Inhalation training device and system for practicing of an inhalation process of a patient

An inhalation training device and inhalation training system for practicing of an inhalation process of a patient. The inhalation training device has a that is housing attachable to and detachable from a mouthpiece of an inhaler designed to provide a drug to the patient and a microphone adapted to measure the airflow occurring in the mouthpiece of the inhaler during an inhalation process of the patient. The inhalation training system includes the inhalation training device, an inhaler and an electronic device configured for evaluation of a signal received from the inhalation training device and for visual and/or audio feedback to the patient.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to an inhalation training device for practicing of an inhalation process of a patient, and to an inhalation training system for practicing of an inhalation process of a patient.

Description of Related Art

Drugs which are to be inhaled constitute a preferred therapy for patients with asthma, a chronically obstructive pulmonary disease or other chronic or acute conditions or diseases of the respiratory tract.

So-called inhalers are used for inhalation of drugs. The most frequently used inhalers are pressurized metered-dose inhalers (pMDIs) and dry powder inhalers (DPIs). pMDIs were developed to supply a precise amount or dose of a drug in the form of a cloud of aerosol droplets to the lungs of the patient when the latter inhales. Dry powder inhalers are made such that when the patient inhales they supply a metered amount of dry pulverized particles to the lungs.

An alternative inhaler is shown e.g., in International Patent Application Publication WO 2008/151796 A1 and corresponding U.S. Patent Application Publication 2008/0314380. This inhaler delivers a metered dose of medication as a slow-moving, soft mist through a nozzle system without use of any propellant.

The effectiveness of drugs which are to be inhaled depends largely on the way the inhaler is used by the patient. Optimally, the correct amount of the drug travels to the desired regions of the lungs at the correct instant of time. Otherwise, the therapeutic effect is reduced and/or the risk of contrary effects is increased.

The literature contains numerous instances substantiating that many patients incorrectly use inhalers. Instruction of the patient with respect to a correct inhalation technique can improve the use of inhalers. In addition to written and oral instructions, practical exercises are helpful for this purpose.

Since inhalation generally proceeds subconsciously and develops over the course of a lifetime, it is however especially difficult for a patient to change his/her manner of inhaling in order to increase the effectiveness of a drug which is to be inhaled. Rather, it is known that many patients again use suboptimum inhalation even a short time after instruction. Therefore, repeated, preferably regular practicing (training) of inhalation and checking of it are recommended.

Inhalation training systems were developed for this purpose. Known inhalation training systems differ, among others, with respect to the inhalation model for which the patient is to be trained, with respect to the type of feedback to the patient (for example, acoustically or visually), with respect to the measured variable (for example inhaled volume, volumetric flow or flow rate or mass flow which is produced during inhalation, velocity of the inhaled particles during the inhalation process), with respect to sensors and actuators (for example mechanical, magnetic or electronic) and with respect to size, handling and costs. Some inhalation training systems use inhalers which are available on the market, while other inhalation training systems copy or emulate inhalers or parts of them.

European Patent Application Publication EP 1 993 642 A1 and corresponding U.S. Patent Application Publication 2009/0308387, which form the starting point of this invention, show an inhalation training device for practicing of an inhalation process of a patient. The known inhalation training device comprises a housing that is attachable to and detachable from a mouthpiece of an inhaler designed to provide a drug to the patient and a microphone adapted to measure the airflow occurring in the mouthpiece of the inhaler during an inhalation process of the patient. The known inhalation training device may further comprise data communication means for communication with, e.g., a computer or a device adapted to forward information from a monitoring device to a doctor or other person for analysis and evaluation.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide an inhalation training device and an inhalation training system that enables effective, simple, reliable, comfortable and/or cost-efficient training of an inhalation process of a patient and/or a simple, cost-efficient, robust and/or regulatory compliant structure and/or a precise measurement of a flow generated by the patient during training and/or a patient-friendly real-time feedback.

The above object is achieved by an inhalation training device and an inhalation training system as described herein.

According to one aspect of this invention, the housing of the inhalation training device is formed of two housing parts snap-clicked together during assembly of the housing. The two housing parts are two simple mechanical parts designed to fit over the mouthpiece of the inhaler. Thus, a robust and cost-efficient unit is created that sits firmly over the mouthpiece, with shortest possible tolerance chain thereby ensuring best possible performance with regards to precise microphone position, with regards to minimal leakage between the mouthpiece of the inhaler and the housing of the inhalation training device thereby supporting the measuring accuracy and finally with regards to mechanical stability. Furthermore, the housing has adequate space inside to contain and protect the microphone, further electronics and cables.

The inhalation training device in accordance with the invention enables effective, comfortable and reliable practicing of an inhalation process.

Preferably, both housing parts are made of molded plastic, in particular acrylonitrile butadiene styrene (ABS), with a smoothed surface. This embodiment enables a cost-efficient structure and a reduction of handling noise caused by the patient practicing an inhalation process, e.g., by sliding or scratching with his fingers over the inhalation training device. Therefore, this embodiment enables higher measurement accuracy.

The measurement accuracy can be increased further by coating both housing parts at least partially with a low-friction layer, in particular glossy chrome. It was found that as much as 15 dB of friction noise difference may exist between a smooth ABS surface and the same surface coated with glossy chrome.

Preferably, the housing comprises molded parting lines for sealed fit with the mouthpiece of the inhaler. This embodiment enables a reliable training of an inhalation process, a robust structure and a precise flow measurement.

According to another aspect of this invention, the microphone is positioned in the housing, outside the mouthpiece of the inhaler and near an air-vent of the mouthpiece of the inhaler, when the inhalation training device is attached to the mouthpiece of the inhaler. This enables a precise flow measurement without any need of intervention within the function of the inhaler and without the need of changing the design of the inhaler. This embodiment does not change the aerodynamic behavior of the flow path of the inhaler. In that manner, the medical compliance of the inhaler is not affected by the presence (or absence) of the inhalation training device.

Preferably, the housing comprises a pad and/or a sleeve around the microphone, in particular made of foam plastic or soft silicone. Thus, insulation of the microphone is improved and vibrations coupling from the inhalation training device into the microphone are reduced. This will further reduce handling noise and improve flow measurement accuracy.

Preferably, the microphone is an electret microphone.

Preferably, the microphone is adapted to measure the noise of the airflow through the air-vent of the mouthpiece of the inhaler. It is well known from acoustics that sound travels well in most solid materials. When a patient inhales using the inhaler, the flow path within the inhaler creates a characteristic flow noise sound depending on flow rate and turbulences. Some of this sound is transmitted through the solid structure of the inhaler. As losses in the solid material are small, it is in principle possible to detect the sound anywhere on the inhaler surface. The preferred embodiment of measuring the noise of the airflow through the air-vent of the mouthpiece of the inhaler enables an effective and reliable training and a precise flow measurement during training.

