Device for Administration of Fluid Medicaments

Abstract

A device 2 for the administration of fluids to a human or animal body comprising a housing 3 with a first inlet 28, at least one second inlet 29, 30, one outlet 31 and a collecting point, wherein the first inlet 28 communicates with the collecting point through a first channel and the outlet 31 communicates with the collecting point. The second inlet 29, 30 communicates with the collecting point or an indicator chamber 24, 25 through a second channel 21, 22 in which a valve 26, 27 is arranged, the valve 26, 27 being adjustable between a first position and a second position, wherein, in the first position of the valve 26, 27, the second channel 26, 27 communicates with the indicator chamber 24, 25 and, in the second position of the valve 26, 27, the second channel 21, 22 communicates with the collecting point.

Claims

1. Device (2) for the administration of fluids to a human or animal body, comprising a housing (3) with a first inlet (28), at least one second inlet (29, 30), one outlet (31) and a collecting point, wherein the first inlet (28) communicates with the collecting point through a first channel and the outlet (31) communicates with the collecting point, characterized in that the second inlet (29, 30) communicates with the collecting point or an indicator chamber (24, 25) through a second channel (21, 22) in which a valve (26, 27) is arranged, the valve (26, 27) being adjustable between a first position and a second position, wherein, in the first position of the valve (26, 27), the second channel (21, 22) communicates with the indicator chamber (24, 25), and, in the second position of the valve (26, 27), the second channel (21, 22) communicates with the collecting point.

2. Device (2) according to claim 1, characterized in that the indicator chamber (26, 27) and/or the housing (3) is at least in part transparent or translucent for visible electromagnetic radiation.

3. Device (2) according to claim 1, characterized in that the indicator chamber (24, 25) comprises a hydrophobic filter element and/or an indicator element (60, 61) which changes its color in case of fluid contact.

4. Device (2) according to claim 3, characterized in that the indicator element (60, 61) is made of a sintered plastic material.

5. Device (2) according to claim 4, characterized in that the plastic material comprises at least one additive which changes its color in case of fluid contact.

6. Device (2) according to claim 4, characterized in that the plastic material is polyethylene.

7. Device (2) according to claim 3, characterized in that the hydrophobic filter element or the indicator element (60, 61) abuts on a wall of the indicator chamber (24, 25) with at least one opening (58, 59) communicating with the ambience air of the device (2).

8. Device (2) according to claim 1, characterized in that an inlet opening (50, 51) of the indicator chamber (24, 25) is covered by an elastic sealing element (52, 53) acting as a check valve which is closed in a pressure-less state.

9. Device (2) according to claim 3, characterized in that the indicator chamber (24, 25) comprises at least one insertion element (54, 55) which holds the sealing element (52, 53) in its position by contacting the sealing element (52, 53) and/or which receives the hydrophobic filter element and/or the indicator element (60, 61).

10. Device (2) according to claim 7, characterized in that the wall of the indicator chamber (24, 25) with at least one opening (58, 59) is embodied as a wall element (56, 57), which is fixed on the insertion element (54, 55).

11. Device (2) according to claim 1, characterized in that an indicator mechanism is arranged within the indicator chamber, comprising at least one movable part which moves with respect to the indicator chamber when the indicator chamber is filled with a fluid.

12. Device (2) according to claim 11, characterized in that the movable part has a color mark.

13. Device (2) according to claim 1, characterized in that the second channel (21, 22) and/or the first channel (20) comprises a filter chamber (36, 37) in which a hydrophilic filter member (70, 100) and/or a hydrophobic filter member (71, 101) is arranged, wherein the hydrophilic filter member (70, 100) separates the filter chamber (36, 37) into to sub-chambers and wherein the hydrophobic filter member (71, 101) covers an opening (72) of the filter chamber (36, 37) which is in communication with the ambience air of the device.

14. Device (2) according to claim 13, characterized in that the hydrophilic filter member (70, 100) is supported by protrusions (80) extending from at least one wall of the filter chamber (36, 37).

