Note: Descriptions are shown in the official language in which they were submitted.
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-- PAUL RITZAU PARI-WERK GmbH ~ u~ -
Moosstrasse 9, D-82319 Starnberg
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DESCRIPTION
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MOUTHPIECE FOR INHALATION THERAPY DEVICE ;; ~
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The invention in question concerns a mouthpiece for inhalation therapy devices.
An inhalation therapy device for which the mouthpiece as per the invention can be
used, is, for example, known from EP 87 13 416.1. The device has a nebulizer with a ~``"`~.
chimney~for en rained air and a nebulization chamber in which a nebulization nozle ` - h
produces an aerosol containing medication. The aerosol consists of a fine droplet or
partical mist which is inhaled by the patient. Thè known inhalation therapy device has
a mouthpiece which is inserted on the outlet connection of the nebulizer and through "~
which th~pàtient inhal~s the aerosol. Thus, surrounding air flows through the
entrained` air~chimney and the nebulization chamber into the mouthpiece. When
exhalin~ into the mouthpiece, a nonreturn valve in the entrained air chimney of the
nebulizèr~closes. In order to make exhalation through the mouthpiece possible `~
anyway,`a nonr~eturn valve on the familiar mouthpiece which opens during exhalation ` -`~
is locàted on the branched-off tube-shaped connection through which the air leaves
to the: surroundings. ~
In the known moùthpiece a very large dead space exists in the area of the nonreturn
valve~which~allows the~aerosol droplets or particles to separate. Above and beyond
this, the~vèry large~ dead space negàtive~ influen s the flow relationships in the
mouthpiece and thereby the composition of the aerosol inhaled by the patien~
Therefore,iit is-the~job`of this invention to make a~mouthpiece for inhalation therapy
devicès which doès not inflùence the aerosol flow~during inhalation, spec fically
prevents a`sepàration of the aerosol and also ~allows exhalation into the mouthpiece. ~
This task is~ solved by a mouthpiece for inhalation therapy devices with a basic body of
a rnostl~tube-shaped shape in whose wall there is an opening and a nonreturn valve
for~sealing the opening during inhalation through the mouthpiece and for allowing the
exhaled `air through the opening during exhalation through the~mouthpiecs. The
rnouthpiecè~as~per the`in~ention is~ characterized in that the basic body has at least
one~mostly level ~vall in which the opèning is located and the nonreturnvalve has a
flàt, elastic valve element whose~dimensions and shape for closing the opening are
adàpted to it and which is fastened onto the leve! wall portion in such a manner that,
due to~t~hè effective èlastic forces, it lies on the exterior of the basic body during rest
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and closes the opening, and that, in order to open the opening, it can be partially lifted
from the basic body.
In an advantageous design the basic body has a connection area for connecting the
mouthpiece on the inhalation therapy device, has an ergonomically shaped area for
placing in the mouth and a transition area for transforming the shape of the
connection area into the shape of the ergonomically shaped portion, and is located in ;`
the mostly level wall portion in which the opeing is located in the transition area. ` -
Furthermore, the flat elastic valve element can be held on the basic body from the ;~
outside by a clamp assembly.
In another design, the clamp assembly has an one-piece valve element cover which is
locatad on the outside of the basic body over the vaive element and serves to protect ~ ~
the flat, elastic valve element. :-
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Above and beyond this, in the mouthpiece as per the inventionl the opening can be
equipped with a circumferential peripheral step which protrudes into the opening and - --
on which the flat, elastic valve element lies in its normal position so that the flat, elastic
valve element is mostly situated in the opening. Beneficial is to equip the peripheral r- `
step with a circumferential sealing lip.