Preferably, the microphone exhibits directionality, in particular a cardioid, super-cardioid, hyper-cardioid or a bi-directional characteristic. The directional microphone characteristic allows for the microphone itself cancelling out signals that originate from outside the mouthpiece of the inhaler, however not affecting sounds that originate from within. Thus, influence from ambient noise during training can be reduced and flow measurement accuracy can be increased.

Preferably, the inhalation training device provides an interface to an electronic device. The electronic device preferably is a portable communications device capable of capturing, transmitting and/or outputting information and which can be easily transported by an individual. Typical applications of portable communications devices are telephony, data transmission, games, text processing, table processing, image processing, photography and music playback. Typical examples of portable communications devices are mobile phones, smartphones, tablet PCs, handhelds and PDAs.

This embodiment enables exploitation of the functionality of the electronic device, especially for processing and/or evaluation of the signal measured by the microphone of the inhalation training device and/or for feedback to the patient and/or a third party in a simple, intuitive, reliable and cost-efficient manner. At the same time, this embodiment enables expansion of the functionality of the electronic device in a simple and cost-efficient manner with respect to practicing of an inhalation process of a patient.

As a result of the popularity of portable communications devices, access to inhalation training can also be provided to patients who would not like to buy a special electronic device only for inhalation training. Since the owners of portable communications devices are accustomed to their handling, the embodiment in accordance with the invention also enables easier and faster learning of an optimum inhalation process. Since many individuals continually carry a portable communications device, the embodiment in accordance with the invention can also lead to more frequent, possibly regular inhalation training. Furthermore, the embodiment in accordance with the invention increases the ease of operation and the portability of inhalation training.

In particular, the interface to the electronic device is realized by means of an audio jack, especially a 3.5 mm TRRS headset connector. Audio jack is a generic term for a family of connectors typically used for analog audio signals. An audio jack typically has a cylindrical shape, typically with two, three or four contacts. Four-contact versions are known as TRRS connectors, where T stands for “tip”, R stands for “ring” and S stands for “sleeve”. Modern audio jacks are available in three standard sizes, i.e. 6.35 mm, 3.5 mm and 2.5 mm.

As the 3.5 mm TRRS headset connector is the globally most common connector for portable communications devices, the proposed embodiment ensures that the inhalation training device is compatible to a wide range of portable communication devices and is required only in one variant. Thus, the proposed embodiment enables a comfortable and cost-efficient training of an inhalation process of a patient and a patient-friendly real-time feedback.

However, even if manufacturers have agreed on the physical format for the 3.5 mm TRRS headset connector, they disagree on various details associated with the electronic interfacing. One of the most fundamental differences is the polarity of the microphone connections, which, e.g., differ between the family of Apple devices compared to most other manufacturers, e.g., Samsung, HTC, LG, Sony, Motorola, Microsoft, Blackberry and Nokia. The typical connection schemes is given by the following table.

Preferably, the inhalation training device comprises electronics configured to swap the electric connection to the microphone and to ground in dependence of the connection scheme of the TRRS headset connector. In particular, the differing polarity of the microphone connections are handled automatically using analog electronic switches placed in the connection between the microphone and the TRRS headset connector. Especially, the microphone bias voltage (i.e., the positive voltage on the microphone connection) is used directly to select the relevant switching and both the microphone and the ground connections will hence be swapped as necessary. Such analog switching provides excellent audio properties and very limited resistance down to well below 1 Ohm.

Besides the polarity of the microphone connections there also exist minor differences in how and when a specific portable communications device recognizes that an external connection is established, related to the impedance level between the microphone and ground connectors.

Preferably, the inhalation training device comprises electronics configured to adjust the frequency range in which the microphone operates as a function of the analog front-end sensitivity of the electronic device. The flow-induced noise measured by the microphone of the inhalation training device is to be analyzed to assess the air-flow and typically this means to convert the sound pressure level (e.g., in selected frequency bands) to a sound pressure level and then use established correlation patterns between noise and flow to determine the appropriate flow level. This however assumes well-specified audio properties of the electronic device, in particular the analog front-end sensitivity but also linearity and (for wide band signals) frequency range and linearity.

In order to handle speech in high quality, electronic devices typically filter a frequency range from 200 Hz to 20000 Hz. From the perspective of the inhalation training device, turbulent flow noise will generally have a wide-band noise profile covering at least the frequencies from 100 Hz to 10000 Hz, but typically the flow signal is carried well within narrow bands, e.g., 500 Hz to 1000 Hz (dependent on the inhaler type among others). The preferred embodiment of the inhalation training device therefore allows for adjusting the frequency range in which the microphone operates depending on the audio properties of the electronic device, in particular, its analog front-end sensitivity.

With respect to the amplitude linearity, the inhalation training device preferably targets the typical speech range of amplitudes in order to be less prone to potential (unknown) compression. The electronics of the inhalation training device is, however, tunable to stay in the linear region of the most restrictive electronic device thereby ensuring an adequate uniform electronics interface to all selected electronic devices.

Preferably, the inhalation training device comprises electronics configured to generate a reference tone during training. Thus, the reference tone accompanies the microphone signal to at all times make available a known reference. This reference tone can be realized by implementing a precise oscillator of a well-defined frequency (e.g., 10 kHz) and amplitude into the electronics of the inhalation training device and mixing the reference tone into the microphone signal.

Preferably, the oscillator for the reference tone is build up around a low voltage operational amplifier and a precision voltage controller which defines an amplitude of 1.2 V.

Preferably, the housing of the inhalation training device is designed to prevent wrong positioning (e.g., up/down and/or right/left rotation from correct position) of the housing when being attached to the mouthpiece of the inhaler.

According to another aspect of this invention, the housing is designed to prevent drug release and/or dispensing of any fluid during training. In particular, parts of the housing of the inhalation device cover the drug release actuator of the inhaler when the inhalation training device is attached to the mouthpiece of the inhaler. This embodiment ensures that the inhalation training device complies with regulatory requirements, e.g., the EU Medical Device Directive (MDD/93/42/EEC) and the US Medical Device guidelines (FDA 21 CFR Part 820).

Another aspect of the present invention relates to an inhalation training system for practicing of an inhalation process of a patient. According to this aspect, the inhalation training system comprises an inhalation training device according to one or more of the preceding aspects, an inhaler and an electronic device configured for evaluation of a signal received from the inhalation training device and for visual and/or audio feedback to the patient.

