Question

What are ultrasonic waves? Write any two uses of ultrasonic waves in the field of medicine.

Answer 1

Hint: Ultrasonic waves are a type of sound waves whose ranges fall into the inaudible category for a human ear. Their high energy vibrations are an important tool for various medical diagnostics.

Complete step by step answer:
Two uses of ultrasonic waves in the field of medicine are:
- It is used in ultrasonic scans or ultrasound or ultrasonography, where the pictures of internal organs can be produced by using these high-frequency sounds. The waves are produced by a device named transmitter. It aims or transmits ultrasonic waves. These waves can easily travel through the body tissues and deduce the differences in tissue densities. The detectors detect the changes in the trajectory of these waves and produce an image accordingly.

- Due to the high energy vibration of ultrasonic waves, they are employed to perform lithotripsy wherein these waves are passed through the body in order to break down the kidney stones into pieces that are as small as the units of grains. These fine-grain particles can then be easily removed by the kidney tubules via urine.

Additional Information:
- A wave is created to transfer energy through mediums like water or air. A sound wave is a type of longitudinal wave. The frequency of a wave is defined as the number of complete cycles in one second. Its unit is Hertz or Hz.
- A human ear can hear the voice in the range of 20Hz to 20 kHz. Any sound lower than 20 Hz is known as an infrasonic sound while any sound which exceeds 20kHz is known as ultrasonic sound. Both fall in the inaudible range for the human ear.

Note:
- The waves can travel in two patterns namely a transverse wave and a longitudinal wave. In a transverse wave, the disturbance of the particles is in a direction perpendicular to the direction in which a wave is travelling.
- On the other hand, in a longitudinal wave, the direction of disturbance of particles is in the same direction to which the wave propagates.