Drill guide fixtures, cranial insertion fixtures, and related methods and robotic systems

Abstract

A drill guide fixture may be configured to prepare a skull for attachment of a cranial insertion fixture. The drill guide fixture may include a central drill guide and a bone anchor guide at a base of the drill guide fixture. The central drill guide may define a central drill guide hole therethrough, wherein the central drill guide hole has a first opening at a base of the drill guide fixture and a second opening spaced apart from the base of the drill guide fixture. The bone anchor drill guide may define a bone anchor drill guide hole therethrough, and the bone anchor drill guide hole may be offset from the central drill guide hole in a direction that is perpendicular with respect to a direction of the central drill guide hole. Related cranial insertion fixtures, robotic systems, and methods are also discussed.

What is claimed is: 
     
         1 . A robotically guided method of attaching an electrode holder to a skull of a patient, the electrode holder configured to receive an electrode to be inserted into a brain of the patient, the method comprising:
 attaching on the skull a dynamic reference base including a plurality of optical tracking markers;   attaching to the dynamic reference base a temporary fiducial base including a plurality of radiopaque markers;   obtaining with a medical imaging system a medical image of a brain in which a field of view of the medical imaging system includes the dynamic reference base with the attached temporary fiducial base;   registering the medical image in the imaging space to an optical space using the plurality of radiopaque markers contained in the obtained medical image;   causing the robot to automatically place an end-effector to a desired location adjacent to the skull along a planned trajectory based on tracking of the optical tracking markers of the attached dynamic reference base;   drilling a hole in the skull through a guide tube of the end effector while the robot is holding the end effector at the desired location;   causing the robot to move away from the desired location;   attaching, to the skull and over the drilled hole, a stand including an electrode holder and a shaft coupled to the electrode holder;   inserting an electrode into the shaft and through the electrode holder; and   removing the shaft from the electrode holder.   
     
     
         2 . The method of  claim 1 , prior to attaching a dynamic reference base, further comprising planning a trajectory, using the robot, for insertion of the electrode into the brain. 
     
     
         3 . The method of  claim 1 , wherein attaching a stand includes attaching an adjustable stand having a plurality of height adjustable legs to allow adjustment of an angle of the shaft relative to the skull, the adjustable stand configured to slide over the shaft, wherein each leg is shaped to rest on the skull without being screwed to the skull 
     
     
         4 . The method of  claim 3 , wherein attaching a stand includes attaching an adjustable tripod stand configured to slide over the shaft to allow adjustment of an angle of the shaft relative to the skull. 
     
     
         5 . The method of  claim 3 , wherein removing the shaft includes removing the shaft while the electrode holder remains threaded into the drilled hole. 
     
     
         6 . The method of  claim 1 , wherein attaching a stand includes threading the electrode holder into the drilled hole. 
     
     
         7 . The method of  claim 3 , wherein a tracking array is attached to the stand, further comprising adjusting the legs while an angle of the shaft is being tracked through the tracking array via a camera. 
     
     
         8 . The method of  claim 8 , further comprising adjusting the height of at least one leg via a knob. 
     
     
         9 . The method of  claim 4 , further comprising temporarily locking the tripod to the shaft with a set screw. 
     
     
         10 . The method of  claim 1 , further comprising removing the temporary fiducial base from the attached dynamic reference base after the step of obtaining a medical image. 
     
     
         11 . A method of using a surgical robot for attaching an electrode holder to a skull of a patient, the electrode holder configured to receive an electrode to be inserted into a brain of the patient, said method comprising:
 planning a trajectory, using the surgical robot, for insertion of the electrode into the brain, wherein the surgical robot comprises:
 a robot base comprising a computer; 
 a robot arm coupled to the robot base; 
 an end effector configured to be coupled to the robot arm; 
 a guide tube having a detachable electrode holder disposed at a distal tip of the guide tip and a tracking array disposed near a proximal end of the guide tube, the guide tube configured to couple to the end effector; 
   a tripod mechanism configured to slide over the guide tube and allow adjustment of an angle of the guide tube relative to the skull;   positioning a dynamic reference base on the skull;   positioning a temporary skirt fixture to the dynamic reference base;   obtaining medical images of the dynamic reference base and temporary skirt feature;   registering the dynamic reference base to the medical images using the temporary skirt fixture;   removing the temporary skirt fixture;   planning a trajectory of the electrode using the obtained medical images;   using the robot to move the robot arm and end-effector to a desired location adjacent to the skull along the planned trajectory;   using a drill to provide a hole in the skull while the robot guides the drill;   providing the guide tube and electrode holder in the hole and removing the robot;   lowering and locking the tripod mechanism to the guide tube;   providing the tracking array to the guide tube and checking alignment of the guide relative to the planned trajectory;   inserting an electrode into the guide tube and through the electrode holder; and   removing the guide tube from the electrode holder.   
     
     
         12 . The method of  claim 11 , wherein guide tube is configured to receive an electrode. 
     
     
         13 . The method of  claim 12 , wherein the detachable electrode holder comprises threads that are configured to be received by the skull. 
     
     
         14 . The method of  claim 13 , wherein the guide tube is configured to be removed from the electrode holder after the electrode has been introduced into the skull. 
     
     
         15 . The method of  claim 14 , wherein the tracking array is configured to allow tracking of an angle of the guide tubed via a camera. 
     
     
         16 . The method of  claim 15 , wherein the tripod mechanism comprises one or more feet that may be configured to rest on the skull without penetrating the skull. 
     
     
         17 . The method of  claim 16 , wherein each of the feet are configured to be adjusted via a knob. 
     
     
         18 . The method of  claim 17 , wherein the one or more feet are configured to angularly adjust the guide tube. 
     
     
         19 . The method of  claim 18 , wherein the tripod mechanism is configured to be temporarily locked to the guide tube with a set screw. 
     
     
         20 . The method of  claim 19 , wherein the robot base is configured to position the end-effector adjacent to the skull at a trajectory consistent with a desired trajectory for insertion of the electrode.