Over the past year, the USPTO seems to have raised the patentability bar to some degree.  Since 2013, we have perceived that applicants are increasingly required to defend their applications against examiners rejecting patent claims as “indefinite,” that is, the applicant has not presented claims “particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention” as required under the U.S. patent law. See 35 USC 112, second paragraph (“Section 112”).

This increased scrutiny of  applicants’ compliance with Section 112 patentability requirements may be a direct result of the Obama Administration’s desire to “combat patent trolls” at the Agency level.  Unlike USPTO office actions in the past, applicants claims are now routinely rejected as indefinite whenever claimed structure is even arguably only limited by a recited function, as opposed to a description of the actual structure for performing the function. Office actions issuing the rejection often present the applicant with two options: either the claim will be construed as a “means plus function claim” under Section 112, sixth paragraph, or the claim is un-patentable as indefinite.

Meanwhile, in the litigation context, the Federal Circuit’s precedent for interpreting indefiniteness under Section 112 is under review. In December the Supreme Court granted certiorari in Nautilus, Inc. v. Biosig Instruments, Inc., 2014 U.S. LEXIS 18 (U.S., Jan. 10, 2014). The case involves a dispute over whether a claim reciting a “spaced relationship” between electrodes satisfies Section 112 requirements. Applying its “insolubly ambiguous” test for definiteness, the Federal Circuit upheld the validity of the claim under Section 112, in part relying on functional claim language that provided “inherent parameters sufficient . . . to understand the bounds of ‘spaced relationship.’” Petitioners contend that the “insolubly ambiguous” standard does not properly reflect the statutory intent behind Section 112 because it disproportionately favors patentee rights over the public’s right to fair notice of what is covered under the patent.

It remains to be seen whether an increase in Section 112 rejections at the USPTO and/or the pending challenge to Section 112 legal precedent in Nautilus will have any profound impact on the use of functional language in patent claims. Nevertheless, given the potential outcome of patent invalidity for “indefiniteness,” patent practitioners should practice more vigilance to ensure patent disclosures avoid ambiguity whenever functional language is needed in claims.