U.S. patent application number 10/815049 was filed with the patent office on 2004-10-07 for shock wave aerosolization method and apparatus.
Invention is credited to Piper, Samuel David.
Application Number | 20040195364 10/815049 |
Document ID | / |
Family ID | 26929062 |
Filed Date | 2004-10-07 |
United States Patent
Application |
20040195364 |
Kind Code |
A1 |
Piper, Samuel David |
October 7, 2004 |
Shock wave aerosolization method and apparatus
Abstract
A pneumatic inhaler that is able to deliver a controlled burst
or dose of aerosol from a reservoir of liquid medication. The
inhaler is suitable for the aerosolization of liquid medication
that is in solution or suspension form. The inhaler is also ideal
for the delivery of unique and specialty liquid medications in
short aerosol bursts because no additional formulation development
is needed and has the further advantage of being able to deliver
multiple medications, as mixed by the patient, doctor, or
pharmacist, with a single burst at a repeatable output. Because
medication and propellant are not mixed until aerosolization
occurs, the inhaler is appropriate for more pharmaceutical agents
than the current inhalers available and at a substantial cost
savings.
Inventors: |
Piper, Samuel David;
(Sacramento, CA) |
Correspondence
Address: |
JOHN P. O'BANION
O'BANION & RITCHEY LLP
400 CAPITOL MALL SUITE 1550
SACRAMENTO
CA
95814
US
|
Family ID: |
26929062 |
Appl. No.: |
10/815049 |
Filed: |
March 30, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10815049 |
Mar 30, 2004 |
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09963886 |
Sep 25, 2001 |
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6742721 |
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60235597 |
Sep 25, 2000 |
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60305088 |
Jul 12, 2001 |
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Current U.S.
Class: |
239/265.11 |
Current CPC
Class: |
A61M 15/0028 20130101;
A61M 11/06 20130101; B05B 7/0433 20130101; A61M 2205/0233 20130101;
A61M 15/0045 20130101; A61M 2205/21 20130101; A61M 2205/12
20130101; A61M 11/002 20140204; A61M 2205/8225 20130101; A61M
2205/07 20130101 |
Class at
Publication: |
239/265.11 |
International
Class: |
A61M 011/00 |
Claims
1. An apparatus for producing shock wave aerosolization,
comprising: a source of compressed gas; a nozzle; and means
associated with said nozzle for generating a supersonic jet of gas
from said source of compressed gas.
2. An apparatus as recited in claim 1, further comprising a sonic
shock chamber configured for receiving said supersonic jet of
gas.
3. An apparatus as recited in claim 1, further comprising: a user
actuated valve; and means for releasing said compressed gas in
bursts by said valve and delivering said supersonic jet of gas to
said shock chamber.
4. An apparatus as recited in claim 1, further comprising: means
for delivering a burst of compressed gas to said nozzle and forming
said supersonic jet prior to liquid being entrained and mixed with
said jet.
5-10. (canceled)
11. An apparatus for producing shock wave aerosolization,
comprising: a source of compressed gas; a nozzle; means associated
with said nozzle for generating a supersonic jet of gas from said
source of compressed gas; and a sonic shock chamber configured for
receiving said supersonic jet of gas.
12. An apparatus as recited in claim 11, further comprising: a user
actuated valve; and means for releasing said compressed gas in
bursts by said valve and delivering said supersonic jet of gas to
said shock chamber.
13. An apparatus as recited in claim 12, further comprising: means
for delivering a burst of compressed gas to said nozzle and forming
said supersonic jet prior to liquid being entrained and mixed with
said jet.
14-19. (canceled)
20. An inhaler apparatus, comprising: a reservoir for containing
compressed gas; a supersonic shock nozzle; and a user actuated
valve configured to release said compressed gas in bursts for
delivery to said supersonic shock nozzle.
21. An apparatus as recited in claim 20, wherein said supersonic
shock nozzle comprises: a jet orifice configured to receive
compressed gas from said reservoir; and a sonic shock chamber
configured to receive compressed gas discharged from said jet
orifice.
22. An apparatus as recited in claim 21: wherein said jet orifice
is configured to produce a supersonic jet from said compressed gas;
and wherein said shock chamber is configured to receive said
supersonic jet and produce shock waves.
23-24. (canceled)
25. An apparatus as recited in claim 22, wherein if said supersonic
jet is perfectly expanded, a cylindrical shock wave will be
generated in said shock chamber that envelopes the entire jet.
26. An apparatus as recited in claim 22, wherein upon formation of
said supersonic jet and resulting shock waves in said shock
chamber, a vacuum is generated which causes liquid from a liquid
reservoir to be entrained through a liquid feed into said shock
chamber.
27. An apparatus as recited in claim 26, wherein upon entrainment
of liquid into the shock chamber, the initial liquid entrained
comes in contact with shock waves, producing copious amounts of
aerosol particles suitable for inhalation.
28-34. (canceled)
35. An inhaler apparatus, comprising: a reservoir for containing
compressed gas; a jet orifice configured to receive compressed gas
from said reservoir; a sonic shock chamber configured to receive
compressed gas discharged from said jet orifice; and a user
actuated valve configured to release said compressed gas in bursts
for delivery to said supersonic shock nozzle.
36. An apparatus as recited in claim 35: wherein said jet orifice
is configured to produce a supersonic jet from said compressed gas;
and wherein said shock chamber is configured to receive said
supersonic jet and produce shock waves.
37-38. (canceled)
39. An apparatus as recited in claim 36, wherein if said supersonic
jet is perfectly expanded, a cylindrical shock wave will be
generated in said shock chamber that envelopes the entire jet.
40. An apparatus as recited in claim 36, wherein upon formation of
said supersonic jet and resulting shock waves in said shock
chamber, a vacuum is generated which causes liquid from a liquid
reservoir to be entrained through a liquid feed into said shock
chamber.
41. An apparatus as recited in claim 40, wherein upon entrainment
of liquid into the shock chamber, the initial liquid entrained
comes in contact with shock waves, producing copious amounts of
aerosol particles suitable for inhalation.
42-48. (canceled)
49. An inhaler apparatus, comprising: a reservoir for containing
compressed gas; a jet orifice configured to receive compressed gas
from said reservoir and produce a supersonic jet; a sonic shock
chamber configured to receive said supersonic jet and produce shock
waves; and a user actuated valve configured to release said
compressed gas in bursts for delivery to said supersonic shock
nozzle.
50. (canceled)
51. An apparatus as recited in claim 50, wherein said supersonic
jet will be approximately the diameter of the jet orifice and
travel down the axis of the shock chamber.
52. An apparatus as recited in claim 49, wherein if said supersonic
jet is perfectly expanded, a cylindrical shock wave will be
generated in said shock chamber that envelopes the entire jet.
53. An apparatus as recited in claim 49, wherein upon formation of
said supersonic jet and resulting shock waves in said shock
chamber, a vacuum is generated which causes liquid from a liquid
reservoir to be entrained through a liquid feed into said shock
chamber.
54. An apparatus as recited in claim 53, wherein upon entrainment
of liquid into the shock chamber, the initial liquid entrained
comes in contact with shock waves, producing copious amounts of
aerosol particles suitable for inhalation.
55-61. (canceled)
62. An inhaler apparatus, comprising: a reservoir for containing
compressed gas; a jet orifice configured to receive compressed gas
from said reservoir and produce a supersonic jet; a sonic shock
chamber configured to receive said supersonic jet and produce shock
waves; a valve configured to release said compressed gas in bursts
for delivery to said supersonic shock nozzle; and an actuator
handle coupled to said valve.
63-64. (canceled)
65. An apparatus as recited in claim 62, wherein if said supersonic
jet is perfectly expanded, a cylindrical shock wave will be
generated in said shock chamber that envelopes the entire jet.
66. An apparatus as recited in claim 62, wherein upon formation of
said supersonic jet and resulting shock waves in said shock
chamber, a vacuum is generated which causes liquid from a liquid
reservoir to be entrained through a liquid feed into said shock
chamber.
67. An apparatus as recited in claim 66, wherein upon entrainment
of liquid into the shock chamber, the initial liquid entrained
comes in contact with shock waves, producing copious amounts of
aerosol particles suitable for inhalation.
