Arbitrary waveform constant current stimulator for long-term wearable applications

Paul P Breen; Jorge M Serrador; Gaetano D Gargiulo

doi:10.1016/j.medengphy.2019.04.001

Arbitrary waveform constant current stimulator for long-term wearable applications

Med Eng Phys. 2019 Jun:68:108-115. doi: 10.1016/j.medengphy.2019.04.001. Epub 2019 Apr 16.

Authors

Paul P Breen¹, Jorge M Serrador², Gaetano D Gargiulo³

Affiliations

¹ The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Penrith, NSW, Australia; Translational Health Research Institute, Western Sydney University, Penrith, NSW, Australia. Electronic address: p.breen@westernsydney.edu.au.
² Department of Pharmacology, Physiology & Neuroscience, Rutgers Biomedical and Health Sciences, Newark, NJ, USA; National University of Ireland Galway, Galway, Ireland; Department of Veteran Affairs, NJ Health Care System, War Related Illness & Injury Study Center, East Orange, NJ, USA. Electronic address: serradjo@njms.rutgers.edu.
³ The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Penrith, NSW, Australia; Translational Health Research Institute, Western Sydney University, Penrith, NSW, Australia. Electronic address: g.gargiulo@westernsydney.edu.au.

PMID: 31003910
DOI: 10.1016/j.medengphy.2019.04.001

Abstract

Subsensory electrical noise stimulation has been shown to improve sensory perception in humans. However, the majority of this work has been limited to the laboratory due to unavailability of portable body-worn stimulators. In this paper, we present a robust and reliable stimulator, engineered for wearable applications and designed to extend modulation of human sensory perception outside the physiology laboratory. The stimulator provides an arbitrary waveform constant current stimulation, offering continuous current stimulation up to ±5 mA with a voltage compliance of ±25 V (expandable up to 70 V). A graphical user interface allows setting of stimulus parameters within fixed ranges via a USB connected computer. The interface is very simple using a single power switch and a single multi-coloured LED for device feedback. The applied stimulus voltage and current are continually monitored and used to detect short circuit, high impedance conditions. These conditions, and other errors e.g. low battery state, put the device in a safe state with the user disconnected via a relay. All captured data, including accelerometer data, is logged to a removable SD card. Powered by an interchangeable, Li-Ion battery pack >4 h stimulation is achievable. The full circuit, system software and bench tests performed are presented.

Keywords: Constant current stimulation; Neural facilitation; Stochastic resonance.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Electric Power Supplies
Electric Stimulation / instrumentation*
Equipment Design
Sensation / physiology
Time Factors
User-Computer Interface
Wearable Electronic Devices*