Method for manufacturing a bipolar or multipolar conductor

Abstract

The invention relates to a method for manufacturing a bipolar or multipolar conductor for a medical device, comprising the following process steps: a) Providing a hollow cylindrical inner lining with an inner lining length that is a multiple of the line length of the line for the medical device; b) Providing a plurality of electrically conductive channels, each of which is formed by at least one insulated conductor comprising an electrical conductor and an insulating layer comprising a first thermoplastic having a first melting point T1; c) Spiral winding of the electrically conductive channels around the inner lining, providing a cable with a cable length that is a multiple of the conductor length; d) Coaxial extrusion of a second thermoplastic with a second melting point T2 around the cable to provide an insulated cable with the extruded second thermoplastic as an outer insulation; e) Cutting the insulated cable to a length corresponding to the line length, providing an insulated line cable; f) Providing a large number of electrodes; (g) Creating a plurality of contact openings in the vicinity of a distal end of the insulated conductor cable, wherein, in order to create a contact opening, parts of the outer insulation and parts of the insulating layer of at least one of the electrically conductive channels are removed, so that the at least one electrically conductive channel can be selectively contacted via each of the contact openings; h) Electrically contacting the plurality of electrodes with the plurality of electrically conductive channels via the plurality of contact openings, wherein each of the electrodes is selectively electrically connected to at least one of the electrically conductive channels via one of the contact openings; wherein the first melting point T1 and the second melting point T2 have a temperature difference ΔT of greater than or equal to 30 °C.

Description

[0001] The invention relates to a method for manufacturing a bipolar or multipolar conductor for a medical device, comprising the following process steps: a) Providing a hollow cylindrical inner lining with an inner lining length that is a multiple of the line length of the line for the medical device; b) Providing a plurality of electrically conductive channels, each of which is formed by at least one insulated conductor comprising an electrical conductor and an insulating layer comprising a first thermoplastic having a first melting point T1; c) Spiral winding of the electrically conductive channels around the inner lining, providing a cable with a cable length that is a multiple of the conductor length; d) Coaxial extrusion of a second thermoplastic with a second melting point T2 around the cable to provide an insulated cable with the extruded second thermoplastic as an outer insulation; e) Cutting the insulated cable to a length corresponding to the line length, providing an insulated line cable; f) Providing a large number of electrodes; (g) Creating a plurality of contact openings in the vicinity of a distal end of the insulated conductor cable, wherein, in order to create a contact opening, parts of the outer insulation and parts of the insulating layer of at least one of the electrically conductive channels are removed, so that the at least one electrically conductive channel can be selectively contacted via each of the contact openings; h) Electrically contacting the plurality of electrodes with the plurality of electrically conductive channels via the plurality of contact openings, wherein each of the electrodes is selectively electrically connected to at least one of the electrically conductive channels via one of the contact openings; wherein the first melting point T1 and the second melting point T2 have a temperature difference ΔT of greater than or equal to 30 °C.

[0002] The bipolar or multipolar cable is suitable for a medical device and, in one embodiment, for a temporary measuring cable. However, the bipolar or multipolar cable can also be used in other technical fields. Background of the invention

[0003] Bipolar or multipolar cables, and especially multipolar cables, for medical devices are generally very complex to manufacture, as their production requires a large number of different components that must be assembled in numerous individual steps. Manufacturing is even more complex for small-format cables, which are in high demand in the medical device sector. The complex design of bipolar or multipolar cables, and especially their manufacturing, typically results in high prices for the final product.

[0004] The high prices of well-known bipolar or multipolar cables are particularly problematic when the cables are intended for use in medical devices for a relatively short period, such as in a temporary device for medical trials. To conduct temporary medical trials in an economically viable manner, cheaper unipolar cables are therefore chosen. However, the use of a unipolar cable can limit the success of the trial, potentially resulting in fewer patients receiving the appropriate medical treatment in the form of a permanent medical device.

[0005] Furthermore, a bipolar or multipolar cable designed and manufactured using a large number of individual components may exhibit lower reliability due to the greater number of potential failure modes for each component. This lower reliability can lead to a higher risk of cable failure, which in turn can have significant consequences, such as for a patient's health if the cable is used in a medical device.

[0006] In view of the above, it is desirable to provide a method for manufacturing a bipolar or multipolar conductor that is simple, safe to use, flexible and efficient.

[0007] Furthermore, it is desirable that the process allows the production of a mechanically stable and simultaneously flexible bipolar or multipolar conductor. In particular, the resulting bipolar or multipolar conductor should be bendable without its electrically conductive channels kinking or breaking. Tasks

[0008] One object of the present invention is to overcome at least some of the disadvantages arising from the prior art.

[0009] A further objective of the invention is to provide a method for manufacturing a bipolar or multipolar conductor that is as simple, application-safe, flexible and cost-effective as possible.

[0010] Furthermore, the resulting bipolar or multipolar conductor should be as mechanically robust as possible, so that bending, in particular bending due to proper use in the tissue of a patient, is possible without mechanical damage to the electrically conductive channels of the bipolar or multipolar conductor. Preferred embodiments of the invention

[0011] The features of the independent claims contribute to at least partially fulfilling at least one of the aforementioned tasks. The dependent claims provide preferred embodiments that contribute to at least partially fulfilling at least one of the tasks.

