EP1448311A1

EP1448311A1 - A modified nebulizer

Info

Publication number: EP1448311A1
Application number: EP02789931A
Authority: EP
Inventors: James M. Davenport; Walter Van Horne; Laurence Mcgann
Original assignee: Salter Labs Inc
Current assignee: Salter Labs Inc
Priority date: 2001-11-30
Filing date: 2002-11-27
Publication date: 2004-08-25
Also published as: WO2003047763A1; AU2002352971A1

Abstract

A nebulizer (210) having a container, an inlet valve, an outlet and a user connection port. A reservoir (230) in a lower portion (262) of the container contains a medicament to be mixed with a pressurized supply gas to generate the medicated aerosol for inhalation by a user. The mixed gas and medicament are nebulized by impacting the aerosol mixture against a deflector (254) and upon inhalation the nebulized aerosolized medicament is drawn along a flow path towards the outlet of the nebulizer. Prior to reaching the outlet of the nebulizer, a baffle (258) nis interposed in the flow path of the aerosolized medicament to facilitate the flow of desirably sized nebulized medicament particles which are more readily absorbed into the bloodstream by the user.

Description

[001] A MODIFIED NEBULIZER

[002] FIELD OF THE INVENTION

[003] The present invention relates to an inhaler device, particularly though 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 for a more efficient use of medication.

[004] BACKGROUND OF THE INVENTION

[005] 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 and, PCT/US01/12684 to Salter. These references and the subject matter disclosed therein are herein incorporated by reference and their more pertinent specific portions are described below.

[006] The nebulizer of 4,746,067 (Fig. 1) is a device for aerosolizing 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.

[007] 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.

[008] In the nebulizer of No. 5,584,285 (Figs. 2, 3 and 4), a breathing circuit apparatus 110 is used in combination with a nebulizer device 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 sourcel 14.

[009] 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.

[010] 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 after the 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. [011] 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.

[012] 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 "P.," while deflector member 154 defines a second imaginary plane "P₂" facially opposed to and parallel with one another.

[013] 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.

[014] 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 annular flange 172 extends circumferentially about and projects radially outwardly from upper rim portion 168 of lower container section 162.

[015] 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/or tolerances 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.

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

[017] 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 inner wall 180 and the outer wall 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.

[018] 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.

[019] 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.

[020] 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 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.

[021 ] 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 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.

[022] 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 standoff 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.

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

[024] 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 delivery to the medicament user. [025] 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.

[026] 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.

[027] OBJECTS AND SUMMARY OF THE INVENTION

[028] 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 effective 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.

[029] Another object of the invention is to provide a deflector and a baffle in conjunction with the nebulizing cone wherein the gas and the medicament are combined via the nebulizing cone before being ejected into contact with the deflector and nebulized into particular sized aerosolized medicament particles.

[030] A still further object of the present invention is to ensure that the particular sized aerosolized medicament particles which are most absorbable in a user's lungs and bloodstream are delivered to the user by providing the baffle in the flow path of the aerosolized particles to rain out larger aerosolized particles prior to inhalation by the user. [031] Another object of the invention is to provide an integral nebulizer cone, deflector and baffle wherein the distances between these elements are maintained at a certain fixed distance relative to one another to maintain a consistent delivery of the particular sized aerosol particles to the user.

[032] An even further object of the invention is to provide a nebulizing cone which maintains the associated deflector member in a fixed relationship with respect to the tip of the nebulizing cone, such that when the lower container of the breathing apparatus is attached to the upper container, no matter to what tolerance the attachment mechanism is adjusted, the critical static distance between the outlet orifice in the tip of the nebulizer cone and the deflector member does not change.

[033] 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.

[034] The lower container defines an internal reservoir for the aerosol and an inlet for pressurized gas for intermixing with the medicament stored in the reservoir. Seated in the lower container is a nebulizing cone having an inlet orifice through which the mixed gas and medicament aerosol is ejected into a deflector target which breaks up the aerosolized gas and medicament into smaller particles which are more readily absorbed by the user's lungs.

