Claim Interpretation And Use of Specification, Prosecution History, And Common Meaning To Interpret “Substantially Uniform”

Medrad owns a patent drawn to radio frequency coils used in the manufacture of magnetic resonance imaging (MRI) devices.  As recited in claim 1, the patented coils provide a “substantially uniform” magnetic field that is “applied to a “region of interest.”  Medrad accused MRI Devices of infringement and MRI Devices asserted, as a defense, that the patent was invalid as reading on the prior art.  The District Court granted a summary judgment of invalidity.  In affirming the invalidity of the patent, the Federal Circuit noted that Medrad’s definitions of the terms “substantially uniform” and “region of interest” to avoid invalidity are not supported by the specification, which includes in its objects of the invention and specific examples, support for the interpretation of the claim terms afforded by the District Court.  Further, Medrad’s definition of the term “substantially uniform” in the context of a magnetic field does not conform to the examples of coils used to generate the magnetic field disclosed in the patent.  Thus, in the context of a claim term which provides little guidance as to the appropriate meaning, the written description is to be consulted and any resulting claim construction should be consistent with the written description since a “‘claim construction that does not encompass a disclosed embodiment is … rarely, if ever, correct.  Johns Hopkins Univ. v. Cellpro, 152 F. 3d 1342, 1355 (Fed. Cir. 1998).”  (Opinion at Pg. 11).  Lastly, the mere fact that the term “substantially uniform” has been differently interpreted by the Federal Circuit in an unrelated case is not dispositive since the unrelated case, Ecolab, Inc. v. Envirochem, Inc., 264 F.3d 1358 (Fed. Cir. 2001), did not relate to magnetic fields used in MRI imaging as does the claimed invention.   Medrad Inc. v. MRI Devices Corp., Civ. Case No. 04-1134 (Fed Cir. March 16, 2005).


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