Portable infusion pump for administering a defined quantity of a fluid, in particular an infusion solution.

Abstract

The invention relates to a portable infusion pump for administering a defined quantity of a fluid, wherein the infusion pump (1) comprises a reservoir container (2) and a cannula assembly (3) with an infusion cannula (4) and a cannula insertion mechanism (5), wherein the infusion cannula (4) is fluidically connected or connectable to the interior of the reservoir container (2) via a container-side cannula end (6) and extends from the container-side cannula end (6) along its axial extent to a receiver-side cannula end (7) on which a first cannula tip (8) is formed, wherein the infusion cannula (4) has between the container-side cannula end (6) and the receiver-side cannula end (7) a central cannula section (9) and at least one adjacent end cannula section (10) and a cannula section extending towards the container-side cannula end. (6) has adjacentand wherein the cannula insertion mechanism (5) is designed such that, upon actuation, the infusion cannula (4) is subjected to radial stress and causes elastic bending of the infusion cannula (4), so that the recipient-side cannula end (7) is moved from an initial position (12) to an insertion position (13). It is proposed that the central cannula section (9) has a higher bending strength and / or bending stiffness than the respective adjacent end cannula sections (10, 11).

Description

The present invention relates to a portable infusion pump for administering a defined amount of a fluid, in particular an infusion solution, according to the preamble of claim 1 and according to the preamble of claim 18.Portable infusion pumps, also called patch pumps, which are the subject of the proposed solution shown below, are usually carried fixed on the body and convey a specific amount of an infusion solution into the human body in a specific time, continuously or over a predefined amount-time profile, either subcutaneously or intravenously, in order to achieve a desired concentration there and thus a corresponding effect in the human body. The range of such fluids, in particular infusion solutions, ranges from low viscosity to high viscosity, from simple low molecular weight substances of a few daltons molecular size to high molecular weight substances of up to 1,000,000 daltons molecular size. From simple saline solution to highly complex biologically active substances, such as peptides, proteins, monoclonal antibodies, vaccines of all kinds, pain medications, the desired amount can be delivered precisely and safely to the suitable location in the human body by means of an infusion pump. However, not only immunizing, preventively or prophylactically effective or therapeutic fluids or infusion solutions, but also fluids of importance in analytics as well as fluids with nutrients or even a combination of all the aforementioned fluids can be administered with such infusion pumps with the required precision and / or within a desired therapeutic and / or useful window.Infusion pumps have been known, inter alia, for the therapy of diabetes mellitus since the 1970s. These pumps typically deliver a fluid consisting of water, adjuvants and the peptide (hormone) insulin. Sometimes such infusion pumps also deliver one to three additional fluids. For the years, infusion pumps delivering such insulin-containing infusion solutions have been able to be reduced from the dimensions of a tamper-holder backpack to the currently most compact infusion pump (Omnipod® by Insulot, Acton, MA, USA) of 52 x 39 x 14 mm by continuous innovation. If pumps with infusion sets (this is simplified by a hose with a connection for the infusion pump at one end and an infusion port, which usually directly provides access to the body of the infusion receiver, at the other end) were still customary in the years 1990 to 2015, patients have changed more and more to particularly small pumps fixed or bonded to the skin, so-called patch pumps, for some years. Patch pumps are not only extremely compact and therefore also usually discrete, but also often have the advantage that no infusion set connected to this pump is required any longer as an interface to the human body. The tube of an infusion set has the disadvantage that it can become entangled and, in the worst case, be torn off, especially in playing children or in sports. In addition, the tube can buckle and therefore a certain pressure can build up within the tube and / or the infusion pump, which is suddenly reduced when the buckle is opened again. Furthermore, a tube can cause an error in the precise infusion, in that the difference in height potential from an infusion pump, for example carried on the abdomen, to an infusion port mounted on the upper arm causes a counterpressure, which amounts to 10,000 Pa in the case of a liquid column of, for example, in the case of large persons, and acts on the mechanics of the infusion pump. If the infusion receiver now moves into the horizontal for example for sleeping, the pressure created by the aforementioned liquid column is omitted. These changes in position in turn result in changes in the precision of administration. In the theoretical tests according to IEC 60601-2-24, such variations for precision of the infusion rate are not taken into account, since only one static system is tested. Nevertheless, risk analyses of the risks of an infusion set are usually critical. Especially in the case of small children, continuous and close-mesh monitoring is indispensible in an infusion pump with an infusion set.Patch pumps are supplied either as an infusion pump ready for operation, except for filling, or as a set of parts consisting of several components. After the unpacking and, where necessary, assembly, these infusion pumps are filled. Filling is usually effected by means of a syringe, with which usually a part of the contents of a bottle containing an infusion solution of, for example, 10 ml is transferred into the reservoir of the infusion pump. After filling, the patch pump is placed on the body of the infusion recipient and the infusion cannula, which is directly or indirectly connected to the reservoir, is connected by its second end subcutaneously or in inventory with the body. During filling, the user must take care to transport as few air bubbles as possible into the reservoir. Such air bubbles prevent, on the one hand, the delivery from running in a controlled manner, since gases can be compressed to a greater extent by orders of magnitude than fluids and thus result in undefined delivery rates in the case of pressure differences. On the other hand, the accidental puncture of the infusion cannula connected directly or indirectly to the reservoir into a vein may occur, and the air bubbles could lead to an air embolism in the worst case.The known prior art (US 2004-010207 AA), on which the invention starts out, relates to a portable infusion pump which has a reservoir container with a container interior and a cannula arrangement with an infusion cannula and a cannula injection mechanism. The infusion cannula is fluidically connected to the container interior of the reservoir container via a container-side cannula end. Upon actuation of the cannula injection mechanism, the infusion cannula is radially loaded and an elastic bending is effected, so that the other cannula end, namely the cannula end on the receiver side, is displaced from an initial position into a puncture position.Infusion cannulas of such infusion pumps usually have external diameters above 350 μm, in some cases even up to 500 μm, for simple production, since these can be processed within the infusion pump by standard production methods. Smaller external diameters have the disadvantage that when the infusion cannulas are bent to angles of 90° or less, the infusion cannulas buckle, since no bending mandrel which is customary when bending tubes can be introduced into the infusion cannula and would prevent the buckling. Such infusion cannulas can also be optimally resistant to the usual radial loads to which they are exposed by the cannula