Method of making a hollow lumen cable

摘要

A hollow lumen cable is formed by helically winding inner and outer coils with the helices of each coil being in an abutting relationship and the outer coil inner diameter being less than the outer, peripheral, diameter of the inner coil. Preferably, each coil is multifilar. After the coils are wound, an unwinding force is applied to the outer coil and the inner coil is inserted into the outer coil to have its winding inclined opposite to that of the outer coil; and thence, the outer coil is allowed to contract to form an interference fit with the inner coil. The cable may be incorporated as part of various medical systems e.g., implantable pumps or other rotatable medical apparatuses. The cable is bendable about the tight radii, has a high torque transfer, a small outer diameter, and a hollow lumen through which fluid, wires or medical devices may pass.