Patent Description:
Oxygen concentrator systems generate substantially pure (e.g., <NUM>-<NUM>% pure) oxygen gas using ambient air as an input gas. Oxygen concentrator systems are commonly used for medical applications by patients who have a need for substantially pure oxygen. Oxygen concentrator systems include portable systems that can be carried by patients, and non-portable systems that are often used in a medical facility or in a residential setting.

Some known oxygen concentrator systems operate on a pressure swing adsorption or vacuum pressure swing adsorption cycle. In such systems, ambient air is pressurized in a sieve module that includes a bed of an adsorptive material that adsorbs nitrogen (e.g., zeolite), and substantially pure oxygen is then released from the sieve module while the nitrogen is retained by the adsorptive material. The nitrogen may then be purged from the adsorptive material. <CIT> and <CIT> disclose sieve modules for oxygen concentrators that can be easily released by a simple user-friendly mechanism. Replacement sieve modules may be installed easily by patients, and all gas seals will function properly after installation.

Disclosed herein are embodiments of sieve modules for oxygen concentrators, interface assemblies of sieve modules for oxygen concentrators, and methods for using the sieve modules with oxygen concentrators.

An aspect of the disclosure is a sieve module. The sieve module includes an impermeable housing including a first end, a second end opposite the first end, and a diffuser positioned at the second end that defines a first interior space and a second interior space within the impermeable housing. The first interior space and the second interior space are in fluid communication solely at the second end of the impermeable housing. The sieve module also includes an interface assembly connected to the first end of the impermeable housing. The interface assembly includes an inlet port in fluid communication with the first interior space of the impermeable housing, wherein the inlet port is configured to receive gas from an exterior of the impermeable housing, and an outlet port in fluid communication with the second interior space of the impermeable housing, wherein the outlet port is configured to expel the gas to the exterior of the impermeable housing. The sieve module also includes an adsorptive material that is disposed within the first interior space of the impermeable housing, wherein the interface assembly is configured such that the gas travels from the inlet port to the outlet port by traveling through the adsorptive material.

The interface assembly includes a spacing portion pneumatically connected to the first end of the impermeable housing and extending perpendicular to a housing axis of the impermeable housing in a direction away from the impermeable housing, wherein the housing axis extends through the first end and the second end of the impermeable housing. The interface assembly also includes an axial portion pneumatically connected to the spacing portion and extending parallel to the housing axis in a direction generally toward the second end of the impermeable housing.

The inlet port and the outlet port are both disposed on the axial portion of the interface assembly. In some implementations, the interface assembly further comprises a gasket disposed within the spacing portion of the interface assembly, wherein the gasket defines an inlet channel that pneumatically connects the inlet port to the first interior space of the impermeable housing and an outlet channel that pneumatically connects the outlet port to the second interior space of the impermeable housing.

In some implementations, the interface assembly further comprises a first seal disposed along the axial portion, and a second seal disposed along the axial portion and spaced apart from the first seal, wherein the inlet port is disposed between the first seal and the second seal, and the outlet port is disposed at an end of the axial portion that is distal from the spacing portion. In some implementations, the first seal and the second seal extend circumferentially around the axial portion of the interface assembly.

In some implementations, the outlet port is disposed at an end of the axial portion that is distal from the spacing portion, and the inlet port extends through a side wall of the axial portion. In some implementations, the outlet port has an orientation that is in alignment with a housing axis of the impermeable housing and the inlet port has an orientation that is substantially perpendicular to the outlet port.

In some implementations, the adsorptive material is configured to filter nitrogen from the gas traveling through the adsorptive material. In some implementations, the adsorptive material comprises zeolite.

An aspect of the disclosure is an interface assembly for a sieve module. The interface assembly includes a spacing portion configured to be connected to an impermeable housing of the sieve module such that the spacing portion extends away from a housing axis of the impermeable housing. The interface assembly also includes an axial portion that is connected to the spacing portion, is configured to be located radially outward from the impermeable housing, and extends away from the spacing portion of the interface assembly in a direction parallel to the housing axis of the impermeable housing. The interface assembly also includes an inlet port positioned on the axial portion and an outlet port positioned on the axial portion.

In some implementations of the interface assembly, the spacing portion is configured to be connected to the impermeable housing at a first end of the impermeable housing, and the axial portion is configured to extend from the spacing portion toward a second end of the impermeable housing.

In some implementations of the interface assembly, the outlet port is disposed at an end of the axial portion that is distal from the spacing portion, and the inlet port extends through a side wall of the axial portion. In some implementations of the interface assembly, the outlet port has an orientation that is in alignment with a housing axis of the impermeable housing and the inlet port has an orientation that is substantially perpendicular to the outlet port.

In some implementations of the interface assembly, the interface assembly includes an inlet channel extending from the inlet port through the axial portion and the spacing portion for fluid communication with the impermeable housing and an outlet channel extending from the inlet port through the axial portion and the spacing portion for fluid communication with the impermeable housing.

In some implementations of the interface assembly, the interface assembly includes a gasket disposed within the spacing portion and configured to separate the inlet channel from the outlet channel in the spacing portion. In some implementations of the interface assembly, the axial portion includes a divider wall to separate the inlet channel from the outlet channel in the axial portion.

An aspect of the disclosure is an interface assembly for a sieve module. The interface assembly includes a first interface part and a second interface part that is connected to the first interface part. The interface assembly also includes a gasket disposed between the first interface part and the second interface part to define at least part of an inlet channel and an outlet channel, wherein the inlet channel and the outlet channel are separated by the gasket.

In some implementations of the interface assembly, the first interface part and the second interface part cooperate to define a spacing portion that is configured to extend away from a housing axis of an impermeable housing of the sieve module. The first interface part also defines an axial portion that is connected to the spacing portion, is configured to be located radially outward from the impermeable housing, and extends away from the spacing portion of the interface assembly in a direction parallel to the housing axis of the impermeable housing.

In some implementations of the interface assembly, an inlet port is positioned on the axial portion and is in communication with the inlet channel. In some implementations of the interface assembly, an outlet port is positioned on the axial portion and is in communication with the outlet channel.

