Medicine reservoir and device for -the automated release of a liquid medicament

Cross References to Related Applications

This application claims the priority of

European patent application 07 007 306.9, filed April 10, 2007 , the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to a medicine reservoir, a device for the automated release of a liquid medicament with a medicine reservoir of the aforementioned type and a set which includes that type of medicine reservoir and a filling aid in accordance with the preambles of the independent patent claims.

Background Art

Devices for the automated release of liquid medicaments normally are used with patients who have a continuous and in the course of the day varying need of a medicine which can be administered subcutaneously. Specific applications are, for example, certain pain therapies and the treatment of diabetes, in which computer controlled medicine pumps, such as insulin pumps, which can be carried on the body, are used, which often contain amounts of medicine sufficient for several days in a medicine reservoir and supply the liquid medicament to the patient's body from the medicine reservoir through an infusion cannula in accordance with a pre-programmed daily profile. This increasingly entails

the need to carry the pump invisibly, and to this end its dimensions and in particular its overall length should be as small as possible in order not be evident through clothing and to be carried as comfortably as possible. The medicine pumps which are known today and which can be carried on the body have a medicine reservoir with a cylindrical ampoule in which there is a displacement piston which can be pushed into the ampoule by a piston rod or threaded spindle in order to deliver the medicine. The connection of a medicine conveying conduit or of a connection adapter of said medicine conveying conduit is made along the longitudinal axis of the ampoule or along the displacement axis of the displacement piston, respectively. These known designs have the disadvantage of having an overall length that is longer than that desired and which is detrimental to the provision of compact medicine pumps.

■ Disclosure of the Invention

This presents the task of making available a medicine reservoir and a device for the automated release of a liquid medicament which do not have the disadvantages of the prior art or which at least partially avoid them.

This task is solved by the medicine reservoir and the device according to the independent patent claims . A first aspect of the invention relates to a medicine reservoir with one or more containers which is or are designed to receive a liquid medicament or which does or do already contain a liquid medicament. Liquid medicaments are understood to refer to, for example, liquid painkillers or insulin. Each container has an interior with a front wall from which a medicine outlet leads outside either directly or through one or several

other containers. The medicine outlet can, for example, be closed by a septum which must be perforated by a cannula to allow a release of the liquid medicament such that the latter gains a passage to the outside. The interior of the container is sealed in a fluid tight manner from the outside by a displacement piston which can move longitudinally. The displacement piston is bounded, fluid-tight over its entire periphery, in the radial direction by the boundary walls of the container, wherein the container is designed such that the displacement piston can move longitudinally within the container while remaining fluid-tight against the boundary walls. This enables the volume of the interior of the container to be reduced by displacing the displacement piston inside the container while fluid is being displaced from the container interior. Accordingly, with such container interior filled with a liquid medicament and the medicine outlet open to the outside, it is possible to displace a liquid medicament from the container interior and to transport it to the medicine outlet by displacing the displacement piston. In addition, each container is designed such that, at the end of its stroke, which it assumes on having completed the supply of the medicine and when the medicine reservoir is totally empty, the displacement piston abuts the front wall of the container from which the medicine outlet leads to the outside, wherein preferably the full face of said piston abuts said front wall. At the same time, the design exit direction from the medicine outlet or outlets, or in the case of several containers with a common medicine outlet, from that common medicine outlet, is transverse, i.e. at an angle, for example, of 100°, preferably orthogonal to the displacing direction of the displacement piston assigned to the respective container, or in the case of several containers with a common medicine outlet, is transverse or orthogonal to the

displacing direction of at least one of the displacement pistons .

The medicine reservoir according to the invention makes possible the provision of devices for the automated release of liquid medicaments whose overall length is reduced significantly compared with those currently known devices of established structure.

