US2807504A - Nebulization apparatus - Google Patents

Description

Sept. 24, 1957 A. P. BLOXSOM NEBULIZATION APPARATUS Filed July l0, 1953 3 Sheets-Sheet l A. P. BLOXSOM NEBULIZATION APPARATUS sept. 24, 1957 3 Sheets-Sheet 2 Filed July l0. 1953 //an R B/OXJ om IN V EN TOR.

ATTORNEY A. P. BLOXSOM NEBULIZATION PPARATUS Sept. 24, 1957 3 Sheets-Sheet 3 Filed July l0, 1955 /4//0/7 F? B/oxsom INVENTOR. WM?? U44@ ATTORNEY @all United States Patent iice s 2,807,504 Patented Sept,I 24 1,957

2,807,504 NEBULIzATIoNi-APPARATUS AllanP. Bloxsom, Houston, Tex.

Application-July 1953; Serial N0.k 3675178 4 Claims, (Clr299.--8S:5)f

The presentinvention relates to apparatusfo'r nebulizat-ion.

In atomization, large droplets are' produced at high speed. These large dropletsimpinge on, the sensitive mucousmembrane of the respiratory tract and-l produce` coughing,- gagging and other disagreeable sensations.- lilebulizationV differsl from atomizationy in that the large droplets are bafedout-to a large extent, depending` on the particular generator, nad a ne fogf or smoke isproduced withA particles that are non-irritating, and are, practically'insensible tothe respiratory mucosa.

i In aerosol therapy or' administration, a consideration ofpart-icle size is essential. Particles-30-microns in diameter or' larger arey baffled out in the trachea andv go noV further; those of 10` to 30 microns in size reach the terminal bronchioles; those of 3 to lOmicronsl in size stop inthe alveolar ductsewhile thoseof 0.5 to 3 microns in diameterpenetrate into the air sacs themselves.

The process of nebulization breaks the solution into millions of tiny particles in the range of 0.5 to 30'microns in size; thus enormously increasing the surfacev area of vthe solution. This, in turn, causesthe particlel to evaporate at an extremely rapid rate.

It# has been demonstrated that nebulized particles of 10 microns andbelow completelyfevaporate within 0,02 second after production. An` aqueous-- aerosol can be observed to disappear completely within aboutf 3 to 6 inches of themouthof the ordinary nebulizer. Ther-apeutically, this results in arelatively small amountof deposition-onthe-respiratory mucosa beyond the pharynx andilar-ynx. |Ihe reducedsize of those particlesthat are depositedfresults in aslow'coverageof the mucosa, since agreat many of' these tiny particles-mustl bedepositedbcforea there A is a suicient. number to t coalesce and formV at continuous flmt These ditli'culties` have been. overcome by adding the, proper concentrations-off glycerintand a detergentyto the solution". Theglyceriny tends to hold ontofthe waters in the dropletuthereby inhibiting' evaporation; and stabilizingv particle size. This results in. a; deeperv penetration f offthe; Glycerinv alone, however', doesf not;l necessarily'resultin; increased deposit-z mist` into` the.l bronchial: passageway.

tionssince` the s tabilizedjdrop-lets tendlto maintainV their integrity. andrto rebound from; obstructing surfaces.y Re

cent Ydat-a demonstrate .thatY strong.y glycerin; solutions; may

actually, deposit to; a, lesser. extent than plain. aqueous. solutions.` An additional agent is required to lower the` surface tension. of the droplets so that they may become disrupted on contact'with obstructingsur'faces, that is,l

to make them splatter outfrather` than bounce off.

Detergents' orwetting agents, in general, containtwo radicals: (-l;)' A- lipophilic or hydrophobic group, andi In anl aqueous solution, thel (f2)4 ai hydrophilic' group. hydrophilic.' groupis: aligned on thensurface next tothe Water; lthe hydrophobic group is directed upward toward the overlying gas.

thanvwater alone. Detergents possess thevaluable qual- As a result, the surface has, a lilmrv that isoil-like and@ has; amllch'lower surface tension 2 ities of both lower surface and interfacial" tensifm: of reducing ',viscosity, and of. liquefying secretions. In, addie tion', the'lipophilic faction actson fatty secretionsginsub= stances, tending to dissolvethem. Y