Another aspect provides a sieve module, comprising: an impermeable housing including a first end, a second end opposite the first end, and a diffuser positioned at the second end that defines a first interior space and a second interior space within the impermeable housing, wherein the first interior space and the second interior space are in fluid communication solely at the second end of the impermeable housing; an interface assembly connected to the first end of the impermeable housing, the interface assembly comprising: an inlet port in fluid communication with the first interior space of the impermeable housing, wherein the inlet port is configured to receive gas from an exterior of the impermeable housing, and an outlet port in fluid communication with the second interior space of the impermeable housing, wherein the outlet port is configured to expel the gas to the exterior of the impermeable housing; and an adsorptive material that is disposed within the first interior space of the impermeable housing, wherein the interface assembly may be configured such that the gas travels from the inlet port to the outlet port by traveling through the adsorptive material.

The interface assembly may further comprise: a spacing portion pneumatically connected to the first end of the impermeable housing and extending perpendicular to a housing axis of the impermeable housing in a direction away from the impermeable housing, wherein the housing axis may extend through the first end and the second end of the impermeable housing; and an axial portion pneumatically connected to the spacing portion and extending parallel to the housing axis in a direction generally toward the second end of the impermeable housing.

The inlet port and the outlet port may be both disposed on the axial portion of the interface assembly.

The interface assembly may further comprise a gasket disposed within the spacing portion of the interface assembly; and the gasket may define an inlet channel that pneumatically connects the inlet port to the first interior space of the impermeable housing and an outlet channel that pneumatically connects the outlet port to the second interior space of the impermeable housing.

The axial portion may include a divider wall to separate the inlet channel from the outlet channel in the axial portion.

The interface assembly may further comprise a first seal disposed along the axial portion, and a second seal disposed along the axial portion and spaced apart from the first seal, the inlet port may be disposed between the first seal and the second seal, and the outlet port may be disposed at an end of the axial portion that is distal from the spacing portion.

The first seal and the second seal may extend circumferentially around the axial portion of the interface assembly.

The outlet port may be disposed at an end of the axial portion that is distal from the spacing portion, and the inlet port may extend through a side wall of the axial portion.

The outlet port may have an orientation that is in alignment with a housing axis of the impermeable housing and the inlet port has an orientation that is substantially perpendicular to the outlet port.

The interface assembly may include: a first interface part; a second interface part that is connected to the first interface part; and a gasket disposed between the first interface part and the second interface part to define at least part of an inlet channel and an outlet channel, wherein the inlet channel and the outlet channel are separated by the gasket.

The first interface part and the second interface part may cooperate to define a spacing portion that is configured to extend away from a housing axis of the impermeable housing, and the first interface part may define an axial portion that is connected to the spacing portion, may be configured to be located radially outward from the impermeable housing, and extends away from the spacing portion of the interface assembly in a direction parallel to the housing axis of the impermeable housing.

An inlet port may be positioned on the axial portion and is in communication with the inlet channel, and an outlet port may be positioned on the axial portion and is in communication with the outlet channel.

The adsorptive material may be configured to filter nitrogen from the gas traveling through the adsorptive material.

The adsorptive material may comprise zeolite.

The disclosure is best understood from the following detailed description when read, by way of example only, in conjunction with the accompanying drawings.

The disclosure herein relates to sieve modules that, when inserted into an oxygen concentrator, operate to remove nitrogen from ambient air to produce substantially pure (e.g., <NUM>-<NUM>% pure) oxygen. Sieve modules may require servicing or replacing, whereby the sieve modules are disconnected and removed from the oxygen concentrator. Known sieve modules may require an operator to perform multiple actions and/or access multiple locations about the sieve modules and/or oxygen concentrator to disconnect and remove the sieve modules from the oxygen concentrator. What may be desired are an oxygen concentrator and sieve modules that enables an operator to disconnect and remove the sieve modules from the oxygen concentrator with fewer actions and by accessing only one end of the sieve module.

<FIG> is a block diagram showing an oxygen concentrator <NUM> and two sieve modules <NUM>. The oxygen concentrator <NUM> may operate on a pressure swing adsorption (PSA) cycle or a vacuum pressure swing adsorption (VPSA) cycle as are well known in the art. The description herein refers to the PSA cycle as an example, but is also applicable to oxygen concentration according to the VPSA cycle. The oxygen concentrator <NUM> may be a portable system that can be carried by a user, or may be a non-portable system that is used in a medical facility or in a residential setting. The sieve modules <NUM> and the oxygen concentrator <NUM> are cooperatively operable to receive air as an input gas and separate the air into constituent components. In particular, the sieve modules <NUM> and the oxygen concentrator <NUM> may be cooperatively operable to filter nitrogen from the input gas to generate a product gas that is substantially pure oxygen. The substantially pure oxygen has a much higher oxygen concentration than ambient air. As an example, the substantially pure oxygen may be approximately <NUM>-<NUM>% oxygen.

To implement the PSA cycle, the oxygen concentrator <NUM> may include a housing <NUM>, a compressor <NUM>, and valve assembly <NUM>. The housing <NUM> may be configured to contain the compressor <NUM> and the valve assembly <NUM> therein. The housing <NUM> may also be configured to receive the sieve modules <NUM>. Furthermore, the compressor <NUM> may be pneumatically connected to the valve assembly <NUM> to facilitate the transfer of pressurized gas across the valve assembly <NUM> and throughout the oxygen concentrator <NUM> and sieve modules <NUM>.

The oxygen concentrator <NUM> may further include an ambient air inlet <NUM>, a waste gas outlet <NUM>, a product gas outlet <NUM>, and a manifold assembly <NUM> that are in fluid communication with the valve assembly <NUM>. The sieve modules <NUM> may be in fluid communication with the manifold assembly <NUM> when the sieve modules <NUM> are inserted into the housing <NUM>. The ambient air inlet <NUM> may be exposed to ambient air from the environment around the oxygen concentrator <NUM>. The product gas outlet <NUM> may be configured to deliver the product gas for use in an intended application, such as by supplying the product gas to a cannula for administration to a person. The waste gas outlet <NUM> may be configured to expel waste gas produced during the PSA cycle, such as by expelling the waste gas to the environment around the oxygen concentrator <NUM>.

