Stethoscope
- Stethoscope is a medical instrument used for listening to sounds produced within the body, mainly in the heart or lungs. In stethoscopes the sound of the patient’s heartbeat reaches the doctor’s ears by multiple reflection of sound
- The diaphragm of the stethoscope acts as a sensitive membrane that vibrates in response to sound waves. These vibrations are transmitted through the tubing to the earpieces, where they are amplified and heard by the listener.
Ultrasonography
- Ultrasonography, also known as ultrasound imaging or sonography, utilizes high-frequency sound waves to create images of internal body structures.
- In this technique the ultrasonic waves travel through the tissues of the body and get reflected from a region where there is a change of tissue density. These waves are then converted into electrical signals that are used to generate images of the organ. These images are then displayed on a monitor or printed on a film. This technique is called ‘ultrasonography’.
- Ultrasonography is also used for examination of the fetus during pregnancy to detect congenital defects and growth abnormalities.
