Fig. 4
From: Creating nasal cycle simulations by processing MRI and CT scan data with image morphing algorithms
Path planning algorithms. The path planning algorithms generate paths (blue lines) through the open airway space (outlined in red), which lies between the boundary of the original turbinate tissue region and the outer boundary of the nasal airway/cavity (excluding the turbinates). This outlined space also defines the navigable grid space for the algorithms. (A) The linear image morphing algorithm connects corresponding points using straight lines (blue), but it does not respect anatomical boundaries (red). The inset shows a pathway (blue) that crosses outside the open nasal airway boundary (red), highlighting this limitation. (B) The A* algorithm generates paths (blue) on a grid map from the start to goal nodes, while allowing for multiple directional turns and respecting the boundary constraints of the nasal airway contour (red). The algorithm calculates the heuristic cost to move from a particular node to the goal node, selecting the path with the lowest total cost as the best route. Inset grids are illustrative and not to scale.
