Stimulation Efficiency With Decaying Exponential Waveforms in a Wirelessly Powered Switched-Capacitor Discharge Stimulation System.

Lee, Hyung-Min

Howell, Bryan

Grill, Warren M

Ghovanloo, Maysam

2021-09-28T18:46:29Z

2021-09-28T18:46:29Z

2018-05

2021-09-28T18:46:28Z

The purpose of this study was to test the feasibility of using a switched-capacitor discharge stimulation (SCDS) system for electrical stimulation, and, subsequently, determine the overall energy saved compared to a conventional stimulator. We have constructed a computational model by pairing an image-based volume conductor model of the cat head with cable models of corticospinal tract (CST) axons and quantified the theoretical stimulation efficiency of rectangular and decaying exponential waveforms, produced by conventional and SCDS systems, respectively. Subsequently, the model predictions were tested in vivo by activating axons in the posterior internal capsule and recording evoked electromyography (EMG) in the contralateral upper arm muscles. Compared to rectangular waveforms, decaying exponential waveforms with time constants >500 μs were predicted to require 2%-4% less stimulus energy to activate directly models of CST axons and 0.4%-2% less stimulus energy to evoke EMG activity in vivo. Using the calculated wireless input energy of the stimulation system and the measured stimulus energies required to evoke EMG activity, we predict that an SCDS implantable pulse generator (IPG) will require 40% less input energy than a conventional IPG to activate target neural elements. A wireless SCDS IPG that is more energy efficient than a conventional IPG will reduce the size of an implant, require that less wireless energy be transmitted through the skin, and extend the lifetime of the battery in the external power transmitter.

0018-9294

1558-2531

https://hdl.handle.net/10161/23849

eng

Institute of Electrical and Electronics Engineers (IEEE)

IEEE transactions on bio-medical engineering

10.1109/tbme.2017.2741107

Head

Muscle, Skeletal

Brain

Forelimb

Animals

Cats

Electromyography

Deep Brain Stimulation

Equipment Design

Electrodes, Implanted

Models, Neurological

Signal Processing, Computer-Assisted

Male

Wireless Technology

Stimulation Efficiency With Decaying Exponential Waveforms in a Wirelessly Powered Switched-Capacitor Discharge Stimulation System.

Journal article

Howell, Bryan|0000-0002-3329-8478

1095

1106

5

Pratt School of Engineering

Biomedical Engineering

Electrical and Computer Engineering

Neurobiology

Duke Science & Society

Duke Institute for Brain Sciences

Neurosurgery

Duke

Basic Science Departments

School of Medicine

Initiatives

Institutes and Provost's Academic Units

University Institutes and Centers

Clinical Science Departments

Published

65