Steerable medical device and control device thereof

A control device for use with a steerable medical device comprises a steering shaft rotatable about a longitudinal axis thereof, a first steering cam is affixed to the steering shaft to rotate in unison therewith. A second steering cam is mounted on the steering shaft and freely rotatable about the longitudinal axis of the steering shaft independent of the steering shaft. A latch assembly is operatively connected to the first steering cam and the second steering cam and operable in an inactive configuration in which the first and second steering cams are positioned to maintain first and second steering wires in an un-tensioned or reduced tension state, and further operable in an active configuration in which the first and second steering cams are positioned to maintain the first and second steering wires in a tensioned state. A rotary knob assembly is also disclosed.