WO2024126643A1

WO2024126643A1 - Tube reference marking

Info

Publication number: WO2024126643A1
Application number: PCT/EP2023/085747
Authority: WO
Inventors: Eduard FRANSEN
Original assignee: Fresenius Kabi Deutschland Gmbh
Priority date: 2022-12-16
Filing date: 2023-12-14
Publication date: 2024-06-20

Abstract

A method for manufacturing a tube for an infusion set (S) comprises: providing a tube (1) and predetermining a distance (D) from an end (11) of the tube (1). The method further comprises: creating an impression (10) on the tube (1) at the predetermined distance (D) from the end (11) of the tube (1).

Description

Tube Reference Marking

Description

The invention relates to a method for manufacturing a tube for an infusion set, to an infusion set and to an apparatus fur manufacturing such an infusion set.

Infusion sets are usually constructed by joining one or more, e.g., light-transmissive polymeric tubes or tube segments, respectively, to, e.g., a plurality of infusion set components that are either light-transmissive or opaque. To this end, the respective tube ends are connected to the corresponding infusion components and brought in fluid connection to one another. Here, it is regularly of importance to avoid a gap between the respective tube end and an end of a connector of the respective infusion component that - if not controlled - can cause a leak or separation of the infusion set. A common issue in manufacturing infusion sets is consistently connecting the tubes and the infusion components so as to obtain a secure and especially leak-free connection with a desired fluid flow. Therefore, reliable inspections of the fit between the tube and the infusion set component are typically required. This can be done by visual inspection, which may include inspection through translucent components and/or be means of visible markers. However, a multitude of infusion set components is textured or opaque, which, hence, impedes visual inspection. Moreover, visible markers are often not desired.

WO 2021/118939 A1 describes markers for tubes used in infusion sets to provide a visual indicator of the fit between an infusion tube and an infusion set component. A fluorescent dye, here an Ultraviolet (UV) ink, is printed onto the tube that becomes visible when subjected to UV light. However, such solutions commonly require the consumption of a fluorescent fluid as well as a regular refilling and maintenance of the corresponding fluorescent fluid dispenser.

This can be cost- and time-consuming and requires a regular intervention of personnel.

It is an object of the instant invention to provide a simple solution for a reliable connection of a tube of an infusion set to a connector.

This object is achieved by means of a method comprising the features of claim 1.

Accordingly, a method for manufacturing a tube for an infusion set comprises providing a tube and, before or after providing the tube, predetermining a distance from an end of the tube, wherein an impression is created in the tube at the predetermined distance from the end of the tube.

The creation of an impression on the tube enables the design of an (at least essentially) invisible marking on the (e.g., translucent) tube under visible light. This allows a particularly reliable inspection of the fitting to a connector of an infusion component in a simple manner. Thereby, a simple solution for a reliable connection of the tube to the connector is provided. It has been found that such an impression casts a shadow on a surface upon being irradiated with light, especially using an additional light source. The additional light does not have to be UV light. The resulting shadow projected on a surface can be used as (indirect) reference tube marking while the impressed tube remains translucent. Advantageously, no marking dye is required for creating the impression, which makes a dispenser and a refilling obsolete and can reduce the use of personnel. This provides a particularly simple, cost- and time-effective method for manufacturing a tube for an infusion set.

The impression in the tube is positioned at a predetermined distance from an end of the tube. The predetermined distance may correspond to a distance between an external edge and an end of an infusion component. Alternatively, the distance is predetermined to a concise point or edge of a connector in consideration of components of, for example, an apparatus for manufacturing the tube possibly obscuring the impression. For example, the distance at the tube is predetermined to a referenced point, edge and/or area, hereafter also referred to as reference site, of the respective infusion component to be connected with the tube. The tube may be made of a polymer. For example, the tube may be made of PVC (polyvinyl chloride), PE (polyethylene), PUR (polyurethane), FEP (fluorinated ethylene propylene), or PP (polypropylene), or from a mixture of materials, in particular of polymers, e.g., of PVC and PE. In summary, a tube is provided with an impression. The impression is positioned at a predetermined distance from an end of the tube. Particularly under additional light, the impression can cast a shadow on an (external) surface. This shadow provides an external visual indicator for a subsequent connection of the tube, e.g., of the fit between the tube and the component to be engaged with the tube, such as whether there is a gap between the end of the tube and the end of the respective component.

