US 2266704 A
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Dec. 16, 1941. s. L. Fox ET AL NEBULIZING INHALATOR FOR MEDICLXTIO?.T
Filed May 19, 1957 Frei. I
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A is dilcult for the user,
Ywithout extremely Patented Dec. 16, 1941 UNiTED STATES A NEBULIZING INHALATOR FOR MEDICATION Stanley L. Fox and `Charles C. Coghlan, Los Angeles, Calif.
Application May 19, 1937, Serial No. 143,511 3 Claims. (Cl. 12S-194) Our invention relates to an inhalator for a liquid medicament in which such medicament in a partially or completely atomized or vaporized form is drawn into the mouth, throat or lungs or the nasal passage during the inspiration. v 5 There have been a number of instruments devised and used which attempt to apply a liquid medicament in this finely divided form on the air ejector principle in which air is forced under pressure past the end of an aspirating tube or the ,10 like which dips into the liquid medicament. A disadvantage of any type of instrument of this latter character resides partly in the fact that it designated the patient, to judge accurately the pressure and the flow of air V1,5 necessary to secure a proper atomizing or vaporizing ofthe medicament. Another disadvantage is that if an application of the medicament is made to the mouth, throat or lungs or to the nasal passages through an involuntary reaction against inblown air with the vapor and tends to resist drawing this into the throat or lungs or the nasal passages. Even if medication by such a device is administered by a doctor or a nurse, it is difficult for them to25 judge the pressure oi air necessary and thefff' amount of air flow which should be developed to give a proper atomizing spray timed with inspiration so that the medicament may be applied internally in the desired manner. Most of thei devices operated by a pressure air flow utilize a"Y rubber expansible and contractable bulb as a pump but even if the medication is administered by such means in the hands of the nurse, the patient involuntarily reacts against entrance of the atomized stream and thus their medicament is not properly carried and distributed to the place desired. This particularly applies to any applications of a medicament to the lungs or to the throat.
A main object therefore of our invention re-tV sides in an inhalator in which during the inspiration oi the breath the patient may draw in by suction the desired liquid medicament either in a partially or completely vaporized form by in- 45 haling through the mouth or the nostrils. Thisl action creates an air ilow by suction through the instrument so that the action is developed by the inflow of air over the end of the aspirating tube extending into the liquid medicament and draws 50 a minute jet of the liquid into the air inhaled because of the negative pressure developed. This causes the fine atomizing or vaporizing of the liquid medicament so that only a vapor with or minute particles or globules is liliv vinto the air flow. The
the nose, the patient has 20' c passage of air the forcible, c v-35 drawn into the mouth, throat or lungs or into the nasal passages. All the air taken in through the instrument during an inhalation comes in intimate contact with the nely atomized medicament giving a substantially larger concentration than possible by any other means.
A characteristic of our invention resides in part in providing a relatively large space or area for the inflow of air under suction of inhaling in breathing, tapering such opening toward one or more small orices from which the air enters the jvaporizing chamber at relatively high velocity.
This is suiiicient when passing over the open jet end oi a tube extending into the liquid to cause a ne jet or stream of the liquid to be ejected action of the relatively high velocity flow of air under suction and the much slower velocity flow of the liquid through the fine tube causes an initial breaking up or atomizing of the liquid, this producing the socalled nebulizing effect. As the Whole action is controlled by Voluntary inspiration the user or patient thus has a direct control of the amount of vapor which will be drawn into the mouth or through the nose. Thus when it is desired to treat the throat bronchial tree or lungs with a medicament, the act of inhaling draws in a suicient amount of air and at the same time atomizes and vaporizes the liquid and causes its even distribution in the nose, or throat, bronchial tree and lungs. After the initial nebulization further vaporization of the liquid occurs from the stream over the surfaces which expose the fluid to such action as well as from the expansion of the air vapor and globules as it passes the Venturi throat or baiiies, such action being mainly in the upper or dome part of the instrument.
Our invention is illustrated in connection with the accompanying drawing, in which:
Fig. 1 is a vertical section which may be considered as taken on the vertical section line l I--I of Fig. 2 in the direction of the arrows.
Fig. 2 is a horizontal section on the line 2-2 of Fig. l in the direction of the arrows.
