Abstract:
A system for providing prophylaxis against thrombosis comprises in combination a vehicle and a plurality of inflatable compression sleeves. The vehicle has a pneumatic pressure source for supplying a predetermined flow of pneumatic fluid to a plurality of passenger positions. The pneumatic pressure source has a plurality of leads, which extend to a connection port located in each of the passenger positions. Each of the inflatable compression sleeves has a plurality of inflatable chambers therein. The sleeves are constructed to be engaged to a connection port, thereby providing fluid communication between the pneumatic pressure source and the plurality of chambers. The sleeves may be worn by a passenger to help prevent the occurrence of deep vein thrombosis. Individual sleeves comprise at least two inflatable chambers wherein a second inflatable chamber is subsequent to the inflation of a first inflatable chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority from U.S. provisional application No. 60/262,048, filed Jan. 16, 2001, the entire content of which is incorporated herein by reference. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH  
         [0002]    Not Applicable  
         BACKGROUND OF THE INVENTION  
         [0003]    1. Field of the Invention  
           [0004]    The present invention is directed to several embodiments. In at least one embodiment the invention is directed to an apparatus for improving the vascular blood flow in the extremities of individuals who are positioned in a confined manner, such as for example those traveling for long distances in an airplane or other vehicle. In at least one embodiment, the invention is directed to a system having at least one rhythmically inflatable cuff, sleeve, collar or other member that may be fitted around one or more limbs, particularly the leg or legs, of one or more individuals that is pneumatically activated encouraging blood flow and preventing deep vein thrombosis from occurring in the limb or limbs of any individual wearing the rhythmically inflatable member. In such an embodiment any and all rhythmically inflatable members may be in fluid communication with a centralized inflation source. Such a centralized inflation source may be provided to a vehicle, such as a car, bus, train, airplane, etc., to provide passengers therein with access the rhythmically inflatable members.  
           [0005]    2. Description of the Related Art  
           [0006]    It has long been suspected that a link exists between extended airplane flights and the formation of blood clots in a persons legs. This so-called “economy class syndrome” has been blamed for a number of blood clots and other maladies which affected people who were know to have recently traveled over a long distance in the cramped conditions of an airplane.  
           [0007]    As a result, recent studies have been conducted which have shown that there does appear to be a link between extended periods of immobility in confined quarters, such as a person might experience on a long journey in an airplane or other vehicle, and the occurrence of Deep Vein Thrombosis (DVT) or the formation of blood clots in the lower extremities of an individual.  
           [0008]    While several factors, such as advanced age, a persons weight, and other health characteristics may increase or decrease the likelihood of DVT occurring, extended periods of immobility, are a likely cause of DVT occurring in the legs. If a person does suffer from DVT, a potentially fatal blood clot could form which may be large enough that the clot does not naturally dissolve. Such a clot may break loose and travel from the person&#39;s leg to their heart or lungs resulting in serious illness or even death.  
           [0009]    While numerous treatment and preventative strategies exist, the most common way of avoiding the occurrence of DVT is to exercise the legs by flexing the leg muscles or simply getting up and briefly walking around perhaps once an hour or more if possible. The action of walking stimulates blood flow by causing contracting muscles to pump the blood onward through the legs. Unfortunately, under many circumstances a persons mobility may be limited to such an extent that walking around is not possible or is undesirable. For example, as airlines attempt to force more and more seats onto a plane, not only are the seats more cramped but the isles are reduced in size, thus reducing the ability of a passenger to move about. In addition to airline travel there may be a link between DVT and other conditions where people required or chose to sit for long periods of time such as when driving, working at a desk or assembly line, watching television in their home, etc.  
           [0010]    Because people are often restricted in their mobility or simply choose to not get up and walk around in an advisable manner, several devices have been developed to provide people with a means of stimulating blood flow through their limbs, notably the legs, and thus prevent DVT from occurring.  
