A disposable wearable insulin dispensing device, a combination of such a device and a programming controller

The present invention relates generally to wearable insulin dispensing devices.

In connection with injection of insulin for combatting Type I and Type II Diabetes extremely important features are simplicity of operation, reliability, cost and flexibility, which all are related to the issue of compliance which particularly in the cases of relatively mild Type II diabetes is a problem with important consequences regarding the success rate in treating the patients.

<patcit id="pcit0001" dnum="US5919167A"><text>US 5,919,167</text></patcit> describes an apparatus for delivery of a fluid. The apparatus includes a syringe pump with a plunger, an electronic control element which releases at least one electric charge at predetermined time intervals, a shape memory element with a contractible length decreasing from an uncharged length to a charged length, and a driving mechanism connected to both the shape memory element and the plunger so that the change in length of the shape memory element causes the driving mechanism to provide an activating force to move the plunger and force the expulsion of the fluid from the syringe pump's chamber.

<patcit id="pcit0002" dnum="US20020040208A"><text>US 2002/0040208</text></patcit> describes a system for delivering fluid to a patient, including a fluid delivery device having a dispenser for causing fluid from a reservoir to flow to an exit port assembly, a local processor connected to the dispenser and programmed to cause fluid flow to the exit port assembly based upon flow instructions, and a local communication element connected to the local processor.

<patcit id="pcit0003" dnum="US5637095A"><text>US 5,637,095</text></patcit> describes a medication infusion pump is provided for controlled delivery of medication to a patient, wherein the pump includes a space-efficient flexible drive plunger for advancing a piston within a medication-containing syringe or cartridge for administration of the medication to a patient.

<patcit id="pcit0004" dnum="WO0187384A1"><text>WO 01/87384A1</text></patcit> describes an injection device for injecting set doses from an ampoule mounted in the device, which doses are set by operation of a dose setting button by which operation elastic torsion rods positioned parallel with the longitudinal axis of the device are twisted.

The main object of the invention is to provide a wearable insulin dispensing device having features and operation characteristics supporting and easing compliance by the users of the device.

The present invention is defined in the claims. In one example, disposable, wearable, self-contained insulin dispensing device comprises <ul id="ul0001" list-style="dash" compact="compact"><li>a housing,</li><li>an insulin source in said housing,</li><li>a pump means in said housing and adapted for pumping insulin from said insulin source to a catheter for injection of said insulin in a user of the device and, said catheter being associated with said housing and projecting generally perpendicularly to a generally planar surface of said housing intended for abutting a skin surface of a user of the device,</li><li>an adhesive layer provided on said planar surface for adhering said planar surface to said skin surface, and</li><li>a removable release sheet covering said adhesive layer for protecting said adhesive layer prior to use of said dispensing device, said release sheet being provided with catheter protection means to enclose and protect an end portion of said catheter such that removal of said release sheet for exposing said adhesive layer exposes said end portion.</li></ul>

Hereby, in a simple, reliable and cost-effective manner a device is provided which is easy to apply and still in an effective manner protects the catheter against damage and contamination until use of the device is initiated.

In another example, a disposable, wearable, self-contained insulin dispensing device comprises <ul id="ul0002" list-style="dash" compact="compact"><li>a housing,</li><li>an insulin source in said housing,</li><li>a pump means in said housing and adapted for pumping insulin from said insulin source to a catheter for injection of said insulin in a user of the device and, said catheter being associated with said housing and projecting generally perpendicularly to a generally planar surface of said housing intended for abutting a skin surface of a user of the device,</li><li>an adhesive layer provided on said planar surface for adhering said planar surface to said skin surface,</li><li>a combined microphone and loudspeaker associated with said housing, preferably arranged inside said housing, and</li><li>recording and play back means connected to said combined microphone and loudspeaker and associated with said housing, preferably arranged inside said housing, such that verbal messages may be recorded and played back by said dispensing device.</li></ul>

Hereby a device promoting simple communication between a health care provider and the user is provided with readily understandable operation and with good effect on the compliance rate.

In yet another example, a disposable, wearable, self-contained insulin dispensing device comprises <ul id="ul0003" list-style="dash" compact="compact"><li>a housing,</li><li>an insulin source in said housing,</li><li>a pump means in said housing and adapted for pumping insulin from said insulin source to a catheter for injection of said insulin in a user of the device, and</li><li>an actuator for said pump means, said actuator comprising a shape memory alloy wire, said actuator preferably further comprising a ratchet gear or pawl wheel, a pawl adapted for cooperating with said pawl wheel and connected to one end of said shape memory alloy wire and a spring means connected to said pawl, the connections between said pawl and said wire and said pawl and said spring means being such that contraction of said wire rotates said pawl wheel against the spring force of said spring means.</li></ul>

Hereby a pump means requiring very low energy and with a high degree of reliability is provided at a relatively low cost.