The aerosol technique consists in havingthe4 patients simply inhaler ak mist of the nebuli'zed'; solutionsu This technique may be', used for a number of'uses,Y such, as, in neonatal atelectasis, `prevention andtreatment` of .hyaline membrane disease, bulbar poliomyelitis, pertu`ssis,l,diphg theria, kerosene ingestion, irritating and chromatic con; ditions in which trouble from secretions is minimized, general anesthesia,V bronchoscopy,l tracheotom'y; the treatment of inhalation of. gases or dus-t and aspiration ofiforeignmaterial, as wellY as other, pulmonary condi tionsand preventionof respiratory obstructions.`

M any difculties attend' theuse of 'ordinary methods of prolonged aerosoladministration. The .nebulizersnow in common use have,l a maximum capacity of. only about l0 cc: of liquids so that an automatic and continuous source ofadditional liquid is required. In someJ in; stances` this has been achieved' byinsertingja needle through'theeside-stopper of a; nebulizer and drippingthe therapeutiesolution from a clysisbottle into Athe nebulizer throughthis needle. This methodis simple'and wouldbe ideal except thatl the fluid level is utterlyA impossible-to control; No matter how carefully the rate of' drip is measured,- the nebulizer will either run dry or overflow, that-fis rain onto the patient in a shorttime'tlierebyeither failing to provide the continuous aerosol solution or thoroughly: wetting the patient.` In addition, it' is. obvious that suchan apparatus is fragilek and'easilybroken;

Itis, therefore, a major'object ofthe present'invention; to provide an apparatus for nebulization which will neither run drylnor overflow, thatisrain onto thepa-l tient, andwhich provides a continuously-prolonged, trouble-free aerosol administration.

A further majorY object of the-presentinvention is the provision of anebulizerin whichga constant fluid levell is maintained at Various ratesy of ilow therebyr providing al nebulizer capable of' continuously-prolonged' aerosol administration of substantially-uniform micron-particlex size'without runningdryor Aoverflowing onto the patient;

A further object`r of; thex presenti invention'. is the pro'- v-ision-` ofa-nebulize1-which produces a nebulizedsm'oke or -fog principallymade up of 'therapeuticallyaiseful' par*- ticles inthe 0.5 toy 3 micron range.

A- further object-offthe present invention is the' pro*- vision of* a nebulizer in which the reservoirgcharnb'ei is' substantiallysealed off from orl connectedto the turbulence chamber/1 insuch a manner so, that frothing or Soaping upf-"does notoccur'when using a detergent;

Yet a furthervobject of the present invention' is the' provisions of a nebulizerof the above character which is; simple and inexpensiveto construct, shock resistant', requiring no adjustments, and reliable and dependable irruse.

@ther and further objects andi advantages will be ap-.. parent Yfrom the 'following `description of` examples of' the invention, given for the purpose of disclosure, takjen,

in .connectionwiththe accompanying drawings,kin which like character references designate like parts throughoutv the several views, I and Where Figure l is a side elevation, partly in section of, a.,

Figure 4r is aside elevation, partly in section, illus-V` trating a modificationy constructed according to the `m. vention,

Figure 5 is a crossfsectionalview takenalong the liner.

Spf-Stof Figure 4.

Figure 6 is a fragmentary view, partly in section, of yet a further modification of the invention,

Figure 7 is a cross-sectional view taken along 7-7 of Figure 6,

Figure 8 is a fragmentaryview, partly in section, illustrating a still further modication of the invention,

Figure 9 is a cross-sectional View taken along the line 9--9 of Figure 8, and

Figure 10 illustrates a screen or suitable iilter used in connection with the apparatus of the invention.

Referring to the drawings, and particularly to Figures l-3, a housing or casing 12 is provided which has what may be termed the primary reservoir 14 and a compartment 16 to house what may be termed the generator 18, the primary reservoir 14 and compartment 16 being sep aratedby the partition 13. The housing 12 may be formed of any suitable material, and preferably is transparent and formed of a suitable nonbreakable material, such as plastic, in order to be shock resistant.

A closure member 19 is provided in the reservoir 14 so that the primary reservoir may be filled from time to time. The primary reservoir 14, obviously, may be made as large or as small as desired and should be airtight for satisfactory operation, as will be apparent later.

The generator 18 may be formed of any suitable material, such as glass, and may be suspended in the plastic case 12 so that the nebulizer may receive rough treat ment without danger of breaking. The generator 18 may include at its lowermost portion what may be termed the secondary `reservoir 20 which is in fluid communication through a narrow opening or neck 23 with a turbulence chamber 22, which in turn is in `communication with a condensing chamber 24 for condensing larger micron particles so that they coalesce and drop into the secondary reservoir to be renebulized.` Any suitable bailiing means may be used, however, to bathe out the larger micron passages, such as providing a sharp or right-angle bend in the neck extending from the turbulence chamber, and any suitable means may be utilized to seal oif the secondary reservoir 20 from the turbulent action in the turbulence chamber 22 to prevent frothing or Soaping up when a detergent is used.

