U.S. patent application number 11/709535 was filed with the patent office on 2008-01-24 for breath actuated inhaler.
Invention is credited to Dan Deaton, Perry Genova, Matt Khare, Tom Ruckdeschel.
Application Number | 20080017189 11/709535 |
Document ID | / |
Family ID | 37215200 |
Filed Date | 2008-01-24 |
United States Patent
Application |
20080017189 |
Kind Code |
A1 |
Ruckdeschel; Tom ; et
al. |
January 24, 2008 |
Breath actuated inhaler
Abstract
A breath actuated metered dose inhaler including a housing, a
mouthpiece positioned at one end of the housing, and a mechanical
release mechanism positioned at another end of the housing. The
release mechanism is triggered by a diaphragm and the inhaler is
configured such that the air inhalation pathway is unimpeded by the
release mechanism.
Inventors: |
Ruckdeschel; Tom; (US)
; Genova; Perry; (US) ; Deaton; Dan;
(US) ; Khare; Matt; (US) |
Correspondence
Address: |
KOS PHARMACEUTICALS, INC.
1 Cedar Brook Drive
Cranbury
NJ
08512
US
|
Family ID: |
37215200 |
Appl. No.: |
11/709535 |
Filed: |
February 22, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10908133 |
Apr 28, 2005 |
7219664 |
|
|
11709535 |
Feb 22, 2007 |
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Current U.S.
Class: |
128/200.23 |
Current CPC
Class: |
A61M 2205/276 20130101;
A61M 15/009 20130101; A61M 15/0026 20140204; A61M 11/001 20140204;
A61M 2205/16 20130101; A61M 15/0091 20130101; A61M 15/0096
20140204; A61M 2206/16 20130101; A61M 15/008 20140204 |
Class at
Publication: |
128/200.23 |
International
Class: |
A61M 11/08 20060101
A61M011/08 |
Claims
1. A breath actuated metered dose inhaler, comprising: a housing; a
mouthpiece positioned at one end of the housing; and a mechanical
release mechanism positioned at another end of the housing; whereby
the release mechanism is triggered by a diaphragm and the air
inhalation pathway is unimpeded by the release mechanism.
2. A breath actuated metered dose inhaler as recited in claim 1,
wherein the release mechanism comprises a spring that is compressed
to store energy for the purpose of providing the metered dose.
3. A breath actuated metered dose inhaler as recited in claim 2,
wherein the release mechanism further comprises a rocker, and
wherein the spring is nested within the rocker and the rocker is
operable to pivot to allow compression and decompression of the
spring.
4. A breath actuated metered dose inhaler as recited in claim 3,
further comprising a spring cup that provides an interface between
the rocker and the spring.
5. A breath actuated metered dose inhaler as recited in claim 3,
wherein the release mechanism further comprises a release arm for
impeding the rocker prior to triggering of the inhaler.
6. A breath actuated metered dose inhaler as recited in claim 5,
wherein the rocker does not bear on the release arm in a rest state
and does bear on the release arm in a ready-to-fire state.
7. A breath actuated metered dose inhaler as recited in claim 5,
wherein the inhaler is triggered upon movement of the release arm
by the diaphragm.
8. A breath actuated metered dose inhaler as recited in claim 3,
further comprising a mouthpiece cover and a sleeve, wherein the
sleeve contacts the mouthpiece cover and the rocker, and wherein
the rocker is pivoted to compress the spring in response to
movement of the sleeve which is caused by movement of the
mouthpiece cover.
9. A breath actuated metered dose inhaler as recited in claim 8,
wherein the sleeve includes slots for allowing make-up air to enter
the housing.
10. A breath actuated metered dose inhaler as recited in claim 3,
further comprising a mouthpiece cover, a lower sleeve and an upper
sleeve, wherein the lower sleeve contacts the mouthpiece cover and
the upper sleeve contacts the lower sleeve and the rocker, and
wherein the rocker is pivoted to compress the spring in response to
movement of the upper sleeve which is caused by movement of the
lower sleeve produced by movement of the mouthpiece cover.
11. A breath actuated metered dose inhaler as recited in claim 10,
wherein the upper sleeve includes slots for allowing make-up air to
enter the housing.
12. A breath actuated metered dose inhaler as recited in claim 1,
further comprising an event counter for indicating the number of
sprays remaining in the reservoir as well as the number of sprays
taken during a dose sequence.
13. A breath actuated metered does inhaler as recited in claim 1,
wherein the housing comprises a separable upper and lower section
thereby allowing for manual press and breath operation to
facilitate priming or to use in the in the event of release
mechanism failure.
14. A breath actuated metered dose inhaler, comprising: a housing;
a mouthpiece positioned at one end of the housing; a mechanical
release mechanism positioned at another end of the housing; whereby
the release mechanism is triggered by a diaphragm and the air
inhalation pathway is unimpeded by the release mechanism; and a
vortex nozzle positioned within the mouthpiece.
