Ultrasound

Ultrasound

Human ear
1. Detects sound waves with frequencies between 2Hz and 20,000Hz
  1. Higher frequencies than this are called ultrasound waves
Electronic systems
1. Can produce ultrasound waves
2. When a wave meets a boundary between two different materials, part of the wave is reflected
  1. The wave travels back through the material to a detector
    1. The time it takes to reach the detector can be used to calculate how far away the boundary is
      1. The results may be processed by a computer to give an image
  2. In the time between a transmitter to a boundary and back
    1. Twice the distance to the boundary
Formula
1. s = v * t
  1. 's' is the distance travelled in metres, 'm'
  2. 'v' is the speed of the ultrasound wave in metres per second, 'm/s'
  3. 't' is the time taken in seconds, 's'
Uses
1. To scan unborn babies
2. Scan soft tissue
  1. Eye
3. Theropy
  1. Shatter kidney stones into smaller pieces
Risks
1. Non-ionising
2. Safer than X-rays

Resource summary

	Created by Samuel Marsh over 11 years ago