MEDICAL NEBULISING APPARATUS

Abstract: The apparatus is self-contained for carriage in a pocket or handbag and comprises a nebulising chamber (12) from which tangentially extends an outlet tube (14) leading to a perpendicular head (15) provided with a mouthpiece (16). The chamber is cylindrical and houses a rotatable disc (25). An adjustable inlet (30) is provided in the chamber and material to be nebulised is introduced to the chamber (12). The disc (25) is driven by a battery and electric motor in the casing (29) and both draws air in through the inlet and breaks up the material in the casing to nebulise it. Baffles (40, 41) control the size of particles expelled and a damping connection (44) reduces unpleasantness to the user from vibrations.

Description: MEDICAL NEBULISING APPARATUS The present invention relates to medical nebulising apparatus for inhalatory use. In this specification, the term "nebulisation" is -intended to include the formation of a spray from a powder as well as from a liquid. In the medical field, the inhalation of nebulised drugs is an accepted way of treating various medical conditions such as asthma, bronchitis, cystic fibrosis and other conditions of the respiratory tract. Existing medical nebulisers are not easy to use by all patients. They are expensive, bulky and require a separate com¬ pressed air or oxygen supply, e.g. from a compressed air container or from an electric compressor device. A patient, therefore, is unlikely to have or carry his own nebuliser and has to visit a hospital for inhalation ' treatment. It has been proposed to use a rotatable disc for dispersing particles in a medical nebuliser. The material is fed in an axial direction onto the disc to disperse, the particles in a large chamber and an airstrea is independently generated to carry particles out of the chamber-. There is generation of a large proportion of large particles and the apparatus is massive. One common way of producing a spray is the pressurised can, commonly used, for example, for such purposes as paint spraying, air fresheners and insecticide sprays. Although these cans are readily portable and are used as inhalation devices, they suffer several drawbacks. They require a pressurised carrier gas, which itself is undesirable for environmental reasons and the pressure is excessively high, with the result that the spray particles impact in the mouth and coalesce. The devices are not re-usable and they need a very high degree of co-ordination and effort by the patient. OMPI 2 The present invention provides medical nebulising -- -- ' - ' apparatus, eom is^.ϊt^ * a housing including r a chamber pro¬ vided with "' a " re§efvoir for material to be nebulised, the -Housing having ari * outlet portion for nebulised material, 5 ' " - ' pass ge -for nebulised material Between the ' chamber and tKe ' - " outlet portion, and nebulising means in tfie'fbrm " of a - -"driven-rotatable member for effecting nebulisatxori, characterised in that the rotatable member' has- its path o ■'- rotation pass-ing through the reservoir to ' pick up materia 10 ' - * :the passage- ' com unicates - ith the chamber at a port radia - '■* s ' p ' a ' ced " from -the path of rotation and positioned in the ' - ' path of-particles flung from the rotatable member 'and the chamber is shaped -to direct—particles to the port in an air stream- centrifugally generate ' d-by the rotatable membe 15 ; ' The- rotatable element is preferably in the form of a rotatable disc and the chamber preferably has a circular " - " -peripheral wall about the disc periphery. The passage fr the " chamber may be tangential to " the chamber. ' ' " i .. _. ' The air inlet is preferably-an aperture in ' a- wall of 2©-s2 tBeYehamber and a shutter may be-provided to-control the area " " of the inlet. It is preferred that a scale is provi '■' --"- * ■ ' © "" - indicate-the position of the shutter and, therefore, • - ' -• " - prό r vide p e ' determined settings for- r~ tfi -inlet area"." * - The s off " the inlet area determines the rat -oέ "delivery"of 25 ' * lieb ϊised material by controlling the :" rate " of adm±≤rsion o • ..--::"aϊ-r " --to -the chamber during operation.- ; <J - " ■ ;t - ~ ; ■ ' 3 -- Ξ i" The- passage- ' between the chamber- anf the o-ά€ ~ hrr ' portio • : ---prefe-r-a_bly--i-ήcludes a baffle arrahgemeϊfi: to ssϊst" in con - • > • '" ""ti ' olliΩ^ ' "the particle size at the' * oiitϊe by- ' returning la 30 pai%-icl s to the chamber. "• •- -Apparatus according to the " invention can be made sufficiently small for carrying in ' a pocket or handbag an can provide -a fine mist ' with particles not exceeding 30^ or even.as ' lo " -Ss 15M. :' - 35 O PI WIPO 3 „ c~* of a rotating- ^ A -~ ~'P'- a ,^^- s streaιn is a very olς practice-in, , s<=.ιse..v r « r - f cindustries, for example, for comminuting a metals w and £.