15. Device (2) according to claim 1, characterized in that a check valve (33, 34, 35) is arranged within the first channel (20) and/or within the second channel (21, 22).

16. Device (2) according to claim 1, characterized in that the collecting point is embodied as a collecting chamber (23).

17. Device (2) according to claim 16, characterized in that the collecting chamber (23) is ring-shaped.

18. Device (2) according to claim 1, characterized in that at least one section (73) of the valve (26, 27) has a cylindrical shape, the radial surface of which comprises a recess (43, 44) extending over the circumference of the radial surface, wherein the recess (43, 44) provides a communication between the second channel (21, 22) and the indicator chamber (24, 25) in the first position of the valve (26, 27), and between the second channel (21, 22) and the collecting point in the second position of the valve (26, 27).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] A particular preferred embodiment of the device according to the invention is described hereinafter with reference to figures, whereat

[0032] FIG. 1 shows a perspective view of an infusion system comprising a preferred embodiment of the device according to the present invention,

[0033] FIG. 2 shows a sectional view of the preferred embodiment of the device,

[0034] FIG. 3 shows a further sectional view of the preferred embodiment of the device,

[0035] FIG. 4 shows a further sectional view of the preferred embodiment of the device,

[0036] FIG. 5 shows a perspective view of an insertion member being one component of the preferred embodiment of the device,

[0037] FIG. 6 shows a sectional view of the insertion member depicted in FIG. 5,

[0038] FIG. 7 shows a perspective view of a further insertion member being one component of the preferred embodiment of the device,

[0039] FIG. 8 shows a perspective view of a valve being one component of the preferred embodiment of the device,

[0040] FIG. 9 shows a sectional view of the valve depicted in FIG. 8,

[0041] FIG. 10 shows a perspective view of an insertion element being one component of the preferred embodiment of the device,

[0042] FIG. 11 shows a sectional view of the insertion element depicted in FIG. 10,

[0043] FIG. 12 depicts an exploded view of the preferred embodiment of the device, and

[0044] FIG. 13 shows a chart of measurement values of flow rates over time, measured both with a device according to prior art and with the preferred embodiment of the device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] FIG. 1 shows the preferred embodiment of the device 2 according to the invention in a perspective view, which is shown as a part of an infusion system 1, and in more detail, in the following figures. The device 2 comprises a housing 3 to which tubes 4, 5, 6, 7 are connected. The tube 6 leads to the first inlet of the housing 3, the tubes 5, 7 lead to a second inlet of the housing 3, respectively, and the tube 4 is connected to the outlet of the housing 3 and leads to an external filter chamber 8 enclosing a hydrophobic filter. The external filter chamber 8 has an opening 9 formed in its housing such that gas bubbles can escape through the hydrophobic filter and the opening 9. Such an external filter chamber 8 is already employed with state of the art infusion systems and is therefore not part of the present invention. The tube 10 leads to the patient. On the end portion of the tube 10, a male connector 11 of a luer-lock-connection is attached. The connector 11 is connected to an infusion needle (not shown) during the use of the infusion system 1. A female connector 12 of a luer-lock-connection is attached to the end portions of tubes 5, 6, 7, respectively, allowing for a connection of the respective tube 5, 6, 7 to a medicament source or a pump driving medicaments to the respective tubes 5, 6, 7. The device 2 comprises moreover two grip portions 13, 14, to which is made reference hereinafter.

[0046] FIG. 2 shows a horizontal sectional view of the device 2. The device comprises a housing 3, in which a first channel 20, two second channels 21, 22, a collecting chamber 23, two indicator chambers 24, 25 and two valves 26, 27 are arranged. The housing 3 further comprises a first inlet 28, two second inlets 29, 30, an outlet 31 communicating with the collecting chamber 23 through an outlet channel 32, three check valves 33, 34, 35, and two filter chambers 36, 37.

[0047] The first channel 20 extends through the housing starting from the first inlet 28 and ending at the collecting chamber 23. Within the first channel 28 check valve 33 is arranged in the vicinity of the collecting chamber 23, preventing back flow from the collecting chamber 23 into the first channel 20.

