Abstract:
Apparatus ( 500 ) and components for coupling fluid or gas conducting elements, such as apparatus and components for connecting a nebulizer ( 501 ) with a gas flow system. In particular, the apparatus ( 500 ) and components are useful for connecting, in a gas-tight and quick release manner, a nebulizer ( 501 ) to a pressure-assisted breathing system, such as a mechanical ventilator or a continuous airway pressure (“CPAP”) system.

Description:
RELATED APPLICATION 
       [0001]    This application relates to U.S. Provisional Application No. 60/710,932, filed 23 Aug. 2005, from which a claim for priority is made under 35 USC §119(e), and which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to apparatus and components for coupling fluid or gas conducting elements, such as apparatus and components for connecting a nebulizer (also known as an aerosol generator) with a gas flow system. In particular, the present invention relates to apparatus and components for connecting a nebulizer to a pressure-assisted breathing system, such as a mechanical ventilator or a continuous positive airway pressure (“CPAP”) system. As used herein, the term “pressure-assisted breathing system” means any artificial ventilation system that applies continuous or intermittent pressure, usually positive, (i.e. above a certain baseline such as atmospheric pressure), to gas(es) in or about a patient&#39;s airway during inhalation as a means of augmenting movement of gas(es) into the lungs. The present invention is contemplated as being useful in any pressure-assisted breathing system and “pressure-assisted breathing system” is intended to include, for example, standard CPAP, nCPAP and Bi-level CPAP systems as well as mechanical ventilators that perform the breathing function for the patient and/or provide CPAP to assist in spontaneous breathing by the patient. The term “pressure-assisted breathing system” is also intended to include both invasive and non-invasive systems. Systems that utilize an endotracheal or tracheostomy tube are examples of invasive pressure-assisted breathing systems. Systems that utilize nasal prongs or a mask are examples of non-invasive pressure-assisted breathing systems. 
         [0003]    Pressure-assisted breathing systems utilize positive pressure during inhalation to increase and/or maintain lung volumes and to decrease the work of breathing by a patient. The positive pressure effectively dilates the airway and prevents its collapse. The delivery of positive airway pressure may be accomplished through the use of a positive air flow source (“flow generator”) that provides oxygen or a gas containing oxygen through a flexible tube connected to a patient interface device such as nasal prongs (cannula), nasopharyngeal tubes or prongs, an endotracheal tube, mask, etc. The tubes associated with commercially available pressure-assisted breathing systems create a “circuit” for gas flow by maintaining fluid communication between the elements of the circuit. Tubes may be made of a variety of materials, including but not limited to various plastics, metals and composites and can be rigid or flexible. 
         [0004]    A nebulizer may be connected to a circuit of a pressure-assisted breathing system to deliver an aerosol of medication (sometimes herein referred to as “aerosolized medicament”) into the respiratory system of a patient. The nebulizer is adapted to emit aerosolized medicament into the gas flow in the circuit, which delivers the aerosol to the patient through a patient interface device. Nebulizers suitable for the practice of the present invention preferably comprise a reservoir for holding a liquid medicament to be delivered to a patient&#39;s respiratory system and a vibrating aperture-type aerosol generator for aerosolizing the liquid medicament. The nebulizer is typically connected to the circuit using a generally “T”-shaped connector (sometimes referred to herein as a “T”-piece). For example, U.S. Pat. No. 6,615,824, issued Sep. 9, 2003, co-pending U.S. patent application Ser. No. 09/876,542, filed Jun. 7, 2001; Ser. No. 09/876,402, filed Jun. 7, 2001; Ser. No. 09/812,987, filed Mar. 20, 2001; Ser. No. 09/849,194, filed May 4, 2001; Ser. No. 09/812,755, filed Mar. 20, 2001; Ser. No. 10/284,068, filed Oct. 30, 2002; Ser. No. 10/345,875, filed Jan. 15, 2003; Ser. No. 10/465,023, filed Jun. 18, 2003; Ser. No. 10/284,068, filed Oct. 30, 2002; Ser. No. 10/828,765, filed Apr. 20, 2004; Ser. No. 10/883,115, filed Jun. 30, 2004; Ser. No. 10/957,321, filed Sep. 30, 2004; Ser. No. 11/080,279, filed Mar. 14, 2005, and Ser. No. 11/090,328, filed Mar. 25, 2005 describe apparatuses and methods for ventilators and connecting nebulizers to pressure-assisted breathing systems, and are all incorporated by reference herein. 
