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Title:
DISPENSING REGULATOR UNIT AND BREATHING AID SYSTEM
Document Type and Number:
WIPO Patent Application WO/2020/159374
Kind Code:
A1
Abstract:
A breathing aid system (200) and a dispensing regulator unit (205, 206, 211) for dispensing liquid, gaseous or dry powder inhalant in order to prevent or relieve problems, such as asthma, other breathing difficulties or dehydration, into a breathing system for a pressurized environment is disclosed. The dispensing regulator unit comprises a housing (205) defining a dispensing chamber (207) for the substance and a coupling interface for connecting the housing to the breathing system. A dispensing channel (209) connects the dispensing chamber (207) to a breathing gas flow (204) and a demand valve (211) maneuverable for permitting flow communication between the dispensing chamber (207) and the breathing gas flow (204) upon demand by a user.

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Inventors:
MILSEM ORESTA (NO)
Application Number:
PCT/NO2020/000002
Publication Date:
August 06, 2020
Filing Date:
January 17, 2020
Export Citation:
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Assignee:
MILSEM ORESTA (NO)
International Classes:
B63C11/22; A61M11/02; A61M15/00
Domestic Patent References:
WO2004045720A12004-06-03
WO2008012509A12008-01-31
WO2016193649A12016-12-08
Foreign References:
EP0615899A21994-09-21
US20110297153A12011-12-08
DE102017011623A12019-06-19
FR3075160A12019-06-21
Download PDF:
Claims:
Claims

1. A dispensing regulator unit (20; 80; 100; 120} tor a pressurized environment, adapted to be coupled to a breathing gas passage, dispense an Inhaiabie substance Into said breathing gas passage y In order to prevent or s relieve problems such as asthma, other breathing difficulties or dehydration, the dispensing regulator unit characterized by; a housing (21 ; 81 ; 102; 121) defining a dispensing chamber (23; 53; 82; 103; 122) for the !nha!able substance, a coupling interface (31, 32; 09, 90; 109; 126, 12?) for connecting the

10 housing to the breathing gas passage, a dispensing channel (35; 84; 106; 123) connecting the dispensing chamber (23; 82: 103; 122} to the breathing gas passage (F),

- a user actuated demand valve (29; 40; 85; 1 11 ; 129) maneuverable for permitting flow communication between ibe dispensing chamber (23; 82; 15 103; 122} and the breathing gas passage (F) upon demand by a user, said breathing gas passage allowing passage of breathing gas Irrespective of the position of the demand valve.

2. The dispensing regulator unit of claim 1 , wherein the demand valve (40) comprises a dose metering valve and/or a fixed diameter orifice (30;106),

20 3. The dispensing regulator unit of claim 1 or 2, comprising

- a plunger (22; 101 ) movable in the housing (21 ; 102), the plunger

dividing the housing Into the dispensing chamber (23; 103) and a compensation chamber (24; 104), arid

- an elastic member (25: 105) In the compensation chamber biasing tie as plunger towards the dispensing chamber.

4. The dispensing regulator unit of claim 3, comprising a pressure

communication channel (28; 46) connecting the compensation chamber (24; 5?) with the breathing gas flow (F), the pressure communication channel (26; 46) introducing breathing gas pressure into the compensation chamber (24 57),

5. The dispensing regulator unit of claim 3, wherein the compensation chamber (104) is subjected to ambient environment pressure via a flexible diaphragm (115),

8 The dispensing regulator uni of claim 1„ comprising a pressure communication channel (91) connecting the dispensing chamber (82) to the breathing gas dew (F), the pressure communication channel (91 ), which may contain a check valve (96k introducing breathing gas pressure into the dispensing chamber (82),

7 The dispensing regulator unit of claim 8, wherein the user maneuverable demand valve (85) simultaneously opens and closes, or vice versa, the pressure communication channel (91 ) and the dispensing channel (84),

8 The dispensing regulator unit of any previous claim, wherein the housing (81) has coupling means (86: 87) tor connecting the dispensing chamber (82) with a pm-pressurized canister providing supply of inhaiab!e liquid, gaseous or a canister providing dry powder substance

9, The dispensing regulator unit of any previous claim, wherein the demand valve (128) is electrically operated 10, The dispensing regulator unit of any previous claim, wherein the mhaiab!e substance is one of: a gaseous, a liquid or a dry powder medical substance, sue s a asthma, bronchitis or COPD medicine, or a substance for preventing dehydration.

