Patent Application
20060167419
This application claims the benefit of German Application No. DE 10 2004 063 649.9, filed on Dec. 31, 2004, the contents of which are incorporated in its entirety herein by reference.
The invention relates to devices for administering, dispensing or delivering substances and methods of making and using such devices. More particularly, it relates to medical devices, including devices for administering measured doses of a liquid product. The device may be an injection device, including an injection device in the form of an injection pen.
Injection devices are known, including from their use or applications involving the treatment of diabetes and the administration of growth hormones or osteoporosis preparations. On the one hand, devices of this type should offer some assurance that the correct dose will be administered and, on the other hand, the devices should be easy and comfortable to use, two requirements which are of particular importance if the user is self-administering the relevant product.
Injection devices, including injection pens, designed for self-administering settable doses of a product to be injected are known. For example, U.S. Pat. No. 6,547,763 describes a dose display integrated in such an injection pen, comprising two flexible discs, each of which has a scale. In the middle of the discs is a circular orifice, by means of which they can be mounted in an injection pen so as to be freely displaceable. On a radius that is bigger than that of the orifice but smaller than that of the disc, a larger number of small orifices or perforations is provided. In the assembled state, cams locate in these perforations, which are borne by means of a cylindrical body coaxially integrated in an injection device and connected to a dose-measuring element so as to be prevented from rotating. A rotation on the dose-measuring element transmits this rotating motion to the flexible discs.
An object of the present invention is to provide a dose display for injection devices, which can be fitted onto pre-fabricated injection devices at a date later in time than that on which the devices were manufactured, for example, on the delivery date of the devices or before the delivery of the devices to care-givers or patients.
In one embodiment, the present invention comprises a dose display for coupling to an injection device or the like, comprising at least one display element, a gear mechanism and a central element which connects the display element, the gear mechanism and the injection device whereby the dose display can be coupled as a unit to appropriately prepared injection devices after the injection devices are manufactured.
In one embodiment, the invention comprises an injection device comprising a dose display comprising at least one display element, a gear mechanism and a central element which connects the display element, the gear mechanism and the injection device whereby the dose display can be coupled as a unit to the injection device after the injection device has been manufactured.
In one embodiment, the invention relates to a dose display of compact construction, which can be laterally docked. It comprises at least one, but in some embodiments, preferably and advantageously precisely two display elements, for example counter dials, a gear mechanism and a central element which connects all of the components of the dose display in such a way that they do not have to be fitted or retrofit as a functional unit to appropriately prepared devices until shortly before delivery to the customer. Docking, fitting and the like are intended to encompass connecting, attaching, mounting, operably coupling, retrofitting, mounting, linking, etc.
In one embodiment, the present invention comprises a device for administering measured doses of a liquid product with a dockable dose display (i.e., a dose display that can be connected, attached, operably coupled to, fitted or retrofit on the device after the device is manufactured), the device including a housing with a reservoir for the product, a plunger rod displaceable to convey the product in a forward drive direction, a dose-measuring member for making a dose-measuring movement to set a product dose to be administered, a dose display with at least a first display element for displaying the set dose, and a coupling which couples the dose display with the dose-measuring member to record, track and/or display a dose-measuring movement, wherein the dose display comprises an interface coupled with the dose-measuring member for communicating the dose measuring to a user.
Although a drive member of a device may simultaneously also serve as a dose-measuring member of the device on which the user sets the dose, in some preferred embodiments a device in accordance with the present invention has a dose-measuring member in addition to the drive member. The dose-measuring member is coupled with the drive member, preferably by purely mechanical means, so that a dose-measuring movement of the dose-measuring member also results in a dose-measuring movement of the drive member. The dose-measuring movement of the drive member is effected in the direction opposite the driving force applied by or via the drive member during the dispensing process. The device has a dose display of the type provided by the present invention for displaying the set product dose. The display may be of the acoustic, tactile and/or visual type. The dose display is coupled with the dose-measuring member so that a movement effected by the dose-measuring member when a product dose is set causes a change in the displayed product dose. When the coupling members are in the retaining position, the dose-measuring member and/or the dose display are uncoupled from the conveying mechanism. As a result of the uncoupling, the dose can be set and corrected if necessary in the uncoupled state, without affecting the conveying mechanism.
