A gentle introduction to simulation
From WickedSim
The contents of this page are at present under discussion. Please feel free to contribute.
Whether you are new to simulation, considering the integration of simulation into your program, or an interested passer-by, you're in the right place!
Contents |
What is Simulation?
If you're here, you're probably interested in simulation for the purpose of educating healthcare students. In this context, simulation takes on a very broad meaning. A standardized patient or a scenario given verbally are two examples of medical simulation that can be and are applied anywhere medicine is taught. They are unsophisticated technically, but effective and dependable.
More modern approaches to simulation education can include the use of computer software, specialized hardware, or both, together with verbal scenarios and sometimes even standardized patients thrown in. The right approach for you will depend on your audience and your goals.
Computer software alone is a useful tool for self-teaching and review. Often, it is employed for lay people and basic learners. Textbooks often come with instructional CDs offering quizzes and basic scenarios and places like Games for Health promote, as the name implies, games for healthcare education. This type of simulation is usually limited to assistance with rote memorization and systems level medicine where limited choices are given in a scenario and the user must then select the appropriate action. The computer then gives feedback in the form of a score, or on more complicated programs, a more detailed analysis of the user's actions. Despite these limitations, this form of simulation is useful because of its low cost (a standard PC will do to run the software) and the huge audience that can benefit from the education provided by it.
When some specialized hardware is added, cost increases quickly and the audience shrinks dramatically, but the potential for learning is greatly increased. Immersion Medical and Select IT offer simulation tools of this sort. In this case, a partial task trainer is connected to a computer, allowing self teaching or supervised instruction. Either way, the result is more realistic with a greater focus on the physical task rather than the mental process behind the task.
A partial task trainer can also be used without the attached computer. The reduced cost of this solution often makes it readily available to many organizations in need of simulation technology. Many companies currently produce trainers of this type for a wide variety of medical fields.
The State of the Art
Finally, there is the combination of all approaches. Full body mannequins attached to a computer are available from a few companies (such as Laerdal and METI}. When these mannequins are used in a room designed to simulate an OR, ED or other setting the result can be very realistic. The advantage to the learner is the increased immersion that allows a patient encounter to flow as it would in real life, temporarily removing the 'simulation' aspect. The experience leads to greater confidence for the learner when faced with the same situation on a living patient. This realism comes at a great cost, however, and the field is very new. Simulators suffer from a lack of standardization both in hardware and software. Some simulators, notably METI's, have built in software physiology. While this is a bold step in the right direction for some, the physiology is not entirely accurate or complete, and takes direct control away from the educator. These simulators also suffer from other problems: a lack of certain features forcing educators to resort to partial task trainers and breaking the immersion, and a very low reliability, especially after extensive use. The cost of these simulators is usually compounded by the need to create an entire simulation center around the mannequin, complete with control room, realistic patient bays, and any miscellaneous AV equipment, debriefing rooms, etc. With all these problems, these simulators are still the cutting edge of healthcare simulation technology and their incorporation into a healthcare curriculum can yield excellent results.
This type of simulation is the main focus of much discussion in the field. This is due in part to its current capability, but also to its potential to become a very powerful, dependable technology that is the centerpiece of modern healthcare education.
Simulation Resources
For those new to simulation and veterans alike, there are many resources to assist in your goal of bringing the best possible education to your students.
Simulation societies and interest groups provide a place to share ideas, both practical and conceptual. This is done through mailing lists, conferences, and web pages. Societies also carry more weight in statements made regarding the direction of the industry than would a single simulation center. A list of groups related to medical simulation follows.
SSIH SAEM Simulation Interest Group Games for Health, part of the Serious Games Initiative (please feel free to insert more groups here)
Manufacturers of simulation mannequins, task trainers, and software are our main source of supplies. Here is a list of suppliers.
METI - Makers of HPS, ECS, iStan Laerdal - Makers of SimMan, SimBaby Ambu Gaumard Simulaids (Suppliers' names and URLs can be inserted here)
Simulation centers can themselves be great stores of knowledge! Many will let you visit, see a simulation session, and get a tour of the facility. Feel free to put a link to your own simulation center here.
- EMSTAT at SUNY Upstate Medical University (NY, USA)
- Advanced Clinical Skills Centre (Auckland, New Zealand)
Other web pages, though not necessarily created for the healtcare simulation community, may be of great use. Radiography libraries, sound libraries, medical image libraries, are a few examples. A list of these sites is included below.
MedPix Medical Image Database RTStudents - Links to Radiology Resources (Please place other web links here)
Organising your simulation centre
This topic is covered on a separate page.