Description:
DISPENSING REGULATOR UNIT AND BREATHING AID SYSTEl

Technical Field

The present inversion relates to a regulator unit and a system for on-demand dispensing of a liquid. gaseous or dry powder inhalant into a breathing system, as delated in the preamble of subsequent claim 1

Background Art

The present invention relates particularly to a dispensing regulator unit arranged for dispensing an inhalable substance of medical effect info breathing gas supplied horn a breathing system, such as a breathing apparatus for underwater activities.

In this connection, the term“breathing system * comprises the necessary components such as pressure containers, hoses, regulators and mouthpieces, which are typically included In an open-circuit (Fig. 1 ) or closed-circuit demand valve-controlled breathing apparatus

The term“breathing aid system * on the other hand refers to a breathing system which is modified for adding an inhalable substance to the breathing gas.

Without limiting the scope of the invention hereto, the Inhalable substance” referred to may include any therapeutic fluid, gaseous or dry powder system that provides a medicinal effect on, e g„ asthma, bronchitis, COPD or other lung conditions. Trie inhalable substance may contain a fluid e g. water to he dispensed into the breathing gas as prevention against dehydration.

As used herein, the ierrn“pressurized environment” refers to an environment which holds a pressure that is different horn the atmospheric pressure in air at sea level. Further in this disclosure, the term“breathing gas * Includes oxygen and/or mixtures of oxygen with other gas which may he added in order to prevent decompression sickness or oxygen toxicity, e.g. Another term of frequent use in this presentation is the word“plunger’, which can he

understood as a moveable object at least partially powered and driven by, or against, a fluid or gas pressure

Although described herein essentially in connection with diving in water, embodiments of the invention can he implemented in breathing systems for ot er pressurized environments suets as in submerged vessels, in smoke filled buildings or at high altitudes, and trie invention shall not be restricted to diving.

However, divine in waters entails particular difficulties for persons with a breathing problem such as asthma, bronchitis or obstructive lung disease, in practice, persons with any kind of medical lung condition have hitherto been prevented from use of breathing systems required for sea diving, such as the SCUBA or the Aqua Lung breathing systems, e.g.

Medical drugs, such as hronchodiiators or corticosteroids, are generally administered in the form of a micronized dry powde or as a mist or aerosol wherein the medication is dissolved or suspended in a gas propellant. The medicine Is typically dispensed from a container via a mouthpiece that is put in the mouth of the user which inhales e released dose of the medicine together with Inhaled air. Among these commonly used devices are nebulizers, dry powder inhalers (DPI), metered ese inhalers ( DI) and soft mist inhalers (S I), designed to operation in air and at atmospheric pressure,

EP08158893 desrlhes a regulator having a valve that either opens or closes a breathing gas passage depending on the pressure differential between the breathing gas passage and a trie chamber. When the diver inbales, the valve will open trie breetrilng gas passage and when the diver exhales the valve will dose the passage. The solution does not have a dispensing chamber that is capable of bolding an inrialariio substance. The chamber is open to the breathing gas passage whenever the diver inhales. This results In ail the content of trie chamber being Inhaled by trie diver. If trie chamber contains a medicine, this medicine will be inhaled at trie first inhalation by the diver. When the diver exhales, any medicine left in the chamber will be blown out of the regulator. This means that there will be no medicine left after trie first respiration. Consequently, this known regulator Is not suitable for administering an inhaiariie substance on demand.

Summary of invention

It is an object of the present invention to provide means by which a breathing system for a

pressurized environment can be adapted for use by a person with asthma, or by a person suffering from other king or respiratory condition.

it is likewise an object of the present invention to provide a breathing aid system adapted for use by a person with asthma, or by a person sabering from other lung or respiratory condition, in a pressurized environment.

The above stated first object is met in a dispensing regulator unit comprising a housing which defines a dispensing chamber lor an inhaiable substance; a coupling interface for connecting the housing to a breathing gas passage; a dispensing channel connecting the dispensing chamber to the breathing gas passage; and a use actuated demand valve maneuverable tor permitting how communication between the dispensing chamber and the breathing gas passage upon demand by a user, said breathing gas passage allowing passage of breathing gas irrespective of the position of the demand valve.