This inhalation training system enables an effective, simple, reliable, comfortable and cost-efficient training of an inhalation process of a patient and a precise measurement of a flow generated by the patient during training and a patient-friendly real-time feedback.

Preferably, the inhalation training system is configured to detect the presence of exhalation of the patient during training. When the patient should accidentally exhale into the mouthpiece of the inhaler during training, this can wrongfully reinforce an incorrect or inefficient patient behavior. Therefore, detecting the presence of exhalation of the patient during training enables an effective training of an inhalation process of the patient.

Measurements of either inhalation or exhalation flow and then extraction of the frequency spectra for each individual flow level, separately for inhalation and exhalation, showed that generally the inhalation flow produces flatter spectral responses compared to exhalation flow. This means that when calculating the ratio between the low frequency versus high frequency energy contents then exhalation produces a greater ratio than would inhalation. The inhalation training system exploits this relationship by defining a suitable threshold separating these two frequency clusters. For example, the low frequency signal content is assessed using as a 300 Hz filter whereas the high frequency signal content is assessed using a 7000 Hz filter and a threshold of 70 has been identified to provide good separation between inhalation and exhalation for low flow rates of approximately 10-30 l/min.

Towards higher flow rates, however, the spectral curves for inhalation and exhalation respectively tend to look more and more alike meaning that this separation will not have sensitivity for high flow rates. To handle this situation, another cue is employed based on another characteristic tendency for the above flow sound spectra, namely that the exhalation sound spectra tend to reach higher levels in the low frequency region than does the complementary inhalation sound spectra. Based on this observation, an additional indicator for presence of exhalation flow is the low frequency signal energy. Preferably, the inhalation training system decides on having detected an exhalation if the low frequency signal energy exceeds a threshold of 7. This threshold provides adequate separation between the inhalation and exhalation for high flow rates of approximately 50-90 l/min.

The definition of the preferred thresholds has been made with a clear ambition to have a high degree of detection specificity, i.e., the inhalation training system should not give a warning of exhalation while the patient is actually inhaling correctly.

Preferably, the electronic device is configured to detect the presence of a characteristic voice signal in the signal received from the inhalation training device. Human voice typically does not have a flat sound spectrum but rather consist of an equally spaced train of peaks and valleys starting with the lowest formant frequency. The electronic device can be configured to cease flow evaluation temporarily if the signal received from the inhalation training device is dominated by such a characteristic voice signal or spectrum. Thus, robustness against the influence of voice is improved.

Preferably, the electronic device is configured to detect the presence of the inhalation training device and/or a specific type of the inhaler, in particular by means of a reference tone generated by the inhalation training device during training. For this purpose, the reference tone generated by the inhalation training device as described above can be utilized, especially for automated robust detection that an inhalation training device as claimed has been plugged via the interface (3.5 mm TRRS headset connector) into the electronic device. The electronic device can be configured to not provide any feedback related to flow detection if this is not the case.

The electronic device preferably is a portable communications device capable of capturing, transmitting and/or outputting information and which can be easily transported by an individual. Typical examples of portable communications devices are mobile phones, smartphones, tablet PCs, handhelds and PDAs. The electronic device within the scope of this invention is a device which is separate or independent of the inhalation training device.

Preferably, the electronic device is designed for storage, output and/or interactive feedback of a measured, processed and/or evaluated signal to the patient and/or a third party. In particular, the electronic device has a device for acoustic feedback of the evaluation, for example, a speaker, and/or for visual feedback of the evaluation, for example a screen.

The electronic device can, in particular, provide instructions for correct inhalation and/or advice for optimization. For more effective training of the patient the electronic device can additionally display pictures and/or videos which illustrate an optimum inhalation process.

The term “interactivity” designates the properties of making available to the patient intervention and control possibilities for individualized learning. To do this, for example, the choice and the type of representation of information can be adapted to prior knowledge, the interests and needs of the patient or can be manipulated by him. Solely making available information does not constitute interactive feedback for the purposes of this invention.

Preferably, the electronic device is designed for wireless transmission of a measured, processed and/or evaluated signal to another electronic device. In this way, the signal can be transmitted, for example, to a physician who on this basis can prepare a diagnosis and/or can give advice for improving the inhalation process.

Preferably, the electronic device is designed or can be used for practicing an effective inhalation time Tin, effwhich is as optimal as possible. In this way, the patient is enabled to achieve an effective inhalation time that is as optimal as possible. The effective inhalation time is the time during an inhalation of an inhalation training process, especially the time of simulated inspiration, in which the delivery of an amount or dose of a drug is simulated. In particular, the effective inhalation time is the portion of time in which the inhalation and the simulated delivery of the dose of drug overlap.

Based on the effective inhalation time an inhaled dose of drug (iDoD) can be estimated. This applies especially when the drug is typically delivered at a constant rate. The inhaled dose of drug can be given as a percentage of the delivered dose of drug. The effective inhalation time and the inhaled dose of drug are indicative with respect to the quality of the inhalation process.

To practice the effective inhalation time, the electronic device is preferably designed for determination of the effective inhalation time. To determine the effective inhalation time, the electronic device can determine a delivery time or spray time. The delivery time or spray time is the time during which a delivery of a dose of drug is simulated. The end of delivery is preferably fixed by a fixed delivery duration or spray duration (SDur). Preferably, the effective inhalation time is given in a percentage of the spray duration.

In one preferred embodiment, the effective inhalation time is 0% when the delivery time is outside the time of the inhalation process or of inhalation (Tin), i.e., when the delivery time has passed before the start of the inhalation process. In this embodiment, the effective inhalation time is 100% when the delivery time is completely within the time of the inhalation process.

If the delivery begins before the start of the inhalation process and the delivery ends after the end of the inhalation process, the effective inhalation time is determined preferably according to the following formula:
Tin,eff[%]=Tin*100/SDur

If the delivery starts after the start and before the end of the inhalation process and the delivery ends after the end of the inhalation process, the effective inhalation process is preferably determined according to the following formula:
Tin,eff[%]=(1−(Δ+SDur−Tin)/SDur)*100,

Δ being the difference between the start of the delivery and start of the inhalation process, i.e., Δ has a positive value when the delivery starts after the start of the inhalation process and Δ is a negative value when the delivery starts before the start of the inhalation process.

If the delivery starts before the beginning of the inhalation process and the delivery ends after the start and before the end of the inhalation process, the effective inhalation process is preferably determined according to the following formula:
Tin,eff[%]=(Δ+SDur)/SDur*100,
Δ being the difference between the start of the delivery and start of the inhalation process.

