Use of a Precise and Portable Flow Standard to Improve the Accuracy of Medical and Scientific Laboratory Flow Measurements
Sixteenth Southern Biomedical Engineering Conference, Proceedings, 10, (1997)

J.C. CONTI , E.R. Strope, L.D. Spence

Dynatek Dalta Scientific Instruments, PO Box 254, Galena, MO 65656


There is an ever increasing utilization of high technology products in both the medical imaging laboratories as well as various industrial scientific and research laboratories aimed at accurately measuring the flow rate and velocity of liquids. The most obvious example of this is the use of Doppler ultrasound in non-invasive cardiovascular and vascular laboratories. A convenient flow standard that assures the accuracy of a particular patient's flow and velocity information would allow physicians to track patients over long periods of time. This would improve the chances that patients are brought in for interventional procedures before severe illness progressed to the point of compromising the outcomes of the interventional procedures.

In addition, the use of a precise flow standard is very beneficial for the calibration of indwelling flow probes used with increasing frequency, particularly in the controversial area of right heart analysis.

Industrial, scientific, and research laboratories find it quite helpful to have a flow standard available to check quickly and easily the calibration characteristics of various ultrasonic and electromagnetic flow probes and systems. This device can also facilitate the initial assembly and debugging of various laser and ultrasound flow measuring systems that, at the present time, must rely upon home-built devices.

A series of experiments has been done at a number of hospital imaging centers and scientific research laboratories demonstrating the usefulness of this approach to ensuring accurate flow and velocity measurements. Twenty-six medical institutions were visited and sixty-five medical ultrasound machines were tested with the flow standard. The results of these evaluations and examples of the use of a flow standard in these situations will be presented. Accuracy before and after flow standard use will be compared to demonstrate the effectiveness of this approach.

Additional examples using the flow standard and the hydrodynamic laboratory will also be presented. These will include the use of a standard to calibrate electromagnetic flow probes as well as indwelling ultrasonic flow probes. A final example will be presented in which a flow standard is used to help initial set-up and instrument debugging in a state-of-the-art laser flow laboratory.