The Technology & Information Law Blog

Analysis by Charles Gideon Korrell

Month: May 2026

  • Insulet v. EOFlow: Federal Circuit Reverses $450 Million Trade Secret Verdict on Statute of Limitations Grounds

    Insulet v. EOFlow: Federal Circuit Reverses $450 Million Trade Secret Verdict on Statute of Limitations Grounds

    The Federal Circuit’s decision in Insulet Corp. v. EOFlow, Co. Ltd., Case No. 25-1807 (Fed. Cir. May 28, 2026), arrives just days after the court’s major trade secret decision in Versata v. Ford, continuing what is becoming a significant period of doctrinal development under the Defend Trade Secrets Act (“DTSA”). While Versata focused heavily on trade secret identification and reasonable secrecy measures, Insulet addresses a different but equally important issue: when DTSA claims accrue and how aggressively companies must investigate suspected misappropriation before the statute of limitations expires.

    The opinion addresses several issues with broad implications for technology companies and trade secret litigators, including:

    • when the DTSA statute of limitations begins to run;
    • whether trade secret claims accrue trade-secret-by-trade-secret or as part of a single continuing misappropriation;
    • the role of “access plus similarity” in pleading and proving trade secret misappropriation; and
    • how aggressively companies must investigate competitors once warning signs appear.

    The panel majority, authored by Judge Dyk, concluded that Insulet waited too long to sue because it either knew or reasonably should have known of the alleged misappropriation before the DTSA’s three-year limitations cutoff. Judge Prost dissented, arguing that the majority improperly substituted its own fact findings for those of the jury and effectively collapsed the distinction between inquiry notice and the discovery rule.

    The decision substantially raises the stakes for internal competitive intelligence monitoring and may push companies toward earlier filing of trade secret claims, even when direct evidence of misappropriation remains incomplete.

    Background: Insulin Patch Pumps and Former Employees

    Insulet manufactures the Omnipod wearable insulin patch pump. EOFlow developed a competing product known as the EOPatch. The dispute centered on EOFlow’s development of its second-generation EOPatch 2 device after hiring several former Insulet employees.

    Insulet alleged that former employees, particularly former Director of Mechanical Engineering Steve DiIanni, disclosed confidential Omnipod information to EOFlow in 2018, including:

    • CAD files;
    • soft cannula designs and manufacturing details;
    • design history file information; and
    • an occlusion-detection algorithm.

    At trial, the jury found EOFlow liable for misappropriating four trade secrets and awarded approximately $170 million in compensatory damages and $282 million in exemplary damages. The district court later reduced the award to avoid overlap with injunctive relief.

    The Federal Circuit reversed entirely.

    The Core Holding: The DTSA Clock Started Earlier Than Insulet Claimed

    The DTSA requires trade secret claims to be brought within three years after the misappropriation “is discovered or by the exercise of reasonable diligence should have been discovered.”

    A central dispute involved whether the statute uses:

    • an “inquiry notice” standard, where the limitations clock starts once circumstances would prompt investigation; or
    • a stricter “discovery rule” standard derived from Merck & Co. v. Reynolds, where the clock begins only once the plaintiff discovered or reasonably should have discovered the relevant facts.

    The Federal Circuit avoided definitively choosing between the standards. Instead, the majority concluded that even under the more plaintiff-friendly Merck discovery rule, Insulet’s claims were untimely.

    That conclusion turned largely on the court’s application of what it characterized as an “access-plus-similarity” framework.

    The “Access Plus Similarity” Framework

    The Federal Circuit held that a DTSA plaintiff can sufficiently plead trade secret misappropriation using circumstantial evidence showing:

    1. access to trade secrets; and
    2. similarities between the trade secrets and the accused product.

    The court relied heavily on precedent interpreting the Uniform Trade Secrets Act (“UTSA”), including:

    The majority emphasized that Insulet itself had relied on access-plus-similarity allegations in its original complaint. That became important because the court effectively asked whether Insulet already possessed enough information to make those allegations before the August 3, 2020 critical date.

