Mathematical modelling of the normal swallow
A problem presented at the UK MMSG Strathclyde 2010.
- Presented by:
- Department of Clinical Language Sciences, University of Reading) (
There are an estimated 40% of people who have dysphagia (eating, drinking and swallowing problems) following stroke. Management of dysphagia includes provision of modified foods and drinks to attempt to address this problem, based on the assumption that these foods/liquids have the best rheological properties for the normal swallowing process.
There is currently no complete mathematical model of the whole of the dynamic swallow process to allow us to consider the following questions:
- What occurs during the normal swallow at each stage and how do the stages interrelate and interact with each other?
- What impact do food and drinks have on the whole of this process?
- What occurs during swallow breakdown?
- What impact do the rheology of adapted foods and drink process (and is this the effect we predict at present)?
A model of the normal swallow would allow us to introduce specific types of disorder into the swallow such as difficulty with anterior posterior tongue movement, a common feature found in Parkinson’s disease and model the impact of this on other parts of the dynamic process. In addition, modelling of the normal swallow could help us look at the impact of modified foods and liquids.
Study Group Report
During the Study Group the group managed to acquire a good understanding of the anatomical structures and of the dynamical process generally involved in swallowing by constantly comparing and contrasting normal to abnormal cases (dysphagia). We developed a simple fluid dynamical model of the second and third stages of the swallow process, i.e. whereby a bolus is ejected from the oral cavity by the tongue. Various boli types were considered which allowed us to simplify the governing equations for liquid, semi-liquid and solid boli. Initial numerical simulations for these three cases have allowed us to determine how the pressure field varies within the oral cavity varies. Results for all three cases showed the bolus moving from the high pressure regions on the left of the region to the lower pressure on the right, indicating a normal swallow.