Laser doppler flowmeter and vascular diseases

The laser Doppler Flowmeter (LDF) is designed for the measurement of blood flow in superficial tissues. Many difficulties were so far encountered in such hemodynamic assessments. Doppler effect principle is used here. Microcirculatory geometry and hemodynamics do not allow the use of ultrasound velocimetry. A laser beam is thus used. All moving elements located in a half sphere of 1mm radius below skin surface are actively taken into account in the LDF signal. We used this technique for various purposes o Skin blood flow result reproductibility is 80 % and varies following environmental conditions. The factors leading to an increase of skin blood flow are: heat, hyperventilation, aneasthesia, sympathectomy, vasoactive drugs. Those entailing flow decrease are cold, respiratory maneuvres, emotion, tobacco smoke, upright position, ischemic disorders. We set up a LDF / Raynaud protocole in order to forecast the efficiency of the medical treatment. LDF has become an easy method for the measurement of skin blood flow.