Cranial drill with sterile barrier

A method for providing access to a site within a body of a surgical patient, the method comprising:

• providing a medical device comprising in combination:
• a MRI compatible drill;
• a sterile drill bit;
• and
• a sterile barrier having an interior portion, a proximal end, a distal end, a proximal opening at the proximal end and an opening at the distal end, the opening at the distal end further comprising a sealed aperture, the drill being insertable into the proximal opening, the sealed aperture constructed and arranged to seal around the drill bit such that the drill is enclosed in the interior portion of the sterile barrier and only a portion of the drill bit extends exteriorly of the barrier;
• providing a locking trajectory guide;
• mounting the trajectory guide on the patient's body;
• selecting a predetermined depth and adjusting a depth stop to the predetermined depth;
• advancing the medical device to the body and aligning it with the trajectory guide;
• utilizing the medical device to cause the sterile drill bit to penetrate the body the predetermined depth to which the depth stop is adjusted;
• and
• removing the sterile drill bit from the body.

A method for providing access to a brain of a surgical patient, the method comprising:

• providing a medical device comprising in combination:
• a MRI compatible cranial drill having a removable sterile drill bit and an adjustable depth stop whereby the depth of penetration of the drill bit is controlled;
• and
• a sterile barrier having an interior portion, a proximal end, a distal end, a proximal opening at the proximal end and an opening at the distal end, the opening at the distal end further comprising a sealed aperture, the drill being insertable into the proximal opening, the sealed aperture constructed and arranged to seal around the drill bit such that the drill is enclosed in the interior portion of the sterile barrier and only a portion of the drill bit extends exteriorly of the barrier;
• providing a skull mounted locking trajectory guide;
• mounting the trajectory guide on the patient's skull;
• selecting a predetermined depth and adjusting the depth stop to the predetermined depth;
• advancing the medical device to the skull and aligning it with the trajectory guide;
• utilizing the medical device to cause the sterile drill bit to penetrate the skull the predetermined depth to which the depth stop is adjusted;
• and
• removing the sterile drill bit from the skull.