In a preferred embodiment of the medicine reservoir, the surface of the respective displacement piston operative in displacement, thus, its surface when projected in the displacing direction, is the entire surface which is surrounded by its outer circumference and by the boundary walls surrounding its outer circumference, respectively. This type of medicine reservoir is cost effective in manufacture, has a maximum volume of medicine for a given displacement path and in addition is preferable from the point of view of hygiene since only a circumferential seal is required between the displacement piston and the boundary walls of the container, which seal can be produced in a simple and proven way.

In still a preferred embodiment of the . medicine reservoir, a medicine conveying conduct can be joined directly to the medicine outlet of the medicine reservoir or is connected to it permanently or in removable manner. This enables the medicine reservoir to be produced together with the infusion set as a cost effective and, from a hygienic point of view optimal disposable part. In still a further preferred embodiment of the medicine reservoir, in embodiments having a single container, the displacement piston of the medicine reservoir is designed such that the smallest extent of its surface operative in displacement is less than the diameter of a cylinder, the volume of which is, at a height corresponding to the design displacement path of the displacement piston provided for the delivery of

medicine, corresponding to the design volume of supply of the medicine reservoir. In embodiments with several containers, the displacement pistons of the medicine reservoir are ^' designed such that the largest of the respective smallest extents of said surfaces of the displacement pistons operative in displacement is less than the diameter of a cylinder which has, at a height corresponding to the largest of the design displacement paths of the displacement pistons for the delivery of medicine, a volume corresponding to the design volume of supply of the medicine reservoir. This makes possible the provision of devices for the automated release of liquid medicaments which are extremely flat and at the same time meet high sanitary requirements. In still a further preferred embodiment of the medicine reservoir, it has exactly one container for receiving a liquid medicament or which contains a liquid medicament, respectively. Such medicine reservoirs are cost effective to produce and due to their simple structure are particularly reliable in operation.

In another preferred embodiment of the medicine reservoir, it comprises several in particular identical containers, and, in particular, exactly two or exactly three preferably identical containers . By deliberately choosing a specific configuration, for a given volume of medicine the dimensions of the medicine reservoir and thus the dimensions of a medicine pump to receive the reservoir can be influenced to a great degree. In this way, for example, extremely flat medicine reservoirs can be made available which can also be extremely compact, for example, in the case of identical containers with a rectangular cross section which are arranged parallel beside each other.

In still a further preferred embodiment of the medicine reservoir, at least one container, and preferably all the containers of the medicine reservoir, each has a displacement piston whose surface operative in

displacement is circular. This design is preferred since it fulfils highest requirements regarding leak-tightness and hygiene and production can in addition be simple and cost effective. In still a further preferred embodiment of the medicine reservoir at least one container, and preferably all the containers of the medicine reservoir, have a displacement piston whose surface which is operative in displacement is not circular in area, but is preferably an oval, bone-shaped, elongated hole-shaped, rectangular, triangular or hexagonal area, wherein the last named preferably has a flat or extended hexagonal shape. This provides the advantage that, for a given volume of medicine, by deliberately selecting a specific structure and configuration, the thickness of the medicine reservoir and thus the dimensions of a medicine pump to receive the reservoir can be influenced to a great degree. In this arrangement, to stabilise the container, its walls, which abut the longer sides of the surface of the displacement piston operative in displacement, are provided with supporting ribs running transversely to the displacing direction of the displacement piston or with an increased wall thickness such that the walls can provide a higher bending moment to counter the outward bowing under internal pressure. This is of particular advantage in displacement pistons with a bone-shaped surface operative in displacement because this measure can be applied here without increasing the total thickness of the medicine reservoir. In still a further preferred embodiment of the medicine reservoir, it has at least two containers in which the displacement pistons of the containers are mechanically connected to each other such that their displacement must occur inevitably at the same time. This is advantageous because it is possible to provide a supply from all containers by means of a drive unit engaged at a common force transmission point, thus saving

costs and installation space when providing a medicine pump with this type of medicine reservoir.

