Development of an Evaluation Simulator for Gastrointestinal Stents by Applying a Peristaltic Pump: Prototype fabrication of evaluation simulators and characteristic tests

This study proposes an evaluation simulator for gastrointestinal stents that reproduces the three-dimensional (3D) behavior of the intestine. One of the symptoms of colorectal cancer is intestinal obstruction. When an intestinal obstruction occurs, the contents of the intestinal tract become blocked, which has various adverse effects on the body. Treatment of intestinal obstruction is generally conservative, but surgery is performed when improvement is not expected. Currently, there are two methods of evaluating the performance of gastrointestinal stents: durability and movement tests. In the durability test, a compression test is repeatedly performed to evaluate the durability of the gastrointestinal stent. In the movement test, the stent is compressed continuously like a wave, and the displacement of the gastrointestinal stent with respect to the number of repetitions is measured. These two types of evaluation tests are used to evaluate the function of the gastrointestinal stent. However, there is no unified standard for evaluation tests of gastrointestinal stents, and each manufacturer conducts their own performance tests. In addition, current evaluation test methods differ from the actual intestine at multiple points. Therefore, an evaluation test method that can reproduce the environment of the intestinal tract with high accuracy is needed. Therefore, the authors focused on a peristaltic pump that mimics a living body. We propose an evaluation simulator for gastrointestinal stents that can reproduce 3D behavior similar to actual intestinal peristalsis, based on the driving principle of a unit-connected peristaltic pump. This paper first establishes the concept behind the development of an evaluation simulator for gastrointestinal stents, and then describes the developed evaluation simulator. Finally, we conducted experiments to measure the contraction pattern and internal pressure during contraction of the evaluation simulator and evaluated this simulator by comparing it with the actual peristalsis of the intestinal tract. The experimental results confirmed that it is possible to reproduce behavior similar to the actual intestinal tract movement.