           [0011]    One device is a compression stocking or sock available from BeiersdorfJobst, Inc. of Charlotte, N.C. Compression stockings are effective at preventing leg swelling by providing a custom fit stocking that provides supportive pressure distribution to the legs. Unfortunately, compression stockings do not provide a flexing or pumping action to the legs to actively stimulate blood flow as is desired.  
           [0012]    A more desirable approach is taken by several medical devices which provide a pumping action to the leg or legs by sequential pressurization of an inflatable collar or sleeve which may be fitted over an individual&#39;s limbs.  
           [0013]    U.S. Pat. No. 4,013,069 to Hasty, describes an elongate pressure sleeve having a plurality of separate inflatable chambers. The sleeve is enclosed about a patients&#39; limb and a pressure source provides a plurality of pressure pulses to the chambers in a timed sequence to provide a compression pressure gradient to the limb.  
           [0014]    A similar device is described in U.S. Pat. No. 4,029,087 to Dye et al., which describes an elongate sleeve having a plurality of inflatable chambers which may be gradually inflated from an inflation source to provide a greater pressure in each inflated lower chamber than the pressure in any upper inflated chamber.  
           [0015]    U.S. Pat. No. 6,007,559 to Arkans describes an apparatus having a plurality of inflatable chambers wherein at least two of the chambers are separated from each other to allow observation of the limb exposed therebetween.  
           [0016]    The entire content of each of the above cited patents being incorporated herein by reference in their entirety.  
           [0017]    Of the various chambered sleeve devices described above, none of the devices described appear to be suitable for use en mass by passengers on an airplane. The devices, their control systems and the equipment required to inflate the devices would be prohibitively bulky, heavy, and potentially dangerous in the controlled environment of an aircraft. An additional problem with current devices is the need to include an electronic power supply which could interfere with the radio frequency used by the aircraft of an aircraft resulting in potentially fatal consequences for those on board.  
           [0018]    Presently there does not exist an anti-thrombosis device which is suitable for use for individuals traveling on vehicles, such as airplanes. Such a device would need to be light weight, especially if the device were to be provided to each passenger on a commercial airliner; potentially several hundred devices. In order to further reduce the devices weight the device should be capable of being adapted for connection to a central pressure supply of the aircraft in order to avoid the use of an individual inflation apparatus for each device. The device must be easy to apply and be used, such that virtually anyone could utilize the device safely and effectively with little or no assistance and/or instruction.  
         BRIEF SUMMARY OF THE INVENTION  
         [0019]    As indicated above the present invention may be embodied in a variety of forms. In at least one embodiment, the invention provides for an anti-thrombosis device which addresses the need to provide individuals with a light weight low complexity anti-thrombosis device capable of being used on a vehicle, such as an airplane, in a safe and effective manner.  
           [0020]    Currently most commercial aircraft have an internal pneumatic air source. Each passenger position or seat may have one or more access ports and associated controls which allows the passenger to access the air source to provide an individual with a directed flow of warmed or cooled air as desired. In addition, some aircraft have employed a pneumatic system for providing each seat with audio output, which may be accessed by headphones.  
           [0021]    Some embodiments of the invention may be configured to employ the existing internal pneumatic air source of an aircraft, to inflate a collar, cuff, sleeve or other inflatable member, hereinafter collectively referred to as a sleeve, which may be worn over a limb, such as a leg, or portion thereof, of a passenger. Alternatively, one or more sleeves may be provided with a separate pneumatic source.  
           [0022]    In an airplane, the pneumatic air source supplies air to each seat of the airplane to supply an individual anti-thrombosis sleeve with sufficient pneumatic pressure to inflate the sleeve in a manner desired. The sleeve may employ one or more valves which allow pressure to be sequentially directed through the sleeve and then released. The pneumatic pressure may be controlled such that the sleeve is inflated and deflated in a continuous and repeating pattern or cycle, i.e. rhythmic inflation and deflation.  
