NEXUS Lab: Optimizing Health Outcomes Through Comparative Study

Mr. Geoffrey Miller
Division Chief
Medical Modeling, Simulation,
Informatics & Visualization

From Combat & Casualty Care, Summer 2021

Geoffrey T. Miller is a Research Scientist and Division Chief of the Medical Modeling, Simulation, Informatics & Visualization (MMSIV) Division at the Telemedicine and Advanced Technology Research Center (TATRC), U. S. Army Medical Research and Development Command (USAMRDC). In this role, Geoff oversees and conducts research and technology development into future generation medical modeling, simulation, training, sustainment, and readiness efforts focused on Trauma Combat Casualty Care and Military Medical Health System needs. Geoff is also an Associate Professor, School of Health Professions at Eastern Virginia Medical School (EVMS) in Norfolk, Virginia. Geoff joined EVMS in 2011, overseeing the expansion of simulation-based educational activities, curriculum development and educational outcomes and translational analysis, with an emphasis on the creation and improvement of operational and clinical competence assessment using advanced educational technology, modeling and simulation, specializing in immersive virtual environments, serious gaming and innovative educational technology development. Previously, Geoff was the Associate Director of Research and Curriculum Development for the Division of Prehospital and Emergency Healthcare (2000-2011) at the Michael S. Gordon Center for Research in Medical Education (GCRME), University of Miami Miller School of Medicine where he also served as a consultant and collaborator for the United States Army Trauma Training Center (USATTC).

Recently, the U.S. Army Medical Research and Development Command (USAMRDC) Telemedicine and Advanced Technology Research Center’s (TATRC), Medical Modeling, Simulation, Informatics and Visualization (MMSIV) unveiled the NEXUS laboratory – a new research environment designed to explore, analyze and understand the intersection of humans, data, and technology both within and across the Military Health System or MHS. The lab combines a range of state-of-the-art technologies (such as motion capture, volume capture, and synchronized psychophysiological monitoring) to record military medical professionals performing medical tasks to better understand clinical procedural performance, the use and impact of medical devices and technologies, and data and visualization tools with current and future technologies in combat casualty care by individuals and teams. Data derived from the NEXUS laboratory will enable research into how current or new procedures, medical devices, and digital health technologies impact caregiver performance in military operational medicine contexts.

Combat & Casualty Care had the chance to speak with Geoffrey T. Miller, a Research Scientist and the Division Chief of the MMSIV Division at TATRC. In this role, Miller oversees the NEXUS lab and conducts research and technology development into future generation medical modeling, simulation, training, sustainment, and readiness efforts focused on trauma combat casualty care and MHS needs.

C&CC: Why start the NEXUS lab now as opposed to some other time? What’s so important about now?

Mr. Miller: Why now? I wish we could’ve done it sooner. The NEXUS laboratory combines a collection of state-of-the-art performance measurement technologies that allow us to really explore and understand what human performance in healthcare looks like. Now what do I mean by that? What I mean is that most people are trained to do procedures using guidelines or evidence-based practice where it exists; or – in the example of a combat medic’s training, they have instructors and manuals, they’re taught how to do a procedure, when do to a procedure, and why they would do it. From there, they go to a simulation-based setting where they work with task trainers or manikins to practice skill development.

Following skill development and training, they typically get evaluation by instructors who observe and rate their performance for a “go, no-go” decision. What we’re trying to do with NEXUS is leverage technologies that are readily available to improve the objectivity of performance measurement of military healthcare providers, which also influences the training and development phases. Instead of me observing a student as they go through a sequence of clinical procedural skills – using a checklist or some other criteria to say “you’re good, you’re ready-to-go, you’ve checked all the boxes”, we are mapping healthcare procedural performance to improve acquisition, retention and transfer of learning, simply we want to achieve two primary goals; ensuring expert instruction for everyone, and measure performance accurately with individualized expert feedback. So employing technologies like motion capture, psycho-physiological monitoring or stress monitoring, pupillometry, clinical assessment and intervention data from human patient simulators, the accuracy of those tied to task-load monitoring, and cognitive saturation, or understanding where your attentional focus is, we start to understand and appreciate a more complete picture about a healthcare providers ability to do something in a way a human observer just can’t measure.

Through systematic collection of these data, over time, and with a large number of subjects, we can then begin to aggregate the data into what we call a “master model of performance.” A “master model” considers the measured performance of hundreds of trained professionals doing the same task, ideally hundreds of times. When we have sufficient data, we aggregate the sum of all data to develop a model of, ‘what right looks like, what expertise looks like when you’re doing this particular procedure.’
As an example I’ll use endotracheal intubation via direct laryngoscopy. The nice thing about this procedure – one performed by medics physician assistants, nurses and physicians to establish an airway for a casualty that the procedure as written is described as a very specific series of steps, and there’s really no deviation from the steps; there’s simply ‘the’ pathway for doing it. Because of that, it’s something that’s easy for us to model and capture performance. Once we have created a model of what ‘right’ looks like – well, now we can leverage this into educational training systems so new students can train against that expert model and receive, in some cases, automated expert assessment with individualized ‘prescriptive’ feedback for performance improvement and monitoring.

