Patent Application
20220016363
The present invention relates to a vibration head for an aerosol generator, a controller for an aerosol generator, an aerosol generator, and an electric connecting element, in particular for implementing an inductive coupling based electrical connection for vibration heads of an aerosol generator.
Aerosols for therapeutic purposes are generated and delivered to a desired location within a user's or patient's body with an aerosol delivery device. A fluid or liquid (including a medicament or drug) to be aerosolized or nebulized is supplied to an aerosol generator, the fluid or liquid is aerosolized or nebulized by the aerosol generator and the resultant aerosol is delivered to the user or patient.
The fluid or liquid may be aerosolized or nebulized in the aerosol generator by a vibratable element which is referred to as a vibratable nebulizer, membrane nebulizer, mesh nebulizer, vibration component, or vibration head in the following. Such a vibration head is provided at least with a membrane and an oscillation generator or vibration generating element, such as a piezoelectric element (electromechanical transducer element). The characteristics (mechanical and/or electrical) of the vibration head of the aerosol generator are decisive for the quality of the generated aerosol. At the same time, the vibration head is also generally very sensitive, especially with respect to dimensional specifications. For example, a misalignment of the vibration head may negatively affect the oscillatory or vibration motion of the vibration head during aerosol generation and therefore compromise the quality of the generated aerosol and the dosage accuracy. Also, problems with the electrical connection of the vibration head may lead to problems with the aerosol quality and dosage accuracy.
In operation, an aerosol (i.e. liquid droplets) is generated on one side of the vibratable membrane 8 from a liquid or fluid that is provided on the other side of the vibratable membrane. In particular, the fluid abutting the membrane 8 is conveyed through the holes or openings (not shown) in the vibrating membrane 8 and is thereby aerosolised into an aerosol cavity or chamber (not shown) of an aerosol delivery device (not shown) arranged below the vibrating membrane 8. The aerosol thus provided in the aerosol cavity or chamber can be inhaled by a user or patient through a mouthpiece, nosepiece, nasal prongs, endotracheal tube, ventilator tube system, and/or face mask (not shown) of the aerosol delivery device.
Further, the vibration head 4 of
The support member 6 and the vibratable membrane 8 as shown in
Alternatively, a vibration head may also be provided without a fixed combination of the support member 6 and/or the membrane 8 with the vibration generating element 10, for example in such a case the support member 6 and/or the membrane 8 is replaceably inserted into an aerosol generator by bringing a piezoelectric element into contact with a support member 6 and/or a vibratable membrane of the aerosol generator.
The electrical contacts 14, 14′ for the vibration head are not restricted to the example shown in
For example,
An electric connection used for power transfer between the vibration head of the aerosol generator and the controller is conventionally provided via an electric cable having plug connectors. Using an electric plug connector has technical disadvantages due to the fact that a plug-in connector has a limited lifetime being related to a limited number of plug-in operations or plugging cycles, of e.g. 2,000-10,000 plug application cycles, that guarantee a secure electrical connection.
In addition, moisture, steam or the like which may be formed as a result of the aerosol generation process or the cleaning process may enter the plug connector and thus leads to leakage currents or even a short circuit between the electric contacts, even in cases in which a sealing is provided. Moisture or high humidity within an electrical contact region (related to the connecting unit 12′ in
Further, a mechanical contact by means, for example, of the plug connector results in regions that are difficult to clean, at least in part.
U.S. Pat. No. 9,962,505 B2 describes a magnetic field (inductive) coupling between a transmitter coil and a receiver coil to electrically drive a vibration source (piezoelectric element). This solution has, however, several disadvantages. First, to achieve a sufficient inductive coupling, a relatively high frequency AC drive current of above 1 MHz is provided through a primary winding of the inductive coupling. Such a high frequency is, however, detrimental to the aerosol quality. Moreover, the spatial maximum dimension of the transmitter coil and the receiver coil in U.S. Pat. No. 9,962,505 B2 as compared to the spatial maximum dimension of the membrane and the piezoelectric element does not allow the integration of such coils into the vibration heads as shown in
Solution
Therefore, a need exists in the art for overcoming the above technical problems related to the conventional way of power connecting aerosol generators.