[0048] The collecting chamber 23 is essentially ring-shaped. There is a protrusion 38 formed on the inner wall of the ring-shaped collecting chamber 23, which protrusion 38 extends marginally into the first channel 20. The protrusion 38 results in the fluid fed to the first channel 20 being separated into two half streams, flowing through the collecting chamber 23 in different directions, i.e. clockwise and counterclockwise, when it enters the collecting chamber 23. The end of outlet channel 32 and protrusion 38 have an angle difference of 180. The collecting chamber 23 is realized by providing a clearance in the housing 3, into which a cylindrical-shaped insertion member 64 with a recess 65 formed on its radial surface is inserted. The collecting chamber 23 is formed by the recess of insertion member 64 and the circumferential surface of the clearance.

[0049] The second channels 21, 22 extend through the housing 3, starting from the second inlets 29, 30 and ending at the indicator chambers 24, 25, or at the collecting chamber 23. The second channels 21, 22 each have a branched structure, wherein one of the valves 26, 27 is arranged at the branching point such that an adjustable fluid connection between the second channels 21, 22 and the indicator chambers 24, 25 or between the second channels 21, 22 and the collecting chamber 23 can be provided there. In each second channel, one of the check valves 34, 35 is arranged preventing backflow from the collecting chamber 23 or the indicator chambers 24, 25 towards the second inlets 29, 30. In order to minimize the dead volume of the device 2 the branches 39, 40, 41, 42 of the second channels 21, 22 are designed to be very short and extend merely through the walls separating the valves 26, 27 from the indicator chambers 24, 25 and the walls separating the valves 26, 27 from the collecting chamber 23. The minimal thickness of these walls depend on the desired mechanical stability of the device 2. The second channels 21, 22 further comprise filter chambers 36, 37, in which a hydrophilic filter member (not shown) or, in the present embodiment, a respective hydrophobic filter member (not shown) are arranged. In the sectional view of FIG. 2 the outlets 45, 46 of the filter chambers 36, 37 are shown, which are covered by said hydrophilic filter members. These hydrophilic filter members extend horizontally throughout the entire respective filter chambers 36, 37 in the present embodiment, such that the latter are separated into two sub-chambers, one of which communicates with the upstream portion of the respective second channel 21, 22 and one of which communicates with an outlet 45, 46 of the respective filter chamber 36, 37.

[0050] Each of the valves 26, 27 comprise a cylindrical section. On the radial surface of the cylindrical sections a corresponding recess 43, 44 is formed. The recesses 43, 44 extend over the radial surface of the cylindrical sections of the valves 26, 27 in order to provide an adjustable fluid connection between the second channels 21, 22 and the indicator chambers 24, 25 (first position of the valves 26, 27) or the collecting chamber 23 (second position of the valves 26, 27), whereat the adjustment is carried out by turning the cylindrical sections about their axial directions, moving the recesses 43, 44 at the same time. The grip portions 13, 14 shown in FIG. 1 are formed on the cylindrical sections. Each valve 26, 27 comprises therefore one of the grip portions 13, 14 and one cylindrical section extending into the housing 3, whereat the cylindrical sections extend vertically into the housing 3 in the present embodiment. Clearances for receiving the cylindrical sections of the valves 26, 27 are provided in the housing 3.

[0051] Indicator chambers 24, 25 communicate with the second channels 21, 22 in the first position of the valves 26, 27, which is the starting adjustment during employment of the device 2. The indicator chambers 24, 25 comprise each an inlet opening 50, 51, a sealing element 52, 53, an insertion element 54, 55, a wall element 56, 57 with an opening 58, 59 and an indicator element 60, 61. The inlet openings 50, 51 have a protruded edge against which the sealing elements 52, 53 rest. Sealing elements 52, 53 are supported by protrusions 62, 63 formed on the insertions elements 54, 55. Protrusions 62, 63 exert an initial tension on sealing elements 52, 53 such that they seal inlet openings 50, 51 in a pressure-less state. The sealing elements 52, 53 can be fixed on the protrusions 62, 63, by welding, gluing or the like, in order to simplify the assembly of the device 2 during manufacturing. The sealing elements 52, 53 act as check valves, as their outer edges can only be raised in the inflow direction.