         [0005]    Pressure-assisted breathing systems such as those described in the patents and pending applications cited above must have leak-free, or gas-tight, circuits to maintain adequate pressure. As a result, ventilation and positive airway pressure may have to be interrupted in those systems to insert and withdraw the nebulizer from the circuit, for example, when the nebulizer needs to be refilled with liquid medicine, or needs cleaning, replacement, adjustment or repair. Furthermore, it is often desirable to prevent or mitigate escape of gases and/or aerosolized materials, for example, medicaments, from within the circuit. Additionally it is desirable that replacement of a nebulizer in a gas circuit be accomplished quickly, and with a minimum of effort. 
       SUMMARY OF THE INVENTION 
       [0006]    One or more embodiments of the present invention satisfies one or more of these needs. The various embodiments of the invention provide various novel apparatus, components and methods for the delivery of an aerosol to a pressurized gas flow system, such as delivery of a medicament to a pressure-assisted breathing system. In particular, the invention relates to apparatus comprising a nebulizer that is adapted to aerosolize a liquid medicament and a connector that operably connects the nebulizer to a circuit of the pressure-assisted breathing system. 
         [0007]    In one or more embodiments a connector of the present invention comprises a gas conduit, an aerosol supply conduit and a sealing device configured to seal the aerosol supply conduit from the gas conduit when a nebulizer is not connected and provide an unimpeded path for aerosol when the nebulizer is connected. The gas conduit has an inlet opening and an outlet opening adapted to be attached to a circuit of the pressure-assisted breathing system so that the flow of gas in the circuit is conducted therethrough. The aerosol supply conduit has an inlet opening adapted to receive the nebulizer and an outlet opening that communicates with the gas conduit so that aerosolized medicament produced by the nebulizer passe through the aerosol conduit and into the gas flow in the gas conduit. The sealing device is configured to allow unimpeded flow of aerosolized medicament through the aerosol supply conduit into the gas conduit when the nebulizer is positioned in the aerosol supply conduit, and to seal off the aerosol supply conduit from the gas conduit when the nebulizer is removed therefrom. 
         [0008]    In one or more embodiments, the sealing device comprises a hinged lid covering the inlet opening of the aerosol supply conduit. The lid is attached by a spring-loaded hinge and is configured to be lifted so as to allow the nebulizer to be received into the aerosol supply conduit. When the nebulizer is removed from the aerosol supply conduit opening, the lid is forced by the spring of the hinge to flip down over the inlet opening and seal off the aerosol supply conduit from the gas conduit. In some embodiments, the sealing device further comprises a flap-type valve disposed in the aerosol supply conduit proximal to the inlet opening. The valve comprises resilient flaps that are displaced by the nebulizer when the nebulizer is inserted in the aerosol supply conduit and return to a closed position when the nebulizer is removed from the aerosol supply conduit. This valve quickly seals off the aerosol supply conduit from the gas conduit before the lid is closed, and helps maintain the seal after the lid is closed. 
         [0009]    In other embodiments, the inlet opening of the aerosol supply conduit comprises a planar surface having an opening that is off-set from the center axis of the aerosol supply conduit. The sealing device comprises a rotatable disc positioned between the nebulizer and the inlet opening of the aerosol supply conduit. The disc comprises a planar surface having an off-set opening therein that is adapted to receive the nebulizer. The disc is configured to be rotated between a first position in which the off-set inlet opening of the aerosol supply conduit and the off-set opening in the disc are aligned, thereby allowing unimpeded flow of aerosol from the nebulizer into the aerosol supply conduit, and a second position in which the off-set inlet opening of the aerosol supply conduit is sealed off by the planar surface of the disc, thereby allowing the nebulizer to be removed without losing gas pressure in the system. 
