A preliminary study on using a Robotically-Actuated Delivery Sheath (RADS) for transapical aortic valve implantation

Recent technological advancements in cardiovascular surgery such as transapical transcatheter aortic valve implantation (TA-TAVI) enabled treatment to elderly that were initially declined surgery. However, valve malpositioning during TA-TAVI have been reported in several cases. In this preliminary study, we present a novel approach in which a Robotically-Actuated Delivery Sheath (RADS) is used to potentially facilitate valve positioning. A model is developed that describes the shape and articulating tip position of the RADS. We developed a two-dimensional ultrasound tracking method that evaluates the tip position of the RADS in ultrasound images. Both modeling and ultrasound tracking are combined into an integrated system that facilitates closed-loop control of the articulating tip of the RADS. Experiments are performed in order to evaluate the tracking accuracy of the RADS. Experiments show mean positioning errors of approximately 2 mm along the x- and y-axes. Our study demonstrates that the RADS can potentially provide compensation for beating heart and respiratory motions during valve positioning and deployment in TA-TAVI.