Torqueable steerable sheaths

A steerable sheath having a proximal end and a distal end, the steerable sheath comprising:

• an inner liner extending from a proximal end of a non-deflectable portion of the steerable sheath to a distal end of a deflectable portion of the steerable sheath;
• a torque transfer layer surrounding the inner liner and extending from the proximal end of the non-deflectable portion of the steerable sheath to the distal end of the deflectable portion of the steerable sheath;
• a first polymeric layer having an outer circumferential surface and surrounding the torque transfer layer, the first polymeric layer extending from the proximal end of the non-deflectable portion of the steerable sheath to the distal end of the deflectable portion of the steerable sheath;
• a first electrode wire positioned on the outer circumferential surface of the first polymeric layer, the first electrode wire positioned along a first helical path from the proximal end of the non-deflectable portion to a distal end of the non-deflectable portion and positioned along a second helical path from a proximal end of the deflectable portion to the distal end of the deflectable portion;
• a second polymeric layer surrounding the first electrode wire, wherein the first and second polymeric layers are made of different materials, and wherein the first electrode wire is located at an interface between the first and second polymeric layers;
• and
• wherein the first electrode wire is electrically connected to a first electrode positioned on the deflectable portion.