Ambiguity Squared: U.S. Supreme Court finds test for Determining Patent Claim Invalidity Based on Claim Ambiguity, Ambiguous

Nautilus's uphill climb to avoid patent infringement may have gotten a bit easier yesterday in view of the U.S. Supreme Court's decision in Nautilus, Inc. v. Biosig Instruments, Inc.  The U.S. Supreme Court found that the test previously used to validate alleged infringement patent claims of Biosig, based on claim ambiguity, improper.  Ironically, the reason that the Supreme Court found the previous test for patent claim invalidity (based on claim ambiguity) improper was that the test, itself, was ambiguous.  The new test finds that a patent is invalid for indefiniteness if its claims, fail to inform, with "reasonable certainty", those skilled in the art about the scope of the invention.  This opens the door for Nautilus to (again) challenge the validity of the alleged infringed patent claims under this new test.  If successful, Nautilus can avoid patent infringement by invaliding the alleged infringed claims based on the patent claims being insufficiently clear (i.e.vague and indefinite under 35 U.S.C. §112, second paragraph).

Summary
In the patent suit at issue in this case, Biosig had accused Nautilus of infringing one of its patents.  Nautilus responded by asserting that the alleged infringed patent claims were insufficiently clear (e.g. vague and indefinite) and thus the alleged patent claims are invalid.  Although Nautilus was successful at the district court level in invalidity the patent claims, on appeal by Biosig, the Federal Circuit reversed the district court and found the patent claims were not indefinite and the claims were sufficiently clear based on a test which includes determining if the claims are "amenable to construction" or "insolubly ambiguous".  The U.S. Supreme Court found the Fed. Circuit's test improper.

The U.S. Supreme Court's rationale for finding the test improper was that the test "tolerates some ambiguous
claims but not others."  As a result, the Supreme Court determined that the prior test would find some patent claims valid even though there is uncertainty as to the exact meaning of the patent claims.  The Supreme Court said that this scenario is inconsistent with the statutory requirement that patent claims be sufficiently definitive to provide the public (including those skilled in the art) "reasonable  certainty" of the scope of the invention.  If not, the Court reasoned, the public would not have sufficient notice of the scope of a patent, and thus not have sufficient knowledge to avoid patent infringement.

Unlike prior Supreme Court patent cases, the Court announced a new test for determining patent claim definiteness.  The new test finds a "patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention."

Take Home Lesson
For patent practitioners, the take home lesson from this decision is to draft patent claims and patent specifications with sufficient disclosure to ensure patent claims are definitive and not ambiguous, so that the public, and in particular, those skilled in the art, will have "reasonable certainty" of the scope of the patent claims.  In order to satisfy a balance between intentionally having broad patent claims to cover many different embodiments, the use of dependent claims directed to specific embodiments may help ensure that at least some patent claims survive an indefiniteness challenge.  Further, including many different embodiments in the patent specification may provide the public with reasonable certainty of the scope of the patent claims.

Finally, announcing a test is a departure from some prior U.S. Supreme Court patent cases, e.g. Bilski v. Kappos.   Often the Supreme Court remands patent cases back to the Federal Circuit to develop a test based on its instructions in its opinion.  This may signal a change in the Court and may mean that the Court will be more active in establishing its own tests rather than relying on the Federal Circuit to develop tests, later confirmed or found invalid by the Supreme Court. Observers of the Supreme Court, including us here at OP-IP anxiously await the decision in the other U.S. Supreme Court intellectual property cases this term, including patent cases, such as Alice Corp. v. CLS Bank.

© Stephen J. Weyer 2014

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