FIELD OF THE INVENTION

The invention relates generally to devices, systems, and methods for carrying out adsorption processes for separating and purifying fluid mixtures and, more particularly, to portable devices, systems, and methods for separation and purification processes employing advanced molecular sieve materials, especially for concentrating medical oxygen.

BACKGROUND OF THE INVENTION

The supply of therapeutic oxygen to patients in homes and other residential settings is an important and growing segment of the health care industry. Oxygen can be supplied to a patient by liquid or compressed oxygen with an appropriate vaporization or pressure regulation system and a gas delivery cannula. Alternatively, oxygen can be supplied by the generation of oxygen using a small onsite air separation device or medical oxygen concentrator located near the patient that delivers the generated oxygen via a cannula.

Respiratory oxygen usage rates typically range up to 3 LPM (liters per minute at 22° C. and 1 atmosphere pressure) for ambulatory patients with relatively low oxygen requirements, up to 5 LPM for patients with more serious respiratory problems and possibly limited mobility, and in certain cases up to 10 LPM for those with the most serious respiratory problems and more limited mobility. A patient initially may require a higher oxygen supply rate during an illness and later may require less oxygen as recovery is achieved. Alternatively, a patient may require increasing oxygen rates as a chronic condition worsens. A conserver may be used to provide oxygen flow only when the patient inhales, thereby reducing the amount of oxygen required by eliminating the supply of oxygen that is wasted when the patient exhales.

Portable medical oxygen concentrators often are preferred over liquid or compressed oxygen supply systems in home and residential settings, and small air separation devices for these applications are being developed by numerous vendors in the home health care field. Patients typically are encouraged to be ambulatory whenever possible to increase the effectiveness of oxygen therapy and improve their overall health. The portability of a medical oxygen concentrator therefore is an important feature allowing the patient to move about easily and comfortably. To maximize portability and ease of use, the medical oxygen concentrator must be designed to have minimum weight and compact dimensions. Patient ambulation time can be maximized by the use of a conserver.

There is a need in the home health care field for an improved, lightweight, battery-powered portable oxygen concentrator for delivering oxygen product to ambulatory patients. These patients typically require a concentrator that can generate up to about 3 LPM of oxygen on a continuous basis and that includes a built-in conserver that maximizes ambulation time. The invention is directed to these, as well as other, important ends.

SUMMARY OF THE INVENTION

The invention provides lightweight, portable oxygen concentrators that operate using an ultra rapid, sub one second, adsorption cycle based on advanced molecular sieve materials. The amount of sieve material utilized is a fraction of that used in conventional portable devices. This dramatically reduces the volume, weight, and cost of the device. Innovations in valve configuration, moisture control, case and battery design, and replaceable sieve module are described. Patients with breathing disorders and others requiring medical oxygen are provided with a long lasting, low cost alternative to existing portable oxygen supply devices.

In one embodiment, the invention is directed to removable modules for a portable oxygen concentrator, comprising:

at least one cartridge, comprising:

a housing having a feed end and a product end;

at least one input port for incoming air flow in said feed end;

a feed end plug;

a diffusion channel in said feed end;

an optional rupture plate for said input port;

at least one adsorbent bed contained in said housing, wherein said adsorbent bed comprises at least one molecular sieve material having an average particle size of about 60 μm to 180 μm and having a substantially spherical shape;

wherein said adsorbent bed has an aspect ratio of length to diameter of less than about 6;

an optional fibrous pad positioned at either end or both ends of said adsorbent bed;

at least one output port for an oxygen-enriched product flow in said product end; and

a product end plug comprising a gas flow controls and at least one collection channel;

at least one enriched-oxygen product tube, comprising:an input end plug;an oxygen input port in said input end plug;an output end plug;an oxygen output port in said output end plug; andan optional rupture plate for said oxygen output port; and

a product end block comprising at least one passageway for transport of said oxygen-enriched product;

wherein said at least one cartridge and said at least enriched-oxygen product tube are connected to said product end block.

