Surgery – Liquid medicament atomizer or sprayer – Pre-pressurized container holding medicament
Reexamination Certificate
2000-01-20
2002-05-21
Weiss, John G. (Department: 3761)
Surgery
Liquid medicament atomizer or sprayer
Pre-pressurized container holding medicament
C128S200140, C128S204230, C128S205230
Reexamination Certificate
active
06390088
ABSTRACT:
The invention relates to an aerosol inhaler for a medicinal substance to be inhaled and to an electronic module for use in association with such an inhaler.
An aerosol inhaler is to be understood as a device with the aid of which a patient can actively breathe in a given dose of a medicinal substance to be inhaled. A typical application for such a device is an acute asthma attack. Upon the actuation of a corresponding actuating element, the aerosol, consisting of a propellant and of the medicinal substance present in said propellant and distributed therein, passes from the supply container provided therefor, through a nozzle, into the air channel of a mouthpiece from where it is actively inhaled by the patient. The aerosol emission and atomization can be triggered electronically or mechanically.
Previously it was not possible to detect whether, upon the actuation of the actuating element, atomization had actually taken place or not. For example, this can be prevented by obstruction of the nozzle. Naturally atomization also does not take place when the aerosol supply container is empty. This can lead to complications as the patient has supposedly inhaled the medicine necessary to combat an acute attack, whereas in fact this is not true or only partially true. An only partial supply of the given dose frequently gives rise to a desire on the part of the patient to augment the effect of the medicinal substance by further inhalation. This can lead to a dangerous situation as a result of overdosing. Furthermore, the doctor caring for the patient loses an overview of the number of doses administered within a predetermined time interval, which is an impediment to responsible medical treatment.
Therefore, with this background, the object of the present invention is to further develop an aerosol inhaler of the type defined in such manner that it is at least possible to reliably recognise and evaluate the atomization of the aerosol upon the actuation of the actuating element. In accordance with further aspects of the invention, a series of evaluations relating to some treatment parameters, such as the number of administered doses, the doses remaining in the supply container and the indication thereof, as well as for example the checking of the aerosol to determine whether it corresponds to the doctor's prescription, are to be possible. Furthermore, an electronic module is to be provided for use in association with such an inhaler, which electronic module fulfills the electronic part of the object of the invention but in principle can also be used in the case of all known aerosol inhalers, and thus as an accessory to an aerosol inhaler.
This object is fulfilled in terms of the inhaler by the features of the characterising clause of Claim 1 and in terms of the electronic module in accordance with Claim 8.
Advantageous further developments are set forth in the associated sub-claims.
In accordance with the invention, it is thus provided that the inhaler be equipped with an electronic module which comprises an evaluating electronic unit for function monitoring which is supplied with signals from at least one thermal sensor arranged in the flow region of the nozzle and from a device for recognising the actuation of the actuating element, and comprises a display device for the output of the evaluation result produced by the evaluating electronic unit.
The crux of the invention thus consists in that a thermal sensor is arranged directly on the nozzle in which the atomization of the aerosol takes place. This permits a positive detection of the atomization of the aerosol on the basis of the recognition of the actuation and of the cooling of the propellant which occurs upon atomization, in that the cooling of the propellant leads to the cooling of the thermal sensor and a clearly defined electric signal can be generated. Malfunctions, such as obstructed nozzles or an empty aerosol supply container, can thus be reliably detected.
In a special and simple exemplary embodiment, the evaluating electronic unit generates a warning signal when atomization does not take place, and a signal representing the number of inhalation doses still contained in the supply container. These signals are communicated to the patient by means of a suitable display or, in the case of the warning, with an acoustic signal. As a result of the monitoring of the atomization the User can be warned when no atomization has occurred and thus he has not inhaled any medicinal substance, as can happen when a supply container is empty or also in particular when a nozzle is obstructed.
In accordance with a further advantageous development, it is provided that the thermal sensor detects the air flowing past it at the start of the inhalation, generates a corresponding signal therefrom, and sends this signal to the evaluating electronic unit which itself generates a signal which is optically and/or acoustically displayed as a coordination aid for the patient in the inhalation process.
The background to this further development is as follows:
The correct inhalation of the aerosol ideally proceeds in such manner that, having exhaled, the patient applies the device to his mouth and after the start of the inhalation triggers the atomization by depressing the actuating element. Many users have problems however in coordinating their breathing and the triggering of the atomization. An incorrect timing sequence of inhalation and triggering diminishes the effect of the medicament however, and impairs the clinical result. It is here that the described further development comes into effect in that immediately following the start of the inhalation the patient is informed by means of the optical or acoustic display that atomization is imminent. In this way the clinical result of the treatment is distinctly improved.
In accordance with a further embodiment it is provided that a further thermal sensor is arranged outside of the flow path of the aerosol, which further thermal sensor generates a reference signal which is likewise fed to the evaluating electronic unit and is linked with the signal from the first thermal sensor in such manner that the result permits the emitted quantity of aerosol to be deduced. The linking can take place, for example, in a differential amplifier in which it is possible to form the time characteristic of the difference between the temperature of the first thermal sensor arranged directly on the nozzle and the environmental temperature. The downstream, evaluating electronic unit then receives this difference signal and the integration of said signal within suitable limits supplies a value which, with the aid of a relation stored in a memory of the evaluating electronic unit, leads to the atomized quantity of aerosol. As a result of the quantitative detection, after each inhalation the patient can be given precise information as to whether a further inhalation is necessary. In the event of the undershooting of a specified quantity, preset in the program of the evaluating electronic unit, a warning signal can be generated which informs the patient that too little active ingredient has been inhaled. This monitoring possibility leads to greater reliability in the use of inhalers and to a more efficient therapy.
Alternatively, the emitted quantity of aerosol can be determined in that prior to the atomization the environmental temperature of the thermal sensor, which is anyhow arranged in the region of the nozzle, can be detected, digitalized and stored in the evaluating electronic unit. When the aerosol is now atomized during inhalation, the time characteristic of the temperature changes of the sensor is detected as so-called temperature profile. This temperature profile is digitalized and the previously stored environmental temperature is subtracted therefrom. The integration of the difference within suitable limits supplies a value which, with the aid of a relation stored in the memory of the evaluating electronic unit, leads to the atomized quantity of aerosol. The relation between the output voltage of the sensor signal a
Nöhl Klaus
Sprenger Harald
Boehringer Ingelheim KG
Devlin Mary-Ellen M.
Patel Mital
Raymond Robert P.
Stempel Alan R.
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