Portable oxygen delivery device

1. An oxygen delivery device comprising: an oxygen delivery module to produce at least concentrated oxygen; and a first gas moving device to deliver air to the oxygen delivery module, the first gas moving device comprising:

a first piston rotatable around a first portion of a shaft inside a first piston chamber defined in a housing, the rotational movement of the first piston resulting in varying pressure generated in a first portion of the first piston chamber;

a first vane member rigidly coupled to a portion of the first piston, the first vane member being configured to move inside a first vane chamber defined in the housing; and a first stator of the first gas moving device;

wherein the first vane and the first piston collectively divide the first piston chamber into the first portion and a second portion, each of the first portion and the second portion varying in size based on a position of the first vane and the first piston;

a first vane chamber vent in the first vane chamber, the first vane chamber vent in communication with a source of pressure; and

a second gas moving device to receive exhaust gases from the oxygen delivery module, the second gas moving device comprising:

a second piston rotatable around a second portion of the shaft inside a second piston chamber defined in the housing, the rotatable movement of the second piston resulting in varying pressure generated in a first portion of the second piston chamber;

a second vane member coupled to a portion of the second piston, the second vane member, the second vane member being configured to move inside a second vane chamber defined in the housing; and

a second stator of the second gas moving device, the second stator configured to be connected to the first stator via an endplate that overlays the first stator and the second stator;

the endplate completely positioned between and separating the first gas moving device from the second gas moving device, wherein a stator of the compressor, a stator of the vacuum pump, and the endplate all have the same height measured along a dimension perpendicular to a long axis of the shaft, and wherein the endplate includes only a single vent hole that extends through the endplate and communicates with ambient pressure, wherein the entire vent hole extends only along a linear axis that is orthogonal to an axis of rotation of the shaft and wherein the vent hole has (1) a first end that communicates solely with an endplate chamber entirely defined by the endplate and entirely contained within the endplate (2) a second end that communicates with the ambient pressure, wherein the vent hole is straight along its entire length so as to provide unrestricted air flow and extends radially outward from the endplate chamber to a radial end of the endplate and provides a sole passageway for fluid to vent out of the endplate chamber through the endplate and to atmosphere, and wherein the endplate chamber fluidly communicates with both the compressor and the vacuum such that gas can leak from the compressor or the vacuum into the endplate chamber, wherein the vent hole vents the gas that leaks into the endplate chamber to atmosphere.

2. The oxygen delivery device of claim 1 , wherein the first piston defines a radial clearance between tangential surfaces of the first piston and a wall surface of the first piston chamber, the clearance being less than or equal to 50 microns.

3. The oxygen delivery device of claim 1 , wherein the varying pressure resulting in the first piston chamber is represented as a first periodic function of the pressure generated in the first portion of the first piston chamber.

4. The oxygen delivery device of claim 1 , wherein the first gas moving device is a compressor, and the second gas moving device is a vacuum pump.

5. The oxygen delivery device of claim 1 , further comprising:

a plurality of gas moving devices other than the first gas moving device and the second gas moving device enclosed within the housing, each gas moving device of the plurality of gas moving devices including a corresponding piston configured to rotate around a respective portion of the shaft,

wherein the first gas moving device, the second gas moving device, and the plurality of gas moving devices are driven by a single rotary power source.

6. The oxygen delivery device of claim 5 , wherein forces resulting from the rotational movement of the first piston in the first piston chamber destructively interfere with forces resulting from the rotational movement of the second piston in the second piston chamber, such that net forces created in the oxygen delivery device are reduced.

7. The oxygen delivery device of claim 1 , wherein:

the housing includes axially separated surfaces, and the endplate sealing the first piston chamber;

the first piston includes a cylindrical piston with an exterior diameter, the cylindrical piston being rotated around a first eccentric located at the first portion of the shaft, the first eccentric rotating to offset the first piston with respect to a centerline of the first piston chamber such that the exterior diameter of the first piston is in close proximity to bounds of the first piston chamber during an orbit of the first piston; and

the orbiting first piston dividing the first piston chamber into a suction chamber portion and a compression chamber portion.

8. The oxygen delivery device of claim 1 , wherein the oxygen delivery device has a weight of between 2-15 pounds.

9. The oxygen delivery device of claim 1 , wherein compressor pressure generated in the first piston chamber is represented as a first sinusoidal function, and wherein pressure formed in the second piston chamber is represented as a second sinusoidal function that is approximately 180° out of phase relative to the first sinusoidal function.

10. The oxygen delivery device of claim 1 , wherein relative radial position of the first piston in the first piston chamber is represented as a first periodic function, and wherein relative radial position of the second piston in the second piston chamber is represented as a second periodic function that is out of phase in relation to the first periodic function.

11. The oxygen delivery device of claim 1 , wherein forces resulting from the rotational movement of the first piston in the first piston chamber destructively interfere with forces resulting from the rotational movement of the second piston in the second piston chamber such that net forces created in the oxygen delivery device are reduced.