In recent years, Fiber Bragg Grating (FBG) optical fibers have gained popularity to be used for shape sensing (SS) of continuum manipulators (CMs) developed for various minimally invasive surgeries. Despite their benefits, arduous, time-consuming, and costly fabrication procedure together with the limited and discrete sensing nodes on each fiber are some of the main shortcomings of FBG-based SS of CMs. Aiming at addressing these challenges and leveraging the Optical Frequency Domain Reflectometry (OFDR) technology, in this paper, we propose design and fabrication of a shape sensing assembly (SSA) that consists of solely one distributed fiber optic sensor and a flat Nitinol wire. The proposed SSA and fabrication procedure can collectively address the mentioned drawbacks of FBG-based SSAs (i) by continuously measuring the strain along the length of fiber at a very high resolution, and (ii) offering a simple, cost-efficient, and repeatable manufacturing process that reduces the assembly time and improves its accuracy. Performed calibration experiments indicated the consistent and robust strain-curvature relationship (R ² = 0.99) for the proposed OFDR-SSA.