Systems and methods for patient-proximate vapor transfer for respiratory therapy

1. A system for heating and humidifying a breathing gas, the system comprising:

a source of pressurized breathing gas;

a vapor transfer unit external to the source of pressurized breathing gas, the vapor transfer unit having a first end portion and a second end portion opposite the first end portion,

a gas inlet, liquid inlet, and liquid outlet located at the first end portion,

a gas outlet located at the second end portion,

a gas passage coupling the gas inlet to the gas outlet, the gas passage configured to allow gas to flow from the gas inlet to the gas outlet in a gas flow direction, and

a liquid passage coupling the liquid inlet to the liquid outlet, the liquid passage configured to allow liquid to flow from the liquid inlet to the liquid outlet in a liquid flow direction, the liquid flow direction opposite the gas flow direction along at least a portion of the vapor transfer unit;

and a membrane separating the gas passage and the liquid passage, wherein the membrane is positioned to transfer vapor from the liquid passage to the gas passage;

a first gas tube connecting the source of pressurized breathing gas to the gas inlet of the vapor transfer unit and having a first length;

a liquid supply having a heater that heats liquid of the liquid supply and having a heated liquid outlet;

a first liquid tube coupling the heated liquid outlet to the liquid inlet of the vapor transfer unit; and

a second gas tube having a second length and connecting the gas outlet to a nasal cannula, wherein the first length is greater than the second length.

2. The system of claim 1 , wherein the second length is about 7 feet or less.

3. The system of claim 1 , wherein the vapor transfer unit includes a fixation device configured to secure the vapor transfer unit to a patient.

4. The system of claim 3 , wherein the fixation device includes at least one of a lanyard, a clip, a holster, a headband, a strap, armband, sling, and a vest.

5. The system of claim 1 , wherein the source of pressurized breathing gas is configured to deliver the breathing gas at a pressure equal to or less than about 13 psi.

6. The system of claim 1 , further comprising a second liquid tube connecting the liquid supply to the liquid outlet of the vapor transfer unit.

7. The system of claim 1 , wherein the source of pressurized breathing gas includes a gas blender.

8. The system of claim 1 , wherein the source of pressurized breathing gas is configured to heat the breathing gas.

9. The system of claim 1 , wherein the source of pressurized breathing gas is configured to display a temperature of the breathing gas.

10. The system of claim 1 , wherein the source of pressurized breathing gas includes at least one of a mechanical ventilator, a high flow therapy system, an oxygen concentrator, and an oxygen tank.

11. A vapor transfer unit for humidifying a breathing gas, the vapor transfer unit comprising:

a housing having:

a first end portion,

a second end portion opposite the first end portion,

a gas inlet, liquid inlet, and liquid outlet located at the first end portion,

a gas outlet located at the second end portion,

a gas passage coupling the gas inlet to the gas outlet, the gas passage configured to allow gas to flow from the gas inlet to the gas outlet in a gas flow direction,

a liquid passage coupling the liquid inlet to the liquid outlet, the liquid passage configured to allow liquid to flow from the liquid inlet to the liquid outlet in a liquid flow direction, the liquid flow direction opposite the gas flow direction along at least a portion of the vapor transfer unit, and

a membrane separating the gas passage and the liquid passage, wherein the membrane is configured to transfer vapor from the liquid passage to the gas passage;

a gas input tube having a first end connected to a source of pressurized breathing gas and a second end opposite the first end, the second end being connected to the gas inlet, wherein the gas input tube has a first length; and

a gas output tube having a first end connected to the gas outlet and a second end opposite the first end, the second end having a nasal cannula for delivering humidified gas to a patient, wherein the gas output tube has a second length;

wherein the first length is greater than the second length.

12. The vapor transfer unit of claim 11 , wherein the first length is greater than about two feet.

13. The vapor transfer unit of claim 11 , wherein the gas passage is enveloped by the liquid passage.

14. The vapor transfer unit of claim 11 , wherein the membrane is pleated.

15. The vapor transfer unit of claim 11 , wherein the membrane comprises a plurality of hollow fiber tubes.

16. The vapor transfer unit of claim 11 , wherein the liquid passage is enveloped by the gas passage.

17. The vapor transfer unit of claim 11 , further comprising a liquid input tube having a first end configured to connect to a source of pressurized liquid and a second end opposite the first end, the second end being connected to the liquid inlet.

18. The vapor transfer unit of claim 17 , further comprising a liquid output tube having a first end connected to the liquid outlet and a second end opposite the first end, the second end being configured to connect to the source of pressurized liquid.

19. The vapor transfer unit of claim 11 , further comprising a fixation device for coupling the vapor transfer unit to the patient.

20. The vapor transfer unit of claim 19 , wherein the fixation device includes at least one of a lanyard, a clip, a holster, a headband, a strap, and a vest.