Air injector for an infusion system

Abstract

An air injector (1, 1') for an infusion system (2, 2') comprises an air container (10, 10'); a connecting device (11) adapted to establish a fluid connection (C1) between the air container (10, 10') and a liquid container (20) of the infusion system (2, 2') so as to allow air (A) from the air container (10, 10') to be injected into the liquid container (20); and a valve (12) arranged in the fluid connection (C1)

Description

[0001] Air Injector for an Infusion System

[0002] Description

[0003] The invention relates to an air injector for an infusion system and to an infusion system.

[0004] Infusion systems are used for administering liquids to patients. Typically, a liquid, e.g., comprising a drug, is contained in a liquid container of the infusion system, such as a flexible bag. A tube, e.g., with a needle at its one end, is brought into fluid connection with the liquid container at its other end. Via the tube and, e.g., the needle, the liquid is provided from the liquid container to the patient.

[0005] The liquid may be conveyed simply using gravitation. Alternatively, an infusion pump such as a volumetric infusion pump may be used to convey the liquid from the liquid container to the patient.

[0006] In many cases it is important to administer the entire liquid content of the liquid container to the patient. Also, in many cases leakage of potentially hazardous liquid must be avoided. In further cases, two liquid containers are connected with the tube via a Y connector, and it may be a prerequisite of a therapy of the patient that first the liquid of one of the liquid containers is administered (entirely) before the infusion of the liquid of the other liquid container starts. In current practice, such requirements are often very cumbersome to address and typically require many manual steps.

[0007] It is an object of the instant invention to simplify the infusion of liquids. This object is achieved by means of an air injector comprising the features of claim 1 .

[0008] Accordingly, an air injector for an infusion system is provided, the air injector comprising an air container, a connecting device adapted to establish a fluid connection between the air container and a liquid container of the infusion system so as to allow air from the air container to be injected into the liquid container, and a valve arranged in the fluid connection, e.g., configured to selectively open or close the fluid connection.

[0009] This is based on the idea to provide an air container for injecting air into the liquid container so as to create an overpressure in the liquid container which presses a rest of a liquid out of the liquid container, e.g., into a connected tube. By arranging the valve in the fluid connection, the air flow via the fluid connection can be controlled. This allows to administer the entire liquid content of the liquid container to the patient while avoiding leakage of potentially hazardous liquid, e.g., in an oncologic therapy. By this, the infusion of liquids may be simplified in a reliable manner.

[0010] Optionally, the connecting device comprises a cannula and / or a Luer lock. This allows a simple and secure fluid connection of the air container with a connector of the liquid container.

[0011] According to an embodiment, the air container is foldable. The air container may, alternatively or in addition, be made of a flexible material. For example, the air container may be compressible. By this air can be pressed out of the air container manually and in a particularly simple manner.

[0012] Optionally, the air container comprises a bellows. A bellows allows to easily discharge air from the air container in a controlled manner.

[0013] According to an embodiment, the air container comprises a syringe. Optionally, the syringe has a scale indicating a size of an inner volume of the syringe. This allows to discharge a very precise amount of air into the liquid container of the infusion system.

[0014] Optionally, the valve is a first valve, and the air injector comprises a second valve. The second valve may be adapted to selectively open or close and / or be arranged in a fluid connection between the air container and surrounding ambient air. This allows to pump a larger volume of air into the liquid container using the air container than can be received in the air container by pumping more than once. This allows to use the same (relatively small) size of an air container for various applications.

[0015] It may be provided that the first valve, the second valve and the air container are connected with one another by means of a Y connector. Thus, the first valve, the second valve and the air container may be in fluid connection with one another by means of the Y connector. Thereby, air may flow though the second valve into the air container via the Y connector, and from the air container though the connecting device (into the liquid container) via the Y container. This allows a simple setup.

