Original article published on Surgical Robotics Lab, 11 May 2021.
Congratulations to EDEN PhD student Fouzia Khan, who successfully defended her PhD! The defence of her doctoral thesis titled “Fiber Bragg Grating Sensors for Flexible Medical Instruments” was held on 12 of May 2021 at the University of Groningen.
The main objective of this thesis is to utilize optical sensors called Fiber Bragg gratings (FBG) to acquire the position and orientation of flexible medical instruments such as catheters. These instruments are frequently used in minimally invasive surgeries where small incisions are made to perform the surgery. These minimally invasive surgeries are beneficial for patients because there is no large wound therefore the patient experiences less pain, fast recovery, and fewer complications; thus it contributes to lower hospital costs.
The small size of the incision means that during a minimally invasive surgery the instrument cannot be directly seen, thus the position and orientation of the instrument are concealed. This issue is mitigated currently in practice by utilizing imaging like X-rays or laparoscopes (camera with light source); but these solutions have certain drawbacks such as harmful radiation used in X-rays and inability to use laparoscopes for all minimally invasive surgeries. A laparoscope can only be used in cavities that can be illuminated, such as the abdominal cavity or the ventricles in the brain. However, it is not possible to use a light source in a blood vessel or in solid tissues. These limitations motivate research into alternative methods of acquiring position and orientation of a flexible instrument.
This thesis is an outcome of one such research endeavour and it presents techniques of acquiring the position and orientation of a flexible instrument based on measurements from FBG sensors. Moreover, a method to estimate the forces at the instrument’s tip from the sensor measurements is also presented.
The research in the thesis shows that FBG sensors are effective as position and orientation sensors for flexible medical instruments. Thus, FBG sensors can be applied to instruments utilized in minimally invasive surgery where the instrument is not directly visible. Continuing research in this field will provide insight into the full spectrum of applications of these sensors.