[0012] A first embodiment of the invention is a method for manufacturing a bipolar or multipolar line for a medical device comprising the following process steps: a) Providing a hollow cylindrical inner lining with an inner lining length that is a multiple of the line length of the line for the medical device; b) Providing a plurality of electrically conductive channels, each of which is formed by at least one insulated conductor comprising an electrical conductor and an insulating layer comprising a first thermoplastic having a first melting point T1; c) Spiral winding of the electrically conductive channels around the inner lining, providing a cable with a cable length that is a multiple of the conductor length; d) Coaxial extrusion of a second thermoplastic with a second melting point T2 around the cable to provide an insulated cable with the extruded second thermoplastic as an outer insulation; e) Cutting the insulated cable to a length corresponding to the line length, providing an insulated line cable; f) Providing a large number of electrodes, in particular at least two electrodes; (g) Creating a plurality of contact openings in the vicinity of a distal end of the insulated conductor cable, wherein, in order to create a contact opening, parts of the outer insulation and parts of the insulating layer of at least one of the electrically conductive channels are removed, so that the at least one electrically conductive channel can be selectively contacted via each of the contact openings; h) Electrically contacting the plurality of electrodes with the plurality of electrically conductive channels via the plurality of contact openings, wherein each of the electrodes is selectively electrically connected to at least one of the electrically conductive channels via one of the contact openings; wherein the first melting point T1 and the second melting point T2 have a temperature difference ΔT of greater than or equal to 30 °C.

[0013] In a preferred embodiment of the method, the first melting point T1 is higher than the second melting point T2. This embodiment is a second embodiment of the invention, which preferably depends on the first embodiment of the invention.

[0014] In a preferred embodiment of the method, the first melting point T1 lies in a range between 230 °C and 290 °C. This embodiment is a third embodiment of the invention, which preferably depends on the first or second embodiment of the invention.

[0015] In a preferred embodiment of the method, the second melting point T2 lies in a range between 150 °C and 260 °C, preferably in a range between 160 °C and 220 °C. This embodiment is a fourth embodiment of the invention, which preferably depends on one of the previous embodiments of the invention.

[0016] In a preferred embodiment of the method, the first thermoplastic comprises a fluorinated polymer or, more preferably, consists of a fluorinated polymer. This embodiment is a fifth embodiment of the invention, which preferably depends on one of the preceding embodiments of the invention.

[0017] In a preferred embodiment of the process, the fluorinated polymer is an ethylene-tetrafluoroethylene copolymer (ETFE), a perfluoroalkoxy polymer (PFA), a polyvinylidene fluoride (PVDF), a tetrafluoroethylene hexafluoropropylene copolymer (FEP), or a mixture of an ethylene-tetrafluoroethylene copolymer, a perfluoroalkoxy polymer, a polyvinylidene fluoride, or a tetrafluoroethylene hexafluoropropylene copolymer. This embodiment is a sixth embodiment of the invention, which preferably depends on the fifth embodiment of the invention.

[0018] In a preferred embodiment of the method, the second thermoplastic is a polyurethane (PU). This embodiment is a seventh embodiment of the invention, which preferably depends on one of the preceding embodiments of the invention.

[0019] In a preferred embodiment, the polyurethane is an aromatic polyurethane based on polyethers or polyesters, preferably on polyether bases. This embodiment is an eighth embodiment of the invention, which preferably depends on the seventh embodiment of the invention.

[0020] In a preferred embodiment of the method, the inner lining comprises a polytetrafluoroethylene (PTFE) or, more preferably, consists of a polytetrafluoroethylene. This embodiment is a ninth embodiment of the invention, which preferably depends on one of the preceding embodiments of the invention.

[0021] In a preferred embodiment of the method, the extrusion in process step d) is carried out in a temperature range between 170 °C and 220 °C, preferably between 180 °C and 215 °C. This embodiment is a tenth embodiment of the invention, which preferably depends on one of the preceding embodiments of the invention.

[0022] In a preferred embodiment of the method, the provision in process step b) comprises coaxial extrusion of the first thermoplastic around the electrical conductor to form the insulating layer. This embodiment is an eleventh embodiment of the invention, which preferably depends on one of the preceding embodiments of the invention.

[0023] In a preferred embodiment of the method, the coaxial extrusion of the first thermoplastic around the electrical conductor is carried out in a temperature range between 250 °C and 300 °C. This embodiment is a twelfth embodiment of the invention, which preferably depends on the eleventh embodiment of the invention. General

[0024] For each embodiment described herein, whose elements "have" or "comprise" a particular feature (e.g., a material), a further embodiment is always considered in which the element in question consists solely of that feature, i.e., it includes no other components. The word "comprise" or "comprise" is used synonymously with the word "have" or "have" in this context. If an element in an embodiment is designated in the singular, an embodiment containing several such elements is also considered. The use of a plural term for an element generally also includes an embodiment containing only a single corresponding element.Unless otherwise stated or clearly excluded from the context, it is generally possible, and hereby expressly considered, that features of different embodiments may also be present in the other embodiments described herein. Likewise, it is generally considered that all features described herein in connection with a method are also applicable to the products and devices described herein, and vice versa. For the sake of brevity, not all of these considered combinations are explicitly listed in every case. Technical solutions that are known to be equivalent to the features described herein are also generally considered to be within the scope of the invention.

[0025] In this description, range specifications also include values ​​referred to as limits. A specification such as "in the range from X to Y" with respect to a quantity A therefore means that A can take on the values ​​X, Y, and values ​​between X and Y. Similarly, a range limited on one side, such as "up to Y" for a quantity A, means that A can take on the values ​​Y and less than Y.

[0026] Some of the described characteristics are linked to the term "essentially." The term "essentially" means that, under real-world conditions and manufacturing techniques, a mathematically exact interpretation of terms such as "superposition," "perpendicular," "diameter," or "parallelism" can never be exact, but only within certain manufacturing tolerances. For example, "essentially perpendicular axes" include an angle of 85 to 95 degrees to each other, and "essentially equal volumes" encompass a deviation of up to 5% by volume. A "device consisting essentially of plastic," for example, comprises a plastic content of ≥95% to ≤100% by weight. "An essentially complete filling of volume B," for example, encompasses a filling of ≥95% to ≤100% by volume of the total volume of B.

