An Innovative 3D Colonoscope Shape Sensing Sensor Based on FBG Sensor Array

Colonoscopy is now the gold standard method for investigating most colonic symptoms. In the process of diagnosis, it is easy to cause the apex of loop splitting the colonic wall because the shape of colon is invisible for the colonoscopist who only relies on his experience to insert the colonoscope into the body and it brings the patients much pain and danger. So shape sensing technologies for colonoscope become a focus of this research field. At present, one solution is magnetic-based shape sensing system, but this technology must work in a non-metallic operating ambient. This paper presents an innovative way which use base-Fiber Bragg Grating (FBG) senor array to reconstruction the shape of colonoscope while advancing inside the colon. In this paper design and packing of shape sensing sensor is discussed and shape reconstruction principle based on differential geometry is described. Some simulation and model experiments have been done to testify validity of shape sensing.