LASER DOPPLER FLOWMETRY - MEASUREMENTS IN A LAYERED PERFUSION MODEL AND MONTE-CARLO SIMULATIONS OF MEASUREMENTS

Fluid flow in a flow model was measured with a laser Doppler flowmeter normally used for tissue perfusion measurements. The flow parameter is deduced from the first moment of the spectral power density of intensity fluctuations at a detector viewing the model, which is illuminated by a laser. The model consisted of layers, filled with liquid, containing scattering particles, at different distances to the optics of the flowmeter. To each of the layers a flow can be applied. The configuration of the optical components could be varied, which resulted in an adjustable relative sensitivity for the flow in the different layers. Here, the feasibility of depth-dependent flowmetry with the laser Doppler flowmeter is shown experimentally. The measurements in the flow model were simulated with Monte Carlo calculations. The results indicate that these calculations may be of help to interpret experimentally obtained flow results.