Note: Descriptions are shown in the official language in which they were submitted.
B&PFILE NO.79544
`5~ 6
Title: rARNT~G DEVICE FOR MæDICAM~NT DI~N~K
FIELD OF THE INVENTION
This invention relates to medicament dispensers
which may be used to dispense pressurized aerosol
medicaments or dry powder aerosol medicaments. This
invention relates to such a medicament dispenser which
alerts the user when the amount of medicament rer~ining in
the dispenser i8 low and the dispenser should be refilled
or replaced.
BACRGROUND OE Tn~ lNvkr.llON
Various types of medicament dispensers, also
called inhalers, have been developed. These can be broadly
grouped in two categories. The first category comprises
dispensers which are used to dispense a pressurized
aerosol medicament. Generally, these dispensers are
adapted to receive a pressurized container which includes
the medicament and a suitable carrier. Upon activation, a
metered dosage of the aerosol is ejected under pressure
from a mouth end opening in the contA i ner 80 a6 to be
inhaled by the user. The second group of medicament
dispensers are for -dry powder aerosols. This group of
dispensers has a contA~er for storing an aerosol
medicament. The device also includes means for dispensing
a metered dosage of medicament into a holding area that is
in air flow communication with a mouth end portion of the
inhaler. Once a pre-set dosage of medicament has been
dispensed into the holding area, inhalation by the user
causes the medicament to travel from the holding area,
through the mouth end opening and into the respiratory
system of the user.
- Rand et al. (United States Patent No. 4,817,822)
and Dessertine (United States Patent No. 5,020,527)
di6close inhalers with count$ng means. These devices are
passive devices which are designed to advise the user of
the number of times that a medicament dispenser has been
21 58716
activated. The disadvantage with thi6 device is that
different medicament dispensers may contain differing
numbe~s of dosages. Further, a user msy not read the
instructions which are included with the medicament
dispenser and may accordingly not be aware of, or may not
remember, the number of dosages available in a medicament
dispenser. Accordingly, it is incumbent upon the user to
determine and remember the number of doses which are
present in a particular medicament container and to
monitor the number of doses remaining.
Burns et al. (United States Patent No.
5,284,133) discloses an inhalation device with a dose-
timer, an actuator mechanism and patient compliance
monitoring means. The device of Burns et al. allows the
history the actuation, non-actuation and improper attempts
at actuation to be recorded and analyzed off-site at a
later time by a physician, pharmacist or other authorized
health care professional.
None of these devices provide an automatic,
accurate, reliable means for advising a user when the
dispenser is low and the dispenser ~hould be refilled or
replaced.
S~MMARY OF 'rn~ lNv~ ON
In accordance with the instant invention, there
is provided a medicament dispenser compri~ing:
(a) medicament di6pensing means for dispensing
a metered dosage of a medicament;
(b) electronic counting means, ~aid counting
means being advanced by each activation of ~aid
medicament dispensing mean6;
(c) signAlling means for providing a wAr~
signal to the user after the dispenser has been
actuated a preset number of times; and,
(d) a controller for actuating said signalling
means after said dispenser has been actuated a
pre~et number of times.
-~ l 5 8~
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The controller may include means for storing a
preset warning number, comparison means for comparing the
number of times the dispenser has been actuated with the
preset warning number after each activation of the
dispenser, and activation means for actuating the
signalling means when the number of actuations of the
dispenser exceeds the preset warning number. Preferably,
each time the medicament dispenser is actuated in excess
of the preset warning level, the activation means actuates
the signalling device to issue a warning signal.
The signalling device may be of various design
and may provide a warning by emitting an audio signal, a
visual signal or a combination thereof.
The counting means is electronic and,
accordingly, the dispenser is adapted to receive a power
source ~e.g. a battery). The power source may be included
as part of the dispenser. For example, when a user
purchases the medicament, the medicament may be sold
together with a medicament dispenser which includes a long
life battery. In order to extend the storage life of the
medicament dispenser, the medicament dispenser may also
include an on/off ~witch connected to the power supply.
