Accuracy in Velocity Measurements for Fault Detection in a Curvilinear Ultrasound Probe: a case study Simulating Failures Using Nylon Wires

Based on findings in the scientific literature, the ultrasound (US) probe is the most failure-prone component in the US diagnostic imaging chain. Defective elements of the probe have been found to impact Doppler sensitivity and maximum and average velocity estimation significantly. The present study fits into this context, focusing on the sensitivity evaluation of an image analysis-based measurement method at varying degrees of probe defect. The measurement method objectively quantifies the Velocity Measurements Accuracy (VeMeA) parameter, which has been proposed in the literature for pulsed wave Doppler (PWD) quality assurance. Dead elements were simulated by attaching consecutive nylon wires in the middle of the aperture of a curvilinear ultrasound transducer. Two fault conditions, simulating a failure of the emitting surface of 0.9% and 1.8%, and one functional condition were considered. Data collection was repeated for different US system settings and flow regimes for each test condition. Although preliminary, the experimental results suggest that the measurement method is sensitive enough to detect a failure of a few piezoelectric elements of the transducer. This outcome was found mainly at the higher operating Doppler frequency of the probe under test.