High speed laser Doppler perfusion imaging system e.g. blood flow imaging system, detects laser Doppler signal and/or laser speckle signal from light reflected from selected blood vessel area, to obtain flow data
An instrument for high-speed laser perfusion imaging comprises a laser source, a detector, a signal-processing unit, data memory, and a screen to display the results. A section of the sample surface is illuminated with laser light; the reemitted light from the irradiated surface is collected by the focusing optics on a 2D array of integrating photo detectors. The elements of the 2D array can be accessed individually or in a pre-defined selection of pixels at high speed. This 2D array of random-pixel-access integrating photo detectors (for example an integrating CMOS image senor) is utilized to measure the intensity variations at each individual pixel. The average amplitude and the mean frequency of the measured signal contain information about concentration and speed of moving blood cells. For real-time imaging, the exposure time is used as a parameter to measure relative perfusion changes. These data are stored in a memory and processed with a signal-processing unit. The instrument delivers 2D flow maps of the illuminated sample section. In parallel a conventional image of the sample can be obtained with the same 2D array of photo detectors allowing a simple overlay between a conventional image and processed flow maps. The instrument enables objective high-speed tissue perfusion imaging and real-time perfusion monitoring.