[035] The deflector target or member 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. This distance is not absolute as it can change depending upon the medicament used in the nebulizer. [036] The deflector is captively held in a fixed arrangement adjacent the tip of the nebulizer cone by at least a support extending from the nebulizing cone above and beyond a plane defined by the tip of the nebulizing cone. The deflector is positioned in a holder, or notches in the support at this fixed static distance such that any movement of the nebulizing cone results in a cooperative movement of the deflector member thus maintaining the critical static range described above. The deflector itself may be removed from the attachment portion with the at least one support member such that it can be replaced or to provide for ease of separate manufacture between the nebulizing cone and the deflector member.

[037] The container of the above described 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.

[038] 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.

[039] A baffle is provided in a position between the tip of the nebulizing cone and the output of the nebulized medicament to the user. The baffle is positioned in a passageway through which the nebulized medicament passes to the user in order to provide an increased effectiveness of nebulized medicament going to the user. Due to the impact of the mixed gas and liquid medicament and the subsequent nebulizing of the particles, via the deflector, numerous different sizes of particles are produced, only a certain range of which are considered to be particularly effective in being absorbed by the blood stream of the user. The baffle, which is provided with a number of passages therethrough, facilitates the propagation to the user of the substantially greater volume of absorbable particle sizes. The nebulizing cone can statically and directly support the deflector and the baffle at a fixed distance so that a consistent nebulizing and baffling process is maintained throughout operation of the nebulizer.

[040] BRIEF DESCRIPTION OF THE DRAWINGS

[041] 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:

[042] Fig. 1 is a cross-sectional side view of a nebulizer of the prior art represented by United States Patent No. 4,746,067;

[043] 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;

[044] 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;

[045] 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;

[046] 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;

[047] 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

[048] 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. [049] Fig. 8 details an exploded view of a nebulizer of the present invention showing the relative vertical alignment of the upper container and lower container, nebulizing cone and deflector. [050] Fig. 9 is a assembly view of the individual components shown in Fig. 8.

[051] Fig. 10 is a cross-sectional view of the nebulizing cone and deflector support members and baffle. [052] Fig. 10A is a perspective view of the deflector.

[053] Figs. 11 and 12 show a perspective view of the nebulizer cone and baffle passages. [054] Figs. 13A, 13B disclose graphical comparison representations of prior art nebulizer particle size volumetric distributions of a production embodiment and a prior art nebulizer. [055] Figs. 14A, 14B and 14C are a graphical comparison of a two-hole prototype, a two-hole production, and a four-hole production embodiments. [056] Figs. 15A, 15B disclose graphical comparison representations of the volumetric particle size distributions of a production embodiment and a prior art nebulizer. [057] Figs. 16A, 16B disclose graphical comparison representations of the volumetric particle size distributions of a further production embodiment and a prior art nebulizer.

[058] DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[059] 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. [060] 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 an example, the liquid medicaments which are used with the present nebulizer include, but are not limited to, for example water soluble drugs such as Albuterol, a bronchodilator manufactured by Dey Laboratories, used for asthma, Mucocil a mucolytic also manufactured by Dey Laboratories which is a relatively thick and sticky viscous medicament, and Budesonide manufactured by Astra Pharmaceuticals, an antibiotic steroid.

[061] 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 detailed discussion of these prior art components is deemed unnecessary.

[062] Referring now to Fig. 8, an embodiment of the present invention is now described. The nebulizer 210 is provided with an upper container 260, a lower container 262, a nebulizing cone 294, a substantially horizontal baffle 258 and a deflector 254. The upper container 260 has an outer wall 220 defining a breathing passage 228 leading to a mouthpiece passage 280. The mouthpiece passage 280 provides for attachment of a mouthpiece (not shown) to the upper container 260, through which the user maintains oral inhalation and exhalation communication with the nebulizer 210. The upper container 260 is also provided with at least an ambient air inlet 236 having a valve 238 positioned in the inlet 236 to allow a supply of air into the nebulizer 210 during inhalation by the user. The inlet 236 leads to an inlet air passage 248 defined by an inner wall 246 of the upper container 260. The outer wall 220 of the upper container 260 is further provided with a lower lip 264 which is formed so as to separably and sealably connect with an upper lip 266 of the cup type lower container 262.

