UBC Theses and Dissertations
3D biomechanical oropharyngeal model for training and diagnosis of dysphagia Farazi, Md Moshiur Rahman
Swallowing is a complex oropharyngeal process governed by intricate neuromuscular functions. Dysfunction in swallowing, clinically termed as dysphagia, can significantly reduce the quality of life. Modified barium swallow (MBS) studies are performed to produce vidoefluoroscopy (VF) for visualizing swallowing dynamics to diagnose dysphagia. To train the clinicians learning standardized dysphagia diagnosis, 2D animated videos coupled with VF are used. However, it is hypothesised that the physiologic components of the oral domain may benefit from extension of the training materials, such as inclusion of 3D models. We develop a 3D biomechanical swallowing model of the oropharyngeal complex to extend the clinical dysphagia diagnosis training materials. Our approach incorporates realistic geometries and accurate timing of swallowing events derived from training animations that have been clinically validated. We develop rigid body models for the bony structures and finite element models (FEM) for the deformable soft structures, and drive our coupled biomechanical model kinematically with accurate timing of swallowing events. We implement an airway-skin mesh using a geometric skinning technique that unifies geometric blending for rigid body model with embedded surface for FEMs to incorporate the deformation of upper airway during a swallowing motion. We use smoothed particle hydrodynamics (SPH) technique to simulate a fluid bolus in the airway-skin mesh where the model dynamics drive the bolus to emulate bolus transport during a swallowing motion. We validate this model in two phases. Firstly, we compare the simulated bolus movement with input data and match the swallowing kinematics identified in the standardized animations. Secondly, we extend existing training material for standardized dysphagia diagnosis with our 3D model. To test the usefulness of the extended training set using 3D visualizations, we conduct a pilot user study involving Speech Language Pathologists. The pilot data indicate that clinicians believe the additional 3D views are useful for identifying the salient features for differentiating between different swallowing impairments, such as direction, strength and timing of the tongue motion, and could be a useful addition to the current standardized MBSImP™© training system.
Item Citations and Data
Attribution-NonCommercial-NoDerivs 2.5 Canada