A Configurable Portable System for Ambulatory Monitoring of Gastric Bioelectrical Activity and Delivering Electrical Stimulation

The purpose of this paper is to develop and validate a configurable system that can wirelessly acquire gastric electrical activity called slow waves, and deliver high energy electrical pulses to modulate its activity. The system is composed of a front-end unit, and an external stationary backend unit that is connected to a computer. The front-end unit contains a recording module with four channels, and a stimulating module with two channels. Commercial off-theshelf components were used to develop front- and back-end units. A graphical user interface (GUI) was designed in LabVIEW to process and display the recorded data in realtime, and store the data for off-line analysis. Besides, the gain of the analog conditioning circuit as well as the stimulation pulse configuration is programmable directly through the GUI. The system was successfully validated on bench top. The benchtop studies showed an appropriate frequency response for analog conditioning and digitization resolution to acquire gastric slow waves. Moreover, the system was able to deliver electrical pulses at amplitudes up to ±24 mA and ±12 mA to a load of up to 0.5 k $\Omega $ and 1 $\textbf{k}\Omega $, respectively. This study reports the first high-energy stimulator that can be controlled wirelessly and integrated into a gastric bioelectrical activity monitoring system. The system can be used for treating functional gastrointestinal disorders.