The Federal Court of Appeal has dismissed Nova's appeal of an earlier finding that it had infringed Dow's patent relating to polyethylene used to make film products (2014 FC 844).
The Court of Appeal characterized the appeal as concerning disagreements with the Judge's factual findings and assessment of the expert evidence. The Court of Appeal found the Judge did not err in law.
Nova had alleged the Judge erred in not finding: a promise of synergistic utility; that the invention was obvious; and that the claims were broader than the invention claimed or disclosed. Further errors relating to construction and infringement were also alleged.
The Court of Appeal described the standard of review on construction to be a matter of law, but since construction of a patent is heavily dependent on the evidence given by persons skilled in the art, that evidence will bear heavily on the judge's findings. Thus, the Court of Appeal found that "trial judges are nevertheless entitled to some leeway as they are often in a much better position than appellate judges to understand the intricacies of the art underlying the invention disclosed in a patent."
The Court of Appeal also found the Judge's approach to the promise of the patent to be broadly consistent with the most recent jurisprudence. That approach held that first, one must look for the elevated promise or claimed utility in the claims of the patent. Second, consider any statement found elsewhere in the disclosure, which should be taken as "mere statement of advantage" unless the inventor "clearly and unequivocally" states that it is part of the promised utility of the invention.
On this basis, the Judge did not find an explicit promise of a specific result. There was no finding of a statement of utility in the claims, and only one reference elsewhere to support an argument of enhanced utility. The Court of Appeal was also wary of using a stray phrase on page 1 of the patent to define the promise of the patent.
Ultimately, the Court of Appeal agreed that the Judge could find that the inventors did not make an explicit promise of a specific result, and that the patent did meet the test of a "mere scintilla" of utility.
The remaining points of appeal were dismissed, with the Court of Appeal holding that the findings of fact were open to the Judge to make, and there was no palpable and overriding error sufficient to overturn the decision.