15. A breath actuated metered dose inhaler as recited in claim 14,
wherein the vortex nozzle comprises: a nozzle housing including an
inlet which opens into a swirl chamber having an outer
circumference, a diameter and a first swirl chamber end having a
diameter, the inlet being tangential to the outer circumference and
set at an angle to the first swirl chamber end, an exit passage
positioned at a second swirl chamber end having a diameter, the
diameter of the first swirl chamber end having a diameter greater
than the diameter of the second swirl chamber end, the exit passage
communicating with a nozzle face through which an aerosol is
discharged.
16. A breath actuated metered dose inhaler as recited in claim 15,
wherein the nozzle face is flat.
17. A breath actuated metered dose inhaler as recited in claim 15,
wherein the nozzle face has a conical shaped.
18. A breath actuated metered dose inhaler as recited in claim 15,
wherein the nozzle face has a parabolic shaped.
19. A breath actuated metered dose inhaler as recited in claim 14
further comprising an event counter for indicating the number of
sprays remaining in the reservoir as well as the number of sprays
taken during a dose sequence.
20. A breath actuated metered dose inhaler, comprising: a housing;
a mouthpiece positioned at one end of the housing; a mechanical
release mechanism positioned at another end of the housing; whereby
the release mechanism is triggered by a diaphragm and the air
inhalation pathway is unimpeded by the release mechanism; and an
event counter for indicating the number of sprays remaining in the
reservoir as well as the number of sprays taken during a dose
sequence.
21. A breath actuated metered dose inhaler as recited in claim 20,
wherein the event counter comprises: a display; a battery to
provide power necessary to operate the dose counter; an event
counter switch trigger; and a printed circuit board for mounting
all or substantially all of the said dose counter components.
22. A breath actuated metered dose inhaler as recited in claim 20
further comprising a vortex nozzle.
Description
[0001] This application is a continuation of U.S. Patent
Application No. 10/908,133, filed April 28, 2005, pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed to a breath actuated
pulmonary drug delivery device used in the delivery of fluid
dispensations from a drug-containing canister. The delivery device
provides a metered dose of drug or other therapeutic agent when the
patient inhales from the device.
[0004] 2. Description of the Prior Art
[0005] There are a variety of inhalation devices which release
aerosol medication, either in a continuous spray or in a
predetermined amount of medication, commonly referred to as a
metered dose. Most common in this category are "press and breathe",
canister in actuator, delivery systems (pMDIs or pressurized
metered dose inhalers). In these devices, drug for multiple doses
is stored under pressure in a canister fitted at one end with a
metering valve and an associated discharge port or stem. When
inserted into an actuator body with mouthpiece, a "puff" or single
dose of the stored drug is metered and delivered when the patient
depresses the canister within the actuator. The spray is applied
directly into the patient's mouth, nasal area or respiratory
airways. Typically, these devices are actuated by the pressure
applied by the user's fingers, button action, or other related
manual techniques.
[0006] Proper use of these manually actuated devices requires that
the spray be activated at the appropriate point in the inspiratory
cycle, so that the medication is carried into the lungs rather than
being deposited in the mouth or throat. If this actuation is not
correctly coordinated with the inspiratory phase, the metered dose
may be deposited differently with each actuation and potentially
compromise the therapeutics and safety of the product.
[0007] There are numerous factors leading to poor coordination of
actuation of the spray and the inspiration cycle. Included in those
factors are poor training, the inherent limitations of the users
(if any), such as impaired physical abilities of geriatric patients
or the as-yet-undeveloped skills of children, or their inability of
either group to comprehend the correct way to use the device. In
view of the difficulties associated with manually actuated devices,
it has been recognized that there is a need for correct and
accurately delivered doses for patients having either local or
systemic pulmonary diseases. It has been further recognized that a
reliable breath activated device would improve the quality of life
for these afflicted people.
[0008] A breath actuated inhaler helps eliminate the problems
associated with manually actuated inhalers by making the product
easier to coordinate and more patient friendly, with predictable
delivery and dispersion in the respiratory airways. Breath-actuated
inhalers (U.S. Pat. Nos. 5,408,994 and 5,447,150) address the
problems associated with synchronization of drug delivery with
inhalation. Both commercially available devices, however, rely on
either pneumatic or mechanical functions that generally limit their
utility. Further, they do not incorporate added features of
importance to patients, i.e. low spray velocity and indication of
number of drug doses or "puffs" remaining after each use.
SUMMARY OF THE INVENTION
[0009] The inventors have recognized that while there are metered
dose inhalation devices that are activated by the breath of users,
a greatly improved breath actuated device could be developed. The
present invention is directed toward a breath actuated metered dose
inhaler that overcomes many of the drawbacks associated with prior
inhalers.
[0010] A breath actuated metered dose inhaler according to the
invention includes a housing, a mouthpiece positioned at one end of
the housing, and a mechanical release mechanism positioned at
another end of the housing. The release mechanism is triggered by a
diaphragm and the inhaler is configured such that the air
inhalation pathway is unimpeded by the release mechanism.