The mouthpiece as per the invention can finally be designed in such a way that the flat
elastic valve element has a restraining opening, that the basic body has a restraining ` ~
opening and that the clamp assembly is hinged so that it can flap from an open ~ :
position to a valve-element-clamping position and has a restraining projection. - -
The flat elastic valve element is made of a plastic or rubber material. ~;} ~ ~`
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As per the invention the wall of the mouthpiece basic body is simulated by a flat elastic
valve element in the area of the opening. In the area of the opening the inner surface -~
of the mouthpiece basic body is practically replaced by the surface of the flat elastic -
valve element pointing toward the inside. This has the effect that the dead space in the
area of the valve is reduced considerably and, due to the similation of the inner wall,
there is practically no influence on the flow in the mouthpiece. ` -
The invention will be described below based on application examples which are ~-
shown in the drawings. The drawings show the following~
Fig. 1 a first application example of the mouthpiece as per the invention on an ~ ~ -
exemplary nebulizers shown in its cross section;
Fig.2 a second design example of the mouthpiece as per the invention in a cross ~ ;
sectional view;
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Fig. 3 a perspective view of a third application example of the mouthpieces as per
the invention, and
Fig. 4 an enlarged view of a detail of the third application example. `~
With reference to Fig. 1 first, the basics of the design and function of the mouthpiece 1
as per the invention which, in Fig. 1 's view, is placed on an intake connection 2 of a -
nebulizer 3, will b~ described. Naturally, the mouthpiece as per the invention can be
used together with other inhalation therapy devices which produce an aerosol for the -
patient to inhale. :
The exemplary nebulizer 3 chosen has an entrained air chimney 4 through which
ambient air is sucked into the nebulization chamber 5 during inhalation. In the
nebulization chamber a nozzle 6 produces an aerosol from a powder or liquid
nebulization substance, specifically a medication which is stored at the lower end of
nozle 6 in a nebulization substance reservoir 7. In order to produce aerosol
compressed air is forced through a compressed air channel 8 in the nozle 6 which ~ ~ ~Y
exits at the upper end of the nozle and nebulization substance is sucked through the
two nebulization substance channels which are located on both sides of the
compressed air channel. Supported by an air flow control 9 with ba~fle edge, aerosol,
which is stored in the`nebulization chamber 5, is produced by nebulization. Aerosol
can be produced continuously or shortly before or during inhalation. For continuous
aerosol production a continuous compressed air flow is forced through the
compressed air channel 8 of the nozle 6. In this case the entrained air chimney 4 is
closed to the surroundings by a nonreturn valve 10 which prevents the aerosol
proquced in the nebulization chamber ~ from exiting through the entrained air
chimney 4.
During inhalation the patient sucks the aerosol stored in the nebulization chamber 5
through the mouthpiece 1 and the intake connection 2. Due to the negative pressure
produced, ambient airflows through the opened nonreturn valve 10 viathe entrained
air chimney 4 into the nebulization chamber 5 and is then sucked through the
mouthpiece 1 and the intake connection 2. During continuous nebulization the ~ ~ -
surrounding air mixes continuously with the produced aerosol. The flow cross
sections of the entrained air chimney 4, the nebulization chamber 5 and the intake
connection 2 as well as the behaviour of the nonreturn valve 10 are adapted to the
nebulization performance of the nozle 6 in such a way that an aerosol of desiredconcentration and particle distribution can be inhaled by the patient during inhalation. ;
No further ambient air should be added to the sucked aerosol in the area of the ;~
mouthpiece 1 and the intake connection 2 in order to insure a maximum output of the
nebulization substance with the help of the entrained air. Ab~ve and beyond ~his a
flow-favorable geometry in the inside of the mouthpiece is strived for in order to
prevent unwanted vorticities and inhomogenities in the aerosol. For inhalation, an -
ideal mouthpiece therefore has the shape of a closed, mainly tube-shaped basic ~ ~ ~
2 1 2 Ll ~ 1 9
body, in which the cross sections and cross section shapes change continuously. ~
The cross section surFace remains the same or becomes smaller in the direction of ~ -
flow during inhalation. In such a design the flow is not turbulent and the deposition of
the aerosol droplets and/or particles is minimized.
