Metered-Dose Inhaler Counter (MDI) with Lateral Switches and Metered-Does Inhaler Including such a Counter

A dose counter for a metered-dose inhaler (MDI) has an actuator housing and canister with an activation valve at a valve end of the canister. The dose counter includes a circuit assembly having a substrate with at least a first and a second switch thereon. The first and second switches are sized and positioned to interact with the valve end of the canister when the canister moves from a rest position to an activation position, such that the first switch is triggered when the canister reaches a first longitudinal position and the second switch is triggered when the canister reaches a second longitudinal position that is offset from the first longitudinal position during movement of the canister from the rest position to the activation position. A counting circuit is configured to receive a signal from the first and second switches and to determine when the metered dose inhaler is activated.

FIELD OF THE INVENTION

The present invention relates to a metered-dose inhaler (MDI) counter, to metered dose inhalers including the metered dose inhaler counter, and to related methods.

BACKGROUND

Metered-dose inhalers (MDIs) are medication delivery devices that deliver a pharmaceutical formulation including one or more pharmaceutically active compounds (“active ingredients”) to a human or other mammalian patient.

Typically the pharmaceutical formulation is delivered by the metered-dose inhaler (MDI) as unit doses in the form of an aerosol. Each actuation of the metered-dose inhaler (MDI) delivers one unit dose. The unit dose is expelled by the metered-dose inhaler (MDI) and is taken into the body of the patient on inhalation, via the nose or mouth. The pharmaceutical formulation is delivered to or via the respiratory tract, notably to the lungs, of the patient on inhalation.

The metered-dose inhaler (MDI) includes a metering valve which is configured to ensure that each dose of the pharmaceutical formulation expelled by the metered-dose inhaler (MDI) is the same, within permitted tolerances. In particular, each dose should include the same amount of the active ingredient(s). Generally, the metering valve is configured to dispense a constant volume of the pharmaceutical formulation on each actuation of the metered-dose inhaler (MDI).

A metered-dose inhaler (MDI) dose may become less accurate after the metered-dose inhaler (MDI) has been used more than the recommended number of times. Patients typically have difficulty tracking the number of doses that they have used on a metered-dose inhaler (MDI). Although efforts have been made to provide mechanical dose counters, these dose counters may add significant cost and materials to the device and may be inaccurate. Mechanical dose counters may not be able to differentiate events when a dose is actually delivered as compared with other events, such as when a metered-dose inhaler is dropped on the ground or otherwise experiences movement that does not press the metering valve sufficiently for a dose to be delivered. Hence mechanical dose counters have not gained widespread acceptance from healthcare providers. Electro-mechanical and electronic dose counters have also been proposed but have yet to achieve a sufficiently low cost and sufficiently high reliability.

SUMMARY OF EMBODIMENTS OF THE INVENTION

In some embodiments, a dose counter for a metered-dose inhaler has an actuator housing and canister with an activation valve at a valve end of the canister. The canister is configured to be received in the actuator housing and to move from a rest position to an activation position in which the valve is depressed against a bottom portion of the actuator housing. The dose counter includes a circuit assembly positioned on the bottom portion of the actuator housing. The circuit assembly includes a substrate with at least a first and a second switch thereon. The first and second switches are sized and positioned to interact with the valve end of the canister when the canister moves from the rest position to the activation position, such that the first switch is triggered when the canister reaches a first longitudinal position and the second switch is triggered when the canister reaches a second longitudinal position that is offset from the first longitudinal position during movement of the canister from the rest position to the activation position. The circuit assembly further includes a counting circuit that is configured to receive a signal from the first and second switches indicating at least a first time when the first switch is triggered by the canister and a second time when the second switch is triggered by the canister, and to determine when the metered dose inhaler is activated responsive to the first and second time.

In some embodiments, the first and second switches are mounted on the substrate and the first switch comprises a first switch end that extends away from the bottom wall of the actuator housing and triggers the first switch when the first switch end is depressed a first distance toward the bottom wall, and the second switch comprises a second switch end that extends away from the bottom wall of the actuator housing and triggers the second switch when the second switch end is depressed a second distance toward the bottom wall, wherein the first distance is different from the second distance.

In some embodiments, in the first longitudinal position, the first switch is activated by the canister without activating the second switch.

In some embodiments, the first switch has a height that is offset from a height of the second switch.