[0011] The velocity, with which the inhaler discharges drug and
propellant, is extremely important. If too high drug particles may
impact upon the throat inducing a gagging or choking reflex thus
limiting the amount of drug reaching the lung. It is also important
that the actuator nozzle delivering the plume provide
aerosolization and deaggregation of drug in suspension to insure
particle sizes appropriate for delivery to the desired target area
within the lung. The device of the present invention may employ a
nozzle of conventional design. A preferred embodiment, however,
might utilize a vortex nozzle as described in U.S. Patent No.
6,418,925, which is commonly assigned and the contents of which are
expressly incorporated herein by reference, producing a slowly
moving spray while meeting aerosolization requirements with less
retention of drug within the structure.
[0012] An additional feature of the invention, herein, is the
inclusion of a record keeping means as described in U.S. Pat. Nos.
5,544,647 and 5,622,163, which are commonly assigned and the
contents of which are expressly incorporated herein by reference.
An electronic event counter provides the patient with a numerical
indication of puffs remaining in the canister as well as the number
of puffs taken in a sequence to obtain a prescribed dose. This
information display assures that the patient can be kept aware of
depletion of medication in time to refill their prescription. This
breath-actuated inhaler overcomes deficiencies apparent in earlier
mechanical and pneumatic devices while adding additional user
benefits. A breath-actuated metered dose inhaler according to the
invention is housed within a structure in a form to comfortably fit
in the hand of the user. Said housing includes a mouthpiece
positioned at one end and a mechanical release mechanism at another
end. A diaphragm in the inhalation air passageway triggers the
release mechanism. Inclusion of an event counter and a vortex drug
delivery nozzle are facilitated by the design of the structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The following detailed description, given by way of example
and not intended to limit the present invention solely thereto,
will best be appreciated in conjunction with the accompanying
drawings, wherein like reference numerals denote like elements and
parts, in which:
[0014] FIG. 1 is an external view of one embodiment of the compact,
hand held, breath-actuated inhaler;
[0015] FIG. 2 is a rotated, perspective view, of the
breath-actuated inhaler of FIG. 1 showing the location of an
electronic event counter not visible in FIG. 1;
[0016] FIG. 3 is a plan view of the mechanism of the
breath-actuated inhaler of FIG. 1 in the initial armed, at rest,
state;
[0017] FIG. 4 is a plan view of the mechanism of the
breath-actuated inhaler of FIG. 1 in the mouthpiece cover open,
armed, cocked and ready to fire state.
[0018] FIG. 5 is a plan view of the mechanism of the
breath-actuated inhaler of FIG. 1 in the actuated state;
[0019] FIG. 6 is a perspective view of the cocking lever with a
mouthpiece cover showing the location of the cams for arming and
cocking the inhaler;
[0020] FIG. 7 is a perspective view of a sleeve, which is a
component of the arming and cocking system contained within the
bottom section of the housing;
[0021] FIG. 8 is a perspective view of the sliding load sleeve
showing the detail of the arms and right angle supporting
cylinders;
[0022] FIG. 9 is a perspective view of the toggle showing details
of the functional elements;
[0023] FIG. 9A is a plan view of the toggle shown in FIG. 9;
[0024] FIG. 10 is a perspective view of the escapement that
releases the toggle upon initiation of an inhalation maneuver;
[0025] FIG. 11 is a perspective view of the elastomeric diaphragm,
which upon inhalation displaces the escapement triggering automatic
drug delivery;
[0026] FIG. 12 is a perspective view of the spring cup positioned
between main the spring and the drug canister;
[0027] FIG. 13 is a perspective view of the membrane event counter
switch trigger;
[0028] FIG. 14 is an internal plan view of breath actuated inhaler
having a dose counter;
[0029] FIG. 15 is a cross-section view of a vortex nozzle design;
and
[0030] FIG. 16 is a plan view of a vortex nozzle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The breath actuated inhaler of the present invention is
suitable for the delivery of practically any inhaled aerosol
medication that would benefit from the controlled, precision
delivery offered by a breath actuated inhaler.
[0032] Prior to discussing the advantages of the present breath
actuated inhaler, the structure and function of the inhaler will be
described.
[0033] The device of the invention can generally be made using
parts molded of plastic materials, with the exception of springs,
generally made of metal and seals, gaskets and diaphragms made of
elastomeric materials. Components of the electronic event counter
may include semiconductor elements, battery, circuit board and
display means.
[0034] FIG. 1 depicts an external view of the hand held,
breath-actuated inhaler 1 according to the present invention. The
housing structure 100 consists of a lower section 2 with a
mouthpiece 3, and an upper section 4. A bayonet type twist lock at
mid portion 5 joins the lower section 2 and the upper section of
the housing structure 100.
[0035] Pivotally attached to lower section 2 is a cocking lever 6
which may have an integral mouthpiece cover 7. Not visible in this
view but located on the back of the inhaler 1 in lower section 2 is
a window for viewing the numerical display of event counter 8
(described in more detail below). Between lower section 2 and upper
section 4 is included a vent port 9 for inspiratory "make up" air.
