Patent Description:
A variety of diseases exists that require regular treatment by injection of a medicament. Such injection can be performed by using injection devices, which are applied either by medical personnel or by patients themselves. As an example, type-<NUM> and type-<NUM> diabetes can be treated by patients themselves by injection of insulin doses, for example once or several times per day. For instance, a pre-filled disposable insulin pen can be used as an injection device. Alternatively, a re-usable pen may be used. A re-usable pen allows replacement of an empty drug or medicament cartridge by a new one. Either pen may come with a set of one-way needles that are replaced before each use. The insulin dose to be injected can then for instance be manually selected at the insulin pen by turning a dosage knob and observing the set dose shown on part of a number sleeve that is visible through a dose window of the insulin pen. In other cases, the set dose is show on an electronic display of the insulin pen. The dose is then injected by inserting the needle into a suitable skin portion and pressing an injection button of the insulin pen.

To be able to monitor insulin injection, for instance to prevent false handling of the insulin pen or to keep track of the doses already applied, it is desirable to measure information related to a condition and/or use of the injection device, such as for instance information on the injected insulin type and dose.

<CIT> discloses a supplementary device for a manually operable injection device. The device has a body and a mating unit configured to releasably mount the body to the injection device in a specific position relative to an outside surface of the injection device.

A first aspect of the specification provides a supplementary device for attachment to a drug delivery device, the supplementary device being as recited in claim <NUM>.

This supplementary device may allow a user easily to identify whether a currently set dose is a dose that is permitted for the user, even if they are unable to determine that information directly from the drug delivery device. This can improve usability, and also safety, for the user. Moreover, this can be achieved in an intuitive way, according to various optional features which are described below.

The processor arrangement may be configured to process the image data representing the captured image to identify one or more characteristics of the number sleeve at the location by determining a colour of the background of the number sleeve at the location.

The processor arrangement may be configured to process the image data representing the captured image to identify one or more characteristics of the number sleeve at the location by determining a colour of the numbers on the number sleeve at the location.

The processor arrangement may be configured to determine from the determined characteristics of the number sleeve whether the currently set dose of drug is a permitted dose by determining whether the characteristics of the number sleeve at the location are light coloured numbers on a dark coloured background.

The processor arrangement may be configured to determine from the determined characteristics of the number sleeve whether the currently set dose of drug is a permitted dose by determining whether the characteristics of the number sleeve at the location are dark coloured numbers on a light coloured background.

The processor arrangement may be configured to cause the indication that the currently set dose of drug is not a permitted dose to be provided by causing display of a message.

The processor arrangement may be configured to cause the indication that the currently set dose of drug is not a permitted dose to be provided by causing display of a message simultaneously with causing display of the quantity of the currently set dose of medicament.

The processor arrangement may be configured to cause the indication that the currently set dose of drug is not a permitted dose to be provided by causing display of a message alternately with causing display of the quantity of the currently set dose of medicament.

The processor arrangement may be configured to cause the indication that the currently set dose of drug is not a permitted dose to be provided by causing illumination of an LED or other optical transducer.

The processor arrangement may be configured, in response to determining that the currently set dose of drug is not a permitted dose, to actuate a locking arrangement to prevent drug delivery.

The specification also provides a system comprising the supplementary device above and a drug delivery device having a number sleeve with numbers provided thereon.

Disclosed in the specification but not claimed is a number sleeve for a drug administration device, the number sleeve comprising a generally cylindrical outer surface on which are provided a sequence of numbers arranged at different locations on the surface with the sequence provided in a helix, each of the numbers relating to a drug dose, where the surface at locations corresponding to doses within a specific dose range has different characteristics to the surface at locations corresponding to doses that are outside of the specific dose range.

Through these features, a supplementary device may be able to determine from viewing the number sleeve not only a currently dialled or set dose but also whether the currently dialled or set dose is one that is permitted to be delivered to the user. This does not require the supplementary device to be pre-programmed with information relating to permitted dose sizes for the user. Also through these features, a user may be able to determine from observing a drug delivery device including the number sleeve not only a currently set or dialled dose but and whether the set or dialled dose is within a range of doses that are permitted for the user by their drug administration plan or regime.

The different characteristics may be different colours for the numbers on the surface of the number sleeve.

The different characteristics may be different colours for a background to the numbers on the surface of the number sleeve.

The different colours may be detectable by the human eye.

The surface at locations corresponding to doses within the specific range may indicate the dose as a number that is coloured black on a white background, and the surface at locations corresponding to doses outside the specific range may indicate the dose as a number that is coloured white on a black background.

The specification also discloses but does not claim a drug delivery device including the number sleeve above.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:.

