This paper proposes a finite element method (FEM)-based interaction modeling with multi-modal 3D meshes for neurosurgical simulation. The model solves a problem of overlapped region between meshes by defining new boundary and calculating mesh-mesh interaction. The proposed model considered energy preservation during collisions of objects. The method was implemented in the system with a haptic display. Simulation results showed real-time simulation of soft-body deformation with mesh-mesh interaction.

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In this paper, we present human interface software of our dental surgical system. The system is based on mixed reality. With the help of this, a student virtually scrapes a concave tooth by a bar located at the tip of turbine. First of all, all dental data of teeth, dental bar, dental turbine, and dental mirror are captured from a dental CT-scanner as triangular polyhedrons with the STL formal. Secondly, by using GPU (Graphics Processing Unit), we convert many triangular polyhedrons (STL) of teeth and dental bars into octrees (a set of voxels) and sets of points, respectively. Then, we develop an efficient interference check algorithm between octree-based tooth and point-based bar. On the basis of the digital algorithm, we identify their intersection points quickly. Moreover, according to the intersection set, we scrape an octree-based tooth by a point-based bar, and simultaneously make an artificial force and moment quickly. Finally, a dental doctor flexibly selects visual and tactile parameters according to their many experiences. On the other hand, our dental surgical system evaluates a student operation against a professional one by comparing their scraping teeth shapes. For this reason, all the students learn many surgical operations in our system on demand via PC and internet.

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Objective: The aim of this research was to evaluate a deformable simulation system that can be operated simply and quickly, aiming at daily use in clinical practice of neurosurgery. We examined whether this method would be useful for preoperative simulation. Methods: Subjects comprised 10 patients who underwent microneurosurgery. Using Avizo 5.1 computer visualization software, the 3-dimensional images were created from preoperative 2-dimensional DICOM (Digital Imaging and Communication in Medicine) data. A brain retraction simulation program was added to Avizo 5.1. We evaluated the simplicity of the operation, and usefulness in preoperative review. Results: With this software, we performed a virtual simulation of brain retraction. Between 3 minutes (minimum) and 30 minutes (maximum), 3-dimensional spatial relationships between nerves, vessels, skull, brain surface, and how to retract brain surfaces such as direction and degree of brain retraction are easily recognized. Conclusion: Virtual operative simulation of brain retraction with this system was simple, quick and effective for surgery review in the neurosurgical field.

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In endoscopic surgery, surgeons should be highly professional to do the operation precisely using a 2D display as the image lacks depth perception. We aim at developing an endoscopic surgery system that consists of intuitive depth perception, enabling effective forceps operations by 3D vision. In this paper, we propose the 3D dome-shaped display system for endoscopic surgery. Developed system has been evaluated with a simulated situation and the results show that our developed system increases the degree of freedom of the forceps movement in comparison with the conventional 2D display for novice surgeons, especially depth directional distance and axial rotation of forceps.

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We have developed the Leg-Robot, a leg-shaped haptic simulator of patients with any nerve disease for the purpose of educational training of physical therapy. In this paper, we suggest a control method to demonstrate ankle clonus with the Leg-Robot and evaluate its performance by students of school of physical therapy. According to the comparison of the experimental results of young students and a matured physical therapist, we were able to find obvious differences between their manners of manual tests.

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