Ultrasound-guided stabilization of a robotically-actuated delivery sheath (RADS) for beating heart mitral valve motions

Minimally invasive mitral valve (MV) repair surgery significantly reduces trauma compared to an open heart procedure, which enables fast recovery and treatment to high-risk patients. However, limited vision and dexterity of the instrument at the treatment location poses a challenge for minimally invasive surgery. Additionally, MV repair surgery performed without cardiopulmonary bypass often requires the surgeon to deal with beating heart motions. By autonomous stabilization of the instrument, a virtually-still treatment location could be provided. This allows the surgeon to perform surgery as if the heart was stopped. In this study, we present and evaluate a framework that assists the surgeon by stabilizing the instrument for the beating heart MV motions. Our work contributes a robotically-actuated delivery sheath (RADS), which is stabilized in a realistic and functional MV model embedded in a heart motion system. The heart motion system is mounted on a six degrees-of-freedom Stewart platform, which reproduces beating heart MV motions based on pre-operative patient data obtained from three-dimensional magnetic resonance and ultrasound images. Experimental results shows stabilization of the RADS in a beating heart MV model with a mean absolute tracking error of 1.31 mm. The presented framework for stabilization of the RADS in the beating heart could be applicable to a wide variety of existing and potential future cardiovascular interventions.