Design,Modeling,and Validation of a Pneumatically Actuated Distal Segment for Endoscopy

Abstract

To reduce the risk of patient cross-contamination associated with reusable endoscopes, health care systems are increasingly turning to single-use devices. While this shift improves hygiene, it raises significant environmental and economic concerns due to increased medical waste and long-term costs. In response, this study proposes a semi-disposable pneumatic endoscope concept designed to support the transition toward greener endoscopy. It is composed of a reusable handle and a disposable, pneumatically actuated insertion tube. The study focuses on the design, modeling, and prototyping of the flexible part of the endoscopic tube to address challenges linked to soft actuation. A finite element model was developed to simulate the bending behavior of the flexible segment made of silicone. It allows the study of key geometrical parameters, such as pneumatic chamber diameter and wall thickness. A ring-based constraint system was implemented to address excessive radial expansion and associated bulging under pressure, which effectively minimized radial deformation without compromising bending capability. The design obtained through simulation integrates all essential functionalities of a clinical gastroscope (imaging, tool insertion, and insufflation/suction) within an outer diameter of 14 mm. It was experimentally validated using physical prototypes, confirming the ability to bend up to 180°, with deformation patterns closely matching simulation predictions. In addition, the prototype supports future integration of a variable stiffness mechanism using jamming-based techniques, further enhancing its potential for clinical use. This work thus proposes a viable path toward more sustainable and clinically relevant endoscopic solutions using pneumatic actuation.