The Federal Circuit recently denied Dow Chemical’s request for rehearing and rehearing en banc of Dow Chem. Co. v. Nova Chems. Corp. decided on August 28, 2015.1 The panel decision found that when multiple methods of measurement for a claimed parameter exist, a patentee must designate which method is being used. For a review of the court’s decision in the Dow Chem case, see our previous article here.

Although the Order gave no explanation for the denial, the opinion contained two concurrences and one dissent.

Chief Judge Prost, in a concurrence with Judges Dyk and Wallace joining, stated:

that clear and convincing evidence is the standard for patent invalidation; that the burden to establish indefiniteness rests with the accused infringer; that findings of fact by juries are entitled to deference; and that knowledge of someone skilled in the art may be pertinent to the indefiniteness question. In particular, we agree that if a skilled person would choose an established method of measurement, that may be sufficient to defeat a claim of indefiniteness, even if that method is not set forth in haec verba in the patent itself.

Judge Moore’s concurrence (with Judges Newman, O’Malley, and Taranto joining and Judge Chen joining in part) stated that the panel’s opinion in the case did not change any case law that has been created by the Supreme Court or the Federal Circuit. Judge Moore highlighted that extrinsic evidence can be relied upon to determine whether a patent’s specification is sufficiently definite, that fact finding made incident to the ultimate legal conclusion of indefiniteness receive deference on appeal, and the burden of proving indefiniteness lies ultimately with the party challenging validity. Judge Moore’s concurrence acknowledged that she “may disagree with and even find troubling” the panel’s resolution of the case, this alone was not a sufficient reason for en banc review.2

Judge O’Malley, in a dissent with whom Judge Reyna joined, theorized that the Dow Chem case should not have been heard by the Federal Circuit in the first instance as there was no jurisdiction under the Federal Rules of Civil Procedure. Judge O’Malley highlighted that the Federal Circuit had already affirmed the district court’s Rule 54(b) (partial final judgment) ruling on validity, infringement, and damages. She also noted that the only judgment appealed to the Federal Circuit in this instance pertained to a calculation of damages for infringement but not the indefiniteness issue itself. Therefore, Judge O’Malley asserted that the issue decided upon was not in the jurisdiction of the court.