[063] The lower container 262 is a cup defining a reservoir 230 which during operation contains the liquid medicament which is eventually nebulized and inhaled by the user. The reservoir 230 is specifically defined by a circumferential outer wall 278 and a tapering cone-shaped inner wall 276. The outer wall 278 and the cone-shaped inner wall 276 meet at a substantially V-shaped groove forming the reservoir base 282. The tapering cone-shaped inner wall 276 is defined by a concentrically decreasing diameter from the reservoir base 282 toward an apex defining a venturi throat 284. The base 282 of the reservoir may be provided with stand off nubs 190 as shown in the background for the nebulizing cone 294 to be described in further detail below.

[064] The lower container 262 includes a venturi tube 286 centrally located in the cone-shaped inner wall 276. The venturi tube 286 has an inlet end 288 for connection with a pressurized gas source and an outlet end at the apex of the cone-shaped inner wall 276 defining the venturi throat 284 from which the pressurized gas supplied to the inlet 288 emanates from and subsequently mixes with the liquid medicament drawn from the reservoir 230 to produce the inhalable medicament as described in further detail below.

[065] In order to provide the appropriate intermixing of the liquid medicament and the pressurized gas, the nebulizing cone 294 operates in conjunction with the tapering cone shaped inner wall 276 and the outlet end of the venturi tube 286, i.e. the venturi throat 284, to supply a desired dosage of a medicament from the reservoir region 230 to be mixed with the pressurized supply gas from the venturi tube 286. The nebulizing cone 294 has a tapering wall 296 consistent with but generally spaced by a specified stand off distance from the inner tapering wall 276 of the lower container 262. The nebulizing cone 294 has a flangeless base portion 299 designed to correspond to and fit substantially within the reservoir base 282 of the circumferential V-shaped groove formed by the intersecting tapering wall 276 and circumferential outer wall 278 of the reservoir 230. The stand off distance between the nebulizing cone 294 and the inner tapering wall 276 can be provided by the previously described nubs 190 supporting the base portion 299 or vertically extending ribs or other such similar elements as could be appreciated by those of ordinary skill in the art.

[066] The tapering wall 296 of the nebulizing cone 294 tapers from the wider base portion 299 toward the narrow tip portion 300 of the cone 294 which is provided with an orifice 301 and formed to communicate with and work in conjunction with the venturi throat 284 to define the inlet orifice 234. The inlet orifice 234 facilitates the confluence of the aerosol supply gas delivered via the venturi tube 286 and the liquid medicament which is drawn up to the inlet orifice 234 from the reservoir 230 between the inner tapering wall 276 and the nebulizing cone tapering wall 296. The supply gas and the medicament are mixed at the inlet orifice 234 and ejected through the orifice 301 into the deflector 254 to form the nebulized medicament necessary for inhalation by a user. As described above, the spacing or stand-off between the inner wall 280 and the nebulizing cone 294 may be provided by standoff nubs as shown in the prior art or by axial ribs running longitudinally in the direction of flow between the tapering wall 296 of the nebulizing cone 294 and the cone-shaped inner wall 280 of the lower container 262. The standoff provided by such features may be necessary in order that the flow of medicament between the adjacent surfaces will not be restricted.

[067] Turning now to Fig. 9, the nebulizing cone 294 is discussed in further detail.

