Lung surfactant is a substance that regulates surface tension on the inner surface of alveoli and prevents collapse, but its deficiency in premature infants is a factor that causes respiratory disorders. We investigate the effects of lung microstructure in mouse pups and the differences between the presence and absence of surface tension on the mechanical response by performing finite element analysis. The lung microstructure models are generated based on synchrotron radiation micro-CT images at 0 and 56 days after birth. The surface tension is modeled considering the hysteresis loop. Under positive pressure, the volume strain of 0-day-old mouse pups is larger than that of adult mice. The volume strain is suppressed by the surface tension effects, and its hysteresis loop can be captured with the proposed model. The mechanical response observed in our study may help in understanding the precise setting of ventilators for neonates.
YOSHITOMI et al. (Wed,) studied this question.