Dealing with the construction of Figs. 1 and 2,
y in our invention we employ a medicament reservoir structure II which includes a cylindrical tube I2 having at the bottom a thickened collar I3 with a cone shaped Wall I4 extending upwardly having a horizontal upper end I5. This is provided with a plurality of small air intake ports I6, four of these being illustrated. The
. air passing through these ports operates on the ejector principle todraw liquid through the small bore tubes I'I which have a jet end I8 preferably formed beveled. These tubes are attached by a cemented connection I9 to the upper end I5 of the conical bottom or base I 4. The lower end 20 of each tube is provided with an opening 1ocated in proximity to the angle formed by the cone shaped bottom I4 and a cylindrical outer wall I2. There is thus provided an annular reservoir 2| for the medicament. The liquid in this should always be below the top of the transverse portion I of the bottom. A distributing tube 25 has a cylindrical lower section 26 with .a threaded connection 21 to the upper end of the tube I2. Tube 25 has a contracted neck 28 forming a Venturi type of throat 29. An upper cylindrical section 30 terminates with a closed dome 3l. AnV
air suction pipe 33 leads through the dome and preferably has a beveled end 34 with the bevel extending upwardly and thus having the lower portion somewhat pointed as indicated at 35 extending well beyond the axial center of the tube sections 26 and '36 and the Venturi forming section 28. This produces an under-surface 36 of the suction air tube on which globules of liquid may collect and condense. Preferably flexible pipe or tube 3l is connected to the outer end of the xed pipe 33 and this may have a suction end piece for inserting in the mouth or connecting to either or both of the nostrils.
Although the device may be used as above described, however, we prefer to have the air intake through a flutter valve construction designated by the assembly numeral 40. This employs a cyiinder 4I having a threaded connection at 42 to the thickened collar section I3 at the lower part of the reservoir. At the lower end of the cylinder there is an annular valve seat 43 leaving a circular valve opening or port 44. A disc-like flutter valve 45 is seated on the annular seat 43 and is maintained pressed downwardly by a coil compression spring 46 which bears at its upper end against the end of the collar I3 of the upper part of the instrument and at its lower portion on the valve disc 45.
The operation of the device including the flutter valve is as follows: It will be understood that on account of the threaded connection at 42 a slight adjustment may be made as to the compressible action of the spring 46. Thus when the flutter valve construction is slightly unthreaded the spring pressure is less'than when the threaded connection is made tight. This gives a slightly variable action in the flutter valve. After the instrument has been filled to the proper level with the medicated liquid which may be either poured through the iixed pipe 33 or may be inserted after unthreading the connection at 21, then when air is sucked into the mouth or nostrils through the pipes 31 and 33, during inspiration of the breath, a partial vacuum is created in the relatively large chamber in the distributing tube 25. This, on account of the open port I6 likewise produces a partial vacuum above the flutter valve disc and causes this to raise, allowing inflow of air. On account of the relatively large area the velocity of flow of this air is comparatively low, however on account of the Vconverging air path due to the conical bottom I4, the velocity is increased and the air flows through the ports I6 at a relatively high velocity. This causes an ejector action 'in regard to the liquid in the annular reservoir 2l, such liquid being drawn up through the small bore tubes II and as the jet openings I8 are directly over the center of each air port 75 I6, globules of the liquid are immediately carried oiT by the inflowing air stream developed by suction. This action causes an atomizing of the liquid producing a nebulous type of vapor. In the formation of the vapor if the air suction is too great small globules of the liquid are carried upwardly, that is, in part impinge on the contracted throat portion 28 and ow downwardly on the inside wall of the distributing tube 25 and thus iiow into the reservoir 2I. However, due to the Venturi type action of the contracted throat 29, a relatively high velocity is produced through this throat. This brings the air into intimate contact with the minute globules of liquid which have been elevated against the force gravity and causes these to be broken up in the -air stream into more minute particles. In addition the crowding action of the air flow with the Vliquid pas-sing through th'e Venturi type of throat brings the larger globules into contact with the lower portion of the neck 28 and these globulesflow downwardly on the cylindrical portion 2S and the wall Istructure 'I2 into the reservoir 2|.
