Background
Kyocera Senco, a maker of professional power nailers, filed a complaint at the International Trade Commission (ITC) under Section 337 of the Tariff Act, alleging that Koki Holdings (formerly Hitachi Koki) was importing power nailers that infringed Kyocera’s patents. The patents covered a gas-spring nailer design that uses compressed gas to drive fasteners. After an evidentiary hearing, the Administrative Law Judge (ALJ) found infringement and issued a limited exclusion order against Koki’s imports. The ITC affirmed. Koki appealed.
A central issue on appeal was the qualifications of Kyocera’s technical expert. The parties had stipulated that a person of ordinary skill in the art required at least two years of experience specifically in designing power nailers. Kyocera’s expert, Dr. John Pratt, had extensive engineering experience and credentials in fastener driving tools generally — but not specifically in the design of power nailers. The ALJ nonetheless admitted and credited his testimony. Koki argued this was reversible error.
The Court’s Holding
The Federal Circuit agreed with Koki and vacated the ITC’s infringement determination. The court held that an expert who testifies about infringement, claim construction, or invalidity from the perspective of a person of ordinary skill in the art (PHOSITA) must, at a minimum, actually possess ordinary skill in the art. This is not merely a suggestion — it is a threshold requirement. An expert who lacks the relevant technical background cannot reliably testify about what a person of ordinary skill would have understood, designed, or concluded.
The court rejected the argument that Dr. Pratt’s general engineering background and adjacent experience in fastener tools was close enough. The stipulated definition of ordinary skill specifically required experience in power nailers, and Dr. Pratt did not meet that standard. Because his testimony on infringement and claim construction was improperly admitted and credited, the ITC’s findings rested on an insufficient evidentiary foundation. The court also held that one of the asserted claim terms — “lifter member” — triggered means-plus-function treatment under 35 U.S.C. § 112 ¶ 6, further narrowing the scope of the claims at issue.
Key Takeaways
- A technical expert testifying from the perspective of a PHOSITA must actually meet the ordinary skill threshold — broad expertise in adjacent technology areas is insufficient if the agreed-upon or legally determined skill level requires specific experience.
- Parties should carefully scrutinize opposing experts’ credentials against the agreed definition of ordinary skill in the art before or during the Daubert/qualification phase.
- If a court or commission has adopted a specific definition of ordinary skill that an expert does not satisfy, that expert’s testimony on PHOSITA-dependent issues (infringement, obviousness, claim construction) is vulnerable to exclusion or vacatur.
- The case also reinforces that “lifter member” and similar coined terms without structural meaning can trigger means-plus-function construction, limiting claims to the specification’s disclosed structures and equivalents.
Why It Matters
Expert testimony is the lifeblood of patent litigation, and Kyocera Senco sharpens the rules for who qualifies. Companies defending against infringement claims — whether at the ITC or in district court — now have a clearer path to challenging opposing experts whose backgrounds don’t match the specific technology at issue. The case underscores that courts will look not just at whether an expert is a credentialed engineer, but at whether the expert’s actual experience maps to the level and type of skill the art requires.
At the ITC, where Section 337 proceedings move fast and expert testimony often determines outcomes, the lesson is particularly important. Patent owners need to ensure their experts have the right credentials before the hearing begins — discovering a qualification gap mid-proceeding or on appeal can unwind an otherwise favorable result, as it did here. The decision remains a frequently cited reference point for evaluating PHOSITA-based expert qualifications across all IP litigation venues.