Wasica Decision Reinforces Federal Circuit Guidance on Claim Construction

The Federal Circuit’s recent decision in Wasica Finance v. Continental Automotive Systems touched on a number of well-worn patent issues, but this article focuses on a few key claim construction principles discussed by the CAFC, including that the contents of the specification are highly relevant when performing claim construction, and a claim generally will not be construed in a manner that renders recited terms meaningless or superfluous.

Wasica is the result of the CAFC consolidating two appeals based on two IPRs arising from petitions filed with respect to Patent Owner’s U.S. Patent No. 5,602,524 (“the ‘524 patent”). The claims at issue were directed, generally, to a system for measuring tire pressure. In the system, each tire included a pressure measuring device and a transmitter, and each transmitter transmitted pressure data to a corresponding receiver. A transmission from a transmitter to a corresponding receiver also included an “identification signal” for identifying the transmitter that sent the transmission. A receiver receiving the identification signal stored the identification signal and processed transmissions only from the corresponding transmitter.

As to the first claim construction issue, Patent Owner argued that the PTAB erred in determining that a particular pressure sensor disclosed by the prior art taught a “pressure measuring device” because the pressure sensor only output a binary signal that indicated whether a measured pressure is abnormal. Patent Owner argued that the recited pressure measuring device, when properly construed, must output a tire’s pressure as a numerical value, and that such a numerical value cannot be represented by a single bit of a binary signal. The CAFC sided with the PTAB and rejected the claim construction presented by Patent Owner. The CAFC relied, in part, on the ‘524 patent, itself, which identifies a family of European patents as including examples of manners in which a sensor of the ‘524 patent may output a pressure signal. The CAFC decided that the family of European patents identified by the ‘524 patent disclose switch-based (e.g., binary) pressure sensors and non-numeric pressure signals. The CAFC pointed out that, in accordance with previous decisions, the CAFC generally does not interpret claim terms in a manner that excludes examples disclosed in the specification. Id. at 13.

As to the second claim construction issue, Petitioners argued that the proper claim construction for the term “bit sequence,” from claim 9, was a sequence of “one or more bits.” Patent Owner argued that the plain meaning of “sequence” implies at least two elements. The PTAB agreed with Patent Owner, but on appeal, the CAFC disagreed. The CAFC explained that the recited element required “at least a 4 bit sequence” which included 4 constituent bit sequences, and thus, interpreting a “sequence” as requiring at least two bits would result in a minimum size of 8 bits for the “at least 4 bit sequence.” The CAFC determined that such an interpretation would essentially rewrite “at least 4 bits” from claim 9 to “at least 8 bits.” The CAFC explained that it is highly disfavored to construe terms in a way that renders them void, meaningless, or superfluous. Id. at 28. As further support for reversing the PTAB’s decision regarding the patentability of claim 9, the CAFC pointed to a portion of the ‘524 patent interpreted by the CAFC as disclosing an embodiment in which a bit sequence included a single bit, thereby contradicting the at-least-two-bit interpretation of “bit sequence” sought by Wasica Finance.

In the end, the Patent Owner and Petitioner both took home partial victories, while the rest of us take home additional insight into the Court’s construction of claim limitations.