The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The test system includes a control device and a cable group. A method of repairing tissue is also disclosed. Of these two sections of the closed space 57, the one on the side of the head block 47 constitutes a first closed space 57a. Desirably, the stressed layer is then removed to expose the first and second portions of the active semiconductor region.