Development of FBG sensor system for force-feedback in minimally invasive robotic surgery

Force feedback plays a very important role in medical surgery. In minimally invasive surgery (MIS), however, the very long and stiff bars of surgical instruments greatly diminish force-feedback to the surgeon. In the case of minimally invasive robotic surgery (MIRS), force-feedback is 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 force information in MIRS. Recently, many sensors are being developed for MIS and MIRS, but some obstacles to their application in actual medical surgery must be surmounted. The most critical problems are size limit and sterilizability. Optical fiber sensors are among the most suitable sensors for the surgical environment. The optical fiber Bragg grating (FBG) sensor in particular offers an important additional advantage over other optical fiber sensors in that it is not influenced by the intensity of the light source. In this paper, we present the initial results of a study on the application of a FBG sensor to measure reflected forces in MIRS environments and suggest the possibility of successful application to MIRS systems.