In FIG. 2, the breath-actuated inhaler 1 is rotated so as to show
the position of event counter 8 in the back of lower section 2.
[0036] FIG. 3 is a plan view of the mechanism within the housing
structure 100 of FIG. 1 in the initial, armed, at rest, state.
Lower section 2 of housing structure 100 has a cylindrical cavity
10 in which a sleeve 12 (shown in detail in FIG. 7) is fitted.
Projecting from the lower end 17 of sleeve 12 are two posts 14 that
are displaced 180-degrees apart. Posts 14 extend through openings
16 in the bottom of lower section 2 and bear upon cam lobes 18
(shown by dotted line) on the inside of cocking lever 6 (shown in
detail in FIG. 6). Lower and upper sections 2, 4 are joined by
means of a bayonet twist lock 5. A cylindrical cavity 20 in upper
section 4 of housing structure 100 retains sliding load sleeve 22
(shown in detail in FIG. 8), the lower end 29 of which is in
contact with the upper edge 27 of sleeve 12 (see FIG. 7). A slot 23
in the upper edge of the sliding load sleeve 22 is an element of a
shuttle valve for the ingress of ambient air post drug delivery
(makeup air) to insure an uninhibited continuation of the
inhalation maneuver.
[0037] The upper end of load sleeve 22 has two projecting arms 24,
which at their upper extremity have cylindrical bosses 26 set at
right angles to the projecting arms 24. Cylindrical bosses 26
engage receiver slot 28 in toggle 30. The top radius of the
cylindrical bosses 26 bear against the lower surface of platen 33
to oppose the force of main spring 44. Toggle 30 rotates on
integral axle 32, the ends of which are seated within bearing
sockets molded into upper section 4 of housing structure 100. The
features of toggle 30 are best understood by the study of FIG. 9. A
platen 33 on toggle 30 has projecting nodes 34 at a junction with
shelf 36. The center section of toggle 30 is cut away at 35 to
allow for passage there through of spring cup 38 that is depicted
in FIG. 12. Upper end 40 of spring cup 38 is a platform which
projects out from spring clamp 38, where upon the under side of
platform end 40 bears nodes 34 of toggle 30. Interior floor 42
forms a seat in the cylindrical portion 41 of spring cup 38 for
main spring 44, which is held captive between 42 and the inner,
top, surface of upper section 4 of housing structure 100.
[0038] A pressurized metered dose inhaler (pMDI) canister 46 rides
within sleeve 12 and load sleeve 22. The lower end of spring cup 38
rests against the bottom of the pMDI canister 46. Canister 46 has,
at the other end, a ferrule 48 retaining a metering valve therein
which discharges a discrete dose of drug upon displacement of a
delivery stem 50. Delivery stem 50 engages vortex nozzle 49
(described in more detail below) within mouthpiece 3. The twist
lock feature 5 facilitates separation of upper and lower sections
2, 4 in order to access pMDI canister 46 for priming and vortex
nozzle 49 for cleaning. Additionally, accessing pMDI canister 46
allows a user to manually operate the inhaler 1 by pressing down on
the canister 46 in order to manually operate the device in the
event of a failure of the actuating mechanism.
[0039] An escapement 52 as shown in FIG. 10, pivots about post 54,
which is retained by bearings molded in upper section 4 of housing
structure 100. Rollers or rounded, low friction surfaces, 56 on
escapement 52 support cylindrical bars 57 projecting from the
distal inner end of platen 33 of toggle 30 when the inhaler is
armed and cocked. As depicted in FIG. 9, an opening 37 is provided
in toggle 30 to permit rollers 56 to pass through upon displacement
of escapement 52.
[0040] A finger 58 projecting from the face of escapement 52
contacts the center 59 of elastomeric diaphragm 60 shown in FIG.
11. Elastomeric diaphragm 60 is retained within a channel 61 that
is molded into upper section 4. Rail 62 at the bottom edge of
escapement 52 rests on stop 64 in upper section 4 in order to
accurately set the angular position of the escapement 52. Mounted
within lower section 2 is an electronic event counter 8. Count
recordation and display occurs in event counter 8 when switch 66 is
depressed by the displacement of ramp 68 of diaphragm 70 as
depicted in FIG. 13. The event counter 8 will be discussed in
further detail below.
[0041] FIG. 4 depicts the breath-actuated inhaler 1 of FIG. 1 in
the armed, cocked, and ready to fire state. Cocking arm 6 with
mouthpiece cover 7 has been lowered to expose mouthpiece 3 and is
now ready for patient inhalation. Cams 18, integral with arm 6
rotate such that the short radius comes into position beneath posts
14 of sleeve 12 allowing sleeve 12 to fall away from the lower end
of load sleeve 22. This action permits load sleeve 22 to retract
slightly allowing toggle 30 to rotate a few degrees such that
cylindrical support bars 57 come to bear on rollers 56 of
escapement 52. The breath actuated inhaler 1 is now armed and
cocked and ready to fire upon patient inhalation. The inhalation
air pathway A-A is directed from openings 19 at the back of vortex
nozzle 49 within mouthpiece 3 between canister 46 and sleeve 12 and
load sleeve 22 to diaphragm 60. In the pre-fire state, the raised
position of load sleeve 22 obstructs vent port 9 in housing
structure 100.
