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Karl Storz v. Sryker: District Court Strikes Infringement Expert Who Provided No Analysis of Infringement

In this patent infringement action, Stryker moved to strike the expert report of Karl Storz’ (“KSEA”) infringement expert because the expert did not provide any analysis of infringement of the patent-in-suit. As explained by the district court, Karl Storz’ infringement expert’s, Mr. Gould Bear, report included six sections: (1) introduction, (2) summary of conclusions, (3) background and qualifications, (4) materials reviewed, (5) legal principals and methods, and (6) conclusion.

The expert report did not provide any analysis regarding how “the accused products literally include each element of Claims 1, 2 and 3 of the ’420 Patent.” And the district court explained that “[e]ven Mr. Gould Bear’s description of his process is conclusory: ‘I have analyzed literal infringement with respect to each limitation of the asserted patent claim, comparing the accused products – in their ordinary and intended uses – to the invention described in the patent claim they are alleged to infringe. When analyzing a dependent claim, I determined whether the allegedly infringing products include each and every element of the dependent claim, the independent claim from which it depends and all intermediate dependent claims.’ (Id. at 14-15 ¶ 32.)

The expert report made no effort to explain how the expert determined that the allegedly infringing products include each element of the dependent claim and instead just stated he had made that determination.

In response, Karl Storz argued that Mr. Gould Bear “considered dozens of public and confidential documents regarding the accused Stryker product and KSEA’s patented user interface” as well as KSEA’s infringement contentions and the documents Stryker identified as providing the most accurate description of its product.  The district court disagreed that this was sufficient. “[T]he review of certain documents does not meet the requirement under Rule 26 to describe the ‘reasons and basis’ for his expert opinion.”

Karl Storz also argued that Mr. Gould Bear “compared the accused products with the claim that KSEA asserts is infringed, as a person of skill in the art at the time of the invention would understand the meaning of the patent claims” by following a set of rules outlined in his report. The district court also disagreed that this was sufficient as it was “merely a description of Mr. Gould Bear’s process, not a description of his reasons for arriving at his conclusion.”

Because Stryker had shown that Karl Storz had failed to meet its obligations under Rule 26, the burden shifted to Karl Storz to show that its failure to provide Mr. Gould Bear’s analysis was “substantially justified or harmless.” To meet this burden, Karl Storz did not argue that the failure to disclose Mr. Gould Bear’s reasoning was substantially justified, but instead argued that the lack of reasoning the report was substantially harmless “because Stryker is taking Mr. Gould Bear’s deposition.”

The district court was not impressed with this argument. “But that is not how Federal Rule 26 works. It requires each expert to provide its “reasons and basis.” To conclude that a deposition can substitute for the reasoning and analysis in an expert report would render Rule 26(a)(2)(B)(i) meaningless. Indeed, ‘the purpose of the expert disclosure rule is to ‘provide opposing parties reasonable opportunity to prepare for effective cross examination and perhaps arrange for expert testimony from other witnesses.’ Rembrandt Vision Techs., L.P. v. Johnson & Johnson Vision Care, Inc., 725 F.3d 1377, 1381 (Fed. Cir. 2013).”  The district court also concluded that “Stryker’s failure to provide Mr. Gould Bear’s basis for his conclusions harms Stryker because it cannot effectively prepare its questioning for Mr. Bear’s deposition or counter Mr. Bear’s reasoning with its own experts.”

As a result, the district court excluded the infringement report.

Karl Storz Endoscopy America, Inc. v. Stryker Corp., Case No. 14-cv-00876-RS (JSC) (N.D. Cal. March 30, 2018)

The authors of are patent trial lawyers at Jeffer Mangels Butler & Mitchell LLP. For more information about this case, contact Stan Gibson at 310.201.3548 or

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