Not only structural navigation, but also functional navigation should be developed for cardiac and pulmonary surgeries, because those organs function by deforming their own configurations. In order to obtain functional information duringsurgery, computational biomechanics will be useful. We have been constructing a 4D lung model which links its functionwith its structure under normal and abnormal conditions. Our model will be useful for developing a structural-functionalnavigator for lung surgery.

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Robotic laparoscope positioners are now accepted and expected as assistant devices for solo surgeryamong endoscopic surgeons. In such robotic systems, the human-machine (surgeon-robot) interface is ofparamount importance because it is the means by which the surgeon communicates with and controls therobotic camera assistant. Various types of human-machine interfaces such as remote hand switches, instrument-mounted joysticks, foot pedals, voice recognition, head/face control and instrument tracking havebeen suggested, and their effectiveness has been discussed individually. This paper attempts to bring togetherthe human-machine interface in robotic camera positioning systems that have been devised in the last tenyears. I herein organize the survey by breaking the laparoscope positioning systems into the following threetypes based on the view of “autonomy” :(i) non-autonomous systems, (ii) semi-autonomous systems, and (iii) full-autonomous systems.

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Magnetic Resonance Imaging (MRI) is unique for interventional use in that it has a spatial resolution independent of the wave length of the electromagnetic field used for imaging, various image parameters relating to physical properties of the subject, superior soft-tissue contrast, freedom in slicing angle, and non-radiation nature. Total treatment assistancebased on lesion identification, treatment planning, device tracking, temperature imaging and treatment assessment is possiblewith these features. In this article, a few latest topics in the interventional MRI are introduced with a short review ofthe instrumentation engineering aspect of the techniques.

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Under real-time MR image navigation using a double-donut type open MR system, various surgical procedures, such as microwave thermocoagulation therapy of liver tumors, have been carried out for 4.5 years. We have developed new MR compatible surgical instruments and navigation software by ourselves. Such devices have been increased the availability of MR-guided procedures and quite effective for the accurate and safe treatment.

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Application of navigation systems to otorhinolaryngology head and neck surgery should permit safer, sounder operationswhen attempting revision surgery on anatomically ambiguous target organs, surgery on lesions expanding to organswith risk factors for complications, and in minimally invasive surgery. If such systems were used in ear surgery, the locationof important organs in the temporal bone could be checked. In operations on the nose or paranasal sinus at risk organscould be avoided (e.g. orbit and basal skull) and residual cells and incision locations on postoperative cyst could be identified.When operating tumors of head and neck, the preoperative and pretreatment status could be grasped and the area oftumors resection could be determined, including the safety margin. In addition to these applications, navigation systemsare useful for operations such as choanal atresia and aural atresia, fracture repair, skull base surgery, and on biopsy, nerveblock and surgical training. Although this system has the potential to improve the surgeon's confidence and knowledgeof patient anatomy, the overestimate its ability should be careful without any knowledge of anatomy and surgical experiences.

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For advanced right colon cancer, we perform lymph node dissection exposing so called the surgical trunk. For theresection of advanced proximal sigmoid cancer, we sometimes perform lymph node dissection around root of IMA withpreserving the left colic artery and superior rectal artery. For either of these procedures performing safely, it is importantto know the precise individual vascular anatomy bearing their variations. However, there are major issues in laparoscopicsurgery, such as no tactile sensation, limitation on visual fields. To overcome these issues and to accurately identify thevascular anatomy of each patient, we have applied Integrated 3D-CT as preoperative simulation and intraopetative navigationsince July, 2000. Under the precise recognition of laparoscopic surgical anatomy, additionally simulated and navigatedby Integrated 3D-CT imaging for each patient, systematic lymphadenectomy with tailor-made vascular dissection bylaparoscopy appears to be feasible and more meticulous compared to one by conventional open surgery.

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This paper introduces a dental crown production system. The crown designed in this system not only had nointerference at intercuspal position but also given functional occlusal surfaces. The functional occlusal surface was createdwith virtual articulator which reproduces the movement of subject's mandible on a computer system. Finally, validity of theprocesses in this crown production system, errors which were caused in each process and the necessity of dental CAE (Computer-Aided Engineering) system were discussed.

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There are several problems in conventional dental trainings using a mannequin due to the lack of reality. To solve such problems, we proposed in this study a dental training system using the virtual reality technology. In our system, a virtual environment and a virtual patient were produced in a virtual space, where the dental mirror and hand pieces can be operated real-timely. The force feedback of operations and a tooth cutting operation in training were realized using two computers. Furthermore, in order to be aware of and to avoid possible dangers, the tongue of the patient was moved randomly in training, and warnings with sound and a signal of blood were given when the drill contacts tongue or mucous membrane of mouth. Experiments of tooth cutting and operating were carried out with good training effects confirmed.

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