EP0194258A1

EP0194258A1 - All purpose nebulizer

Info

Publication number: EP0194258A1
Application number: EP19840903731
Authority: EP
Inventors: Nathaniel Hughes; Richard F. Koniusky
Original assignee: VORTRAN CORP
Current assignee: VORTRAN CORP
Priority date: 1984-09-18
Filing date: 1984-09-18
Publication date: 1986-09-17
Also published as: WO1986001731A1

Abstract

Vaporisateur (10) permettant d'atomiser un médicament pour l'inhalation. Le vaporisateur est portatif et compact et comprend un récipient (12) contenant une certaine quantité de médicament et définissant une chambre (17). Une partie supérieure (16) est fixée sur le récipient. Cette partie comprend une cavité (46) en communication avec la chambre, ainsi qu'un orifice d'admission et de sortie (42, 44) conduisant de l'intérieur de la cavité à l'extérieur du dispositif. Un atomiseur (20) à l'intérieur de la chambre sert à atomiser le médicament pour l'inhalation. Le gaz sous pression qui actionne l'atomiseur peut être contenu dans une boîte remplaçable (32, 32') de gaz comprimé fixée de manière amovible sur le vaporisateur. L'inhalation du médicament depuis la chambre au niveau de l'orifice de sortie provoque l'entrée d'un gaz de balayage, par ex. de l'air, par l'orifice d'admission, de manière à solliciter le passage du médicament vers l'orifice de sortie et dans les poumons du patient. Afin d'assurer un balayage efficace du médicament atomisé, un déflecteur (120) peut être utilisé pour diriger l'écoulement du gaz de balayage à travers la chambre, pour entraîner le médicament atomisé vers l'orifice de sortie.Spray bottle (10) for atomizing a medicament for inhalation. The vaporizer is portable and compact and includes a container (12) containing a certain amount of medication and defining a chamber (17). An upper part (16) is fixed to the container. This part comprises a cavity (46) in communication with the chamber, as well as an inlet and outlet orifice (42, 44) leading from the interior of the cavity to the exterior of the device. An atomizer (20) inside the chamber is used to atomize the medication for inhalation. The pressurized gas which actuates the atomizer may be contained in a replaceable box (32, 32 ') of compressed gas removably attached to the vaporizer. Inhaling the drug from the chamber at the outlet orifice causes the entry of a purge gas, e.g. air, through the inlet, so as to urge the passage of the drug towards the outlet and into the patient's lungs. In order to ensure efficient sweeping of the atomized medicament, a deflector (120) can be used to direct the flow of the sweeping gas through the chamber, to drive the atomized medicament to the outlet.

Description

ALL PURPOSE NEBULIZER Field of the Invention

This invention relates to atomizing nebulizers and more particularly for nebulizing liquid medicaments for inhalation.

Background of the Invention

It has long been known to administer medicaments (medicaments as used herein shall be understood to include drugs, solutions, vaccines, water and the like) to patients through injection and via ingestion. For certain respiratory problems (i.e., asthma) it has also been generally known to provide for the inhalation of aerosol medicaments. While injection and ingestion are quite popular in a hospital setting, for home use, particularly, injection can be troublesome. Associated with injection are hepatitis, vein collapse and the like and overall discomfort to the patient.

It is believed that some, if not many, medicaments heretofore injected or ingested could be better and more conveniently administered by inhalation. Particularly for respiratory problems, direct inhalation of the medicament is highly preferred to injection or ingestion which both require relatively large dosages to assure that a desired amount of medicament reaches the lungs or the desired effect takes place therein.

To provide for inhalation, various devices have been developed as exemplified by U.S. Patent No. 4,453,542 issued June 12, 1984 to Hughes and entitled "Vortex Generating Medical Products". These types of products, while being well suited for inhalation of medicaments, do not provide for in/out breathing through the device in a manner to efficiently supply the medicament to the patient and, at the same time, conserve the medicament. Further, often these devices require a standing source of compressed oxygen, detracting from portable and in-home use.

