Abstract:
A dose counter is provided for coupling with a metered dose inhaler. The dose counter includes a top cover that has a top forming an observation window. The top cover forms an interior space receiving therein a circuit board and an electrical cell supplying electrical power. The circuit board includes a counting circuit and a display screen that is arranged under the window. As such, in the use of the inhaler, depression of the top cover actuates the inhaler and causes the display screen to display the number of times of actuation so as to allow a user to realize the remaining number of times for use of the inhaler thereby improving safety of medication use.

Description:
(a) TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to an electronic inhaler dose counter with displaying window to clearly showing the number of doses released from a medication containing canister, and more particularly to such a structure applicable to a metered dose inhaler or the likes for releasing a predetermined dose of medication for asthma patients. 
       (b) DESCRIPTION OF THE PRIOR ART 
       [0002]    To administrate the medications correctly in time is the most important thing to keep patients in a healthier condition whether he or she is in an acute or chronic disease status in her or his life. Most medications are in visible forms, such as tablet, capsule, injectable, patches, ointment or cream etc., hence patients will clearly know that they have took the medication after they administer them. 
         [0003]    However, an asthma patient is often prescribed with a metered dose inhaler or dry powder inhaler prefilled with certain amount of medication. In addition to routine controller treatment, when the patient experienced exacerbations of asthma, he or she can put the inhaler in front of his or her mouth and press the inhaler to release the dose and inhaled sprayed drug into his or her lungs in order to relive the symptom. However, the existing inhaler does not allow a user to visually identify the residual amount of the medication remaining in the medication canister. Under situations where additional inhaler can be immediately available during the exacerbation of asthma, severe consequences can be avoided, however, if patients cannot immediately get a spared inhaler and no one nearby to help, the patient will be put under a dangerous condition with high mortality. 
         [0004]    Conventional metered dose inhalers use chlorofluorocarbons (CFCs) as propellants. Since CFC has low water absorbability, it is a common practice to drop the inhaler into water to roughly identify the residual amount of medication by observing the floating condition of the inhaler. Such a way provides only a rough result of inspection and may not be feasible when the patient is leaving away from home. Further, since CFC is a substance that damages the ozone layer of the atmosphere, although the use of CFC in the inhalers is considered an essential use, yet the conventional CFC propellant based inhalers will eventually be replaced by inhalers using hydrofluoroalkane (HFA) as a propellant. 
         [0005]    For the HFA based inhalers, since HFA has a strong water absorbability, to ensure stability of medication, it is often not recommended that an inhaler using HFA as propellant be put in water to identify the residual amount of medication. However, a measure that shows the counts of release of individual doses must be provided to allow an inhaler user to identify the residual amount of medication in order to ensure safety of use of medication. 
         [0006]    The current solution in practice to such a problem is to add a mechanical window counter to the plastic mouthpiece or actuator of the inhaler. However, this solution greatly increases the cost of the mouthpiece or actuator and made them cost more than ten times higher of the regular mouthpiece or actuator. Furthermore, such design also caused the additional consumption of plastic materials which in return also caused additional burden to the environment. In addition, due to the smaller size of the counting window and designing limits, it is not easy for those having poor eye sights to read, may lead to incorrect reading or counting of the medication quantity. Apparently, there are drawbacks in association with easy to use and correct reading for the known mechanical inhaler counter. 
       SUMMARY OF THE INVENTION 
       [0007]    The primary objective of the present invention is to provide a separated dose counter for an inhaler, which could clearly displays the numbers of doses of medication used so as to avoid the trouble of getting unexpectedly aware of insufficiency of medication, to allows the resetting or zeroing function for the replacement of new medication canister in order for repeating uses, with which the consumption of plastic materials for making a mouthpiece of the inhaler can be reduced for environmental protection and patient could realized the amount of medication used by just watching the large display screen designed for facilitate reading thereof. 
         [0008]    To achieve the above objective, the present invention provides a electronic dose counter for use with a medication canister of inhalers. The does counter is composed of a top cover having a top forming an observation window, a circuit board, a positioning ring, an electrical cell, and a bottom cap. The circuit board forms a counting circuit and a display screen. The display screen is arranged below the window. The circuit board is positioned by the positioning ring and the bottom cap is mounted in a bottom-up manner to hold the electrical cell inside the top cover. As such, the bottom cap mounts the dose counter to a rear end of a medication canister and once the medication canister is depressed and actuated, the display screen shows the number of dose released of the medication canister to allow the user to identify the residual amount of medication in the canister. 
         [0009]    In the above-described dose counter of the present invention, an elastic device is arranged between the circuit board and the positioning ring and the elastic device is normally in a released condition. 
