The United States Court of Appeals for the Federal Circuit is addressing appeals from a district court decision in the case of Hologic, Inc. and Cytyc Surgical Products, LLC against Minerva Surgical, Inc., specifically concerning the validity of claim 1 of U.S. Patent No. 9,095,348. The Supreme Court remanded the case after vacating the appellate court's previous judgment, which had upheld a summary judgment of no invalidity based on assignor estoppel. Although the Supreme Court confirmed the validity of assignor estoppel, it specified that its application has limits. The appellate court is tasked with evaluating whether claim 1 is "materially broader" than the claims originally assigned to Hologic, which would determine if assignor estoppel applies. The court concluded that claim 1 is not materially broader and thus affirmed the district court's judgment that claim 1 is valid, while also reinstating its prior judgment on other matters.
The dispute traces back to 1993 when Csaba Truckai co-founded NovaCept, Inc., which developed the NovaSure endometrial ablation device and filed a patent application in 1998. Truckai assigned rights to the application to NovaCept, which was later acquired by Cytyc Corporation. In the acquisition, NovaCept warranted the validity of the intellectual property assigned, claiming no reasonable knowledge of any invalidity. The application led to U.S. Patent No. 6,813,520, and Truckai later founded Minerva, which developed and received FDA approval for a competing Endometrial Ablation System in 2015.
Hologic acquired Cytyc in 2007 and is the assignee of the ’348 patent, issued in 2015, which claims priority from the earlier ’072 application. The ’348 patent addresses issues of steam and liquid buildup that hinder the effectiveness of previous ablation devices. This moisture buildup prevents electrical current from properly targeting tissue for ablation, instead causing passive heating that extends thermal ablation beyond desired depths. To resolve this, the patent describes devices designed to actively or passively remove moisture during the dehydration process.
Key components of the exemplary ablation device include an applicator head, a main body, and a handle. The applicator head features an electrode carrying means with an array of electrodes, constructed from a non-conductive material that can absorb or allow moisture to pass through. Additionally, the device includes a deflecting mechanism to position the electrode array, which can adapt to various uterine shapes.
Hologic sued Minerva in November 2015, claiming infringement of the ’348 patent. Minerva countered with defenses of invalidity, including lack of enablement and written description. Hologic sought summary judgment asserting that assignor estoppel barred Minerva from contesting the patent's validity, which the district court upheld, also ruling in favor of Hologic for infringement of claim 1. Following a jury trial regarding willful infringement and damages, both parties appealed, with Minerva challenging the assignor estoppel ruling and specific claim constructions. The Federal Circuit affirmed the district court's decision regarding assignor estoppel and summary judgment of no invalidity.
The district court's constructions of terms challenged by Minerva were upheld, affirming the summary judgment of infringement. Minerva petitioned the Supreme Court, contesting the doctrine of assignor estoppel, claiming it lacked statutory support and arguing for a reevaluation of its applicability. The Supreme Court granted certiorari, declined to discard assignor estoppel, but clarified its limits, stating it applies only when an inventor makes conflicting representations regarding a patent's validity. The Court noted that if a claim is materially broader than those assigned, the assignor cannot be deemed to have warranted its validity, thus negating the basis for estoppel. Following this guidance, the remand focuses on whether claim 1 of the ’348 patent is materially broader than claim 31 of the canceled ’072 application. Minerva contends that all claims at the time of a 2004 assignment included a limitation for moisture-permeable applicators and argues that claim 31, canceled in 2002, was not assigned, meaning Hologic cannot claim Mr. Truckai represented its validity. Additionally, Minerva asserts that claim 31 does not cover devices with moisture-impermeable applicators. Hologic counters that Mr. Truckai did warrant the validity of claim 31 at the assignment’s time.
Hologic acknowledges that claim 31 was canceled before the 2004 assignment but argues the context of this cancellation is significant. The cancellation was 'without prejudice' in response to an Examiner's restriction requirement, implying that the claim could potentially be reintroduced in future applications. Hologic contends that claim 1 is not materially broader than claim 31, as neither includes a moisture-permeability limitation. The key questions are whether Mr. Truckai warranted the validity of claim 31 at the time of the assignment, given the implications of the 2002 cancellation, and whether claim 31 is materially broader than claim 1, particularly regarding moisture-impermeable devices.