„.. electrostatic, powder coating. These industria^-.gro- s. n 5 jesses are described in the following U.K..patent;- specifications, which have been loca^ed_by .search:fcng, _ ^ -→ _.. since the invention was made. - → - z-rc->- - j ._,- Gr - U.K..patent No.1,173,380 describes an_-a pa?jatus j.-.. ..for developing electrostatic σharge_ r lmages,;which, r i-nvolves 1 ,. the use of a disc electrode in an enclosed 'cha berswhich ? dips, while revolving, in a dye liquid^..A high voltage r , is applied to the electr-ode to cause atomization of the ._ .dye liquid and t ^. atomised particles migrate, by virtue „.pf an applied electrical field, to a conductive support . ~5 jcox a recording ^ material carrying a charge image. - •r ,£, aa_s. .U.K. patentsNo. 1,085,092 describes an apparatus which uses a rotating toothed-disc to direct liquid ^ particles from a reservoir into a gas stream. This ^apparatus essentially requires a separate supply 3 σf gas ~ . 20 under pressure -to ^ enable the apparatus to function.- . - .-c, An appa^a ^s ~ or copiminuting molte metal -fe_ ~ \ the _ purpose of f - j -f^r-example, producing a -oxide of tha.t. metal ^.i j S.describe^ 3 !^ U.K. patent No. 519,..784 c .and a. very . B aijpilaς apparatus is described in U.K^paten-fc. θ / ^ζ-74,385. 25 The apparatus of each of these specifications ,squires a fgzc. obta ning a mass : αf, molten metal and a ._r tatj ig . h ^.i i gs the particles of the molten-πmetal into a gas ^r£am. s _ Specification- o. 519, : 78 ^ wjvich was published forty years ago, does fleetingly, in_ png; _, , 30 sentence, consider : that the rotating wheel might serve to produce the gas stream, but .for these industrial processes, as for present day medical- nebulise^s, it is accepted that a separate gas stream-producing apparatus is essential. 35 C r Reference is now made to the accompanying drawings, wherein:- Figure 1 is a perspective view of a first embodiment of a medical nebulising apparatus according 5 to the invention; Figure 2 is a perspective view of a broken away portion of the apparatus of Figure 1 showing a reservoir thereof; Figure 3 is a sectional side elevation on the 10 line 3—3 of Figure 1; .Figure 4 is a sectional view on the line 4—4 of Figure 1; Figures 5 and 6 are sectional views similar to Figures 3 and 4 of a second embodiment; and 15 Figures 7 and 8 are sectional views similar to Figures 3 and 4 of a third embodiment. Referring to Figures 1 to , there is shown a medical nebulising apparatus comprising a housing 11 having a hollow cylindrical portiorT 12 having a chamber '20 13 therein. An outlet tube 14 leads upwardly (in the position of use shown in Figure 1) .from the cylindrical portion to define an outlet passage tangential to the chamber 13 and communicating therewith through a port 13 The outlet tube 14 leads to a tubular head 15, which has 25 a T connection with the tube 14. A mouthpiece 16 is connected to one end of the head 15. In use, material to be nebulised is contained in the chamber 12 and a fin spray consistingof an air stream entraining particles of the material is provided at the mouthpiece, as described hereafter. 30 The lower portion of the' chamber 13 opposite to th tube 14 defines a reservoir 18 and internal sloping surfaces 19, 20 cause the reservoir to narrow towards th periphery, each sloping surface being arcuate and following the internal peripheral contour of the chamber 35 as is apparent from Figure 2. Each surface is defined in this construction by a solid internal wall 21, 22 c ~ _ - . « ._._._.. / O O M M of substantially triangular section as is. apparent from Figure 4. A nebulising disc 25 is rotatably mounted in the chamber 13 by an axle 26, so that part of the marginal 5 periphery of the disc lies between the sloping surfaces 19, 20 in the reservoir, the diameter of the disc being only slightly less than that of the container and the general plane of the disc being parallel to the side walls 12a_, 12b of the cylindrical portion 12. The axle J is driven by an electrical motor 27 and a replaceable electric battery 28 mounted in a casing 29 on one side wall I2a_ of the cylindrical portion 12, which defines the chamber 13. A switch 28a. is accessible externally of the casing and is actuable to operate the moter. l ~ The opposite side wall 12b of this portion has a central air inlet 30, the size of which is variable by means of a.shutter 31. The shutter in this embodiment is in .the form of a disc pivotally mounted by pivot pin 32 on the side wall 12b. The shutter has an aperture ' 33 '20 of equal diameter to the inlet 30, so that the inlet is fully open with the aperture 33 and the inlet in register. The shutter can be angularly moved to reduce the area of the inlet exposed. The shutter carries a pointer 35 associated with an arcuate scale 36 marked on the side 25 wall 12b, so that a predetermined area of the inlet can be exposed recording the scale reading. The outlet parts of the device have an internal baffle arrangement