[0016] The (first) valve may be a check valve. If the air injector comprises the second valve, at least one of the first valve and the second valve may be a check valve. The (first) check valve is arranged such that it allows an airflow from the air container towards the connecting device (and towards the liquid container) but blocks an airflow in the opposite direction. The second check valve may be arranged such that it allows an airflow from a surrounding environment towards the air container (and / or towards the connecting device and / or towards the Y connector) but blocks an airflow in the opposite direction. By this, it is possible to simply pump multiple times using the air container without the need to manually open and close a valve or the like.

[0017] Optionally, the air container is filled with sterilized air. This allows to avoid any contamination of a liquid in the liquid container. If the air container is used to pump more than once, ambient air is pumped from the second pumping motion and onwards; however, this is air from the surrounding and thus under control of the user, and it is not stored in the air container over a long period of time.

[0018] According to an aspect, an infusion system is provided, comprising a liquid container; and an air injector comprising an air container and a connecting device adapted to establish a fluid connection between the air container and the liquid container so as to allow air from the air container to be injected into the liquid container. Regarding the technical effects, reference is made to the air injector described above to avoid repetition.

[0019] The liquid container may define a volume of liquid that can be received therein. The air container may define a volume of air that can be received therein. Therein, the volume of air may be 50 ml or less, in particular between 10 ml and 50 ml. The volume of air may be smaller than the volume of liquid. This allows a small size of the air container. The liquid container may comprise a (first) connector and, optionally, a second connector, wherein the (first) connector is configured to deliver liquid from the liquid container to a patient. The connecting device may be adapted to establish the fluid connection between the air container and the liquid container via the second connector (and / or via the (first) connector). This allows a simple connection and an injection of air into the liquid container while an infusion is ongoing.

[0020] Optionally, the liquid container is a secondary liquid container, and the infusion system further comprises a primary liquid container, wherein the primary and secondary liquid containers are in fluid connection with an infusion cannula via a Y connector. This allows to transition from an infusion using the secondary liquid container to an infusion from the primary liquid container such that first the liquid from the secondary liquid container is entirely infused and, due to an overpressure creatable using the air injector, without mixing the liquids from the two liquid containers.

[0021] Optionally, at least one of the primary liquid container and the secondary liquid container is a flexible bag. This allows a simple use and an application of standard products as liquid containers.

[0022] The air injector of the infusion system may be configured in accordance with any aspect or embodiment described herein.

[0023] The idea underlying the invention shall subsequently be described in more detail by referring to the embodiments shown in the figures. Herein:

[0024] Fig. 1 shows an air injector for an infusion system for injecting air into a liquid container of the infusion system, the air injector comprising an air container with a foldable bellows;

[0025] Fig. 2A shows an infusion system with the air injector of Fig. 1 ;

[0026] Fig. 2B shows the infusion system of Fig. 2A, wherein the bellows of the air container manually is folded together;

[0027] Fig. 3 shows an air injector for an infusion system for injecting air into a liquid container of the infusion system, the air injector comprising an air container with a syringe; Fig. 4A shows an infusion system with the air injector of Fig. 3;

[0028] Fig. 4B shows the infusion system of Fig. 4A, wherein a piston of the syringe of the air container is pushed into a barrel of the syringe;

[0029] Fig. 5A shows more components of the infusion system of Fig. 2; and

[0030] Fig. 5B shows an enlarged part of the infusion system of Fig. 5A.

[0031] Subsequently, particularly air injectors for infusion systems and infusion systems shall be described. The embodiments described herein shall not be construed as limiting for the scope of the invention.

[0032] Fig. 1 illustrates an air injector 1 for an infusion system, such as the infusion system of Figs. 2A and 2B. The air injector 1 is configured to inject air in a liquid container 20 of the infusion system 2. For this purpose, the air injector 1 comprises an air container 10, a connecting device 11 and a valve 12.

