A steering mechanism may comprise an actuation system for one-fingered operation by a user, the system configured to move at least a distal portion of the medical device such that 360 degree articulation is achievable, and a housing coupled to the system, the housing having proximal and distal ends. The system may comprise a first lever rotatable about a first axis, the first lever coupled to a first cam and configured to move the first cam from a first position to a second position when rotated about the first axis to deflect the distal portion； and a second lever rotatable about a second axis, the second lever coupled to a second cam and configured to move the second cam from a first position to a second position when rotated about the second axis to deflect the distal portion, wherein the first lever is coupled to the second lever.
