In order to perceive the image as moving, with no flicker, a frame refresh rate greater than 20 per second (Hertz - Hz) is required. This can be performed in real time or put together as an animation sequence and then replayed. For minimally invasive surgery (MIS)to work, near real time is required. One needs to achieve "The willing suspense of disbelief" in the mind of the operator. This term, poached from acting, is used to describe the psychological transformation necessary to induce the optimal learning environments, where the individual temporarily ceases to perceive the procedure as simply being a part of their training schedule. In VR modelling this is termedPresence. There are some fundamental reasons for adopting this approach: e.g.,
operating on real patients carries a significant potential risk related to the indications8 and complications of their arthroscopic shoulder surgery. To a lesser degree, there are also risks for the operator. This may be a physical threat to the self in the form of an
8Indications and complications of shoulder arthroscopy are outlined under the appropriate
headings of the shoulder section in VOEU under
http://voeu.ecs.soton.ac.uk/VOEU/library/section marked:VOEU: Library:Shoulder:
Arthroscopy . This is a virtual path rather than absolute and so needs to be located via the main VOEU site.
inoculation of a viral pathogen such as hepatitis B, C or HIV, or a legal complication as a result of malpractice litigation.
The associated Multimedia Educational Orthopaedic Modules (MEOMs) could accommodate this aspect into the simulation environment by incorporating relevant sectionse.g.microbiological cognitive recall as one of the sub-skills requisite in the pre- operative section.
So how can this ‘panacea’ for surgical training be achieved? If virtual reality modelling is considered in the traditional sense, the trainee should be induced to perceive the risk of consequence associated with failure to achieve an acceptable standard of performance, where in fact no actual physical risk exists.
The particular training environment in which the trainee is learning and demonstrating their skills can generate this. For example the trainee could be using such a simulator as part of the regular professionally supervised training schedule, e.g. Continuing Professional Development (CPD) or part of their ‘specialist’ training scheme (e.g. Higher Surgical Training - HST, in the UK). The demands of the examinations, standards for qualification and ultimately of the work practice focus upon hurdles such as the Certificate of Completion of Specialist Training (CCST) and preparation for this is integrated with the effort an individual makes during their specialist training programme. They are subject to the Regional In-service Training Assessments (RITAs), a process for monitoring the progress of an individual. Then the validity of their performance would necessitate their attempting to achieve the best possible results.
This thesis describes the development of a method for the evaluation of the performance of the arthroscopic simulator. Since the human mind is adept at "filling in the blanks", users will overcome the shortfalls in certain areas of the simulation, such as the interactivity to control the fluid irrigation normally used in arthroscopy. The limitations become less significant to the trainee if they are receiving adequate simulation via other senses. The principle was first demonstrated in mechanical simulators, such as the 1920’s Link flight simulator see Figure 2.1 and the motorcycle simulator that provided a representative sensory experience of riding a motorcycle known as theSensoramabuilt by Morton Heilig in the 1960’s (41).
In a surgical operating environment there are certain aspects of reality which people use, such as types of clothing and drapes to demarcate who is able to perform
tasks in the sterile arena and thus able to work within the operating field, or the recognition of other people within the surgical team as fulfilling discrete designated rolese.g.nursing staff, operating department assistants and the anaesthetist.
Teamwork is essential. This is often overlooked. In any real operating environment this is a significant factor in the smooth running of a procedure, both with regards to safety and the satisfaction of all those who participate. Though not fundamental within the actual simulator itself, teamwork can be emphasised within the tutorial part of a training package to achieve a compromise between an individual’s role within the team and the focus upon training for skills. One of the foundations of building trusting relationships in healthcare is the ability of individuals to communicate clearly and concisely by distinct use of terms and language (42).
An intrinsic advantage of designing, building, and emulating arthroscopy (for that matter any minimal access surgery) is that the trainee obtains a monitor-based view of the operating environment, hence is already immersed within the appropriate operating environment. This offers considerable advantage since the display system interface mimics the normal colour monitor (HDTV) display with which all operators are familiar, avoiding cognitive dissonance. Surgeons can therefore focus upon specific purpose such as pattern recognition sub-skills training.