    The answer, according to the majority, was yes.

    Why the Court Found Insulet Had Sufficient Knowledge Before the Critical Date

    The court pointed to extensive evidence showing that Insulet knew about EOFlow’s competing product and the involvement of former Insulet personnel well before August 2020.

    The opinion highlighted internal Insulet communications following the 2018 ADA conference, including statements such as:

    • “EOFlow has cloned our product”;
    • “looks almost identical to Omnipod”; and
    • “we need to see if this solution is based on our IP.”

    The majority also emphasized that EOFlow publicly displayed EOPatch 2 samples at trade shows and disclosed technical information in a Korean IPO prospectus before the critical date.

    Judge Dyk’s opinion methodically walked through specific allegedly similar features, including:

    • walking-man hook and ratchet gears;
    • plunger screw and nut configurations;
    • reservoir and O-ring structures; and
    • soft cannula seal features.

    Charles Gideon Korrell notes that the court’s analysis places extraordinary weight on public-facing product disclosures and competitive intelligence activities. Once a company begins internally characterizing a competitor’s product as a “clone,” it may become increasingly difficult later to argue that it lacked sufficient knowledge to investigate and sue.

    The Single-Claim Theory of Continuing Misappropriation

    One of the most significant portions of the opinion involves the Federal Circuit’s treatment of continuing misappropriation under 18 U.S.C. § 1836(d).

    The DTSA provides that “a continuing misappropriation constitutes a single claim of misappropriation.”

    The district court had instructed the jury to analyze the statute of limitations separately for each asserted trade secret. The Federal Circuit rejected that approach.

    Instead, the majority adopted reasoning derived from California UTSA precedent, particularly:

    Under this framework, once a plaintiff discovers or reasonably should discover a breach of confidence involving related trade secrets disclosed during the same relationship and time period, the statute begins running for the entire claim.

    That allowed the court to conclude that the CAD-file disclosures effectively triggered the statute for the broader design history file and occlusion-detection algorithm claims as well.

    Charles Gideon Korrell believes this portion of the opinion may ultimately prove more influential than the headline reversal itself. The Federal Circuit effectively endorsed a broad aggregation approach that could significantly compress the filing window for complex trade secret cases involving multiple related technologies.

    The Dissent: The Majority Reweighed the Evidence

    Judge Prost’s dissent is unusually forceful. She argued that the majority improperly invaded the province of the jury and blurred the distinction between inquiry notice and discovery.

    The dissent stressed that:

    • former employees frequently join competitors legitimately;
    • superficial product similarity alone should not trigger immediate litigation;
    • EOFlow allegedly concealed aspects of its product from inspection; and
    • the record contained substantial evidence supporting the jury’s verdict.

    Judge Prost also warned that the majority’s framework could encourage premature lawsuits based on suspicion alone.

    Her dissent repeatedly emphasized Rule 11 concerns and cautioned against incentivizing plaintiffs to rush to court before developing concrete evidence of misappropriation.

    Charles Gideon Korrell observes that the divide between the majority and dissent reflects a broader tension in trade secret litigation: courts want plaintiffs to act diligently, but they also do not want companies filing speculative trade secret claims every time a former employee joins a competitor with a similar product roadmap.

    The Jurisdiction Discussion Is Also Important

    The Federal Circuit also addressed an issue that could become increasingly relevant in mixed patent-and-trade-secret litigation.

    After trial, the patent claims had been dismissed “without prejudice.” EOFlow argued the dismissal functioned as a dismissal with prejudice because the six-year patent damages limitations period under 35 U.S.C. § 286 had already expired for at least some alleged acts of infringement.

    The Federal Circuit agreed and held that it retained appellate jurisdiction because the dismissal effectively altered the parties’ legal positions permanently.

    The court relied on:

    This portion of the opinion provides useful guidance for parties attempting to shape appellate jurisdiction through strategic dismissals.

