D. Crowley, 2008

UltrasoundTo know what ultrasound is, and how this is used in hospitals

Ear Protectors Stick in the ear protectors

worksheet, and answer the questions in your book

Ear Protectors1. Ear muffs with the headband have the greatest noise reduction, so

would be most suited to a noisy environment Ear protectors B and C reduce noise by the same amount (30dB) Ear protectors A and B are likely to work loose Ear protectors C, D and E are likely to be uncomfortable Ear protectors A need give the least protection Ear protectors A, B and C need clean hands, otherwise you risk

microorganisms entering the ear causing ear infections

2. All the ear protectors have trapped air in

3. All the ear protectors have soft materials in them

4. The head is protected (falling materials etc…) so the ear protectors with the helmet are most suited for a building site

Ultrasound Ultrasound is sound with a higher frequency than we can

hear (i.e. above 20’000 Hertz)

In nature some organisms, including bats, utilise ultrasound (they produce very high pitched squeaks, and convert the echoes into a picture of their surroundings, which is why they can fly at night)

Although we cannot hear ultrasounds, we can use them for a variety of things…

Industrial Cleaning Ultrasound can clean delicate machines without the need to

dismantle them

Ultrasounds can be directed to very precise areas and be uses to vibrate dirt away – this is also used for cleaning teeth (ultrasounds can remove tartar (this can lead to gum disease)

Kidney Stones Ultrasound can also be used to break down kidney stones –

high energy shockwaves can be aimed precisely at the kidney stone, breaking it down allowing the body to remove them

This means the patient does not need surgery, and is relatively painless

Pre-Natal Scanning Ultrasound waves pass through some materials better than

others

Different parts of the body reflect the sound waves differently (echoes)

A computer picks these reflected waves up, and processes them into a image so we can see inside the womb

It is not known for sure if ultrasound is entirely safe, but it is certainly safer than using X-rays!

Sonar Some animals have been using ultrasounds for millions of

years

Humans have only recently taken advantage of ultrasounds, and although we cannot hear the sounds, we can use equipment to make and detect thee signals

Ultrasounds are produced, and a computer analyses how long the sound reflections (echoes) take to get back to a detector – this enables you to calculate the distance of certain objects

Sonar Sonar equipment sends out a pulse of sound (ping) – the

sound is reflected off objects, and the echo of the sound returns

The time taken for the echo to return is measured, and the distance calculated

This is used by boats to identify the depth of the seabed; fish finding; and by the military, especially within submarines (this is how they ‘see’ where they are going)

Ultrasound Scans Complete the ultrasound scans

worksheet

Ultrasound Scans1. Ultrasound

2. Ultrasounds are used to get a picture of an unborn foetus

3. X-rays show bones (and other dense materials)

4. Ultrasounds show the outside of the foetus (its outline)

5. X-rays can damage cells; ultrasound can provide moving pictures; ultrasound can show the outline of the foetus

6. The gel ensures sound waves can pass into the mother’s abdomen

7. Sex can be determined if a penis is visible. However the position the baby is in come sometimes obscure this

8. Moving pictures can identify if the baby is still alive (heart beating; general movement etc…)

9. Ultrasound can also be used to detect lumps in the body (tumours, gallstones etc…); removing tartar from teeth; breaking down kidney stones etc…