The inha!abfe substance as also mentioned in the introduction may be one of; a gaseous, a liquid or a dry powder medical substance, such as asthma, bronchitis or CORD medicine, or a substance for preventing dehydration

A benefit and technical effect provided by this solution is that medicine or humidify can be administered below the water surface in the form of an aerosol or as a colloidal suspension.

According to one embodiment, the demand valve comprises a dose metering valve or a fixed diameter orifice. When comprising a dose metering valve, the embodiment offers dispensing of individually sized doses of inhaiable substance. When comprising an orifice with a fixed diameter, the embodiment typically oilers aerosoilxatlon of a liquid or gas substance for inhalation.

According to one embodiment, a plunger is arranged movable In the housing, the plunger dividing the housing into a compressible dispensing chamber and an expandable compensation chamber. An elastic member, such as a coiled spring e.g., arranged In the compensation chamber is effective for urging and biasing the plunger towards the dispensing chamber

A technical effect provided by the spring-loaded plunger is that it offers an ability to preload the dispensing regulator unit with a discharge force component which can be adapted to the subject inhalant, to the environmental pressure and to the breathing gas pressure. According to one embodiment, a pressure communication channel is arranged connecting the compensation chamber with the breathing gas flow, the pressure communication channel, which may contain a check valve, introducing breathing gas pressure into the compensation chamber.

A technical effect provided by this solution is that a variation In breathing gas pressures between inhalation and exhalation is available as another discharge force component.

According to further embodiments of the invention, the dispensing chamber communicates with a dose metering chamber of either a fixed or variable volume via a dose release channel which is formed in tire plunger. The dose metering chamber on the other hand communicates with a supply of inhalable substance via a dose filling channel which Is formed in the plunger.

These embodiments provide several technical effects: primarily, the dosage size can in this way be adapted to customer needs, and the return movement of the plunger is operatively utilized fo preparation of the dispensing regulator unit for a subsequent inhalation and dispensing sequence.

According to one embodiment, the compensation chamber is subjected to environmental pressure applied from the ambient media. This solution, which may comprise a flexible diaphragm that separates the compensation chamber from fee ambient media, provides several technical effects depending on Its application: on one hand, when applied to the compensation chamber, fee environmental pressure can be utilized as a discharge force component during an inhalation sequence, and if applied to the dose metering chamber on the other hand, the environmental pressure can be utilized for compensation of dosage size in relation to environmental pressure.

The embodiments as herein described (e,g.) can have Incorporated a measuring device or similar for indication of fill level.. These can be made as pop out Indicators reacting on pressure, proximity sensors, flag indicators, magnetic switch indicators, pin indicators ate,

None of these fill level indicators are shown in any of the drawings, as they are to be found in several oilier applications, and as such, are already known techniques. According to ne embodiment another pressure communication channel connects the dispensing chamber to the breathing gas flow, this pressure communication channel introducing breathing gas pressure Into the dispensing chamber, such as via a one-way valve in the pressure communication channel. This embodiment operates without the plunger and spring and provides simplicity In design. Operatively, the dispensing chamber is pressurized e static breathing gas pressure via the pressure communication channel during exhalation. At Inhalation, the pressure communication channel closes whereas the dispensing channel opens for discharge ef inha!ab!e substance into the flow of breathing gas, if the demand valve is actuated. Discharge into the breathing gas flew occurs instantly as a result of the slightly reduced static pressure and the high increase In dynamic pressure in the flowing breathing gas. in this embodiment, release of inhaiabie substance on demand can be accomplished by meatus ef a user maneuverable valve that simultaneously opens and closes, or vice versa, the dispensing channel and the pressure communication channel respectively.

According to one embodiment the demand valve is electrically operated. This embodiment provides the technical advantage of possibility for remote control, and enhanced freedom of Installation point In a breathing system.

In several embodiments the housing has coupling means tor connecting the dispensing chamber w th a canister/container providing supply of inhaiabie liquid, gaseous or dry powder substance. The inhaiabie substance may be stored under pressure In a pre-pressunaed cenistar/conlalner, If appropriate.

