Abstract: A cerebral instrument guide includes first and second arcs with aligned openings adjacent their ends, the openings defining a common axis about which the arcs are pivotal. The rods are mounted for movement along the common axis into contact with a human patient's auditory meati. A nasal bridge fixation element mounted on the first arc, as well as orbit pads, engage the bridge of a patient's nose, and his/her bony orbits. The appropriate angle to which the arcs should be pivoted with respect to each other is calculated by a computer program, as is the position to which a tubular instrument guide, slidable along the second arc and a projection from it intersecting the mid point of the common axis, is to be positioned to mark the burr hole on the patient's skull for performing a neurological procedure, such as a ventriculostomy. A needle is passed through the tubular instrument guide to mark the burr hole site.

Abstract: A cerebral instrument guide includes first and second arcs with aligned openings adjacent their ends, the openings defining a common axis about which the arcs are pivotal. The rods are mounted for movement along the common axis into contact with a human patient's auditory meati. A nasal bridge fixation element mounted on the first arc, as well as orbit pads, engage the bridge of a patient's nose, and his/her bony orbits. The appropriate angle to which the arcs should be pivoted with respect to each other is calculated by a computer program, as is the position to which a tubular instrument guide, slidable along the second arc and a projection from it intersecting the mid point of the common axis, is to be positioned to mark the burr hole on the patient's skull for performing a neurological procedure, such as a ventriculostomy. A needle is passed through the tubular instrument guide to mark the burr hole site.

Abstract: A stereotactic neurological instrument placement guide is utilized to facilitate ventriculostomy procedures, or other neurological procedures such as biopsy, radioactive seed placement, and lesion generation. The guide has a pair of point members disposed on a common linear axis. The proposed position of a burr hole in the patient's skull is marked, the location of a target point (e.g. ventricle) within the patient's skull is decided upon, and the patient is given a CT or MRI scan. Utilizing data from the scan, a coordinate line is calculated between the burr hole proposed position and the target point. Utilizing the calculated coordinate line, a fixing point on the patient's skull opposite the proposed position of the burr hole is determined, and the fixing point is marked.