title: Laser-scanning Doppler photoacoustic microscopy based on temporal correlation.
abstract: We present a methodology to measure absolute flow velocity using laser-scanning photoacoustic microscopy. To obtain the Doppler angle, the angle between ultrasonic detection axis and flow direction, we extracted the distances between the transducer and three adjacent scanning points along the flow and repeatedly applied the law of cosines. To measure flow velocity along the ultrasonic detection axis, we calculated the time shift between two consecutive photoacoustic waves at the same scanning point, then converted the time shift to velocity according to the sound velocity and time interval between two laser illuminations. We verified our method by imaging flow phantoms.
authors.affiliation: Department of Physics, Harbin Institute of Technology, 92 West Da-Zhi Street Nangang District, Harbin, Heilongjiang 150080, People's Republic of China ; Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Liu
authors.forename: Hao F
authors.initials: HF
authors.lastname: Zhang