Ultrasonic error compensation method to correct instrumental and systematic errors in volumetric flow measurements: a...

A computational model has been developed to observe the effects of several instrumental parameters and systematic error sources on ultrasonic volumetric flow measurements in vessels using an error compensation method proposed previously by the authors. The effects of two essential instrumental parameters, the gate length and pulse duration, on two intermediate flow results and an optimal correction factor as a function of the beam width-to-vessel diameter ratio (BWR) have been studied under steady flow conditions. The corrected flow results under typical combinations of those parameters show that by proper selection of a correction factor, the proposed method can compensate for those systematic errors. If the estimated BWR is within +/- 0.1 of the actual BWR value, the systematic error can be limited to within 6.5%. The study also shows that the compensation method can effectively reduce the errors caused by other systematic error sources such as the system sensitivity and high-pass filter function, as well as misalignment of the ultrasound beam from the center of the vessel.