Articulation mechanisms for robotic surgical tools

A method, comprising:

• locating a robotic surgical tool adjacent to a patient, the robotic surgical tool comprising:
• a drive housing having a first end, a second end, and one or more splines extending between the first and second ends, wherein each spline has a spline longitudinal axis that is eccentric to a longitudinal axis of the drive housing, and wherein each spline is rotatable about the respective spline longitudinal axis;
• a carriage mounted to the one or more splines and movable between the first and second ends;
• and
• a cylindrical lead screw operatively coupled to the first end and extending toward the second end, the cylindrical lead screw including an interior sized to receive the one or more splines and the carriage, the carriage being operatively coupled to the cylindrical lead screw and movable between the first and second ends in response to rotation of the cylindrical lead screw about the longitudinal axis of the drive housing;
• rotating the cylindrical lead screw by actuating a drive input arranged at the first end and operatively coupled to the cylindrical lead screw, thereby moving the carriage axially between the first and second ends.

A robotic surgical tool, comprising:

• a drive housing having a first end, a second end, and one or more splines extending between the first and second ends;
• a carriage mounted to the one or more splines and movable between the first and second ends;
• a cylindrical lead screw operatively coupled to the first end and extending toward the second end, the cylindrical lead screw including an interior sized to receive the one or more splines and the carriage;
• one or more cam profiles defined on an inner surface of the interior of the cylindrical lead screw;
• one or more follower pins provided on the carriage and slidably matable with the one or more cam profiles;
• and
• a drive input arranged at the first end and operatively coupled to the cylindrical lead screw such that rotation of the drive input correspondingly rotates the cylindrical lead screw about the longitudinal axis,
• wherein the carriage is operatively coupled to the cylindrical lead screw such that rotation of the cylindrical lead screw correspondingly causes the carriage to move between the first and second ends, and when the cylindrical lead screw rotates, the one or more follower pins traverse the one or more cam profiles and thereby cause the carriage to move between the first and second ends.