Computerized measurement of Doppler flow velocity waveforms: validation of a new system

Manual measurement of Doppler flow velocity waveforms is time-consuming and carries unavoidable and significant intraobserver and interobserver variability. Those drawbacks limit the routine use of Doppler-derived indexes of systolic and diastolic function. This report describes a system that performs automatically all relevant measurements currently obtained from mitral, tricuspid, aortic, and pulmonary waveforms. One hundred and sixty waveforms, obtained from patients whose ages ranged from a 19-week fetus to a 21-year-old adult, were measured both manually and automatically. High correlations were found for all types of measurement: r = 0.993 for velocity measurements, r = 0.995 for time interval measurements, r = 0.881 for acceleration measurements, r = 0.867 for pressure half-time measurements, and r = 0.993 for flow integral measurements. When compared with manual measurements, automatized measurements displayed significantly lower intraobserver and interobserver variabilities for all types of measurements. Finally, the automatized measurement system cuts the time spent by a factor of more than five. Such a system of computerized measurements of Doppler flow velocity waveforms should become increasingly valuable as both a clinical and a research tool.