Virtually Saving Lives: A Visualization Solution for Medical Triage Training
National Capital Area Medical Simulation Center (NCAMSC)
June, 2007
When Dr. Alan Liu, Director of Virtual Medical Environments at the Uniformed Services University of the Health Sciences (USUHS), initially introduced his plan for a virtual reality-based training center for medical triage, his ideas were met with some skepticism in the medical community. In 2001, despite success with traditional training methods, he foresaw that practical applications of virtual reality could, paradoxically, increase the realism of his scenarios and expand their potential. Six years later, with the help of Mechdyne virtual displays, the USUHS’s virtual reality laboratory, the National Capital Area Medical Simulation Center (NCAMSC) is at the forefront of advanced medical response training, preparing teams not only for complex triage and invasive procedures but also for new challenges on the world stage. Cost-effective and yielding powerful results, the center is forging a fresh approach to medical training that could dramatically enhance healthcare for hospitals as well as the military cadre.
The need for new learning tools has long been apparent to educators and medical professionals. While scientific discoveries are resulting in more sophisticated treatments, mass casualty events such as 9/11 are driving a greater demand for emergency response teams. As such, insular classroom settings often do not prepare students for the realities of a high-pressure medical situation. Indeed, one of the most crucial elements of medical team training is learning to perform within stressful surroundings.
Yet prior to virtual technology, the re-creation of a medical emergency, namely disaster situations, posed the biggest obstacle to educators and instructors. For disaster scenario simulations, training methods have centered on elaborate role-playing sessions with hundreds of volunteers posing as casualties. Involving a multi-disciplinary team of make-up artists, actors, set designers as well as medical professionals, these rehearsals are expensive and require extensive preparation and time. In addition, live rehearsals can only simulate one type of situation per session, with inconsistent degrees of realism. Most importantly, the level of instruction and learning during these scenarios can be quite limited since feedback is only available after the event and it is difficult to interrupt or re-run a session if errors are made.
The solution for Dr. Liu was to move these scenarios indoors, using a large virtual reality environment in what he describes as “Blended Reality.” While a limited number of live actors are still an integral part of training, the location of the scenario is virtually simulated. For example, the scene could be a foreign city such as Baghdad, a battlefield or a heavily populated urban area. Already, the system has proven its value as an efficient and cost-effective alternative to live-actor rehearsals.
The virtual display, designed by Mechdyne Corporation to meet the SimCen’s requirements, consists of three angled, vertical screens and surround sound to fully immerse an observer in a 3D environment. A total of six projectors create stereoscopic imaging to make the virtual locations more realistic. Students wear lightweight, polarized glasses to create the stereo effect; eyewear that is not intrusive and does not affect their performance. The display system is driven by a PC with dual CPUs and dual 7800 GPUs, with nVidia graphics cards. Coupled with the display screen, fully customized software enables trainees to interact with a wide range of modeled scenes in real-time, from a fire in downtown L.A. to a combat mission in Baghdad. Visual effects, such as fire, smoke, debris and explosions are incorporated along with virtual characters and vehicles, creating a highly realistic environment.
Remote participants can also connect to the scenario, either to watch or participate, via an established network. Remote users can wear head-mounted displays or view on large, stereoscopic screens. Their image appears as an avatar in the virtual space and they can directly interact, in real time, in the virtual space.
Immersive images and sound are not the only features of the blended environment – the system also allows students to physically treat simulated and live actor patients. The display software is programmed to work in combination with several computerized mannequins, controlled remotely from a laptop. When a student selects an animated victim for treatment in the virtual world, the mannequin automatically exhibits the symptoms and wounds of the chosen patient. Students can intubate, insert an I.V. and perform various surgical procedures on the character that would not be possible on a live actor. And, just like a real patient, the mannequin breathes, bleeds, lives and dies based on the actions of the student. Live actors are used appropriate to the scenario and together with the mannequins, these simulations allow students to safely practice and refine their skills for more complex procedures. Moreover, the enhanced realism of the blended environment gives trainees a better idea of what to expect in an emergency situation and of how to cope under austere conditions.
The system has become the cornerstone of training procedures at the SimCen, leading the way for new medical training methods worldwide. With little co-ordination or investment, training teams can gain experience with any number of recreated past events or potential situations, from disaster relief after a terrorist event to damage control after a chlorine spill. During these sessions, instructors can coach students in real-time and participate more freely in the scenario.
Dr. Liu claims that, “the most compelling reason to go virtual is the “Reset Button.” Unlike a live rehearsal, a virtual scenario can easily be stopped and restarted at any point during a session, allowing students to practice the same situation multiple times. Since the outcome of a scenario can vary dramatically depending on the choices of the user, the system is a powerful tool in understanding the consequences of a successful or erroneous triage. As Dr. Liu notes, “people learn from their decisions – even incorrect decisions.” For instance, if at a disaster site, a student spends too much time on patients with minor injuries, those with more serious wounds might not survive. The ability to re-do a session can coach students to make fast, efficient assessments by showing “not only how many lives you have lost but how many lives you could have saved if you could go back and do things differently.” With each practice run, in-house writers draft case scenarios for further review after the training session.
Not surprisingly, the center has generated significant interest from the wider academic community as well as government agencies such as branches of the military. For now, when it’s not running tours and demos, the center serves primarily as an advanced training facility for various types of medical teams and students. However, given the capabilities of such a system, one can only imagine the vast potential for research and analysis in the near future. In the meantime, Dr. Liu is dedicated to further developing the system for educational purposes, insisting that the center is “a prototype of what is possible.”
