Closed-Loop or Automated Titration of IV Anaesthesia: Impact on Routine Anaesthesia

Closed-loop studies date back over 60 years. One of the early studies published in 1950 included 50 patients who received thiopental or ether using the closed-loop controller. Anaesthesiologists were already aware then of how to quantify the depth of anaesthesia using electroencephalogram (EEG) activity.