Auckland Bioengineering Institute


Lungs and Respiratory System

The pulmonary research group develops anatomically- and biophysically- based mathematical models of the pulmonary system, from the cellular level through to integrative whole organ function and interaction with other organ systems.

Structure-function relationships in the human lung


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We aim to to understand the complex structure-function relationships in the lung and respiratory system, through a combination of experiment, imaging, and interpretation using mathematical models. This approach increases our understanding of lung physiology, and has clinical relevance in understanding the regional mechanisms that contribute to standard clinical measures of lung function.

Lung tissue mechanics


Simulation of lung tissue deformation is a complex problem as microscopic features of pulmonary structure affect the macroscopic behavior of lung tissue. We are constructing models that aim to predict accurate  deformation and recoil pressures in the lung of individuals and can be applied in healthy and diseased states across a range of lung volumes.

In modelling structure-function relationships in the human lung, fitting of the lobes from the CT scan is important for purposes of simulating finite elastic deformation and for accurately growing airway and vessel trees. This video shows the steps: manual segmentation of a left oblique fissure, automatic digitization of (left) lobes and finally fitting the lobes with a Hermite mesh. The mesh was fitted to an RMS error of 1.6 mm. In this video, the digitized lung surface is shown as purple dots. The left oblique fissure is shown as blue dots.The left lower lobe is shown as white dots and left upper lobe as gold dots. 
 

 

Pulmonary hypertension and pulmonary embolism


Pulmonary hypertension is a critical component of a wide range of cardiorespiratory disorders. We are developing a new understanding of factors contributing to pulmonary hypertension in pulmonary embolism (obstruction of the pulmonary vessels). We have constructed integrated functional models of perfusion, ventilation and gas exchange in subject-specific models of patients with pulmonary embolism, and found strong correlations with model predictions and patient outcome.

Airway hyper-responsiveness


We are constructing a predictive computational model of the lung that integrates experimental data relevant to airway hyperresponsiveness from all relevant length (molecular to whole organ levels) and time scales. This includes models of airway smooth muscle (ASM) dynamics, and the balance of ASM force development with force from the surrounding tissue and whole organ levels. This will allow us to identify variable material properties in normal and asthmatic lungs that correlate to experimental data on pulmonary dynamics.