This object is achieved, in a first aspect, by the features of a vibration head for an aerosol generator as defined in claim 1. Advantageous embodiments of the vibration head are described in the corresponding dependent claims.
This object is achieved, in a second aspect, by the features of a controller for an aerosol generator as defined in claim 10. Advantageous embodiments of the controller are described in the corresponding dependent claims.
This object is achieved, in a third aspect, by the features of an aerosol generator for an aerosol generator as defined in claim 21.
This object is also achieved, in a fourth aspect, by the features of an electric contacting element as defined in claim 22.
Further, preferred embodiments are defined in the respective dependent claims.
Embodiments of the present invention are described with reference to the Figures. It is noted that the following description should not be construed as limiting the invention. In the following and the above, similar or same reference signs indicate similar or same elements or operations.
The aerosol generator 200 has a housing (not shown) with at least a first holing member and a second holding member. The vibration head 210 is at least partially accommodated in the housing and is held between the first and second holding member. For example, the vibration head 210 may be placed with regard to the first holding member and the aerosol generator may be brought into an operating state by closing the second holding member with regard to the first holding member. Further aspects of the mechanical placement, appropriate orientation, and the like of the vibration head 210 within the aerosol generator 200, for example also with regard to a liquid reservoir provided in the aerosol generator are known to the skilled person, see, for example, EP 2 957 349 A1. It is noted that a liquid reservoir is not part of the described vibration head 210. As such, when taking out or detaching the vibration head 210 from the aerosol generator 200, the vibration head 210 may be completely cleaned or disinfected without a further intervention on the vibration head 210, such as opening parts of the vibration head or the like.
As further shown in
The connection unit 110 of
For simplifying the understanding,
In other words, as further schematically illustrated in
The electric contacting element 300 may therefore be connectable with both the controller 100 and the vibration head 210, or may have at least a fixed connection with the controller and is only connectable with the vibration head 210. In other embodiments, the electric contacting element 300 may be a contacting element providing a contacting mechanism for a direct connection of the controller 100 with the aerosol generator 200 (including the vibration head 210) so that the primary and secondary coils are brought close to each other by the plug-type connection unit shown in
As further illustrated in
As shown in
Inserting the plug 310b into the vibration head 210 provides a mechanically fixed placement of the primary coil 320 with regard to the secondary coil 220 which, conversely, may be provided in close proximity to a cable connector region.
Such a configuration allows for a sufficient inductive coupling between the primary coil 320 and the secondary coil, and therefore achieves an inductive coupling between the controller 100 and the vibration head 210 for the purpose of power transfer to the aerosol generator 200, in particular at an AC drive current frequency of significantly less than 1 MHz which guarantees an optimal aerosol quality (see below). In particular, an electric excitation of the primary coil 320 having a plurality of windings generates a magnetic flux which acts upon the secondary coil 220 and a voltage is induced in the secondary coil 220. Here, the electric excitation and configuration parameters of the primary and secondary coils are selected in such a way that a sufficient coupling constant is achieved so that a suitable voltage is induced which allows for the vibration generating element 10 to vibrate the membrane 8 to generate an aerosol. Here, the primary and secondary coils preferably have inductance values between 20 to 500 μH which determines the coil material and the number of windings that may be used for the respective plugs.
The inductive coupling is thus provided here for an electric driving (inductive power transfer) of the vibration generating element 10 (piezoelectric element) of the vibration head 210, not for the purpose of charging a battery.
The provision of the vibration head 210 with a mechanically stable mechanism to plug-in and lock the electric contacting element 300 may provide the additional advantage that a lateral offset between the primary and secondary coils is minimized and thus an improved inductive coupling is achieved which minimizes power loss, in particular because an (practically) identical placement of the primary and secondary coils over the lifetime of the plug-in connection may be secured.