In a yet further example, a disposable, wearable, self-contained insulin dispensing device comrpises <ul id="ul0004" list-style="dash" compact="compact"><li>a housing,</li><li>an insulin source in said housing,</li><li>a pump means in said housing and adapted for pumping insulin from said insulin source to a catheter for injection of said insulin in a user of the device,</li><li>an actuator for said pump means, preferably an actuator comprising a shape memory alloy wire, and</li><li>controlling means for controlling the operation of said actuator according to a programme, said programme consisting in a sequence of a certain amount of actuations of said actuator per 24 hours time periods, or, in connection with provision of a timing means connected to said controlling means said programme consisting in a sequence of actuations of said actuator that varies according to the time of day or, in connection with provision of a timing means connected to said controlling means and an input device for inputting data to said controlling means, adapting said controlling means so as to be programmable by means of said data, or adapting said programme of said controlling means to comprises algorithms for automatically altering the sequence of actuations of said actuator according to input of data relative to actual glucose level in the blood of the use of the device and/or intake of nutrients by said user.</li></ul>

Hereby, compliance is enhanced by providing a device with capabilities of rendering a very specific and well-tuned dosage which may be altered according to the specific development of the individual user.

In a yet further example a combination of a dispensing device as specified above and a programming controller is provided, said dispensing device and said programming controller comprising cooperating transmission and/or receiving means for mutual communication of data, said programming controller preferably being a cellular telephone or a personal computer or a laptop computer or a hand held computer.

Moreover, an example method of controlling the operation of a disposable, wearable, self-contained insulin dispensing device comprises <ul id="ul0005" list-style="dash" compact="compact"><li>a housing,</li><li>an insulin source in said housing,</li><li>a pump means in said housing and adapted for pumping insulin from said insulin source to a catheter for injection of said insulin in a user of the device,</li><li>an actuator for said pump means, preferably an actuator comprising a shape memory alloy wire, and</li><li>controlling means for controlling the operation of said actuator according to a programme,</li></ul> said method comprising the steps of: <ul id="ul0006" list-style="dash" compact="compact"><li>providing said controlling means with data for generating and/or amending said programme prior to and/or after initiation of use of said dispensing device.</li></ul>

Furthermore, in a yet other example, a method of controlling the operation of a disposable, wearable, self-contained insulin dispensing device comprises <ul id="ul0007" list-style="dash" compact="compact"><li>a housing,</li><li>an insulin source in said housing,</li><li>a pump means in said housing and adapted for pumping insulin from said insulin source to a catheter for injection of said insulin in a user of the device and, said catheter being associated with said housing and projecting generally perpendicularly to a generally planar surface of said housing intended for abutting a skin surface of a user of the device,</li><li>an adhesive layer provided on said planar surface for adhering said planar surface to said skin surface,</li><li>a combined microphone and loudspeaker associated with said housing, preferably arranged inside said housing,</li><li>recording and play back means connected to said combined microphone and loudspeaker and associated with said housing, preferably arranged inside said housing, such that verbal messages may be recorded and played back by said dispensing device, an</li><li>manual operating means for manually controlling the operation of said dispensing device</li></ul> said method comprising the steps of: <ul id="ul0008" list-style="dash" compact="compact"><li>recording verbal instructions in said recording means for instructing the user of the device in the operation of said dispensing device, and</li><li>playing back said verbal instructions.</li></ul>

Finally, an example method of controlling the operation of a disposable, wearable, self-contained insulin dispensing device comprises <ul id="ul0009" list-style="dash" compact="compact"><li>a housing,</li><li>an insulin source in said housing,</li><li>a pump means in said housing and adapted for pumping insulin from said insulin source to a catheter for injection of said insulin in a user of the device and, said catheter being associated with said housing and projecting generally perpendicularly to a generally planar surface of said housing intended for abutting a skin surface of a user of the device,</li><li>an adhesive layer provided on said planar surface for adhering said planar surface to said skin surface,</li><li>a combined microphone and loudspeaker associated with said housing, preferably arranged inside said housing,</li><li>a programmable computing means associated with said housing, preferably arranged inside said housing, and</li><li>signal conversion means connected to said combined microphone and loudspeaker and associated with said housing, preferably arranged inside said housing, and adapted for converting received audio signals into input signals for said computing means and for converting output signals from said computing means to audio signals,</li></ul> said method comprising the steps of: <ul id="ul0010" list-style="dash" compact="compact"><li>transmitting audio signals to said microphone for controlling the operation of said dispensing device,</li><li>receiving audio signals from said loudspeaker for evaluating the operation of said dispensing device.</li></ul>