injection mechanism.Infusion cannulas for such infusion pumps therefore have comparatively large outer diameters for stability reasons. One challenge is that the larger the diameter of an infusion cannula, the greater the resistance to puncture and the more tissue is destroyed by the facet cut. Intercell fluid exits. This has the consequence, on the one hand, that a chemical stimulus is transmitted to the nerves (pain) and, on the other hand, that the body attempts to repair the injured site. The healing test can cause closure or encapsulation of the foreign body, the greater the more comprehensive. Injury to a blood vessel is also more likely with increasing diameter. Furthermore, nerve endings can be injured in the epidermis, which, although clearly less dense than in the dermis lying underneath, are particularly sensitive.The invention is based on the problem of configuring and further developing the known portable infusion pump in such a way that an optimization with regard to the two opposing aspects of a sufficient stability of the infusion cannula on the one hand and a resistance as low as possible during puncturing on the other hand is achieved.The above problem is solved by the features of the characterizing part of claim 1.The fundamental consideration is to provide the infusion cannula with cannula sections of different mechanical properties along its axial extension, in particular in the area between the fixed bearing assigned to it and its cannula end on the receiver side. Thus, a cannula section ("central cannula section"), which is subjected to a particularly high mechanical stress, in particular a bending stress, during use, is designed to be particularly stable, and at least one further cannula section ("end cannula section"), in particular the cannula section to be inserted into the tissue of the infusion recipient, is designed to be particularly thin, whereby the resistance during puncturing is minimized. Pain and injuries can be minimized in the infusion recipient by a particularly thin receiver-side cannula section; a septum of the reservoir container can be easily pierced by a particularly thin container-side cannula section. Thus, two targets opposing one another - a stability as high as possible on the one hand and a resistance as low as possible on the other hand - can be achieved with one and the same infusion cannula, and this in a particularly simple manner.Further advantages of the design of the infusion cannula according to the invention are, to name just a few examples, an optimal flexibility in the piercing movement, in spite of the high stability, in which the infusion cannula is rotated, a simpler productivity by means of standard tube bending machines and the possibility of additional functions such as, for example, that of an automatic retraction from the tissue, which is explained in more detail below.For the latter, the cannula arrangement is in particular designed in such a way that the infusion cannula, in particular when it is inserted into the tissue of the infusion recipient, can automatically execute a restoring movement, by means of which the cannula end on the recipient side is displaced back from the puncture position to the initiation position, preferably as far as the initial position. The infusion cannula is thus mounted and designed such that the cannula end on the receiver side can be displaced from the injection position to the initial position after termination of the intended use of the proposed infusion pump without a separate reset mechanism. In this case, the bending moment, which counteracts the radial load exerted by the cannula injection mechanism on the infusion cannula, i.e. the transverse force introduced into the infusion cannula, is decisive for the automatic restoring movement. Thus, no external transverse force additionally introduced into the infusion cannula and / or no external moment additionally introduced into the infusion cannula is decisive for the restoring movement. Corresponding separate devices, which would engage the infusion cannula for the purpose of restoring from the puncture position to the initial position, can thus be dispensed with. This allows a simpler construction of the infusion pump, since the need for a separate reset mechanism is dispensed with and correspondingly less installation space is required for the individual functional components of the infusion pump.A further important advantage is also that a transverse force or radial force has to be introduced into the infusion cannula only at a single point. Only the cannula injection mechanism has to engage the infusion cannula. Since the restoring movement can be carried out automatically by the infusion cannula, no elastic counter bearing such as a separate spring must be provided for restoring, against the prestressing of which the cannula injection mechanism would have to work. In this way, the infusion cannula is loaded only to a minimum, which prevents undesired deformations of the infusion cannula.In detail, it is proposed that the central cannula section has a higher bending strength and / or bending strength than the respectively adjacent, end-side cannula section.According to the particularly preferred embodiment according to claim 2, the cannula injection mechanism acts on the central cannula section with the higher bending strength and / or bending stiffness, which particularly effectively prevents undesired deformations on the infusion cannula.Claim 3 relates to particularly preferred possibilities for producing the particular mechanical properties of the central cannula section, the increased bending strength and / or bending rigidity. This can be done in a particularly simple manner by sheathing the tube which forms the channel for the fluid. In principle, however, it is also conceivable to increase the material thickness with respect to the adjacent sections.In claims 4 to 9, particularly advantageous paths of the infusion cannula or individual cannula sections along their axial extension as well as a preferred mounting of the infusion cannula are specified. In particular, by suitably selecting the locations at which the infusion cannula is mounted and / or has a deflection location, it is achieved that bending stress of the infusion cannula takes place mainly in the central cannula section.According to a particularly preferred embodiment according to claims 10 to 13, the proposed infusion pump has not only a single reservoir container, but two or more reservoir containers. Accordingly, two or more infusion cannulas can also be provided. In this way, overall larger amounts of a fluid or different fluids can be administered in a simple manner.Claims 14 and 15 relate to a housing of the infusion pump, in which the individual components, in particular the reservoir container and the infusion cannula, optionally a drive source, are arranged. It is particularly preferred if the housing is formed of multiple parts and has a housing part on which disposable components, i.e. components not reused after the reservoir container has been emptied, are mounted, and a further housing part on which reusable components, i.e. components reusable after the reservoir container has been emptied, are arranged. Thus, it is advantageous, especially from an environmental point of view, but also from an economic point of view, if the entire infusion pump does not have to be disposed of after the reservoir container has been emptied. In principle, it is even conceivable to design the reservoir container as an exchangeable cartridge and thus to exchange only the reservoir container, optionally with the infusion cannula and / or the traction means, after application has taken place.In claim 16 a preferred arrangement of a power source for the electrical components is defined and in claim 17 a preferred arrangement of a user interface is defined.According to the further teaching according to claim 18, which is of independent significance, a portable infusion pump is claimed for administering a defined amount of a fluid, in particular an infusion solution, wherein the infusion pump has a reservoir