Water-jet outer sheath with braided shape memory polymer tubes for upper gastrointestinal tract screening

Background Flexible endoscopes have become an important tool for the diagnosis and treatment of gastric cancer. However, there are several limitations to the use of endoscopes in rural areas, including their high cost, poor portability, and unstable platform. Methods This paper presents a novel low-cost outer sheath for stomach screening. The sheath uses braided shape memory polymer (SMP) tubes with a water-jet to control the stiffness and bending motion. The insertion part of the prototype is 250 mm long with a maximum outer diameter of 16 mm and incorporates an internal charge-coupled device camera. Results We have tested the workspace and stiffness of the outer sheath. The prototype has also been validated with phantom and ex vivo porcine stomach experiments. Conclusions By controlling the water-jet and temperature of the braided SMP tubes, the outer sheath achieves a large workspace and a remarkable variability in stiffness, demonstrating the potential clinical value of the outer sheath system.