During the PSA cycle, the sieve modules <NUM> may undergo at least two phases, including an adsorption phase in which the product gas is produced, and a purge phase in which waste gas is purged. In embodiments including two of the sieve modules <NUM>, during the PSA cycle, one of the sieve modules <NUM> may undergo the adsorption phase while the other one of the sieve modules <NUM> undergoes the purge phase. To produce the product gas (e.g., substantially pure oxygen), during the adsorption phase, air from the ambient air inlet <NUM> is supplied to the compressor <NUM> by operation of the valve assembly <NUM>. The air is then supplied to one of the sieve modules <NUM> at a pressure that is higher than ambient pressure. The air is subsequently released from the one of the sieve modules <NUM> as the product gas. In particular, after the one of the sieve modules <NUM> is pressurized, the valve assembly <NUM> is operated to establish fluid communication between the one of the sieve modules <NUM> and the product gas outlet <NUM> to supply the product gas to the product gas outlet <NUM> for use. After a certain amount of the product gas has been produced, the one of the sieve modules <NUM> may transition from the adsorption phase to the purge phase, and the other one of the sieve modules <NUM> may transition from the purge phase to the adsorption phase where the above-described process is repeated by the other one of the sieve modules <NUM>.

The sieve modules <NUM> may include an adsorptive material <NUM> that is used to separate oxygen from other components of ambient air, such as nitrogen. In some embodiments, the adsorptive material <NUM> may be a zeolite material. The pressure at which the air is supplied to the sieve modules <NUM> during the adsorption phase is selected based on the material properties of the adsorptive material <NUM>. In particular, adsorption is dependent on pressure, and the volume of a gas that is adsorbed by the adsorptive material <NUM> increases as the pressure increases. In addition, nitrogen is adsorbed by the adsorptive material <NUM> that is used in the sieve modules <NUM> (e.g., zeolite) more readily than oxygen is at the same pressure. Thus, pressurization of the sieve modules <NUM> causes adsorption of a portion of the nitrogen in the air supplied to the sieve modules <NUM>. During the purge phase, the sieve modules <NUM> may be purged by lowing the pressure in the sieve modules <NUM> so that the nitrogen is released from the adsorptive material <NUM> as the waste gas. The waste gas may then be vented out of the waste gas outlet <NUM> of the oxygen concentrator <NUM>. In particular, the valve assembly <NUM> may be operated to establish fluid communication between the sieve modules <NUM> and the waste gas outlet <NUM> to expel the waste gas out of the waste gas outlet <NUM>.

The oxygen concentrator <NUM> may further include a controller <NUM> and a user interface <NUM>. The controller <NUM> is configured to regulate operation of the oxygen concentrator <NUM> and control operation of various components of the oxygen concentrator <NUM> (e.g., the compressor <NUM>, the valve assembly <NUM>, and/or other components). In some embodiments, the controller <NUM> may include a general-purpose computing device, such as a computing device that includes one or more processors, a short term memory device, and a long term storage device. In some embodiments, the controller <NUM> may include a special purpose computing device, such as an integrated circuit or an application specific integrated circuit. The controller <NUM> may be provided with control software that is executed by the controller <NUM> to cause the controller <NUM> to cause operation of the various components of the oxygen concentrator <NUM> in the desired manner. The user interface <NUM> may include components such as buttons, knobs, and other types of input components that allow a user to change the operating state of the oxygen concentrator <NUM>, such as by starting and stopping production of the product gas. The user interface <NUM> may include output components that show information regarding the system of the oxygen concentrator <NUM>.

<FIG> is a perspective view illustration showing the oxygen concentrator <NUM> and two of the sieve modules <NUM>, wherein one of the sieve modules <NUM> is shown in a partially inserted position and the other one of the sieve modules <NUM> is shown in a fully inserted position. In some embodiments, the sieve modules <NUM> may each include an impermeable housing <NUM> and an interface assembly <NUM>. The impermeable housing <NUM> may be configured to contain the adsorptive material <NUM> therein. The interface assembly <NUM> may be configured to facilitate fluid communication between the impermeable housing <NUM> and the oxygen concentrator <NUM>.

In some embodiments, the impermeable housing <NUM> may have a geometry that is substantially cylindrical (as shown in <FIG>) in order to resist deformation (i.e., elastic or plastic deformation) resulting from repeated pressurization of the sieve modules <NUM> that occurs during the PSA cycle. In other embodiments, the impermeable housing <NUM> may have some other elongated geometry that is resilient against pressurization induced deformation. As an example, the impermeable housing <NUM> may be an elongated cuboid with rounded edges. The impermeable housing <NUM> may be comprised of any generally rigid material that is suitable to resist the deformation forces associated with the PSA cycle and that is substantially impermeable to gas (e.g., oxygen and nitrogen). For example, the impermeable housing <NUM> may be comprised of steel, aluminum, titanium, fiber-reinforced polymer, or any other substantially impermeable material that is resilient to repeated pressurization cycles.

In some embodiments, the impermeable housing <NUM> may include a first end <NUM> and a second end <NUM> opposite the first end <NUM>. In such embodiments, the interface assembly <NUM> may be connected to the first end <NUM>. Furthermore, the impermeable housing <NUM> may include an alignment feature <NUM> located at the second end <NUM> of the impermeable housing <NUM>. The alignment feature <NUM> may be operable to facilitate alignment of the sieve module <NUM> with the housing <NUM> of the oxygen concentrator <NUM> when the sieve module <NUM> is inserted into the housing <NUM>.

The interface assembly <NUM> may include a spacing portion <NUM> and an axial portion <NUM>. The spacing portion <NUM> may be connected to the first end <NUM> of the impermeable housing <NUM> and may extend away from the impermeable housing <NUM>. The axial portion <NUM> may be connected to the spacing portion <NUM> and may extend away from the spacing portion <NUM> in a direction generally toward the second end <NUM> of the impermeable housing <NUM>. In some embodiments, the spacing portion <NUM> may extend away from the impermeable housing <NUM> in a direction perpendicular to a housing axis <NUM> that extends axially along the impermeable housing <NUM> through the first end <NUM> and the second end <NUM>. In other embodiments, the spacing portion <NUM> may extend away from the impermeable housing <NUM> at some other angle relative to the housing axis <NUM> (e.g., forty-five degrees, sixty-seven degrees, or some other angle). The axial portion <NUM> may be located outward (e.g., radially outward) from the impermeable housing <NUM> and may extend away from the spacing portion <NUM> of the interface assembly <NUM> in a direction parallel to the housing axis <NUM>.