container with a container interior which is configured, in particular at least in one section, for receiving the fluid, wherein the infusion pump has a cannula arrangement with an infusion cannula and a cannula injection mechanism, wherein the infusion cannula is or can be fluidically connected to the container interior of the reservoir container via a container-side cannula end and the infusion cannula extends from the container-side cannula end along its axial extension to a receiver-side cannula end, at which a first cannula tip is formed, wherein the infusion cannula between the container-side cannula end and the receiver-side cannula end has a central cannula section and at least one adjacent, in particular adjacent, cannula section, The device according to the invention has a cannula section at the end of the cannula, in particular a first end-side cannula section adjacent to the cannula end at the receiver end and a second end-side cannula section adjacent to the cannula end at the container end, and wherein the cannula injection mechanism is configured to load the infusion cannula radially upon actuation thereof and to cause elastic bending of the infusion cannula, so that the cannula end at the receiver end is displaced from an initiation position into a injection position, in particular abruptly.It is essential according to the further teaching that the cannula arrangement is designed in such a way, in particular the infusion cannula is mounted and designed in such a way that the infusion cannula, in particular when it is inserted into the tissue of the infusion recipient, can automatically execute a restoring movement, by means of which the cannula end on the recipient side is displaced back from the puncture position to the initial position, preferably as far as the initial position.Reference is hereby made to all explanations concerning the portable infusion pump according to the first teaching.The invention is explained in more detail below with reference to a drawing which merely represents an exemplary embodiment. The drawing shows FIG. 1 shows a portable infusion pump a) according to the invention, arranged in use on the upper arm of the infusion receiver, and b) in a perspective top view and c) in a perspective bottom view, FIG. 2 shows a perspective illustration of a proposed infusion pump in the "open" state, divided into two housing parts, with correspondingly assigned functional components, FIG. 3 a) a plan view of a proposed lower housing part, with the functional components assigned to the lower housing part, b) a detail section from this plan view, showing a cut-away portion of the functional components reservoir container with infusion cannula connected in fluidic terms, and c) a side view corresponding to the representation b), and FIG. 4 shows a perspective illustration of the infusion cannula according to the proposal.The exemplary embodiment illustrated in the figures and thus preferred relates to a portable infusion pump 1 for administering a defined amount of a fluid, in particular an infusion solution. With regard to the definition and fields of application of an infusion pump 1, reference is made to the introductory part of the description.The infusion pump 1 has a reservoir container 2 with a container interior which is configured, in particular at least in one section, for receiving the fluid.Furthermore, the infusion pump 1 has a cannula arrangement 3 with an infusion cannula 4 and a cannula injection mechanism 5.The infusion cannula 4 is fluidically connected or connectable to the container interior of the reservoir container 2 via a container-side cannula end 6 and extends from the container-side cannula end 6 along its axial extension to a receiver-side cannula end 7, on which a first cannula tip 8 is formed.The infusion cannula 4 has a central cannula section 9 between the cannula end 6 on the container side and the cannula end 7 on the receiver side and at least one adjacent, in particular adjacent, end-side cannula section, in particular a first end-side cannula section 10 adjacent to the cannula end 7 on the receiver side and a second end-side cannula section 11 adjacent to the cannula end 6 on the container side. In this case, the terms "adjacent" and "adjacent" refer in the present case to the axial extent of the infusion cannula 4. "adjacent" means that the respective end-side cannula section 10, 11 directly adjoins the central cannula section 9. In the present exemplary embodiment, the central cannula section 9 is adjoined on both sides by an end-side cannula section 10, 11 respectively. In principle, however, it is also conceivable for a said end-side cannula section 10 to adjoin the central cannula section 9 only on one side, namely on the receiver side, but not on the other side, that is to say towards the reservoir container 2, so that in this case the central cannula section 9 extends on the container side as far as the reservoir container 2.The cannula injection mechanism 5 is designed such that upon its actuation the infusion cannula 4 is loaded radially, which causes an elastic bending of the infusion cannula 4, so that the receiving-side cannula end 7 is displaced from an initial position 12 into a puncture position 13, in particular abruptlyAs shown in FIG. 1, the infusion pump 1 can be worn by the infusion receiver 14 on the body under clothing, in particular in the state fixed and / or adhered to the skin, and is thus "wearable" independently of location."Administration" of an infusion solution is here carried out intravenously and / or subcutaneously, and thus corresponds to a delivery of an infusion directly into the tissue of an infusion recipient 14, in particular into the human body.The term infusion cannula 4 used here denotes a tube, here and preferably made of plastic or of metal, in particular a stainless steel alloy or a nickel-titanium alloy, which is already fluidically connected at its first tube end directly or via a further interface to the reservoir container 2, or is only fluidically connected to the reservoir container 2 during the preparation of an infusion directly or via a further interface, for example by puncturing a septum. During subcutaneous infusion, the second tube end is usually introduced directly into the body of the infusion recipient 14, or is inserted into the skin tissue thereof. Here and preferably, the infusion cannula 4 has an outer diameter of less than 500 μm, preferably less than 350 μm, more preferably less than 300 μm.The exemplary embodiment is explained below with reference to only one set of functional components (reservoir container 2, infusion cannula 4, cannula injection mechanism 5, etc.). It should be emphasized that the exemplary embodiment here and preferably has two such sets of functional components. The following explanations regarding the one set of functional components preferably also apply equally to the other set of functional components.The reservoir container 2 arranged in a housing part 15 in FIG. 2 can be designed as an exchangeable container, also referred to as a cartridge, or as a functional component rigidly connected to the housing part 15 of the infusion pump 1, in particular configured integrally therewith.The term infusion cannula 4 used here denotes an arrangement with a tube 16, here and preferably made of plastic or of metal, in particular a stainless steel alloy or a nickel-titanium alloy, which is already fluidically connected at its first tube end directly or via a further interface to the reservoir container 2, or is only fluidically connected to the reservoir container 2 during the preparation of an infusion directly or via a further interface, for example by puncturing a septum. During subcutaneous infusion, the second tube end is usually introduced directly into the body of the infusion recipient 14, or is inserted into the skin tissue thereof.In contrast, in intravenous infusion, the connection of the second tube end to the infusion receiver 14 can also take place with an infusion set which is fluidically connected in between, wherein an infusion cannula 4 can again be located