In brief, the specification describes a supplementary device according to embodiments of the invention (alternatively known as a companion device, a clip-on device or a sensor device) that is operable with drug delivery device, e.g. an injection device, such as a pen injector. The supplementary device is configured to view a number sleeve of the drug delivery device and determine therefrom a set drug dose, and also a delivered dose. The supplementary device is configured also to detect from the number sleeve whether a currently dialled dose is a dose that is indicated by the drug delivery device to be a permitted dose. This is indicated by the number sleeve of the drug delivery device, and not by the numbers that are present on the number sleeve at a location that is being viewed but by some other optical characteristic of the number sleeve. In some embodiments, the currently set dose being a permitted dose is indicated by the numbers being provided as black numerals on a white background and the currently set dose not being a permitted dose is indicated by the numbers being provided as white numerals on a black background. The supplementary device is configured to respond to a detection of a currently set dose not being a permitted dose by providing an indication to a user, for instance in the form of a message. The supplementary device may also act to prevent drug delivery unless the set dose is a permitted dose.

The specification also describes a number sleeve for a drug delivery device, and a drug delivery device including the number sleeve. The number sleeve is provided with different characteristics at different locations, where locations corresponding to a dose in a specific dose range, corresponding to permitted doses, have a first characteristic and locations corresponding to a dose that are not in the permitted dose range have a second characteristic. These characteristics allow a supplementary device to sense from the drug administration device whether the dialled dose is a permitted dose even if the supplementary device does not have any pre-existing information about which doses are permitted for the user. These characteristics also allow a user easily to see from the injection device <NUM>, when the supplementary device <NUM> is not in place (e.g. when not in use), whether the currently set or dialled dose is permitted. In some embodiments, locations corresponding to a dose which is permitted indicate the dose as a number that is coloured black on a white background, and locations corresponding to a dose that is not permitted are indicated by a number that is coloured white on a black background.

In the following, embodiments of the present invention will be described with reference to an insulin injection device. The present invention is however not limited to such application and may equally well be deployed with injection devices that eject other medicaments, or with other types of drug delivery device.

<FIG> is an exploded view of an injection device <NUM>, which may for instance represent Sanofi's Solostar (RTM) insulin injection pen. More generally, it is a pen-type injector device.

The injection device <NUM> of <FIG> is a pre-filled, disposable injection pen that comprises a housing <NUM> and contains an insulin container <NUM>, to which a needle <NUM> can be affixed. The needle is protected by an inner needle cap <NUM> and an outer needle cap <NUM>, which in turn can be covered by a cap <NUM>. An insulin dose to be ejected from injection device <NUM> can be selected by turning the dosage knob <NUM>, and the selected dose is then displayed via dosage window <NUM>, for instance in multiples of so-called International Units (IU), wherein one IU is the biological equivalent of about <NUM> micrograms of pure crystalline insulin (<NUM>/<NUM>). An example of a selected dose displayed in dosage window <NUM> may for instance be <NUM> IUs, as shown in <FIG>. It should be noted that the selected dose may equally well be displayed differently. A label (not shown) is provided on the housing <NUM>. The label includes information about the drug included within the injection device, including information identifying the medicament. The information identifying the drug may be in the form of text. The information identifying the drug may also be in the form of a colour. The information identifying the drug may also be encoded into a barcode, QR code or the like. The information identifying the drug may also be in the form of a black and white pattern, a colour pattern or shading.

Turning the dosage knob <NUM> causes a mechanical click sound to provide acoustical feedback to a user. The numbers displayed in dosage window <NUM>, in the sense that they are visible through the dosage window <NUM>, are present on a number sleeve <NUM>. The numbers are for instance provided on the number sleeve <NUM> by printing. As can be seen best from <FIG>, the numbers are provided in a continuous sequence on the number sleeve <NUM>. Individual numbers (including numbers formed from two characters) are formed at consecutive locations in the shape of a helix around a generally cylindrical outer surface of the number sleeve <NUM>.

The number sleeve <NUM> is contained in housing <NUM> and mechanically interacts with a piston in insulin container <NUM>. When needle <NUM> is stuck into a skin portion of a patient, and then injection button <NUM> is pushed, the insulin dose displayed in display window <NUM> will be ejected from injection device <NUM>. When the needle <NUM> of injection device <NUM> remains for a certain time in the skin portion after the injection button <NUM> is pushed, a high percentage of the dose is actually injected into the patient's body. Ejection of the insulin dose also causes a mechanical click sound, which is however different from the sounds produced when using dosage knob <NUM>.

Injection device <NUM> may be used for several injection processes until either insulin container <NUM> is empty or the expiration date of injection device <NUM> (e.g. <NUM> days after the first use) is reached.

Furthermore, before using injection device <NUM> for the first time, it may be necessary to perform a so-called "prime shot" to remove air from insulin container <NUM> and needle <NUM>, for instance by selecting two units of insulin and pressing injection button <NUM> while holding injection device <NUM> with the needle <NUM> upwards.

For simplicity of presentation, in the following, it will be exemplarily assumed that the ejected doses substantially correspond to the injected doses, so that, for instance when making a proposal for a dose to be injected next, this dose equals the dose that has to ejected by the injection device. Nevertheless, differences (e.g. losses) between the ejected doses and the injected doses may of course be taken into account.