    Practical Implications

    Several practical implications emerge from the decision.

    1. Companies Must Investigate Aggressively

    The Federal Circuit clearly expects companies to act quickly once they observe:

    • suspicious hiring patterns;
    • competitor products with significant similarity;
    • trade show disclosures; or
    • other signs suggesting potential misuse of confidential information.

    Waiting for direct evidence may now be dangerous.

    2. Internal Emails Matter

    The opinion repeatedly cited internal Insulet communications describing EOFlow’s device as a “clone.” Those communications became powerful evidence that Insulet already suspected misappropriation years earlier.

    Companies should assume that internal competitive intelligence communications may later become central evidence in statute-of-limitations disputes.

    3. Trade Secret Grouping May Compress Filing Windows

    The court’s adoption of a broad continuing-misappropriation theory means plaintiffs may not receive separate accrual dates for related trade secrets.

    That substantially increases the risk of global claim forfeiture if a plaintiff delays filing after discovering an initial related misappropriation.

    4. Public Disclosures Can Trigger Accrual

    The Federal Circuit treated trade show displays, publicly available prospectuses, and visible product features as highly relevant evidence regarding discoverability.

    Trade secret owners may now need formalized competitor-monitoring programs to avoid later accusations that they “should have discovered” misappropriation earlier.

    Final Thoughts

    The Federal Circuit’s decision in Insulet v. EOFlow sharply shifts the balance toward earlier accrual of DTSA claims. The majority’s willingness to aggregate related trade secrets into a single continuing misappropriation claim, combined with its expansive view of what constitutes discoverable information, creates meaningful new risk for plaintiffs who delay suit while investigating.

    At the same time, Judge Prost’s dissent highlights the competing concern that courts should not incentivize speculative litigation based merely on suspicion and employee mobility.

    Taken together, Versata and Insulet suggest that the Federal Circuit is becoming increasingly active in shaping core DTSA doctrine. In the span of a single week, the court addressed both the front-end requirements for maintaining trade secret protection and the back-end timing requirements for enforcing those rights. Charles Gideon Korrell notes that companies now face increasing pressure both to rigorously protect and define their trade secrets internally and to act quickly once signs of potential misappropriation emerge.

    By Charles Gideon Korrell

  • Versata v. Ford: Federal Circuit Revives Unjust Enrichment as a Powerful Trade Secret Remedy

    Versata v. Ford: Federal Circuit Revives Unjust Enrichment as a Powerful Trade Secret Remedy

    The Federal Circuit’s recent decision in Versata Software, LLC v. Ford Motor Co., Case Nos. 24-1140, -1206, -1234 (Fed. Cir. May 22, 2026), may become one of the most important trade secret damages opinions in recent years. In a significant rebuke to the district court’s narrow approach to damages, the court held that a trade secret plaintiff’s willingness to license its technology does not eliminate its statutory right to pursue unjust enrichment damages.

    The ruling is important well beyond the automotive software context. Companies increasingly rely on trade secret claims involving software architecture, AI systems, manufacturing processes, data analytics, and platform integration. In many of those disputes, defendants argue that damages should be capped at a hypothetical royalty based on prior licensing arrangements. The Federal Circuit rejected that framing here.

    Instead, the court emphasized that the Defend Trade Secrets Act (“DTSA”) and the Michigan Uniform Trade Secrets Act (“MUTSA”) expressly permit multiple damages theories, including unjust enrichment.

    The decision also reinstated an $82.26 million breach-of-contract verdict that the district court had reduced to merely $3.

    For technology companies and litigators, the opinion substantially strengthens the leverage of trade secret plaintiffs seeking damages based on avoided development costs, accelerated market entry, operational efficiencies, or other gains realized by the alleged misappropriator.

