title: Continuous real-time photoacoustic demodulation via field programmable gate array for dynamic imaging of zebrafish cardiac cycle.
abstract: A four dimensional data set of the cardiac cycle of a zebrafish embryo was acquired using postacquisition synchronization of real time photoacoustic b-scans. Utilizing an off-axis photoacoustic microscopy (OA-PAM) setup, we have expanded upon our previous work with OA-PAM to develop a system that can sustain 100 kHz line rates while demodulating the bipolar photoacoustic signal in real-time. Real-time processing was accomplished by quadrature demodulation on a Field Programmable Gate Array (FPGA) in line with the signal digitizer. Simulated data acquisition verified the system is capable of real-time processing up to a line rate of 1 MHz. Galvanometer-scanning of the excitation laser inside the focus of the ultrasonic transducer enables real data acquisition of a 200 by 200 by 200 pixel, volumetric data set across a 2 millimeter field of view at a rate of 2.5 Hz.
authors.affiliation: Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, Texas A&M University, College Station, TX 7784, USA.
authors.forename: Scott P
authors.initials: SP
authors.lastname: Mattison
authors.forename: Ryan L
authors.initials: RL
authors.lastname: Shelton
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Maxson
authors.forename: Brian E
authors.initials: BE
authors.lastname: Applegate
keywords: (100.2000) Digital image processing; (110.5120) Photoacoustic imaging; (110.5125) Photoacoustics