Doppler shift or Doppler effect is defined as the change in frequency of sound wave due to a reflector moving towards or away from an object, which in the case of ultrasound is the transducer.
F = 2fo(v/c)cos(Q)
- F is doppler frequency shift
- fo is transmitted frequency from ultrasound probe
- v is the velocity of moving reflector
- c is the velocity of sound in the medium
- Q is the angle between ultrasound beam and axis of flow
History and etmyology
Named after Austrian physicist, Christian Doppler.