The first published work on closed-loop control of anesthesia authored by Mayo, Bickford and Faulconer dates back to 1950. However, feedback control of anesthesia has yet to become adopted for clinical use despite the fact that since 1950, and especially since the availability of depth-of-hypnosis monitors many systems have been developed and clinically tested. For clinical adoption to take place, benefits to the patient have to be demonstrated while patient safety has to be guaranteed. This presentation will focus on the engineering design process that can ensure patient safety by design. A major characteristic of the anesthesia closed-loop control problem is the significant inter and intra-patient variability and that under such circumstances, the control system has to perform adequately and safely for a patient it has never seen and with very limited learning opportunity. This is why it is crucial for such systems to be designed by expert control engineers well versed in robust control theory. I will briefly describe the theory of robust control and demonstrate its use for closed-loop anesthesia in order to guarantee closed-loop stability and a minimum level of performance acceptable to the clinician. Furthermore, the system has be able to handle safely a number of exceptions with well-designed fallback modes. This is where the field of safety-preserving control, a concept developed for aeronautic applications, can provide a number of attractive solutions. This will be demonstrated through work performed at the University of British Columbia when developing our closed-loop TIVA control system, iControl. Finally, because the anesthesiologist will remain in the loop and has to be able to take over in a safe manner should the need arise, the Human-Computer Interaction (HCI) aspects have to carefully studied and designed. I will cover some of our nascent work on this topic, also inspired by aeronautics applications.