A Survey of Patient Simulators for Safe Anesthesia: Advancing Closed-Loop Control Systems

Anesthesia is arguably one of the most significant milestones in medical history, fundamentally transforming surgery from a traumatic last resort into a safe, humane, and sophisticated science. Closed-loop anesthesia represents the cutting edge of surgical pharmacology, utilizing automated systems to maintain a patient’s state of sedation or analgesia. Designing and testing controllers can be easily facilitated using dedicated patient simulators. This review provides a critical assessment of current patient simulators, specifically examining their mathematical models, functional capabilities, and utility in control system engineering. Through a series of simulation examples and a comparative analysis, the paper illustrates the incremental value of each tool relative to earlier iterations. Additionally, the scope extends to web-based simulators and engines, culminating in a roadmap for future research and technological advancements in the field. By highlighting the advantages and limitations of existing patient simulators and providing insight into possible developments, this survey emphasizes the need for further and deeper research on this topic. Such improvements are vital for the possible acceptance of closed-loop anesthesia in clinical settings.