In this paper, an open data format for three-dimensional surgical planning of total hip arthroplasty based on XML is described. We design an XML (eXtensible Markup Language) format to save position and orientation of the implants, references to the 3D images and surface models, anatomical coordinate system, joint coordinate system for motion analysis, and quantitative evaluation results for planning. The main feature of the proposed method is an embedded script for generating drilled bone models at the client planning system. The embedded script reduces an amount of transfer data from the planning server as compared with generating the drilled bone models at the planning server and transferring them. In order to evaluate the usability of the XML data format, we implemented a client-server system for remote browsing of 3D planning. We applied the proposed system to five cases (three planning datasets for each) and compared the total time of transfer and processing for visualization of planning datasets between by the server-side model generating system and by the client-side model generating system with embedded script. In secondary and thirdly received planning dataset in each case, the total time of the client-side system was shorter than that of the server-side system. The results showed a potential usefulness of the proposed XML data format which embedding the script.
Intraoral radiography is basically used in order to diagnose patients' dental diseases. Recently, it was reported that this radiographic skill of dental students of both domestic and overseasis declining. The dental students use an actual radiographic system in their training course, so that the use of x-ray radiation, consumption of films, and film processing time narrow the amount of their training before graduation. We have developed a training system for intraoral radiography based on virtual reality technique. In our training system, virtual reality technique is adopted to show the computed image of intraoral radiograph on a computer display. Both position of an indicator cone, which determines x-ray beam direction and area, and a film are steadied by multi-links arms of the system, each length of the linkages is optimally designed for the training system. This paper describes the training system and the result of functional evaluation by the coauthor dentists in respect to image quality, operationality, and educational effects of the system.
Most of the instruments for laparoscopic surgery are slender because they need to be inserted into the abdominal cavity through the small hole of a trocar. Large traditional instruments for abdominal surgery cannot be utilized for laparoscopic surgery. To overcome this problem, we have proposed assemblable instruments for laparoscopic surgery that can be disassembled to pass through a trocar and assembled into large instruments inside the abdominal cavity. As an example, we developed an assemblable pursestring suture instrument (PSI) for laparoscopic surgery. The PSI is a T-shaped instrument used to suture the cut end of a tubular organ; it is required to anastomose the cut end to another cut end. A PSI needs to have adequate rigidity and a grip force. To meet these requirements, this paper proposes a two degree of freedom folding mechanism. Experiments with the assemblable PSI show that it can be assembled in 46 s, and disassembled in 32 s on an average and generate a large grip force of 75 N. Moreover, in vivo experiments confirm that the assemblable PSI can effectively make a purse string suture.
The use of the conventional network infrastructures is essential for future wide use of tele-surgery applications. In this paper, a tele-surgery experiment, which was conducted between Japan and Thailand by using the developed minimally invasive surgical system is described. The direct distance between master and slave sites was 3750km. A high speed Internet, JGN2 (Japan Gigabit Network 2) was used as an information transmission channel. In the experiment, a laparoscopic cholecystectomy was successfully performed on a pig. The network time-delays of robot and images were 62.4 ms and 270.0 ms respectively (one way in average). The time-delay of image was shortened by introducing a newly developed low latency CODEC despite of the longer distance compared with the past tele-surgery experiments.
In recent years, endovascular coil embolization is becoming a standard treatment option for people with a cerebral aneurysm. Since the coil embolization needs advanced coil insertion technique, an analysis of the technique and development of a surgery system for assistance and training are desired. In this study, we have developed both a novel optical force sensor for coil delivery wire and a surgery system using this sensor. The system consists of the force sensor, a recorder of force signal, aneurysm image and surgeon's oice, and a force indicator using sound. We have evaluated the system and the first coil insertion force using simulated aneurysms of an arterial model and an in vivo. The results show that the insertion force relates to the deployment shape of the coil, the feedback through the force indicator using sound is very effective, and the recorder is useful for analysis of the coil embolization.