A robotic assistant system for cardiac interventions under MRI guidance

Abstract

In this paper we present a surgical assistant system for implanting prosthetic aortic valve transapically under MRI guidance, in a beating heart. The system integrates an MR imaging system, a robotic system, as well as user interfaces for a surgeon to plan the procedure and manipulate the robot. A compact robotic delivery module mounted on a robotic arm is used for delivering both balloon-expandable and self-expanding prosthesis. The system provides different user interfaces at different stages of the procedure. A compact fiducial pattern close to the volume of interest is proposed for robot registration. The image processing and the transformation recovery methods using this fiducial in MRI are presented. The registration accuracy obtained by using this compact fiducial is comparable to the larger multi-spherical marker registration method. The registration accuracy using these two methods is less than 0.62±0.50 deg (mean ± std. dev.) and 0.63±0.72 deg (mean ± std. dev.), respectively. We evaluated each of the components and show that they can work together to form a complete system for transapical aortic valve replacement.