A medical device delivery system including a mechanism to concurrently move an inner member and an outer member in opposite directions and at pre-set speed ratio can be operated, for example, to reconstrain a foreshortening self-expanding stent with a known foreshortening ratio between the crimped diameter in an intraluminal catheter based delivery system and the nominal deployed diameter in the body lumen. The mechanism can include two oppositely handed lead screws that concurrently turn and two followers, each follower operatively connected to one of the two shafts (e.g., the inner and outer member).