[0042] In FIG. 5, the mechanism of the breath-actuated inhaler 1 is
in an actuated state. The negative pressure created upon inhalation
at mouthpiece 3 is conducted through openings 19 at the rear of
vortex nozzle 49 along pathway A-A from FIG. 4, between canister 46
and sleeve 12 and load sleeve 22 to draw diaphragm 60 inward. The
displacement of diaphragm 60, bearing upon finger 58 of escapement
52 causes escapement 52 to pivot on post 54, swinging support
rollers 56 out from beneath cylindrical bars 57 on platen 33 of
toggle 30. A very small displacement of diaphragm 60 is all that is
required to impart adequate motion to escapement 52 for rollers 56
to travel "over center" of bars 57 at which point the force of
spring 44 further displaces escapement 52. Toggle 30 rotates on
axle 32 urged by the downward force of compression spring 44 upon
the floor 42 of spring cup 38. Platform 40 slides off of nodes 34
on toggle 30, moves downward, and comes to rest on toggle shelf 36.
Integral spring cup body 38, the lower (floor) end of which is in
contact with the bottom of canister 46, drives the canister down
displacing metering valve stem 50, discharging a dose of drug into
vortex nozzle 49. As canister 46 descends, ferrule 48 (shown in
dotted line) engages ramp 68 on diaphragm 70 in the wall of lower
section 2 depressing switch 66 of event counter 8. The placement
and angle of ramp 68 insure that the count is decremented
immediately prior to or at drug delivery.
[0043] Simultaneous with the displacement of canister 46, the
rotation of toggle 30 on axle 32 forces down cylindrical bosses 26
riding in toggle receiver slot 28. Cylindrical bosses 26 transmit
the force to load sleeve 22 via arms 24. Motion of load sleeve 22
downward uncovers vent port 9 in housing structure 100, opening
make up air route B-B by which an inhalation maneuver post drug
delivery may continue. Ambient air entering vent port 9 passes
through slot 23, between canister 46 and sleeve 12, to openings 19
in the rear of vortex nozzle 49.
[0044] FIG. 6 depicts the cocking lever 6 with integral mouthpiece
cover 7. Cocking lever 6 attaches to the lower section 2 of housing
structure 100 by means of posts 27 which are molded integral with
cams 18 into the interior surface of side plates 25. Posts 27 snap
into openings in lower section 2 of housing structure 100. Rotation
of cocking lever 6 raises and lowers sleeve 12 within cylindrical
cavity 10.
[0045] As shown in FIG. 7, sleeve 12 has an upper edge 27 that
abuts the lower end 29 of load sleeve 22 in the raised, armed,
position. Projecting downward from the bottom edge 17 of sleeve 12
are two posts 14 that pass through openings in the bottom of lower
section 2 to engage cam lobes 18 on cocking lever 6. Posts 14 are
rounded at corners 21 to facilitate engagement with cams 18. Flat
regions 23 on the bottom of posts 14 bear on cam lobes 18 during
the arming, cocking and firing processes. A slot 15 in the bottom
edge 17 of sleeve 12 straddles ramp 68 of diaphragm 70 allowing
free access to ferrule 48 on canister 46 for event counter 8
function.
[0046] The structure of arms 24 that extend from the upper side of
load sleeve 22 is depicted in greater detail in FIG. 8. At the
extremities of arms 24 and at right angles thereto are cylindrical
bosses 26 that engage slot 28 in toggle 30. Slot 23 in the body of
load sleeve 22 opens to the vent port 9 in housing structure 100
between lower section 2 and upper section 4 for makeup air when
load sleeve 22 descends within cylindrical cavity 10 upon breath
actuation. Therefore, in effect, load sleeve 22 acts as a shuttle
valve in performing this function.
[0047] Toggle 30 is shown in FIG. 9 and pivots on axle 32 that
rides in bearings molded into the top of upper section 4 of housing
structure 100. In the armed state, the load force of main spring 44
carried by spring cup 38 is borne on nodes 34 of toggle 30 and the
cylindrical bosses 26 on load sleeve 22 act through sleeve 12 with
cams 18 of cocking lever 6, to oppose the force of main spring 44.
In the ready to fire state, rollers 56 on escapement 52 maintain
toggle 30 in the cocked state by supporting cylindrical bars 57
projecting from platen 33. When support at cylindrical bars 57 is
removed, toggle 30 rotates on axle 32 urged by main spring 44
forcing spring cup 38 to travel downward coming to rest on shelf
36. The drop from nodes 34 to toggle shelf 36 transfers, via spring
cup 38, the force of main spring 44 to canister 46. Spring cup 38
moves within opening 35 in toggle 30. An opening 37 in toggle 30
provides clearance for escapement rollers 56 when toggle 30
rotates, as support at bars 57 slides away. Slot 28 provides
translation of the rotation of toggle 30 to a linear travel of load
sleeve 22.