Summary of the Invention

There is, therefore, provided in the present invention a nebulizer adapted to atomize a quantity of liquid or powder medicament for inhalation and to efficiently provide for the inhalation of the medicament. The nebulizer is adapted to be portable and is desired to be self-contained.

Accordingly, the nebulizer includes a container adapted to hold a quantity, for example, one dose, of medicament. The container has an open end and the ullage above the medicament to the open end defines a chamber. Preferably, the container has a conical bottom with a lowermost apex creating a deep well and to provide for the substantially complete utilization of the quantity of medicament.

Secured to the container open end is a top. Preferably, means are provided for removability of the top and for secure re-attachment to the container. The top includes a cavity which is in communication with the chamber and further includes an inlet and an outlet port leading from the cavity to outside of the device.

To atomize the medicament, means are provided to atomize the liquid medicament into droplets, each preferably of a diameter of between 1-3 microns monodispersed. Droplets in this size range are indispensable to proper penetration and coating of the receptor sites in the bronchial tree to properly and fully medicate the patient. These atomizing means include a source of pressurized gas which may be an oxygen tank or the like. To provide for complete portability of the nebulizer, the pressurized gas source can be embodied as a replaceable canister of compressed gas or liquified gas propellant removably affixed to the nebulizer. Conveniently, the container is provided with base means for receiving the canisters. Hose and valve means are provided to selectively provide the pressure gas to the atomizer for the atomization of the medicament. Introduction of pressurized gas to the atomizer lifts the medicament from the container and its well and discharges the atomized medicament into the chamber in readiness for the inhalation thereof. A conduit extends from the atomizer to the apex of the well for lifting substantially all the medicament to the atomizer.

Inhalation of the medicament from the chamber at the outlet port causes a sweeping gas, which may be air or oxygen, to enter the inlet port. The sweeping gas displaces the atomized medicament to the outlet port and to the patient's lungs. To provide for the efficient sweeping of atomized medicament, means may be provided to divert the flow of sweeping gas through the chamber to sweep the atomized medicament to the outlet port.

To conserve medicament and provide for in/out breathing, the nebulizer may be provided with a normally closed inlet check valve adapted to allow flow in a direction into the nebulizer, i.e., admit sweeping gas. 'At the outlet port means are provided for the inhalation of the medicament and for the venting of a breath exhaled into the nebulizer. Preferably, these means are embodied as a mouthpiece adapted to be positioned in the patient's mouth for inhalation and exhalation. On the mouthpiece or at the outlet port a

normally closed vent check valve is provided. Upon inhalation, the inlet check valve opens (the vent check valve remains closed) to admit the sweeping gas which delivers the atomized medicament through the mouthpiece to the lungs. Exhalation closes the inlet check valve and opens the vent check valve to discharge the exhaled breath from the nebulizer. In this fashion medicament is conserved in that the exhaled breath is vented before comingling with the atomized medica¬ ment, thereby preventing the exhaled breath from releasing medicament from the nebulizer. Further, the inlet check valve remains generally closed to prevent release of the medicament as does the vent check valve. The opening at the mouthpiece can be fashioned to limit the free release of medicament when inhalation/exhalation are not taking place.

Q-..?I Brief Description of the Drawings

These and other features of the present invention will become appreciated as the same becomes better understood with reference to the following specification and drawings wherein:

FIG. 1 is a side view of an embodiment of the nebulizer according to the present invention;

FIG. 2 is a side section view of one embodiment of the nebulizer according to the present invention;

FIG. 3 is a side view of an alternative embodiment of a top for the nebulizer;

FIG. 4 is a section view of the nebulizer according to the present invention;

FIG. 5 is a bottom view of the nebulizer top of FIG. 1;

FIG. 6 is an exploded view of the atomizer for the nebulizer;

FIG, 7 is an enlarged side section view of the atomizer; and

FIG. 8 is a partial side section view of another embodiment of the nebulizer adapted for use with a replaceable cannister of propellant.

Detailed Description

Turning to the drawings, a nebulizer 10 according to the present invention is shown. The nebulizer 10 includes a container 12, a base 14 secured to the lower portion of the container and a top 16 sealably connected and preferably removable from the container 12.

