Siemens Medical Solutions USA, Inc. manufactures positron emission tomography (PET) medical imaging devices, and uses scintillation crystals known by their chemical name as cerium-activated lutetium oxyorthosilicate,” i.e. LSO.[1] Saint-Gobain sold another kind of scintillation crystal (LYSO) to Philips Medical Systems, which manufactures competing PET scanners.[2] In April of 2007, Siemens sued Saint-Gobain for infringement of their U.S. Patent No. 4,958,080 (the ‘080 patent) which claimed a “detector comprising a scintillator composed of a transparent single crystal of cerium-activated lutetium oxyorthosilicate,” i.e. LSO.[3] According to Siemens, Saint-Gobain’s infringement is due to its manufacturing of cerium-doped lutetium yttrium orthosilicate (LYSO).
The accused LYSO crystals are similar to LSO except that about 10% of the lutetium atoms are replaced with yttrium atoms. Thus, Siemens asserts that Saint-Gobain infringes the Read the remainder of this entry »
