System and method for filling a portable liquified gas storage/delivery system

A liquefied gas storage/delivery system and method that includes a liquefied gas storage system. The liquefied gas storage system includes a housing containing a storage vessel suited to contain a supply of liquefied gas, such as liquid oxygen (LOX). A rotatable turntable is provided on an exterior surface of the housing. An interface shaped to match the shape of at least a portion of a portable liquid storage/delivery device is provide in or on the turntable. A connector is disposed in the interface that couples to a corresponding connector on the portable liquid storage/delivery device. The two connectors are coupled by placing the portable liquid storage/delivery device in the interface and rotating the turntable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to an ambulatory liquefied gas system, and, in particular, to a system and method for filling a portable liquefied gas storage/delivery unit from a liquefied gas storage system.

2. Description of the Related Art

The delivery of supplemental oxygen to a patient is typically prescribed for individuals suffering from pulmonary/respiratory problems. The prescription and delivery of supplemental oxygen is undertaken to ensure that sufficient oxygen levels are received by the patient. Situations where supplemental oxygen may be prescribed include individuals afflicted with a chronic obstructive pulmonary disease, such as asthma, as well as individuals suffering from diseased or damaged lungs.

It is known to deliver supplemental oxygen using a liquid oxygen (“LOX”) system. A conventional LOX system includes a large stationary LOX storage canister that is located at and remains in the user's home. The stationary LOX canister is replenished periodically from a mobile LOX storage vessel, which is typically a truck carrying a large quantity of LOX. A conventional LOX system also includes a small, portable storage/delivery apparatus weighing from five to thirteen pounds that can be filled from the stationary unit for trips outside the home.

One such LOX system is disclosed in U.S. Pat. No. 6,742,517 (“the '517 patent”) entitled, High Efficiency Liquid Oxygen Storage and Delivery System. As disclosed in this patent, a typical LOX system includes a stationary LOX storage canister located in an individual's home and a portable LOX delivery unit that the patient uses outside the home. The name of the portable delivery unit in the commercial implementation of this LOX system and described in the '517 patent is the HELiOS®. As identified at the HELiOS website, www.heliosoxygen.com, the HELiOS H300 portable LOX delivery unit has a limited capacity for storing liquid oxygen.

The HELiOS system is refilled by firmly forcing the HELiOS H300 portable LOX delivery unit onto the LOX storage canister by pressing down on the HELiOS H300 portable LOX delivery unit to cause it to engage with the LOX storage canister. While forcing the HELiOS H300 portable LOX delivery unit onto the LOX storage canister the user must manually move a vent valve level on the exterior of the portable deliver unit to an open position. This requires simultaneously applying a downward force on the HELiOS H300 portable LOX delivery unit and moving the valve level. Naturally, this requires using both hands or using more than one person to fill the portable delivery unit.

During filling, the user must maintain a watch on the HELiOS H300 portable LOX delivery unit until sputtering in the filling noise associated with the filling of the unit. In addition, the user must watch for the release of white vapor from the HELiOS H300 portable LOX delivery unit in order to ensure that the unit has been completely filled. After which, the user is instructed to release the portable LOX delivery unit from the storage canister.

In another system, such as the Stroller/Spirit sold by Caire, Inc., the portable LOX delivery unit can be attached to the LOX storage canister. This requires engaging a connector on the portable LOX delivery unit with a connector of the LOX storage canister. There is no interconnection between the portable LOX delivery unit and the LOX storage canister other than the connector-to-connector coupling. The coupling process also requires manually rotating or turning the portable LOX delivery unit relative to the LOX storage canister to engage the coupling on the portable LOX delivery unit with the coupling on the LOX storage canister. Once the couplings are engaged, the user must maintain a vigil over the portable LOX delivery unit to determine when the unit has been filled.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a liquefied gas storage/delivery system that overcomes the shortcomings of conventional systems. This object is achieved according to one embodiment of the present invention by providing a liquefied gas storage system for use in a liquefied gas storage/delivery system. The liquefied gas storage system includes a housing and a storage vessel disposed in the housing and adapted to contain a supply of liquefied gas, such as LOX. A turntable is provided on an exterior surface of the housing and is rotatable with respect to the housing. An interface is provide in or on the turntable. The interface has a shape generally corresponding to a shape of at least a portion of a housing of a portable liquid storage/delivery device. A first connector is disposed in the interface and in fluid communication with the storage vessel. The first connector is adapted to be coupled to a corresponding second connector on the portable liquid storage/delivery device so that the portable liquid storage/delivery device is placed in the interface and the turntable rotated, the connectors engage, thereby placing the storage vessel in the liquefied gas storage system in fluid communication with the portable liquid storage/delivery device.

It is a further object of the present invention to provide a liquefied gas storage/delivery system that includes the above-described liquefied gas storage system and a portable liquid storage/delivery device adapted to operate in conjunction with the liquefied gas storage system.

It is yet another object of the present invention to provide a method of providing ambulatory liquefied gas that does not suffer from the disadvantages associated with conventional ambulatory liquefied gas delivery techniques. This object is achieved by providing a method that includes (1) providing a housing adapted to contain a supply of liquefied gas in a storage vessel, (2) coupling a portable liquid storage/delivery device to a turntable provided on an exterior surface of the housing, (3) moving the turntable to engage a first connector disposed on the portable liquid storage/delivery device with a second connector provided on the housing, and (4) transferring liquefied gas from the storage vessel to the portable liquid storage/delivery device responsive to the first connector engaging the second connector.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1schematically illustrates an exemplary embodiment of a liquefied gas storage/delivery system30for providing ambulatory liquefied gas for delivery to a user according to the principles of the present invention. Further details of the liquefied gas storage/delivery system and its use to provide an ambulatory supply of a liquefied gas, such as oxygen, will be discussed below with reference toFIGS. 1-9.

Liquefied gas storage/delivery system30includes a liquefied gas storage system32and a portable liquid storage/delivery device34adapted to be coupled to liquefied gas storage system32. Liquefied gas storage system32is adapted to contain a quantity of liquefied gas, such as liquid oxygen, for delivery to the portable liquid storage/delivery device. Portable liquid storage/delivery device34is a relatively small, ambulatory unit that is used to carry a quantity of liquefied gas for delivery to the user. In an exemplary embodiment of the present invention, the liquefied gas is liquefied oxygen (LOX) of a grade suitable for medical purposes, and the LOX is delivered to the user via the portable liquid storage/delivery device in any conventional manner.

In the illustrated exemplary embodiment, liquefied gas storage system32includes a housing36and a storage vessel38disposed in the housing and adapted to contain a supply of liquefied gas, such as LOX. Storage vessel can have any configuration suitable for storing a liquefied gas. In an exemplary embodiment, the storage vessel is a double-walled vacuum insulated vessel typically used in the cryocooling art for storing very cold materials. In an exemplary embodiment of the present invention, the liquefied gas is produced by a liquefaction system40that is also contained in housing36and provided by the liquefaction system to the storage vessel38, as indicated by arrow42.