In another embodiment, the invention is directed to manifolds for portable oxygen concentrators, comprising:

a solid body having a passageway for transporting fluid;

a connection for fresh air from a compressor to said passageway for transporting fluid;

a 2-way compressor valve within said connection for fresh air;

at least one first connection from said passageway to a cartridge comprising an adsorbent bed for separating air components;

at least one second connection to said passageway from an oxygen-enriched product source;

a valve within said second connection;

two 3-way adsorbent bed valves within said passageway for transporting fluids positioned on both sides of said first connection;

at least one exhaust port;

an optional piercing mechanism attached to said solid body at said one first connection; and

an optional piercing mechanism attached to said solid body at said one second connection.

In yet other embodiments, the invention is directed to portable oxygen concentrators, comprising:

at least one removable module described herein;

a compressor;

an optional moisture control unit comprising a getter material for moisture positioned between said compressor and said inlet port of said removable module;

a manifold to control gas flow into and out of said removable module comprising:a solid body having a passageway for transporting fluid;a connection for fresh air from a compressor to said passageway for transporting fluid;a 2-way compressor valve within said connection for fresh air;at least one first connection from said passageway to a cartridge comprising an adsorbent bed for separating air components;at least one second connection to said passageway from an oxygen-enriched product source;a valve within said second connection;two 3-way adsorbent bed valves within said passageway for transporting fluids positioned on both sides of said first connection;at least one exhaust port;an optional piercing mechanism attached to said solid body at said one first connection; andan optional piercing mechanism attached to said solid body at said one second connection;

at least one optional moisture control unit;

an optional oxygen sensor; and

at least one battery cell.

In other embodiments, the invention is directed to systems, comprising:

a portable oxygen concentrator described herein;

a docking station; and

a battery recharger.

In another embodiment, the invention is directed to methods of producing an oxygen-enriched gas flow, comprising:

compressing an ambient air flow comprising oxygen and nitrogen to form a compressed air flow;

transporting said compressed flow through an adsorbent bed to adsorb at least a portion of said nitrogen to form an oxygen-enriched gas flow; and

removing said oxygen-enriched gas flow to form an oxygen-enriched product;

wherein the pressure drop across said adsorbent bed is less than about 50 kPa.

The method may further comprise the step of desorbing from said adsorbent bed said portion of said nitrogen. The method may further comprise the step of exhausting said portion of said nitrogen desorbed from said adsorbent bed. The method may further comprise the step of collecting said oxygen-enriched product. The oxygen-enriched product is delivered to a recipient in need thereof.

In another embodiment, the invention is directed to methods of reducing the power requirement of a zirconium-based oxygen sensor, comprising:

intermittently operating said zirconium-based oxygen sensor.

In another embodiment, the invention is directed to methods of reducing the power requirement of a zirconium-based oxygen sensor comprising a heater and a heater control, said method comprising:

modulating the pulse-width of said heater control of said heater during operation of said zirconium-based oxygen sensor.

In another embodiment, the invention is directed to methods of increasing the lifetime of an electrochemical oxygen sensor in a portable oxygen concentrator, comprising:

periodically turning gas flow off to said electrochemical oxygen sensor in said portable oxygen concentrator.

In another embodiment, the invention is directed to portable oxygen concentrator systems, comprising:

a portable oxygen concentrator module having a first partial handle portion and at least one removable module having an enriched-oxygen product tube and at least one cartridge comprising adsorbent; and

a battery pack module having a second partial handle portion;

wherein said battery pack module releasably connects to said portable oxygen concentrator module;

wherein said first partial handle portion and said second partial handle portion align to form a single integrated handle; and

wherein said first partial handle portion inserts and secures said removable module in said portable oxygen concentrator system by lever action.

In another embodiment, the invention is directed to methods of reducing moisture content and increase throughput in a portable oxygen concentrator providing an enriched-oxygen product, comprising:

providing a moisture control unit comprising a getter material that scavenges moisture when said portable oxygen concentrator is not operating;

providing compressed air comprising oxygen and nitrogen to an adsorbent bed to adsorb said nitrogen and produce said enriched-oxygen product;

wherein said getter material is gas impervious to prevent contamination of said enriched-oxygen product by said nitrogen in said compressed gas.

