Terason t3000, Руководство пользователя

Страница: 194 / 421

Chapter 7 - Working With Measurements Measuring Cardiac Exams
Terason t3000 / Echo Ultrasound System User Guide 194
Formulas Used for Measurements in Doppler Windows
Doppler Formulas
Name Variables Formula Units
Pressure
Gradient V: velocity mmHg
Mean Velocity V: average velocity between two
successive velocity trace points
(m/s)
N: number of velocity trace points

ti
: time between two successive
velocity trace points (sec)
m/s
Mean Pressure
Gradient V: average velocity between two
successive velocity trace points
(m/s)
N: number of velocity trace points

ti
: time between two successive
velocity trace points (sec)
mmHg
Time Velocity
Integral TVI = area under curve cm
Stroke Volume
TVI: time velocity integral (cm)
Flow Area: derived from the flow
diameter (cm
2
)
ml
Cardiac Output SV: stroke volume (ml)
HR: heart rate (bpm)
l/min
Cardiac Index CO: Cardiac Output
BSA: body surface area (m
2
)
l/min/
m
2
Pressure Half
Time Vmax: Maximum velocity (m/s)
Deceleration Slope (ms
2
)
ms
Valve Area by
PHT PHT: Pressure half time (msec)
cm
2
PG 4 V
2
=
Vmean
V
i

ti
i
1 =
N 1 –


ti
i 1 =
N 1 –

----------------------- =
Pmean
4
V
2
i

ti
i 1 =
N
1 –


ti
i 1 =
N 1 –

----------------------------- =
SV TVI FlowArea

=
TVI Flow Area
Aortic: AoV TVI LVOT FA
Mitral: MV TVI Mitral FA
Pulmonic: PV TVI Pulmonic FA
Tricuspid: TV TVI Tricuspid FA
CO
SV HR
  
1000
---------------------------- =
CI
CO
BSA
------------ =
PHT
Vmax
1
1
2
------- –
 
 

DecelerationSlope
------------------------------------------------------
 
 
 
 
 
1000

=
VA
220
PHT
------------ =