Robotic Steerable Sheath for Left Atrial Appendage Occlusion

Atrial fibrillation, the most common cardiac arrhythmia, increases stroke risk due to clot formation in the left atrial appendage (LAA), where over 90% of thrombi originate. Left atrial appendage occlusion (LAAO) reduces this risk by mechanically sealing the LAA through an occluder. A key challenge is achieving coaxial alignment of the delivery sheath with the LAA, which varies in shape and orientation among subjects. Fixed-curve sheaths lack adaptability, while steerable sheaths improve alignment but still expose operators to fluoroscopic radiation. This study introduces the first robotic steerable delivery sheath (SDS) for LAAO. The SDS incorporates a notched Nitinol tip with two bending segments, providing three steering degrees of freedom, rotation, and translation, all controlled remotely through motorized actuation. Bench-top experiments confirmed superior dexterity and reachable workspace compared to existing delivery sheaths. A phantom-based validation with 17 users demonstrated successful teleoperated coaxial alignment with the LAA. Quantitative evaluation showed high accuracy, with mean angular and positional errors of 5.52$^{\circ }$and 1.99 mm for the central axis, and 5.00$^{\circ }$and 2.33 mm for implant depth, respectively. These findings support the feasibility of robotic-assisted LAAO, with the potential to enhance procedural precision while reducing radiation exposure for operators.