Novel Shape Detection Systems Based On FBG Sensor Net For Intelligent Endoscope

The technology for intelligent medical instruments and medical robots is a crucial method and an important means of minimal invasive surgery. With the development of novel sensing technology, mechatronics,bio-engineering, intelligent material, computer graphics and other relevant disciplines, many novel kinds of intelligent medial instruments come out continually and remarkably enhances the function and application area of traditional medical instruments. A colonoscope is a typical instrument for the diagnosis and treat of intestinal disease. However, many difficulties arise as a result of unpredictable and invisible shape of the colonoscope within the colonic anatomy, bringing the patients much pain and danger. Driven by the impending clinical requirement and the favorable commercial foreground, significant research efforts have been made for the amelioration and invention of endoscopic system using intelligent sensing, automation and visualization technology. Among them, novel shape sensing system for endoscope has become a research focus of general interests.This dissertation aims to provide steady sensing systems for the shape detection of colonoscopes. The research especially deals with the key technology of Fiber Bragg Grating (FBG) large curvature sensor and sensor net, integrates the technologies of mechatronics and computer graphics, and then develops real time FBG shape sensing system and incremental shape sending system for colonoscopies. After the analysis of state-of-the-art for the development of the endoscope and the difficulties of colonoscopy, the actualities of both endoscopic shape sensing and of FBG structure monitoring are summarized. By the analysis of the reconstruction principles and optional sensor components, integrated design of the shape sensing systems and the development roadmap of each unit are proposed respectively.Based on the experimental research on FBG sensing response under different strain and temperature separately, the key technologies of typical FBG system are discussed. According to the limitation and requirement of the shape sensing of colonoscope, the principle design, encapsulation and calibration method of FBG large curvature sensor are discussed in detail. The research work mainly includes:â‘ By the design of substrate material, encapsulation mechanism and encapsulation technology, a novel slim FBG large curvature sensor wire is developed.â‘¡FBG sensor with pre-strain is mounted on a slim cylindrical substrate to deal with the limitation caused by unbalanced mechanical property of the optical fiber.â‘¢At the same time, by changing the encapsulation condition, the curvature sensitivity can be adjusted in a large range.In the dissertation, based on the research on the large curvature sensor and the curve fitting method, real time and incremental FBG shape sensing systems have been developed respectively.â‘ A four-channel SDM/WDM FBG sensor net comprised 20...