The method may further comprise the subsequent step of connecting the end of the tube to a connector to bring the tube in fluid connection with the connector. The connector is, e.g., a part of the infusion component to be connected with the tube, especially the part to be engaged with the tube. However, the connector can also be the entire infusion component. The connection of the tube with the connector enables a fluid flow. The aforementioned impression in the tube and the shadow resulting particularly under additional light as visual indicator for the fit between the tube end and the end of the connector allows for a particularly precise and, thus, secure fluid connection. The predetermined distance may correspond to the length of the connector, which may be the part of the infusion component to be engaged with the tube.

In addition, connecting the end of the tube to the connector may comprise engaging the tube and the connector with one another over a length equal to or less than the predetermined distance. As mentioned previously, the predetermined distance may be equal to the length or longitudinal extension of the connector, in concrete terms the length from the end and/or hard stop of the connector pointing to the tube to be engaged with and an external end and/or concise point or area of the connector. In this case, the impression in the tube is positioned so that the distance between the edge of the impression and the tube end is substantially equal to the length or longitudinal extension of the connector to be engaged with the tube. Alternatively, the predetermined distance may extend from a reference site at the connector to a position at the tube, whereby the extension corresponds to a distance longer than the length or longitudinal extension of the connector relative to the reference site.

The method may further comprise emitting light on the impression on the tube for casting a shadow on a surface. Further, connecting the end of the tube to the connector may comprise monitoring a distance of the shadow on the surface to the connector. Using the additional light, a clearly visible shadow can be projected onto an especially adjacent surface. This shadow is an image of the impression. The shadow may serve as actual (reference) mark and be used as visual indicator. Specifically, upon connection of the connector of the respective infusion component to the corresponding tube, a distance can be determined from the shadow to a reference site of the connector, especially on the surface on which the shadow is projected, following the longitudinal extension of the tube in direction to the tube end and the connector, respectively. If, for example, the obtained distance is longer than the predetermined distance, this may be an indicator of a gap between the tube end and the respective infusion component.

According to an embodiment, the impression is elongate and/or extends at least partially around an external surface of the tube. Such an impression allows to cast a shadow that provides a particularly precise reference. Optionally, the impression is elongated substantially perpendicular to the longitudinal axis of the tube. The impression may run circle-cylindrical or, at least in sections, part-circle-cylindrical around the tube and/or along the surface of the tube. More particularly, the impression is created in the form of one or more elongated and/or linear, especially cylindrical, notches or furrows. This allows a particularly clear projection of a particularly defined and/or sharp shadow and, hence, a particularly reliable reference mark for visual inspection.

Further, the impression on the tube may be created by exerting a pressure with an edge of a preferably mechanical marking tool. In this way, the tube marking is performed or achieved mechanically. For example, the tube or the tube material is squeezed or deformed by the marking tool and/or its especially one or more edges. The simple use of a marking tool allows for a particularly easy and cheap method to create a reference mark in the tube as well as a broad and especially universal applicability, as only one tool may be necessary without changing the marking tool. The edges may be made of a hard material, especially of steel or another metal-containing material. This allows for a particularly high durability and universal applicability for creating tube impressions with no or minimal maintenance effort.

In an embodiment, creating the impression on the tube comprises exerting a pressure of between 2 N/mm² and 20 N/mm². The pressure exerted on the tube for creating the impression is particularly at least or more than 2 N/mm² and/or at most or less than 20 N/mm². The shadow resulting under emission of light of the impression can be particularly well and easily visible using the abovementioned pressure ranges, while, at the same time, the impression can be created in the tube in such a way that it is not or at least barely visible to the naked eye. Particularly good results were achieved with pressure values of at least or more than 5 N/mm² and/or at most or less than 10 N/mm².

The predetermined distance may be at least 1 cm and/or 5 cm or less, e.g., between 1 cm and 5 cm. Such distances allow a simple handling during connection of the tube with the connector. According to an aspect, an infusion set is provided comprising a tube, particularly manufactured with the method according to any aspect or embodiment described herein, wherein the tube has an impression adjacent to an end of the tube, and a connector connected to the end of the tube.

