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Biomedical subjects

L R Brynildson

Publications and source records attributed to L R Brynildson.

4 recordsLinked to original sources

The micro-laserbot: an alternative method for frameless stereotactic localization.

An alternative method for frameless stereotactic localization which combines an articulating arm for spatial positioning with a three-dimensional laser beam localization technique will be presented. The moveable segments of the arm are counterbalanced, and allow it to smoothly glide to a given position. Micro-brakes in the arm joints permit rigid spatial fixation. The proximal end of the micro-laserbot attaches to the operating room table and the distal end, with the laser localizer apparatus, can be either free or attached to the operating microscope around the objective lens assembly. When attached to the surgical microscope, the laser light beams projected on the brain surface are seen while viewing the surgical field through the operating microscope. When used in this mode, the standard surgical microscope is converted into a stereotactic positional device, and the lasers guide the surgeon during the surgical dissection. Intersection of the laser beams indicate the spatial position of targets and volumes which are referenced and seen on the multi-modality computer imaging system. When not attached to the microscope, various other instruments can be affixed to the distal end of the micro-laserbot for stereotactic referencing.

Equipment Design↗

Three-dimensional imaging for brachytherapy planning.

A computerized 3-D brachytherapy treatment planning program has been developed which simulates catheter trajectories, radioisotope seed positioning and percentage dosimetry zones about a catheter/seed array in relationship to CT or MRI images. The high activity 125I seed is used in this program. A visual and a non-linear mathematical optimization program will also be described.

Brachytherapy↗

Magnetic resonance imaging and anatomic atlas mapping for thalamotomy.

A computerized anatomic atlas mapping technique has been developed and used to determine target sites for stereotactic thalamotomies. The digitized stereotactic atlases of Schaltenbrand and Bailey, Van Buren and Borke, and Schaltenbrand and Wahren are used in conjunction with an associated electrophysiological data base to determine the intended target site on MR images of the diencephalon. This mapping technique uses the 'Brierley and Beck' proportional hypothesis for thalamic nuclear determination. Target site determination by this method was found to be very accurate, and frequently the mere placement of the probe in the target site resulted in tremor cessation.

Brain Mapping↗

Three-dimensional whole-brain mapping.

The implementation and use of a computerized whole-brain mapping system which can be used in conjunction with MRI, CT, angiographic and other brain imaging techniques is described. Three mapping systems based upon common reference structures about the third and fourth ventricular core of the brain are used in conjunction with internationally recognized nomenclature to create a normalized whole-brain mapping system according to the Talairach/Tournoux proportional grid technique.

Brain↗