The optimum frequency and angle of insonation for a Doppler ultrasonic flow velocity meter

A simple model is used to indicate the optimum ultrasonic frequency and angle of insonation for Doppler studies on vessels at different depths in the body. The criterion taken in determining this optimum frequency is the minimum error in a mean or root mean square frequency meter. The analysis shows that theoretically there is an optimum angle and frequency that depends on the depth of the vessel being examined, and that the optimum frequency is much lower than that normally used.