Patent Description:
Pressurised metered dose inhaler (pMDI) devices are the most popular and widely prescribed devices for respiratory drug delivery, with approximately <NUM> million manufactured each year.

In such devices, the active ingredient/drug is typically provided in the form of a solution or suspension held in a pressurised canister. Actuation of the canister is typically achieved by depressing the canister towards a main body of the device. This causes an interaction between the canister valve and a valve seat/stem block that causes a metered dose to be ejected from the valve, along with a propellant gas (typically a hydrofluoroalkane (HFA) gas). The dose becomes aerosolised and available for inhalation by the patient.

Dry powder inhaler (DPI) devices are an alternative to these aerosol-based inhalers in which a powdered respiratory drug may be held within a capsule, for example, which is perforated by the device as the patient inhales. Alternative drug formats include blisters and reservoirs. An insufficient inhalation rate will result in reduced dose delivery and incomplete de-aggregation of the powdered drug, potentially leading to poor control of the respiratory problem.

Whilst it may appear that these devices are easy to use, this is not the case: seemingly simple steps such as coordination of actuation of the device with inhalation, and inhaling at the appropriate flow rate are often performed incorrectly. This misuse of drug delivery inhaler devices can lead to drug wastage and ineffective treatment.

<CIT> discloses a device for providing an indication of the respiratory flow rate of a patient. The device includes two reeds adapted to generate an audible signal at different air flow speeds through the device. The first reed generates an audible signal of a first pitch when the air flow reaches a predetermined minimum and the second reed generates an audible signal of a second pitch when the air flow reaches a predetermined maximum. Thus, the patient is informed when the air flow is within a desirable range, between a predetermined minimum and maximum.

<CIT> discloses an adaptor that may be fitted to a pMDI inhaler that incorporates an air flow rate indicator comprising a reed which oscillates and generates a sound signal at a predetermined minimum level suitable for delivery of the drug to the patient.

It is known that pMDls, for example, can differ in internal resistance. Examples include the relatively high resistance Atrovent® pMDI and the low resistance Flutiform® pMDI. When the patient inhales, air is drawn through the device via channels surrounding the canister in the pMDI. It is easier for air to passage through a low resistance inhaler than through a high resistance inhaler. DPI devices function via turbulent de-aggregation of the powder formulation. The turbulence property is differently sized within each device depending on its technical design. There are high, medium, and low resistance DPI devices. Patients, who may be using multiple inhaler types and drug formualations, are advised and tutored to inhale through their pMDI between approximately <NUM> - <NUM>/min inspiratory flow rate, and through their DPI device at a much higher rate, approximately <NUM>/min inspiratory flow rate. Inspiratory flow can also vary with the patient's ability, often dictated by disease severity. It is possible to anticipate clinical situations in which patients are both thoroughly confused and not capable of reproducing the ideal inspiratory flow rate for each device they may be required to use to control their disease.

The following inhalers for acoustically indicating a fluid flow rate through the device are also known, namely <CIT>, <CIT>, <CIT> and <CIT>.

There is a desire to provide an improved air flow rate indicator for such devices (e.g. drug delivery inhaler devices including pMDIs and DPIs) that has a simple construction and improves a user's inhaling technique, to thus reduce drug wastage and provide effective treatment.

In a first aspect, there is provided an inhaler device comprising: an open tube whistle; and a mouthpiece in fluid communication with an external opening of the inhaler device and a first end of the open tube whistle, wherein an inner diameter of the open tube whistle has a stepped profile such that, upon user inhalation through the mouthpiece, an audible/sound signal is generated at a predetermined fluid flow rate through the open tube whistle.

When a user inhales on the mouthpiece, air is drawn through both the external opening, and the open tube whistle. The stepped profile of the inner diameter of the open tube whistle acts as an acoustic impedance, such that, when the inhalation technique of the user is correct and the predetermined fluid flow rate is generated, an audible/sound signal is generated. The inventors have found that by providing the stepped profile of the inner diameter of the open tube whistle, a clear audible/sound signal is produced only when the fluid flow rate through the whistle is within a predetermined range of fluid flow rates. Thus, if the fluid flow rate through the whistle is too low, or too high, no (or a poor) audible/sound signal is produced.

The audible/sound signal provides feedback to the user that they have the correct inhalation technique. This helps to reduce drug wastage and provides effective treatment for the user/patient. Furthermore, the whistle provides immediate feedback to the user, thus efficiently teaching the user a correct inhalation technique.

As used herein, the term "open tube whistle" is to be understood as a whistle comprising a tube (e.g. a cylinder) which is open at both ends.

As used herein, the term audible signal is to be understood as a sound signal audible to (e.g. capable of being detected or heard by) a human and/or a computing device. In other words, an audible signal may be a sound signal including frequencies that can be detected/heard by a human and/or frequencies that can be detected by a computing device having a sound receiver.

The stepped profile of the inner diameter of the open tube whistle is to be understood such that that the inner diameter of the open tube whistle changes in a step-wise manner along its length. For example, an inner diameter of a first portion of the open tube whistle may be greater than an inner diameter of a second portion of the open tube whistle with a stepped transition therebetween. The stepped transition is considered to be a discrete transition, or reveal, between the first portion of the open tube whistle and the second portion of the open tube whistle. The audible/sound signal may be generated only when the fluid flow rate through the open tube whistle is within a predetermined range of fluid flow rates.

A second end of the open tube whistle may provide an additional external opening of the inhaler device. The second end of the open tube whistle may be at an opposing end of the open tube whistle to the first end of the open tube whistle.

In this way, the inhaler device may comprise a first fluid flow path extending between the mouthpiece and the external opening of the inhaler device, and a second fluid flow path extending between the mouthpiece and the second end of the open tube whistle.

The second fluid flow path through the open tube whistle may be separate and distinct from the first fluid flow path.

Air may be drawn to the mouthpiece via the external opening, and also via the additional external opening and therefore through the open tube whistle. When a user inhales through the mouthpiece, more air may flow through the inhaler device via the external opening than via the additional external opening (and therefore via the open tube whistle). For example, <NUM>-<NUM>% of the total air flow through the inhaler device may flow via the additional external opening (and therefore via the open tube whistle) in a single inhalation effort. More particularly, <NUM>-<NUM>%, and more particularly approximately <NUM>% of the total air flow through the inhaler device may flow via the additional external opening (and therefore via the open tube whistle).

Including the additional external opening in the inhaler device lowers the resistance (and therefore pressure drop) across the inhaler device because more air is able to flow through the device. The effect of the open tube whistle on inhaler device resistance may be dependent on the location of the open tube whistle, air flow bypass (i.e. first fluid flow path) and leakage rates (for example, via a dose counter of the inhaler device) of the first fluid flow path, and open tube whistle parameters.

In these embodiments, a uniform air resistance, and pressure drop, through the open tube whistle may be provided in any inhaler device which is designed to include the open tube whistle which sounds at a particular flow rate (e.g. designed with specific air flow bypass and leakage rates). Therefore, a uniform audible/sound signal is generated in any such inhaler device, which may help the user to establish whether or not they have the correct inhalation technique.

The open tube whistle may be completely internally embedded within the inhaler device. In these embodiments, a second end of the open tube whistle does not form an additional external opening. Instead, the second end of the open tube whistle may be in fluid communication with the external opening of the inhaler device. More particularly, there may be only one external opening in fluid communication with the mouthpiece in the inhaler device.

The second end of the open tube whistle (which may provide an additional external opening of the inhaler device), the first end of the open tube whistle, and an opening of the mouthpiece for communication with the mouth of the user may be substantially collinear. In this way, the second end of the open tube whistle and the mouthpiece may be on opposing sides of the inhaler device.

In some embodiments, the stepped profile of the inner diameter of the open tube whistle may comprise only one step. This may provide a simple sound generating mechanism which is easy to manufacture. Alternatively, the stepped profile of the inner diameter may comprise more than one step i.e. a plurality of steps such as two or more steps, three or more steps, four or more steps etc. Each step may have a same or similar height (e.g. rise) and/or width (e.g. run, going, or tread). Alternatively, the steps may have different heights and/or widths. The height and width of the steps may be chosen to generate sound with a specific (e.g. preferred) frequency.

In embodiments in which the stepped profile comprises only one step, the step may be closer to the second end of the open tube whistle, than the first end of the open tube whistle.

The inner diameter of a second portion of the open tube whistle adjacent to the second end of the open tube whistle (e.g. adjacent to the additional external opening) may be less than the inner diameter of a first portion of the open tube whistle adjacent to the first end of the open tube whistle.

The outer cross-sectional profile of the open tube whistle may be substantially circular, oval, barrel-shaped, or any other shape. The outer diameter of the open tube whistle may be substantially constant along its length. The inner cross-sectional profile of the open tube whistle may be substantially circular, oval or barrel-shaped.

Optionally, the open tube whistle may have an axial length of between <NUM> and <NUM>, preferably between <NUM> and <NUM>, more preferably between <NUM> and <NUM>. The inventors have found that if the axial length of the open tube whistle is increased, the frequency of the generated audible/sound signal will be lower, and conversely, if the axial length of the open tube whistle is decreased, the frequency of the generated audible/sound signal will be higher. Furthermore, if the rate of air flow through the open tube whistle increases or decreases, the frequency of the generated audible/sound signal will naturally become higher or lower, respectively.

