Methods and Techniques for Closed-Loop Gastrointestinal Pacing

Gastrointestinal slow waves are rhythmic electrical events that contribute to the coordination of motility. Functional motility disorders such as gastroparesis are linked to abnormal slow wave activity, and current treatments do not target the underlying electrical dysfunction. Gastrointestinal electrical pacing restores normal rhythms, but open-loop pacing lacks adaptation to underlying slow wave activity, leading to reduced energy efficiency and potential overstimulation.

A novel closed-loop pacing system was developed to detect gastric and intestinal slow waves and dynamically pace in response to the underlying rhythm. High-resolution electrode arrays were placed on the serosal surface of anesthetized pigs for simultaneous pacing and mapping. The control strategy comprised two steps: (i) continuous detection and classification of slow waves as normal rhythm (stomach: 15-25 s; small intestine: 3-5 s) or abnormal rhythm; and (ii) pacing delivery and entrainment assessment, with pulses (100-400 ms, 3-8 mA) triggered by abnormal rhythms or failed entrainment.

Detection of slow wave events achieved an accuracy of 78% for both the stomach and the small intestine. Entrainment detection yielded an accuracy of 73% for the stomach and 67% for the small intestine. Closed-loop pacing successfully restored abnormal gastric and small intestinal slow wave periods to normal physiological ranges and reduced the number of pulses delivered by 60% compared to open-loop pacing.

Closed-loop pacing significantly reduced pulse delivery, demonstrating the feasibility of a targeted, adaptive approach that may reduce pacing burden, although effects on motility and gastric emptying warrant further investigation.