GB2514767A - Inhaler indicator spacer interface - Google Patents

Abstract

An adapter or spacer 5 allows a generic inhaler usage counter 1 to be assembled on to different inhaler housings 2 by changing the spacer interface and may be used on any type of canister 4 that dispenses through a nozzle when placed inside a housing in order to count the number of displacements between the canister and housing. It may provide an extra security measure on the reliability of the counter when used in-conjunction of other techniques of counting the remaining drug inside the canister. A battery, switch, and PCB sealed within the dose counter unit electronically count drug doses and a motion sensor detects movement of the inhaler and displays the amount of remaining drug uses.

Description

INHALER INDICATOR SPACER INTERFACE

The invention is for a spacer or adapter to allow a generic form of inhaler indicator or counter to be used to provide a count of the amount of drug remaining inside the canister with the counter attached to the canister.

The spacer design allows the indicator to be attached to any housing that the canister is placed into. This allows the spacer to provide an extra security measure on the reliability of the counter when used in-conjunction of other design techniques of counting the remaining drug or medication inside the canister. This allows other sensor means to work in conjunction to the spacer to provide a means of secondary checks that the inhaler canister has actually been depressed to a point of actuation.

The current designs available are all limited to a particular canister design and dimensions. Each manufacturer has their own design and dimension of housing that their canister fits into. Thus limiting the ability of any counter indicator to be used as a universal indicator. The spacer interface allows the inhaler indicator to be attached to any canister housing thus allowing the indicator to fit onto different canister housing. This then turns an existing canister/housing that has no indicator into one that has a drug status indicator. The spacer can be fixed by the plastic snap fit barbs (protrusions on the side) which house into the corresponding holes or a friction fit or glued by various techniques not limited to any type of adhesive. The status of the drug can be checked at any time by a quick movement of the inhaler in any axis, to allow the motion sensor to initiate the display of the JO amount of remaining drug uses.

BACKGROUND

Inbalers are commonly used to administer medication such as bronchodilators, corticosteroids and anti-allergenics to the pulmonary tracts of humans and other animals, and in particular to treat nasal and bronchiaL complaints such as asthma.

A typical inhaler includes a canister, having a nozzle, containing the drug or medicine, and a detachable casing for attachment to the canister. In most applications, the canister contains the drug in powder or liquid form, and the dispensing action forces out a regulated dose of the drug in aerosol form.

The aerosol may be created using a propellant e.g. CEO or HFA forced through the drug by the dispensing motion, or more preferably in PMDIs (pressurised measured-does inhaler) by creation of a significant overpressure inside the canister.

In most PMDIs, the dispensing action consists of moving the canister relative to the casing, the action of the casing on the nozzle of the canister causing the predetermined dose to be released when the nozzle has been depressed a set distance.

Existing inhalers therefore include a detachable casing having a seat member that is engaged with the canister nozzle when the canister is removably inserted to the casing. In most existing inhalers the seat member includes a gripping portion for gripping the nozzle, so that the canister is held in the casting, but only held so that the canister can be easily withdrawn from the casing by simply pulling the canister and casing in opposite directions.

This is the problem that exists. Once the inhaler canister is detached from the housing and mixed with other canisters, for example, to wash the mouth piece out or clean the canister nozzles, there is no means of being able to determine the number of uses that particular oanister has left, espeoia11 when it is mixed in with other oanisters of the same type. It is common for users to have several canisters to ensure that they do not run out of the drug. Keeping count of which canister is still with drugs inside can he a problem.

Typical PMDI canisters for use in PMDIs contain between 60 and 200 doses, and may be used on a daily basis, or only occasionally to relieve particular symptoms. In most cases the patient is unlikely to keep a reoord of the number of doses administered, so will not be aware when the canister is near to being empty. The patient will not necessarily be immediately aware that the drug is no longer being dispensed when they use the canister as the pressure of the canister, or the dispensing motion, may not change. This could be a potentially serious problem for the patient, resulting in an emergency when they find that the drug in their inhaler had been exhausted by an earlier use. This can cause more anxiety and lead to more emotional distress.

Therefore, there is a need for some form of counting device which can count the number of medication doses dispensed from a canister to provide an indication of when the canister is empty. In order to be of use, such a counting device must accurately record each actuation of the canister.