In addition, in medicine reservoirs according to the invention which comprise several containers, it is preferred that said containers are arranged with their longitudinal axes parallel to each other, thus with the displacement axes of the displacement pistons, in particular such that the longitudinal axes of all containers are arranged in one plane. This allows designs with specific dimensions to be realised.

Furthermore, in medicine reservoirs according to the invention comprising several containers, it is preferable that there is a fluid connection between said containers, i.e. the container interiors are interconnected. In this way the containers interact as if they were a single container.

Furthermore, in medicine reservoirs according to the invention which comprise several containers, it is preferable for these containers to be formed as a single piece, wherein it is preferably for them to have one common medicine outlet which is integral with them. Such medicine reservoirs are robust, reliable in operation and cost effective to produce.

As an alternative to the aforementioned embodiment, it is preferable in medicine reservoirs according to the invention which comprise several containers for the containers to be designed as separate components, wherein it is preferred that there is a fluid connection between said containers established by a further component preferably such that their medicine outlets are interconnected. This enables a large number of different medicine reservoirs according to the invention to be assembled from a limited number of different containers and coupling adapters. In a further preferred embodiment, it is preferable for medicine reservoirs comprising several containers to have a space between two adjacent

containers. In this way it is possible in designing medicine pumps with such medicine reservoirs to locate components, in particular of the drive unit to actuate the displacement pistons, such as, for example, a motor with a drive spindle and/or transmission, between the containers, thus saving overall length. In addition, this enables the containers to be symmetrically arranged around the force transmission point of the drive unit, thus helping to avoid tilting of the displacement arrangement formed by drive unit and displacement piston.

In still a further preferred embodiment of the medicine reservoir, each displacement piston, preferably by one piece design, is rigidly connected to an assigned piston rod. Here, it is preferable for the piston rod in the medicine reservoir or in the respective container holding the assigned displacement piston to be guided radially by the container walls, so that the overall length of the actual displacement piston can be reduced to an amount that it merely serves for sealing functions but is not prevented from tipping due to its overall length. The latter function in this case is assumed by the guided piston rod. Again, this allows the overall length to be reduced. Also, it is preferable in the two aforementioned embodiments for the piston rod to be manufactured from a harder material than the displacement piston in order to allow for their different functions. Here it is advantageous if the piston rod and the displacement piston are formed with each other as one piece produced by multi-component injection moulding. In this way said components can be manufactured as large scale high quality components at minimum unit cost. Furthermore, it is also preferable in medicine reservoirs with at least two containers according to the invention for the piston rods of the displacement pistons preferably to be joined to each

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other as one piece such that any displacing of the displacement pistons must take place inevitably at the same time by the same amount. In this way a cost effective medicine reservoir, reliable in operation, can be made available which, from the viewpoint of the medicine pump to be formed with it, requires only a minimum number of components inside the pump to drive the displacement piston.

In yet a further preferred embodiment of the medicine reservoir, it comprises one or more stops which by positive locking restrict the displacement path of the displacement piston or pistons in a direction opposite to the design displacing direction for delivery of medicine. This prevents the displacement piston from being drawn out of the container when it is retracted inside the container, for example, when the medicine reservoir is being filled, which would present a hygiene problem. In yet another preferred embodiment, the medicine reservoir is filled with insulin, preferably with an amount of insulin corresponding to at least 150 Iϋ (units of insulin) , even more preferably corresponding to 300 IU (units of insulin) . With insulin UlOO which is currently normal for such pumps, this corresponds to a filling volume of at least 1.5 ml or, respectively, 3 ml of insulin. Such medicine reservoirs represent preferred articles of trade, in particular in the form of disposable packs.

