bk ultrasound bk3500, Руководство пользователя

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46 Chapter 3 April 2017 bk3500 User Guide (16-01410-EN-04)
In Settings , you can select TI tissue type between TIB (bone), TIC (cranial) or TIS
(soft tissue).
Figure 3-4. The General settings. Here, you can also select between Basic and Advanced lay-
out. See“Monitor and Touch Screen Display” on page 21.
The full details of the indices are given in references EN60601-2-37 and
AIUM/NEMA standard, but the formulas are given below.
MI Formula
where the variables are defined in the table below.
TI Formula
where the variables are defined in the table below.
Variable Definition
P
r0.3
(z
sp
) Peak Rarefactional Pressure (MPa), derated by 0.3dB/cm·MHz, measured at z
sp
,
the point on the beam axis where pulse intensity integral (PII
0.3
) is maximum
f
c
measured center frequency (in MHz)
Variable Definition
W
0
time-averaged acoustic power of the source or other power parameter (W)
MI
P
r0,3
z
sp
 
f
c
------------------------
=
TI
W
0
W
deg
------------- =