B. General principles recording and measurement of Doppler data. The document is not a comprehensive Doppler echocardiography is a noninvasive technique that provides unique of Doppler principles and flow dynamics. This document provides recommendations hemodynamic information otherwise not available without invasive monitoring. The blood flow toward (positive) or away (negative) from the transducer. The Doppler The Doppler principle states that the frequency of reflected ultrasound is altered