In the context of driving the vibration head 210 of the aerosol generator 200, the primary and secondary coils are preferably configured for a transfer of an alternating voltage at 70 Vpp at a frequency of 30-180 kHz, more preferably 110-170 kHz, at an electrical power of 2 W. As such, the control unit 120 may provide a corresponding electric excitation to the primary coil 320, i.e. an alternating voltage at 70 Vpp at a frequency of 30-180 kHz, more preferably 110-170 kHz, at an electrical power of 2 W. Surprisingly, the present inventors have found that these electrical parameters may be used by integrating secondary coils into vibration heads, as described above, without changes of the physical dimensions thereof and also without detrimental effects on the aerosol properties, such as TOR (Total Output Rate) and MMD (Mass Median Diameter), in particular at these excitation frequencies (for example between 110-170 kHz). In particular, MMD values smaller than 5 μm may be achieved even with the present inductive coupling at these AC drive currents.
In a further embodiment, the secondary coil 220 may be integrated with the vibration head 210, for example within corresponding plastic or synthetic parts of the vibration head 210. As such, when the vibration head 210 is taken out from the aerosol generator 200, for example for the purpose of cleaning, then the secondary coil 220 is removed together with the vibration head 210, while a complete enclosure is provided so that the secondary coil is not damaged when cleaning the aerosol head.
Further, by providing the matching network 230 in the vibration head 210, an additional electrical load (in addition to the vibration generating element 10) may by supplied with electric energy, such as one or more sensors which may require different electrical parameters than the vibration generating element 10. In such a case, the primary and secondary coils thus provide a single inductive coupling with regard to at least two different electric loads. This avoids a scenario in which the relatively small space available for the primary and secondary coils would have to be shared with a second inductive coupling due to additional coils for the purpose of providing electric energy to the sensors.
As further shown in
Preferably the magnetic field confining elements 250 and 350 may be provided with a pot-shaped core. Typically, the shape of such a pot core is round with an internal hollow that almost completely encloses the coil. Such a pot core may be made by two halves which fit together around a coil former and has a confining effect and prevents radiation and reduces electromagnetic interference. The usage of such pot-shaped cores as magnetic field confining elements 250 and 350 provides a simpler positioning of the primary and secondary coils, in particular in the relatively small space of the plug-type connection units. Preferably, the pot-shaped cores should deviate from each other by less than 1 mm in the cross-area or diameter, even more preferred by less than 0.5 mm, 0.3 mm, or 0.1 mm providing successively improved coupling efficiency.
It is further noted that also a spatial maximum dimension of the magnetic field confining elements 250 and 350 is smaller than a spatial maximum diameter of the membrane 8 and/or the vibration generating element 10. In particular, the spatial dimension of the magnetic field confining elements 250 and 350 related to receive the respective coil windings of the primary and secondary coils, e.g. the spatial dimension of the pot-shaped core is smaller than a diameter of the membrane 8 and/or the vibration generating element 10.
Based on the contactless, inductive coupling provided between the control unit 120 and the vibration head 210, the controller 100 and the vibration head 210 are separate structural components and may be provided with a complete enclosure, i.e. no open electrical contacts. In particular, each component may be provided with a separate casing to avoid moisture/water entry. In addition, this allows for an improved chemical and/or thermal disinfection, for example because the disinfection does not affect the moulded coils as compared to the open electric contacts of the conventional system that leads to corrosion. In particular, a synthetic material that may be used for overmolding the coils is resistant to temperatures of 100° C. and above. The positioning of the coils for inductive coupling may thus be maintained without deformation.
In a further embodiment, the contactless, inductive coupling may further be used for the additional transmission of information data, for example for the purpose of transmitting control parameter/inhalation data to/from the vibration head 210. For this, a transmission-side unit at the controller 100 and/or the vibration head 210 appropriately modulates the information data onto the excitation signal (described above) and a corresponding reception-side unit at the controller 100 and/or the vibration head 210 filters/demodulates this excitation signal. Here, the information data may refer to sensor and/or storage data, for example to drive sensors or actuators or to read out storage areas of the sensors at the aerosol generator or at the vibration head.
An example of such a sensor is a fluid presence sensor for detecting whether a sufficient amount of fluid/liquid is present in the reservoir. Another example of such a sensor is a flow sensor for detecting whether a patient/user is inhaling or exhaling. As illustrated above, one or more such sensors may be supplied with electric energy via the single inductive coupling provided between the primary and secondary coil, preferably in addition to enabling data transmission.