Where do we go from here?
As a community of educators and as individual centers, we have limited resources of time, money, and physical space. We need the best we can get to fill our needs for the least time, money and space, but we don't have the time, money, or space to develop our own mannequins. At least, most of us don't. We must, however, make the time to discuss, network, and educate ourselves on developments in our field, especially because it is developing so rapidly. If we take an active part in shaping the course of medical simulation technology, we can reap great benefits.
If you are part of an existing simulation center, you may have encountered the issues mentioned here, and you are encouraged to participate in their discussion and development. If you haven't yet created your simulation center, it may be beneficial to read what others have encountered and put forth your own ideas for improvement.
A Common Voice
This is not the only forum for the discussion of healthcare simulation. Even if it were, discussion does not translate directly into action. More mature industries have a society that, among other things, establishes that society's needs and creates a standard that manufacturers must meet to be acceptable to that society. Standardization is a topic in itself, but also important is the need for a society to discuss the needs of its members so that standardization can occur. Do we want physiological models or more direct control of physiology? Do we want two separate standards, one for each? Do we want modular mannequins, mannequins with universal functionality, or partial task trainers? Do we want to have kits to make or modify our own mannequins? How many standards do we want to lay out? We already have the SSIH, but what we need is not only to discuss these topics and swap tricks of the trade, we need to come to conclusions on these topics, create standards, and demand better quality for our money.
Standardization
The two most common healthcare mannequin manufacturers are Laerdal and METI. If you try to take any part from one and use it on the other, software or hardware, it won't work. Often, a part from one METI mannequin won't work on another METI mannequin. Still more often, the same scenario run twice in a row will give you two different results. This situation is unacceptable. Hardware standardization, and more importantly software standardization must become a reality. If physiological models are to be in widespread use, one must be able to refer to specifically which model is being used in a simulation.
With that information, the scenario can be looked up in your own database and the standards can be looked up online. A manual for programming that standard should be found, and a hardware manual should be found describing exactly what is inside the mannequin. For software, every physiological factor should be described in detail and every factor should have a real life analog so that a technician with little medical knowledge can communicate with a physician with little technical knowledge and get the precise information required to translate a case into a scenario. When all of this is done, the mannequin should respond predictably, repeatedly, as a real patient would be expected to respond. For hardware, the manual would be useful in maintenance, troubleshooting, and comparison shopping. If you own 2.1 compatible parts, you would want a 2.1 mannequin.
The importance of Crew Resource Management
Some might see simulation as primarily related to acquisition of technical skills. Such a focus ignores perhaps 90% of what is important in simulation.
We now know that many harmful and even lethal healthcare errors are related more to `systems errors' than to lack of technical competence. Healthcare systems are becoming increasingly complex, and in such environments the interaction between participants becomes even more important than mere technical skill. The simulated healthcare environment then becomes useful in reproducibly examining such interaction, and favourably modifying behaviours within complex medical environments. Healthcare personnel need to acquire other skills and behaviours which transcend technical competence.
Such 'non-technical skills' are largely about human interaction at its many levels. Unfortunately evaluation of such skills is at its early stages in medicine, but we can learn a lot from cognate development in other fields like commercial aviation. Particularly important in aviation is 'Crew Resource Management' (initially termed 'Cockpit Resource Management'). The importance of this skill, initiated at NASA in about 1979, is starkly revealed by contrasting two real-life air disasters, the Tenerife air disaster in 1977 on the one hand, and United Airlines Flight 232 on the other.
The Tenerife air disaster
This disaster, which claimed more lives than any airline disaster before or since, occurred when multiple factors conspired together. After a bomb exploded at Las Palmas passenger terminal, several large airliners were diverted to a small fog-bound airport which had difficulty coping with the rush. It seems reasonable to believe that tempers were frayed due to the delays, and the senior KLM pilot was probably in a bit of a hurry related to overtime regulations. Communication was far from optimal, and reading through the cockpit voice recorder transcripts is revealing --- conversations are confusing, multilingual and informal. The key event was probably interference in radio transmissions, when the KLM aircraft (Flight 4805) and a Pan Am aircraft (Flight 1736) tried to communicate with the tower at the same time. A misunderstanding occurred, was not corrected, and five hundred and eighty-three people died in consequence.
The KLM pilot who has largely been blamed for the incident had just finished a six month stint training new pilots on a simulator. His flight engineer had in fact been trained by him only recently, and seems to have been in awe of his senior.
