Self-mixing laser-Doppler velocimetry of liquid flow and of blood perfusion in tissue

The velocimetry method of self-mixing, i.e., the feedback of Doppler-scattered light into the laser cavity, is used for the measurement of liquid flow and of blood perfusion in human tissue. The method is elucidated by the registration of the blood perfusion of a finger under repeated occlusion of the veins in the upper arm and with the velocity measurement of a liquid flow containing scattering particles.