Fiber Bragg Grating Sensors for Flexible Medical Instruments

Minimally invasive procedures are favored over open surgeries as they cause less trauma to healthy tissue and this leads to shorter recovery time, and thus lower medical costs. These procedures often utilize flexible instruments because they improve access to the operating areas within the body. However, localization of flexible instruments relative to the anatomy is a challenge. In this thesis, this challenge is undertaken, and a technique is developed to localize these instruments. More specifically, methods are presented that can acquire the shape, position, and orientation of a flexible instrument. Fiber Bragg gratings are employed as strain gauges, and the sensor measurements are combined with a mathematical model of curves to determine the instrument's location. Various validation experiments are conducted where these methods are applied to a flexible instrument designed for minimally invasive neurosurgery. The results show that fiber Bragg gratings are effective localization sensors for flexible medical instruments. Moreover, optical fiber sensors have a high potential to further enhance these instruments and research continues to utilize them to their full potential.