Smithkline Diagnostics, Inc. v. Helena Laboratories Corp.

• Decision Date: 12 October 1988
• Docket Number: 87-1533,Nos. 87-1532,s. 87-1532
• Citation: 859 F.2d 878,8 USPQ2d 1468
• Parties: SMITHKLINE DIAGNOSTICS, INC., Plaintiff-Appellant, v. HELENA LABORATORIES CORPORATION, Defendant/Cross-Appellant. Appeal
• Court: U.S. Court of Appeals — Federal Circuit

Page 878

859 F.2d 878

8 U.S.P.Q.2d 1468

SMITHKLINE DIAGNOSTICS, INC., Plaintiff-Appellant, v. HELENA LABORATORIES CORPORATION, Defendant/Cross-Appellant.

Appeal Nos. 87-1532, 87-1533.

United States Court of Appeals Federal Circuit.

Oct. 12, 1988.

Suggestion for Rehearing In Banc Declined Jan. 19, 1989.

Donald Dunner, Finnegan, Henderson, Farabow, Garrett and Dunner, Washington, D.C., argued for plaintiff-appellant. With him on the brief was Allen M. Sokal. Also on the brief were Alan D. Lourie and Stuart R. Suter, Philadelphia, Pa., of counsel.

Jerald I. Schneider, Spencer & Frank, Washington, D.C., argued for defendant/cross-appellant. With him on the brief was Charles R. Rutherford, Cullen, Sloman, Cantor, Grauer, Scott & Rutherford, Detroit, Mich.

Before RICH and NIES, Circuit Judges, and NICHOLS, Senior Circuit Judge.

NIES, Circuit Judge.

SmithKline Diagnostics, Inc. (SKD) appeals the final judgment of the United States District Court for the Eastern District of Texas, SmithKline Diagnostics, Inc. v. Helena Laboratories Corp., 662 F.Supp. 622 (E.D.Tex.1987), holding United States Patent No. 4,365,970 ('970) valid as between the parties but not infringed by either of two accused products of Helena Laboratories Corp. Based on its holding of noninfringement, the court dismissed SKD's complaint. SKD appeals the findings of noninfringement. In a cross appeal, Helena asserts that if the judgment of noninfringement is not affirmed, this court should reverse the judgment that the asserted claims are not invalid for obviousness. Helena also asserts error in that the court did not uphold other pleaded defenses or its counterclaim for unfair competition, matters on which the court made no explicit findings or conclusions.

We affirm the judgment of validity, but on different grounds from those stated by the district court. On the issue of infringement, we affirm the finding that Helena's product containing lead acetate does not infringe the asserted claims but reverse with respect to Helena's product containing hemoglobin. Helena has failed to persuade us that the record shows triable issues on the other matters raised in its cross appeal. Thus, we affirm-in-part on modified grounds, reverse-in-part, and remand for calculation of damages.

I BACKGROUND

SKD owns the '970 patent, issued to two of its employees, Dr. Paul Lawrence and Charles Townsley, on December 28, 1982. The patent covers a specimen test slide and method for detecting occult (hidden or invisible) blood in fecal matter, an early symptom of a variety of gastroenterological diseases including colorectal cancer. More specifically, the test slide contains a piece of paper impregnated with a colorless compound, guaiac, which turns blue in the presence of a developing solution, such as hydrogen peroxide, and a catalyst, such as hemoglobin in the blood. Thus, a blue color indicates blood is present, a "positive" result; the absence of blue, a "negative" result, indicates the absence of blood. In practice, a patient places fecal samples on each of several designated test areas on the slide and returns the slide to his physician or a laboratory for testing. To test, a developing solution is placed on the test areas, and the areas are observed for color. This much of the subject invention is in the prior art. See United States Patent No. 3,996,006 (issued to Pagano on Dec. 7, 1976).

It is important to verify that the guaiac paper and developing solution are working properly. If either the paper or solution has lost effectiveness, a false negative result may occur, failing to detect the presence of existent cancer. Conversely, if the paper or solution becomes contaminated, a false positive test may occur, causing patient anxiety and unnecessary clinical investigations. To ensure accuracy, separate materials (external controls) were sold which could be used to check that the paper and solution were actually working. The parties dispute whether external controls consisted only of a representative unused slide from a batch of slides or also included a slide having three test areas with only one area being used for the fecal smear, the others for testing performance of the product. There is no dispute, however, that in either case the control was not built into the slide.

The invention of the '970 patent improves on the Pagano test slide and separate verification controls by providing built-in positive and negative monitors separate from the test areas. The positive monitor contains (i.e., is printed with) a catalyst, which must be a compound that reacts to environmental conditions in a manner similar to hemoglobin. The negative monitor lacks the catalyst; thus, it consists of the guaiac-laden paper alone. In practice, developing solution is added to the two monitors after it is applied to the fecal test areas. A blue color on the positive monitor indicates that the paper and solution are working. The absence of blue on the negative monitor assures that the slide has avoided contamination.

