Processes for producing a sleeve for an electrode for medical applications
One aspect relates to a method of producing a sleeve for a ring electrode for electrophysiological and neuro-medical applications from a biocompatible metallic tape. Repetitive structures are punched into the tape and each includes at least one surface that is connected by at least one fin to at least one external strip. The at least one external strip connects the repetitive structures to each other on the margin. A sleeve mold is formed from a multiple of the repetitive structures through multiple reforming steps by a reforming technique. The sleeve mold is punched off the such that the sleeve is formed with a first tube-shaped region with a larger diameter and a second tube-shaped region with a smaller diameter. The first region with the larger diameter has a larger external diameter and internal diameter than the second region with the smaller diameter, and the two regions are connected.
1. A method of producing a sleeve for a ring electrode for electrophysiological and neuro-medical applications from a metallic tape, wherein the tape and the sleeve fabricated from the tape consist of a biocompatible metal or a biocompatible metallic compound, the method comprising:
punching into the tape to define repetitive structures, wherein the repetitive structures each comprise at least one surface that is connected by at least one fin to at least one external strip, wherein at least the at least one external strip connects the repetitive structures to each other on a margin;
subsequently forming a sleeve mold from a multiple of the at least one surfaces of the repetitive structures through multiple reforming steps by deep-drawing; and
punching off the sleeve mold such that the sleeve is formed comprising a first tube-shaped region with a larger diameter and a second tube-shaped region with a smaller diameter, wherein the first region with the larger diameter comprises a larger external diameter and internal diameter than the second region with the smaller diameter, and the two regions are connected to each other such that the sleeve forms a continuous tube characterized in that the second region with the smaller diameter has a circumferential flange formed in it for attaching a coil or a wire by welding, wherein the external diameter of the flange is at least 0.1 mm larger than the external diameter of the second region.
2. The method of claim 1 , characterized in that the tape and the sleeve fabricated from the tape consist of a precious metal, titanium, tantalum or a metallic compound thereof or a metallic compound containing at least one precious metal as main component or titanium or tantalum as main component.
3. The method of claim 1 , characterized in that the multiple reforming steps of the deep-drawing take place using a single tool, whereby the tool is being pressed onto the metallic tape, whereby multiple modules are arranged in series one after the other in the tool and a step of reforming or punching off or punching-reforming is performed with each module.
4. The method of claim 3 , characterized in that the tape is transported a distance on to the next module after each punching and/or reforming, whereby, the distance of all modules with respect to each other in a conveying direction of the metallic tape are equal.
5. The method of claim 3 , characterized in that at least four chronologically separate reforming steps take place in order to generate the sleeve mold, wherein the tool comprises at least four modules for this purpose.
6. The method of claim 1 , characterized in that the metallic tape and the sleeve fabricated from the tape consist of tantalum, titanium, palladium, platinum, gold or a platinum-iridium alloy, an alloy comprising at least two of the elements tantalum, titanium, palladium, platinum, gold, and iridium or a metallic compound containing gold and/or platinum as its main component.
7. The method of claim 1 , characterized in that the tape is being annealed before or right after the repetitive structures are punched in, and is being annealed at a temperature between 300° C. and 1,000° C.
8. The method of claim 1 , characterized in that the metallic tape is produced by rolling followed by annealing.
9. The method of claim 1 , characterized in that a thickness of the metallic tape before the repetitive structures are being punched is in a range from 50 μm to 2 mm.
10. The method of claim 1 , characterized in that the surfaces of the repetitive structures comprise a surface area of between 10 mm 2 and 2,000 mm 2 .
11. The method of claim 1 , characterized in that a wall thickness of the sleeve is between 30 μm and 300 μm.
12. The method of claim 1 , characterized in that at least all outward-facing structures of the sleeve are produced to have a radius of curvature (R 1 , R 2 , R 3 ) of more than 0.1 mm.
13. The method of claim 1 , characterized in that the first region with the larger diameter comprises a length of between 1 mm and 20 mm, and the second region with the smaller diameter comprises a length of between 1 mm and 10 mm.
14. The method of claim 1 , characterized in that the external diameter of the first region with the larger diameter is between 0.5 mm and 5 mm and the external diameter of the second region with the smaller diameter is between 0.4 mm and 4.5 mm.
15. The method of claim 1 , characterized in that depressions and/or recesses are provided on an external circumference of the sleeve of the first and/or second region that are suitable for connecting other components by welding, crimping, soldering and/or gluing.
16. The method of claim 1 , characterized in that the sleeve mold is appropriately reformed during the reforming steps such that the sleeve comprises, aside from the first tube-shaped region with the larger diameter and the second tube-shaped region with the smaller diameter, a third tube-shaped region, wherein the third region has a smaller diameter than the first tube-shaped region with the larger diameter, wherein all three regions are connected to each other in one-part manner, in particular are appropriately connected to each other in one-part manner such that the sleeve forms a continuous tube.
17. The method of claim 1 , further comprising producing a neuro-medical sensor or an electrophysiological ring electrode by welding a first wire to a flank of a transition from the first region to the second region or on a flange, wherein the first wire extends around the second region of the sleeve helically and extends in a direction away from the first region.
18. The method of claim 17 , characterized in that a second helical wire, is drawn through an inside of the sleeve, wherein the second wire is electrically insulated with respect to the sleeve and the first wire.
19. The method of claim 17 , characterized in that a sensor for measuring a change of an electrical field strength and/or a contact surface for a sensor for measuring a change of the electrical field strength, which is connected in electrically conductive manner to the first wire, is attached to an outside of the first region of the sleeve.