Ring electrode for a medical device
One aspect relates to a process for preparing a ring electrode including the steps of a) providing a monolithic metal precursor, wherein the monolithic metal precursor includes an outer tube forming a first cavity of the precursor, and wherein the outer tube has a wall including in one section an inner tube forming a second cavity of the precursor; b) preparing a composite precursor by inserting a first sacrificial core element into the first cavity of the precursor provided in a) and a second sacrificial core element into the second cavity of the precursor provided in a); c) forming the composite precursor obtained in b) to obtain a formed composite having a smaller outer diameter than the composite precursor obtained in b); d) separating a composite disk from the formed composite obtained in c); e) removing the first and the second sacrificial core element from the composite disk obtained in d).
1. A process for preparing a ring electrode comprising:
a) providing a monolithic metal precursor,
wherein the monolithic metal precursor comprises an outer tube forming a first cavity of the precursor, and
wherein the outer tube has a wall comprising in one section an inner tube forming a second cavity of the precursor;
b) preparing a composite precursor by inserting a first sacrificial core element into the first cavity of the precursor provided in a) and a second sacrificial core element into the second cavity of the precursor provided in a);
c) forming the composite precursor obtained in b) to obtain a formed composite having a smaller outer diameter than the composite precursor obtained in b);
d) separating a composite disk from the formed composite obtained in c);
e) removing the first and the second sacrificial core element from the composite disk obtained in d).
2. The process according to claim 1 , wherein the monolithic metal precursor is prepared by at least one process selected from the group of electrical discharging machining, additive manufacturing, deep-hole drilling, and milling.
3. The process according to claim 1 , wherein the monolithic metal precursor comprises a metal selected from the group consisting of platinum, gold, iridium, steel, titanium, hafnium, niobium, tantalum, cobalt, nickel, chromium, zirconium, rhenium, tungsten, molybdenum, and alloys of each one of these metals, and selected from the group consisting of nickel cobalt alloy, steel, platinum and platinum iridium alloy,
and wherein the first sacrificial core element or the second sacrificial core element comprise(s) a non-noble metal or non-noble metal alloy, selected from the group of nickel, copper, steel, and alloys of each one of these metals.
4. The process according to claim 1 , wherein the inner tube is arranged on the inner side of the outer tube of the monolithic metal precursor provided in a), or
wherein the outer tube of the monolithic metal precursor provided in a), as seen in a radial cross section, has a circular outer shape, and the section of the wall of the outer tube which comprises the inner tube protrudes into the first cavity of the outer tube.
5. The process according to claim 1 , wherein the first and second sacrificial core elements inserted in b) comprise a metal, and
wherein the metal of the monolithic metal precursor has a higher standard electrode potential than the metal of the first and the second sacrificial core elements.
6. The process according to claim 1 , wherein c) comprises a drawing process, which is preferably carried out with a deformation factor of between 5 and 40%, per individual drawing, and a die cast having a total included angle 2 α in the range of from 5 to 20°.
7. The process according to claim 1 , wherein c) comprises a drawing process, which is preferably carried out with a deformation factor of between 15 and 30%, per individual drawing, and a die cast having a total included angle 2 α in the range of from 5 to 15°.
8. The process according to claim 1 ,
wherein the outer tube of the monolithic metal precursor provided in a) comprises at least one further inner tube forming at least one further cavity of the monolithic metal precursor in at least one further section of the wall,
wherein b) further comprises inserting at least one further sacrificial core element in the at last one further cavity of the precursor, and
wherein c) further comprises removing the at least one further sacrificial core element from the composite disk obtained in d).
9. The process according to claim 1 , wherein the outer diameter of the outer tube of the monolithic metal precursor provided in a) and the outer diameter of the formed composite obtained in c) have a ratio which is in the range of 60:1 to 2:1.
10. The process according to claim 1 , wherein the outer diameter of the outer tube of the monolithic metal precursor provided in a) and the outer diameter of the formed composite obtained in c) have a ratio which is in the range of 30:1 to 5:1.
11. A composite for preparing a ring electrode comprising
i) a monolithic metal element comprising an outer tube forming a first cavity,
wherein the outer tube has a wall comprising in one section an inner tube forming a second cavity,
ii) a first sacrificial core element, wherein the first sacrificial core element is located in the first cavity of the monolithic metal element, and
iii) a second sacrificial core element, wherein the second sacrificial core element is located in the second cavity of the monolithic metal element.
12. A ring electrode for a medical device,
wherein the ring electrode is a monolithic metal,
wherein the ring electrode comprises an outer tube forming a first cavity of the electrode,
wherein the outer tube has a wall comprising in one section an inner tube forming a second cavity of the electrode, and
wherein the wall of the outer tube has at least one section having a thickness of below 150 μm.
13. The ring electrode according to claim 12 , wherein the outer tube of the ring electrode has an outer diameter in the range of 0.2 to 5 mm, and
wherein the first cavity formed by the outer tube has an inner diameter in the range of 0.05 to 4.8 mm, and
wherein the second cavity formed by the inner tube has an inner diameter in the range of 0.01 to 1.0 mm.
14. The ring electrode according to claim 12 , wherein the outer tube of the ring electrode has an outer diameter in the range of 0.5 to 2 mm, and
wherein the first cavity formed by the outer tube has an inner diameter in the range of 0.1 to 1.8 mm, and
wherein the second cavity formed by the inner tube has an inner diameter in the range of 0.05 to 0.3 mm.
15. A process for preparing a ring electrode or a part thereof, wherein the process comprises:
1) Providing a sacrificial outer element comprising a cavity A, wherein the sacrificial outer element, as seen in a radial cross section, has a circular outer shape;
2) Providing a monolithic metal precursor comprising a tube comprising a cavity B;
3) Providing a sacrificial core element;
4) Preparing a composite precursor by inserting the monolithic metal precursor into cavity A of the sacrificial outer element, and by inserting the sacrificial core element into cavity B of the monolithic metal precursor;
5) Forming the composite precursor obtained in 4) to obtain a formed composite having a smaller outer diameter than the composite precursor obtained in 4);
6) Separating a composite disk from the formed precursor obtained in 5);
7) Removing the sacrificial outer element and the sacrificial core element from the composite disk obtained in 6).
16. The process according to claim 15 , wherein the outer shape of the monolithic metal precursor, as seen in a radial cross section, has a non-circular outer shape of, an oval, polygonal, cubic or rectangular outer shape, or
wherein the cavity B of the monolithic metal precursor, as seen in a radial cross section, has a different shape than the outer shape of the monolithic metal precursor, or a circular shape.
17. A composite for preparing a ring electrode or a part thereof comprising:
i) a sacrificial outer element comprising a cavity A′, wherein the sacrificial outer element, as seen in a radial cross section, has a circular outer shape,
ii) a monolithic metal element comprising a tube comprising a cavity B′, wherein the monolithic metal element is located in cavity A′ of the sacrificial outer element,
iii) a sacrificial core element, wherein the sacrificial core element is located in cavity B′ of the monolithic metal element.
18. A ring electrode or a part thereof for a medical device:
wherein the ring electrode or the part thereof comprises a tube comprising a cavity, and
wherein the ring electrode or the part thereof is a monolithic metal, and
wherein the ring electrode or the part thereof, as seen in a radial cross section, has a non-circular outer shape.