title: Integration of Low-Power ASIC and MEMS Sensors for Monitoring Gastrointestinal Tract Using a Wireless Capsule System.
abstract: This paper presents a wireless capsule microsystem to detect and monitor the pH, pressure, and temperature of the gastrointestinal tract in real time. This research contributes to the integration of sensors (microfabricated capacitive pH, capacitive pressure, and resistive temperature sensors), frequency modulation and pulse width modulation based interface IC circuits, microcontroller, and transceiver with meandered conformal antenna for the development of a capsule system. The challenges associated with the system miniaturization, higher sensitivity and resolution of sensors, and lower power consumption of interface circuits are addressed. The layout, PCB design, and packaging of a miniaturized wireless capsule, having diameter of 13 mm and length of 28 mm, have successfully been implemented. A data receiver and recorder system is also designed to receive physiological data from the wireless capsule and to send it to a computer for real-time display and recording. Experiments are performed in vitro using a stomach model and minced pork as tissue simulating material. The real-time measurements also validate the suitability of sensors, interface circuits, and meandered antenna for wireless capsule applications.
authors.forename: Md Shamsul
authors.initials: MS
authors.lastname: Arefin
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Redoute
authors.forename: Mehmet Rasit
authors.initials: MR
authors.lastname: Yuce
mesh_terms: D000465:Algorithms; D001831:Body Temperature / Q000502:physiology; D004867:Equipment Design; D041981:Gastrointestinal Tract / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011312:Pressure; D012815:Signal Processing, Computer-Assisted; D059015:Wireless Technology / Q000295:instrumentation*