The axial portion <NUM> may have any substantially elongated geometry. In the illustrated implementation, the axial portion <NUM> has a geometry that is substantially cylindrical and includes a recessed portion extending circumferentially around the axial portion <NUM>. In other embodiments, the axial portion <NUM> may be substantially cylindrical but not include such a recessed portion. In other embodiments, the axial portion <NUM> may have some other substantially elongated geometry. For example, the axial portion <NUM> may have a geometry that resembles an elongated cuboid, a triangular prism, or some other shape.

The interface assembly <NUM> includes an inlet port <NUM> and an outlet port <NUM> that are located on the axial portion <NUM> of the interface assembly <NUM>. The inlet port <NUM> and the outlet port <NUM> are configured to form a pneumatic connection with the oxygen concentrator <NUM>. In the illustrated implementation, the inlet port <NUM> and the outlet port <NUM> are configured to form a pneumatic connection with the manifold assembly <NUM> when the sieve module <NUM> is in the fully inserted position. In some embodiments, the manifold assembly <NUM> may include a manifold inlet <NUM> and a manifold outlet <NUM> that are configured to facilitate fluid communications with the inlet port <NUM> and the outlet port <NUM>, respectively. The inlet port <NUM> may be operable to receive pressurized air from the manifold inlet <NUM> to be transferred to the adsorptive material <NUM> during the adsorption phase of the PSA cycle. Furthermore, the inlet port <NUM> may be operable to transfer the waste gas from within the impermeable housing <NUM> to the manifold inlet <NUM> to be expelled out of the waste gas outlet <NUM> during the purge phase of the PSA cycle. The outlet port <NUM> may be configured to transfer product gas from within the impermeable housing <NUM> to the manifold outlet <NUM> to be expelled out of the product gas outlet <NUM> for use in an intended application.

In some embodiments, the housing <NUM> of the oxygen concentrator <NUM> may define one or more housing cavities <NUM> and one or more interface cavities <NUM> that are configured to receive the impermeable housing <NUM> and the interface assembly <NUM> of the sieve modules <NUM>. Particularly, the interface cavities <NUM> may be configured to receive the axial portion <NUM> of the interface assembly <NUM>. In some embodiments, one of each of the housing cavities <NUM> and the interface cavities <NUM> may be provided for each of the sieve modules <NUM> (as shown in <FIG>). In such embodiments, a number of the sieve modules <NUM> may correspond to a number of the housing cavities <NUM> and/or the interface cavities <NUM>. In other embodiments, a single one of the housing cavities <NUM> and/or the interface cavities <NUM> may be provided for multiple of the sieve modules <NUM>. In such embodiments, for example, the impermeable housing <NUM> of multiple of the sieve modules <NUM> may be received by a single one of the housing cavities <NUM>. As another example, the interface assembly <NUM> of multiple of the sieve modules <NUM> may be received by a single one of the interface cavities <NUM>.

The housing cavities <NUM> may have any geometry that facilitates a mating engagement with the impermeable housing <NUM>. For example, where the impermeable housing <NUM> has a geometry that is substantially cylindrical, the housing cavities <NUM> may also have a geometry that is substantially cylindrical to be complementary to the impermeable housing <NUM>. The term "complementary" as used herein refers to a geometry (e.g., the geometry of the impermeable housing <NUM>) that may be received by another geometry (e.g., the geometry of the housing cavities <NUM>), such that the geometries engage each other to define a desired position of the geometries relative to each other. The relative position of the geometries may deviate slightly as a result of variations in the geometries resulting from manufacturing tolerances, deviations, or the like.

In embodiments where the impermeable housing <NUM> of the sieve modules <NUM> include the alignment feature <NUM>, the housing cavities <NUM> may include a corresponding alignment feature <NUM>. In such an embodiment, the corresponding alignment feature <NUM> may have a geometry that is complementary to the alignment feature <NUM> of the impermeable housing <NUM>.

Furthermore, the housing cavities <NUM> may be configured to conceal the impermeable housing <NUM> from the environment around the oxygen concentrator <NUM> when the sieve modules <NUM> are in the fully inserted position (as shown in <FIG>). Alternatively, the housing cavities <NUM> may be configured to expose portions of the impermeable housing <NUM> to the environment around the oxygen concentrator <NUM> when the sieve modules <NUM> are in the fully inserted position. In embodiments where the housing cavities <NUM> are configured to conceal the impermeable housing <NUM> from the environment around the oxygen concentrator <NUM>, for example, the housing cavities <NUM> may extend around sides of the impermeable housing <NUM> and around the second end <NUM> of the impermeable housing <NUM>. In such an embodiment, however, the first end <NUM> may remain exposed to the environment around the oxygen concentrator <NUM> to enable the sieve modules <NUM> to be inserted into and/or removed from the housing cavities <NUM>. In embodiments where the housing cavities <NUM> are configured to expose portions of the impermeable housing <NUM> to the environment around the oxygen concentrator <NUM>, for example, the housing cavities <NUM> may include a cup that extends around the second end <NUM> of the impermeable housing <NUM>, and may further include a collar that extends circumferentially around the first end <NUM> of the impermeable housing <NUM>. In such an embodiment, the sides of the impermeable housing <NUM> may remain exposed to the environment around the oxygen concentrator <NUM> when the sieve modules <NUM> are in the fully inserted position.

The interface cavities <NUM> may have any geometry that facilitates a mating engagement with the interface assembly <NUM> (e.g., the axial portion <NUM> of the interface assembly <NUM>) of the sieve modules <NUM>. For example, where the axial portion <NUM> of the interface assembly <NUM> has a geometry that is substantially cylindrical, the interface cavities <NUM> may also have a geometry that is substantially cylindrical to be complementary to the axial portion <NUM> of the interface assembly <NUM> (as shown in <FIG>). The impermeable housing <NUM> and the axial portion <NUM> of the interface assembly <NUM> both being aligned parallel with the housing axis <NUM> enables the sieve modules <NUM> to slide in and out of the housing cavities <NUM> and the interface cavities <NUM> by pulling or pushing on the first end <NUM> of the impermeable housing <NUM> in an axial direction parallel to the housing axis <NUM>.

