A Miniature Mobile Robot for Precise and Stable Access to the Beating Heart

Abstract

For a wide array of procedures, cardiologists and cardiac surgeons currently compete with one another to provide minimally invasive therapy with the goal of decreasing associated morbidity while providing quality treatment. Although the thoracoscopic techniques used by cardiac sur-geons greatly reduce morbidity compared to open surgery, the percutaneous transvenous ap-proaches favored by cardiologists are less invasive and can be performed on an out-patient basis. In light of this convergence, it is reasonable to consider the development of hybrid instrumenta-tion and techniques that address the goals of both cardiologists and cardiac surgeons. In this thesis, we propose that the development of a miniature mobile robot (HeartLander) that adheres to and traverses the epicardium will provide a tool for precise and stable interaction with the beating heart. The ability of the robot to adhere to the epicardium obviates the need for cardiopulmonary bypass or mechanical stabilization, while the mobility overcomes access limita-tions that currently limit thoracoscopic techniques. Additionally, the ability of HeartLander to be deployed to the apex of the heart through a percutaneous subxiphoid approach may enable cardiac surgeons to provide out-patient procedures. To demonstrate the utility of HeartLander, we focus on a subset three intrapericardial thera-pies that require precise and stable treatments at multiple sites on the surface of the heart: myo-cardial injection of regenerative materials, epicardial lead placement, and epicardial ablation. To facilitate these clinical tasks, HeartLander must provide access over the entire epicardium, dem-onstrate precise positioning to selected targets, and ensure safe and stable interaction with the sur-face of the beating heart. To minimize the associated morbidity, the robot must achieve these goals with the chest closed, the pericardium intact, and the heart beating. Through a series of closed-chest, beating-heart porcine studies, HeartLander demonstrated navigation over the entire circumference of the heart, the acquisition of targets within 1.0 mm, and stability with residual motion less than 1.0 mm. The novel HeartLander paradigm combines the tracking techniques, anatomical models, and minimal access morbidity of transvenous procedures with the epicardial access and fine control of thoracoscopic techniques. A hybrid device of this nature may provide advantages over current approaches within the field of cardiac care for certain procedures.