A Novel Steerable Catheter for Vascular Interventional Surgery

To improve the operation success rate, the steerable catheter is theoretically significant and practically valuable to design. However, it is still difficult for most existing catheters to realize this function. In this paper, to steer the catheter head, a novel spring-based tendon-drive structure was proposed with a diameter of 1.5mm. To obtain precise tip poses, based on the local force analysis, it is demonstrated that the contact force at each point between the tendon and spring is equal. And under the premise of frictionless, the curvature at each point of the tendon is equal, which is only related to the tension of the tendon. Then the proposed structure is simplified to a cantilever beam only subjected to bending moment. And the deformation of the catheter tip with the control parameters is expressed. Finally, the experimental setup is established and the experimental results showed that the proposed spring-based tendon-driven catheter deflected in a circular. And the results justified the feasibility of the cantilever beam assumption and the correctness of the deformation formulas. The proposed tendon-driven catheter has the potential in improving the success rate of the vascular approach and operation safety.