The second portion of the open tube whistle having a smaller inner diameter may have an inner diameter of between <NUM> and <NUM>, preferably between <NUM> and <NUM>, more preferably between <NUM> and <NUM>. The first portion of the open tube whistle having the larger inner diameter may have an inner diameter of between <NUM> and <NUM>, preferably between <NUM> and <NUM>, more preferably between <NUM> and <NUM>. The ratio between the inner diameter of the second portion and the first portion may be between <NUM>:<NUM> and <NUM>:<NUM>, and preferably between <NUM>:<NUM> and <NUM>:<NUM>. The difference between the inner diameter of the first portion and second portion of the open tube whistle may be approximately <NUM>, for example.

The axial length of the second portion having the smaller inner diameter may be less than the axial length of the first portion having the larger inner diameter. The ratio of the axial length of the second portion to the axial length of the entire open tube whistle may be between <NUM>:<NUM> and <NUM>:<NUM>, for example. The ratio of the axial length of the second portion to the axial length of the entire open tube whistle may be between <NUM>:<NUM> and <NUM>:<NUM>.

The second portion of the open tube whistle having the smaller inner diameter may have an axial length between <NUM> and <NUM>, more preferably, <NUM> and <NUM>, and more preferably less than <NUM>. The inventors have found that providing the second portion of the open tube whistle having the smaller diameter with an axial length of less than <NUM> provides a loud and clear audible/sound signal.

Optionally, a side wall of the open tube whistle may define at least one lateral hole. The inventors have found that providing a lateral hole in the side wall of the open tube whistle acts to shorten the length of the open tube whistle, and that introducing a lateral hole in the side wall results in a higher frequency generated audible/sound signal.

The lateral hole may be provided in the first portion of the open tube whistle having the larger inner diameter. The inventors have found that moving the lateral hole from a position closer to the first end of the open tube whistle to a position closer to the second end of the open tube whistle results in an increase in frequency of generated audible/sound signal (i.e. being higher). In other words, when the lateral hole is provided closer to the step, the frequency of the generated audible/sound signal is higher than if the lateral hole is provided further from the step.

By changing the parameters of the open tube whistle (e.g. axial length, ratio of first and second portions, positioning of lateral holes etc.), resistance effects of the open tube whistle are altered and so the sound generated by the open tube whistle is altered. Different inhaler devices for different medications, or treatments could incorporate open tube whistles with different parameters, to thus help a user to differentiate between inhaler devices (and therefore different medications/treatments). However, the resistance of the open tube whistle may largely still be controlled by the air flow bypass rate through the first fluid flow path (and therefore via the external opening).

The inhaler device is preferably adapted such that the audible/sound signal is generated at an air flow rate of between <NUM> and <NUM>/min, and more preferably between <NUM> and <NUM>/min.

In some embodiments, the inhaler device may further comprise a stem block for location of a drug reservoir (e.g. canister), the drug reservoir being operable to deliver a dose of drug through a drug delivery output aperture into the mouthpiece for inhalation by the user. The stem block may act as a seat for location of the drug reservoir. The stem block may ensure a good fit with a canister valve stem in fluid communication with the drug reservoir such that leakage or failure does not occur. The stem block may differ in geometry to accommodate different canister valve stem types or formulation parameters, for example. The drug delivery output aperture (e.g. spray hole) may be included in the stem block, and may vary in diameter and length according to aerosol spray characteristics.

Optionally, the open tube whistle may extend through the stem block to be in fluid communication with the mouthpiece.

The drug delivery output aperture may be separate, distinct, and spaced from the first end of the open tube whistle.

The inhaler may comprise an upright main body for housing the drug reservoir. The mouthpiece may extend transversely from a lower end of the upright main body. The upright main body and the mouthpiece may be integrally formed.

The second end of the open tube whistle (and therefore the additional external opening of the inhaler device) and the mouthpiece may be on opposing lateral sides of the upright main body.

One or more balance protrusions may extend from the lower end of the upright main body and/or the mouthpiece. In some embodiments, one or more balance protrusions may extend from a bottom surface of the upright main body, wherein the bottom surface is at the lower end of the upright main body. The balance protrusion(s) may stabilise the inhaler device when the inhaler device is placed on a flat surface, by providing multiple points of contact with the flat surface. In some embodiments, multiple points of contact with a flat surface may be provided by the mouthpiece and at least two (e.g. a pair of) balance protrusions extending from the bottom surface of the upright main body, and this may stabilise the inhaler device when the bottom surface of the upright main body is placed on the flat surface (i.e. when the inhaler device is standing upright).

Optionally, the upright main body, the stem block and the open tube whistle may be integrally formed. For example, the upright main body, stem block and open tube whistle may be injection moulded as a single part. In this way, no assembly or disassembly of the inhaler would be required by the user, and the device would be simple to use.

In further embodiments, the upright main body, stem block, open tube whistle and mouthpiece may be integrally formed (e.g. injection moulded as a single part). In alternative embodiments the mouthpiece may be formed separately and thus reversibly detachable from/attachable to the integrally formed stem block, upright main body and open tube whistle.

In other embodiments, the open tube whistle may be reversibly and slidably receivable in the inhaler device. For example, the open tube whistle may be reversibly and slidably receivable in the upright main body. The open tube whistle may be reversibly and slidably receivable in the stem block. In these embodiments, the open tube whistle and the stem block may be formed as separate components of the inhaler device.

In other embodiments, the stem block and the open tube whistle may be integrally formed. For example, the stem block and the open tube whistle may be injection moulded as a single part. The single-part stem block and open tube whistle may be reversibly and slidably receivable in the inhaler device. Specifically, the single-part stem block and open tube whistle may be reversibly and slidably receivable in the upright main body (which may or may not be integral with the mouthpiece). In this way, a user may assemble/disassemble their own inhaler device. By providing the single-part stem block and open tube whistle separately from the remaining parts of the inhaler device (e.g. the upright main body and mouthpiece), some components of the device can be reused. Accordingly, the inhaler device has improved sustainability, by improving the reusability of many components of the inhaler device, and reducing the burden on recycling and landfill.

The single-part stem block and open tube whistle may alternatively be irreversibly fixed within the inhaler device, and specifically within the upright-main body (e.g. during manufacture). In this way, a user is not required to assemble their own inhaler device, thus making use of the device simpler.

Optionally, the open tube whistle, stem block and upright main body may be formed as separate components of the inhaler device. Optionally, the open tube whistle, stem block, upright main body and mouthpiece may all be formed as separate components of the inhaler device.

By providing the components of the inhaler device separately, any contaminated (e.g. drug-contaminated) components of the inhaler device (such as the stem block and the drug reservoir) can be removed and disposed of, whereas other components of the inhaler device (such as the open tube whistle, the upright main body and the mouthpiece) can be reused. Accordingly, the inhaler device has improved sustainability, by improving the reusability of many components of the inhaler device, and reducing the burden on recycling and landfill.

When the open tube whistle, stem block and upright main body (and optionally the mouthpiece) are formed as separate components of the inhaler device, the stem block may be reversibly and slidably receivable in the upright main body, and the open tube whistle may extend through the stem block to lock the stem block to the upright main body.

Accordingly, in these embodiments, not only does the open tube whistle provide audible feedback to a user to indicate when the user is inhaling correctly, the open tube whistle also acts as a locking mechanism to lock the stem block to the upright main body. The open tube whistle can therefore be incorporated as a sliding locking component to engage and disengage the removable stem block from the upright main body. This helps to improve sustainability.

Furthermore, stem blocks can often be prone to shrinkage during injection moulding/manufacturing process due to material thickness. Deformation of the stem block may occur for this or other reasons. In order to address this problem, it is known to include a cut-out below the drug delivery output aperture, which is formed purely to prevent this deformation. However, by providing the open tube whistle, stem block and upright main body as separate components, and by using the open tube whistle as a locking mechanism to lock the open tube whistle to the upright main body, this cut-out in the stem block is no longer required. This is because the open tube whistle, stem block and upright main body are not manufactured in a single injection moulding process, and so the stem block of the present disclosure is no longer prone to shrinkage during manufacture. This helps to improve manufacturability, quality and appearance of the inhaler device.

A counter may be arranged within the upright main body and the open tube whistle may extend through the counter for fluid communication with the mouthpiece. The counter may count the number of user actuations of the inhaler device.

The open tube whistle and counter may be integrally formed.

Alternatively, the counter, open tube whistle, upright main body, and optionally stem block, may be formed as separate components. In these embodiments, the open tube whistle may be reversibly and slidably receivable in the counter. Removing the open tube whistle from the counter may automatically reset the counter.

The counter may be reversibly and slidably receivable in the upright main body, and the open tube whistle may extend through the counter to lock the counter to the upright main body. The open tube whistle therefore also acts as a locking mechanism to lock the counter to the upright main body. The open tube whistle can therefore be incorporated as a sliding locking component to engage and disengage the removable counter from the upright main body. This further helps to improve sustainability.

Optionally, the inhaler device may further comprise a magnifying lens. The magnifying lens may be arranged to enhance the visibility of the counter, and specifically a number of user actuations of the inhaler device indicated by the counter. In other words, the magnifying lens may magnify the number of user actuations of the inhaler device indicated or displayed by the counter, for improved visibility.