In the following, the invention will be described and explained more in detail in connection with a currently preferred insulin dispensing device according to the invention shown, solely by way of example, in the accompanying drawings where: <ul id="ul0011" list-style="none"><li><figref idref="f0001">Fig. 1</figref> is a schematic isometric view of a disposable insulin dispensing device according to the invention before the adhesive pad for adhering the device to a user has been mounted on the device,</li><li><figref idref="f0002">Fig. 2</figref> is a schematic isometric view of the device of <figref idref="f0001">Fig. 1</figref> seen from another angle and with the adhesive pad mounted thereon,</li><li><figref idref="f0003">Fig. 3</figref> is a schematic isometric partly exploded view of the device of <figref idref="f0002">Fig. 2</figref>,</li><li><figref idref="f0004">Fig. 4</figref> is a schematic entirely exploded view of the device of <figref idref="f0002">Fig. 2</figref>,</li><li><figref idref="f0005">Fig. 5</figref> is a schematic isometric view of the device of <figref idref="f0002">Fig. 2</figref> together with a programming device according to the invention,</li><li><figref idref="f0006">Fig. 6</figref> is a schematic enlarged scale exploded view of a shape memory alloy actuator mechanism according to the invention of the device of <figref idref="f0002">Fig. 2</figref>, and</li><li><figref idref="f0007">Fig. 7</figref> is a schematic view corresponding to <figref idref="f0006">Fig. 6</figref> with the elements of the shape memory actuator shown in interconnected operative relative positions.</li></ul>

Referring now to <figref idref="f0001">Fig. 1</figref>, a disposable insulin dispensing device according to the invention, generally referenced by the numeral 1, comprises a water-tight generally cylindrical housing 2 provided with a push button 3 for activating and deactivating the device as well as for activating a so-called bolus operation as explained in the following.

The housing further comprises a transparent window 4 for inspecting the operation of the device and apertures 5 for transmission of sound waves as explained in the following.

At one end of the housing 2 there is provided a stiletto 6 having a sharp needle 7 extending through a catheter 8 connected to a not shown insulin container or capule inside the housing 2 as explained in the following.

Referring now to <figref idref="f0002 f0003">Figs. 2-3</figref>, the housing 2 is fixedly received in a trough 9 of an adhesive pad 10 made of a combination of a plate 11 of skin-friendly adhesive material, for instance as well known in the field of ostomy pouches, see for instance European patent application no. <patcit id="pcit0005" dnum="EP0413250A"><text>0413250</text></patcit> and European patent application no. <patcit id="pcit0006" dnum="EP0092999A"><text>0092999</text></patcit>, and a relatively compressible portion 10a made of foam material attached to the plate 11. The catheter 8 extends through the planar portion 11 of the pad 10. The push button 3 is protected by the foam material 10a so as to avoid inadvertent operation of the button for instance when the user is asleep.

A slip release film 12 is adhered to the bottom surface of the adhesive plate 11 for protecting the adhesive surface of the plate 11 such that the adhesive properties are intact when the pad is to be adhered to the skin of a user of the dispensing device. The release film 12 is provided with a protective hollow projection 13 for receiving the catheter 8 and the needle 7 of the stiletto 6 so that the needle 7 and the catheter 8 are protected by the projection 13 before use of the dispensing device 1. The housing 2 is provided with and end cover 14 on which the catheter 8 is mounted by means of a communication bushing 15 provided with an internal not shown elastomer mass and a communication passage for communicating the catheter 8 with the interior of the housing 2 as explained in the following in connection with <figref idref="f0004">Fig. 4</figref>.

In use, the user removes the protective release sheet 12 thereby exposing the tip of the needle 7 such that the needle may be inserted subcutaneously at the same time that the adhesive pad 10a, 11 is adhered to the abdominal skin of the user. When the needle 7 and the catheter 8 have been inserted subcutaneously and the device has been adhered to the skin of the user, the stiletto 6 is removed whereby communication is established between the catheter 8 and the interior of the housing 2 for supplying insulin subcutaneously to the user of the device.

The elastomer mass in the bushing 15 seals the exit opening of the needle 7 when it is removed such that no insulin may leak trough said exit opening but is constrained to flow solely from the carpule to the catheter 8.

