Endoscopic surgery on the beating heart has become a major research objective due to the morbidity associated with median sternotomy and cardiopulmonary bypass. The motion of the beating heart creates significant problems for ac- curate manipulation. In addition, most existing techniques for minimally invasive cardiac surgery involve the use of thoracoscopic incisions and rigid endoscopes, making access to certain parts of the epicardium highly problematic. We hypothesize that for many clinical procedures the problems of beating heart motion and full epicardial access can be solved simultaneously by developing a miniature detachable robotic device that adheres to the heart using suction and travels like an inchworm across the surface, connected to the outside world only by a wire or tether for communication and power. Because this device can move to any desired point on the epicardial surface, a subxiphoid videopericardioscopic approach can be used instead of thoracoscopy. As a result, selective lung ventilation is not needed. By obviating endotracheal intubation, this technology will allow the use of local or regional rather than general anesthesia, creating the potential for ambulatory outpatient cardiac surgery for certain procedures. Potential clinical applications are numerous; as an exemplary application we propose to demonstrate the technology in myocardial injection, such as is used for delivery of myoblasts for cardiac revascularization. The specific aims are to: 1. Develop a self-contained detachable tethered epicardial crawling device (HeartLander) that can enter the pericardium via endoscope, attach itself to the unconstrained beating heart, and maneuver itself to establish a suitably stable worksite at any location specified by the surgeon. 2. Develop the necessary surgical end-effectors or tools to enable the HeartLander to perform accurate injections into the myocardium. 3. Test the technology preclinical in an anthropomorphic beating-heart phantom or dummy. 4. Test the safety and capability of the technology in vivo in a porcine model.