A second aspect of the invention relates to a device for the automated release of a liquid medicament, also designated as a medicine pump, or in the case of the release of insulin, as an insulin pump. The device according to the invention comprises a medicine reservoir according to the first aspect of the invention, to supply a liquid medicament, and a drive unit provided with a preferably electronic control by means of which the displacement piston, or, in a medicine reservoir with several displacement pistons, the displacement pistons

of the medicine reservoir can be moved in the respective container holding them in order to effect the delivery of liquid medicament from the container.

Such medicine pumps according to the invention can be produced in very compact form and at the same time meet high hygiene requirements.

In a preferred embodiment of the device, the direction of the connection for joining a medicine conveying conduct to the device runs transversely, preferably orthogonal to the displacement path of the displacement piston or, in the case of several displacement pistons, orthogonal to the displacement path of at least one of the displacement pistons. It is preferable in this case for the device to be designed such that the medicine conveying conduct can be or is connected directly to the medicine outlet of the medicine reservoir. This provides the advantage that costs can be saved since only a minimum number of components is required to connect the medicine conveying conduct. In a further preferred embodiment, the device according to the invention comprises a medicine reservoir with at least two containers, wherein the displacement pistons in the containers are mechanically connected to each other such that their displacement must inevitably occur simultaneously, preferably by the same amount. This construction enables such devices to be produced cost effectively and in a robust design.

In still a i further preferred embodiment, the device comprises a medicine reservoir with at least two containers wherein there is a space between two adjacent containers in which at least one part of the drive unit is located, preferably a drive motor, a drive spindle and/or a transmission of the drive unit. In this way the overall length can be reduced and it is possible to arrange the containers symmetrically around the force transmission point of the drive unit, thus helping to prevent tilting.

In still a further preferred embodiment of the device, the device is an insulin pump which can be carried on the patient's body. In such embodiments of the invention, the advantages of the invention are particularly evident.

A third aspect of the invention relates to a set comprising a medicine reservoir according to the first aspect of the invention and a filling aid which can be connected to the medicine reservoir for retracting the displacement piston or pistons in order to fill the medicine reservoir. This significantly facilitates the filling of the medicine reservoir with liquid medicament from a bulk pack.

Brief Description of the Drawings

Further preferred embodiments of the invention arise from the dependent claims and from the following description with the aid of the illustrations, which show:

Fig. 1: a perspective top view of a first medicine reservoir according to the invention;

Fig. 2: a longitudinal cross-section through the medicine reservoir from Fig. 1 with the displacement piston in the rear displacement end position;

Fig. 3: an illustration as in Fig. 2 with the displacement piston in a front displacement position;

Fig. 4: a perspective top view of the displacement piston of the medicine reservoir from Fig. 1;

Fig. 5: a cross-section through A-A in Fig. 2;

Figures 5a and 6 to 8 : illustrations as in Fig. 5 of preferred embodiment variants of the medicine reservoir from Fig. 1 according to the invention;

Fig. 9: an illustration as in Fig. 4 of a preferred embodiment variant of the displacement piston of the medicine reservoir from Fig. 1;

Fig. 10: a perspective top view of a filling aid for a medicine reservoir according to the invention with the displacement piston from Fig. 9;

Fig. 11: a perspective top view of the filling aid from Fig. 10 and the displacement piston from Fig. 9 in the connected condition; Fig. 12: a perspective top view of a medicine reservoir according to the invention with the displacement piston from Fig. 9 after the displacement piston has been moved into the front displacement end position and the filling aid from Fig. 10 has subsequently been connected;

Fig. 13: a longitudinal cross-section through the arrangement from Fig. 12;

Fig. 14: a perspective top view of the medicine reservoir from Fig. 12 after the displacement piston has been retracted to the rear displacement end position by the filling aid;

Fig. 15: a longitudinal cross-section through the arrangement from Fig 14;

Fig. 16: a perspective top view of a second medicine reservoir according to the invention;

Fig. 17: a longitudinal cross-section through the medicine reservoir from Fig. 16 with the displacement piston arranged in a front displacement position;

Fig. 18: an top view as in Fig. 17 with the displacement piston arranged in a rear displacement position;

Fig. 19: a perspective top view of the displacement piston of the medicine reservoir from Fig. 16; Fig. 20: a cross-section through B-B in Fig.

