A Variable-Stiffness Catheter with Integrated Force Sensing for Surgical Applications

In this paper, we present the first integration of a novel variable-stiffness (VS) catheter with a bespoke poly (vinylidene fluoride-trifluoroethylene) (P(VDF - TrFE)) miniaturized piezoelectric force sensor. This VS catheter with force sensing offers a robust approach for avoiding tissue damage in clinical scenarios that require flexibility during navigation, while maintaining sufficient durability to prevent dislodgement from target sites. Unlike previous VS catheters, our approach functionalizes shape memory polymer into a VS catheter, enabling significant stiffness variation under a safe scope of temperature for human body. The integration of the force sensor further enhances tissue protection by simultaneous intrabody pressure monitoring. The merit of the simple fabrication process of the sensor also provides the potential to form a sensing array, achieving a higher spatial resolution.