In an alternate embodiment, the medicament
dispenser has verification means for sensing when a
sufficient inhalation has occurred for inhalation of a
complete dose of the medicament from the medicament
dispenser. For example, the medicament dispenser may
include an air flow passage into which the medicament is
dispensed. Upon 1nhAlAtion, the user causes an air stream
to flow through a passage in the medicament dispenser
entr~ n~ ~g the medicament. The air stream then passes a
mouth end p$ece and lnto the resp$ratory system of the
user. A pressure trsnsducer may be provided in the a$r
flow passage. The pressure transducer may be coupled to
the controller for sctuat$ng signalling means after the
sufficient ~n~AlAt$on by the user to cause the ~nhAlAtion
by the user of a metered dosage of the med$cament. The
7`1 ~
signal actuated by the verification means may be a
different signal to the warning signal.
This embodiment is particularly important in the
case of a dry powder inhaler since it i6 important that a
sufficient air flow be generated by the user to ensure
that the medicament is properly received into the lungs of
the user.
In a further alternate embodiment, a medicament
- dispenser for dispensing metered dosages of the dry powder
aerosol includes a medicament container for storing the
dry powder aerosol medicament, means for dispensing the
metered dosage of the medicament, means for receiving the
metered dosage of the medicament and sensing means for
sensing the dispensing of the metered dosage. The sensing
means is preferably coupled to the controller for
actuating signalling means to provide a confirmation
signal after a metered dosage of the medicament has been
dispensed. The confirmation signal may be different to the
warning signal and the signal actuated by the verification
means.
The dispenser according to one embodiment of the
instant invention will automatically advise the user when
additional medicament must be obtained. Accordingly, the
user at that time may purchase an additional inhaler.
Alternately, if the inhaler is adapted to removably
receive a contAiner of medicament or if the medicament
contA~ner is adapted to be refilled, the user may insert
a new medicament container or refill the contAiner. In
this embodiment, the medicament dispenser also include
reset means to reset the counter to zero when the
contAiner is replaced, refilled or a new container is
inserted into the dispenser.
The medicament dispenser according to a further
embodiment of the instant invention has verification means
will advise the user when the user has applied a
sufficient inhAlAtion to cause a metered dosage of
medicament to be inhaled. In an alternate embodiment, the
- :215~71~
-- 6 --
medicament dispenser may be adapted to issue a warning
signal when an insufficient inhalation has been applied
thus advising the user to continue the inhalation to take
all of the metered dosage of medicament.
S As discussed above, the medicament dispenser may
also advise the user if a metered dosage of a dry powder
aerosol is deposited for inhalation in the inhaler.
Alternately, the dispenser may advise the inhaler only
when a metered dosage of medicament is not dispensed and
available for inhalation.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other advantages of the instant
invention will be more fully and completely understood by
reference to the following drawings of a preferred
embodiment of the medicament dispenser in which:
Figure 1 is a cross-sectional view of an inhaler
according to the instant invention;
Figure 2 is a cross-section of a dry powder
inhaler according to the instant invention;
Figure 3 is an enlargement of the dose loading
means of the inhaler of Figure 2;
Figure 4 is a cros6-section along the line 4-4
of Figure 2;
Figure 5 is an enlargement of area A of Figure
2; and
Figure 6 is a block diagram of a circuit for an
inhaler according to the instant invention.
PESCRIPTION OF THE PREFERRED EMBODINENT
~ edicament dispensers according to the instant
invention may be for use w~th a pres6urized aerosol
medicament or a dry powder aerosol medicament. An example
of an inhaler for a pressurized aerosol medicament i6
6hown in Figure 1. An example of an inhaler for a dry
powder aerosol medicament is shown in Figure 2.
.
- 2 1 ~
-- 7 --
Referring to Figure 1, inhaler 10 according to
the instant invention comprises an outer shell 12,
pressurized medicament contA i ner 14 and mouth end piece
16. Pressurized medicament contAiner 14 may be removably
S provided in inhaler 10. Accordingly, when purchased by a
user, inhaler 10 may already contain a pressurized
medicament contA1ner 14. Once the medicament in
pressurized medicament container 14 has been taken by the
user, a new inhaler 10 may be purchased. Alternately, a
replacement container 14 may be obtained and inserted for
container 14 which was initially present when inhaler 10
wa~ purchased.
To this end, medicament container 14 may be
received in mounting means 18. Mounting means 18 has an
opening adapted to receive nozzle 24 of medicament
container 14. When inserted in mounting means 18, nozzle
24 is in air flow communication with diffuser 22 via
passage 20. Accordingly, when container 14 is activated,
a metered dosage of medicament is expelled from container
14 through diffuser 22, through mouth end piece 16 and
into the respiratory system of the user.