In another aspect of the Invention, the above stated second object is met in a breathing aid system for a pressurized environment, comprising e breathing system having a high-pressure breathing gas container, a first pressure reducing valve, a breathing gas connection at medium or Intermediate pressure level, an inhalation device fe.g. a mouthpiece) Including a second pressure reducing valve, delivering breathing gas at Inhalation pressure, wherein flow of breathing gas from the high-pressure breathing gas container to the inhalation device Is initiated upon demand by a user. The breathing aid system comprises a dispensing regulator unit for dispensing inhaiabie liquid, gaseous or dry powder inhalabie substance Into breathing gas, the dispensing regulator unit comprising:

* a housing defining a dispensing chamber for the inhalabie substance, and a coupling interface for connecting the housing to the breathing system,

* a dispensing channel connecting the dispensing chamber to a breathing gas flow,

* a demand valve maneuverable for permitting flow communication

between the dispensing chamber and the breathing gas flow upon demand by the user.

Further details, advantages and technical effects will appear below from drawings and from the following detailed description of embodiments.

Short description of the drawings

Embodiments of the invention will be more closely described below with reference made to the accompanying schematic drawings, wherein

Fig 1 Is a simplified illustration and overview of a breathing system for diving, fig. 2 is a sectional view showing a first embodiment of a dispensing regulator unit for a breathing alb system.

Fig. 3 is a sectional view snowing a dose metering demand valve for a

dispensing regulator unit in dose-metering mode,

Fig. 4 is a sectional view shewing the dose metering demand valve of Fig, 3 in dose-release mode.

Fig. 5 is a sectional view showing a dispensing regulator unit of alternative design, shown in dispensing chamber pressurizing mode,

F g. 6 i a broken away sectional view showing a cut out portion of the

dispensing regulator unit of Fig. 5 In medical substance discharging mode.

Fig, 7 is a sectional view showing a dispensing regulator unit of alternative design, Hg. a Is a sectional view showing a dispensing regulator unit and demand valve of yet an alternative design, Fig, 9 Is a broken away sectional view showing a portion of a dispensing regulator unit and dose metering valve wth a metering chamber of variable volume, responsive to ambient media pressure, and

Fig. 10 is a symbol diagram over a breathing aid system comprising a

dispensing regulator unit embodiment In accordance with the invention.

Detaile description of the invention

For the detailed disclosure it shall be pointed out that trie accompanying drawings are merely illustrative and not true to scale, and that no conclusions on dimensions or proportions should be based on these schematic drawings.

A breathing system 1 suitable for implementation of a dispensing regulator unit 2 in accordance with the present invention Is illustrated briefly in Fig. 1. The breathing system 1 is conventionally composed for underwater activities and comprises a high-pressure container 3 suitable for storing breathing gas which may be compressed to a pressure in the order of 100-300 bar (a) or 10-30 MPa, typically. A first stage regulator 4, which can be responsive to the ambient media pressure (i.e, the water pressure at the subject depth), reduces the high pressure gas in the container to an intermediate pressure level in the order of about 10 bar (a) or 1 MPa. Breathing gas at this intermediate pressure level is conveyed via a flexible hose 5 to a second stage regulator 6, the latter typically comprising a mouthpiece for a biting grip by the user or in some applications a helmet mainly lor underwater working operations.

When re-breathers are used, trie C02 is removed and 02 is recycled while necessary 02 is constantly given in accordance with the equipment settings and ambient pressure. However, the principle of giving adequate breathing gas to the user while being submerged, is basically the same as the open-circuit shown In fig. 1.

By moans of a restriction valve and a lever mechanism which is actuated upon by a flexible diaphragm, the second stage regulator 6 is responsive to the ambient media pressure to deliver breathing gas for inhalation at a pressure which is substantially equal to the pressure of the ambient environment. Exhalation of used breathing gas to the ambient is accomplished via an exhaust valve in the second regulator.

The structure and operation of a conventional breathing system for diving Is commonly known by persons of the diving community and requires no detailed explanation here.