In some embodiments, the first switch is configured to trigger at a first depression distance and the second switch is configured to trigger at a second depression distance that is offset from the first depression distance.

In some embodiments, the counting circuit is configured to determine when the metered dose inhaler is activated responsive to the first and second times from the first and second switches such that the counting circuit increments a dose count if the first and second times have a time difference that is less than a threshold amount indicating that the canister is moving at a sufficient speed to activate the canister.

In some embodiments, the circuit assembly comprises a generally arcuate shape having an opening that receives the canister valve during operation.

In some embodiments, when the counting circuit determines when the metered dose inhaler is activated responsive to the first and second time, the counting circuit increments a counting indicia, and displays the counting indicia on the display.

In some embodiments, the dose counter further includes an accelerometer in communication with the counting circuit, and the accelerometer is configured to activate the counting circuit when the accelerometer is moved with sufficient movement to indicate shaking of the metered-dose inhaler.

In some embodiments, a metered-dose inhaler (MDI) assembly includes a metered-dose inhaler (MDI) having an actuator housing and canister with an activation valve at a valve end of the canister. The canister is configured to be received in the actuator housing and to move from a rest position to an activation position in which the valve is depressed against a bottom portion of the actuator housing. A dose counter in the actuator housing includes a circuit assembly positioned on the bottom portion of the actuator housing. The circuit assembly includes a substrate with at least a first and a second switch thereon. The first and second switches are sized and positioned to interact with the valve end of the canister when the canister moves from the rest position to the activation position, such that the first switch is triggered when the canister reaches a first longitudinal position and the second switch is triggered when the canister reaches a second longitudinal position that is offset from the first longitudinal position during movement of the canister from the rest position to the activation position. The circuit assembly further includes a counting circuit that is configured to receive a signal from the first and second switches indicating at least a first time when the first switch is triggered by the canister and a second time when the second switch is triggered by the canister, and to determine when the metered dose inhaler is activated responsive to the first and second time.

In some embodiments, the first and second switches are mounted on the substrate and the first switch comprises a first switch end that extends away from the bottom wall of the actuator housing and triggers the first switch when the first switch end is depressed a first distance toward the bottom wall, and the second switch comprises a second switch end that extends away from the bottom wall of the actuator housing and triggers the second switch when the second switch end is depressed a second distance toward the bottom wall, wherein the first distance is different from the second distance.

In some embodiments, in the first longitudinal position, the first switch is activated by the canister without activating the second switch.

In some embodiments, the first switch has a height that is offset from a height of the second switch.

In some embodiments, the first switch is configured to trigger at a first depression distance and the second switch is configured to trigger at a second depression distance that is offset from the first depression distance.

In some embodiments, the counting circuit is configured to determine when the metered dose inhaler is activated responsive to the first and second times from the first and second switches such that the counting circuit increments a dose count if the first and second times have a time difference that is less than a threshold amount indicating that the canister is moving at a sufficient speed to activate the canister.

In some embodiments, the circuit assembly comprises a generally arcuate shape having an opening that receives the canister valve during operation.

In some embodiments, when the counting circuit determines when the metered dose inhaler is activated responsive to the first and second time, the counting circuit increments a counting indicia, and displays the counting indicia on the display.

In some embodiments, the dose counter further includes an accelerometer in communication with the counting circuit, and the accelerometer is configured to activate the counting circuit when the accelerometer is moved with sufficient movement to indicate shaking of the metered-dose inhaler.

In some embodiments, the counting circuit is further configured to generate usage data regarding usage of the metered-dose inhaler (MDI), and the assembly further includes a data transmitter for receiving usage data from the counting circuit and transmitting the usage data to a remote processor. In some embodiments, the usage data comprises a number of administered doses, a date and/or time of each of the administered doses, a low and/or no dose indication and/or an indication of whether the metered-dose inhaler was shaken prior to administration of a dose.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity.

The present invention is described below with reference to block diagrams and/or flowchart illustrations of methods, apparatus (systems) and/or computer program products according to embodiments of the invention. It is understood that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, and/or other programmable data processing apparatus or circuit to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

Accordingly, the present invention may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, embodiments of the present invention may take the form of a computer program product on a computer-usable or computer-readable non-transient storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system.

