Home Diagnostics, Inc. v. Lifescan, Inc., 03-1370.

• Decision Date: 31 August 2004
• Docket Number: No. 03-1370.,03-1370.
• Parties: HOME DIAGNOSTICS, INC., Plaintiff-Appellee, v. LIFESCAN, INC., Defendant-Appellant.
• Court: U.S. Court of Appeals — Federal Circuit

381 F.3d 1352

HOME DIAGNOSTICS, INC., Plaintiff-Appellee, v. LIFESCAN, INC., Defendant-Appellant.

No. 03-1370.

United States Court of Appeals, Federal Circuit.

August 31, 2004.

Rehearing and Rehearing En Banc Denied October 22, 2004.

Appeal from the United States District Court for the Northern District of California, James Ware, J Barbara C. McCurdy, Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P., of Washington, DC, argued for plaintiff-appellee. With her on the brief were Herbert H. Mintz and Kathleen A. Daley.

Dianne B. Elderkin, Woodcock Washburn LLP, of Philadelphia, PA, argued for defendant-appellant. With her on the brief were Joseph Lucci, Lynn A. Malinoski and Steven D. Maslowski.

Before RADER, DYK, and PROST, Circuit Judges.

RADER, Circuit Judge.

The United States District Court for the Northern District of California held that Home Diagnostics, Inc.'s (HDI's) Prestige blood glucose meters do not infringe LifeScan, Inc.'s (LifeScan's) patent on the use of reflectance to measure analyte concentration in a colored biological fluid. Home Diagnostics, Inc. v. LifeScan, Inc., No. 5:01-cv-20725-JW (N.D.Cal. Oct. 2 2002) (Claim Construction Order); Diagnostics, Inc. v. LifeScan, Inc., No. C 01-20725 JW (PVT)(ADR) (N.D.Cal. Apr. 14, 2003) (Order Entering Judgment). Because the district court did not give the claim language its full scope and customary meaning, this court reverses the district court's claim construction order, vacates the order entering judgment, and remands for determination of validity and infringement.

I.

LifeScan's U.S. Patent No. 6,268,162 (the '162 patent) claims a method for determining the concentration of an analyte in colored biological fluids. '162 patent, col. 1, ll. 31-35. Thus, the claimed invention detects the concentration of glucose in whole blood, an important measure for diabetics. This technology facilitates both medical diagnosis and treatment of conditions where less than a microgram per deciliter of an analyte has clinical significance. Id. at col. 1, ll. 37-39.

Claim 4 of the '162 patent claims a method of measuring glucose concentration in whole blood with a reflectance-reading device. The prior art teaches a minimally automated process that requires the user to place a drop of blood on a test strip, simultaneously start a timer, wait a specified period of time, and then blot the test strip to remove excess blood. Finally the prior art requires the patient to stop the reaction between the glucose in the blood and the chemicals on the test strip. These somewhat complex steps can cause measurement inaccuracies that could result in improper treatment. The claimed invention relieves the patient of timing the operation while blotting excess blood. Claim 4 of the '162 patent recites:

A method for measuring glucose concentration in a sample of whole blood using a reflectance-reading device which comprises the steps of:

(a) providing a test strip for placement in the reflectance reading device, the test strip having a matrix pad with a sample receiving surface and a testing surface opposite the sample-receiving surface, which matrix pad further comprises a reagent for reacting with the glucose in the blood sample and creating a change in reflectance at the testing surface indicative of the glucose concentration in the sample;

(b) applying a sample of whole blood to the sample-receiving surface and allowing at least a portion of the sample to travel to the testing surface and react with the reagent;

(c) taking a sequence of reflectance readings from the testing surface of said matrix at specified time intervals upon detecting a predetermined drop in reflectance sufficient to indicate that said sample has reached said first surface; and

(d) upon detection of a suitably stable endpoint, calculating said glucose concentration in said sample from one of said reflectance readings, without having determined the time at which the sample was initially applied to the matrix pad.

Id. at col. 22, l. 59—col. 23, l.18 (emphases added).

HDI initiated this suit by seeking a declaratory judgment that its Prestige blood glucose meters do not infringe the '162 patent either directly or under the doctrine of equivalents. LifeScan filed a counterclaim for infringement. The parties dispute the meaning of four claim terms, but the issue central to these disputes focuses on the meaning of "upon detection of a suitably stable endpoint." LifeScan construes this claim language to mean, "when the stated reaction between glucose in the blood sample and reagents in the test strip is sufficiently complete that the glucose concentration of the sample can be calculated `accurately,' i.e., without an error of clinical significance." HDI construes the same language as, "at the expiration of a predetermined time period."

