On-Chip Analysis of Gastric Slow Waves: Toward a Closed-Loop System for Managing Gastrointestinal Disorders

This paper aims to develop and validate a closed-loop system that can wirelessly acquire gastric electrical activity, called slow waves, from multiple channels, and deliver electrical stimulation pulses automatically to modulate the slow-wave activity in the presence of abnormality. The system utilizes a front-end unit and a stationary back-end unit connected to a computer. A 32-channel recording module and a 32-channel simulating module comprise the front-end unit. Both the front-end and back-end units were developed using commercial off-the-shelf components. A graphical user interface (GUI) was designed to process and display the recorded data in real-time and store the data for offline analysis. The gain of the analog conditioning circuit, the range of the optimal slow wave frequency, as well as the stimulation pulse configuration, are also programmable directly through the GUI. The GUI can be used to configure the system to either manually deliver stimulation or to automatically deliver stimulation when a signal is detected outside the optimal slow wave frequency. The system was successfully validated on a benchtop setting. The system was able to detect slow-wave abnormal frequencies on-chip and apply stimulation commands automatically. The system can be used for treating functional gastrointestinal disorders in the future.