1. SOUND WAVES « How can we use sound waves in medicine ? »

2. I/ Introduction : What is a sound wave ? II/ How can we use sound waves in health ? III/ Are sound waves harmful for the body ? IV/ Conclusion : When are we using sound waves ? SOMMARY

3. I/ What is a sound wave ?

4. * A sound wave is a longitudinal pressure wave of audible or inaudible sound. * It's a pressure caused by the vibration of something in a medium that transfers energy, like air. * A sound wave is a wave that is formed when a sound is made and that moves through the air and carries the sound to your ear. * Human ear can only hear sound waves between 20Hz and 20kHz.

5. II/ How can we use sound waves in health ? I/ To see in our body : Diagnostic sonography or ultrasonography is an ultrasound-based diagnostic imaging technique used for visualizing subcutaneous body structures. Ultrasound images called sonograms are made by sending a pulse of ultrasound into tissue using an ultrasound transducer.

6. Ultrasonography can be used in several ways : * For pregnant women, it's called obstetric ultrasonography.

7. * To visualize the hearth, it is an echocardiography :

8. * Ultrasonography can be used in watching tendons, muscles, joints, vessels, arteries and internal organs in order to diagnose possible pathology or lesion.

9. II/ Therapeutically : Ultrasounds can also be used therapeutically : - to break up gallstones and kidney stones. - or to heat and destroy diseases or cancerous tissues.

10. III/ Are sound waves harmful for the body ? Ultrasounds, from a certain frequency can have harmful effects. These effects can be : loss of the hearing (temporaly or not), excessive bleeding, headache, fever, nausea or dizziness. Audible sound can be harmful too, noise is one of the leading causes of professional diseases.

11. IV/ When are we using sound waves ? Out of medecine, ultra sounds are used also in marine (for the sonar detecting objects under water), in weapons, in automotive too : for parking sensors witch calculate the distance between two cars. Some insects and animals have ultrasonic hearing like dogs, bats and birds. So we can use ultrasounds to keep them away from a place cause they don’t support it, like in airports, where we keep birds away from runway thanks to ultrasounds.

13. THE END (Calvi Elsa, Laachi Clara, Thuries Adrien, Msellem Pablo)