Ultrasound Doppler Subsystem Design And Computer Simulation

Ultrasound is the sound that has a frequency above the audible range of 20 kHz. In imaging the usual range of frequencies is between 2 MHz and 10 MHz. It is now widely used, especially in medical applications. Because ultrasonic examinations are non-invasive, cost effective and free of ion-radiation, the ultrasound imaging is one of the fastest growing image modalities. The demand of ultrasound machines is very big. Moreover, ultrasound instrument is a high-tech product and the capacity to make high quality ultrasound system may show the competitiveness of a country's technology advantage.Doppler effect has been discovered for measuring the frequency (for the speed) change from sound reflection on moving targets. Technologies based on the Doppler effect has been used to estimate the velocity of blood flow and also the fast tissue motion (e.g., the heart motion) in clinical ultrasound exams.There are three development stages of Doppler ultrasound: the continuous wave (CW) Doppler during 1950s to 1960s, the pulse wave Doppler (PW) in 1970s, and the audio and color flow imaging starting from 1980s, all going with the development of the computer and digital audio card.