An inlet pipe or conduit to the nebulizer is provided and indicated by the reference numeral 26, to which may be threaded or otherwise secured the tubing or conduit 28 `to a supply of solution for the aerosol of nebulized mist, not shown. Disposed at the upper end of the ncbulizer and communicating with the condensing chamber 24 is the outlet pipe 30 to which is secured the plastic tubing or pipe 32 which carries the nebulized fog or mist to the enclosure surrounding the patient or to the patient to be administered in other ways, as desired.

Passing upwardly through the lower end of the secondary reservoir 20 and connected to the inlet pipe 26 is the upstanding tube 34 which is gradually tapered upwardly and terminates with a very small opening at its upper end. A second tube 36, open at its lower end and overturned at its upper end as at 38 is provided and secured to the upstanding tube 34. Thus, oxygen or air, or whatever iluid is being used, enters inlet tube 26 from the tube 28 and passes upwardly in the tube 34. The upper overturned end 38 is directly over the outlet of the tube 34 and a siphoning or venturi action is provided as gas ilows out the upper end of the tube, drawing liquid from the second reservoir and saturating the gas.

As best seen in Figure 2, a tube or conduit 40 is provided which extends upwardly into the upper portion of thc primary reservoir 14 and extends downwardly into the upper portion of the secondary reservoir 20. Similarly, a second pipe or tube 42 is provided which extends from the lower portion of the primary reservoir 14 to the lower portion of the secondary reservoir 20. Thus, the primary and secondary reservoirs 14 and 20, respectively, are in tiuid communication with one another.

A screen or lter 44 may be provided in the tubing the line 42 delivering iluid to the secondary reservoir 20 to screen out impurities and the like, and as best seen in Figure l0, the screen 44 may comprise the housing 46 and screen element 48, the screen being connected to a cap member 5D so that it may readily be removed and cleaned as required.

In use, the primary reservoir 14 may be filled with a suitable liquid by removal of the closure member 19. In order to prevent all the liquid from running into the generator 18, the case 12 is turned on its side to fill the reservoir i4. After stoppering with closure member 19, the case is then returned to the position illustrated in Figures l and 2 and pipe 26 connected to a suitable supply of gas, such as oxygen or air ilowing in the pipe 28. The outlet pipe 32 is inserted into a suitable enclosure or otherwise connected for desired use. As illustrated in Figure l, the nebulizer is shown as secured to an incubator such as a Gordon-Armstrong incubator for aiding newborn infants in beginning their respirations to expand more rapidly a greater number of alveoli, and a fragmentary portion of a wall 52 thereof is illustrated to which the nebulizer is secured by means of the bracket 54. It is understood, of course, that the nebulizer may be placed on or secured to a suitable support as desired and may be used advantageously in all cases where an aerosol mist or fog is employed.

On turning the nebulizer to the position illustrated in Figures l and 2, the liquid in the primary reservoir 14 will iiow downwardly through the pipe 42, the screen 44 and into the secondary reservoir 20 until the iluid level L is reached, a vacuum in the primary reservoir 14 is then produced preventing the flow of any more liquid into the secondary reservoir 2t). Thus, a constant liquid level L is provided.

As gas is ilowed through pipe 28, inlet pipe 26 and the upstanding pipe 34 at the upper end thereof, the liquid is drawn upwardly from the secondary reservoir in the pipe 36 out the overturned end 38 because of the gas owing beyond the open end 38. As illustrated in the drawings, these openings are very small and the liquid is broken up into very small particles to produce a nebulized fog. The turbulence chamber 22 may be of a generally round or elliptical shape, viewed in cross section, and provides considerable turbulence of the gas and liquid thereby assuring a complete saturation of the air. The fog or mist passes upwardly from the turbulence chamber 22 into the condensing chamber 24, which also is of generally rounded configuration, viewed in cross section, and which serves to baiie out larger micron particles so that they coalesce and drop downwardly through the turbulence chamber 22 into the secondary reservoir 20 to be renebulized. The nebulized fog or smoke then passes from the condensing chamber 24 upwardly in the outlet pipes 30 and 32 for the desired use.

The apparatus illustrated in Figures 1-3 is highly advantageousin that it produces a very high percentage of nebulization of particles of iiuid in the 0.5 to 3 microns range which, as indicated heretofore, is small enough so that it passes and penetrates into the air sacs themselves.