The stem block, open tube whistle and magnifying lens may be integrally formed. Specifically, the stem block, open tube whistle and magnifying lens may be formed (e.g. injection moulded) as a single part. This single-part stem block, open tube whistle and magnifying lens may be reversibly and slidably receivable in the inhaler device, and specifically in the upright main body. It may be secured in the upright main body by an interference or snap fit connection. It may further comprise a pair of assembly tabs to aid the insertion and removal of the single-part stem block, open tube whistle and magnifying lens in the upright main body. In this way, a user may assemble/disassemble their own inhaler device. By providing the single-part stem block, open tube whistle and magnifying lens separately from the remaining parts of the inhaler device (e.g. the upright main body and mouthpiece), some components of the device can be reused. Accordingly, the inhaler device has improved sustainability, by improving the reusability of many components of the inhaler device, and reducing the burden on recycling and landfill.

The single-part stem block, open tube whistle and magnifying lens may alternatively be irreversible fixed within the inhaler device, and specifically within the upright-main body (e.g. during manufacture). In this way, a user is not required to assemble their own inhaler device, thus making use of the device simpler.

Alternatively, the stem block, open tube whistle and magnifying lens may be formed as separate components. In further alternative embodiments, the stem block may be formed as a separate component from the open tube whistle and magnifying lens which may be formed as a single component.

The magnifying lens may be formed from a transparent polymer material. When the stem block, open tube whistle and magnifying lens are formed as a single integral part, this single integral part may be formed from a transparent polymer material.

Optionally, the upright main body may comprise a locating feature for correctly positioning the stem block in the upright main body. The stem block may also comprise a locating feature which complements the locating feature on the upright main body. These complementary locating features on the upright main body and the stem block may correspond (e.g. interlock) with each other to thereby correctly position and align the stem block within the upright main body.

The stem block locating feature may be a locating protrusion and the main body locating feature may be a locating recess, the stem block locating protrusion being configured to interlock with the main body locating recess. Alternatively, the stem block locating feature may be a locating recess and the main body locating feature may be a locating protrusion, the main body locating protrusion being configured to interlock with the stem block locating recess.

In some embodiments, the upright main body may comprise a stem block receiving portion for receiving the stem block, the stem block receiving portion comprising the main body locating features. The stem block may be retained in the stem block receiving portion by a push-fit fitting.

Optionally, the inhaler device may comprise a stem block guider for guiding the stem block along one or more protruding ribs in the upright main body. The one or more protruding ribs in the upright main body may act as a guide rail to guide the stem block into the stem block receiving portion in the correct orientation and position. The stem block guider and the one or more ribs may have a sliding fit.

The stem block guider may be integrally formed with the stem block (i.e. as a single component). Alternatively, the stem block guider and the stem block may be formed as two separate and distinct components, which may interlock, or be attachable to one another.

Optionally, the open tube whistle may comprise a handle tab. This may help a user to slidably insert and remove the open tube whistle in the stem block. The handle tab may be adjacent to the second end of the open tube whistle, for example.

The open tube whistle may be biased into an assembled position in which the open tube whistle extends through the stem block. The open tube whistle may be biased into the assembled position by a snap-fit mechanism. Specifically, the open tube whistle may comprise a projection for biasing the open tube whistle into the assembled position. Alternatively/additionally, the open tube whistle may be biased into the assembled position by a spring mechanism.

The open tube whistle, the stem block, the mouthpiece and/or the upright main body may be formed of plastic.

The inhaler device may further comprise the drug reservoir. The external opening of the inhaler device may completely encircle the drug reservoir. When a user inhales, more air may flow through the inhaler device via the external opening of the inhaler device than via the additional opening of the inhaler device (and therefore via the open tube whistle).

The inhaler device may comprise a plurality (e.g. <NUM>, <NUM> or more) open tube whistles, wherein the plurality of open tube whistles may have different parameters to one another. In this way, the plurality of open tube whistles may generate audible/sound signals of different pitches/frequencies at different predetermined fluid flow rates through the respective open tube whistles. These audible/sound signals of different pitches/frequencies may indicate an upper and lower limit of a preferred fluid flow rate range, for example.

The inhaler device may be a drug delivery inhaler device. For example, the inhaler device may be a pressurised metered dose inhaler (pMDI) device. Alternatively, the inhaler device may be a dry powder inhaler (DPI) device, a breath-actuated pressurised metered dose inhaler, a soft mist inhaler, or a spacer.

The drug reservoir may contain an active ingredient/drug, which may be provided in the form of a solution or suspension. The active ingredient may be salbutamol, which is marketed as Ventolin® among other brand names. The drug reservoir may also contain a propellant formulation/gas, such as hydroflouroalkane (HFA) gas, in particular HFA152a, which is marketed as Zephex® 152a. In particular, the inhaler device may be a drug delivery inhaler device, comprising a salbutamol/HFA152a formulation.

Optionally, the audible/sound signal generated by the open tube whistle may be detectable by software. The software may be configured to monitor, record and analyse the fluid flow rate through the open tube whistle and/or to monitor, record and analyse breathing patterns, and to determine whether a user is using the inhaler device correctly (i.e. using the device too little or too often, for example).

Furthermore, the software may be configured to detect frequencies and harmonics of the audible/sound signal generated by the open tube whistle(s) which occur at predetermined fluid flow rates. The inventors have found that the fundamental frequency of the audible/sound signal is controlled predominantly by the axial length of the open tube whistle and the fluid flow rate, whereas other open tube whistle parameters (such as step length, inner diameter etc.) determine the harmonics, whistle quality and duration of the audible/sound signal. Therefore, software may be configured to detect different shaped open tube whistles (which could indicate different inhaler devices used for different medications/treatments) based on the monitoring and analysis of frequencies and harmonics of the generated audible/sound signal. The software may also be configured to provide feedback to a user via an application on a mobile device, or a smart speaker, for example.

According to a second aspect, there is provided a system comprising an inhaler device according to the first aspect, and a computing device having a sound receiver for detecting the audible/sound signal.

The computing device may be a mobile device, such as a mobile phone, for example.

The system may further comprise computer software for running on the computing device. The computing device may be configured to monitor, record and/or analyse the fluid flow rate through the open tube whistle and/or breathing patterns based on the audible/sound signal detected by the sound receiver, for example by detecting frequencies and/or harmonics of the audible/sound signal.

According to a third aspect, there is provided a method of monitoring use of an inhaler device, the method comprising:.

The method may further comprise recording (e.g. using computer software such as an application for running on a computing device) the duration, frequency and/or harmonics of the audible/sound signal. This information may be used to monitor use of the inhaler device by the user/patient. It can be used to ensure that the user had a correct inhalation technique.

The method may further comprise providing user feedback, via an application on a mobile device or a smart speaker, for example.

According to a fourth aspect, there is provided a kit of parts for indicating a desired fluid flow rate, the kit of parts comprising:.

The open tube whistle may be as described above with respect to the first aspect. The stem block may be as described above with respect to any option of the first aspect.

Therefore, the open tube whistle may have a stepped profile such that an audible/sound signal is generated at a predetermined fluid flow rate through the open tube whistle.

The kit of parts may comprise the drug reservoir. The drug reservoir may contain an active ingredient/drug, which may be provided in the form of a solution or suspension. The active ingredient may be salbutamol, which is marketed as Ventolin® among other brand names. The drug reservoir may also contain a propellant formulation/gas, such as hydroflouroalkane (HFA) gas, in particular HFA152a, which is marketed as Zephex® 152a. The kit of parts may further comprise an upright main body for housing the drug reservoir and the stem block, and/or a mouthpiece.

The kit of parts may be configured to be assembled to form the inhaler device as described above with respect to the first aspect.

According to a fifth aspect, there is provided a method of using an inhaler device for indicating a desired fluid flow rate, the method comprising the steps of:.

The inhaler device may be as described above with relation to the first aspect.

The method may further comprise using a locating feature on the main body for correctly positioning the stem block in the main body.

The step of locating the stem block in the main body may comprise receiving the stem block in a stem block receiving portion by interlocking a locating feature on the stem block with a locating feature on the stem block receiving portion.

Optionally, the method may further comprising using a stem block guider for guiding the stem block along one or more protruding ribs in the main body.

The method may further comprise the step of removing the open tube whistle from the stem block, and removing the stem lock from the main body by pushing the stem block from the main body via a hole in the main body.

According to a sixth aspect, there is provided an apparatus for indicating a desired fluid flow rate through an inhaler device, the apparatus comprising:.

The open tube whistle may be as described above with respect to the first aspect. Therefore the open tube whistle may have a stepped profile such that an audible/sound signal is generated at a predetermined fluid flow rather through the open tube whistle.

The stem block may be as described above with respect to the first aspect.

The apparatus may further comprise a magnifying lens. The magnifying lens may be as described above with respect to the first aspect. The stem block, open tube whistle and magnifying lens may be integrally formed.

According to a seventh aspect, there is provided a method of using an inhaler device for indicating a desire fluid flow rate, the method comprising the steps of:.

According to an eighth aspect, there is provided a system for monitoring breathing patterns of a user, the system comprising:.

The open tube whistle may be as described above with relation to the first aspect. The computing device may be a mobile device, such as a mobile phone, for example.

The system may further comprise computer software for running on the computing device. The computing device may be configured to monitor, record and/or analyse the fluid flow rate through the open tube whistle and/or breathing patterns based on the audible/sound signal detected by the sound receiver.

