title: Closed-loop control of anaesthesia.
abstract: OBJECTIVE
  Closed-loop systems are able to make decisions on their own and try to reach and maintain a preset target. As a result, they might help the anaesthesiologist in optimizing the titration of drug administration without overshooting, controlling physiological functions and guiding monitoring variables. Thanks to the development of fast computer technology and more reliable pharmacological effect measures, the study of automation in anaesthesia has regained popularity.
  
  
  RESULTS
  This short review focuses on the most recently developed and tested feed-back systems in anaesthesia. Various new approaches for controlling the administration of intravenous and inhaled hypnotic-anaesthetic drugs have been published recently. For analgesics, a framework for further research has been presented in the literature. For other drugs, such as muscle relaxants and haemodynamics, a short review can be found.
  
  
  CONCLUSIONS
  Until now, most of these systems are still under development. The challenge is now to establish fully the safety, efficacy, reliability and utility of closed-loop anaesthesia for its adoption into the clinical setting. Besides the optimization of controlled variables and control models, these systems have to be tested in extreme circumstances.
authors.affiliation: Department of Anesthesia, Ghent Univerity Hospital, Ghent, Belgium. michel.struys@rug.ac.be
authors.forename: Michel M R F
authors.initials: MM
authors.lastname: Struys
authors.forename: Tom
authors.initials: T
authors.lastname: De Smet
authors.forename: Eric P
authors.initials: EP
authors.lastname: Mortier