Development of Integrated 3-Dimensional Computer Graphics Human Head Model.

BACKGROUND: Understanding the complex anatomy of neurostructures is very important in various stages of medical education, from medical students to experienced neurosurgeons, and, ultimately, for the knowledge of human beings. OBJECTIVE: To develop an interactive computer graphics (CG) anatomic head model and present the current progress. METHODS: Based on the prior head 3-dimensional CG (3DCG) polygon model, 23 additional published papers and textbooks were consulted, and 2 neurosurgeons and 1 CG technician performed revision and additional polygon modeling. Three independent neurosurgeons scored the clear visibility of anatomic structures relevant to neurosurgical procedures (anterior petrosal and supracerebellar infratentorial approaches) in the integrated 3DCG model (i model) and patients' radiological images (PRIs) such as those obtained from computed tomography, magnetic resonance imaging, and angiography. RESULTS: The i model consisted of 1155 parts (.stl format), with a total of 313 763 375 polygons, including 10 times more information than the foundation model. The i model was able to illustrate complex and minute neuroanatomic structures that PRIs could not as well as extracranial structures such as paranasal sinuses. Our subjective analysis showed that the i model had better clear visibility scores than PRIs, particularly in minute nerves, vasculatures, and dural structures. CONCLUSION: The i model more clearly illustrates minute anatomic structures than PRIs and uniquely illustrates nuclei and fibers that radiological images do not. The i model complements cadaveric dissection by increasing accessibility according to spatial, financial, ethical, and social aspects and can contribute to future medical education.

The chicken egg and skull model of endoscopic endonasal transsphenoidal surgery improves trainee drilling skills.

BACKGROUND: We verified the effectiveness of training in endoscopic endonasal transsphenoidal surgery (eETSS) techniques using chicken eggs and a skull model. METHODS: We verified the area of eggshell removed by drilling when five residents and four experts used the chicken eggs and a skull model. RESULTS: When residents performed drilling on 10 eggs, a mean (± standard deviation [SD]) area of 31.2 ± 17.5 mm2 was removed from the first egg, and 104.8 ± 3.3 mm2 from the tenth and final egg, representing an increase in area and a decrease in SD. The experts performed the same drilling operation on a single egg, and removed a mean area of 257± 31.7 mm2. These results demonstrated that skills improved as a result of this training, and suggested that this method was also capable of overcoming the initial individual differences in the amount of force applied and ability. An obvious difference between residents and experts was seen in the area removed (p = 0.00011); however, this was attributed to differences in endoscopic manipulation, rather than drilling skill. CONCLUSION: Our findings suggest that this training method could be adequate for acquiring eETSS techniques. Although experts showed superior endoscopic manipulation, residents may also be able to acquire adequate endoscopic skills through further training, and our training method appears to offer an effective means of improving eETSS techniques.

A new force-based objective assessment of technical skills in endoscopic sinus surgery.

We propose objectively assessing endoscopic sinus surgery (ESS) skills by measuring the force applied to a patient model. We collected data on 16 subjects performing gauze packing task using a precise human nasal model with a six-degree-of-freedom force/torque sensor. Mann-Whitney's U test was used to analyze their performance. Intermediates (ESS: 10-50 cases) used significantly greater force than students or experts (ESS: over 150 cases) at the 5 % level. Maximum force improved only among experts. These results imply that young surgeons pay too little attention to force applied to patients or tissues.

An endoscopic sinus surgery training system for assessment of surgical skill.

The apprenticeship of procedures in endoscopic sinus surgery has several limitations, including potential risk for the patients and lack of feedback to the trainees. In this paper, we present a new surgical training system that combines a head dummy, force and position sensors: this system can be used to assess surgical skills and provide visual feedback to the trainees.