The open tube whistle of the system of the eighth aspect may be incorporated into an inhaler device, such as that described above in relation to the first aspect, although the eighth aspect is not limited to inhaler devices. Instead, the system of the eighth aspect may be configured to monitor breathing patterns of babies (while awake or asleep); first responders in extreme environments (e.g. monitor for stress and/or overexertion); pilots, high altitude climbers, mountain rescue or the military (to detect early signs of altitude sickness), scuba divers (to detect early signs of lung function problems), mine workers (to detect early signs of tachycardia or hypoxia) or animals (to identify lung abnormalities). For example, the open tube whistle may be incorporated into an oral mask assembly, as discussed in relation to the tenth aspect below.

The computing device may be configured to monitor a frequency (e.g. pitch) of the audible/sound signal, a duration of the audible/sound signal and/or a number of audible/sound signals produced in a predetermined period of time (e.g. per minute). Based on this monitoring, the computing device may be configured to detect a lung function condition and/or a lung function abnormality, such as eupnoea (normal breathing rate and pattern), tachypnoea (increased respiratory rate), bradypnoea (decreased respiratory rate), apnoea (absence of breathing), hyperpnoea (increased depth and rate of breathing), Cheyne-Stokes condition (gradual increases and decreases in respirations with period of apnoea), Biot's condition (abnormal breathing patterns with clusters of rapid respiration of equal depth and regular apnoea periods), Kussmaul breathing (tachypnoea and hyperpnoea) and apneustic respiration (prolonged inspiratory phase with a prolonged expiratory phase). Based on such a detection, the computing device may be configured to provide feedback, such as a warning, to a user or a health care professional, e.g. via a display.

Accordingly, to a ninth aspect, there is provided a method of monitoring breathing patterns of a user, the method comprising:.

The method may further comprise recording (e.g. using computer software such as an application for running on a computing device such as a mobile device) the duration and/or frequency of the audible/sound signal.

According to a tenth aspect, there is provided an oral mask assembly comprising a breathing mask for covering the mouth and nose of a user, and at least one open tube whistle incorporated into the breathing mask, wherein an inner diameter of the at least one open tube whistle has a stepped profile such that, upon user inhalation and/or exhalation when the breathing mask is covering the mouth and/or nose of a user, an audible/sound signal is generated at a predetermined fluid flow rate through the open tube whistle.

When a user is wearing the breathing mask such that the breathing mask is covering their mouth and/or nose, air is drawn through the open tube whistle. The stepped profile of the open tube whistle acts as an acoustic impedance, such that when a predetermined fluid flow rate is generated by the user inhalation and/or exhalation, an audible/sound signal is generated. As described above in relation to the first aspect, the inventors have found that by providing the stepped profile of the inner diameter of the open tube whistle, a clear audible/sound signal is produced only when the fluid flow rate through the whistle is within a predetermined range of fluid flow rates. Thus, if the fluid flow rate through the whistle is too low, or too high, no (or a poor) audible/sound signal is produced.

The incorporation of the open tube whistle into the breathing mask allows for monitoring of inspiratory and/or expiratory breathing patterns. In particular, the audible/sound signal may be audible to a human and/or a computing device, and thus the audible/sound signal frequency (e.g. pitch), the audible/sound signal duration and/or the number of audible/sound signals produced in a predefined period of time (e.g. per minute), may provide feedback to a user (directly, or via a computing device) to indicate a lung function condition and/or abnormality.

The open tube whistle may be as described above in relation to previous aspects.

The open tube whistle may be configured to generate an audible/sound signal at an (average) fluid flow rate of <NUM>-<NUM>/min. This audible/sound signal may indicate eupnoea (e.g. normal breathing rate and pattern). The open tube whistle may be configured to generate an audible/sound signal at an (average) fluid flow rate of ><NUM>/min. This audible/sound signal may indicate tachypnoea (increased respiratory rate).

The open tube whistle may extend through the breathing mask, between an internal side of the breathing mask (e.g. adjacent to the user's mouth and nose, in use) and an external side of the breathing mask.

As described above in relation to previous aspects, an inner diameter of a first portion of the open tube whistle may be greater than an inner diameter of a second portion of the open tube whistle with a stepped transition therebetween. The first portion of the open tube whistle having the greater inner diameter may be in fluid communication with (e.g. adjacent to) the internal side of the breathing mask and the second portion of the open tube whistle having a smaller inner diameter may be in fluid communication with (e.g. adjacent to) the external side of the breathing mask. Alternatively, the first portion of the open tube whistle may be in fluid communication with (e.g. adjacent to) the external side of the breathing mask and the second portion of the open tube whistle may be in fluid communication with (e.g. adjacent to) the internal side of the breathing mask.

The oral mask assembly may comprise a plurality of (e.g. two) open tube whistles incorporated into the breathing mask. One of the open tube whistles may be for generating an audible/sound signal at a predetermined fluid flow rate through the open tube whistle upon user inhalation, and the other may be for generating an audible/sound signal at a predetermined fluid flow rate through the open tube whistle upon user exhalation.

The stepped profiles of the plurality of open tube whistles may have different dimensions and/or geometries, and therefore may generate an audible/sound signal at different predetermined fluid flow rates and/or frequencies to indicate different lung function conditions, for example. For example, a first open tube whistle may be configured to generate an audible/sound signal at a fluid flow rate of <NUM>-<NUM>/min (therefore indicating eupnoea), and a second open tube whistle may be configured to generate an audible/sound signal at a fluid flow rate of ><NUM>/min (therefore indicating tachypnoea).

A main body of the breathing mask may be injection moulded from a polymer material such as silicone, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), polypropylene (PP) etc. A rim of the main body of the breathing mask may be configured to provide a tight seal to the user around the user's nose and mouth, in use. For example the rim may comprise rubber, a plastic/polymer, silicone and/or a foam (e.g. Polyvinyl Chloride, PVC), and may be lip-shaped for providing a tight seal to the user's skin. The oral mask assembly may comprise strap attachment means, such as loop buckles, strap handles or strap slots, for attaching to a strap configured to strap the oral mask assembly to the user's face.

The breathing mask may comprise a pair of one-way valves. A first of the one-way valves may be for user inhalation and a second of the one-way valves may be for user exhalation. Accordingly, the first one-way valve may only permit fluid flow from the external side to the internal side of the breathing mask, whereas the second one-way valve may only permit fluid flow from the internal side of the breathing mask to the external side of the breathing mask. The one-way valves may be assembled into the breathing mask via a snap-fit connection and/or an interference fit.

Additionally/alternatively, the breathing mask may comprise one or more bypass channels extending through the breathing mask between the internal and external sides of the breathing mask. Each bypass channel may comprise a hole or a slot and may act as a fluid/air leak point or fluid/air bypass. The bypass channel(s) (in addition to the open tube whistle dimensions) may help to adjust/control the resistance of the fluid (e.g. air) flow between the internal and external sides of the breathing mask. In particular, a bypass channel having a larger inner diameter will provide less resistance, and therefore enable less restrictive breathing, than a bypass channel having a smaller inner diameter. The size/geometry of the bypass channel(s), in addition to the open tube whistle(s) geometries, impacts the predetermined fluid flow rate at which the audible/sound signal is generated. In particular, the larger the inner diameter of the bypass channel, the greater the predetermined fluid flow rate at which the open tube whistle(s) generates an audible/sound signal.

The breathing mask may comprise a plurality of bypass channels. Each bypass channel may have a same/similar geometry (e.g. inner diameter), or the bypass channels may have different geometries (e.g. different inner diameters). For example, one or more bypass channels may be formed in fluid communication with (e.g. in, at or adjacent to) a respective one-way valve, and the bypass channel(s) formed in fluid communication with the one-way valve for user inhalation may have a different geometry/size to the bypass channel(s) formed in, at or adjacent to the one-way valve for user exhalation. Therefore, the resistance, and thus the acoustic performance of the open tube whistle (e.g. the predetermined fluid flow rate), is controlled for inhalation and exhalation separately, and with improved accuracy.

The one or more open tube whistles, one or more filters, and/or the one-way valves may be reversibly attachable to the main body of the breathing mask. In this way, the main body be (re)usable with replacement open tube whistles, filters and/or one-way valves.

The oral mask assembly may comprise one or more open tube whistles integrally moulded within the main body and/or an add-on component attachable to the main body of the breathing mask, wherein one or more open tube whistles are incorporated in the add-on component. The one or more open tube whistles may be integrally moulded in the add-on component.

The add-on component may be attachable to the main body of the breathing mask via a threaded connection, or a snap-fit or push-fit connection. The add-on component may comprise one or more bypass channels and/or a pair of one-way valves, as described above.

The breathing mask and/or the add-on assembly may comprise a filter. The filter may be an antimicrobial medical grade filter, for example.

The audible/sound signal may be detectable by a computing device, as described above. Alternatively/additionally, the audible/sound signal may be detectable by a human ear. The disclosure includes the combination of the aspects and optional features described above except where such a combination is clearly impermissible or expressly avoided.

Aspects and embodiments will now be discussed with reference to the accompanying figures.

