Silicon ultrasonic microprobes with collocated and concurrent strain and bio-electrical potential wireless transmission

This paper reports on the first-ever integrated silicon microprobes for measuring strain and bio-electrical potentials wirelessly from the same location in biological tissue concurrently. Combining both modalities allows the study of coupled mechanical and electrical problems by simultaneous measurement. This can be useful for studying electrical and mechanical wave propagation in cardiac arrhythmias, which is the primary application in this paper. We demonstrate a sensitivity of 0.013 mV/μstrain for strain and have a 40 dB amplifying stage for electrical potential gain. The measured signals were transmitted using a FM modulating integrated ASIC radio at frequencies in the FM range 88-108 MHz. The action potential duration (APD) and diastolic interval (DI) were extracted from collected data.