at the end of the infusion set, which infusion cannula is either introduced directly into the body of the infusion receiver 14 or is connected to the body via a further interface.As can be seen from the overview of FIGS. 1 to 3 and in this respect is shown as a preferred variant, the infusion cannula 4 establishes the fluidic connection to the body of the infusion receiver 14 on the one hand in the simplest case (FIG. 1 ), wherein the fluid / the infusion solution is conducted through the infusion cannula 4 to the body of the infusion receiver 14 and is discharged to the latter.On the other hand, the infusion cannula 4 can be fluidically connected to the reservoir container 2 (FIGS. 2 and 3 ), by which is meant that the connection can be produced manually before the first administration, or can be produced automatically during the insertion of the cartridge, in particular by the insertion movement of the cartridge relative to a housing part 15 of the infusion pump 1.As can also be seen from FIGS. 2 and 3, the cannula arrangement 3 is a unit of infusion cannula 4 and functional components which act thereon for the purpose of mounting and deforming it.The cannula injection mechanism 5, which is schematically illustrated in FIG. 3 c ) and is preferred in this respect, is to be understood as a mechanism, in particular a lever mechanism, which acts on the infusion cannula 4 during its actuation and deflects the latter in such a way that it penetrates into the tissue of the infusion receiver 14."First cannula tip" 8 in this context and also in the present case, in particular shown in FIG. 4, means the section of the infusion cannula 4 that can be introduced directly into the tissue of the infusion receiver 14, in particular into the human body, for administering the infusion solution.The term "radial load" as used herein means that a force is introduced radially with respect to the central axis of the infusion cannula 4.A "sudden" displacement of a position is meant here and preferably that infusion cannulas 4 are usually inserted "abruptly" into the tissue of the infusion recipient 14, since a deliberate or slow insertion of an infusion cannula into the body represents a psychological hurdle in very many people. For this reason, a strong acceleration of the first cannula tip 8 is thus generated here in the direction of the provided puncture site 13.Before the infusion cannula 4 is moved, in this case abruptly, it is located with its cannula end 7 on the receiver side in the initial position 12.After the infusion cannula 4 has been displaced, it is located with its receiving-side cannula end 7 in the piercing position 13.Here and preferably, the infusion pump 1 also has a conveying device for conveying the fluid from the reservoir container 2 into the infusion cannula 4. Here and preferably, as part of the conveying device, a metering piston, not shown in more detail, which can be moved in a feed direction is provided in the container interior, which metering piston can be guided along the inner side of the reservoir container 2 in a sealing manner and divides the reservoir container 2 into a sealed front section for receiving the fluid and a rear section.Furthermore, the conveying device here and preferably has a drive arrangement 17 for generating a fluid flow, in particular by a feed movement of the metering piston along the inner side of the reservoir container 2.Concerning an embodiment according to the invention, two thrust pistons of the drive arrangement 17 are visible in FIG. 2, which act directly or indirectly on the metering piston or pistons to produce a feed movement.Otherwise, the drive arrangement 17, not shown in detail here, has in particular a drive source, e.g. a drive motor, and a drive train, which couples the drive source in particular to the respective metering piston in terms of drive technology and has one or more drive components, e.g. wheels, shafts, belts or the like transmitting a drive force or a drive torque.It is now essential that the central cannula section 9 has a higher bending strength and / or bending strength than the respectively adjacent, end-side cannula section 10, 11.The "bending strength" is defined as the characteristic value for the bending stress in a component subject to bending, here the infusion cannula 4, which, when exceeded, causes the component to fail due to breakage. It thus indicates the resistance of the component to deformation and indicates how much force is necessary to break the component - in short: the higher the bending strength, the more applied forces the material holds.The "bending stiffness" describes the resistance of a component under bending stress, here the infusion cannula 4, to elastic deformation under bending stress.The cannula arrangement 3 is here and preferably designed in such a way that the infusion cannula 4, in particular when it is inserted into the tissue of the infusion recipient 14, can automatically execute a restoring movement, by means of which the cannula end 7 on the recipient side is displaced back from the puncture position 13 to the initial position 12, preferably as far as the initial position 12.As shown in FIG. 3 c), the receiving-side cannula end 7 of the infusion cannula 4 can preferably assume two positions: the initial position 12 and the puncture position 13."Automatically" in this context means that the infusion cannula 4 deforms itself back due to its own elasticity-i.e., the receiver-side cannula end 7 can reach the initial position 12 without the need to introduce an external force or without the need for a separate reset mechanism. Therefore, the infusion pump 1 is preferably designed without a corresponding reset mechanism.As can be derived from FIG. 3 c ), the resetting movement is triggered in that the cannula injection mechanism 5 releases and / or releases the infusion cannula 4 previously held with the receiver-side cannula end 7 in the injection position 13, at least to such an extent that a resetting movement is possible.Accordingly, the term "toward the initial position 12" means a displacement, at least so far back in the direction of the initial position 12, that the cannula end 7 on the receiver side no longer protrudes, or no longer protrudes significantly, from the infusion pump 1.Here and preferably, it is also the case that the cannula injection mechanism 5 acts on the central cannula section 9 of the infusion cannula 4 when it is actuated, that is to say only on the cannula section which is in any case of particularly stable configuration.Thus, the central cannula section 9 is here and preferably reinforced. The central cannula section 9 is preferably provided with a casing 18, in particular made of plastic. Furthermore, the casing 18 is preferably fixed to the central cannula section 9 in a materially bonded, force-fitting and / or form-fitting manner, in particular with radial play or radially free of play. For example, as shown in the figures, the jacket 18 represents a sleeve and thus a component separate from the inner tube 16. Additionally or alternatively, the central cannula section 9, which is not shown here, can also be reinforced by providing it with an increased material thickness. "Material thickness" means that the radial thickness of the material, for example metal, which forms the channel for the fluid on the inside, is increased compared to the radial thickness of this material in the adjacent cannula section or sections 10, 11."Materially bonded" in this context means a connection in which the connection partners are held together by atomic or molecular forces. The "frictional engagement", also called frictional engagement, of two connection partners presupposes a normal force on the mutually connected surfaces, which therefore prevents a mutual displacement as long as the counterforce caused by the static friction is not exceeded. The "form fit" of two connection partners is formed by the engagement of the connection partners.As shown in FIG. 4, the reinforcement by the sheathing 18 can be seen. This ensures the bending strength and / or bending rigidity described above in the region