Attenuation of Ultrasound wave

Defining Ultrasound:

Audible 20Hz and 20 000Hz. 

Infra sound Below 20Hz 

Ultrasound Above 20 000Hz

 

 

When an ultrasound wave passes through tissues: 

• Attenuation: Reduction in amplitude and intensity of wave

• Refraction: Change in direction & velocity of wave

 

 

Attenuation is the rate at which intensity wave diminishes with the depth it covers or its penetration. 

3 Types: 

• Reflection.
• Scattering
• Absorption: the main form of attenuation - loss of sound energy occurs and heat is produced

 

Affecting attenuation: 

• Frequency of wave - Higher the frequency, higher the attenuation and less penetration of the wave
• Type of tissue the wave is traveling
• Depth the wave travels - more distance wave has to travel the more energy is lost.