63 / 2019-08-16 02:00:31

The Design and Analysis of a Deployable Mechanism for Transoral Endoscopic Surgery

variable-dimension overtube,deployable structure,natural orifice transluminal endoscopic surgery

全体主题 > Medical diagnosis and surgical robotics

In natural orifice transluminal endoscopic surgery, the insertion of the surgical instruments can cause patient discomfort, even the bleeding and perforation. This paper proposes a design of an overtube which can vary its radial dimension. It can be inserted to the target tissue in a small size and then enlarge its size and form a hollow and rigid channel for the subsequent instruments to protect the human orifice. The Bricard linkage is used as the basic unit of the overtube and a specific spatial mechanism is designed to drive multiple Bricard units fold or deploy. The design parameter optimization has been studied and comparison experiments have been completed to verify the feasibility of the design on reducing the shear force and normal force during surgical instrument insertion. It was found that inserting the overtube with folded configuration, the average peak values of shear force and normal force decrease by 52% and 45.2% respectively compared to inserting the instrument directly. Furthermore, after the overtube is deployed, the shear and normal force applied to the lumen is significantly reduced from 2.523N and 2.063N to 0.176N and 0.565N respectively.