defined by a constriction 40 near the mouth of the outlet tube 14, adjacent the head 15, and a conical 30 projection 41 provided in the .head 15 directly opposite the outlet tube 14, the apex 42 of the projection 41 being on the axis of the outlet tube. The end of the head opposite to the mouthpiece 16 is closed except for a vent 43. A flexible bellows 44 attaches the mouthpiece 16 to 35 the head 15. OMPI . WWIIPPOO - The outlet tube 14 comprises an upper part 14a_, integral with the head 15 and a lower part 14b, integral with the cylindrical portion 12. The upper and lower parts are push-fitted together. The head 15, with the upper part 14a_, can, therefore, be removed, so that the mouth 14c of the lower part defines an inlet. In use, the material to be nebulised is introduced to the reservoir 18 through the inlet mouth 14c. The patient's mouth is put to the mouthpiece 16 and the electric motor is energised by operating the switch 28a. •The nebulising disc 25 is thereby rotated in the direction of arrow B in Figure 3. A part of the periphery is immersed in the material in the reservoir 18, so that the disc flings particles of the material along the tangential passage in the outlet tube 14. The rotating disc also serves as a centrifugal pump to draw air in through the inlet 30 and produce a gas stream along the passage in the outlet tube, the particles of the material being entrained in the gas stream so that nebulised material passes out of the mouthpiece 16 in a fine spray. The amount of air drawn into the chamber can be controlled by the position of the shutter 31. As the disc flings particles of the material at a high speed, these particles (especially the larger ones) tend to impact against the inner walls of the chamber 13 and shatter into even smaller particles. The larger particles entering the tube 14 tend to coalesce and drip back into the reservoir 18 or onto the disc for further treatment. This continuous and repeated action leads to the generation of very small particles. The constriction 40 obstructs flow of larger particles and assists this action as does the conical projection 41 which serves to direct particles which coalesce there back into the reservoir. The spray at the mouthpiece may therefore be made up of particles of maximum size of 15 . OMPI 7 The vent permits sucking in of extra air by a patient and also prevents a sucking action at the mouth¬ piece from drawing in material from the reservoir and relieves pressure, if the patient obstructs the mouth- piece or blows back into the mouthpiece. The patient can breathe freely, therefore, without interfering with the operation of the apparatus. Venting in this case also prevents wetting of the material in the reservoir from the user's breath, which is important, if the material is a powder. The shaping of the reservoir 18 minimises changes in the depth of material therein, with changes in orientation of the apparatus. The disc may be rotationally mounted off-centre or may be unbalanced about the axis by other means such as weighting to cause vibrations, which assist in breaking up and fluidising the material in the reservoir to improve nebulisation. ' This may be especially useful where the material is a powder. Large particles incapable of being nebulised in the apparatus could be contained in the reservoir to cause such vibration and assist in breaking the powder particles into even smaller ones. These vibrations could cause unpleasant sensations in the lips of the user and the flexible bellows 44 serves to damp the vibrations at the mouthpiece. The disc is preferably rotated at 8000 r.p.m. or more to provide a good rate of delivery of nebulised material. The described nebulising apparatus is small and is capable of being held in a pocket or handbag. This is assisted by the connection between the tube parts 14a., 14b, which permits swivelling of the parts to make the apparatus more compact. The motor casing 29 may be removable to facilitate sterilisation, unless the casing is watertight. The OMPI 8 casing may have, for example, a bayonet or screw fitting with the cylindrical portion 12 and the shaft 26 may have two parts with a spline connection. The battery may be recharageable from the mains. An alternative embodiment is shown in Figures 5 and 6, in which the overall construction is substantially the same as the embodiment described above. In this case there are two parallel closely spaced nebulising discs and the internal walls of the reservoir 118 are further spaced at the periphery of the chamber 114 to accommodate the two discs. In this case the walls 119, 120 are con- vexly curved in section instead of straight. Instead of the projection 41 and constriction 40, baffles 140, 141 are provided in the head 115. Ventilati holes 150 are optionally provided in this case adjacent t the mouthpiece 116, the size being adjustable by relative movement of the mouthpiece 116 and