HUMAn, a Real-Time Evolutive Patient Model for Major Incident Simulation: Development and Validation Study (Preprint)

BACKGROUND Major incident management must be both efficient and effective to save as many lives as possible. All paramedics and emergency medical technicians may unexpectedly have to respond to such incidents. However, they are infrequently, if ever, exposed to major incidents and regular training is therefore mandatory. Initial training and refresher sessions are usually based on simulations. Most major incident simulations are limited by the fact that simulated patients do not evolve during the simulation, regardless of the time elapsed and despite treatment and transport decisions. Therefore, most simulations fail to incorporate a critical temporal effect of decision-making. OBJECTIVE To develop and validate a simplified yet realistic physiological model capable of simulating the real-time evolution of several casualties. METHODS A modified version of the user-centered design framework was used to define the development process of the physiological model. This framework is based on the five modes of design thinking (empathize, define, ideate, prototype, and test), with the addition of the knowledge base mode of the information systems research framework. To validate the developed model, a validation phase was added. To determine whether the developed model was clinically realistic, 15 experienced prehospital professionals (5 advanced paramedics and 10 senior registrars working in ground and helicopter emergency medical systems) participated in a validation phase. They were asked to rate clinical and physiological parameters according to a 5-point Likert scale ranging from 1 (impossible) to 5 (absolutely realistic). RESULTS A collaborative development team including prehospital professionals and computer scientists agreed on the most important feature of the model: it has to be clinically realistic, include all the elements required to compute prehospital vital signs and their evolution, yet be simple enough to allow real-time computation of these parameters for several simulated patients simultaneously, on regular computers or tablets. Multiple iterations led to the development of a heart-lung-brain interaction model coupled to functional blocks representing the main anatomical body parts. These blocks enabled the management of neurovascular elements used to provide neurological information and to create hemorrhages at different levels with different blood flows. The professional prehospital providers who participated in the validation phase assessed nine simulated patients presenting pathologies devised to test the different systems and their interactions. All initial and final states of all patients had a median rating of 5 (absolutely realistic) for both clinical and physiological parameters. The overall median rating was also 5 for each individual patient. CONCLUSIONS A simplified model of trauma patient evolution was successfully created and deemed clinically realistic by experienced clinicians. This model should now be included in computer-based simulations and its impact on the teaching of major incident management assessed through randomized trials. CLINICALTRIAL None