In a further embodiment illustrated in
As illustrated in
The detection/determination unit 130 is configured to detect an energy storage parameter related to the connected electric contacting element 300 and to determine whether the vibration head 210 is connected with the electric contacting element 300 based on a determined energy storage parameter.
Such a detection and determination mechanism may be of particular interest for patients in intensive medical care, for which a medication or drug administration is provided via a respiratory device, and which themselves are not capable of verifying the proper/correct aerosolization of the medication or drug. In addition, such an intensive medical care setup may require the presence of rather long electrical cables that connect the controller 100 with the aerosol generator 200 (being provided with an inserted inductive coupling based vibration head 210) and which are thus prone to disconnection errors. Therefore, a determination as to a correct connection of the vibration head 210 minimizes errors in medical treatments. Such a detection and determination mechanism may also be of particular interest in situations in which the controller 100 is in a remote position from the aerosol generator (being provided with an inserted inductive coupling based vibration head 210). In such a situation, the proper connection may, for example, not be visually checked.
In the following, two cases are distinguished. In a first case, the electric contacting element 300 is connected only with the connection unit 110 of the controller 100, while in a second case the electric contacting element 300 is connected with both the connection unit 110 of the controller 100 and the vibration head 210 is properly placed into the aerosol generator 200 and the plug 330 of the electric contacting element 300 is mechanically connected with the vibration head 210 so that an inductive coupling between the primary coil 320 and the secondary coil 220 is efficiently achieved. Only in the second case, the vibration head 210 has a contactless electric connection with the controller 100 and a proper aerosol generation can be ensured.
The present inventors have realized that the controller 100 itself is able to distinguish between these two cases on the basis of an energy storage parameter. Here, the energy storage parameter is associated or related to the connected electric contacting element 300 in the above first case, and is associated or related to the connected electric contacting element 300 and the connected vibration head 210 combined in the above second case. The energy storage parameter refers to at least one of capacity (electric charge storage in a capacitor) and inductance (magnetic field energy) that may be (temporarily) stored in the vibration head 210 and the electric contacting element 300, respectively.
The energy storage type of a piezoelectric element in a vibration head 210 may be primarily of capacitive nature with values of 4-7 nF, while the primary/secondary coil typically has inductance values from 20 to 10.000 pH. The storage type of an electric cable may be primarily of capacitive nature with values of 0.05-0.25 nF. In other words, both the vibration head 210 and the electric contacting element 300 have distinguishable energy storage parameters.
Based on the above, in the above first case, the energy storage capacity related to the connected electric contacting element 300 is thus the energy storage capacity of the electric contacting element 300. In the above second case, i.e. when also the vibration head 210 is connected due to inductive coupling, then the energy storage capacity related to the connected electric contacting element 300 is the energy storage capacity of both the electric contacting element 300 and the vibration head 210, i.e. the amount of electric energy (electric field and/or magnetic field) that may be stored in both the electric contacting element 300 and the vibration head 210.
As will be further detailed below, the detection of a parameter related to the energy storage capacity may be performed by a pulsed measurement, for example by a mono-polar or bi-polar electric pulse measurement. This may be considered as a test pulse measurement or a pre-phase measurement. The mono-polar test pulse may be provided by a simple pulse generating set up, while a bi-polar test pulse is advantageous in order to electrically discharge the piezoelectric element 10 of the vibration head 210 completely. Here, responsive to applying an electrical test pulse to the connected electric contacting element 300, an electric discharge profile, i.e. an electric discharge curve over a defined electric load in the first case (only electric contacting element connected) or second case (electric contacting element and inductive coupling based vibration head connected), may be detected by the detection unit 120. Such electric discharge curves may be a voltage discharge profile typically having an exponential temporal decay U(t)=U0×exp(-t/τ) in which U is a measured voltage, t is time, and τ is an example of an energy storage parameter that indicates a corresponding capacitance and/or inductance value of the connected load. In the above first case in which only the electric contacting element 300 is connected, the energy storage parameter T1 is thus a value that is typically much smaller than in the above second case in which also the inductive coupling based vibration head 210 is connected and the energy storage parameter is τ2, i.e. τ1<τ2.
