A robotics-assisted catheter manipulation system for cardiac ablation with real-time force estimation

Lack of dexterous control over the position of a catheter's distal tip and not having any feedback from the quality of tip - tissue contact are among the factors that make the conventional catheter-based method of performing cardiac ablation very challenging. To resolve these issues, in this paper, we present a robotic catheter manipulation system that accommodates a conventional ablation catheter, places the ablation tip at the desired target and reports the forces that the tip exerts on the environment in real-time. In this system, the manual proximal handle is replaced with a mechanism that is capable of measuring the tension force along the pull-wire while actuating it to flex the distal shaft of the catheter. The placement of force/pressure sensors at the distal end of the catheter is avoided by developing a model-based force estimation technique using the measured tension force and information on the position and orientation of the distal tip. The developed system is further enhanced with an interface to assist the user in placing the catheter tip at the desired location while providing him/her with a real-time measure of the contact force. Extensive experiments show that using the proposed robotic system, the catheter tip is positioned within ±1 mm of the designated target and contact forces are reported in real-time with an accuracy of 3 gf.