         [0010]    In the above-described dose counter of the present invention, the top cover forms an opening adjacent to the window for receiving and holding therein a reset button provided on the circuit board. 
         [0011]    In the above-described dose counter of the present invention, the counting circuit of the circuit board comprises a micro-controller unit (MCU), a display screen, a reset button, and an increment button, wherein the reset button is arranged on a top side of the circuit board, while the increment button is set on a bottom side of the circuit board to which a projection formed on the positioning ring corresponds in position to be engageable with the increment button. 
         [0012]    In the above-described dose counter of the present invention, the MCU of the counting circuit sets a predetermined time period of depression of the increment button to identify an effective count by which the number of count shown in the display screen is incremented by 1. 
         [0013]    In the above-described dose counter of the present invention, the reset button of the counting circuit is arranged, in a recessed manner, in a horizontal top surface of the top cover. 
         [0014]    The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
         [0015]    Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is an exploded view of an embodiment according to the present invention. 
           [0017]      FIG. 2  is a perspective view, partially broken, of the embodiment of the present invention in an assembled form. 
           [0018]      FIG. 3  is a cross-sectional view of the embodiment of the present invention. 
           [0019]      FIG. 4  is an enlarged view of a portion of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
         [0021]    Referring to  FIGS. 1 and 3 , the present invention provides a dose counter, which is generally designated at  1 , for an inhaler. The dose counter  1  comprises a top cover  20 , a circuit board  25 , a positioning ring  30 , an electrical cell  35 , and a bottom cap  37 . The dose counter is installed by fitting the bottom cap  37  to a rear end of a medication canister  15 . The medication canister  15  can then installed by fitting a tube formed at a front end thereof into a pump  11  formed in a mouthpiece  10  of the inhaler, whereby the dose counter  1 , when depressed for actuation, shows the number of times of actuation by which doses of the medication have been sprayed through the mouthpiece. 
         [0022]    The mouthpiece  10  is a known component, showing an L-shaped angled configuration. The mouthpiece has a vertical limb in which the pump  11  (see  FIG. 3 ) is mounted. When the front end tube of the medication canister  15  is fit into and thus coupled to the pump  11 , depression can be carried out to cause the medication to be sprayed through an open end. A of the mouthpiece for being inhaled by a patient into the lungs. 
         [0023]    Referring to  FIG. 2 , the top cover  20  is constructed to show an inverted U-shaped cross-section, forming a transparent window  21  in a central portion thereof. An opening  22  is formed next to the window  21 . The top cover  20  forms a plurality of coupling holes  24  in an inside surface of. Further, two fixation pegs  23  are formed in a circumferential portion around the window  21  and the two fixation pegs  23  are each provided with an elastic component, which in the embodiment illustrated, comprises a spring  29 . 
         [0024]    The circuit board  25  carries a counting circuit that is constituted by a micro-controller unit (MCU). The counting circuit is operated with a control parameter of time period of depression or actuation. In the embodiment illustrated, the control parameter is defined as a threshold of time period of depression or actuation, which, when exceeding the threshold, is considered an effective count, with which a display screen  26  increases the total count by one. A preferable pre-set time period for depression or actuation in this respect is set greater than 0.01 seconds but less than 0.5 seconds to be considered an effective counting signal. Further, the counting circuit comprises a power-saving mode which forces the circuit to enter a sleeping or standby condition when no actuation has been taken for a pre-set time period, such as 30 seconds. The counting circuit is connected to the display screen  26 , an increment button  27 , and a reset button  28  (see  FIG. 3 ). The display screen  26  and the reset button  28  are arranged on a top face of the circuit board  25 , while the increment button  27  is set on a bottom face of the circuit board  25 . The circuit board  25  forms a plurality of through holes  25   a , through which bolts  25   b  can be fit to secure the circuit board to the coupling holes  24  formed in the inside surface of the top cover  20 . 
         [0025]    The positioning ring  30  has a top forming a projection  31 , which opposes an underside of the increment button  27 . The positioning ring  30  forms through holes  32  corresponding, in position, to the two fixation pegs  23 . The positioning ring  30  has a bottom forming an accommodation chamber  33 , in which a positive terminal  34  and a negative terminal  34   a  are mounted. The positive and negative terminals  34 ,  34   a  are electrically connected through electrical wires to the circuit board  25 . Bolts  38  are set through the through holes  32  to secure the positioning ring  30  to the fixation pegs  23  that have ends forming inner-threaded holes for threading engagement with the bolts. In the embodiment illustrated, the present invention comprises a bottom ring  36 , which functions to couple the positioning ring  30  and the bottom cap  37  together. 
