䕔
4-12
4.5 Ultrasound wave output
4.5.1 MI (mechanical index)
MI is a parameter that indicates the mechanical effects of ultrasound
waves on biological tissue ultrasound.
Mechanical effects are, for example, movement (or flow) around air
bubbles compressed when an acoustic pressure wave of the ultrasound
wave passes through biological tissue, or energy released when
cavitation temporarily bursts the air bubbles.
4.5.2 TIS (thermal index of soft tissue)
TIS is a parameter that indicates the thermal effects of ultrasound waves
on biological tissue ultrasound.
Thermal effects mean an increase in the tissue temperature due to
emission of ultrasound waves.