Compliant electrical stimulation leads and methods of fabrication

A method of fabricating a neurostimulation lead adapted for electrical stimulation of tissue of a patient, comprising:

• forming a lead body of insulative material, the insulative material being fused through a substantial volume of the lead body and along a substantial length of the lead body, wherein (i) a plurality of conductors are embedded within the insulative material, (ii) the plurality of conductors are disposed in a helical manner in a repeating pattern of groups of conductors separated by gaps along a substantial length of the lead body, each gap being larger than an inter-conductor pitch within the groups of conductors, (iii) the insulative material is a compliant polymer material, wherein after being formed, the lead body is adapted to permit repetitive elastic axial elongation, without damaging the plurality of conductors, along a majority of the length of the lead body at low stretching forces on the lead body imposed by posture changes of the torso of the patient after implant within the patient's body, and (iv) the lead body assumes a generally linear configuration when a stretching force is not applied to the lead body;
• creating a plurality of electrodes on a distal end of the lead body;
• and
• creating a plurality of terminals on a proximal end of the lead body, wherein the plurality of electrodes are electrically coupled to the plurality of terminals through the plurality of conductors.