<FIG> is a close-up of the end of the injection device <NUM>. This Fig. shows a locating rib <NUM> that is located between the viewing window <NUM> and the dosage knob <NUM>.

<FIG> is a schematic illustration of an embodiment of a supplementary device <NUM> to be releasably attached to injection device <NUM> of <FIG>. Supplementary device <NUM> comprises a housing <NUM> with a mating unit or attachment mechanism configured and embrace the housing <NUM> of injection device <NUM> of <FIG>, so that supplementary device <NUM> sits tightly on housing <NUM> of injection device <NUM>, but is nevertheless removable from injection device <NUM>, for instance when injection device <NUM> is empty and has to be replaced. <FIG> is highly schematic, and details of the physical arrangement are described below with reference to <FIG>.

Supplementary device <NUM> contains optical and acoustical sensors for gathering information from injection device <NUM>. At least a part of this information, for instance a selected dose (and optionally a unit of this dose), is displayed via display unit <NUM> of supplementary device <NUM>. The dosage window <NUM> of injection device <NUM> is obstructed by supplementary device <NUM> when attached to injection device <NUM>.

Supplementary device <NUM> further comprises at least one user input transducer, illustrated schematically as a button <NUM>. These input transducers <NUM> allow a user to turn on/off supplementary device <NUM>, to trigger actions (for instance to cause establishment of a connection to or a pairing with another device, and/or to trigger transmission of information from supplementary device <NUM> to another device), or to confirm something.

<FIG> is a schematic illustration of a second embodiment of a supplementary device <NUM> to be releasably attached to injection device <NUM> of <FIG>. Supplementary device <NUM> comprises a housing <NUM> with a mating unit configured and embrace the housing <NUM> of injection device <NUM> of <FIG>, so that supplementary device <NUM> sits tightly on housing <NUM> of injection device <NUM>, but is nevertheless removable from injection device <NUM>.

Information is displayed via display unit <NUM> of supplementary device <NUM>. The dosage window <NUM> of injection device <NUM> is obstructed by supplementary device <NUM> when attached to injection device <NUM>.

Supplementary device <NUM> further comprises three user input buttons or switches. A first button <NUM> is a power on/off button, via which the supplementary device <NUM> may for instance be turned on and off. A second button <NUM> is a communications button. A third button <NUM> is a confirm or OK button. The buttons <NUM>, <NUM>, <NUM> may be any suitable form of mechanical switch. These input buttons <NUM>, <NUM>, <NUM> allow a user to turn on/off supplementary device <NUM>, to trigger actions (for instance to cause establishment of a connection to or a pairing with another device, and/or to trigger transmission of information from supplementary device <NUM> to another device), or to confirm something.

<FIG> is a schematic illustration of a third embodiment of a supplementary device <NUM> to be releasably attached to injection device <NUM> of <FIG>. Supplementary device <NUM> comprises a housing <NUM> with a mating unit configured to embrace the housing <NUM> of injection device <NUM> of <FIG>, so that supplementary device <NUM> sits tightly on housing <NUM> of injection device <NUM>, but is nevertheless removable from injection device <NUM>.

Information is displayed via display unit <NUM> of the supplementary device <NUM>. The dosage window <NUM> of injection device <NUM> is obstructed by supplementary device <NUM> when attached to injection device <NUM>.

Supplementary device <NUM> further comprises a touch-sensitive input transducer <NUM>. It also comprises a single user input button or switch <NUM>. The button <NUM> is a power on/off button, via which the supplementary device <NUM> may for instance be turned on and off. The touch sensitive input transducer <NUM> can be used to trigger actions (for instance to cause establishment of a connection to or a pairing with another device, and/or to trigger transmission of information from supplementary device <NUM> to another device), or to confirm something.

<FIG> shows a schematic view of the supplementary device <NUM> of <FIG> in a state where it is attached to injection device <NUM> of <FIG>.

With the housing <NUM> of supplementary device <NUM>, a plurality of components are contained. These are controlled by a processor <NUM>, which may for instance be a microprocessor, a Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA) or the like. Processor <NUM> executes program code (e.g. software or firmware) stored in a program memory <NUM>, and uses a main memory <NUM>, for instance to store intermediate results. Main memory <NUM> may also be used to store a logbook on performed ejections/injections. Program memory <NUM> may for instance be a Read-Only Memory (ROM), and main memory may for instance be a Random Access Memory (RAM).

In embodiments such as those shown in <FIG>, processor <NUM> interacts with a first button <NUM>, via which supplementary device <NUM> may for instance be turned on and off. A second button <NUM> is a communications button. The second button may be used to trigger establishment of a connection to another device, or to trigger a transmission of information to another device. A third button <NUM> is a confirm or OK button. The third button <NUM> can be used to acknowledge information presented to a user of supplementary device <NUM>. In embodiments such as those shown in <FIG>, two of the buttons <NUM>, <NUM> may be omitted. Instead, one or more capacitive sensors or other touch sensors are provided.