The deflector 254 is spaced from the tip 300 of the nebulizing cone 294 by a distance d measured between the deflector member 254 and the inlet orifice 234 which define an imaginary plane P1 , P2, respectively. As known, for a particular medicament the spacing d should be maintained relatively constant to ensure that the proper size particles as well as the proper dosage of medicament are produced by the confluence of the gas supply and the medicament impacting on the deflector member. As the required distance d for producing appropriately sized nebulized particles may vary depending upon the medicament and its associated physical and chemical properties utilized in the nebulizer and as such appropriate distances d may be readily ascertained by those of ordinary skill in the art without undue experimentation, no further description is provided. [068] Observing Fig. 10, the nebulizing cone 294 carries a plurality of deflector support members 256 extending from the surface of the tapering wall 296 of the nebulizing cone 294. The support members 256 are attached at a first end to the tapering wall 296 at a point between the base 299 and the tip 300 and extend generally upwardly to a second end supporting a baffle 258 at a location spaced above and beyond the level of the nebulizing cone tip 300. A deflector support position 257 is defined by a location between the first and second ends of the deflector supports 256 and preferably located between the tip 300 of the nebulizing cone 294 and the baffle, and more particularly located substantially adjacent the tip 300 and spaced from the baffle 258.

[069] The deflector 254, shown in Fig. 10A as a separate element and with reference to Fig. 9, is positioned and supported by the deflector supports 256 at the deflector support position 257. The deflector 254 positioned from but relatively adjacent the tip 300 of the nebulizing cone 294 to provide the appropriate distance d and impacting surface for nebulizing the pressurized gas and mixed medicament aerosol. The deflector 254 is held in a substantially static spaced relationship, i.e. the distance d between the plane P1 , P2 with the tip 300 via at least a receiver 259 at the deflector support position 257 being formed in at least one of the plurality of deflector supports 256. The receivers 259 may be notches in the individual deflector supports 256 which receive at least an edge portion of the deflector 254 therein and hold the deflector 254 at the distance d from the tip 300 of the nebulizer 294. A number or plurality of deflector support positions 257 may also be provided at different support positions along the deflector support members 256 for varying the distance d to accommodate different drugs utilized in the nebulizer. Other receiver 259 arrangements besides the notches may be provide to secure the deflector 254 in the deflector support position 257 as would be apparent to those of skill in the art. The deflector in the present depiction is shown separate from the support 256 but may also be formed integral with the deflector support members 256, but for ease of manufacturing in the present embodiment is provided as a separate element. As discussed, the distance d may vary depending on the drug to be nebulized, the static distance d tends to be most effective when in the range of 0.01 to .2 inches and more particularly in the range of 0.05 to 0.1 inches and even more particularly 0.07 inches.

[070] The deflector 254 is, in general, a removable and replaceable element which can be inserted within the receiver 249 of the deflector supports 256. The deflector 254 is usually substantially circular and provided with an edge portion for engaging within the receiver 259 and the individual deflector supports 256. The deflector 254 is provided with a deflecting surface 255 which includes a target 257 made of a plurality of concentric rings 257 which assist in the break up and intermixing of the medicine and pressurized gas forced through the inlet orifice of the nebulizing cone and impacted upon the target 257. However, despite being shown as circular, it is to be understood that the deflector 254 member could be of a different shape or even manufactured so as to be permanently affixed to the deflector support members 256 stemming from the nebulizer cone surface 296.

[071] Turning now to Figs. 11 and 12, where the nebulizer cone 294 is shown as a substantially integral element without the deflector for clarity sake, during inhalation by a user the nebulized gas and medicament mixture is drawn upward from the lower container 262, impacted on the deflector 254 emanating into the upper container 260 and past the baffle 258. The baffle 258 is provided for the purpose of ensuring that the more effective nebulized particle sizes, e.g. 1-6 microns, more preferably 2-5 microns, are inhaled by the user and that a substantial portion of the less effective nebulized particles, which are not as readily absorbed through the alveoli in the users lungs are collected and returned by raining back down into the reservoir to be nebulized again. The baffle 258 of the present embodiment is a circumferential ring supported by the deflector supports 256 and extends substantially horizontally across the flow direction of the nebulized particles between the inner wall 246 of the upper container and the outer wall 220 of the upper container 260.

