Mechanisms for pulling a tensile member (24) a predetermined distance from a medical device (10) having an intracorporeal end and an extracorporeal end are disclosed. Such mechanisms may be safely operated using a robot, two hands, or in some embodiments, only one hand. Such mechanisms may include one or more cams, drums, or pulley- like members (34) and a lever (48), and may be physically coupled to an extracorporeal portion of the medical device.
