US3404843A - Aerosol apparatus for inhalation therapy - Google Patents

Description

Oct. 8, 1968 G. SZEKELY 3,404,843

AEROSOL APPARATUS FOR INHALATION THERAPY Filed Jan. 23, 1967 FIG! flrv'r-vvv- 4- 20 INVENTOR,

GEORGE 5 Z E KELY,

ATTORNEY United States Patent Office 3,404,843 Patented Oct. 8, 1968 ABSTRACT OF THE DISCLOSURE An aerosol producing apparatus in which a liquid is forced upwardly under pressure through a spray nozzle housed in the small tubular inlet of a comparatively large upright casing having-asingle principal baffle therein. The

issuance of the spray automatically creates an air flow through the casing in the nebulization process and forces the manufactured aerosol through an upperoutlet from the casing for delivery to a patient. Both the baffle and the interior surface of the casing are of bulb form, and the tubular inlets inner surface is convex and merges smoothly with the interior surface of the casing whereby a streamlined path for the air and fluid particles is offered through the apparatus. The bafile is adjustable in position along the vertical to alter the quality of the aerosol produced. A valve arranged to be operated by baflle movement, closes more as the baffle is raised and opens more as the baffle is lowered in the casing, to maintain an aerosol delivery of practically constant quantity to the patient. A valve controlling the delivery to the outlet, has its movable member which moves with the baflle, above the bafiie in the casing, and the underside at least, of said valve member is convex so it also offers streamlining.

The present invention relates to improvements in high lflow aerosol apparatus to make and deliver a therapeutically dry aerosolized high output for use in inhalation therapy affording treatment over prolonged periods of time. More particularly, this apparatus is of the type which automatically produces a pressurized air supply to act on an atomized liquid spray and cause its propulsion and nebulization, that is, this apparatus employs a liquid which is forced under pressure through a spray nozzle whereupon there is automatically created an air flow in the nebulization process, an example of which is set forth in my Patent No. 3,302,374.

The principal object of this invention is to provide a novel and improved aerosol apparatus of the type mentioned, which delivers larger quantities of finely nebulized liquid particles than was heretofore obtainable from a given liquid spray issuing from a nozzle, hence the delivery is an aerosol of very high quality.

A further object thereof is to provide a novel and improved aerosol apparatus of the character set forth, which automatically decreases the aerosol volume delivered when the apparatus is adjusted to increase the quality of the aerosol produced, and automatically increases the aerosol volume delivered when the apparatus is adjusted to decrease the quality of the aerosol produced, so that the richness of the aerosol coming to the patient is substantially of constant therapeutic value.

A further object thereof is to provide an aerosol apparatus having the mentioned attributes, which is simple in construction, reasonable in cost, easy to use, extremely compact, manually portable and efiicient in carrying out the purposes for which it is designed.

Other objects and advantages will become apparent as this disclosure proceeds.

From the following explanation, those versed in the art will understand the nature of the aerosol apparatus which I-have devised for the practice of this invention.

The spray issuing from a nozzle determines a conical formation comprising a mass of separate liquid particles. Those particles which are in the outermost zone of said cone-form, are finely nebulized and suitable for inhalation therapy. Those particles which lie within the cone-form, are heavier and need be nebulized to be made suitable for this therapy. Such nebulization or breaking up is effected by impact against baflle means within a container into which the nozzle discharges. From this container, the total aerosol output is led by a suitable hose to the patients mouth.

The intensity of flow from the nozzle is not suflicient to force the liquid particles to travel the distance they need go even when very fine, to reach the patient and have momentum to traverse the respiratory tract. So I utilize the liquid pressure system to automatically create an air flow which is snflicient to cause the breaking up of the larger particles in cooperation with the baffle means, and to propel all the finer particles entering or manufactured in the container, to the patient with sufficient reserve momentum. Parts of broken up particles which are yet too large for this therapy, are too heavy to be propelled the entire way by said air flow. They collect on the 'baffle means, grow heavier, and finally drop to the bottom of the container and are drained off. Heavy particles also collect on the container wall, drop and drain olf.

