Genuine Enabling Technology LLC v. Nintendo Co., Ltd., Appeal No. 2020-2167 (Fed. Cir. Apr. 1, 2022)

The Federal Circuit’s only precedential patent opinion this week turned on issues of claim construction.  In particular, the issue was the effect of statements made by the applicant during the patent’s prosecution.  The Court held that the district court erred in applying too narrow a construction, and reversed with a modified construction.

The patent at issue concerns the use of certain inputs into a computer, created as part of an invention of a “voice mouse.”  The patent claims “at least one input signal.”  During prosecution the examiner considered a reference (Yollin) that disclosed using various physiological responses, such as “a [Galvanic Skin Response or GSR] sensor, an electromyograph (muscle tension), electrocardiograph (heart activity), electroencephalograph (brain activity), thermometer (skin temperature), blood pressure sensor, and the like.”  In response, the inventor argued that Yollin failed to adequately teach the limitation.  Mr. Nguyen distinguished the “slow varying” physiological response signals discussed in Yollin from the “signals containing audio or higher frequencies” contemplated by his invention.

The patent issued, and Genuine sued Nintendo for infringement.  During claim construction, the parties differed as to the meaning of “input signal.”  Genuine proposed the construction, “a signal having an audio or higher frequency.”  Nintendo sought a construction involving signals that are more than 500Hz.  Buttressed by an expert’s opinion, Nintendo argued that many of the physiological signals in the Yollin reference involve signals up to at least 500Hz.  The district court granted Nintendo’s proposed construction, finding that the range below 500Hz was disclaimed as part of patent prosecution.  Notably, the audio range is widely considered to be 20Hz – 20,000Hz, thus including an overlap with the range Nintendo sought to exclude between 20Hz and 500Hz.  Based on its claim construction, the district court granted summary judgment of non-infringement to Nintendo.

The Federal Circuit disagreed, finding that the district court relied too heavily on an expert’s opinion as part of its claim construction analysis.  The Court held:

“Expert testimony, one type of extrinsic evidence, may be useful in claim construction ‘to provide background on the technology at issue, to explain how an invention works, to ensure that the court’s understanding of the technical aspects of the patent is consistent with that of a person of skill in the art, or to establish that a particular term in the patent or the prior art has a particular meaning in the pertinent field.’  However, expert testimony may not be used to diverge significantly from the intrinsic record . . . . Reliance on expert testimony regarding the claim interpretation is thus permissible where the testimony is ‘consistent with [the interpretation] required by the’ intrinsic evidence.”

The Court found that the only disavowal of claim scope was to signals below the audio frequency spectrum.  To the extent the inventor’s statements during prosecution may have implicated signals with frequencies above the audio range, this did not rise to the level of a clear and unmistakable disavowal.

Additionally, the Court held that the district court applied a threshold—500Hz—that was not part of the intrinsic record, based solely on extrinsic evidence—i.e., an expert’s opinion, which itself was based on other extrinsic sources.  The Court thus found that the district court “relied on extrinsic evidence upon extrinsic evidence to draw a bright line in claim scope not suggested anywhere in the intrinsic record.  Such evidence cannot properly overcome the clarity with which [the inventor] disavowed signals below the audio frequency spectrum.”

The Court remanded, holding that the proper construction of “input signal” is “a signal having an audio or higher frequency.”

The opinion can be found here.