Sonic Nebulizer

Abstract

A sonic nebulizer having an electronic powered piezo-electric crystal to produce mechanical vibrations which are transmitted through a coupling fluid and focused on a second fluid contained in a chamber having a tangentially directed pressurized air inlet and a central opening whereby the nebulized second fluid is entrained by the vortex air flow generated in the chamber and the resulting fluid mixture carried through the outlet. The coupling fluid, electric power oscillator, piezo-electric crystal and associated control apparatus are contained by a portable casing which presents a compact, lightweight and rugged unit particularly adapted for short or long term use in supplying medicated air or oxygen to a patient undergoing medical care. The chamber containing the nebulized second fluid is made of an inexpensive, transparent material which is quickly and easily mounted to the casing and attached to inlet and outlet hoses. The inlet and outlet hoses, like the chamber, may be made from inexpensive material and together with the chamber constitute a disposable portion to avoid contamination between patients.

Description

BACKGROUND OF THE INVENTION

In general, nebulizers for medical treatment are not new and various forms thereof exist for hospital or home use. However, the nebulizers of which I am aware have a number of serious disadvantages including high cost, lack of simplicity and attendant maintenance problems as well as need for skilled therapists, limited life and lack of reliability due to inability to withstand repeated shock and the like resulting from rough handling and/or other mistreatment, susceptibility to contamination of hoses, etc., as a result of being exposed to a patient's breath and subsequent need for disassembly to permit sterilization before use on another patient. Other undesirable characteristics include disassembly problems involved in replacing critical parts subject to deterioration and replacement under normal usage.

In particular, the design of prior art nebulizers precludes accurate control over the quantity of medicament nebulized over a given period of time so that a specified medicant-air and/or oxygen mixture can be maintained to a patient over a short or long time period.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a sonic nebulizer characterized by structural simplicity, compactness and lightweight which renders the same readily portable for use at substantially any desired location in a hospital or home.

It is an important object of the present invention to provide a sonic nebulizer characterized by reliability of operation and ruggedness even under continuous usage.

It is another object of the present invention to provide a sonic nebulizer which is relatively inexpensive to manufacture and operate and capable of providing a wide range of aerosol output with or without medicaments.

It is another object of the present invention to provide a sonic nebulizer which is easy to clean and sterilize and wherein the portions thereof normally exposed to contamination by a patient temporarily using the same are disposable to prevent cross contamination to a subsequent patient using the same.

It is another object of the present invention to provide a sonic nebulizer characterized by a wide range of aerosol output flow thereby adapting the same for medical use with a face mask or tent.

It is still another object of the present invention to provide an inexpensive, disposable nebulizer chamber including medicant cup which is rugged, efficient and easily attached to or removed from associated nebulizer apparatus.

Other objects and advantages will be apparent from the following description taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents a sectional view of a sonic nebulizer embodying the present invention;

FIG. 2 represents an end view of the apparatus of FIG. 1;

FIG. 3 represents a sectional view of a piezo-electric transducer assembly;

FIG. 4 represents a sectional view taken on line 4--4 of FIG. 1.

FIG. 5 represents a portion of FIG. 1 modified to provide greater output flow for tent use.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, FIG. 1 in particular, numeral 20 designates a generally rectangular shaped, multi-section casing having an upper section 22 defining a fluid reservoir and a lower section 24 housing various control elements as will be described. The upper section 22 rests upon the lower section 24 and is readily separable therefrom. Preferably, the casing 20 is constructed from any suitable plastic material which may be easily and quickly formed to the required shape and having desirable characteristics including low cost, strength as well as being impact resistant, lightweight, electrically non-conductive and corrosion resistant.

The lower section 24 is supported by a plurality of spaced-apart legs generally indicated by 26 suitably secured thereto. An air inlet 28 in lower section 24 is provided with an air filter element 30 secured therein by integral flexible clips 32 which engage casing 20. A floor or platform 34 is positioned on a plurality of spaced apart supports 36 integral with casing 20 by fasteners 35, only one being shown. The supports 36 hold the platform 34 a uniform distance from the base 38 to form a passageway 33 therebetween.

A control panel 40 fixedly secured to platform 34 by suitable fastening means such as screws 41 is held in spaced-apart relationship to an air outlet 42 in lower section 24 through which pressurized air is discharged from the interior of lower section 24. An air outlet opening is defined by a fitting 44 fixedly secured to control panel 40 by a lock nut 46 threadedly engaged therewith. Various control members including a power regulator 48 having an adjustable control knob 50 movable between low and high power settings, an air control push to operate control member 52, a fuse block 54, an ON-OFF push button switch 56 and a timer 58 for indicating elapsed time of operation are suitably connected to panel 40 for control purposes.

