One defense to a patent infringement lawsuit is that the patent should not have been granted because the patented invention is based on an obvious modification of existing ideas. The issue in HVLPO2, LLC v. Oxygen Frog, LLC was whether a lay witness could testify about the obviousness of an invention. The Court of Appeals for the Federal Circuit ruled that expert testimony is often required to establish obviousness.

Facts of the Case

The two patents at issue involved a device that manages the flow of oxygen gas mixtures to torches used by glass artists. There was no question that Oxygen Frog infringed two patents held by HVLP02. The only question at trial was whether the device used a method for controlling the flow of oxygen that would have been obvious to a person with ordinary skill in the field in light of existing ideas and technology.

To establish that the technology underlying the patents was a matter of public knowledge before the patents were issued, Oxygen Frog pointed to a blog post on a glass blowing internet forum that described an oxygen system. That system was similar to the patented device, but it involved a single circuit while the patented device used two circuits, one to provide power to oxygen generators and the second to provide power to an air compressor.

Oxygen Frog also pointed to a video that was posted online by Tyler Piedbes, a glass blowing artist. Oxygen Frog deposed Piedbes and played most of the deposition for the jury. Oxygen Frog did not offer Piedbes as an expert witness.

Piedbes was asked whether he thought adding a second circuit to the oxygen system described online was an obvious modification. HVLPO2 objected that Piedbes was not offering admissible lay testimony because an opinion about obviousness could only be provided by an expert witness. The trial judge overruled the objection and Piedbes answered “yes.”

The court instructed the jury that Piedbes could offer an opinion as to whether the modification “would occur to him from his perspective” and whether the modification was obvious. The court also instructed the jury that it was to make its own determination of obviousness.

The jury decided the obviousness question in favor of Oxygen Frog. HVLPO2 appealed. It contended on appeal that Piedbes’ testimony was inadmissible because he did not testify as an expert.

Appellate Opinion

Obviousness is not analyzed from the perspective of an ordinary person. Rather, the question is whether the patented invention modified an existing invention or technology in a way that would have been obvious to a person of ordinary skill in the relevant field (“a person of skill in the art,” in the language of patent law).

The Court of Appeals noted that it “is often helpful to have a technical expert explain, for example, the scope of the prior art or motivations for combining various components.” That explanation cannot typically be provided by a lay witness, because explanations of facts that are beyond the knowledge of ordinary jurors can only be made by expert witnesses. A person who is not an expert in the relevant “art” cannot usually assist the jury’s determination of obviousness.

Priebes might have been an expert, but he did not testify as an expert. He was not disclosed as an expert witness and did not prepare an expert report. The appellate court rejected the argument that Priebes was entitled to provide lay testimony about obvious modifications of oxygen system that had been described online. That testimony was “the province of qualified experts, not lay witnesses.”

Oxygen Frog argued that Priebes’ testimony, even if inadmissible, did not harm HVLPO2. Of course, Oxygen Frog only called Priebes as a witness because it hoped his testimony would influence the outcome. The Court of Appeals noted that the jury may have relied entirely on Priebes’ testimony when it decided the question of obviousness.

The trial court’s limiting instruction did not cure the error because it expressly allowed the jury to consider Priebes’ inadmissible opinion. In addition, HVLPO2 could not make a Daubert challenge to test the reliability of Priebes’ testimony since Priebes was not designated as an expert. Under those circumstances, the failure to designate Priebes as an expert could not be dismissed as harmless error. HVLP02 was therefore entitled to a new trial.