Processor <NUM> controls a display unit <NUM>, which is presently embodied as a Liquid Crystal Display (LCD). Display unit <NUM> is used to display information to a user of supplementary device <NUM>, for instance on present settings of injection device <NUM>, or on a next injection to be given. Display unit <NUM> may also be embodied as a touch-screen display, for instance to receive user input.

Processor <NUM> also controls an optical sensor <NUM>, embodied as an Optical Character Recognition (OCR) reader, that is capable of capturing images of the dosage window <NUM>, in which a currently selected dose is displayed. The dose is displayed by way of numbers present on the number sleeve <NUM> contained in injection device <NUM>, which numbers are visible through the dosage window <NUM>. Optical sensor/OCR reader <NUM> is further capable of recognizing characters (e.g. numbers) from the captured image and to provide this information to processor <NUM>. In this case, the optical sensor/OCR reader <NUM> includes a processor arrangement that is programmed by software stored in memory to be configured to perform optical character recognition. Alternatively, unit <NUM> in supplementary device <NUM> may only be an optical sensor, e.g. a camera, for capturing images and providing information on the captured images to processor <NUM>. Then processor <NUM> provides the function of performing OCR on the captured images.

The optical sensor <NUM> or the processor <NUM> provides the function also of detecting whether characteristics of the number sleeve <NUM> at the location being viewed by the optical sensor indicate whether or not the set or dialled dose is permitted.

Processor <NUM> also controls light-sources such as light emitting diodes (LEDs) <NUM> to illuminate the dosage window <NUM>, in which a currently selected dose is displayed. A diffuser may be used in front of the light-sources, for instance a diffuser made from a piece of acrylic glass. Furthermore, the optical sensor may comprise a lens system, for instance including two aspheric lenses. The magnification ratio (image size to object size ratio) may be smaller than <NUM>. The magnification ratio may be in the range of <NUM> to <NUM>. In one embodiment the magnification ration may be <NUM>.

Processor <NUM> further controls a photometer <NUM>, that is configured to determine an optical property of the housing <NUM> of injection device <NUM>, for example a colour or a shading. The optical property may only be present in a specific portion of housing <NUM>, for example an insulin container comprised within injection device <NUM>, which colour or colour coding may for instance be visible through a further window in housing <NUM> (and/or in number sleeve <NUM>). Information on this colour is then provided to processor <NUM>, which may then determine the type of injection device <NUM> or the type of insulin contained in injection device <NUM> (e.g. SoloStar Lantus with purple colour and SoloStar Apidra with blue colour). Alternatively, a camera unit may be used instead of photometer <NUM>, and an image of the housing or insulin container may then be provided to processor <NUM> to determine the colour of the housing or insulin container by way of image processing. Further, one or more light sources may be provided to improve reading of photometer <NUM>. The light source may provide light of a certain wavelength or spectrum to improve colour detection by photometer <NUM>. The light source may be arranged in such a way that unwanted reflections, for example by dosage window <NUM>, are avoided or reduced.

Processor <NUM> further controls (and/or receives signals from) an acoustic sensor <NUM>, which is configured to sense sounds produced by injection device <NUM>. Such sounds may for instance occur when a dose is dialled by turning dosage knob <NUM> and/or when a dose is ejected/injected by pressing injection button <NUM>, and/or when a prime shot is performed. These actions are mechanically similar but nevertheless sound differently (this may also be the case for electronic sounds that indicate these actions). Either the acoustic sensor <NUM> and/or processor <NUM> may be configured to differentiate these different sounds, for instance to be able to safely recognize that an injection has taken place (rather than a prime shot only).

Processor <NUM> further controls an acoustical signal generator <NUM>, which is configured to produce acoustical signals that may for instance be related to the operating status of injection device <NUM>, for instance as feedback to the user. For example, an acoustical signal may be launched by acoustical signal generator <NUM> as a reminder for the next dose to be injected or as a warning signal, for instance in case of misuse. Acoustical signal generator may for instance be embodied as a buzzer or loudspeaker. In addition to or as an alternative to acoustical signal generator <NUM>, also a haptic signal generator (not shown) may be used to provide haptic feedback, for instance by way of vibration.

Processor <NUM> controls a wireless unit <NUM>, which is configured to transmit and/or receive information to/from another device in a wireless fashion. Such transmission may for instance be based on radio transmission or optical transmission. In some embodiments, the wireless unit <NUM> is a Bluetooth transceiver. Alternatively, wireless unit <NUM> may be substituted or complemented by a wired unit configured to transmit and/or receive information to/from another device in a wire-bound fashion, for instance via a cable or fibre connection. When data is transmitted, the units of the data (values) transferred may be explicitly or implicitly defined. For instance, in case of an insulin dose, always International Units (IU) may be used, or otherwise, the used unit may be transferred explicitly, for instance in coded form.

