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

A robotically guided method of attaching a temporary guide fixture to a skull of a patient, the temporary guide fixture configured to receive a needle to be inserted into a brain of the patient, the method comprising:

• controlling a robot to automatically place an end effector having a tube to a desired location adjacent to the skull along a planned trajectory based on tracking of tracking markers of a dynamic reference base attached to the skull;
• inserting a first drill through the placed end effector tube;
• drilling a recess in the skull with the inserted drill through the tube of the end effector while the robot is holding the end effector at the desired location;
• drilling a fastener hole for the temporary guide fixture, the fastener hole being laterally spaced from the recess, with assistance from the end effector under the control of the robot such that the robot is holding the end effector at a fixed location while the fastener hole is being drilled;
• inserting a second drill having a smaller drill diameter than the first drill through the temporary guide fixture;
• drilling a through hole in the skull with the inserted second drill through the drilled recess;
• after drilling the through hole and the fastener hole, causing the end effector to move away from the desired location;
• inserting, into the drilled recess, a distal end of the temporary guide fixture;
• inserting a fastener into the drilled fastener hole to affix the temporary guide fixture to the skull;
• inserting the needle using the affixed temporary guide fixture without any assistance from the end effector.