A prototype anesthesia delivery system using N2O was developed to test the appropriateness of new technological design approaches. The objectives were to eliminate human-factors problems associated with present anesthesia apparatus and to lay a suitable technical foundation for the development of new techniques in anesthesia management. This prototype equipped with a microcomputer performed all the functions of a conventional anesthesia machine and many monitoring and surveillance tasks. Eventual incorporation of new teaching functions, additional monitoring and record-keeping activities, were intended. The system was fundamentally electronic with few moving parts. Reliability, safety and clarity of operation were the primary criteria in selection and application of the specific technologies employed.