An electronically controlled gas blending device, comprising: a primary gas delivery subsystem for delivering a set dose of a therapeutic gas; and a secondary delivery subsystem comprising: a flow control channel (161(a)) in fluid communication with a therapeutic gas supply, wherein the flow control channel (161(a)) comprises: at least one secondary subsystem flow control valve, wherein the at least one secondary subsystem flow control valve is configured to be in communication over a communication path with a therapeutic gas delivery system controller; and two secondary subsystem flow sensors (166, 168), wherein the two secondary subsystem flow sensors (166, 168) are in fluid communication with the at least one secondary subsystem flow control valve, and the two secondary subsystem flow sensors (166, 168) are configured to be in communication over a communication path with the therapeutic gas delivery system controller; one or more inlets configured to connect to a gas supply; one or more inlet flow sensors (174, 176) in fluid communication with at least one of the one or more inlets; and a blending junction in fluid communication with the one or more inlet flow sensors (174, 176), and the blending junction is connected to and in fluid communication with the flow control channel (161(a)); and the therapeutic gas delivery system controller configured to be in electrical communication with at least the at least one secondary subsystem flow control valve and the two secondary subsystem flow sensors (166, 168) to form a feedback loop, and configured to: receive the set dose of therapeutic gas from the primary gas delivery subsystem and a flow value from the one or more inlet flow sensors (174, 176); calculate a flow rate of the therapeutic gas through the two secondary subsystem flow sensors (166, 168) to provide a dose of the therapeutic gas exiting the blending junction corresponding to the set dose; and confirm the dose of the therapeutic gas exiting the blending junction is the set dose. a primary gas delivery subsystem for delivering a set dose of a therapeutic gas; and a secondary delivery subsystem comprising: a flow control channel (161(a)) in fluid communication with a therapeutic gas supply, wherein the flow control channel (161(a)) comprises: at least one secondary subsystem flow control valve, wherein the at least one secondary subsystem flow control valve is configured to be in communication over a communication path with a therapeutic gas delivery system controller; and two secondary subsystem flow sensors (166, 168), wherein the two secondary subsystem flow sensors (166, 168) are in fluid communication with the at least one secondary subsystem flow control valve, and the two secondary subsystem flow sensors (166, 168) are configured to be in communication over a communication path with the therapeutic gas delivery system controller; one or more inlets configured to connect to a gas supply; one or more inlet flow sensors (174, 176) in fluid communication with at least one of the one or more inlets; and a blending junction in fluid communication with the one or more inlet flow sensors (174, 176), and the blending junction is connected to and in fluid communication with the flow control channel (161(a)); and at least one secondary subsystem flow control valve, wherein the at least one secondary subsystem flow control valve is configured to be in communication over a communication path with a therapeutic gas delivery system controller; and two secondary subsystem flow sensors (166, 168), wherein the two secondary subsystem flow sensors (166, 168) are in fluid communication with the at least one secondary subsystem flow control valve, and the two secondary subsystem flow sensors (166, 168) are configured to be in communication over a communication path with the therapeutic gas delivery system controller; one or more inlets configured to connect to a gas supply; one or more inlet flow sensors (174, 176) in fluid communication with at least one of the one or more inlets; and a blending junction in fluid communication with the one or more inlet flow sensors (174, 176), and the blending junction is connected to and in fluid communication with the flow control channel (161(a)); and the therapeutic gas delivery system controller configured to be in electrical communication with at least the at least one secondary subsystem flow control valve and the two secondary subsystem flow sensors (166, 168) to form a feedback loop, and configured to: receive the set dose of therapeutic gas from the primary gas delivery subsystem and a flow value from the one or more inlet flow sensors (174, 176); calculate a flow rate of the therapeutic gas through the two secondary subsystem flow sensors (166, 168) to provide a dose of the therapeutic gas exiting the blending junction corresponding to the set dose; and confirm the dose of the therapeutic gas exiting the blending junction is the set dose. receive the set dose of therapeutic gas from the primary gas delivery subsystem and a flow value from the one or more inlet flow sensors (174, 176); calculate a flow rate of the therapeutic gas through the two secondary subsystem flow sensors (166, 168) to provide a dose of the therapeutic gas exiting the blending junction corresponding to the set dose; and confirm the dose of the therapeutic gas exiting the blending junction is the set dose.