[0048] FIG. 9a, which is a different view of toggle 30, shows the
distance that spring cup 38 drops from the node 34 to the shelf 36.
This occurs as toggle 30 rotates on axle 32 when rollers 56 of
escapement 52 release bars 57 of platen 33 (platen 33 moves from
position A to position B). The 45-degree rotation of axle 32, as
illustrated, conveys the force of main spring 44 to canister 46.
The displacement of canister 46 by a distance X (which is anywhere
from 0.125 to 0.150 inches depending on drug canister
specifications), is adequate to insure drug delivery.
[0049] Escapement 52 is depicted in FIG. 10. Axle 54 of escapement
52 is retained by bearings molded in upper section 4 of housing
structure 100. A finger 58 projecting from the front surface of
escapement 52 touches the center 59 of diaphragm 60 when the
inhaler is at rest or cocked. A spring (not shown) bearing upon the
back of escapement 52 biases the escapement 52 toward diaphragm 60.
Rail 62 at the lower edge of escapement 52, rests against stop 64
in upper section 4 maintaining the proper angle for rollers 56 to
support cylindrical bars 57 on platen 33 of toggle 30 when the
inhaler is cocked.
[0050] As shown in FIG. 1, elastomeric diaphragm 60 has a center 59
that contacts finger 58 of escapement 52. Deflection of diaphragm
60 at inhalation is the breath actuation trigger for the inhaler 1.
Diaphragm rim 63 is retained in a channel 61 molded in the wall of
upper housing section 4. There are vents 65 in the outside wall of
upper section 4 in front of diaphragm 60 to permit unrestrained
displacement.
[0051] FIG. 12 depicts spring cup 38 that has a lower end surface
42 of cylinder 41 which retains main spring 44 between lower
surface 42 and the inside top of upper section 4 of housing 100.
The lower end of spring cup 38 bears upon the bottom of canister
46. Nodes 34 and shelf 36 of toggle 30 support top plate 40 from
the bottom side. Keyways 43 in plate 40, straddle rails molded into
upper housing section 4 preventing rotation of spring cup 38 as it
drives canister 46 down when fired.
[0052] In FIG. 13 is depicted an event counter switch membrane
trigger 70. Membrane trigger 70 is sealed by edge bead 75 within
the inner wall 71 of lower housing section 2 as shown in FIG. 3.
Membrane trigger 70 is molded of elastomeric material with an
external ramp 68 that is deflected by contact with ferrule 48 of
canister 46 as the canister 46 descends during firing. The
displacement of ramp 68 depresses switch 66 of event counter 8
causing a decrement of one in the display of the doses
remaining.
[0053] Returning mouthpiece cover 7 to the closed position over
mouthpiece 3 after use, rearms the inhaler for the next breath
actuation. Rotation of cocking lever 6 (integral with 7) in
closing, raises cam lobes 18 into contact with posts 14 on sleeve
12. As sleeve 12 rises, it pushes adjacent load sleeve 22 up in
such a manner that cylindrical bosses 26 on arms 24 of load sleeve
22 force toggle 30 to rotate up to the armed, latched, position.
Toggle 30 rotates on axle 32 as it is moved upward to a position at
which escapement 52, urged by a biasing spring, returns to rest
with rail 62 against stop 64. During rotation, toggle 30 also
forces spring cup 38 upward, compressing main spring 44 as the
bottom edge of 38 shifts from a seat on shelf 36 of toggle 30 to
nodes 34. The full, armed, spring force is born by the vertically
aligned elements of spring cup 38, toggle 30, sleeve 12 and load
sleeve 22, and cams 18. Escapement 52 and diaphragm 60 are
effectively decoupled from the inhaler mechanism. This insures
against misfire due to accidental impact or other unanticipated
events.
[0054] As previously discussed, the breath actuated inhaler 1 of
the present invention includes an event counter 8. The dispensation
history of the event counter 8 can include, but is not limited to,
the number of doses of medication or actuations remaining in the
canister, the number of actuations of the inhaler during a dosage
sequence, the number of doses or actuations taken over a period of
time, and the time since the last dispensation of the
medication.
[0055] Depicted in FIG. 14 is a typical event counter 8 with the
display 200 electrically connected thereto. The display 200 is
shown physically mounted to the event counter 8, however, other
arrangements of the two components may be made. A battery 300
provides the power necessary to operate the event counter 8 and
display 200. Also provided as part of the event counter 8 is the
event counter switch membrane trigger 70. As shown, the switch
membrane trigger 70 is mounted external to a printed circuit board
340 and is isolated from canister 46 and mouthpiece 3 by an
elastomeric edge bead seal 75. The switch membrane trigger 70 is
electrically connected to circuit board 340, using wires or
flexible circuitry (not shown).
[0056] The event counter 8 is comprised of a circuit board 340 for
mounting all or substantially all of the components of the event
counter 8. These components include the battery 300, the display
200, the switch membrane trigger 70, and an application specific
integrated circuit (ASIC). The event counter 8 can operate in a
variety of counting modes. The manufacturer may select the mode of
the apparatus during production. Alternatively, the user may select
the mode in an apparatus that is enabled with two or more counting
modes.