The present invention contemplates that liquefaction system40can be any system for generating a supply of liquefied gas from a gas source. Examples of suitable liquefaction systems include those described in U.S. Pat. Nos. 5,617,739; 5,724,832; 5,893,275; 6,212,904; 5,979,440; 6,651,653; 6,681,764; 6,698,423; and 7,213,400 and U.S. patent application Ser. No. 11/130,646 (publication no. 2006/0086102)(collectively referred to as “the liquefaction references”), the contents of each of which are incorporated herein by reference. In further embodiment discussed in greater detail below with respect toFIGS. 13 and 14, liquefaction system40includes a device for generating a supply of gas to be liquefied, such as an oxygen concentrator, and a device for liquefying the gas, typically referred to as a “liquifier.”

Examples of devices for generating a supply of gas include conventional oxygen concentrators, which use a pressure swing absorption (PSA) process to produce a supply of enriched oxygen from air. U.S. Pat. Nos. 5,183,483; 5,997,617; 6,190,441; 6,348,082; 6,395,065; and 6,497,755; and U.S. patent application Ser. Nos. 10/935,733 (publication no. 2006/0048644), 11/636,235 (publication no. 2008/0047435), and 11/636,233 (publication no. 2008/0047426), the contents of each of which are incorporated herein by reference, disclose various oxygen concentrators and oxygen concentrations systems suitable for use in the present invention. It is to be understood that this list of pressure swing absorption systems is not intended to be limiting. In addition, other types of gas generating systems, such as ceramic and distillation processes, are contemplated for use in the present invention.

The present invention contemplates that any conventional device or system for liquefying a gas can be used in liquefaction system40, including any conventional cryocooling system. Such systems super-cool a gas supply to a cryocooling temperature so that the gas supply converts from a gas to a liquid. Examples of cryocooling systems suitable for us in liquefaction system40include those disclosed in the liquefaction references as well as those disclosed in U.S. Pat. Nos. 5,617,739 and 5,724,832, the contents of each of which are incorporated herein by reference. Examples of other cryocooling systems suitable for use in the present invention include Sterling cryocoolers, Joule Thompson cryocoolers, Gifford-McMahon cryocoolers, and pulse tube cryocoolers. It is to be understood that this list of cryocooling techniques is not intended to be limiting.

The present invention contemplates that both of the elements of liquefaction system40, i.e., (1) a system for generating a supply of gas to be liquefied, and (2) a system for liquefying the gas, can be contained in liquefied gas storage system32. The present invention also contemplates providing only one of the elements of liquefaction system40in the liquefied gas storage system. For example, the system for generating a supply of gas to be liquefied (typically an oxygen concentrator) can be located outside of housing36as a separate device. The output of the oxygen concentrator can be coupled to an input on the housing so that the oxygen enriched gas from the oxygen concentrator is provided to the liquefaction system for liquefaction.

Liquefied gas storage system32includes a turntable44provided on an exterior surface of housing36. Turntable44is rotatable with respect to the housing as discussed in greater detail below. An interface46is provided on the turntable to receive at least a portion of portable liquid storage/delivery device34. More specifically, interface46includes an opening48having a shape generally corresponding to a shape of at least a portion of a housing50of portable liquid storage/delivery device34so that the portable liquid storage/delivery device sits, at least partially, within the opening of interface46. In the illustrated exemplary embodiment, opening48has a general “kidney-shape” that corresponds to the kidney shape of the lower portion of housing50. Of course, other shapes, sizes, and geometries for opening48are contemplated by the present invention.

In an exemplary embodiment, interface46and opening48are sized and configured such that when the portable liquid storage/delivery device is coupled to the interface its is supported by the interface so that the user need not hold the portable liquid storage/delivery device in the interface. For example, the present invention contemplates making the walls defining opening48high enough to support or hold the portable liquid storage delivery device in the opening.FIGS. 2A and 2Bshow the placement of portable liquid storage/delivery device34into opening48of interface46.

A pneumatic connector52, which is also referred to as a first connector, is disposed in interface46and in fluid communication with storage vessel38via a pneumatic circuit54. Details of pneumatic connector52are shown inFIGS. 6 and 9and discussed in detail below. Connector52is adapted to be coupled to a corresponding pneumatic connector56, which is also referred to as a second connector, provided on portable liquid storage/delivery device34. Coupling first connector52to second connector56is accomplished by aligning the connectors and rotating one connector relative to the other. More specifically, the second connector is rotated relative to the first connector, because first connector52is disposed on liquefied gas storage system32, which remains stationary during filling.

Details of pneumatic connector56are shown inFIGS. 7-9and discussed in detail below. When first and second connectors52and56are engaged, storage vessel38is in fluid communication with the portable liquid storage/delivery device. More specifically, storage vessel38is in fluid communication with a storage vessel58, which is also referred to as a dewar, provided in portable liquid storage/delivery device34so that liquefied gas can be transferred from storage vessel38to dewar58. A pneumatic circuit60in the portable liquid storage/delivery device couples dewar58to connector56.

The present invention also contemplates providing features associated with interface46or portable liquid storage/delivery device34to ensure that the portable liquid storage/delivery device remains coupled to the interface. In an exemplary embodiment, friction members62are provided in an interior wall of opening48to engage housing50of portable liquid storage/delivery device34. Friction members62help ensure, for example, that the portable liquid storage/delivery device does not unexpected slip from opening48, especially during rotation of turntable44and/or when connectors52and56are not positively secured to one another.

It should be noted that the present invention also contemplates that the shape of opening48need not generally match the shape of housing50of portable liquid storage/delivery device34. To ensure that the portable liquid storage/delivery device is held to the turntable, support elements can be provided in the opening that selectively join the portable liquid storage/delivery device to the turntable. In addition, interface46need not include an opening defined in the turntable in order to attach the portable liquid storage/delivery device to the turntable. The present invention contemplates that interface46can include any support element that allows the portable liquid storage/delivery device to be selectively coupled or attached to the turntable. For example,FIG. 1schematically shows a generally planar turntable (viewed from the side in this figure) with a pair of posts schematically illustrating interface46. Posts, bars, rails, and arms are a few examples of structures suitable for use in interface46to couple the portable liquid storage/delivery device to the turntable.

It should be noted that the present invention also contemplates using features or elements to ensure that the portable liquid storage/delivery device remains coupled to the interface in addition to or in place of friction members62and regardless of the configuration for the interface. For example, locking tabs, hooks, snaps, claps, straps, cords, magnets, releasable fasteners (such as hook and loop fasteners), or any other type of coupling mechanism can be provided on portable liquid storage/delivery device34and/or liquid gas storage system32to ensure that these to items remain coupled in a secure fashion.

Turntable44is rotatable relative to housing36so that when the turntable moves, the portable liquid storage/delivery device that is mounted on the turntable also moves relative to the housing. In the illustrated exemplary embodiment best shown inFIGS. 3-5, turntable44includes a movable member64rotatably mounted to a base66. In the illustrated embodiment, movable member64is a rigid member having a generally circular, disk, or dome shape that generally matches the surface of base66. Base66also serves as a wall or side of liquefied gas storage system32. In the illustrated embodiment, base66defines a top surface of the liquefied gas storage system.