Previous attempts to provide such a counting device have had a number of drawbacks. In particular, some solutions have been proposed with a counting device which is mounted on the casing of the inhaler and records each actuation of the canister using, for example, a pressure pad or a lever based switch. These devices suffer from the problem that they either have to be reset manually, or if a canister is removed from the inhaler, the counter automatically resets, so if the same canister is replaced (e.g. after cleaning), the reading will be incorrect.

To overcome this problem, there are many other solutions proposed to try and keep a count of the contents of the remaining drug. However most of these also still have the problem that the designs are complex and too costly to implement and with the variations of canister housings it can be almost impossible to have a universal indicator.

These devices can use different technigues but most of them being too costly to manufacture or are too complex in function to allow them to function correctly when mass produced. While these patents are novel in the technique, non of them consider the impact in manufacturing a solution for the public to use the design sufficiently to provide a reasonably accurate indication of the remaining drug or medication.

The design outlined in this patent is to show how a spacer or adapter can he designed to integrate an indicator counter using the manufacturing experience of the Inventor as well as novel design techniques to provide a calibration free design that can be o manufactured for the mass market and provide a form of indication to asthmatic users. It is documented that the University of Michigan in 1995 conducted a survey in which it is reported that 54% of asthmatic users do not know the amount of drug remaining in the canister while only 8% actually tracked the amount of usage. It is apparent that major reasons on the lack of designs in the market are precisely because of the cost and complexity of the designs to provide a manufacturability solution.

For example the following patents are considered too complex for manufacture:-PCT W092/17231 by INNOMED shows a set of contact rings on the canister and a set of sensors in the housing. There is no reference to how this would work in the field when you consider calibration, contact problems inside the housing, assembly and user friendly of removing and reinserting the oanister.

Patent U8006148815A by James L Wolf shows very complex design built into the housing that will allow to do a number of functions of counting and interfacing to external devices. Again for manufacture assembly it is very complex and difficult making the unit costly and difficult to use.

EP 0684047 A3 by Walker, William shows a complex counting system attached to the side of the housing and using the vertical displacement of movement of the canister to count. The housing contains the count while the canister once removed has no means of indication what amount of drug is remaining.

Patent US0054ll173A by Albert Weinstein shows a spray dispenser. This is similar to the Walker William version except it is upside down for use with an upright spray. The problem again is the complexity to achieve the count.

Patent US006202642B1 by Robert J McKinnon shows a very complex design in which the canister is complexly housed in the housing. Assembly for manufacture is very complex and difficult to use.

Patent WO 02/36190 A2 by Glaxo Group ltd gives a design whioh incorporates feedback of the drug being released when the dispenser is used. This is accurate but complex to manufacture and calibrate for the user.

Patent U5005284133A by James S Burns gives a detailed design based on the counter on the housing.

Again the count is not retained by the canister once removed from the housing.

The above list is just a few of the designs that o have been invented. They all use the relative motion of the canister to the housing to dispense the drug and have numerous ways of indioating the usage. The problem with most of them is that they are complex to manufacture and cannot be transported to any other inhaler housing.

Other patents such as WO 031/103759 Al by Trumeter company ltd and WO 01/28887 by Glaxo Oroup Ltd has the indicator on the nozzle and has it assembled onto the front part of the canister. The relative movement of nozzle to this attachment is the method of count. This is an acceptable design but it is complex to manufacture and difficult to port to other inhaler housing.

All of the designs use power from a battery and do not necessarily disclose the replacement of it and some may be subject to being thrown away after use due to the battery expiring. This Inhaler design can provide several uses of canisters before It needs to be discarded. On this basis the indicator can last for upto 2 years providing the canister is replaced within the expiry time of the drug.

SUMMARY OF THE INVENTION

The design herein shows a design that is relatively simple to manufacture while allowing the indicator to fit any canister using a spacer interface.

Accordingly, in its broadest description, the

present invention provides a spacer adapter which adapts a usage counter for a canister assembly including: a canister which has a canister body for containing a substance, for example, a drug, a usage counter assembly which indicates the count and a spacer interface which fits into the standard housing which houses the canister assembly such that the top counter assembly engages with the spacer interface and then translated directly onto the canister housing to count the number of uses. The spacer allows the indicator to be interconnected. As the design is sealed by plastic welding techniques, it will be water proof.

