Legal professionals worldwide may have grown accustomed to the Federal Circuit’s claim construction gospel as set forth in Phillips over the last two decades. This doctrine traditionally posits the intrinsic evidence – such as claims, specification, and the prosecution history – as the key determiner often “dispositive” and is “the single best guide to the meaning of a disputed term”. The recent case involving a disputed patent term, however, has rekindled the debate around the role of extrinsic evidence in interpreting patents.
The case, Axinn, Veltrop & Harkrider LLP, involves the construction of the phrase “a pH of 13 or higher”. Despite the seemingly definitive numerical value, the interpretation of this phrase resulted in a legal conundrum, leading some to question the efficacy of the traditional claim construction gospel.
While the intrinsic evidence remains the primary basis for patent disputes, this case illustrates that extrinsic evidence may play a more significant role in interpreting disputes over technical terms than previously assumed. The decision in Axinn heralds a possible turning point in how courts may view the balance between intrinsic and extrinsic evidence in future patent litigation. The consideration of scientific definitions and expert testimonies adds another layer to the interpretive exercise that could potentially bring more precision to technical patent disputes.
This case offers a case study for how extrinsic evidence can impact claim construction and the potential pitfalls of relying solely on intrinsic evidence. For lawyers specializing in patent law, the outcome of this case could signal an increased need to prepare for the introduction of external sources and expert testimony when litigating technical terms.
To get a detailed understanding of the case and all its implications, it’s worth looking at the specifics discussed in this JDSupra article.