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Atomizer |
| RE40591 |
Atomizer
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| Patent Drawings: | |
| Inventor: |
Denyer |
| Date Issued: |
December 2, 2008 |
| Application: |
09/425,031 |
| Filed: |
October 19, 1999 |
| Inventors: |
Denyer; Jonathan Stanley H. (Chichester, GB)
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| Assignee: |
Profile Respiratory Systems Limited (West Sussex, GB) |
| Primary Examiner: |
Douglas; Steven O |
| Assistant Examiner: |
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| Attorney Or Agent: |
Pillsbury Winthrop Shaw Pittman LLP |
| U.S. Class: |
128/200.18; 128/200.21; 239/338; 239/343; 239/366 |
| Field Of Search: |
128/200.17; 128/200.18; 128/200.19; 128/200.21; 128/200.22; 128/200.12; 239/4; 239/318; 239/337; 239/338; 239/339; 239/365; 239/366; 239/368; 239/370; 239/371; 239/423; 239/424; 239/424.5; 239/433; 239/434; 261/78.1; 261/DIG.65 |
| International Class: |
A61M 11/00 |
| U.S Patent Documents: |
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| Foreign Patent Documents: |
3429411; 170715; 0587380; 627266; 1 070292; 675524 |
| Other References: |
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| Abstract: |
An atomizer including a gas exit, an outlet adjacent the gas exit, and a deflector for deflecting gas issuing from the gas exit over the outlet for drawing a substance to be atomized out from one outlet and atomizing the substance in the gas issuing from the gas exit characterised in that the deflector is movable between a first position in the path of the gas issuing from the gas exit for atomization and a second and non-atomizing position. |
| Claim: |
I claim:
1. An atomizer comprising: a head having a gas exit and at least one outlet adjacent said gas exit; a deflector for deflecting gas issuing from said gas exit over at least one of saidoutlets, for drawing a substance to be atomized out from at least one of said outlets and atomizing the substance in the gas issuing from said gas exit; and said deflector mounted with respect to said head so that said deflector is movable between afirst position in which said deflector is adjacent said gas exit and directly in the path of gas issuing from said gas exit so that atomization of the substance takes place, and a second position spaced from said gas exit so that no atomizing takesplace.
2. An atomizer as recited in claim 1 further comprising condition responsive means for automatically moving said deflector between said first and second positions in response to a condition.
.[.3. An atomizer as recited in claim 2 wherein said condition responsive means comprises a vane connected to said deflector and effecting movement of said deflector in response to air pressure conditions acting on said vane..].
4. An atomizer as recited in claim 1 wherein said deflector is mounted with respect to said jet head by a pivot, so that said deflector pivots between said first and second positions.
5. An atomizer as recited in claim 1 further comprising a vane for moving said deflector between said first and second positions.
6. An atomizer as recited in claim 5 wherein said deflector comprises a bar connected to said vane.
7. An atomizer as recited in claim 1 further comprising an air inlet and an air outlet providing for the flow of air toward and past said head, said outlet permitting flow of atomized substance to a human.
.[.8. An atomizer as recited in claim 7 wherein said deflector moves into said first position when air flows from said air inlet to said air outlet..].
.[.9. An atomizer as recited in claim 7 wherein said deflector moves into said second position when air is not flowing from said air inlet to said air outlet..].
10. An atomizer as recited in claim .[.3.]. .Iadd.2, wherein said condition responsive means comprises a vane connected to said deflector and effecting movement of said deflector in response to air pressure conditions acting on said vane; wherein the atomizer .Iaddend.further .[.comprising.]. .Iadd.comprises .Iaddend.an air inlet and an air outlet for providing the flow of air to and past said head; and wherein said deflector is biased to said second position and wherein said vane isbiased to a position closing said air inlet.
11. An atomizer as recited in claim 10 wherein said vane is positioned to direct a flow of air toward said gas exit when air flows from said air inlet to said air outlet.
12. An atomizer as recited in claim 10 wherein said vane is mounted to allow air flow from said air outlet directly through said air inlet, without passing past said head.
13. An atomizer as recited in claim 10 wherein said vane is mounted so as to allow a proportion of the air flowing from said air inlet to said air outlet to by-pass said head when the air flow rate exceeds a predetermined value.
14. An atomizer as recited in claim 4 wherein said deflector comprises a bar with an arcuate surface.
.[.15. An atomizer as recited in claim 2 wherein said condition is a human inhaling and exhaling during breathing..].
