A ring electrode for an implantable medical device includes a conductive
tubular member adapted to be attached to a lead body and having a
continuous generally helical slot formed therein to form a coil thereby
enabling omni directional bending. The coil is of flattened cross section
and in one embodiment, the coil is shaped as a spiral of uniform pitch.
In another embodiment, a plurality of uniformly spaced dovetail joints
connect a plurality of first and second adjacent loops. Each dovetail
joint includes a plurality of uniformly spaced wedge-shaped tenons
projecting longitudinally from a first loop, a plurality of uniformly
spaced wedge-shaped mortises longitudinally indented into a second loop,
the wedge-shaped mortises being similarly shaped and sized in relation to
the wedge-shaped tenons, the plurality of wedge-shaped tenons being
fittingly received by the wedge-shaped mortises at all locations between
the proximal and distal ends of the ring electrode.