In the event the canister is placed accidentally in the water the counter circuit will not he at any risk.

The electronics inside the counter can store the count of the number of drugs dispensed at any time of its use. This can be done in a variety of ways using memory or a special register which contains the usage information.

The design is based on indicating its use by visual means of either a Liguid crystal display (LCD) or o preferably a light emitting diode (LED) form when the user uses the inhaler to administer the drug. The display is not limited to electrical means but can also be a mechanical view adjusted by a set of wheels to display the count value. The means of saving power for giving the status of the unit a vibration sensor is used to detect severe side force which will cause an internal electrical contact to be made and so Initiate an indication of the LEDs or LCD to display the current usage of the indicator. This technique allows the non use of an external switch keeping the electronics isolated from the external user. It also prevents the drainage of the battery as it will always require a force to cause the indication as a result nothing will happen if it is stationary. Alternative designs can make use of this feature with the use of the adapter to provide the decision that wakes the processor or to only increment the count if the distance of actuation has been reached.

Therefore, it is preferable that a canister assembly according to the present invention of using a spacer interface can be inserted to any standard inhaler housing. The spacer interface thus also can connect directly to the indicator thus making the indicator part of the overall assembly and allows the counter indicator to be precisely referenced to the canister housing and mechanical movement preventing the indicator from any distance errors in use or counting errors.

The design of the spacer will allow any generic indicator or counter to be used to provide an additional dimension on the counting or to safe guard the counter from errors. As an example, if the indicator uses a pressure switch to activate the electronics, then it can use the distance displacement to activate the switch as a reference to count the actuation. This then provides a robust means of ensuring the count is made to prevent underoounting or un-necessary over counting. It also allows the technigue to allow different indicator designs to be modified to make use of the displacement. The spacer can be made generic to friction fit in the host housing (canister housing) . It can also mean that the canister housing can be modified to have 2 holes on each side to allow the spacer to snap fit into the canister housing, while having 2 snap barbs on the top to also snap fit into the counter indicator. Thus, providing a complete encapsulation of the inhaler canister and the counter, into one piece. This gives a completely integrated product.

o Brief Description of the drawings

The following figures show the assembly of the counter assembly as follows: * Figure 1 is the complete system assembly.

* Figure 2 is the exploded view of the standard housing, spacer interface, canister and counter assembly.

* Figure 3 is the design of the spacer interface.

Figure 4 is the view of the spacer inserted into the canister housing.

S Figure 5 is the view of the counter assembly from the side and from underneath showing the interaction area for the spacer interface.

* Figure 6 shows the exploded view of all the main parts etc but not the smaller components such as resistor, capacitors etc. * Figure 7 shows the cross section view of the counter and how the parts interact with the canister.

* Figure 8 shows a modified spacer that has the snap fit barbs. These locate into the corresponding slots/holes on the inhaler housing and the inhaler counter indicator.

* Figure 9 shows the full assembly of parts and how they are fully connected using the snap fits.

Detail Description

With Reference to figure 1 this shows the fully assembled inhaler unit ready for use. The spacer interface [51 is assembled onto the main housing[2] and in the orientation showing the position of the mouthpiece [3] . Figure 3 shows the spacer [5] part on its own, the design is that it inserts into the housing [2] as shown in figure 4. This allows the spacer [5] to interact with the oounter [1] . Figure 4 shows the assembly without the oounter [1] . Figure 5 shows the oounter view from the side and underneath. This shows the area where the switch is interacted in the counter.

Figure 6 shows the exploded view of the major parts and how they are assembled. The entire electronics are housed inside the counter housing, sealed from the external environment.