           [0023]    In at least one embodiment of the invention, the invention is directed to a portable sleeve which is sized to be fitted around the limb or limbs of an individual. The sleeve has a plurality of inflatable chambers which may be sequentially inflated to provide an advancing pressure or “milking” action from one end of a limb to another. For example, the chambers may be rhythmically inflated to apply pressure that advances from a lower portion of the limb to the upper portion of the limb. In at least one embodiment of the invention the sleeve or sleeves are portable and have at least one connection member in fluid communication with the inflatable chambers and which is adapted to be connected to a pneumatic air source. The pneumatic air source may be a centralized source with sufficient pressure to inflate one to a plurality of sleeves. Alternatively, the pneumatic air source may be configured to supply pneumatic pressure to only one or only a few sleeves and which may be readily portable by the wearer of a sleeve or sleeves.  
           [0024]    In at least one embodiment of the invention, the portable sleeve is constructed of lightweight plastic.  
           [0025]    In at least one embodiment of the invention, the portable sleeve is disposable.  
           [0026]    In at least one embodiment of the invention, the sleeve is an adjustable cuff which may be adjusted to accommodate a variety of limb sizes.  
           [0027]    In at least one embodiment of the invention the sleeve employs a plurality of pressure control valves, wherein the pressure control valves are in fluid communication with adjacent chambers, whereby when a first chamber is inflated to a predetermined pressure, the pressure valve opens to transmit the pressure of the first chamber to a second adjacent chamber.  
           [0028]    In at least one embodiment of the invention the sleeve includes a plurality of pressure relief valves, the pressure relief valves providing the chambers of the sleeve with the capacity to accumulate and release pressure according to a predetermined cycle.  
           [0029]    In at least one embodiment of the invention, the sleeve has at least one control valve, the at least one control valve providing an individual with the ability to control the pressure of the sleeve as may be desired.  
           [0030]    In at least one embodiment of the invention, the pneumatic air source has a plurality of pressure supplying leads. Each of the pressure supplying leads providing a flow of pneumatic pressure sufficient to inflate a sleeve in a manner desired.  
           [0031]    In at least one embodiment of the invention, each of the pressure supplying leads having a shut-off valve.  
           [0032]    In at least one embodiment of the invention, the pneumatic air source having a central control device. The central control device being adapted to provide the plurality of pressure supplying leads with a predetermined flow of pressure, such that a sleeve associated with the pressure supplying lead is inflated and deflated according to the predetermined flow of pressure. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0033]    a detailed description of the invention is hereafter described with specific reference being made to the drawings.  
         [0034]    [0034]FIG. 1 is a side view of an embodiment of an inflatable sleeve which may be utilized in at least one embodiment of the inventive system.  
         [0035]    [0035]FIG. 2 is a side view of an embodiment of the invention wherein the inventive system is utilized on an airplane.  
         [0036]    [0036]FIG. 3 is a schematic depiction of an embodiment of a controller utilized in at least one embodiment of the inventive system.  
         [0037]    [0037]FIG. 4 is a frontal view of an embodiment of an inflatable sleeve which is a cuff that may be utilized in at least one embodiment of the inventive system.  
         [0038]    [0038]FIG. 5 is a close-up side view of an embodiment of an inflation member and plug utilized with the inflatable sleeve depicted in FIG. 4.  
         [0039]    [0039]FIG. 6 is a frontal view of an embodiment of an embodiment of the invention wherein inflatable sleeve is a cuff.  
         [0040]    [0040]FIG. 7 is a schematic view of a valve assembly configuration which may be utilized in an embodiment of the present invention.  
         [0041]    [0041]FIG. 8 is a schematic view of a valve assembly configuration which may be utilized in an embodiment of the present invention.  
         [0042]    [0042]FIG. 9 is a schematic view of a valve assembly configuration which may be utilized in an embodiment of the present invention.  
         [0043]    [0043]FIG. 10 is an environmental view showing an embodiment of the invention wherein the pneumatic source is portable. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0044]    As may be seen in FIG. 1, the present invention is directed to an anti-thrombosis collar or sleeve  10  which may be worn about the extremities or legs  12  of an individual  14  when the individual  14  is positioned in a confined manner such as when sitting in a seat  16  for an extended period of time.  