68-74. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 09/963,886 filed on Sep. 25, 2001, now U.S. Pat. No. ______
incorporated herein by reference, which in turn claims priority to
U.S. provisional application serial No. 60/235,597 filed on Sep.
25, 2000, incorporated herein by reference, and from U.S.
provisional application serial No. 60/305,088 filed on Jul. 12,
2001, incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0003] Not Applicable
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION
[0004] A portion of the material in this patent document is subject
to copyright protection under the copyright laws of the United
States and of other countries. The owner of the copyright rights
has no objection to the facsimile reproduction by anyone of the
patent document or the patent disclosure, as it appears in the
United States Patent and Trademark Office publicly available file
or records, but otherwise reserves all copyright rights whatsoever.
The copyright owner does not hereby waive any of its rights to have
this patent document maintained in secrecy, including without
limitation its rights pursuant to 37 C.F.R. .sctn. 1.14.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] This invention pertains generally to aerosol generating
devices, and more particularly to inhalers which may be used to
dispense liquid medication in short bursts of aerosol.
[0007] 2. Description of the Background Art
[0008] Some medicines cannot withstand the environment of the
digestive tract and must be delivered to the bloodstream
intravenously or by some other means. One effective means for
delivery of such medications to the blood stream is through the
membranes and air passageways of the lung.
[0009] Inhalers of various types have been widely used for
inhalation delivery of aerosols containing medication or other
constituents to the conductive airways of the lung and the gas
exchange regions of the deep lung. Aerosols are relatively stable
suspensions of finely divided droplets or solid particles in a
gaseous medium. When inhaled, aerosol particles may be deposited by
contact upon the various surfaces of the respiratory tract leading
to the absorption of the particles through the membranes of the
lung into the blood stream and providing the desirable therapeutic
action, or planned diagnostic behavior depending on the particular
properties of the particles.
[0010] Because of the high permeability of the membranes of the
lung and the copious flow of blood through the lung, medications
deposed in the lung can readily enter the blood stream for action
throughout the body. This may also allow for lower initial doses
than would be required to be taken orally to achieve the desired
concentration of medication in the blood. Other medications can
directly influence the airway epithelium and effect responses via
various airway receptors.
[0011] Properly generated and formulated aerosols can therefore be
helpful in medical treatment. Inhalable aerosol particles capable
of deposition within the lung are those with an aerodynamic
equivalent diameter between 1 and 5 micrometers.
[0012] Still other types of aerosol particles deposited in the lung
can act as tracers of airflow or indicators of lung responses and
otherwise be a valuable diagnostic tool.
[0013] An inhaler produces a burst of aerosol consisting of fine
particles intended for inhalation by a patient with a single
breath. Inhalers are popular aerosol delivery devices because they
are generally portable and are convenient to use. The particle size
of the aerosol emitted from a typical inhaler is required to be
considerably smaller than a conventional spray atomizer to ensure
the appropriate deposition within the lungs. Atomizers are
typically equipped with reservoirs, nozzles, and bulbs. Upon
squeezing the bulb, liquid medication, which is placed within the
reservoir, is entrained and sprayed by the nozzle for inhalation by
the patient. However, the particle size produced by atomizers is
too large for effective deposition in the lungs, although variants
of the technique are still used for deposition of topical
medication into the nasal cavity and associated tissues. A further
disadvantage of atomizers is that they are unable to deliver a
consistent dose due to discrepancies in user technique and the
duration of each burst. Accordingly, atomizers are appropriate for
delivery of medication to the sinus cavity, where the larger
aerosol particle size is more effective for deposition but
inappropriate for deposition in the deep lung.
[0014] Inhalers known in the art employ several techniques to
achieve effective aerosolization of medicines for deposition in the
lung. Commonly, inhalers are pre-packaged containers containing a
mixture of medication to be aerosolized and a low saturation
pressure vapor or gas, such as chlorofluorocarbons (CFCs), which
are used as a propellant. The canister carrying the mixture of
medication and propellant is equipped with a valve. When the valve
is actuated, the inhaler dispenses a set amount of liquid and
medication through a jet orifice, creating a spray. Upon release
into the atmosphere, the low saturation pressure propellant is able
to evaporate quickly leaving small aerosol particles of medication
that are suitable for immediate inhalation. One disadvantage to
this approach is that the propellant and the medication must be
mixed for a significant period of time prior to inhalation by the
patient, making them unsuitable for many medications. Furthermore,
the pre-mixing of the medication and the propellant requires a
different approach to gain regulatory approval, necessitating
significant development time and capital, thereby significantly
increasing the ultimate cost to the patient than with liquid
formulations of same medication. To prevent agglomeration of the
medication within the canister, surfactants are also added to the
formulation, which often leave an undesirable taste in the mouth of
the patient after inhalation.
[0015] Another inhaler strategy increasingly being employed is the
aerosolization of dry medicament powders. Medicinal powders are
prepared in advance and placed in a reservoir within the inhaler,
or within blister pouches. Blister pouches have the advantage of
being able to better preserve the powder from contamination and
moisture. When the patient is ready for a dose of medication, they
either access the reservoir to dispense an appropriate amount of
powdered medication, or puncture a blister pouch containing the
powder medicament. Aerosolization is typically achieved by the gas
flow produced by the inhalation of the patient. However, the
aerosolization of medicinal powders is plagued by problems of
moisture contamination and the inconsistencies in inhalation effort
by the patient from dose to dose. Furthermore, powder formulations
are as expensive to develop as pre-mixed propellants.
[0016] A third inhaler strategy employs ultrasonic energy to
aerosolize bursts of liquid medication. These devices require
precise electronic valves and associated electronic circuitry,
making them expensive to manufacture and prone to malfunction.
Additionally, the particle size of the aerosol produced by these
devices is often too large for optimal deposition in the lung.
[0017] Therefore, a need exists for a technology which can deliver
aerosol bursts of liquid medication at a particle size that is
appropriate for lung deposition and which is inexpensive for the
patient, produces consistent output, uses a formulation which is
inexpensive to develop and produce, that is reliable, that is easy
to use, and which does not require the mixing of medication and
propellant until the moment of aerosolization. The present
invention satisfies this need, as well as others and has the
further advantages of providing superior aerosol quality, and being
lightweight and portable.
BRIEF SUMMARY OF THE INVENTION
[0018] The present invention generally pertains to a pneumatic
inhaler that is able to deliver a controlled burst or dose of
aerosol from a reservoir of liquid medication. The invention is
appropriate for the aerosolization of liquid medication that is in
solution or in suspension form. The invention is also ideal for the
delivery of unique and specialty liquid medications in short
aerosol bursts because no additional formulation development is
needed. The apparatus has the further advantage of being able to
deliver multiple medications, as mixed by the patient, doctor, or
pharmacist, with a single burst of aerosol at a repeatable output.
Because the medication and the propellant are not mixed until
aerosolization occurs, the current invention is appropriate for
more pharmaceutical agents than can be used by currently available
inhalers at a substantial cost savings.
[0019] By way of example and not of limitation, a first embodiment
of the present invention employs a cartridge or cylinder for
containing virtually any type of compressed gas. Typically, carbon
dioxide gas is used at a preferred pressure of approximately 750
psi, because the gas has a low critical temperature and pressure,
allowing a small canister to carry significantly more than if
filled with many other gases. The compressed gas is released in
small bursts by a valve actuated by the patient, which delivers the
gas to the supersonic shock nozzle. The nozzle comprises a jet
orifice from which the compressed gas discharges into a sonic shock
chamber. Provided that substantial backpressure is supplied, a
supersonic jet exits from the jet orifice of the nozzle, which may
be over expanded, under expanded or perfectly expanded. If the jet
is over or under expanded, the supersonic jet, which remains at
approximately the diameter of the jet orifice and which travels
down the axis of the shock chamber, establishes a series of
reflected compression and expansion shock waves. A perfectly
expanded jet will have a cylindrical shock wave that envelops the
entire jet. Although this would be preferable for the production of
aerosol, it is impractical as a result of changes in supply
pressure and the desired dimensional scale of the preferred
embodiment of the current invention. Therefore, the nozzle is
designed to be over expanded, and this is considered optimum.
