Siemens ACUSON Cypress

Cardiac Calculations
6-20 ACUSON Cypress™ Operator’s Manual
Doppler Formulas
TABLE 31. Doppler Formulas (Cardiac)
Type Formula Units
Pressure
Gradient
V is velocity.
mmHg
Mean Velocity
V is the average velocity between two successive velocity
trace points (m/s).
N is the number of velocity trace points.
is the time increment between two successive velocity
trace points (seconds).
m/s
Mean Pressure
Gradient
V is the average velocity between two successive velocity
trace points (m/s).
N is the number of velocity trace points.
is the time increment between two successive velocity
trace points (seconds).
mmHg
Time Velocity
Integral
m
Pressure Gradient 4V
2
=
Vmean
V
i
Δ
ti
i 1=
N 1–
∑
Δ
ti
i 1=
N 1–
∑
-----------------------=
Δ
ti
Pmean
4V
2
i
Δ
ti
i 1=
N 1–
∑
Δ
ti
i 1=
N 1–
∑
-----------------------------=
Δ
ti
TVI area under curve=