         [0010]    In other embodiments, the sealing device comprises a hinged door with a spring-loaded or biased hinge positioned on the interior wall of the gas conduit adjacent to the outlet opening of the aerosol supply conduit. When inserted into the inlet opening of the aerosol supply conduit, the nebulizer forces the hinged door into a notch or recess in the internal surface of the gas conduit, thereby providing a first position in which unimpeded flow of aerosol from the nebulizer into the gas conduit is provided. When the nebulizer is removed, the spring on the hinge forces the door to a close over the outlet opening of the aerosol supply conduit to seal off the aerosol supply conduit from the gas conduit. 
         [0011]    In other embodiments, the gas conduit further comprises an intermediate opening located between the inlet opening and the outlet opening, and the aerosol supply conduit is positioned on a rotatable sleeve configured to receive the gas conduit longitudinally therein. The sleeve is configured to be rotated around the longitudinal axis of the gas conduit between a first position in which the outlet opening of the aerosol supply conduit is aligned with the intermediate opening of the gas conduit and a second position in which the outlet opening of the aerosol supply conduit is sealed off by the external surface of the gas conduit. The first position provides and unimpeded path for aerosol to travel from the nebulizer to the gas conduit when a nebulizer is positioned in the inlet opening of the aerosol supply conduit. The second position effectively seals off the aerosol supply conduit from the gas conduit so that the nebulizer can be removed without interrupting the gas flow in the gas conduit. 
         [0012]    In one or more embodiments, the coupling device or assembly provides a gas-tight seal between components. 
         [0013]    In one or more embodiments, the coupling device or assembly provides a quick-release connection between components. 
         [0014]    In one or more embodiments, the coupling device or assembly provides both a gas-tight seal, and a quick-release connection between components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1 a    is a perspective view of a known apparatus for the delivery of a medicament to a pressure-assisted breathing system. 
           [0016]      FIG. 1 b    is an enlarged, cross-section view of a known connector similar to the one shown in  FIG. 1 a   , wherein a commercially available spring-loaded valve is used to prevent release of gas flowing in a pressure-assisted breathing system when a nebulizer is not inserted in the connector. 
           [0017]      FIG. 1 c    is an enlarged, cross-section view of a known apparatus using the connector shown in  FIG. 1 b   , wherein the spring-loaded valve is actuated by insertion of a nebulizer into the connector to allow aerosol to enter the gas flowing through the connector in a pressure-assisted breathing system. 
           [0018]      FIG. 2  is a perspective view of one embodiment of a connector according to the present invention, wherein a spring-loaded or biased lid is disposed over an inlet opening of an aerosol supply conduit. 
           [0019]      FIG. 3  is an enlarged, cross-section view of the connector of  FIG. 2  showing movement of the lid. 
           [0020]      FIG. 4 a    is a prospective view of a flap seal for positioning in the connector shown in  FIG. 3  according to one embodiment of the present invention. 
           [0021]      FIG. 4 b    is a cross-section view of the flap seal shown in  FIG. 4 a    wherein the flaps of the seal are deflected by the barrel of a nebulizer inserted therein. 
           [0022]      FIG. 5  is an exploded, perspective view of another embodiment of apparatus according to the present invention, wherein a rotatable disc adapter with an off-set opening is positioned between the nebulizer and an off-set inlet opening of an aerosol supply conduit. 
           [0023]      FIG. 6 a    is an exploded, top-view of the connector and adapter shown in  FIG. 5  when in the closed position that seals off an aerosol supply conduit from a gas conduit. 
