in the presence ... Full text Cite

Regional electric field induced by electroconvulsive therapy in a realistic finite element head model: influence of white matter anisotropic conductivity.

Journal Article Neuroimage · February 1, 2012 Featured Publication We present the first computational study investigating the electric field (E-field) strength generated by various electroconvulsive therapy (ECT) electrode configurations in specific brain regions of interest (ROIs) that have putative roles in the therapeu ... Full text Link to item Cite

Stimulation strength and focality of electroconvulsive therapy with individualized current amplitude: a preclinical study.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2012 This study investigates the stimulation strength and focality of electroconvulsive therapy (ECT) with individualized current amplitude in a nonhuman primate (NHP) model. We generated an anatomically realistic finite element model of a NHP head incorporatin ... Full text Link to item Cite

Transcranial magnetic stimulation induces current pulses in transcranial direct current stimulation electrodes.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2012 Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation technique where weak direct current is administered through electrodes placed on the subject's head. Transcranial magnetic stimulation (TMS) is a noninvasive method for focal b ... Full text Link to item Cite

A model of variability in brain stimulation evoked responses.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2012 The input-output (IO) curve of cortical neuron populations is a key measure of neural excitability and is related to other response measures including the motor threshold which is widely used for individualization of neurostimulation techniques, such as tr ... Full text Link to item Cite

Optimization of magnetic neurostimulation waveforms for minimum power loss.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2012 Magnetic stimulation is a key tool in experimental brain research and several clinical applications. Whereas coil designs and the spatial field properties have been intensively studied in the literature, the temporal dynamics of the field has received litt ... Full text Link to item Cite

Optimization of magnetic neurostimulation waveforms for minimum power loss.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · 2012 Cite

Stimulation strength and focality of electroconvulsive therapy with individualized current amplitude: a preclinical study.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · 2012 Cite

A model of variability in brain stimulation evoked responses.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · 2012 Open Access Cite

An integrated four-phase buck converter delivering 1A/mm2 with 700ps controller delay and network-on-chip load in 45-nm SOI

Journal Article Proceedings of the Custom Integrated Circuits Conference · November 9, 2011 We present a four-phase integrated buck converter in 45nm SOI technology. The controller uses unlatched pulse-width modulation (PWM) with nonlinear gain to provide both stable small-signal dynamics and fast response (∼700ps) to large input and output trans ... Full text Cite

Circuit topology comparison and design analysis for controllable pulse parameter transcranial magnetic stimulators

Journal Article 2011 5th International IEEE/EMBS Conference on Neural Engineering, NER 2011 · July 20, 2011 We compare half-bridge and full-bridge circuit topologies for controllable pulse parameter transcranial magnetic stimulation (cTMS) devices. The full bridge can generate two more distinct coil voltage levels for enhanced pulse shaping, does not need an act ... Full text Cite

Repetitive transcranial magnetic stimulator with controllable pulse parameters.

Journal Article J Neural Eng · June 2011 Featured Publication The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topolo ... Full text Link to item Cite

Electric field strength and focality in electroconvulsive therapy and magnetic seizure therapy: a finite element simulation study.

Journal Article J Neural Eng · February 2011 Featured Publication We present the first computational study comparing the electric field induced by various electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) paradigms. Four ECT electrode configurations (bilateral, bifrontal, right unilateral, and focal elec ... Full text Link to item Cite

Introduction to electrotherapy technology

Journal Article · January 1, 2011 Electrotherapy involves electric or magnetic stimulation of the human body in a range of therapeutic applications including pain alleviation. A wide spectrum of electrotherapy paradigms have been deployed in pain treatment, illustrating the inherent flexib ... Cite

METHODS, APPARATUS, AND SYSTEMS FOR MAGNETIC STIMULATION

Journal Article · 2011 A coil suitable for tissue stimulation and especially for transcranial magnetic stimulation (TMS) may be used in conjunction with a pulse generator to induce electric field in the brain with less attenuation in depth compared to existing TMS coils. In an e ... Cite

Influence of white matter conductivity anisotropy on electric field strength induced by electroconvulsive therapy.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2011 The goal of this study is to investigate the influence of white matter conductivity anisotropy on the electric field strength induced by electroconvulsive therapy (ECT). We created an anatomically-realistic finite element human head model incorporating tis ... Full text Link to item Cite

Transcranial magnetic stimulation coil with electronically switchable active and sham modes.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2011 Blinded studies with transcranial magnetic stimulation (TMS) require a valid sham condition. A wide range of sham approaches have been implemented but they have various limitations including residual electric field in the brain, inadequate reproduction of ... Full text Link to item Cite

Repetitive transcranial magnetic stimulator with controllable pulse parameters (cTMS).

