Abstract:
An aerosol medication delivery apparatus includes a fixed volume holding chamber which is constructed to allow for a uniformly mixed, concentrated bolus of medicated aerosol to be delivered with each breath. The device further includes a universal inlet, so that any standard small volume nebulizer, as well as any standard metered dose inhaler (MDI), may be utilized therewith. Also filtration can be added to address contaminated patient air and aerosol. A one-way valve is positioned in the patient mouthpiece, to help control the loss of aerosol, and thereby reduce waste.

Description:
[0001]    This application is a continuation-in-part of application Ser. No. 09/610,801, also entitled Aerosol Enhancement Device, filed on Jul. 6, 2000, which is commonly assigned and herein expressly incorporated by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates generally to an improved aerosol inhalation device, and more particularly to an aerosol enhancement device which is usable in combination with both a nebulizer and a metered dose inhaler.  
           [0003]    Aerosol inhalation devices, for the purpose of delivering medication, entrained in an aerosol spray, to a patient using inhalation therapy, as an alternative to oral medications such as capsules or pills, or to injected medications, are well known in the art. For example, U.S. Pat. No. 4,210,155 to Grimes is representative of the prior art. In the Grimes patent there is disclosed a fixed volume mist accumulation chamber for use in combination with a nebulizer and a tee connection of an inhalation conduit for accumulating medicated mist and facilitating its delivery to a patient.  
           [0004]    However, the Grimes device, as is typical for prior art devices, is plagued with problems typical of such devices. These problems include, for example, nonuniform concentrations of medication, resulting in difficulties in regulating patient dosage, and significant waste of medication. Additionally, the Grimes device is relatively complex, so that it is expensive to manufacture and difficult to use.  
           [0005]    Many other such devices are available which do not include a mixing chamber. In other words, the nebulizer is attached directly to the aforementioned tee connection. Of course, such devices are even less suited to satisfactory regulation of the medication being delivered to the patient than the Grimes device, because there is substantially no ability to uniformly mix the medication with entrained fluid, such as air, before delivery to the mouthpiece on which the patient is inhaling.  
           [0006]    In addition to nebulizers, metered dose inhalers (MDI) are also available for delivering a medicated aerosol to a patient. These MDI devices differ from nebulizers primarily in that a propellant is used to deliver the medication.  
           [0007]    It would be advantageous to have an aerosol medication delivery device which included a mixing chamber between the medication delivery apparatus and the mouthpiece, wherein the medication could be uniformly mixed with entrained air in an improved manner over that achieved by the Grimes patent apparatus. It would also be beneficial for such a device to be simple to manufacture and assemble, and easy to use. Finally, if such a device could be made universally adaptable for use with any known nebulizer on the market, as well as with MDI&#39;s, this would be a great advance in the art.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention provides an aerosol medication delivery apparatus which incorporates the aforementioned advantages. The inventive device includes a fixed volume holding chamber which is constructed to allow for a uniformly mixed, concentrated bolus of medicated aerosol to be delivered with each breath. The device further includes a universal inlet, so that any standard small volume nebulizer, as well as any standard MDI, may be utilized therewith. Also filtration can be added to address contaminated patient air and aerosol. A one-way valve is positioned in the patient mouthpiece, to help control the loss of aerosol, and thereby reduce waste.  
           [0009]    More particularly, an aerosol enhancement device is provided which comprises a mouthpiece and a spacer member fluidly attached to the mouthpiece. The spacer member has interior walls which define an interior volume, which comprises a mixing chamber. An inlet port is disposed in the spacer member for receiving a medicated aerosol from an exterior source into the mixing chamber. An air inlet port is disposed in the spacer member, as well, for receiving air into the air passage. Advantageously, the mixing chamber is generally octagonal in configuration, which the inventors have found assists in collecting and refusing excess medication.  
           [0010]    In another aspect of the invention, an aerosol enhancement device is provided which comprises a mouthpiece and a spacer member fluidly attached to the mouthpiece. The spacer member is fluidly attached to the mouthpiece via a mouthpiece port, and has an outer body which defines an interior volume. An inlet port is disposed in the spacer member for receiving a medicated aerosol from an exterior source into the interior volume. Advantageously, an adapter is associated with the medicated aerosol inlet port. The inventive adapter comprises a universal fitting which is capable of attaching the spacer member to either a nebulizer or a metered dose inhaler (MDI).  
