Laser Speckle Contrast Blood Flow Imaging System Based On Scanning Line Beam Illumination

Traditional laser speckle contrast imaging technique use wide-field illumination; mostof the detected photons are reflected from the surface of the tissue, which thereby limited theimaging depth. Recently a lateral laser speckle contrast analysis method was proposed. Itused local illumination improving the portion of multi scattering photons and succeeds inimproving the detecting depth. Nevertheless, it uses stepping motor to scan and processesdata offline, which make it not capable for real-time monitor.Here, based on the method above, we design a scanning laser speckle contrast imagingsystem, achieving real-time imaging and processing while improving the imaging depth oflaser speckle contrast imaging. The main content of the thesis includes:Aim at fast scanning requirement, using galvanometer instead of stepping motor toimprove the scanning speed. Galvanometer type is6240H, which can be used for broadbeam scanning as large as25mm; the small angel step time is350μs. Use cylindrical lens tosharp the laser to a slim beam, width of which is90μm. Use high speed EthernetCCD(Charge Coupled Device) camera to capture raw data: TXG03mono CCD supportingGigE Vision standard, and can be control using IMAQdx general driving software. Imagingspeed is90FPS(max), and pixel depth is12bit.Aim at real-time imaging acquiring and processing requirement, designing softwarebased on LabVIEW development platform, which can control galvanometer and CCDcamera, succeed in continuous scanning and image acquiring. Using CUDA to process rawimage data by call Library Function Node in LabVIEW，achieving image acquiring andprocess parallelly.Last, we use phantom/animal experiment to verify the system, and analysis the systemperformance.