Swallowable sensing device for long-term gastrointestinal tract monitoring

Abstract

This paper presents a swallowable sensor device that can be ingested orally, later arriving to the stomach, where the device can indwell for a long term and can be egested at any time after it is triggered using wireless communication. This device can inflate a silicone balloon in the gastrointestinal tract using a chemical reaction. The balloon can be deflated later using electrolysis of water at the time of egestion. A motorless chemical-reaction-based egestion method is proposed to minimize the sensor device size. This device can achieve long-term monitoring in the gastrointestinal tract.

Ingestible devices for long-term gastrointestinal residency: a review

“…Another method for achieving gastric residency is incorporating an inflatable balloon in the ingestible device [35][36][37][38][39]97]. The ingestible device with a balloon is first swallowed, and the balloon is inflated inside the stomach through a chemical reaction producing CO 2 for attaining gastric residency.…”

Ingestible Sensors and Sensing Systems for Minimally Invasive Diagnosis and Monitoring: The Next Frontier in Minimally Invasive Screening

“…The measured small intestine peristaltic contact pressure, contraction pressure, and propagation speed are of 0.29 kPa, 1.08 kPa, and 0.08–2 cm/s, respectively. − A preferable actuation design targeting the lower GI tract should have a small form factor and reduced power consumption or a passive mechanism. Commonly used actuators include precompressed springs − and flexures, , balloons, , and magnets. − …”

“…A gelatin plug is designed in the system which will liquefy at body temperature to expose an onboard sodium bicarbonate reservoir to gastric acid. Subsequently, an electrolysis reaction creates gas pressure that drives a needle into the silicone balloon causing it to deflate for a retrieval process . This work also used a flexible PCB to integrate a flexible antenna in the device, providing an innovative packaging technique suitable for the stringent system requirement.…”

“…79−83 A preferable actuation design targeting the lower GI tract should have a small form factor and reduced power consumption or a passive mechanism. Commonly used actuators include precompressed springs 84−87 and flexures, 88,89 balloons, 90,91 and magnets. 92−94 A key consideration from both an engineering and medical perspective are the materials requirements to meet both the specifications of the system as well as the stringent biocompatibility requirements for medical devices.…”

“…Subsequently, an electrolysis reaction creates gas pressure that drives a needle into the silicone balloon causing it to deflate for a retrieval process. 91 This work also used a flexible PCB to integrate a flexible antenna in the device, 143 providing an innovative packaging technique suitable for the stringent system requirement. Additional actuation devices/mechanisms have been incorporated in ingestible capsule systems, including the design of mechanical legs, the use of compressed air, and the application of an external magnetic field to steer the system.…”