[Show abstract][Hide abstract] ABSTRACT: One of the essential requirements of a realistic surgical simulator is to reproduce haptic sensations due to the interactions in the virtual environment. However, the interaction need to be performed in real-time, since a delay between the user action and the system reaction reduces the immersion sensation. In this paper, a prototype of a coronary stent implant simulator is present; this system allows real-time interactions with an artery by means of a specific haptic device. The user can interactively navigate in a reconstructed artery and the force feedback is produced when contact occurs between the artery walls and the medical instruments. In order to obtain a realistic simulation, the Finite Element Method has been used to model the artery soft tissues, but several simplifications have been introduced to reduce the computational time and to speed up the interaction rate. The building of the virtual environment is based on real patients' images and a Web Portal is used to search in the geographically remote medical centres a virtual environment with specific features in terms of pathology or anatomy; this information are included in the metadata associated with the virtual environment.
[Show abstract][Hide abstract] ABSTRACT: Minimally invasive surgery procedures are getting common in surgical practice; however the new interventional procedure requires different skills compared to the conventional surgical techniques. The need for training process is very important in order to successfully and safely execute a surgical procedure. Computer-based simulators, with appropriate tactile feedback device, can be an efficient method for facilitating the education and training process. In addition, virtual reality surgical simulators can reduce costs of education and provide realism with regard to tissues behaviour and real-time interaction. This work take into account the results of the HERMES Project (HEmatology Research virtual MEdical System), conceived and managed by Consorzio CETMA-Research Centre; the aim of this project is to build an integrate system in order to simulate a coronary angioplasty intervention.
Studies in health technology and informatics 02/2004; 98:4-6.
[Show abstract][Hide abstract] ABSTRACT: One of the essential requirements in order to have a realistic surgical simulator is real-time interaction by means of a haptic interface is. In fact, reproducing haptic sensations increases the realism of the simulation. However, the interaction need to be performed in real-time, since a delay between the user action and the system reaction reduces the user immersion. In this paper, we present a prototype of the coronary stent implant simulator developed in the HERMES Project; this system allows real-time interactions with a artery by means of a specific haptic device; thus the user can interactively navigate in a reconstructed artery and force feedback is produced when contact occurs between the artery walls and the medical instruments Keywords—Collision Detection, Haptic Interface, Real-Time Interaction, Surgical Simulator. I. INTRODUCTION IRTUAL reality technology brings numerous advantages to the medical community including improved surgical training. Training on patients can to some extent be avoided by using live animals and human cadavers. However, with the continuously increasing speed of computers, surgical simulators are now being offered to hospitals as a means of improving training and reducing the costs of education. Some simulators are based on phantoms (e.g. plastic structures) and others are virtual reality computer based simulators (1), (2). Although phantoms may provide realism with regard to tissue behaviour, computer based simulators will increasingly become more eligible as a training aid, especially due to their extensive range of educational features. By means of kind of simulator it is possible to model unusual and rare cases and to practise new procedures avoiding risk for real patients; in
[Show abstract][Hide abstract] ABSTRACT: Virtual reality technology can be utilised to provide new systematic training methods for surgical procedures. Our aim is to build a simulator that allows medical students to practice the coronary stent implant procedure and avoids exposing patients to risks. The designed simulation system consists of a virtual environment and a haptic interface, in order to provide both the visualization of the coronary arteries and the tactile and force feedback generated during the interactions of the surgical instruments in the virtual environment. Since the arteries are soft tissues, their shape may change during an operation; for this reason physical modelling of the organs is necessary to render their behaviour under the influence of surgeon's instruments. The idea is to define a model that computes the displacement of the tissue versus time; from the displacement it is possible to calculate the response of the tissue to the surgical tool external stimuli. Information about tools displacements and tissue responses are also used to graphically model the artery wall and virtual surgical instrument deformations generated as a consequence of their coming into contact. In order to obtain a realistic simulation, the Finite Element Method has been used to model the soft tissues of the artery, using linear elasticity to reduce computational time and speed up interaction rates.