What is Ultrasound: Definition and 111 Discussions

Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz (20,000 hertz) in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and accelerating chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and obstacles.

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  1. J

    I want to build an electronic device that transmits ultrasound

    I want to build an electronic device that transmits ultrasounds (I guess that is in the LF frequency range [?]). Does anyone know where I can find a kit that creates ultrasounds?
  2. A

    Ultrasound or Infrasound - directed at a horse

    Hello, I am researching an article on the past uses of sound on animals whether it be for medical research (e.g. development of ultrasound imaging) or other uses. I remember there being a case of a sound wave directed at a race horse in the UK some years ago. This disrupted the horse and...
  3. cronxeh

    Looking for ultrasound transducer

    I can't seem to find a simple ultrasound transducer probe (that won't have "medical" tagged on it, hiking up the price). I need at least 1.2-2.5 mhz, 360 deg cone, high power. Dual element PZT. This is for marine application (side scan sonar/ROV imaging). Can anyone tell me where I can find...
  4. magi

    Ultrasound Scans of teeth instead of x-ray?

    Hello. I took a course in Ultrasound and I wonder why dentists don't use that instead of X-ray. The patient only need to fill his/hers mouth with water and then it is possible to use Ultrasound Scans in the mouth of the patient without any jonisating radiation. It could even be possible...
  5. Mk

    Electrostimulators and ultrasound machines for healing

    I heard something about electrostimulators and ultrasound thingys that athletes can use over their sprains and alike that will help them heal faster. Sounds like quackery to me, but what is it about?
  6. S

    Fetal Heart Wall Velocity from Ultrasound Reflection

    A sound wave travels at a frequency 2.25 MHz through a pregnant woman's abdomen and is reflected from the fetal heart wall of her unborn baby. The heart wall is moving toward the sound receiver as the heart beats. The reflected sound is then mixed with the transmitted sound, and 87.0 beats per...
  7. S

    Is ultrasound technology cheaper compared to x-ray technology?

    is ultrasound technology cheaper compared to x-ray technology? is it easier to construct? for example the ones to probe foetus in pregnant females. what is the advantage for using ultrasound for probing foetus compared to x-ray, apart from safety issue? thanks.
  8. C

    What is the beat frequence in Hz of ultrasound

    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 in Hz? (Velocity of sound in blood = 1540 m/s.)
  9. R

    Ultrasound Problem: Detecting Small Objects in Eye Scan at 20Mhz

    The smallest object which can be resolved with a given frequency of ultrasound in a diagnostic scanner is on the order of the wavelength of ultrasound used. If 20 mhz ultrasound is used for a scan of the eye, and the speed oft the wave is 1500 m/sec, how small an object could be detected in the...
  10. S

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

    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...
  11. J

    Ultrasound reflected from an oncoming bloodstream

    Ultrasound reflected from an oncoming bloodstream that is moving at 31 cm/s is mixed with the original frequency of 1.3 MHz to produce beats. What is the beat frequency? (Velocity of sound in blood = 1540 m/s.) I know that there are two doppler shifts; one where the source is fixed and the...
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