C&CC: What does the future look like? At what point do you look at what you’re doing and feel successful in accomplishing your goals – or is that effort constantly evolving?

Mr. Miller: Like all technologies, there will be a constant state of evolution. The NEXUS incorporates a lot of different technologies, but most of these technologies or systems are independent of each other – and what we want is to bring them together into a single modeling system. There will be a lot of additional development needed in this respect. I mentioned earlier when we try to combine the motion capture data with the stress monitoring data with the electroencephalogram (EEG) data, with casualty care data; each of these is coming from a separate system; bringing them together and simply synchronizing them on an common time stamp for model creation is not an insignificant task and takes a lot of computing power. One of the priorities of this effort is to understand how we optimize data collection to achieve model development and construction.

So, there is more discovery and experimentation needed. That’s why we have projects like the ‘Data Commons Project,’ a collaborative effort by Johns Hopkins University, Applied Physics Laboratory to store data from TATRC (data which is de-identified prior to submission, according to Miller) from the different systems and sources to harmonize and synchronize them to achieve more complete repositories for models and research and development.

C&CC: What is the purpose of personnel wearing the motion capture suits in the NEXUS lab? Is it to quantify how long, exactly, it takes any given person to perform any given task?

Mr. Miller: It allows us to understand that; how to catalogue physical actions in time and space, so we can actually create 3-D models of what healthcare providers look like for every second of procedural performance, down to the position and angle of each individual joint in time. From this, we are able to [going back to the intubation example] measure all their joint distances, movements, and angles associated with a specific step of a procedure. Once we aggregate all the data together, and figure out what the expert model looks like, we can leverage these models into research and training efforts. For example, a master model could be used to train and assess new healthcare providers. An early prototype training system with a single depth-sensing camera, was able to measure learners against a developed model. A range of training aids were included such as visual indicators to assist in learning – like red, yellow, green – when your frame is green, you’re in the right position; when it starts to get yellow, [you] need to move your right arm a little closer to [your] torso; if it’s red, I’m way out of zone. This same system can recognize objects (e.g., laryngoscopes, syringes, airway devices, etc.). So if you’re holding a laryngoscope in your right hand – [it can tell you] that’s incorrect, it needs to be in your left hand. This same system can even map in the patient simulators that we use. Knowing the exact human patient simulator in use, allows us to map the position of internal structures, for example, where the trachea is in relationship to the exterior contour.

Understanding this special relationship allow the system to tell you where the tip of the laryngoscope is based on the position of the operator holding it, even when it’s inside of the airway, because they all have fixed shape, dimension, and structure. Now, as a human observer, I can only tell you that the laryngoscope is inside the oral airway, but with this system I can tell you where the tip of it is in relationship to the vocal cords, the epiglottis, all of those features.

C&CC: Can the systems within the NEXUS lab also identify psychological stressors impacting a Soldier?

Mr. Miller: Yes, we’re able to do a battery of measurements that start to indicate levels of stress. We can do a range of different electrocardiography monitoring, we can look at heart rate, we can look at [a certain measurement] that is indicative of increased or decreased stress as it related to the electrocardiogram. We measure skin galvanic response – so, how sweaty are you getting? Are you as cool as a cucumber? We can look at jitter and movement using accelerometers. We also measure respiratory rate and breathing patterns. While this may seem odd for performance measurement, over time, we have noticed that people do funny things when focusing on a task. And again, using the intubation as an example – one thing a lot of people are taught is breath holding during intubation. Simply, when you get ready to intubate and place the laryngoscope into the airway, the operator should take a breath and hold it. The reason is because if you need to breathe, then the patient needs to breathe. So if you have to take a breath, and you haven’t gotten the patient intubated, you need to back out, re-ventilate your patient so they don’t become hypoxic, and reattempt. Understanding the full range of human behaviors during medical procedural performance allow us to better understand techniques and mechanisms that optimize outcomes.

C&CC: How could technology like this have helped you during your own healthcare career, and do you see this kind of information informing work done in the public healthcare arena as well?

Mr. Miller: Without a doubt. When I started, I went through my training in the late 1980s, and while medical simulation and simulators were used, it was a very, very different level of medical simulation then. The history of medical simulation is actually much older than most people give it credit for however, it’s only been in the last 15-20 years that you’ve seen rapid advances in the technology and fidelity around medical simulation.

Looking back, in my training, we had very basic devices and tools – [but] it’s what we had to learn from. Actually, in a lot of cases, we learned from each other – we were each other’s simulators. In that time it was not uncommon to practice blood draws on each other, or intravenous (IV) placement on each other. The ‘state-of-the-art’ has progressed substantially, and our ability to measure and assess and provide feedback to people has progressed as well. Feedback is the single most important feature that leads to improved learning. You can practice clinical procedural skills all day long, but if you don’t receive any information [e.g., feedback] about how well you are doing, or how well you’re not doing, then you risk establishing poor performance as a habit, because if you repetitively perform incorrectly, the same way in training, then you risk permanence of poor practice. It is significant to the mantra ‘fight as you train, and train as you fight’ – our goal, and the goal of NEXUS, is to ensure expertise in both training and the ‘medical fight’ for all of our military medical providers and Soldiers.