Calibration method and uncertainty evaluation of ultrasonic Doppler foetal heartbeat detector

This article analyzes the structure and measurement principle of ultrasonic Doppler fetal heartbeat detector, based on YY/T 0749-2009 Ultrasonic -- Hand-held probe Doppler fetal heartbeat detectors -- Performance requirements and method of measurement and reporting and other standards and technical specifications, studies and determines the key technical indicators that affect the metrological performance of ultrasonic Doppler fetal heartbeat detector, puts forward an novel and effective metrological traceability method to measure fetal heartbeats at different detection depths in order to accurately evaluate the metrological performance of fetal heartbeat detectors, and evaluates the uncertainty of fetal heartbeat measurement error, providing a reliable metrological technical support for ensuring the quality of ultrasonic Doppler fetal heartbeat detector.