With regard to the advantages, reference is made to the above explanations concerning the method for manufacturing a tube for an infusion set.

According to a further aspect, an apparatus for manufacturing an infusion set is provided comprising a marking tool for creating an impression on a tube at a predetermined distance from an end of the tube and a mounting tool for connecting the end of the tube to a connector. This allows to make a reliable connection of the tube to the connector in a simple manner.

Particularly, the apparatus comprises a lighting device arranged to emit light on the impression on the tube for casting a shadow on a surface proximate the tube. This enables casting a sharp shadow for a precise fitting.

Advantageously, the lighting device is adapted to emit visible light. As the shadow is clearly visible upon emission of the additional visible light onto the impression in the tube, no special light source, such as a UV light source, is necessary and the lighting device can be of a particularly cheap and simple construction.

The marking tool may comprise at least one blade having an edge for creating the impression. The at least one blade and/or the edge are designed to deform or squeeze the tube at the predetermined distance, such that at least one impression is remaining, as a result, on the tube. The at least one blade and/or the edge may be blunt. This serves for a safe creation of the impression in the tube, especially avoiding any irreversible damage or cut in the tube.

In an embodiment, the edge has a width of 2 mm or less, particularly of 1 mm or less. This relatively small or narrow dimension allows the creation of a particularly defined impression in the tube and, hence, a particularly clearly visible shadow as visual indicator.

The marking tool can also comprise a plurality of blades, particularly two blades, each having an edge for creating an impression. In an embodiment, the number of impressions corresponds to the number of blades and/or edges of the marking tool. However, the number of impressions can also differ from the number of blades and/or edges, for example depending on the geometry or arrangement of the blade relative to the tube. The blade of the marking tool may be made of a metal or a metal alloy, in particular made of steel. The use of a hard material allows for a particularly efficient and defined squeezing and impression of the softer tube material and to make sure that the impression is remaining long enough in the tube so as to enable visual inspection.

According to an embodiment, the marking tool comprises pliers. The pliers have two especially elongated blades with one elongated edge each, which are preferably facing one another. This way, two elongated impressions can be created in the tube, which as a result are circumferentially on opposite sides of the tube. The use of pliers enables a particularly efficient and easy creation of the impression, in particular because pliers allow to apply a simultaneous and especially identical pressure to the blades or edges. Alternatively, or in addition, the marking tool may comprise a pressure die configured to exert a pressure towards a, particularly flat, base, such as an anvil. The pressure die has one blade with one edge preferably facing the flat base. This way, one impression can be created in the tube, especially on one side of the tube, namely on the site being impressed by and/or facing the edge of the pressure die. This allows for a creation of an impression in the tube in a particularly targeted and safe manner.

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

Fig. 1 shows a view of an infusion set comprising infusion components and tubes connecting the infusion components to one another;

Fig. 2A shows a section of a tube for use in an infusion set with an impression under ambient light;

Fig. 2B shows a detailed view of the impression of the tube section of Fig. 2A;

Fig. 2C shows a perspective view of a section of a tube;

Fig. 2D shows the tube section according to Fig. 2A under additional visible light;

Figs. 3A and 3B show partial side views of a tube engaged with an infusion component with two variants of predetermined distances; Fig. 3C shows a view of a tube engaged with an infusion component and shadows casted onto a surface under additional light;

Fig. 4A shows a marking tool in the form of pliers for squeezing a tube;

Fig. 4B shows a marking tool in the form of a pressure die exerting a pressure on the tube;

Figs. 4C-4E show possible contours of edges of a marking tool for squeezing a tube;

Fig. 5 shows a cross-sectional view of blades of a marking tool for squeezing a tube;

Fig. 6 shows an apparatus for manufacturing an infusion set; and

Figs. 7A-7E show steps of a method for manufacturing a tube for an infusion set, and for manufacturing an infusion set.

The embodiments described herein shall not be construed as limiting for the scope of the invention.

