Therapeutic gas delivery device with pulsed and continuous flow control
Described are methods and devices for therapeutic or medical gas delivery that utilize at least one proportional control valve and at least one binary control valve. The proportional control valve may be in series with the binary control valve to provide a valve combination capable of pulsing therapeutic gas at different flow rates, depending on the setting of the proportional control valve. Alternatively, the proportional control valve and binary control valve may be in parallel flow paths.
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 introduces the therapeutic gas to a patient;
at least two binary control valves in fluid communication with the inlet and outlet, wherein the first binary control valve and the second binary control valve deliver pulses of therapeutic gas at different flow rates;
at least one variable pressure regulator in fluid communication with at least one of the binary control valves that varies the pressure upstream of at least one of the binary control valves; and
a control system that delivers the therapeutic gas through at least one of the binary control valves, wherein the control system is adapted to deliver the therapeutic gas to the patient in an amount proportional to a flow of breathing gas.
2. The therapeutic gas delivery device of claim 1 , wherein the control system is in communication with the variable pressure regulator and varies the pressure upstream of at least one of the binary control valves.
3. The therapeutic gas delivery device of claim 1 , wherein the variable pressure regulator comprises a proportional control valve and a pressure sensor.
4. The therapeutic gas delivery device of claim 1 , wherein the second binary control valve and the first binary control valve are in parallel with each other.
5. The therapeutic gas delivery device of claim 4 , wherein the ratio of the flow rate of the first binary control valve to the flow rate of the second binary control valve is in the range from about 1:2 to about 1:10.
6. The therapeutic gas delivery device of claim 4 , wherein the control system delivers multiple pulses per breath through one or more of the first binary control valve and the second binary control valve.
7. The therapeutic gas delivery device of claim 1 , wherein the device that introduces the therapeutic gas to the patient is in fluid communication with a ventilator.
8. The therapeutic gas delivery device of claim 1 , wherein the device that introduces the therapeutic gas to the patient is a nasal cannula, an endotracheal tube or a face mask.
9. The therapeutic gas delivery device of claim 1 , wherein the control system is adapted to provides a single pulse in a patient's breath.
10. The therapeutic gas delivery device of claim 1 , further comprising at least one proportional control valve parallel to or in series with at least one of the binary control valves.
11. The therapeutic gas delivery device of claim 1 , wherein the source of therapeutic gas comprises nitric oxide or a nitric oxide-releasing agent.
12. A method of administering a therapeutic gas to a patient, the method comprising:
providing a therapeutic gas delivery device having at least two binary control valves, wherein the first binary control valve and the second binary control valve deliver pulses of therapeutic gas at different flow rates, and at least one variable pressure regulator in fluid communication with at least one of the binary control valves that varies the pressure upstream of at least one of the binary control valves;
delivering therapeutic gas to the patient during inspiration through at least one of the binary control valves; and
a control system that is adapted to delivering the therapeutic gas to the patient in an amount proportional to a flow of breathing gas.
13. The method of claim 12 , wherein the variable pressure regulator comprises a proportional control valve and a pressure sensor.
14. The method of claim 12 , wherein the second binary control valve and the first binary control valve are in parallel with each other.
15. The method of claim 14 , wherein the ratio of the flow rate of the first binary control valve to the flow rate of the second binary control valve is in the range from about 1:2 to about 1:10.
16. The method of claim 12 , further comprising sensing the beginning of the patient's inspiration and delivering one or more pulses of therapeutic gas to the patient during inspiration.
17. The method of claim 16 , wherein at least one pulse is delivered in the first half of the patient's inspiration.