16. An atomizer as recited in claim .[.15.]. .Iadd.1, .Iaddend.wherein said deflector is positioned so that during exhaling, exhaled air does not entrian the substance to be atomized.
17. An atomizer as recited in claim 1 further comprising a baffle extending outwardly and downwardly about said gas exit; and wherein said deflector is mounted within said baffle and movable with respect to said baffle.
18. An atomizer comprising: a head having a gas exit and at least one outlet adjacent said gas exit; a deflector for deflecting gas issuing from said gas exit over at least one of said outlets, for drawing a substance to be atomized out fromat least one of said outlets and atomizing the substance in the gas issuing from said gas exit; said deflector mounted with respect to said head so that said deflector is movable between a first position in the path of gas issuing from said gas exit foratomization, and a second, non-atomizing, position; and a vane for moving said deflector between said first and second positions.
19. An atomizer as recited in claim 18 wherein said deflector is mounted with respect to said head by a pivot, so that said defector pivots between said first and second positions.
20. An atomizer as recited in claim 18 wherein said vane is integral with said deflector.
21. An atomizer as recited in claim 18 wherein said deflector comprises a surface elongated in a first dimension and having a first width; and wherein said vane comprises a surface elongated in a second dimension substantially perpendicular tosaid first dimension and has a second width much greater than said first width so that said vane moves, and effects movement of said deflector, in response to breathing action by a human.
22. An atomizer as recited in claim 21 further comprising a baffle extending outwardly and downwardly about said gas exit; and wherein said deflector is mounted within said baffle and movable with respect to said baffle.
23. An atomizer comprising: a head having a gas exit and at least one outlet adjacent said gas exit; a deflector for deflecting gas issuing from said gas exit over at least one of said outlets, for drawing a substance to be atomized out fromat least one of said outlets and atomizing the substance in the gas issuing from said gas exit; and said deflector pivotally mounted with respect to said head so that said deflector is pivotally movable between a first position in the path of gasissuing from said gas exit for atomization, and a second, non-atomizing, position.
24. An atomizer as recited in claim 23 further comprising a baffle extending outwardly and downwardly about said gas exit; and wherein said deflector is mounted within said baffle and movable with respect to said baffle.
25. Spray forming apparatus comprising: a housing having an outlet for a spray of atomized substance; a head mounted within said housing and including a pressuzied gas exit, and at least one outlet adjacent said gas exit; a deflector fordeflecting gas issuing from said gas exit over at least one of said outlets, for drawing a substance to be atomized out from at least one of said outlets and atomizing the substance in the gas issuing from said gas exit; and said deflector mounted withrespect to said head so that said deflector is movable between a first position in which said deflector is adjacent said gas exit and directly in the path of gas issuing from said gas exit so that atomization of the substance takes place, and theatomized substance is sprayed out of said housing outlet, and a second position in which said deflector is spaced from said gas exit so that no atomized substance is sprayed out of said spray outlet.
.Iadd.26. The atomizer of claim 1, further comprising: an air inlet and an air outlet for providing the flow of air to and past said head, an air passage being defined between the air inlet and air outlet; and a structure movable relative tothe air passage between a first position that at least substantially prevents air flow through the air passage and a second position that permits air flow through the air passage, the structure being constructed and arranged to move between the first andsecond positions in response to inhalations by a patient, wherein the deflector is constructed and arranged to move between the first and second positions in response to the inhalations by the patient, and wherein the deflector is constructed andarranged such that when the patient inhales, the deflector moves into its first position before the structure moves into its second position..Iaddend.
.Iadd.27. The atomizer of claim 26, wherein said structure operatively connects to the deflector for effecting the automatic movement of said deflector between the first and second positions in response to the inhalations by thepatient..Iaddend.
.Iadd.28. The atomizer of claim 26, wherein the structure closes the air inlet when in its first position, and opens the air inlet when in its second position..Iaddend.
.Iadd.29. The atomizer of claim 26, wherein the structure seals the air passage when in the first position..Iaddend.
.Iadd.30. The atomizer of claim 26, wherein said structure comprises a flap valve..Iaddend.
.Iadd.31. The atomizer of claim 26, wherein said structure comprises a vane..Iaddend.
.Iadd.32. The atomizer of claim 31, wherein said vane operatively connects to the deflector for effecting the automatic movement of said deflector between the first and second positions in response to the inhalations by the patient..Iaddend.
