Background
Metrom Rail, LLC owned two patents related to collision-avoidance systems for railroads using ultra-wideband sensing and global positioning systems. Siemens Mobility, Inc. and other cross-appellants petitioned for inter partes review of both patents, arguing all claims were unpatentable as obvious. The Patent Trial and Appeal Board determined that most claims were unpatentable but found claims seventeen through twenty of the first patent were not unpatentable. Metrom appealed the unpatentability findings, and the cross-appellants cross-appealed the finding that claims seventeen through twenty were valid.
The court’s reasoning
The court reviewed the obviousness determination de novo for legal conclusions and for substantial evidence for factual findings. Regarding the main appeal, the court affirmed that the Board properly rejected Metrom’s secondary considerations of nonobviousness due to a lack of nexus and found that the claims were obvious over prior art references Grisham, Douglas, and Nixon. Regarding the cross-appeal, the court reversed the Board’s decision on claims seventeen through twenty. The court concluded the Board erred by construing the term data representing the separation distance to mean only the computed distance rather than the data used to calculate the distance via time-of-flight techniques. The court found that Grisham disclosed transmitting data used in the time-of-flight technique over the air, which satisfied the claim limitation.
The dissent
What it means going forward
The decision clarifies that data used in a time-of-flight calculation to determine separation distance satisfies claim limitations requiring data representing separation distance to be sent over the air. It reinforces the requirement that parties must preserve specific claim construction arguments before the Patent Trial and Appeal Board to avoid forfeiture on appeal.