[0033] The air container 10 has an inner volume and defines a volume VA of air A that can be received therein. In the present example, the volume VA is about 50 ml. The air container 10 is made of a flexible material that can be elastically bent manually. Here, the air container 10 is made of plastics. The air container 10 of the example of Fig. 1 forms a bellows 100. The bellows 100 has a plurality of rings. The bellows 100 can be squeezed together, thereby reducing the length of the air container 10. The air container 10 is foldable, wherein squeezing the air container 10 folds the rings of the bellows 100 together. By squeezing the bellows 100 together manually, the inner volume of the air container 10 is reduced and a portion of the volume VA of air A has to exit the air container 10.

[0034] The connecting device 11 is adapted to establish a fluid connection C1 between the air container 10 and the liquid container 20 of the infusion system 2 so as to allow air A from the air container 10 to be injected into the liquid container 20. Here, the connecting device 11 comprises a cannula 110. Using the cannula 110, the connecting device 11 can be pierced into a connector 201 of the liquid container 20 (as will be described in greater detail below). The connecting device 11 further comprises a Luer lock 112. By means of the Luer lock 112, the cannula 110, together with the valve 12, is connected to a Y connector 14. It is worth noting that the connecting device 11 could alternatively only comprise a Luer lock 112, for connection to a corresponding connector of the liquid container 20 and no cannula 110, or vice versa.

[0035] Before (and after) use, the cannula 110 is covered by a cap 111 for protection.

[0036] The valve 12 is arranged in the fluid connection C1. An air flow from the air container 10 to the connecting device 11 passes the valve 12 (see vertical arrow in Fig. 1). The valve 12 is a check valve. The valve 12 allows air A to flow from the air container 10 to the connecting device 11 and prevents air A (and other fluids) from flowing in the opposite direction. The valve 12 is arranged between the Luer lock 112 and the cannula 110, but it could alternatively be arranged between the Luer lock 112 and the Y connector 14, or between the Y connector 14 and the air container 10. Thus, when squeezing the air container 10 together, air A flows along the fluid connection C1 through the connecting device 11.

[0037] Since the air container 10 is made of a flexible material, it expands and returns to its form before being squeezed. However, the air container 10 is, with the exception of a connector 103, airtight. So, to allow the air container 10 to expand, air A needs to be filled into the air container 10. Since the valve 12 is a check valve disallowing air A to flow from the connecting device 11 towards the air container 10, the air container 10 maybe disconnected or, as in the present example, a second valve 13 may be provided. The second valve 13 is arranged in a fluid connection C2 between ambient air, i.e., the environment, and the air container 10. The second valve 13 is a check valve. The second valve 13 is arranged so as to allow an air frow from the environment through an opening 15 into the air injector 1 (see horizontal arrow in Fig. 1), more specifically, via the (second) fluid connection C2 into the air container 10. An air flow in the opposite direction is prevented by the second valve 13.

[0038] The (first) valve 12, the second valve 13 and the air container 10 are connected with one another by means of a Y connector 14. The second valve 13 is arranged between the Y connector 14 and the opening 15. In the arm of the Y connector 14 leading to the air container 10, the two fluid connections C1 , C2 overlap.

[0039] As shown in Fig. 1 , the air container 10 is filled with sterilized air A.

[0040] Fig. 2A shows the infusion system 2 already mentioned above. The infusion system 2 comprises a liquid container 20 and the air injector 1 of Fig. 1 .

[0041] The liquid container 20 of the infusion system 2 is a flexible bag. The liquid container 20 is hung on a pole 27. The liquid container 20 comprises a first connector 200 and a second connector 201 . Both connectors 200, 201 are arranged at a lower end of the liquid container 20. The first connector 200 is configured to be connected to tube to deliver liquid L contained in the liquid container 20 to a patient. The connecting device 11 of the air injector 1 is in fluid connection with the second connector 201 of the liquid container 20. That is, the fluid connection between the air container 10 and the liquid container 20 extends through the second connector 201.