.Iadd.33. The atomizer of claim 32, wherein the vane is integral with the deflector..Iaddend.
.Iadd.34. The atomizer of claim 26, wherein the deflector is mounted with respect to said head by a pivot, so that the deflector is pivotally movable between the first and second positions..Iaddend.
.Iadd.35. The atomizer of claim 26, wherein the structure is movably mounted with respect to the air inlet by a pivot..Iaddend.
.Iadd.36. The atomizer of claim 26, wherein the structure is biased toward its first position..Iaddend.
.Iadd.37. An assembly comprising: an atomizer having an atomizing chamber, and an air inlet and an air outlet for enabling flow of air through the atomizing chamber, an air passage being defined between the air inlet and air outlet, theatomizer being constructed to atomize liquid in response to inhalations by a patient; and a first structure movable relative to the air passage between a first position that at least substantially prevents air flow through the air passage and a secondposition that permits air flow through the air passage, the first structure being constructed and arranged to be movable between the first and second positions in response to the inhalations by the patient, wherein the atomizer is constructed such thatwhen the patient inhales, the atomizer begins atomization before the first structure moves into its second position..Iaddend.
.Iadd.38. The assembly of claim 37, wherein the atomizer further comprises: a pressurized gas outlet disposed in the atomizing chamber; and a deflector movable relative to the pressurized gas outlet, the movable deflector being constructed andarranged to move between an atomizing position and a non-atomizing position in response to the inhalations by the patient..Iaddend.
.Iadd.39. The assembly of claim 37, wherein the atomizer further comprises: a pressurized gas outlet disposed in the atomizing chamber; and a second structure that is movable relative to the pressurized gas outlet, the second structure beingconstructed and arranged to move between an atomizing position and a non-atomizing position in response to the inhalations by the patient..Iaddend.
.Iadd.40. The assembly of claim 39, wherein the second structure is constructed and arranged such that when the patient completes an inhalation, the second structure moves into the non-atomizing position after the first structure moves into thefirst position..Iaddend.
.Iadd.41. The assembly of claim 39, wherein the second structure is constructed and arranged such that when the patient's inhalation pressure falls below a predetermined threshold, the second structure moves into the non-atomizing positionafter the first structure moves into the first position..Iaddend.
.Iadd.42. The assembly of claim 39, wherein the first structure is resiliently biased toward its first position, and the second structure is resiliently biased toward its non-atomizing position..Iaddend.
.Iadd.43. The atomizer of claim 37, wherein the first structure is resiliently biased toward its first position..Iaddend.
.Iadd.44. The assembly of claim 37, wherein the first structure seals the air passage when in the first position..Iaddend.
.Iadd.45. The assembly of claim 37, wherein the atomizer is constructed such that when the patient completes an inhalation, the atomizer stops atomization after the first structure moves into the first position..Iaddend.
.Iadd.46. The assembly of claim 37, wherein the atomizer is constructed such that when the patient's inhalation pressure falls below a predetermined threshold, the atomizer stops atomization after the first structure moves into the firstposition..Iaddend.
.Iadd.47. An assembly comprising: an atomizer having an atomizing chamber, and an air inlet and an air outlet for enabling flow of air through the atomizing chamber, an air passage being defined between the air inlet and air outlet, theatomizer being constructed to atomize a liquid in response to inhalations by a patient; and a first structure movable relative to the air passage between a sealed position that at least partially seals the air passage and an unsealed position thatunseals the air passage, the first structure being constructed and arranged to move between the sealed position and the unsealed position in response to the inhalations by the patient, wherein the atomizer is constructed such that when the patientinhales, the atomizer begins atomizing before the first structure moves into its second position..Iaddend.
.Iadd.48. An assembly comprising: an atomizer having an atomizing chamber, the atomizer being constructed to atomize liquid in response to inhalations by a patient; an air inlet fluidly connected to the chamber; and a first structure movablerelative to the air inlet between a first position that at least substantially prevents air flow through the air inlet and a second position that permits air flow through the air inlet, the first structure being constructed and arranged to move betweenthe first and second positions in response to the inhalations by the patient, wherein the atomizer is constructed such that when the patient inhales, the atomizer begins atomization before the first structure moves into its second position..Iaddend.