In particular, when determining the effective inhalation time solely the inspiration times can be considered as the inhalation time Tin. Therefore, if inspiration is interrupted by holding the breath or expiration, these times are preferably subtracted from the inhalation time.

Alternatively or in addition, the electronic device can be designed for determination or estimation of a volumetric flow or flow rate which has been generated in the inhalation process and/or a flow velocity generated here. These two physical quantities are highly indicative with respect to the quality of the inhalation process.

The electronic device can also be designed for determination or estimation of the flow velocity. It has been found that depending on where the drug is to be deposited (throat, lungs), the velocity of the inhaled drug must be different. Thus, the flow velocity may be of interest in the determination whether the inhalation was correct. The electronic device can also be designed for determination or estimation of the time during which the flow was within a certain flow velocity interval or above a certain lower limit, again to ensure that the inhalation was correct or sufficient.

Preferably, practicing of inhalation is carried out with support by software which is matched to the electronic device and can be ordered, in particular, via an online portal and installed. Typically, this software is called an “App”. The use of an App improves the flexibility and ease of operation.

The App can be used, for example, for processing and interpretation of the measured signal and for feedback to the patient and/or a third party. To do this, the App can be made available or executed using an information storage medium. The information storage medium is preferably made for use in a portable communications device, especially optimized with respect to the space requirement, energy consumption, reliability and data transmission rate.

Preferred steps of the App are described below.

In the preferred steps of the App, the App is started in a first step. In a later step a graphic user interface (GUI) is initiated and preferably displayed on a screen of the electronic device. In particular, a visual start indication or visual trigger indication is also displayed.

In another step a loop function is started using which the GUI is updated in order to display for example altered contents of the GUI.

Preferably, the start indication or trigger indication is evaluated using the App. In particular, an input of the user or patient, quite especially the actuation of the start indication or of the trigger indication by the user or patient, is monitored. The monitoring of the input leads preferably to a decision whether the start indication or trigger indication has been actuated. If it is decided that an actuation of the start indication or trigger indication has taken place, preferably two parallel branches are followed by the App.

On the one hand, in a first branch, it is preferably monitored whether a visual stop indication (especially on the screen) is actuated. This monitoring leads preferably to a decision whether the stop indication has been actuated. On the other hand, in a second branch parallel to the monitoring of the stop indication an electrical signal value or several electrical signal values of the inhalation training device is or are read out. Preferably the App or the electronic device induces processing of the electrical signal values, especially digitization and storage of the electrical signal values.

In another step, in the second branch, a volumetric flow or flow rate which has been produced in the inhalation process is determined and/or a flow rate profile is prepared using the App or the electronic device.

Within the second branch, preferably, the starting of an inhalation process is monitored by the App or the electronic device. Monitoring leads preferably to a decision whether the inhalation process has been started. Here the App or the electronic device is preferably designed such that an actuation of the trigger indication is interpreted as starting of an inhalation process; this leads to the decision that the inhalation process has started.

If it is decided that an inhalation process has started, on the one hand, preferably a starting time is determined by the App or the electronic device. In addition, preferably further time values can be determined by the App or the electronic device via time keepers.

If it is decided that an inhalation process has started, on the other hand, preferably the ending of the inhalation process is monitored by the App or the electronic device. The monitoring leads preferably to a decision whether the inhalation process has ended. Here the App or the electronic device is preferably designed such that a repeated actuation of the trigger indication or an actuation of the ending indication (especially on the screen) is interpreted as ending of the inhalation process; this leads to the decision that the inhalation process has ended.

If it is decided that the inhalation process has ended, preferably a stop time is determined by the App or the electronic device.

If the monitoring of the ending of the inhalation process after passage of a defined time (for example 20 seconds) beginning from a fixed start of the inhalation process does not lead to a decision that the inhalation process has ended, preferably ending or abort of the App or the sequence takes place. If an abort is ascertained by the App or the electronic device, the App is ended. For example, the GUI can be ended so that it is no longer displayed. Furthermore, time values can be reset and/or memories can be released.

If a stop time is determined, a time keeper is preferably determined by the App or the electronic device. Moreover, preferably an evaluation of the electrical signal values is undertaken. Thus, for example using the App or the electronic device an effective inhalation time and/or inhaled dose of drug can be determined, as already described.

Results of the evaluation can be displayed on the GUI, for which the GUI can be updated.

Furthermore, the App or the electronic device is preferably made such that feedback to the patient and/or a third party takes place, especially an alarm indication is output, when the flow rate which has been determined by the App or the electronic device rises above a value of roughly 40 liters per minute and/or drops below a value of roughly 20 liters per minute.

If it is decided that the stop indication has been actuated, preferably the GUI is updated and/or an abort is checked. The App can also be ended or aborted by actuating an abort indication (especially on the screen).

Another aspect of this invention relates to an information storage medium, especially for a portable communications device. Instructions are stored on the information storage medium in accordance with the invention and when they are executed by a processor they preferably cause the following steps to be carried out:initialization of a graphic user interface,read-out of an electrical signal value of an inhalation training device as described above,digitization and/or storage of the electrical signal value anddetermination of an effective inhalation time and/or inhaled dose of drug.

The information storage medium in accordance with the invention enables effective, simple, reliable and cost-efficient practicing of a patient inhalation process.

Before describing the drawings, some terms are defined below.

The term “inhalation process” in accordance with the invention preferably comprises inhalation of the patient, wherein inhalation can be interrupted over a short time interval, therefore it can comprise the inhalation breaths in rapid succession. Furthermore, an inhalation process can also comprise stopping of the air or of the inhalation and/or the exhalation and/or a coughing of the patient.

The term “patient” in accordance with the invention designates preferably an individual who must and/or would like to use an inhaler, especially an individual who is suffering from a disease of the respiratory tract, quite especially from asthma or a chronically obstructive pulmonary disease, and is treating the disease by means of an inhaler.

The terms “flow” and “airflow” for the purposes of this invention are defined as a measurable flowing movement of air with or without turbulence.

The above aspects and features of this invention and the aspects and features of the invention which follow from the further description and the claims can be implemented independently of one another, but also in any combination.

Other advantages, features, properties and aspects of this invention will become apparent from the following description of preferred embodiments with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

In the figures, the same reference numbers are used for the same or similar parts, corresponding properties and advantages being achieved even if a repeated description is omitted.

FIG. 1schematically shows a perspective view of a preferred embodiment of an inhalation training device1according to the present invention in a state prior to its final assembly.