In some embodiments, the manifold assembly <NUM> may define the interface cavities <NUM> rather than the housing <NUM> of the oxygen concentrator <NUM>. In such embodiments, the housing <NUM> of the oxygen concentrator <NUM> may include an aperture positioned adjacent to the interface cavities <NUM> to allow the interface assembly <NUM> to be inserted into the interface cavities <NUM>. Furthermore, in some embodiments, the manifold assembly <NUM> and the housing <NUM> of the oxygen concentrator <NUM> may cooperatively define the interface cavities <NUM>. In such an embodiment, the housing <NUM> may define some portions of the geometry of the interface cavities <NUM> and the manifold assembly <NUM> may define other portions of the geometry of the interface cavities <NUM>.

In some embodiments, the oxygen concentrator <NUM> may include a door <NUM> configured to secure the sieve modules <NUM> to the housing <NUM> of the oxygen concentrator <NUM> when the sieve modules <NUM> are in the fully inserted position. When the sieve modules <NUM> are in the fully inserted position, the door <NUM> may be removably connected to the housing <NUM> adjacent to the first end <NUM> of the impermeable housing <NUM> to prevent the sieve module <NUM> from becoming removed from the housing <NUM> of the oxygen concentrator <NUM>. The door <NUM> may be removably connected to the housing <NUM> by any conventional means, such as, for example, with a threaded fastener <NUM>, clips, snaps, magnets, or the like. In embodiments where the threaded fastener <NUM> is employed, the threaded fastener <NUM> may extend through a door aperture <NUM> located on the door <NUM> and into a threaded housing aperture <NUM> located on the housing <NUM>.

<FIG> shows a cross-sectional, schematic view illustration of one of the sieve modules <NUM>, wherein arrows <NUM> represent a path in which gas may travel during the adsorption phase of the PSA cycle. During the purge phase of the PSA cycle, gas may travel in a direction that is opposite the direction of the arrows <NUM>. During the adsorption phase of the PSA cycle, pressurized air may be received through the inlet port <NUM> of the interface assembly <NUM>. The pressurized air may then travel into the impermeable housing <NUM> where a portion of the pressurized air (e.g., nitrogen) may be removed from the air by the adsorptive material <NUM> to form the product gas (e.g., substantially pure oxygen). The product gas may then travel out of the impermeable housing <NUM> to be expelled through the outlet port <NUM>.

The impermeable housing <NUM> may be comprised of two or more interconnected portions or may be comprised of a unitary body. In embodiments where the impermeable housing <NUM> is comprised of two or more interconnected portions, the impermeable housing <NUM> may, for example, include a cap portion <NUM> positioned at the second end <NUM> of the impermeable housing <NUM>, a base portion <NUM> positioned at the first end <NUM> of the impermeable housing <NUM>, and a middle portion <NUM> positioned between the cap portion <NUM> and the base portion <NUM> (as shown in <FIG>). In such an embodiment, the two or more portions may be connected in any sealed manner such as to prevent gas from escaping from within the impermeable housing <NUM> to an exterior of the impermeable housing <NUM>. For example, the cap portion <NUM> and the base portion <NUM> may each threadedly engage with the middle portion <NUM>. Furthermore, a first end seal <NUM> may be positioned at an interface between the base portion <NUM> and the middle portion <NUM>, and a second end seal (not pictured) may be positioned at an interface between the middle portion <NUM> and the cap portion <NUM>.

In some embodiments, the sieve module <NUM> may further include a first end diffuser <NUM> positioned at the first end <NUM> of the impermeable housing <NUM>, a second end diffuser <NUM> positioned at the second end <NUM> of the impermeable housing <NUM>, and a transfer tube <NUM> extending between the first end <NUM> and the second end <NUM> of the impermeable housing <NUM>. Furthermore, a first interior space <NUM> and a second interior space <NUM> may be defined within the impermeable housing <NUM>. The first interior space <NUM> may be defined between the middle portion <NUM> of the impermeable housing <NUM> and the transfer tube <NUM>, and between the first end diffuser <NUM> and the second end diffuser <NUM>. The first interior space <NUM> may be configured to contain the adsorptive material <NUM> therein. Although the adsorptive material <NUM> is depicted in <FIG> as filling only a portion of a volume of the first interior space <NUM>, the adsorptive material <NUM> is only depicted in this way for clarity purposes, and a person having ordinary skill in the art will understand that the adsorptive material <NUM> may substantially fill an entirety of the volume of the first interior space <NUM>. The second interior space <NUM> may be defined between the cap portion <NUM> of the impermeable housing <NUM> and the second end diffuser <NUM>. In some embodiments, the first interior space <NUM> and the second interior space <NUM> may be in fluid communication solely through the second end diffuser <NUM> located at the second end <NUM> of the impermeable housing <NUM>. The transfer tube <NUM> may be operable to facilitate fluid communication between the second interior space <NUM> and the outlet port <NUM> of the interface assembly <NUM>.

To facilitate containment of the adsorptive material <NUM> within the first interior space <NUM>, a spring <NUM> may be positioned between the second end diffuser <NUM> and the cap portion <NUM> of the impermeable housing <NUM> such that a force is exerted by the spring <NUM> onto the second end diffuser <NUM>. Furthermore, the second end diffuser <NUM> may slidingly engage with the middle portion <NUM> of the impermeable housing <NUM> such that the spring <NUM> may cause a compressive force to be exerted upon the adsorptive material <NUM> by the second end diffuser <NUM>. Additionally, a diffuser seal <NUM> may be positioned at an interface between the second end diffuser <NUM> and the middle portion <NUM> of the impermeable housing <NUM> such that the adsorptive material <NUM> may not escape from the first interior space <NUM> into the second interior space <NUM>.

The first end diffuser <NUM> and the second end diffuser <NUM> may include a plurality of diffuser apertures <NUM> that are positioned in a spaced relationship along a surface of the first end diffuser <NUM> and the second end diffuser <NUM>. For example, the diffuser apertures <NUM> may be positioned equidistant to each other and extend around a central aperture <NUM> that the transfer tube <NUM> extends through. During the adsorption phase of the PSA cycle, the diffuser apertures <NUM> of the first end diffuser <NUM> may be operable to diffuse pressurized air through the adsorptive material, whereby the product gas may travel through the diffuser apertures <NUM> of the second end diffuser <NUM> to be expelled out of the outlet port <NUM>. During the purge phase of the PSA cycle, the diffuser apertures <NUM> of the second end diffuser <NUM> may be operable to diffuse gas through the adsorptive material <NUM>, whereby the waste gas may travel through the diffuser apertures <NUM> of the first end diffuser <NUM> to be expelled out of the inlet port <NUM>. Furthermore, in some embodiments, diffuser membranes <NUM> may be positioned adjacent to the first end diffuser <NUM> and the second end diffuser <NUM> to further facilitate diffusion of gas throughout the adsorptive material <NUM>.

