Patent ID: 9616193
Date: 2017-04-11
CPC Classifications: A61M

Claim:
1. A therapeutic gas delivery device comprising: an inlet to connect to a source of therapeutic gas; an outlet to connect to a device that is adapted to introduce the therapeutic gas to a patient; at least one binary control valve in fluid communication with the inlet and outlet that delivers a constant flow of the therapeutic gas; at least one proportional control valve in fluid communication with the inlet and outlet that delivers a variable flow of the therapeutic gas; a control system that delivers the therapeutic gas through one or more of the binary control valve and the proportional control valve; wherein the control system delivers the therapeutic gas into a flow of breathing gas through one or more of the binary control valve and the proportional control valve to provide a combined flow of therapeutic gas and breathing gas with a substantially constant concentration of therapeutic gas; and wherein the binary control valve and the proportional control valve are in parallel flow paths and the control system delivers a continuous flow of therapeutic gas through the proportional control valve when a therapeutic gas demand is greater than or equal to 5% of a delivery range and delivers one or more pulses of therapeutic gas through the binary control valve when the therapeutic gas demand is less than or equal to 1% of the delivery range.