The inhalation training device1is or can be used for practicing an inhalation process of a patient who is not shown.

The inhalation training device1comprises a housing2attachable to and preferably detachable from a mouthpiece3or any other component of an inhaler4, in particular a so-called RESPIMAT® inhaler as shown, e.g., in WO 2008/151796 A1 and corresponding U.S. Patent Application Publication 2008/0314380. The inhaler4is designed to provide a drug to a patient.

In the preferred embodiment, the inhalation training device1only works in combination with a specified or definite inhaler4, such as the RESPIMAT® inhaler4. In particular, the inhalation training device1only works as intended when mounted over or to the inhaler4, in particular its mouthpiece3.

The inhalation training device1comprises a microphone5adapted to measure the airflow occurring in or into the mouthpiece3during an inhalation process of the patient.

In the preferred embodiment, the microphone5is an electret microphone.

Preferably, the inhalation training device1or microphone5is adapted to measure the noise of the airflow through an air-vent, such as an opening34shown inFIG. 3, of the inhaler4or the mouthpiece3.

Preferably, the housing2of the inhalation training device1comprises or consists of two housing parts2a,2b, preferably a lower housing part2aand an upper housing part2b.

Preferably the housing2or lower housing part2ahas a holding or cylindrical section2aa, which has preferably the shape of a hollow oblique cylinder with an elliptic base. The shape of the section2aais preferably similar or adapted to the shape of the mouthpiece3of the inhaler4, preferably so that the section2aacan be pushed onto the mouthpiece3.

In particular, the circumference of the cylindrical section2aaof the lower housing part2ais greater than the circumference of the mouthpiece3of the inhaler4.

The section2aaor lower housing part2acomprises preferably an outward or essentially radial protrusion2ab.

The lower housing part2apreferably comprises a finger or cover2acprotruding from or connected to the cylindrical section2aa. Preferably, the finger2acis spaced from the protrusion2abof the lower housing part2aalong the circumference of the cylindrical section2aa.

The upper housing part2bcomprises preferably a cylindrical section2ba, which has preferably the shape of a hollow oblique cylinder with an elliptic base. The circumference of the cylindrical section2baof the upper housing part2bis preferably greater than the circumference of the cylindrical section2aaof the lower housing part2a. The height of the cylindrical section2baof the upper housing part2bis preferably smaller than the height of the cylindrical section2aaof the lower housing part2a. The cylindrical section2baof the upper housing part2bcomprises preferably an outward protrusion2bb. The upper housing part2bcomprises preferably a finger or cover2bc. Preferably, the finger or cover2bcprotrudes from the cylindrical section2baof the upper housing part2band/or is spaced from the protrusion2bbof the upper housing part2balong the circumference of the cylindrical section2baof the upper housing part2b.

During assembly of the housing2, the microphone5is mounted in the protrusion2acof the lower housing part2aand an audio cable6connected to the microphone5is lead out of the protrusion2acof the lower housing part2aalongside the cylindrical section2aaand the cover2acof the lower housing part2a. Furthermore, the upper housing part2bis put over the lower housing part2aand both housing parts2a,2bare snap-clicked together such that the cylindrical section2baof the upper housing part2bsurrounds the cylindrical section2aaof the lower housing part2aand that the protrusion2bbof the upper housing part2bcovers the protrusion2abof the lower housing part2aand that the cover2bcof the upper housing part2bcovers the cover2acof the lower housing part2a.

Preferably, the housing parts2aand2bare connected with each other by snap-fit and/or form-fit.

Preferably, the housing2holds or receives the microphone5and/or an associated cable6.

Preferably, the microphone5is received between the housing parts2aand2b.

Preferably, the cable6is received and/or guided between the housing parts2aand2band/or the sections2acand2bc.

The inhalation training device1or housing2comprises preferably a blocking device2cfor blocking actuation of the inhaler4. Preferably, the blocking device2cis formed by the section2acand/or2bc.

Preferably, the blocking device2cis formed or realized as a finger covering a blocking element15of the inhaler4as schematically shown inFIGS. 4 and 5.

Preferably, the blocking device2cand/or sections2ac,2bcextend at least partially in axial direction and/or parallel to a longitudinal direction of the inhaler4and/or to a longitudinal axis of the housing2or holding section2aa.

The holding section2aais adapted to mount the inhalation training device1or its housing2to the associated inhaler4, in particular to its mouthpiece3or any other component. Most preferably, the section2aaallows a mechanical connection by press-fit to the mouthpiece3or the like.

Preferably, the outer contour of the mouthpiece3and the inner contour of the section2aaare slightly tapered towards the free end and adapted so that the desired clamping can be achieved when the section2aais pushed onto the mouthpiece3. However, other forms and/or constructional solutions are possible.

FIG. 2schematically shows a section through the housing2of the inhalation training device1after final assembly of the housing2, but without microphone5, cable6, and the like.

Both housing parts2a,2bare made preferably of molded plastic with a smoothed surface. Thus, handling noise caused by the patient practicing an inhalation process, e.g., by sliding or scratching with his fingers over the inhalation training device1, is reduced. Therefore, measurement accuracy is increased.

The inhalation training device1provides an interface and/or is connectable to an electronic device7. In the preferred embodiment ofFIG. 1, the electronic device7is a smartphone.

In the preferred embodiment, the interface and/or connection to the electric device7is realized preferably by means of cable6and/or a connector8, such as an audio jack, in particular a 3.5 mm TRRS headset connector or the like.

As the 3.5 mm TRRS headset connector8is the globally most common connector for smartphones, the inhalation training device1is preferably compatible to a wide range of smartphones and is required only in one variant. This enables a comfortable and cost-efficient training of an inhalation process of a patient and a patient-friendly real-time feedback.

Additionally or alternatively, the inhalation training device1can be connected with the electric device7wireless, e.g., via Bluetooth.

In the preferred embodiment, the inhalation training device1comprises electronics5a(indicated inFIGS. 1 and 3) configured to process any microphone signal and/or to generate a reference tone during training. Thus, the reference tone accompanies the signal of the microphone5at all times and makes available a known reference. In particular, this reference tone is realized preferably by implementing a precise oscillator of a well-defined frequency of about 10 kHz and an amplitude of preferably 1.2 V into the electronics5aof the inhalation training device1and mixing the reference tone into the microphone signal.

FIG. 3schematically shows a section through the inhaler4with the inhalation training device1attached to the mouthpiece3of the inhaler4.FIG. 4schematically shows also a section through the inhaler4with the inhalation training device1attached to the mouthpiece3of the inhaler4, whereas the inhaler4and the attached inhalation training device1are axially rotated about 90°.

