A coil assembly for use in medical devices, the assembly including a first coil having a first coil length and a first coil lumen, the first coil wrapped in a first direction, and a second coil disposed within the first coil lumen. The second coil is wrapped in a second direction opposite the first direction....http://www.google.com.au/patents/US20070083132?utm_source=gb-gplus-sharePatent US20070083132 - Medical device coil