In the practice of the present invention, I avoid the use of 'bafiles to act in succession to break up the heavier liquid particles of the spray. I find that much of the very fine particles supply produced in the apparatus is lost in previous devices by the action of a series of baffies. They deplete the energy of the air flow to a great extent by the resistance they offer thereto, so that there is not enough strength left in the air fiow to transport them although here is a greater breaking up of liquid particles. I provide but a single bafile which occupies a substantial part of the casing. This baffie presents a substantially semispherical surface to be impacted by the particles from inside the cone-form of the nozzle spray, to break them up. Said baflle and the casing, are each of bulb-form so as to offer a streamlined path for the air flow and thus conserve its energy. The streamlining is also of advantage for the passage of the fine particles through the casing. I grab for use only the fine particles entering the casing and those manufactured therein by the breaking up of the larger particles, and find the resulting yield of fine aerosol delivered to the patient, is greater in quantity as compared to the performance of previous devices of this class.

The single baffle is adjustable towards and away from the spray nozzle, and operates a valve which controls the output delivery to the aerosol quality remains practically a constant.

A detailed description of a preferred embodiment of my new apparatus and its mode of operation will now be given, for which I shall refer to the accompanying drawing forming part of this specification. In the drawing, similar characters of reference indicate corresponding parts in all the views.

FIG. 1 is an elevational View shown for the most part in section, of a preferred embodiment of aerosol apparatus in accordance with the teachings of this invention.

FIG. 2 is a section taken at line 22 in FIG. 1.

In the specific embodiment shown in the drawing, the numeral 15 designates a comparatively large casing pro vided with a tubular outlet 16 at its upper region and with a relatively small tubular inlet 17 at its lower end; such being a neck whose intake end is in connection with the atmosphere by having said inlet enclosed by a downward extension 18 from the casing, which extension is closed by a floor 19 slanting to a drain pipe 20, said extension having an outer hollow elbow branch 21, whose exposed intake end is controlled by a valve plate 22. A nozzle 23 extends into said tubular inlet 17 and is positioned to discharge into the casing 15, the position of said nozzle being such that particles of liquid issuing therefrom will impinge all around the inner surface of the tubular inlet 17, before entering said casing 15, the nozzle being spaced from said surface. The feed pipe 24 of said nozzle, is for directing thereto a continuous flow of a liquid under pressure, and when such flow is provided, a supply of atmospheric air will be automatically drawn by jet action through said inlet 17 and into the casing 15; said draw of air producing an air fiow which drives and carries the spray issuing from the nozzle, through the easing 15, for action by the baffle 25 suspended in said casing; the force of such air flow being sufiicient therefor and to drive the aerosol produced through the outlet tube 16 and thence through the delivery hose 26, with sufficient momentum to invade the respiratory tract. The casing 15, the baffle 25 and the discharge orifice of the nozzle 23, are coaxial. The larger liquid particles collect on the baffle and casing surfaces, and fall off to the floor 19 of the casing, wherefrom they are drained off through the pipe 20. The valve plate 22 is rotatable on the axis pin 22, to regulate the air intake which includes supplementary air necessary for the patients breathing.

It is evident that this apparatus will operate automatically to make an aerosol while a liquid under pressure is fed to the nozzle and discharged as a fine spray as described. If the liquid is to be water, it may be fed by hose from a house tap whose discharge is of suitable pressure; said hose being connected to the intake pipe 24 of the nozzle. Or, as shown in my said previous invention, the liquid, whether water or a medicated fluid, can be supplied by a pump whose discharge port is connected to the nozzle intake pipe 24, its intake port to a supply container, and the drain pipe 20, arranged to empty into such container.

Of importance to note is the streamlining of the inner surfaces of the casing 15 and its neck 17, and of the upper surface of the bafile 25. The inner wall 15' of the casing 15, is shallow concave along its height. The inner wall 17' of the construction of said neck 17, is convex along its height. The baffle 25 is bulb-form, with its lower surface part, semi-spherical in form, and preferably roughened as indicated by the numeral 25.

The baflle 25 is at the end of a rod 27 extending into the casing 15. The rod is slidably supported in the bearings 28, 29, and extends upwardly out of the casing where it terminates in a knob 30, for its manipulation. The intake to the outlet tube 16, is controlled by a valve, whose movable'member 31 is fixed on said rod, below the opening 32 in the partition 33, for cooperation with said opening.

The spray nozzle may be of the usual type whose discharge is a cone formation, and better yet, is to have the nozzle of the type whose discharge is a hollow cone, as for instance marketed by the Delavan Manufacturing Company, of West Des Moines, Iowa, and shown in their Catalog 34, page 6, as the Types WR and WRW, because it offers minutely divided spray from both its outermost and inermost zones, which are indicated by the numerals 34 and 35 respectively, in FIG. 1 herein.