In a preferred embodiment, the coupling between the dose display and drive member stays in coupled engagement so that during progressive dispensing, a driving movement of the drive member effected in the direction opposite the dose-measuring movement is likewise progressively covered. If the administration process is prematurely interrupted, whether deliberately or in error, the dose display therefore shows the remaining quantity of the set dose that has not yet been dispensed. This may be of advantage if the set dose is bigger than the amount still available.
If, as in preferred embodiments, a dose-measuring member is provided in addition to the drive member, the drive member and the dose-measuring member are advantageously uncoupled from one another when the coupling engagement is established, so that the dose-measuring member can not be manipulated in any way which might affect the drive member as the drive member is being moved.
In another embodiment, when the coupling members are in the retaining position, the coupling output member is secured on the housing so that it is not able to make any movement which might affect a dispensing movement of the conveying mechanism. The coupling output member must be deliberately released, preferably directly in conjunction with dispensing the product. It is of advantage if the connection to the housing part is released as the coupling motion is effected. The coupling engagement is produced during a first portion of travel covered during the coupling movement in a first phase, and the connection on the housing is then released in a subsequent second phase, advantageously against the elastic rebound force of the retaining device. The coupling output member is advantageously fixed on the housing by means of the coupling interconnecting member when the coupling members are in the retaining position. The locking engagement of the coupling interconnecting member with respect to the housing or a structure connected to it for this purpose is expediently released when the coupling movement is effected. It is of advantage if the coupling interconnecting member can be moved out of the locking engagement in the direction of the coupling movement because such a movement enables the coupling interconnecting member to be simply driven during the coupling movement, for example pushed out of the locking engagement. The locking engagement may be of the positive and/or friction type.
In a first variant, the return member acts on the at least one coupling member effecting the coupling movement via the coupling interconnecting member, retaining it in the retaining position. In a second variant, the return member acts directly on the at least one coupling member effecting the coupling movement, preferably the coupling input member, and is supported on the housing or a structure which is fixedly connected to the housing for the purpose of the coupling movement or to the coupling output member in order to apply pressure, for example.
In some embodiments, the coupling movement is preferably an axial stroke movement. If a plunger and a plunger rod constitute the conveying mechanism, the stroke movement is preferably effected in the forward-drive direction of the plunger and the plunger rod. As the driving force drives the coupling input member in rotation, which in turn drives the coupling output member in rotation due to the coupling engagement, advantageously about an axis of rotation pointing in the forward drive direction, those coupling members which between them form the coupling engagement are specifically provided with locating elements, which co-operate in the manner of axially, mutually displaceable grooves and springs or as teeth axially directed towards one another or preferably conical teeth. Although a single tooth and a single tooth gap would be sufficient to produce the coupling engagement in theory, it is preferable for at least one of the coupling members co-operating in the coupling engagement to have a set of teeth extending peripherally around the axis of rotation. Even more preferably, in some embodiments, both of the coupling members co-operating in the coupling engagement each have a set of circumferentially extending teeth. The same applies if the engaging elements are provided in the form of grooves and springs or some other means. Irrespective of what shape or form the coupling surfaces are, the coupling engagement is designed so that no slip occurs in the coupling engagement.
To render production of the injection devices as flexible as possible, it is advantageous to split the devices into modules, which are individually manufactured and stored and not assembled until packaging. The dose display may be one such module, in which case it is assembled with a prefabricated injection device shortly before being delivered to the customer. The dose display proposed by the invention is a dose display with a modular construction of this type.
The dose display consists of a first and an additional display element, a gear mechanism consisting of a display coupling member which establishes the connection to the device in the assembled state and simultaneously drives the first display element, a mechanism by means of which the first display element is able to drive an additional display element about a circle segment with every complete turn, and a centrally disposed sleeve serving as a connecting element for these individual components.
When setting the dose by turning a dose-measuring mechanism, for example, which in the case of self-injection devices is done manually by the user as a rule, the rotating movement of the drive member, which is connected to both the dose-measuring member and the dose display during the dose-measuring process, is deflected via the gear interface and transmitted to the dose display. The user continues to rotate the dose-measuring mechanism until a reading of the desired dose appears on the dose display. If a higher dose is unintentionally set, a correction can be made to the desired value by a simple backward turn on the dose-measuring member, which backward turn likewise causes the requisite correction to be made to the dispensed quantity. Instead of effecting a rotating movement on the dose-measuring device, it would also be possible to use a setting mechanism operated on the basis of an axial displacement or a permitted tipping movement of the dose-measuring device transversely to the device longitudinal axis. The dose measurement can likewise by operated by an electric, pneumatic or some other drive, in addition to which the forward drive of the dispensing mechanism need not be limited to a manual driving action and/or spring force.