During exhalation however, the exhaled air must not flow into the surrounding in a - ` ~
reverse direction since exhalation through intake connection 2, nebulization chamber `; -
5 and entrained air chimney 4 would lead to the continuously produced aerosol or at
least aerosol residues from the nebulization chamber 5 being forced out whereby the
nebulization substance, in the form of the aerosol, would be lost. This is the reason for -
the nonreturn valve 10 which closes the entrained air chimney during exhalation so ;
that exhalation through the entrained air chimney 4 and therefore through the ;
nebulization chamber 5 is not possible. ;
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However, in order to make exhalation through the mouthpiece possible for the patient,
the mouthpiece 1 has a valve 11. In the invention this valve is designed such that it `- -~
simulates the wall of an ideal mouthpiece as far as possible. The basic idea of the i~
invention is to equip a mouthpiece with a valve in such a manner that the wall of the -- -
mouthpiece at tha location of the opening of the valve is simulated by an elastic valve ~ : ~
element in such a manner that the deviation from the originally existing wall is as small --
as possible. Thus, as per the invention, the lowest possible influence of the flow
relationships is achieved and the deposition of aerosol droplets or particles isavoided. .. -
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~th this in mind, the mouthpiece 1 of the first application example is divided into three ~ -
part~ 1a, lb and 1c. The valve is located in part lb, which is a transition between la - `
and 1c. Part la of the mouthpiece 1 is mainly circular cylindrical and adapted to the - ` n
tube-shaped intake connection 2 of the inhalation therapy device. Thus, the ~ -
mouthpiece 1 can be placed on intake connection 2 in such a manner thatl first off a
secure ft is insured and, secondly, an unwanted influx of ambient air is prevented due
to the achievable air-tightness at the mounting site ~a. In part 1c the mouthpieca is
flatted for ergonomic reasons and, for example, has a mainly elliptical cross section. ` -
Part 1 b lies between parts 1 a and 1 c and converts the shape from one to the other in
a flwx-favorable manner. As per the invention mouthpiece 1 has an at least one mainly
level wall surface in zone 1 b in which the opening 14 for tha breathed air during
exhàlation is located and in whose immediate zone valve 11 is located. -
In the application example shown in Fig. 1 the valve 11 consists of a flat elastic
element 12 which is fastened on one end to the exterior of the mouthpiece 1 by aclamp assembly. The free end of the elastic element 12 lies flat on the level wall
surface of zone 1 b durîng rest and closes the opening 14 located in this zone. For this
the elastic element 12 has the corresponding dimensions and a shape adapted to the -
opening 14. The ciamp assembly is not located in the area of the level wall surfaces
but rather in their \licinity so that the valve element 12 is held and for which it extends
to the clamp assembly.
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In Fig. 1 the elastic element 12 is shown in a raised position which occurs when the
patient exhales through the mouthpiece 1. When inhaling through the mouthpiece 1the negative pressur~ arising in the mouthpiece supports the elastic forces which
make the elastic valve element 12 close the opening 14 in the mouthpiece during rest.
Thus, no surrounding air can enter through the opening 1~ in the mouthpiece during
inhalation thereby mixing with the sucked aerosol.
As per the invention the elastic element 12 is situated on the level wall portion of the
zone 1 b of the mouthpiece in such a way that the wall portion missing in the area of
opening 14 of the mouthpiece 1 is replaced by the elastic element 12. Only the volume
which results from the opening surface of the opening 14 and the wall thickness of the
mouthpiece 1, influences the flow relationships in mouthpiece 1 in the valve 11 as per
the invention. However, due to the design of the mouthpiece valve 11 as per the
invention, this volume is already very small in this application so that the flow ~.
relationships correspond entirely to the flow relationships of a mouthpiece without an ~ `
opening. The volume in the area of opening 14 is so small that nearly none of the
droplets or particles in the aerosol separate. The flow is not influenced worth
mentioning by the dead space in the area of the valve. In the end, during inhalation -
the mouthpiece as per the invention behaves as R the opening 14 did not exist. Thus,
the mouthpiece as per the invention corresponds mostly to the above mentioned ideal
situation.
