Unsteady diffusional screening in 3D pulmonary acinar structures: from infancy to adulthood

Area of Science:

• Physiology
• Biophysics
• Computational Biology

Background:

• Diffusional screening describes oxygen depletion in lung airways due to their structure.
• Understanding oxygen transport is crucial for respiratory health, especially during lung development.

Purpose of the Study:

• To investigate diffusional screening and oxygen transport in anatomically accurate lung models across developmental stages.
• To analyze the impact of breathing patterns and lung growth on oxygen molecule distribution.

Main Methods:

• Developed 3D computational models of pulmonary acinar airways.
• Simulated unsteady oxygen transport incorporating convection and diffusion under cyclic breathing.
• Analyzed oxygen transport across four developmental stages: 3 months, 1 year, 3 years, and adulthood.

Main Results:

• Observed significant changes in oxygen transport during lung development, with highest efficiency in young infants.
• Demonstrated rapid convergence of oxygen transport efficiency towards adult levels with age.
• Revealed that increased ventilatory effort fundamentally alters oxygen transport dynamics, enhancing the role of convection.

Conclusions:

• The study provides a detailed, time-resolved characterization of oxygen transport in the pulmonary acinus from infancy to adulthood.
• Findings highlight the dynamic nature of oxygen transport and its dependence on lung morphology and breathing.
• This research offers novel insights into respiratory physiology across the lifespan.