When the injection is initiated, the dose display is connected via appropriate coupling elements to the drive mechanism causing the dispensing action and is driven by it during dispensing. Once the set dose has been fully administered, the dose display indicates the value zero on termination of the injection. If the injection process is inadvertently or deliberately interrupted as the product is being dispensed, the dose display indicates the quantity of product which still has to be dispensed at that instant. In this case, the user can set the display to zero or continue administering the product and thus administer the product quantity which has not yet been injected. If, during the injection, the user notices that he has set too low or too high a dose on the dose-measuring member, he can interrupt the injection at any time, correct the remaining quantity of product to be dispensed at this point in time and then finish the injection.
A real-time display proposed by the invention may be provided with mechanical elements of two or more mutually encompassing counter dials, which are printed with the figures “0” to “9” in the circumferential direction. A display of this type incorporating mutually encompassing counter dials may be provided with a setting knob or dose-measuring member, coupled so that whenever the setting knob or the dose-measuring member is moved, the mechanical display also turns during the process of measuring the dose and/or correcting the dose, for example.
The mechanical dose display proposed by the invention consisting of mutually encompassing counter dials, for example, may likewise be coupled with the dispensing mechanism by means of appropriate coupling members so that the counter dials also turn during the dispensing process but in the direction opposite the setting direction. In other words, the mechanical display counts back from the set dose to the value zero as the product contained in the injection device is being dispensed. If the injection is unintentionally or deliberately interrupted, the movement of the dose display also stops and the reading indicates the part-dose which has not as yet been dispensed.
The first display element is preferably sub-divided into ten equal parts and serves as a counter dial for indicating the single figure units. A disc with a cam is mounted on the base end of the first display element which turns with the first display element and turns the latter one circle segment further with every rotation by means of a capstan wheel connected to the second display element.
The other display element may serve as a counter dial for the tens and, like the first display element, is divided into ten segments. In this embodiment, the circle segment about which the first display element drives the second display element with each rotation is exactly 36°. This rotation on the other display element would take place during the switch of the first counter dial from the digit “9” to the digit “0”, for example. However, any other sub-division may be used for the other counter dial by designing the capstan wheel accordingly.
The counter dials may be totally or partially transparent. This being the case, at least one light source, preferably a LED or OLED may be provided as a fixed component of the device. In some embodiments, the light source is preferably mounted underneath the circle segment which indicates the actual dose. The light source may be permanently illuminated or switched on by a defined event, for example at the start of the dose-measuring movement on the dose-measuring member, and be switched back off again at the end of the dispensing process, i.e. on reaching the zero position. However, it would also be conceivable to opt for a system which has to be deliberately switched on by the user in darkness or poor light conditions, for example by means of a knob or any other appropriate means which might be used for switching purposes.
Another possible solution is to apply the digits to the counter dials with fluorescent paint, in which case stored luminescent energy will enable a reading to be taken from the dose display in darkness.
A dose display proposed by the invention may be integrated in both an injection pen for self-administration of a product and in a mechanical, pneumatic or electrical injection device. It is also possible to replace the mechanical dose display with an electronically generated display. To this end, the rotation of the dose-measuring member and the movement of the dispensing mechanism are detected by appropriate sensors. The information obtained in this manner is converted into a digital display in an appropriate manner, by suitable hardware and/or software. It is also possible to display a real-time reading of the product quantity waiting to be dispensed in any situation, as described above.
For the purpose of integrating it in prefabricated injection devices, the dose display has an interface, which ensures both a reliable coupling of the drive with the drive of the injection device but also simultaneously ensures that the dose display is securely attached to the device.
a is a detailed diagram showing a plan view of the dose display,
a is a plan view of the dose display with an alternative drive and a light element.
