Bionic design of the oral swallowing in vitro and its application in the dysphagia

Dysphagia, the swallowing disorder, is a common disease among the elders and stroke patients. Therefore, based on the bionic swallowing device (BSD) in vitro of similar human-tongue motion during swallowing, the development of functional food is necessary to improve the food swallowing quality of the deglutition disorders patients. In this study, the tongue motion was thoroughly investigated by extracting the characteristic data, and appropriate mechanisms in vitro were adopted to replicate the motion of the tongue swallowing according to the normal swallowing oropharyngeal data. The application of the BSD was also investigated at different swallowing grades (SGs). The study results indicated that the tongue motion consisted of tongue root point (TRP) and several tongue motor points (TMPs). The cam-link and push-rod mechanisms showed ellipse lines for TRP motion and straight lines for TMPs, respectively. Higher correlation coefficients between the tongue trajectories in the oropharyngeal data and simulated curves of the combined mechanism were observed. The average correlation coefficients between the tongue trajectories of patients at five SGs and those of the BSD were 0.87, proving its effectiveness and potential application. Furthermore, the corn-paste experiments of the BSD showed that dysphagia at five SGs could be a suitable choice for certain food concentrations. This will provide valuable insight into developing more functional foods in vitro for high deglutition disorders.