A fully integrated multisite pressure sensor for wireless arterial flow characterization

This paper presents a fully integrated battery-free sensing system that uses a two-site wireless pressure measurement for the detection of arterial stenosis. The remotely powered system uses a backscatter-modulated passive-telemetry interface and transmits sensor as well as reference information to an external system. The monolithic process used to realize the system integrates a 3 /spl mu/m BiCMOS circuit with silicon-on-glass absolute pressure sensors and an on-chip antenna. The wireless sensor interface consumes 340 /spl mu/W and uses capacitance-to-frequency conversion for readout of the vacuum-sealed pressure transducers. The integrated device has a 200 /spl mu/m profile and a volume of 2 mm/sup 3/. The system can sense a reduction in flow of 13%, corresponding to a differential pressure of 3 mmHg.