[0020] Upon formation of the jet and the resulting reflected shock
waves in the shock chamber, a vacuum is generated which causes
liquid from the reservoir to be entrained through the liquid feed
channels into the shock chamber. The preferred design channels the
incoming fluid circumferentially around the shock chamber. Upon
entrainment of the liquid into the shock chamber, the initially
entrained liquid comes in contact with the shear forces created by
the shock waves, producing copious amounts of aerosol particles
suitable for inhalation. Shock waves are uniquely able to produce
tremendous quantities of aerosol with good particle size for
inhalation because they have the property of having large pressure
differences over very small distances, thus making them able to
generate substantial shear forces. The result of liquid traveling
across this shock boundary is to be violently and physically
disturbed, thus disintegrating into a dense burst of aerosol with
appropriate particle size for inhalation. This represents a
significant advance over traditional atomizers, which lacked the
ability to produce shock waves of any design or magnitude,
resulting in lower output and larger particle size.
[0021] Once the liquid has been entrained into the shock chamber
and jet, the integrity of the jet and resulting reflecting shock
waves is destroyed, resulting in a reduction in the subsequent
production of aerosol particles than is produced in the initial
burst. The subsequent production also has a generally larger
particle size than the initial burst. The overall result is an
initial burst of aerosol ideally suited for an inhaler, generally
lasting less than a second. The output and particle size of such an
inhaler is substantially better than would be predicted from the
steady state operation of an atomizer or nebulizer nozzle of
similar design. It is not possible to employ the same technique in
the design and manufacture of an atomizer or nebulizer, because
these devices are intended to run for durations of time longer than
the first initial moments and the unique phenomena of the current
invention only occurs at the moment of introduction of fluids to
the reflected shock waves. Since the majority of aerosolization
takes place in the first moment of liquid entrainment, little
compressed gas is required for a burst of aerosol, making it
possible, and efficient, to store enough carbon dioxide in a small
canister for 200 bursts or more.
[0022] Although not of optimum design under most conditions, a
similar result is obtained by having a shock region instead of a
shock chamber. In such a design, the jet exits directly into a
generally unenclosed region allowing the formation of reflected
shock waves within the exiting jet. Liquid is entrained through one
or more feed tubes placed proximally to the jet at a sufficient
distance to generate a vacuum. Again, once the entrained liquid
comes into contact with the reflected shock waves, a tremendous
amount of aerosol particles are produced, and the integrity of the
sonic jet and the shock waves is destroyed. Based on
experimentation, such an approach was not found to be optimum
because it did not allow for the precise introduction of fluid to
the shock waves, which affects the output and particle size of the
resulting aerosol burst. It should be noted that such an open
design does have distinct advantages for thick, viscous fluids,
because of the potential of clogging involved with the closed
design, above first mentioned.
[0023] The preferred embodiment of the current invention draws
liquid from a reservoir of medication that is preferably sufficient
to hold 200 doses, and has been shown to produce reproducible doses
of liquid medication. In the event that extremely precise dosing is
desired, or if a change in dosing is desired from burst to burst,
the current invention may be modified to consist of a small
reservoir, or multiple small reservoirs, that contain the exact
amount of liquid desired for delivery, and which is less than the
nozzle will entrain with a given burst. Thus, the output of the
inhaler is exactly equal to the contents of the reservoir, and may
be easily changed from dose to dose.
[0024] Another approach that has been shown to be quite successful,
is the use of blister packs pre-filled with the exact amount of
liquid intended for aerosolization rather than the use of a
reservoir. Prior to the contents of a blister cell being delivered,
a feed tube, which is in fluid communication with the supersonic
shock nozzle, is caused to puncture and penetrate the blister cell.
Upon actuation of the nozzle, the contents of the blister cell is
completely entrained into the shock nozzle and aerosolized. Blister
packs also have the added advantage of better preserving medication
than multiple dose reservoirs due to the limited exposure of the
medication to air prior to aerosolization.
[0025] A complete discussion of the requirements for over, under,
and perfectly expanded supersonic jets may be found in a text on
compressible fluid dynamics. In general, the minimum pressure
required to achieve supersonic flow in a nozzle is dependant upon
the ambient discharge pressure and the supply pressure such that
the ratio of the two should preferably be at least 0.5283 for air
or oxygen and 0.5457 for carbon dioxide. Since all known inhalers
have always discharged into roughly atmospheric conditions (14.7
psi), the resulting minimum supply pressure can be determined as
being approximately equal to 27.8 psi or 13.1 psig for air or
oxygen and 26.9 psi or 12.2 psig for carbon dioxide. In theory,
these minimum supply pressures are sufficient to produce a flow of
gas through the throat of a nozzle with a velocity equal to the
speed of sound. In practice, higher pressures are required due to
pressure losses and the expansion of gas into the internal volume
of the device between the supply canister containing the stored gas
and the choke of the nozzle. Although lower pressures above the
calculated minimums will produce a degree of aerosolization,
superior results are achieved with even higher pressures or
continual increases in output for higher pressures. The increase in
output for higher pressures is due to the increasing speed of the
supersonic jet and the resulting increase in strength of the
resulting shock waves. In the current embodiment of the invention,
the pressure vessel is preferably filled with carbon dioxide to a
pressure of approximately 750 psig, and the valve mechanism is
designed to deliver a set amount of carbon dioxide with each
actuation thereby controlling the repeatability of each dose and
insuring that aerosol exiting the inhaler is produced primarily
during the first few moments of contact between entrained liquid
and the supersonic jet.
[0026] Supersonic jets produce shock waves in part because the jets
don't expand gradually to the diameter of the shock chamber. Due to
the nature of the fluid dynamics involved, and conservation of
momentum, supersonic jets expand by producing shock waves, thus
producing an extreme change in pressure from one side of a shock
wave to the other. Unlike other exiting flow patterns, supersonic
jets, through the dynamics of the shock waves, maintain roughly the
same diameter that the jets had as they exited from the nozzle from
which the jets were produced. Similarly, vacuum and entrainment of
liquid is not primarily due to the Bernoulli principle, but more to
boundary layer friction between the exiting jet and the surrounding
gas in the shock chamber.
[0027] Any nozzle (orifice) which supplies a compressed gas to the
nozzle at pressures above the calculated minimums will have a
supersonic jet exiting from it which is either over, under, or
perfectly expanded, provided that there is nothing present to
disturb the jet, such as a liquid. A nozzle may achieve a velocity
greater than the speed of sound if it is supplied with sufficient
supply pressure and has a gradually increasing cross-sectional area
downstream of the throat or choke. The potential increase in
velocity with increasing cross-sectional area is dependant on the
total supply pressure. For the perfectly expanded supersonic jet,
the cross-sectional area is increased to the maximum possible for
the given supply pressure, resulting in a supersonic jet with a
shock wave entirely enveloping the jet. Although this is ideal for
the production of aerosol, it is impractical in practice because of
variance in the supply pressure and the dimensional tolerances
required.
[0028] An under expanded supersonic jet has a maximum
cross-sectional area which is less than the perfectly expanded
supersonic jet. The extreme example of an under expanded jet is a
simple orifice with no increasing cross sectional area. The result
of a under expanded supersonic jet is a series of expansion and
compression reflected shock waves, with the first shock waves
immediately after the exit of the jet being expansion waves.
[0029] An over expanded supersonic jet has a maximum cross
sectional area which is greater than the maximum cross sectional
area of the perfectly expanded supersonic jet. The result is also a
series of reflected compression and expansion shock waves. In the
preferred embodiment, an over expanded supersonic jet is instigated
by placing a large radius on the exit edge of the nozzle. Upon the
jet traveling through the jet and then subsequently along the
radius, the initial response is for the jet to increase to a speed
greater than the speed of sound followed by an over expansion of
the jet, which will produce reflected shock waves. An over expanded
supersonic jet has the slight advantage over an under expanded
supersonic jet in that the first reflected shock waves emanating
from the exit plane of the jet are compression waves and not
expansion waves. In general, compression waves produce higher shear
forces and thus would be expected to produce more aerosol and a
smaller particle sizes.