More specifically, the detection/determination unit 130 may thus be configured to analyze the measured discharge curve and determine an energy storage parameter therefrom. Here, the analysis of the measured discharge curve may be performed by the detection/determination unit 130 by applying one or more fitting parameters to the measured discharge curve. Based on the determined energy storage parameter (τ1, τ2), the detection/determination unit 130 thus determines whether the inductive coupling based vibration head 210 is correctly connected (τ≅τ2) or whether the inductive coupling based vibration head 210 is not connected (τ≅τ1). Thus, determination may be performed by comparing the detected energy storage parameter with a predetermined threshold. Such a predetermined threshold may be set on the basis of typical values τ1 for the electrical contacting element 300. It is noted that different electrical contacting elements (electronic cable, a connector, a print circuit, a circuit path, a conductive polymer, an electric wire, a pin, a plug, or a combination thereof) may be used in practical applications, but that the energy storage parameter of an inductive coupling based vibration head is always significantly larger, as explained above.
The notification unit 140 is configured to notify a user, via at least one of a visual, audio, or a haptic feedback, of a determination result of the detection/determination unit 130. For example, if an inductive coupling based vibration head 210 is connected a green light may be shown to thus user, while a red (e.g., blinking) light is shown to the user if the determination result indicates that an inductive coupling based vibration head 210 is not connected. In particular, the notification may provide a warning that an inductive coupling based vibration head is not connected with the controller 100 and, therefore, the aerosolization is not started and an aerosol generation cannot be accomplished. This is, for example, helpful in hospital environments in which rather long electric cables 300 are used and the proper electric connection between the controller 100 and the vibration head 210 may be lost due to obstacles or the like. Alternatively, or in addition, the notification unit 140 may send a communication message, e.g. an e-mail, SMS, warning signal, or the like, to a third party (e.g. a central hospital monitoring system or the like).
The above measurement may be performed during the regular activation of the inductive coupling based vibration head 210, i.e. an electric activation of the inductive coupling based vibration head 210 when an aerosol is generated (online operation), and may also be performed in a pre-phase (i.e. a starting phase) of the aerosol generation activation, or during a stand-by mode in which no aerosol is generated. During the stand-by operation, for example, a pulsed electric excitation of the inductive coupling based vibration head (via the electric contacting element 300) uses electric parameters (voltage, current) which are not sufficient to vibrate the vibration head 210 in a way to generate aerosol. Such a stand-by measurement therefore avoids an actual aerosol generation and associated drug loss that would result from an operation of the aerosol generator during an on-line operation in which the inductive coupling based vibration head is supplied with alternating current. In this way, no liquid medication is wasted when it is determined (only) that a proper electric connection of the inductive coupling based vibration head 210 is achieved.
In another embodiment, the detection/determination unit 130 may be further configured to determine a vibration head type. As discussed above, different inductive coupling based vibration head types may be provided for the aerosol generator 200. In particular, different electrical excitation parameters may be required for the different inductive coupling based vibration head types so that the determination of the connected vibration head type enables the controller 100 to select and apply corresponding control and/or drive parameters (voltage, current, and/or frequency).
The detection/determination unit 130 may distinguish between a plurality of different inductive coupling based vibration head types on the basis of the detected energy storage parameter. For each connected inductive coupling based vibration head type a distinguishable electric discharge curve can be obtained. As such, the detection/determination unit 130 may be provided with respective ranges for the energy storage parameter that are vibration head specific. In other words, these ranges may be specific for different inductive coupling based vibration heads to uniquely identify the respective vibration head type. For example, for a Type 1 vibration head, a specific parameter range between a minimal (min) and maximum (max) value may be provided, i.e. τ2(min) ≤τ2≤τ2(max), and a specific parameter range may also be provided for a Type 2 vibration head, i.e. τ2(min) ≤τ2≤τ2(max). The detection/determination unit 130 may then determine the connected inductive coupling based vibration head 210 by comparing the detected energy storage parameter τ2 with these ranges.
