Computer-assisted tele-operated surgery systems and methods

A medical device comprising:

• a cannula assembly comprising a proximal cannula portion, a distal cannula portion and a user-actuatable adjustment mechanism configured to adjust a position of the distal cannula portion relative to the proximal cannula portion;
• wherein the proximal cannula portion is configured to be releasably coupled to a computer-assisted teleoperated surgery manipulator arm;
• wherein the distal cannula portion and the proximal cannula portion engaged together define a central lumen configured for slidably receiving a surgical instrument and define an overall assembly length of the cannula assembly and the central lumen along a longitudinal axis defined by the central lumen and
• wherein the user-actuatable adjustment mechanism comprises:
• a stationary collar fixed to the proximal cannula portion,
• a sliding collar configured to move relative to the distal cannula portion and the proximal cannula portion, and
• a spring disposed between the stationary collar and the sliding collar, the spring exerting a biasing force biasing the sliding collar into a first position,
• wherein in the first position of the sliding collar, the sliding collar exerts a latching force releasably latching the distal cannula portion in a fixed position relative to the proximal cannula portion,
• wherein the sliding collar is movable away from the first position and toward the stationary collar in response to a force sufficient to overcome the biasing force of the spring, and
• wherein in a position of the sliding collar moved away from the first position toward the stationary collar, the latching force exerted by the sliding collar is released and the distal cannula portion is moveable relative to the proximal cannula portion and the sliding collar to adjust the overall assembly length of the cannula assembly and central lumen along the longitudinal axis.