A training model head of plaster of Paris for stereotactic localization

Department of Neurosurgery, Ondokuz Mayis University, Faculty of Medicine, Samsun, Turkey.
Surgical Neurology (Impact Factor: 1.67). 12/2007; 68(5):544-6; discussion 546. DOI: 10.1016/j.surneu.2006.12.059
Source: PubMed


A head model for experiencing stereotactic localization will supply familiarity with stereotactic instruments and self confidence for attempters of stereotaxy before real experience.
Plaster of Paris was molded as a model head in a plastic ball. Then, it was partly chipped at its superior half, and metal pieces were inserted into those chipped surfaces. Later, the stereotactic frame was applied, and axial computed tomographic scanning was obtained. The metal pieces seen on scans were selected as targets, and their coordinates were calculated using the software of the stereotactic equipment. Lastly, the stereotactic needle was introduced with these coordinates for investigation of targeting.
The model of plaster of Paris head was very suitable for rigid frame fixation. The metal pieces in the model head were clearly observed on computed tomographic scans. The stereotactic biopsy needle introduced with the perviously calculated coordinates was always successful in true targeting.
This easily performed model head supplied us with familiarity with our stereotactic apparatus and convinced us for further attempts. This kind of model and more complicated ones may help for stereotaxy training in neurosurgery.

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    • "The material simulating the skull is generally assumed to have the following characteristics: (a) high similarity to the skull in terms of resistivity within an environment akin to the human body (including temperature and humidity); (b) a stable resistivity in a wide frequency range; (c) steady resistivity over time; (d) easy shaping; and (e) high rigidity that ensure no deformation. Thus far several materials are suitable for simulating the skull for brain EIT: conductive silicone rubber, carbon doped resin and plaster, all of which are able to meet the requirements in terms of stability and reproducibility [16]-[19]. However, it is technically difficult to integrate parts of rubber or resin into one. "
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    ABSTRACT: Brain electrical impedance tomography (EIT) is an emerging method for monitoring brain injuries. To effectively evaluate brain EIT systems and reconstruction algorithms, we have developed a novel head phantom that features realistic anatomy and spatially varying skull resistivity. The head phantom was created with three layers, representing scalp, skull, and brain tissues. The fabrication process entailed 3D printing of anatomical geometry for mold creation followed by casting to ensure high geometrical precision and accuracy of the resistivity distribution. We evaluated the accuracy and stability of the phantom. Results showed that the head phantom achieved high geometric accuracy, accurate skull resistivity values, and good stability over time and in the frequency domain. Experimental impedance reconstructions performed using the head phantom and computer simulations were found to be consistent for the same perturbation object. In conclusion, this new phantom could provide a more accurate test platform for brain EIT research.
    Full-text · Article · Nov 2013 · IEEE transactions on bio-medical engineering