Curved cannula

Abstract

A robotic surgical system is configured with rigid, curved cannulas that extend through the same opening into a patient's body. Surgical instruments with passively flexible shafts extend through the curved cannulas. The cannulas are oriented to direct the instruments towards a surgical site. Various port features that support the curved cannulas within the single opening are disclosed. Cannula support fixtures that support the cannulas during insertion into the single opening and mounting to robotic manipulators are disclosed. A teleoperation control system that moves the curved cannulas and their associated instruments in a manner that allows a surgeon to experience intuitive control is disclosed.

1 . A surgical system comprising:
 a first robotic manipulator, a first curved cannula coupled to the first robotic manipulator, and a first surgical instrument comprising a flexible shaft that extends through the first curved cannula, wherein the first robotic manipulator is configured to move the first cannula around a first center of motion;   a second robotic manipulator, a second curved cannula coupled to the second robotic manipulator, and a second surgical instrument comprising a flexible shaft that extends through the second curved cannula, wherein the second robotic manipulator is configured to move the second cannula around a second center of motion;   wherein the first and second centers of motion are positioned proximate to one another; and   wherein distal ends of the first and second curved cannulas are oriented to direct the distal ends of the first and second surgical instruments towards a surgical site.   
     
     
         2 . The surgical system of  claim 1 :
 wherein the first curved cannula comprises a rigid tube having a proximal straight portion and a curved section adjacent the proximal straight section; and   wherein the first robotic manipulator is coupled to the proximal straight portion of the first curved cannula.   
     
     
         3 . The surgical system of  claim 1 :
 wherein the flexible shaft of the first surgical instrument comprises a passively flexible shaft;   wherein the passively flexible shaft comprises a middle section and a distal section; and   wherein a stiffness of the distal second of the passively flexible shaft is larger than a stiffness of the middle section of the passively flexible shaft.   
     
     
         4 . The surgical system of  claim 1  further comprising:
 a port feature; 
 wherein the port feature comprises a port feature body comprising a top surface and a bottom surface; 
 wherein the port feature comprises a first channel through which the first surgical instrument extends in a first direction towards a vertical midsection of the port feature body from the top surface to the bottom surface; and 
 wherein the port feature comprises a second channel through which the second surgical instrument extends in a second direction, opposite the first direction; towards the vertical midsection of the port feature body from the top surface to the bottom surface. 
 
     
     
         5 . The surgical system of  claim 1  further comprising:
 a port feature; 
 wherein the port feature comprises a funnel portion, a tongue, a waist portion between the funnel portion and the tongue, a first instrument channel defined in the waist portion through which the first surgical instrument extends, and a second instrument channel defined in the waist portion through which the second surgical instrument extends. 
 
     
     
         6 . The surgical system of  claim 1  further comprising:
 a cannula mounting fixture; 
 wherein the cannula mounting fixture comprises an endoscope cannula mounting bracket and a curved cannula mounting bracket; and 
 wherein the endoscope cannula mounting bracket and the curved cannula mounting bracket are each oriented to hold a cannula at the same opening into a patient's body. 
 
     
     
         7 . The surgical system of  claim 1  further comprising:
 a pointed cap comprising an interior; 
 wherein the interior of the cap is configured to removably hold a distal end of an endoscope and a distal end of the first curved cannula. 
 
     
     
         8 . The surgical system of  claim 1  further comprising:
 a master manipulator; and 
 a control system; 
 wherein a straight line instrument insertion and withdrawal axis is defined extending from a longitudinal center axis of the first curved cannula at a distal end of the first curved cannula; and 
 wherein in response to a movement of the master manipulator, the control system commands the first robotic manipulator to move the distal end of the first curved cannula around the first remote center of motion as if the first surgical instrument were positioned straight along the instrument insertion and withdrawal axis.