[0030] Once the entrained liquid is aerosolized, the momentum of
the jet carries the aerosol into a mouthpiece for immediate
inhalation by the patient. Depending on the ability of the patient
to coordinate actuation and inhalation, and the desired portion of
the lung targeted for deposition, a spacer or valved holding
chamber may be attached to the mouthpiece. Spacers and chambers
allow for easier coordination of patient's inhalation with device
actuation, baffle out larger aerosol particles which are
inappropriate for deposition within the lung, and allow more time
for the liquid aerosol particles to evaporate, producing superior
sized aerosol particles (1-3 microns) for deposition in the
alveolar portions of the lung.
[0031] In accordance with another embodiment of the invention, a
valve design is provided which is easier and less expensive to
manufacture than in the previous embodiments. This embodiment
includes a built in valved chamber for storing aerosol during
inhalation, in contrast to the previous embodiments that allow for
a chamber to be attached when desired. However, the invention is
not limited to the use of a valved chamber or specific valve
design.
[0032] The valved chamber stores aerosol upon actuation for
subsequent inhalation in this embodiment. As is well known in the
industry, and recently reported during in-vitro investigations
(Respiratory Care, June 2000, Volume 45, Number 6, "Consensus
Conference on Aerosols and Delivery Devices", page 628), valved
chambers often maintain a static electric charge due to rinsing
with water that causes a significant loss of aerosol particles due
to mutual static electric attraction. This embodiment employs an
anti-static plastic that prevents this phenomenon from
occurring.
[0033] In addition to the properties described in the previous
embodiments, the aerosolization process can be further optimized
through placement of a liquid feed choke between the fluid
reservoir containing the medication, and the liquid feeds that lead
into the shock chamber. By further choking the flow of liquid down,
it is possible to better control the introduction of fluid into the
supersonic jet produced in the shock chamber, thus allowing for
better aerosolization and an increase in the duration of the
aerosol burst, although it is still a momentary phenomena relative
to normal jet nebulization technologies.
[0034] Additionally, the shock wave aerosolization process
functions remarkably well with micronized powder in blister packs
as well. Blister packs, containing one or more cells, are used to
store a pre-determined amount of liquid or powder. Prior to
aerosolization, a feed tube, which is in fluid communication with
the shock wave aerosolization process nozzle, is inserted into the
blister pack cell. Subsequent to the insertion of the feed tube,
the carbon dioxide valve is actuated, creating a set burst of gas.
As previously described, the carbon dioxide exits the throat of the
jet, causing a vacuum, which entrains the micronized powder or
liquid through the feed tube and into the shock chamber. As
previously described with liquid medication, when medicinal powder
is entrained it becomes efficiently aerosolized in the reflected
shock waves and carried out to the mouthpiece or valve chamber, as
intended.
[0035] An object of the invention is to provide an inhaler, which
can deliver a repeatable dose of aerosol containing particles
appropriately sized for deposition within the patient's lung.
[0036] Another object of the invention is to provide an inhaler,
which can produce aerosol particles appropriate for deposition in
the bronchial airways.
[0037] Another object of the invention is to provide an inhaler,
which can produce aerosol particles appropriate for deposition in
the alveolar portions of the lung.
[0038] Another object of the invention is to provide an inhaler,
which can aerosolize an aqueous solution.
[0039] Another object of the invention is to provide an inhaler,
which can aerosolize a suspension of medication in liquid.
[0040] Another object of the invention is to provide an inhaler,
which can aerosolize liquid pharmaceutical formulations currently
available only for nebulizers.
[0041] Another object of the invention is to provide an inhaler,
which does not mix medication and propellant prior to
aerosolization.
[0042] Another object of the invention is to provide an inhaler,
which can deliver combinations of different medications with one
burst.
[0043] Another object of the invention is to provide an inhaler
with an acceptable aftertaste.
[0044] Another object of the invention is to provide an inhaler,
which is portable, convenient and easy to use.
[0045] Another object of the invention is to provide an inhaler,
which is inexpensive to produce.
[0046] Another object of the invention is to provide an inhaler
that has a built in valved chamber for storage of aerosol.
[0047] Another object of the invention is to provide an invention
that works in conjunction with blister packs that contain either
liquid or powder.
[0048] Further objects and advantages of the invention will be
brought out in the following portions of the specification,
wherein, the detailed description is for the purpose of fully
disclosing preferred embodiments of the invention without placing
limitations thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0049] The invention will be more fully understood by reference to
the following drawings that are for illustrative purposes only:
[0050] FIG. 1 is a side view of an embodiment of an inhaler
according to the present invention.
[0051] FIG. 2 is a perspective view of the inhaler of FIG. 1.
[0052] FIG. 3 is a side view in cross-section of the inhaler of
FIG. 1.
[0053] FIG. 4 is a perspective view of the actuator portion of the
inhaler of FIG. 1.
[0054] FIG. 5 is a side view in cross-section of the actuator of
FIG. 4.
[0055] FIG. 6 is a side view in cross-section showing the valve
portion of the actuator of FIG. 4 in the actuated state.
[0056] FIG. 7 is a perspective view of the aerosol generator
portion of the inhaler of FIG. 1.
[0057] FIG. 8 is a side view in cross-section of the aerosol
generator of FIG. 7.
[0058] FIG. 9 is a detail side view in cross-section view of the
nozzle portion of the aerosol generator of FIG. 7.
[0059] FIG. 10 is a front view of aerosol generator of FIG. 7.
[0060] FIG. 11 is a rendering of an over expanded supersonic jet
used in the inhaler of FIG. 1.
[0061] FIG. 12 is a schematic representation of the over expanded
supersonic jet of FIG. 11.
[0062] FIG. 13 is an exploded view of a second embodiment of an
inhaler according to the present invention showing the reusable
actuator handle, aerosol generator, and carbon dioxide
cartridge.
[0063] FIG. 14 is a perspective view of the disposable carbon
dioxide refill cartridge portion of the inhaler of FIG. 13.
[0064] FIG. 15 is a exploded view of the carbon dioxide canister of
FIG. 14.
[0065] FIG. 16 is a perspective view of the reusable inhaler
actuator portion of the inhaler of FIG. 13.
[0066] FIG. 17 is a exploded view of the reusable actuator of FIG.
16.
[0067] FIG. 18 is a perspective view of the valve portion of the
inhaler of FIG. 13.
[0068] FIG. 19 is a exploded view of the valve of FIG. 18.
[0069] FIG. 20 is a side view in cross-section view of the valve of
FIG. 18.
[0070] FIG. 21 is a perspective view of the disposable inhaler
aerosol generator portion of the inhaler of FIG. 13.
[0071] FIG. 22 is a exploded view of the aerosol generator of FIG.
21.
[0072] FIG. 23 is a top view of the jet employed in the inhaler of
FIG. 13.
[0073] FIG. 24 is a top view of the secondary employed the inhaler
of FIG. 13.
[0074] FIG. 25 is a bottom view of the secondary of FIG. 24.
[0075] FIG. 26 is a perspective view of the cap employed in the
inhaler of FIG. 13.
[0076] FIG. 27 is a perspective view of the column base employed in
the inhaler of FIG. 13.
[0077] FIG. 28 is a perspective view of the end of the column of
FIG. 27.
[0078] FIG. 29 is an assembled perspective view of the inhaler of
FIG. 13.
[0079] FIG. 30 is a side view in cross-section of the inhaler of
FIG. 29.
[0080] FIG. 31 is a detail side view in cross-section of the
supersonic nozzle assembly portion of the inhaler of FIG. 13.
[0081] FIG. 32 is a detail side view in cross-section of the jet
and shock chamber portion of the nozzle assembly of FIG. 31.
[0082] FIG. 33 is a side view in cross-section of an embodiment of
an inhaler according to the present invention employing a
disposable cartridge containing both the nozzle and a blister pack
of medication.
DETAILED DESCRIPTION OF THE INVENTION
[0083] FIG. 1 through FIG. 3 show the overall configuration of an
embodiment of a shock wave aerosolization apparatus according to
the present invention is shown. The inhaler portion of the
apparatus comprises two primary parts; an actuator 12 shown in FIG.
4, FIG. 5, and more specifically in FIG. 6, and an aerosol
generator 14 shown in FIG. 7, FIG. 8 and more specifically in FIG.