A cavity68is defined in base66that receives movable member64. In this configuration, the exposed surface of movable member64is generally flush with the exposed surface of base66so that the top of the liquefied gas storage system has a generally smooth or clean appearance. The present invention contemplated a wide variety of other configurations for the turntable including the moveable member. For example, as shown inFIG. 10, movable member64can be mounted above a top surface70of base66so that the exposed surface of the moveable members is above or spaced art from the exterior surface of the base. Conversely, as shown inFIG. 11, moveable member64of turntable44can be mounted below surface70of the base66so that the entire moveable member is below the surface of the base. A portion of the moveable member can be covered by or disposed under base66or the base need not cover any portion of the moveable member.

The present invention contemplates rotatably coupling movable member64to the remaining portions of liquefied gas storage system32in any one of a variety of different ways. In the illustrated exemplary embodiment, movable member64is snap fit into cavity68. To this end one or more protrusions70are provided on a perimeter of movable member64. A groove or channel72is defined around a perimeter or a portion of a perimeter of cavity68to receive protrusions70. In this embodiment, the engagement between moveable member64and base66takes place at the perimeter of the moveable member. In other words, the bearing surfaces of the moveable member and the base are at the perimeter of the moveable member and the adjacent surface of the base.

Bearings74are provided at various locations on moveable member64and/or base66to reduce the friction between the moveable member and the base during rotation of the moveable member. In an exemplary embodiment of the present invention bearing74are nylon rivets having one end mounted to moveable member64and a convex or rounded surface at the other end that slides along a surface76of base66. It can be appreciated that the present invention contemplates other bearing configurations and techniques. For example, the position of the nylon rivets can be reversed, i.e., mounted on base66. Reduced friction surfaces can also be provided on moveable member64and/or base66. Similarly, roller bearings, ball bearings, or other friction reducing mechanisms can be used as bearings74.

Coupling the connectors is accomplished by rotating portable liquid storage/delivery device34disposed on turntable44relative to housing36or base66. In an exemplary embodiment of the present invention, moveable member64need only rotate over a certain range of angles in order to couple first connector52with second connector56. Thus, the present invention contemplates providing one or more stops78that limit the range of rotation for the turntable. In an exemplary embodiment, stops78engage protrusions70to limit further movement of moveable member64in that direction. It should be understood that other configurations and techniques for limiting the range of rotation of the turntable are also contemplated by the present invention. For example, in the embodiment ofFIG. 11, base66can serve as a stop to control the range of motion of the turntable. The present invention also contemplates eliminating all stops, and allowing a full 360° range of movement of the turntable relative to housing36.

As best shown inFIGS. 3A and 3B, base66and first connector52are mounted to a frame80. The other components of liquefied gas storage system32can also be mounted to frame80, either directly or indirectly. For example, front and/or side panels81can be mounted to the frame. In addition, storage vessel38and the pneumatic circuits coupling the various components of the liquefied gas storage system can also be mounted to frame80. Frame80can have any one of a variety of configurations, and should be strong enough to support the components of the liquefied gas storage system that are coupled to it. It is to be understood that the configuration for the liquefied gas storage system shown inFIGS. 3A and 3Brepresent only one of many ways for positioning and mounting the components of the in housing36and should not be considered as exclusive.

An opening82is provided in base66through which first connector52passes when the liquefied gas storage system is assembled. A similar opening84is provided in interface46of turntable44. In the illustrated embodiment, opening84is provided in the flow of the well formed by opening48of interface46. First connector52, base66, and moveable member64are sized, configured, and arranged such that a portion of the first connector remains sufficiently exposed so that it can engage second connector56.

Referring now toFIGS. 6-9, the details of connectors52and56will be discussed. Connector52, which is associated with liquefied gas storage system32, includes a housing having a stem90and an outer basket92such that a space94is defined between the stem and the outer basket. A pair of helical or spiral slots96are defined in the outer basket to receive pins120from first coupling member44. The slots includes a portion98at the end that is not helical, so that once pin120moves to portion98, the pin remains within the slot. First connector52also includes a valve100. Connector56, which is associated with portable liquid storage/delivery device34, includes a central housing110having a stem receiving cavity112defined therein. A one way valve114is located in housing100. Valve114includes a moveable valve member116biased in the closed position by a biasing force. When open, liquid gas is free to flow through housing110. In the illustrated embodiment, this biasing force is provided by a spring118.

A pair of pins120are provided on housing100. In an exemplary embodiment, each pin120includes a stem122and an outer casing124rotatably mounting on the stem. This allows the outer surface, i.e., the casing, to rotate as the pin engages another surface, thereby reducing friction between the pin and the other surface.

Engaging first connector52with second connector56, requires inserting stem90into stem receiving cavity112, which also results in placing a wall113of housing110into space94. Pins120must be aligned with the open ends of helical slots96. The first connector and the second connector are then pushed toward one another while twisting or rotating one relative to the other so that pins120move along slots96. Valve100engages valve114causing both to move to an open position. Opening of valve114is indicated by arrow119inFIG. 8. When fully inserted, an outer edge115of wall113abuts a shoulder95in first connector52. The bias forces that tend to urge valves114and100in the closed position push against each other, which tends to force the first and second connectors apart. However, they are held together so long as pins120are located in flat portions98of slots96. Thus, the user us able to cease forcing the first and second coupling members together with the coupling member remaining engaged to facilitate hands-free filling of portable liquid storage/delivery device34.

The length of cavity112in second connector56and the length of stem90in first connector52, which is indicated as length “L” inFIG. 9, are selected so that the outer edge115of wall113abuts shoulder95when the connectors are engaged. In an exemplary embodiment of the present invention, the overall length of first connector52and second connector56is minimized by reducing the length of cavity112and stem90below that of conventional liquid oxygen coupling members. For example, the present invention contemplates that length L is ⅝ inch or less.

The process for coupling portable liquid storage/delivery device34to liquefied gas storage system32, which is done to fill the portable liquid storage/delivery device with liquefied gas, such as LOX, will be described with reference toFIGS. 1-2Cand4. In order to couple the portable liquid storage/delivery device to the liquefied gas storage system the turntable, the turntable should be in the first or “unlocked” position. In this position, interface46and first connector52are arranged configured such that when the portable liquid storage/delivery device is inserted into the well or pocket formed by opening48of interface46in turntable44, pins120are aligned with the opening of helical slots96. Because the shape of the pocket or opening48generally matches that of housing50of portable liquid storage/delivery device34, a user is able to quickly and easily align the second connector56of the portable liquid storage/delivery device with the first connector52of liquefied gas storage system32.

To ensure that the turntable is in the first or “unlocked” position the present invention contemplates providing indicators on turntable44and base66. As shown inFIG. 4a position indicator130is provided on turntable44and a “first position” or “unlocked position” indicator132is provided on base66. When position indicator130is aligned with the indicator132, the turntable is in the “unlocked” position, indicating that portable liquid storage/delivery device34can be inserted into opening48. The indicators can have an variety of configurations. For example, the present invention contemplates lighting one or both indicators130,132when the two are correctly aligned. More specifically, when the indictors are not aligned, both are illuminated red. When they are aligned, one or both are illuminated green. This visual indication provides a clear and concise indication of when the turntable is in the “unlocked” position.

