A NEBULIZER Field of the Invention The present invention relates to an inhalerdevice, particularlythough not exclusively a nebulizer, adapted for use with a breathing circuit apparatus so that a user can inhale an aerosol generated by the nebulizer from the breathing circuit apparatus. More particularly, the present invention is directed to an improved nebulizer which ensures the proper particle size distribution or break up of the fluid introduced into the nebulizer for generating a medicament-containing aerosol so that a breathing user/patient obtains a substantially more effective medicated aerosol during inhalation of the medicinal aerosol from the breathing circuit apparatus together more efficient use of medication.

Background of the Invention Various types of nebulizers have been used in commerce for a variety of applications and are well known in the art. One common application for a nebulizer is in the medical industry. Such a nebulizer has been used in the medical industry for effective delivery of medicines to a patient's lungs.

An example of a nebulizer capable of delivering medicine to a patient's lungs is disclosed in United States Patent Nos. 4,746,067 to Svoboda and 5,584,285 to Salter.

The nebulizerof4, 746,067 (Fig. 1) is a device foraerosolizing a liquid medicine 7 with a pressurized gas (the source of which is not shown) which is typically compressed air. The prior art nebulizer includes a container 1 for holding liquid medicine 7, a mixing mechanism 50 and a deflector member 11. Mixing mechanism 50 comprises a venturi tube 2 and a liquid conduit means 6. Venturi tube 2 has an upstream opening 3 adapted for connection to the source of pressurized gas, a throat portion 4 and a discharge opening 5. Liquid conduit means 6 is connected to container 1 and has an outlet opening 8 adjacent to a downstream end 9 of throat portion 4. Venturi tube 2 is dimensioned and positioned to withdraw liquid

medicine 7 from reservoir 19 and through liquid conduit means 6 and to project a mixture of liquid and gas out of discharge opening 5 at a high velocity in a nebulized liquid/gas stream.

A deflector member 11 is positioned adjacent to and disposed from discharge opening 5 of venturi tube 2 and has a surface 12 intersecting the liquid/gas stream and causing a dispersion of the liquid/gas stream in a second direction different from the first direction. Deflector member 11 is employed to further reduce the liquid droplet size in the nebulized liquid/gas stream thereby causing a fine mist which dispersed about an interior chamber of container 1.

In the nebulizer of No. 5,584,285 (Figs. 2,3 and 4), a breathing circuit apparatus 110 is used in combination with a nebulizerdevice 112 which may be formed either as a unitary construction with breathing circuit apparatus 110, or alternatively the nebulizer device 112 may also be detachable from the apparatus 110, and in either case is operably coupled to an aerosolizing pressurized gas source114.

Nebulizer device 112 is operative to generate an aerosol at gas pressures of from about 20 psi to 50 psi at a flow rate of 6 to 8 liters per minute. Breathing circuit apparatus 110 is adapted for use by a user 116 for inhaling the aerosol through an opening 118, the user's mouth, in a respiratory system of user 116 and into the user's lungs and thereafter exhaling exhalation gas from opening 118 in the user's respiratory system and through breathing circuit apparatus 110.

In Figs. 3 and 4, the nebulizer comprises a container 120, an inlet valve 122 controlling an inlet port 136, an outlet valve 124 and a user connection port 126. The container 120, generally cylindrical in shape, defines an interior chamber 128 therein. The nebulizer 110 as an interior chamber 128 including a reservoir region 130 which holds the liquid to be nebulized and an aerosol region 132 for receiving the aerosol afterthe liquid becomes nebulized. Container 120 is operatively coupled to nebulizer device 112 having an inlet orifice 134 which provides fluid communication

between interior chamber 128 and nebulizer device 112. At least reservoir region 130 of interior chamber 128 is sized and adapted to receive the aerosol generated by nebulizer device 112 through inlet orifice 134.

The nebulizer 110 includes a downdraft tube 146 which extends within interior chamber 128 to define a downdraft duct 148. Downdraft tube 146 includes a first, inlet, end 150 and a free second, outlet, end 152.

