Capsule tracking in the GI tract: A novel microcontroller based solution

Telemetry capsules that will provide facilities for on-site drug delivery and those that are capable of taking tissue/fluid samples within the human gastro-intestinal (GI) are quite invaluable for diagnosing GI related diseases where diagnosis can only be made by taking a biopsy from the intestinal walls. Such biopsies have traditionally been preformed using custom endoscopes. To be effective in the above named tasks, accurate knowledge of the location of telemetry capsules within the GI tract is a necessity. This paper presents a method of tracking a capsule inside the human GI tract based on the application of a microcontroller to control the generation and transmission of ultrasonic pulses. The capsule, i.e. object, and the central receiver are capable of transmit and receive functions, others are receive-only stations. This ensures the collection of a reliable round-trip time of flight (TOF) data. Application of triangulation to the TOF data facilitates the determination of the real-time positions of the object with less than 10% aggregate measurement error.