[072] In order to facilitate the passage of the nebulized medicament and gas particles past the horizontally extending baffle 258, The baffle 258 is provided with a plurality of holes or passages 259 to facilitate the passage of appropriate size nebulized particles past the baffle 258 and upward through the passages 259 and into the breathing passage 228 for inhalation by the user. The baffle 258 tends to trap a significant portion of the less desirable particles, not allowing these particles to emanate into the breathing passage 228 for inhalation and raining these particles back down into the medicament supply reservoir 230. In the present embodiment both 2 and 4 hole baffles are contemplated, although other numbers of holes and the relative size and location of such holes could be effective as well.

[073] The passages or holes 259 are equi-distantly spaced circumferentially around the horizontally extending baffle 258. In the embodiment of Fig. 12, the baffle 258 is shown having 4 holes, the holes 259 are positioned adjacent the outer edge 266 of the baffle 258 and spaced from the inner edge of the baffle 258. The holes 259 have a corresponding curvature to that of the outer edge 266 of the baffle 258 and one embodiment are shown are spaced at an angle of about 90° apart and each of the holes 259 may have a length of curvature extending between 10° and 30° of the circumference of the baffle 258. Fig. 11 reveals an embodiment showing two holes 259 separated by about 180 degrees and sized and positioned on the baffle 258 in a manner similar to that described for the 4 hole example.

[074] As an example and as set forth in Tables I, II and III below, tests were performed utilizing the above described device with a different drugs, specifically Albuterol, a second drug Mucocil and a third antibiotic Budesonide using pressurized wall air at 7 Ipm (liters per minute).

[075] Table I Albuterol

[078] The output of the device is measured in milliliters per minute and is the rate of the drug per unit time which is output by the device. In most cases the higher the output value, for instance with respect to Table I and Albuterol, as shown by the 2 hole example, the more of the drug which is introduced to the user's lungs for absorption into the blood stream per minute. The residual volume, RV, is the amount of drug in milliliters which is left over after nebulizing. The third column is the nebulizing time, i.e. the time in minutes in which substantially all of the drug is used or inhaled into the user's lungs. For example, as again seen in the 2 hole variation, the nebulizing time for the significant portion of the drug is 5.14 minutes and is the fastest of the nebulizing times in this data.

[079] Of particular interest in the nebulization of particles of different drugs is the mean average diameter in microns of the nebulized particles. In order words, the size of the particle. Whereas discussed above, the preferred size of the particles is between 0 and 6 microns. It is usually more preferable to have between 2 and 4 microns and even more preferable between 2 and 3 microns. The 2 and 4 hole embodiments, as shown in this experiment, produce the mass median aerodynamic diameter, MMAD, of particles at 2.93 and 2.68 as shown. Finally, GSD discloses the standard deviation of the remaining particles from the MMAD and thus, the lower the number in the present case, the more effective the nebulization. As can be seen from the 2 hole embodiment, which maintains the lowest standard deviation of 3.33 microns as the preferable nebulization production from the above data.

[080] To further expound on the desired particle size, the Applicant points to

Figs. 13A and 13B disclosing the particle size by percentage volume of the prior art A and prior art B nebulizers. In observing Figs. 13A and specifically 13B, it is preferable that the larger particle sizes of, for example, 8 to 16 microns are kept to a minimum, for as discussed above, these particles which are less likely to absorb into the blood stream.