         [0045]    The sleeve  10  may have a wide range of configurations for directing blood flow through pneumatic action. The sleeve  10 , employs a plurality of chambers  18  which may be sequentially inflated starting at the ankle  20  and ending in the upper thigh  22  to provide a “milking” action which helps to stimulate venous blood flow upward through the leg(s)  12 . Once the chambers  18  are all pressurized, the air pressure may be released to deflate all of the chambers  18  to a predetermined ambient pressure. The chambers may then be once again reinflated from the ankle  20  to the thigh  22  to repeat the inflation cycle. If desired, the sleeve  10  may be inverted to provide rhythmic inflation in the opposite direction.  
         [0046]    In some embodiments of the invention, the sleeve  10  may be a component of a larger system designed to provide a vehicle with the ability to pressurize one or more sleeves, thereby allowing passengers the ability to enjoy the anti-thrombosis treatment provided by the sleeve  10  while seated in the vehicle. Such a system may be provided with a centralized pressure source to which one or more sleeves may be fluidly engaged. An example of such a system as utilized on an airplane is illustrated in FIG. 2. Such a system of a centralized pressure source and sleeves are not limited to applications involving vehicles. For example the central air system of a hospital could be adapted to supply the necessary pneumatic pressure to one or more sleeves  10 .  
         [0047]    In various embodiments, the sleeve  10  may be constructed from light weight plastic, rubber or other material that is easily collapsed. When utilized with a system on a vehicle, the entire sleeve  10  may be folded up and stored in the magazine compartment of a seat  16  or in some other easily accessible compartment for re-use. The sleeve  10  may be employed by anyone who remains seated or is restricted in movement. In the embodiments described below, the sleeve  10  is described as it may be employed on an airplane. However, it should be understood, that the sleeve  10  may be utilized on any type of vehicle in addition to airplanes, such as busses, trains and even automobiles, among others. Any type of vehicle could be supplied with the required pressure source described below to provide operative pressure to the sleeve  10 . It should be further understood that in some embodiments the sleeve  10  may be utilized on an individual basis with a portable pressure source  42  as is shown in FIG. 10. In the embodiment shown in FIG. 10, the air source  42  is shown as a belt worn device. Such an air source  42  could be an electrically powered, such as by battery, air compressor, or alternatively may be a simple container of compressed air and a air flow regulator. Other types of portable air sources that may be known may also be alternatively utilized.  
         [0048]    Whether the sleeve  10  is a portable unit or otherwise, the sleeve  10  may be constructed from plastic or any other type of flexible material capable of enclosing a fluid to a predetermined pressure. The sleeve  10  may be disposable or it may be more constructed of higher grade material to be made more rugged for repeated use.  
         [0049]    As may be seen in FIG. 2, in at least one embodiment of the invention an airplane  40  may be equipped with a pneumatic pressure source  42  which provides a predetermined flow of pneumatic fluid, such as air, to be distributed throughout the passenger cabin  44  via a system of pneumatic conduits or leads  46 .  
         [0050]    The air source  42  may be any type of pressure source which may be located on an airplane  40  or other vehicle such as a bus, train, boat or car. The pressure source  42  may be air redirected from the planes engine or may be compressed air supplied by an air compressor. If the air source requires electricity to operate, it must be configured to be run off of the electrical system of an aircraft and meet the appropriate regulations and guidelines set forth for aircraft components. The air source  42  may be an air compressor, a bellows system, or some other type of pneumatic pressure distributor.  
         [0051]    A system of leads  46  provides fluid communication between the air pressure source  42  and one or more individual passenger positions or seats  16 . The system of leads  46  may be comprised of different sized leads. In the embodiment shown in FIG. 2, leading directly from the pressure source  42  is one or more primary pressure busses  48 . Theses primary buses may be hollow tubes of a diameter sufficient to transport pneumatic fluid, preferably air, indicated by arrow  50 , throughout the lead system  46  of aircraft  40 . Leading off of the primary buses  48 , are a plurality of smaller pressure busses or leads  52 . These smaller pressure busses  52  run from the primary buses  48  to the individual passenger positions or seats  16 , where individual sleeves  10  (shown in FIG. 1) may be connected to the system  46 .  
