Millipore Corp v WL Gore & Assoc., Inc., Civil Action No. 09-10765-DPW, 2010 U.S. Dist. LEXIS 99704 (D. Mass. Sept. 20, 2010) (Woodlock, D.J.) [Claim Construction, Summary Judgment of Infringement].

Plaintiff Millipore Corporation (“Millipore”) brought this action against Defendant W.L. Gore Associates, Inc. (“Gore”) for infringement of U.S. Patent No. 7,293,477 (the “’477 patent”), concerning fluid sampling devices and kits comprising of components of same. The District Court (Woodlock, D.J.) construed several terms of the patent-in-suit and entered summary judgment of non-infringement in favor of Gore.

The District Court analyzed both literal infringement and infringement under the doctrine of equivalents. With respect to literal infringement, the Court focused upon those limitations related to the function, structure, and location of the cap of the elongate members of the device. Although Gore’s products were found to literally infringe the elements of the patent-in-suit with respect to the function of the “cap” because the cap created a liquid tight seal, the District Court found no literal infringement with respect to the structure and location of the cap. Specifically, the Gore product was found to have a cap as a distinct and separate element whereas the Court’s claim construction required that the cap be part of the same structure as the elongate members. In addition, the Court found that the opening through which fluid flows in the Gore device is placed in front of the silicone seal whereas the patent requires that it be behind that seal.

In the absence of literal infringement, Gore’s device could still infringe under the doctrine of equivalents. The District Court, however, found that no such infringement existed here.

First, the Court agreed with Gore that Millipore was estopped from arguing infringement under the doctrine of equivalents with respect to the cap-related limitations. During prosecution, Millipore added the “cap” as an additional limitation to the elongate member in order to overcome prior art rejections made by the examiner. It described this limitation as follows: “the elongate member having a cap and an opening to a passage of the elongate member behind the cap, the elongate members being displaceable between ‘open’ and ‘closed’ positions such that fluid can flow into the opening behind the cap.” Millipore attempted to argue that it could rebut the presumption of prosecution history estoppel in order to argue infringement under the doctrine of equivalents because this limitation was only tangential to the equivalent in question—“a tight silicone seal that creates a liquid tight seal that is distinct from, rather than part of, the elongate member and is located in the back, rather than in the front, of the opening.” The District Court, rejected this argument. It found that the amendment focused on a cap with distinct qualities and concluded that Millipore was estopped from arguing that the function, structure, and location of the cap have merely a tangential, rather than a direct, relation to the seal in Gore’s product.

Second, the District Court found that Millipore failed to present particularized testimony and linking argument as to the “‘insubstantiality of the differences’ between the claimed invention and accused device or process, or with respect to the function, way, result test.” The Court examined both the affidavit of Millipore’s expert as well as the product itself to find that Millipore did not establish infringement by the doctrine of equivalents as a matter of law.