.Iadd.49. An assembly comprising: an atomizer having an atomizing chamber, the atomizer being constructed to atomize liquid in response to inhalations by a patient; an air inlet fluidly connected to the chamber; and a first structure movablerelative to the air inlet between a sealed position that at least partially seals the air inlet and an unsealed position that unseals the air inlet, the first structure being constructed and arranged to move between the sealed position and the unsealedposition in response to the inhalations by the patient, wherein the atomizer is constructed such that when the patient inhales, the atomizer begins atomization before the first structure moves into the unsealed position..Iaddend.
.Iadd.50. The assembly of claim 49, wherein the atomizer further comprises: a pressurized gas outlet disposed in the atomizing chamber; and a second structure that is movable relative to the pressurized gas outlet, the second structure beingconstructed and arranged to move between an atomizing position and a non-atomizing position in response to the inhalations by the patient, wherein the second structure is constructed and arranged such that when the patient inhales, the second structuremoves into the atomizing position after the first structure moves into the unsealed position..Iaddend.
.Iadd.51. The assembly of claim 50, wherein the second structure is constructed and arranged such that when the patient completes an inhalation, the second structure moves into the non-atomizing position after the first structure moves into thesealed position..Iaddend.
.Iadd.52. The assembly of claim 50, wherein the first structure is resiliently biased toward its sealed position, and the second structure is resiliently biased toward its non-atomizing position..Iaddend.
.Iadd.53. An atomizer comprising: an atomizing chamber; a pressurized gas outlet disposed in the atomizing chamber; an air inlet for enabling flow of ambient air into the atomizing chamber; an air outlet for enabling flow of air out of theatomizing chamber to a patient; an air passage defined between the air inlet and air outlet; a deflector movable relative to the pressurized gas outlet, the deflector being constructed and arranged to move between an atomizing position and anon-atomizing position in response to inhalations by the patient; and a variable size orifice in the air passage, wherein the orifice is constructed and positioned so as to change in size in response to the inhalations by the patient..Iaddend.
.Iadd.54. The atomizer of claim 53, further comprising a structure movable relative to the air passage between a first position that at least substantially prevents air flow through the air passage and a second position that permits air flowthrough the air passage, the structure being constructed and arranged to be movable between the first and second positions in response to the inhalations by the patient..Iaddend.
.Iadd.55. The atomizer of claim 53, wherein the orifice is constructed and positioned to increase in size during atomization..Iaddend.
.Iadd.56. A method of atomizing liquid with an atomizer comprising an atomizing chamber, a pressurized gas outlet disposed in the atomizing chamber, an air inlet extending from an ambient environment to the atomizing chamber, a variable sizeorifice disposed in the air inlet, an air outlet fluidly connected to the atomizing chamber, and a deflector movable relative to the pressurized gas outlet, the method comprising: moving the deflector from a non-atomizing position to an atomizingposition in response to an inhalation by a patient of air through the air outlet; and varying the size of the orifice in response to the inhalation..Iaddend.
.Iadd.57. The method of claim 56, further comprising: increasing the size of the orifice in response to the inhalation; reducing the size of the orifice in response to completion of the inhalation; and moving the deflector from the atomizingposition to the non-atomizing position in response to the completion of the inhalation..Iaddend.
.Iadd.58. The method of claim 56, wherein the method further comprises, after moving the deflector to the atomizing position, increasing a size of the orifice in response to the inhalation by the patient..Iaddend.
.Iadd.59. The method of claim 58, further comprising: reducing the size of the orifice in response to completion of the inhalation; and after reducing the size of the orifice, moving the deflector from the atomizing position to thenon-atomizing position in response to the completion of the inhalation..Iaddend.
.Iadd.60. A method of atomizing liquid with an atomizer comprising an atomizing chamber, and an air inlet and an air outlet for enabling flow of air through the atomizing chamber, an at least partially sealable air passage being defined betweenthe air inlet and air outlet, the method comprising, sequentially: (a) starting atomization of the liquid by the atomizer in response to a patient inhaling through the air outlet; (b) after starting atomization, unsealing the air passage; and (c)passing air from the air inlet to the air outlet to carry atomized liquid through the air outlet..Iaddend.
.Iadd.61. The method of claim 60, wherein unsealing the air passage comprises unsealing the air passage in response to the inhaling by the patient..Iaddend.
.Iadd.62. The method of claim 61, wherein: the atomizer further comprises a first structure movable relative to the air passage between a sealed position that at least partially seals the air passage and a first unsealed position that unsealsthe air passage; and the step of unsealing the air passage comprises moving the first structure from the sealed position to the first unsealed position..Iaddend.