The force with which the very fine liquid particles issue from the nozzle 23, is sufiicient to propel them quite high in the casing 15, but it remains for the action of the air flow automatically created through the intake 17, to propel them the rest of the way into the patient. The force with which the heavier particles issue from the nozzle, is sulficient to propel them against the baffle 25,

[4 and part way up the casing against the casings wall, to be broken up, but such force though aided by said air flow, is not enough to get them much higher. When such larger particles are broken up, said air flow propels them further upward, but those particles which are still too large, fall and are drained off through the pipe 20.

In previous aerosol apparatus of this type, successive bafiles were provided, spaced along the casings height, to act so as to successively break up liquid particles of intermediate size reaching them. It was found however, that though additional bafiles did some breaking up, they caught smaller particles which grew and becomeheavy. So in the end, much of the possible gain in small particles was lost, and the final aerosol output was much less than in my present apparatus which relies principally on a single breaking up by the lower part 25' of the battle, with the casing wall acting as a bafile for the larger particles, but it is the quick collection of the finer particles entered into or produced in the casing, that yields a larger aerosol supply from a given spray, than was heretofore possible. This quick collection is accomplished because in the present apparatus, the air flow is subject to a minimum of resistance in its travel and .so it remains strong enough to do its work instead of its energy being depeleted as was an incident in previous devices Where the air flow lost too much of its energy in its passage through the baflle system in the casing.

It must be noted that the air flow energy is further protected from undue dissipation in the casing, by the guiding, easing and uninterrupted path provided by the streamlining for its passage through the apparatus without undue hindrance, and that such streamlining also aids the passage of the very fine liquid particles. This streamlining is offorded by the convexity along the vertical of the interior surface 17' of the inlet tube 17, the shallow concavity along the vertical of the interior surface 15 of the casing 15, said surfaces merging smoothly, and the use of the bulb-form bafile 25 which occupies a substantial part of the casings interior. Also to be noted is the streamlining of the undersurface and side of the valve member 31, which guides the fine particles reaching it, into the chamber 36, where a mixing action occurs before final discharge of the aerosol through the outlet tube 16, and thence to the patient, through the delivery hose 26.

The air stream automatically created by jet action, has its greatest upward flow at its maximum energy while it is passing through the inlet tube 17. Therefore, all spray particles which impinge on the wall 17', will be forced upwardly along said wall and will thereafter follow on the concave surface 15' of the container 15, in an upwardly direction without impingement thereon, due to the streamlined path it is afforded. In prior devices, the casings interior wall was straight, hence impingement did occur with attendent loss of velocity and dissipation of the capability of said particles to ascend. The fine particles in the outer zone of the spray, thus quickly and without hindrance, ascend with the air flow, and provide good aerosol through the discharge tube 16. The force of the spray issuing from the nozzle 23, without the air of the air flow, is sufiicient to propel the larger spray particles against the underside 25' of the bafile 25, to be broken up and bounce into space. These have spent their energy on such impact, but now the air flow comes and carries the finer particles caused by such nebulization upwardly, while the heavier particles, fall and are drained off through the drain 20. Any of the larger particles of the spray which hit the casing wall 15', may be nebulized by such impact, and the finer particles of such result, and carried upward by the air fiow, while the heavier particles fall to the drain. Since the air flow on entering the casing 15 spreads, very little of it comes against the baffle to be stifled, and most of it which touches the baffle, is guided for upward flow by the streamlining of the battle. Many fine spray particles entering into or manufactured in the casing, are driven upward by the airflow, without contacting any surface before they come to the discharge outlet. Those making contact with any surface, are afforded a streamlined path thereon, and just glide thereon, propelled upwardly by the air flow. Fine particles moving up on the casing surface 15 are not intercepted by any larger particles and added to the latter, but glide around them, always in upwardly direction due to the action of the air flow on the fine particle. This may be due to surface tension. But in any event, the small particles are not lost by accretion, except when a large particle hits a fine particle against a wall, which is a rare occurrence except at the very lowest region of the baflie. Such impact occurring other than head on merely causes the finer particle to shift away from the larger particle, and its path is unobstructed due to the streamlining. Even the roughness 25' on the baflie surface, has no appreciable resistance to offer a fine particle from traveling thereon. Such roughness does hasten the breaking up of larger particles forced against it, but as soon as fine particles come into being, the air flow propels them upwardly. There is a quick accumulation of fine particles in the air flow, and so the aerosol eflected from any given spray, is larger in quantity and richer in quality than was attainable with previous devices of this class.