<FIG> shows an exploded perspective view of a pressurised metered dose inhaler (pMDI) <NUM> adapted to deliver respiratory drugs to a patient. The pMDI comprises an upright main body <NUM> and a transverse mouthpiece <NUM> extending from a lower end of the upright main body <NUM>. The mouthpiece <NUM> has an opening for communication with the mouth of a patient. The upright main body <NUM> is substantially cylindrical (with a substantially cylindrical transverse cross-section) and the transverse mouthpiece <NUM> has a substantially oval or barrel-shaped transverse cross-section so that the mouthpiece <NUM> can easily form a seal with the patient's mouth.

The pMDI <NUM> further comprises a stem block <NUM> for location of a drug canister <NUM> for containing a respiratory drug. Although not shown in <FIG>, in an assembled state, the stem block is positioned at the junction between the upright main body <NUM> and the transverse mouthpiece <NUM>. In the assembled state, a canister <NUM> is inserted into the upright main body <NUM> and is housed in the upright main body <NUM>. The canister <NUM> is pressurised and contains the respiratory drug in the form of a liquid in solution or suspension.

In the assembled state, the mouthpiece <NUM> is in fluid communication with an external opening of the pMDI <NUM> surrounding the canister <NUM>.

The pMDI <NUM> further comprises an open tube whistle <NUM>. As shown in <FIG>, the open tube whistle is a cylindrical tube which is open at both ends.

In the embodiment shown in <FIG>, the upright main body <NUM> and mouthpiece <NUM> are integrally formed as a single plastic component, and the stem block <NUM> and open tube whistle <NUM> are formed as separate components. Although not shown in <FIG>, the open tube whistle <NUM> is insertable into the upright main body <NUM> such that a first end 10a of the open tube whistle <NUM> is in fluid communication with the mouthpiece <NUM>, and a second end 10b of the open tube whistle <NUM> forms an additional external opening of the pMDI <NUM>. The second end 10b of the open tube whistle (which provides the additional external opening of the inhaler device <NUM>) is on an opposing lateral side of the upright main body <NUM> to the mouthpiece <NUM>. Specifically, the second end 10b of the open tube whistle <NUM>, the first end 10a of the open tube whistle and the opening of the mouthpiece <NUM> are substantially collinear.

Accordingly, the open tube whistle <NUM> extends transversely (relative to the axial length of the upright main body) into the upright main body <NUM> of the pMDI <NUM>.

The open tube whistle <NUM> shown in <FIG> further comprises a handle tab 10c adjacent to the second end 10b of the open tube whistle <NUM>. The handle tab 10c is discussed in further detail below.

<FIG> shows an open tube whistle <NUM> for an inhaler device, such as the pMDI <NUM> of <FIG>, without a handle tab. The outer cross-sectional profile of the open tube whistle <NUM> is substantially circular, and the outer diameter of the open tube whistle is substantially constant along its length. As previously mentioned, the open tube whistle <NUM> is open at both ends.

The open tube whistle may have an axial length of between <NUM> and <NUM>.

<FIG> is a cross-section of the open tube whistle <NUM> of <FIG>, which illustrates the outer diameter and inner diameter of the open tube whistle <NUM>. The inner cross-sectional profile of the open tube whistle <NUM> is substantially circular.

The inner diameter of the open tube whistle <NUM> has a stepped profile having a single step between a first portion <NUM> and a second portion <NUM>. The first portion <NUM> of the open tube whistle <NUM> has a larger inner diameter than the second portion <NUM> of the open tube whistle, and the axial length of the first portion <NUM> of the open tube whistle <NUM> is greater than the axial length of the second portion <NUM> of the open tube whistle <NUM>. The stepped profile of the inner diameter of the open tube whistle <NUM> acts as an acoustic impedance within the whistle <NUM>, such that an audible/sound signal is only generated when a predetermined fluid flow rate is generated through the open tube whistle.

The second portion <NUM> of the open tube whistle <NUM> is adjacent to the second end 10b of the open tube whistle which forms the additional external opening of the pMDI <NUM>, and the first portion <NUM> of the open tube whistle <NUM> is adjacent to the first end 10a of the open tube whistle <NUM> (when the open tube whistle is inserted into the pMDI <NUM>).

To use the pMDI, a user places the mouthpiece <NUM> into their mouth and inhales. Air is drawn through the open tube whistle <NUM> via the additional external opening of the pMDI defined by the second end 10b of the open tube whistle <NUM>. When the air flow through the open tube whistle <NUM> is at a predetermined air flow rate (which may be between <NUM> and <NUM>/min), the stepped profile of the inner diameter of the open tube whistle <NUM> generates an audible/sound signal to indicate that the user is inhaling correctly. Therefore, a user is provided with instant feedback on their inhalation technique.

<FIG> are different perspective views of the stem block <NUM> of the pMDI <NUM>. The stem block <NUM> comprises a drug delivery output aperture <NUM>. When the stem block is positioned in the main body <NUM>, the drug delivery output aperture <NUM> is in fluid communication with the mouthpiece <NUM> such that the drug canister <NUM> can deliver a dose of drug through the drug delivery output aperture <NUM> into the mouthpiece <NUM> for inhalation by the user. Specifically, when a user actuates the drug canister <NUM> (typically by depressing the canister <NUM> downwards into the upright main body <NUM>), an interaction between the canister <NUM> and the stem block <NUM> causes a metered dose of liquid drug to be ejected from the drug delivery output aperture <NUM> into the mouth of the user via the mouthpiece <NUM>, along with a propellant gas. In this way, the liquid drug is aerosolised for inhalation by the user.

The stem block <NUM> has a passage <NUM> extending therethrough for receiving the open tube whistle <NUM>. The passage <NUM> is spaced from the drug delivery output aperture <NUM>. The stem block <NUM> also comprises a locating protrusion <NUM> for correctly positioning the stem block <NUM> in the main body <NUM>.

Specifically, as shown in <FIG>, the stem block locating protrusion <NUM> helps to correctly position the stem block <NUM> in a stem block receiving portion <NUM> of the main body <NUM>. The stem block receiving portion <NUM> has a corresponding locating recess <NUM> which interlocks with the stem block locating protrusion <NUM> when the stem block <NUM> is correctly positioned in the stem block receiving portion <NUM>. Accordingly, the stem block <NUM> can be easily and accurately assembled in the main body <NUM>. The stem block <NUM> can be pushed into and retained in the stem block receiving portion <NUM> by a push-fit fitting, as shown in <FIG>.

In <FIG>, the open tube whistle <NUM> is in a first position in which only the first end 10a of the open tube whistle is positioned within the pMDI <NUM>. As shown in <FIG>, after the stem block <NUM> has been pushed into the stem block receiving portion <NUM>, the open tube whistle <NUM> is pushed through the passage <NUM> of the stem block <NUM>, and into a second position in which the open tube whistle <NUM> extends through the stem block <NUM>, and the first end 10a of the open tube whistle <NUM> is in fluid communication with the mouthpiece <NUM>.

Accordingly, the open tube whistle <NUM> acts as a locking mechanism to lock the stem block <NUM> to the upright main body <NUM>, by extending all the way through the stem block <NUM>. The open tube whistle <NUM> is therefore incorporated as a sliding locking component to engage and disengage the removable stem block <NUM> from the main body <NUM>.

As shown in <FIG>, to remove the stem block <NUM> from the main body <NUM>, the open tube whistle <NUM> is moved from the second position in which the open tube whistle <NUM> locks the stem block <NUM> into the stem block receiving portion <NUM>, back into the first position in which the open tube whistle <NUM> does not extend through the stem block <NUM>. The user may push the stem block out of the stem block receiving portion <NUM> via an opening <NUM> in an underside of the main body <NUM>.

<FIG> shows the open tube whistle <NUM> in the first position, and <FIG> shows the open tube whistle <NUM> in the second position. As shown in <FIG>, in the first position, the open tube whistle <NUM> does not extend through the passage <NUM> in the stem block <NUM>. However, the first end 10a of the open tube whistle <NUM> is retained in the main body by a first projection <NUM>. The first projection <NUM> of the open tube whistle <NUM> prevents the open tube whistle <NUM> from being completely removed from the main body <NUM>, and therefore prevents the open tube whistle <NUM> from getting lost.

As shown in <FIG>, in the second position, the open tube whistle <NUM> extends through the passage <NUM> in the stem block <NUM> to lock the stem block <NUM> to the main body <NUM>. The stem block <NUM> is biased into the second position by a second projection <NUM> on the open tube whistle <NUM> with a snap-fit fitting. Specifically, the second projection <NUM> holds the open tube whistle <NUM> in the second position.

In alternative embodiments, the open tube whistle <NUM> may be biased into the second position by a spring loaded mechanism.

The handle tab 10c is used by the user to slide the open tube whistle <NUM> between the first position and the second position.

<FIG> shows a pMDI <NUM> which is very similar to the pMDI <NUM> shown in <FIG>. Like reference numerals are used to indicate corresponding features. pMDI <NUM> is the same as pMDI <NUM> shown in <FIG>, except for that the stem block <NUM> has a stem block guider <NUM> for guiding the stem block <NUM> into the stem block receiving portion <NUM> (see e.g. <FIG>) in the main body <NUM>.

In <FIG>, the stem block guider <NUM> is formed integrally with the stem block <NUM> as a single component. In <FIG>, the stem block guider <NUM> is formed as a separate component from the stem block <NUM>. <FIG> is an exploded view of the stem block <NUM> and the stem block guider <NUM>. In use, the stem block guider <NUM> is attached to the stem block <NUM>.