Fig. 1 shows an example of a typical infusion set S. An infusion set S includes one or more infusion components 2A-2D and at least one tube 1 connected with the one or more infusion components 2A-2D, particularly for bringing the infusion components in (fluid) connection with one another. The shown infusion set S comprises a drip chamber 2A, a pump section 2C for insertion into an infusion pump, and a Luer connector 2D as infusion components, which are all (fluidly) connected by tubes 1. The infusion set S further comprises a roller clamp 2B. A typical infusion set may include further infusion components, e.g. Y-junctions etc., and may be formed of any combination of infusion components and tubes 1 . For example, the infusion set S could comprise just one tube 1 and the drip chamber 2A.

Fig. 2A shows a section of a tube 1 for use in the infusion set S. The tube 1 is made of a polymer and/or polymeric. For example, the tube may be made of PVC (polyvinyl chloride), PUR (polyurethane) or PP (polypropylene). However, the tube may be also made of another material. Further, the tube 1 is light-transmissive. This enables to visually track the fluid flow in the infusion set S. In the shown embodiment, the tube 1 has an impression 10, which is indicated by a dashed line and illustrated in detail in Fig. 2B. The impression 10 is almost not visible for the naked eye. In the shown embodiment, the impression 10 is elongate. Concretely, the impression 10 is elongated substantially perpendicular to the longitudinal axis L of the tube 1. Here, also other angles of the impression 10 relative to the axis L are possible.

The impression 10 extends, wholly at least partially, around the tube 1 , in particular, circumferentially, along the external surface 12 of the tube 1. The impression 10 runs, at least partly, circle-cylindrical around the tube 1 , in particular, along the surface 12 of the tube 1.

The impression 10 comprises at least one section, in the shown example two sections, as schematically illustrated in Fig. 2C. In the shown embodiment, the sections of the impression 10 are elongated notches or furrows. The impression 10 has a width of less than 2 mm, more specifically, of less than 1 mm. Along the impression 10, the material of the tube 1 has a plastic deformation.

In Fig. 2A, the tube 1 is shown under ambient (visible) light casting a blurred shadow T on an adjacent surface 3. The surface 3 may be a separate part or a part of an apparatus A (see Fig. 6 and discussed further below). In the shown example, the impression 10 is almost not visible and under the ambient light.

Fig. 2D shows the section of the tube 1 according to Fig. 2A subjected to visible light 40 of a lighting device 4. In the shown example, the lighting device 4 emits the light 40 onto the tube 1 in addition to the ambient light. As can be seen from Fig. 2D in comparison to Fig. 2A, the shadow T of the tube 1 projected on the surface 3 is more prominent, sharper, and better visible under the additional light 40 compared to only under the ambient light.

Further, a shadow 10’ is projected onto the surface 3 by the impression 10 exposed to the additional light 40 from the lighting device 4. The shadow 10’ is an image of the impression 10.

The irradiation of the additional light 40 by the lighting device 4 onto and in the direction of the tube 1 and the impression 10 is performed in a directed, e.g., focused manner. In the shown example, the additional light 40 is at least partially directed on the shortest path, here in an orthogonal direction M indicated by an arrow, onto the tube 1 in the region of the impression 10. For example, a center axis of the lighting device 4 is aligned with the impression 10. This enables the shadow 10’ to be a particular precise image of the impression 10. In the shown embodiment, the shadow 10’ is at least substantially of the same size as the impression 10, i.e., with a width of 2 mm or less.

The shadow 10’ can be used as (indirect) reference marking or external visual indicator for a subsequent connection of the tube 1 and a connector 20 of an infusion component.

Fig. 3A-3C show a tube 1 engaged with a connector 20 of an infusion component 2 (e.g., the drip chamber 2A, the pump section 2C or the luer connector 2D). The impression 10 is positioned at a predetermined distance D from an end 11 of the tube 1 . As shown in Fig. 3A, the predetermined distance D may correspond to the distance between a reference site 200 of the connector 20 and an end 21 of the infusion component 2 and/or the connector 20. In this example, the predetermined distance D corresponds to the length of the connector 20. In this case, the impression 10 is positioned on the tube 1 so that the distance D between the edge of the impression 10 and the end 11 of the tube 1 is substantially equal to the length or longitudinal extension of the connector 20 to be engaged with the tube 1.