When turntable44is in the unlocked position, portable liquid storage/delivery device34is inserted into opening48of interface46, as indicated by arrow A. As a result, connector56engages connector52. Turntable is then rotated, as indicated by arrows B, to move the portable liquid storage/delivery device relative to liquefied gas storage system32. More specifically, rotating the turntable causes portable liquid storage/delivery device34to pivot about an axis, where this axis corresponds to the location of connector52. The result of rotating the turntable is that connector56on the portable liquid storage/delivery device is rotated into engagement with connector52, i.e., pins120of connector56slide along helical slots96of connector52.

In the illustrated exemplary embodiments, rotating turntable44approximately 90° is sufficient to engage connector56with connector52fully. It can be appreciated that the angle of rotation needed to complete this connection, i.e., fully lock the first and second connectors, will depend on the configuration for the connectors. In the illustrated embodiment, connector52has helical slots that spiral approximately 90°. Thus, 90° of rotation for the turntable are needed. When the turntable is rotated to the second or locked position, first and second connectors are coupled, as shown, for example, inFIG. 9and fluid is capable of flowing through these connectors. In this position, pins120are located at areas98of slots96and the connectors will remain engaged to one another.

To allow the user to quickly visualize that the turntable has been moved to the proper position, i.e., the position in which the connectors are fully engaged and fluid transfer is possible, an second indicator134is provided on base66. Alignment of indicator130with indicator134provides a visual indication that the turntable is in the second or “locked” position so that fluid transfer is possible. As before, the present invention contemplates that indicators130and/or134can be illuminated or animated in some fashion to provide a clear indication of when the turntable has been moved to the second position.

In the illustrated exemplary embodiment, rotating the turntable between the first and second (locked and unlocked) positions is done manually. For example, the user may push on the portable liquid storage/delivery device itself, while it is docked to the liquefied gas storage system via interface46. The user may also manually spin turntable44, for example, by pushing on a protruding portion136of the turntable. In the illustrated embodiment, protruding portion136also serves to define the wall of the pocked or well in which the portable liquid storage/delivery device is seated. Of course, the present invention also contemplates providing other griping elements, such as handles, friction pads, or knobs on the turntable to facilitate its manual movement. Providing a handle on the turntable can be done such that the handle acts as a level arm, reducing the overall forces needed to rotate the turntable.

Due to the design of the first and second connectors, namely the inclusion of a flat portion98of helical slot96, the first and second connectors remain engaged when they are in the second or locked position. The present invention also contemplates that the turntable can be configured to maintain it in the second or locked position, regardless of the design of the first and/or second connectors. For example, a locking mechanism can be provided on the turntable that engages once the turntable has been rotated the necessary amount to coupling the connectors together. A latch or sliding bolt are examples of such a locking mechanism. Moreover, this locking mechanism can be manually actuated or automatically actuated. For example, an electronic lock can be automatically closed when the turntable is moved to the second position. The electronic lock can also be closed by the user, for example by activating a user interface device, such as switch, when the turntable is moved to the second position.

The lock can be manually or automatically opened upon completion of the filling process. For example, the present invention contemplates monitoring the filling process and unlocking the turntable when filling is complete. Monitoring the filling process to determine when filling is complete can be accomplished, for example, by monitoring the amount of liquid transferred to the portable liquid storage/delivery device. This can be accomplished using any conventional monitoring technique, such as monitoring the rate of flow to determine the volume transferred to the portable liquid storage/delivery device or monitoring the weight of the portable liquid storage/delivery device. To accomplish the latter technique, a scale can be included in the turntable so that the liquefied gas storage system can keep track of the weight of the portable liquid storage/delivery device relative that is couple to it.

Once the turntable is in the second position, liquefied gas is transferred from the storage vessel to the portable liquid storage/delivery device. The flow of fluid can be initiated automatically or manually using either the portable liquid storage/delivery device or the liquefied gas storage system. For example, in one embodiment of the present invention, a controller/processor140is provided in liquefied gas storage system32along with a valve142that operates under the control of the processor. Controller/processor140can be any suitable device, and includes any necessary storage capability for storing any algorithms implemented by the processor.

In an exemplary embodiment, an input/output device144is also provided to enable a user to communicate with the processor. For example, to cause controller140to open or close valve142. The present invention contemplates that input/output device144is used to communicate, information, data and/or instructions and any other communicatable items, collectively referred to as “data”, between a user and controller140. This can be done locally or remotely.

Examples of common input/output interfaces suitable for local communication with the controller include a keypad and display, touch screen, buttons, switches, etc. Other communication techniques, either hard-wired or wireless, are also contemplated by the present invention. For example, the present invention contemplates providing a smart card terminal that enables data to be loaded into controller140from the smart card or loaded onto the smart card from the controller. Other exemplary, interface devices and techniques adapted for use with the pressure support system include, but are not limited to, an RS-232 port, CD reader/writer, DVD reader/writer, RF link, and modem (telephone, cable or other). In short, any conventional technique for providing, receiving, or exchanging data with controller140are contemplated by the present invention as input/output device144.

In an exemplary embodiment, the users activates input/output device144to cause valve142to open so that the liquefied gas can flow to portable liquid storage/delivery device34. Of course, the processor can determine, based on sensors or the like, whether the system is properly configured to dispense the liquefied gas to the portable liquid storage/delivery device. For example, the system can detect the position of the turntable, the weight of portable liquid storage/delivery device34and/or its contents, the amount of fluid in storage vessel38(which can be monitored using any conventional technique, such as floats, level detection, etc.), the temperature of the system, or any other characteristic of the system that may be of importance when determining whether to dispense fluid to the portable liquid storage/delivery device.

In another embodiment of the present invention, the once the portable liquid storage/delivery device is placed in fluid communication with storage vessel38, i.e., by moving turntable44to the second or locked position, the portable liquid storage/delivery device is used to initiate the flow of gas. An example of a portable liquid storage/delivery device having this capability is disposed in U.S. provisional application No. 60/898,307, the contents of which are incorporated herein by reference. In this embodiment, portable liquid storage/delivery device34includes a manually actuated filling process. As shown schematically inFIG. 1, this process includes opening a vent valve150that couples storage vessel58to ambient atmosphere. Opening vent valve150is accomplished using a vent handle152that is manually is actuated by virtue of being exposed on the exterior of housing50. In the open position, a vent line154communicates storage vessel58to the ambient atmosphere, and a closed position that substantially prevents communication of storage vessel58to the ambient atmosphere.

When the turntable is moved to the second position, connectors52and56are engage such that the valves in each are opened enabling fluid to flow through these connectors. Of course, fluid will not flow from storage vessel38into storage vessel58unless the pressure in the storage vessel58is less than that of storage vessel38. In an exemplary embodiment of the present invention, the fluid storage system in liquefied gas storage system32, including storage vessel38, is maintained or can be selectively pressurized to a pressure greater than ambient atmospheric pressure. Details of how storage vessel38and/or other portions of the fluid storage system in liquefied gas storage system32are pressurized are discussed below.