The nebulizer container 12, as shown in FIG. 2, is adapted to retain an amount of liquid medicament 18. The ullage above the medicament defines a chamber 17 for the medicament when it is atomized. Additionally, the container 12 provides a housing for means for atomizing the medicament into droplets of a diameter substantially within the range of between 1-3 microns. Preferably, the atomizing means are embodied as an atomizer 20 of the type the structure and function of which are set forth below. As shown, the container 12 is cylindrical and is upwardly open, having an upper edge 22 and a bottom 24. The bottom 24 preferably is contoured in a conical fashion to have a lowermost apex 26 to create, in effect, a deep well for the medicament 18. The contour of the bottom 24 provides for complete utilization of substantially all the medicament 18 within the nebulizer 10. The container 12 may be fashioned from plastic, glass or the like.

To enable the nebulizer 10 to stand upright and for other purposes the base 14 is provided. The base 14 has a cylindrical skirt 28 joined to the container 12 by a tapered portion 30. The diameter of the skirt 28 is greater than the diameter of^* the base 14, thereby providing a sturdy stand to maintain the nebulizer 10 upright.

To drive the atomizer 20, as described below, a source of compressed gas such as air or oxygen is required. While the source may be separate from the nebulizer 10, means are provided for removably attaching a compressed gas or propel- lant canister 32 to the nebulizer 10 to provide for complete portability thereof. For this purpose, the skirt 28 along the inner surface thereof includes an inwardly projecting lip 34 as shown in FIG. 2. The canister 32 includes an upper margin 36 with a circumferential tab 38, the upper margin 36 adapted to be inserted into the base skirt 28 with the tab 38 snapping over the lip 34. In this position the canister 32 is removably attached to the nebulizer 10. Alternatively, a canister of propellant, again preferably oxygen, air or other compatable propellants may be secured to the nebulizer 10 via its lower rim (35) defining the joinder of its side and the bottom. From the canister 32 a hose 33 (FIG. 1) is used to transport the gas to the atomizer 20. A depressible or other type of valve (not shown) is also provided at the canister to initiate the flow of gas to drive the atomizer 20.

The top 16 is adapted to provide means for inhaling the atomized medicament present in the container chamber 17. For this purpose the top 16 is Y- or T-shaped as shown in FIGS. 1 and 3, having a trunk 40 adapted to be joined to the container 12 with branching, cylindrical inlet and outlet ports 42 and 44, respectively. Since the Y- and T- shaped tops are substantially identical except for the coaxial arrangement of the inlet and outlet ports for the T- shaped embodiment (FIG. 3) and the obtusely angled inlet and outlet ports in the Y-shaped embodiment, only details of the latter will be set forth.

The top 16 is hollow so as to define a Y-shaped cavity including inlet and outlet passages 48 and 50. When the top 16 is affixed to the container «12, the cavity 46 is in communication with the chamber 17 of the container.

The top may be permanently affixed to the container. However, it is preferable that the top be removable to provide access to the chamber 17 and atomizer 20 to, for example, add medicament, clean or repair the device.

For this purpose, as shown in FIGS. 2, 4 and 5, the trunk 40 includes a sleeve-like bottom portion 51 having at least one and preferably a plurality of upwardly projecting J- shaped slots 52. As shown in the drawings, three such J-shaped slots are spaced at 120° intervals around the bottom portion 51. To cooperate with the J-shaped slots the container includes spaced, inwardly projecting tabs 54, each adapted to be received by a corresponding J-shaped slot 52 to form a bayonet connection between the top 16 and container 12. Accordingly, to attach the top to the container, the top is positioned such that the tabs 54 are aligned to be received with the slots 52. Inserting the top bottom portion 51 into the container 12 causes the tabs 54 to be received into the J-shaped slots 52. Rotation of the top thereafter causes the tabs to be frictionally engaged within the J-shaped slots 52 connecting and sealing to top 16 to the container 12. To remove the top it need only be reversely rotated to position the slots for separation of the bottom portion 51 from the container 12.