With regard to fastening, mounting, attaching or connecting the components of devices of the present invention, unless specifically described as otherwise, conventional fasteners such as screws, rivets, toggles, pins and the like may be used. Other fastening or attachment means appropriate for connecting components include friction fitting, adhesives, welding and soldering, the latter particularly with regard to electrical or processing components or systems of the devices. Any suitable mechanical or power communicating links, linkages or transmission may be used. Any suitable electronic, electrical, communication, computer or processing components may be used, including any suitable electrical components and circuitry, wires, wireless components, sensors, chips, boards, micro-processing or control system components, software, firmware, hardware, etc.
Housing part 4 accommodates a plunger rod 15 and the dose-measuring and drive unit, which constitutes the dose-measuring and drive mechanism. In a dose-measuring and drive train, the dose-measuring and drive unit has a drive member 5 and a coupling, which, in a coupled state, i.e., in a coupling engagement, joint or mesh, couples the drive member 5 with the plunger rod 15. The plunger rod 15 forms a conveyor unit in conjunction with the plunger 3. In the coupled state, the coupling members 6-10 transmit a driving force applied to the plunger rod 15 to the drive member 5. In
The drive member 5 is sleeve-shaped. It has a thread on its external surface extending around a thread axis R pointing in the forward drive direction V. The drive member 5 sits in a threaded engagement with a coupling input member 6 by means of this thread. The coupling input member 6 is also sleeve-shaped and is provided with a matching internal thread in order to establish the threaded engagement. The thread pitch in the threaded engagement is big enough to prevent any sticking due to friction. The dose-measuring member 18 surrounds the coupling input member 6 and is secured to the coupling input member 6 so that it is fixed with it in rotation and is connected to it so that it can not be axially displaced. The plunger rod 15 projects into the drive member 5 and the coupling input member 6.
The plunger rod 15 is provided with an external thread across its axial length. By means of the external thread, it sits in a thread engagement with a coupling output member 9, which is provided with a matching internal thread. The pitch of these two threads is also such that it prevents any sticking due to friction. The thread pitch is preferably smaller than the thread pitch of the thread engagement between the drive member 5 and the coupling input member 6. A coupling sleeve 8 is secured to the coupling output member 9 so as to be fixed to it in rotation and can not be axially displaced. The coupling sleeve 8 and the coupling output member 9 may be regarded as an integral component in terms of the movements which can be effected between the drive member 5 and the plunger rod 15; however, in order to accommodate a compensating spring 17, they are effectively provided in two pieces and are fixedly connected to one another. The coupling output member 9 and the coupling sleeve 8 are able to rotate about the thread axis R of the coupling output member 9 but are mounted in the housing part 4 so that they can not be axially displaced. When the coupling output member 9 is engaged by the thread, the plunger rod 15 projects through the coupling sleeve 8. A compensating spring 17 is biased between a proximal end of the coupling sleeve 8 and a proximal end of the plunger rod 15, which acts on the plunger rod 15 as a compression spring in the forward drive direction V. The compensating spring 17 is pushed onto the plunger rod 15 by means of a plate 15a, rotatably supported on the plunger rod 15, which forms a flange of a sleeve placed on the plunger rod 15.
Disposed in a linear guide 4a, the plunger rod 15 is not able to rotate relative to the housing part 1 and is linearly guided in and opposite the forward drive direction V. The drive member 5 is also displaceable relative to the housing part 4 and is likewise linearly guided in and opposite the forward drive direction V, for which purpose the housing part 4 directly serves as a linear guide 4b.
The thread axis of the plunger rod 15 forms the main displacement axis of the device. It constitutes a rotation axis R for the rotating driving motion of the coupling input member 6 and, via the coupling interconnecting member 7, of the coupling output member 9 as well. It also constitutes the translation axis for the plunger rod 15 and the drive member 5.
The coupling additionally comprises a coupling interconnecting member 7 and a return member 10, provided in the form of a compression spring which biases the coupling interconnecting member 7 with an elastic force acting in the direction opposite the forward drive direction V. The return member 10 is biased between the coupling output member 9 and the coupling interconnecting member 7.