An additional actionof distribution takes place in the upper portion 36 of the tube 25 as above the Venturi throat to an expansion of the upwardlyflowing air. This tends to allow separation of any large globules of liquid. Some of these Vcome in contact with the wall 30 and iiow downwardly. Other large globules strike the under portion 36 oi the tube 33 and as the beveled inner end 34 slopes upwardly the vapors passing through the tube '3 are very nely atomized and practically without any large globules of liquid. Thus `the liquid medicament is given a more even spread on entry in the mouth or through the 'nasal passages. T'he action of the utt'er valve is to allow entry of a quantity of air, this ,acting against the compres-sion of the spring '46. The spring then reacts to close the valve which again opens when the vacuum inside the instrument increases. Thus 'there is yan intermittent inflow of the air which develops an improved action of the ejector in elevating the liquid from the reservoir and in the atomizing of such liquid. However it is to be understood that if desired the flutter valve construction may be removed from the instrument Aor the instrument may be made without provision for attaching such valve in which case the air ilo-ws inwardly through the relatively large annular collar IS3.
The chamber above the throat or Venturi construction of Fig. 1 acts as an expansion chamber in which ,liquid globules may condense, some of theser contact the wall and are then subjected to an evaporati-ng action due to the air passing over such small globules. The action of vaporization of the liquid medicament by the suction which creates a minus pressure is one of slight refrigeration in which the air entering `the mouth or nostrils is slightly cooler than the air flowing in through the instrument. Therefore it will vbe understood that where a hot or warm application of medicament is desired that the air .may be heated blefore being drawn into the instrument by ysuction or as is a more or less common practice, there may be an intermediate chamber between the patient and the inha-lator, the patient :by suction drawing the air Vand medicament ythrough such intermediate chamber which may-be .heated to apply hot .applications. Where-cold applications are required,
manifestly 'this intermediate chamber could be chilled. In some cases it is also desirable to have a washing action of certain medicanfents by bubbling the air through water or other washing solution contained in an intermediate chamber. The action of the flutter valve is to intermittently increase the vacuum and thus lassist in vaporization of the liquid, hence increasing the concentration of the medicament in the air stream.
The method of operation of our inhalator involves the creation of a partial vacuum or negative pressure in the hollow body structure solely by air inspired in breathing either through the mouth or nostrils. This creates a positive air flow from the' outside atmosphere which operates on the liquid medicament in the reservoir. By providing the small bore ejector tube or tubes, the partial vacuum created in such tubes by the flow of air thereover on the operation of suction creates the positive elevation of the liquid from the reservoir into the air stream. At first the liquid leaves these small bore tubes in the form of small globules producing an atomized effect. As these globules come in contact with the air flowing at different velocities and the more or less turbulence of the air as well as by impinging on the sides of the body structure, they become broken up and form a medicated vapor which on being drawn into the mouth or nostrils and on the further inhalation will operate to carry the medicament to the mouth, nasal passages, the throat, bronchial tree and lungs. Thus the sole act of inhaling changes the form of the liquid carrying the medicament into an atomized and vaporized form.
An important characteristic of our invention resides for instance as to the construction of Fig. 1 in providing an annular reservoir with the bottom of the inhalator having an upwardly sloping wall, this being the wall I4 which is cone shaped. Such provides a relatively large opening or channel for the inflow of air which air enters through the plurality of small ports I6. As these ports are located in the upper horizontal end I5 of the bottom structure they may be located but slightly above the level of the liquid in the reservoir therefore the small bore injector tubes I1 may have their orice or jet end I8 positioned but slightly above the liquid. Therefore on the inflow of air entering through the plurality of ports it is only necessary that the liquid be elevated by suction a comparatively short distance. This produces a plurality of atomized streams of the medicated liquid and these streams mingle together, the medicated vapor thus being taken by the patient through the mouth or through the nose into the bronchial tract and lungs. In cases where the patient finds difiiculty in breathing, that is, inhaling, the flutter valve assembly 40 may be removed.