As shown in FIGS. 1, 3 and 5, the inlet and outlet ports 42 and 44 are preferably of a standard size and are adapted to be connected to medical-type hoses (i.e., patient oxygen supply). For this purpose, the outer surface of each of the inlet and outlet is contoured to have a flange 56 adjoined by a reduced diameter neck 58. By this design, hoses shown in phantom in FIG. 1 as 60 and other attachments as described below can quickly and easily be attached and detached from the device 10.

To transform the liquid medicament 18 into droplets of a size within the range of 1-3 microns, the atomizer 20 as shown in FIGS. 6 and 7 may be used.

The atomizer 20 includes a body member 62 and an insert 64 which are preferably injection-molded parts. A large cylindrical bore 66 and a small cylindrical bore 68, which

OMPI opens into bore 66, are formed in body member 62. Bores 66 and 68 lie on intersecting orthogonal axes. Body member 62 includes a hollow, cylindrical rod 70 that extends the length of bore 66 in axial alignment therewith. A small cylindrical bore 72 is formed in body member 62 behind rod 70. Bores 68 and 72 lie on parallel axes. A bore 74 extends through rod 70 from bore 72 to the exterior end of bore 66.

A counterbore 76 is formed in bore 66 at its exterior end. Insert 64 fits into counterbore 76, where it is cemented in place. A cylindrical bore 78, which has a slightly larger diameter than rod 70, is formed in insert 64. Rod 70 extends through bore 78 in axial alignment therewith to form therebetween a small annular passage. The open end of bore 74 is preferably recessed slightly from the exit end of bore 78. The interior end of insert 64 has a conical concavity 80 and the exterior end thereof has a spherical convexity 82. A conical concavity 84 is formed between the center of convexity 82 and bore 78.

Oppositely disposed radial bores 86 extend through insert 64 from its periphery to bore 78. A pair of oppositely disposed axial bores 88 extend through insert 64 from concavity 80 to bores 86, thereby forming with bores 86 a pair of auxiliary passages. Liquid medicament 18 (FIG. 2) is delivered by a conduit 90 and a coupling 92 to bore 72, which serves as the liquid inlet of the vaporizer 20. Bore 68 serves as a gas inlet to receive pressurized gas from the hose 33. Bore 66 serves as an upstream section of a flow passage while bore 78 serves as a restriction in the flow^'passage. Concavity 84 serves as the outlet of vortex generating atomizer 20. Bores 66 and 78 and concavity 84 all are aligned with a flow axis. The gas inlet is aligned with an inlet axis that intersects the flow axis at a right angle.

The atomizer 20 further includes a spin chamber 94 embodied as a tubular member 96 having a cylindrical inner surface 98 aligned with the flow axis of the atomizer. At one end, member 96 has on its inner surface a recess 100 adapted to receive the outer surface of body member 62, where insert 64 fits therein. At the other end, the outer surface of member 96 has a recess 102 that receives the inner surface of a tubular end cap 104. End cap 104 has a circular end opening 106 with the same diameter as surface 98. A resonant member is embodied as a circular screen 108. The edges of screen 108 are secured to an annular frame 110, which is clamped between the end of member 96 and end cap 104. The inside diameter of frame 110 has the same diameter as surface 98. Screen Ϊ 0 is made of criss-crossing wires, preferably nylon, each having a circular or square cross section. Screen 108 is spaced from the outlet of the insert 64 and the spin chamber 94 is coupled between the insert 64 and screen 108 to completely close the space therebetween.

Drag bar 112 has in a one-piece construction a cylindrical drag member 114 connected by a support arm 116 to a cap 118 that fits over end cap 104 and is so mounted on spin chamber 94 that the cylindrical axis of drag member 114 lies at a right angle to the flow axis and is downstream and in front of the screen 108. Cap 118 has a circular opening with the same diameter as surface 98.

Briefly, a pressure source such as air or gas from canister 32, is introduced into the atomizer through gas inlet 68. The gas forms rapidly spinning vortices in the upstream section of the flow passage. The vortically flowing gas travels through the restriction formed by bore 78 and rod 70 and through the auxiliary passage so as to converge near the open end of rod 70 where the rapidly moving gas meets liquid supplied through rod 70. The gas

thus entrains and atomizes the liquid to form liquid particles in the gas of the order of 1-10 microns. At the outlet of the insert 64 a sub-atmospheric pressure is produced that draws liquid through rod 70 and causes cavitation in this liquid as it emanates from the end of rod 70. Liquid atomization is enhanced by a supersonic process taking place in the atomizer. As a result, shock waves are formed as the gas exits bore 78 and sonic energy in addition to vortex energy is present in spin chamber 94.