         [0052]    Each of the smaller buses  52  end in a connection port  56  which may be positioned on or around the seat  16  to provide the passenger  14 , such as depicted in FIG. 1, to access the port  56  with a variety of devices such as the sleeve  10 . In the embodiment shown in FIG. 2, the lead system  46  is sized to support the total flow rate of all the downstream seat loads. The number of primary leads  48  as well as the number of smaller leads  52  may vary depend on the size of the aircraft  40 , the number of passengers seats  16 , and the possible pressure output of the pressure source  42 .  
         [0053]    In one embodiment of the invention, the pneumatic pressure source  42  may also be equipped with a centralized pressure controller  58  which may be configured to interrupt the air flow traveling from the pneumatic pressure source  42  to the lead system  46 . The controller  58  may be configured to interrupt the flow of air from the pressure source  42 , to the sleeves  10 , such as shown in FIG. 1, with a predetermined inflation and deflation cycle, thereby allowing a single controller  58  to provide a desired cycle of inflation and deflation to any and all sleeves  10  which are plugged into the ports  56 .  
         [0054]    The controller  58  may be embodied in a wide variety of forms. For example the controller  58  may an electric regulator which merely acts as a “circuit breaker” to intermittently cease the flow of pneumatic fluid  50  from the source  42 . However, in such a basic embodiment, the individual sleeves would include a pressure/release valve or other regulator device for releasing pressure from within each sleeve.  
         [0055]    In at least one embodiment of the invention the controller  58  may be a be a pneumatic oscillator, such as may be seen in FIG. 3 and indicated generally at  60 , which regulates the constant flow of fluid pressure  50  supplied by the pressure source  42  and produces a time varying output pressure which is used to cycle the pressure of the sleeve  10  automatically without intervention, except to adjust the rate of pressure cycling as desired.  
         [0056]    As is also shown in FIG. 3 the oscillator  60  has a housing  62  which contains a flexible bladder  64 , and a vent  65 . The bladder  64  is operatively engaged to a plunger  66  which is actuated by the flow of fluid  50  into the housing  62 . In the at rest state the first spring  68  exerts a sufficient biasing force to retain the plunger  66  against the seal  70  to close the vent  65 . In operation, the fluid  50  enters the housing  62  from the pressure source  42 . Because the vent  65  is held closed by the plunger  66 , the fluid  50  is transmitted into the lead system  46  and eventually to any sleeves  10  connected thereto. When the sleeves  10  have been inflated to a predetermined pressure an output pressure  82  will build within the bladder  64  and cause the bladder  64  to expand into the remaining portion of the housing  62 . As the pressure on the plunger side  72  of the bladder  64  increases, the output pressure  82  will rise to equal the bleed air input pressure  80  and remain there until the bladder  64  begins to expand.  
         [0057]    As the bladder  64  expands a second spring  74  is provided with sufficient force to overcome the biasing force of the first spring  68 . In addition, bladder expansion is restrained by the constant flow valve  76 . The constant flow valve  76  may be a small hole or an opening in the housing  62  to allow for venting. Alternatively, the flow valve  76  could take the form of an adjustable needle valve to allow adjustment of the period of the oscillation, if desired.  
         [0058]    Eventually, the bladder  64  expands far enough so that the second spring  74  exerts enough force to overcome the force of the first spring  68  plus some additional force necessary to overcome the bleed air pressure  80  against the plunger  66 . As the seal breaks and the fluid is no longer directed into the lead system  46 , but is also free to exit the housing through the vent  65 . As a result the output pressure  82  drops to the ambient value, and the sleeves  10  are able to deflate. At this point, the plunger side  72  of the bladder is now at ambient pressure so the first spring  68  pulls the plunger  66  back toward the seal  70  at a rate limited by the constant flow valve  76 . This flow rate limitation may vary the time required before the plunger  66  will again close and the cycle can repeat. Eventually the plunger  66  moves back to the seal  70  and seals the vent  65  and then the inflation process is repeated.  
