Modeling and estimation of ablation catheter contact force under blood flow disturbance

Real-time, accurate estimation of catheter tip-atrial tissue contact force (CF) is essential for safe, effective robot-assisted radiofrequency catheter ablation (RFCA). Conventional models often neglect intracardiac hemodynamics or reduce them to steady flow, missing cardiac-cycle velocity variations and pulsatile disturbances, thus causing large errors. This study proposes a CF estimation framework using cubic Bezier splines for catheter morphology, a sinusoidal velocity model for pulsatile blood flow, and a quasi-static Euler-Bernoulli beam moment equilibrium with distributed hydrodynamic loads. CF is inversely estimated via least-squares and the Moore-Penrose pseudoinverse. FE and in-vitro results show improved dynamic-condition accuracy and physiologically relevant intraoperative feedback.