[0057] The breath actuated inhaler 1 of the present invention also
includes a vortex nozzle 49 as depicted in FIG. 3 and disclosed in
commonly assigned U.S. Patent No. 6,418,925, the contents of which
are expressly incorporated herein by reference. The vortex nozzle
49 is designed to cause the medicament contained within canister 46
to aerosolize when ejected or sprayed into the nozzle. The
aerosolization or atomization of the sprayed medicament results in
a higher, more uniform dose of medication reaching a patient.
[0058] FIG. 15 shows a design of vortex nozzle 49. The vortex
nozzle 49 works as follows. In nozzle 49 the medicament is fed,
under pressure, into a swirl chamber 120 through an inlet 140 into
an inlet chamber 160 having an outlet passage 180. The swirl
chamber 120 has a first end and a second end where the diameter of
the first end is greater than the diameter of the second end.
Outlet passage 180 is tangential to the outer circumference of
swirl chamber 120. The inlet 140, particularly the outlet passage
180 is set at a specified angle which is 105-degrees from the axis
through exit orifice 200 but can be perpendicular to this axis. The
liquid entering swirl chamber 120 from outlet passage 180 imparts a
high angular velocity creating a low-pressure central region that
creates an air-cored vortex. This vortex spins through swirl
chamber 120 and emerges with tangential and axial components via an
exit orifice 200. Here, a hollow annular spray is produced. This
spray exits orifice 200 as a conical sheet through nozzle face 220.
The air core in conjunction with the swirl motion creates
tremendous shear forces to the exit orifice 200 thereby causing the
exiting annular spray to break up into ligaments and drops.
[0059] Nozzle face 220 may be flat as shown in FIG. 15 or may have
other shapes, such as but not limited to, a conical or parabolic
shape. The shape of the nozzle face 220 along with the internal
angle of the swirl chamber 120 may be modified to affect the
desired retention, plume force, and angle of the resulting
plume.
[0060] A corresponding nozzle back seal 240 forms the backside of
the vortex chamber and is a means for manufacturing the device.
Nozzle back seal 24 is inserted into back of the nozzle and extends
to the very edge of the tangential passage 180, which feeds liquid
into swirl chamber 120. Back seal 240 is preferably attached to the
nozzle using ultrasonic welding. In essence, the back surface of
the vortex nozzle 46 is flat while the main vortex chamber is shown
as primarily funnel shaped with a 90-degree cone leading to the
exit orifice 200 but may be modified as aforesaid.
[0061] FIG. 16 depicts construction of a vortex nozzle where there
is shown mouthpiece insert 436, which is intended to be inserted
into the mouthpiece 3 of housing structure 100. Insert 436 has a
forward or open end 440 and a rearward end 442. Coupled at end 442
is nozzle 410 by way of ribs 444, 446 and 448. Rib 446 has an
opposite rib (not shown). Nozzle 410 is positioned at a spaced
distance from end 442 so as to create slits 434. A back seal or
plug 460 is provided for insertion into the rear of nozzle 410. In
this regard, nozzle 410 and insert 436 may be fabricated integrally
or separately and then coupled together in an appropriate means
suitable for purpose. The material used may be HDPE or any other
appropriate material. Plug 460 may be made of a somewhat resilient
material as to allow for its insertion into the back of nozzle 410.
As can be seen in FIG. 3, upon completion of insertion of insert
436, plug 460 abuts flange 462 on lower section 2 of housing
structure 100. This assures plug 460 stops in place and also helps
maintain the proper position of inlet 140.
[0062] Having described the structure and operation of the breath
actuated inhaler 1 of the present invention, the advantages of the
inhaler over prior inhalers will now be discussed in detail.
[0063] The inhaler of the present invention includes several
advantageous structural features. One such feature is the nesting
of the main spring within the toggle mechanism. To implement this
feature, the release arm was "de-coupled" from the toggle and
pivotally attached to the upper unit of the housing, where its
motion during actuation does not move it into the space occupied by
the main spring. This allows for the use of a main spring of
increased diameter, thereby increasing the actuation force capacity
of the device.
[0064] Another advantageous feature is the interfacing of the
diaphragm and release mechanism within a very small space. That is,
the toggle is designed to pass over the moving escapement, within
the same space envelope, without interference. Such "nesting
action" reduces the space occupied by the release mechanism.
Nevertheless, the escapement still has access outside the "travel
envelope" for interfacing with the diaphragm and travel stops on
the housing.
[0065] Still another advantageous feature is the interfacing of the
sleeves with the release mechanism. In particular, the two
cylindrical bosses on the upper sleeve fit into mating slots on the
toggle, causing the upper sleeve to move vertically in response to
the pivoting motion of the toggle. Upon closure of the mouthpiece
cover, the upper sleeve pivots the toggle to its closed position,
compressing the main spring and resetting the device.
