What is certain, however, is that expert testimony and other forms of extrinsic evidence will take a back seat to intrinsic evidence in claims construction.
In Phillips, an en banc majority of the U.S. Court of Appeals for the Federal Circuit held July 12 that courts must construe patents by referring primarily to the claim and its prosecution history and only secondarily to extrinsic evidence such as dictionaries, treatises and expert testimony.
"Extrinsic evidence may be useful," the court said, "but it is unlikely to result in a reliable interpretation of patent claim scope unless considered in the context of the intrinsic evidence."
While the decision focused on the use of dictionaries as extrinsic evidence, it has clear implications for the role of expert testimony, lawyers say.
"The Federal Circuit underscored that the claim construction process includes determining the meaning of claims to persons of ordinary skill in the art to which the invention pertains," says Edward D. Manzo, a partner with the Chicago firm Cook, Alex, McFarron, Manzo, Cummings & Mehler.
"How judges arrive at that meaning is not the subject of any strict formula, and the court will allow the use of such extrinsic evidence as dictionaries and expert witnesses," notes Manzo, who filed an amicus brief in Phillips on behalf of The Intellectual Property Law Association of Chicago. "However, extrinsic evidence cannot change the plain import of the intrinsic documents – the patent and its file history."
Whether expert testimony is needed in a claim interpretation proceeding probably will depend on the specific patent at issue, Manzo says. "If the topic is rudimentary and within the ready comprehension of the ordinary jurist, then expert testimony may not be helpful to the court. However, cases definitely exist where the judge is completely unfamiliar with the technology, and reading the intrinsic documents may not be enough for the judge to arrive at a sound understanding. In such cases, experts should testify."
Back on Track
While Phillips will not exclude the use of experts, Anthony R. Zeuli, author of an amicus brief in Phillips on behalf of the Association of Patent Law Firms, believes it may call for them to take a different tack.
"What the court did with Phillips is to reaffirm what many trial and circuit judges had forgotten was the test for claim construction – the ordinary and customary meaning to one of skill in the art," say Zeuli, a partner with Merchant & Gould in Minneapolis. "We'd gotten off track with that, and thankfully the court brought that back."
This creates an important role for the expert, Zeuli believes, in helping the court understand what that ordinary and customary meaning would be to one skilled in the art.
"Don't have the expert do the court's job of construing the claim," he says. "Rather, have the expert take the pieces of information that the court will look at and say, 'Here is how this term is commonly used.'"
You want the court to be comfortable with the notion that this is a skilled artisan helping by providing one more piece of information, Zeuli says. "He's not trying to supplant the court's role in deciding what it means, but trying to help."
Courts were moving in this direction before Phillips came down, Zeuli notes, using experts to get closer to an understanding of what is customary in the art.
The real battle over experts will remain the same, Zeuli believes, and that has to do with the fact that they come into the picture after the fact. "You need an expert who's an industry veteran who can pull up contemporaneous documents to back up what he's saying about what is customary."
Lack of Deference
One lawyer who believes Phillips will reduce the use of expert witnesses in claims construction is Michael R. Dzwonczyk, who filed a brief in the case on behalf of his firm, Sughrue Mion.
In part, this is because of what the court had to say about the secondary role of extrinsic evidence. But of equal concern to Dzwonczyk is the Federal Circuit's failure to take up the question of what deference, if any, it should give to the trial judge's rulings on claim construction.
As it now stands, the appellate court's review is de novo. But some circuit judges believe that when a district judge has taken pains to listen to an expert, the court should give the court's rulings some degree of deference, says Dzwonczyk, who is based in Washington, D.C.
Given the circuit's de novo review, some judges may see it a waste of their time to listen to experts in Markman hearings. "This decision gives trial judges the freedom to deny requests for two- or three-day Markman hearings," Dzwonczyk says.
As a result, the role of experts will be attenuated, he believes. "There are judges who will say, 'I don't need experts, I want to hear about the technology.'"
Later Cases Consistent
Some of the uncertainty as to the impact of Phillips on the use of experts has been eased by subsequent Federal Circuit decisions, according to William F. Heinze, a lawyer with Thomas, Kayden, Horstemeyer & Risley in Atlanta.
In at least two cases issued in the wake of Phillips, the Federal Circuit has cited the testimony of experts in arriving at its construction of the claims, Heinze says. "The issue in Phillips was the reliance on dictionaries as extrinsic evidence, but courts still can consider extrinsic evidence."
For Heinze, these later cases confirm his belief that Phillips does not materially change the use of experts in patent cases. "You have to have an expert to testify what one of ordinary skill in the art would understand a term to mean," he says. "The expert will look at the intrinsic evidence and say, 'Here is what this term means.'"
Stephen M. Nipper, a lawyer with Dykas, Shaver & Nipper in Boise, Idaho, who handles both patent prosecution and patent litigation, describes the impact Phillips will have on litigation this way: "You can no longer put words in the patent writer's mouth."
"In writing a patent," Nipper explains, "you are allowed to be your own lexicographer. Experts will now need to spend more time reviewing the specifications, looking at how the inventor defined the terms."
While lawyers agree Phillips is unlikely to have much impact on the use of expert testimony in claims construction, they also agree that both the trial and appellate courts have broad discretion in this regard.
Perhaps the Federal Circuit in Phillips said it best: "[T]here is no magic formula or catechism for conducting claim construction. Nor is the court barred from considering any particular sources or required to analyze sources in any specific sequence, as long as those sources are not used to contradict claim meaning that is unambiguous in light of the intrinsic evidence."