Bending stiffness variability between a deployable robotic laser osteotome and its insertion device

Abstract

Varying device stiffness on purpose can provide safety and performance improvements in interventions involving flexible minimal-invasive surgical robotic devices. For example, when flexible robotic devices are used for inserting minimal-invasive tools along curved paths into the knee joint for arthroscopy, a high device stiffness can allow precise path following where desirable. In contrast, when the minimalinvasive flexible device has reached its desired location inside the patient’s body, decoupling the surgical tool (end-effector) from the flexible robotic insertion device can be beneficial in avoiding transferring disturbances such as vibrations to the robot-patient interaction. In this paper, we investigate bending stiffness variability in dependence on the length of a flexible supply channel. Our experiments have shown that bending stiffness in fact decreases with the length of the supply channel but the highest stiffness connection is not sufficiently rigid and we plan to implement a more rigid connection to allow precise path following during insertion.

Keywords

• robotic surgery
• supply channel
• variable stiffness
• parallel robot
• robotic endoscope
• minimally invasive surgery
• laser osteotomy