A signal-processing system for real-time ultrasonic measurement of urine flow parameters

An application of a signal-processing system to the urethra is described which allows for real-time measurement of the average velocity of the urine at a particular location along the urethra during voiding through measurement of the average frequency in ultrasonic return from scatterers in the flowing urine. In addition, this comparatively simple system provides, without additional instrumentation, the relative urethral cross-sectional area at this location and the relative urine flow rate as functions of time throughout the voiding period. Tests indicate its potential as a valuable transcutaneous diagnostic aid in the detection, study, and treatment of various disorders and diseases of the lower urinary system. The key element of the system is a circuit having a voltage transfer function magnitude proportional to the square root frequency.