Ultrasound

Teacher recommended

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  • Created by: Jo Wells
  • Created on: 21-04-13 12:59
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  • Ultrasound
    • is sound with a higher frequency than humans can hear
      • electrical systems can be made which produce electrical oscillations of any frequency
        • can easily be converted into mechanical vibrations to produce sound waves of higher frequency than the upper limit of human hearing = ultrasound
    • can use oscilloscope traces to find boundaries
      • given the 'seconds per division' setting of the oscilloscope, you can work out the time between pulses by measuring on the screen
        • if you know the speed of sound in the medium, you can work out the distance between boundaries
          • s = v X t
            • s = distance (m)
            • v = speed (m/s)
            • t = time (s)
    • Uses
      • medicine
        • breaking down kidney stones
          • hard masses that can block urinary tract
          • an ultrasound beam concentrates high-energy waves at the kidney stone & turns it into sand-like particles
            • these particles then pass out of the body in the urine
          • is a good method as there's no surgery & = relatively painless
            • an ultrasound beam concentrates high-energy waves at the kidney stone & turns it into sand-like particles
              • these particles then pass out of the body in the urine
        • pre-natal scanning of a fetus
          • ultrasound waves are partially reflected when reach a boundary
            • the exact timing & distribution of these echoes are processed by a computer to produce a video image of the fetus
          • the exact timing & distribution of these echoes are processed by a computer to produce a video image of the fetus
      • medical imaging is full of compromises
        • Safety
          • ultrasound waves are non-ionising & safe
          • x-rays are ionising - can cause caner if over exposed to them
            • not safe to use on babies
          • CT scans use a lot more x-ray radiation than normal x-rays so patient is even more exposed
            • aren't usually used unless really needed
        • Image quality
          • ultrasound images are quite fuzzy - harder to diagnose some conditions
          • x-ray photographs produce clear images of bone & metal - not a lot else
          • CT scans produce detailed images & can be used to diagnose complicated illnesses
            • high resolution images can make it easier to work out problem
            • high quality 3D images can also be used in planning of complicated surgery

Comments

Miss KHP

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Good mind map for P3 AQA.

Will help you to compartmentalise everything such as USES and SAFETY.

Once you have completed it, test yourself and check your progress.

Redpanda_2880

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its a bit long tbh

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