The air inlet of fitting 44 is isolated from air flowing to air outlet opening 42 by partition means including a wall 60 extending at an angle to panel 40 and provided with suitable integral end wall portions 62 only one of which is shown. A truncated plug or valve member 59 fixed to a plate 61 is adapted to move relative to the inlet of fitting 44 to vary the effective flow area of fitting 44. The plate 61 is secured to a shaft 63 suitably mounted for rotation and actuated by a link 65 connected to air control member 52. The wall 60 is suitably flanged to permit opposite edge portions thereof to be fixedly secured to control panel 40 and platform 34 by suitable fastening means such as screws 64.

A power control unit generally indicated by 66 is connected to a source of electric power via insulated power cord 68. The power control unit 66 is provided with suitable flange members 70 fixedly secured to platform 34 by any suitable means such as rivets 72 to thereby provide support for power control unit 66. The power control unit 66 including internal electronic circuitry thereof is fully described as well as claimed in co-pending application Ser. No. 45,163 filed June 10, 1970 now U.S. Pat. No. 3,648,188 in the name of H. Ratcliff, owned by the common assignee of this application and incorporated by reference. In general, the power control unit 66 is adapted to receive an electric input via lead 68 and control the same to a desired oscillating electric output of predetermined frequency and amplitude. To that end, the power regulator 48 is electrically connected to power control unit 66 such that any desired electrical power output within the established range may be selected by rotating control knob 50 to the proper position.

A housing 74 is fixedly secured to platform 34 by suitable fastening means including a plurality of nut and bolt combinations 76. The housing 74 houses a conventional air blower 78 rotatably supported therein and driven by an electric motor 80 suitably connected to lead 68. The housing 74 is provided with an air inlet 82 exposed to filtered air from air inlet 28 and an air outlet 84 for discharging pressurized air to an air channel partially defined by platform 34 and base 38 between which the air flows to an opening 86 in platform 34 thence to air outlet fitting 44. A fan 87 driven by shaft 77 of electric motor 80 receives air from air inlet 28 and urges the same through lower section 24 to air outlet 42 to thereby provide cooling air flow which passes over power control unit 66 to dissipate heat generated thereby. A shroud 88 suitably mounted around fan 87 confines the incoming air to passage through fan 87.

The lower section 24 is provided with a dished upper wall portion 90 provided with an opening 92 having a flanged edge 94. A cup-shaped receptacle 96 flanged to mate with flanged edge 94 is fixedly secured thereto by any suitable means such as an adhesive or the like. An opening 98 in the base of receptacle 96 is provided for a purpose to be described.

The upper section 22 is contoured to mate with dished upper wall portion 90 and has a flanged opening 100 formed therein. A sleeve 102 having a shoulder 104 formed in the upper end thereof is received by flanged opening 100 to which the sleeve 102 is fixedly secured by any suitable means such as an adhesive providing a fluid seal. The inner wall of sleeve 102 is threaded as at 106 and adapted to threadedly receive an energy transducer or piezo-electric crystal assembly generally indicated by 108. The upper section 22 is provided with a cover 110 having a channeled edge section 112 adapted to engage a resilient seal 113 secured to the wall of upper section 22 to thereby hold cover 110 in position securely. An opening 114 in cover 110 is adapted to receive a standard U.S.P. bottle, not shown, for supplying fluid to the reservoir defined by upper section 22. A cap 116 suitably secured in opening 114 serves to plug the same in the event a conventional U.S.P. bottle is not used as will be described. An opening 118 in cover 110 is aligned with a sleeve 120 having a radially extending wall 123 fixedly secured to cover 110 by any suitable means such as adhesive or the like. The sleeve 120 is aligned with sleeve 102 containing the piezo-electric crystal assembly 108 and extends below the level of fluid in upper section 22.

