Ring electrode for a medical device

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.

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.

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).