daniel's blog: journals
Surgical Simulation (Part 1 of 25)
Medical education on the Internet is commonly available and widely used by health care practitioners, but the current available media-based learning environments, mostly represent a passive medium of information retrieval by clicking a mouse. (Temkin et al. 2002) Traditional methods of teaching anatomy include the use of cadavers and 2-D illustrations with labels to identify structures. Though these techniques have been proven effective over many years, computerized techniques can be of assistance to medical students. Many researches have been conducted in the area of simulated training for medical students. Even in the 1990s, simulators were in development for knee arthroscopy, laparoscopy, endoscopy, epidural needle insertion, and sinus endoscopy. These were three-dimensional graphical simulations of anatomy, some with haptic feedback, to support planning a surgical or clinical procedure. Some included the ability to cut and move tissue, others supported deformation of tissue. The rapid progress of this young field can be seen in the proceedings of two annual conferences, Medicine Meets Virtual Reality, and the IEEE Virtual Reality Conference. (Parvati et al. 2002) Based on the paper published by Parvati et al. in 2002, there are eight surgical manipulations which must be considered when designing a software for medical students: probing, aspirations or injection, incision, evacuation, scarification, extraction, excision, and closure. A ninth more modern procedure is implant or transplant. Also interaction with tissue and feeling its texture and resistance are critical components of learning. An important feature of this kind of software is the inclusion of haptic technology and force-feedback, as for training of new physicians and surgeons, the acts of touching, feeling, and cutting are believed to be essential. Also if the computer-assisted surgical simulation is to be effective, the objects in the environment must react to the user’s actions dynamically with correct visual information. This includes dragging and cutting that cause changes in geometry, topology and appearance. (Wei-te Lin et al. Mayo Foundation, US) The sense of touch is an integral part of medical practice, and simulating it, even at an imperfect level, is essential. The capability of simulating palpation of different tissue types is an enormous hurdle for developers of computer haptics. Three important issues when talking about haptic technology should be taken into consideration: 1. It is important to distinguish between haptic, tactile, and force feedback. Haptics is a broad term used to describe both cutaneous (tactile) and kinesthetic (force) information. Both are necessary to form the typical sensations felt with the human hand. Force feedback, is where forces are resolved to a single point, and are displayed to the user through a tool. A haptic device such as the PHANTOM from SensAble Technologies can provide this type of feedback. Tactile display devices are not yet commercially available, and are not likely to meet the size and weight constraints for multi-degree-of-freedom systems in the near future. 2. If decided to use the haptic technology in e-Learning software, the appropriate method of displaying haptic data should be chosen: visually, aurally, or haptically. 3. Tissue mechanical properties are needed if the graphic models are also to be perceived haptically (Temkin et al. 2002). Also the significant challenges to the use of this technology, such as cost and complexity should be taken into consideration.
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