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2010 We describe a novel transcranial magnetic stimulation (TMS) device that uses a circuit topology incorporating two energy-storage capacitors and two insulated-gate bipolar transistors (IGBTs) to generate near-rectangular electric field E-field) pulses with ... Cite

Electroconvulsive therapy in the presence of deep brain stimulation implants: electric field effects.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2010 The safety of electroconvulsive therapy (ECT) in patients who have deep brain stimulation (DBS) implants represents a significant clinical issue. A major safety concern is the presence of burr holes and electrode anchoring devices in the skull, which may a ... Cite

Regional electric field induced by electroconvulsive therapy: a finite element simulation study.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2010 The goal of this study is to investigate the regional distribution of the electric field (E-field) strength induced by electroconvulsive therapy (ECT), and to contrast clinically relevant electrode configurations through finite element (FE) analysis. An FE ... Cite

Transcranial magnetic stimulation in the presence of deep brain stimulation implants: Induced electrode currents.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2010 The safety of transcranial magnetic stimulation (TMS) in patients with an implanted deep brain stimulation (DBS) systems has not been thoroughly investigated. One potential safety hazard is the induction of significant voltages in the subcutaneous leads in ... Cite

Electroconvulsive therapy stimulus parameters: rethinking dosage.

Journal Article J ECT · September 2010 Featured Publication In this article, we review the parameters that define the electroconvulsive therapy (ECT) electrical stimulus and discuss their biophysical roles. We also present the summary metrics of charge and energy that are conventionally used to describe the dose of ... Full text Link to item Cite

SYSTEMS AND METHODS FOR INDUCING ELECTRIC FIELD PULSES IN A BODY ORGAN

Journal Article · 2010 Systems and methods for providing controllable pulse parameter magnetic stimulation are described. One aspect is directed to a magnetic stimulation system for inducing approximately rectangular electric field pulses in a body organ, comprising an electrica ... Cite

SYSTEMS AND METHODS FOR INDUCING ELECTRIC FIELD PULSES IN A BODY ORGAN

Journal Article · 2010 Systems and methods for providing controllable pulse parameter magnetic stimulation are described. One aspect is directed to a magnetic stimulation system for inducing approximately rectangular electric field pulses in a body organ, comprising an electrica ... Cite

METHODS, APPARATUS AND SYSTEMS FOR MAGNETICS STIMULATION

Journal Article · 2010 A coil suitable for tissue stimulation and especially for transcranial magnetic stimulation (TMS) may be used in conjunction with a pulse generator to induce electric field in the brain with less attenuation in depth compared to existing TMS coils. In an e ... Cite

SYSTEMS AND METHODS FOR INDUCING ELECTRIC FIELD PULSES IN A BODY ORGAN

Journal Article · 2010 Systems and methods for providing controllable pulse parameter magnetic stimulation are described. One aspect is directed to a magnetic stimulation system for inducing approximately rectangular electric field pulses in a body organ, comprising an electrica ... Cite

Transcranial magnetic stimulation in the presence of deep brain stimulation implants: Induced electrode currents.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2010 The safety of transcranial magnetic stimulation (TMS) in patients with an implanted deep brain stimulation (DBS) systems has not been thoroughly investigated. One potential safety hazard is the induction of significant voltages in the subcutaneous leads in ... Full text Link to item Cite

Repetitive transcranial magnetic stimulator with controllable pulse parameters (cTMS).

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2010 We describe a novel transcranial magnetic stimulation (TMS) device that uses a circuit topology incorporating two energy-storage capacitors and two insulated-gate bipolar transistors (IGBTs) to generate near-rectangular electric field E-field) pulses with ... Full text Link to item Cite

Electroconvulsive therapy in the presence of deep brain stimulation implants: electric field effects.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2010 The safety of electroconvulsive therapy (ECT) in patients who have deep brain stimulation (DBS) implants represents a significant clinical issue. A major safety concern is the presence of burr holes and electrode anchoring devices in the skull, which may a ... Full text Link to item Cite

Regional electric field induced by electroconvulsive therapy: a finite element simulation study.

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2010 The goal of this study is to investigate the regional distribution of the electric field (E-field) strength induced by electroconvulsive therapy (ECT), and to contrast clinically relevant electrode configurations through finite element (FE) analysis. An FE ... Full text Link to item Cite

Electroconvulsive therapy in the presence of deep brain stimulation implants: electric field effects.

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · 2010 Cite

Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research.

