The Patent Trial and Appeal Board (PTAB) denied institution of inter partes review (IPR) after determining that the challenged claims were indefinite and that therefore the Board could not apply the prior art to them. American Honda Motor Company, Inc. v. Signal IP, Inc., IPR2015-01003 (PTAB, Oct. 1, 2015) (Petravick, APJ).

The petitioner filed a petition requesting inter partes review of claims 1 and 7 of a Signal IP patent. Before considering the alleged basis for invalidity, the Board addressed construction of the claims (claims that had already been found to be indefinite by a district court in companion infringement litigation). The challenged claims, directed to a method of airbag control in a vehicle, require a vehicle passenger seat having an array of pressure (force) sensors on the passenger seat coupled to a controller for determining whether to allow airbag deployment based on sensed force and force distribution.  The last three steps in the claimed method include determining the existence of a local pressure area when the calculated total force is concentrated in one of the seat areas, calculating a local force as the sum of forces sensed by each sensor located in the seat area in which the total force is concentrated, and allowing deployment if the local force is greater than a predefined seat area threshold force.

During claim construction, the analysis turned on the meaning of the term “concentrated,” the same term found indefinite by the district court. The Board categorized the term as one of degree but not inherently indefinite. The Board noted however, that the use of such a term requires the patent to provide some standard for measuring that degree. Using the plain and ordinary meaning, the construction proposed by the patent owner, coupled with disclosure in the specification, the Board found that the specification failed to provide objective boundaries for determining what percentages of total force would or would not be considered to be “concentrated.” Based upon its finding of indefiniteness, the Board declined to consider the prior art, noting that when a claim’s meaning is indefinite, any rejection based on prior art is improperly based on speculation.

Practice Note: While an IPR petitioner cannot rely on an indefiniteness challenge, PTAB panels routinely address claim construction prior to applying prior art to the challenged claims. This necessarily involves some consideration of 35 USC §112. While, in the context of an IPR, the Board cannot invalidate claims for indefiniteness, it can use such a determination as a basis for non-institution.

Since PTAB decisions on institution are not appealable, both patent owners and petitioners should carefully consider how a finding of indefiniteness might impact their position in a dispute. In cases where claim indefiniteness is a concern, a patent owner may consider including in its preliminary response a more robust discussion regarding claim construction, or filing a reissue application to clarify claim scope. Petitioners should consider the ramification of a potential finding of indefiniteness, which could result in a non-institution decision (as opposed to cancellation of claim) albeit under a shadow of a PTAB finding of indefiniteness (a finding that is neither dicta nor binding in a district court).