The dispensing regulator unit 2, the particulars of which will be more closely explained below, can be integrated at various locations In the breathing system 1; an the first stage regulator 4, on the hose 5, or on the second stage regulator 6.. Thus, depending on location In the breathing system, the dispensing regulator unit of the present invention can be equipped to operate on breathing gas at either of a pressure separately reduced from the first stage regulator or equipped to operate on the reduced intermediate pressure delivered from the first stage regulator, or equipped to operate on the ambient media pressure, as an operative force component for dispensing of an inhalable substance Into the breathing gas. As to the second stage the dispensing regulator unit may bo equipped to operate on the Intermediate pressure or, in the case the regulator unit is directly attached onto the second stage (e.g. mouthpiece), equipped to operate on a pressure which may be manually set before diving.

With reference to Fig, 2, one embodiment 20 of the dispensing regulator unit 2 comprises a housing 21 which is adapted tor holding a supply of inhalable substance within its interior, A plunger 22 Is arranged movable In the housing 21 , The plunger 22 divides the housing Interior into a dispensing chamber 23 and a compensation chamber 24, An elastic member, here a coll spring 25, preloads the plunger 22 towards the dispensing chamber 23. A pressure communication channel 26 transmits system pressure to the compensation chamber 24. The dispensing chamber 23 is oonnoctabie to a breathing gas passage 2? via a dispensing channel 26. A demand valve 26 in the dispensing channel 28 Is maneuverable for permitting how communication between the dispensing chamber 23 end the breathing gas passage 2? upon demand by the user. In the schematic illustration of Fig. 2, by way of example, the demand valve 29 is Indicated to be a pivot valve here shown in closed position. A fixed diameter orifice 30, effective as atomizer or aerosolizer upon discharge of a liquid or gaseous substance, may be arranged In the demand valve 29 or optionally arran ed in the dispensing channel 28, Connectors 31 and 32 provide a coupling interface by which the diepensing regulator unit 20 is connectable in flow communication with a breathing gas flow F in the breathing system

Charging the dispensing chamber 23 with inha!abie substance is accomplished 5 via a Fill valve 33/34. An indloaier (not shewn) may ha arranged to indicate the nine level, ae appropriate.

In F g. 2 the dispensing regulator unit 20 is shown in its charged state if under inhalation the demand valve 29 Is set in open mode, the dose of substance In the dispensing chamber 23 will be discharged into the breathing gas passageo 27, Discharge will result regardless of internal pressure in the dose of

substance, filling the dispensing chamber 23 in Fig, 2. Discharge is effectuated and driven by the combined forces of the spring 25 and the system pressure introduced In the compensation chamber 24, the sum of these forces always exceeding the static pressure in a breathing gas flew at the mouth 35 of thes dispensing channel. If appropriate, an inlet 36 to the pressure communication channel 28 may be directed towards the flow F to take full advantage of the dynamic pressure in the breathing gas flow F.

The discharge of inha!ahle substance into the breathing gas How F may be further enhanced and accelerated through the utilization of a Venturi effect. Theo Venturi effect can be accomplished and enhanced if optionally the breathing gas passage 27 is formed with a region of reducing inner diameter !Dr upstream of the mouth 36 of the dispensing channel as seen in the flow direction F, followed by a region of increasing inner diameter IDs downstream of the mouth 35. With reference to Figs. 3 and 4, showing a dose metering demand valve 40$ in dose-metering and dose-release modes respectively. The dose metering demand valve 40 can alternatively serve as a dose metering demand valve in the dispensing regulator unit 20 of Fig 2, or in any subsequently described embodiment of the invention.

The dose metering demand valve 40 comprises a plunger 41 arranged movable0 in a housing 42. The plunger 41 divides the housing interior into a dose release space 43 and a plunge head space 44, A spring member 45 preloads the plunger towards the dose release space 43. A pressure communication line 46 transmits breathing gas system pressure, into the plunger head space 44 A demand valve outlet 4? sets the dose release space 43 in flow communication with a breathing gas flow f in the breathing gas passage 48 Connectors 46 and 50 provide a coupling interlace by which the dose metering demand valve 40 Is connectable in flow communication with a breathing gas How in the breathing system.

Charging the dispensing regulator unit with inhalabie substance or medicine is accomplished via a fill port (such as 34 In F g. 2), which ma contain a pressure connection and/or check valve, if appropriate.