To cause a pressure difference between storage vessel58and storage vessel38, a user moves vent handle152to the open position thereby opening vent valve150. This causes storage vessel to communicate with the ambient atmosphere, so that it assumes the atmospheric pressure. Because the atmospheric pressure is now lower than the pressure at which storage vessel38is maintained, fluid, such as LOX, will flow from storage vessel38into storage vessel58via pneumatic circuit54connectors52and56, and pneumatic circuit60. See arrows C inFIG. 1. When filling is complete or otherwise terminated, the user moves vent handle152to the closed position.

After the filling is complete or otherwise ended, turntable44is moved to the first “unlocked” position to disengage first and second connectors52and56from one another. Moving the turntable to the first position can be done manually or automatically, and can be done when the system determines that a sufficient supply of liquefied gas has been delivered to portable liquid storage/delivery device34. Once the turntable is in the first “unlocked” position, portable liquid storage/delivery device34can be lifted out of interface46and used to deliver a flow of gas, such as oxygen, to the user as known in the art.

Liquefied gas storage system32includes a pressure intensifier160disposed in housing36. The pressure intensifier is used to increase the pressure within storage vessel38so that fluid in the storage vessel can be transferred to portable liquid storage/delivery device34during the filling process. In an exemplary embodiment of the present invention, pressure intensifier160can be operated as needed, i.e., to increase the pressure in storage vessel38only when the filling process is initiated. In another embodiment, pressure intensifier160can be operated to maintain the pressure in storage vessel38as a certain threshold level. That is, the pressure in storage vessel38is monitored and used in a feedback fashion to actuate the pressure intensifier so that the pressure is at or above the threshold level.

In one embodiment of the present invention, pressure intensifier160includes a compressor operatively coupled to storage vessel38so as to increase the pressure within this container. Compressor is any suitable device that delivers a flow of pressurized gas to the storage vessel or to a pneumatic circuit, such as a circuit54, coupled to the storage vessel. In an exemplary embodiment, the pressured gas delivered by the compressor is the same or similar gas as that stored in the storage vessel. For example, a portion of the oxygen generated by the oxygen concentrators in liquefaction system40can be provided to the compressor, where it is delivered at an elevated pressure to the interior of storage vessel38.

In another embodiment, pressure intensifier160includes a heater adapted to increase a temperature of the liquefied gas contained in the storage vessel. The heater can be used alone, or in combination with the compressor discussed above. Heating the cryocooled, liquefied gas causes it to boil-off. Because the volume of storage vessel38and the pneumatic circuit coupled to it remain the same, the boiling off of the liquefied gas causes the pressure in the storage vessel to rise. Of course, the present invention contemplates providing pressure a relief valve associated with storage vessel38so that excess pressure is relieved.

It can be appreciated that the above-described system provides a rotational engagement mechanism that includes a pocket provided in a generally round, substantially horizontally mounted turntable. The pocket's shape is generally the same as the portion of the portable liquid storage/delivery device that fits into the pocket. That is, the pocket has a shape that is generally the same, but slightly bigger than the portion of the housing of the portable liquid storage/delivery device that is received in this pocket. The depth of the pocket and/or the height of the wall is sufficient to prevent the portable liquid storage/delivery device from easily being dislodged. A connector is provided in the pocket generally at the center of the turntable within a corner or side of the pocket. It should be noted that the shape of interface46, e.g., generally kidney-shaped or curved on one side and flat on the other, generally matching that of portable liquid storage/delivery device34, allows only the portable liquid storage/delivery device having this specific shape to be placed in or coupled to interface46so that other portable liquid storage/delivery device cannot be connected to interface46.

In addition, the shape of the pocket helps facilitate correctly placing the portable liquid storage/delivery device in the pocket of the interface. That is, the shape of the interface ensures that the portable liquid storage/delivery device can only be placed in the pocket one way. The pocket self-aligns the portable liquid storage/delivery device by both the shape and depth of the pocket. The sidewalls of opening/pocket48of interface46serve to straighten the portable liquid storage/delivery device as it is inserted into the pocket, which also aids in aligning connectors52and56. The shape of the pocket also provides a clear visual indication to the user how the orient to the portable liquid storage/delivery device so that it can be inserted into the interface.

As noted above, in one exemplary (but not limiting) embodiment, turntable44has a generally round and dome shaped. This shape provides a visual cut to the user of the process for coupling the portable liquid storage/delivery device to liquefied gas storage system32. Moreover, visual indicators, such as arrows, can be provided on or near the turntable to direct the user how to rotate the turntable to engage the portable liquid storage/delivery device to the liquefied gas storage system and when the turntable has been properly rotated so that the portable liquid storage/delivery device is properly coupled to the liquefied gas storage system. The dome shape of turntable44also discourages users from placing items on the top of the liquefied gas storage system, allows liquids to roll off the top of the liquefied gas storage system, and reduces the overall perception that the liquefied gas storage system.

The operation of liquefied gas storage system32can result in the generation of heat. For example, the compressor used to generate enriched oxygen gas and/or the components used to cryo-cool the gas stream can generate heat within housing36. The present invention contemplates venting the warm air from within housing36to ambient atmosphere. More specifically, the present invention contemplates providing a fan (not shown) that draws the warm air out of housing36. In one exemplary embodiment, the fan is provided proximate to base66and is oriented so as to pull cool air in to housing36through louvers162in the front and/or side panels and expel the warm air from the housing through a fan vent164provided in base66under turntable44. SeeFIGS. 3A and 3B. The warm air from housing36passed between base66and turntable44and exits the chamber defined between the base and the turntable at a perimeter of the turntable and around connector52.

In addition to cooling the components of liquefied gas storage system32, the warm air venting system as described above, provides a warm air flow across connector52and/or connector56. This warm air, keeps the connectors from frosting or icing up during and/or between fills. During a filling process, the extremely cold liquid oxygen passing through the couplings52and56and into portable liquid storage/delivery device34may cause the temperature of the connectors to drop below the dew point of the surrounding air. When this happens, frost forms on the coupling. In an extreme case, ice could form. The warm air that is being circulated by the fan under turntable44keeps frost from accumulating on or near the connectors, and, furthermore, provides eliminates the frost and dries the connector or connectors after the fill.

During the liquid oxygen generation process, a large percentage of the oxygen enriched gas is liquefied, although not all of it. In one embodiment of the present invention, the excess oxygen-enriched gas is allowed to exit storage vessel38, which is kept at a constant pressure, through an oxygen manifold and eventually through a phase separator166located in base66under turntable44. The warm air venting system, as describe above, allows the warm air being pushed out of housing36to mix with the oxygen enriched-gas existing separator166. This mixing of the air from housing36and the oxygen-enriched gas, dilutes the oxygen ratio of the gas providing an additional safety benefit.

The present invention contemplates that there may be reasons why liquefied gas storage system32interfaces, i.e., fills, a certain portable liquid storage/delivery device. For example, it is known when an oxygen concentrator is used to generate oxygen-enriched gas, the gas produced typically has a purity of 90-96% oxygen. The FDA requires portable liquid storage/delivery device having this purity range be labeled so as not be confused with portable liquid storage/delivery device that store liquid oxygen having a higher purity, e.g., 99% oxygen. Thus, it may be desirable to ensure that portable liquid storage/delivery devices labeled for purity ranges of 90-96% oxygen are allowed to be coupled to the liquid storage/delivery device, while portable liquid storage/delivery devices labeled for purity ranges of 99% oxygen and up are not permitted to be coupled and/or filled by liquefied gas storage system32.