the rest of the head 1 Figures 7 and 8 show a modification of the embodimen of Figures 5 and 6, in which the nebulising discs are eccentrically positioned relative to the peripheral wall the chamber and are of smaller diameter than in the previously described embodiment. The discs can be rotate in either direction. The discs are positioned near the bottom of the chamber to extend into the reservoir 218, a previously. In this case, a radial baffle 260 is provide in the chamber extending towards the discs. This enhance agitation and disruption of particles within the chamber a result of impact and also redirects larger particles on the discs for further treatment. The mouthpiece 216, in this case is mounted in the outlet from the head 215 by means of a resilient bung 244 absorb vibrations. An outlet nozzle 245 extends through bung to communicate the interior of the mouthpiece with t interior of the head. Ventilation holes 250 are provided around the mouthpiece. This arrangement is preferred and particularly effective to permit the user to breathe free OMPI and to prevent air from the lungs of the user reaching the reservoir. Each of the described embodiments can be easily cleaned and sterilised. A very simple arrangement may be effective where the head, such as 15 in Figure 1, is not provided, but the outlet tube 14 itself may define the mouthpiece. The inlet for air may be difined by the outlet tube, the latter being sufficiently wide to permit sucking of air into the chamber. In this case, a mouthpiece may be ' provided having an inner outlet tube surrounded by venting, as shown in figure 7. It is envisaged that a nebuliser may be constructed according to the invention for use in an incubator. The nebuliser may also be usable in non-medical fields, for example, for providing a fine spray in a greenhouse for dispersing an insecticide. OMPI SUBSTITUTE: SHEET . \ °

Claims: 10 CLAIMS 1. Medical nebulising apparatus comprising a housing (11 including a chamber (12) provided with a reservoir (18) for material to be nebulised and having an air inlet (30) , the housing having an outlet portion (16) for nebulised materia and a passage (14) for nebulised material between the chamber and the outlet portion, and nebulising means in the form of a driven rotatable member (25) for effecting nebulisation, characterised in that the rotatable member (2 has its path of rotation passing through the reservoir to pick up material, the passage (14) communicates with the chamber (12) at a port (13a_) radially spaced from the path of rotation and positioned in the path of particles flung from the rotatable member, and the chamber is shaped to dir particles to the port in an air stream centrifugally ■ generated by the rotatable member. 2. Medical nebulising apparatus according to Claim 1, wherein the rotatable member (25) is a disc pivotally mount approximately at its centre and the chamber has a generally circular section generally perpendicular to the axis (26) of rotation of the rotatable member. 3. Medical nebulising apparatus according to Claim 2, wherein the rotatable member comprises a pair of closely spaced generally parallel discs (125a_, 125b) mounted on a common axis of rotation. 4. Medical nebulising apparatus according to Claim 2 or wherein the reservoir is defined by a narrowed portion (21, 22) of the chamber opposite to the port (13a) , which is in the peripheral wall of the chamber, and the passage (14) joining the chamber tangentially. 5. Medical nebulising apparatus according to any precedi Claim, wherein the air inlet is in a wall (12b_) of the cham and its effective area is selectively variable. 6. Medical nebulising apparatus according to Claim 5, co prising a shutter (31) , the wall (12b) of the chamber and t shutter being provided one with a pointer (35) and the othe OMPI with a scale (36) for indicating selectable positions of the shutter. 7. Medical nebulising apparatus according to any preceding Claim, wherein the rotatable element is unbalanced to produce vibrations in the reservoir and vibration damping means (44) is provide -between the outlet portion (16) and the housing (11) . 8. Medical nebulising apparatus according to any preceding claim, including a baffle arrangement (40, 41) to assist return of larger particles to the chamber, so as to control the size of particles of material in the air stream to a maximum of 30,< . 9. Medical nebulising apparatus according to any preceding Claim, wherein the passage is defined by a first portion (14) leading from the chamber (12) and a second portion (15) generally perpendicular thereto and leading to the outlet portion (16) . 10. Medical nebulising apparatus according to Claim 9 including one or more vents (43, 150) in the second portion (15) or in the outlet portion (116) . .,,-«.-»■

Inventors: MALEM H
Applicants: MALEM H
Application year: 1981
Main classification: A61M15
IPC codes: A61M11, A61M15