Implant, a mandrel, and a method of forming an implant

An implant comprising:

• a coil having a coil length that is biased to conform to a winding pattern, the coil comprising a primary, substantially linear configuration for delivery of the coil to a vascular site, and a secondary, substantially spherical configuration in an unrestrained state for positioning at said vascular site, the winding pattern approximately conforming to an outer surface of a sphere, the winding pattern consisting of only substantially triangular shapes, each triangular shape having a center, four of the triangular shapes having sides that bow outward away from the center, four of the triangular shapes having sides that bow inward towards the center, the coil comprising a proximal end, a distal end, and a longitudinal axis that, when the coil is in the linear configuration, extends from the proximal end to the distal end, the coil formed by winding about a mandrel and twisting the proximal end at least half a turn with respect to the distal end about the longitudinal axis.