[081] Turning now to Figs. 14A, 14B and 14C, Fig. 14A and the comparison to the above data, is the volumetric output particle size utilizing a 2 hole prototype baffle, Fig. 14B is particle size output from the 2 hole production baffle and Fig. 14C is the particle size output resulting from a 4 hole production baffle. Specifically observing the 4 hole production of Fig. 14C, it should be noted that this embodiment shows a substantial decrease in the larger particle size particularly from the prior art B nebulizer and that the 2 hole production, Fig. 14B, shows an even greater difference and substantial improvement over not only the prior art B but the prior art A data as well. Figs. 14A, 14B and 14C reveal a substantially larger population of particle sizes in the range of 4 microns again than either of the prior art nebulizers. Additionally, Figs. 15A-B disclose the particle size range for Budesonide in a production model of the present embodiment in comparison to the prior art A, and Figs. 16A-B disclose the particle size data for Mucocil in a production model of the present embodiment in comparison to the prior art A. Therefore, the baffle embodiments of the horizontal baffles as described above are shown to provide desirable improvements over the prior art in light of the recited experimental data. Since certain changes may be made in the above described solid, unitary rotor and shaft device, without departing from the spirit and scope of the invention herein involved, it is intended that all of the subject matter of the above description or shown in the accompanying drawings shall be interpreted merely as examples illustrating the inventive concept herein and shall not be construed as limiting the invention.

Claims

1/ we claim:

1. A nebulizer for aerosolizing a liquid with a gas comprising: a housing defining a longitudinal axis and forming a reservoir for the 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 of the housing, the conical portion having a conical external surface intersecting an outer wall of the housing to define 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 an apex of the nebulizing cone for aerosolizing gas from the venturi tube and liquid from the reservoir; and a baffle positioned in a flow path of the aerosolized gas and liquid, having at least a passage therethrough to facilitate the inhalation of a desired size of nebulized medicament particles.

2. The nebulizer as set forth in claim 1 , wherein the baffle is inserted horizontally with respect to the longitudinal axis and the flow path of the aerosolized gas and liquid.

3. The nebulizer as set forth in claim 2 wherein the passage through the baffle is substantially parallel relative to the longitudinal axis of the nebulizer.

4. The nebulizer as set forth in claim 3 wherein the baffle is integrally connected to the nebulizing cone at a fixed distance therefrom.

5. The nebulizer as set forth in claim 1 further comprising a deflector to receive and deflect the liquid and gas discharged by the liquid and gas discharge thereby producing a nebulized gas and liquid mixture for inhalation by the user.

6. A method for effectively controlling accurate efficient administration of a medication by inhalation using a nebulizer, the method comprising the steps of: a) providing a housing defining a longitudinal axis and forming a reservoir for the 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 of the housing, the conical portion having a conical external surface intersecting an outer wall of the housing to define 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 for aerosolizing gas from the venturi tube and liquid from the reservoir; and c) positioning a baffle in a flow path of the aerosolized gas and liquid, having at least a passage therethrough to facilitate the inhalation of a desired size of nebulized medicament particles.

7. A nebulizer for providing an aerosolized liquid medicament to a patient, the nebulizer comprising: a reservoir containing liquid medicament; an aerosolizing gas inlet defining a nozzle for mixing pressurized aerosolizing gas with the liquid medicament from the reservoir; an impact surface located adjacent the nozzle for aerosolizing and diverting a flow of the pressurized aerosolizing gas and liquid medicament from the nozzle; and a baffle positioned between the impact surface and a patient supply opening to ensure that substantially only effective sized aerosolized liquid medicament particles are inhaled by the patient via the patient supply opening.

8. The nebulizer as set forth in claim 7 wherein the baffle comprises a barrier defining a passage permitting substantially only effectively sized aerosolized liquid medicament particles to pass through the barrier.

9. The nebulizer as set forth in claim 7 wherein the baffle is defined by a wall positioned substantially perpendicular with respect to the flow of the aerosolized medicament, the wall having a plurality of equidistant spaced holes formed therein, the holes permitting delivery of substantially only effectively sized aerosolized liquid medicament particles to the patient.

10. The nebulizer as set forth in claim 7 wherein the impact surface is spaced from the nozzle at a distance between about .01 to .2 inches