Tissue strains induced in airways due to mechanical ventilation

Area of Science:

• Biomedical Engineering
• Computational Biology
• Respiratory Medicine

Background:

• Mechanical ventilation is vital for respiratory failure but can cause lung injury.
• Quantifying stress and strain in airway tissues is challenging experimentally.
• Airway tissue heterogeneity influences mechanical stress and potential damage.

Purpose of the Study:

• To develop and utilize a computational model to analyze strain distribution in airway tissues.
• To investigate the impact of airway tissue material property heterogeneity on strain.
• To compare strain predictions between heterogeneous and homogeneous airway tissue models.

Main Methods:

• A computational model of airway tissue was developed, incorporating heterogeneity.
• Tissue strain analysis geometry and boundary conditions were derived from an organ-level model.
• Simulations were performed using both heterogeneous and homogeneous airway tissue properties.

Main Results:

• The homogeneous model inaccurately predicted strain levels across airway wall layers.
• Maximum strain in the mucosa layer was overestimated by the homogeneous model.
• Maximum strain in smooth muscle and cartilage layers was underestimated by the homogeneous model.

Conclusions:

• Airway tissue heterogeneity significantly affects strain distribution.
• Inaccurate strain predictions from homogeneous models can misrepresent tissue stress.
• Understanding precise strain is critical for preventing ventilator-induced lung injury and inflammation.