A deflector member 154 is disposed within interior chamber 128 and is interposed between free second end 152 of downdraft tube 146 and inlet orifice 134. Deflector member 154 is positioned in a spaced apart relationship from free second end 152 of downdraft tube 146 and inlet orifice 134. Deflector member 154 and inlet orifice 134 are spaced apart at a distance"d"shown in Fig. 4 which is selected from a range between approximately 0.019 inch and 0.036 inch. Inlet orifice 134 defines a first imaginary plane"P1"while deflector member 154 defines a second imaginary plane"P2"facially opposed to and parallel with one another.

A plurality of spacers 156 interconnect free second end 152 of downdraft tube 146 and deflector member 154 and define spacer openings 158 by which ambient air"a"which enters container 120 through inlet valve 122, passes outwardly into chamber 128.

Container 120 comprises an upper container section 160 and a lower container section 162 which is releasably connected to upper container section 160. As shown in Fig. 3, upper container section 160 includes a lower rim portion 164 having a plurality of channels 166 formed therein while the lower container section 162 includes an upper rim portion 168 having a plurality of flanges 170 projecting radially outwardly from upper rim portion 168. Flanges 170 and channels 166 are sized and adapted for matable engagement with each other so that upper container section 160 and lower container section 162 can be releasably connected together in a fluid tight relation to form a unitary container. An annularflange 172 extends circumferentially about and projects radially outwardly from upper rim portion 168 of lower container section 162.

The upper and lower container sections 160,162 are often connected by threads which as with the flange construction described are subject to overtightening and/ortolerances which facilitate undesirable variations in the spacing between the base 182 and the deflector member 154 with the consequent undesirable variation of"d"thereby possible.

The nebulizer also includes an outlet conduit 174 for communication between chamber 128 and a patient.

Lower container 162 includes the reservoir region 130 defined by a substantially cylindrical outer wall 178 and a tapering cone-shaped inner wall 180. The reservoir 130 has a base 182 formed by the acute intersection between the tapering innerwall 180 and the outerwall 178. The intersection forms a circumferential generally V-shaped groove between the inner and outer walls thus constituting the reservoir base 182 of the reservoir region 130.

The tapering cone shaped inner wall 180 tapers upwardly and inwardly with respect to the reservoir base 182 from a larger diameter at the acute intersection between the tapering inner wall 180 and the outer wall 178 to a smaller diameter venturi throat 184 vertically spaced from the reservoir base 182. The venturi throat 184 is located at the apex of the cone shaped inner wall and establishes the exit of a venturi tube 186 through which the pressurized supply gas is ejected into the nebulizer and against the deflector member 154.

The venturi tube 186 is an elongate tubular passage having a gas entrance end 188 for communicating with the pressurized gas supply source 114 (Fig. 2) and the gas exit near which the passageway narrows to communicate with a smaller constant diameter passageway forming the exit and venturi throat 184 at the apex of the tapering cone shaped inner wall which increases the velocity at which the gas is ejected from the venturi throat 184 against the deflector 154.

The nebulizer is further provided with a nebulizing cone 194 operating in conjunction with the tapering cone-shaped inner wall 180 and the exit and

venturi throat 184 to supply an amount of a medicament from the reservoir region 130 to be mixed with the pressurized supply gas from the venturi tube 186. The nebulizing cone 194 has a tapering wall 196 designed to match with and fit concentrically over the inner tapering wall 180 of the lower container 162. The cone 194 has a circumferential wider base flanged portion 198 designed to correspond to and fit substantially within the circumferential V-shaped groove formed by the intersecting tapering inner wall and outer wall 178,180. A tip 200 of the cone 194 encompasses the gas exit and venturi throat 184 and is provided nozzle a hole therein which defines the orifice 134 through which the mixture of supply gas and medicament is directed onto the defector member 154.

The nebulizer cone 194 has a taperdefined by a decreasing diameter which concentrically with respect to the tapering inner wall 180 narrows the diameter of the cone from the base portion 198 towards the tip portion 200 formed to communicate with and work in conjunction with the venturi throat 184 to define the inlet orifice 134. The inlet orifice 134 facilitates the confluence of the aerosol supply gas and the medicament to be ejected into the deflector 154 to form the nebulized medicament necessary for inhalation by a user. The wider base portion is formed by an annular flange having a radial cross-section substantially filling the V-shaped groove.