A nebulizing chamber is defined by a container 122 preferably circular in form and molded from any suitable relatively inexpensive thermoplastic material. The container 122 is provided with an integral tubular extension 124 defining an air inlet located to direct pressurized air tangentially into container 122 as indicated in FIG. 4. An integral two diameter tubular extension 126 centrally located in the top of container 122 provides an air outlet for container 122. The tubular extensions 124 and 126 are provided with corrugations 128 adapted to engage respective mating coupling members 130 and 132 suitably fixed to one end of flexible inlet and outlet hoses 134 and 136, respectively. The opposite end of inlet hose 134 is provided with a coupling 138 suitably fixed thereto which is adapted to engage a corrugated portion 128 of fitting 44. The opposite end of outlet hose 136 is adapted to be removably attached to a conventional breathing mask, not shown. The container 122 has an integral outwardly extending annular rib 140 and an adjacent integral annular recess 142 molded therein and located at approximately the mid-portion of container 122. An annular recess 144 is defined by an outwardly extending annular rib 146 formed in a reduced diameter which transitions into a substantially flat base portion 148 of container 122. The base portion 148 and, in particular, the portion thereof exposed to the piezo-electric crystal assembly 108 is carefully controlled during molding thereof for a purpose to be explained. It will be noted that the container 122 is received by sleeve 120 and securely held in position therein by the edge portion of opening 118 which snap fits into recess 142.

Referring to the two diameter extensions 126, the smaller diameter portion 150 thereof is adapted for connection to hose 136 which, in turn, connects to a breathing mask. However, the above-described apparatus may be readily modified for tent use in which case the air flow volume as well as the volume of nebulized fluid must be increased significantly over that required for mask use. To that end, the base portion of container 122 is adapted to be cut off at the annular recess 144 to expose the interior of container 122 to the liquid reservoir in upper section 22.

The larger diameter portion 152 of extension 126 is provided with an annular recess 154 defined by spaced-apart annular ribs 156 and 158. The extension 126 may be cut off at recess 154 thereby providing an enlarged diameter outlet for the container 122 as indicated in FIG. 5. A sleeve 160 attached to one end of a corresponding relative large diameter flexible hose 162 leading from a tent, not shown, is slidably received by the larger diameter portion 152 and extends axially through container 122 to approximately the open end thereof. A shoulder 162 formed on sleeve 160 engages the rib 158 to thereby locate the axial position of sleeve 160.

The container 122 may be provided with an integral nipple 163 which is snipped off in the event that oxygen enrichment is desired. To that end, a source of pressurized oxygen, not shown, is provided with an outlet hose adapted to be secured to the inlet opening defined by the snipped off nipple 163.

Referring to FIG. 3, the piezo-electric crystal assembly 108 is shown in section. An annular housing 164 preferably formed from an electrically non-conductive material is provided with a threaded section 166 and a reduced diameter end portion defining an opening 168 and shoulder 170. A flat piezo-electric crystal assembly is defined by a disc 172 of suitable piezo-electric material such as a lead-zirconate-titanate composition of suitable thickness which is polarized to vibrate in an axial direction. A stainless steel disc 174 (.lambda./2) thick is suitably bonded to the disc 172 by means of an epoxy to thereby establish a well-known resonant system. In general, the stainless steel disc 174 functions to load the piezo-electric disc 172 to prevent self destruction thereof when a high electrical input is applied thereto and further functions to store energy thereby increasing the mechanical Q operation as will be recognized by those persons skilled in the art. An electrically conductive slug or disc 176 bears against the disc 172 and has a terminal 178 fixedly secured thereto which receives a wire lead 180. The slug or disc 176 is securely mounted on an annular flange 181 of a conventional thermostat assembly 182 by means of an adhesive 184 or the like. The thermostat assembly 182 is provided with terminals 186 and 188, each of which extend through an associated opening of a plurality of openings 190 in insulating disc 192 of electrically non-conductive material.

A cap 194 is provided with an annular extension 196 which extends into the interior of housing 164 into engagement with one end of a sleeve 198 slidably engaged with the interior wall of housing 164. The opposite end of sleeve 198 bears against piezo-electric disc 172. An O ring seal 200 trapped between shoulder 170 and disc 174 is compressed thereby establishing a fluid seal between disc 174 and annular housing 164 which compression also serves to force load piezo-electric disc 172 into engagement with sleeve 198 and maintain positive electrical contact therebetween. An insulating sleeve 202 of suitable electrically non-conductive material is inserted within sleeve 198 to electrically insulate the thermostat assembly 182, slug 176 and associated mechanism from sleeve 198. A compression spring 204 interposed between cap 194 and insulating disc 192 loads the thermostat assembly 182 and thus slug 176 to thereby maintain positive electrical contact between slug 176 and piezo-electric disc 172. A wire 206 connects terminal 188 with slug 176.