At very low flow velocities, i.e., Reynolds numbers, the drag coefficient, and thus the drag forces, increase rapidly. At such low Reynolds numbers, viscosity is a predominant parameter in determining drag and viscosity effects dominate over gravitational effects.

Drag member 114 presents drag to an induces vortex action in the gas and liquid stream. Screen 108 serves to slow the velocity of the moving gas and thus increases the drag effect of member 114 thereon and, additionally, further breaks up the droplets in the liquid/gas stream. As a result, member 114 exerts more drag force on the gas and atomized liquid, creating vortical action and pulsating, dancing fluid activity of the surface of member 114 facing toward screen 108. It has been found that the effectiveness of member 114 in atomizing the liquid depends upon the distance between member 114 and screen 108. For this reason, it is believed that member 114 also serves to cause resonance to one or more components of the sonic energy impinging thereon. Thus, the spacing between screen 108 and member 114 is empirically selected to cause resonance of one or more components of the sonic waves generated by the atomizer 20. The liquid particles emanating from the apparatus in the region of drag bar 112 are sub¬ stantially of the order of 1-3 microns monodispersed.

In summary, the described apparatus processes the gas and liquid to be atomized in three stages. In the first stage, a high velocity stream of vortices and sonic waves is produced. In the second stage, velocity of the stream is reduced to an intermediate value and the sonic waves are enhanced by resonance. In the third stage, the sonic waves are further enhanced by resonance, the velocity of the stream is reduced to a creeping motion, and further vortex action takes place. As a result, the energy of the gas from the source is effectively utilized to finely atomize the liquid.

As can be appreciated from the foregoing, the atomizer 20, when powered by the compressed gas, transforms the liquid medicament in the container into the aforesaid droplets within the chamber 17. With reference to FIG. 1, the atomized medicament may be delivered to one or several patients by simply allowing the medicament to flow outwardly from both the inlet and outlet passages 48 and 50 which naturally occurs due to the slight superatmospheric pressure within the chamber. One of the inlet and outlet passages may be blocked by any suitable means for delivery of the atomized medicament from the remaining open passage. In this embodiment the patient breathes the atomized medicament as it gently is discharged from the device 10.

Alternatively, for patients on breathing systems such as an oxygen supply system, the device 10 may be incorporated into the oxygen supply hose as shown in phantom in FIG. 1. As illustrated, the supply hose 60 is connected over the inlet port to provide a flow of oxygen through the inlet passage 48 upon the patient's inhalation at the base 60 connected to the outlet port 44. Inhalation causes the oxygen entering the inlet passage 48 to sweep the atomized medicament present in the cavity 46 and chamber 17 to the outlet passage 50 and therefrom to the base 60 and to the

patient. In this fashion, the nebulizer 10 is well suited for hospital and other institutional uses where breathing systems are present. Many medicaments can thusly be admini¬ stered to the patient through the breating means, thereby avoiding problems such as hepatitis and vein collapse associated with injections.

To assure efficient delivery of the atomized medicament, means may be provided to divert the flow of the sweeping gas entering the inlet to urge substantially all atomized medicament through the outlet passage 50. With reference to FIG. 2, the oxygen entering the inlet passage 48 is directed downwardly into the chamber 17 by a flow diverter 120 to sweep the atomized medicament from the chamber 17 and urge it to flow from the device through the outlet passage 50. Preferably, the flow diverter.120 is disposed midway between the inlet and outlet passages. The atomized medicament swept from the chamber 17 by the incoming oxygen passes through the outlet passage 50 to hose 60 for inhalation by the patient.