Objects and Summary of the Invention An object of the present invention is to provide a new and improved nebulizer device for a breathing circuit apparatus operative to generate an appropriate and properly diffused aerosol so that a user can inhale a more effectual medicated aerosol through an opening, i. e., nose and/or mouth, in the user's respiratory system and into the user's lungs where the improved medicated particle distribution facilitates a more effective absorption of the medicament through the user's respiratory system and into the bloodstream.

Another object of the invention is to ensure a critical minimum spacing between the pressurized gas supply air inlet and the medicament supply

channel defined by a nebulizing cone wherein the gas and the medicament are combined before being ejected into contact with the deflector.

A further object of the invention is to provide this critical spacing via a plurality of circumferential nubs around the base of the reservoir such that the base of the nebulizing cone is supported at no less than a minimum stand-off distance to ensure that the tip of the nebulizing cone never falls below a reciprocal minimum stand-off with respect to the venturi throat of the venturi tube.

A still further object of the invention is to provide a circumferential stop in the lower rim portion of the upper container of the breathing circuit apparatus, such that when the lower container of the breathing apparatus is attached, the upper rim thereof cannot proceed past the circumferential stop member, thus ensuring that another critical minimum distance between the inlet orifice and the deflector member does not fall below a minimum value.

Accordingly, the invention may be summarized as follows.

The breathing circuit apparatus of the present invention includes a downdraft tube extending within the interior chamber to define a downdraft duct. The downdraft tube has a first end connected to the container which surrounds the air inlet port of the inlet valve and a free second end which is disposed opposite of the first end. When exterior ambient air enters through the air inlet port at the first end when the inlet valve is in the opened condition, the ambient air flows through the downdraft duct to the free second end.

The breathing circuit apparatus of the present invention also includes a deflector member that is disposed within the interior chamber and interposed between the free second end of the downdraft tube and the inlet orifice. The deflector member is positioned in a spaced apart relationship from the free second end of the downdraft tube and the inlet orifice. The deflector member and the inlet orifice are spaced apart from one another at a distance selected from a range between approximately 0.019 inch and 0.036 inch.

The container of the breathing circuit apparatus of the present invention can be either unitary in construction or can be formed of two sections, an upper container section and a lower container section releasably connected to the upper container section. The upper container section includes a lower rim portion having a circumferential stop member for preventing over tightening between the upper container and the lower container. The stop member ensures that a minimum distance is maintained between the deflector member and the inlet orifice.

A standoff distance between the venturi throat of the supply gas and the inlet orifice is maintained by a plurality of nubs in the base of the reservoir supporting the nebulizing cone at a minimum distance from the tapering inner walls of the lower container, this also ensures that a consistent mixing of the gas and medicament is provided and maintained throughout each inhalation by the user.

According to the invention there is provided a nebulizer for aerosolizing a liquid with a gas comprising: a housing defining a longitudinal axis and forming a reservoirforthe liquid, the housing defining a venturi tube having an upstream opening adapted for connection to a source of pressurized gas and a downstream outlet opening located at the apex of a conical portion on said axis, of the housing, defining a conical external surface, the conical portion together with an outer wall of the housing defining the reservoir; a nebulizing cone having a conical internal surface disposed over the external conical surface in close conformity therewith and a liquid and gas discharge opening at the apex of the cone on said axis to receive gas from the venturi tube and liquid from the reservoir; and a plurality of spacers disposed between the housing and a lower rim of the nebulizing cone to maintain desired minimum axial spacing between the conical internal and a external surfaces along said axis for passage of the liquid therebetween from the reservoir to the liquid and gas discharge opening when gas is discharged form the venturi tube.