[0027] When an indefinite or definite article is used when referring to a singular noun, e.g., "a," "an," or "the," this includes a plural of that noun unless expressly stated otherwise. The use of the term "comprehensive" in this description and the claims does not exclude other elements.

[0028] For the purposes of the present invention, the terms "essentially consisting of" and "consisting of" are considered embodiments of the term "comprising". Where it is defined below that a group comprises at least a certain number of embodiments, this is also to be understood as disclosing a group which, in one embodiment, consists essentially only of these embodiments or, in one embodiment, consists only of these embodiments.

[0029] Terms such as "available" or "definable" and "obtained" or "defined" are used interchangeably. This means, for example, that the term "obtained" does not imply that an embodiment must be obtained, for instance, by the sequence of steps following the term "obtained," unless the context clearly specifies otherwise, although such a limited understanding is always included in the terms "obtained" or "defined" as an embodiment. Whenever the terms "including" or "with" are used, these terms are synonymous with "comprehensive" as defined above. Detailed description

[0030] A first object of the invention relates to a method for manufacturing a bipolar or multipolar cable for a medical device comprising the following process steps: a) Providing a hollow cylindrical inner lining with an inner lining length that is a multiple of the line length of the line for the medical device; b) Providing a plurality of electrically conductive channels, each of which is formed by at least one insulated conductor comprising an electrical conductor and an insulating layer comprising a first thermoplastic having a first melting point T1; c) Spiral winding of the electrically conductive channels around the inner lining, providing a cable with a cable length that is a multiple of the conductor length; d) Coaxial extrusion of a second thermoplastic with a second melting point T2 around the cable to provide an insulated cable with the extruded second thermoplastic as an outer insulation; e) Cutting the insulated cable to a length corresponding to the line length, providing an insulated line cable; f) Providing a large number of electrodes; (g) Creating a plurality of contact openings in the vicinity of a distal end of the insulated conductor cable, wherein, in order to create a contact opening, parts of the outer insulation and parts of the insulating layer of at least one of the electrically conductive channels are removed, so that the at least one electrically conductive channel can be selectively contacted via each of the contact openings; h) Electrically contacting the plurality of electrodes with the plurality of electrically conductive channels via the plurality of contact openings, wherein each of the electrodes is selectively electrically connected to at least one of the electrically conductive channels via one of the contact openings; wherein the first melting point T1 and the second melting point T2 have a temperature difference ΔT of greater than or equal to 30 °C.

[0031] The method serves to produce a bipolar or multipolar cable for a medical device in a simple and efficient manner. Due to the temperature difference ΔT between the first melting point T1 and the second melting point T2 of 30 °C or more, no material bond forms between the insulating layer of the electrically conductive channels and the outer insulation. This allows the windings of the conductive channels, which are generated by the spiral winding in process step c) and are arranged between the inner lining and the outer insulation, a certain degree of freedom of movement. This reduces the risk of kinking or even breakage during proper bending of the bipolar or multipolar cable.The windings of the electrically conductive channels can be stretched or compressed, for example, when a bipolar or multipolar cable is bent, which can lead to a reduction in mechanical stress on the electrically conductive channels. If the insulating layers were bonded to the outer insulation, this freedom of movement would be significantly restricted, and the risk of kinking or breakage would be considerably increased.

[0032] Furthermore, due to its high flexibility, the process allows for a wide variety of conductors, particularly those of varying lengths and / or with different numbers of electrodes, making these types of bipolar or multipolar conductors easily and efficiently accessible. The process also enables electrical contact of the electrodes, especially in the form of ring electrodes, at any point along the insulated conductor cable. Thanks to the efficient execution of the process, conductors can also be manufactured for temporary applications, such as temporary medical measuring setups, which would not be economically viable with other methods.

[0033] A “bipolar” conductor within the meaning of the invention is a conductor comprising two electrodes, each electrically connected to one or more electrically conductive channels near the distal end of the conductor cable. A “multipolar” conductor within the meaning of the invention is a conductor comprising at least three electrically conductive channels and three electrodes, each electrically connected to one of the conductive channels near the distal end of the conductor cable. Generally, the polarity of the conductor is determined by the number of conductive channels. Since each conductive channel is selectively connected to an electrode near the distal end of the conductor cable, the number of electrodes also determines the minimum number of electrically conductive channels near the distal end of the conductor cable.Thus, a multipolar line comprising four electrodes includes a minimum of four electrically conductive channels.

[0034] “Near the distal end” of the cable means that a position is located within the last 30%, preferably the last 20%, most preferably the last 10% of the cable length, and “near the proximal end” means that a position is located within the first 30%, preferably the first 20%, most preferably the first 10% of the cable length.

[0035] An “electrically conductive channel” within the meaning of the invention is a means for selectively electrically connecting an electrical part (e.g., a ring electrode) near the proximal end of the conductor to an electrode, preferably a ring electrode, near the distal end of the conductor.

[0036] Within the scope of the invention, the term "thermoplastic" refers to a class of polymers characterized by a particular thermal behavior. Thermoplastics are materials that soften or melt when heated to a specific temperature, their melting point, and solidify again upon cooling. This property enables repeated shaping through thermal processes such as extrusion, injection molding, or thermoforming.

[0037] Within the scope of the invention, the term "melting point" is used to describe the phenomenon at which the polymer under consideration, in particular the thermoplastic under consideration, transitions from a solid to a liquid state. It should be noted that this melting point should not necessarily be understood as a discrete temperature, but in certain cases it may also be a melting range. The melting range refers to a temperature interval in which the polymer, in particular the thermoplastic, begins to melt and progressively loses its solid structure until it has completely transitioned into the liquid state. This understanding takes into account the fact that many polymers, in particular thermoplastics, especially those with a semi-crystalline, heterogeneous structure, do not have a uniform melting point, but rather a range in which the melting processes occur successively.