Referring to <FIG> and <FIG>, the interface assembly <NUM> may be connected to the base portion <NUM> of the impermeable housing <NUM> or may be formed integrally with the base portion <NUM> (as shown in <FIG> and <FIG>). In the illustrated implementation, the outlet port <NUM> is positioned on the axial portion <NUM> such that the outlet port <NUM> forms an opening at an end of the axial portion <NUM> that is opposite an end of the axial portion <NUM> that is connected to the spacing portion <NUM>. Furthermore, the inlet port <NUM> is positioned on the axial portion <NUM> such that the inlet port <NUM> extends through a side wall <NUM> of the axial portion <NUM>. In other embodiments, the outlet port <NUM> may extend through the side wall <NUM> of the axial portion <NUM> and the inlet port <NUM> may form an opening at the end of the axial portion <NUM> that is opposite the end of the axial portion <NUM> that is connected to the spacing portion <NUM>. In other embodiments, both the inlet port <NUM> and the outlet port <NUM> may extend through the side wall <NUM> of the axial portion <NUM>.

In embodiments where the inlet port <NUM> and/or the outlet port <NUM> extends through the side wall <NUM> of the axial portion <NUM>, the inlet port <NUM> and/or the outlet port <NUM> may be positioned at any location along the side wall <NUM>. For example, where the outlet port <NUM> forms an opening at the end of the axial portion <NUM> and the inlet port <NUM> extends through the side wall <NUM> of the axial portion <NUM>, the inlet port <NUM> may be centered between the end of the axial portion <NUM> that includes the outlet port <NUM> and the end of the axial portion <NUM> that is connected to the spacing portion <NUM> in the longitudinal direction. Alternatively, the inlet port <NUM> may not be centered between the end of the axial portion <NUM> that includes the outlet port <NUM> and the end of the axial portion <NUM> that is connected to the spacing portion <NUM> in the longitudinal direction, and instead may be positioned at some other location along the side wall <NUM> of the axial portion <NUM> (i.e., may be positioned proximal the end of the axial portion <NUM> that includes the outlet port <NUM>, or proximal the end of the axial portion <NUM> that is connected to the spacing portion <NUM>, relative to a center between the ends of the axial portion <NUM>).

Furthermore, although the inlet port <NUM> is shown to be aligned with a plane that bisects the impermeable housing <NUM> and the interface assembly <NUM> (i.e., a plane that extends longitudinally along the spacing portion <NUM> of the interface assembly <NUM>), in some embodiments the inlet port <NUM> may be axially rotated about the axial portion <NUM> of the interface assembly <NUM> such that the inlet port <NUM> is not aligned with the plane. For example, the inlet port <NUM> may be positioned <NUM> degrees relative to the plane, <NUM> degrees relative to the plane, <NUM> degrees relative to the plane, or at some other angle relative to the plane. Positioning the inlet port <NUM> such that the inlet port <NUM> is not aligned with the plane may permit additional locations with which components (e.g., the manifold assembly <NUM>, the valve assembly <NUM>, etc.) may be packaged within the housing <NUM> of the oxygen concentrator <NUM>.

In the illustrated implementation, the outlet port <NUM> has an orientation that is in alignment with the housing axis <NUM> and the inlet port <NUM> has an orientation that is substantially perpendicular to the outlet port <NUM> (i.e., has an orientation that is perpendicular to the housing axis <NUM>). In other embodiments, the outlet port <NUM> may not have an orientation that is in alignment with the housing axis <NUM>. Furthermore, the inlet port <NUM> may have an orientation that is not perpendicular to the outlet port <NUM>, but is rather oriented at some other angle relative to the inlet port <NUM> (e.g., <NUM> degrees, <NUM> degrees, etc.).

The interface assembly <NUM> may define an inlet channel <NUM> and an outlet channel <NUM>. The inlet channel <NUM> may extend through the axial portion <NUM> and the spacing portion <NUM> from the inlet port <NUM> to an area adjacent to the first end diffuser <NUM> to facilitate fluid communication between the inlet port <NUM> and the first interior space <NUM>. The outlet channel <NUM> may extend through the axial portion <NUM> and the spacing portion <NUM> from the outlet port <NUM> to the transfer tube <NUM> to facilitate fluid communication between the outlet port <NUM> and the second interior space <NUM>. To separate the inlet channel <NUM> and the outlet channel <NUM>, the interface assembly <NUM> may include an axial portion divider wall <NUM> and a spacing portion divider wall <NUM>. The axial portion divider wall <NUM> may be disposed within the axial portion <NUM> of the interface assembly <NUM> and extend longitudinally along the axial portion <NUM> (e.g., in a direction generally parallel with the housing axis <NUM>), such that the inlet channel <NUM> is positioned on a first side of the axial portion divider wall <NUM> and the outlet channel <NUM> is positioned on a second side of the axial portion divider wall <NUM> that is opposite the first side. The spacing portion divider wall <NUM> may be disposed within the spacing portion <NUM> of the interface assembly <NUM> and extend longitudinally along the spacing portion <NUM> (e.g., in a direction generally perpendicular to the housing axis <NUM>), such that the inlet channel <NUM> is positioned on a first side of the spacing portion divider wall <NUM> and the outlet channel <NUM> is positioned on a second side of the spacing portion divider wall <NUM> that is opposite the first side. Separating the inlet channel <NUM> and the outlet channel <NUM> enables pressurized air to flow into the impermeable housing <NUM> through the inlet channel <NUM> while product gas flows out of the impermeable housing <NUM> through the outlet channel <NUM>.