Referring to Figures 2 and 3, inhaler 30 has an
outer ~hell 32 and a mouth end piece 34. The inhaler has
medicament container 36 which ~tore~ a dry powder
medicament.
Air enter~ inhaler 30 by air inlet 40 which ha~
a perforated membrane 42. Air travel~ through inhaler 30
via pasfiage 44. Mouth end conduit 46 is positioned at the
end of pas~age 44 distal from air inlet 40. As air pas6es
through mouth end conduit 46, it passes by a di~rupter 48.
Di6rupter 48 may, for example, be a rotating means which
is inte~e~ to difirupt sggregated particulate medicament
which may be present in the air stream. ~he air then exits
inhaler 30 via mouth end piece 34.
A metered dose of medicament i8 dispensed from
medicament container 36 via dose loading means 38. Dose
loading mean~ 38 compri~es a perforated membrane 50,
- 2 1 5871 ~6
- 8 -
scrapers 52 and holder 54. Nembrane 50 is positioned below
medicament contAiner 36 so that the rotation of scrapers
54 relative to membrane 50 causes a metered dose of dry
powder medicament to pass from medicament contAiner 36
into the perforations of perforated membrane 50. The
portion of perforated membrane 50 into which the
medicament passes is rotated 80 as to be positioned in
passage 44. The user may then inhale by placing their
mouth over mouth end piece 34. Air flow through the
inhaler causes the air entering inhaler 30 via air inlet
40 to entrain the medicament in perforated membrane 50.
Membrane 50 may be affixed to rotation member 58. Thus,
rotation of unit 58 causes perforated membrane 50 to
rotate relative to scrapers 52. Accordingly, by simply
rotating member 58, the user may load a metered dose of
medicament into air passage 44 for inhalation.
In order to allow inhaler 30 to be reusable,
medicament container 36 may be provided with plug 60 so
that the container may be refilled. Dry powder inhalers
are discussed in more detail in United States Patent No.
4,S24,769, the contents of which are incorporated herein
by reference.
- In general, the instant invention may be
utilized with any medicament dispenser for dispensing a
metered dosage of a medicament. The medicament may either
a pres6urized aerosol medicament or a dry powder aerosol.
While examples of such inhalers have been discussed in
terms of the inhalers shown in Figures 1 - 3 inclusive,
the invention is not limited by its application to these
particular embodiment6 of inhalers.
Reference is next made to Figure 6, which shows
a diagram, largely in block form, o an exemplary circuit
according to the present invention. The circuit of Figure
6 may be provided on a circuit board 76 (Figure 1)
internal to the inhaler and may be powered by a battery 78
which is provided in the inhaler. If the inhaler i6
designed as a di6posable inhaler, then a battery of
2158716
suitable life may be provided. Optionally, an ON/OFF
switch (not shown) may be provided. In that case, when the
user obtains the inhaler, the user may activate the
circuit by ad~usting the ON/OFF switch to the ON position.
When the medicament has been consumed, the user may
dispose of the inhaler. If the inhaler is reusable, then
the battery may be positioned at an easily accessible
position so that it can be replaced as required.
As shown in Figure 6, the circuit includes a
counting switch 82, across which is located a capacitor C1
to suppre~s transients caused by the switch opening and
closing. The switch 82 is connected to the clock terrinAl
84 of a binary counter 86. A driver 88 located between the
positive supply voltage and ground is connected to the
reset ter~in~l 90 of the counter to reset it if the power
goes off and then on.
Two selected terminals 92, 94 of the counter
(for example the 32 count and the 64 count terminals) are
connected to an OR gate 96, the output of which i~
connected to an AND gate 98. Another terminal (e.g. the
128 count terminal) 100 of counter 86 is connected to the
other input of AND gate 98. The output of AND gate 98 is
connected to one input of another AND gate 102.
The other input of AND gate 102 is driven by a
2S one shot multivibrator 104, which is driven by a driver
106 connected to counter clock input 84. One shot 104
provides a pulse of short duration, e.g. a 4 second pulse,
each time it is clocked.
