Tags:impedance, needle, robot, sensing, surgery and suturing
Abstract:
This paper presents a step towards autonomous robotic suturing. Specifically, we propose a method for suture needle state estimation during insertion into soft tissue based on electrical bioimpedance (EBI) sensing. EBI is an advantageous sensing modality in RMIS, given that it is non-invasive and requires only minor modifications to existing surgical instruments. In this study, we equip a surgical robot with EBI sensing capabilities, allowing the robot to measure the electrical impedance between a needle driver instrument and a common ground electrode. The proposed method requires a suture needle with insulation coating except for its tip, end, and notch in the middle. We conducted an experiment for concept validation based on ex vivo animal tissue where we obtained a 98.8% prediction accuracy on four different suture needle insertion states. Most interestingly, we could accurately determine when the needle tip exits after being pushed through soft tissue, which is challenging to do with, e.g., computer vision due to the needle’s small size and occlusions. The needle tip exiting is valuable information as often one wishes to grasp the needle tip with a second manipulator to complete the suture throw by pulling the needle through the tissue.
A New Suture Needle State Estimation Method Based on Electrical Impedance Sensing