Detecting the flow velocity in the 2 mm2-cross-section vessel using multi-exposure speckle imaging

Multi-Exposure Speckle Imaging (MESI) is a method that obtains speckle images at different exposure durations and has the capability to predict the relative flow rate in the presence of static scatters and the camera noise. The MESI technique has been performed in relatively small vessels (80μm–300μm) before, such as the cerebrum, the retina and the skin. Here we firstly, to the best of our knowledge, detected the flow rate in a 2 mm² –cross-section vessel using the MESI method, whose size medically mimicked the artery coronary. The phantom experiment was conducted to measure the flow rate ranging from 1 mm/sec to 10 mm/sec and the linear response of the velocity measurements was determined. In addition, the coherent parameter β was separately computed by MESI and the laser speckle contrast imaging (LSCI) method. It turned out the coherent parameter β obtained by the former model was more accurate with taking the static noise into account. The experimental results found that the MESI technology is promising to be applied in the biomedical measurement of the blood flow in the coronary artery bypass grafting.