Fabrication of tip position tracking sensor for high-bending minimally-invasive surgery robot

We described a fabrication process of thin 3-dimensional tip position tracking sensor. This sensor was composed of optical fibers molded by epoxy. A few fiber Bragg gratings of different pitches were written in each optical fiber, then the light of specified wavelength is reflected from each fiber Bragg grating. Because the optical fibers are molded not on the center of the fabricated sensor beam, the gratings get strain as the sensor beam is bent. Therefore, the curvature and bending direction is achieved, and final tip position of the sensor beam could be calculated from the data. To fabricate sensor beam of submillimiter diameter which is applicable to the high-curvature condition, Teflon tube and align jigs were fabricated and used. This sensor would enable tip position tracking without help of other imaging devices such as camera and lenses.