Evaluation of different signal processing algorithms in Laser-Doppler perfusion measurements

The Laser-Doppler (LD) method is extensively used in clinical experiments for microcirculation measurement. The results of LD perfusion measurements depends on technical factors such as laser light wavelength, LD prob e arrangement, and signal processing algorithm. The aim of this study is to compare the output of various signal processing algorithms (LDP) with the use of digital spectral analysis of the photodetector current. Comparison is made with the output of a commercial LD instrument (LDF). The results obtained using a simple one-tube physical model confirm that the best linearity of response of the LD instrument for changes of flow velocity is given by the algorithm based on first moment of power spectral density of AC component of photodetector's signal.