Photoacoustic Doppler flowmetry of whole blood by pulsed laser

In order to measure the flow velocity of whole blood in vessel mimicking tube inside optically scattering media, a 1064nm pulsed laser with the repetition rate of 10Hz was used as a pumping source to generate photoacoustic doppler signal. A 75MHz spherical focus ultrasound transducer was used to collect time-domain photoacoustic doppler signal successively. The flow velocity of whole blood was calculated by time-domain correlation algorithm. The whole blood was driven by a syringe pump. The measured velocity linearly changed in 0.5,1.0,1.5mm/s, respectively. The experimental results demonstrated the feasibility of using pulsed laser and time-domain correlation algorithm in the flowmetry of whole blood with low flowing velocity inside optically scattering media. © 2012 IEEE