It is evident that in the apparatus illustrated, the nearer the bafiie 25 is to the spray nozzles orifice, the larger will be the amount of fine particles manufactured. The larger the specific gravity of the fluid fed to the nozzle is, the nearer is the distance the baffle should be from the nozzle to get a proper aerosol. It is to be noted that change of position of the baffie, does not influence the streamlining effect. If the valve 37 is included in the apparatus, the extent of its opening bears an inverse ratio to the distance the baflle is from the discharge orifice of the nozzle. Hence, a larger amount of aerosol delivered to the patient, will have a larger amount of fine particles of liquid dispersed therein. Thus, the quality of the aerosol delivered remains practically a constant, regardless of the position of the baflle, because the valve opening is automatically determined by the baflles position in relation to the nozzle.

The entrance to the intake tube 17 need not be flared, but it is preferable that it be so because of the Venturi action afforded thereby. The casing and its extensions may be of plastic or metal which is not affected by the liquids used through the nozzle, and a suggested overall height therefor is between 8 and 10 inches, with all other dimensions in proportion to those of the embodiment herein illustrated.

This invention is capable of numerous forms and various applications without departing from the essential features herein disclosed. It is therefore intended and desired that the embodiment shown herein shall be deemed merely illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claims rather than to the specific showing and description herein, to indicate the scope of this invention.

I claim:

1. In an apparatus for producing an aerosol for inhalation therapy, of the type comprising a comparatively large upright casing provided at its upper end with an outlet and at its lower end with a relatively small tubular inlet having an intake end which is communicative with the atmosphere; said casing enclosing the tubular inlet and having at least one opening adjacent said inlet for establishing the connection to atmosphere, a nozzle extending into said tubular inlet and positioned to discharge upwardly; there being a space between the discharge end longitudinal portion of said nozzle and the tubular inlet, for the flow of air therethrough and into the casing; the position of the nozzle being such that particles of liquid issuing therefrom will impinge all around the inner surface of said tubular inlet before entering said casing, thereby drawing a supply of atmospheric air into the intake end of the tubular inlet and through said tubular inlet and into said casing; said draw of air producing an air flow which drives and carries the spray through the casing, a baflie in the space inside said casing between said tubular inlet and the outlet and in a position to nebulize the particles of liquid spray entering said casing through said tubular inlet from said spraying nozzle and carried upwardly in the casing by said air flow; the space between the discharge end longitudinal portion of the nozzle and the tubular inlet, being of such size that the air flow is of such force that it will drive and carry the sprayed liquid particles through the baflie-occupied casing and resulting aerosol out of the outlet, and a drain pipe leading from the bottom of the casing and extending to discharge outside the casing, the improvement being that the inner surface of the casing is shallow concave along its height; the inner surface of the tubular inlet being flared at its upper end; the inner surface of said flared end being convex and merging smoothing with said concave surface of the casing; the lower surface of the baffle being substantially of semi-spherical shape; said baflle being spaced from said concave surface of the casing and occupying a substantial part of the casing, whereby a streamlined path is offered spray particles moving along on any of said surfaces.

2. An apparatus as defined in claim 1, wherein the inner surface of the tubular inlet is convex along its height.

3. An apparatus as defined in claim 1, wherein the baffle is a bulb-form.

4. An apparatus as defined in claim 1, wherein the lower surface of the baflle is roughened.

5. An apparatus as defined in claim 1, including means mounting the baffle for movement along the height of the casing, means accessible exterior the casing for moving the baflle to any position along said height, and a valve controlling the passage of aerosol into the outlet, adapted to be adjusted by the battle-moving means whereby said valve opens more as the baflle is lowered, and closes more as the baffle is raised in the casing.

6. An apparatus as defined in claim 5, wherein the valve is above the baffle within the casing and includes a movable member which moves along with the baffle; at least the undersurface of said movable member being convex.

7. An apparatus as defined in claim 1, wherein the casing has a reduced upper end and a reduced lower end;

the outlet being communicative with said upper reduced end, and the tubular inlet being within the said lower reduced end of the casing.

References Cited UNITED STATES PATENTS 3,302,374 2/1967 Szekely 55226 EVERETT W. KIRBY, Primary Examiner.

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