.Iadd.63. The method of claim 62, wherein: the atomizer further comprises a pressurized gas outlet disposed in the atomizing chamber, and a deflector movable relative to the pressurized gas outlet between an atomizing position and anon-atomizing position; and the step of starting atomization of the liquid comprises moving the deflector into the atomizing position to cause atomization of the liquid..Iaddend.
.Iadd.64. The method of claim 62, wherein: the atomizer further comprises a pressurized gas outlet disposed in the atomizing chamber; and a second structure that is movable relative to the pressurized gas outlet, the second structure beingconstructed and arranged to move between an atomizing position and a non-atomizing position in response to the inhalations by the patient, and the step of starting atomization of the liquid comprises moving the second structure into the atomizingposition..Iaddend.
.Iadd.65. The method of claim 64, further comprising, after (c), sequentially: (d) moving the first structure from the first unsealed position to the sealed position to at least partially seal the air passage in response to completion of aninhalation by the patient; and (e) moving the second structure into the non-atomizing position in response to the completion of the inhalation by the patient..Iaddend.
.Iadd.66. The method of claim 65, further comprising, after (e): (f) moving the first structure from the sealed position to a second unsealed position that unseals the air passage in response to an exhalation by the patient..Iaddend.
.Iadd.67. The method of claim 64, further comprising, after (c), sequentially: (d) moving the first structure from the first unsealed position to the sealed position to at least partially seal the air passage in response to the patient'sinhalation pressure falling below a first predetermined threshold; and (e) moving the second structure into the non-atomizing position in response to the patient's inhalation pressure falling below a second predetermined threshold..Iaddend.
.Iadd.68. The method of claim 61, further comprising, after (c), sequentially: (d) at least partially sealing the air inlet in response to completion of an inhalation by the patient; and (e) stopping atomization of the liquid into theatomizing chamber in response to the completion of the inhalation by the patient..Iaddend.
.Iadd.69. The method of claim 68, further comprising, after (e), repeating (a) through (e) in response to another inhalation by the patient..Iaddend.
.Iadd.70. A method of atomizing liquid with an atomizer having an atomizing chamber, an air inlet and an air outlet for enabling flow of air through the atomizing chamber, an air passage defined between the air inlet and air outlet, and astructure disposed in the air passage in a first position that at least substantially prevents air flow through the air passage, the method comprising, sequentially: (a) starting atomization of the liquid by the atomizer in response to a patient inhalingthrough the air outlet; (b) moving the structure into a second position in response to the inhaling by the patient, the second position permitting air flow through the passage; and (c) passing air from the air inlet to the air outlet to carry atomizedliquid through the air outlet..Iaddend. |
| Description: |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to atomizers and, in particular, to atomizers of the type which include a gas exit, at least one outlet in the region of the gas exit and a deflector for deflecting gas issuing from the gas exit across the at leastone outlet whereby a substance to be atomized is drawn out of the at least one outlet and atomized. These atomizers atomize liquids or powders into the gas.
Most conventional atomizers of the above type operate continuously whether atomization is required or not. Strictly speaking, when such atomizers, frequently called nebulisers, are used in medical applications, atomization is only requiredduring the inhalation phase of a breathing cycle so that a drug can be administered by deposition in the lungs. In practice a patient usually inhales for about 30 percent of the breathing cycle, consequently, use of a continuously operating atomizerresults in a large proportion of the atomized drug being wasted.
Some designs of medical atomizer overcome such wastage by giving the patient a trigger to start the atomization when they begin to inhale. Such a trigger controlled type of atomizer is not satisfactory since the patient must coordinateinhalation with trigger operation.
In one conventional atomizer a gas duct leads gas under pressure to a gas exit, a reservoir for holding the substance to be atomized is formed around the base of the gas duct, and a sleeve placed around the gas duct defines a passageway throughwhich the substance to be atomized may pass to at least one outlet. A fixed deflector in the form of a bar is disposed in line with the gas outlet so that gas issuing from the gas exit is defected so as to pass over the outlet or outlets. The passageof gas over each outlet draws the substance to be atomised from the reservoir, through the passageway to each outlet. The deflected gas atomizes the substance, and atomized particles of the substance are carried away during the inhalation phase of thepatient since the patient breathes air or gas in through the atomizer some of the drug is lost while the patient is not inhaling.