[0052] The insertion elements 54, 55 are of cylindrical shape. They are each inserted into a corresponding clearance provided on the housing 3 and fixed on the circumferential surfaces of the clearance by, for instance, a frictional connection, tongue and groove connection, welding or gluing. The wall elements 56, 57 are adapted to the cross sectional shape of the insertion elements 54, 55 and are fixed on the wall elements 56, 57. They, furthermore, are transparent or translucent for visible light. The insertion elements 54, 55 receive indicator elements 60, 61 which consist in the present embodiment of sintered polyethylene (PEL). Indicator elements 60, 61 abut on the wall elements 56, 57 and cover the openings 58, 59. As mentioned hereinbefore, sintered polyethylene is a porous plastic material such that air can pass through it. However, if the material is in contact with a fluid, it gets densified to an impervious state. Therefore, the openings 58, 59 are sealed by indicator element 60, 61, if a fluid enters the indicator chambers 24, 25 and gets in contact with indicator elements 60, 61. So, the air located within the second channels 21, 22 before employment of the device 2 is driven to indicator chambers 24, 25 by the fluids entering the second inlets 29, 30 and escapes via the openings 58, 59, provided that the valves 26, 27 are in their first positions. When the fluids reach the indicator elements 60, 61, the latter are densified and seal openings 58, 59.

[0053] Indicator elements 60, 61 furthermore feature the property of a change in colour in case of fluid contact, which property can be achieved by additives. This allows for an easy observation whether a fluid has reached not only the respective indicator chamber 24, 25, but the indicator element 60, 61 as well, i.e. that the air contained in the second channel 21, 22 upstream the indicator element 60, 61 was removed, and that the second channel 21, 22 and the recess 43, 44 of the valve 26, 27 are filled with the fluid fed to the respective second inlet 29, 30. If administration of the fluid fed to one of the second inlets 29, 30 is to be started, the respective valve 26, 27 is switched from its first position to its second position, in which the respective second channel 21, 22 communicates with the collecting chamber 23. Switching of both valves 26, 27 can occur at the same time or at different points in time, depending on the administration schedule set for a patient. Due to the fact, that the respective second channel 21, 22 and the respective recess 43, 44 are already filled with fluid, the delay between switching of the valve 26, 27 and administration of the fluid to a patient is shortened, which allows for a more precise dosage. In the second positions of the valves 26, 27, the fluids fed to the second inlets 29, 30 flow to the collecting chamber 23 via recesses 43, 44 and enter the collecting chamber 23 at locations with an angle difference with respect the protrusion 38 and thus, with respect to the end portion of the first channel 20, of 90. The fluids fed to the second inlet 29, 30 converge with the fluid fed to the first inlet 28 at these locations. The mixture of said fluids flows from there to the outlet channel 32 and to the outlet 31 of the device 2.

[0054] The check valves 33, 34, 35 comprise each a cylindrical body with a protruding edge on one side and an elastic cover being fixed on the other side and having a slit formed therein. The elastic cover is formed such that it is openable by a fluid flowing in the inflow direction and closable by fluid flowing in the outflow direction. The protruding edge rests against a corresponding contact surface of the housing 3 to which the protruding edge can be fixed, e.g., by means of welding or gluing.

[0055] FIG. 3 shows a sectional view of the present embodiment of the device 2, whereat one half of a vertical section through the first channel 20 is shown. A check valve 33 is arranged within a first channel 20 in the vicinity of collecting chamber 23. The collecting chamber 23 is formed by the circumferential surface of a clearance provided in the housing 3 and a recess 65 on the radial surface of an insertion member 64. The insertion member 64 is inserted into said clearance and fixed there by means of, for instance, a frictional connection, welding or gluing. Furthermore, FIG. 3 shows an outlet 31, an outlet channel 32 communicating with the collecting chamber 23 and a valve 27 with a grip portion 14. Moreover, it is shown that the device 2 has a hollow structure, while the channels and sections necessary for the intended functionality are formed by walls of a particular thickness and the rest of the housing 3 is hollow.

