An apparatus for dissociating gases includes a plasma chamber that may be formed from a metallic material and a transformer having a magnetic core surrounding a portion of the plasma chamber and having a primary winding. The radiating patches define a plurality of slots for increasing a bandwidth of the antenna. Each of the symbols has a value and a probability. A device for using a medical clamp for providing a reference position for a positioning system for percutaneous interventions and a method for determining a reference position for a positioning system for percutaneous interventions, are also provided.