A torque coil 10 includes a first filar configured in an inner layer 14 that is helically wound in a constricted state such that it defines an inner lumen providing access between a proximal and distal end of the torque coil. A second filar is configured in an outer layer 18 that is helically wound over the inner layer in a constricted state. At least one of the first and second filars includes a signal transmitting material surrounded by an isolating material thereby allowing transmission of signals between the proximal and distal end of the torque coil in one of the layers. At least one of the first and second filars includes a torque transmitting material thereby configuring the torque coil to transfer torque from the proximal to the distal end.