A conventional RF connector plug 208 threadedly engaged with cap 194 is suitably connected via a wire 210 to terminal 186 of thermostat assembly 182. Current flow passes through thermostat assembly 182 to terminal 188 then via wire 206, slug 176, piezo-electric disc 172, sleeve 198 and cap, in that order, to plug 208. It will be noted that the sleeve 198 and cap 194 are necessarily made from electrically conductive material. Also, it will be recognized that the thermostat assembly 182 and piezo-electric disc 172 are in series flow relationship such that current flow through the disc 172 is automatically interrupted by the thermostat assembly 182 in response to a predetermined temperature condition.

The housing 164 is adapted to be screwed into mating threads 106 in sleeve 102 attached to upper section 22. The RF connector plug extends through opening 98 in receptacle 96 into a mating socket, not shown, provided in power control unit 66.

Referring to the fitting 44, reverse air flow therethrough is obstructed by a flexible wall or flapper 210 suitably enclosed as by member 212 at its center to fitting 44. The flexible wall 210 allows pressurized air to pass therethrough to hose 134. However, in the event of a patient coughing or the like in his mask, the resulting back flow through container 122 and thus hose 134 is prevented from entering fitting 44 by closing of flexible wall 210 thereby eliminating contamination of the structure upstream from the fitting 44.

OPERATION OF THE PREFERRED EMBODIMENT

Applicant's nebulizer apparatus may be easily and quickly set up for operation in any suitable location relative to a patient requiring aerosol therapy. To that end, the upper section 22 is positioned on lower section 24 with the connector plug 208 engaged with the power control unit 66. The therapist may then fill the upper section 22 defining the liquid reservoir to the indicated level by removing cap 116 and inserting standard U.S.P. bottles containing water or saline solution in opening 114. When the liquid in upper section 22 reaches the desired level, the neck of U.S.P. bottle is immersed thereby blocking air flow into the bottle and controlling the liquid level accordingly.

The container 122 or nebulizing chamber is inserted into opening 118 and secured in position therein by cover 110 which snaps into recess 142. The desired quantity of a liquid medicant to be nebulized is poured into container 122 through extension 126. The coupling members 130 and 138 on opposite ends of flexible hose 134 are snapped in position on corrugations 128 of extension 124 and fitting 44, respectively. The coupling member 132 on one end of flexible hose 136 is snapped in position on the corrugations 128 of the smaller diameter portion 150 of extension 136.

The power cord 68 is plugged into a suitable electrical receptacle and the push button switch 56 actuated to the ON position. The power control knob 50 is adjusted to the desired power setting and the air control 52 set to position valve member 59 which, in turn, establishes the effective flow area of fitting 44 and thus air volume to the container 122.

The setting of power control knob 50 determines the electrical output impressed on piezo-electric disc 172 and thus resulting sonic energy generated thereby which sonic energy is directed through opening 168 causing the liquid reservoir or coupling liquid in upper section 22 to pile up into a fountain shaped wave. The created sonic energy will be concentrated at a flat peak of the fountain shaped wave causing the tip of the wave to be dispersed as droplets into the surrounding space. However the base portion 148 of container 122 is placed in the fountain shaped wave. The base portion is carefully molded of a thickness which will not affect the transmission of sonic energy from crystal assembly 108. A thickness for the base 148 equal to one quarter wave length or less of the acoustic wave imposed on the base portion 148 will be acoustically transparent to the sonic energy passing therethrough permitting the formation of the fountain shaped wave in the medicament. The resulting agitation of the medicament causes the same to be dispersed into a mist defined by small particles of the medicant.

The pressurized air introduced into the container 122 via inlet hose 134 is directed tangentially into container 122 and follows a vortex path in passing to the outlet extension 126. The nebulized medicament in container 122 is entrained by the air flow which causes the larger particles of medicament to move radially outwardly in container 122 in response to the centrifugal force imposed on the particles by virtue of the vortex action such that only thoroughly dispersed relatively small particles of medicament are carried by the air flow through outlet extension 126 to the outlet hose 136 for subsequent inhalation by the patient. Treatment is discontinued when the medicament in container 122 is used up following which the power unit 66 is shut off whereupon upper and lower sections 22 and 24 may be transferred to another location for use by a second patient if desired. The inlet and outlet hoses 134 and 136 are disconnected from fitting 44 and the inhalation mask, respectively, and the container 122 detached from cover 110, all of which may be discarded and replaced by an unused container 122 and unused inlet and outlet hoses 134 and 136 thereby preventing cross contamination between patients. The sections 22 and 24 including the liquid reservoir are not contaminated and may be used repeatedly since the sections are not exposed to a patient.

