Control of an endoscope by a surgical robot
An endoscope is controlled by a surgical robotic system. A user input with six degrees of freedom maps to control of an endoscope by a robotic arm having a fewer number of degrees of freedom. For example, untethered user interface devices control motion of an endoscope through a series of projections from user command, to endoscope motion, and to joint motion of the robotic arm. The projection from user command to endoscope motion may project a singular angular motion from three angular motions of the user interface devices. The projection may account for the remote center of motion and/or an angular orientation of the view of the endoscope relative to a shaft of the endoscope.
1 . A method for control of an endoscope by a surgical robotic system, the method comprising:
detecting movement by a handheld user input device having six degrees of freedom;
mapping the movement by the handheld user input device to movement of the endoscope coupled to a robotic manipulator of the surgical robotic system, the mapping using projection from the six degrees of freedom of the handheld user input device limited to a fewer number of degrees of freedom of the endoscope, the projection further comprising projecting the movement by the handheld user input device from a motion command for the endoscope to a remote center of motion frame of the robotic manipulator;
calculating movements of one or more joints of the robotic manipulator to facilitate the movement of the endoscope, wherein calculating comprises projecting from the remote center of motion frame of the robotic manipulator to joint position commands for the robotic manipulator; and
driving the one or more joints according to the calculated movements.
2 . The method of claim 1 wherein the six degrees of freedom correspond to translations along three spatial dimensions and rotations about the three spatial dimensions, the one or more joints comprise four or fewer joints providing less than six degrees of freedom of the robotic manipulator as the fewer number, and wherein mapping the movement of the handheld user input device to the movement of the endoscope comprises projecting only in roll space without yaw and pitch.
3 . The method of claim 1 wherein detecting comprises detecting the movement based on change in position and/or orientation of two handheld user interface objects, the movement being at a center between the two handheld user interface objects.
4 . The method of claim 1 wherein detecting comprises detecting the movement by a base sensor where the handheld user input device comprises one or more untethered objects.
5 . The method of claim 1 wherein mapping the movement by the handheld user input device to the movement of the endoscope comprises passing linear translation and projecting angular motion as a shaft rotation of the endoscope.
6 . The method of claim 1 wherein mapping the movement by the handheld user input device to the movement of the endoscope comprises mapping an angular motion about an axis from the remote center of motion of the robotic manipulator to a control point based on a non-zero angle of a viewer of the endoscope.
7 . The method of claim 1 wherein mapping the movement by the handheld user input device to the movement of the endoscope comprises constraining the movement of the endoscope by the remote center of motion of the robotic manipulator.
8 . The method of claim 1 wherein projecting comprises removing yaw and pitch from the movement of the handheld user input device and adding yaw and pitch of the endoscope to maintain the remote center of motion.
9 . The method of claim 1 further comprising scaling a linear component of the movement of the endoscope with an amount of the scaling being based on a distance of the endoscope from the remote center of motion of the robotic manipulator.
10 . The method of claim 1 wherein calculating the movements of the one or more joints comprises performing inverse kinematics.
11 . A method for control of an endoscope by a surgical robotic system, the method comprising:
sensing input translation and rotation about three axes in space;
projecting the input rotation about the three axes to rotation about a single axis for the endoscope mounted to a robotic arm, wherein projecting the input rotation comprises projecting from the sensing to an input motion command for the endoscope;
projecting from the input motion command for the endoscope to a remote center of motion frame of the robotic arm, and projecting from the remote center of motion frame of the robotic arm to joint position commands for the robotic arm; and
controlling the robotic arm to move the endoscope based on the sensed input translation and the protected rotation about a single axis.
12 . The method of claim 11 wherein sensing comprises sensing of a first handheld, physically unconnected object in a left hand of a user and sensing a second handheld, physically unconnected object in a right hand of the user, the input translation and rotation about the three axes corresponding to six degrees of freedom at a center point between the first and second handheld, physically unconnected objects.
13 . The method of claim 11 wherein projecting from the input motion command for the endoscope to the remote center of motion frame comprises converting from an arm frame for the endoscope to the remote center of motion frame and converting back from the remote center of motion frame to the arm frame with added rotation from the remote center of motion frame.