Also according to the invention there is provided a method for effectively controlling accurate efficient administration of a medication by inhalation using a nebulizer, comprising the steps of: a) providing a housing defining a longitudinal axis and forming a reservoirforthe liquid, the housing defining a venturi tube having an upstream opening adapted for connection to a source of pressurized gas and a downstream outlet opening located at the apex of a conical portion on said axis, of the housing, defining a conical external surface, the conical portion together with an outer wall of the housing defining the reservoir; b) providing a nebulizing cone having a conical internal surface disposed over the external conical surface in close conformity therewith and a liquid and gas discharge opening at the apex of the cone on said axis to receive gas from the venturi tube and liquid from the reservoir; and c) positively spacing the housing and a lower rim of the nebulizing cone to maintain desired minimum axial spacing between the conical internal and a external surfaces along said axis for passage of the liquid therebetween from the reservoir to the liquid and gas discharge opening when gas is discharged form the venturi tube.

Brief Description of the Drawings These and other objects of the present invention will become more readily appreciated and understood from consideration of the following detailed description of the exemplary embodiments of the present invention when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a cross-sectional side view of a nebulizer of the prior art represented by United States Patent No. 4,746,067; Fig. 2 is a perspective view of a nebulizer, of the prior art represented by United States Patent No. 5,584,285, partially broken away and illustrated in combination with a nebulizer shown operatively coupled to a pressurized aerosolizing gas source and a medicament source with a user/patient breathing into and from the breathing circuit apparatus;

Fig. 3 is a cross-sectional side view of the prior art nebulizer in the breathing circuit apparatus of Fig. 2 showing an inlet valve having an air inlet port being in an opened condition and an outlet valve having an outlet port being ain a closed state; Fig. 4 is an enlarged fragmentary side view in cross-section of the prior art nebulizer of Fig. 3 disposed within an interior chamber and positioned in a facially-opposing, spaced-apart, parallel relationship with a deflector member ; Fig. 5 is a fragmentary diagrammatic cross-sectional side view in elevation of the upper and lower section of the nebulizer of the present invention; Fig. 6 is an enlarged fragmentary cross-sectional view of a portion A, circled in Fig. 5, of the circumferential V-shaped joint between the tapering inner wall and the tapering nebulizing cone; and Fig. 7 is an enlarged fragmentary cross-sectional view B, circled in Fig. 5, showing the relationships between the critical spacings of the deflector member and the nebulizing cone due to the circumferential stop member in the upper container, as well as the tapering side wall spacing between the nebulizing cone and the inner tapering wall of the lower container.

Detailed Description of the Exemplary Embodiments A nebulizer device which produces a medicated aerosol used in combination with breathing circuit apparatus is adapted for use by a user for inhaling the aerosol through an opening, i. e. nose and/or mouth in a respiratory system of the user and into the user's lungs and thereafter exhaling exhalation gas from the opening in the user's respiratory system and through the breathing circuit apparatus.

One of ordinary skill in the art would appreciate that many different types of nebulizer devices exist that produce an aerosol for many different types of applications. Furthermore, a skilled artisan would appreciate that

nebulizer devices are often employed in the medical industry to produce a medicament-containing aerosol from a liquid medicament for inhalation by a user/patient.

As the description proceeds, the skilled artisan would appreciate that the nebulizer device of the present invention can be utilized in combination with any type of breathing circuit apparatus that produces an aerosol regardless if the aerosol produced contains medicament. Only by way of example and not of limitation, the breathing circuit apparatus of the present invention is described and illustrated hereinafter with components of a prior art nebulizer discussed hereinabove and understood by one of ordinary skill in the art. Further discussion of these prior art components is deemed unnecessary.

In the following description, elements and relationships common to the hereinabove described prior art are not again described in detail and reference numerals for such elements are reused.

Referring to Figs. 5,6 and 7, situated at the V-shaped groove in the reservoir base 182 at the acute intersection between the circumferential outer wall 178 and the tapering cone-shaped inner wall 180, are a plurality of three stand-off nubs 190 integrally formed with the outer wall 178 and inner wall 180. The stand-off nubs 190 are evenly spaced from one another about the circumference of the V-shaped groove in the reservoir base 182.

The nubs 190 extend upwardly along the inner and outer wall to a height"t" from the base of the reservoir to form a support surface 192 spaced at the height"t"from the reservoir base 182. The supporting surfaces 192 of the nubs 190 are of equal height to provide stable support of the cone.

It will be appreciated that the nubs may, alternatively, be formed on the lower rim of the nebulizing core 196.