Regarding the incorporation of the nebulizer 10 into a hose 60, it has been found that the atomized medicament is ionized carrying a slightly negative charge. Therefore, the atomized medicament is often repelled by the inside walls of the hose 60, preventing deposit and condensation of the medicament thereon. Accordingly, it has been found a substantial portion of the atomized medicament does indeed reach the patient for inhalation thereof.

To provide for a hand-held, portable nebulizer, the attachments as shown in FIG. 2 may be used. These attachments include a mouthpiece 122 having a sleeve portion 124 adapted to slide over the outlet port 44 of the top 16. Opposite the sleeve portion 124, the mouthpiece 122 has a bite 126 contoured to be easily received into a patient's mouth. The bite 126 is hollow to permit the atomized medicament to be inhaled through the mouthpiece and its bite.

In that it is preferable for a patient to breathe the atomized medicament deeply so that such medicament can be efficiently dispersed throughout the lungs alveoli, means are required to augment the volume of atomized medicament within the chamber 17 and cavity 46 to constitute a volume sufficient for a deep breath inhalation. For this purpose, the inlet port 42 may be left open so that, upon inhalation by a patient through the bite and mouthpiece, fresh air is brought in through the inlet passage 48 to sweep the atomized medicament from the cavity 46 and chamber 17 to the outlet passage 50 and to the patient's lungs. By virtue of the flow diverter 120, the incoming fresh air is urged downwardly to sweep a maximum amount of atomized medicament from the nebulizer 10. After inhalation the patient would release the mouthpiece, back away from the nebulizer 10 and exhale. The foregoing would be repeated until a prescribed dosage of medicament had been inhaled. Failure of the patient to back away from the nebulizer 10 and instead exhale through the mouthpiece 122 would tend to sweep the atomized medicament from the chamber and cavity and outwardly through the inlet passage 48.

To provide for the inhalation and exhalation of a patient while retaining the mouthpiece in the mouth, a flapper- type inlet check valve 128 is provided at the inlet port 42 and a vent check valve 130 is associated with the mouthpiece 122 and outlet port 44. Preferably, the vent check valve 130 is secured in an aperture 132 formed on the mouthpiece 122 between the bite and cylindrical portion. In this fashion, the nebulizer 10 can also be used in the afore¬ mentioned oxygen breathing systems. Each of the check valves is normally closed and includes a cylindrical housing 134 adapted to be closely received by the designated aperture or inlet passage. A button 136 is supported at the axis of

O PI the check valve by a plurality of spokes 138 emanating therefrom and connected to the housing. Supported by the button 136 over the spokes 138 is a resilient flapper member 140 which lifts from the spokes 138 when a fluid passes through the check valve in a first direction and forms a seal over the spokes 138 and housing when a reverse flow of fluid is attempted. As shown in FIG. 2, by securing these check valves to the inlet port and mouthpiece in their proper orientation, the following operation of the nebulizer 10 can be achieved. During inhalation the vent check valve 130 at the mouthpiece 122 remains closed due to the subatmospheric pressure present within the nebulizer during inhalation. As a result of the subatmospheric pressure, the inlet check valve 128 at the inlet port 42 opens admitting air which .sweeps the atomized medicament from the chamber and cavity through the mouthpiece to the. patient's lungs. Again, the flow diverter 20 aids in the efficient sweeping of the medicament through the mouthpiece 122. After the patient has deeply inhaled the atomized medicament, he/she then exhales through the mouthpiece creating a superat ospheric pressure within the nebulizer 10. This superatmospheric pressure opens the vent check valve 130 at the mouthpiece and closes the inlet check valve 128 resulting in the exhaled breath, for the most part, passing from the nebulizer 10 through the mouthpiece without sweeping the atomized medicament present within the chamber and cavity out from the device. As can be appreciated, the foregoing construction enables the hand-held nebulizer 10 to be easily used by patients of all ages.

Turning to FIG. 8, an alternative embodiment of the nebulizer 12 is shown. Like components will carry the same reference numerals whereas modified elements will carry a prime ( ' ) designation.

