4-1
4. REFERENCE TECHNICAL
INFORMATION
4.1 How to calculate corneal thickness
The corneal thickness is calculated in the following calcula-
tion by using the converted sound velocity in the cornea.
Tc =
where,
Tc:Corneal thickness
V: Converted sound velocity in the cornea
t: Measuring time
4.2 Acoustic Output
4.2.1 MI (Mechanical Index)
MI is a parameter to show mechanical bio-effects of ultrasound.
Examples of mechanical
effects are motion (or streaming) around compressible gas bubbles
as ultrasound pressure
waves pass through tissues, and energy released in the collapse,
via cavitation, of
transient gas bubbles.
4.2.2 TIS (Soft Tissue Thermal Index)
TIS is a parameter to show thermal bio-effects of ultrasound.
Thermal effect is
temperature rise of tissue by ultrasonic exposure.
4.1 How to calculate corneal thickness
V x t
2