Biomedical Engineering Reference
In-Depth Information
140
120
100
3
2
80
SV
60
40
4
20
1
0
30
40
50
60
70
80
90
Left Ventricular Volume [ml]
ESV
EDV
FIGURE 4.47
Pressure-volume work loop corresponding to the left ventricular data in Figure 4.46.
refilling from 4 to 1. Also shown are volumes EDV, ESV, and SV. The area bounded by the
work loop corresponds to mechanical work performed by the left ventricle.
Figure 4.48 shows work loops calculated from the generalized pressure model of the left
ventricle (Eq. (4.75)) pumping into the three-element arterial load model (Figure 4.37) using
human parameter values for both the ventricle and arterial load. The left ventricle was filled
from a constant pressure reservoir. The control work loop (center) may be compared to
those corresponding to a 10 percent increase and 10 percent decrease in filling pressure.
140
+10% filling
pressure
120
-10%
100
80
60
40
20
0
60
80
120
Ventricular Volume V
LV
[ml]
100
140
160
FIGURE 4.48
Pressure-volume work loops computed for the human left ventricle (Eq. (4.75)) and arterial load
(Figure 4.37) for control (middle curve) and varied preload (filling) conditions.
