Development of optical FBG force measurement system for the medical application

Haptic feedback plays a very important role in medical surgery. In minimally invasive surgery (MIS), however, very long and stiff bar of instruments take haptic feeling away from the surgeon. In minimally invasive robotic surgery (MIRS), moreover, haptic feelings are totally eliminated. Previous researchers have reported that the absence of force feedback increased the average force magnitude applied to the tissue by at least 50%, and increased the peakforce magnitude by at least a factor of two. Therefore, it is very important to provide haptic information in MIRS. Recently, many sensors are being developed for MIS or MIRS, but they have some obstacles in their application to real situations of medical surgery. The most critical problems are size limit and sterilizability. Optical fiber sensors are one of the most suitable sensors for this environment. Especially, optical fiber Bragg grating (FBG) sensor has one additional advantage than the other optical fiber sensors. FBG sensor is not influenced by intensity of light source. In this paper, we would like to present the initial results of study on the application of the FBG sensor to measure reflected forces in MIRS environments and then suggest the possibility of successful application to the MIRS systems.