           [0024]      FIG. 6 b    is an exploded, top-view of the connector and adapter shown in  FIG. 5  when in the open position that provides an unimpeded path for aerosol from the nebulizer to a gas conduit. 
           [0025]      FIG. 7 a    is an enlarged, cross-section view of one embodiment of a connector according to the present invention in closed position wherein a spring-loaded or biased hinged door covers an outlet opening of an aerosol supply conduit to seal off the aerosol supply conduit from a gas conduit. 
           [0026]      FIG. 7 b    is an enlarged, cross-section view of apparatus using the connector of  FIG. 7 a    in open position wherein the spring-loaded or biased hinged door is deflected into a notch or recess in an internal surface of a gas conduit to provide an unimpeded path for aerosol from the nebulizer to the gas conduit. 
           [0027]      FIG. 8 a    is a perspective view of another embodiment of a connector according to the present invention wherein an aerosol supply conduit comprises a rotatable sleeve through which a gas conduit is placed. 
           [0028]      FIG. 8 b    is an exploded, perspective view of the connector shown in  FIG. 8   b.    
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0029]    Unless otherwise stated, a reference to a compound or component includes the compound or component by itself, as well as in combination with other compounds or components, such as mixtures of compounds. 
         [0030]    As used herein, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. 
         [0031]    All publications, patents and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference. 
         [0032]    Medicament, “active agent” or pharmaceutical may be used interchangeably, and individually or collectively comprise any drug, solution, compound or composition which induces a desired pharmacologic and/or physiologic effect, when administered appropriately to the target organism (human or animal). 
         [0033]    Reference herein to “one embodiment”, “one version” or “one aspect” shall include one or more such embodiments, versions or aspects, unless otherwise clear from the context. 
         [0034]    As an overview, the present invention comprises apparatus, systems, assemblies, components and ventilator circuits. In some embodiments, one or more components may be used independently of the other combinations and/or assemblies described herein. Moreover, the various embodiments of the coupling apparatus are not limited to use with the ventilator circuits of the invention. Thus the various embodiments of the coupling apparatus of the present invention may be used in a variety of fluid and/or gas flow applications where a device to atomize a fluid is to be incorporated into a fluid or gas supply system. This includes, without limitation, systems for distributing or supplying an aerosolized material within a gas or fluid manifold or distribution circuit, such as fuel supply systems, coating systems, biological test systems and the like. Such systems can have aesthetic purposes, as for example, distributing a fragrance or other aesthetic component, or may be for functional purpose. 
         [0035]    One or more embodiments of the apparatus, systems, assemblies and components are configurable to administer aerosolized medicament to a patient on-ventilator or off-ventilator. On-ventilator treatment methods comprise administering the nebulized aerosol through a ventilator circuit to the patient. Aerosol doses, containing an effective dose, such as about 1 to about 500 mg of a medicament, may be delivered through the ventilator circuit in a phasic or non-phasic manner. Off-ventilator treatment methods comprise taking the patient off the ventilator before administering the nebulized aerosol. Once the treatment session is completed the patient may be put back on the ventilator, or may breathe on his or her own without assistance. Off-Vent devices often are self-contained, for freely-breathing patients, and may comprise an aerosol generator (e.g. a nebulizer) and a mask, cannula, lipseal or mouthpiece to administer an aerosolized liquid or powder formulation, such as a medicament. Administration may be continuous, phasic (such as during inspiration), and/or intermittent (such as timed). Devices, especially off-vent devices, used to administer the aerosol formulations, such as medicaments, may comprise a reservoir or holding chamber to permit or allow continuous flow of aerosol. While one benefit of the apparatus, systems, assemblies, components of the present invention is in conjunction with positive pressure-type apparatus, the apparatus, systems assemblies and components of the present invention may also be useful in non-pressurized systems, neutral pressure systems, or negative pressure (e.g. vacuum) systems, as being rapidly and easily replaceable, exchangeable or interchangeable. 
