A surgically implantable multiple orifice heart valve having a valve frame with at least two orifices, each of which can accommodate a tissue valve. When the target panel is clamped between the first and second jaws of the target holder, separate electrical contacts are established between the front layer and the first jaw on the one hand, and between the second layer and the second jaw on the other hand, the first and second jaws being further connectable to a hit-scoring unit. The magnetic maker for a SQUID magnetic sensor is prepared by causing the surface of a magnetic fine particle to adsorb a hydrophilic macromonomer having a polymerizable vinyl group at the terminal thereof and having a molecular weight of 500 to 1000, and then adding a monomer of a hydrophilic vinyl compound having carboxyl group and a crosslinking agent for carrying out copolymerization reaction. The device may include a laterally grown charge compensated area to form a superjunction device. The controller is configured to provide a load loss warning based on the signals.