Abstract-This paper presents a SoC (System-on-aChip) dedicated for a single-chip smart capsule which can be used to continuously monitor human alimentary canal pH and temperature values. The SoC is composed of the pH and temperature sensor interface circuit, a wireless transceiver, the power management circuit and the flow control logic. Fabricated in 0.18 μm standard CMOS technology, the SoC occupies a die area of ~9 mm 2 . The SoC consumes 6.15 mW from a 3 V power supply, guaranteeing the smart capsule battery life is no less than 24 hours when using 50 mAh coin batteries. The experimental results show that measurement accuracy of the smart capsule is ±0.1 pH and ±0.2°C for pH and temperature sensing, respectively, which meets the requirement of in-body pH and temperature monitoring in clinical practice.

This paper presents a smart capsule for in body pH and temperature continuous monitoring in non-invasive gastrointestinal examination. The capsule offers 24-hour continuous monitoring with less discomfort compared with conventional diagnosis. The whole system consists of a smart capsule for pH value and temperature sensing, and a portable data logger. The sensing part of the smart capsule includes electrodes and a chip of analog-to-digital converter. The smart capsule inside the body and the data logger are connected wirelessly with a chip of short distance RF transceiver. Design details of the smart capsule with pH/temperature sensor, data converter, wireless transceiver, MCU will be provided throughout this paper.