[0042] As shown in Fig. 2A, the liquid container 20 is partially filled with the liquid L. The liquid L comprises a drug. Further, the liquid container 20is also partially filled with air A. In total, the liquid container 20 defines an inner volume VL for liquid L and / or air A. The volume VL of the liquid container 20 is larger than (a multiple of) the volume VA of air A in the air container 10, through the first connector.

[0043] As shown in Fig. 2B, the air container 10 can be squeezed (manually) to inject air A via the fluid connection C1 into the liquid container 20. This procedure can be repeated several times until the pressure in the liquid container 20 is high enough, e.g., to press all liquid L out of the liquid container 20.

[0044] Fig. 3 shows an air injector T. The air injector T of Fig 3 is similar to the air injector 1 of Fig. 1 . However, instead of a bellows-shaped air container, the air container 10’ of Fig. 3 comprises a syringe 101. The syringe 101 comprises a barrel 104 and a piston 105. The barrel 104 is in fluid connection with the connecting device 11. The piston 105 may be pushed into the barrel

[0045] 104 to discharge air A from the syringe 101.

[0046] The syringe 101 of the present example has a scale 102. The scale 102 indicates an inner volume of the syringe 101. Therefore, using the syringe 101 , an exact amount of Air A may be discharged from the syringe 101. The syringe 101 defines an inner volume of 50 ml. In general, the inner volume may be, e.g., between 10 ml and 50 ml.

[0047] Similar to Figs. 2A and 2B, Figs. 4A and 4B show an infusion system 2’ comprising a liquid container 20 and the air injector T. In order to pump air A into the liquid container 20, the piston

[0048] 105 may be pressed into the barrel 104. This may be repeated two or more times, until an intended overpressure is achieved in the liquid container 20.

[0049] Also shown in Figs. 4A and 4B is an infusion pump 24. The infusion pump 24 is a volumetric pump. A tube may be connected to the liquid container 10 and inserted into the infusion pump 24. The infusion pump 24 conveys the liquid L towards a patient. Turning now to Figs. 5A and 5B, the infusion system 2 is shown to include a primary liquid container 21 , wherein the liquid container 20 connected to the air injector 1 is a secondary liquid container. The primary and secondary liquid containers 20, 21 are both flexible bags.

[0050] The primary and secondary liquid containers 20, 21 are in fluid connection with an infusion cannula 22 via tubes 25 and a Y connector 23. Therefore, the primary and secondary liquid containers 20, 21 are also in fluid connection with one another. By creating overpressure in the secondary liquid container 20, the liquid L is discharged from the secondary liquid container 20, before liquid is discharged from the primary liquid container 21. Tubes 25 connect each of the liquid containers 20, 21 with the Y connector 23. A further tube connects the Y connector 23 with the infusion cannula.

[0051] The primary and secondary liquid containers 21 , 20 are hung on the pole 27 at the same height. Normally, a concurrent flow from both liquid containers 21 , 20 would start, but here, the overpressure in the secondary liquid container 20 leads to a flow only from the secondary liquid container 20.

[0052] For example, a full dose delivery is considered to be achieved when the liquid in the tube 25 of the secondary liquid container 20 is about 2,5 cm above the Y connector 23.

[0053] The air injector 1 , T (or only the air container 10, 10’) is disposable.

[0054] By the describes air injectors 1 , T, a solution is provided to generate a positive pressure in the liquid container 20 without a detachment or the like, to achieve a full dose delivery, reducing the work effort and minimizing the risk of liquid leakage (e.g., of hazardous drugs in the oncology).