of the central cannula section 9, which is pushed here and preferably during production onto the tube 16, optionally with the aid of anti-silk means. Ideally, the outer surface of the tube 16 abuts the inner surface of the jacket 18 with radial play or radially free of play, preferably loosely. Thus, even when bending very small radii to very small angles, the tube 16 cannot buckle but nestles against the inner surface of the shroud 18. According to the proposal, such a tube 16 can have an outer diameter of less than 350 μm, preferably of less than 320 μm, further preferably of less than 300 μm. The volume of air within the tube 16, which ideally does not enter the body, is also thereby minimized. In addition, the handling of the complete infusion cannula 4 during assembly is less sensitive.The cannula arrangement 3 is preferably designed in such a way, in particular the infusion cannula 4 is mounted and designed in such a way that, during the insertion and / or in the inserted state, a bending stress of the infusion cannula 4 takes place mainly in the central cannula section 9.This means here that a bending moment acting on the infusion cannula 4 preferably ensures a bending exclusively of the central cannula section 9.Furthermore, it is provided here and preferably that the infusion pump 1 and / or the reservoir container 2 has a fixed bearing 19 assigned to the infusion cannula 4. The infusion cannula 4, in particular via its central cannula section 9, is preferably fixed radially and / or axially on the fixed bearing 19. Here and preferably, the central cannula section 9 has a rigid subsection 20 which is fixed by the fixed bearing 19 and / or a bendable subsection 21 which extends from the fixed bearing 19 in the direction of the first end-side cannula section 10.FIGS. 3 and 4 show the fixed bearing 19 arranged otherwise in the disposable housing part 22. For a better understanding of FIGS. 3 b) and c), in which the disposable housing part 22 is hidden, the fixed bearing 19 is indicated only schematically there. As can be seen, the fixed bearing 19 provides a rigid subsection 20 of the central cannula section 9 according to the proposal, so that the mentioned bending stress can only develop its effect beyond the fixed bearing 19. At the same time, the container-side cannula end 6 is also fixed in a fixed position, at least in sections."Radial" in this context and as shown in FIG. 3 means a geometric position orthogonal to the longitudinal extension of the infusion cannula 4 and "axial" in the longitudinal extension of the infusion cannula 4, wherein the longitudinal extension means the extension from the container-side cannula end 6 to the receiver-side cannula end 7. The term "fixed" refers to an assembled and immovable state relative to the infusion pump 1, in particular relative to the reservoir container 2 and / or a receptacle for the reservoir container 2.The infusion cannula 4 here and preferably between the container-side cannula end 6 and the receiver-side cannula end 7 has one or more deflection points 23, at which the infusion cannula 4 changes its direction of extension along the longitudinal extension.As can be seen from FIG. 4, the deflection points 23 are configured in such a way that they provide a bend and are preferably situated in such a way that a bendable subsection 21 which is as long as possible and a shorter insertion section which runs transversely thereto and serves for insertion into the tissue of the infusion receiver 14 and which ends in the first cannula tip 8 are produced. It is advantageous in this case that a long lever arm is formed by providing a long bendable subsection 21, which lever arm causes the insertion section and / or the first cannula tip 8 to be inserted into the tissue of the infusion receiver 14 in a virtually rectilinear manner, which results in less injury to the tissue.In the exemplary embodiment illustrated in FIGS. 3 and 4 and thus preferred, it is further provided that the infusion cannula 4 has at least or exactly one deflection point 23 between the container-side cannula end 6 and the receiver-side cannula end 7, at which deflection point the infusion cannula 4 changes its direction of extension along the longitudinal extension by more than 70°, preferably by more than 80°, more preferably by more than or exactly 90°. Here and preferably, it is such that this at least or exactly one deflection point 23 is arranged adjacent to or adjacent to the end of the central cannula section 9 and / or bendable subsection 21 facing the receiver-side cannula end 7, and / or that this at least or exactly one deflection point 23 is followed by a straight piercing section which ends in the first cannula tip 8.Furthermore, it is provided here and preferably that the ratio of the axial length of the entire central cannula section 9 to the axial length of the first end-side cannula section 10 is at least 3, preferably at least 3.5, further preferably at least 4, and / or that the ratio of the axial length of the bendable subsection 21 to the axial length of the first end-side cannula section 10 is at least 2.5, preferably at least 3, further preferably at least 3.5.As explained above, the advantage here too is that by providing a long bendable subsection 21, a long lever arm is formed, which causes the insertion section and / or the first cannula tip 8 to be inserted almost rectilinearly into the tissue of the infusion receiver 14, which results in less injury to the tissue.As shown in FIG. 4, here and preferably the infusion cannula 4 now has the following structure along its longitudinal extension, purely by way of example:On the receiver side, the first end-side cannula section 10 is provided, which extends from the receiver-side cannula end 7 and / or from the first cannula tip 8 to the central cannula section 9, which in turn is adjoined on the container side by the second end-side cannula section 11, which extends from the central cannula section 9 to the container-side cannula end 6 and / or, as here, to a second cannula tip 24. The first end-side cannula section 10 here has an axial length of 7 to 10 mm, the central cannula section 9 here has an axial length of 35 to 45 mm, and the second end-side cannula section 11 here has an axial length of 7 to 10 mm.A "second cannula tip" 24 provided here and preferably serves for piercing an associated section of the reservoir container 2 in order to establish the fluidic connection with the container interior. For example, this serves for piercing a septum of the reservoir container 2. a second cannula tip 24 is provided in particular when the reservoir container 2, preferably pre-filled, and the infusion cannula 4 are provided separately from one another and are to be assembled only for preparation of the application. In the assembled state, the second cannula tip 24 then protrudes so far into the container interior that it is surrounded by the fluid.On the receiver side of the central cannula section 9, a deflection point 23 is provided at which the infusion cannula 4 changes its extension direction along the longitudinal extension, here by more than 90°. This deflection point 23 directly adjoins the central cannula section 9 and is here a component of the first end-side cannula section 10. From the deflection point 23, a straight first piercing section 25 extends as far as the receiver-side cannula end 7 and / or the first cannula tip 8. The first piercing section here has an axial length of 4 to 8 mm.The central cannula section 9 is divided into a bendable subsection 21 adjoining the first end-side cannula section 10 and a rigid subsection 20 adjoining the second end-side cannula section 11. The central cannula section 9 here also has one or more deflection points 23. At a deflection point 23, the infusion cannula 4 changes its direction of extension along the longitudinal extension here by exactly 90°, at two more by less than 10°. The bendable subsection 21 here has an axial length of 30 to 35 mm. The rigid subsection 20 here has an axial length of 5 to 10 mm.On the container side of the central cannula section 9, a deflection