[0038] In process step a), a hollow cylindrical, i.e., in the broadest sense, tube- or pipe-shaped, inner lining is provided. The inner lining defines an inner lumen, i.e., a free space, preferably in the center, of the conduit, which extends axially through the conduit being manufactured. The inner lumen represents a cavity within the conduit being manufactured, into which further devices, such as guide wires, can be inserted and / or through which further devices can be inserted into a patient's body. The inner lining serves as a support structure for the conduit and can provide it with improved stability.

[0039] The inner lining can, for example, comprise or consist of a hollow cylinder, for instance made of a polymer, a fabric, for instance made of a metal, a mesh, for instance made of a metal, and / or a spiral or helix, both, for instance, made of a metal. For example, the inner lining consists of a tube made of a polymer, the wall of which is mechanically reinforced with a spiral made of a metal.

[0040] The inner lining has a length that is multiples of, for example, five to two hundred times the length of the cable being manufactured. Such a long inner lining is therefore suitable for producing a large number of cables. This simplifies the manufacturing process and also allows cables of varying lengths to be produced from the same raw material, thus making the manufacturing process more flexible.

[0041] The inner lining preferably has an outer diameter in a range of 50 µm to 500 µm, in one embodiment in a range of 200 µm to 400 µm, and a wall thickness in a range of 10 µm to 100 µm and in one embodiment from 20 µm to 80 µm.

[0042] In process step b), a plurality of electrically conductive channels, for example two to thirty, preferably four to twenty, most preferably six to fourteen, are provided. Each of the channels comprises at least one insulated conductor comprising an electrical conductor and an insulating layer. The insulating layer serves to electrically isolate the electrically conductive channel from another electrically conductive channel.

[0043] The electrical conductor of the at least one insulated conductor can be a single conductor or a plurality of single conductors. Preferably, the conductor is a metal wire or a plurality of metal wires, wherein the plurality of metal wires is preferably wound, stranded, braided, or coiled into a bundle of metal wires. The metal wire or metal wire bundle can have a diameter in the range of 5 to 250 µm, preferably in the range of 10 to 120 µm. For example, the conductor (e.g., the metal wire or metal wire bundle) can have a diameter of about 85 µm.

[0044] The electrical conductor preferably consists of a metal selected from the group comprising platinum, iridium, tantalum, palladium, titanium, iron, gold, molybdenum, niobium, tungsten, nickel, chromium, cobalt, stainless steel, nitinol, alloys of any of these metals, and composite materials, for example, in the form of a sheathed wire, of any of these metals. Suitable electrical conductors include stainless steel, e.g., AISI 316L, AISI 301, or AISI 304. Platinum and platinum alloys, e.g., Pt / Ir 10 or Pt / Ir 20, are also suitable electrical conductors. Nickel-cobalt alloys, such as MP35N, are also suitable electrical conductors.

[0045] To increase corrosion resistance, the electrical conductor can also be coated (e.g., with platinum) or plated. The electrical conductor could, for example, be a Pt-coated MP35N conductor or a Pt-coated tungsten-based conductor.

[0046] The insulating layer of the electrically conductive channels comprises a first thermoplastic with a melting point T1. Preferably, the insulating layer of the electrically conductive channels consists of a first thermoplastic with a melting point T1.

[0047] In process step c), the electrically conductive channels are wound spirally around the inner lining, with a cable provided. During winding, the inner lining is preferably coaxially surrounded by the electrically conductive channels in turns. The cable provided in this way has a length that is a multiple of the conductor length; in particular, the cable length corresponds substantially to the inner lining length provided in process step a). Preferably, the electrically conductive channels are wound spirally around the inner lining, lying side by side. More preferably, in the wound state, the electrically conductive channels extend substantially from a proximal end of the inner lining to a distal length of the inner lining.

[0048] The spiral winding has the advantage of improving the stability and flexibility of the cable. Furthermore, the arrangement of the electrically conductive channels in coils allows for a certain degree of compression or stretching of these coils when bending the inner lining and later the finished cable.

[0049] In process step d), a second thermoplastic with a second melting point is coaxially extruded around the cable. This encases the cable in the second thermoplastic, which, after cooling, acts as an outer insulation, specifically external electrical insulation. For clarification, it should be noted that the cable obtained in process step c) is already "insulated" by the electrically conductive channels provided with the insulating layer. The term "insulated" in the context of "insulated cables" refers to the presence of the, in particular electrically, insulating outer insulation.

[0050] In process step e), the insulated cable is cut to a length that essentially corresponds to the desired conductor length, using a single insulated conductor cable. Cutting also allows for the production of multiple insulated conductor cables from a single insulated cable. The desired conductor length is determined by the cutting process. The insulated cable can be cut into equal lengths, ensuring that each final conductor has the same length, or it can be cut into different lengths, allowing for the production of conductors of varying lengths. Cutting thus increases the flexibility of the process and can also be carried out cost-effectively. The cutting can be performed in various ways.For example, cutting can be done using pliers, scissors, or a wire cutter. Alternatively, cutting can be done using a laser.

[0051] In process step f), a plurality of electrodes are provided for the conductor. The exact number of electrodes depends on the application of the conductor. Preferably, a maximum of as many electrodes as electrically conductive channels are provided, so that each electrode can be electrically connected to an electrically conductive channel during the process. More preferably, the number of electrodes is half the number of electrically conductive channels provided, so that each electrode can be electrically connected to two electrically conductive channels during the process. In this way, each electrode has a second electrically conductive channel as a backup system in case the first electrically conductive channel should fail. Preferably, the electrodes are ring electrodes. The electrodes can comprise a plurality of different materials or be made of different materials.Preferably, the electrodes comprise a metal selected from the group consisting of platinum, iridium, tantalum, palladium, titanium, iron, gold, molybdenum, niobium, tungsten, nickel, chromium, cobalt, steel, nitinol, alloys of any of these metals, and composite materials of any of these metals. Suitable electrodes include stainless steel, for example, AISI 316L, AISI 301, or AISI 304. Platinum and platinum alloys, for example, Pt / Ir 10 or Pt / Ir 20, or nickel-cobalt alloys such as MP35N, are also suitable electrodes.

