Multiple Exposure Time Based Laser Speckle ...

The applicability of multiple exposure time based LASCA was demonstrated on skin blood perfusion monitoring. The method was compared to ?-corrected and non-corrected single exposure time measurements while the data simultaneously recorded by a laser Doppler system were used as reference. The skin of the forearm was illuminated with the light of an 808 nm laser diode. Speckle images were recorded in the exposure time range of 1-100 ms and relative perfusion changes caused by ischemia were determined. The results showed an obvious nonlinear relationship between the data of the non-corrected single exposure time LASCA method and the laser Doppler system, while a good linearity was observed for the multiple exposure time method with a correlation factor of 0.83.