point 23 is also provided here, at which the infusion cannula 4 changes its direction of extension, here by exactly 90°, along the longitudinal extension. This deflection point 23 also directly adjoins the central cannula section 9 and is here a component of the second end-side cannula section 11. From the deflection point 23, a straight second piercing section 26 extends as far as the container-side cannula end 6 and / or the second cannula tip 24. The second piercing section is a component of the second end-side cannula section 11.Furthermore, it is provided here and preferably that the outer diameter of the respective cannula section is constant over the axial extension of the central cannula section 9 and / or over the axial extension of the first end-side cannula section 10 and / or of the second end-side cannula section 11. Additionally or alternatively, as provided here, it can be provided that the inner diameter of the respective cannula section is constant over the axial extension of the central cannula section 9 and / or over the axial extension of the first end-side cannula section 10 and / or of the second end-side cannula section 11, preferably that the inner diameter is constant over the entire longitudinal extension of the infusion cannula 4.The term "constant" is to be understood in the present case such that even slight deviations can be present over the axial extent on account of tolerances caused by the production. In the region of a deflection point, too, the diameter can deviate somewhat by the deformation during the production of the infusion cannula 4.It can be seen from FIG. 4 that here and preferably both the tube 16 and the casing 18 of the infusion cannula 4 otherwise each have a constant inner diameter and outer diameter. In this way, semi-finished profiles, i.e. semi-finished products which have a constant profile along their longitudinal extent, can be used during the production of the infusion cannula 4, which contributes to low production piece costs of the infusion cannula 4.As already stated above, the infusion pump 1 has here and preferably two or more reservoir containers 2 each with a container interior which is configured, in particular at least in one section, for receiving a fluid. In the present case, two reservoir containers 2 are illustrated at the bottom in FIG. 2 and FIG. 3.If these also contain different fluids according to the proposal, here two different fluids, the infusion pump 1 can be configured to deliver these fluids to the infusion receiver 14 simultaneously or also independently of one another by appropriate actuation of the drive arrangement 17."Actuating" in the present case always means an actuation initiated by a control device of the infusion pump 1.The cannula arrangement 3 here and preferably has two or more infusion cannulas 4, one of which is assigned to each of the reservoir containers 2. The infusion cannulas 4 can all be configured in the manner proposed.The plurality of infusion cannulas 4 and reservoir containers 2 are of particular importance with regard to the aforementioned possible dispensing of at least two different fluids, since this prevents a mixing of the fluids in a common infusion cannula 4 before the dispensing to the infusion receiver 14, and accordingly the fluids are introduced into the tissue of the infusion receiver 14 in a single type. However, it is also conceivable to provide one and the same fluid in a plurality of reservoir containers 2 and thus to achieve seamless delivery of this fluid into the tissue of the infusion recipient 14 over a longer period of time. In both cases, it is conceivable that initially only one infusion cannula 4 is shot in and the associated reservoir container 2 is taught at least partially, and the fluid is introduced into the tissue of the infusion receiver 14, before a further infusion cannula 4 is then shot in and the reservoir container 2 associated therewith is taught at least partially, and the fluid is introduced into the tissue of the infusion receiver 14. Alternatively, a plurality of infusion cannulas 4 can also be injected from the front and the reservoir containers 2 can be taught successively, at least partially, and the fluid introduced into the tissue of the infusion receiver 14In the case explained here and illustrated in the figures, in which two reservoir containers 2 and / or two infusion cannulas 4 are provided, it is also possible here and preferably in such a way that the respective infusion cannula 4 is or can be fluidically connected to the container interior of the associated reservoir container 2 via a container-side cannula end 6 and extends in each case from the container-side cannula end 6 along its axial extent to a receiver-side cannula end 7 on which a first cannula tip 8 is formed, that the respective infusion cannula 4 has a central cannula section 9 between the container-side cannula end 6 and the receiver-side cannula end 7 and at least one adjacent, in particular adjacent, end-side cannula section, in particular a first end-side cannula section 10 adjacent to the receiver-side cannula end 7 and a second end-side cannula section 11 adjacent to the container-side cannula end 6, and that the cannula arrangement 3 is designed such that the respective infusion cannula 4 can automatically execute a restoring movement, by means of which the receiver-side cannula end 7 is displaced back from the puncture position 13 to the initial position 12, preferably as far as the initial position 12.Furthermore, in the case illustrated here, too, in which two reservoir containers 2 and / or two infusion cannulas 4 are provided, here and preferably the cannula arrangement 3 has a cannula injection mechanism 5 which is configured to load the respective infusion cannula 4 radially upon actuation thereof and to bring about elastic bending of the infusion cannula 4, such that the receiver-side cannula end 7 is displaced from an initial position 12 into a injection position 13, in particular abruptly.The cannula injection mechanism 5 illustrated in FIG. 2 and thus preferred has two partial areas, wherein the rear of the two partial areas is concealed in the perspective illustration. In this way, the cannula injection mechanism 5 preferably permits selective actuation, that is to say that it either acts upon a first of the infusion cannulas 4 during its actuation and deflects the latter in such a way that it penetrates into the tissue of the infusion recipient 14, or acts upon a second of the infusion cannulas 4 and deflects the latter in such a way that it penetrates into the tissue of the infusion recipient 14. This is also important with regard to the aforementioned possible delivery of two different fluids, since sequential delivery of different fluids also only then requires the penetration of the respective infusion cannula 4 into the tissue of the infusion receiver 14.Furthermore, it is provided here and preferably that the infusion pump 1 has a multi-part housing 27, wherein here and preferably the housing 27 has a disposable housing part 22 and a reusable housing part 28.Particularly preferably, the reservoir container 2 and the infusion cannula 4 are mounted on the disposable housing part 22, which preferably together form a pre-assembled disposable unit 29. The energy source 33, for example a primary or secondary battery, which can be removed in particular individually, is also preferably part of the disposable unit 29, which is stored in particular in a battery compartment and can thus be separated from the disposable unit 29 for disposal of the same type. Furthermore, the disposable unit 29 also has, for example, an adhesive patch for attaching the infusion pump 1 to the body. The disposable unit 25 is preferably composed of not more than 15 components (individual parts).A drive source, in particular a drive motor, and optionally further drive elements of the drive arrangement 17 can be mounted on the reusable housing part 28, which preferably together form a pre-assembled reusable unit 30. As reusable components of the infusion pump 1, in addition to the drive arrangement 