         [0036]    Referring to the drawings and initially to  FIG. 1 a    thereof, there is illustrated a known aerosolized medicament delivery apparatus  100  that is suitable for coupling with a circuit of a pressure-assisted breathing system connected to the respiratory system of a patient, for example as described in detail in the aforementioned U.S. Pat. No. 6,615,824, incorporated by reference herein. In its most basic form, delivery apparatus  100  comprises a nebulizer  101  having an aerosol generator (not shown) for aerosolizing a liquid medicament, and a generally “T”-shaped hollow connector  102  for coupling nebulizer  101  to a circuit of a pressure-assisted breathing system. Although reference is made herein for convenience to a “T”-shaped connector, or “T”-piece, it is understood that the connector  102  may have other shapes, for example, a “Y” or other shape. 
         [0037]    Connector  102  comprises an aerosol supply conduit  103  having inlet opening  105  into which barrel  104  of nebulizer  101  may be inserted, a gas conduit  106  having an inlet opening  109 , which may be attached to one tube of the pressure-assisted breathing system circuit, and outlet opening  107 , which may be attached to another tube of the circuit, thereby completing the circuit through gas conduit  106 . Gas flow  108  flowing under positive pressure in the circuit enters inlet opening  109  and is conducted to the junction of aerosol supply conduit  103  and gas conduit  106 . An aerosol of medication generated by nebulizer  101 , preferably using a vibrating aperture-type aerosol generator, passes through barrel  104  into aerosol supply conduit  103  and into the junction, where it is entrained in gas flow  108  to form gas flow  110  comprising entrained aerosolized medicament. Gas flow  110  exits gas conduit  106  through outlet opening  107  into the pressure-assisted breathing system circuit. The aerosol of medicine is than ultimately carried by the gas flow in the pressure-assisted breathing system to the patient&#39;s respiratory system, e.g. though a patient interface device. When nebulizer  101  is withdrawn from connector  102  in the arrangement illustrated in  FIG. 1 a   , gas flows  108  and  110  may be disrupted since they will be diverted into aerosol supply conduit  103  and out opening  105  to the atmosphere, thereby eliminating the positive airway pressure in the circuit. 
         [0038]      FIG. 1 b    illustrates one proposal that has been advanced to solve the above-described problem. As shown in  FIG. 1 b   , a spring-loaded valve  112  is positioned in aerosol supply conduit  103  of connector  102 . The force of the spring holds valve  112  over inlet opening  105  when barrel  104  of nebulizer  101  is not present in aerosol supply conduit  103 , and therefore valve  112  seals off aerosol inlet opening  105 . As shown in  FIG. 1 c   , when barrel  104  is inserted into aerosol supply conduit  103 , valve  112  is forced downwards by barrel  104  and inlet opening  105  is uncovered, thereby allowing aerosol  113  emitted by nebulizer  101  to be released into and entrained by air flow  108 . An example of a commercially available “T”-piece is provided by Thayer Medical and is designed to work with a pneumatic nebulizer. Although this device may effectively seal the circuit when nebulizer  101  is withdrawn, the efficiency of delivery of aerosol to the pressure-assisted breathing system is drastically reduced since valve  112  is in the path of the aerosol and impedes its flow. As shown in  FIG. 1 c   , aerosol  113  impacts valve  112  and is deflected from gas flow  108  through gas conduit  106 . 