Referring now to <figref idref="f0004">Fig. 4</figref> showing an exploded view of the components of the insulin dispensing device according to the invention, the housing 2 contains a container or a carpule 16 for storing and dispensing insulin. The container or carpule 16 is of a well-known type having a perforatable dispensing projection 17 for receiving a catheter 18 for communicating the interior of the container 16 with the catheter 8 through the communication bushing 15 when the needle 7 has been retracted from said elastomer mass inside the bushing 15 as explained above.

A spindle 19 provided with a piston 20 is received in the container 16 such that axial displacement of the spindle towards the dispensing projection 17 will press insulin through the catheter 18 to the catheter 8. The spindle 19 is rotated and displaced by means of a shape memory alloy actuator described more in detail in the following with reference to <figref idref="f0006">Fig. 6</figref>.

A battery 21 for supplying power to the shape memory actuator is provided adjacent an end cover 22 of the housing 2.

The shape memory actuator comprises a pawl or ratchet wheel 23, a guide bushing 24, a spring wheel 25 and a shape memory wire 26. The operation of the shape memory actuator will be described more in detail in the following with reference to <figref idref="f0006">Figs. 6</figref> and <figref idref="f0007">7</figref>.

A printed circuit board 27 is provided for controlling the function of the dispensing device and the various operational steps thereof as described in the following.

Finally a combined microphone/loudspeaker 28 is arranged inside the housing 2 adjacent the apertures 5 for receiving and emitting sound waves for the purposes described below.

Referring now to <figref idref="f0005">Fig. 5</figref>, a programming device or controller 29 having programming keys 30 and a display 31 is shown proximate the dispensing device for communicating with a not shown receiver/transmitter arranged inside the housing 2. The communication may take place by infra red signals or other suitable signals transmitted from and to an opening 32 leading to a transmitter/receiver inside the controller 29 to and from, respectively an opening 33 (see <figref idref="f0002">Fig. 2</figref>) in the end cover 22 of the housing 2 leading to said not shown transmitter/receiver inside the housing 2.

Referring now to <figref idref="f0006">Figs. 6</figref> and <figref idref="f0007">7</figref>, the spindle 19 is displaced axially in the direction of the arrow R1 by counter-clockwise rotation of the pawl wheel 23 in the direction of the arrow R2 whereby the thread 36 meshing with the internal thread 37 results in said axial displacement whereby the piston 20 is displaced further into the carpule 16 to dispense insulin through the catheter 18 to the catheter 8 (<figref idref="f0004">Fig. 4</figref>).

Rotation of the pawl wheel 23 is accomplished by means of the shape memory alloy (for instance Nitinol) wire 26 attached to electrically conductive rods 38 and 39 that are fixed in recesses 40 and 41, respectively, in the electrically non-conductive guide bushing 24 and the electrically conductive spring wheel 25, respectively.

The recess 40 is provided with not shown electrical contacts for electrically connecting the rod 39 to the battery 21 for supplying electrical current to the SMA wire 26 to heat it in a manner and sequence controlled by the programme elements in the print board 27.

The spring wheel 25 has U-shaped spring arms 44 and 45 for exerting a spring force on the ends 46 and 47 thereof, respectively, in a direction towards the centre of the pawl wheel 23 such that the ends 46 and 47 are constantly biased to enter into engagement with the teeth of the pawl wheel 23.

The stop pins 42 and 43 are electrically connected to the print board 27 for emitting an electrical signal thereto when the spring wheel arm 48 contacts said stop pins.

The rod 38 is as mentioned above electrically connected to the power source such that an electrical current may be passed through the rod 38, the wire 26, the rod 39, the loop recess 41 and the spring wheel 25 to heat the wire 26 to cause the wire to contract and rotate the pawl wheel the distance of one tooth in the direction of arrow R2 by means of the arm end 46 engaging a tooth of the wheel until the arm 48 contacts the stop pin 42 that emits a signal to the control print board 27 whereby the current through the wire 26 is interrupted and the SMA wire 26 cools off and expands.

The other arm end 47 engages a tooth of the wheel 23 as a pawl and prevents the wheel 23 from rotating clock-wise. The spring effect of the spring wheel 25 in the tangential direction causes the arm 48 to move back into contact with the stop pin 43 thereby tightening the expanded SMA wire 26.

The signals from the stop pins 42 and 43 are also utilized to indicate correct functioning of the pump and as an indication of the number of doses administered through the catheter 8.