17, preferably also the cannula injection mechanism 5, electronics, in particular control components, a user interface 34 with a display 35 and / or with an operating unit 36, which can have one or more keys, are mounted as part of the reusable unit 30 and here on the reusable housing part 28.The display 35 is here exemplarily one that does not need to be permanently powered, such as ePaper or memory in pixel display.As can be seen from Figure 2, the disposable unit 29 is the unit facing the user during application. After its intended use, this is removed from the body, separated from the reusable unit 30 and subsequently disposed of.The reusable unit 30 illustrated above in FIG. 2 is, as described above, separated from the disposable unit 29 after the intended use thereof and can subsequently be placed again on a new, unused disposable unit 29 since the reusable components mounted thereon are reusable.FIG. 1 a) shows the use-specific arrangement of the portable infusion pump 1, for example on the upper arm of the infusion receiver 14. The housing 27 can be fixed or bonded to the skin.As can be seen from FIG. 3 b), the reservoir container 2 has a fluid opening 31 for fluidic connection of the container interior of the reservoir container 2 to the infusion cannula 4.When producing the mechanical connection between the two housing parts 15 shown in FIG. 2, in addition to any positive connection, at least one frictional connection is produced which ensures, on the one hand, the coupling from the drive arrangement 17 to the reservoir container 2, in particular to the metering piston, and also, if appropriate, ensures a desired electrical connection between electrical contacts 32.Furthermore, it is provided here and preferably that the reservoir container 2 is non-detachably connected to the housing 27, in particular to the disposable housing part 22, or forms a replaceable cartridge, preferably that the reservoir container 2 can be installed together with the disposable housing part 22 as a pre-assembled unit in a pre-filled state or the replaceable cartridge can be installed in a pre-filled state.In this context, the term "non-detachably" means a non-destructively detachable connection between reservoir container 2 and housing 27, in particular disposable housing part 22.According to a further teaching, which is of independent significance and which is likewise illustrated in FIGS. 1 to 4, a portable infusion pump 1 for administering a defined amount of a fluid, in particular an infusion solution, in particular an infusion pump 1 according to the proposal, is proposed, wherein the infusion pump 1 has a reservoir container 2 with a container interior which is configured, in particular at least in one section, for receiving the fluid, wherein the infusion pump 1 has a cannula arrangement 3 with an infusion cannula 4 and a cannula injection mechanism 5, wherein the infusion cannula 4 is or can be fluidically connected to the container interior of the reservoir container 2 via a container-side cannula end 6, and the infusion cannula 4 extends from the container-side cannula end 6 along its axial extent to a receiver-side cannula end 7, at which a first cannula tip 8 is formed, wherein the infusion cannula 4 has a central cannula section 9 between the cannula end 6 on the container side and the cannula end 7 on the receiver side and at least one adjacent, in particular adjacent, end-side cannula section, in particular a first end-side cannula section 10 adjacent to the cannula end 7 on the receiver side and a second end-side cannula section 11 adjacent to the cannula end 6 on the container side, and wherein the cannula injection mechanism 5 is configured to load the infusion cannula 4 radially upon actuation thereof and to cause an elastic bending of the infusion cannula 4, such that the cannula end 7 on the receiver side is displaced from an initial position 12 into a injection position 13, in particular abruptly.It is essential here that the cannula arrangement 3 is designed in such a way, in particular the infusion cannula 4 is mounted and designed in such a way that the infusion cannula 4, in particular when it is inserted into the tissue of the infusion recipient 14, can automatically execute a restoring movement, by means of which the cannula end 7 on the recipient side is displaced back from the puncture position to the initial position, preferably as far as the initial position.Reference is hereby made to all explanations concerning the portable infusion pump 1 according to the first teaching.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 2004-010207

[0005]

Claims

Portable infusion pump for administering a defined amount of a fluid, in particular an infusion solution, wherein the infusion pump (1) has a reservoir container (2) with a container interior which is configured, in particular at least in one section, for receiving the fluid, wherein the infusion pump (1) has a cannula arrangement (3) with an infusion cannula (4) and a cannula injection mechanism (5), wherein the infusion cannula (4) is or can be fluidically connected to the container interior of the reservoir container (2) via a container-side cannula end (6) and the infusion cannula (4) extends from the container-side cannula end (6) along its axial extension to a receiver-side cannula end (7) on which a first cannula tip (8) is formed, wherein the infusion cannula (4) has a central cannula section (9) between the container-side cannula end (6) and the receiver-side cannula end (7) and at least one adjacent, in particular adjoining, end-side cannula section, in particular a first end-side cannula section (10) adjacent to the receiver-side cannula end (7) and a second end-side cannula section (11) adjacent to the container-side cannula end (6), and wherein the cannula injection mechanism (5) is configured to load the infusion cannula (4) radially upon actuation thereof and to cause an elastic bending of the infusion cannula (4), such that the receiver-side cannula end (7) is displaced, in particular abruptly, from an initial position (12) into a injection position (13), characterized in that the central cannula section (9) has a higher bending strength and / or bending stiffness than the respectively adjacent, end-side cannula section (10, 11).Portable infusion pump according to claim 1, characterised in that the cannula injection mechanism (5) acts on the central cannula section (9) of the infusion cannula (4) when it is actuated.Portable infusion pump according to claim 1 or 2, characterised in that the central cannula section (9) is reinforced, preferably in that the central cannula section (9) is provided with a casing (18), in particular made of plastic, and / or an increased material thickness, further preferably in that the casing (18) is fixed to the central cannula section (9) in a materially bonded, force-fit and / or form-fit manner, in particular with radial play or radially free of play.Portable infusion pump according to one of the preceding claims, characterized in that the cannula arrangement (3) is designed in such a way, in particular the infusion cannula (4) is mounted and designed in such a way that, during the insertion and / or in the inserted state, the infusion cannula (4) is subjected mainly to bending stress in the central cannula section (9).Portable infusion pump according to one of the preceding claims, characterized in that the infusion pump (1) and / or the reservoir container (2) has a fixed bearing (19) assigned to the infusion cannula (4), preferably in that the infusion cannula (4) is fixed radially and / or axially on the fixed bearing (19), in particular via its central cannula section (9), further preferably in that the central cannula section (9) has a rigid subsection (20) which is fixed by the fixed bearing (19) and / or a bendable subsection (21) which extends from the fixed bearing (19) in the direction of the first end-side cannula section (10).Portable infusion pump according to one of the preceding claims, characterized in that the infusion cannula (4) has one or more deflection points (23) between the