The nebulizing cone 194 operates in conjunction with the tapering cone-shaped inner wall 180 and the exit and venturi throat 184 to supply a desired dosage of a medicament from the reservoir region 130 to be mixed with the pressurized supply gas from the venturi tube 186.

The nebulizing cone 194 has a tapering wall 196 consistent with but spaced from the inner tapering wall 180 of the lower container 162. The cone 194 has a flangeless base portion 199 designed to correspond to and fit substantially within the circumferential V-shaped groove formed by the intersecting tapering inner wall and outer wall 178,180 supported at a desired height by the nubs 190 without obstructing flow of medication from reservoir 19 through the V-shaped groove to the space between walls 180 and 196. Compared to the prior art, any axially extending ribs in the cone 194 have no function in this design except, in some circumstances, to limit radial flop of the cone 194 relative to surface 180.

The nebulizer device is further provided with a nebulizing cone 194 operating in conjunction with the tapering cone-shaped inner wall. 180 and the exit and venturi throat 184 to supply an amount of a medicament from the reservoir region 130 to be mixed with the pressurized supply gas from the venturi tube 186. The nebulizing cone 194 has a tapering wall 196 designed to match with and fit concentrically overthe innertapering wall 180 of the lower container 162. The cone 194 has a circumferential wider base portion 198 designed to correspond to and fit substantially within the circumferential V-shaped joint formed by the intersecting tapering inner wall and outer wall 178,180. A tip 200 of the cone 194 encompasses the gas/liquid exit 183 and venturi throat 184 and is provided with a hole therein which defines the inlet orifice 134 through which the mixture of supply gas and medicament is directed onto the defector member 154.

The nebulizer cone 194 has a taper defined by a decreasing diameter which concentrically with respect to the tapering inner wall 180 narrows the diameter of the cone from the wider base portion 198 towards the tip portion 200 formed to communicate with and work in conjunction with the venturi throat 184 to define the inlet orifice 134. The inlet orifice 134 facilitates the confluence of the aerosol supply gas and the medicament to be. ejected into the deflector 154 to form the nebulized medicament necessary for inhalation by a user.

Due to the spacing"t"provided by the stand-off nubs 190, the lower base portion 198 of the cone 194, flow of medicament between the cone's inner surface 204 and surface 180 cannot be constricted. Thus, the flow of medicament from the reservoir remains essentially uninterrupted despite any variance in the position of the cone with respect to the inner tapering wall 180 and this together with the omission of flange 198 provides improved efficiency of medicament user.

As best seen in Fig. 6, the stand-off nubs 190 provide a consistent critical spacing, the stand-off spacing. This spacing is critical in order to draw the specific desired amount of medicament into contact with the supply gas. With the proper amount of medicament nebulized into desired particle size for the medicated aerosol the user is provided with consistent dosage of medication from one inhalation to the next.

Fig. 7 also shows the upper container 160 of the nebulizer which includes the lower rim portion 164 which is provided with a circumferential groove 208 having a circumferential axially facing stop surface 209 to abut and rest on an uppermost annular surface 210 of the upper rim portion 168 of the lower container 162 to positively locate the upper container section 160 axially relative to the lower container section 162. The upper and lower portions 160,168 may be attached together by snap together grooves/flanges threads, etc.

The groove 208 provides the critical distance"d"between the deflector member 154 and the inlet orifice 134 cannot be changed during assembly. This distance"d"between the imaginary planes P1 and P2 as discussed previously is a critical spacing which should not be decreased beyond a desired point to ensure that the proper sized particles, as well as the proper dosage, are produced by the confluence of the gas supply and medicament impacting on the deflector member. Thus the critical spacing"d"between the deflector member 154 and the inlet orifice 134 has a set value dependent upon the interaction between the uppermost

edge 210 of the upper rim portion 168 and the circumferential stop surface to ensure improve output and partial size of nebulizer output.

The use of nubs 190, the positive abutting surfaces 209 and 210 together wit the elimination of the prior art flange on the lower rim 198 of the nebulizer cone 194 can, together, provide a reduction in waste (unused) medicament from about 20 percent to about 10 percent for 5 ml to 3 mi of medicament, respectively.