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 Andreas Doppler (1803-1853) 1.
- 1. Katsi V, Felekos I, Kallikazaros I. Christian Andreas Doppler: A legendary man inspired by the dazzling light of the stars. (2013) Hippokratia. 17 (2): 113-4. Pubmed