Concentric tube robot

A robotic surgical apparatus comprising:

• a robotic arm comprising at least two tubes having a nested, concentric configuration with an inner tube positioned in an outer tube, wherein the tubes are constructed of a superelastic material, have pre-curved configurations, and are configured to deliver surgical therapy via a distal tip of the robotic arm, wherein the position and orientation of the distal tip is effectuated through individual or collective rotation of the tubes about a tube axis and/or individual or collective translation of the tubes along the tube axis;
• wherein the robotic arm further comprises a first tube carrier connected to the outer tube and a second tube carrier connected to the inner tube, wherein each of the first and second tube carriers comprise externally threaded structures arranged coaxially with each other along the tube axis;
• and
• an actuator for actuating the robotic arm, wherein the actuator is configured to receive the robotic arm via a tube insertion interface into which the robotic arm can be inserted, wherein the actuator comprises:
• a first translator comprising an internally threaded structure through which the first tube carrier extends, wherein internal threads of the first translator engage external threads of the first tube carrier;
• a motor for imparting rotation to the first translator to produce translational movement of the first tube carrier and the outer tube along the tube axis;
• a second translator comprising an internally threaded structure through which the second tube carrier extends, wherein internal threads of the second translator engage external threads of the second tube carrier;
• a motor for imparting rotation to the second translator to produce translational movement of the second tube carrier and the inner tube along the tube axis;
• a first collar through which the first tube carrier extends, the first collar and first tube carrier comprising a keyed mechanism configured such that rotation of the first collar imparts rotational movement of the first tube carrier;
• and
• a motor for imparting rotation to the first collar to produce rotational movement of the first tube carrier and the outer tube about the tube axis;
• a second collar through which the second tube carrier extends, the second collar and second tube carrier comprising a keyed mechanism configured such that rotation of the second collar imparts rotational movement of the second tube carrier;
• and
• a motor for imparting rotation to the second collar to produce rotational movement of the second tube carrier and the inner tube about the tube axis.