Embodiments according to the present invention will now be described with reference toFIGS. 1-11. As illustrated inFIGS. 1-9, a metered-dose inhaler (MDI)100includes an actuator housing200, a canister300, a dose counter400and a display assembly500. The actuator housing200includes an interior cavity210, a dispensing opening212, a dose counter opening214and a bottom portion220. The canister300includes an activation valve310on a valve end312thereof and another end314opposite the valve end312. The dose counter400includes a circuit assembly401that has a substrate402, a display connector404and at least two switches406,408. The dose counter400includes a counting circuit410on one side of the substrate402and batteries412on the other side of the substrate402. The switches406,408include respective switch knobs406A,408A that register an activation of the switch406,408when depressed. The display assembly500includes a display510with a display face512and a display housing520having an opening522and attachment arms524.

The canister300is received in the actuator housing cavity210and, as illustrated inFIGS. 7-9, the canister300is configured to move from a rest position (FIG. 6) to an activation position (FIG. 9) in which the valve310is depressed against the bottom portion220of the actuator housing200when the user presses against the end312of the canister300. The circuit assembly401is positioned on the bottom portion220of the actuator housing200and is secured in position by the attachment arms524of the display housing520.

The switches406,408are sized and positioned to interact with the valve end312of the canister300when the canister300moves from the rest position (FIG. 7) to the activation position (FIG. 9) such that one switch408is triggered when the canister300moves downward and reaches the longitudinal position shown inFIG. 8without depressing the other switch406. The switch406is triggered when the canister200moves further downward and reaches the longitudinal position shown inFIG. 9such that both switch knobs406A,406B are depressed. The longitudinal position of the canister200inFIG. 8is offset from the longitudinal position ofFIG. 9such that inFIG. 8, the switch408is depressed without triggering depression of the other switch406, and inFIG. 9both switches406,408are depressed.

As illustrated, the knobs406A,406A of the switches406,408are at different heights so that the knob408A is higher than knob406A. Consequently, the knob408A is depressed by the canister valve end312(FIG. 8) before the knob406A (FIG. 8) during actuation of the canister valve210. In this configuration, the switches406,408trigger at different times during the actuation of the canister valve210(FIGS. 7-9). The counting circuit410is configured to receive a signal from the switches406,408indicating the triggering times of the switches406,408, e.g., a time corresponding to when the switch408is triggered by being depressed by the valve end312and another subsequent time when the switch406is triggered by being depressed by the valve end312. The counting circuit410is further configured to determine when the canister valve310is activated based on the triggering times of the switches406,408. For example, in some embodiments, the counting circuit410registers a dose count if the triggering times of the switches406,408are sufficiently close together to indicate that the canister is moving at a velocity that would generate enough force to activate the valve310.

Although the switch knobs406A,408A are illustrated as being at different heights inFIGS. 7-9, it should be understood that any suitable configuration of switches that trigger actuating at different canister positions during activation may be used. For example, the switch knobs406A,408A and switches406,408may be the same size and positioned at different heights with respect to the bottom wall or portion220so that the knobs406A,408A trigger at different depression distances when depressed toward the bottom portion220of the actuator housing200. As another example, the switches406,408may be configured to trigger at different depression distances even if the knobs406A,408A are at the same height from the bottom portion220of the actuator housing200. Moreover, other types of switches may be used, such as deflection switches, optical switches, force sensors (piezoelectric force sensors) and the like.

When the counting circuit410determines when the metered dose inhaler is activated responsive to the signals received from the switches406,408(e.g., the activation times of the switches), the counting circuit410increments a counting indicia, and provides instructions to the display510to display the counting indicia on the display510.

As shown inFIG. 10, the activation times of the switches406,408are received as inputs to the counting circuit410. The counting circuit410further includes a switch activation timer450, a counter452and a display controller454. The counting circuit410may also be in communication with an accelerometer460and a data transmitter470.