Atomizers are used in other applications. For example, powders or liquid may be sprayed from a jet, the liquid or powder being atomized and entrained by a propellant. In conventional sprays, operation is controlled by a valve for releasingpropellant. When the valve is released, the spraying operation is stopped and some of the liquid or powder collects in the jet since insufficient propellant has been released. The collected spray either dries to block the jet or is propelled by are-started spraying operation in large droplets. Where paint is being sprayed, this causes splatter and uneven deposition on a surface to be painted.
It is an object of this invention to reduce at least some of the above disadvantages of the above-mentioned prior art.
The present invention is defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are described below by way of example only with reference to the accompanying drawings in which:
FIG. 1 shows a first embodiment of the invention in a relaxed position;
FIG. 2 shows the first embodiment of the invention in a first operational position in which atomization takes place;
FIG. 3 shows the first embodiment of he invention in a second operational position in which atomization takes place;
FIG. 4 shows the first embodiment of the invention in a third operational position in which no atomization takes place;
FIGS. 5 and 6 show one embodiment of the flap valve and gas deflector;
FIG. 7 shows a second embodiment of the invention in a second operational position in which atomization takes place,
FIG. 8 shows a further embodiment of the invention in which the movable baffle bar is located beneath the baffle, and
FIG. 9 shows the further embodiment during inhalation by a patient.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to FIGS. 1 to 4, an atomizer includes a gas duct 6 which leads gas under pressure to a gas exit 4 within a jet head 3. The gas duct 6 passes through a wall of a reservoir 7 within which a substance to be atomised is held. A sleeve 8is disposed around the jet head 3 and the gas duct 6. Passages are formed between the inner surface of the sleeve 8 and the outer surface of the gas duct 6 for leading the substance to be atomized from the reservoir 7 to outlets 5 in the jet headadjacent to the gas exit 4. For atomization of the substance to take place, a deflector 1 must be placed in the path of the pressurised gas exiting from the gas exit 4 so that it is redirected to pass directly over the outlets 5. This flow of pressureair draws the substance to be atomized from the reservoir 7, through the passage between the sleeve 8 and the gas duct 6 to the outlets 5. The flow of pressure air atomizes the substance as the substance leaves the outlets 5.
A downwardly and outwardly shaped baffle 9 is disposed around the jet head 3 to deflect the atomized substance downwards before it is carried away. It is important that the substance is atomized into very fine droplets. In medical applications,the substance to be atomized is a drug for administering to a patient by lung deposition. The finer the droplets, the deeper into the lungs the drug will pass. This maximises the deposition of the drug. Larger droplets collect on the inside of thebaffle 9 where they coalesce to drop back down into the reservoir 7.
The atomizer also includes an air inlet 13 and an air outlet 14. In the above-mentioned medical application, as a patient inhales, ambient air is drawn into the atomizer through the inlet 13. The air then passes into the region of the air exit4 and outlets 5 where droplets are entrained by the inhaled ambient air. The air then passes down under the baffle 9 before passing upwardly and out via the air outlet 14 carrying droplets of the drug to the patient. This action is described in moredetail in British Patent application 9219327.5 and U.S. Pat. No. 5,533,501, which are hereby imported into this description in their entirety.
A planar arcuate gas deflector 1 is mounted above the gas exit to be movable about a pivot in that plane. The gas deflector 1 may be disposed across the gas exit 4, in which case atomization takes place, or may be disposed away from the gas exit4, in which case no atomization takes place.
A vane 2 is joined to the deflector bar 1 so as to be pivotally mounted and to move with the deflector bar 1. The flap 2 responds to the breathing pattern of a patient by moving around the pivot.
When the apparatus is not in use, the vane assumes the positions shown in FIG. 1 in which the gas deflector is not disposed across the gas exit. The vane forms a partial seal against a curved surface 12 (shown in outline). Even when pressuregas is issuing from the gas exit, no atomization takes place since the deflector is not disposed in the path of the gas.
When a patient inhales, ambient air is drawn into the atomizer through the air inlet 13. The vane 2 is displaced into the position shown in FIG. 2 permitting and directing the ambient air to pass into the region of the gas exit before beingdirected downwardly and outwardly around the baffle. The air then escapes via the air outlet 14 to the patient. The displacement of the flap moves the deflector bar into the path of the gas issuing from the gas exit. Atomization therefore begins assoon as the patient begins to breath in. The atomized drug is carried away by the air passing through the atomizer. The vane must move only a few degrees before the deflector bar 1 is brought into position to commence atomization, but must move a fewmore degrees before breaking the seal between the flap and the curved surface to permit ambient air to enter the nebulizer. This ensures that the deflector is fully in position and atomizing cleanly before the ambient air passes through the atomizer tocarry the droplets away.