This requirement is satisfied, at least in part, by providing the uniquely shaped interface46for liquefied gas storage system. That is, portable liquid storage/delivery devices labeled for purity ranges of 90-96% oxygen can be configured to fit into the pocket of interface46, while portable liquid storage/delivery devices labeled for purity ranges of 99% oxygen can have shapes that they will not allow them to fit into opening48of interface46.

In another embodiment of the present invention, a communication system is provided that allows liquefied gas storage system32to recognized and/or communicate with portable liquid storage/delivery device34. Using this system, liquefied gas storage system32can determine, for example, whether a portable liquid storage/delivery device is a device that is approved for or can otherwise be properly filled by the liquefied gas storage system. The controller can then determine whether to enable fluid to be transferred to the portable liquid storage/delivery device. For example, the data provided to the controller can include identification information indicating the type, size, brand-name, company name, or any other information about the portable liquid storage/delivery device. The controller can then whether that particular portable liquid storage/delivery device can be filled by the liquefied gas storage system. For example, the liquefied gas storage system may prevent filling of a portable liquid storage/delivery device that is not approved for receiving the liquefied gas.

In addition or in place of the identification information, the RFID information may include information about the size, condition, or usage, of the portable liquid storage/delivery device the liquefied gas storage system. The liquefied gas storage system can use this information to determine how much fluid to transfer to the portable liquid storage/delivery device. The liquefied gas storage system may also prevent the filling of a portable liquid storage/delivery device in which the condition information indicates, for example, that the portable device has suffered a malfunction. Of course, the portable liquid storage/delivery device would need to contain the necessary monitoring, processing, and storing capability for determining whether the unit has suffered a malfunction. The liquefied gas storage system may also prevent the filling of a portable liquid storage/delivery device in which the usage information indicates that the portable liquid storage/delivery device has been used for a period of time or a number of fills that exceeds a predetermined limit. Of course, the portable liquid storage/delivery device would need to contain the necessary monitoring, processing, and storing capability for determining the device usage and/or number of fills received. The present invention contemplates that any information, such as the condition or usage, can be output to the user by the liquefied gas storage system via user interface144.

In an exemplary embodiment of the present invention, liquefied gas storage system32includes a communication element170disposed in housing36and in communication with controller140. In addition, an information device172is provided in or otherwise associated with portable liquid storage/delivery device34. Communication element170is adapted to read information associated with the portable liquid storage/delivery device when the portable liquid storage/delivery device is placed near liquefied gas storage system32or disposed in interface46.

The present invention contemplates that communication element170and information device172are any suitable components of a data communication system that enables information about the portable liquid storage/delivery device to be transmitted to the liquefied gas storage system. In a further embodiment, the data communication system enables information to be transmitted by the liquefied gas storage system to the portable liquid storage/delivery device in place of or in addition to data being provided by the portable liquid storage/delivery device to the liquefied gas storage system. For example, valves provided in the portable liquid storage/delivery device can be operated under the control of controller140in liquefied gas storage system32.

The following are brief discussions of examples of suitable communication systems or technologies that are capable of providing the data transmission function of communication element170and identification device172. It is to be understood that the following list of suitable communication systems or techniques is not intended to be exhaustive or exclusive, but is provided to indicate the wide variety of communication systems or techniques that can be used in the system of the present invention. Indeed, the type of communication system used may depend on a variety of factors, such as the type and amount of data to be exchanged/transmitted, the durability of the components, the operating features of the components (such as whether battery power is to be used, or whether electromagnetic, magnetic, radio, infrared (IR) or other type of radiation is desired or permitted).a) Electro-Magnetic Devices. Wireless communication systems that communicate wirelessly using energy can be used for the communication system. Such systems typically include an antenna or other data transmission device and a receiver. The transmission of information takes place via electromagnetic, radio frequency (RF), d infrared (IR), or any other energy transmission technique. In this embodiment, for example, the data transmission device can be provided in the portable liquid storage/delivery device, with the corresponding data transceiver being provided in the liquefied gas storage system32. For example, an RFID element in the portable liquid storage/delivery device and an RFID reader in the liquefied gas storage system.b) Optical Based Systems. Communication systems that provide an optical communication between the portable liquid storage/delivery device and the liquefied gas storage system can be used. For example, a bar code or other type of optical pattern can be provided on the portable liquid storage/delivery device and a bar code reader or other optical pattern recognition device provided on the liquefied gas storage system.c) Acoustic and Ultrasonic Systems. The present invention contemplates using a system that provides an acoustic or ultrasonic data transmission as the communication system.d) Mechanical Interfaces. The communication of information between the portable liquid storage/delivery device and the liquefied gas storage system can take place via an interaction of mechanical components. Switches, detents, pins or other mechanical elements can be provided on either the portable liquid storage/delivery device, the liquefied gas storage system, or both. For example, depending on which switches on the liquefied gas storage system are actuated as a result of the portable liquid storage/delivery device being coupled to the liquefied gas storage system, the liquefied gas storage system can know what type of portable liquid storage/delivery device is coupled to it. Of course, the portable liquid storage/delivery device is configured so that it actuates the set of switches on the liquefied gas storage system that let the liquefied gas storage system know information about that portable liquid storage/delivery device.e) Electrical Connections/Interfaces. The present invention also contemplates providing electrical contacts on the portable liquid storage/delivery device, the liquefied gas storage system, or both. These contacts can be used to communicate information between the portable liquid storage/delivery device and the liquefied gas storage system, i.e., as hard-wired data terminal. They can also be used to enable the portable liquid storage/delivery device to be recognized by the liquefied gas storage system. For example, a certain portable liquid storage/delivery device may have a know pattern for the connection terminals. If this pattern is not recognized by the liquefied gas storage system, it will know that an improper portable liquid storage/delivery device has been coupled to it. The electrical terminals on the portable liquid storage/delivery device can also be used by the liquefied gas storage system, for example, to make a resistance or other electrical measurement. Based on the result of this measurement, the liquefied gas storage system can determine information about the portable liquid storage/delivery device coupled to it.f) Magnetic Couplings. The communication system between the portable liquid storage/delivery device and the liquefied gas storage system can also be done via magnets. For example, one or more magnets can be provided in the portable liquid storage/delivery device, the liquefied gas storage system, or both. Devices for detecting the magnets or for being actuated by the magnets, such as a reed switch, can be provided in the associated portable liquid storage/delivery device, the liquefied gas storage system, or both.

FIG. 12illustrates an second embodiment for a liquefied gas storage/delivery system190that embodies the basis principles of the present invention. This embodiment is provided to illustrate various alternative configurations for some of the components of the liquefied gas storage/delivery system

In the previous embodiments, turntable44is described as being rotated manually. It is to be understood that the present invention contemplates moving the turntable via a motor192. In an exemplary embodiment, motor192operates under the control of controller140. As noted above, the actuation of the motor can be done based on an input from the user and/or based on an input from a monitored parameter or sensor. For example, a switch may be provided in the interface of the turntable that is actuated when the portable liquid storage/delivery device is placed in the pocket of the turntable. Actuating the switch causes motor192to move the turntable to the locked position. Sensors, such as flow or weight sensors, can monitor the filling process, so that the motor is actuated to move the turntable to the unlocked position when the filling process is complete. Thus, little or no action is required by user during the filling process.