In dose-metering mode, see Fig. 3, the plunger 41 is forced by the spring 45 and system pressure into an extended position wherein the plunger provides communication between a dose metering chamber 52 and a dispensing chamber 53 (Illustrated in dashed lines) of inhalabie substance. Filling the dose metering chamber 52 itts inhalabie substance from the dispensing chamber 53 is accomplished via the plunge fit! port 51 and a dose filling channel 54 formed in the plunger. The dose filling channel 54 runs between entries 55 and 56 which open in the side of the plunger. The distance between the entries 56, 56 is determined such that the entries are simultaneously placed in register with the plunger nil port 51 and the dose metering chamber 52 respectively, in this position the dose metering chamber 52 can he filled with inhalabie substance from a pressurized or pro-pressurized dispensing chamber 53. The pressure required for discharge of inhalabie substance from the dispensing chamber 53 into the dose metering chamber 52 may be introduced via pressure

communication line 46 providing breathing gas pressure.

in dose-metering mode, communication via the valve outlet 47 is prevented by the plunger in its extended position.

in dose-release mode, see Fig, 4, the plunger 41 is pushed against the force of the spring 45 into a retracted position through the operation of a lever SB, which can be manually or electrically actuated, in the retracted position, the dose metering chamber 52 is set in flow communication with the dose release space 43 via a dose release channel 59 which runs from a side entry 60 to an exit 61.

In this retracted position of the plunger, the entries 55, 56 to the dose filling channel 54 arc blinded and out of register with the fill port 51 and the dose metering chamber 52. Upon release of the lever 58, the plunger Is again extended and driven by the combined forces of the spring 45 and the system pressure for releasing the !nha!ab!e substance in the dose release space 43 into the flow of breathing gas In the passage 46.

Means am advantageously provided for changing the volume of the dose metering chamber 52, thereby adapting the size of the close to user needs. In Figs. 3 and 4 the means for varying the volume of the close metering chamber 52 Is schematically Indicated by a nut 62 which runs on an inner thread 63 to be set at a predetermined Insertion depth in the dose metering chamber.

The size of the dose, l.e. the volume of the dose metering chamber 52, may alternatively be made dependent on the ambient media pressure In order to adapt the medical effect achieved from a medical substance, whan

administered at different ambient pressures and different inhalation gas pressures.

With reference to Fig. 9 a close metering chamber 52 Is termed in a cylindrical cavity, the dose metering chamber housing a plunger 64 which Is movable In the cylindrical cavity. The plunger 64 has an inner end 65 terming a sliding wail to the dose metering chamber 52. The other end of the plunger carries a flange 66 which Is journaled io a radially widened extension 6T of the cylindrical cavity (o if appropriate, depending on the physical effect of the specific medical substance in use, also radially narrowed) if appropriate, depending on the physical effect of the specific medical substance in use, the medical substance may be increased with increasing anfeienf pressure as opposed to the solution as shown in Fig. 9 A ooil spring 68, acting between the flange 66 and a radial shoulder 66 which connects the radii of the dose metering chamber 52 and the widened extension 67, urges the plunger 64 towards an ultimate extended position corresponding to the maximum possible volume of the dose metering chamber 52, A retainer nog 70 or similar maintains the plunger and spring seated in the dose metering chamber.

The plunger 64 Is responsive to the ambient pressure via an opening 71 In the retainer ring 70, Ambient media may either be allowed to act directly towards an outer ace 72 of the flange 66, or ambient media pressure may if appropriate be transmitted via an elastic diaphragm which covers the opening in the retainer ring increasing ambient pressure will urge the plunger further inwards, this way reducing the volume In the dose metering chamber 52 The volume of the extension 67 which is defined on that side of the flange which is opposite from the face 72 can be ventilated to the ambient or to the breathing system, as appropriate, via a cavity 73 formed in the housing 74. An orifice of very small diameter or any other suitable device may ba arranged between the cavity 73 and tie breathing gas channel. This is only an example of how to avoid pressure entrapment in the cavity 73 and must not he understood as an open communication channelfwide open orifice between cavity 73 and the breathing gas channel.

Another embodiment 30 of the dispensing regulator unit will now be described with reference to Figs. 5 and 8, showing the dispensing regulator unit 80 in pressurizing and discharging modes respectively.

