Measurement of Pulsatile Blood Flow Velocity in Microvessels from Single Photometric Detector

A method for the in vivo detection of pulsatile blood velocity in transilluminated microvessels using data contained in single photometric signals is described. The system design is based on the assumption that pulsatile velocity information is contained in frequency- modulated components of the photometric signal spectrum. Results are in agreement with a previously reported cross-correlation technique utilized to measure the time delay between signals from upstream and downstream photodetectors aligned in the direction of flow.