The two housing parts2a,2bare designed preferably to exactly fit together and to firmly fit over the mouthpiece3of the inhaler4. This ensures minimal leakage between the mouthpiece3of the inhaler4and the housing2of the inhalation training device1. Thus, high measurement accuracy and high mechanical stability is achieved. At the same time, the housing2has adequate space inside to contain and protect the microphone5, audio cable6and further electronics5a.

Furthermore, the described design of the housing2, in particular non-circular cross-section of the section2aaand the mouthpiece3, prevents wrong positioning of the housing2when being attached to the mouthpiece3of the inhaler4.

In the illustrated and preferred embodiment, the housing2is designed such that drug release during training is prevented. In particular, the blocking device2cor covers2ac,2bcof the two housing parts2a,2bcover a drug release actuator, such as blocking element15, of the inhaler4when the inhalation training device1is attached to the mouthpiece3of the inhaler4.

When the inhalation training device1is attached to the mouthpiece3of the inhaler4, the microphone5is positioned preferably automatically, outside the mouthpiece3of the inhaler4and/or near an air-vent or opening34of the mouthpiece3of the inhaler4. This enables a precise flow measurement without any need of intervention within the function of the inhaler4or fluid flow in the mouthpiece3and without the need of changing the design of the inhaler4. Preferably, the aerodynamic behavior of the flow path of the inhaler4is not changed by the inhalation training device1. In that manner, the medical compliance of the inhaler4is not affected by the presence (or absence) of the inhalation training device1.

Measurements were taken using calibrated TetraTec flow measuring equipment (TetraTec Instruments GmbH, 71144 Steinenbronn, Germany) and comparison was made using a stand-alone inhaler4and then the same inhaler4where the inhalation training device1was mounted over the mouthpiece3of the inhaler4. In both situations the flow resistance was measured for a tube connected to the mouthpiece3(not covering the air vents). Measurements showed that airflow is not restricted by the presence of the inhalation training device1. The flow resistance when using the inhalation training device1is unchanged compared to the stand-alone inhaler4thereby supporting the requirements to not train patients with another type of inhalation experience.

In the following, the inhaler4is described in more detail.

The inhaler4is designed to atomize a fluid9, particularly a highly effective pharmaceutical composition, medicament or the like, diagrammatically shown in a relaxed state (FIG. 3) and in a tensioned state (FIG. 4). The inhaler4is constructed, in particular, as a portable inhaler and preferably operates only mechanical and/or without propellant gas.

The inhaler4is provided with or comprises an insertable or replaceable container10containing the fluid9. The container10thus forms a reservoir for the fluid9, which is to be nebulized. Preferably, the container10contains multiple doses of fluid9or active substance in particular sufficient to provide up to 200 dosage units or doses, for example, i.e., to allow up to 200 sprays or applications. A typical container10, as disclosed in WO 96/06011 A1 and corresponding U.S. Pat. No. 5,833,088, holds, e.g., a volume of about 2 to 20 ml.

It is noted that the dose can vary, in particular depending on the fluid9or medicament. The inhaler4can be adapted respectively.

Further, the number of doses contained in the container10and/or the total volume of the fluid9contained in the container10can vary depending on the fluid9or respective medicament and/or depending on the container10and/or depending on the necessary medication or the like.

Preferably, the container10can be replaced or exchanged, wherein the number of containers10, which can be used with the same inhaler4, is preferably restricted, e.g., to a total number of four or five containers10.

The container10is preferably substantially cylindrical or cartridge-shaped and once the inhaler4has been opened the container10can be inserted therein preferably from below and changed if desired. It is preferably of rigid construction, the fluid9in particular being held in a collapsible bag11in the container10. In particular, the container10comprises a venting opening or hole30which is opened before or during first use.

The inhaler4comprises a delivery mechanism, preferably a pressure generator12, for conveying and nebulizing the fluid9, particularly in a preset and optionally in an adjustable dosage amount.

The inhaler4or pressure generator12comprises preferably a holder13for releasably holding the container10, a drive spring14associated to the holder13, only partly shown, and/or a blocking element15preferably in form of or with a button for preferably manual actuation or depressing. The blocking element15can catch and block the holder13and can be manually operated to release the holder13allowing drive spring14to expand.

The inhaler4or pressure generator12comprises preferably a conveying element, such as a conveying tube16, a non-return valve17, a pressure chamber18and/or a nozzle19for nebulizing the fluid9into the mouthpiece3.

The completely inserted container10is fixed or held in the inhaler4via the holder13such that the conveying element fluidically connects the container10to the inhaler4or pressure generator12. Preferably, the conveying tube16penetrates into the container10.

The inhaler4or holder13is preferably constructed so that the container10can be exchanged.

When the drive spring14is axially tensioned in the tensioning process, the holder13with the container10and the conveying tube16are moved downwards in the drawings and fluid9is sucked out of the container10into the pressure chamber18of the pressure generator12through the non-return valve17. In this state, the holder13is caught by the blocking element15so that the drive spring14is kept compressed. Then, the inhaler4is in the tensioned state.

If actuation or pressing of the blocking element15was possible (which is not the case when the inhalation training device1is attached to the inhaler4) a relaxation would follow in the nebulization process, during which the fluid9in the pressure chamber18would be put under pressure as the conveying tube16with its then closed non-return valve17would be moved back in the pressure chamber18, here in the drawings upwards, by the relaxation or force of the drive spring14and then would act as a pressing ram or piston. This pressure would force the fluid9through the nozzle19, whereupon it would be nebulized into an aerosol and, thus, dispensed.

Generally, the inhaler4operates with a spring pressure of 5 to 200 MPa, preferably 10 to 100 MPa on the fluid2, and/or with a volume of fluid2delivered per stroke of 10 to 50 preferably 10 to 20 μl, most preferably about 15 μl. The fluid9is converted into or nebulized as aerosol, the droplets of which have an aerodynamic diameter of up to 20 μm, preferably 3 to 10 μm. Preferably, the generated jet spray has an angle of 20° to 160°, preferably 80° to 100°.

The inhaler4comprises preferably a housing31and/or (upper) housing part23and optionally a biasing or inner part24preferably which is rotatable relative thereto (FIG. 4) and/or has an upper part24aand a lower part24b(FIG. 3).

The inhaler4or housing31comprises preferably a (lower) housing part25. This part25is in particular manually operable, and/or releasable fixed, particularly fitted or held onto the inner part24, preferably by means of a retaining element26.