           [0011]    Preferably, the inventive adapter is reversible, being disposable in a first orientation for attachment of the spacer member to a nebulizer, and being disposable in a second orientation for attachment of the spacer member to an MDI. In its preferred configuration, the universal adapter comprises a first rigid connector end and a second flexible connector end, the first rigid connector end being adapted for attachment to a nebulizer and the second flexible connector end being adapted for attachment to an MDI. The adapter preferably further comprises a flange portion for engaging the adapter with the spacer member.  
           [0012]    In still another aspect of the invention, an aerosol enhancement device is provided which comprises a mouthpiece having a first port for fluid communication with a patient&#39;s mouth, a second port which is open to atmosphere, and a third port, wherein an airway fluidly communicates with each of the first, second, and third ports. A medication dispenser is attached to the third port and a one-way flap valve is disposed in the second port. The one-way flap valve advantageously includes a valve seat for receiving the flap valve and for preventing the flap valve from entering the airway.  
           [0013]    In yet another aspect of the invention, a spacer member is provided which is usable with a mouthpiece, for dispensing medicated aerosol to a patient. The inventive spacer member comprises an outer body which defines an interior volume or mixing chamber. An inlet port is disposed in the spacer member for receiving a medicated aerosol from an exterior source into the mixing chamber. An air inlet port is also disposed in the spacer member for receiving air into the mixing chamber. An outlet port is provided for dispensing a mixture of the medicated aerosol and inlet air from the mixing chamber into the mouthpiece. Advantageously, a one-way valve is disposed in the air inlet port, for ensuring that there is no loss of medicated aerosol from the mixing chamber.  
           [0014]    The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying illustrative drawing. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view of an aerosol enhancement device constructed in accordance with the principles of the present invention;  
         [0016]    [0016]FIG. 2 is a cross-sectional view, taken from the top, of the device shown in FIG. 1;  
         [0017]    [0017]FIG. 3 is a cross-sectional view, taken from the bottom, of the device shown in FIG. 1;  
         [0018]    [0018]FIG. 4 is a cross-sectional view taken along lines A-A of FIGS. 2 and 3;  
         [0019]    [0019]FIG. 5 is a cross-sectional view taken along lines A-A of FIGS. 2 and 3, showing the embodiment of FIG. 1 when it is set-up to function in conjunction with a metered dose inhaler (MDI);  
         [0020]    [0020]FIG. 6 is a cross-sectional view taken along lines A-A of FIGS. 2 and 3, showing the embodiment of FIG. 1 when it is set-up to function in conjunction with a nebulizer;  
         [0021]    [0021]FIG. 7 is a perspective view of a presently preferred embodiment of the mouthpiece portion of the aerosol enhancement device illustrated in FIGS.  1 - 6 ;  
         [0022]    [0022]FIG. 8 is a perspective cut-away view of the mouthpiece portion shown in FIG. 7;  
         [0023]    [0023]FIG. 9 is an enlarged perspective view of the filter and valve portions of the mouthpiece portion shown in FIGS. 7 and 8;  
         [0024]    [0024]FIG. 10 is a view similar to FIG. 8, illustrating the airflow pattern through the mouthpiece portion during exhalation by a patient using the device;  
         [0025]    [0025]FIG. 11 is a view similar to FIGS. 8 and 10 illustrating the airflow pattern through the mouthpiece portion during inhalation by a patient using the device;  
         [0026]    [0026]FIG. 12 is a schematic view of an alternative embodiment of the aerosol enhancement device of the present invention, wherein the aerosol enhancement device is configured for use with a nebulizer;  
         [0027]    [0027]FIG. 13 is a schematic view of the embodiment of FIG. 12, wherein the aerosol enhancement device is configured for use with an MDI;  
         [0028]    [0028]FIG. 14 is a schematic view illustrating, in somewhat greater detail, the structural features of the embodiment shown in FIGS. 12 and 13;  
         [0029]    [0029]FIG. 15 is an exploded schematic view of the embodiment shown in FIG. 14; and  
         [0030]    [0030]FIG. 16 is a cross-sectional view of an embodiment of the invention, wherein the aerosol enhancement device is disposed in-line in an assisted breathing ventilator system. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]    Referring now more particularly to FIGS.  1 - 6 , there is shown a first embodiment of the inventive aerosol enhancement device  10 . The device  10  comprises a mouthpiece  12  which is fluidly attached to a mouthpiece port  14  on a tower or spacer body  16 . The spacer body  16  comprises an interior volume or mixing chamber  18  and two additional inlet ports  20  and  22 , which communicate with the mixing chamber  18 . In the illustrated embodiment, the ports  14  and  22  are disposed on opposing ends of the spacer body  16 , with the port  20  disposed between the ports  14  and  22 , on the bottom of the body  16  and at a transverse orientation with respect to the ports  14  and  22 .  