9 and FIG. 10. FIG. 11 and FIG. 12 are for illustrative purposes
regarding the nature of reflected shock waves in a supersonic jet.
FIG. 13 and FIG. 29 show the overall configuration of a second
embodiment of the invention. FIG. 14 and FIG. 15 show the gas
canister assembly. FIG. 16 through FIG. 20 detail the actuator
handle assembly and FIG. 21 through FIGS. 28, 31 and 32 shows the
aerosol generator assembly of the second embodiment. FIGS. 29 and
30 shows the configuration of the apparatus during use. FIG. 33
shows a third embodiment of the invention employing a supersonic
shock nozzle assembly enclosed in a small disposable cartridge
along with a single blister pack 352 containing sufficient
medication for one aerosol treatment. It will be appreciated that
the embodiments of the apparatus may vary as to configuration and
as to details of the parts, and that the method may vary as to
details of steps and their sequence, without departing from the
basic concepts as disclosed herein.
[0084] Referring now to FIG. 1, the aerosolization apparatus 10 of
the present invention generally includes an actuator 12 and an
aerosol generator 14. The actuator 12 and the aerosol generator 14
are separable components in the embodiment shown, however, it will
be understood that these components may be fully integrated and
inseparable.
[0085] As seen in FIG. 2 and FIG. 3, the actuator 12 of apparatus
10 has a handle 16 that is preferably configured to fit in the
notch between the thumb and first finger of the hand of the user.
In the embodiment shown, the actuator 12 has a trigger 18 that
pivots about trigger pin 20 and is brought toward the body of
actuator 12 by the fingers of the user to actuate the device. The
actuator 12 also has a cap 22 that can be removed from the body of
the actuator 12 as needed.
[0086] The aerosol generator 14 is operably coupled with actuator
12 and provides aerosolized medications to a user through a
mouthpiece 24 when the trigger 18 is depressed. Medicine is
disposed within a reservoir through a port that is sealed with a
plug 26.
[0087] Turning now to FIG. 3, a cross section of the apparatus 10
with the actuator 12 coupled with the aerosol generator 14 is
shown. The primary components of the actuator 12 are the handle 16,
cap 22, carbon dioxide canister 28, trigger 18, valve body 30,
valve poppet 32, and valve spring 34. Carbon dioxide canister 28 is
disposed within handle 16 and is held in place by cap 22.
[0088] The primary components of the aerosol generator 14 are
reservoir 38, mouthpiece 24, aerosolization nozzle 36 and plug 26.
It can be seen that canister 28 provides a source of supply of gas
to the aerosol generator 14 that is regulated by poppet 32. Gas
from the canister 28 is directed through the aerosolization nozzle
36, mixed with medicine from reservoir 38 and out through the
mouthpiece 24 to the user.
[0089] Referring also to FIG. 4 and FIG. 5, the aerosol generator
14 is releasibly coupled with the actuator 12. The aerosol
generator 14 component can be quickly removed from the actuator 12
for refilling and cleaning. Likewise, different medications can be
administered sequentially to a single patient by removing the first
aerosol generator 14 after the first dosage is administered and
replacing it with a second aerosol generator 14 that has a
different medication. Thus, it can be seen that a practitioner can
administer appropriate medications to any number of patients using
one actuator 12 and aerosol generators 14 specially prepared for
each patient.
[0090] Turning now to FIG. 4, FIG. 5 and more specifically FIG. 6,
actuator 12 is shown without the aerosol generator 12 in place. The
actuator 12 is a source of gas supply that can be regulated by the
actions of poppet 32. When cap 22 is removed from handle 16, carbon
dioxide canister 28 can be placed into cap 22 and then inserted
into the internal space of handle 16. With the tightening of cap
22, carbon dioxide canister 28 is caused to be punctured by hollow
prong 40, which is part of valve body 30, and thereafter the
canister is sealed against canister o-ring 42.
[0091] Once punctured and sealed, carbon dioxide canister 28 is in
fluid communication with valve poppet 32 disposed within valve
poppet chamber 46 through canister conduit 44 within hollow prong
40 and the wall of valve body 30.
[0092] Valve poppet 32 comprises a trigger head 48 with an
actuating cam surface 50 that smoothly engages trigger 18 through
the full range of motion of the trigger pull. The poppet 32 is
biased to the far left or "rest" position, as shown, by spring 34,
such that shoulder 54 is caused to rest against stop plate 56.
Spring 34 preferably fits within spring indent 58 at the distal end
of poppet 32.
[0093] The valve poppet in the activated position is shown in FIG.
6. It will be seen that valve poppet 32 is caused to move to the
right, or "actuated" position, when trigger 18 is squeezed,
resulting in force being applied to actuating cam surface 50 of
trigger head 48 of poppet 32 in opposition to the force of valve
spring 34.
[0094] The body 52 of poppet 32 preferably has a first o-ring
groove 60, a second o-ring groove 62, and a third o-ring groove 64
that are mated with first o-ring 66, second o-ring 68, and third
o-ring 70 respectively. The poppet body 52 also has a charging
volume groove 72, preferably positioned between the second o-ring
groove 62 and the third o-ring groove 64. First o-ring groove 60,
second o-ring groove 62, third o-ring groove 64, and charging
volume 72 all consist of geometry which is circumferential to valve
poppet 32, which is generally cylindrical in shape. O-rings 66, 68
and 70 are all made preferably of urethane, which is compatible
with high-pressure carbon dioxide.
[0095] Although o-rings are preferred, it will be understood that
other alternative sealing means known in the art may also be used
to eliminate leakage of gas from the canister conduit 44 into
poppet chamber 46 and out of the apparatus.
[0096] Referring more particularly to FIG. 5, it can be seen that
when valve poppet 32 is in the rest position, as shown, the
internal gas pressure of carbon dioxide canister 28 is in fluid
communication with charging volume 72 and the space between poppet
32 and the walls of poppet chamber 46, between o-rings 68 and 70
through canister conduit 44, resulting in charging volume 72 being
filled with carbon dioxide to the same pressure that is in carbon
dioxide canister 28. The contents of carbon dioxide canister 28,
and charging volume 72, is prevented from escaping around the valve
poppet 32 into the ambient environment primarily by second o-ring
68 and third o-ring 70 that seal the sections of the chamber 46
between the o-rings.
[0097] As valve poppet 32 is moved into the actuated position, as
shown in FIG. 6, second o-ring 68 passes over canister conduit 44,
preventing further fluid communication between carbon dioxide
canister 28 and charging volume 72, and third o-ring 70 is caused
to pass over valve exit conduit 74, thus releasing the pressurized
gas in charging volume 72 through valve exit conduit 74 to valve
exit port 76. Second o-ring groove 62 and third o-ring groove 64
are preferably spaced apart from charging volume 72 so that the
second o-ring 68 terminates fluid communication between carbon
dioxide canister 28 and charging volume 72 prior to the third
o-ring 70 passing over valve exit conduit 74, thus preventing the
contents of carbon dioxide canister 28 from ever being in fluid
communication with valve exit conduit 74 and valve exit port 76,
and creating a burst of pressurized gas to be released from
charging volume 72.
[0098] Obviously, charging volume 72 may be designed for different
volumes allowing for different amounts of carbon dioxide being
released with each actuation. It will also be seen that first
o-ring 66 prevents escape of contents of carbon dioxide canister 28
around valve poppet 32 into the ambient environment when valve
poppet 32 is in the actuated position.
[0099] As shown in FIG. 1, FIG. 2, and FIG. 3, aerosol generator 14
is caused to mate with actuator 12. As seen in FIG. 7 and FIG. 8,
aerosol generator 14 has a pair of locking tabs 78 that pass
through corresponding tab slots 80 and snap into tab receptacles
82, as shown in FIG. 4. When locking tabs 78 on aerosol generator
14 are fitted into tab receptacles 82 of actuator 12, inlet stem 84
of FIG. 8 is configured to fit to valve exit port 76 of actuator 12
as seen in FIG. 4, FIG. 5, and FIG. 6. Inlet stem 84 is mated with
valve exit port 76 of actuator 12 such that sealing is established
between the base of inlet stem 84 and actuator outlet o-ring 88 of
FIG. 6. This allows for fluid communication between valve exit port
76 of actuator 12 and inlet stem 84 of aerosol generator 14 via
valve exit conduit 74 of FIG. 6 and supply inlet 86 of FIG. 8.