Alternatively, as shown in Fig. 3B, the predetermined distance D may extend from a reference site 200 at the connector 20 to a position Q on the tube 1 , whereby the extension corresponds to a distance D longer than the length or longitudinal extension of the connector 20 relative to the reference site 200. If, for example, a component, such as a retainer 7 for the tube 1 , e.g. applied in the apparatus A for manufacturing the tube 1 , is at a position which would obscure the impression 10 to be created on the tube 1 , the distance D is predetermined in such a way that the impression 10 on the tube 1 and the resulting shadow 10’ are not obscured by the retainer 7 or other components.

The reference site 200 may be the end of the connector 20 connected to the rest of the infusion component 2. However, the reference site 200 can also be any point, edge or area of the infusion component 2, depending on which part of the infusion component is set as reference site 200. In the present example, the reference site 200 corresponds to an end surface serving as a stop for the tube 1.

The predetermined distance D may be 1 cm or more and/or 5 cm or less. Such distances D allow a particularly simple handling during connection of the tube 1 with the connector 20.

To check the quality of the fitting between the tube 1 and the connector 20, additional light 40 is emitted onto the tube 1 and especially the impression 10. Fig. 3C shows a shadow T of the tube 1 , a shadow 2’ of the infusion component 2 and a shadow 10’ of the impression 10 casted onto an adjacent surface 3. For visual inspection, a distance D’ from the reference site 200 of the connector 20 to an edge of the shadow 10’ can be determined and/or monitored. A comparison between the distance D’ and the predetermined distance D gives information about the fitting between the tube 1 and the infusion component 2, e.g. whether there is a gap between the end 11 of the tube 1 and the end reference site 200 of the respective infusion component 2. In the example depicted in Fig. 3C, there is a gap between the end 11 of the tube and the reference site 200 of the infusion component 2. As a consequence, the determined distance D' is longer than the length of the connector 20 and, in this case, the predetermined distance D. As such, the shadow 10’ provides a visual indicator for the quality of the fitting between the tube 1 and an infusion component 2.

In the following, the creation of the impression 10 on the tube 1 will be described.

As depicted in Fig. 4A, the impression 10 on the tube 1 may be created by means of a marking tool 5 and/or mechanically. The marking tool 5 can be designed as or comprise pliers 5A.

The marking tool 5 comprises one or more, here two, especially elongated blades 50A, 50B. Further, the blades 50A, 50B have one elongated edge 500A, 500B each, here facing one another. This way, at least one, here two elongated impressions 10 can be created in the tube 1 on circumferentially opposite sides of the tube 1.

The blades 50A, 50B and/or edges 500A, 500B are designed to exert a pressure P onto the tube 1 for creating the impression 10 in the tube 1. The blades 50A, 50B and edges 500A, 500B are movable to one another. For example, the blades 50A, 50B and edges 500A, 500B are moved to each other for squeezing, in particular, for deforming the tube 1 .

The pressure P exerted on the tube 1 for creating the impression 10 is particularly at least or more than 2 N/mm² and/or at most or less than 20 N/mm². In the abovementioned pressure range, the shadow 10’ of the impression 10 resulting under additional light 40 can be particularly well and easily visible and be created in the tube 1 in such a way that it is not or only barely visible to the naked eye. In an example, the pressure P amounts to at least or more than 5 N/mm² and/or at most or less than 10 N/mm².

The use of pliers 5A allows to apply a simultaneous and identical pressure P by means of the blades 50A, 50B and their edges 500A, 500B on opposite sides of the tube 1. This allows a particular uniform and reliable creation of the impression 10 in the tube 1. Alternatively, the marking tool 5 may be designed as or comprise a pressure die 5B, which is configured to exert a pressure P on one side of the tube 1 (Fig. 4B). In the shown example, the pressure die 5B is facing a base 5C, here a flat base, which may be part of the marking tool 5 or separate from it. The pressure die 5B has (exactly) one blade 50A with one edge 500A facing the base 5C. This way, the pressure P can be exerted by the pressure die 5B onto the tube 1 towards the base 5C being opposite from the impression side of the tube 1 .

In another embodiment, the marking tool 5 can also comprise more than one and/or different component(s) each having one blade 50A, 50B and/or edge 500A, 500B. For example, the blades 50A, 50B can be mounted at one component each without being directly interconnected with one another, as depicted in Fig. 6 and 7C.

