Functional patent claim language not only justified an Examiner’s indefiniteness rejections under 35 USC § 112(b), but also justified a new ground of indefiniteness rejection in In re Xie, Ex parte Appeal 2017-000540, Application 12/774,138 (March 20, 2018). Why? Because the PTAB found sua sponte that the applicant had not overcome the weakened presumption of Williamson v. Citrix Online, LLC (Fed. Cir. 2015), that functional claim language is not subject to the means-plus-function strictures of 35 USC § 112(f) (or, this being a pre-AIA case, § 112, 6th paragraph).
The entire lengthy representative claim 1 is reproduced below – focus on the emphasized portions, the emphases being highlighted by the PTAB as “key limitations:”
A system comprising:
an assay test strip including a test portion and an encoder portion, the test portion including at least one analyte reaction section, the encoder portion including a plurality of optically detectable markings each at one of a plurality of known positions;
an assay test strip reader comprising a body sized to receive the assay test strip;
at least one detector fixedly connected to the body, the at least one detector positioned within the body such that an inserting of the assay test strip or a removing of the assay test strip by an operator, which results in movement of the assay test strip with respect to the body and the at least one detector, causes the at least one detector to detect signals based on different points on the assay test strip, the at least one detector configured to detect an encoder optical signal indicative of the position of the assay test strip within the body and to detect an analyte optical signal indicative of a reaction of at least one analyte;
at least one light source associated with the at least one detector, the at least one light source configured to illuminate at least a portion of the assay test strip adjacent to the at least one detector; and
control electronics coupled to the at least one detector, the control electronics configured to:
receive analyte optical signals and encoder optical signals from the at least one detector,
determine, using the encoder optical signals, the relative position of the assay test strip with respect to the detector at a given point in time, even when a first portion of the assay test strip is moved more quickly or more slowly than a second portion of the assay test strip,
construct, using the analyte optical signals and the relative position of the assay test strip with respect to the detector at the given points in time, a representation of the spacing of detected analyte reaction regions, regardless of the speed with which the assay test strip is moved through the reader by the operator, and
generate at least one result signal based on the representation.
As seen in the Examiner’s Answer, the Examiner had rejected claim 1 under Section 112, second paragraph, alleging that the claim “recites functional language, which is indefinite regarding the structure of the test strip system.” The examiner explained that the claim was “not clear” regarding “what structurally does it mean that the detector is positioned within the body such that an inserting of the assay strip or removing [it] will cause a detector to detect signals based on different points.”
Analyzing the recitation in claim one of "control electronics configured to: receive ... , determine ... , construct ... , and generate ...,” the PTAB entered a new ground of rejection under 35 USC § 112, 2nd paragraph, based on Aristocrat Techs. Australia Pty Ltd. v. Intern. Game Tech., 521 F.3d 1328 (Fed. Cir. 2008) and Williamson. The presumption that the language of claim 1 was “not a means-plus-function limitation” was overcome because the claims recited control electronics performing a function “without reciting sufficient structure for performing that function.” The PTAB explained that control electronics by themselves require means for accomplishing “recited functions, and “the term ‘a control electronics configured to’ seems little more than a synonym for ‘taking control electronics comprising means for.’”
Further, the specification did not disclose structure corresponding to the recited means, as required by Aristocrat. There was no algorithm disclosed for determining the relative position of a portion of a test strip, or for “constructing the analyte signal ‘regardless of the speed with which the assay test strip is moved through the reader by the operator.’”
Making the applicant’s life even worse, the PTAB also affirmed rejections under 35 U.S.C. § 112, 1st paragraph, for lack of written description because “limitations that are indefinite for the reasons explained in the new ground above also indicate” an insufficient disclosure. Prior art rejections under 35 USC §§ 102, 103 were reversed “pro forma” because “any consideration of the merits of the outstanding rejections would be improperly based on speculative assumptions as to the scope of the claims.”
Lessons for Practice
When drafting any patent claim that has a whiff of functionality about it, consider how well your specification will stand up to support the claim if the claim’s functional language is construed as a means-plus-function limitation under Section 112(f). This is not to say that functional claim language will always be interpreted under the means-plus-function rubric. It won’t be. But be as prepared as you can. One suspects that here the inventors would have thought that the functional recitations were well within the grasp of one skilled in the art. The succinct argument at page 34 of the applicant’s appeal brief (see above link) certainly seems to say that the applicant thought the claim was clear – and not indefinite – on its face. Perhaps so – but you never know when 112(f) will be invoked, and when it is, functional claim language requires not just understanding by one skilled in the art, but explicit support in the form of a physical or algorithmic structure, as an initial hurdle.