<FIG> illustrate how the stem block guider <NUM> longitudinally slides along longitudinally extending ribs <NUM> in the main body to guide the stem block <NUM> into the stem block receiving portion <NUM> in the correct orientation. In <FIG>, the open tube whistle <NUM> is in the first position, as previously described with reference to <FIG>. When the stem block <NUM> is positioned in the stem block receiving portion <NUM>, the open tube whistle <NUM> can be moved into the second position such that the open tube whistle extends through the passage in the stem block <NUM> (see e.g. <FIG>). In this way, the open tube whistle <NUM> locks the stem block <NUM> to the main body <NUM>.

Similarly to <FIG>, and as shown in <FIG>, to remove the stem block <NUM> from the main body <NUM>, the open tube whistle <NUM> is moved from the second position in which the open tube whistle <NUM> locks the stem block <NUM> into the stem block receiving portion <NUM>, back into the first position in which the open tube whistle <NUM> does not extend through the stem block <NUM>. Then, a user may push the stem block <NUM> out of the stem block receiving portion <NUM> via an opening <NUM> in an underside of the main body <NUM>.

The longitudinally extending ribs <NUM> in the main body <NUM> of pMDI <NUM> have multiple uses. Ribs <NUM> can be used to help locate and guide drug canister <NUM> (shown in <FIG>), and specifically a canister valve stem of the drug canister <NUM>, into the stem block <NUM>. Ribs <NUM> can also be used to add strength to the main body <NUM>. Furthermore, ribs <NUM> can also be used to guide the stem block into a correct position/orientation for interlocking with the open tube whistle. <FIG> correspond to <FIG> respectively. <FIG> shows the open tube whistle <NUM> of pMDI in the first position, and <FIG> shows the open tube whistle <NUM> in the second position. As shown in <FIG>, in the first position, the open tube whistle <NUM> does not extend through the passage <NUM> in the stem block <NUM>. However, the first end 110a of the open tube whistle <NUM> is retained in the main body <NUM> by a first projection <NUM>. The first projection <NUM> of the open tube whistle <NUM> prevents the open tube whistle <NUM> from being completely removed from the main body <NUM>, and therefore prevents the open tube whistle <NUM> from getting lost.

The handle tab 110c is used by the user to slide the open tube whistle <NUM> between the first position and the second position.

<FIG> show different perspective views of a pMDI <NUM> according to an alternative embodiment. pMDI <NUM> is similar to pMDI <NUM> and pMDI <NUM> except for that the main body <NUM>, mouthpiece <NUM>, stem block <NUM> and open tube whistle <NUM> are integrally formed as a single component. Accordingly, although this embodiment is not as sustainable as pMDI <NUM> or pMDI <NUM> (because the uncontaminated parts such as the main body and the open tube whistle cannot be removed from the drug-contaminated parts, and reused), it does not require assembling and so is easy to use.

<FIG> illustrate stem block guider <NUM>, which is similar to stem block guider <NUM> as shown in <FIG>, and so like reference numerals are shown. Stem block guider <NUM> comprises a plurality of channels <NUM> which correspond to longitudinally extending ribs <NUM> in the main body <NUM> of pMDI <NUM> (which is similar to pMDI <NUM>) such that stem block guider <NUM> can longitudinally slide along the longitudinally extending ribs <NUM> (see e.g. <FIG>). The channels <NUM> may comprise chamfers <NUM>, which help to correctly align the channels <NUM> with respective longitudinally extending ribs <NUM> when the stem block <NUM> and stem block guider <NUM> are introduced into the main body <NUM>. This may help to correctly align the stem block <NUM> in the main body <NUM>.

pMDI <NUM> is illustrated in <FIG>, and is similar to pMDI <NUM>. Therefore, like reference numerals are shown. pMDI <NUM> differs from pMDI <NUM> in that stem block guider <NUM> comprises a location indicating feature <NUM>. Main body <NUM> of pMDI <NUM> comprises a corresponding location indicating feature <NUM>. The location indicating feature <NUM> on the main body <NUM> is located at an end of the main body <NUM> distal to mouthpiece <NUM>, and is located on an external surface of the main body <NUM> (although in other embodiments, the location indicating feature <NUM> may be located on an internal surface of the main body).

The location indicating features <NUM>, <NUM> may help a user to correctly align the stem block <NUM> in a correct orientation in the main body <NUM>, and specifically in the stem block receiving portion of the main body <NUM>. The correct orientation may be an orientation in which an open tube whistle (such as open tube whistle <NUM>, <NUM> described above) may be inserted into the main body through passage <NUM> in the stem block <NUM>. A user may align the location indicating features <NUM>, <NUM> on the stem block guider <NUM> and main body <NUM> in order to position the stem block <NUM> in the main body <NUM> in the correct orientation.

In alternative embodiments, only one of the stem block guider and the main body may have a location indicating feature.

In <FIG>, the location indicating features <NUM>, <NUM> on the stem block guider <NUM> and main body <NUM> comprise visual location indicating features. The visual location indicating features <NUM>, <NUM> are colour coded (e.g. have the same colour) and are manufactured by injection moulding (e.g. two shot injection moulding). In alternative embodiments, the visual location indicating features <NUM>, <NUM> may comprise stickers. In some embodiments, the location indicating features may comprise protrusions and corresponding cut-outs, or may be formed from portions of the stem block guider/main body having a different surface texture to the remaining portion of the stem block guider/main body, or may comprise the Braille tactile reading and writing system. For example, a majority of the stem block guider may have a smooth surface texture, and the location indicating features may have a rough surface texture.

<FIG> illustrate a pMDI <NUM> which is similar to pMDIs <NUM>, <NUM>, <NUM> and so like reference numerals are shown. However, pMDI <NUM> additional comprises a mouthpiece cap <NUM> which is tethered to the open tube whistle <NUM>. As shown in <FIG>, mouthpiece cap <NUM> can cover the entire opening in the mouthpiece <NUM> to ensure the opening in the mouthpiece <NUM> remains clean when not in use. As the mouthpiece cap <NUM> is tethered to the open tube whistle <NUM>, the mouthpiece cap <NUM> cannot be lost when removed from the mouthpiece <NUM>. Furthermore, open tube whistle <NUM> cannot be lost from the main body <NUM> when the mouthpiece cap <NUM> is positioned over the mouthpiece <NUM>.

Mouthpiece cap <NUM> is attached to open tube whistle <NUM> via tether <NUM>, which is formed integrally with the mouthpiece cap <NUM>. However, in other embodiments, the tether <NUM> and mouthpiece cap <NUM> may be formed as separate components. In order to attach the tether <NUM> to the open tube whistle <NUM>, the length of the open tube whistle is extended compared to that shown in 6a and 6b, for example. Accordingly, open tube whistle <NUM> may generate an audible/sound signal with a lower frequency than the audible/sound signal generated by open tube whistle <NUM> shown in <FIG>.

In <FIG>, open tube whistle <NUM>, stem block <NUM> and mouthpiece cap <NUM> are all manufactured as separate components. Main body <NUM> is also manufactured as a separate component. In this embodiment, and similarly to open tube whistle <NUM> in pMDI <NUM>, open tube whistle <NUM> is reversibly receivable in the stem block <NUM>, as described above with reference to <FIG>.

<FIG> illustrate an alternative embodiment in which the mouthpiece cap <NUM> and the open tube whistle <NUM> (and tether <NUM>) are integrally formed as a single component, but stem block <NUM> is formed as a separate component. Main body <NUM> is also manufactured as a separate component. In this embodiment, and similarly to in <FIG>, open tube whistle <NUM> is reversibly receivable in stem block <NUM>. <FIG> show the open tube whistle <NUM>, tether <NUM> and open tube whistle <NUM> integrally formed as a single component.

<FIG> illustrate a further alternative embodiment in which main body <NUM>, mouthpiece <NUM>, stem block <NUM> and open tube whistle <NUM> are integrally formed as a single component (similarly to pMDI <NUM> as shown in <FIG>). Mouthpiece cap <NUM> and tether <NUM> are integrally formed as a separate single component, and the mouthpiece cap <NUM> is attached to the open tube whistle <NUM> via tether <NUM>.

<FIG> illustrate embodiments of the inhaler device in which a counter <NUM> is arranged within the main body <NUM> of pMDI <NUM>.

In <FIG>, the counter <NUM>, open tube whistle <NUM>, main body <NUM> and stem block <NUM> are formed as separate components. The open tube whistle <NUM> is slidably and reversibly receivable in the counter <NUM>. The open tube whistle <NUM> extends through the counter <NUM> in order to lock the counter <NUM> to the main body <NUM>.

In <FIG>, the counter <NUM> and open tube whistle <NUM> are integrally formed as a single component.

<FIG> and <FIG> illustrate further embodiments of an inhaler device having a counter <NUM> arranged within the main body <NUM> of pMDI <NUM>. The inhaler device further comprises a magnifying lens <NUM> arranged to enhance the visibility of the counter <NUM> arranged within the main body <NUM>. Specifically, the magnifying lens <NUM> magnifies the number of actuations of the pMDI displayed on the counter <NUM>, as best shown in <FIG>.

