Final answer:
Echocardiograms use the Doppler effect to detect the change in frequency of an echo from moving blood, allowing the calculation of blood velocity, which aids in diagnosing valvular disorders and other cardiac conditions.
Step-by-step explanation:
The student's question relates to the application of the Doppler effect in medical diagnostics, specifically using echocardiograms. The Doppler effect describes the change in frequency of a wave in relation to an observer moving relative to the source of the wave. When an ultrasound echo is reflected off of moving blood, the frequency shift can be used to calculate the blood's velocity using the formula:
v = Δf * c / (2 * f0 * cos(θ))
where:
v = velocity of the blood
Δf = observed change in frequency (500 Hz)
c = speed of sound in the medium (blood)
(assumed to be 1540 m/s for human soft tissues)
f0 = original frequency of the ultrasound (2.00 MHz)
θ = angle between the ultrasound beam and the direction of blood flow
In the absence of the exact angle (θ), we can't provide a specific velocity. However, for medical ultrasound where the angle is nearly parallel, cos(θ) is often near 1 due to the alignment of the probe, simplifying the formula. This understanding allows physicians to diagnose and investigate potential valvular disorders and other heart issues.