Question

An ultrasound unit is being used to measure a patient’s heartbeat by combining the emitted 2.0 MHz signal with the sound waves reflected from the moving tissue of one point on the heart. The beat frequency between the two signals has a maximum value of 520 Hz. What is the maximum speed of the heart tissue?

Answer 1

Answer: v= 0.2m/s

Explanation:

from Doppler effect

f = (2v/c) * fo

where:

f = the max beat frequency between two signals

fo = the emitted signal frequency from the organ.

v= The max speed of the organ tissue

c= 1540m/s (speed of Ultrasound wave in human tissue)

substituting the values, we have

520 Hz/ 2000000Hz = 2v/1540m/s

simplifying,

2v = (520 x 1540)/2000000

2v = 0.4004

v = 0.4/2 = 0.2 m/s

The max speed of the heart tissue is 0.2m/s