         [0026]    The bottom ring  36  has a bottom forming retention pins  36   a  and a top forming through holes  36   b . The bolts  38  are put through the through holes  36   b  of the bottom ring  36  and the through holes  32  of the positioning ring  30  to secure the bottom ring  36  and the positioning ring  30  to the fixation pegs  23 . 
         [0027]    The bottom cap  37  has a top forming retention slots  37   a . The bottom cap  37  comprises a circumferential portion forming a resilient structure  37   b , whereby the bottom cap  37  can be coupled to the bottom ring  36  by the retention slots  37  that receive and engage the retention pins  36   a  of the bottom ring  36 , while the resilient structure  37   b  of the bottom cap  37  allows for secure coupling of the bottom cap to the rear end of the medication canister  15 . In an alternative form, the bottom ring  36  is integrally formed with the positioning ring  30  and the bottom cap  37  can then be directly coupled to the positioning ring  30 . 
         [0028]    Referring to  FIGS. 2 and 3 , to assemble, the circuit board  25  is set, in a bottom-up manner of moving upward from bottom side, into the top cover  20  with the display screen  26  and the reset button  28  facing upward to have the display screen  26  opposing the window  21  and the reset button  28  received in the opening  22 . The bolts  25   b  are applied to secure the circuit board  25  to the underside of the inside surface of the top cover  20 . The springs  29  are then respectively fit over the fixation pegs  23 . The positioning ring  30  is set, in a bottom-up manner, to position under the circuit board  25  with the projection  31  faces upward to have the projection  31  in alignment with the increment button  27 . The two fixation pegs  23  of the top cover  20 , together with the springs  29  fit thereon, are respectively set into the two through holes  32  of the positioning ring  30 . The positive and negative terminals  34 ,  34   a  of the circuit board  25  are set in the accommodation chamber  33  formed in the bottom of the positioning ring  30  through electrical wires extending from the circuit board. The electrical cell  35  is deposited in the accommodation chamber  33  and the bottom ring  36  is stacked under the positioning ring  30  and secured by the bolts  38 . Then, the bottom cap  37  is fit and coupled to the underside of the bottom ring  36 . A medication canister  15  can then be installed by having the rear end of the canister fit to the bottom cap  37  and the front end of the canister  15  is fit to the pump  11  of the mouthpiece  10 , whereby depression or actuation of the top cover  20  may immediately cause the medication to be sprayed and the number of times of individual doses of the medication that have been sprayed can be shown. 
         [0029]    Referring to  FIGS. 3 and 4 , the dose counter  1  of the present invention uses the bottom cap  37  to couple to the rear end of a medication canister  15 , whereby when the medication canister is not put into operation, the springs  29  are in a released condition and resiliently support the circuit board  25  to separate the increment button  27  from the projection  31 ; and when in use, which is operated by manually depressing the top cover  20 , the increment button  27  is indirectly depressed down, causing the counting circuit to resume from the sleeping condition into an actuated condition, or alternatively, in case of replacing a new medication canister and the reset button  28  being triggered, the counting circuit can also be caused to switch from a sleeping condition into an actuated condition. After the display screen  26  is energized to show full illumination for one second, the counter enters a regular operation condition, when the count recorded in the counting circuit is set to zero. When the top cover  20  is depressed to have the increment button  27  on the bottom of the circuit board  25  contacting the projection  31  with the time period of contact therebetween exceeding a threshold, the depression is considered an effective count. In the embodiment illustrated, the depression time is set to be greater than 0.01 seconds and less than 0.5 seconds to be considered an effective count, with which the count of the counting circuit automatically incremented by “1” and the display screen  26  simultaneously shown the digit “1”. In this way, successive depression will cause incrementing of the count and the total count of actuation is shown in the display screen  26  by which a user may get aware of the amount of medication remaining in the medication canister  15 . 
         [0030]    In case that the depression time period of the top cover  20  does not reach the preset range, then it is considered a fault operation and the counting circuit does not count it and the display screen  26  still shows the original number of count. 
         [0031]    Further, when the medication canister  15  is used up and replacement of a new canister is required, the top cover of the dose counter according to the present invention is first removed and a sharp article, such as pen tip, is applied to depress the reset button  28  for a long while, so as to reset and zero the original number of counts displayed on the display screen  26 . Then, the dose counter is re-set on the new medication canister  15  with the bottom cap  37  and counting can be started again. 
         [0032]    In summary, the dose counter according to the present invention makes it possible to clearly show the times of individual dose has been released for a medication canister and thus allows for timely preparation of new medication. 
         [0033]    It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
         [0034]    While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.