The canister [4] is inserted into the main housing actuator. Under normal operation the top part of the counter is depressed and the nozzle is depressed into the actuator until the valve inside the canister releases the drug into mouth piece [3] . The drug then disperses through the mouth piece. In this embodiment the tn colour LED is via the lens[7] shown at the top of the counter and that would then light up into the magnified lens to indicate successful drug release and indicate the remaining amount of drug in the canister. The current embodiment is based on a traffic light system such that if the number of doses is 200 in the canister, then the LED will change its colour of light based on the amount of drug left. It is preferable that the following table shows the way the light changes colour according to the remaining drug. drugs could be while there is more than drugs inside the canister the light emitted by the LED[14] shown in Figure 7 and his can be done by using a display to show the numerical use of the canister counting down from 200 or up from 0 to 200, or by a simple means of light ohanging similar to a traffic light system where GREEN single flash indicates more than 100 does remaining, AMBER single flash can indicate less than doses remaining and RED single flash indicating less than 20 remaining and the user should think about replacing the canister and a RED flashing many times indicating either empty or less than 5 doses.

Example of Indicator status No of doses more then 100 single LED flashes GREEN No of doses less then 100 two LED flashes AMBER No of doses less then 25 three LED flashes RED No of doses less than 0 3* 3*LED Flashes Red The above is an example of the function and the organisation is not set in stone and can be changed to alternative values depending on what the range of doses is present in the canister. Also the choosing of LED colour is a choice by the manufacturer and can be any colour available whether it is a tn colour LED or single colour LEDs placed together under the magnification dome [7] The Spring motion sensor [15] assembly allow the function of a motion sensor in its simplest form to provide a short circuit to the spring in the event the spring is displaced with side to side movement. Any motion sensor can be used but this form allows minimum power to be used to detect vibration or movement in any axis.

In an alternative embodiment an LCD can replace the LED and so the number can be viewable from the dome on the number of remaining doses. The embodiment would depend on the user friendliness required. A Traffic light system requires no reading for children and is much more acceptable by changing colours. Children usually associate colcurs much mcre readily than with text or numbers. Seeing the colour red will make them much aware of danger than a numeral setting. In a different embodiment, the display means may include at least two or three LEDs. Preferably, the display means includes control means for operating one or more of the LEDs for a predetermined time interval, at a predetermined point in the operation of the device. The operation of the LEDs for a suitable time after a dose is dispensed from the canister has the advantages of conserving battery life and also serving as an indication that a dose has been dispensed.

The cross section view of the counter shown in Figure 4 gives a view of the assembly of the counter and the position of parts within the counter. The elastomeric Nat switch [10] is the main switch that will detect the movement of the canister with respect to the housing wall. When this is depressed in it will allow the main processor on the pcb[8] to count the drug and then light the LED with the correct colour.

The switch [10] is actuated when the spacer [5] depresses the switch due to the movement of the spacer in the vertical orientation. The different housings can be o catered for by simply changing the spacer interface to one that fits the design. This makes the counter adaptable to many different shapes without changing the actual functional characteristics of the design. The base can be adjusted so the contour of the base design follows the housing form. Figure 8 shows how the spacer with its snap barbs [16] can be inserted into the inhaler housing shown in figure 9. The snap barbs [16] slot into the corresponding slots [19] . The upper slots [17] are for the usage counter to snap fit onto the spacer.

In the cross section figure 7, the switch is held in position by a plate [9] which is ultrasonically welded to the base plate and so creates a seal against the ingress of liguid. The base and cover plate together provide a housing for the battery [11] which connects to the pcb[8] using the metal contacts [12] which clip into the pcb and hold the battery in place. No soldering is required in this battery clip design. It uses the pre-formed legs to provide a spring force which is always constant. The battery contact can be preformed made by any conductive material and is not just limited to metal. Figure 6 and 7 shows how the battery is pressed fitted into the pcb. The arrow heads then spring out holding the battery against the pob.

The whole design is ultrasonically welded together to allow the design to make it completely sealed from liquid ingress. The battery size is dependant on the power required by the counter assembly and its predicted life time design. In some uses the battery can be reduced In size to allow a one time function so that it can provide an indication to the user that when a new canister is to be used, however in the current usage counter design the calculation's give a lifetime of over 2 years in use.

The typical lite usage ot an inhaler drug can be up to 6 months from first use. This then allows the power caLculations to be done in order to match the lifetime of the drug use date. In this application the usage indicator counter can be used upto 4 times before re-cycled. Note the counter indicator can be returned back to supplier for a replacement. The manufacturer can then tear the usage counter down to its main parts and then re-use the pcb, electronics and replace the battery. This then allows the device to be continually re-used until at such point it is deemed to be expired.

