4. SYSTEM DESIGN DESCRIPTION
1.”SOUND IS A COMPRESSIONAL WAVE” and is
different from electromagnetic waves in that it
requires medium to travel.
ULTRASONIC SOUND:
5. THE DOPPLER EFFECT
Doppler effect is change observed in the
wavelenth of sound wave due to reletive motion
betweet source and receiver
6. DOPPLER PHENOMENON
The perceived frequency (f ´) is related to the actual
frequency (f0) and the relative speeds of the source (vs),
observer (vo), and the speed (v) of waves in the medium
by an equation:
7. The Doppler shift frequency is given by the equation-
FD=((2fecos θ)/c)
Where fD =Doppler shift,
fe= emitted frequency,
c=speed of sound in tissues,
v= blood flow velocity,
θ= cosine Doppler angle
8. WHY TO ZOOM
Minute variatinon in blood flow can be seen;
Eg;starting stage of blood clot
9. APPLICATION OF FFT
An FFT computes the DFT and produces exactly the
same result as evaluating the DFT definition directly;
10. MATLAB
Entire system is developed in matlab environment for
the system to both simple and cost effective