Processor <NUM> receives an input from a pen detection switch <NUM>, which is operable to detect whether the pen <NUM> is present, i.e. to detect whether the supplementary device <NUM> is coupled to the injection device <NUM>. A battery <NUM> powers the processor <NUM> and other components by way of a power supply <NUM>.

The supplementary device <NUM> of <FIG> is thus capable of determining information related to a condition and/or use of injection device <NUM>. This information is displayed on the display <NUM> for use by the user of the device. The information may be either processed by supplementary device <NUM> itself, or may at least partially be provided to another device (e.g. a blood glucose monitoring system).

<FIG> is a flow chart illustrating operation of the supplementary device <NUM>. It will be appreciated that <FIG> is schematic, and omits many of the low level details of operation of the supplementary device.

The operation starts at step <NUM>. At step <NUM>, the supplementary device <NUM> detects the dose that is dialled into, or set in (these terms are used interchangeably), the injection device <NUM>. The dialled dose is detected by performing optical character recognition on the image that is provided by the optical sensor <NUM>, which is directed to read the number sleeve <NUM> of the injection device <NUM> at the location of the dosage window <NUM>, as described above. Initially, the dialled dose typically is <NUM>, before the user operates the injection device <NUM>. Following step <NUM>, the dialled dose is displayed in step <NUM> on the display <NUM>. In this way, the user is able to determine the dose that is dialled into the injection device <NUM> even though they are unable to view directly the number sleeve <NUM> through the dosage window <NUM>.

At step <NUM>, the supplementary device detects characteristics of the number sleeve <NUM>. The characteristic detected at step <NUM> are not the numbers that are present on the number sleeve <NUM>, but are some other characteristics.

The number sleeve <NUM> of the injection device <NUM> is provided with different characteristics at different locations, where locations corresponding to a dose that is permitted have a first characteristic and locations corresponding to a dose that are not permitted have a second characteristic. As shown in <FIG>, <FIG>, locations corresponding to a dose which is in a permitted range of doses indicate the dose as a number that is coloured black on a white background, and locations corresponding to a dose that is not permitted are indicated by a number that is coloured white on a black background. These characteristics allow a user easily to see from the injection device <NUM>, when the supplementary device <NUM> is not in place, whether the currently set or dialled dose is permitted.

In the <FIG> injection device <NUM>, the number sleeve <NUM> is marked to indicate that doses of <NUM> and higher are permitted. The whole of the number sleeve <NUM> of this injection device <NUM> is shown in <FIG>.

As can be seen in particular from <FIG>, locations corresponding to doses of <NUM> and above indicate the dose as a number that is coloured black on a white background. Locations corresponding to doses between <NUM> and <NUM> are indicated by a number that is coloured white on a black background.

In the <FIG> injection device <NUM>, the number sleeve <NUM> is marked to indicate that doses of <NUM> and higher value are permitted. The whole of the number sleeve <NUM> of this injection device <NUM> is shown in <FIG>.

In addition to the colour scheme described above, the number sleeve <NUM> is marked to indicate that doses of <NUM> and higher value are permitted by the size of the numbers, i.e. the font size. The feature of font size can be used in combination with the colour scheme feature, as can be seen in <FIG> for example. However, it is immanently clear to the skilled person that each feature - font size, colour scheme - can also be used alone, i.e. independently of the other.

When the supplementary device <NUM> is installed on the injection device <NUM>, the user is unable to see the number sleeve <NUM>, or at least is unable to see the part of the number sleeve that is coincident with the dosage window <NUM>. However, the supplementary device <NUM> is able to detect the characteristics of the number sleeve <NUM> by examining the output of the optical sensor/OCR <NUM>. The determination of the characteristics may be performed as part of the processing of the optical sensor/OCR <NUM> output when performing optical character recognition, or it may be performed as a separate step.

After the characteristics of the number sleeve <NUM> at the location currently being viewed by the optical sensor <NUM> have been detected, at step <NUM> it is determined by supplementary device <NUM> whether the characteristics indicate that the currently set dose is permitted. In the event that step <NUM> provides a negative response, because the number on the number sleeve <NUM> is provided in the colour white on a black background, the operation proceeds to step <NUM>. Here, the supplementary device <NUM> indicates that the currently set dose is not permitted. The indication may be provided in one of a number of manners which are described below.

After step <NUM>, the operation returns to step <NUM>. Here, the dialled dose is again detected, before the dose is then displayed at step <NUM>. Afterwards, the characteristics of the number sleeve <NUM> are again detected at step <NUM> and a determination as to whether the characteristics indicate that the dose is permitted is performed at step <NUM>. This loop continues until it is detected at step <NUM> that the dose is permitted, when the operation proceeds to step <NUM>. In this way, the user is continually provided with an indication that the dose is not permitted until such time that the supplementary device <NUM> determines that the currently set dose is permitted.