[0056] FIG. 3 shows a sectional view of the present embodiment of the device 2, whereat the other half of a vertical section through the first channel 20 is shown. A second channel 22 leads at first from a second inlet 30 to a filter chamber 37. Within the filter chamber 37, a hydrophilic filter member 70 and a hydrophobic filter member 71 are arranged, whereat hydrophilic filter member 70 extends horizontally throughout the entire filter chamber 37 separating thus the filter chamber 37 into two sub-chambers. The filter member 70 is welded or glued with its outer edge to a corresponding contact surface of the housing. The hydrophobic filter member 71 covers an opening 72 arranged in the housing 3, and is fixed on the surface of the filter chamber 37 that surrounds the opening 72 by, for example, welding or gluing. The opening 72 communicates with the ambience air of the device 2. The hydrophobic filter 71 and the opening 72 allow gas bubbles to escape from the fluid fed through second channel 22. Moreover, air contained within second channels 22 upstream the filter chamber 37 can escape through the hydrophobic filter member 71 and the opening 72. The filter chamber 37 is delimited partly by an insertion member 76, which is essentially cylindrical-shaped. An insertion member 76 has a protruding edge 77 on its one side, which allows for a defined positioning of the insertion member 76 during the assembly of the device and, moreover, which provides a contact surface for the fixation of the insertion member 76 on the housing 3, for instance, by welding or gluing.

[0057] The upper sub-chamber of the filter chamber 37 communicates with the downstream portion of the second channel 22 via an outlet 46, which is formed on the insertion member 76. Within the downstream portion of the second channel 22, a check valve 35 is arranged. Downstream the check valve 35, the second channel 22 leads to a recess 44 located on the radial surface of the cylindrical section 73 of the valve 27. The valve 27 is fixed on the housing by means of a tongue 74 and groove 75 connection, whereat the groove 75 is formed on the radial surface of the cylindrical section 73. By means of the grip portion 14, the valve 27 is manually turnable in an easy manner. The lower sub-chamber of the filter chamber 37 communicates with the second inlet 30.

[0058] FIG. 5 shows the insertion member 76. The insertion member 76 has a substantially cylindrical shape and comprises a protruding edge 77 on one side and protrusions 80 on the frontal surface of the other side. The protrusions 80 support the hydrophilic filter member 70 and can be fixed on it, e.g., by welding or gluing. Furthermore, the outlet 46 is formed on the insertion member 76.

[0059] FIG. 6 shows a vertical section view of the insertion member 76. Protrusions 80 are formed on its frontal surface, and a protruding edge 77 on its other side. The outlet 46 extends from said frontal surface to the cylindrical-shaped radial surface of the insertion member 76.

[0060] FIG. 7 shows the insertion member 64 by means of which the collecting chamber 23 is realized. The insertion member 64 has a cylindrical shape, whereat on its radial surface a recess 65 is formed, which extends almost along its entire circumference. Between the two ends of the recess 65, a protrusion 38 is located and serves the purpose of splitting the fluid flow fed to the first channel 20, as previously described. The insertion member 64 is inserted into a corresponding clearance of the housing 3 during the assembly of device 2.

[0061] FIG. 8 depicts valve 27 in a perspective view. The structure of valve 27 is mirrored symmetrically to the structure of valve 26, in case the grip portions 13, 14 are oriented parallely in their first and second positions. Valve 27 comprises a cylindrical section with a recess 44 on its radial surface. Recess 44 provides a fluid connection between the second channel 22 and the indicator chamber 25 or collecting chamber 23, depending on whether valve 27 is in its first position or its second position. Adjustment between both positions can be carried out by turning the grip portion 14 about the axial direction of the cylindrical section and changing its orientation by 90.

[0062] FIG. 9 shows valve 27 in a vertical section view. The grip portion 14, a part of the recess 44 and the groove 75 are shown. By means of the groove 75 and the corresponding tongue 74, the valve 27 is turnably and imperviously fixed on the housing 3.

