US Patent 9750486 Trackable biopsy needle

A trackable biopsy needle assembly including an inner tube of an outer cannula, an inner dielectric layer, a first coil, a second coil, a third coil, an outer dielectric layer, and an outer tube of the outer cannula. The inner tube defines a bore. The inner dielectric layer is secured onto an outer surface of the inner tube. The first, second, and third coils are wound over the inner dielectric layer. The outer dielectric layer is secured onto the first coil, the second coil, and the third coil. The outer tube is fastened to the outer dielectric layer.