Implantable medical devices and methods of manufacture

An implantable lead, comprising:

• a) an elongated lead body core having a plurality of ribs that extends axially along a longitudinal axis from a proximal end to a distal end of the lead body core and that are circumferentially spaced apart from each other around the longitudinal axis by an intermediate one of a plurality of axially extending open channels, wherein each rib comprises an axially extending segmented cylindrically-shaped outer peripheral surface;
• b) a plurality of electrical conductors;
• c) a plurality of electrically conductive sleeves, wherein one of the sleeves is supported on a respective one of the electrical conductors, and wherein one of the electrical conductors supporting a sleeve is positioned in a respective one of the axially extending open channels adjacent to the segmented cylindrically-shaped outer peripheral surfaces of immediately adjacent axially extending ribs;
• d) a plurality of electrode rings supported on the outer peripheral surface of the lead body core so that an inner surface of each electrode ring faces the electrically conductive sleeve supported on a respective one of the plurality of electrical conductors, wherein each of the electrode rings has a cylindrically-shaped electrode ring inner surface that matches and directly contacts the segmented cylindrically-shaped outer peripheral surfaces of the plurality of axially extending ribs;
• e) a plurality of dielectric insulator rings supported on the outer peripheral surface of the lead body core between two electrode rings to prevent the electrode rings from contacting each other, wherein each of the dielectric insulator rings has a cylindrically-shaped insulator ring inner surface that directly contacts the segmented cylindrically-shaped outer peripheral surfaces of the plurality of axially extending ribs;
• f) a weld connecting the inner surface of a respective one of the electrical rings to the electrically conductive sleeve supported on a respective one of the plurality electrical conductors;
• and
• g) a distal dielectric end cap supported on the distal end of the lead body core,
• h) wherein the distal dielectric end cap and the plurality of dielectric insulator rings are heat bonded to the lead body core.

A method for manufacturing an implantable lead, comprising the steps of:

• a) extruding an elongated lead body core comprising a plurality of axially extending ribs that are circumferentially spaced apart from each other around a longitudinal axis by an intermediate one of a plurality of open channels, wherein each rib comprises a segmented cylindrically-shaped outer peripheral surface extending axially from a proximal end to a distal end of the lead body core;
• b) providing a plurality of electrical conductors;
• c) supporting an electrically conductive sleeve on a respective one of the plurality of electrical conductors and positioning the electrical conductor in a respective one of the axially extending open channels so that the conductive sleeve resides adjacent to the segmented cylindrically-shaped outer peripheral surfaces of immediately adjacent axially extending ribs;
• d) providing a plurality of electrode rings and supporting the electrode rings on the outer peripheral surface of the lead body core so that an inner surface of each electrode ring faces the electrically conductive sleeve of a respective one of the electrical conductors, wherein each electrode ring has a cylindrically-shaped inner surface that matches and directly contacts the segmented cylindrically-shaped outer peripheral surfaces of each of the plurality of axially extending ribs;
• and
• e) supporting a plurality of dielectric insulator rings on the outer peripheral surface of the lead body core, each of the dielectric insulator rings having an inner surface that directly contacts the segmented cylindrically-shaped outer peripheral surfaces of the plurality of axially extending ribs, wherein one of the plurality of dielectric insulator rings is positioned between two of the plurality of electrode rings;
• f) welding the electrode ring, inner surface of each of the electrode rings to the electrically conductive sleeve supported on a respective one of the plurality of electrical conductors;
• g) positioning a distal dielectric end cap on the distal end of the lead body core;
• and
• h) heating the lead body core to bond the distal dielectric end cap and the plurality of dielectric insulator rings to the lead body core.