[0063] FIG. 10 shows the insertion element 55 of the indicator chamber 25, which is identical to the insertion element 54 of the indicator chamber 24, in a perspective view. It is of cylindrical shape and comprises a protrusion 63 and openings 90, through which the fluid flowing into the indicator chamber 25 passes the insertion element 55 and reaches indicator element 61. The sealing element 53 rests against the protrusion 63 such that only the outer edge of the sealing element 53 is raisable in order to allow fluid to enter the collecting chamber 25.

[0064] FIG. 11 shows the insertion element 55 in a vertical section view. Openings 90 and a protrusion 63 are shown. The inner space 91 of the insertion element 55 receives the indicator element 61, and can additionally receive a separate hydrophobic filter element.

[0065] FIG. 12 shows an exploded perspective view of the present embodiment of device 2. Next to the components described above, a hydrophilic filter member 100, a hydrophobic filter member 101, an insertion member 102 and housing elements 103, 104, 105, 106 are shown. The filter members 100, 101 are the equivalents of filter members 70, 71 and are arranged in the filter chamber 36 comprised by the second channel 21. The insertion member 102 is the equivalent of the insertion member 76. Housing elements 103, 104, 105, 106 constitute the housing 3. The housing elements 103, 104, 105, 106 are designed such that they are as few as possible in number and allow for an easy assembly of all components of the device 2. When assembling the device 2, check valves 33, 34, 35 are arranged in their final positions and fixed on the housing element 103 with their protruding edges by, for example, a frictional connection, a tongue and groove connection, welding, in particular ultra sonic welding, or gluing. Then, the housing element 103 and the housing element 104 are plugged together and fixed to one another by, for example, a frictional connection, a tongue and groove connection, welding, in particular ultra sonic welding, or gluing. Then, all other components, except valves 26, 27 and housing element 104, are arranged in their respective final positions and fixed there by, for example, a frictional connection, a tongue and groove connection, welding, in particular ultra sonic welding, or gluing. Then, the housing element 105 is fixed on housing elements 103, 104, by, for example, a frictional connection, a tongue and groove connection, welding, in particular ultra sonic welding, or gluing. Finally, the valves 26, 27 are inserted into the corresponding clearances of housing elements 103, 105 and fixed there by means of the said tongue and groove connection (see description of FIGS. 4 and 9).

[0066] FIG. 13 shows a chart of measurement values of flow rates 110, 111 taken with the preferred embodiment of device 2 as shown in FIGS. 1 to 12, and measurement values of flow rates 112, 113 taken with an infusion system according to prior art, by means of which several fluids converge and are fed to a patient as mixture through a single tube. The dashed lines 114, 115 show the pump settings of pumps that drive the fluids through the first 20 and one of the second 21, 22 channels. One pump is allocated to each tube leading to device 2, so as to independently adjust the flow rates. The dashed line 114 shows the pump setting of the pump connected to the first inlet 28, whereas the dashed line 115 shows the setting of the pump connected to one of the second inlets 29, 30. A sodium chloride solution or nutritive solution will generally be fed through the first channel 20, whereas medicaments will normally be fed through the second channels 21, 22. Therefore, the flow rate of the fluid fed through the first channel 20 usually amounts to between 6 ml/h and 12 ml/h, whereas the flow rate of the fluids fed through the second channels 21, 22, amounts to between 0.5 ml/h and 2 ml/h. The pressure within the fluid guiding parts of the device 2 and the tubes leading to it typically amounts to 2 bar to 3 bar.

[0067] Referring to FIG. 13, there are three effects observable with prior art infusion systems. First, the delay between activation of the pumps occurring at 0 on the x-axis of FIG. 13 and administration of the fluids, i.e. the point in time at which the fluids have reached at least the connector 11 (FIG. 1). The delay is noticeably shorter with the device according to the invention. This is due to the fact that the infusion system 1 comprising the device 2 is already filled up to the valves 26, 27, including the recesses 43, 44. If the administration of a medicament is to be initiated, the corresponding valve is turned from its first position to its second position, whereat the remaining length of the flow path, i.e. the length of the flow path between valves 26, 27 and the connector 11, is shorter. So, the reference time serving as a basis for the dose calculation is closer to the point in time at which administration actually starts. The presence of fluids in the indicator chambers 24, 25 is easily observable thanks to the indicator elements 60,61 changing their colour in case of fluid contact, and the wall elements 56,57 being transparent or translucent for visible light.

