Laser Doppler vibrometry sensors implemented in a silicon photonic integrated circuit for measuring cardiovascular signals on bare skin

Abstract

Laser Doppler vibrometer (LDV) sensors can measure skin vibrations originating from propagating superficial arterial pulse waves, which can be used to assess arterial stiffness and identify stenosis and heart failure. A key challenge is to get sufficient diffusely reflected power from bare skin in order to avoid the use of a retroreflective patch. Here we report a prototype, enabled by silicon photonics, that can directly measure the vibrations of bare human skin. We demonstrate a resolution better than 10 pm/sqrt(Hz) when the skin surface is placed at the focal plane of the sensing beams. This result holds great promise for the targeted cardiovascular applications.