[A three dimensional fractal simulation of the lung bronchial tree]

The lungs are naturally irregular and asymmetrical organ in anatomy. The conducting bronchial trees in the lungs display complex self-similar structure. We have established the host mesh coordinates of the right lung on the basis of the anatomical data from the literature. A three-dimensional fractal model of the conducting airways was set up by calculating the coordinates of the mass centers of the divided blocks, searching the branch direction and determining branch lengths with the use of the drawing tool OpenGL. Specific data of the lengths at various grades, branching angles, and capillary diameters were obtained. As a result, the computed data were identical with those of the existing statistical data. The fractal covering dimensionality obtained in the computation of this model was 2.19, which is very close to the ideal dimensionality, 2.17, from the literature. The present model has laid the foundation for further research of the gas diffusion and transfer performance in the lungs using the fractal concept, and furthermore, it helps to save the computer memories and fastening the graphic transfer.