Howtosignalprocessing
- What is the relationship between frequency and Doppler shift?
- What is Doppler phase shift?
- What are the two types of Doppler shift?
- What is frequency shift in ultrasound?
What is the relationship between frequency and Doppler shift?
The amount the frequency is changed, fd, is known as the Doppler-shift frequency and the value depends upon the vector velocity, , of the scatterer relative to the vector of the ultrasound frequency, , in the direction of travel of the ultrasonic wave (speed c).
What is Doppler phase shift?
With the "Doppler shift", the sound pitch of an object moving toward your location is higher due to compression (a change in the phase) of sound waves. As an object moves away from your location, sound waves are stretched resulting in a lower frequency.
What are the two types of Doppler shift?
In Doppler mode, the Doppler frequency shift of moving objects (described earlier) is used for image formation in the form of color or spectrum. There are two different types of Doppler modes: pulsed wave and continuous for specific clinical application.
What is frequency shift in ultrasound?
The Doppler shift frequency (fd) is the the difference between transmitted and received frequencies. It depends on the insonating frequency, the velocity of moving blood, and the intercept angle between the sound beam and direction of blood flow, as described in the Doppler equation.
