- Sound waves above 20 kHz is called Ultrasound which humans ears cannot detect.
- Ultrasound waves are partially reflected at a boundary between media.
- Partial reflection is when a wave is passed from one medium to another, some of the wave is reflected off the boundary between the two media and some is transmitted and refracted.
- You can point a pulse of ultrasound at an object and if there are boundaries between one substance and another, the ultrasound gets reflected back.
What is ultrasound used for?
- It is used to break down kidney stones which is then passed through urine and for body scans to detect gal stone, tumors or pregnancy.
- It is used for sonar detection.
How does ultrasound work?
- When ultrasound is directed at a human body, the surface of different tissues inside the body due to partly reflect the ultrasound.
- The detector will receive the ultrasound echoes at different time depending on how deep inside the body the tissue surface are.
- The detector produces electrical signals which are sent to a computer and then displayed on a screen as a picture.
- Ultrasound can be used safely to see an image of a developing baby inside the uterus during pregnancy.