         [0032]    As shown particularly in FIGS. 5 and 6, the aerosol enhancement device  10  may be configured for use with a metered dose inhaler (MDI), as shown in FIG. 5, or a nebulizer, as shown in FIG. 6. Traditionally, an MDI is positioned “in-line” with the patient&#39;s mouth, so that the delivered medication flows directly through the chamber  18  in a straight line to the mouthpiece  12 , and the air entering through the inlet port  20  becomes entrained in the flow of medication. Thus, in FIG. 5, the MDI (not shown) is connected to the inlet port  22 , preferably using a flexible, universal boot  24 . Additionally, though not required for an MDI, in the illustrated embodiment a stem valve (check valve)  26  is disposed in the other inlet port  20 .  
         [0033]    In FIG. 6, on the other hand, when a nebulizer (not shown) is utilized in conjunction with the aerosol enhancement device  10 , it is preferably connected to the bottom inlet port  20 , and the stem valve  26  is re-positioned in the other inlet port  22 . The flexible universal boot  24  may be used to assist in connecting the nebulizer to the inlet port  20 , as well, as is discussed more particularly in conjunction with the embodiments shown in FIGS.  12 - 15 , and is particularly useful for accommodating odd-sized nebulizer stems. Typical nebulizer applications are adapted so that the medication becomes entrained in the airflow, as opposed to MDI applications wherein the air preferably is arranged to become entrained in the flow of medication, although there is no requirement that the arrangements be such.  
         [0034]    It should be noted that, although the device  10  has been configured as shown in FIGS. 5 and 6, respectively, for the MDI and nebulizer applications, the illustrated configurations, although preferred, are not required. Each of the ports  14 ,  20 , and  22  are preferably constructed to be substantially identical and interchangeable, so that they may each, as desired, accommodate any one of the mouthpiece, valve, and MDI or nebulizer, in any combination.  
         [0035]    As shown in FIG. 4, for example, wherein the device  10 , having a slightly modified construction as compared with the construction shown in FIG. 6, is configured for attachment to a nebulizer (not shown). The lower inlet port  20  supplies a medicated aerosol, as shown by arrows  28 , into the mixing chamber  18 , which functions as a mixing zone for mixing the incoming medication with incoming air from the inlet port  22 , represented by arrows  30 .  
         [0036]    The purpose for the holding or mixing chamber  18  is to thoroughly mix the incoming medication and air together, which occurs as the two components flow together, in turbulent fashion, through the mixing chamber  18 , becoming mixed together and exiting the chamber through port  14 , as shown by arrows  32 . Once thoroughly mixed, the medicated mixture flows into the mouthpiece  12  for inhalation by a patient. The mouthpiece  12  includes an exhaust port  34  in a sidewall thereof, as shown in the drawings, which preferably includes an optional filter  36 , and a one-way valve  38 , which may also be a stem valve of the same type as valve  26 . The filter  36 , though optional, has been found to be useful in dealing with circumstances involving contaminated or infectious patient air and aerosol, to minimize the spread of infection. During inhalation, the one-way valve remains tightly closed, so that the medicated mixture flows through the mouthpiece  12  and out of the proximal mouth port  40  into the patient&#39;s mouth. Then, during exhalation, as shown by arrows  42 , the airflow from the patient&#39;s mouth, back through the mouthpiece  12 , exits the mouthpiece through the now-opened one-way valve  38 .  
