In human health, stable blood circulation is very important for transporting nutrition, maintaining the temperature, and preserving cell-level metabolism. Diffuse speckle contrast analysis (DSCA) is in-vivo multi-channel blood flow measurement system with simple data analysis, flexibility, and fast measurement speed. This system estimates blood flow index (BFI) dependent on the correlation of speckle pattern caused by blood flow. 

  The laser fiber is coupled with a 1×4 coupler. Four optical fibers as detection channels are closely placed in front of the CCD chip in a CCD camera. The system performance is evaluated using a phantom which is similar to optical properties of human skin. As the flow velocity from a syringe pump increases, the BFI shows increasingly larger value. Also, the DSCA system is applied to blood flow measurement on both human arm and chick embryos. In human arm experiment, the protocol has three periods including baseline, cuff-occlusion, and release, controlled by a blood pressure meter. At different periods, the BFI dramatically decreases and increases corresponding to the blood flow. In the chick embryo experiment, the BFI is measured during incubation period of chick embryos. As the embryo develops, the BFI gradually increases. In addition, the DSCA could determine the vital sign of the embryos. In conclusion, the DSCA system could secure in-vivo measurement of blood flow in deep tissues.