Successful patent infringement cases hinge on expert testimony. KRANOS v. RIDDELL

A patent grants its owner the exclusive right to make, use, sell and import the invention described in the patent. In the United States an inventor gains a patent by filing a patent application with the United States Patent and Trademark Office. The United States Patent and Trademark Office reviews the patent application to ensure that the invention is eligible for patent protection. If the invention described in the patent application is new, useful and not obvious, then the patent application is granted. If someone other than the patent owner exercises one of the exclusive rights granted by the patent, this can be considered patent infringement. A patent owner can stop patent infringement by filing a lawsuit which requests and injunction against the infringer and the patent owner can get monetary damages for patent infringement which has occurred.

Patent lawsuits are the jurisdiction of federal courts in the United States. The judges of these courts are intelligent scholars that are appointed by the president of the United States for life terms. Despite their intelligence and knowledge of the law, federal court judges are humans beings and are not experts in every facet of technology and industry. When a judge is presented with a patent infringement lawsuit, the judge may have no experience with the technology surrounding the invention. How can a judge determine whether a defendant’s product infringes on a plaintiff’s patent if the judge is not familiar with the technology described in the patent?

The answer is expert testimony. Expert testimony is evidence presented to the court by an expert witness. The plaintiff and the defendant will both hire expert witnesses to present evidence to demonstrate or disprove that patent infringement has occurred. Having the right expert can make the difference between winning and loosing a patent infringement case. An expert witness should be able to educate the judge and jury about subjects which are outside of the experience of a normal person. The credibility of an expert witness is crucial to the effectiveness of the testimony the witness provides. Objective testimony, based on facts and evidence is more persuasive than opinion and conclusory statements.

A case which highlights the importance of expert testimony is KRANOS IP CORP, d/b/a SCHUTT SPORTS, vs. RIDDELL, INC., 17-cv-6802 (N.D.IL 2019). The plaintiff in this case owns three patents on sports helmets for playing football and other contact sports. The defendant manufacturers sports helmets which allegedly infringed on the plaintiff’s patents. The defendant filed a motion for summary judgement on the grounds that its products did not infringe on two of the plaintiff’s patents and that the third patent was invalid. Both parties hired expert witnesses to present evidence to the court.

The court reviewed the evidence presented and found for the defendant. In its opinion the court praised the defendant’s expert witness for using scholarly articles on the biomechnaics of head trauma to explain how the defendant’s product did not infringe on the plaintiff’s patent. The plaintiff’s expert only offered purely conclusory opinions. See Phillips v. AWH Corp., 415 F.3d 1303 , 1318 (Fed. Cir. 2015) (“[C]onclusory, unsupported assertions by experts as to the definition of a claim term are not useful to a court.”). The court noted that the plaintiff’s expert witness cited no evidence and offers no rationale for his conclusions that the defendant’s products infringe on the plaintiff’s patents. See Sport Dimension, Inc. v. Coleman Co., 820 F.3d 1316 , 1323 (Fed. Cir. 2016) (“District court judges . . . must ensure that expert testimony is reliable and that the testimony relates to scientific, technical or other specialized knowledge, which does not include unsubstantiated speculation and subjective beliefs.” Because the plaintiff’s expert witness was not based on a reliable methodology, the district court deemed it inadmissible and granted summary judgement in favor of the defendant.

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