[0052] The choice of metal for the electrodes (and for the electrical conductors) may depend on the intended use of the conductor according to the invention. For example, if the conductor according to the invention is to be used in a permanent medical device, the electrodes may comprise platinum or a platinum-iridium alloy, or in one embodiment consist thereof. If the conductor according to the invention is to be used in a temporary medical device, the electrodes may comprise stainless steel, or in one embodiment consist thereof. It is understood, however, that the application of the conductor is not limited by the use of a particular metal.

[0053] The electrodes may also have a coating. Suitable coatings include metal nitrides such as TiN, metal oxides such as IrO2, or conductive polymers. The electrode surface may also be surface-structured, e.g., laser-structured. Each electrode, preferably a ring electrode, may have an outer diameter in the range of 200 to 5000 µm, in one embodiment in the range of 300 to 3000 µm, and in another embodiment in the range of 500 to 1500 µm. Each electrode may have a wall thickness in the range of 10 to 200 µm, in one embodiment 10 to 100 µm, and in another embodiment 30 to 70 µm. Furthermore, each of the electrodes can have a length in the range of 200 to 5000 µm, in one embodiment 300 to 3000 µm and in another embodiment in the range of 500 to 1500 µm.According to one embodiment, each of the electrodes has an outer diameter in the range of 300 to 3000 µm and in another embodiment in the range of 500 to 1500 µm, a wall thickness in the range of 10 to 100 µm and in another embodiment in the range of 30 to 70 µm and a length in the range of 300 to 3000 µm and in another embodiment in the range of 500 to 1500 µm.

[0054] In process step g), a plurality of contact openings, preferably the same number as the provided electrodes, are created near the distal end of the insulated conductor cable. For this purpose, a portion of the outer insulation (i.e., a portion of the second thermoplastic) and a portion of the insulating layer (i.e., a portion of the first thermoplastic) are removed at the corresponding locations, along with at least one of the electrically conductive channels running there, so that at least one electrical conductor of an electrically conductive channel is accessible and electrically contactable from the outside at each contact opening. Preferably, only a radially outer portion of the insulating layer of the electrical conductor is removed. Thus, in the further course of the process, one of the provided electrodes can be electrically connected to at least one of the electrically conductive channels at each contact opening.In one embodiment, parts of the insulating layer of two electrically conductive channels are removed at the contact openings, so that one of the electrodes can be selectively electrically connected to two electrically conductive channels via these contact openings.

[0055] In axial extent, the contact openings preferably have a length that essentially corresponds to the axial extent of the electrodes. The contact opening can be created in various ways. For example, the opening can be produced by cutting, punching, or, preferably, by laser ablation.

[0056] In process step h), the multitude of electrodes are electrically contacted with the multitude of electrically conductive channels via the multitude of contact openings. Each electrode is selectively, i.e., specifically, electrically connected to at least one of the electrically conductive channels via one of the contact openings. This electrical contacting can be carried out in various ways. For example, direct electrical contact can be established between the electrode and the electrically conductive channel by bringing both parts into direct electrical contact.Furthermore, an indirect electrical contact can be created by electrically connecting the electrode and the electrically conductive channel via an electrically conductive bridge element, i.e., a separate, electrically conductive component, such as a wire or a wire segment, comprising an electrically conductive material, such as a metal or an electrically conductive polymer. The bridge element serves, in particular, to bridge the distance between the electrically conductive channel(s), especially their electrical conductors, and the electrode to be contacted, a distance caused primarily by the radial thickness of the outer insulation.

[0057] For example, the electrodes are ring electrodes which are pressed onto the electrical conductor of the electrically conductive channel by external force, thus being radially compressed to establish an electrical contact, directly or indirectly. Furthermore, to securely connect the electrode to the electrically conductive channel, a fastening, such as a weld, preferably using a laser, can be formed between the electrode and the electrically conductive channel.

[0058] The first melting point T1 of the first thermoplastic and the second melting point T2 of the second thermoplastic have a temperature difference ΔT of at least 30 °C, preferably at least 40 °C, more preferably at least 50 °C, more preferably at least 60 °C, and most preferably at least 70 °C, wherein it is preferred that the first melting point T1 is higher than the second melting point T2. Thus, the first thermoplastic preferably melts at a higher temperature than the second thermoplastic.

[0059] This allows the second thermoplastic to be extruded, preferably directly, onto the first thermoplastic without the two thermoplastics forming a material bond or any other mechanical connection.

[0060] For extrusion, the second thermoplastic should preferably be heated to at least its melting point T2, or at least to a temperature close to its melting point T2. Furthermore, due to the spatial proximity of the two thermoplastics during extrusion, and preferably even through their direct contact during extrusion, heat is transferred from the heated second thermoplastic to the first. However, the extrusion temperature is preferably set such that the heat transferred to the first thermoplastic is insufficient to heat it to its first melting point T1. Preferably, the extrusion temperature, i.e., the temperature to which the second thermoplastic is heated during extrusion, is below the first melting point T1, and more preferably between the melting point T1 and the melting point T2.

[0061] The electrically conductive channels are therefore not connected to the outer insulation in such a way that any movement of the outer insulation is directly and immediately transmitted to the electrically conductive channels. This allows the outer insulation to bend, which can be compensated for, at least to some extent, by the electrically conductive channels through compression and / or stretching of the windings of the electrically conductive channels around the inner lining. This reduces the risk of the electrically conductive channels kinking or even breaking off during the proper use of the bipolar or multipolar cable, particularly in patient tissue.