The deflector extends further from the pivot than the flap so that the deflector can be positioned very close to the gas exit without obstruction from the flap. The curved surface 12 against which the vane seals therefore includes an arcuateslot through which the deflector may pass.
If the patient inhales sharply or quickly, the vane 2 assumes the position shown in FIG. 3 wherein the deflector bar 1 remains in the path of the gas exit so that atomization takes place, but excess air passes directly from the air inlet 13 tothe air outlet 14 without entraining the atomized substance. The main reason for this is that the efficiency of entrainment of droplets decreases where air passes through the atomizer too quickly since a proportion of droplets will impact against thewalls of the atomizer. A typical optimum flow rate is of the order of twenty five liters per minute.
When the patient exhales, the vane 2 is displaced to a position as shown in FIG. 4 where the deflector is displaced such that it is not in the path of the gas exit. Atomization therefore does not occur, and so no drug is wasted. The vane allowsexhaled air to pass directly from the air outlet 14 to the air inlet 13 without having to pass through the atomizing chamber. The combination of the vane 2 and the deflector 1 therefore constitutes a one-way valve.
When the patient is not breathing in or out, the vane 2 is biased towards the position shown in FIG. 1. The vane 2 and deflector 1 are mounted on a rubber tongue 11 extending from a fixed rubber block 10. The vane 2 and deflector 1 aretherefore resiliently mounted.
The atomizer shown in FIGS. 1 to 4 includes three separable units. A base unit 15 includes the reservoir 7, the gas duct 6, the jet head 3 and outlets 5. The reservoir 7 includes a threaded rim. An upper unit 16 includes three air inlet 13,and the air outlet 14. The baffle 9, sleeve 8, frame members 17, the vane 2, gas deflector 1, the rubber tongue 11 and the fixed rubber block 10 constitute the third unit. Separation of the third unit permits the atomizer to be more easily cleaned. The vane 2 and gas deflector are connected to the air inlet 13 in the upper unit 16, and to the baffle 9 since the gas deflector 1 must pass though a slot in the baffle. The sleeve 8 may be part of the base unit 15, or part of the third unit.
FIGS. 5 and 6 show the vane 2 and deflector 1 mounted on the fixed rubber block and rubber tongue. The rubber tongue 11 is held at the ends by the frame members 17 so that when the tongue 11 is bent by the vane, a load is applied. The vane 2and deflector 1 are attached directly to the tongue 11 so that they are pivotally displaceable.
FIG. 7 shows a second embodiment of this invention in which the base unit 15 is exactly as described in relation to FIGS. 1 to 4. The vane 2 and deflector 1 are also mounted as described above. The main difference in this second embodiment isthat the air outlet 14 leading to a patient extends vertically from the atomizer as shown in FIG. 7. Drug laden air does not have to pass around a sharp corner into the air outlet 14 once it has passed around the baffle 9. Fewer drug droplets willcollect on the inner surface of the air outlet 14.
Referring to FIGS. 3, 4 and 7, the lower edge of the vane 2 forms a seal with the curved surface 12 as explained above. The vane 2 also includes two other edges which must be sealed. The vane 2 swings between two vertical wedge-shaped framemembers 17 which form a seal so that flow of air to bypass the vane 2 is restricted when the vane 2 is disposed in any of the positions shown in FIGS. 1, 2 or 7. In the first and second embodiments shown in FIGS. 1 to 7, the frame members 17 also act assupports for the fixed rubber block 10. The frame members 17 may extend from the baffle 9, from the edge of the curved surface 12 or from the base unit 15. Where the frame members extend from the edge of the curved surface 12, the vane 2, deflector 1and rubber block 10 are all mounted on the frame members 17 and within the upper unit 16.
According to another embodiment (not shown), the rubber block 10 is replaced by a metal spring eg, a leaf spring which permits the vane 2 and deflector 1 to be pivotally moveable in the same manner as described in relation to the rubber block 10and tongue 11.