In some embodiments, the interface assembly <NUM> may include a first portion <NUM> that is connected to, or formed integrally with, the base portion <NUM> of the impermeable housing <NUM>, a second portion <NUM> that is connectable to the first portion <NUM>, and a gasket <NUM> disposed between the first portion <NUM> and the second portion <NUM>. The first portion <NUM> may be referred to as a first interface part and the second portion <NUM> may be referred to as a second interface part. In some embodiments, the axial portion <NUM> of the interface assembly <NUM> may be comprised primarily of the first portion <NUM>. Furthermore, the first portion <NUM>, the second portion <NUM>, and the gasket <NUM> may cooperatively define the inlet channel <NUM> and the outlet channel <NUM>. In such an embodiment, the first portion <NUM> may include the axial portion divider wall <NUM> to separate the inlet channel <NUM> and the outlet channel <NUM> along the axial portion <NUM>. Furthermore, the gasket <NUM> may form the spacing portion divider wall <NUM> to separate the inlet channel <NUM> and the outlet channel <NUM> along the spacing portion <NUM>. The gasket <NUM> may include gasket apertures <NUM> through which the outlet channel <NUM> may extend while maintaining separation between the inlet channel <NUM> and the outlet channel <NUM>. The interface assembly <NUM> may be pneumatically connected to the transfer tube <NUM> using a coupling <NUM> to provide fluid communication between the outlet channel <NUM> and the second interior space <NUM>.

The first portion <NUM> of the interface assembly <NUM> may include features <NUM> on which the gasket <NUM> may be supported. In some embodiments, the features <NUM> may extend through the gasket apertures <NUM> to further support the gasket <NUM> on the first portion <NUM> of the interface assembly <NUM> (as shown in <FIG> and <FIG>). Additionally or alternatively, the second portion <NUM> of the interface assembly <NUM> may include protrusions (not pictured) that extend toward the first portion <NUM> of the interface assembly <NUM> that are operable to urge the gasket <NUM> toward the first portion <NUM>.

The gasket <NUM> may have any geometry and may be comprised of any material that, in combination, are sufficient to separate the inlet channel <NUM> and the outlet channel <NUM> during the PSA cycle (i.e., to prevent gas from traveling between the inlet channel <NUM> and the outlet channel <NUM>). However, in some embodiments, the sieve modules <NUM> and the oxygen concentrator <NUM> may be configured such that during the PSA cycle, gas may travel through the inlet channel <NUM> at a pressure that is the same as a pressure with which gas travels through the outlet channel <NUM>. Therefore, forces acting upon the gasket <NUM> resulting from different pressures existing on either side of the gasket <NUM> may be minimal, and thus may enable the gasket <NUM> to have a geometry that is relatively thin.

The second portion <NUM> of the interface assembly <NUM> may be connectable to the first portion <NUM> by any conventional means that are sufficient to maintain a sealing connection between the first portion <NUM> and the second portion <NUM>. In some embodiments, the second portion <NUM> may be fixedly connected to the first portion <NUM> by, for example, welding, gluing, or the like. In other embodiments, the second portion <NUM> may be removably connected to the first portion <NUM> by, for example, clips, fasteners, or the like. In embodiments where the second portion <NUM> is removably connected to the first portion <NUM>, a seal (not pictured) may be positioned at an interface between the first portion <NUM> and the second portion <NUM> to prevent gas from escaping from the inlet channel <NUM> or the outlet channel <NUM> during the PSA cycle. Furthermore, the first portion <NUM> and the second portion <NUM> may include opposing flanges that facilitate the connection between the first portion <NUM> and the second portion <NUM> (as shown in <FIG> and <FIG>).

<FIG> is a partial cross-sectional, schematic view illustration showing an interface between the interface assembly <NUM> and the manifold assembly <NUM> of the oxygen concentrator <NUM>, wherein the arrows <NUM> represent a path in which gas may travel during the adsorption phase of the PSA cycle. During the purge phase of the PSA cycle, gas may travel in a direction that is opposite the direction of the arrows <NUM>.

In some embodiments, the interface assembly <NUM> may include a plurality of interface seals <NUM> (e.g., two or more of the interface seals <NUM>) positioned along the axial portion <NUM> of the interface assembly <NUM>. In such an embodiment, the interface seals <NUM> may extend circumferentially around the axial portion <NUM> (e.g., may be an O-ring). In other embodiments, the interface seals <NUM> may be some other type of seal. The interface seals <NUM> may be operable to pneumatically connect the interface assembly <NUM> to the manifold assembly <NUM> by forming an airtight seal between the axial portion <NUM> of the interface assembly <NUM> and the interface cavity <NUM> when the sieve module <NUM> is in the fully inserted position. Furthermore, in some embodiments, the interface seals <NUM> may be configured to form separate pneumatic connections between the inlet port <NUM> of the interface assembly <NUM> and the manifold inlet <NUM> of the manifold assembly <NUM> and between the outlet port <NUM> of the interface assembly <NUM> and the manifold outlet <NUM> of the manifold assembly <NUM> (as shown in <FIG>).

In the illustrated implementation, a first of the interface seals <NUM> in the form of an O-ring is positioned along the axial portion <NUM> between the inlet port <NUM> and the outlet port <NUM>, such that the first of the interface seals <NUM> is positioned on a side of the inlet port <NUM> proximal the outlet port <NUM> (i.e., positioned proximal the outlet port <NUM> relative to the inlet port <NUM> in the longitudinal direction). Additionally, a second of the interface seals <NUM> in the form of an O-ring is positioned along the axial portion <NUM> between the inlet port <NUM> and the end of the axial portion <NUM> that is connected to the spacing portion <NUM>, such that the second of the interface seals <NUM> is positioned on a side of the inlet port <NUM> distal from the outlet port <NUM> (i.e., positioned distal from the outlet port <NUM> relative to the inlet port <NUM> in the longitudinal direction). Positioning the first and the second of the interface seals <NUM> in such a configuration enables a pneumatic connection to be formed between the inlet port <NUM> and the manifold inlet <NUM> that is defined between the first and the second of the interface seals <NUM> when the axial portion <NUM> is fully inserted into the interface cavity <NUM>. Such a configuration also enables a separate pneumatic connection to be formed between the outlet port <NUM> and the manifold outlet <NUM> that is defined by the first of the interface seals <NUM> when the axial portion <NUM> is fully inserted into the interface cavity <NUM>. Therefore, when the axial portion <NUM> is fully inserted into the interface cavity <NUM>, pressurized air may flow from the manifold inlet <NUM> to the inlet port <NUM> while product gas flows from the outlet port <NUM> to the manifold outlet <NUM>.