         [0039]      FIGS. 2, 3, 4   a  and  4   b  illustrate embodiments of a connector according to the present invention wherein insertion and removal of a nebulizer from the aerosol supply conduit may be accomplished without interrupting the positive pressure gas flow in the circuit of the pressure-assisted breathing system with which it is coupled, while maintaining a high efficiency of aerosol delivery, and further without impeding flow of aerosol or gas. In one or more embodiments, there is provided a connector  200 , which comprises aerosol supply conduit  203  having inlet opening  205  into which a nebulizer barrel may be inserted, gas conduit  206  having inlet opening  209  for the entrance of gas from a circuit, and outlet opening  211  for the exit of entrained aerosol and gas into the circuit. In addition, connector  200  has a hinged lid  212  attached to aerosol supply conduit  203  by spring-loaded or otherwise biased hinge  213 . As shown in  FIG. 3 , lid  212  is held in a closed position over inlet opening  205  by the hinge  213  when the nebulizer barrel is not present, thereby sealing the circuit and maintaining positive pressure. Lid  212  may be rotated upwards to uncover inlet opening  205  and accommodate the insertion of the nebulizer barrel when desired. This position provides an unimpeded path for aerosol to travel from the nebulizer to the gas conduit. Upon removal of the nebulizer barrel, spring-loaded hinge  213  causes lid  212  to return to the closed position over inlet opening  205  to re-seal the circuit. 
         [0040]    In some embodiments, lid  212  may have an “O”-ring seal  214  around its lower periphery to aid in the sealing of inlet opening  205 . In some embodiments, a slotted flap seal or valve  215  may be positioned in inlet opening  205 , as shown in  FIG. 3 . Slotted flap seal  215  is preferably made of a suitable sealing material, e.g. silicone, and may comprise a plurality of deformable flaps  216  defined by crossed slots  217 , as illustrated in  FIG. 4 a   .  FIG. 4 b    illustrates the deflection of flaps  216  when nebulizer barrel  104  of nebulizer  101  is inserted into inlet opening  205 . The deflection of flaps  216  allows unimpeded flow of aerosolized medicament  218  from nebulizer through aerosol conduit  203 . When nebulizer barrel  104  is removed from inlet opening  205 , flaps  216  return to their original position to re-seal the circuit before lid  212  is returned to the closed position shown in  FIG. 3 . Closed flap seal  215  also aids in maintaining the seal when the nebulizer is removed. In some embodiments, the slotted flap seal  215  may be made sufficiently robust to function alone to seal the inlet opening  205 , yet permit insertion of the nebulizer barrel  104 . In such embodiments, the lid  212  and hinge  213  may be omitted. 
         [0041]      FIG. 5  illustrates another embodiment of the apparatus of the present invention, represented by the reference character  500 . Apparatus  500  comprises a nebulizer  501 , a rotatable disc adaptor  502  and a sleeve connector  503 . Adapter  502  has an off-set opening  504  in planar surface  506  into which barrel  505  of nebulizer  501  may be inserted. The offset opening  504  is preferably off-set about a central axis of the adapter  502 . Sleeve connector  503  comprises aerosol supply conduit  507  having off-set inlet opening  508  in planar surface  509  that is substantially equal in size and shape to opening  504  in adaptor  502 . The offset opening  508  is also preferably off-sat about a central axis of the surface  509 . Adaptor  502  is preferably mounted on connector  503  such that it can be rotated about a central axis as indicated by arrows  510 . Accordingly, adapter  502  may be placed in the position shown in the overhead view of  FIG. 6 a    during removal or insertion of nebulize  501  into opening  504 . In the position illustrated by  FIG. 6 a   , opening  504  in adapter  502  is not aligned with opening  508  in aerosol supply conduit  507  and therefore opening  508  is effectively blocked by planar surface  506  of adaptor  502  (and opening  504  is effectively blocked by planar surface  509  of aerosol supply conduit  503 ). This position seals the circuit and allows barrel  505  of nebulizer  501  to be removed from opening  504  without interrupting gas flow through connector  503  or losing pressure in the pressure-assisted breathing system. When it is desired to connect nebulizer  501  to connector  503 , barrel  505  is inserted in opening  504  and adapter  502  is rotated in the direction of arrow  511  to the position illustrated in  FIG. 6 b   . In this position, opening  504  is aligned with opening  508 , thereby providing an unimpeded path for aerosol emitted from nebulizer  501  to enter aerosol supply conduit  507  of connector  503  and become entrained in the gas flow of the system such as a pressure-assisted breathing system, as previously described. If required, it is contemplated that suitable sealing means (such as O-rings, gaskets or the like) may be placed between adapter  502  and planar surface  509  to further reduce the possibility of leaks. Additionally, suitable detents, indents, tabs or indicators (not shown) may be provided on appropriate engaging surfaces of conduit  507  and adaptor  502  to positively identify engagement and disengagement of openings  504  and  508 . 