[0062] A preferred embodiment of the method is characterized in that the first melting point T1 lies in a range between 230 °C and 290 °C, preferably between 240 °C and 285 °C, and more preferably between 245 °C and 280 °C. This temperature range allows for a wide selection of second thermoplastics to be used, while maintaining the inventive difference between the melting temperatures T1 and T2.

[0063] A preferred embodiment of the method is characterized in that the second melting point T2 is in a range between 150 °C and 260 °C, preferably between 160 °C and 220 °C.

[0064] This temperature range allows for a wide selection of first thermoplastics to be used, while maintaining the inventive distance between the melting temperatures T1 and T2.

[0065] The first thermoplastic can be selected from a variety of different thermoplastics or combinations of thermoplastics.

[0066] A preferred embodiment of the method is characterized in that the first thermoplastic comprises a fluorinated polymer, preferably consisting of a fluorinated polymer. Fluorinated polymers are preferred because, compared to non-fluorinated polymers, they typically have improved sliding properties, or, in other words, a low coefficient of friction. This further reduces the risk of kinking or breakage of the electrically conductive channels during proper bending of the bipolar or multipolar conductor.

[0067] A preferred embodiment of the process is characterized in that the fluorinated polymer is an ethylene-tetrafluoroethylene copolymer (ETFE), a perfluoroalkoxy polymer (PFA), a polyvinylidene fluoride (PVDF) and / or a tetrafluoroethylene-hexafluoropropylene copolymer (FEP).

[0068] The second thermoplastic can be selected from a variety of different thermoplastics or combinations of thermoplastics.

[0069] A preferred embodiment of the method is characterized in that the second thermoplastic is a polyurethane. Polyurethanes can typically be processed at relatively low temperatures, in particular by extrusion.

[0070] A preferred embodiment of the method is characterized in that the polyurethane is a polyester-based or polyether-based polyurethane.

[0071] The inner lining can comprise or consist of different materials or combinations of materials. Preferably, the inner lining consists of a polymer.

[0072] A preferred embodiment of the method is characterized in that the inner lining comprises a fluorinated polymer. Preferably, the inner lining consists of a fluorinated polymer. Preferably, the fluorinated polymer of the inner lining is polytetrafluoroethylene (PTFE). PTFE is preferred because it has a low coefficient of friction, so that the windings of the electrically conductive channels are not restricted in their relative movement by the inner lining. Furthermore, an inner lining made of a fluorinated polymer, in particular ETFE, ensures that no material bond is formed between the inner lining and an outer insulation made of an extruded polyurethane, which is preferred as a second thermoplastic. This further ensures the relative freedom of movement of the windings of the electrically conductive channels between the inner lining and the outer insulation.

[0073] The extrusion in process step d) can take place at different temperatures. Preferably, the extrusion takes place at an extrusion temperature that is lower than the first melting point T1. More preferably, the extrusion takes place at an extrusion temperature that is higher than the second melting point T2, but lower than the first melting point T1, i.e., between the first melting point T1 and the second melting point T2. This effectively prevents a material bond between the insulating layer of the electrically conductive channels and the outer insulation.

[0074] A preferred embodiment of the method is characterized in that the extrusion in process step d) is carried out in a temperature range between 170 °C and 220 °C.

[0075] The provision of the electrically conductive channels in process step b) can be done in different ways.

[0076] A preferred embodiment of the method is characterized in that the provision in process step b) comprises coaxial extrusion of the first thermoplastic around the electrical conductor, forming the insulating layer. It is understood that this coaxial extrusion of the first thermoplastic may have already taken place prior to the commencement of the method according to the invention. Extruding the first thermoplastic represents a simple and cost-effective method for manufacturing the multitude of electrically conductive channels.

[0077] The process conditions for coaxial extrusion of the first thermoplastic must be selected depending on the first thermoplastic used.

[0078] A preferred embodiment of the method is characterized in that the coaxial extrusion of the first thermoplastic around the electrical conductor, preferably around all electrical conductors, is carried out in a temperature range between 250 °C and 300 °C. Examples

[0079] The invention will now be explained in more detail using an exemplary method. The invention is not limited by this example.

[0080] To produce an exemplary line according to the invention, a 500 m long inner lining in the form of a polymer tube made of PTFE with an inner diameter of 400 µm and an outer diameter of 450 µm was provided.

[0081] Furthermore, 12 electrically conductive channels, each 1000 m long, were provided. Each of the 12 electrically conductive channels consisted of a 1x7 microcable with MP35N microcable conductors with a silver core. Each conductor was sheathed with ETFE as a first thermoplastic insulating layer. The first melting point T1 of the first thermoplastic was 263 °C. The individual electrically conductive channel had an outer diameter of 150 µm, with an insulating layer thickness of 30 µm.

[0082] The 12 electrically conductive channels were laid side by side and wound spirally around the inner lining using a stranding machine, essentially wrapping the entire length of the inner lining.

[0083] The cable, obtained by spirally winding electrically conductive channels around the inner lining, was provided with an outer insulation layer by coaxial extrusion of a polyurethane (Pellethane® 2363 55DE, available from Lubrizol Corporation, USA) as a second thermoplastic with a second melting point T2 of 210 °C. The extrusion was carried out at an extrusion temperature of 212 °C. The thickness of the outer insulation was 200 µm.

[0084] The insulated cable obtained by extruding the second thermoplastic was cut into individual insulated conductor cables, each 90 cm long, using a wire cutting machine.

[0085] Subsequently, 6 ring electrodes made of Pt / Ir 10 (platinum-iridium alloy with 10 weight percent iridium based on the total mass of the alloy) with a wall thickness of 200 µm were provided.

