Does the Federal Circuit use the wrong standard for indefiniteness?

Nautilus Inc. says yes, according to its certiorari petition, seeking Supreme Court review. The Federal Circuit concluded that Biosig Instrument’s patent claims were sufficiently definite. Nautilus’s petition, along with the petition from amici Electronic Frontier Foundation and Public Knowledge, argue the Federal Circuit’s use of the “insolubly ambiguous” test for determining definiteness is nearly impossible to satisfy, leaving the public with no clear idea of how far the patent owner’s property rights extend. Biosig counters that both the district court and the Federal Circuit found the claims amenable to construction and that Nautilus is trying to create a conflict between the “insolubly ambiguous” test and prior Supreme Court precedent where none exists.

The requirement for definite patent claims is statutory, found in 35 U.S.C. § 112(b): “The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.” (emphasis added). The Federal Circuit has repeatedly held that a claim is indefinite only when “it is not amenable to construction or insolubly ambiguous,” most recently in an ANDA case involving Teva’s multiple sclerosis drug Copaxone. Teva Pharms. USA, Inc. v. Sandoz, Inc., 723 F.3d 1363, 1368 (Fed. Cir. 2013). There, the claim term at issue for one group of claims was “molecular weight.” The ANDA filers argued was “insolubly ambiguous” because “molecular weight” could mean any of three difference measures, Mp, Mw, and Mn, which produced three different numerical results. The Federal Circuit agreed, finding nothing in the specification or the prosecution history that would allow one of skill in the art to know which of the three measures the claim was using.

It remains to be seen whether the Supreme Court is interested in weighing in on the “insolubly ambiguous” test now, but history suggests it is unlikely. The Court was presented with a very similar challenge to the “insolubly ambiguous” test in 2010 by Applera Corp. v. Enzo Biochem, Inc. et. al., No. 10-426. In deciding whether to grant certiorari, the Supreme Court invited the Solicitor General to file an amicus brief to set forth the United States’ views. In that brief, the Solicitor General argued that there was no conflict justifying Supreme Court review between the “insolubly ambiguous” or “open to construction” and the requirements of 35 U.S.C. § 112 and the Court’s jurisprudence. Shortly after receiving the Solicitor General’s brief, the Supreme Court denied review. Applera Corp. v. Enzo Biochem, Inc., 131 S. Ct. 3020 (U.S. 2011).
One interesting point to note is that the phrase “insolubly ambiguous” did not actually appear in the Federal Circuit’s opinion in Applera, which distinguishes it from Nautilus. But we see no reason to think inclusion of this phrase alone would make the Supreme Court any more interested, especially given the United States’ view that this phrase is consistent with both the statute and prior Supreme Court jurisprudence.