Nonstandard user modification of gas cylinder pin indexing.
D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D004867:Equipment Design / Q000592:standards*; D006801:Humans; D008284:Maintenance and Engineering, Hospital / Q000592:standards; D009609:Nitrous Oxide / Q000009:adverse effects
D009609:Nitrous Oxide