A fuzzy logic approach to intelligent alarms in cardioanesthesia

One of the most important tasks of the anaesthetist performing anaesthesia to a patient undergoing cardiac surgery is the evaluation of the patient's hemodynamic state. During cardiac operation when the heart comes to work again after hours of cardioplegia the vital parameters (blood pressure, heart rate, etc.) can reach extreme values and fluctuations. Current alarm facilities are triggered yielding an alarm cascade and often turned off because the permanent noise level in the operating theatre disturbs the surgical team. An intelligent alarm system to support the anaesthetist in this situation has been developed. The system works online, gathering all required data from a general anaesthesia information system. Based on the decision making process of the anaesthetist, the most important vital parameter constellations are evaluated using a fuzzy inference approach, and are presented graphically on the user interface.<>