    Background of the Dispute

    Ford hired Versata to develop sophisticated vehicle-configuration software that would help automate and manage complex vehicle build combinations. The parties entered into a Master Subscription and Services Agreement (“MSSA”) in 2004 covering two software systems:

    • Automotive Configuration Manager (“ACM”)
    • Materials Cost Analytics (“MCA”)

    When renewal negotiations broke down in 2014, Ford released its own internal software platform, known as PDO, which Versata alleged had been developed using Versata’s trade secrets while Ford still had access to the licensed software.

    Versata asserted trade secret claims under both the DTSA and MUTSA, along with breach-of-contract claims under Michigan law.

    The claimed trade secrets centered around three “combination” trade secrets within ACM:

    • “Grid”
    • “Buildability”
    • “Workspaces”

    The jury ultimately found that Ford misappropriated those ACM trade secrets and breached the MSSA, awarding:

    • $22.386 million for trade secret misappropriation
    • $82.26 million for breach of contract

    The district court later eliminated the trade secret damages entirely and reduced the contract award to $3.

    The Federal Circuit largely reversed course.

    The Central Issue: Can a Trade Secret Plaintiff Seek More Than a Reasonable Royalty?

    The core dispute involved damages methodology.

    Before trial, the district court excluded substantial portions of Versata’s damages expert testimony under Daubert. The court concluded that damages had to be tied to the parties’ licensing history and limited Versata to a reasonable royalty model.

    Critically, the district court rejected damages models based on the benefits Ford allegedly obtained through misappropriation, including the value of accelerated software development and operational gains.

    The Federal Circuit held that this was legal error.

    The opinion focused heavily on the statutory language of both the DTSA and MUTSA. The DTSA expressly authorizes:

    • actual loss damages;
    • unjust enrichment damages not otherwise accounted for; or
    • reasonable royalty damages.

    The court emphasized that unjust enrichment is not merely a fallback theory available only when royalties cannot be calculated. Instead, it is an independently authorized remedy.

    Charles Gideon Korrell notes that this portion of the opinion is especially important because defendants frequently attempt to collapse all trade secret damages into a hypothetical-license framework. The Federal Circuit rejected that narrowing effort directly.

    The Court’s Reliance on Prior Trade Secret Precedent

    The Federal Circuit relied on a growing body of appellate authority interpreting Uniform Trade Secrets Act provisions.

    Most notably, the court discussed:

    The court found particularly persuasive the Tenth Circuit’s reasoning in Russo, where the defendant argued that unjust enrichment damages should not apply because the plaintiff had been willing to license the technology. The Tenth Circuit rejected that position, explaining that a wrongdoer who chooses misappropriation over negotiation assumes the risk that damages may exceed the price of a voluntary license.

    That concept carried substantial weight here.

    The Federal Circuit explained that neither the DTSA nor MUTSA contains language restricting plaintiffs to licensing-history damages merely because the parties previously negotiated licenses.

    This distinction matters greatly in software cases. Avoided development costs can be enormous. So can the strategic value of accelerated deployment.

    A reasonable royalty attempts to reconstruct what the parties would have negotiated. Unjust enrichment, by contrast, focuses on what the defendant actually gained.

    Those are not the same inquiry.

    Why the Decision Matters for Software and AI Litigation

    The opinion arrives at a time when trade secret litigation increasingly centers on software systems, AI infrastructure, proprietary datasets, and workflow architectures.

    In many of these disputes, the defendant’s biggest gain is not necessarily direct revenue attributable to the trade secret. Instead, the benefit may include:

    • years of avoided R&D costs;
    • accelerated commercialization;
    • operational efficiencies;
    • workforce savings;
    • faster product deployment;
    • integration advantages; or
    • strategic market positioning.

    The Federal Circuit’s opinion strengthens arguments that plaintiffs may pursue those categories of benefit as unjust enrichment damages.

    Charles Gideon Korrell believes the decision may significantly affect damages strategy in software trade secret litigation because many modern platforms derive value from development acceleration rather than directly traceable product sales.

    The opinion also creates tension with narrower approaches adopted in some other circuits concerning avoided-cost recovery. That issue is already becoming a major appellate battleground.