This embodiment is adapted for use with replaceable cannisters 32' of, for example, the liquid propellant type. The container 12 includes a bottom 24' which is fashioned to also define a cannister receiving cup 142. Cup 142 is cylindrical and has an axis offset with respect to that of the smaller cannister container 12. At the axis of the cup 142 is formed a receptacle 144 to receive the stem 146 of the cannister valve 148. Within the container 12 a conduit 90' extends from the atomizer 20 to a fitting 150. The fitting 150 may be integrally molded with the container and cup and includes a base 152 which provides communication between the receptacle and the conduit.

The cup 142 has a lip 34' to snap over the circumferential tab 38' of the cannister 32'. The lip 34* and receptacle 144 are positioned to permit the cannister 32' to move upwardly. Accordingly, pressing the cannister 32' causes the stem 146 to be depressed, releasing propellant into the conduit 90' to power the atomizer 20.

While the embodiments described above have been directed to liquid medicaments, it is to be understood that finely ground powders are also deliverable by the nebulizer 10. The powder is disposed in the container 12. The conduit 90, 90' is removed and the bore 72 is blocked. Additionally, the drag bar 112 and arm 116 are removed. When powered by compressed gas, the vortices and sonic energy produced by the atomizer 20, lift and agitate the powder within the chamber 17 for inhalation or delivery to the patient.

While we have shown and described certain embodiments of the present invention, it is to be understood that it is subject to many modifications without departing from the spirit and scope of the claims.

Claims

WHAT IS CLAIMED IS:

1. A nebulizer comprising: a container adapted to hold a quantity of liquid medicament, the ullage of the container defining a chamber; a top secured to the container and including at least one inlet port and one outlet port each communicating with the chamber; and means within the container for atomizing the liquid medicament, the atomized medicament occupying the chamber, inhalation at the outlet port causing a gas to enter the inlet port and sweep the atomized medicament from the chamber to the outlet port.

2. The nebulizer of claim 1 wherein the atomizing means includes a conduit within the container to supply liquid medicament thereto, the container including a bottom contoured to define a deep well of small volume to retain at least the last portion of the medicament to be atomized, said conduit communicating with the deep well for atomization of substantially the entire quantity of medicament.

3. The nebulizer of claim 2 wherein the bottom is conical with a lowermost apex, the conduit communicating with the apex.

4. The nebulizer of claim 1 wherein the atomizing means is of the type powered by pressurized gas, the nebulizer further including a canister of compressed gas and means for supplying such gas to the atomizer.

5. The nebulizer of claim 4 wherein the nebulizer includes a base adapted to releasibly attach a replaceable liquified propellant canister to the nebulizer.

6. The nebulizer of claim 1 further including means for diverting the flow of the sweeping gas through the chamber to sweep the atomized medicament to the outlet port.

7. The nebulizer of claim 6 wherein the diverting means includes a flow diverter surface interposed between the inlet and outlet ports.

8. The nebulizer of claim 1 further including means for inhalation and exhalation including means for restricting flow at the inlet port to a direction into the nebulizer and at the outlet port to a direction out of the nebulizer such that, upon inhalation at the outlet port, sweeping gas passes the flow restricting means and sweeps atomized medicament to the outlet port and upon exhalation at the outlet port, the exhaled breath is vented via the flow restricting means from the nebulizer.

9. A nebulizer for inhalation and exhalation comprising: a container adapted to hold a quantity of liquid medicament, the ullage defining a chamber; a top secured to the container including an inlet port and an outlet port, each communicating with the chamber; means for normally closing the inlet port, the closing means opening upon inhalation at the outlet port to admit a sweeping gas into the chamber to sweep the atomized medicament to the outlet port for inhalation thereof; and normally closed means for venting the chamber adjacent the outlet port to, upon exhalation into the outlet port, vent the exhaled breath from the chamber, the closing means closing the inlet port to prevent jettisoning of atomized medicament therefrom.

OMFI

10. The nebulizer of claim 9 further including a mouthpiece disposed over the outlet port, the mouthpiece including said venting means.

11. The nebulizer of claim 10 wherein the venting means is a check valve of the type having a resililent flapper which is displaced upon exhalation to vent the chamber.

12. The nebulizer of claim 9 wherein the closing means is a check valve of the type having a resilient flapper which is displaced upon inhalation to admit the sweeping gas to the chamber.