As best shown in <FIG> and <FIG>, the magnifying lens <NUM>, open tube whistle <NUM> and stem block <NUM> are integrally formed as a single component that can be slidably received in the main body <NUM> by a snap-fit connection. Specifically, as best shown in <FIG>, bumps and/or tapers <NUM> (i.e. angled faces) may be formed on one or more of the main body <NUM>, magnifying lens <NUM>, stem block <NUM> and open tube whistle <NUM> to provide an interference or snap-fit connection when the single component formed from the magnifying lens <NUM>, open tube whistle <NUM> and stem block <NUM> is slidably received in the main body <NUM>. For example, bumps may be located on the magnifying lens <NUM> to provide a snap-fit (e.g. clip) connection with the main body <NUM>. The main body <NUM> may be chamfered to guide the single component formed from the magnifying lens <NUM>, open tube whistle <NUM> and stem block <NUM> thereinto. The single component formed from the magnifying lens <NUM>, open tube whistle <NUM> and stem block <NUM> and/or the main body <NUM> may have angled or tapered faces to provide an interference fit when the single component is slidably received in the main body <NUM>.

When the single component formed from the magnifying lens <NUM>, open tube whistle <NUM> and stem block <NUM> is received in the main body <NUM>, the single component may be secured (e.g. locked) in three dimensions within the main body <NUM>. The single component and/or the main body <NUM> may comprise one or more securing elements for securing the single component within the main body <NUM> in three dimensions. For example, the main body <NUM> may comprise one or more securing protrusions and the single component may comprise one or more securing grooves (or vice versa). The securing protrusions and the securing grooves may interlock when the single component is received in the main body <NUM> to prevent vertical displacement of the single component (e.g. displacement in a direction parallel to a central longitudinal axis of the main body <NUM>) in the main body <NUM>.

A pair of assembly tabs <NUM> are formed either side of the magnifying lens <NUM> to aid the insertion and removal of the single component from the main body <NUM>. As best shown in <FIG>, a stop face <NUM> of the main body <NUM> ensures that the open tube whistle <NUM> is correctly positioned inside the main body <NUM>.

<FIG> illustrate an integrally formed main body <NUM> and mouthpiece <NUM> for an inhaler device such as the pMDIs described above. A pair of balance protrusions <NUM> extend from the lower end of the main body <NUM>. The balance protrusions <NUM> provide points of contact with a flat surface when the bottom surface of the inhaler device is resting on the flat surface. Specifically, as shown in <FIG>, the balance protrusions <NUM> and the mouthpiece <NUM> provide points of contact with the flat surface to improve stability of the inhaler device when the device stands upright on a flat surface.

<FIG> illustrate various possible cross-sectional profiles of open tube whistle <NUM> which may be incorporated into any of the pMDIs described above, or any of the oral mask assemblies described below. <FIG> corresponds to <FIG> respectively, with exaggerated cross-sectional profiles.

<FIG> illustrate open tube whistles <NUM> having internal step faces <NUM> between the first portion <NUM> and second portion <NUM> of the open tube whistles <NUM>, and external step faces <NUM>, which correspond to the end face of the open tube whistle <NUM> adjacent to the second portion <NUM> of the open tube whistle. As described herein, flat step faces are understood as being perpendicular to the axial length of the open tube whistle, whereas angled step faces are understood as being not perpendicular to the axial length of the open tube whistle.

The open tube whistle <NUM> of <FIG> has angled internal step faces <NUM>, but flat external step faces <NUM>. The angled internal step faces <NUM> are angled outwardly such that the second portion <NUM> of the open tube whistle <NUM> has a greater axial length at a region closer to a central longitudinal axis of the open tube whistle <NUM> than at a region further from a central longitudinal axis of the open tube whistle <NUM>.

The open tube whistle <NUM> of <FIG> has both angled internal step faces <NUM> and angled external step faces <NUM>. The angled internal and external step faces <NUM> are both angled outwardly such that the second portion <NUM> of the open tube whistle <NUM> has a greater axial length at a region closer to a central longitudinal axis of the open tube whistle <NUM> than at a region further from a central longitudinal axis of the open tube whistle <NUM>.

The open tube whistle <NUM> of <FIG> has angled internal step faces <NUM>, and flat external step faces <NUM>. The angled internal step faces <NUM> are angled inwardly such that the second portion <NUM> of the open tube whistle <NUM> has a smaller axial length at a region closer to a central longitudinal axis of the open tube whistle <NUM> than at a region further from a central longitudinal axis of the open tube whistle <NUM>.

The open tube whistle <NUM> of <FIG> has both angled internal step faces <NUM> and angled external step faces <NUM>. The angled internal and external step faces <NUM> are both angled inwardly such that the second portion <NUM> of the open tube whistle <NUM> has a smaller axial length at a region closer to a central longitudinal axis of the open tube whistle <NUM> than at a region further from a central longitudinal axis of the open tube whistle <NUM>.

<FIG> illustrate open tube whistles <NUM>, wherein the inner diameter of the second portion <NUM> of the open tube whistle <NUM> tapers along its axial length. In <FIG>, the inner diameter of the second portion <NUM> of the open tube whistle <NUM> tapers towards the first portion <NUM> of the open tube whistle. In <FIG>, the inner diameter of the open tube whistle <NUM> tapers away from the first portion <NUM> of the open tube whistle <NUM>.

<FIG> illustrates an open tube whistle <NUM>, wherein the inner diameter of the first portion <NUM> of the open tube whistle <NUM> tapers along its axial length. Specifically, the inner diameter of the first portion <NUM> of the open tube whistle <NUM> tapers towards the second portion <NUM> of the open tube whistle <NUM>. Although not shown, alternative open tube whistles may be formed such that an inner diameter of the first portion of the open tube whistle tapers away from the second portion of the open tube whistle.

<FIG> illustrates an open tube whistle <NUM>, wherein the first end of the open tube whistle <NUM> (for fluid communication with the mouthpiece), and adjacent the first portion <NUM> of the open tube whistle <NUM> is non-planar. In this example, the first end of the open tube whistle <NUM> is concave.

<FIG> illustrate cross-sectional profiles of open tube whistle <NUM> which may be incorporated into any of the pMDIs described above, or any of the oral mask assemblies described below. The stepped profile of open tube whistle <NUM> comprises a plurality of steps. In <FIG>, each step has a similar height and width (e.g. relative to neighbouring steps), whereas in <FIG>, the steps have different heights and widths (e.g. relative to neighbouring steps). The height and width of the steps may be chosen to generate sound with a specific (e.g. preferred) frequency. The arrows in <FIG> indicate the direction of fluid (e.g. air) flow through the open tube whistle <NUM>, in use.

The audible/sound signal generated by open tube whistle <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be detectable by a sound receiver on a mobile device, such as a mobile phone. The mobile device may be configured to monitor, record and/or analyse the fluid flow rate through the open tube whistle and/or breathing patterns based on the frequencies/harmonics of the audible/sound signal detected by the sound receiver.

<FIG> is a graph showing a comparison of the performance of an inhaler device comprising an open tube whistle (labelled as "OTW"), with an inhaler device without an open tube whistle (labelled as "Ventolin Inhaler"), based on experimental data from experiments conducted by the inventors. <FIG> is a graph showing a comparison of the performance of a pMDI comprising a salbutamol/HFA152a formulation, and an integral stem block and open tube whistle (labelled as "SB+OTW") with a standard pMDI comprising a salbutamol/HFA152a formulation (labelled as "CONTROL"), based on experimental data from experiments conducted by the inventors. As shown in <FIG> and <FIG>, performance of the inhaler device is not unduly compromised by the presence of an open tube whistle. Therefore, the presence of the open tube whistle, which provides feedback to the user that they have the correct inhalation technique, does not unduly affect the performance of the inhaler device to deliver an active ingredient/drug to a user.

<FIG> show different views of an oral mask assembly <NUM>. The oral mask assembly <NUM> comprises a breathing mask <NUM> which is configured to be worn by a user so that the breathing mask <NUM> covers the mouth and nose of the user. The oral mask assembly <NUM> comprises strap loop buckles <NUM> for attaching to a strap for fixing the breathing mask <NUM> to the user's face. A main body <NUM> of the breathing mask <NUM> is injection moulded from a polymer material such as PVC, ABS or PP, and a rim of the main body <NUM> is lip-shaped and comprises rubber, a plastic/polymer, silicone and/or foam (e.g. Polyvinyl Chloride, PVC), for providing a tight and comfortable seal with the user's face.

As shown in <FIG>, the oral mask assembly <NUM> comprises two one-way valves 2020a, 2020b, one for user inhalation and the other for user exhalation. As shown in <FIG>, the one-way valves 2020a, 2020b are attachable to the main body <NUM> of the breathing mask <NUM> in a pair of valve receiving recesses <NUM> by way of a snap-fit connection. The valve receiving recesses <NUM> are formed on an internal side <NUM> of the main body <NUM> of the breathing mask <NUM>.

Each valve receiving recess <NUM> comprises a bypass channel 2024a, 2024b, as best shown in <FIG>. When the one-way valves 2020a, 2020b are received in the valve receiving recesses <NUM>, each of the one-way valves 2020a, 2020b is in fluid communication with a respective bypass channel 2024a, 2024b. As shown in <FIG>, <FIG>, the inner diameter of the bypass channels 2024a, 2024b are different. In particular, the inner diameter of the bypass channel 2024b in fluid communication with the one-way valve 2020b for user exhalation is greater than the inner diameter of the bypass channel 2024a in fluid communication with the one-way valve 202a for user inhalation 2020a.

