Motion Compensated Catheter Ablation of the Beating Heart Using Image Guidance and Force Control

Cardiac catheters allow physicians to access the inside of the heart and perform therapeutic interventions without stopping the heart or opening the chest. However, conventional manual and actuated cardiac catheters are currently unable to precisely track and manipulate the intracardiac tissue structures because of the fast tissue motion and potential for applying damaging forces. This paper addresses these challenges by proposing and implementing a robotic catheter system that use 3D ultrasound image guidance and force control to enable constant contact with a moving target surface in order to perform an interventional procedure, in this case tissue ablation. The robotic catheter system, consisting of a catheter module, ablation and force sensing end effector, drive system, and imageguidance and control system, was commanded to apply a constant force against a moving target using a position-modulated force control method. As compared to a manual catheter system, the robotic catheter was able to apply a more consistent force on the target while maintaining ablation electrode contact with 97% less RMS contact resistance variation. These results demonstrate that the 3D ultrasound guidance and force control allow the robotic system to maintain better contact with a moving tissue structure, thus allowing for more accurate and repeatable tissue ablation procedures.