A dispensing device or insulin pump according to the invention may function in several different manners depending on the design and programming of the various control elements of the circuit board 27:

1. Stand alone pump with constant flow:

The pump functions as a constant flow pump and may be designed for different flow rates, for instance 20 units/24 hours, 30 units/24 hours, etc. By depressing the bolus button 3 and holding it down, the pumping programme is initiated and by again pressing the button 3 down and holding it, the pumping programme is terminated while a short duration pressure on the bolus button 3 activates a bolus additional dosage of insulin of a certain magnitude.

2. Stand alone pump with varying flow:

A timing device is incorporated in the print board 27 so that a standard programme controls the flow dispensed by the pump during recurring 24 hour periods. The pre-programmed operating instructions may for example result in a lower dosage at night than during the day and an extra dosage at mealtimes.

3. Programmable pump type 1:

The pump is not provided with a predetermined programme, but is provided with a programmable unit in the print board 27 and can be programmed by the user or a doctor by means of a controller 29. The programming must be able to take place through the packing material in which the dispensing device is supplied so that the user can transport the device in a sterilized out packaging on vacations or the like without having to carry the controller along. The controller is a dedicated unit that for instance via a USB plug can be connected to a PC or it can be provided with cellular telephone capability for transmission of data. The controller can thus be programmed by a doctor or a user and be used for programming of the functioning of all subsequently used disposable dispensing devices.

4. Programmable pump type 2:

This pump functions in the same manner as programmable pump type 1, but the controller is a palm pilot or a laptop PC. This gives the additional advantage that the user may input health information and glucose level measurement results directly into the controller or programming unit and thus communicate such information to the doctor who may use this information when deciding whether the programming function of the controller or the programming unit is to be altered for subsequently used disposable dispensing devices.

5. Programmable pump with audio input and output:

By providing the dispensing device with the microphone/loudspeaker 28 and a suitable recording/play-back chip in the printed circuit 27, short messages may be recorded by the dispensing device, and the short messages may be emitted by the device upon suitable manipulation of the bolus push button 3 or a separate recording button (not shown) mounted on the housing 2.

By means of this audio capability the user may record verbally formulated information regarding glucose levels, meal composition, exercise, etc. A timer may record the timing of each recorded message. A doctor may then use these recorded messages together with information about number and timing of bolus dosages, pumping stops and the programme utilised for the dispensing of the insulin so as to evaluate the treatment and decide upon any changes in the programming and instructions to the patient which may be recorded by the doctor via a mobile telephone or the like such that messages are automatically delivered to the user at predetermined times. Such a message could for example be 'remember to measure your glucose level' (message programme to be delivered by the dispensing device to the user each morning at 8 o'clock) and so on.

Furthermore, standard instructions can be included in the programming circuit so that the pump may deliver verbal messages to the user instead of audio signals such as beep sounds. The message could for instance be: 'Pump is stopped' or 'This is your third bolus in a row and you have taken a total of eight bolus dosages today' or The pump will be empty in two hours' and so on. Generally speaking, the audio capability described above will render the dispensing device provided with such capability much more user-friendly, especially for users initiating a treatment or not very disciplined as regards compliance.

6 Closed loop re-programmable pump:

Either the controller or the computing unit mounted in the printed circuit 27 may be programmed to react to information regarding actual glucose blood level inputted by the user perhaps together with other information, such as data regarding the timing and constitution of the last meal, to alter the programme of the dispensing flow or dosage to take into consideration this information such that the dispensing device to a certain extent constitutes a closed loop, fuzzy logic, semi-automatic self re-programming insulin dispensing device.

The programming controller 29 may be a mobile wire-less communication device such as a cellular telephone communicating with the dispensing device by audio signals transmitted to and received from the transmitter/receiver 28. The transmissions should be preceded and terminated by an identification code to avoid disruption of the programming of the device by extraneous audio signals. Other signal identification or protection procedures such as encryption may be utilized. The audio signals may be converted to controlling signals for altering the programming of the re-programmable computing unit mounted in the circuit board 27.

Signal conversion means may be provided for converting the audio signals received by the receiver into input signals for the computing means and for converting output signals from the computing means into audio signal fro being transmitted by the loudspeaker.

So-called SMS signals may also be utilized for transferring information between a wire-less mobile communications unit and the dispensing device, for instance by means of IR signals or so-called Bluetooth communication technology.

Although the basic concept of the invention is that the entire device is disposable, a variation may be that the receiver/transmitter unit 28 with recording and play back components and corresponding battery and perhaps circuit board with computing means is reusable and may be releasably received in a holder provided on the disposable portion of the device.