Estimating the configuration of a continuum dexterous manipulator with variable curvature bending using partial shape-sensing

Reliably estimating the shape of variable curvature continuum dexterous manipulators (CDMs) is necessary to use these devices in biomedical applications. Embedding shape-sensing elements have been shown to effectively measure the shape of constant curvature CDMs. This paper explores several methods for estimating the configuration of variable curvature CDMs. Experiments bent the CDM in varying configurations, applied an external load, and measured the configuration. Three methods are described that use the measurements from simulated shape-sensing elements. Analyses included varying the number and placement of the shape sensors. The results showed at least three shape-sensing elements are necessary to predict manipulator configuration, with one method demonstrating average error less than 0.35 mm for a CDM under an external load. The presented techniques offer promise for successfully predicting, tracking, and controlling CDM configuration during surgery.