Computer simulations of human Lungs

• CFD modelling within the human lungs is a challenging problem, because of the range of length scales and flow rates encountered, for example turbulent flow conditions in the upper airways, to relatively slow laminar flows in the deeper lungs.
• CT (Computed Tomography) imaging

• Recent developments in multi-detector high resolution CT (HRCT) scanning means that we are now in a position to study the architecture of the airway in detail typically to the 6th airway generation, and to segment the airway tree and develop well-validated complex models of airway flow. This can be further informed by functional imaging such as hyperpolarized helium magnetic resonance imaging (MRI) to assess flow metrics (Velocitometry).
• The large airway model does not typically extend beyond the 6th airway generation due to limitations imposed by resolution of low dose CT scans, so smaller airways are beyond the conventional resolution of computed tomography. To address this issue, the large airway models can be extended using computer algorithms that incorporate realistic Weibel airway branching geometry to include small airway structure.
• A surface mesh model will be built up from the CT airway imaging (above), and then 3D volume meshes will be generated with good quality meshes that resolve the flow boundary layers efficiently.
• Such a model can be used for CFD simulations. CFD codes (Star_CCM+, ANSYS FLUENT or OpenFOAM) will be used in this project.

Images

• Airway model
• Healthy patient
  • Pressure and Velocity
• Asthmatic patient
  • Pressure and Velocity