         [0037]    A significant advantage the inventors have discovered is gained by use of a valved exhaust port  34 , as opposed to an unvalved, open port, is that the valve helps to retain substantially greater quantities of medication in the device by confining medicated aerosol within the mixing chamber  18  and mouthpiece  12  during the critical inhalation phase.  
         [0038]    Advantageously, the mixing chamber  18  in the preferred embodiments is constructed to be defined by interior walls which are arranged to result in a generally octagonal-shaped chamber when viewed in any plane. In other words, the interior wall defining the chamber  18  comprises a plurality of interior generally planar wall segments  42   a ,  42   b ,  42   c ,  42   d ,  42   e , and  42   f , for example, which together with the two segments comprising the ports  14  and  22 , form the eight generally planar surfaces of the octagon when viewed in cross-section from either the top or the bottom side of the device, as shown in FIGS. 3 and 4, respectively. However, the number of wall segments defining the chamber is not particularly important. Any polygonal shape will suffice, because the key is to have a plurality of corners, or transition zones  44   a ,  44   b ,  44   c ,  44   d ,  44   e ,  44   f ,  44   g , and  44   h , for example, again as shown in FIGS. 2 and 3, between wall segments and/or ports. In this regard, having eight planar surfaces, as opposed to four, or six, produces substantially better results, as will be described below, with respect to the preservation of medication, because there will be more corners than in a fewer-sided polygon, and thus, greater reduction in wall surface area for a particular volume.  
         [0039]    Of course, as is known, the mixing chamber  18  has a function of collecting aerosol distributed from either the nebulizer or MDI, and permitting it to become denser, for supplying an effective amount of medication to the patient. However, sometimes this results in an aerosol mixture which is overly dense, resulting in the wasting of valuable medication, either by over medicating the patient (which may be dangerous as well as wasteful) or by causing the excess medication to merely drain out of the mouthpiece through the exhaust port  34 , into the surrounding environment. Advantageously, Applicants have found that the aforementioned corners or angled surfaces, in combination with the plurality of interior wall segments of the polygonal chamber, minimize this waste of medication, by functioning to reduce the interior wall surface area required to define a desired interior volume, and to thereby promote the “raining out” or draining of excess medication within the aerosol mixture to the bottom of the chamber, where it can be collected and reused, before it flows into the mouthpiece.  
         [0040]    FIGS.  7 - 11  illustrate a presently preferred embodiment of the mouthpiece  12  of the inventive aerosol enhancement device  10 . In this embodiment, the exhaust port  34  comprises the filter  36 , the one-way valve  38 , which is in this case a flap valve, and a grid structure  46 , which functions as a valve seat when the flap valve is in a closed position, for preventing the valve from descending into the mouthpiece airway  48 . A pin or pins  50  are provided to secure one end of the flap valve  38  to the grid structure, in a pivotable manner. The flap valve  38  is preferably made of a pliable medical grade plastic, while the grid structure  46 , the remainder of the mouthpiece  12 , and the tower or spacer body  16  are all preferably made of a rigid molded plastic, such as ABS, and may be injection molded, if desired.  
         [0041]    [0041]FIG. 11 illustrates the flow of aerosol through the mouthpiece airway  48  during inhalation, which as shown by the arrows  52  is along an axial path therethrough, from the distal end  54 , which engages the mouthpiece port  14 , to the proximal mouth port  40 . The flap valve is closed, as shown, during this cycle. During the exhalation cycle, illustrated in FIG. 10, the exhaled air is directed, as shown by arrows  56 , through the exhaust port  34 , filter  36 , and now-opened flap valve  38 .  