As illustrated inFIGS. 10-11, the switch activation timer450receives the switch activation signals (Block600;FIG. 11) and determines whether the switch activation signals satisfy a timing criteria (Block602). For example, the timing criteria can be a time difference that is less than a predetermined threshold amount that indicates a successful actuation of the canister300. The threshold amount may be an experimentally determined amount of time that indicates, for example, that the speed at which the canister300is depressed is sufficient to actuate the valve310. The timing criteria may also include confirming that both switches406,408have been activated. The timing criteria may be selected to reduce “false counts” or switch activation that occurs when the meter-dose inhaler (MDI) is jostled or dropped, but no dose is administered. If the timing criteria are met at Block602, then the switch activation timer450increments counting indicia at the counter452to indicate that a dose has been dispensed (Block604). The display controller454receives the counting information from the switch activation timer450and/or the counter452and updates the display510(Block606). The counter452may increment counting indicia in either a positive or negative direction. That is, the term “increment” is meant to include both increases and decreases in counting. For example, the display510may display a number of doses left in the canister300and decrease the counter452when the canister300is depressed and the valve308is activated, or the display510may display a number of doses that have been dispensed and increase the counter452when the valve310is activated. In addition, the display controller454may also control the display510to display other information, such as an expiration date of the medication, a number of prescription refills remaining for the prescription, a time of day or a time at which the last dose was administered, and/or a message to show whether there was a sufficient dose (e.g., an error message). In particular embodiments, the display510is an electronic ink display, such as an electrophoretic display (E Ink Corporation, Cambridge, Mass., USA), which may reduce power consumption. However, LED displays or other suitable displays may be used.

As illustrated, for example, inFIGS. 2-9, the substrate402or circuit board of the circuit assembly401may have a generally arcuate or horseshoe shape that defines an opening430through which the valve310of the canister300passes during activation. In this configuration, the circuit assembly410may be positioned within the actuator housing200without requiring significant additional space to reduce or eliminate the need for additional bulky counters that may inhibit ease of use and/or user acceptance of the counter400. The display510and the dose counter400may be held in position in the actuator housing by the display housing520and, in particular, by the display housing arms524, which may be positioned such that the substrate402rests on the arms524. The display housing arms524may also engage with a corresponding engagement feature in the actuator housing200. The display510is viewable by a user via the opening522of the housing520.

In some embodiments, the metered-dose inhaler (MDI) assembly100may store and/or transmit data from the dose counter400using the data transmitter470(FIG. 10) when the device is used by the user, for example, to track patient compliance and use of the metered-dose inhaler (MDI) assembly100. In some embodiments, the data may be transmitted by the transmitter470to a processor that can analyze the data, for example, for patient compliance tracking. The data can include a number of administered doses, a date and/or time of each of the administered doses, a low and/or no dose indication (e.g., based on whether the canister300was properly depressed) and/or an indication of whether the metered-dose inhaler was shaken prior to administration of a dose. In some embodiments, the transmitter470can transmit dose counts to another device remote from the dose counter400, which can be used to analyze the data and/or transmit the data again to a network or other processor for additional analysis. The other device can be a handheld device such as a smart phone, a local computer or another medical device with additional processor capacity, such as a spirometer. The other device can either analyze the data, store the data for download, or relay the data to a computer network or other system for tracking and analysis. The transmitter470may be a low-energy Bluetooth connection, a radiofrequency connection, or other wireless connection and may both transmit and receive data. However, in some embodiments, a USB drive or wired connection may be used to collect and transmit the data.

As illustrated inFIG. 10, the metered-dose inhaler (MDI) assembly100may include an accelerometer460that is in communication with the dose counter counting circuit410. The accelerometer460may be used to activate the dose counter400when the metered-dose inhaler (MDI) assembly100is shaken or moved by a user, for example, by activating the batteries412of the dose counter400. For example, the batteries412may be disconnected from the circuit410by a switch, and the shaking of the accelerometer460may trigger the switch to connect the batteries412to the circuit410using a smaller power supply connected to the accelerometer460to conserve usage of the batteries412. The activation of the batteries412by shaking helps increase the battery life of the counter400. In some embodiments, the circuit410may include a timer that disconnects the batteries from the circuit410after a predetermined amount of time until re-activated by the accelerometer460. The accelerometer460may also be used to provide data to the counting circuit460to indicate that the metered-dose inhaler (MDI) assembly100was properly shaken before use. If the dose counter400is moved insufficiently to properly shake the contents of the metered-dose inhaler (MDI) assembly100before use by the user, for example, then the signal from the accelerometer460may be used to activate the dose counter400, but the data will indicate that the metered-dose inhaler (MDI) assembly100was not properly shaken before use. If the user properly shakes the inhaler, then the accelerometer460both activates the dose counter400(to register the dose via a force sensor or switch) and provides data indicating that the metered-dose inhaler (MDI) assembly100was properly shaken before use.