Interleaved continuum-rigid manipulation: An augmented approach for robotic minimally-invasive flexible catheter-based procedures

In recent years, minimally-invasive surgical systems based on flexible robotic manipulators have met with success. One major advantage of the flexible manipulator approach is its superior safety characteristics as compared to rigid manipulators. However, their soft compliant structure, in combination with internal friction, results in poor position and force regulation and has limited their use to simpler surgical procedures. In this paper, we discuss a new approach to continuum robotic manipulation that combines flexible, actively actuated continuum segments with small, limited stroke rigid-link actuators. The small rigid-link joints are interleaved between successive continuum segments and provide a redundant motion and error correction capability. The authors refer to this approach as interleaved continuum-rigid manipulation. In this paper, we describe the overall approach and investigate its performance using a one degree-of-freedom testbed and two degree-of-freedom planar simulation.