# What is the blood beat frequency?

#### confused1

Ultrasound reflected from an oncoming bloodstream that is moving at a 30 cm/s is mixed with the original frequency of 2.5 MHz to produce beats. What is the beat frequency? (Velocity of sound in blood = 1540 m/s.)

Beat Frequency in Hz =

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#### OlderDan

Homework Helper
confused1 said:
Ultrasound reflected from an oncoming bloodstream that is moving at a 30 cm/s is mixed with the original frequency of 2.5 MHz to produce beats. What is the beat frequency? (Velocity of sound in blood = 1540 m/s.)

Beat Frequency in Hz =
This exact question appeared recently and there were some responses to it. Maybe you can find it and if need be continue the discussion there.

#### bahamut

Ultrasound reflected from an oncoming bloodstream that is moving at a 30 cm/s is mixed with the original frequency of 2.5 MHz to produce beats. What is the beat frequency? (Velocity of sound in blood = 1540 m/s.)
It is called what what effect(I don't know how to say it in english)

The frequency the blood receive isf1=f(sound)*(V(sound)+V(blood))/V(sound)

The frequency blood reflect and mixed with the original Ultrasound is
f2=f1*V(sound)/( (V(sound)-V(blood))

So f2=f(sound)*(V(sound)+V(blood))/(V(sound)-V(blood)) ,you caculate it yourself.

And the f(beat)=|f2-f(sound)|.

If you still have any questions,contact me at wangkehandsome@hotmail.com,Iwill be very glad to anwser it for you.

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