Last Week in the Federal Circuit (November 1-5): Killing Bacteria with Light – An Unexpected Result?

Last week saw recently confirmed Judge Cunningham sitting for her first oral arguments (alongside her former boss, Judge Dyk). But we’ll have to wait a bit longer for her first authored opinion. Below we provide our usual weekly statistics and our case of the week—our highly subjective selection based on whatever case piqued our interest.

Precedential opinions: 3

Non-precedential opinions: 4

Rule 36: 6

Longest pending case from argument: University of Strathclyde v. Clear-Vu Lighting LLC, No. 20-2243 (185 days)

Shortest (non-Rule 36) pending case from argument: Kent International, Inc. v. United States, No. 21-1065 (63 days)

Case of the week: University of Strathclyde v. Clear-Vu Lighting LLC, No. 20-2243

Panel: Judges Reyna, Clevenger, and Stoll, with Judge Stoll writing the opinion.

You should read this case if: you have a matter involving obviousness of a claim that requires a particular result.

35 U.S.C. § 103 (pre-AIA) contains the familiar prohibition against granting patent claims “if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.” To prove that a claim would have been obvious, one must generally show (1) that all the claimed limitations are disclosed in the prior art and (2) that a person of ordinary skill in the art would have been motivated to combine or modify the teachings in the prior art and would have had a reasonable expectation of success in doing so.

The patent in our case of the week claimed methods for inactivating certain bacteria by exposing them to light at specific wavelengths without using a photosensitizer. Clear-Vu Lighting LLC challenged the claims by petitioning the Patent Trial and Appeal Board for inter partes review. The Board instituted review and issued a final written decision finding that the challenged claims were unpatentable for obviousness. Strathclyde appealed, and the Federal Circuit reversed.

In the first part of its two-part analysis, the Court held that the Board’s finding that the prior art disclosed all the claimed limitations was not supported by substantial evidence. The Court focused on the Board’s analysis of a combination of two prior art references. One reference discussed using light to inactivate bacteria but disclosed only bacteria grown in the presence of a photosensitizer. Another reference disclosed illuminating bacteria without a photosensitizer but reported that the illumination failed to inactivate any of the bacteria. The Court explained that the combination of these references failed to teach inactivation of bacteria without using a photosensitizer, as the claimed methods required.

In the second part of its analysis, the Court held that the Board lacked substantial evidence to find that a person of skill in the art would have had a reasonable expectation of success in combining those same references to arrive at the claimed invention. The Court faulted the Board for relying on one reference’s statement that certain wavelengths of light “may” inactivate certain bacteria. The Court held that “where the prior art evidences only failures to achieve that at which the inventors succeeded, no reasonable fact finder could find an expectation of success based on that teachings of that same prior art.” Here, because the references disclosed only a failure to inactivate bacteria in the absence of a photosensitizer, a skilled artisan would not have reasonably expected the opposite result; a mere prophetic statement about the contrary possibility was insufficient to support a different conclusion.