The storage unit 150 of
Based on the above, a cost-efficient way to determine whether an inductive coupling based vibration head is connected with the controller of the aerosol generator is provided. The controller may be used, without further programming, with regard to different vibration head types, and thus simplifies the usability. In addition, an independent signal connection as well as an independent identification device (characterization device) for the purpose of identifying the vibration head type, as shown in U.S. Pat. No. 8,720,432 B2, for example, may be omitted.
According to a further embodiment, the control unit 120 of the controller 100 may be configured to alternatingly generate excitation signals of at least two different frequencies. Here, the excitation signal of a first frequency (f1) may be the above described excitation signal which is supplied via the contactless inductive coupling in the vibration head 210 to the vibration generating element 10 in order to cause the membrane 8 to oscillate/vibrate and to generate the aerosol. The excitation signal of the second frequency (f2), on the other hand, may be related to a frequency that is used for determining an operating state of the vibration head 210. The time periods in which the second frequency signal is supplied to the vibration generating element 10 via the inductive coupling, provided by the primary coil 320 and the secondary coil 220, are typically much shorter than the time periods in which the first frequency signal is supplied. This is because the second frequency signal is supplied for measuring purposes only and should prevent a disturbance or interruption of the generation of the aerosol.
Here, the operating state of the vibration head 210 may refer to respective specific characteristics during nebulization and during an operation without a liquid, i.e. operating states with and without a liquid on the vibrating membrane 8. By detecting an electric parameter of the vibration head, such as electric current, voltage, electric power, phase shift, which are dependent on the capacity of the vibration generating element 10, the present inventors have surprisingly found that the operating states with and without liquid on the membrane can also be reliably determined when an inductive coupling to the vibration head 210 is provided, as described above, and the influence of the inductance of the primary and secondary coils cannot be ignored.
In order to detect at least one of the parameters of the vibration head 210, the detection/determination unit 130 of the controller 100 is configured in such a way that, during operation of the control unit 120 and responsive to the above described alternating excitation signals of at least two different frequencies, the at least one electric parameter is tapped from respective connecting lines of the electric contacting element 300 that supplies the excitation signals to the primary coil 320. That is, parameters of the vibration head 210 are inferred by detecting one or more electric parameters related to the primary coil 320. b
A determination of the operating state, i.e. a determination of whether liquid is present or not, may be performed in the detection/determination unit 130 by comparing the detected value of the at least one parameter with a value for this parameter stored in the storage unit 150 of the controller 100. It is noted that the stored parameters are parameters that have been predetermined for the specific case of inductive coupling based vibration heads.
Detecting the at least one electric parameter of the vibration head to determine the presence of a liquid to be nebulized is thus even possible when providing inductive coupling based vibration heads.
If, by comparing a detected parameter with a stored parameter, the detection/determination unit 130 determines that there is no more liquid in the liquid reservoir, then, in a preferred embodiment, a corresponding notification signal is sent to the control unit 120 and to the notification unit 140. Upon reception of this notification signal, the control unit 120 automatically and immediately stops the supply of excitation signals to the primary coil, i.e. automatically switches off the aerosol generator 200. Further, the notification unit 140 provides a feedback (at least one of a visual, audio, or a haptic feedback, as described above) to indicate to the user that the aerosol generator has consumed the stored liquid.
In a further embodiment, the detection/determination unit 130 may also determine a breathing state of a user based on one or more electric parameters that are detected with regard to the primary coil 320 (e.g., voltage tap, current consumption, current/voltage phase position at the primary coil). This embodiment follows the observation that pressure fluctuations during breathing (i.e. during inhalation and during exhalation) act upon the vibrating membrane 8 and are sufficiently large to lead to an output signal that is emitted by the vibration generating piezoelectric element 10 and may be also transferred via the inductive coupling to the primary coil where such an output signal may be detected. The detection characteristic may be improved by further providing the detection/determination unit 130 with a low-pass filter unit and an amplifier unit (not shown). As such, a conventional flow sensor may not be necessary simplifying the aerosol generator and reducing the manufacturing costs.
| Number | Date | Country | Kind |
|---|---|---|---|
| 18212622.7 | Dec 2018 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/084869 | 12/12/2019 | WO | 00 |