container-side cannula end (6) and the receiver-side cannula end (7), at which deflection points the infusion cannula (4) changes its direction of extension along the longitudinal extension.Portable infusion pump according to claim 6, characterised in that the infusion cannula (4) has at least or exactly one deflection point (23) between the container-side cannula end (6) and the receiver-side cannula end (7), at which deflection point the infusion cannula (4) changes its direction of extension along the longitudinal extension by more than 70°, preferably by more than 80°, further preferably by more than or exactly 90°, preferably in that this at least or exactly one deflection point (23) is arranged adjacent to or adjacent to the end of the central cannula section (9) and / or bendable subsection (21) facing the receiver-side cannula end (7), and / or in that this at least or exactly one deflection point (23) is followed by a straight puncture section which ends in the first cannula tip (8).Portable infusion pump according to one of the preceding claims, characterized in that the ratio of the axial length of the entire central cannula section (9) to the axial length of the first end-side cannula section (10) is at least 3, preferably at least 3.5, more preferably at least 4, and / or in that the ratio of the axial length of the bendable subsection (21) to the axial length of the first end-side cannula section (10) is at least 2.5, preferably at least 3, more preferably at least 3.5.Portable infusion pump according to one of the preceding claims, characterized in that the outer diameter of the respective cannula section is constant over the axial extent of the central cannula section (9) and / or over the axial extent of the first end-side cannula section (10) and / or of the second end-side cannula section (11), and / or in that the inner diameter of the respective cannula section is constant over the axial extent of the central cannula section (9) and / or over the axial extent of the first end-side cannula section (10) and / or of the second end-side cannula section (11), preferably in that the inner diameter is constant over the entire longitudinal extent of the infusion cannula (4).Portable infusion pump according to one of the preceding claims, characterized in that the infusion pump (1) has two or more reservoir containers (2) each with a container interior which is configured, in particular at least in one section, for receiving a fluid.Portable infusion pump according to claim 10, characterised in that the cannula arrangement (3) has two or more infusion cannulas (4), one of which is assigned to each of the reservoir containers (2).Portable infusion pump according to claim 11, characterised in that the respective infusion cannula (4) is or can be fluidically connected to the container interior of the associated reservoir container (2) via a container-side cannula end (6) and extends in each case from the container-side cannula end (6) along its axial extension to a receiver-side cannula end (7) on which a first cannula tip (8) is formed, in that the respective infusion cannula (4) has a central cannula section (9) between the container-side cannula end (6) and the receiver-side cannula end (7) and at least one adjacent, in particular adjacent, end-side cannula section, in particular an adjacent, first end-side cannula section (10) adjacent to the receiver-side cannula end (7) and a second end-side cannula section (11) adjacent to the container-side cannula end (6), and in that the cannula arrangement (3) is configured such that, the respective infusion cannula (4) can automatically execute a restoring movement, by means of which the receiving-side cannula end (7) is displaced back from the piercing position (13) to the initial position (12), preferably as far as the initial position (12).Portable infusion pump according to one of claims 10 to 12, characterised in that the cannula arrangement (3) has a cannula injection mechanism (5) which is designed, upon actuation of which, to load the respective infusion cannula (4) radially and to cause elastic bending of the infusion cannula (4), so that the receiving-side cannula end (7) is displaced from an initial position (12) into a injection position (13), in particular abruptly.Portable infusion pump according to one of the preceding claims, characterized in that the infusion pump (1) has a multipart housing (27), preferably in that the housing (27) has a disposable housing part (22) and a reusable housing part (28), further preferably in that the reservoir container (2) and the infusion cannula (4) are mounted on the disposable housing part (22), which preferably together form a pre-mounted disposable unit (29), and / or in that a drive source, in particular a drive motor, and optionally further drive elements, are mounted on the reusable housing part (28), which preferably together form a pre-mounted reusable unit (30).Portable infusion pump according to claim 14, characterised in that the reservoir container (2) is permanently connected to the housing (27), in particular to the disposable housing part (22), or forms a replaceable cartridge, preferably in that the reservoir container (2) can be installed together with the disposable housing part (22) as a pre-assembled unit in a pre-filled state or the replaceable cartridge can be installed in a pre-filled state.Portable infusion pump according to one of the preceding claims, characterized in that the infusion pump (1) has as energy source (33) a primary or secondary battery, which can be removed in particular individually, preferably in that the energy source (33) is a component of the disposable unit (29).Portable infusion pump according to one of the preceding claims, characterized in that the infusion pump (1) comprises a user interface (34) with a display (35) and / or with an operating unit (36), which can have one or more keys, preferably in that the user interface (34) is part of the multiway unit (30).Portable infusion pump for administering a defined amount of a fluid, in particular an infusion solution, in particular according to one of the preceding claims, wherein the infusion pump (1) has a reservoir container (2) with a container interior which is configured, in particular at least in one section, for receiving the fluid, wherein the infusion pump (1) has a cannula arrangement (3) with an infusion cannula (4) and a cannula injection mechanism (5), wherein the infusion cannula (4) is or can be fluidically connected to the container interior of the reservoir container (2) via a container-side cannula end (6) and the infusion cannula (4) extends from the container-side cannula end (6) along its axial extension to a receiver-side cannula end (7) on which a first cannula tip (8) is formed, wherein the infusion cannula (4) has a central cannula section (9) between the container-side cannula end (6) and the receiver-side cannula end (7) and at least one adjacent, in particular adjoining, end-side cannula section, in particular a first end-side cannula section (10) adjacent to the receiver-side cannula end (7) and a second end-side cannula section (11) adjacent to the container-side cannula end (6), and wherein the cannula injection mechanism (5) is configured to load the infusion cannula (4) radially upon actuation thereof and to cause an elastic bending of the infusion cannula (4), such that the receiver-side cannula end (7) is displaced, in particular abruptly, from an initial position (12) into a injection position (13), characterized in that the cannula arrangement (3) is configured such that, in particular, the infusion cannula (4) is mounted and configured such that the infusion cannula (4) is mounted and configured such that the infusion cannula (4), In particular, when it is inserted into the tissue of the infusion recipient (14), it can automatically execute a restoring movement, by means of which the cannula end (7) on the recipient side is displaced back from the puncture position to the initial position, preferably as far as the initial position.

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