Fig. 2 shows a second application example of the mouthpiece 1 for an inhalation
therapy device as per the invention for which only a portion of the intake connection 2
is sh'own. In the second application example the elastic valve element 12 is shown in
the resting position in which the opening 14 is covered. From ~ig. 2 one can see that
the dead space determined by the opening 14 and the elastic valve element 12 in its
resting position, is nearly completely eliminated For this, the elastic valve element 12
has two layers. The first layer 1 2a, which, due to its inherent elastic forces in its resting
position forces the valve element to lie on basic body 1, corresponds fqr the most part
to the elastic valve element 12 of the first application example. Above and beyond this
in the seGond application example the valve element 12 has a second layer 12b which
is located on the side of the first layer 12a facing the opening 14 and whose shape
and dimensions are adapted to the opening 14 is such a way that this part of the valve
element can be arranged in the opening and that a movement of the valve element 12 ~ -
is possible anyway through which the opening 14 is opened during exhalation. The ~ ~-
thickness of layer 12b of the valve element 12 corresponds to the wall thickness of the - ;
basic body 1 of the mouthpiece. Therefore in the resting position the opening 14 in
basic body 1 is close`d in such a way that the inner wall of the basic body 1 continues
nearly without interruption in thatthe surface of the second layer 12b facing toward
the inside simulates the inner wall of the basic body 1. Both layers 1 2a and 1 2b can be
of the same material and made as a single piece or of different materials. ~i
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As in the first application example the elastic valve element 12 is fastened to
mouthpiece 1 by means of a clamp assembly 13. However, in comparison with the - ;
first application example, the second application example as per Fig. 2 has a single-
piece valve element cover 13a tip-stretched on the clamp assembly 13 which is
iocated above the valve element and has, for the most part, the same shape as the -
elastic valve element 12. The valve cover 13a's job is to protect the elastic valve -
element 12 against contact and damage. In order to allow the elastic valve element 12
to move during inhalation, the valve cover 13a is bent away from the wall piece of
zone 1b of mouthpiece 1 which contains the opening 11. The resulting opening angle
can be chosen freely in wide ranges as long as it is insured that the elastic valve
element 12 can move sufficiently enough that the opening is opened during
exhalation
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Fig. 3 shows a third application example of the mouthpiece as per the invention. Just -
like in the first and second application examples, the mouthpiece has three zones 1 a, ;
1 b and 1 c. Zone 1 a serves to secure the mouthpiece on the inhalation therapy device
and has a tube-shaped design. Zone 1 b is the transition to the ergonomically shaped - `
zone 1c. An opening 14 in a mainly level wall portion of the mouthpiece 1 is located in ; ` ~;
zone 1 b. An elastic valve platelet 12 is shown in its raised position. When assembled,
the elastic valve platelet 12 is located on the mouthpiece 1 in such a manner that a -
restraining opening 15l which is located in the elastic valve platelet 12, lies over a
restraining opening 16 in the basic body 1 of the mouthpiece. The elasticvalve platelet
12 then covers the opening 14 of the mouthpiece 1 whereby the outer edge of the
movable part of the valva platelet 12 lies on the opening 14. ~ -
For ~larification, Fig. 4 shows an enlarged view of the part of the mouthpiece marked
by reference letter A in Fig. 3. One can see that opening 14 has a circum~erential
peripheral step 14a on the lower wall section which protrudes into opening 14 and on
which the elastic valve platelet 12 lies during rest and inhalation phases. Due to this
design, the dead space in the area of the mouthpiece valve is reduced to the volume
defined by the thickness of the edge, marked by reference letter d, and the surface of
the opening 14.
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The circumferential peripheral step 14a can have a circumferential sealing lip in the ;
immediate vicinity of the opening 14 which protrudes from the surface of the
peripheral step facing the valve platelet; however, the sealing lip is not shown in Fig. 4.
In this case the elastic valve platelet is Iying on the sealing lip.
The elastic valve platelet 12 has a thickness which is not greater that the remaining
edge area on which the edge of the elastic valve platelet 12 borders in its resting -~
position. Thus, during rest, the platelet 12 does not protrude out of the surFace of the - ~ `
mouthpiece1.
Clamp assembly 13 is in the form of a bracket which can be designed as a single
piece with the basic body 1 of the mouthpiece for restrainment. A hinge allows the -
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clamp b~acket to be raised upward as shown in Flg. 3. The valve platelet 12 Is then
brought to the assembly position and the clamp brackett 13 is closed. A restraining
projection 13b on the side f the clamp bracket toward the valve platelet grips into the
restraining openings 15 and 16 in the valve platelet 12 and/or basic body 1. By
chosing the dimensions correctly, a sure fixation of the valve platelet is insured which
is positioned based on the restraining projection 13b and clamped by the clamp
brackett 13b. However, the valve platelet 12 remains flexible in the area of the opening
14 so that air can flow through the opening 14 during exhalation.
A cover 13a on the clamp brackett located above the elastic valve platelet as in the
second application example, serves to protect the elastic valve platelet from contact
and damages when the clamp brackett 13 clamps the valve platelet 12.
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