Real-Time Tracking of a 3D-Printed Smart Capsule Using on-Board Near-Infrared Led Array

Accurate sensing and drug delivery at designated locations within the GI-tract is needed to increase the performance and efficacy of smart capsules. In this work, we utilize the near infrared (NIR) penetration of light within the tissue for real-time tracking of a 3D-printed capsule. The capsule incorporates an array of three 875 nm NIR-LEDs powered by an on-board battery. Ex vivo experiments using porcine tissue and a paired photodiode receiver showed a light penetration depth of 6.2 cm. Three on-board batteries (1.5 V, 10 mAh) can provide enough power to continuously track the capsule in the small intestine for 2 hours, thus providing a good coverage of capsule positioning in the jejunum.