Pop-Up Tissue Retraction Mechanism for Endoscopic Surgery

Abstract

Numerous therapeutic transendoscopic procedures exist to treat lesions in the GI tract. However, these procedures are limited both by their difficulty and by the amount of training required to successfully perform them. The surgeon is tasked with simultaneously steering the distal tip of the endoscope, applying and maintaining tension to retract tissue, and manipulating electro-cautery tools with limited dexterity. In this thesis, I propose a device designed to assist with anchoring and tissue retraction during endoscopic surgical procedures. The designed solution decouples the tissue-grasping function from endoscope tip movement, leaving the surgeon free to use the endoscope tip solely for positioning of electro-cautery or biopsy tools deployed through the endoscope working channel. The anchoring and retraction device uses “pop-up book MEMS” techniques, allowing for a relatively flat structure to expand into a 3-dimensional structure many times its initial height. The proposed device has three main integrated components: a rigid expandable geometric structure, inflatable pneumatic actuators, and a vacuum gripper. These inflatable actuators include internal rigid discs, allowing for resistance to buckling while maintaining the benefits of the established lightweight, low profile actuator design scheme. Proof-of-concept ex vivo testing demonstrates that the integrated device can be used to retract tissue to a height of 13.5 mm, providing access for endoscopy tools to contact a sample of porcine stomach tissue. Additional testing presented here demonstrated functionality of the proposed device deployment scheme.