Towards Model-based Contact Force Estimation for Flexible Catheter

Robotic flexible catheter has been used for minimally invasive cardiac surgery including curing atrial fibrillation, and guaranteeing the safety of patients during surgery is naturally the top priority. However, the working environment of the catheter makes it hard to directly measure the contact force. This paper introduces two model-based catheter contact force estimation algorithms, geometric features-based contact force estimation algorithm and geometric error-based contact force estimation algorithm. The algorithms are developed and validated using an experimental platform that can capture the shape of the catheter and convert it into coordinate points and sensor readings for algorithm verification. The geometric features-based contact force estimation algorithm has an average contact force size error of 5.37%, an average contact force direction error of 4.04%, and the average run time is 0.197s The geometric error-based contact force estimation algorithm has an average contact force size error of 6.92%, an average contact force direction error of 7.97%, and the average run time is 2.202s.