Abstract
Respiratory muscles have the function of generating ventilation, and muscle weakness of respiratory muscles is known to be one of the causes of respiratory failure. Previous reports have not directly measured the muscle strength of the respiratory muscles, and have used indices to evaluate the strength of the respiratory muscles as a whole, so the effects and mechanisms of the degree and location of muscle weakness on respiratory function are unknown. In this study, using a finite element model of the thorax, we conducted a breathing simulation that reproduced muscle weakness of the respiratory muscles by adjusting the excitability of the external intercostal muscles and diaphragm individually. As a result, it was clarified how the ventilation rate changes depending on the excitability of the respiratory muscles. The respiratory muscles were divided into five groups, and each group was analyzed by applying normal excitability and reduced excitability. The results showed that the upper right side of the external intercostal muscles decreased the volume of ventilation the most. Furthermore, it was found that diaphragm muscle weakness reduced the amount of air inflow, but did not reduce ventilation because it increased the amount of air outflow.