Here's the communication between the flight engineer and captain immediately prior to the fatal accident, just after the engineer heard the Pan Am crew saying "OK, we'll report when we're clear."
Engineer: "Is hij er niet af dan?" (Is he not clear then?) Captain: "Wat zeg je?" (What did you say?) Engineer: "Is Hij niet af, die Pan American?" (Is he not clear that Pan American) Captain: "Jawel" (Oh yes --- emphatic)
Now let's look at another airline disaster, where against the odds, many lives were saved.
UA Flight 232
On this flight in 1989, the tail-mounted number 2 engine failed, destroying all three of the aircraft's hydraulic systems, a so-called 'one-in-a-billion' chance which had nevertheless previously occurred on Japan Airlines Flight 123 in 1985, resulting in the death of 520 of the 524 people on board. All control of the plane appeared to have been removed, and it began to oscillate up and down in a sine wave fashion with a period of about a minute (in aviation speak this slow oscillation is called a 'phugoid cycle'), losing 500 metres of altitude with each cycle of the oscillation. The plane also was veering to the right. The captain, Alfred Haynes enlisted the services of Dennis Fitch, a DC-10 flight instructor who happened to be on board. Dennis had read about the Japanese disaster, and had then practised flying DC-10 flight simulators using throttles only!
Based on Dennis' expertise, they found a method of controlling the plane --- generating differential thrust from the two remaining engines by running one engine faster than the other, and using overall accelleration or deceleration to change altitude. (If one takes any aeroplane and adjusts the trim so that it's at a constant altitude, and then decreases power, it will enter a phugoid cycle and gradually lose altitude overall). They managed to achieve a shallow angle of descent, and remarkably 185 of the 296 people on board survived the crash landing. Here's a detailed description of the flight on Wikipedia, and even more interesting is a transcript of a talk by Al Haynes. Here's a quote:
Thank you, thank you very much. "Land" is a rather loose term for that. Anyone who has seen this video seems to have this one question in their mind, and that is: how did anyone survive an accident of that magnitude? I think there are five factors that contribute to the degree of success that we had at Sioux City: that is, luck, communications, preparation, execution, and cooperation. And I would like to talk about those five things today.
Two flights: a comparison
I could perhaps wax eloquent about the differences between the autocratic style of the captain of Flight 4805, contrasting this with the co-operation shown on Flight 232. I won't. Instead, here's a rather long transcript from Al Haynes' talk:
"As for the crew, there was no training procedure for hydraulic failure. Complete hydraulic failure. We've all been through one failure or double failures, but never a complete hydraulic failure. But the preparation that paid off for the crew was something that United started in 1980 called Cockpit Resource Management, or Command Leadership Resource Training, or any number of things that you want to call it. I think we called it CLR to start with. All the other airlines are now using it. Up until 1980, we kind of worked on the concept that the captain was THE authority on the aircraft. What he said, goes. And we lost a few airplanes because of that. Sometimes the captain isn't as smart as we thought he was. And we would listen to him, and do what he said, and we wouldn't know what he's talking about. And we had 103 years of flying experience there in the cockpit, trying to get that airplane on the ground, not one minute of which we had actually practiced, any one of us. So why would I know more about getting that airplane on the ground under those conditions than the other three. SO if I hadn't used CLR, if we had not let everybody put their input in, it's a cinch we wouldn't have made it. It was, I don't know if any of you remember the old movie Marty, I kind of refer to that, it was Ernest Borgnine, and a group of his cronies, trying to find something to do on a Saturday night, and they said, what do you want to do Marty, and he said, i don't know, what do you want to do Joe, and that's kind of the way we flew the airplane now. What do you want to do, I don't know, and let's try this, and you think that'll work, beats me, and that's about the way it went, really. If you read the cockpit voice recorder transcript, there's a lot of that on there. When are we going to put the gear down, I don't know, how are we going to put it down, well, we do two things, two ways to get it down, which one we're going to use, that type of thing. So CLR really paid off. And CLR is being taken out into other areas. I think it was originally a management course anyway, but now it's being spread all over. I'm going next year to Harrisburg, PA to talk to the Nuclear Power Association. Because they are beginning the CLR concept in their control rooms. There have five stations in a control room. You have a nuclear disaster, you want those people working together, you don't want them working separately. So CLR that we had really prepared the crew for what happened.
Now you tell me! Is CRM important in healthcare simulation?
Johanvs 05:45, 3 April 2007 (EDT) ( Object )
Other links and References
Check out:
- A paper by Medeiros et al from the Proceedings of the 1998 Winter Simulation Conference.
