Ultrasound Flashcards Preview

Physics Module 4 > Ultrasound > Flashcards

Flashcards in Ultrasound Deck (14):
1

Recognise the features of a longitudinal wave

Wavelength
Compression
Frequency
Rarefaction

2

Recognise that ultrasound can be used in medicine for diagnostic purposes

- to look inside people by scanning the body
- to measure the speed of blood flow in the body

3

Define wavelength

The distance between corresponding points on two compressions

4

Define frequency

The number of waves produced in one second

5

Define amplitude

The maximum disturbance caused by a wave

6

Define compression

A region of higher pressure (loops closer together)

7

Define refraction

A region of lower pressure (loops further apart)

8

What frequencies does ultrasound have

Higher than 20 000 Hz, i.e. Above the upper threshold of the human hearing range

9

Recognise that ultrasound can be used in medicine for non-invasive therapeutic purposes

Breaking down kidney stones

10

Describe and compare the motion and arrangement of particles Longitudinal and transverse waves

In transverse waves each particle moves up and down about its normal position at right angles (90°) to the direction of the wave movement

In longitudinal waves each particles moves up and down about its normal position parallel to the direction of wave movement

11

Explain how ultrasound is useful in body scans

- Ultrasound waves are reflected at a boundary as they pass from one medium (or subtsance) into another. The time taken for these reflections can be used to calculate the depth of the reflecting surface. The reflected waves are usually processed to produce a visual on screen

12

Explain how ultrasound is used in breaking down kidney stones

It allows kidney stones in the body to be removed without the need for painful surgery. Ultrasonic waves cause the kidney stones to vibrate, making them break up and disperse. They are then passed out of the body in urine.

13

Explain the reasons for using ultrasound rather than X-rays for certain scans

- able to produce images or soft tissue
- does not damage living cells

14

What type of wave is ultrasound

Longitudinal wave