[0066] Yet another advantageous feature of the device is that of
using a "sleeve valve" to open a make-up air pathway. More
specifically, the openings in the upper sleeve provide the make-up
air pathway. When the device fires, the toggle rotates downward,
urging the upper sleeve downward. When the upper sleeve reaches the
lower limit of travel, the two openings in the sleeve align with
ports in the upper housing unit. The alignment of the holes creates
an open pathway to ambient air outside the device, allowing it to
be drawn through the device as "make-up" air for inhalation. The
size and shape of the openings on the upper sleeve, and/or the
ports in the upper housing unit, may be tailored to manage
inhalation resistance and flow rate.
[0067] An additional advantage of the device of the present
invention is that the bayonet twist lock joining the upper and
lower parts of the assembly provide for easy disassembly for
cleaning of the nozzle orifice and, in the event of mechanical
failure, operation as a conventional "press and breathe"
device.
[0068] An additional advantage is the means by which the event
counter is affixed to the inhaler. The counter is totally isolated
from the airflow path and all other components by a membrane/ramp
switch seal in the wall of the inhaler body. This feature also
prevents moisture from reaching the event counter during rinsing or
washing of the drug delivery nozzle.
[0069] Still another advantageous feature is the way the event
counter is integrated into the device, particularly the interfacing
of the event counter with the ferrule of the canister. Access to
the ferrule is facilitated by the location of the release mechanism
and triggering function above the canister, leaving the entire
lower portion of the canister and metering valve open to
access.
[0070] The present inhaler uses a mechanical (non-vacuum) release
mechanism that is located at the top of the device, above the
canister. This approach provides for ample stored energy capacity,
while avoiding the issues associated with a mechanism that
"surrounds" the metering valve. In particular, it is noted that
there are no small parts or features in the inhalation air pathway;
the canister ferrule is accessible to an isolated event counter via
a membrane/ramp interface; and the layout does not require
compromise of any kind in the design of the vortex nozzle.
[0071] The present inhaler uses a flexible diaphragm for
triggering, instead of a rotating vane/door. A diaphragm is much
easier to locate away from the inhalation airflow path,
facilitating the placement of the release mechanism at the top of
the device. There are two significant advantages to this
arrangement, first the mechanism does not encroach upon the airflow
pathway and second, there is no way components can be inhaled in
the event of mechanical failure. Further, in as much as the present
inhaler does not employ a vacuum "holdup" mechanism to retain
stored energy in the spring, the overall force capacity of the
inhaler is sufficient to actuate any metering valve commonly used
in pressurized metered dose inhalers (pMDIs).
[0072] The present inhaler uses sliding sleeves to link the
mouthpiece cover to the arming mechanism. Thereby, allowing the
actions of opening and closing the mouthpiece cover to be used to
input energy to arm the device (no separate arming lever is
needed). The sleeves (upper and lower) also serve as an interface
between the detachable upper and lower units of the device. In the
rest state (mouthpiece-cover-closed), the force of the compressed
main spring is resisted by the sleeves and the mouthpiece cover,
which is closed past an actuation point. Importantly, the release
mechanism components--physically smaller than prior release
mechanism components--are not loaded in this state. Therefore,
motion-induced misfires are unlikely.
[0073] The advantages of the present invention stand in contrast to
some of the disadvantages of prior breath actuated inhalers. The
disadvantages of one type of prior breath actuated inhalers
include: (1) small parts and/or features in the inhalation air
pathway, allowing for the possibility of a user inhaling a
mechanical component of a failed device; (2) susceptibility to
inadvertent triggering; (3) triggering mechanisms that effectively
prevent access to the ferrule of the canister, which is a very
desirable area from which to activate a counter mechanism (FDA
guidance currently recommends a counter on all new devices); (4) a
triggering vane located in the mouthpiece and hinged very close to
the nozzle orifice, acting as a "ceiling" just above the orifice
during delivery of the dose potentially compromising spray quality
and metrics of the emitted dose, (5) the use of a lever to arm the
device, requiring added parts and an additional user operational
step and; (6) components of the device do not separate enabling the
patient to use the device as a conventional "press and breathe"
inhaler in the event of mechanical failure.
[0074] The disadvantages of another type of prior breath actuated
inhalers include: (1) the use of a "vacuum-holdup" mechanism that
retains stored energy in the compressed spring, limiting the stored
energy capacity of the device according to the ambient air
pressure, the volume of the device and the integrity of the vacuum
seals--for this reason the device does not have enough stored
energy capacity to actuate all metering valves, significantly
limiting the device's applicability; (2) preloading of the metering
valve, that is maintaining the medicament canister in a state in
which the valve stem is partially depressed, can have undesirable
side effects, such as allowing for gradual leaking of drug or
propellant; and (3) dependence on the creation of a consistently
reproducible vacuum seal can adversely affect reliability and
manufacturing yield of the device.
[0075] Modifications to the present invention would be obvious to
those of ordinary skill in the art in view of this disclosure, but
would not bring the invention so modified beyond the scope of the
appended claims.
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