A Highly Distensible, Cable Loop-Driven Soft Robotic Gastric Simulator for Endoscopy Training

Abstract

With the increased demand for endoscopic diagnosis in the upper gastrointestinal (GI) tract, gastric simulators have been developed for endoscopy training. However, most of them remain nonideal due to their static and nondistensible nature. This paper presents a new soft robotic gastric simulator, comprising mainly of a silicone-based stomach model that mimics the size and inner surface condition of a human stomach. It also features peristaltic effect on its stomach wall via five cable loop-driven mechanisms, sphincter mechanisms at two ends of the stomach model, and structural pathology phantoms that can be magnetically controlled for multi-location deployment. Finite element simulation of the stomach behavior was performed under different insufflation pressures to determine the cable loop mechanism design parameters. During the simulator evaluation, the performances of the sphincters and cable loop mechanisms were first characterized. The simulator was then actuated to provide sequential contraction across the stomach model at different contraction ratios, leading to intragastric pressures similar to those reported in the literature. Finally, a preliminary user study was performed to face validate the simulator in terms of its realism, usability, and usefulness for endoscopy training. It is envisioned that the soft robotic gastric simulator could be adopted in endoscopy training programs to replace the use of animal models.