Preferably, the housing parts23and25and/or other parts form the housing31of the inhaler4.

In order to insert and/or replace the container10, preferably the housing31can be opened and/or the housing part25can be detached from the inhaler4, inner part24or housing31.

Generally and preferably, the container10can be inserted before the housing31is closed and/or before the housing part25is connected to the housing31. Preferably, the container10is inserted, opened and/or fluidically connected to the delivery mechanism automatically or simultaneously when (completely) connecting the housing part25to the housing31/inhaler4and/or when (completely) closing the housing31/inhaler4.

Preferably, the inhaler4or drive spring14can be manually activated or tensioned, in particular by actuation of an actuation member, here preferably by rotating housing part25or any other component.

The actuation member, preferably the housing part25, can be actuated, here rotated relative to the upper housing part23, carrying with it or driving the inner part24. The inner part24acts on a gear or transmission to transform the rotation in an axial movement. As a result, the drive spring14is tensioned in the axial direction by means of the gear or transmission (not shown) formed between the inner part24, in particular its upper part24a, and the holder13and acting on the holder13. During tensioning the container10is moved axially downwards until the container10assumes an end position as shown inFIG. 4. In this activated or tensioned state the drive spring14is under tension and can be caught or held by the blocking element15. During the nebulizing process the container10is moved back into its original position (non-tensioned position or state shown inFIG. 3) by (the force of) the drive spring14. Thus, the container10executes a lifting or stroke movement during the tensioning process and during the nebulizing process.

The housing part25preferably forms a cap-like lower housing part and/or fits around or over a lower free end portion of the container10. As the drive spring14is tensioned the container10moves with its end portion (further) into the housing part25or towards the end face thereof, while an aeration means, such as an axially acting spring27arranged in the housing part25, comes in contact with base28of the container10and pierces the container3or a base seal or foil50thereon with a piercing element22when the container3makes contact with it for the first time, to allow air in or aeration, preferably by opening or piercing venting hole23.

The inhaler4comprises preferably an indicator device25, which counts in particular actuations of the inhaler4, preferably by detecting tensioning of the drive spring14or the rotation of the inner part24relative to the upper part23or housing31. Preferably, the counter device32or an associated locking device33locks the inhaler4against (further) actuation or use, e.g., blocks further rotation of the housing part25/inner part24and, thus, tensioning of the inhaler4or its drive spring14and/or blocks actuation of the blocking element15, in a locked state when a certain number of actuations or operations or discharged doses has been reached or exceeded.

Unlike freestanding equipment or the like, the inhaler4is preferably designed to be portable, and in particular, is a portable hand operated device.

Preferably, the fluid9is an aqueous pharmaceutical formulation or an ethanolic pharmaceutical formulation. However, it may also be some other pharmaceutical formulation, a suspension or the like.

Alternatively, the fluid9may also comprise particles or powder. In this case, instead of the expulsion nozzle17, some other kind of supply device may be provided, especially an expulsion opening (not shown) or a supply channel (not shown) for supplying the fluid to or powder or the like into the mouthpiece3. An optional air supply opening (not shown) then serves to supply ambient air preferably in parallel so as to generate or allow an airflow with a sufficient volume for breathing in or inhaling through the mouthpiece3.

If necessary, the fluid9may also be atomized by means of a propellant gas.

Preferred ingredients and/or formulations of the preferably medicinal fluid9are listed in particular in WO 2009/115200 A1, preferably on pages25to40, and in corresponding U.S. Pat. No. 8,650,840, or in EP 2 614 848 A1, paragraphs [0040] to [0087], which are incorporated herein by reference. In particular, these fluids may be aqueous or non-aqueous solutions, mixtures, formulations containing ethanol or free from any solvent, or the like.

FIG. 5schematically shows a perspective view of a preferred embodiment of an inhalation training system35according to the present invention.

The inhalation training system35is used or usable or designed for practicing of an inhalation process of a patient.

The inhalation training system35comprises the inhalation training device1as described above, an inhaler4preferably as described above, and a separate and/or mobile electronic device7, preferably a smartphone.

The smartphone7is configured for evaluation of a signal received from the inhalation training device1and for visual and/or audio feedback to the patient, in particular via a display7a, a loud speaker7bor the like.

The purpose of the inhalation training system35is to further educate the patient to inhale correctly with the range of inhalers. Due to the preferred soft mist technology of the inhalers which generate a homogeneous droplet aerosol cloud of 1 to 1.5 seconds duration and where the instructions for correct inhalation is to inhale with relative low flow over an extended period of time, some patients may potentially be confused on correct use as they previously might have been subjected to other inhalers specifically requiring them to inhale forcefully and with only very short duration (e.g., passive dry powder inhalers).

The inhalation training system35enables an effective, simple, reliable, comfortable and cost-efficient training of an inhalation process of a patient and a precise measurement of a flow generated by the patient during training and a patient-friendly real-time feedback.

In the preferred embodiment, the inhalation training system35is configured to non-invasive detection (i.e., with unchanged flow resistance of the inhaler4) of correct inhalation flow in the range of at least 20 to 40 l/min with an accuracy of at least +/−50% but preferably better than +/−20%.

The electronic device7is configured preferably to detect the presence of the inhalation training device1by means of the reference tone generated by the inhalation training device1during training as described above. Thus, the electronic device7can detect if an inhalation training device1has been plugged via connector8into the electronic device7. The electronic device7is configured to not provide any feedback related to flow detection if this is not the case.

The electronic device7is capable of interfacing to the external microphone5of the inhalation training device1.

In the preferred embodiment, the electronic device7is equipped with a dedicated App which in combination is capable of real-time measuring and displaying information (preferably via display7a) related to patient inhalation flow thereby providing feedback regarding correct and incorrect inhalation techniques.

The App presents flow feedback to the patient in a simple and intuitive manner (non-scientific) and is available for download onto the electronic device7. For this purpose, the App is developed for all main platforms, especially iOS and Android.

Even if the App has been developed to contain all technical analysis capabilities as presented above, the App is targeted at a very broad audience of patients and hence leverages a very simple and intuitive user interface. Preferably, the App and/or electronic device7are adapted to give an audible and/or visible feedback, preferably via the display7aof the electronic device7and/or most preferably by showing one or more respective symbols7, such as a balloon or the like, which can be easily understood by most people (compareFIG. 5which shows as an example a balloon as symbol7dfor indicating the inhalation process or the like).