SKD asserts that independent device claim 1, claims 2 and 4 which depend from claim 1, and independent method claim 5 of the '970 patent are infringed. ¹ Claims 1 and 5, the only independent claims asserted, both contain the limitation that the catalyst of the positive monitor is "a compound that reacts to environmental conditions in a manner similar to hemoglobin." Whether that claim limitation, as properly interpreted, excludes hemoglobin itself is critical, as we shall see, to the issues of validity and infringement.

When the '970 patent issued in December of 1982, SKD was marketing a slide, under the trademark HEMOCCULT, which contained hemin as the catalyst. At that time, Helena had competitive slide products on the market, sold under its COLOSCREEN mark, which used hemoglobin as the catalyst in a positive test monitor. Later, in April of 1984, Helena changed to use of lead acetate rather than hemoglobin as the positive monitor's catalyst. Until November 1985, however, Helena continued to enclose literature in its slide packages stating that the positive monitor contained hemoglobin.

SKD asserted infringement of the '970 claims, both literally and under the doctrine of equivalents, by the Helena products containing hemoglobin. With respect to Helena's lead acetate product, SKD asserted that Helena should be estopped to deny that its product contains hemoglobin because it continued to indicate that the product contained hemoglobin after the change was made to lead acetate. SKD did not assert that the lead acetate product would be covered by the claims but for the misrepresentation.

Helena contended that its products containing hemoglobin do not infringe because the claim language "similar to hemoglobin" literally excludes hemoglobin itself, and that the prosecution history precludes interpreting the claim to cover a hemoglobin product. Helena also asserted that the '970 claims in issue are invalid as obvious within the meaning of 35 U.S.C. Sec. 103 (1982), and invalid under 35 U.S.C. Sec. 116 (1982) for failure to name the proper inventors. In addition, Helena asserted the defense of inequitable conduct and raised an unfair competition counterclaim.

The district court interpreted the claim limitation at issue as excluding hemoglobin itself. Based upon that interpretation, the court found the invention of the '970 patent nonobvious. Had the claims covered hemoglobin, however, the court stated that the claim would have been invalid as obvious over prior art disclosing hemoglobin as a catalyst in positive test monitors.

Under its interpretation of the claim limitation "similar to hemoglobin" recited in claims 1 and 5, the court found Helena's hemoglobin-containing slides noninfringing, either literally or under the doctrine of equivalents. It rejected SKD's estoppel argument with respect to Helena's products containing lead acetate. It further held that, if Helena were found to infringe, the infringement was not willful, an issue not appealed.

Neither in its judgment nor in its findings of fact and conclusions of law did the district court mention Helena's other defenses or its counterclaim for unfair competition. Both parties have appealed, each asserting error in certain findings and conclusions made adverse to them, and each raising various arguments concerning issues not explicitly ruled on by the court.

II

OPINION

A. Claim Interpretation

The claims of the '970 patent measure the invention at issue; thus, the claims must be interpreted and given the same meaning for purposes of both validity and infringement analyses. See, e.g., SRI Int'l v. Matsushita Elec. Corp. of Am., 775 F.2d 1107, 1121, 227 USPQ 577, 585 (Fed.Cir.1985) (in banc). To ascertain the meaning of the claims, we look to the claim language, the specification, and the prosecution history. ZMI Corp. v. Cardiac Resuscitator Corp., 844 F.2d 1576, 1579, 6 USPQ2d 1557, 1560 (Fed.Cir.1988); Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 867, 228 USPQ 90, 93 (Fed.Cir.1985). Also relevant are the other claims and expert testimony. See, e.g., Perini America, Inc. v. Paper Converting Mach. Co., 832 F.2d 581, 584, 4 USPQ2d 1621, 1624 (Fed.Cir.1987). Moreover, the claims should be construed as one skilled in the art would construe them. Specialty Composites v. Cabot Corp., 845 F.2d 981, 986, 6 USPQ2d 1601, 1604 (Fed.Cir.1988).

This court reviews a district court's claim interpretation as a matter of law, unbridled by the constraints of the "clearly erroneous" standard of review. That interpretation may depend, as here, however, on evidentiary material which requires resolution of factual issues, such as what occurred during the prosecution history. See, e.g., ZMI Corp., 844 F.2d at 1578, 6 UPSQ2d at 1559; Uniroyal, Inc. v. Rudkin-Wiley Corp., 837 F.2d 1044, 1054, 5 USPQ2d 1434, 1441 (Fed.Cir.1988); Tandon Corp. v. United States Int'l Trade Comm'n, 831 F.2d 1017, 1021, 4 USPQ2d 1283, 1286 (Fed.Cir.1...