Patent ID: 11857301
Assignee: VERILY LIFE SCIENCES LLC
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A device comprising:
a light source, wherein the light source is configured to emit a beam of coherent illumination into a portion of subsurface vasculature;
a light sensor, wherein the light sensor detects a pattern of constructive and destructive interference in light emitted from the portion of subsurface vasculature in response to the coherent illumination from the light source and outputs a detected light intensity waveform comprising a plurality of pulses corresponding to speckle events caused by motion of one or more individual particles in the subsurface vasculature, wherein each pulse in the plurality of pulses includes a respective rising edge, plateau, and falling edge; and
a controller coupled to the light source and the light sensor, wherein the controller comprises an analog frontend that processes the output of the light sensor, wherein the analog frontend comprises a differentiator configured to output a signal indicative of a rate of increase during a rising edge and/or a rate of decrease during a falling edge of each respective pulse, and wherein the controller (i) determines velocities of the one or more individual particles based on the output of the differentiator, and (ii) determines a flow property of fluid in the portion of subsurface vasculature based on the determined velocities of the one or more individual particles.