Systems, methods and software employ zero-knowledge password protocols to provide strong authentication using low-grade passwords that people can easily memorize. A distal end of the release cable is connected to a rotating coupling assembly structured to removably connect a collar, harness, or similar attachment assembly to the distal end of the lead. Advantageously, the xenon is mixed with an oxygen-containing gas and administered to the patient after the patient has been anesthetized, put to sleep, and intubated. Products can be used directly as a blending component, or fractionated, as by further distillation, to provide more suitable components for blending into fuel.