How Is the Doppler Effect Utilized in Various Fields and Ultrasound in Medicine?

In summary: Any other ways it used? and also how is ultra sound used in medicine?any web links would be cool too, thanx.In summary, the doppler effect is used in radar guns, astronomy, and medicine to determine the distance of planets, and ultrasound is used to visualize blood flow in the body.
  • #1
SwAnK
51
0
hey just wondering about the doppler effect and how it is used in meterology, law enforcment and astronomy.

I know for law enforcment they use it in radar guns, and astronomy i think for finding the distance of planets?

Any other ways it used? and also how is ultra sound used in medicine?
any web links would be cool too, thanx.
 
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  • #2
Just a little clarification on using the doppler effect to find the distance of planets. There are actually two sources of wavelength shifts around massive, moving objects, that due to the change in gravitational potential energy (very slight around objects even of Earth's mass), and the more dominant velocity effect. It's not so much that you can find the distance between planets using the doppler effect because well the planet could potentially be in a galaxy that is moving toward you, but objects further away from us tend to have higher doppler redshifts (moving faster away), so it generally works consistently only for objects incredibly far away such as quasars. I should also note that an entire convention for long-distance objects has been built around the doppler effect, detailed at http://hyperphysics.phy-astr.gsu.edu/hbase/astro/redshf.html#c2 (the second block of text)

As for your question, I found easy-to-understand answers from http://www.howstuffworks.com and simply seraching for "doppler"
 
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  • #3
SwAnK said:
Any other ways it used? and also how is ultra sound used in medicine?
any web links would be cool too, thanx.
Modern ultrasould equipment uses the doppler effect to determine precise motion of membranes inside the body. At every interface within the body (such as the surface of the heart) a partial reflection of sound occurs. This reflection will be shifted by a certain amount if the membrane is moving toward or away from the source.

The latest machines are so good that by changing the frequency just right, you can get a photograph of the face of a baby in the womb; it looks just like a black & white snapshot. A little twist of a dial, and then you can see the skeleton.

Try a google search for ultrasound AND doppler
 
  • #4
Chi Meson said:
Modern ultrasould equipment uses the doppler effect to determine precise motion of membranes inside the body. At every interface within the body (such as the surface of the heart) a partial reflection of sound occurs. This reflection will be shifted by a certain amount if the membrane is moving toward or away from the source.
Doppler is not required to visualize membranes. Doppler ultrasound is not used to visualize objects at all in fact. The most common use is to assess blood flow in arteries and veins.

The latest machines are so good that by changing the frequency just right, you can get a photograph of the face of a baby in the womb; it looks just like a black & white snapshot. A little twist of a dial, and then you can see the skeleton.
Actually ultrasound units (the transducers really) operate at a constant frequency, anywhere from 1 MHz to 12 MHz with a different transducer for each frequency. When the technologist twists the dial or moves the sliders, timing delays are being adjusted that let you visualize structures at different depths. By increasing the timing delay and waiting a longer or shorter time for echoes, you effectively change the depth of field in an ultrasound study (deeper for longer times, closer for shorter times).
 
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  • #5
I got to get a new textbook!
 
  • #6
You are right Chi meson, but I was talking more about Doppler ultrasound, you were explaing the ultrasound that is more commonly used for viewing internal organs or pregnant women.
 
  • #7
Yeah. Thing is, my son was born just two months ago, and I always made sure to be there for the ultrasound viewings during the pregnancy (it was a brand new machine and I'm still agog over it!).
BTW: I had asked the technician "Does that [dial] change the frequency?" and she said "yes." It made sense at the time. :redface:
 

Related to How Is the Doppler Effect Utilized in Various Fields and Ultrasound in Medicine?

What is the Doppler Effect?

The Doppler Effect is the phenomenon where the frequency of a sound or light wave appears to change when the source of the wave is moving relative to the observer. This can be observed in everyday situations, such as the change in pitch of a siren as an ambulance drives by.

How does the Doppler Effect relate to ultrasound?

In ultrasound, the Doppler Effect is used to measure the velocity and direction of blood flow in the body. The ultrasound machine emits high-frequency sound waves that bounce off the moving red blood cells and return to the machine, producing a Doppler shift that can be used to create a visual representation of the blood flow.

What are the applications of ultrasound technology?

Ultrasound technology has a wide range of applications in various fields, including medical imaging, industrial inspection, and navigation. In medicine, it is commonly used for diagnostic purposes, such as imaging the internal organs, monitoring fetal development, and detecting abnormalities in blood flow.

Is ultrasound safe for medical use?

Yes, ultrasound is considered to be a safe medical imaging technique. It does not use ionizing radiation like X-rays do, so there is no risk of exposure to harmful radiation. However, it is important for medical professionals to follow proper guidelines and use the appropriate settings to ensure the safety of the patient.

What are the limitations of ultrasound imaging?

While ultrasound is a valuable tool for medical imaging, it does have some limitations. It is not effective for imaging structures that are surrounded by gas, such as the lungs, and it does not provide as clear images as other imaging techniques, like MRI or CT scans. Additionally, ultrasound may not be suitable for patients who are obese or have a lot of gas in their digestive system.

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