A method of adding power control circuitry to a circuit design at each of an RTL and a netlist level comprising: demarcating multiple power domains within the circuit design; specifying multiple power modes each power mode corresponding to a different combination of onoff states of the multiple demarcated power domains; and defining isolation behavior relative to respective power domains. A user speaks a station name into a mobile device, providing an indication that the request is for a broadcast channel, to tune the mobile device to that channel. The backup end-system may be selected a priori, for example, during connection establishment, in order to reduce switching time once a decision has been made to switch communications from the primary end-system to the backup end-system. Sensing components can include cameras or other sensors that detect the position of a patient’s head, and gas delivery ports may then be controlled to direct treatment gas flow in the direction of the patient’s head. At least some of the treated water is removed from the enclosure, and new water is added to the enclosure.