After a Markman hearing, the district court interpreted claim 4 as limited to predetermined timing methods. In accordance with this understanding, the trial court construed "suitably stable endpoint" to mean "at the expiration of a predetermined time period." This claim construction effectively precluded LifeScan from seeking infringement of its '162 patent because HDI's accused infringing device does not use a predetermined timing methodology. Instead, the accused infringing device uses a rate methodology that monitors the rate at which the chemical reaction between glucose from the sample and the reagent occurs. Under the rate methodology, an endpoint is reached when the rate at which the chemical reaction is occurring falls below a certain level. In an effort to facilitate this appeal, LifeScan stipulated that it could not prove infringement given the trial court's claim construction. Accordingly, the district court entered a judgment of noninfringement for HDI and dismissed LifeScan's infringement counterclaim. The district court's order was rendered final under Federal Rule of Civil Procedure 54(b). Given this sequence of events, the procedural posture of this appeal is analogous to an appeal of summary judgment. That is, if the claim construction is in error, this court will vacate the judgment and remand the case for disposition on the merits.

LifeScan timely appeals. This court has jurisdiction under 28 U.S.C. § 1295(a)(1).

II.

This court reviews claim construction without deference. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed.Cir.1998) (en banc). LifeScan's appeal focuses solely on claim construction. At the center of the debate between the two parties is the claimed method of stopping the measurement period, step (d) of claim 4 of the '162 patent. LifeScan argues the district court erred by overlooking the accepted contextual meaning of the claim term and limiting claim 4 to a preferred embodiment which utilizes a predetermined timing method to determine the end of the measurement period. HDI argues that LifeScan has clearly disavowed claim scope by disclosing only predetermined timing methods.

As always, the claim language itself governs the meaning of the claim. Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed.Cir.1996). This court construes the meaning of claim language according to its usage and context. ResQNet.com, Inc. v. Lansa, Inc., 346 F.3d 1374, 1378 (Fed.Cir.2003). The touchstone for discerning the usage of claim language is the understanding of those terms among artisans of ordinary skill in the relevant art at the time of invention. See Rexnord Corp. v. Laitram Corp., 274 F.3d 1336, 1342 (Fed.Cir.2001). Indeed, normal rules of usage create a "heavy presumption" that claim terms carry their accustomed meaning in the relevant community at the relevant time. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366 (Fed.Cir.2002) (citing Johnson Worldwide Assocs., Inc. v. Zebco Corp., 175 F.3d 985, 989 (Fed.Cir.1999)). The patent applicant may also define a claim term in the specification "in a manner inconsistent with its ordinary meaning." Boehringer Ingelheim Vetmedica, Inc. v. Schering-Plough Corp., 320 F.3d 1339, 1347 (Fed.Cir.2003) (citing Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313 at 1325-26 (Fed.Cir.2002)). In other words, a patent applicant may define a term differently from its general usage in the relevant community, and thus expand or limit the scope of the term in the context of the patent claims. Id.

Another tool to supply proper context for claim construction is the prosecution history. As in the case of the specification, a patent applicant may define a term in prosecuting a patent. CCS Fitness, 288 F.3d at 1366 (a "claim term will not receive its ordinary meaning if the patentee acted as his own lexicographer and clearly set forth a definition of the disputed claim term" in the specification or prosecution history). This court also acknowledges the relevance of extrinsic evidence, often presented in the form of expert testimony. Vitronics, 90 F.3d at 1585; Pitney Bowes, Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1309 (Fed.Cir.1999) ("[C]onsultation of extrinsic evidence is particularly appropriate to ensure that [the court's] understanding of the technical aspects of the patent is not entirely at variance with the understanding of one skilled in the art."). Other useful references for construing disputed terms include dictionary definitions and treatises. See, e.g., Tex. Digital Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193, 1202 (Fed.Cir.2002) ("[D]ictionaries, encyclopedias and treatises are particularly useful resources to assist the court in determining the ordinary and customary meanings of claim terms.").

As noted before, these claim construction aids inform the court's task of ascertaining the meaning of the claim terms to one of ordinary skill in the art at the time of invention. Moba v. Diamond Automation, Inc., 325 F.3d 1306, 1315 (Fed.Cir.2003) ("Moreover, as this court has repeatedly counseled, the best indicator of claim meaning is its usage in context as understood by...