When no force is acting on the drive member 5 in the forward drive direction V, the return member 10 ensures that the coupling engagement is released via the coupling interconnecting member 7. This state is illustrated in
In the uncoupled state, the coupling input member 6 is pushed back away from the coupling sleeve 8 in the direction opposite the forward drive direction V so that the coupling input member 6 is freely rotatable relative to the coupling sleeve 8 and hence the coupling output member 9 fixedly connected to it. At the same time, the coupling output member 9 is rotationally fixed to the housing part 4 by means of the coupling sleeve 8, by means of the coupling interconnecting member 7 and an uncoupling member 11. To establish or create this rotationally fixed coupling, the coupling interconnecting member 7 is provided with engaging elements 7b on an internal surface directed radially towards the coupling sleeve 8 and the coupling sleeve 8 is provided with matching engaging elements 8b. To establish the rotationally fixed engagement with the uncoupling member 11, the coupling interconnecting member 7 is provided with engaging elements 7a on an external peripheral surface and the uncoupling member 11 is provided with radially directed engaging elements 11a on an internal surface, which engage in the same way as the engaging elements 7b and 8b in the uncoupled state in the form of grooves and springs or teeth parallel with the forward drive direction V, which locate in one another. In its rotationally fixed engagement with the coupling sleeve 8 and its rotationally fixed engagement with the uncoupling member 11, the coupling interconnecting member 7 is axially displaceable in and opposite the forward drive direction V and the engagement with the uncoupling member 11 is released when a displacement is effected in the forward drive direction V.
When the drive member 5 is operated by exerting a compression force on a release element 16 in the forward drive direction V, the drive member 5 and the coupling input member 6 jointly effect an axial coupling stroke along the length X. During this driving stroke movement or coupling displacement, the coupling input member 6 pushes the coupling interconnecting member 7 against the rebounding elastic force of the return member 10 in the forward drive direction V. During the course of the stroke movement, the engaging elements 6a and 8a move into engagement with one another, whilst the coupling interconnecting member 7 is simultaneously moved relative to the uncoupling member 11 until it is moved out of the rotationally fixed engagement with the uncoupling member 11. As this happens, the coupling interconnecting member 7 remains in a rotationally fixed engagement with the coupling sleeve 8. The coupling movement is restricted by means of a stop of the release element 16 on the coupling sleeve 8 and, in the embodiment illustrated as an example, on its proximal end face (
To set a the dose, the user turns the dose-measuring member 18, which latches in easily releasable catch positions. The dose-measuring member 18 is connected to the coupling input member 6 in a rotationally fixed arrangement and is also unable to move axially, thus driving the latter with it in rotation. As a result of this dose-measuring movement of the coupling input member 6, the drive member 5, which is linearly guided in and opposite the forward drive direction V at 4b, moves in the proximal direction so that it then projects out from the housing part 4. The axial dose-measuring travel distance of the drive member 5 is the angle of rotation about which the dose-measuring member 18 is turned and the thread pitch in the thread engagement between the drive member 5 and the coupling input member 6, which moves into abutment against the coupling interconnecting member 7 in the forward drive direction V and against the housing part 4 in the direction opposite the forward drive direction V.
When the user releases the pressure on the release element 16, the return member 10 moves the coupling input member 6 via coupling interconnecting member 7 back into the retracted retaining position out of the coupling engagement, as illustrated in
In order to replace the empty container 2, the housing part 1 is released from the housing part 4, and in the embodiment illustrated as an example, by means of a screwing movement. When the housing parts 1 and 2 are released, the uncoupling member 11 is automatically moved relative to the housing part 4 in the direction opposite the coupling movement of the coupling input member 6, which is against the forward drive direction V in the embodiment illustrated as an example here. The housing part 4 provides a mount for the uncoupling member 11 accordingly. The axial distance travelled as a result by the uncoupling member 11 relative to the housing part 4 is as long as the coupling-stroke X, which means that once the housing parts 1 and 4 have been released, the uncoupling member 11 lies axially opposite the coupling input member 6 and blocks it and the coupling input member 6 can no longer be moved in the forward drive direction V, at least not into a coupling engagement with the coupling sleeve 8. The fact that the coupling input member 6 is blocked in the retracted position prevents the coupling output member 9 from moving into a rotationally fixed connection with the housing part 4 and thus prevents the plunger rod 15 from being pushed back. In other words, this ensures that the plunger rod can be pushed back into the housing part 4 without blocking.
a illustrates a plan view of the described dose display.
a shows a plan view of
Embodiments of the present invention, including preferred embodiments, have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms and steps disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principals of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 063 649.4 | Dec 2004 | DE | national |
