PC-integrated laser Do

摘要

Abstract: For a quantitative calculation of a flow spectrum from the Doppler frequencies the velocity-, the irradiation- and scattering-directions must be well known. With the assumption of a random distribution of the velocity and irradiation a realistic flow spectrum can be calculated. Furthermore the flow spectrum depends of the scattering phase function of the moving particles. A flow meter was developed, consisting of a PC and a control card for two Doppler sensors to be fixed on skin. A Pascal program shows the flows on the display with resolution in time greater than 150 Hz. Four different flow domains can be shown simultaneously and the frequency span can be set independently. Flows corresponding to low and high Doppler frequencies are different and provide the possibility to distinguish between the flow in the micro-capillaries and larger vessels. !10