FIG. 12also illustrates an alternative of the present invention in which an adapter194is used to as a bridge between connector52on liquefied gas storage system adapted196and connector56on portable liquid storage/delivery device34. More specifically, adapter includes a first connector196adapted to be coupled to first connector52and a second connector198adapted to be coupled to second connector56. A pneumatic circuit200is provided between first and second connectors196and198. Pneumatic circuit200can be either a rigid piece or a flexible piece. In an exemplary embodiment, first connector196is shaped, sized, and configured to correspond to second connector56, and second connector198is shaped, sized, and configured to correspond to first connector52.

The present invention also contemplates that more than one adapter can be provided between connectors52and56. In addition the adapter or adapters can have a variety of sizes shapes and configurations. For example, pneumatic circuit200can be a relatively long hose so that the portable liquid storage/delivery device need not be brought into close proximity to the liquefied gas storage system. The adapter can also have more than one second connector198so that the adapter can be used to fill more than one portable liquid storage/delivery device simultaneously. In addition, the adapter can include one or more valves to control the flow of liquefied gas through the adapter.

The adapter can also include a mounting plate or other member having a shape that generally matches that of interface46. For example, the adapter can be a rigid piece that mounts onto a portable liquid storage/delivery device so that the fill port (e.g., connector56) of the portable device is coupled to a connector (e.g., connector198). The rigid piece can have a shape that allows it to fit into the pocket of interface46. For example, the shape of the rigid piece can substantially correspond to the shape, size, and/or configuration of opening48or it can be smaller. This enables the adapter, or a portion of the adapter, to be placed into the pocket of the interface, so that it can connect to connector52, effectively operating as the portable liquid storage/delivery device would if it were placed in the interface. The use of an adapter as a bridge between connectors52and56, i.e., between the liquefied gas storage system and the portable liquid storage/delivery device, allows a portable liquid storage/delivery device having a body shape that does not match that of interface46to nevertheless be filled by the liquefied gas storage system.

The present invention also contemplates that turntable44be removably attached to housing36. This enables one turntable to be swapped out or replaced by another even after the liquefied gas storage system has been provided to the user, i.e., while in the user's home. The present invention further contemplates that the interface of the second turntable can be different from that of the first turntable, e.g., have a different size, shape, depth, geometry, or configuration, so that a different portable liquid storage/delivery device suitable to interact with the interface of the second turntable, can be used with in the liquefied gas storage/delivery system. Of course, the second turntable should be configured such that connector52in liquefied gas storage system32is exposed for coupling to the portable liquid storage/delivery device.

By having the ability to attach different turntables, i.e., turntables with different interfaces46, to liquefied gas storage system32, the manufacture of the liquefied gas storage system can produce a liquefied gas storage system that can be used with a variety of different portable liquid storage/delivery devices depending on which turntable configuration is used with a given liquefied gas storage system. The selection of the appropriate turntable can be done after the rest of the liquefied gas storage system has been manufactured and assembled, and can take place in the manufacturing process or post manufacture as a feature change. This allows a manufacture to make a liquefied gas storage system that can be used with differently shaped portable liquid storage/delivery devices, depending on which turntable is assembled with the otherwise common components used in the liquefied gas storage system.

The interchangeable turntable feature of the present invention provides a great deal of flexibility on the field of liquid oxygen supply. For example, a medical device provider may keep a quantity of portable liquid storage/delivery devices having a first housing shape, a quantity of portable liquid storage/delivery devices having a second housing shape, a quantity of liquefied gas storage system of the present invention, a quantity of turntables having a first shaped interface, and a quantity of turntable having a second shaped interface. When the user is prescribed oxygen, the medical device provider may allow the user to select which portable liquid storage/delivery device he or she wants to use. Depending on this selection, the medical device provider will put the matching turntable on the liquefied gas storage system and provide that use with a liquefied gas storage system having a turntable suitable for use with the portable liquid storage/delivery device selected by the user.

Referring back toFIG. 1, the present invention contemplates providing the liquefied gas storage system with additional gas delivery and liquefied gas receiving capabilities. For example, the present invention contemplates that all or a portion of the gas produced by liquefaction system40can be provided to the user, as indicated by dashed line210. A terminal212can be provided on the liquefied gas storage system that can be coupled to an oxygen delivery device, such as a nasal mask or cannula, so that a flow of oxygen-enriched gas can be provided to the user. The present invention contemplates that this flow of oxygen-enriched gas can be provided simultaneously with a flow of oxygen-enriched gas being provided to the liquefying portions of liquefaction system40or it can be provided instead of providing oxygen-enriched gas to the liquefying portions of the liquefaction system. This feature of the present invention allows as user to breathe oxygen-enriched gas from the liquefied gas storage system of the present invention.

In addition to breathing gas from liquefaction system40, the present invention contemplates allowing a user to breathe oxygen-enriched gas from the gas and/or the liquefied gas that is contained in storage vessel38, as indicated by dashed line214. An evaporator216can be provided for converting the liquefied gas into a gas prior to deliver to the user. A terminal218is provided on liquefied gas storage system32that can be coupled to an oxygen delivery device. Although not shown, the present invention contemplated providing an oxygen conserving device, electronic or pneumatic, in the gas flow path from liquefied gas storage system32or from the oxygen generating portion of liquefaction system40. This conserving device can be set via user interface144and operated under the control of processor140to deliver doses or pulses of oxygen to the user, for example, based on the user's breathing cycle.

It should be noted that the present invention contemplates that portable liquid storage/delivery device34can have an oxygen conserving device220, electronic or pneumatic, as is know in the art. In addition, a connection terminal or barb222is provided on the portable liquid storage/delivery device so that an oxygen delivery interface, e.g., nasal mask or cannula, can be coupled to the portable liquid storage/delivery and a flow of gas can be provided to the patient.

The present invention further contemplates that the liquefied gas storage system need not produce its own liquefied gas. That is, liquefaction system40can be omitted entirely from the liquefied gas storage system. Instead, storage vessel38in liquefied gas storage system32,196can be filled from a supply of liquefied gas as is known in the art with respect to existing stationary LOX storage devices. To enable filling of the liquefied gas storage system from a liquid gas supply, the present invention contemplates providing a fill port230so that the supply of liquefied gas can be coupled to the liquefied gas storage system. A pneumatic circuit232is provided between the fill port230and storage vessel38.