The dispensing regulator unit 80 comprises a housing 81 defining a dispensing chamber 82 which is adapted fur holding a supply of inbalabla substance within its interior. The dispensing chamber 82 is connectable to a breathing gas passage 33 via a dispensing channel 84. A demand valve 85 Is maneuverable ter permitting flow communication between the dispensing chamber 82 and a breathing gas flow in the passage 83 vie the dispensing channel 84 upon demand by the user. Filling the dispensing chamber 82 with !nha!ah!e substance is accomplished via either the fill valve 86 or 87. The former optional till valve 86 is typically for dry powder supply. The latter optional fill valve 87 Is typically fo gaseous or liquid supply and contains a pressure connection and check valve, if appropriate. Connectors 89 and 90 provide a coupling interface by which the dispensing regulator unit 80 is connectable In flow communication with a breathing gas flow F.

In the embodiment 89, the dispensing chamber 62 is pressurized by system pressure which is introduced via a pressure communication channel 91 connecting the dispensing chamber 82 and the breathing gas passage 83, It can be in parallel with the dispensing channel 84, however not necessarily, though in the drawing shown as such. In the illustrated embodiment, the demand valve 65 serves fo alternating opening and dosing the dispensing channel and the pressure communication channel respectively. To this purpose, the demand valve 86 is realized as a pushrod formed with first and second restrictions 92 and 93, respectively, located along Use circumference of a valve s body 94 The length of the valve body 94 between the restrictions is adapted to the distance between the channels 84- and 91 such that only one channel at the time Is placed In register with the associated restriction 92 or 93, and thus opened towards the dispensing chamber, while the other channel Is sealed by the valve body or vice versa.. A check valve 95 in foe pressure communication ID channel 91 proverbs back flow from the dispensing chamber 82 into the

breathing gas passage. This and similar embodiments with a cheek valve e.g. s pressurizing the dispensing and/or compensation chamber, may have a dump valve to enable the pressurized dispensing chamber to be unpressurlzod, this enabling substance being filled in the dispensing chamber.

15 in charging mode, see Fig, 6, static pressure is introduced in the dispensing chamber via an open check valve 95 in the pressure communication channel 91 When supply of inhalable substance is demanded for during inhalation, the demand valve 85 is pushed to the position shown In Fig. 6, opening the dispensing channel 84 while simultaneously dosing the pressure

20 communication channel 91. An instant drop In static pressure in the breathing gas during the inhalation sequence results in discharge of inhalable substance from the dispensing chamber to the breathing gas flow F, driven by the pressure difference.

The demand valve 85 in the embodiment 80 is specifically useful for dispensing 25 of a dry powder substance into the breathing gas.

Next, another embodiment 100 of the dispensing regulator unit will be described with reference to Fig ?.

The dispensing regulator unit 100 comprises a plunger 101 arranged movable in a housing 102. The plunger divides the housing interior into a dispensing 30 chamber 103 and a compensation chamber 104. A spring member 105

preloads the plunger towards the dispensing chamber 103. A dispensing channel 106 sets the dispensing chamber 103 in flow communication with a reat ing gas flow a a breathing gas passage 10?, A fixed diameter orifice 108 may be arranged in toe dispensing channel 106 to generate aerosoiixation of an inhalahte substance upon discharge. Connecters 109 provide a coupling interlace by h ch the dispensing regulator unit 100 Is connectable in flow communication with a breathing gas flow in tee breathing system. Charging tee dispensing chamber 103 with inha!aele substance is accomplished via the fill valve 1 0, which contains a pressure connection and a check valve, it appropriate, A demand valve 111 is realized for example as a pushrod formed with a restriction 112 arranged in series with a valve body 113, The pushrod is biased by a spring 114 into the dosing position shown in Fig, ?, Driving the pushrod 111 towards tee right in Fig. ? sets the dispensing chamber In flow communication with the breathing gas flow via the dispensing channel 106 hr tee embodiment 100, the plunger 101 is subjected to ambient madia pressure which is applied to the plunger via a flexible diaphragm 115, sealing the bousing 102 and the compensation chamber 104 from the outer environment.