[0086] Six disjoint contact openings were created near the distal end of the insulated cable using laser ablation, allowing two electrically conductive channels per opening to be selectively electrically contacted by one of the electrodes each. The axial extent of the contact opening was adapted to the wall thickness of the electrodes.

[0087] For electrical contacting of the electrodes, they were pushed onto the corresponding positions of the contact openings on the conductor cables, pressed together radially and electrically fixed to the corresponding electrical conductors by means of laser welding. Figures

[0088] The invention is further illustrated below by means of figures. The invention is not limited to the figures.

[0089] They show Fig. 1. An exemplary flowchart of a process for manufacturing a bipolar or multipolar lead for a medical device, and Fig. 2a-f exemplary intermediate products of the process for manufacturing a multipolar conductor in a schematic cross-section. Description of the characters

[0090] Fig. Figure 1 shows a flowchart of an exemplary process for manufacturing a b- or multipolar conductor for a medical device, comprising process steps 210 to 280.

[0091] In process step 210, a hollow cylindrical inner lining is provided with an inner lining length that corresponds to a multiple of the final line length of the line to be manufactured for the medical device.

[0092] In process step 220, a plurality of electrically conductive channels are provided. Each of the channels has at least one insulated conductor comprising an electrical conductor and an insulating layer arranged around the electrical conductor. The insulating layer comprises a first thermoplastic with a first melting point T1; preferably, the insulating layer consists of a first thermoplastic with a first melting point T1.

[0093] In process step 230, the plurality of electrically conductive channels provided in process step 220 are wound spirally around the inner lining provided in process step 210. Process step 230 thus provides a cable, wherein a cable length corresponds to a multiple of the conductor length, in particular where the cable length corresponds to the inner lining length.

[0094] In process step 240, a second thermoplastic with a second melting point is coaxially extruded around the cable obtained in process step 240, forming an insulated cable with the extruded second thermoplastic as the outer insulation. Preferably, the second thermoplastic is extruded substantially over the entire length of the cable. There is a temperature difference ΔT of at least 30 °C between the first melting point T1 and the second melting point T2. Preferably, the first melting point T1 is higher than the second melting point T2. The extrusion preferably takes place at an extrusion temperature lower than the first melting point T1, and more preferably at an extrusion temperature between the first melting point T1 and the second melting point T2.

[0095] In process step 250, the insulated cable obtained in process step 230 is cut to a length corresponding to the conductor length. This cutting preferably yields a plurality of insulated conductor cables, the insulated conductor cables differing from the insulated cable essentially only in their length. The insulated conductor cables thus obtained preferably have the same length.

[0096] In process step 260, a plurality of electrodes are provided. Preferably, the electrodes are ring electrodes. The number of electrodes depends on the application of the conductor to be produced. Preferably, the number of electrodes corresponds at most to the number of electrically conductive channels used in the process.

[0097] In process step 270, a plurality of contact openings are created near a distal end of the insulated conductor cable. These contact openings serve to electrically connect the electrodes to the electrically conductive channels. For this purpose, a portion of the outer insulation and a portion of the insulating layer of at least one electrically conductive channel are removed from each contact opening, allowing an electrode to be selectively electrically connected to the corresponding electrical conductor of the electrically conductive channel via the contact opening. Exactly one or more than one, for example two or three, electrically conductive channels can be electrically connected to an electrode via a single contact opening. Preferably, the number of contact openings corresponds to the number of electrodes, so that one electrode can be electrically connected via each contact opening.For example, the contact openings can be created using laser ablation.

[0098] In process step 280, the multitude of electrodes are electrically contacted with the multitude of electrically conductive channels via the contact openings. Each electrode is selectively electrically contacted via one of the contact openings with one or more electrically conductive channels that are accessible through the respective contact opening.

[0099] Fig. 2a-f show various exemplary intermediates of the process in Fig. 1 of the method 200 shown for the production of a bipolar or multipolar line in a schematic cross-section.

[0100] This shows Fig. 2a A hollow cylindrical inner lining 110 consisting of polytetrafluoroethylene. The inner lining 110 encloses an inner lumen 115 and has an inner lining length which corresponds to a multiple of the length of the finally manufactured conductor (not visible in the cross-section). Fig. 2b shows a cable 140 encompassing the inner lining 110 made of Fig. 2a and a total of twelve electrically conductive channels 120 (designated with reference numerals for illustrative purposes only), wherein the twelve electrically conductive channels 120, which were previously provided, were wound spirally around the inner lining 11. In the embodiment shown, each of the electrically conductive channels 120 has exactly one insulated conductor, which has an electrical conductor 121 with an insulating layer 122 surrounding the electrical conductor 121, made of a first thermoplastic with a first melting point T1. The electrically conductive channels 120 are shown in adjacent pairs with different hatching, which is solely for the purpose of improving the clarity of the intermediate products shown. Otherwise, the electrically conductive channels 120 do not differ from one another.The electrically conductive channels 120 are wound spirally (not visible in cross-section) and side by side along the entire length of the inner lining 110.

[0101] Fig. Figure 2c shows an insulated cable 150, obtained by coaxial extrusion of a second thermoplastic with a second melting point T2 around the cable 140. Fig. 2b. The second thermoplastic forms an outer insulation 130 of the insulated cable 150. The first melting point T1 and the second melting point T2 are selected such that no bond, and in particular no metallurgical bond, occurs between the two thermoplastics during coaxial extrusion. In this way, the wound electrically conductive channels 120, especially in their axial extent, have a certain degree of freedom of movement, so that they have a reduced risk of breaking or kinking when the final cable is properly bent. In particular, stretching or elongation of the windings is permitted. In the embodiment shown, the first melting point T1 is at least 40 °C higher than the second melting point T2.Furthermore, coaxial extrusion was carried out at an extrusion temperature that is lower than the first melting point T1 and, in particular, lies between the first melting point T1 and the second melting point T2.