In particular, a balloon concept was finally chosen as the core element to provide feedback regarding patient inhalation flow pattern. According to this concept, the patient's inhalation flow rate determines the balloon flight level. If the patent performs a forceful inhalation (e.g., more than 60 l/min) the balloon will fly high on the screen, whereas a very weak inhalation (e.g., less than 10 l/min) will result in the balloon hovering at the bottom of the screen. In the center range of 20-40 l/min the balloon shifts color from red (amber) to green and two sharp arrows start to close in from the sides. After two seconds of correct flow rate the arrows puncture the balloon thereby indicating a successful inhalation. When the balloon pops the screen turns to a 10 seconds countdown clock allowing training of breath holding following inhalation (similar to the use instructions).

The App is split in two parts, a passive guide part and an active training part, and the patient is carefully introduced to the guide before being subject to real training.

The patient initially accept the terms of use and then enters into the guide part of the App where he is carried through all patient related installation steps of mounting the inhalation training device1over the mouthpiece3of the inhaler4and plugging the connector8into the electronic device7. The patient is introduced to the features of the App using animated screens of both balloon flying and breath holding. At any point in the guide the patient may press a highlighted ‘X’ to exit the guide and begin training, otherwise he will on the very last guide page be redirected to the training part of the App by simple button confirmation to ‘Start training’. When entering the training part the App requires the presence of the inhalation training device1to function. If the inhalation training device1is not mounted then a warning will be presented to the patient.

Generally, the user or patient could also press a button7c, the touch screen or the like of the electronic device7for input or confirmation purposes.

Then, the flow training takes place by inhaling through the inhalation training device1mounted over the inhaler4and completing the quest to balance the balloon in the ‘green’ zone for two seconds and following to hold the breath for 10 seconds. After successfully having completed both steps, the green colored symbol will fly into a history bar showing the last five attempts. Since the App has no means to detect the patient holding his/her breath, the last step in this training sequence will never be able to disqualify an otherwise perfect inhalation sequence only the final result adding to the history awaits the 10 seconds delay.

Since the primary training objective of the inhalation training device1is to help patients reduce inhalation flow to a much lower level than, e.g., required with a passive DPI the one element that can cause an unsuccessful inhalation is if the patient inhales too strongly (above 40 l/min) for two seconds (or longer). In this situation the inhalation sequence will be unsuccessful and the negative result will be added directly to the history without going through the sequence of breath holding.

After every test completion, successful or unsuccessful, the patient is presented with the option to ‘Try again’ to motivate him/her to continue training until he/she safely and reliably can balance the balloon right every time (at least for five consecutive trials).

Instructions are preferably stored on an information storage medium and when executed by a processor cause the execution of the steps described above.

Other steps can be added to the described steps of the App. Individual steps of the App can also be omitted. The sequence of the individual steps can be changed and different steps can be combined with one another. Individual steps of the App can also be implemented independently of other steps.

Flow measurement accuracy also depends on the production tolerances of the microphone5which potentially could exhibit +/−3 dB variation in acoustic sensitivity. If no other sources to error did exist such microphone tolerance variation would translate to a measuring uncertainty around +/−35%. This uncertainty does not appear to be critical to perform the inhalation training process where e.g., a measuring uncertainty of +/−50% has been communicated being acceptable.

To mitigate the microphone tolerance variation, the microphone gain and/or the reference tone amplitude can be calibrated. Preferably, each electronics module including the microphone5is subjected (prior to mounting in the housing2of the inhalation training device1) to a test using a reference acoustic signal allowing assessment of variation from ideal reference. In case of deviations, e.g., the reference tone amplitude is adjusted to produce the desired relation to the measured microphone signal. Adjustment could be as simple as cutting a wire on the carrying flexible printed circuitry board (cutting, e.g., a parallel resistor controlling reference voltage attenuation).

Alternatively, the final assembled inhalation training device1could be tested to create a code based on the individual acoustic deviation. The code can then be imported into the App prior to use. For example, the inhalation training device1can have an individual serial number containing a single digit reference to categorize the inhalation training device1. In order to improve measuring accuracy the patient can manually enter the code upon start of the App. Alternatively, a barcode can be printed on the housing2of the inhalation training device1. The patient can then scan the barcode with a camera of the smartphone7during the initialization procedure of the App.

FIG. 5shows another preferred aspect of the present invention. Preferably, the inhalation training device or its housing2comprises the blocking device2cfor blocking any dispensing of fluid9by the inhaler4when the inhalation training device1is mounted to or with the inhaler4. Preferably, the blocking device2ccovers an actuation element or button, such as blocking element15of the inhaler4in order to block or prevent any possible actuation and, thus, any possible dispensing of fluid9. However, other construction solutions are possible as well.

Preferably, the inhalation training device1does not (significantly) amend or restrict the flow of air which is drawn through the at least one opening34into the mouthpiece3during inhalation. However, the microphone5might protrude into an associated opening34and/or is preferably located adjacent, most preferably as near as possible, to one venting opening34.

In the embodiment, the inhalation training device1or its housing2does not cover the other opening34. For this purpose, the inhalation training device1or housing2comprises preferably a recess2das indicated inFIGS. 1 to 3.

In order to not restrict flow of air that is sucked through opening(s)34into the mouthpiece3during inhalation, the inhalation training device1or its housing2comprises preferably at least one supply opening2eor the like as schematically shown inFIGS. 1 and 3.

Preferably, the cable6is guided within the inhalation training device1or its housing2from the mouthpiece3towards the other end of the inhaler4, preferably through the blocking device2cand/or preferably thinner like portions or sections2acand/or2bc.

Preferably, the microphone5and electronics5aform a unit or assembly. In particular, the electronics5ais integrated into the microphone5or vice versa.

Preferably, the training inhalation device1or its housing2holds the unit or assembly of microphone5and/or electronics5aby snap-fit and/or form-fit. A possible realization is indicated inFIG. 3schematically. For example, the unit or assembly can be inserted into or through a holding recess2for the like or mounted, with the microphone5preferably pointing towards the mouthpiece3, adjacent to air vent opening34and/or adjacent to the nozzle19of the inhaler4and/or pointing radially inwards.

Preferably, the blocking device2cis supported or abuts against the inhaler housing31, preferably an upper housing part23of the inhaler4. For this purpose, the blocking device2cor section2acmay comprise a respective protrusion or contact portion2caas indicated inFIGS. 4 and 5.

Preferably, the blocking device2ccovers the blocking element15or any other actuation element, necessary for triggering or initiating dispensing of fluid9from the nebulizer4, preferably completely, such that any dispensing of fluid9from the inhaler4is securely prevented when the inhalation training device1is mounted to the inhaler4or vice versa.