At step <NUM>, the supplementary device <NUM> indicates to the user that the dose that is set in the injection device <NUM> is permitted. Indication may be provided, for instance, by way of a suitable message on the display <NUM>. The indication may be by way of refraining from providing an indication that the dose is not permitted. In particular, if the currently dialled dose is not permitted, a warning message may be provided, with the warning message being removed once the supplementary device <NUM> detects that the currently set dose is permitted. The indication may be instead provided by an LED or other small optical output transducer. The indication may for instance be in the form of a green light.

After step <NUM>, the supplementary device <NUM> determines that step <NUM> whether the dose is being delivered. This determination may be made in any suitable way, as is known in the art. On a positive determination, the operation proceeds at step <NUM>, where it is determined whether the dose has been delivered. This may be performed in any suitable way, as is known in the art. The operation remains at step <NUM> until it is determined that the dose has been delivered, when the operation proceeds to step <NUM>. At step <NUM>, the delivered dose is calculated and displayed on the display <NUM>. This may be performed in any suitable way, as is known in the art. The calculation of the delivered dose may involve subtracting the dose that was set into the injection device <NUM>, following dose delivery from the dose that was set in the injection <NUM> before dose delivery. If all of the set dose was delivered, then the remaining dose is <NUM> and the delivered dose is equal to the set dose.

Following step <NUM>, the operation ends at step <NUM>.

If at step <NUM>, the supplementary device <NUM> determines that the dose is not being delivered, the operation returns to step <NUM>, where the dialled dose is again detected. This loop ensures that the dialled dose is detected and displayed up until the dose is delivered. It also ensures that the supplementary device <NUM> either indicates at step <NUM> that the dose is not permitted or indicates that step <NUM> that the dose is permitted, based on the detected characteristics of the number sleeve <NUM>, up until the dose is delivered. This occurs regardless of the value of the dose that is set in the injection device <NUM>. Indeed, the supplementary device <NUM> does not need to be aware of the range of doses that are permitted by the injection device <NUM>. Instead, the supplementary device <NUM> only needs to determine the characteristics of the number sleeve <NUM> at the location that is being viewed by the optical sensor <NUM> in order to determine whether the dose is permitted.

In the above, the detection as to whether a dose is permitted is carried out by detecting whether the numbers on the number sleeve <NUM> are provided in white-on-black or in black-on-white. In other embodiments, the determination is made based on some other characteristic of the numbers on the number sleeve <NUM>. For instance, the numbers on the number sleeve <NUM> indicates doses in the range that is permitted may have a different colour to numbers in the range that is not permitted but the background remains the same colour in both cases. For instance, the background of the number sleeve <NUM> may be white for the entire range of doses that can be delivered by the injection device <NUM>, and the numbers are provided in a first colour (for instance grey or black) when the number relates to a dose that is permitted and in a different colour (for instance red or orange) when the number relates to a dose that is not permitted. In this case, step <NUM> of <FIG> involves the supplementary device to detecting from signals provided by the optical sensor <NUM> what colour are the numbers on the number sleeve <NUM> and/or what colour is the background at the location currently being viewed by the optical sensor <NUM>. Colour determination may be in terms solely of whether the numbers are relatively light or relatively dark in colour, and/or whether the background is relatively light or relatively dark in colour.

In another example, the colour of the numbers is the same for all numbers on the number sleeve <NUM>, but the colour of the background of the number sleeve <NUM> changes depending on whether the number at the particular location relates to a dose that is permitted. For instance, the numbers on the number sleeve <NUM> may be a first colour (for instance grey or black) for all values, and the background may be a first colour (e.g. yellow or white) for values of a dose that are permitted and a second colour (e.g. orange or red) for dose values that are not permitted. In this case, the detection of the characteristics of the number sleeve <NUM> at step <NUM> involves detecting a background colour of the number sleeve <NUM> and step <NUM> involves determining whether the background colour indicates whether the dose is permitted. Having a red or orange colour as the colour of the background of the number sleeve <NUM> for doses that are not permitted means that the user can easily determine from examination of the number sleeve <NUM> of the injection device when the supplementary device <NUM> is not installed whether the currently set does is a permitted dose.

In another example, the background of the number sleeve <NUM> is provided with a pattern, for instance a striped pattern, at locations corresponding to a dose that is not permitted and is provided with an un-patterned background at locations corresponding to a dose that is permitted. In another example, the converse is true, so that a patterned background is provided at locations corresponding to doses that are permitted.

In other examples, the characteristics of the number sleeve <NUM> are different at different locations in a way that is detectable by the optical detector <NUM> but that is not detectable by human users. For instance, the number sleeve <NUM> is provided with a marking that is visible in ultraviolet or infrared. Either the marking is different at locations on a number sleeve <NUM> corresponding to doses that are permitted compared to the markings that locations on the number sleeve <NUM> where doses are not permitted, or vice versa. With these examples, supplementary device <NUM> is able to determine from processing of signals provided by the optical sensor whether a dose that is currently set is permitted, but a user viewing the injection device <NUM> when the supplementary device is not installed would not be able to determine from characteristics of the number sleeve <NUM> whether the currently set dose was permitted.