         [0042]    FIGS.  12 - 15  illustrate another embodiment of the claimed invention, which is disclosed to emphasize that various arrangements of the components of the inventive device are contemplated within the scope of the invention, and also to illustrate in additional detail the inventive flexible universal boot, or fitting, of the present invention. In this embodiment, like elements are designated by like reference numerals, preceded by the numeral  1 . Illustrated is an aerosol enhancement device  110  is similar to that of the device  10  in FIGS.  1 - 11 . However, a generally rectangular tower or spacer body  116  is disclosed, rather than the generally octagonal spacer body  16  of FIGS.  1 - 11 . Applicants believe this to be a less desirable tower body configuration, but it is still potentially viable within the context of the entire inventive concept of Applicants. As in the prior embodiment, this embodiment is useful for a variety of applications, including usage with a nebulizer  158  or MDI  160 . Of particular note in FIGS.  12 - 15  is a more particular illustration of one preferred form of the universal boot or fitting  124  for securing either the nebulizer or MDI, for example, to the spacer body  116 . The adaptive fitting  124  includes an engagement flange  162 , a rigid connector end  164 , and a flexible connector end  166 . The flexible connector end  166  is preferably in the nature of a boot, fabricated of a soft pliable material, such as Neoprene, while the engagement flange  162  and rigid connector end  164  are preferably fabricated of a medical grade rigid plastic, such as ABS, which, as discussed above, may be the same material that is used to fabricate the remainder of the device.  
         [0043]    The purpose of the adaptive fitting  124  is to permit the tower body  116  to be able to accommodate attachment of the device to both the nebulizer  158  and the MDI  160 , as discussed above. As is shown in FIGS. 12 and 13, the smaller, rigid connector end  164  may be used to attach the device  110  to a nebulizer  158 . On the other hand, an MDI typically has a non-round mouthpiece  168 , and therefore the inventors have found that a pliable boot connector such as connector  166  is required for a successful fit, by providing a flared access for the MDI boot, as shown in FIG. 13.  
         [0044]    [0044]FIG. 16 illustrates yet another embodiment of the invention, wherein any of the prior embodiments of the device  10 , such as the embodiment shown in FIG. 4, may be installed for use with a ventilator  170 , of a type well known for the purpose of providing breathing assistance for patients unable to adequately breathe on their own. Such an installation merely involves attaching the air inlet port  22  (or  20 , depending upon the selection of the practitioner) to the ventilator  170 , using an air line  172 . The inventive aerosol enhancement device  10 ,  110  otherwise operates in the same manner as above described.  
         [0045]    Presently preferred design options include holding chamber volumes ranging from 90 cc to 140 cc, and chamber lengths ranging from 2.95 inches to 1.56 inches, depending upon the chamber volume and the internal diameter of the chamber. The total stacked height of the inventive apparatus, including an attached nebulizer, may range from 6.7 to 8.3 inches in the presently preferred embodiments, depending upon chamber volume and internal diameter.  
         [0046]    In operation, in any of the illustrated embodiments, the apparatus  10 ,  110  is particularly adapted for dual use applications, as noted supra. In particular, the device  10 ,  110  may be utilized in conjunction with a nebulizer, wherein the tower  16 ,  116 , and in particular, the mixing chamber  18 ,  118  functions to recirculate medication introduced by the nebulizer, in order to provide a denser application of medication to the patient. The provided fittings are universally suitable for attachment to any known nebulizer. In an alternative configuration, wherein the device  10 ,  110  is utilized in conjunction with an MDI, the tower  16 ,  116  functions as a spacer, for the purpose of ensuring a more uniformly mixed dose of medication to the patient.  
         [0047]    Whether the device  10 ,  110  is being used with a nebulizer or an MDI, the purpose of the holding chamber  18 ,  118  is to repeatedly capture the generated aerosol from the nebulizer or MDI into the fixed volume chamber, which allows for a concentrated bolus of medicated aerosol to be delivered with each breath taken by a patient who is breathing through the mouthpiece  12 . In the case of a nebulizer  158 , the medicated aerosol is drawn therefrom by the vacuum created by inspiration by the patient through the mouthpiece, while in the case of an MDI, a propellant injects the medicated aerosol therefrom into the chamber  18 ,  118 . Though not shown, in some embodiments, a bridge adapter may be employed to adapt the device to various prior art mouthpieces.  
         [0048]    The apparatus and method of the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.