Multi-Modal, Implantable Colon Activity Sensor.

Continuous monitoring of bowel activity during normal daily activities would improve clinical diagnostics and understanding the mechanisms underlying bowel function or help validate interventions that alter bowel function. This work describes a colon monitor to capture activity (ColoMOCA). The ColoMOCA included two pressure sensors, three impedance-sensing electrodes, and wireless battery recharge and data transmission circuitry. Components were integrated on a flexible printed circuit board, which was encapsulated in biocompatible silicone. Packaged ColoMOCAs were 8 mm in diameter and 85 mm long. ColoMOCAs continuously transmitted sensor data at 10 Hz at 30 cm range, and ran for 21 hours before wireless recharge. Acute in vivo testing in conscious pigs demonstrated ColoMOCA detected colon phasic contractions with comparable accuracy relative to wired manometry sensors. Implantations of 7 days were performed which demonstrated conscious, ambulatory monitoring of colonic behavior, including phasic stool impedance data suggesting motility detection.