Implicit Redefinition Of Claim Scope

Although "the words of a claim are generally given their ordinary and customary meaning," Thorner v. Sony Computer Entm't Am. LLC, 669 F.3d 1362, 1365-67 (Fed. Cir. 2012), if the specification reveals "a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess[,] . . . the inventor's lexicography governs," Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). The Federal Circuit has recognized that determining when a patentee is acting as his own lexicographer can be difficult because "the distinction between using the specification to interpret the meaning of a claim and importing limitations from the specification into the claim can be a difficult one to apply in practice." Id. at 1323; see also Bell Atl. Network Servs., Inc. v. Covad Commc'ns Grp., Inc., 262 F.3d 1258, 1268 (Fed. Cir. 2001). Recently, in SkinMedica, Inc. v. Histogen, Inc., No. 2012-1560 (Fed. Cir. Aug. 23, 2013), the Federal Circuit revisited many of its claim-construction principles, taking a close look at how to determine when a patentee has chosen to be his own lexicographer.

At issue in SkinMedica were U.S. Patent Nos. 6,372,494 ("the '494 patent") and 7,118,746 ("the '746 patent"), owned by SkinMedica. The '494 and '746 patents contain claims related to methods for producing pharmaceutical compositions containing "novel conditioned cell culture medium compositions" and uses for those compositions. SkinMedica appealed the district court's construction of the claim term "culturing . . . cells in three-dimensions." The specifications of the '494 and '746 patents refer at several points to methods of culturing cells in two dimensions, using microcarrier beads, and in three dimensions. SkinMedica argued that the ordinary meaning of "culturing cells in three dimensions" includes growing cells using beads, which was the method allegedly used by the accused infringer Histogen, and that the district court should have interpreted the claim term according to this ordinary meaning. The district court, however, held that, based on statements made in the specification and during the prosecution history, the patentee acted as his own lexicographer and narrowed the scope of "culturing . . . cells in three-dimensions" by excluding the use of beads.

In order to determine whether a patentee has, in fact, chosen to be his own lexicographer and use terms in a manner other than according to their ordinary...