This research is focused on improving personnel training at the Peruvian Fire Department (PFD) using Multimedia Systems in Biomedical Applications. Currently, the PFD performs their prehospital interventions (PI) training using live actors and low-fidelity manikins, these training methods do not simulate a realistic environment that puts the fireman under stress. Besides, it is not possible to measure the evolution of the firemen's performance during their training. In the design stage, a tool was created for emergency training during stressful situations to improve decision-making at PI scenarios. The equipment included a control system, a trauma simulator-manikin, a mixed reality software, and an appropriate algorithm. The system was implemented in the Mechatronics Laboratory at Ricardo Palma University-Peru from 2018 to 2020. The main components were the communication network between the visual interface of the Mixed Reality System (MRS) software and a fuzzy logic program developed in Matlab's Simulink tool. The tests were based on training cases established by the National Association of Emergency Medical Technicians (NAEMT) and the International Trauma Life Support for Emergency Care Providers. The results of the simulation showed a successful design of the diffuse controller and hardware. In addition, there is an improvement in the trainees' decision-making under pressure, which is evidenced in the reduction of time it takes to develop the diagnosis, stabilization, and the total duration of the PI. In conclusion, MRS for simulation of a PI can improve the quality of the personnel training of the PFD at reduced costs.