Evaluating Doppler devices using a moving string test target.

Two moving string test targets have been developed and used to characterize ultrasound Doppler instrumentation. The characteristics investigated were sample volume size and location in space, amplitude sensitivity to Doppler shift, and resolution of Doppler direction. The tests were performed on a combined echo/Doppler instrument and on an annular array system. The procedures can be carried out routinely in the clinical laboratory to ensure that the instrument is working properly or as an aid for correct interpretation of acquired data.