The indication that the dose is not permitted that is provided at step <NUM> may be provided on the display <NUM>, or it may be provided in some other way. As regards the display <NUM>, the indication may be provided as a message that is displayed on the display <NUM>. The message may take the form "dose not permitted", or some other suitable form. The indication may be provided continually. For instance, one part of the display may be used to include the indication that the dose is not permitted and another part of the display may be used to indicate the set dose. Alternatively, the indication may be provided intermittently, for instance, the display <NUM> may be caused to alternate between displaying the dialled dose and displaying a message that the dose is not permitted.

Alternatively, the indication may be by way of a separate transducer, for instance an LED or other small optical transducer. The indication that the dose is not permitted may be of a colour that is traditionally associated with 'stop', or an alert, for instance, the colour red or the colour orange. For instance, the indication may be made by way of a small red LED or other red optical transducer.

Alternatively or in addition, the indication may be made acoustically, for instance by way of a buzzer. Alternatively, the indication may be made haptically. In some embodiments, the supplementary device <NUM> is configured to monitor whether the characteristics of the number sleeve <NUM> that indicate that the doses permitted have been detected after the operation starts at step <NUM>. In these embodiments, the supplementary device <NUM> is configured to indicate, for instance on the display <NUM>, whether the user needs to increase or decrease the currently dialled dose in order to reach a dose that is permitted. After starting, the dialled dose is smaller than the lower limit of the range of doses that is permitted. As such, until the supplementary device <NUM> detects that the characteristics of the number sleeve <NUM> viewed by the optical sensor <NUM> indicate that the currently dialled dose is permitted, the supplementary device <NUM> indicates to the user that the dose needs to be increased. This can occur for example by providing an arrow pointing upwards on the display <NUM>. It can occur alternatively by providing a message "increase dose" on the display <NUM>. Such a message also constitutes an indication that the currently dialled dose is not permitted.

When the currently dialled dose is a permitted dose, no indications that the dose is not permitted are provided. If the user operates the injection device <NUM> such that the currently dialled dose exceeds the upper limit of the range that is permitted, as detected by the supplementary device from the characteristics of the number sleeve <NUM> at step <NUM>, the supplementary device <NUM> may indicate to the user that the dialled dose needs to be reduced. This can occur for instance by causing display on the display <NUM> of a downwardly pointing arrow or a message stating "decrease dose", or such like.

It will be appreciated that the supplementary device <NUM> does not need to be provided with information indicating the range of doses that are permitted in order to provide this function. Instead, the supplementary device <NUM> can determine whether to provide an increase dose message or a decrease dose message firstly by determining whether the currently dialled dose has yet given rise to detecting characteristics of the number sleeve <NUM> indicating that the dose is permitted, and after the characteristics indicate that the dose is permitted by responding to detection that the characteristics of the number sleeve <NUM> indicate that the dose is not permitted by determining whether the dialled dose has increased or decreased since the dose dialled at the time when the characteristics on the number sleeve <NUM> were detected to indicate that the dose is permitted.

In still other embodiments, the supplementary device <NUM> is configured such that it is unable to detect the dose except when the characteristics indicate that the dose is permitted. For instance, the OCR function of the optical sensor <NUM> may be configured such that it is unable to perform optical character recognition of white numbers on a black background, and so be unable to read a number indicating the dialled dose until the user has operated the injection device <NUM> such that the dialled dose is permitted and thus that the dialled dose can be coded by the optical sensor <NUM>. In these embodiments, the currently dialled dose is displayed only when the currently dialled dose is a permitted dose. In these embodiments, the indication that the dose is not permitted that is provided at step <NUM> may simply be the absence of a displayed dialled dose.

In other examples (not shown in the Figures), a number sleeve is provided with a permitted dose range sandwiched between non-permitted dose ranges. For instance, the surface of the number sleeve at locations corresponding to doses of <NUM>, <NUM> and all values in between indicate the dose as a number that is coloured black on a white background. The surface of the number sleeve at locations corresponding to doses between <NUM> and <NUM> and from <NUM> upwards are indicated by a number that is coloured white on a black background. In another example, the number sleeve <NUM> is marked to indicate that doses of between <NUM> and a higher value (e.g. <NUM> or <NUM>) are permitted. In particular, locations corresponding to doses of <NUM>, <NUM> and all values in between indicate the dose as a number that is coloured black on a white background. Locations corresponding to doses between <NUM> and <NUM> and from <NUM> (or <NUM>) upwards are indicated by a number that is coloured white on a black background.