In embodiments including the interface seals <NUM>, the side wall <NUM> of the axial portion <NUM> may include features operable to prevent the interface seals <NUM> from moving along the axial portion <NUM> when the axial portion <NUM> is inserted into the interface cavities <NUM>. For example, the side wall <NUM> may include divots configured to receive the interface seals <NUM> (e.g., divots extending circumferentially around the axial portion <NUM> into which an O-ring may be partially disposed). As another example, the side wall <NUM> may include ribs configured to support the interface seals <NUM> (e.g., ribs extending circumferentially around the axial portion <NUM> against which an O-ring may be positioned).

The manifold assembly <NUM> may be operable to facilitate fluid communication between the interface assembly <NUM> and the oxygen concentrator <NUM> through tubes <NUM>, wherein the tubes <NUM> are operable to transfer gas between the manifold assembly <NUM> and the valve assembly <NUM>. In some embodiments, the manifold assembly <NUM> may be configured to facilitate fluid communication between the interface assembly <NUM> of multiple of the sieve modules <NUM> and the oxygen concentrator <NUM>. In such an embodiment, the manifold assembly <NUM> may extend between the interface cavities <NUM> that are provided for each of the sieve modules <NUM>, such that the manifold assembly <NUM> is positioned adjacent to (or in some embodiments, defines or partially defines) each of the interface cavities <NUM>.

In other embodiments, the manifold assembly <NUM> may be configured to facilitate fluid communication between the interface assembly <NUM> of only one of the sieve modules <NUM>. In such an embodiment, the manifold assembly <NUM> may be positioned adjacent to (or may define or partially define) one of the interface cavities <NUM> corresponding to one of the sieve modules <NUM> (as shown in <FIG>). Another of the manifold assembly <NUM> may be positioned adjacent to (or may define or partially define), another of the interface cavities <NUM> corresponding to another of the sieve modules <NUM>.

The manifold assembly <NUM> may include attachment features <NUM> that pneumatically connect the manifold assembly <NUM> to tubes <NUM>. In some embodiments, for example, the attachment features <NUM> may be tube fittings (as shown in <FIG>). Although the two of the attachment features <NUM> shown in <FIG> are depicted as having similar geometries and sizes, the attachment features <NUM> may not be similar and may instead have different geometries and/or sizes.

In some embodiments, the manifold assembly <NUM> may include one of the attachment features <NUM> for each of the manifold inlet <NUM> and the manifold outlet <NUM> (as shown in <FIG>). In such an embodiment, during the adsorption phase of the PSA cycle pressurized air may be delivered to the inlet port <NUM> through one of the tubes <NUM>, and during the purge phase of the PSA cycle waste gas may be expelled out of the inlet port <NUM> into the same one of the tubes <NUM>. In other embodiments, the manifold assembly <NUM> may include one of the attachment features <NUM> for the manifold outlet <NUM> and may include multiple (e.g., two) of the attachment features <NUM> for the manifold inlet <NUM>. In such an embodiment, during the adsorption phase of the PSA cycle pressurized air may be delivered to the inlet port <NUM> through one of the tubes <NUM>, and during the purge phase of the PSA cycle waste gas may be expelled out of the inlet port <NUM> into a different one of the tubes <NUM> (not shown).

Furthermore, the manifold assembly <NUM> may be comprised of a unitary body or may be comprised of a plurality of interconnected components. In an embodiment where the manifold assembly <NUM> is comprised of a plurality of interconnected components, for example, the manifold assembly <NUM> may include an outlet portion <NUM> and an inlet portion <NUM> (as shown in <FIG>). The outlet portion <NUM> may be configured to facilitate fluid communication between the outlet port <NUM> and one of the tubes <NUM>, and the inlet portion <NUM> may be configured to facilitate fluid communication between the inlet port <NUM> and another one (or other multiple) of the tubes <NUM>. The outlet portion <NUM> may be connected to the inlet portion <NUM> in any suitable manner. For example, the outlet portion <NUM> may be glued or welded to the inlet portion <NUM> to form a fixed connection. As another example, the outlet portion <NUM> may be snapped, clipped, or fastened to the inlet portion <NUM> to form a removable connection.

Claim 1:
A sieve module, comprising:
an impermeable housing (<NUM>) including a first end (<NUM>), a second end (<NUM>) opposite the first end (<NUM>), and a diffuser (<NUM>) positioned at the second end (<NUM>) that defines a first interior space (<NUM>) and a second interior space (<NUM>) within the impermeable housing (<NUM>), wherein the first interior space (<NUM>) and the second interior (<NUM>) space are in fluid communication solely at the second end (<NUM>) of the impermeable housing (<NUM>);
an interface assembly (<NUM>) connected to the first end (<NUM>) of the impermeable housing (<NUM>), the interface assembly (<NUM>) comprising:
an inlet port (<NUM>) in fluid communication with the first interior space (<NUM>) of the impermeable housing (<NUM>), wherein the inlet port (<NUM>) is configured to receive gas from an exterior of the impermeable housing (<NUM>),
an outlet port (<NUM>) in fluid communication with the second interior space (<NUM>) of the impermeable housing (<NUM>), wherein the outlet port (<NUM>) is configured to expel the gas to the exterior of the impermeable housing (<NUM>),
a spacing portion (<NUM>) pneumatically connected to the first end (<NUM>) of the impermeable housing (<NUM>) and extending perpendicular to a housing axis (<NUM>) of the impermeable housing (<NUM>) in a direction away from the impermeable housing (<NUM>), wherein the housing axis (<NUM>) extends through the first end (<NUM>) and the second end (<NUM>) of the impermeable housing (<NUM>), and
an axial portion (<NUM>) pneumatically connected to the spacing portion (<NUM>) and extending parallel to the housing axis (<NUM>) in a direction generally toward the second end (<NUM>) of the impermeable housing (<NUM>), wherein the inlet port (<NUM>) and the outlet port (<NUM>) are both disposed on the axial portion (<NUM>) of the interface assembly (<NUM>); and
an adsorptive material (<NUM>) that is disposed within the first interior space (<NUM>) of the impermeable housing (<NUM>), wherein the interface assembly (<NUM>) is configured such that the gas travels from the inlet port (<NUM>) to the outlet port (<NUM>) by traveling through the adsorptive material (<NUM>).