In a further embodiment (not shown) the vane 2 is omitted, and the deflector is movable into and out of the stream of gas issuing from the gas exit according to the breathing pattern of a patient. The vane is replaced by a flow sensor whichdetects when a patient begins to inhale and moves the deflector 1 into the path of gas issuing from the gas exit. In this embodiment the deflector is a bar which is moveable perpendicularly or laterally relevant to the longitudinal extent of the bar.
In another embodiment the deflector 1 is displaceable up and down in line with the gas issuing from the gas outlet. Once the deflector is raised above a certain height, atomization ceases to take place.
In yet a further embodiment, the deflector is not a straight bar, but is of any suitable shape for deflecting the gas across the outlets to cause atomization. The deflector may, for example, be a spherical ball disposed in the path of gasexiting the gas exit. The deflector may be a longitudinal blade movable into the path of the gas in the longitudinal direction of the blade.
In yet another embodiment (not shown) of this invention, the atomizer is used for producing a spray. This spray may be liquid droplets or powder particles. In medical applications, the spray may contain a drug. This spray producing apparatusmay be used for producing sprays of paint droplets, perfume droplets or any other suitable liquids or powders. A base unit 15 of FIGS. 1-4 may be used to produce a gas exit 4 and outlets 5 for the substance to be atomized. A moveable deflector 1 isdisplaceable by a user. The user first activates a compressor which sends gas through the gas duct. For paint spraying, a mechanical compressor may be used, although this could be substituted for an aerosol propellant. The user then moves thedeflector into the path of the gas issuing from the gas exit 4 to start atomization. The propellant then carries the droplets or powder through an outlet jet to form a spray. The user stops atomization before stopping the flow of gas from the gas exit. This keeps the outlet jet clean and free from paint and the like. A two-stage button can be used whereby atomization only takes place when the button is fully depressed while gas issues from the gas exit when the button is only partially depressed.
Under certain conditions, although 95% of the gas issuing from the gas exit 4 is deflected to either side of the deflector bar 1, a small amount hits the baffle bar depositing the substance to be atomized on the deflector bar 1. The gas whichhits the baffle bar drives the liquid along the baffle bar towards the ends where the liquid can collect on top of the baffle 9 so that it is lost to the atomizer system. The whole dose of medicament is then not available to be administered to thepatient. Furthermore, in some arrangements, as the deflector bar is moved out of the flow of gas issuing from the gas exit 4, the liquid that is running along the edge of the deflector bar 1 is sprayed into the top of the nebulizer where it collectswithout returning back to the reservoir 7. Referring now to FIGS. 8 and 9, the deflector bar 1 is housed entirely within the baffle 9 so that any liquid which collects on the deflector bar merely drips back into the reservoir, or if it is sprayed fromthe deflector bar by the flow of gas from the gas exit 4, is collected on the underside of the baffle 9 whereupon it coalesces and drops back down into the reservoir 7. FIG. 8 shows the nebulizer in a position where the patient is not inhaling. Thesegment shaped deflector bar 1 is disposed outside the line of gas exiting from the gas exit 4 so that nebulization does not take place. The segment is pivoted at a pivot point 21, and is also connected to the vane or flap 2. When a patient inhales,air is drawn into the nebulizer through air inlet 13, and deflects the vane or flap 2 moving the deflector bar 1 into line with the gas exit thus causing atomization of the substance to occur. For clarity, the outlets 5 and the sleeve 8 are not shown inthe Figure. However the jet head is arranged in the same way as described in connection with FIGS. 1 to 7. The atomization of the substance causes the pressure beneath the baffle 9 to be decreased thereby drawing part of the inhaled air under thebaffle 9 as shown by arrow B. The baffle 9 includes an aperture 20 for permitting the flow of air for entraining droplets B to enter beneath the baffle 9. A proportion of the inhaled air passes directly from the air inlet 13 to the air outlet 14 asshown by arrow A. Once the flow of air for entraining droplets B has passed beneath the baffle 9, it returns around the outside of the baffle 9 to rejion the through flow of air A. A further advantage of this embodiment is that only a certain volume ofair passes under the baffle 9 in a given time. The nebulizer works most effectively when the flow of air for entraining droplets is of the rate of about 25 liters per minute. If this rate of flow of air is much greater than this or much less than this,the effectiveness of entrainment decreases. This means that if the patient inhales sharply, the rate of through flow of air A increases without significantly altering the flow of air for entraining droplets B passing beneath the baffle.
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