Method and apparatus for controlling the purity of oxygen produced by an oxygen concentrator

• US 20060174872A1
• Filed: 02/09/2005
• Published: 08/10/2006
• Est. Priority Date: 02/09/2005
• Status: Active Grant

• Current Assignee: VBOX, Incorporated
• Original Assignee: VBOX, Incorporated
• Inventors: Lonnes, Perry B., Jagger, Theodore W., Kivisto, John A., Van Brunt, Nicholas P.
• Granted Patent: US 7,866,315 B2
• Time in Patent Office: Days
• US Class Current: 128/201.210
• CPC Class Codes: A61M 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 16/10 Preparation of respiratory gases or vapours
• CPC Class Codes: A61M 16/101 using an oxygen concentrator
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 2202/0007 introduced into the body
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2202/03 Gases in liquid phase, e.g. cryogenic liquids
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2256/12 Oxygen
• CPC Class Codes: B01D 2257/102 Nitrogen
• CPC Class Codes: B01D 2259/40005 using rotary valves
• CPC Class Codes: B01D 2259/40009 using sensors or gas analysers
• CPC Class Codes: B01D 2259/4006 Less than four
• CPC Class Codes: B01D 2259/403 using three beds
• CPC Class Codes: B01D 2259/4533 for medical purposes
• CPC Class Codes: B01D 2259/4541 for portable use, e.g. gas masks
• CPC Class Codes: B01D 53/0415 Beds in cartridges
• CPC Class Codes: B01D 53/0446 Means for feeding or distributing gases
• CPC Class Codes: B01D 53/0476 Vacuum pressure swing adsorption
• CPC Class Codes: B01D 53/053 with storage or buffer vessel

Abstract

An oxygen concentrator comprises a plurality of adsorbent columns, each having an inlet, an outlet and abed of adsorbent material. The oxygen concentrator also includes a vacuum pump for removing separated nitrogen rich gas from the column inlets, a control valve for controlling flow of fluids in and out of the columns, and a breakthrough sensor for signaling the position of a mass transfer zone (MTZ), the breakthrough sensor controlling operation of the control valve as a function of the breakthrough sensor signal. An electric control module (ECM) receives the signal from the breakthrough sensor, and adjusts the control valve based on the signal.

Claims

1. An oxygen concentrator comprising:

a plurality of adsorbent columns, each having an inlet, an outlet and a bed of adsorbent material;

a vacuum pump for removing separated nitrogen rich gas from the column inlets;

a control valve for controlling flow of fluids in and out of the columns; and

a breakthrough sensor for signaling the position of a mass transfer zone (MTZ), the breakthrough sensor controlling operation of the control valve as a function of the breakthrough sensor signal.

2. The oxygen concentrator of claim 1 further comprising an electric control module (ECM) that receives the signal from the breakthrough sensor, and adjusts the control valve based on the signal.

3. The oxygen concentrator of claim 1 wherein the oxygen concentrator has a volume of less than 1.0 liter.

4. The oxygen concentrator of claim 1 wherein the oxygen concentrator has a mass of less than 2.3 kg.

5. The oxygen concentrator of claim 1 wherein the oxygen concentrator has a mass of less than 1.4 kg.

6. The oxygen concentrator of claim 1 further comprising:

a rechargeable power source for actuating the control valve, drive, and ECM.

7. The oxygen concentrator of claim 1 wherein the adsorbent material comprises a zeolite which preferentially adsorbs nitrogen.

8. The oxygen concentrator of claim 1 wherein the control valve comprises a rotary valve.

9. A method of providing concentrated oxygen product gas to a patient using an oxygen concentrator which separates oxygen from ambient air utilizing a vacuum swing adsorption process, the method comprising:

(a) introducing ambient air into a first end of a column containing an adsorbent material to advance a mass transfer zone toward a second end of the column and to remove product gas out the second end;

(b) sensing a parameter indicative of mass transfer zone position within the chamber;

(c) stopping the introduction of ambient air into the column based upon the parameter to prevent breakthrough of the ambient air at the second end of the column;

(d) storing at least some of the product gas for use by the patient;

(e) drawing a vacuum on the column to remove, through the first end of the column, a waste gas contained in the adsorbent material; and

(f) repressurizing the column by introducing ambient air into the evacuated column through the first end until the column approaches 1.0 atmosphere; and

(g) repeating steps (a)-(f).

10. The method of claim 9 and further comprising:

introducing product gas into the evacuated column through the second end during step (f).

11. The method of claim 9 and further comprising:

delivering pulses of stored product gas to the patient.

12. The method of claim 9 wherein sensing a parameter includes sensing gas flow into the column.

13. The method of claim 9 wherein sensing a parameter includes sensing gas flow out of the column.

14. The method of claim 9 wherein sensing a parameter includes sensing flow into and out of the column.

15. The method of claim 9 wherein sensing a parameter comprises sensing a parameter related to gas volume in the column.

16. The method of claim 9 wherein sensing a parameter comprises sensing a change as the gas stream passes a non-adsorbing material located in the column.

17. The method of claim 9 wherein sensing a parameter comprises measuring a temperature gradient within the column.

18. A method of providing concentrated oxygen product gas to a patient using an oxygen concentrator which separates oxygen from ambient air utilizing a vacuum swing adsorption (VSA) process, the method comprising:

(a) introducing ambient air into a first end of a column containing an adsorbent material to advance a mass transfer zone toward a second end of the column and to remove product gas out the second end;

(b) sensing a parameter indicative of mass transfer zone position within the chamber;

(c) adjusting the introduction of ambient air into the column based upon the parameter to prevent breakthrough of ambient air at the second end of the column;

(d) storing at least some of the product gas for use by the patient;

(e) drawing a vacuum on the column to remove, through the first end of the column, a waste gas contained in the adsorbent material; and

(f) repressurizing the column by introducing ambient air into the evacuated column through the first end until the column approaches 1.0 atmosphere; and

(g) repeating steps (a)-(f).

19. The method of claim 18 wherein sensing a parameter includes sensing gas flow into the column.

20. The method of claim 18 wherein sensing a parameter includes sensing gas flow out of the column.

21. The method of claim 18 wherein sensing a parameter includes sensing flow into and out of the column.

22. The method of claim 18 wherein sensing a parameter comprises sensing a parameter related to gas volume in the column.

23. The method of claim 18 wherein adjusting the feeding of ambient air includes adjusting the speed of a drive actuating the VSA process.

24. The method of claim 18 wherein adjusting the feeding of ambient air includes adjusting the position of a valve connected to the column.