         [0042]      FIGS. 7 a  and 7 b    illustrate yet another embodiment of the invention designated by the general reference character  700 , and represent a cross-section view perpendicular to the longitudinal axis of the connector  700 . Connector  700  has an aerosol supply conduit  702  having an inlet opening  703  at its distal end and an outlet opening  704  at its proximal end. Outlet opening  704  communicates with gas conduit  705  running the length of the main body of connector  700 . Hinged door  706  is attached to the internal wall of gas conduit  705  by spring-loaded or otherwise biased hinge  710 . In the position illustrated in  FIG. 7 a   , door  706  is disposed over outlet opening  704  to seal aerosol supply conduit  702  and prevent the escape of the gas flow in gas conduit  705 . When nebulizer barrel  707  is inserted into aerosol supply conduit  702  through inlet opening  703 , nebulizer barrel  707  forces hinged door  706  downward, opening a pathway for the aerosol  708 . In some embodiments, there is provided a notch or recess  708  in the internal wall of gas conduit  705  to further facilitate insertion of the nebulizer barrel  707  and to provide an unimpeded path for aerosol  709  from the nebulizer into the gas flow in gas conduit  705 , as shown in  FIG. 7 b   . The notch or recess  708  may cooperate with a mating structure (not shown) on the door  706  to assist in removably holding the door  706  in the open position, and/or aligning the door  706 . When nebulizer barrel  707  is withdrawn from aerosol supply conduit  702 , spring-loaded or biased hinge  710  acts to return hinged door  706  to the closed position shown in  FIG. 7 a   , thereby re-sealing the circuit. The hinge or biasing means  710  may be configured to hold the door  706  between two positions, such as an open position as depicted in  FIG. 7 b    and a closed position as depicted in  FIG. 7   a.    
         [0043]    Another embodiment of the present invention is illustrated in  FIGS. 8 a  and 8 b   , wherein connector  800  comprises gas conduit  801  and rotatable sleeve  802 , which may be rotatable about the conduit  801 . Rotatable sleeve  802  comprises aerosol supply conduit  808  and lumen  804 , which is configured to receive gas conduit  801  so that aerosol supply conduit  808  can rotate around the longitudinal axis of gas conduit  801 . Aerosol supply conduit  808  comprises inlet opening  803  configured to accommodate the barrel of a nebuliser, as previously described. Gas conduit  801  comprises intermediate opening  805 , outlet opening  806  and inlet opening  807 . Gas conduit  801  may be positioned within lumen  804  of sleeve  802  so that intermediate opening  805  in gas conduit  801  is aligned with aerosol supply conduit  803 , as shown in  FIG. 8 a   . When a nebulizer is inserted in inlet opening  803 , the position shown in  FIG. 8 a    allows an unimpeded path for aerosol emitted by the nebulizer into aerosol supply conduit  808  to travel through intermediate opening  805  into gas conduit  801  and be entrained in the gas flowing from inlet opening  807  to outlet opening  806 . When the nebuliser is to be removed from connector  800 , sleeve  802  may be rotated relative to conduit  801  in the direction indicated by the arrow in  FIG. 8 a    to a position wherein aerosol supply conduit  803  is effectively blocked by the internal wall of lumen  804 . In this position, the aerosol supply conduit  808  is sealed off from gas conduit  801  and the nebulizer may be removed from connector  800  without the escape of gas from gas conduit  801 . When the nebulizer is re-inserted into aerosol supply conduit  808  through inlet opening  803 , sleeve  802  may be rotated to the position shown in  FIG. 8 a   , thereby again opening up an unimpeded path for aerosol to pass through aerosol supply conduit  808  into the gas flow of gas conduit  808 . Optionally a suitable sealing means  809 , such as an O-ring, gasket or the like, may be placed around opening  805  to further reduce the possibility of leakage. Additionally, suitable detents, indents, tabs or indicators (not shown) may be provided on appropriate engaging surfaces of conduit  801  and sleeve  802  to positively identify engagement and disengagement of openings  803  and  805 . 
