A pressure/oxygen/temperature sensing SoC for multimodality intracranial neuromonitoring

Abstract

A fully integrated SoC for multimodality intracranial neuromonitoring is presented. This SoC includes a capacitive MEMS pressure sensor, an electrochemical oxygen sensor, a solid-state temperature sensor and sensor interface circuits in a single chip. Chopper stabilization and dynamic element matching techniques are applied in sensor interface circuits to reduce circuit noise and offset. On-chip calibration is implemented for each sensor to compensate process variations. Measured accuracies of the pressure, oxygen, and temperature sensors are ±1 mmHg, ±1 mmHg, and ±0.2 oC, respectively. Implemented in 0.18-μm CMOS, the SoC occupies an area of 1.4 mm × 4mm and consumes 188-μW DC power.