         [0059]    Returning to the embodiment of the invention shown in FIG. 1, each chamber  18  of the sleeve  10  are to be inflated and pressurized in a specific sequence so as to inflate the chamber  18  disposed about a passenger&#39;s ankle  20  and then inflate the remaining individual chambers  18   a - f  progressively moving up the leg  12  until all of the chambers  18   a - f  are inflated.  
         [0060]    In FIG. 4, an embodiment of the sleeve  10  may be seen in the open or unworn configuration. The sleeve  10  has a body portion  30  which contains six chambers  18   a - f . It should be noted that, a sleeve  10  may be configured to have any number of a plurality of chambers  18 . Each of the chambers  18  is in fluid communication with a separate inflation tube  32 . Each inflation tube  32  supplies the associated chamber  18  with air to provide the associated chamber  18  with a predetermined pressure. All the chambers  18  may be inflated to a predetermined uniform dynamic pressure of about 20 mmHg to about 80 mmHG.  
         [0061]    As may be seen in FIGS. 4 and 5 the inflation tubes  32  may be organized into a parallel type port or plug  34 , wherein the plug  34  has a number of connection leads  36  which corresponds to the numbers of inflation tubes  32 . The plug  34  may be inserted into a air outlet port  56  such as previously described. The plug  34  may be integral with the sleeve  10  or may be a inflation member  38  which is connectable to the sleeve  10  and the port  56 . Where an oscillator, such as previously described, is used to regulate the inflation of the chambers starting with the lowest chamber  18   a  and moving up the sequence until the upper most chamber  18   f  is pressurized last, an individual oscillator  60  would be required for control of each chamber  18   a - f . However, it should be noted that even where several sleeves are utilized in the same system a single oscillator would control a given chamber of all of the sleeves. The oscillators would be timed such that inflation of the chambers  18   a - f  may occur in the sequence desired.  
         [0062]    In an alternative embodiment shown in FIG. 6, the inflation member  38  may include a plug  34  which has only a single connection lead  36 . In this embodiment the sleeve  10  may have chambers  18  which are inter-connected by a series of valves  15 , rather than each chamber  18  being separately inflatable, such as is depicted in FIG. 4. In the present embodiment, inflation fluid, such as pressurized air, passes from the port via plug  34  into the inflation member  38 , and into to the first chamber  18   a  of the sleeve  10 . When the first chamber  18   a  is inflated to a predetermined pressure, the pressure valve  15  allows fluid to flow from the first chamber  18   a  to the second chamber  18   b . The individual pressure valve assemblies  15  are constructed such that during the inflation of chambers  18 , previously inflated chambers maintain the desired pressure therein. In the same manner as chambers  18   a  and  18   b , the remaining chambers  18   c - f  may be sequentially inflated. In the embodiment shown in FIG. 6 a single oscillator or controller may be used to inflate all of the chambers of all of the sleeves connected to the system. The valves  15  may be configured to control deflation of the chambers  18  as well.  
         [0063]    In another embodiment of the invention shown in FIG. 7, the chambers may be connected by a series of pressure valves  100  and check valves  102 . Each pressure valve  100  comprises a spring  104  and ball  106 . The spring  104  provides a predetermined biasing force on the ball  106  such that the ball seals the valve  100  until a predetermined pressure is reached which overcomes the biasing force of the spring  104  thereby releasing the seal previously provided by the biased ball  106 . In practice, as air enters the first chamber  18   a  via inflation member  38 , the chamber  18   a  will reach a predetermined pressure value. Once chamber  18   a  reaches the predetermined pressure value the pressure valve  100  between chamber  18   a  and  18   b  will be subjected to a sufficient air pressure to overcome the biasing force of spring  104  thereby breaking the seal of ball  106  and allowing air to begin flowing into chamber  18   b . As long as air continues to flow into the sleeve  10  via member  38 , air will cascadingly flow into the remaining chambers  18   c - f . As valves  100  systematically fail to allow air to flow into adjacent chambers  18   a - f , the check valves  102  keep the air pressure of previously filled chambers substantially equal during inflation.  