18;

Figures 21 to 23: illustrations as in Fig. 20 of preferred embodiment variants of the medicine reservoir from Fig. 16 according to the invention; and

Fig. 24: a longitudinal cross-section through a third medicine reservoir according to the invention.

Modes for Carrying Out the Invention

A first preferred embodiment of a medicine reservoir according to the invention in the form of an insulin ampoule for an insulin pump is shown in Figures 1 to 5. As can be seen, the medicine reservoir 1 comprises a container 2 within the boundary walls 7 of which a displacement piston 6 is arranged which can be moved longitudinally to displace fluid out of the interior 3 of said container. The container 2 has an oval cross-section and the displacement piston 6 has a correspondingly oval surface operative in displacement, wherein the smallest extent of the piston surface operative in displacement corresponds to distance H of the two parallel boundary walls (see Fig. 5) . The container interior 3 has a front wall 4 at which a medicine outlet 5 leads outside in a design exit direction which runs orthogonal to the displacing direction of the displacement piston 6. The medicine outlet 5 leads to a connection adapter 12 to which a medicine conveying conduct (not shown) can be directly connected. The displacement piston 6 is made from a soft material, in this case from a thermoplastic elastomer, to form a seal against the boundary walls 7 of the container 2, and is supported by a supporting structure, forming two piston rods 8, which is made from a relatively hard material, in this case from PP (polypropylene) . The displacement piston 6 and the supporting structure are produced in this case in one piece by multi-component injection moulding. It is, however, equally conceivable to manufacture a supporting

structure with a part of the piston made in hard material and to fit a seal on the periphery of the part of the piston, for example, an 0-ring, to form a radial seal against the boundary walls 7. As can be seen by considering Figures 2 and 3 together, which on the one hand show the piston 6 in its intended maximally retracted position (Fig. 2), in which the distance V between the front of the piston and the front wall 4 corresponds to the design displacement path V intended for the supply of medicine and thus the container interior 3 has the design volume of supply of the medicine reservoir 1, and on the other hand in an almost fully inserted position (Fig. 3) , in which the volume of the container interior 3 is almost zero, the displacement piston 6 can be pushed into container 2 by means of the support structure or the piston rods 8 formed by the same, respectively, in order to displace a medicament from its interior 3 and through medicine outlet 5 to the outside. As this takes place, the supporting structure inside container 2 is guided with the piston rods 8 on the boundary walls 7 such that any tilting or tipping of displacement piston 6 can be reliably prevented. As can be seen, each of the two piston rods 8 has a spring tab 13 in the area of its free end which in the fully retracted position of displacement piston 6, as shown in Fig. 2, snap into assigned recesses 9 in the boundary walls 7, thereby positively constraining the displacement path of the displacement piston 6 in a direction opposite to the design direction for delivery of medicament, in which direction said displacement piston is moved, for example, to fill the medicine reservoir. As can be further seen, in the area of their free ends, the two piston rods 8 furthermore in each case comprise two recesses 14 into which detent tabs of a filling aid (not shown) can be snapped in order to connect the filling aid to the medicine reservoir 1.

Figures 5a and 6 to 8 show illustrations as in Fig. 5 of preferred embodiment variants of the medicine reservoir according to the invention from Fig. 1, which have other cross-sectional shapes. As can be seen, the embodiment according to Fig. 5a has a circular cross-section. The embodiments in Figures 6 and 8 have oval cross-sections which have, however, no parallel boundary walls 7. In the embodiment shown in Fig. 6, the boundary walls are exclusively concave towards the interior 3 which is advantageous in retaining a stable shape as pressure increases in the interior 3. In the embodiment shown in Fig. 8, the boundary walls are alternatively convex and concave with respect to interior 3, wherein it is preferable here to provide supporting ribs 15 on the outside of the convex boundary walls

