Rotational actuators for surgical robotic systems

Abstract

A system for use in surgery includes a central body, a visualization system operably connected to the central body, a video rendering system, a head-mounted display for displaying images from the video rendering system, a sensor system, and a robotic device operably connected to the central body. The visualization system includes at least one camera and a pan system and/or a tilt system. The sensor system tracks the position and/or orientation in space of the head-mounted display relative to a reference point. The pan system and/or the tilt system are configured to adjust the field of view of the camera in response to information from the sensor system about changes in at least one of position and orientation in space of the head-mounted display relative to the reference point.

1 . A rotational actuator for a robotic arm of a surgical robotic system, the rotational actuator sized and dimensioned for insertion through a trocar and configured to provide rotational movement about a central axis of the rotational actuator, the rotational actuator comprising:
 a proximal end;   a distal end;   a rotary female body defining an inner chamber extending between the proximal end and the distal end;   a rotary male body rotatable in the inner chamber relative to the rotary female body;   a first rotatable constraint disposed at the proximal end; and   a second rotatable constraint disposed at the distal end, the first and second rotatable constraints supporting axial and rotational loads on the rotational actuator.   
     
     
         2 . The rotational actuator of  claim 1 , wherein an inner surface of the male rotary body defines a channel extending along the central axis of the rotational actuator from the proximal end to the distal end enabling one or more cables to pass along the central axis through an entire length of the rotational actuator in use. 
     
     
         3 . The rotational actuator of  claim 1 , wherein at least a portion of the male rotary body is configured for seating within the inner chamber of the rotary female body, the seating of the rotary male body and the rotary female body enabling rotation of the rotatory male body with respect to the rotary female body about the central axis. 
     
     
         4 . The rotational actuator of  claim 1 , wherein a shape of the female rotary body and a shape of the male rotary body form a first pulley for actuation of the rotary male body relative to the rotary female body in a first direction of rotation, and forming a second pulley for actuation of the rotary male body relative to the rotary female body in a second direction of rotation opposite the first direction of rotation. 
     
     
         5 . The rotary actuator of  claim 4 , further comprising one or more actuation cables configured to actuate the first pulley and the second pulley. 
     
     
         6 . The rotary actuator of  claim 4 , wherein the one or more actuation cables include:
 a first actuation cable coupled to the rotary male body to rotate the rotary male body in the first direction of rotation; and   a second actuation cable coupled to the rotary male body to rotate the rotary male body in the second direction of rotation.   
     
     
         7 . The rotary actuator of  claim 6 , wherein the rotational actuator is configured such that a change in a length of each of the one or more actuation cables within the rotary actuator is less than about 20% when the actuator moves through 360 degree of rotation. 
     
     
         8 . The rotary actuator of  claim 1 , wherein the rotary female body has an outer surface defining a first contoured pathway for seating a first actuation cable and defining a second contoured pathway for seating a second actuation cable. 
     
     
         9 . The rotational actuator of  claim 8 , wherein the rotary female body has an inner surface defining the inner chamber; and wherein the inner surface defines a plurality of axially separated pockets for seating the first actuation cable and the second actuation cable about the rotary male body. 
     
     
         10 . The rotational actuator of  claim 1 , wherein the rotational actuator further comprises a bearing system; and wherein rotation of the rotatory male body with respect to the rotary female body is constrained by the bearing system. 
     
     
         11 . The rotational actuator of  claim 10 , wherein the bearing system comprises a first bearing assembly and a second bearing assembly, the first bearing assembly including the first rotatable constraint and the second bearing assembly including the second rotatable constraint. 
     
     
         12 . The rotational actuator of  claim 11 , wherein a diameter of the first bearing assembly is greater than a diameter of the second bearing assembly. 
     
     
         13 . The rotational actuator of  claim 11 , wherein the first bearing assembly and the second bearing assemblies are each and configured for seating about an outer surface of the rotary male body. 
     
     
         14 . The rotational actuator of  claim 11 , wherein a distal portion of the rotary female body and a portion of the rotary male body each have formed therein a first bearing race for seating a portion of the first bearing assembly. 
     
     
         15 . The rotational actuator of  claim 11 , further comprising:
 a first bearing race ring mounted about the outer surface of the rotary male body and disposed adjacent to the first bearing assembly; and   wherein a distal portion of the rotary female body and the first bearing race ring each include a first bearing race for seating a portion of the first bearing assembly.   
     
     
         16 . The rotational actuator of  claim 15 , further comprising:
 a second bearing race ring sized and configured for seating over the outer surface of the rotary male body and axially separated from the first bearing race ring;   a third bearing race ring sized and configured for seating over the outer surface of the rotary male body and axially separated from the second bearing race ring;   wherein the second ball bearing assembly is disposed between the second bearing race ring and the third bearing race ring; and   wherein each of the second bearing race ring and the third bearing race ring have a second bearing race formed therein for seating a portion of the second bearing assembly.   
     
     
         17 . The rotational actuator of  claim 16 , further comprising a nut element disposed adjacent to the third bearing race ring for axially compressing together the first bearing assembly, the second bearing assembly, the first bearing race ring, the second bearing race ring, and the third bearing race ring. 
     
     
         18 . The rotational actuator of  claim 16 , wherein the third bearing race ring is a splined bearing race ring for mating with a spline formed on the outer surface of the rotary male body for preventing the splined bearing race ring from rotating relative to the rotary male body. 
     
     
         19 . The rotational actuator of  claim 1 , wherein the rotary female connector further comprises first and second outwardly extending and spaced apart first boss elements forming a proximal connection component at a proximal end of the rotary female body for connection to an adjacent first actuator or a first component of the robotic arm;
 wherein the rotary male connector further comprises first and second outwardly extending and spaced apart second boss elements forming a distal connection component for connection to an adjacent second actuator or a second component of the robotic arm; and   wherein the rotary male body is hollow forming a pass-through hole extending along the central axis.   
     
     
         20 . A rotational actuator for a robotic arm of a surgical robotic system, the rotational actuator sized and dimensioned for insertion through a trocar into an internal body cavity, the rotational actuator comprising:
 a rotary female body having a first end and including:
 an inner chamber; and 
 first and second outwardly extending and spaced apart first boss elements forming a first connection component at the first end of the rotary female body for connection to an adjacent first actuator or a first component of the robotic arm; and 
   a rotary male body sized and configured for seating within the inner chamber of the rotary female body, the rotary male body defining a hollow pass-through channel extending along a central rotation axis of the rotational actuator, and the rotary male body including first and second outwardly extending and spaced apart second boss elements forming a second connection component for connection to an adjacent second actuator or a second component of the robotic arm.