The nipple 163 is located adjacent air inlet extension 124 such that oxygen introduced therethrough to container 122 tends to be entrained by the air flow through extension 124.

Applicant's nebulizing apparatus may be set up for tent therapy quickly and conveniently. To that end, the base portion 148 of container 122 is removed by cutting along recess 144 and the smaller diameter portion 150 of extension 126 removed by cutting along recess 154. The sleeve 160 may then be inserted into larger diameter portion 154 of extension 126 as shown in FIG. 5. The sonic energy derived from the piezo-electric crystal assembly 108 is imposed on the liquid reservoir in upper section 22 creating a fountain-like mass of liquid particles adjacent the lower end of sleeve 160 which particles are swept along by the vortex air flow through container 122, which exits through sleeve 160 and hose 162 attached thereto to the tent. In this manner, the large liquid reservoir supplemented by standard U.S.P. bottles attached to cover 110 and replaced as required permits hours of continuous fog in suitable volume for tent therapy.

The upper and lower sections 22 and 24 may be readily cleaned as desired by removing the cover 110 and unplugging the upper section 22 from the lower section 24 which cover 110 and section 22 may be easily and thoroughly washed and sterilized since there are no small, inaccessible places to contend with therein.

With the upper section 22 unplugged from lower section 24, the piezo-electric crystal assembly 108 may be removed therefrom simply and quickly by unscrewing the same from sleeve 102 and screwing in a replacement crystal assembly if required.

Claims

I claim:

1. A portable sonic nebulizing apparatus for use in treating an individual with a respiratory problem requiring conditioned air, said apparatus comprising:

a first housing having an inlet port, a first outlet, a second outlet and a third outlet, said first housing having a flange around said first outlet, said housing retaining an electrical power control adjacent said first outlet;

fan means adjacent the inlet port in said first housing for moving air along a first path to said second outlet and a second path to said third outlet, said air moving in said first path removing thermal energy from said electrical power control;

a filter member located in said inlet port to remove impurities from the air received by said fan means, a second housing positioned on said first housing having a first opening, a second opening and a third opening, said second and third openings being in axial alignment with said first outlet port of the first housing, said second opening having a sleeve extending inwardly toward said third opening a predetermined distance;

sonic energy means sealed in said third opening of said second housing having an extension passing through said first outlet in the first housing connecting said sonic energy means with said electrical power control;

cylindrical container means resiliently retained in said second opening and sleeve of the second housing having a substantially flat base which is in axial alignment with said sonic energy means, said flat base extending into the sleeve a predetermined distance from said second opening, said container means retaining a fluid medicament which aids in relieving said respiratory problem, said container means having a tangential entrance passage and an axial exit passage, said tangential entrance passage being connected to said third outlet in the first housing for delivering all of the filtered air from said fan means in said second path, said tangential entrance causing the filtered air to follow a vortex flow path in said cylindrical container, a coupling fluid located in said second housing; and

control means connected to said electrical power control for activating the sonic energy means for creating a fountain shaped energy wave in said coupling fluid, said base of the cylindrical container means being located in said fountain shaped energy wave, said fountain shaped energy wave passing through said base unobstructed causing the medicament to be dispersed as droplets in said vortex flow path of the filtered air, said droplets being suspended in said air, said exit passage being connected to the patient for delivering the medicament droplets in the filtered air.

2. The apparatus as recited in claim 1 wherein the control means further includes:

flow control means in said second path adjacent the third outlet in the first housing for regulating the quantity of filtered air delivering said tangential entrance into the cylindrical container means to selectively establish said vortex flow path corresponding to the need of the individual user.

3. The apparatus as recited in claim 2 wherein the thickness of the base of said fluid container is less than h/4 wave length of the vibrating frequency of the sonic energy means to prevent destruction of the cylindrical container means by thermal energy.

4. The apparatus as recited in claim 3 wherein the control means further includes:

temperature responsive means for interrupting the operation of the sonic energy means when the sensed thermal level in said sonic energy means corresponds to a predetermined value.

5. The apparatus as recited in claim 2 wherein said third opening in said second housing and the sonic energy means are threadedly engaged to permit easy removal thereof from the sonic energy means.

6. The apparatus as recited in claim 5 further including:

flow restricting means adjacent the third outlet in the second flow path for preventing backflow from the container means.

7. The apparatus as recited in claim 6 wherein said container means further includes:

an additive entrance downstream from said tangential entrance passage connected to a source of oxygen to further condition the filtered air by enriching the oxygen content therein.