[0100] Referring now to FIG. 8, it can be seen that compressed gas
from the actuator 12 passes through supply inlet 86 of inlet stem
84 into supply channel 90 and into insert supply cavity 92 and out
of the aerosolization nozzle 36 through jet orifice 94.
[0101] In the embodiment shown, reservoir 38 of aerosol generator
14 preferably has a liquid feed tube 96 mounted to liquid feed stem
98 that has a medicine channel 100 that is in fluid communication
with the aerosolization assembly 36 as seen in FIG. 8 and FIG. 9.
Thus, liquid entrained for aerosolization is caused to travel up
liquid feed tube 98, medicine channel 100 of liquid feed stem 98
and directly to the nozzle section of the aerosolization nozzle 36,
which is shown in the blown up view of FIG. 9.
[0102] In one embodiment, aerosol generator 14 is made of reservoir
base 102, mouthpiece 104, elbow 106 and nozzle insert 108
components. In this embodiment, the aerosol generator 14 is
assembled by placing liquid feed tube 96 on liquid feed stem 98 of
mouthpiece component 104. Insert 108 is placed into the back of
mouthpiece 104 creating the critical nozzle geometry shown in FIG.
9 where aerosolization occurs. Elbow 106 is placed into backside of
insert 108 and then the assembly consisting of mouthpiece 104,
insert 108 and elbow 106 are coupled with reservoir base 102. Plug
26 is then placed into reservoir component 102. Bonding between
mating pieces may be established using press fits, adhesive
techniques, or ultrasonic welding, except for mating between plug
26 and reservoir base 102, which is intended to be a sliding
fit.
[0103] Liquid medication intended for aerosolization is placed in
reservoir 38 by removing plug 26 and placing the medication
directly into the liquid storage cavity of reservoir 38. Various
liquid medications may be placed in the reservoir, as desired. In
one embodiment, the liquid storage cavity of reservoir 38, contains
a total volume of at least twice the intended liquid volume to be
dispensed. This allows for the prevention of spilling of the
contents of the liquid storage cavity of reservoir 38 and for
different orientations of the aerosol generator 14.
[0104] An alternative to having a reservoir 38 for storing of
medication for multiple doses, as above described, is to have means
by which one dose may be made available to the aerosolization
nozzle 36 at a given time. This would be the preferred embodiment
of the current invention for medication requiring very strict
output control or which requires special handling and storing, such
as refrigeration. Strict output control would be realized because
the aerosolization assembly 36 is designed so that it always
attempts to entrain more liquid than there is present in the single
dose reservoir. In this way, output is controlled solely by what is
in the reservoir and not the critical dimensions of the
aerosolization assembly 36 or the contents of carbon dioxide
canister 28.
[0105] There exists many ways to have single dose reservoirs,
including a very small version of the previously described liquid
storage cavity 38, single ampules, or blister packs. A single dose
may also include multiple puffs until the medication in the
reservoir or ampule is depleted. In the case of ampules or blister
pack cells, the liquid feed tube 96 would preferably be made from
stiff plastic and would puncture the ampule or blister pack cell
when entrainment was desired. After actuation, the empty ampule
would be discarded, or, in the case of the blister pack, the liquid
feed tube 96 would be advanced to the next blister pack cell when
another dose of aerosol was required.
[0106] Still referring to FIG. 8, carbon dioxide gas supplied to
supply inlet 86, is caused to pass up supply conduit 90 and into
insert supply cavity 92. Referring also to FIG. 9, pressurized
carbon dioxide gas that is provided to insert supply cavity 92 is
caused to pass into jet orifice 94 with exit plane radius 110. In
the preferred embodiment, jet orifice 94 has a diameter ranging
from approximately 0.008 inches to approximately 0.016 inches, and
exit plane radius 110 preferably has a diameter ranging from
approximately 0.010 inches to approximately 0.020 inches. Because
the supply pressure of the carbon dioxide canister is normally 750
psig, the jet formed in the jet orifice 94 will go supersonic. The
jet will remain supersonic until such time that the cross sectional
area of the exit area, due to exit plane radius 110, becomes too
large, at which point the jet will be over expanded and reflected
shock waves will form in the jet as shown graphically in FIG. 11
and schematically in FIG. 12. The diamond-shaped patterns of FIG.
11 and FIG. 12 show the shock wave patterns in the jet.
[0107] In the preferred embodiment of the present invention, exit
plane radius 110 is large enough to insure that the supersonic jet
formed from jet orifice 94 is over expanded. This will cause the
first series of reflected shock waves to be compression shock waves
and not expansion shock waves. Although expansion shock waves are
capable of aerosolization, compression shock waves are preferable
and considered slightly more optimum.
[0108] In an alternative configuration in which reflected expansion
waves are desired initially, exit plane radius 110 would be made
small enough, removed, or replaced with an appropriate taper, so
that the exiting supersonic jet from jet orifice 94 was under
expanded.
[0109] The supersonic jet exiting the jet orifice 94 and associated
exit plane radius 110 will travel axially down shock chamber 112
and into the confines of mouthpiece 24. In the preferred
embodiment, shock chamber 112 has a diameter ranging from
approximately 0.020 inches to approximately 0.030 inches, or two to
three times the diameter of the jet orifice 94. The resulting
reflecting shock waves will continue along with the jet well
outside the exit plane of shock chamber 112. Optimally,
interstitial space 114 has a gap distance between the exit plane
and jet orifice 94 and the inlet of shock chamber 112 of between
approximately 0.007 inches and 0.016 inches.
[0110] Referring also to FIG. 11 and FIG. 12, upon the initial
formation of the supersonic jet, a vacuum will be created in
interstitial space 114, which is in fluid communication with the
medicine channel 100, thus causing liquid medication to be
entrained from reservoir 38 through liquid feed tube 96, stem 98,
channel 100 and introduced into shock chamber 112. The initial
liquid entrained into shock chamber 112 comes in contact with the
supersonic jet and the chain of reflected shock waves emanating
from jet orifice 94. Upon contact with the shock waves and the jet,
the initial liquid is agitated violently by the large shear forces
produced by the shock waves and the discrepancy between the high
velocity of the jet and the slow velocity of the liquid, which
produces a tremendous burst of aerosol. The aerosol burst is
carried out of the shock chamber 112 along with the expelled gas to
mouthpiece 24. Subsequent to the initial fluid being introduced to
shock chamber 112, the integrity of supersonic jet and resulting
shock waves are destroyed due to the ongoing entrainment of more
liquid, although shock waves are still present immediately proximal
to the exit plane of jet orifice 94 and exit plane radius 110.
These remaining shock waves are insufficient for the same
production rate of aerosol produced initially due to the smaller
exposed area and the location of the waves with respect to ongoing
entrainment of liquid.
[0111] Accordingly, the charging volume 72 is preferably made large
enough so as to deliver enough carbon dioxide gas to give the jet
time to form, entrain liquid, and create the desired burst of
aerosol. Once the carbon dioxide that is delivered from charging
volume 72 to the jet orifice 94 is depleted, the jet ceases to
exist all together, and no more liquid is entrained.
[0112] Referring back to FIG. 8, the aerosol exiting shock chamber
112 is carried into the internal cavity 118 of mouthpiece 24 where
it is available for immediate inhalation by the patient. Referring
also to FIG. 10, which is a view of aerosol generator 14 looking
directly down the internal cavity 118 of mouthpiece 24, the
backside of the internal cavity 118 of mouthpiece 24 is preferably
equipped with four entrainment ducts 116, which allow ambient air
to be entrained when the patient inhales. The diameter of the
mouthpiece internal cavity 118 and the cross-sectional area of the
four entrainment ports 116 are the primary means of controlling the
geometry and speed of escaping aerosol 120 from shock chamber
112.
