Laser Doppler Velocimetry Using Fiber Optics with Applications to Transparent Flow and Cardiovascular Circulation

120We present a new method of measuring the speed of fluid using laser Doppler velocimetry and a fiber optics. A 0.5-mm diameter plastic fiber optics inserted in the flow transmits both the incident light and collects the light scattered by the moving particles in the fluid. The spectrum of heterodyne beat between the scattered light and the local oscillator, which originates at the end of the fiber optics, are measured using photon correlation spectroscopy. We applied this technique to determining the velocity profile of a transparent flow in a glass tube and the average blood flow velocity both in a glass tube and in the femoral vein of a rabbit.