Journal Article Clin Neurophysiol · December 2009 This article is based on a consensus conference, which took place in Certosa di Pontignano, Siena (Italy) on March 7-9, 2008, intended to update the previous safety guidelines for the application of transcranial magnetic stimulation (TMS) in research and c ... Full text Link to item Cite

Effect of anatomical variability on neural stimulation strength and focality in electroconvulsive therapy (ECT) and magnetic seizure therapy (MST).

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2009 We present a quantitative comparison of two metrics-neural stimulation strength and focality-in electrocon-vulsive therapy (ECT) and magnetic seizure therapy (MST) using finite-element method (FEM) simulation in a spherical head model. Five stimulation mod ... Cite

Introduction to electrotherapy technology

Journal Article Journal of Pain Management · December 1, 2009 Electrotherapy involves electric or magnetic stimulation of the human body in a range of therapeutic applications including pain alleviation. A wide spectrum of electrotherapy paradigms have been deployed in pain treatment, illustrating the inherent flexib ... Cite

Focal electrically administered seizure therapy: a novel form of ECT illustrates the roles of current directionality, polarity, and electrode configuration in seizure induction.

Journal Article Neuropsychopharmacology · July 2009 Electroconvulsive therapy (ECT) is a mainstay in the treatment of severe, medication-resistant depression. The antidepressant efficacy and cognitive side effects of ECT are influenced by the position of the electrodes on the head and by the degree to which ... Full text Link to item Cite

Consensus: New methodologies for brain stimulation.

Journal Article Brain Stimul · January 2009 We briefly summarized several new stimulation techniques. There are many new methods of human brain stimulation, including modification of already known methods and brand-new methods. In this article, we focused on theta burst stimulation (TBS), repetitive ... Full text Link to item Cite

Effect of anatomical variability on neural stimulation strength and focality in electroconvulsive therapy (ECT) and magnetic seizure therapy (MST).

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2009 We present a quantitative comparison of two metrics-neural stimulation strength and focality-in electrocon-vulsive therapy (ECT) and magnetic seizure therapy (MST) using finite-element method (FEM) simulation in a spherical head model. Five stimulation mod ... Full text Link to item Cite

Coil design considerations for deep-brain transcranial magnetic stimulation (dTMS).

Journal Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference · December 1, 2008 Deep-brain transcranial magnetic stimulation (dTMS) could provide new, non-invasive therapeutic options for various psychiatric and neurological disorders. Figures of merit (FoMs) are proposed to evaluate and compare dTMS coil designs. These FoMs character ... Cite

A transcranial magnetic stimulator inducing near-rectangular pulses with controllable pulse width (cTMS).

Journal Article IEEE Trans Biomed Eng · January 2008 Featured Publication A novel transcranial magnetic stimulation (TMS) device with controllable pulse width (PW) and near-rectangular pulse shape (cTMS) is described. The cTMS device uses an insulated gate bipolar transistor (IGBT) with appropriate snubbers to switch coil curren ... Full text Link to item Cite

Coil design considerations for deep-brain transcranial magnetic stimulation (dTMS).

Journal Article Annu Int Conf IEEE Eng Med Biol Soc · 2008 Deep-brain transcranial magnetic stimulation (dTMS) could provide new, non-invasive therapeutic options for various psychiatric and neurological disorders. Figures of merit (FoMs) are proposed to evaluate and compare dTMS coil designs. These FoMs character ... Full text Link to item Cite

Magnetic seizure therapy for the treatment of depression

Journal Article Advances in Biological Psychiatry · December 1, 2007 Cognitive side effects limit the clinical utility of electroconvulsive therapy (ECT), the most effective and rapidly acting treatment for severe depression. Studies suggest that prefrontal cortical involvement may be important to preserving the efficacy of ... Full text Cite

SYSTEMS AND METHODS FOR INDUCING ELECTRIC FIELD PULSES IN A BODY ORGAN

Journal Article · 2007 Systems and methods for providing controllable pulse parameter magnetic stimulation are described. One aspect is directed to a magnetic stimulation system for inducing approximately rectangular electric field pulses in a body organ, comprising an electrica ... Cite

Digital multimode buck converter control with loss-minimizing synchronous rectifier adaptation

Journal Article IEEE Transactions on Power Electronics · November 1, 2006 This paper develops a multimode control strategy which allows for efficient operation of the buck converter over a wide load range. A method for control of synchronous rectifiers as a direct function of the load current is introduced [1]. The function rela ... Full text Cite

Load-line regulation with estimated load-current feedforward: Application to microprocessor voltage regulators

