Laser Doppler blood flowmetry

Laser Doppler flowmetry is a method for continuous quantification of microvascular perfusion. During the measurements, low energy helium-neon laser light is applied to the tissue. Doppler shifted light reflected out of the tissue is then analyzed, and the shift of frequency quantitated. The output signal is proportional to the flux of blood cells in the measuring tissue of some few mm3. Laser Doppler flowmetry can easily be applied for measurements on skin and surgically exposed surfaces. Measurements can also be obtained through an endoscope. Measuring probes of diameter 0.5 mm can be introduced into tissues to quantitate microvascular perfusion within tissues. The article reviews the theory of laser Doppler flowmetry measurements, presents methodological aspects, and gives examples of clinical application. 20 refs., 4 figs