Modular Optic Force Sensor for a Surgical Device Using a Fabry–Perot Interferometer

The ability to sense force in surgery is in high demand in many applications such asforce feedback in surgical robots and remote palpation (e.g., tumor detection in endoscopic surgery).In addition, recording and analyzing surgical data is of substantial value in terms of evidence-basedmedicine. However, force sensing in surgery remains challenging because of the specific requirementsof surgical instruments, namely, they must be small, bio-compatible, sterilizable, and tolerant tonoise. In this study, we propose a modular optic force sensor using a Fabry–Perot interferometer thatcan be used on surgical devices. The the proposed sensor can be implemented like a strain gauge,which is widely used in industrial applications but not compatible with surgery. The proposed sensorincludes two key elements, a fiber-optic pressure sensor using a Fabry–Perot interferometer thatwas previously developed by one of the authors and a structure that includes a carbide pin thatcontacts the pressure sensor along the long axis. These two elements are fixed in a guide channelfabricated in a 3 × 2 × 0.5 mm sensor housing. The experimental results are promising, revealinga linear relationship between the output and the applied load while showing a linear temperaturecharacteristic that suggests temperature compensation will be needed in use.