How is the velocity or magnitude of movement calculated using the doppler effect?

  • The detected Doppler shift frequency (fd) can be used to calculate the velocity of an object the waves reflect off using the ‘doppler equation‘:
v = flow velocity (m/s)

c = the speed of sound in tissues (m/s)

fd = Doppler frequency shift that is received (Hz)

cos θ = cosine of the angle between the sound beam and moving fluid (45°)

fT = frequency of the transmitted ultrasound from the transducer (Hz)