A5016519698- Vagus Nerve Stimulation Research
- Neuroscience and Neural Engineering
- EEG and Brain-Computer Interfaces
- Neurological disorders and treatments
- Glioma Diagnosis and Treatment
- Heart Rate Variability and Autonomic Control
- Muscle activation and electromyography studies
- Barrier Structure and Function Studies
- Neurological Disease Mechanisms and Treatments
- Cancer Research and Treatments
- Peripheral Nerve Disorders
- Cardiac Arrhythmias and Treatments
- Pancreatic and Hepatic Oncology Research
- Neural dynamics and brain function
- Amoebic Infections and Treatments
- Neuroscience of respiration and sleep
- Neurological diseases and metabolism
- Nerve injury and regeneration
- Respiratory and Cough-Related Research
- Cardiac electrophysiology and arrhythmias
- Bone and Dental Protein Studies
- Immunotherapy and Immune Responses
- Photoreceptor and optogenetics research
- Meningioma and schwannoma management
- Advanced Neuroimaging Techniques and Applications
Duke University
2015-2025
Sun Pharma Advanced Research (India)
2024
Southern Plains Agricultural Research Center
2019-2020
National Research Council Institute for Biodiagnostics
2012-2013
National Research Council Canada
2013
Given current clinical interest in vagus nerve stimulation (VNS), there are surprisingly few studies characterizing the anatomy of large animal models as it pertains to on-and off-target engagement local fibers. We sought address this gap by evaluating vagal pig, whose organization and size approximates human nerve.
It is necessary to understand the morphology of vagus nerve (VN) design and deliver effective selective stimulation (VNS) because influences fiber responses electrical stimulation. Specifically, diameter (and thus, electrode-fiber distance), fascicle diameter, fascicular organization, perineurium thickness all significantly affect fibers signals delivered through a cuff electrode. We quantified cervical subdiaphragmatic VNs in humans, pigs, rats: number fascicles, diameters, proportions...
Electrical stimulation of the cervical vagus nerve using implanted electrodes (VNS) is FDA-approved for treatment drug-resistant epilepsy, treatment-resistant depression, and most recently, chronic ischemic stroke rehabilitation. However, VNS critically limited by unwanted nearby neck muscles-a result non-specific activating motor fibers within vagus. Prior studies suggested that precise placement small epineural can modify therapeutic effects, such as cardiac responses. it remains unclear...
Objective. There is growing interest in electrical neuromodulation of peripheral nerves, particularly autonomic to treat various diseases. Electrical signals the kilohertz frequency (KHF) range can produce different responses, including conduction block. For example, EnteroMedics' vBloc® therapy for obesity delivers 5 kHz stimulation block abdominal vagus but mechanisms action are unclear. Approach. We developed a two-part computational model, coupling 3D finite element model cuff electrode...
Abstract Objective Clinical data suggest that efficacious vagus nerve stimulation (VNS) is limited by side effects such as cough and dyspnea have thresholds lower than those for therapeutic outcomes. VNS are putatively caused activation of nearby muscles within the neck, via direct muscle or fibers innervating muscles. Our goal was to determine at which various VNS-evoked occur in domestic pig—an animal model with anatomy similar human—using bipolar helical lead deployed clinically. Approach...
Electrical stimulation and block of peripheral nerves hold great promise for treatment a range disease disorders, but promising results from preclinical studies often fail to translate successful clinical therapies. Differences in neural anatomy across species require different electrodes parameters achieve equivalent nerve responses, accounting the consequences these factors is difficult. We describe implementation, validation, application standardized, modular, scalable computational...
Abstract Objective. We demonstrated how automated simulations to characterize electrical nerve thresholds, a recently published open-source software for modeling stimulation of peripheral nerves, can be applied simulate accurately responses stimulation. Approach. simulated vagus (VNS) humans, pigs, and rats. informed our models using histology from sample-specific or representative device design features (i.e. cuff, waveform), material tissue conductivities, realistic fiber models. Main...
