Robotic spine surgery system and methods
A robotic system and methods for performing spine surgery are disclosed. The system comprises a robotic manipulator with a tool to hold a screw and to rotate the screw about a rotational axis. The screw is self-tapping and has a known thread geometry that is stored by one or more controllers. A navigation system tracks a position of a target anatomy. Movement of the robotic manipulator is controlled to maintain the rotational axis of the surgical tool along a planned trajectory with respect to the target anatomy based on the tracked position of the target anatomy. In autonomous or manual modes of operation, the rotational rate of the screw about the rotational axis and/or an advancement rate of the screw linearly along the planned trajectory is controlled to be proportional to the known thread geometry stored in the memory.
1. A surgical robotic system comprising:
a robotic manipulator;
a surgical tool coupled to the robotic manipulator and configured to hold a screw and to rotate the screw about a rotational axis, the screw having a known thread geometry;
a navigation system configured to track a position of a target anatomy; and
one or more controllers coupled to the robotic manipulator and the navigation system and comprising memory for storing the known thread geometry and wherein the one or more controllers are configured to:
control movement of the robotic manipulator to maintain the rotational axis of the surgical tool along a planned trajectory with respect to the target anatomy based on the tracked position of the target anatomy, and
autonomously control a rotational rate of the surgical tool to rotate the screw about the rotational axis and an advancement rate of the surgical tool to linearly advance the screw along the planned trajectory wherein the rotational rate of the surgical tool and the advancement rate of the surgical tool are proportional to the known thread geometry stored in the memory.
2. The surgical robotic system of claim 1 , wherein the surgical tool comprises a screw driver.
3. The surgical robotic system of claim 1 , wherein the planned trajectory is defined by a haptic object.
4. The surgical robotic system of claim 3 , wherein the haptic object comprises a line haptic object, and the one or more controllers are configured to control the robotic manipulator to generate haptic feedback to a user to indicate that the screw has reached a planned insertion depth at the target anatomy.
5. The surgical robotic system of claim 1 , wherein the one or more controllers are configured to cause autonomous movement of the surgical tool to place the rotational axis along the planned trajectory.
6. The surgical robotic system of claim 1 , comprising a torque sensor to determine a torque being applied to drive the screw, wherein the one or more controllers are configured to stop the surgical tool from driving the screw into the target anatomy once the torque meets or exceeds a torque threshold.
7. The surgical robotic system of claim 6 , wherein the torque sensor comprises a current measuring circuit.
8. The surgical robotic system of claim 1 , wherein the navigation system comprises a navigation controller, and an imaging device coupled to the navigation controller.
9. The surgical robotic system of claim 8 , wherein the navigation system comprises a first tracker to track the surgical tool and a second tracker to track the target anatomy.
10. The surgical robotic system of claim 8 , comprising a display coupled to the navigation controller, wherein the navigation controller is configured to output, on the display, information relating to a location of the screw relative to the target anatomy.
11. The surgical robotic system of claim 1 , wherein the rotational rate of the surgical tool and the advancement rate of the surgical tool are proportional to the known thread geometry according to a relationship
δ
θ
δ
t
=
δ
D
δ
t
*
Pitch
2
π
,
wherein
δ
θ
δ
t
is the rotational rate of the surgical tool,
δ
D
δ
t
is the advancement rate of the surgical tool, and Pitch is a number of threads per unit length of the screw.
12. A surgical robotic system comprising:
a robotic manipulator comprising a sensor;
a surgical tool coupled to the robotic manipulator and configured to hold a screw and to rotate the screw about a rotational axis, the screw having a known thread geometry;
a navigation system configured to track a position of a target anatomy; and
one or more controllers coupled to the robotic manipulator and the navigation system and comprising a memory for storing the known thread geometry and wherein the one or more controllers are configured to:
control movement of the robotic manipulator to maintain the rotational axis of the surgical tool on a planned trajectory with respect to the target anatomy based on the tracked position of the target anatomy,
detect, with the sensor, a force applied by a user;
control one of a rotational rate of the surgical tool to insert the screw about the rotational axis or an advancement rate of the surgical tool to insert the screw linearly along the planned trajectory based on the forces applied by the user to implant the screw into the target anatomy; and
autonomously control the other of the advancement rate of the surgical tool or the rotational rate of the surgical tool so that the advancement rate of the surgical tool and the rotational rate of the surgical tool are proportional to the force applied by the user and to the known thread geometry stored in the memory.
13. The surgical robotic system of claim 12 , wherein the surgical tool comprises a trigger, the sensor coupled to the trigger and configured to generate a signal indicative of a user's input.
14. The surgical robotic system of claim 13 , wherein the one or more controllers control the rotational rate of the surgical tool based on the signal, and autonomously control the advancement rate of the surgical tool to be proportional to the rotational rate of the surgical tool and the known thread geometry.
15. The surgical robotic system of claim 14 , wherein the one or more controllers autonomously control the advancement rate of the surgical tool to be proportional to the rotational rate of the surgical tool and the known thread geometry according to a relationship
δ
θ
δ
t
=
δ
D
δ
t
*
Pitch
2
π
,
wherein
δ
θ
δ
t
is the rotational rate of the surgical tool,
δ
D
δ
t
is the advancement rate of the surgical tool, and Pitch is a number of threads per unit length of the screw.
16. The surgical robotic system of claim 13 , wherein the one or more controllers control the advancement rate of the surgical tool based on the signal, and autonomously control the rotational rate of the surgical tool to be proportional to the advancement rate of the surgical tool and the known thread geometry.
17. The surgical robotic system of claim 16 , wherein the one or more controllers autonomously control the rotational rate of the surgical tool to be proportional to the advancement rate of the surgical tool and the known thread geometry according to a relationship
δ
θ
δ
t
=
δ
D
δ
t
*
Pitch
2
π
,
wherein
δ
θ
δ
t
is the rotational rate of the surgical tool,
δ
D
δ
t
is the advancement rate of the surgical tool, and Pitch is a number of threads per unit length of the screw.