Apparatus and method for expanding a stimulation lead body in situ

An implantable lead for providing therapy to a body comprising:

• an elongate central lead body;
• at least one extendable member having a therapy delivery element disposed thereon for delivering therapy to the body, the extendable member depending from the lead body and being adapted to assume a compact position, wherein the therapy delivery element is disposed in close proximity to the lead body, and an extended position, wherein the therapy delivery element is disposed at a location distal from the lead body;
• the extendable member being formed as a coaxial accessory tube mounted on the lead body and including a central slot forming at least two flexible leaf portions, each leaf portion having a bending joint formed therein;
• and
• at least one central electrode disposed on the lead body;
• wherein the central electrode is not exposed by the leaf portions in the compact position and exposed in the extended position.

An implantable lead for providing therapy to a body comprising:

• an elongate central lead body;
• at least one extendable member having a therapy delivery element disposed thereon for delivering therapy to the body, the extendable member depending from the lead body and being adapted to assume a compact position, wherein the therapy delivery element is disposed in close proximity to the lead body, and an extended position, wherein the therapy delivery element is disposed at a location distal from the lead body;
• the extendable member being formed as a coaxial accessory tube mounted on the lead body and including a central slot forming at least two flexible leaf portions, each leaf portion having a bending joint formed therein;
• at least one central electrode disposed on the lead body;
• and
• at least one ratchet ring formed on the lead body to prevent downward movement of a lower end of the coaxial accessory tube.