Background: Computational modeling provides an important toolset for designing and analyzing neural stimulation devices to treat neurological disorders diseases. Modeling enables efficient exploration of large parameter spaces, where preclinical clinical studies would be infeasible. Current commercial finite element method software packages enable straightforward calculation the potential distributions, but it is not always clear how implement boundary conditions appropriately represent...
Computational modeling is an important tool for developing and optimizing implantable neural stimulation devices, but requires accurate electrical geometrical parameter values to improve predictive value. We quantified the effects of perineurial (resistive sheath around each fascicle) endoneurial (within peripheral nerve stimulation.We implemented 3D finite element models compound nerves cuff electrodes quantify activation block thresholds model axons. also a 2D bundle axons estimate bulk...
Abstract Objective. Vagus nerve stimulation (VNS) is Food and Drug Administration-approved for epilepsy, depression, obesity, stroke rehabilitation; however, the morphological anatomy of vagus targeted by stimulatation poorly understood. Here, we used microCT to quantify fascicular structure neuroanatomy human cervical nerves (cVNs). Approach. We collected eight mid-cVN specimens from five fixed cadavers (three left nerves, right nerves). Analysis focused on ‘surgical window’: 5 cm length,...
ABSTRACT Background and Purpose Peripheral nerve stimulation is approved by the US Food Drug Administration for treating various disorders, but it often limited side effects, highlighting need a clear understanding of fascicular fiber organization to design selective therapies. Micro‐CT imaging contrast‐stained nerves enables visualization tissue microstructures, such as perineurium vasculature. In this work, we evaluated phosphotungstic acid (PTA) contrast agent assessed its compatibility...
Objective. There is growing interest in treating diseases by electrical stimulation and block of peripheral autonomic nerves, but a paucity studies on the excitation small-diameter axons. We conducted vivo quantification strength-duration properties, activity-dependent slowing (ADS), responses to kilohertz frequency (KHF) signals for rat vagus nerve (VN). Approach. acute experiments urethane-anaesthetized rats. placed two cuff electrodes left cervical VN one electrode anterior...
. In nerve stimulation therapies, fibers in larger fascicles generally have higher activation thresholds, but the mechanisms are not well understood. We implemented and analyzed computational models to uncover effects of morphological parameters on thresholds.
Background Peripheral nerve recordings can enhance the efficacy of neurostimulation therapies by providing a feedback signal to adjust stimulation settings for greater or reduced side effects. Computational models accelerate development interfaces with high signal-to-noise ratio and selective recording. However, validation tuning model outputs against in vivo remains computationally prohibitive due large number fibers nerve. Methods We designed implemented highly efficient modeling methods...
Background: Placement of the clinical vagus nerve stimulating cuff is a standard surgical procedure based on anatomical landmarks, with limited patient specificity in terms fascicular organization or vagal anatomy. As such, therapeutic effects are generally by unwanted side neck muscle contractions, demonstrated previous studies to result from stimulation (1) motor fibers near superior laryngeal and (2) within projecting recurrent laryngeal. Objective: Conventional non-invasive ultrasound,...
Reversible block of nerve conduction using kilohertz frequency electrical signals has substantial potential for treatment disease. However, the ability to fibers selectively is limited by poor understanding relationship between waveform parameters and that are blocked. Previous in vivo studies reported non-monotonic relationships signal threshold, suggesting fiber-selective block. mechanisms thresholds were unclear, these findings not replicated a subsequent study. We used high-fidelity...
Peripheral neuromodulation has emerged as a powerful modality for controlling physiological functions and treating variety of medical conditions including chronic pain organ dysfunction. The underlying complexity the nonlinear responses to electrical stimulation make it challenging design precise effective protocols. Computational models have thus become indispensable in advancing our understanding control neural stimulation. However, existing approaches suffer from computational...
Peripheral nerves are primarily composed of unmyelinated axons, and there is growing interest in electrical stimulation the autonomic nervous system to treat various diseases. We present first cable model an vagal nerve fiber compare its ion channel isoforms conduction responses with other published models establishing important tools for advancing modeling nerves.