Thus, in the embodiment illustrated in Figures 1-3, means are provided to maintain a substantially constant fluid level in the secondary reservoir irrespective of the rate of flow of the gas through the nebulizer inasmuch as the faster the rate of ow, the faster the secondary reservoir will be lowered thereby permitting air to enter the lower portion of the tube 40, which rises and passes into the upper portion of the primary reservoir 14 thereby relaxing the vacuum therein and permitting liquid to flow downwardly in the pipe 42 into the secondary reservoir. Thus, the liquid level may beadjusted by the position of the lower end of the pipe 40 and a substantially constant liquid level is obtained at that point for all rates of iiow of gas through the nebulizer. It is, therefore, ap-

parent that prolonged and continuous aerosoled or nebu primary reservoir into the lower portion of the secondary reservoir whereby a constant liquid level is provided substantially at the lower portion of the first tube, a nebulizing tube extending into the secondary reservoir and having its discharge end above the liquid level, a third tube tapering upwardly and having a small opening at its upper end proximate the discharge end of the nebulizing tube, the lower end of the third tube extending downwardly below the liquid level whereby gas passing out the discharge end of said nebulizing tube effects ow of liquid in said third tube and nebulization thereosuch llow of liquid lowering momentarily the liquid level and thereby permitting gas to pass upwardly in said rst tube into said primary reservoir and thereby permitting liquid to flow by gravity in said second tube downwardly into said secondary reservoir to bring said liquid level up to the lower portion of said rst tube, inlet means connected to the nebulizing tube for flow of gas thereinto, and outlet means connected to said secondary reservoir above the liquid level for flow of nebulized particles therefrom.

3. Anebulizing apparatus comprising a substantially airtight primary reservoir, a secondary reservoir disposed below the primary reservoir, a first tube extending from the primary reservoir to the upper portion of the secondary reservoir and a second tube extending from the primary reservoir into the lower portion of the secondary reservoir whereby a constant liquid level is provided substantially at the lower portion of the rst tube a turbulence chamber in iluid communication with and above the secondary reservoir, a nebulizing tube having its discharge end in the turbulence chamber, a third tube tapering upwardly and having a small opening at its upper end, the lower end of the third tube being positioned in the second reservoir and the small opening at its upper end positioned adjacent the discharge end of the nebulizing tube whereby gas passing through said nebulizing tube effects flow of liquid in said third tube and nebulization of said liquid, such flow of liquid lowering momentarily the liquid level and thereby permitting gas to pass upwardly in said first tube into said primary reservoir and thereby permitting liquid to ow by gravity in said second tube downwardly into said secondary reservoir to bring said liquid level up to the lower portion of said first tube,

inlet means connected to said nebulizing tube and outlet means communicating with said turbulence chamber whereby the gas may ow into the turbulence chamber through said nebulizing tube and nebulized particles may ow out of the turbulence chamber.

4. A nebulizing apparatus comprising a substantially airtight primary reservoir, a secondary reservoir disposed below the primary reservoir, a first tube extending from the primary reservoir to the upper portion of the secondary reservoir and a second tube extending from the primary reservoir into the lower portion of the secondary reservoir whereby a constant liquid level is provided substantially at the lower portion of the iirst tube, a turbulence chamber in fluid communication with and above the secondary reservoir, a condensing chamber in uid communication with and above the turbulence chamber, a nebulizing tube extending into and having its discharge end in the turbulence chamber, a third tube tapering upwardly and having `a small opening at its upper end adjacent the discharge end of the nebulizing tube, the lower end of the third tube positioned in said secondary reservoir whereby gas passing through said nebulizing tube effects owof liquid in said third tube and nebulization thereof, such flow of liquid lowering momentarily the liquid level and thereby permitting gas to pass upwardly in said rst tube into said primary reservoir and thereby permitting liquid to flow by gravity in said second tube downwardly into said secondary reservoir to bring said liquid level up to the lower portion of said rst tube, inlet means connected to said nebulizing tube for tlow of gas into the nebulizing tube, and outlet means connected to said condensing chamber for flow of condensed nebulized particles out of the condensing chamber.

References Cited in the le of this patent UNITED STATES PATENTS Re. 8,847 Garland Aug. 12, 1879 1,235,316 Henderson July 31, 1917 1,537,324 Sherman May 12, 1925 1,839,193 Blanchard Ian. 5, 1932 2,582,805 Trumbour et al Jan. 15, 1952

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