Although the Pennypack factors for exclusion are notoriously difficult to meet, judges in D. Del. have been excluding late-disclosed theories more frequently than in the past.

Case in point: on Friday, Judge Andrews granted a motion to strike DOE theories asserted for the first time in an opening expert report. The plaintiff offered a number of excuses for disclosing the theories when it did—"it was only able to collect evidence to support its new DOE theories" after a COVID-delayed source code review, it lacked supporting evidence until a technical deposition in November 2020, and so on.

Judge Andrews not only rejected these excuses, but took it a step further—coming very close to finding that the plaintiff acted in …

Chief Judge Stark this week granted a motion of non-infringement under the doctrine of equivalents due to the slim DOE analysis relied on by the patentee's expert.

Interestingly, the expert had offered some testimony framed in terms of the usual function-way-result DOE test:

[T]he Accused Products perform substantially the same function (producing densitometry/densitometric models for use in assessing bone density), in substantially the same way (determining linear attenuation coefficients of an object in several tomographic scans and combining this information using the Feldkamp algorithm to determine the grayscale values of voxels and the corresponding HU units thereof of a 3D CBCT volume of the object), to achieve substantially the same result (3D volumes that include information for depicting quantitative differences …