         [0044]    The aerosol generators or nebulizers contemplated for use herein may, for example, be a vibrating mesh nebulizer where the energy source is mechanical, such as wave energy, an ultrasonic nebulizer where the energy source is acoustic wave energy, a jet nebulizer where the energy source is compressed air, a metered dosing device where the energy source is a propellant, such as a composition that boils under preselected, such as ambient conditions, or a dry powder device where the energy source is compressed or flowing air or is a vibrating membrane or the like. 
         [0045]    Some specific, non-limiting examples of technologies for producing fine liquid droplets comprise those which supply liquid to an aperture plate having a plurality of tapered apertures, and vibrate the aperture plate to eject liquid droplets through the apertures. Such techniques are described generally in U.S. Pat. Nos. 5,164,740; 5,938,117; 5,586,550; 5,758,637, 6,014,970, and 6,085,740, the complete disclosures of which are incorporated by reference. However, it should be appreciated that the present invention is not limited for use only with such devices. 
         [0046]    For example, in one or more embodiments, the aerosol generator is the commercially available Aerogen (Aerogen, Inc. Mountain View, Calif.) aerosol generator which comprises a vibrational element and dome-shaped aperture plate with tapered holes. When the plate vibrates (at several thousand times per second), a micro-pumping action causes liquid to be drawn through the tapered holes, creating a low-velocity aerosol with a precisely defined range of droplet sizes. The Aerogen aerosol generator does not require propellant. 
         [0047]    Jet nebulizers involve use of air pressure to break a liquid solution into aerosol droplets. In one or more embodiments, a jet nebulizer (e.g., Aerojet, AeroEclipse, Pari L. C., the Parijet, Whisper Jet, Microneb®, Sidestream®, Acorn II®, Cirrus and Upmist®) generates droplets as a mist by shattering a liquid stream with fast moving air supplied by tubing from an air pump. 
         [0048]    In one or more embodiments, an ultrasonic nebulizer that uses a piezoelectric transducer to transform electrical current into mechanical oscillations is used to produce aerosol droplets. Examples of ultrasonic nebulizers include, but are not limited to, the Siemens 345 UltraSonic Nebulizer™ and ones commercially available from, for example, Omron Healthcare, Inc. and DeVilbiss Health Care, Inc. See, e.g., EP 1 066 850, which is incorporated by reference herein in its entirety. 
         [0049]    Vibrating porous plate nebulizers work by using a sonic vacuum produced by a rapidly vibrating porous plate to extrude a solvent droplet through a porous plate. See, e.g., U.S. Pat. Nos. 5,758,637; 5,938,117; 6,014,970; 6,085,740; and 6,205,999, which are incorporated herein by reference in their entireties. 
         [0050]    In condensation aerosol generators, the aerosol is formed by pumping drug formulation through a small, electrically heated capillary. Upon exiting the capillary, the formulation is rapidly cooled by ambient air, and a gentle aerosol is produced that is relatively invariant to ambient conditions and the user inhalation rate. See, e.g., U.S. Pat. No. 6,701,922 and WO 03/059413, which are incorporated herein by reference in their entireties. In one or more embodiments, the condensation aerosol generator comprises one disclosed by Alexza Molecular Delivery Corporation. See, e.g., U.S. Published Application No. 2004/0096402, which is incorporated herein by reference in its entirety. 
         [0051]    It is understood that while the invention has been described above in connection with preferred embodiments, the description and drawings are intended to illustrate and not limit the scope of the invention, which is defined by the appended claims and their equivalents.