Patent ID: 6119684
Filing Date: 2000-09-19
Classification: A61M

Abstract:
An improvement in an inhaler for the administration by inhalation of an aerosol consisting of a medicament an a propellant, said inhaler being of a known design comprising:a) a supply container having propellant and medicament therein;b) a nozzle for atomizing propellant and medicament conveyed thereto, to form an aerosol therefrom, having an opening from which the aerosol so formed is expelled;c) means for conveying propellant from the supply container to the nozzle;d) an actuating element for causing the conveyance of propellant and medicament from the supply container to the nozzle, upon actuation by a user of the inhaler; and,e) a mouthpiece having a channel, through which the aerosol formed by the nozzle is expelled from the inhaler, so that it may be inhaled;wherein the improvement comprises the addition of an an electronic means for sensing and reporting whether aerosol has been expelled from the inhaler upon actuation by the user, said electronic means comprising:f) a first thermal sensor, located in the vicinity of the nozzle opening, which produces an electrical signal that varies in response to the temperature in the vicinity of the nozzle opening, including any decrease in temperature caused by the expuslion of aerosol from the nozzle opening;g) a second thermal sensor, located away from the vicinity of the nozzle opening, for developing a reference signal which represents the ambient temperature and which is not influence by the expulsion of aerosol from the nozzle opening;h) an actuation-recognition device for producing an electrical signal upon actuation of the actuating means;i) an evaluating electronic unit, connected to the first thermal sensor, the second thermal sensor and the actuation recognition device, which evaluating electronic unit compares the signals of the two thermal sensors in order to determine whether there has been a decrease in temperature in the vicinity of the nozzle opening, and which uses the signal from the the actuation recognition device to evaluate whether a decrease in temperature in the vicinity of the nozzle opening has coincided with actuation of the actuating means, and which thereby determines whether aerosol has been expelled from the inhaler upon actuation by the user; and,j) an electronic display, by means of which the determination of the evaluating electronic unit is reported.