         [0064]    Once all of the chambers  18   a - f  are filled to the desired predetermined air pressure, air flow via member  38  is stopped. Preferably, air flow is in fact reversed by applying a vacuum, via member  38  to the sleeve  10 . Through application of a vacuum force or negative air flow, the valves  100  and/or  102  will be in an unsealed state thereby allowing all of the chambers  18   a - f  to be deflated. Once the chambers  18   a - f  are deflated to a predetermined extent, fully or otherwise, the air flow may then again be reversed to allow air pressure to being systematically filling the chambers  18   a - f  again.  
         [0065]    In an alternative embodiment of the invention shown in FIG. 8, the sleeve  10  includes a single piece check valve  110  in fluid communication with each chamber  18   a - f . In the embodiment shown, when air is flowing into the sleeve  10  through member  38 , air is allowed to freely flow into the first chamber  18   a . However, the check valve  110  prevents the air from back flowing into member  38 . Instead, once chamber  18   a  reaches a predetermined pressure, air is directed to the next chamber  18   b , through flow tube  112 . Subsequent chambers  18   c - f  are subsequently filled one at a time in the same manner via flow tube  112 . When all the chambers  18   a - f  are filled to a predetermined pressure, the check valve  110  will allow air flow from the chambers  18   a - f  into member  38 . Preferably, when all the chambers  18   a - f  are filled, a vacuum is applied via member  38  which causes check valve  110  to release the pressure contained in the individual chambers  18   a - f.    
         [0066]    In yet another embodiment shown in FIG. 9, the sleeve  10  has a valve and chamber configuration which includes both a single check valve  110  and a series of pressure valves  100  such as have been previously described. In the embodiment shown in FIG. 9, the chambers  18   a - f  are inflated one after the other as air pressure in preceding chambers is sufficient to overcome the biasing force of springs  104  thereby releasing the seal provided by balls  106 . When all the chambers  18   a - f  are filled to a predetermined pressure, or a vacuum is applied to the sleeve  10  via member  38 , the check valve  100  simultaneously releases the pressure contained in the chambers  18   a - f  in order to return the chambers  18   a - f  to the uninflated state.  
         [0067]    As may be seen in FIGS. 4 and 6, the sleeve  10  may include a plurality of adjustment straps  17 . The adjustment straps may be connected to one another when the sleeve  10  is disposed about the leg(s)  12  of a passenger  14 , such as shown in FIG. 1. The straps may have any type of fasteners such as buckles, hook and loop material such as VELCRO, buttons, clips, etc. The straps  17  are adjustable so that the sleeve  10  may be placed around a wide range of leg sizes.  
         [0068]    In the embodiment shown in FIG. 1, and in all embodiments disclosed herein, the sleeve  10  must be connected to the pressure outlet port  56 . The sleeve  10  and/or inflation member  38  may include a variety of plug  34  types which may be removably engaged to the port  56 . In an alternative embodiment of the invention, the sleeve  10  may be in operatively engaged to the seat belt of the seat  16 . Such that when the passenger  14  places the sleeve  10  about his or her leg(s), the act of fastening the seat belt connects the plug  34  to the port  56 , thereby activating the inflatable sleeve  10 . If desired, the sleeve  10  may be integral with the seat  16 , thus forcing the passenger to utilize the sleeve  10  when the seat belt is fastened.  
         [0069]    In addition to being directed to the specific combinations of features claimed below, the invention is also directed to embodiments having other combinations of the dependent features claimed below and other combinations of the features described above.  
         [0070]    The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.  
         [0071]    Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.