The marking tool 5 can also comprise a plurality of blades 50A, 50B, preferably each having an edge 500A, 500B for creating an impression 10. Correspondingly, the number of impressions 10 corresponds to the number of blades 50A, 50B and/or edges 500A, 500B. However, the number of impressions 10 can also differ from the number of blades 50A, 50B and/or edges 500A, 500B, e.g., when a given edge 500A, 500B is applied to the tube 1 more than once.

The blades 50A, 50B are made of or comprise a stiff material. The blades 50A, 50B may be made of or comprise a metal or a metal alloy, in particular steel. Alternatively, the blades 50A, 50B could be made of a plastics material.

The use of a stiff material allows for a particularly efficient and defined squeezing of the softer material of the tube 1 and to make sure that the created impression 10 is remaining long enough, in particular permanently, in the tube 1 so as to enable visual inspection.

The edges 500A, 500B can have various and/or different shapes. In Fig. 4A, the edges 500A, 500B are linear along their longitudinal extension. Figs. 4C, 4D, and 4E show further embodiments with edges having sections 501 A, 501 B in the form of protrusions, with diverse shapes. While the sections 501 A, 501 B in Fig. 4C are rounded and/or partially elliptical, the sections 501 C, 501 D in Fig. 4D are rectangular and in Fig. 4D the sections 501 E, 501 F are trapezoidal. The shape of the edges 500A, 500B and the sections 501 A-501 F determines the (later) shape of the impression 10. When exerting pressure on the tube 1 , the protruding sections 501A-501 F contact the tube 1 in an elongate area having a length which is smaller than the diameter of the tube 1. This avoids kinks in the tube 1 with stronger deformation.

Fig. 5 shows a sectional view of the blades 50A, 50B according to a plane E-E indicated by a dashed line in Fig. 4A. Here, the cross-section of the blades 50A, 50B is trapezoidal, wherein the side pointing towards the tube 1 is shorter than the opposite side. The shorter sides correspond to the edges 500A, 500B. In this embodiment, the blades 50A, 50B and edges 500A, 500B are blunt. Thus, the blades 50A, 50B comprise surfaces facing one another to squeeze the tube 1 therebetween. This serves for a safe creation of the impression 10 in the tube 1 , especially avoiding any irreversible damage or cut in the tube 1 .

The edges 500A, 500B have a width W. The width W of the edges 500A, 500B determines the (later) width of the impression 10. In an embodiment, the edges 500A, 500B have a width of 2 mm or less, particularly of 1 mm or less. These relatively small or narrow dimensions allow the creation of a particularly defined impression 10 in the tube 1 and, hence, a particularly clearly visible resulting shadow 10’ as visual indicator.

Fig. 6 shows the apparatus A mentioned above for manufacturing an infusion set S. The apparatus A comprises a marking tool 5 tool for creating an impression on a tube 1. Here, the marking tool has two blades 50A, 50B, which are separate from one another and facing one another. Further, the apparatus A includes a(n) (additional) lighting device 4 for irradiating the impression 10 and the tube 1 with (additional) especially visible light 40 and for casting a shadow 10’ on a surface proximate the tube 1. As shown, the apparatus A may contain a retainer 7 for holding the tube 1 to be connected with an infusion component 2. The apparatus A includes an optional mounting tool 6 for connecting the infusion component 2 and the connector 20 with the tube 1 , especially along a mounting direction C indicated by an arrow. Optionally, the mounting tool 6 is adapted to move the infusion component 2 along the mounting direction C relative to the tube 1.

The apparatus A may comprise any of the marking tools 5 and blades 50A, 50B with any of the shapes described herein.

Fig. 7A to 7E show steps of a method for manufacturing a tube 1 for an infusion set S. The steps comprise the following (optionally in the order indicated): Providing a tube 1 (Fig. 7A), predetermining a distance D from an end 11 of the tube 1 (Fig. 7B), and creating an impression 10 on the tube 1 at the predetermined distance D from the end 11 of the tube 1 (Fig. 7C). Optionally, creating the impression 10 on the tube 1 comprises exerting a pressure P with an edge 500A, 500B of a marking tool 5.