[0113] The length of the mouthpiece 24 and its internal cavity 118
also plays a role in the speed of escaping aerosol. Accordingly,
the length of mouthpiece 24 is reduced to a minimum to prevent as
much waste of aerosolized medication 120 as possible. In the
current preferred embodiment, the mouthpiece internal cavity 118
has a diameter of approximately 0.775 inches and the preferred
cross-sectional area of the four entrainment ducts 116 is
approximately 0.08 inches squared or 0.02 inches square for each
duct 116. Reducing the cross-sectional area of the four entrainment
ducts 116 has been shown to reduce the exit velocity of the
resulting aerosol if desired. Additionally, spacers and valve
holding chambers are well known in the industry and can be
connected directly to the outer diameter of mouthpiece 24.
[0114] Referring now to FIG. 13 through FIG. 30, an alternative
embodiment of the invention is shown. As shown in FIG. 13, this
embodiment comprises three principal parts: a reusable actuator
handle 200, a disposable aerosol generator 202 and a disposable
carbon dioxide cartridge assembly 204.
[0115] Turning now to FIG. 14 and FIG. 15 the carbon dioxide
cartridge assembly 204 can be seen. The cartridge assembly 204
comprises a carbon dioxide canister 206 and gas canister cap 208.
The carbon dioxide gas canister 206 includes a top 210 with threads
268 that is configured to engage with corresponding threads 266
within a valve assembly contained in actuator handle 200 as seen in
FIG. 14 and FIG. 20.
[0116] Carbon dioxide represents only one of many different types
of gases that can be used to power the current invention. Although
carbon dioxide gas is preferred, it will be understood that any
appropriate pressurized gas can be used. In one embodiment, gas
canister 206 is bonded to the gas canister cap 208 with an adhesive
and is designed with a large diameter to allow for sufficient
torque during insertion of the carbon dioxide cartridge 206 into
actuator handle 200. Carbon dioxide cartridge 206 preferably fits
longitudinally into the underside of actuator handle 200 through
cartridge port 212.
[0117] Turning now to FIG. 16 through FIG. 19, the preferred
components of the actuator handle 200 are shown. Actuator handle
200 has an elongate actuator body 214 with cartridge port 212 at
the bottom end. The actuator handle also includes a valve assembly
216, valve stem cover 218, trigger 220, and trigger pivot pin 222
as seen in FIG. 17.
[0118] Valve stem cover 218 has a pair of valve stem cover bosses
224 that engage angled edges 226 of trigger 220 such that when
trigger 220 pivots about pin 222 the valve stem cover 218 moves
longitudinally within handle body 214. Accordingly, when assembled,
valve stem cover 218 mates with valve assembly 216 and the bosses
224 engage with trigger 220 such that when trigger 220 is squeezed,
trigger cam surface 226 engages with valve stem bosses 224 such
that valve stem cover 218 is forced to move downward causing valve
assembly 216 to become actuated as described herein.
[0119] Referring now to FIG. 18, FIG. 19 and FIG. 20, the
components of the preferred valve assembly are shown. Valve
assembly 216 has a generally cylindrical body 228 that is
configured to fit within actuator handle 200 as seen in FIG. 17 and
FIG. 18. In one embodiment, valve assembly body 216 has one of more
raised rails 230 on the outer surface that slide within
corresponding slots in the interior of the handle 200 (not shown)
as well as slots 232 in valve stem cover 218. The raised rail 230
and slot configuration securely positions the valve assembly and
eliminates any rotational motion of the valve assembly 216 when the
threads 268 of the top 210 of gas canister 206 are screwed into the
threads 268 of the valve assembly. Rails 230 also facilitate the
linear movement of the valve stem cover 218 with respect to the
valve assembly 216 when the trigger 220 is pressed.
[0120] Referring now to the exploded view of the valve assembly 216
in FIG. 19 and the cross sectional view of FIG. 20, the regulation
of the flow of gas from the canister 206 through the stem exit port
236 can be seen. In the embodiment shown in FIG. 19, the valve
assembly 216 has a canister seal 238, valve body 228, hollow
canister puncture pin 240, puncture pin valve seal 242, valve
spacer 244, central valve seal 246, cylinder 248 with chamber 250,
stem plug 260, valve stem 234, top valve seal 252, and end plate
254. The exploded view in FIG. 19 shows the relative position of
each of these components. The cross sectional schematic view in
FIG. 20 shows the relative position of the components when
assembled.
[0121] Seals 238, 242, 246 and 252 as well as stem plug 260 are
preferably made of urethane, due to the resistance of this material
to compressed carbon dioxide. Valve spacer 244 and cylinder 248 are
preferably made of injected molded nylon. Valve body 228, canister
puncture pin 240, valve stem 234, and end plate 234 are preferably
made of machined aluminum but may also be made of glass-reinforced
nylon. In the embodiment shown, the parts are assembled as shown in
FIG. 19 and then valve body end 256 is rolled over in a machining
operation to keep the parts in place.
[0122] Referring now to FIG. 20, the regulation of the gas flow and
the movements of the valve components of one embodiment of the
valve assembly can be seen. Valve stem 234 can move axially within
chamber 250 of cylinder 248. A circumferential flange 258 on stem
234 stops the outward movement of stem 234 by engaging the interior
side of the top valve seal 252. Valve stem 234 is tubular and has a
plug 260 in the approximate center of the stem. In addition, stem
234 has a valve stem inlet orifice 262 and a valve stem exit
orifice 264 that communicate from the interior of the stem 234 to
the exterior.
[0123] When the top 210 of carbon dioxide canister 206, for
example, is advanced on threads 266 of the valve assembly body 228,
the top of canister 206 will engage hollow puncture pin 240, which
pierces the top 206. The top 210 of carbon dioxide canister 206 is
caused to seat against canister seal 238 as the threads 269 of
canister 206 are advanced along the threads 266 of the valve
body.
[0124] Once seated, carbon dioxide becomes available to valve
assembly 216 through canister puncture pin orifice 270. The valve
assembly 216 in the normally closed position is shown in FIG. 20.
In this position, valve stem 234 is pushed by the pressure of the
compressed carbon dioxide gas so that valve stem flange 258 is
caused to seal against the upper valve seal 252.
[0125] In the closed position, carbon dioxide is allowed to pass
from the canister 206 through orifice 270, valve seal 242 and valve
spacer 244 to valve stem inlet port 272 located at the proximal end
of stem 234. Gas within stem 234 must exit the stem through inlet
orifice 262 because of plug 252 to fill the chamber 250 of cylinder
248 that exists between the outer diameter of valve stem 234 and
the inner diameter of valve cylinder 248. Valve seals 246 and 252
are sized on the internal diameters to fit and seal against the
outer diameter of valve stem 234. In the closed position, chamber
250 ultimately becomes filled with carbon dioxide gas to the same
pressure as that of canister 206.
[0126] In the open position, valve stem 234 is moved in an axial
direction, against the force of internal pressure, toward the
canister 206. It will be seen that when stem 234 is moved axially,
valve stem inlet orifice 262 is caused to pass by central valve
seal 246 thereby disconnecting fluid communication between the
carbon dioxide pressure provided by the carbon dioxide cartridge
206 and interstitial space of chamber 250. Further axial motion of
valve stem 234 causes valve stem exit orifice 264 to pass through
top valve seal 252 allowing the compressed gas in chamber 250 to
exit the chamber through stem exit orifice 264 to the interior of
valve stem 234 and out through valve stem exit port 236. In the
preferred embodiment, the volume of gas that is discharged through
stem exit port 236 is predictable and consistent for each actuation
and is determined by the relative internal volumes of jet 274 and
the volume of chamber 248. When the stem 234 is returned to the
normally closed position, the chamber 250 refills and becomes ready
for the next actuation.
[0127] Turning now to FIG. 21 through FIGS. 28, 31 and 32, the
preferred aerosol generator component of the present invention is
described. As seen in the exploded view of FIG. 22, the preferred
aerosol generator 202 comprises a jet 274, secondary 276, reservoir
cup 278, cap 280, column base 282, column 284, flapper valve 286,
and column end 288.
[0128] The jet 274, shown in FIG. 23, has a set of external threads
300 that allow the aerosol generator 202 to fit onto actuator
handle 200 through the engagement of threads 300 with the
corresponding threads 302 of valve stem cover 218 as shown in FIG.