[0055] The idea of the invention is not limited to the embodiments described above but may be implemented in a different fashion. List of Reference Numerals

[0056] 1 , T Air injector

[0057] 10, 10’ Air container

[0058] 100 Bellows

[0059] 101 Syringe

[0060] 102 Scale

[0061] 103 Connector

[0062] 104 Barrel

[0063] 105 Piston

[0064] 11 Connecting device

[0065] 110 Cannula

[0066] 111 Cap

[0067] 112 Luer lock

[0068] 12 Valve

[0069] 13 Valve

[0070] 14 Y connector

[0071] 15 Opening

[0072] 2, 2’ Infusion system

[0073] 20 Liquid container

[0074] 200, 201 Connector

[0075] 21 Liquid container

[0076] 22 Infusion cannula

[0077] 23 Y connector

[0078] 24 Infusion pump

[0079] 25 Tube

[0080] 27 Pole

[0081] A Air

[0082] C1 , C2 Fluid Connection

[0083] L Liquid

[0084] VL Volume

[0085] VA Volume

Claims

Claims:1 . An air injector (1 , T) for an infusion system (2, 2’), comprising: an air container (10, 10’); a connecting device (11) adapted to establish a fluid connection (C1) between the air container (10, 10’) and a liquid container (20) of the infusion system (2, 2’) so as to allow air (A) from the air container (10, 10’) to be injected into the liquid container (20); and a valve (12) arranged in the fluid connection (C1).

2. The air injector (1 , T) according to claim 1 , characterized in that the connecting device (11) comprises one of a cannula (110) and a Luer lock (112).

3. The air injector (1) according to claim 1 or 2, characterized in that the air container (10) is foldable.

4. The air injector (1) according to any of the preceding claims, characterized in that the air container (10) comprises a bellows (100).

5. The air injector according (T) to claim 1 or 2, characterized in that the air container comprises a syringe (101), the syringe (101) having a scale (102) indicating a size of an inner volume of the syringe (101).

6. The air injector (1 , T) according to any of the preceding claims, characterized in that the valve (12) is a first valve and the air injector (1 , T) comprises a second valve (13), the second valve (13) being arranged in a fluid connection (C2) between the air container (10, 10’) and ambient air.

7. The air injector (1 , T) according to claim 6, characterized in that the first valve (12), the second valve (13) and the air container (10, 10’) are connected with one another by means of a Y connector (14).

8. The air injector (1 , T) according to claim 6 or 7, characterized in that at least one of the first valve (12) and the second valve (13) is a check valve.

9. The air injector (1 , T) according to any of the preceding claims, characterized in that the air container (10, 10’) is filled with sterilized air (A).

10. An infusion system (2, 2’), comprising: a liquid container (20); and an air injector (1 , T) comprising an air container (10, 10’) and a connecting device (11) adapted to establish a fluid connection (C1) between the air container (10, 10’) and the liquid container (20) so as to allow air (A) from the air container (10, 10’) to be injected into the liquid container (20).11 . The infusion system (2, 2’) according to claim 10, characterized in that the liquid container (20) defines a volume (VL) of liquid that can be received therein, and the air container (10, 10’) defines a volume (VA) of air (A) that can be received therein, wherein the volume (VA) of air (A) is 50 ml or less, in particular between 10 ml and 50 ml.

12. The infusion system (2, 2’) according to claim 10 or 11 , characterized in that the liquid container (20) comprises a first connector (200) and a second connector (201), wherein the first connector (200) is configured to deliver liquid (L) from the liquid container (20) to a patient, and the connecting device (11) is adapted to establish the fluid connection (C1) between the air container (10, 10’) and the liquid container (20) via the second connector (201).

13. The infusion system (2, 2’) according to any of claims 10 to 12, characterized in that the liquid container (20) is a secondary liquid container and the infusion system (2, 2’) further comprises a primary liquid container (21), wherein the primary and secondary liquid containers (20, 21) are in fluid connection with an infusion cannula (22) via a Y connector14. The infusion system (2, 2’) according to claim 13, characterized in that at least one of the primary liquid container (21) and the secondary liquid container (20) is a flexible bag.

15. The infusion system (2, 2’) according to any of claims 10 to 14, characterized in that the air injector (1 , T) is configured in accordance with any of claims 1-9.

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