Another embodiment 120 of a dispensing regulator unit and demand valve is shown in Fig 8. The dispensing regulator unit 120 comprises a housing 121 defining a dispensing chamber 122 A dispensing channel 123 sets the dispensing diamber 122 In flow communication with a breathing gas flow F in a breathing gas passage 124, A fixed diameter orifice 125 may be arranged in the dispensing channel 123 to generate aerosol iza lion of inhalable substance upon discharge. Connectors 126 and 127 provide a coupling Interface by which tee dispensing regulator unit 120 is connectable in How communication with a breathing gas flow F in the breathing aid system,

The embodiment 120 comprises an electrically controllable demand valve 128. The demand valve 128 comprises a valve body 129 which Is normally closed and brought into sealing contact with a valve seat 130 arranged In tee mouth of the dispensing channel 123. in sealing position, a breathing gas flow can bypass the valve body 129 on each or either side thereof, inside the breathing gas passage 124. in the illustrated embodiment, the movements cf the valve body 128 are driven by an electric meter 131. Instead of the electric meter 131, an electromagnet or solenoid etc. may bo used in alternative embodiments. The valve body is provided an opening and a closing motion by rotation of a threaded motor shaft 132 h ch engages an internal thread 133 in the valve body while the valve body Is prevented from rotation through the mutual engagement between Uneat guide elements (not Illustrated) formed in the housing end on the exterior of the valve body. The motor 131 is powered from an accumulator 134, whilst drivirm power may be portioned via a step motor control 135 e g. Valve motion is Initiated by actuation of a contact means 136.

The contact means 136, such as a toggle switch e.g„ can be designed to react on pressure applied by the user.

Fig. 10 is a symbolic diagram illustrating a breathing aid system 200 in accordance with the present invention.

The breathing aid system 200 of Fig. 10 thus comprises a breathing gas container 201 containing breathing gas at high pressure. A firs! stage regulator 202 contains an adjustable restriction which, in the subject case, is responsive to the ambient media pressure for delivering breathing gas at an Intermediate pressure to a second stage regulator 203, via a conduit 204. The second stage regulator 203 is responsive to ambient media pressure and to breathing gas pressures In inhalation and exhalation for delivering breathing gas at a pressure that is adapted to the pressurized environment, and for ventilation of exhaled gas to the ambient.

A dispensing regulator unit 205 Is in the subject case connected to breathing gas of intermediate pressure level. Physically, the dispensing regulator unit 205 may alternatively be connected to either of the first or second stage regulators or to the conduit 204 so as to operate on the breathing gas pressure which Is available at each alternative location. The dispensing regulator unit 205 might comprise, or be filled by, a container 206 containing inhalabie substance in liquid, gaseous or soiid/powder phase, which is stored in the container 206. In practice, the container 266 may be an integral part of the dispensing regulator unit 205. Inhalabie substance in the container 206 can be portioned into a dispensing chamber 207 via a fill/supply valve 208. The dispensing chamber 207 can be set in flo communication with the breathing gas flow in the conduit

204 via a dispensing channel 209, optionally containing a fixed diameter orifice 210. A demand valve 211 , normally dosed, presides Hew communication from the dispensing chamber to a breathing gas flow in conduit 204 upon actuation 18 b the usee The dispensing chamber 207 has a compressible volume in a housing containing a movable plunger 212, the plunger separating the dispensing chamber 20? front a compensation chamber 213 The compensation chamber 213 is In flow communication with the intermediate breathing gas pressure via pressure communication channel 214, leading dynamic and static breathing gas pressure into the compensation chamber tor pre-tensioning of the plunger 212 towards the dispensing chamber 207 A spring 215 In the compensation chamber adds to pre-tensioning of the plunger n the direction of discharge and dispensing

An alternative installation of the dispensing regulator unit 205 is indicated with dashed lines In Fig ID More precisely, a regulator 215 contains an adjustable restriction which reduces the high-pressure delivered from the breathing gas container 201 to an independent intermediate pressure to be delivered to the dispensing regulator unit 205, thus eliminating the need of the static and dynamic pressurization from the breathing gas intermediate pressure.

The dispensing regulator unit in the above described embodiments may comprise means to Indicate or monitor the 811 level of the inhaiable substance.