[0068] A second effect observable with prior art infusion systems is the so-called over shoot occurring with the flow rate 112 between 0.5 h and 1 h and between 3.25 h and 3.5 h. This problem is remedied with the device 2, as can be seen on the course of flow rate 110.

[0069] A third effect observable with prior art infusion systems are flow rate fluctuations occurring if one of two or more flow rates is set to another value by means of a pump. Such fluctuations occur with the flow rate 112 between 5.0 h and 5.25 h, where the pump setting is set from 0.5 ml/h to 1.0 ml/h, and between 6.0 h and 6.25 h, where the pump setting 115 is set from 1.0 ml/h to 0.5 ml/h. With the flow rate 113 such fluctuations occur between 3.0 h and 3.25 h, where the pump setting 114 is set from 6.0 ml/h to 10 ml/h, and between 4.0 and 4.25 h, where the pump setting 114 is set from 10 ml/h to 6 ml/h. These fluctuations are remarkably minimized with the device 2, as can be seen on the course of flow rates 110, 111.

[0070] The courses of flow rates 110, 111 are in general remarkably closer to the courses of the respective pump settings 114, 115, i.e. a more precise dosage is achieved.

[0071] While the invention has been described with reference to a specific embodiment, the description is merely explanatory and is not to be construed as limiting the scope of the invention. Various modifications may be conceived by those skilled in the art without departing from the scope of the invention as defined by the claims.

LIST OF REFERENCE NUMERALS

[0072] 1 infusion system [0073] 2 device [0074] 3 housing [0075] 4 tube [0076] 5 tube [0077] 6 tube [0078] 7 tube [0079] 8 external filter chamber [0080] 9 opening [0081] 10 tube [0082] 11 male connector [0083] 12 female connector [0084] 13 grip portion [0085] 14 grip portion [0086] 20 first channel [0087] 21 second channel [0088] 22 second channel [0089] 23 collecting chamber [0090] 24 indicator chamber [0091] 25 indicator chamber [0092] 26 valve [0093] 27 valve [0094] 28 first inlet [0095] 29 second inlet [0096] 30 second inlet [0097] 31 outlet [0098] 32 outlet channel [0099] 33 check valve [0100] 34 check valve [0101] 35 check valve [0102] 36 filter chamber [0103] 37 filter chamber [0104] 38 protrusion [0105] 39 branch [0106] 40 branch [0107] 41 branch [0108] 42 branch [0109] 43 recess [0110] 44 recess [0111] 45 outlet [0112] 46 outlet [0113] 50 inlet opening [0114] 51 inlet opening [0115] 52 sealing element [0116] 53 sealing element [0117] 54 insertion element [0118] 55 insertion element [0119] 56 wall element [0120] 57 wall element [0121] 58 opening [0122] 59 opening [0123] 60 indicator element [0124] 61 indicator element [0125] 62 protrusion [0126] 63 protrusion [0127] 64 insertion member [0128] 65 recess [0129] 70 hydrophilic filter member [0130] 71 hydrophobic filter member [0131] 72 opening [0132] 73 cylindrical section [0133] 74 tongue [0134] 75 groove [0135] 76 insertion member [0136] 77 protruding edge [0137] 80 protrusions [0138] 90 openings [0139] 91 inner space [0140] 100 hydrophilic filter member [0141] 101 hydrophobic filter member [0142] 102 insertion member [0143] 103 housing element [0144] 104 housing element [0145] 105 housing element [0146] 106 housing element [0147] 110 flow rate over time [0148] 111 flow rate over time [0149] 112 flow rate over time [0150] 113 flow rate over time [0151] 114 pump setting over time [0152] 115 pump setting over time