Design and development of laser Doppler velocimetry based on DSP technique for blood flow measurement

A graphic user interface and real-time laser Doppler velocimeter (LDV) based on the digital signal processor (DSP) had been designed and developed. The hardware setup included the Michelson inteferrrometer optics, photo-detector, current to voltage converter, AC amplifer and filtering circuits, as well as a DSP module. The software system on the Dsp module was also developed to access data and to perform the moment weighting algorithms. In addition, the processed data was transmitted to the personal computer and advanced analysis could be achieved. The velocity measurement using developed LDV device was calibrated by a mirror mounted on a linear vibrator. The outcomes presented high linearity and good accuracy. In vitro experiment employing this LDV system was also carried out. The results showed that the developed LDV instrument offered a flexible tool to investigate the blood flow of microcirculation system.