In still further embodiments, the supplementary device <NUM> is operable with a number sleeve <NUM> that is provided with numbers only at locations corresponding to doses that are permitted. For instance, the number sleeve <NUM> may be provided with numbers at locations corresponding to dose values <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>. Alternatively, the number sleeve <NUM> may be provided with numbers at locations corresponding to dose values <NUM>, <NUM> and <NUM>. In all these examples, the number sleeve <NUM> is provided with numbers that do not constitute a continuous series of dose values but instead are members of a discontinuous series. Here, the supplementary device <NUM> is configured such that it is unable to detect the dose except when the characteristics indicate that the dose is permitted. Here, unless a quantity of currently set dose of drug is determined, an indication that the currently set dose of drug is not a permitted dose is caused to be provided.

With these embodiments in which the dose is readable by the supplementary device <NUM> only at locations corresponding to a permitted dose, the user is able to determine accurately the dialled dose only if the dialled dose is within the permitted range or if the supplementary device <NUM> is not installed on the injection device <NUM>.

In addition to providing an indication that the dialled dose is not a permitted dose, the supplementary device <NUM> may prevent dose delivery whilst the dialled dose is not a permitted dose. This may for example be achieved with a locking mechanism as described in <CIT>. Some other suitable locking mechanism may be used instead.

The terms "drug" or "medicament" which are used interchangeably herein, mean a pharmaceutical formulation that includes at least one pharmaceutically active compound.

The term "drug delivery device" shall be understood to encompass any type of device, system or apparatus designed to immediately dispense a drug to a human or non-human body (veterinary applications are clearly contemplated by the present disclosure). By "immediately dispense" is meant an absence of any necessary intermediate manipulation of the drug by a user between discharge of the drug from the drug delivery device and administration to the human or non-human body. Without limitation, typical examples of drug delivery devices may be found in injection devices, inhalers, and stomach tube feeding systems. Again without limitation, exemplary injection devices may include, e.g., syringes, autoinjectors, injection pen devices and spinal injection systems.

Those of skill in the art will understand that modifications (additions and/or removals) of various components of the substances, formulations, apparatuses, methods, systems and embodiments described herein may be made without departing from the scope of protection conferred by the claims.

Without limitation, a drug delivery device may be an injection device (e.g., syringe, pen injector, auto injector, large-volume device, pump, perfusion system, or other device configured for intraocular, subcutaneous, intramuscular, or intravascular delivery), skin patch (e.g., osmotic, chemical, micro-needle), inhaler (e.g., nasal or pulmonary), implantable (e.g., coated stent, capsule), or feeding systems for the gastro-intestinal tract.

Exemplary insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl- ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-gamma-glutamyl)-des(B30) human insulin; B29-N-(N-lithocholyl-gamma-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyhepta-,decanoyl) human insulin. Exemplary GLP-<NUM>, GLP-<NUM> analogues and GLP-<NUM> receptor agonists are, for example: Lixisenatide / AVE0010 / ZP10 / Lyxumia, Exenatide / Exendin-<NUM> / Byetta / Bydureon / ITCA <NUM> / AC-<NUM> (a <NUM> amino acid peptide which is produced by the salivary glands of the Gila monster), Liraglutide / Victoza, Semaglutide, Taspoglutide, Syncria / Albiglutide, Dulaglutide, rExendin-<NUM>, CJC-<NUM>-PC, PB-<NUM>, TTP-<NUM>, Langlenatide / HM-11260C, CM-<NUM>, GLP-<NUM> Eligen, ORMD-<NUM>, NN-<NUM>, NN-<NUM>, NN-<NUM>, Nodexen, Viador-GLP-<NUM>, CVX-<NUM>, ZYOG-<NUM>, ZYD-<NUM>, GSK-<NUM>, DA-<NUM>, MAR-<NUM>, MAR709, ZP-<NUM>, ZP-<NUM>, TT-<NUM>, BHM-<NUM>. MOD-<NUM>, CAM-<NUM>, DA-<NUM>, ARI-<NUM>, ARI-<NUM>, Exenatide-XTEN and Glucagon-Xten.

Claim 1:
A supplementary device (<NUM>) for attachment to a drug delivery device (<NUM>), the supplementary device comprising:
an attachment mechanism for coupling the supplementary device to the drug delivery device;
an imaging arrangement (<NUM>) configured to provide image data representing a captured image of one or more numbers present on a number sleeve (<NUM>) of the drug delivery device at a location on the number sleeve corresponding to a currently set dose of medicament; and
a processor arrangement (<NUM>) configured to:
receive the image data representing the captured image;
perform optical character recognition on the image data to determine a quantity of the currently set dose of medicament; and
cause display of the quantity of the currently set dose of medicament, characterised in that the processor arrangement is configured to:
process the image data representing the captured image to identify one or more optical characteristics of the number sleeve at the location;
determine from the determined optical characteristics of the number sleeve, and not from any numbers that are present on the number sleeve, whether the currently set dose of drug is a permitted dose; and
in response to determining that the currently set dose of drug is not a permitted dose, cause an indication that the currently set dose of drug is not a permitted dose to be provided.