Opinion ID: 757289
Heading Depth: 3
Heading Rank: 1

Heading: Limited Reliance on Extrinsic Evidence

Text: 19 Both Mantech and Hudson argued before the district court that the dispute over the proper meaning of the claim term well could be resolved without resorting to extrinsic evidence. See CleanOX, slip op. at 4-5 n. 3. However, each side presented the testimony of an expert witness in case the court determined that extrinsic evidence was necessary. At the conclusion of the Markman hearing, however, the court advised the parties that the expert testimony was accepted only for the purpose of background in the technical area and construed the claims at issue based solely upon the intrinsic evidence. Id. at 5. 20 Mantech asserts on appeal that the established definition of well comports fully with the patents' specifications. Therefore, according to Mantech, the district court erred in not applying the established meaning. Mantech implies that under a proper interpretation of Vitronics, the district court was obligated to rely on the extrinsic evidence here. 21 Hudson responds that the extrinsic evidence of the established meaning of the term well contradicts the meaning taught by the specifications. Hudson contends that relying on such expert testimony would require ignoring clear intrinsic evidence and improperly basing the construction instead on contrary extrinsic evidence, the expert testimony, in violation of Vitronics. Hudson asserts, therefore, that it would have been improper for the judge to rely on expert testimony for more than background in the relevant art and the patents in suit because the intrinsic evidence unambiguously reveals a different meaning of the term well. In addition, Hudson argues that because the witnesses disagreed, the extrinsic evidence on application of the established meaning to the claim term is in conflict. Further, asserts Hudson, Mantech did not establish that the term well as used in the patent was ambiguous and could not be interpreted without extrinsic evidence, another requirement of Vitronics. 22 The district court agreed with Hudson that [t]he words of the claim and the specification adequately describe the scope of the term 'well,'  as used in the patents. CleanOX, slip op. at 25. Therefore, after admitting the extrinsic evidence as background in the relevant technology, the court held that the written description and the claims were not ambiguous and that the meaning of the claim term well was clear. See id. at 26-27. The district court, therefore, correctly followed the guidance set forth in Vitronics for limiting reliance on contrary extrinsic evidence. 23 Mantech's argument, that the court should have relied on expert testimony which, we hold, contradicts the plain meaning of the specification and would result in exactly what Vitronics and prior cases cited therein forbid. See Vitronics, 90 F.3d at 1584, 39 U.S.P.Q.2d at 1578 ([A]s we have recently re-emphasized, extrinsic evidence in general, and expert testimony in particular, may be used only to help the court come to the proper understanding of the claims; it may not be used to vary or contradict the claim language.) (emphasis added) (citing Markman v. Westview Instruments, Inc., 52 F.3d 967, 981, 34 U.S.P.Q.2d 1321, 1331 (Fed.Cir.1995), aff'd, 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996)); see also Bell and Howell Document Management Prods. Co. v. Altek Sys., 132 F.3d 701, 706, 45 U.S.P.Q.2d 1033, 1038 (Fed.Cir.1997) (holding that when the intrinsic evidence is unambiguous, it is improper for the court to rely on extrinsic evidence for purposes of claim construction). 24 In this case, the district court was legally correct both in admitting and accepting the testimony of the parties' expert witnesses for the purpose of background in the technical area at issue, CleanOX, slip op. at 5, and then basing its claim construction solely upon intrinsic evidence. Although this information always may be admitted by the trial court to educate itself about the patent and the relevant technology, the claims and the written description remain the primary and more authoritative sources of claim construction. Thus, they always must be considered and where clear must be followed. See Markman v. Westview Instruments, Inc., 52 F.3d 967, 981, 34 U.S.P.Q.2d 1321, 1331 (Fed.Cir.1995), aff'd, 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996) (holding extrinsic evidence may be used for the court's understanding of the patent); see also Cybor, 138 F.3d at 1454 n. 3, 46 U.S.P.Q.2d at 1173 n. 3. In this case, the claims and written descriptions are dispositive, for they clearly define a well more narrowly than the extrinsic evidence. Therefore, it was not legal error as Mantech proposes for the district court to refuse to rely on the expert testimony for anything more than background. 25