Sounds & Ultrasound in medicine

Sounds & Ultrasound in medicine

Definition.
To get information about general properties of sound.
Characteristics of human body.
Physics of stethoscope.
Applications of audible sound in medicine.
Physiological effects of ultrasound in therapy.

Its an audible waves of frequency between (20 Hz --- 20 KHz)

Infrasound

Refers to the sound of frequency below normal hearing range ( < 20 Hz)


Ultrasound
Refers to the sound of frequency above normal hearing range (20 KHz)


Infrasound and Ultrasound both these sound can not be heard

General properties of sound

Sound wave require medium ( gas ,liquid or solid) for transmission mean matter must be present for sound to travel


Sound waves
Is mechanical wave, the vibration causes local increase and decrease in pressure relative to atmospheric pressure.The pressure increase called compression, and decrease called rarefaction 

Velocity of sound

V = ? f  f = frequency of vibration of the sound wave. ? = wave length

Sound intensity
Energy carried by waves as kinetic and potential energy

Characteristics of human body

Pitch, refers to the attribute of a sound sensation that enables one to classify a node as high or low.
Loudness, the effect of intensity of the sound wave on human hearing known as loudness.
The unit of the human sound is decibel(dB),  it represents the ratio between two sound intensities and known as (sound intensity level)  Log I/ I? = intensity ratio