by Sarah Elhachimi
“Knock and enter.” A familiar phrase commonly heard overhead by medical students at the start of their Objective Structured Clinical Exam or OSCE. The voice signals to students that they are to suspend reality and enter a simulated environment where they can practice or be assessed on their clinical skills. Simulation-based training is now a foundational part of most medical education curricula, as it offers learners the ability to develop and refine their skills in a low-stakes and controlled environment. Many medical schools and academic hospitals have advanced simulation centers that feature high-fidelity mannequins and virtual reality environments. Simulation-based training has a myriad of benefits, including error reduction, opportunity for repeated practice without harm to actual patients, and immediate feedback. Structured debriefing is a tool that helps further solidify learning. The integration of simulation allows for learners to see clinical skills, decision making, and team communication in action. The use of modern simulation in medical training dates back to the mid 20th century, with anesthesiologists playing a pivotal role in its development.
One of the earliest defining technologies that began the modern era of simulation in medical education was the Resusci-Anne, the cardiopulmonary resuscitation simulator developed in the 1960s. A Norwegian anesthesiologist, Dr. Bjorn Lind, and toy maker Asmund Laerdal fashioned a realistic model of the human torso to allow for the application of Dr. Peter Safar’s head tilt/chin lift to relieve airway obstruction and deliver mouth-to-mouth rescue breaths. Later iterations of this model included spring mechanisms to allow for chest compressions, making Resusci-Anne the most widely used CPR mannequins in the 20th century. In 1968, Dr. Michael Gordon created Harvey, a cardiac auscultation simulator. Both the Resusci-Anne and Harvey laid the groundwork for immersive simulation. Anesthesiologists were among the first specialists to integrate these tools into residency training as ways to aid in improving procedural and diagnostic skills.
Around the same time, Dr. Stephen Abrahamson, an engineer, and Dr. Judson Denson, an anesthesiologist, developed Sim One, the first computer-controlled full-body mannequin capable of simulating human physiological responses with funding from the U.S. Office of Education. Sim One was developed at the University of Southern California to train anesthesiology residents in endotracheal intubation. Abrahamson and Denson were able to demonstrate that residents trained on Sim One achieved professional levels of performance in fewer days and less trails in the operating room than residents without simulator training, albeit small sample size. Though expensive and ultimately not widely accepted at the time, it is considered to be the ancestor of the current high-fidelity mannequin used today.
Dr. David Gaba, an anesthesiologist at Stanford University, is credited with pioneering simulation-based medical education. In the 1980s, he developed one of the first high-fidelity simulators, specifically for training anesthesiology residents. Known as the Comprehensive Anesthesia Simulation Environment (CASE), this tool was now able to produce all of the information typically found on patient monitors in the anesthesia environment. This allowed for the application of skills that a learner already possesses under a pre-established set of conditions. He also introduced the use of Crisis Resource Management (CRM) to medical education. CRM is borrowed from principles used initially used in aviation, focusing on structured communication, leadership, and decision-making in emergencies.
Today, the diversity and complexity of simulation tools used in medical education has advanced. The modalities commonly seen in simulation centers include:
- High-Fidelity Mannequin Simulators: Lifelike mannequins with features such as breathing, heart sounds, pupil responses, and vital signs.
- Task Trainers: Specialized devices designed to teach specific procedures, such as intubation, IV placement, central line insertion, and lumbar puncture
- Standardized Patients: Trained actors who portray clinical scenarios in order for learners to practice physical exam techniques and clinical reasoning
- Virtual and Augmented Reality: Immersive technologies that simulate environments, such as the operating room or emergency department
- Hybrid Simulation: The combination of multiple simulation types, such as an SP wearing a task trainer) to provide a more thorough practice experience.
As medical education continues to evolve, the incorporation of AI will certainly be seen in the above modalities.
Anesthesiologists were foundational in the creation, implementation, and advancement of medical simulation. Their early recognition of its importance, especially in preparing clinicians for high-risk, high-pressure scenarios, has had a lasting impact on how medical professionals are trained. The benefits of simulation are significant, ranging from improved clinical outcomes, increased patient safety, and enhanced communication and teamwork abilities. However, while simulation can replicate many aspects of patient care, it will likely not fully capture the complexity of real-life scenarios. The incorporation of simulation in our training environments should be a complement to, rather than replacement for traditional clinical training. As trainees, we should look forward to combining simulation with hands-on clinical experience, as that will provide the most comprehensive experience.
Sources Used
Abrahamson S, Denson JS, Wolf RM. Effectiveness of a simulator in training anesthesiology residents. The Journal of Medical Education. 1969; 44(6):515-9.
Cooper JB, Taqueti VR. A brief history of the development of mannequin simulators for clinical education and training. Postgrad Med J. 2008;84:563–570.
Elendu C, Amaechi DC, Okatta AU, et al. The impact of simulation-based training in medical education: A review. Medicine (Baltimore). 2024;103(27):e38813. doi:10.1097/MD.0000000000038813
Gaba DM, DeAnda A. A comprehensive anesthesia simulation environment: re-creating the operating room for research and training. Anesthesiology. 1988;69:387–394.
Gaba DM. Simulation is a critical tool for advancing patient safety – avaliable to everyone regardless of location or resources. APSF Newsletter. 2019;33:96–97.
Rosen KR. The history of medical simulation. J Crit Care. 2008;23:157–166.
Date of last update: July 9, 2025