The output of AND gate 102 is connected via lead
110 and through OR gate 111 to a multivibrator 112. The
output of multivibrator 112 is connected to an oscillator,
e.g. 1 KH2 oscillator 114, and also to a driver 116 which
drives a visual signalling means, e.g. red LED 118 which
is positioned in light gu$de 80, through a NAND gate 119.
The output of oscillator 114 i8 connected to
audio signalling means, e.g. piezo speaker 120.
- 2 i 513 7 1 6
-- 10 --
A further driver 122 is provided, connected
through OR gate 123 to the clock terminal 84 of the
counter 86. Driver 122 drives a one shot multivibrator 124
to illuminate a visual means, e.g., green LED 126 for a
time of short duration, e.g. one second, each time switch
82 is closed.
The switch 82 closes with each activation of the
medicament dispenser. For example the switch 82 may
comprise a toggle switch as shown at 82 in Figures 1 and
5. As shown in Figure 1, each time the valve of medicament
container 14 is depressed, a metered dosage of medicament
is released into the mouthpiece 16. At the same time the
valve momentarily depresses toggle switch 82.
Alternatively, as shown in Figure 5, each time member 58
lS is rotated, member 85A is depressed, closing button 85B of
counter switch 82.
When the counter switch 82 is closed, the count
in counter 86 is incremented by one.
When the counter 86 reaches a preset count,
registered by the sum of the counts at terminals 92 and
100, the output from AND gate 98 goes high, producing a
four second output from AND gate 102 (~ince one shot 104
produces as mentioned a four second pulse each time switch
82 is activated). The high output from AND gate 102,
through OR gate 111, activates multivibrator 112 which
operates at the relatively low frequency of e.g. 2 Hz. The
output of multivibrator 112, amplified through driver 116,
operates red LED 118 to flash a four second warning that
the medicament in the inhaler is nearly exhau~ted. At the
6ame time, the output of multivibrator 112 drives 1 ~Hz
oscillator 114, producing a four second warning beep from
speaker 120. This i8 a near end warning 6ignal to the
user. (The 2Hz input to oscillator 114 reduces battery
drain.) A similar audio and visual 6ignal iB provided for
each further activat~on of the circuit.
While Figure 6 has exempllfied the use of a
combined video and audio signal, it will be appreciated
- 2158716
that the circuit in Figure 6 may be altered to provide
merely an audio signal or merely a visual signal.
Inhaler 30 requires that rotating member 58 is
fully rotated 80 that perforated membrane 50 contains a
full metered dosage. Accordingly, in one embodiment
inhaler 30 has sen6ing means for actuating a signalling
means to provide a confirmation 6ignal after a metered
dosage of medicament has been dispensed onto perforated
membrane 50. Alternately, the sensing means may be coupled
to the controller so as to actuate a visual and/or audio
signalling means when a metered dosage of the medicament
has not been dispensed. As shown in Figure 6, one shot 124
lights LED 126 for one second each time switch 82 is
closed. Preferably, LED 126 is a different colour from LED
118 and, for example, may be green.
In an alternate embodiment, the dry powder
inhaler may have a pressure transducer 130 provided close
to the mouthpiece 34. When the pressure in the mouthpiece
34 falls sufficiently to operate the pressure transducer
130, the transducer transmits a signal via OR gate 123 and
driver 122 to operate the one shot 124, and via OR gate
111 to operate the 1 KHz oscillator 114, thereby providing
a different audible signal and a different visual signal
(a green flash) when the user has used the device
properly. A red flash i6 inhibited at this time because of
high signals to both inputs of NAND gate il9.
Alternatively, the circuit may be designed to
provide a signal (e.g. a 1 second beep and a red flash) to
the user if a 6ufficie~t 1nhAlAtion does not occur.
If the inhaler or dispenser is refillable, then
a reset switch (not shown) may be provided to send a pulse
to reset terminal 90 of counter 86 to reset the counter
when refilling occurs.
It will be appreciated by those skilled in the
- 35 art that if the pressure transducer and the sensing means
are provided, then a sufficient number of audio and/or
visual signalling means must be provided 80 that,
2158716
preferably, a distinct signal can be provided to signal a
warning level to replace the inhaler or to refill the
inhaler; to advise that a sufficient inhalation did or did
not occur and to advise that a full do6age of medicament
has or has not been deposited on perforated membrane 50.
