The use of mathematical models and clinical knowledge in intraoperative vital sign trend monitoring

Trend monitoring is a fundamental step in intelligent patient monitoring. When a patient experiences a systemic physiological change, the first sign is very often that a relevant vital-sign trend signal has changed direction. Notifying the decision makers about trend changes help them track vital sign dynamics leading to early diagnosis should an adverse event occur. Furthermore, due to homoeostatic compensation, a patient´s physiological status can be clinically stable with vital signs at different levels following intraoperative treatments. To understand patient´s status, the numerical levels of vital signs should be analyzed together with the trend characteristics, including the temporal patterns (direction, duration, and trend speed) and the interrelationship between the changes in different variables.