16. The distal end of valve stem 234 mates with the inside diameter
of valve stem cover 218 to provide an adequate seal. The interior
of jet 273 is configured to receive valve stem cover exit port 304
when the external threads 300 of jet 274 is coupled with the valve
stem cover 218. Jet 274 also has a jet orifice 306 that allows the
flow of gas received from exit port 236 from valve stem 234 through
valve stem cover exit port 304.
[0129] Jet 274 and the secondary 276 shown in FIG. 24 interlock
together such that the external surfaces 308, 310 of jet 274 and
the internal surfaces of secondary channels 312, 314 of secondary
276, seen in FIG. 25, to form interstitial fluid passages 316.
[0130] Secondary 276, shown in FIG. 24 and FIG. 25 also has an
opening 318 that operates as a shock chamber. As in the previously
described embodiment, jet orifice 306 mates with secondary 276 such
that the shock chamber 318 and jet orifice 306 are aligned to form
the shock wave aerosolization nozzle, and preferably have the same
nozzle dimensions as described in the first embodiment.
[0131] Secondary 276 fits into the bottom of reservoir cup 278 to
form a reservoir for the holding of liquid medication such that
secondary surface 320, shown in FIG. 24, preferably becomes the
lowest point of the liquid reservoir. Penetrating through surface
320 through to secondary channel 314 is liquid choke orifice 322.
Liquid choke orifice 322 provides further means, through the
resistance of the flow of liquid, for limiting the rate and amount
of liquid entrained by the shock wave aerosolization nozzle. The
preferred optimum size range for liquid choke orifice 322 is less
than approximately 0.050 inches.
[0132] Reservoir cup 278 mates with cap 280 through the engagement
of locking clips 324 on reservoir cup 278 shown in FIG. 22 with
locking members 326 as shown in FIG. 26. Reservoir cup 278 and cap
280 are designed to allow the exit plane of secondary 276 to
protrude through a bore 330 in cap 280 allowing for aerosol entry
directly into aerosol chamber 340, while creating at the same time
anti-spill ability for reservoir 332 as shown in FIG. 30.
Anti-spill reservoir volume 332, shown in FIG. 30 is designed such
that when invention is tipped sideways or upside down, liquid in
reservoir does not spill out.
[0133] As seen in FIG. 26, cap 280 is preferably equipped with two
pairs of protruding ribs 328 located on opposite sides of the cap
which allow for column base 282 and spacer column 284 to slide over
cap 280 without rotating.
[0134] Column base 282, shown in FIG. 27, is equipped with
mouthpiece 334 to allow for patient inhalation. Column 284 is
preferably tubular and configured to fit onto column base 282.
Column base 282, column 284, and column end 288 are preferably all
made of anti-static plastic material to prevent the loss of charged
aerosol particles due to the attraction of the particles to
oppositely charged aerosol chamber surfaces.
[0135] Referring now to FIG. 22 and FIG. 28, flapper valve 286 is
preferably a thin rubber circular piece that has a center hole
which fits over flapper valve post 336 of column end 288. Flapper
valve 286 preferably has a large enough outer diameter to encircle
inhalation ports 338. Column end 288 fits onto column 284 to form
an aerosolization chamber 340.
[0136] Once aerosol is produced from the jet 274 and shock chamber
318, it enters into the aerosolization chamber 340 of column 284
where it is stored until patient inhales on mouthpiece 334. Flapper
valve 286 prevents the patient from forcing stored aerosol out of
chamber with an accidental exhalation. Upon inhalation, flapper
valve 286 allows room air to be entrained into chamber 340.
[0137] Referring now to FIG. 29 and FIG. 30, the completed coupling
of the aerosol generator 202, the actuator handle 200 and the gas
canister assembly 204 can be seen. The apparatus can be
conveniently stored in two pieces that are coupled prior to
use.
[0138] Referring also to FIG. 31 and FIG. 32, the full structure of
the preferred alternative embodiment of the apparatus can be seen.
In use, gas from canister 206 that has been previously seated on
canister seal 238, enters the valve assembly 216 through pin
orifice 270. Gas enters chamber 250 through valve stem inlet port
272 and valve stem inlet orifice 262 until the pressure of the gas
in chamber 250 is equal to the pressure of the gas in canister 206.
Upon actuation of trigger 220 as previously described, the contents
of chamber 250 exit through valve stem outlet orifice 264 and valve
stem outlet port 236 as a burst of gas. The burst of gas travels
through the internal conduit 342 of the valve stem cover 218, and
into the interior 344 of jet 274. Jet orifice 306 is dimensioned so
that the jet formed in the jet orifice 306 will be supersonic
producing the aerosolization process as described in the first
embodiment.
[0139] Additionally, jet orifice 306, exit plane radius 348 and
shock chamber 318 preferably have the same dimensions and
performance characteristics as the first embodiment described
herein.
[0140] Medicine held in reservoir 332 enters choke port 322 and
channels 312 and is drawn to interstitial space 346 between the jet
274 and secondary 276 and aerosolized when brought in contact with
the supersonic jet. The aerosolized medication is then contained in
the interior chamber 340 of column 284 for inhalation by the
patient.
[0141] In accordance with a still further embodiment of the
invention, as shown in FIG. 33, the equivalent of jet 274 and
secondary 276, forming the supersonic shock nozzle assembly, can be
enclosed in a small cartridge 350 along with a single blister pack
352 containing sufficient medication for one aerosol treatment. In
this single use embodiment, the cartridge 350 is to be inserted
into the base of the column 282 that is coupled to the body 214 of
actuator handle 200 so as to cause the supersonic shock nozzle to
become oriented above the channel 342 of valve cover port 304.
Cartridge 350 has an exterior housing 354 that is configured to be
disposed in a slot within the base 282 as needed by the patient.
After insertion into the base, cartridge 350 is sealed to the
outlet passage of carbon dioxide with o-ring 356.
[0142] The shock nozzle assembly has a jet orifice 358 and a shock
chamber 360 that are preferably configured as described in the
previous embodiments. Adjacent to jet orifice 358 is liquid feed
line 362 that is in fluid communication with prong 364.
[0143] Simultaneous with insertion of the cartridge 350, the foil
barrier 370 of blister pack 352 is preferably punctured by the
prong 364 by pressing a button 368 and the medicine 366 within
blister pack 352 is capable of being entrained from the blister
pack 352 through liquid feed tube 362 and through to the supersonic
shock nozzle. Aerosol is directed to chamber 340 from the
supersonic shock nozzle for inhalation by the patient. Accordingly,
as gas is caused to pass through the jet orifice 358 and shock
chamber 360, the medicine 366 in the blister pack 352 is entrained
and aerosolized by the supersonic shock nozzle as in the previous
embodiment. Upon completion of the aerosol treatment, the
supersonic shock nozzle/blister cartridge 350 may be removed and
discarded by the user. This single use embodiment may work with or
without an aerosol storage chamber and has the advantage of
reducing possible contamination of the supersonic shock nozzle
between treatments.
[0144] It can be seen, therefore, that the present invention
provides an inhaler device that can deliver a burst of aerosol from
an aqueous solution. In this way a number of advantages are
realized which include, less expense on the part of the patient,
less cost in formulation development, better aftertaste,
portability, and convenience.
[0145] Although the description above contains many specificities,
these should not be construed as limiting the scope of the
invention but as merely providing illustrations of some of the
presently preferred embodiments of this invention. Therefore, it
will be appreciated that the scope of the present invention fully
encompasses other embodiments which may become obvious to those
skilled in the art, and that the scope of the present invention is
accordingly to be limited by nothing other than the appended
claims, in which reference to an element in the singular is not
intended to mean "one and only one" unless explicitly so stated,
but rather "one or more." All structural, chemical, and functional
equivalents to the elements of the above-described preferred
embodiment that are known to those of ordinary skill in the art are
expressly incorporated herein by reference and are intended to be
encompassed by the present claims. Moreover, it is not necessary
for a device or method to address each and every problem sought to
be solved by the present invention, for it to be encompassed by the
present claims. Furthermore, no element, component, or method step
in the present disclosure is intended to be dedicated to the public
regardless of whether the element, component, or method step is
explicitly recited in the claims. No claim element herein is to be
construed under the provisions of 35 U.S.C. 112, sixth paragraph,
unless the element is expressly recited using the phrase "means
for."
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