| Budget Amount *help |
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 2002 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 2001 : ¥1,700,000 (Direct Cost : ¥1,700,000)
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| Research Abstract |
This study was performed by simulating pulmonary circulation to the electric circuit model on the hypothesis that a lung has the function to restrain an energy loss such as the series and the parallel resonance in the altemating current, in addition to the merit explained by Windkessel theory (decrease of the flow resistance by pulsatile circulation). A characterization of pulmonary circulation was examined by fitting the pulmonary arterial input impedance of the isolated perfusion rabbit lung to the six-element lamp model. As a result, the maximum likelihood model was the combination of Landes model and Goldwyn-Watt's model, which was provided with a proximal and a peripheral segment, corresponding to the series and the parallel resonance circuit. It was speculated that the circulation was controlled with flow lead in the proximal segment and with pressure lead in the peripheral segment.
And, new method to analyze the pressure volume curve (PV-curve) was examined. The fundamentally theory is following: we can estimate that the frequency distribution of the volume of alveoli obeys a normal distribution from the law of large numbers. On the other hand, considering the equation of continuity in the hollow sphere receiving extemal force (as lung), there are two solves at the cases of the uniform compression and the compressible process. Then, the volume function should be revealed as logarithmic pressure when the condition is a compressible fluid. Therefore, the alveoli volume distribution of PV-curve measured by a dynamical method has to be explained in the logarithmic nomal distribution. As a result plotting the volume ratio to total lung capacity on the probability graph paper of logarithmic normal distribution, two crossed linear lines are recognized. And this crossing point is the lower inflection point (LIP) of the PV-curve. These were inspected by this study.
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