Of course, the liquefied gas storage system can include both an internal liquefaction system and an external liquefied gas filling feature, as shown inFIG. 1. In addition, the present invention contemplates that a liquefaction system can be coupled to a liquefaction system, for example by connecting the output of a liquefaction system to the fill port230. Liquefied gas storage system32,196of the present invention can also include any other features typically found in existing stationary LOX storage devices.FIG. 13Aschematically illustrates an embodiment of a liquefied gas storage/delivery system30that is generally similar to that shown inFIG. 1. Liquefied gas storage/delivery system30includes a liquefied gas storage system32and a portable liquid storage/delivery device34.FIG. 13Ashows explicitly that the present invention contemplates that liquefaction system40in liquefied gas storage system32includes both a gas generating system246and a liquefying system248. Of course, as noted above, the present invention contemplates that the gas generating system can be omitted from within housing36. In which case, gas to be liquefied is provided to the liquefier from a separate gas source, such as a wall connector, oxygen concentrator, etc.

As shown inFIG. 13A, liquefied gas storage/delivery system30includes gas generating system246that generates gas, such as oxygen, and liquefying system248. Gas from generating system246is provided to liquefying system248via a gas line250. The present invention contemplates providing any convention component or components between generating system246and liquefying system248, such as pressure sensors, flow sensors, oxygen concentration sensor, desiccant dryers, pressure relief valves, shut off valves and the like in line250.

In an exemplary embodiment, gas generating system246is a PSA system, such as that found in a conventional oxygen concentrator, and includes a gas compressor and one or more sieve beds. The present invention contemplates minimizing the size, weight, noise and/or power consumption of liquefied gas storage/delivery system30, or at least the size, weight, noise, and/or power consumption of liquefied gas storage system242, so that the system can be easily transported by a person. To assist in the transportation of the system, wheels, handles, and other mechanisms can be provided on housing36.

In an exemplary embodiment, the gas compressor used in gas generating system246consumes less than 200 Watts, and the gas generating system produces 3 lpm of oxygen enriched gas. Of course, the present invention also contemplates other sizes (power consumption and oxygen output) for the compressor and gas generating system.

In a further exemplary embodiment liquefying system248uses a refrigerant compressor to cryocool the incoming gas flow for liquefaction. The present invention contemplates that the refrigerant compressor and the overall liquefying system be configured such that the liquefying system is capable of producing 1.5 kgs/day of liquid oxygen. This can be achieved using a refrigerant compressor that consumes less than 200 Watts, and, in particular 160-200 Watts. Thus the total power consumption of liquefied gas storage/delivery system is no greater than 400 Watts, while still producing 3 lpm of oxygen enriched gas and generating 1.5 kgs/day of liquid oxygen. The present invention further com

If desired, all of the oxygen enriched gas produced by generating system246can be provided to a user via an oxygen line252and an output port254. In which case, no oxygen enriched gas is provided to liquefying system248. The present invention contemplates that components typically found in oxygen generating systems, such as filters, pressure sensors, oxygen concentration sensors, flow sensors, humidifier, oxygen conservers, buffer tank(s), and the like can be used in conjunction with generating system246, oxygen line250, and output port252. These components are schematically illustrated as dashed box256inFIG. 13A.

The present invention also contemplates that a portion of the gas produced by gas generating system246can be provided to a user via an oxygen line252and a portion can be provided to liquefying system248via gas line250. Thus, the liquid storage/delivery device of the present invention can simultaneously (a) deliver oxygen to the user and (b) fill storage vessel38with liquid oxygen.

FIG. 13Billustrates a liquefied gas storage/delivery system30that is similar to that ofFIG. 13B, except that liquefaction system40includes a valve260at the gas output of gas generating system246. Valve260operates under the control of controller/processor140and controls the flow of oxygen enriched gas to the user via line252and to liquefying system248via gas line250. In an exemplary embodiment, valve260is operated like an oxygen conserver, delivering boluses of gas to the user during a portion of the patient's respiratory cycle. When not delivering gas to the user, the gas is delivered to the liquefying system248. Of course, the components necessary to sense the patient's breathing, such as flow sensors or pressure sensors would be needed.

FIG. 14schematically illustrates a liquefied gas storage/delivery system30that is generally similar to the previous embodiments. In this embodiment, liquefied gas storage system32includes a high pressure gas compressing system270that receives a flow of oxygen enriched gas from gas generating system246via gas line272. High pressure gas compressing system270increases the pressure of the gas from gas generating system246, which is typically 5-40 PSI to a pressure of 2200 or more PSI. The high pressure gas is suitable for filling a high pressure storage vessel (not shown) for subsequent consumption by the user. The present invention contemplates using any conventional high pressure gas compressing system270. U.S. Pat. Nos. 5,354,361; 5,858,062; 5,988,165; 6,393,802; 6,446,630; 6,889,726; 6,904,913; and 6,923,180, the contents of each or which are incorporated herein by reference, all teach examples of high pressure gas compressing systems or components thereof that are suitable for use in the present invention.

The high pressure gas from high pressure gas compressing system270is provided to a storage vessel, such as a cylinder, via high pressure gas line274and outlet port276. The present invention contemplates that outlet port276can be any conventional port that allows a high pressure gas storage vessel to receive the high pressure gas. Typically, this involve locking or otherwise attaching or clamping the high pressure storage vessel to output port276.

FIG. 15. also schematically illustrates a liquefied gas storage/delivery system30that is generally similar to the previous embodiments. In this embodiment, liquefied gas storage system32includes a liquid to high pressure gas transfill system280. Liquid to high pressure gas transfill system280converts a quantity of liquid oxygen into a high pressure gas for filling a portable storage vessel, such as a cylinder. An example of a liquid to high pressure gas transfill system suitable for use in the present invention is disclosed in U.S. provisional patent application No. 60/981,648, the contents of which are incorporated herein by reference.

In an exemplary embodiment, liquid to high pressure gas transfill system280includes a liquid oxygen evaporation device that includes an evaporation chamber. Liquid oxygen from storage vessel38is provided to the evaporation chamber. Once in the evaporation chamber, the liquid oxygen is permitted to boil or evaporate to create a quantity of gaseous oxygen. Boiling of the liquid oxygen can be accomplished or augmented by heating the liquid oxygen via a heater.

The quantity of gaseous oxygen is maintained in the vacant portion, or headspace, of the evaporation chamber. Significantly, the evaporation chamber is configured to maintain the gaseous oxygen at relatively high pressures. In an exemplary embodiment, the evaporation chamber is enabled to maintain gaseous oxygen at pressures ranging from 100 psig to 5,000 psig. For example, and without limitation, the evaporation chamber may consistently maintain gaseous oxygen around 2000 psig. In an alternative embodiment, the evaporation chamber is configured and arranged to maintain oxygen at pressures at or around 4000 psig.

An outlet port282is provided to provide the high pressure gas from liquid to high pressure gas transfill system280to a storage vessel. The present invention contemplates that outlet port282can be any conventional port that allows a high pressure gas storage vessel to receive the high pressure gas. Typically, this involve locking or otherwise attaching or clamping the high pressure storage vessel to output port282.

The present invention contemplates that the various features of the different embodiments discussed above can be combined. For example, the liquid to high pressure gas transfill system ofFIG. 15can be included in the embodiment ofFIGS. 1,12,13A,13B, and14. Also, the present invention contemplates providing power to the liquefied gas storage system using any conventional power source. For example, the power supply from the liquefied gas storage system can be external AC, external DC, such as a car charger or external batter, or an internal DC, such as one or more batteries contained in housing36, or any combination thereof.