[0102] Fig. Figure 2d shows a result of cutting the insulated cable 150 from Fig. 2c. Insulated conductor cable 160 received. It was cut to the desired length (not visible in the cross-section), which is the desired length of the final manufactured cable. The cutting was done using a wire cutter.

[0103] Fig. 2e shows the insulated cable 160 made of Fig. 2d, in contrast to Fig. 2d The insulated cable 160 has a contact opening 170 near a distal end (not visible in the cross-section). The contact opening 170 was created by removing portions of the outer insulation 130 and portions of the insulating layer 122 of two adjacent electrically conductive channels 120. Removing these electrically insulating components allows selective electrical contact of the electrical conductors 121 of the corresponding electrically conductive channels 120 from outside the insulated cable 160. In the illustrated embodiment, a contact opening 170 includes exposing two adjacent electrical conductors 121 so that they can be electrically contacted with a single electrode. This increases the reliability of the final conductor in the event of a failure, for example, due to severing, or in particular, kinking, of one of the electrical conductors 121.In this case, a current flow would still be possible via the second electrically conductive channel 120.

[0104] Fig. Figure 2f shows the final line 100 produced using process 200. Starting from the intermediate product of the Fig.2e The two adjacent electrically conductive channels 120, in particular their electrical conductors 121, were electrically contacted by an electrode 180 in the form of a ring electrode. In the illustrated embodiment, this was done not by direct, but by indirect electrical contact via a bridging element 190 in the form of an electrically conductive wire section. The bridging element 190 serves in particular to bridge the distance between the electrical conductors 121 and the electrode 180, which is mainly caused by the radial thickness of the outer insulation 135. The conductor 100 comprises a total of six electrodes 180, each of which selectively electrically contacts two adjacent electrically conductive channels 120 via a total of six contact openings 170, whereby only one electrode 180 and its contact point are visible in the cross-section shown.Each of the electrically conductive channels 120 is only electrically connected to a single electrode 180, indirectly via a bridge element 190.

[0105] The features disclosed in the claims, the description and the drawings can be essential for different embodiments of the claimed invention, both individually and in any combination with one another. Reference sign 100 lines 110 Interior lining 115 internal lumens 120 electrically conductive channel 121 electrical conductor 122 Insulating layer 130 external insulation 140 cables 150 insulated cable 160 insulated cable 170 Contact opening 180 electrode 190 bridge elements 200 procedures 210 Provide interior lining 220 Providing electrically conductive channels 230 wraps 240 coaxial extrusion 250 Cutting 260 Provide electrodes 270 Create contact openings 280 Contact

Claims

[1] Method (200) for manufacturing a bipolar or multipolar line (100) for a medical device comprising the process steps: a) Providing (210) a hollow cylindrical inner lining (110) with an inner lining length which corresponds to a multiple of a line length of the line (100) for the medical device; b) Providing (220) a plurality of electrically conductive channels (120), each of the channels (120) being formed by at least one insulated conductor comprising an electrical conductor (121) and an insulating layer (122) comprising a first thermoplastic having a first melting point T1; c) Spiral winding (230) of the electrically conductive channels (120) around the inner lining (110) by providing a cable (140) with a cable length which is a multiple of the conductor length; d) Coaxial extrusion (240) of a second thermoplastic with a second melting point T2 around the cable (140) providing an insulated cable (150) with the extruded second thermoplastic as an outer insulation (130); e) Cutting (250) the insulated cable (150) to a length corresponding to the line length, providing an insulated line cable (160); f) Providing (260) a large number of electrodes (180); (g) Creating (270) a plurality of contact openings (170) in the vicinity of a distal end of the insulated conductor cable (160), wherein, in order to create a contact opening (170), parts of the outer insulation (130) and parts of the insulating layer (122) of at least one of the electrically conductive channels (120) are removed, such that the at least one electrically conductive channel (120) can be selectively contacted via each of the contact openings (170); h) electrically contacting (280) the plurality of electrodes (180) with the plurality of electrically conductive channels (120) via the plurality of contact openings (170), wherein each of the electrodes (180) is selectively electrically connected to at least one of the electrically conductive channels (120) via one of the contact openings (170); wherein the first melting point T1 and the second melting point T2 have a temperature difference ΔT of greater than or equal to 30 °C. [2] Method (200) according to claim 1, wherein the first melting point T1 is higher than the second melting point T2. [3] Method (200) according to one of the preceding claims, wherein the first melting point T1 is in a range between 230 °C and 290 °C. [4] Method (200) according to one of the preceding claims, wherein the second melting point T2 is in a range between 150 °C and 260 °C. [5] Method (200) according to any one of the preceding claims, wherein the first thermoplastic comprises a fluorinated polymer. [6] Method (200) according to claim 5, wherein the fluorinated polymer is an ethylene-tetrafluoroethylene copolymer (ETFE), a perfluoroalkoxy polymer (PFA), a polyvinylidene fluoride (PVDF) and / or a tetrafluoroethylene-hexafluoropropylene copolymer (FEP). [7] Method (200) according to any one of the preceding claims, wherein the second thermoplastic is a polyurethane (PU). [8] Method (200) according to claim 7, wherein the polyurethane is a polyester-based or polyether-based polyurethane. [9] Method (200) according to any of the preceding claims, wherein the inner lining (110) comprises a polytetrafluoroethylene (PTFE). [10] Method (200) according to one of the preceding claims, wherein the extrusion (240) in process step d) is carried out in a temperature range between 170 °C and 220 °C. [11] Method (200) according to one of the preceding claims, wherein the provision (220) in process step b) comprises coaxial extrusion of the first thermoplastic around the electrical conductor (121) forming the insulating layer (122). [12] Method (200) according to claim 11, wherein the coaxial extrusion of the first thermoplastic around the electrical conductor (121) is carried out in a temperature range between 250 °C and 300 °C.

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