Although not shown in the figures, the one-way valves 2020a, 2020b may comprise a filter, such as an antimicrobial medical grade filter. A filter may be attachable to each of the one-way valves, and may be configured to be fitted to the respective one-way valve adjacent to the internal side <NUM> and/or the external side <NUM> of the breathing mask <NUM>.

The oral mask assembly <NUM> comprises a plurality, in this case four, open tube whistles 2030a, 2030b. As described above in relation to previous examples, the open tube whistles 2030a, 2030b have a stepped profile and each open tube whistle 2030a, 2030b generates an audible/sound signal at a predetermined fluid flow rate through the open tube whistle. One end of each open tube whistle 2030a, 2030b is in fluid communication with an external side <NUM> of the breathing mask <NUM>, and the other end of each open tube whistle 2030a, 2030b is in fluid communication with the internal side <NUM> of the breathing mask <NUM>.

In <FIG>, two open tube whistles 2030a, 2030b are in fluid communication with a respective one-way valve 2020a, 2020b (e.g. two open tube whistles 2030a are in fluid communication with the one-way valve 2020a for fluid inhalation, and two open tube whistles 2030b are in fluid communication with the one-way valve 2020b for fluid exhalation). The open tube whistles 2030a, 2030b are integrally moulded with the main body <NUM> of the breathing mask <NUM>. Alternatively, one or more of the open tube whistles 2030a, 2030b may be attachable to (e.g. slidably received in) the main body <NUM>. The open tube whistles 2030a, 2030b may be formed in one or more additional components, wherein the one or more additional components are attachable to (e.g. slidably received in) the main body <NUM>.

This would allow for the open tube whistles 2030a, 2030b to be easily replaced, for example with open tube whistles of different tube geometries to thereby generate an audible/sound signal at a different fluid flow rate therethrough. Resistance of fluid flow between the internal and external sides of the breathing mask may also be adjusted by replacing open tube whistles 2030a, 2030b with open tube whistles of different tube geometries.

<FIG> illustrate air flow through the oral mask assembly <NUM> during user inhalation and user exhalation, respectively. In <FIG>, arrows indicate the air flow path through a first one-way valve 2020a which opens to permit fluid flow from the external side <NUM> to the internal side <NUM> of the breathing mask <NUM> as the user inhales (but prohibits air flow in the other direction by closing when the user exhales). During user inhalation, air also flows through two open tube whistles 2030a, which each generate an audible/sound signal at a specific rate of air flow during user inhalation. The stepped profiles of the two open tube whistles 2030a for user inhalation may have the same/similar or different dimensions or geometries (as described above) to each other, such that the two open tube whistles 2030a generate an audible/sound signal at different predetermined fluid flow rates. An inner diameter of a first portion of the open tube whistles 2030a for user inhalation is greater than an inner diameter of a second portion of the open tube whistles 2030a for user inhalation. The first portion having the greater diameter of each open tube whistle 2030a for user inhalation is provided in fluid communication and adjacent to the internal side <NUM> of the breathing mask <NUM>. The second portion having the smaller inner diameter of each open tube whistle 2030a for user inhalation is provided in fluid communication and adjacent to the external side <NUM> of the breathing mask <NUM>.

In <FIG>, the arrows indicate the air flow path through a second one-way valve 2020b which opens to permit fluid flow from the internal side <NUM> to the external side <NUM> of the breathing mask <NUM> as the user exhales (but prohibits air flow in the other direction by closing when the user inhales). During user exhalation, air also flows through two open tube whistles 2030b, which each generate an audible/sound signal at a specific rate of air flow during user exhalation. The stepped profiles of the two open tube whistles 2030b for user exhalation may have different dimensions or geometries (as described above), such that the two open tube whistles 2030b generate an audible/sound signal at different predetermined fluid flow rates during user exhalation. An inner diameter of a first portion of the open tube whistles 2030b for user exhalation is greater than an inner diameter of a second portion of the open tube whistle 2030b for user exhalation. The first portion having the greater inner diameter of each open tube whistle 2030b for user exhalation is provided in fluid communication and adjacent to the external side <NUM> of the breathing mask <NUM>. The second portion having the smaller inner diameter of each open tube whistle 2030b for user exhalation is provided in fluid communication and adjacent to the internal side <NUM> of the breathing mask <NUM>.

As can be seen in <FIG>, the first portions of the open tube whistles 2030a, 2030b having the greater inner diameter are downstream (i.e. in the direction of fluid flow) from the second portions of the open tube whistle having the smaller inner diameter.

The generated audible/sound signal may provide feedback to a user about the user's breathing pattern, lung function condition, and/or any lung function abnormalities. For example, the audible/sound signal may be audible to the user, such that the user is provided with immediate feedback regarding their breathing rate. Alternatively/additionally, the audible/sound signal may be detectable by a computing device which may monitor a frequency (e.g. pitch), duration, and/or rate of audible/sound signals (e.g. number of sound signals per minute), and may provide feedback to the user (e.g. via a display of the computing device).

<FIG> show another oral mask assembly <NUM>. Oral mask assembly <NUM> is similar to oral mask assembly <NUM> shown in <FIG> and <FIG>, except for that oral mask assembly <NUM> does not comprise one-way valves. However oral mask assembly <NUM> does comprise a bypass channel <NUM> that extends between the internal side <NUM> of the breathing mask <NUM> and the external side <NUM> of the breathing mask <NUM>. The absence of the pair of one-way valves allows for a more compact oral mask assembly <NUM>, whilst helping to adjust the resistance of fluid flow through the oral mask assembly <NUM>.

Oral mask assembly <NUM> comprises two open tube whistles 2130a, 2130b, a first open tube whistle 2130a for generating an audible/sound signal during user inhalation, and the other open tube whistle 2130b for generating an audible/sound signal during user exhalation. In particular, the open tube whistle 2130a for generating an audible/sound signal during user inhalation has a first portion with a greater inner diameter in fluid communication with, and adjacent to, the internal side <NUM> of the breathing mask <NUM>, and a second portion with a smaller inner diameter in fluid communication with, and adjacent to, the external side <NUM> of the breathing mask <NUM>. The open tube whistle 2130b for generating an audible/sound signal during user exhalation has a first portion with a greater inner diameter in fluid communication with, and adjacent to, the external side <NUM> of the breathing mask <NUM>, and a second portion with a smaller inner diameter in fluid communication with, and adjacent to, the internal side <NUM> of the breathing mask <NUM>.

<FIG>, <FIG> show an oral mask assembly <NUM> which is similar to the oral mask assemblies <NUM>, <NUM> described above, except that oral mask assembly <NUM> comprises a main body <NUM> and an add-on component <NUM>. The add-on component <NUM> is attachable to the main body <NUM>, in particular within a recess of the main body <NUM>.

The add-on assembly <NUM> comprises a plurality (in this case, four) open tube whistles <NUM>. Two of the open tube whistles are for generating an audible/sound signal during user inhalation, and the other two open tube whistles are for generating an audible/sound signal during user exhalation. The geometries and dimensions of the open tube whistles may be as described above in relation to oral mask assembly <NUM> and oral mask assembly <NUM>.

<FIG> show exploded views of oral mask assembly <NUM>. The add-on component <NUM> comprises a plurality of sub-components, including a whistle sub-component 2214a, a filter 2214b and an attachment sub-component 2214c for attaching to the main body <NUM>. The whistle sub-component 2214a comprises the open tube whistles <NUM> and a bypass channel <NUM>. The whistle sub-component 2214a and the attachment sub-component 2214c may be injection moulded from a polymer material such as PVC, ABS or PP.

The sub-components 2214a, 2214b, 2214c may be attachable together by one or more snap-fit or push-fit connections, by an interference fit or by one or more threaded connections. The add-on component <NUM> (e.g. the attachment sub-component 2214c) may be attachable to the main body <NUM> via a snap-fit, push-fit, interference-fit or threaded connection. The filter 2214b is positioned between the whistle sub-component 2214a and the attachment sub-component 2214c.

Providing the open tube whistles <NUM> in a replaceable sub-component <NUM> means that the open tube whistles can be replaced with open-tube whistles of different geometries and/or dimensions which may thus generate an audible/sound signal at a different predetermined rate of fluid flow. Thus, a single main body <NUM> may be (re)usable with different combinations of open tube whistles, whereas one or more of the sub-components 2214a, 2214b, 2214c may be discarded and/or replaced after use.

Claim 1:
An inhaler device (<NUM>) for indicating a desired fluid flow rate, the device comprising:
an open tube whistle (<NUM>); and
a mouthpiece (<NUM>) in fluid communication with an external opening of the inhaler device and a first end of the open tube whistle (10a), wherein an inner diameter of the open tube whistle has a stepped profile such that, upon user inhalation through the mouthpiece, an audible/sound signal is generated at a predetermined fluid flow rate through the open tube whistle, wherein:
the stepped profile of the inner diameter of the open tube whistle comprises only one step;
the step is closer to a second end (10b) of the open tube whistle than the first end of the open tube whistle; characterized in that
the inner diameter of a first portion of the open tube whistle adjacent to the first end of the open tube whistle is greater than the inner diameter of a second portion of the open tube whistle adjacent to the second end of the open tube whistle.