A computer screen-based simulator for hierarchical fuzzy logic monitoring and control of depth of anaesthesia

Abstract

A computer screen-based simulator has been developed to simulate the administration of intravenous and analgesic drugs. It merges on-line measurements (such as systolic arterial pressure (SAP) and heart rate (HR)) and nonnumerical clinical signs (such as sweating, lacrimation and pupil response), using anaesthetists' experience or self-organizing fuzzy logic control (SOFLC) algorithms to administer drugs into a patient. The hierarchical control architecture includes five parts, which are: monitoring depth of anaesthesia (DOA), drug controller, deciding the sensitivity of the patient, narcotic supplementation and recovery time. It has been developed to predict drug profiles, control the drug levels and assess recovery time during anaesthesia. Meanwhile, linguistic rules and fuzzy set theory have been used to model a patient's SAP and HR during induction and maintenance stages. Successful simulation results have given confidence to perform on-line clinical trials in operating theatre.