A Sensor-less Catheter Contact Force Estimation Approach in Endovascular Intervention Procedures

Catheter/guidewire manipulation in endovascu-lar intervention procedures are associated with risks of injury on vessel wall and embolization. Determination of catheter/guidewire-vessel interaction contact forces can improve the navigation process safety and efficiency which prevent injuries in both manual and robotic vascular interventions. This study proposes a sensor-less sensing solution to estimate multiple contact point forces at the side of catheter/guidewire exerted on the vasculature. This goal is achieved by using image feedback of catheter-vessel interaction and numerical finite element modeling (FEM). Real-time image processing algorithms are implemented to track interaction contact points on catheter/guidewire. Image-based deflection measurement and contact points tracking data are given to a nonlinear finite element beam model to estimate the forces. The variable equivalent bending modulus of the guidewire is found through a series of three-point-bending tests. To directly measure contact point forces, an experimental platform is prepared which simulates catheter/guidewire-vessel interaction with two, three and four contact points. The effectiveness of the proposed approach is tested in six scenarios in which force estimation accuracy of more than 87.9% is achieved. The proposed approach can be applied to various types of under-actuated catheter/guidewire in endovascular intervention procedures. This study proves that multiple catheter/guidewire side contact forces can be estimated by using the deflected shape and equivalent bending modulus property without embedding any force sensor.