Patent ID: 8484841

Claim:
A method of fabricating a stimulation lead for applying electrical pulses to tissue of a patient, the method comprising: providing a central insulator member including elastic polymer material; helically wrapping a plurality of conductors about the central insulator member, the helically wrapping arranging the plurality of conductor wires in groups with an inter-group spacing that is larger than an inter-conductor spacing within each group; providing an outer insulator layer to form an intermediate lead body assembly; forming a lead body by heating polymer material of the intermediate lead body assembly to cause insulative material of the lead body to form a solid, fused cylindrical body about the plurality of conductors, wherein the lead body is adapted to elastically elongate at low stretching forces upon implantation into the patient, wherein the groups of conductors in the lead body comprise a first conductor, a last conductor, and inner conductors between the first and last conductor, wherein the first and last conductor comprise respective helix diameters that are smaller than the helix diameters of the inner conductors; and forming a plurality of electrodes and terminals on the lead body that are electrically connected through the plurality of conductors.