A Microcomputer-Based Real-Time System for Measurement and Analysis of Umbilical Flow Velocity Waveforms Obtained by Doppler Ultrasound

ABSTRACT

A microcomputer-based system for real-time acquisition and analysis of umbilical arterial blood flow velocity waveforms is described. The spatial peak umbilical flow velocity is transduced by a pulsed Doppler flowmeter and digitized by the microcomputer. The computer allows for coherent averaging of flow velocity over several heart cycles in order to minimize noise that is uncorrelated with the fetal heart beats. In addition, it can compute flow velocity indices that do not require knowledge of the angle of beam incidence or umbilical arterial cross-sectional area. The averaged waveform as well as the computed indices may be displayed in real time. Further, these results may be saved on disk along with other relevant clinical information to be subsequently merged into a relational data base covering all patients monitored. Not only does the system facilitate accurate measurement of umbilical flow velocity waveforms, but the relational data base may also be used to evaluate the clinical significance of these measurements in a patient population.