Further, the end 11 of the tube 1 is connected to a connector 20 to bring the tube 1 in fluid connection with the connector 20 (Fig. 7D) (and, optionally, with further components) to obtain an infusion set S comprising the tube 1. Optionally, connecting the end 11 of the tube 1 to the connector 20 comprises engaging the tube 1 and the connector 20 with one another over a length equal to or smaller than the predetermined distance D. The method further comprises emitting light 40 on the impression 10 on the tube for casting a shadow 10’ on a surface 3, as illustrated in Fig. 7E. Herein, connecting the end 11 of the tube 1 to the connector 20 comprises monitoring a distance D’ of the shadow 10’ on the surface 3 to the connector 20. 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

1 Tube

T Shadow

10 Impression

10’ Shadow

11 End

12 Surface

2 Infusion component

2’ Shadow

2A Drip chamber (infusion component)

2B Roller clamp (infusion component)

2C Pump section (infusion component)

2D Luer connector (infusion component)

20 Connector

200 Reference site

21 End

3 Surface

4 Lighting device

40 Light

5 Marking tool

5A Pliers

5B Pressure die

5C Base

50A, 50B Blade 500A, 500B Edge 501A-501 F Section

6 Mounting tool

7 Retainer

C Mounting direction

D, D’ Predetermined distance

L Longitudinal axis

M Direction

P Pressure

Q Position

S Infusion set w Width

Claims

1 . A method for manufacturing a tube for an infusion set (S), comprising: providing a tube (1) and predetermining a distance (D) from an end (11) of the tube (1), characterized by: creating an impression (10) on the tube (1) at the predetermined distance (D) from the end (11) of the tube (1).

2. The method according to claim 1 , characterized by: connecting the end (11) of the tube (1) to a connector (20) to bring the tube (1) in fluid connection with the connector (20).

3. The method according to claim 2, characterized in that connecting the end (11) of the tube (1) to the connector (20) comprises engaging the tube (1) and the connector (20) with one another over a length equal to or smaller than the predetermined distance.

4. The method according to claim 2 or 3, characterized by: emitting light (40) on the impression (10) on the tube (1) for casting a shadow (10’) on a surface (3), wherein connecting the end (11) of the tube (1) to the connector (20) comprises monitoring a distance (D’) of the shadow (10’) on the surface (3) to the connector (20).

5. The method according to any of the preceding claims, characterized in that the impression (10) is elongate and extends at least partially around an external surface (12) of the tube (1).

6. The method according to any of the preceding claims, characterized in that creating the impression (10) on the tube (1) comprises exerting a pressure (P) with an edge (500A,

7. The method according to any of the preceding claims, characterized in that creating the impression (10) on the tube (1) comprises exerting a pressure (P) of between 2 N/mm² and 20 N/mm².

8. The method according to any of the preceding claims, characterized in that the predetermined distance (D) is between 1 cm and 5 cm.

9. An infusion set (S), comprising: a tube (1), particularly manufactured with the method according to any of the preceding claims, the tube (1) having an impression (10) adjacent to an end (11) of the tube (1); and a connector (20) connected to the end (11) of the tube (1).

10. An apparatus (A) for manufacturing an infusion set (S), characterized by: a marking tool (5) for creating an impression (10) on a tube (1) at a predetermined distance (D) from an end (11) of the tube (1) and a mounting tool (6) for connecting the end (11) of the tube (1) to a connector (20).

11. The apparatus (A) according to claim 10, characterized by: a lighting device (4) arranged to emit light (40) on the impression (10) on the tube (1) for casting a shadow (10’) on a surface (3) proximate the tube (1).

12. The apparatus (A) according to claim 11 , characterized in that the lighting device (4) is adapted to emit visible light (40).

13. The apparatus according to any of claims 10 to 12, characterized in that the marking tool (5) comprises at least one blade (50A, 50B) having an edge (500A, 500B) for creating the impression (10), wherein the edge (500A, 500B) has a width of 2 mm or less, particularly of 1 mm or less.

14. The apparatus (A) according to claim 13, characterized in that the blade (50A, 50B) of the marking tool (5) is made of a metal or a metal alloy, in particular made of steel.

15. The apparatus according to any of claims 10 to 14, characterized in that the marking tool (5) comprises pliers (5A) or a pressure die (5B).