(shown as dotted lines) which counteracts a bulking of the walls towards the outside as pressure increases in the interior 3 of the container 2. The smallest extents H of the surfaces of the displacement pistons 6 operative in displacement in each case extend, in these two designs, along the shortest axis of symmetry of the respective cross-sectional shape. The embodiment in Fig. 7 has an extended hexagonal cross-sectional shape where the smallest extent H of the surface of the displacement piston 6 operative in displacement is the distance between the longest parallel boundary walls 7.

The rest of the design of this medicine reservoir is, apart from the other cross-sectional shape of the container 2, identical to that shown in Figures 1 to 5.

Fig. 9 shows a representation as in Fig. 4 of a preferred embodiment variant of the displacement piston 3 with a supporting structure. As can be seen, this arrangement has a threaded rod 16 which can engage with the female thread of a linear drive (not shown) . By the connection to the linear drive, furthermore a piston

retention (free flow prevention) can be formed in a simple manner.

Fig. 10 shows a perspective top view of a filling aid 10 to fill the medicine reservoir according to the invention with the displacement piston according to Fig. 9. The filling aid 10 is produced as one piece by injection moulding and has a protective pipe 17 for the threaded rod 16 of the displacement piston 6. As can be seen, the filling aid 10 forms two spring arms, on the free ends of which there are two detent tabs 18 to snap into the recesses 14 in the piston rods 8. For connecting to the medicine reservoir 1, the filling aid 10 is pushed with the protective tube 17 onto the threaded rod 16 until the detent tabs 18 snap into the recesses. This connected condition is shown in perspective in Fig. 11 without the boundary walls, in perspective with complete medicine reservoir 1 in Fig. 12 and as a cross-section with complete medicine reservoir 1 in Fig. 13. For filling, the medicine reservoir 1 is then gripped with one hand and the filling aid 10 is gripped at its handle 19 with the other hand and the filling aid 10 is retracted with the displacement pistons 6, 8 connected to it out of the container 2 in a direction opposite to the design displacing direction for delivery until the spring tabs 13 of the piston rods 8 snap into the recesses 9 of the boundary walls 7 of the container 2, thereby positively constraining this movement. This situation is represented in perspective in Fig. 14 and as a cross- section in Fig. 15. The spring arms formed with the tabs 18 can be moved towards each other by pressing the disengaging buttons 20 between two fingers such that the tabs 18 are disengaged from the recesses 14 and the filling aid 10 can be removed.

The Figures 16 to 20 show illustrations as in Figures 1 to 5 of a second preferred embodiment of the medicine reservoir according to the invention, where Fig. 16 shows a perspective top view of the medicine

reservoir, Figures 17 and 18 show longitudinal sections through the medicine reservoir from Fig. 16, in one case with the displacement piston arranged in a front displacement position (Fig. 17) and in another case arranged in the rear displacement position (Fig. 18), Fig. 19 shows a perspective top view of the displacement piston of the medicine reservoir and Fig. 20 a cross- section along line B-B in Fig. 18. As can be seen, the medicine reservoir 1 here comprises two containers 2, within each of which boundary walls 7 a longitudinally- movable displacement piston 6 is arranged to displace fluid from the container interior 3. The containers 2 are arranged parallel in relation to their longitudinal axes X and have circular cross-sections of the same size and correspondingly circular displacement pistons 6. In each container 2, the smallest extent of the piston surface operative in displacement corresponds here to the respective diameter of the container cross-section or to the diameter of the assigned displacement piston 6, respectively. Since the diameters of both containers 2 or displacement pistons 6, respectively, are identical, in this case the according to the claims largest of the smallest extents H of the surfaces of the displacement pistons 6 operative for displacement corresponds to the diameter of one of the two displacement pistons 6 or containers 2, respectively. The container interior 3 in each case has a front wall 4 at which a medicine outlet, being common to both containers 2, leads outside in a design exit direction which also runs orthogonal to the displacing direction of displacement piston 6 or to the longitudinal axes X of the containers 2, respectively. The medicine outlet 5 here also leads into a connection point 12, to which a medicine conveying conduit (not shown) can be directly connected. The displacement pistons 6 are here also made from a soft material and the respective piston rods 8 assigned to the displacement pistons 6 are manufactured from a hard material, wherein

