High-precision colonoscope image guidance using OFDR shape sensing with right-angle core configuration in multicore fiber

High-precision colonoscope image guidance using OFDR shape sensing with right-angle core configuration and cosine similarity algorithm is proposed for the first time. The inter-core sensing point misalignment is well corrected and accurate fiber twisting compensation is enabled. Experiment results show less than 1.55% relative error and 2.5 times accuracy improvement when compared with traditional equilateral-triangle core configuration, and the reconstructed shape of the colonoscope matches well with the real shape inside the human intestinal model.