The user can remove the counter assembly from the canister and reuse it onto another canister due to the jo friction fit of the counter onto the canister. In this event it is recommended that the user also resets the usage counter device. The reset method is only achieved by putting the usage counter device into a state which under normal operation -cannot be performed.

The overall function of the counter is to provide a warning when a number of doses egual to the upper limit or the starting number has been dispensed. Alternative warnings means may also be used, be it audible or visual as shown in this embodiment.

Examples of the display can be mechanical display, a clock, bED or an lCD, any of which may display the number of doses dispensed and/or remaining, and may display other information as well, which may, according to the patterns displayed, indicate one or more states of the canister (e.g. full, in use, nearly empty and/or empty) Thus, in normal use, the status of the canister can be clearly seen or heard.

Preferably, all of the components of the counter switch and display means are sealed within the body.

The PCB contains the electronics using a micro-processor or an Application Specific Integrated Circuit (ASIC) which controls the functions of the counting and display drivers. Other components that are needed such as resistors, capacitors and switches are all on the PC3 so that a full electronic function circuit is realised.

These electronic components are used in various orientations and locations placed on the pcb so that the space envelope used is minimised and the manufacturability is optimum for cost and ease of assembly.

It is to be understood that variants of the above described examples of the invention in its various aspects, would be readily apparent to the skilled person, and may be made without departing from the scope of the invention in any of its aspects.

Claims (8)

1. CLAIMS1. A spacer / adapter interface used to connect a usage/counter indicator for a drug dispenser comprising; a spacer interface to connect to the inhaler canister hcusing; to provide a means of checking that the distance between the canister housing and the spacer is equivalent to a valid count for the counter indicator assemfly which by JO display means, indicates how much or how many doses are left in the dispenser.
2. 2. A spacer interface according to Claim 2 wherein the counter indicator fits directly onto the spacer interface thus allowing the counter indicator to be connected onto the canister.
3. 3. A counter indicator according to cThim 1 that counts the number of displacements between the canister and the spacer interface fitted to the inhaler canister housing.
4. 4. A counter indicator according to Claim 1 wherein the count is translated to indicate the status of the contents of the canister onto a display.
5. 5. A counter indicator according to Claim 1 wherein the displacement of the distance between the canister housing and the spacer is used to verify the distance moved by the counter fitted to the canister.o
6. 6. A counter according to claim 1 wherein the d±spacement of the distance between the spacer and inhaier canister is used in conjunction to other counting means to provide a secondary verification that the inhaler has dispensed the medication.
7. 7. A display means according to claim 1 by emitting light to indicate status of the remaining drug.
8. 8. A display means according to claim 1 by using an LCD to indicate status at the remaining drug.Amendments to the claims are made as follows:CLAIMS1. A spacer / adapter interface used to connect a usage/counter indicator for a drug dispenser to a standard inhaler hcusing to allow the distance of canister movement with respect to the inhaler housing to provide a means of counting the number of drug dispense ccmprising of; a spacer interface to connect between the inhaler canister housing 13 and Indicator; to provide a means of checking that the operating distance between the canister housing and the spacer is equals sufficient change to translate into a valid count for the counter indicator assembly which by display means, indicates how much or how many doses are left in the dispenser.2. A spacer interface according to Claim 2 wherein the counter indicator fits directly onto the spacer 23 interface thus allowing the counter indicator to be indirectly connected onto the canister.3. A counter indicator acccrding to claim 1 that counts the number of displacements between the canister and the spacer interface fitted to the inhaler canister housing.4. A counter indicator according to Claim 1 wherein the distance of displacement is translated to provide a valid count and indicate the status of the contents of the canister onto a display.5. A counter indicator according to Claim 1 wherein the Lfl displacement of the distance between the canister ct housing and the spacer is used to verify the distance moved by the counter fitted to the canister. ct6. A counter according to claim 1 wherein the displacement of the distance between the spacer and inhaler canister is used in conjunction to other counting means to provide a seoondary verifioation that the inhaler has dispensed the medioation.22 7. A display means acoording to olaim 1 by emitting light to indioate status of the remaining drug.8. A display means acoording to olaim 1 by using an LCD to indicate status of the remaining drug.