also here, the hard 8 and the soft 6 components are manufactured together in one piece by multi-component injection moulding. It is, however, also conceivable here to produce a supporting structure with piston portion from a hard material and to fit a seal on the circumference of the piston portion, for example an 0- ring, for sealing against the boundary walls 7. As can further be seen, both piston rods 8 of the displacement pistons 6 are connected to each other by a bridge 22 to form one piece in such a way that both pistons must move together inevitably at the same time and in the same manner. The containers 2 are also formed as one piece with each other and with the component that forms the medicine outlet 5, which has been accomplished by injection moulding.

As can be seen by considering Figures 18 and 19 together, the displacement pistons 6 or their piston rods 8, respectively, each have a stop shoulder 23 which, when displacement piston 6 is moved opposite to the design displacing direction of supply of the piston 6, meets a stop 9 on the boundary walls 7 of the assigned container 2 and thus positively constrains the displacement path of the respective piston 6 in a direction opposite to that of the displacement path arranged for the delivery of medicine. At the same time, the stop shoulders 23 serve for guiding the arrangement consisting of the displacement pistons 6, the piston rods 8 and the bridge 22 on the boundary walls 7 of the containers 2 to prevent any tilting or tipping of the displacement pistons 6. As can also be seen, the two piston rods 8 each have a spring tab 21 in the area of their free ends which can serve both to connect a filling aid as well as to connect a drive unit for the displacement pistons 6. Figures 21 to 23 show illustrations as in

Fig. 20 of preferred embodiment variants of the medicine reservoir 1 according to the invention in Fig. 16, which

have other configurations and/or cross-sectional shapes. As can be seen, in accordance with Figures 21 and 22, the embodiments each have three identical containers 2, in one case with circular cross-sectional shape (Fig. 21) and in the other case with oval cross-sectional shape (Fig. 22) . Fig. 23 shows an embodiment in which four containers 2 with identical triangular cross-sectional shapes are arranged beside each other such that the apexes of the triangles alternately point upwards and downwards. In all the embodiments, the containers 2 are produced as one piece with each other and with the component forming the common medicine outlet 5. In these embodiments, the according to the claims largest of the respective smallest extents H of the displacement piston surfaces operative in displacement is given as, in one case, the diameter of one of the containers 2 or of the assigned displacement piston, respectively, (Fig. 21) , in another case as the height of the cross-section of one of the containers 2 along the shortest axis of symmetry of the oval cross-sectional shape (Fig. 22) and, in another case, as the height of the triangular cross-section of one of the containers 2 (Fig. 23) . The embodiment according to Fig. 7 displays an extended hexagonal cross- sectional shape in which the smallest extent H of the displacement piston surface operative in displacement is the distance between the longest parallel boundary walls 7. The rest of the design of these medicine reservoirs, apart from the other configuration or cross-sectional shape of the containers 2, respectively, is identical to that shown in Figures 16 to 20.

Fig. 24 shows a longitudinal section through a third medicine reservoir 1 according to the invention which only differs from that shown in Fig. 17 in that a space 11 is provided between the containers 2 to receive a drive unit (not shown) of an insulin pump and that both piston rods 8 have no spring tabs in the area of their free ends to connect a filling aid or a drive unit,

respectively. The rest of the design of these medicine reservoirs 1 is identical to that shown in Figures 16 to 20.

While there are shown and described presently preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.