Journal Article IEEE Transactions on Power Electronics · November 1, 2006 A consistent framework for load-line regulation design is presented, applicable to microprocessor voltage regulators (VRs) using either electrolytic or ceramic output capacitors. With conventional feedback control, the loop bandwidth is limited by stabilit ... Full text Cite

A 4-μA quiescent-current dual-mode digitally controlled buck converter IC for cellular phone applications

Journal Article IEEE Journal of Solid-State Circuits · December 1, 2004 This paper describes a dual-mode digitally controlled buck converter IC for cellular phone applications. An architecture employing internal power management is introduced to ensure voltage compatibility between a single-cell lithium-ion battery voltage and ... Full text Cite

Digital loss-minimizing multi-mode synchronous buck converter control

Journal Article PESC Record - IEEE Annual Power Electronics Specialists Conference · November 29, 2004 A multi-mode control strategy for a synchronous buck converter operating over a wide load range, is presented. For heavy loads, the converter runs in fixed-frequency continuous conduction mode (CCM). At light loads, it enters discontinuous conduction mode ... Full text Cite

Design of ceramic-capacitor VRM's with estimated load current feedforward

Journal Article PESC Record - IEEE Annual Power Electronics Specialists Conference · November 29, 2004 For voltage regulator module (VRM) designs with ceramic output capacitors, the capacitor size has to be chosen sufficiently large to allow for the use of relatively large inductor values. This enables operation at conventional switching frequencies, while ... Full text Cite

A 4μA-quiescent-current dual-mode buck converter IC for cellular phone applications

Journal Article Digest of Technical Papers - IEEE International Solid-State Circuits Conference · June 2, 2004 This digitally-controlled buck converter IC occupies 2mm 2 active area in 0.25μm CMOS, and the quiescent current is 4μA representing more than a 3-fold improvement over the leading state-of-the-art analog approach. As a result, cellular phone standby time ... Cite

An ultra-low-power digitally-controlled buck converter IC for cellular phone applications

Journal Article Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC · January 1, 2004 This paper describes a dual-mode digitally-controlled buck converter IC for cellular phone applications. An architecture employing internal power management is introduced to ensure voltage compatibility between a single-cell lithium-ion battery voltage and ... Full text Cite

Quantization resolution and limit cycling in digitally controlled PWM converters

Journal Article IEEE Transactions on Power Electronics · 2003 Featured Publication This paper discusses the presence of steady-state limit cycles in digitally controlled pulse-width modulation (PWM) converters, and suggests conditions on the control law and the quantization resolution for their elimination. It then introduces single-phas ... Full text Cite

Architecture and IC implementation of a digital VRM controller

Journal Article IEEE Transactions on Power Electronics · January 1, 2003 This paper develops the architecture of a digital PWM controller for application in multiphase voltage regulation modules (VRMs). In this context, passive current sharing and VRM transient response with nonzero controller delay are analyzed. A scheme for s ... Full text Cite

Low conversion ratio VRM design

Journal Article PESC Record - IEEE Annual Power Electronics Specialists Conference · January 1, 2002 This paper discusses the design considerations for low conversion ratio voltage regulation modules (VRM's) for the next generation of microprocessors, focusing on the handling of large, high-slew-rate current transients. A converter topology which deploys ... Cite

Quantization resolution and limit cycling in digitally controlled PWM converters

Journal Article PESC Record - IEEE Annual Power Electronics Specialists Conference · October 22, 2001 This paper discusses the presence of steady-state limit cycles in digitally controlled pulse-width modulation (PWM) converters, and suggests conditions on the control law and the quantization resolution for their elimination. It then introduces single-phas ... Full text Cite

Architecture and IC implementation of a digital VRM controller

Journal Article PESC Record - IEEE Annual Power Electronics Specialists Conference · January 1, 2001 This paper develops the architecture of a digital PWM controller for application in multi-phase voltage regulation modules (VRM's) with passive current sharing. In this context, passive current sharing and VRM transient response are analyzed. A scheme for ... Cite

A 4pA-quiescent-current dual-mode buck converter IC for cellular phone applications

Conference 2004 IEEE International Solid-State Circuits Conference (IEEE Cat. No.04CH37519) Full text Cite

Systems and Devices for Quiet Transcranial Magnetic Stimulaton and Method of Using Same

Other US 63/079,182 This invention discloses a magnetic stimulation coil (300) for magnetic stimulation in the brain and the peripheral nervous system with reduced sound emissions and a method for manufacturing such stimulation coil. The stimulation coil comprises at least on ... Open Access Cite