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