Testing and Analysis of Migration Displacement of a Flared Stent Deployed in an Esophageal Swallowing Robot.

Dysphagia is one of the common suffering condition occurs in esophageal cancer (EC) patients. Implanting self-expanding metal stents in the esophagus is one of the most effective ways for the palliation of the malignant dysphagia. The stents are associated with a common problem known as stent migration (SM) in the esophagus which occurs due to the axial force applied by the peristaltic contractions. A softbodied esophageal swallowing robot (ESR) has been developed to mimic the human swallowing process. Peristalsis in the ESR was achieved by modelling the biological peristaltic wave contractions. This paper discuss a new methodology to test and analyse a newly designed flared stent and its migration on the esophageal swallowing robot. Stent migration tests were performed on the esophageal swallowing robot to determine the displacement of the stent from its initial position due to the effect of the travelling of the peristaltic contractile waves. It was observed that migration displacement increases with the number of peristalsis cycle until it reaches a saturation point where no further displacement occurs. It was also noted that by increasing the applied input pressure in the esophageal swallowing robot, the stent migration displacement becomes higher. The work discussed here also promises that a tool like esophageal swallowing robot can provide a passage for a better stent design which can illuminate the path of prevention of stent migration.