Our invention is particularly valuable in treatment of patients afflicted with asthma of the type which causes difficult breathing. With such patients inhalation is not only difficult but tires the muscles of the diaphragm and accessory breathing muscles, therefore it is necessary to give the relief with as few inhalations as possible. With our invention a medicament may be used in solution with the water which is practically no more volatile than the water itself and thus the medicament has the characteristics of being a mild drug and on account of the construction of the inhalator, at each inhalation there is the mixing of the plurality of jets or CIA streams of the atomized water with the liquid medicament. In most of the inhalators patented or now on themarket, insufficient provision is made for operation by inhalation by the patient and hence it is customary with such devices to use readily volatile solutions of the medicament and these are too potent and Vtoo irritating and toxic to the lungs andother tissues reached through the mouth and nostrils.
Various changes may b e made in the details of the construction without departing from the spirit or Vscope of the invention as defined by the appended claims.
l. An inhalator comprising in combination a hollow body structure having a large air flow channely at the bottom with a wall extending inwardly and upwardly from the bottom and provided with a thin top wall at the upper end of saidr channel, such wall having a plurality of small air inlet ports of short length with their axes parallel and directed parallel to the longitudinal center of the hollow body structure, said upwardly extending Wall and the lower portion of the body structure defining an annular reservoir for a liquid medicament, and an injector means having a jet orifice positioned above and in alignment with each port with an intake for liquid extending downwardly to dip-in the reservoir, the upper part of the hollow body having an inhalation suction means to be operated solely by inhalation through the mouth or nostrils, such inhalation creating an upward flow of air through the channel at the bottom, the velocity of the air through the channel increasing towards the top and further developing a fine stream of air through each inlet port directed upwardly and parallel one to the other, the velocity of flow through each port being much higher than the velocity in the channel, the ow of air through the ports developing an ejector action at each ejector orifice causing an atomizing of the liquid medicament in a plurality of upwardly flowing parallel streams, such streams being adapted to mix in the upper part of the hollow body, such medicament being carried upwardly with the flow of air to be inhaled through the mouth or nostrils into the bronchial tract and lungs producing a local as well as a systematic reaction by absorption into the blood stream, a flutter valve device connected at the bottom of the hollow body structure and below the entrance end of the air flow channel, such flutter valve device having a valve opening with a valve seat and a flutter valve disk, a compression spring seating the disk on the seat adjacent the opening, the spring being tensioned to maintain the utter valve closed until a desired degree of vacuum is created in the hollow body structure, such vacuum by producing a negative pressure facilitating the vaporization of the liquid, the spring having the characteristic of yielding at a higher degree of vacuum and admitting air to carry the evaporated liquid to the inhalation suction means and then on the increase of internal pressure the spring again closing the flutter valve and during inhalation developing an intermittent action of opening and closing the valve.
2. An inhalator comprising in combination a hollow body structure having one or more inlet air ports, the bottom of the structure forming a reservoir for a medicament, an ejector means having a jet orifice positioned in alignment with the port or lports and having an intake end extending into the reservoir, an air suction outlet construction connected to the bottom of the body structure and having a spring closed valve operative to open on a partial vacuum being created in the hollow body structure by inhalation and to close when the internal pressure is increased and thereby develop an intermittent Opening and closing of the flutter valve during a continuing inspiration through the suctionpipe.
3. An inhalator comprising vin combination a closed hollow body vstructure having an air ilow channel at the bottom including a `Wall at the upper end of such channel, an air port extending through such wall, there being a reservoir below the said wall for a liquid medicament, an injector means having a jet orifice positioned above and in alignment with the por-t with an intake for liquid in the reservoir, the upper part of the hollow body having an inhalation suction means to be operated solely by inhalation through the mouth or nostrils, a -utter valve device connected yremote from the port and orifices, a flutter valve at the bottom of the hollow body structure and below the entrance end `of the air flow channel,
such iiutter valve device having a valve opening with a valve seat and a flutter valve disk, a compression spring seating the ,disk on the seat adjacent the opening, the spring being .tensioned to maintain the utter valve closed until a desired degree of vacuum is created in the hollow body structure, such vacuum by producing a negative pressure facilitating the vaporization of the liquid, the spring having the characteristic of yielding at a higher degree of vacuum and admitting air to carry the evaporated liquid to the inhalation suction means and then on the increase of internal pressure the spring again closing the flutter valve and during inhalation developing an intermittent action of opening and closing the valve.
STANLEY L. FOX.
CHAS. C. COGHLAN.