The analysis begins with the 2004 assignment's context, focusing on the prosecution history of the ’072 application, which was filed on June 23, 1998, with 31 claims. Claim 31 was initially rejected by the Examiner on June 21, 1999, for anticipation under 35 U.S.C. 102, but was later allowed on October 3, 2000. On May 21, 2001, the Examiner issued a restriction requirement, categorizing the claims into distinct inventions—apparatus claims (including claim 31) and method claims. Mr. Truckai elected to pursue the method claims after the restriction was maintained, and subsequently requested the cancellation of claim 31 without prejudice on February 28, 2002. Hologic argues that the cancellation does not reflect on the patentability of claim 31, indicating it was canceled for reasons unrelated to its validity.
An assignee understands that a restriction requirement and its subsequent cancellation allow for the future prosecution of the subject matter in claim 31, as non-elected claims are withdrawn from further examiner consideration without a final patentability determination. An applicant can file a divisional application for canceled claims resulting from a restriction requirement, which remain viable for prosecution. Contrary to Minerva’s claims, the cancellation of claim 31 does not nullify it or imply unpatentability; instead, it travels with the original application. The 2004 assignment included rights to future divisional applications, ensuring claim 31 remained associated with the ’072 application and its assignment to Hologic. Mr. Truckai affirmed a belief in the patentability of the claims in the application through an oath and subsequent representations during the assignment process, indicating that claim 31 was not invalid. The document then transitions to evaluating whether claim 1 of the ’348 patent is "materially broader" than claim 31 of the ’072 application, which is a legal question resolved through claim construction based solely on intrinsic evidence. The parties agreed to compare only these two claims, focusing on the distinction between moisture-permeable and moisture-impermeable devices to determine if claim 1 is materially broader.
Claim 1 of the patent broadly encompasses moisture-impermeable devices as established in Hologic II, where the court rejected Minerva's interpretation that required a moisture-permeable applicator head. It is agreed that if claim 31 is limited to moisture-permeable devices, claim 1 is "materially broader," allowing Minerva to assert its invalidity defenses without being barred by assignor estoppel. Both parties concur that claim 31 lacks an express moisture-permeability limitation, suggesting it can cover both moisture-permeable and moisture-impermeable devices. Minerva contends that the absence of an 'applicator head' in claim 31 implies it cannot include moisture-impermeable devices; however, this claim, being an open-ended 'comprising' claim, supports the inclusion of both types. Furthermore, Minerva's argument that the 'electrode array' must be moisture-permeable lacks support in the intrinsic record. The principle of claim differentiation reinforces that the inventors were aware of how to draft moisture-permeability requirements, as seen in claims 1 and 16, but consciously chose not to include such a limitation in claim 31, indicating their intent for broader coverage.
Differences among patent claims can clarify the meaning of specific claim terms. Minerva contends that claim 31 of the ’348 patent is limited to a moisture-permeable device based on a written description referencing an electrode array that is 'permeable to moisture.' However, the relevant portion of the description indicates that moisture permeability is a 'preferable characteristic' rather than a mandatory one. The court cites precedent stating that claims should not be confined to preferred embodiments. It finds that the language of claim 31 is broad enough to encompass both moisture-permeable and non-permeable devices, and thus, the absence of an alternative embodiment in the specification does not exclude it from the claim's coverage. The court acknowledges the written description's emphasis on moisture removal but ultimately disagrees with Minerva's assertion of a limitation to moisture-permeable devices.
Regarding assignor estoppel, the court notes that Minerva did not dispute key facts related to Mr. Truckai's assignment of patent rights to NovaCept, the value received by NovaCept, Truckai's founding of Minerva, and his efforts to compete with Hologic. Consequently, the court concludes that claim 1 of the ’348 patent is not materially broader than claim 31 of the ’072 application, affirming the district court's application of assignor estoppel and its summary judgment that claim 1 is valid.
The court's decision reinstates several prior judgments, including the denial of Hologic's requests for injunctions and enhanced damages, the affirmation of the infringement ruling regarding claim 1 of the ’348 patent, and the vacating of a prior award of interest on supplemental damages for recalculation. The ruling is affirmed in part, vacated in part, and remanded without costs.