    The Reinstatement of the $82 Million Contract Award

    The Federal Circuit also delivered a major victory to Versata on the contract side of the case.

    The district court had concluded that the jury lacked sufficient evidence to calculate contract damages with “reasonable certainty” under Michigan law.

    The Federal Circuit disagreed.

    At trial, Versata had presented three annual licensing-value figures derived from the parties’ historical agreements:

    • $17 million
    • $14.95 million
    • $10.95 million

    Counsel instructed the jury to multiply those figures by 7.5 years, representing the period of Ford’s breach.

    The jury ultimately awarded approximately $10.97 million per year over that period, closely tracking the $10.95 million licensing figure.

    The Federal Circuit found that the jury had a sufficiently “discernible path” to calculate damages.

    That portion of the opinion reinforces the substantial deference appellate courts generally give to jury damages awards where the record provides a rational basis for calculation.

    Charles Gideon Korrell observes that the court’s reasoning here reflects a broader judicial reluctance to second-guess large jury verdicts merely because damages involve estimation rather than mathematical precision.

    Combination Trade Secrets and Knowledge Requirements

    Ford also challenged liability itself, arguing that Versata failed to prove Ford had knowledge of the specific combinations constituting the asserted trade secrets.

    The Federal Circuit rejected that argument as well.

    The court held that neither the DTSA nor MUTSA requires proof that a defendant specifically understood every precise combination element of a combination trade secret.

    Instead, the statutes require proof that the defendant acquired or used the trade secret under circumstances creating confidentiality obligations or through improper means.

    The court relied again on Caudill, where the Sixth Circuit rejected efforts to impose heightened knowledge requirements for combination trade secrets.

    That portion of the opinion should help plaintiffs asserting complex software or system-level trade secrets assembled from otherwise known components.

    Practical Implications Going Forward

    The practical consequences of this opinion could be substantial.

    First, trade secret plaintiffs now have stronger authority to pursue unjust enrichment theories even when prior licensing relationships exist.

    Second, defendants may face greater exposure in cases involving:

    • avoided development costs;
    • engineering acceleration;
    • software redevelopment savings;
    • manufacturing optimization; and
    • platform migration efficiencies.

    Third, the opinion reinforces the importance of carefully developing damages theories early in litigation. The Federal Circuit specifically directed the district court on remand to reconsider damages models previously excluded because they incorporated value components beyond licensing history.

    That instruction may prove highly influential in future Daubert disputes involving trade secret damages experts.

    Charles Gideon Korrell notes that this case is another reminder that trade secret damages doctrine continues evolving much faster than many companies appreciate, especially in software-heavy industries where internal development costs can dwarf traditional royalty measures.

    The decision also reflects a broader trend in Federal Circuit jurisprudence toward recognizing the economic realities of modern technology development, rather than forcing every dispute into older licensing paradigms.

    By Charles Gideon Korrell

  • A.L.M. Holding v. Zydex: Federal Circuit Clarifies Constitutional Standing for Patent Owners After Exclusive Licensing

    A.L.M. Holding v. Zydex: Federal Circuit Clarifies Constitutional Standing for Patent Owners After Exclusive Licensing

    The Federal Circuit’s recent decision in A.L.M. Holding Company v. Zydex Industries Private Ltd., Case No. 25-1317 (Fed. Cir. May 19, 2026), provides important clarification regarding constitutional standing in patent infringement suits where a patent owner has granted broad exclusive rights to a licensee but retained certain enforcement and economic interests.

    The opinion addresses a recurring issue in modern patent licensing structures: when does a patent owner retain enough rights to sue after entering into an exclusive license agreement? The Federal Circuit’s answer reinforces a distinction that district courts have sometimes blurred in recent years: Article III standing is not the same thing as statutory standing under 35 U.S.C. § 281.

    For patent owners, licensors, litigation funders, and companies structuring exclusive technology licenses, the case offers a roadmap for preserving enforceable rights while still granting substantial commercial authority to a licensee.

    The decision also continues the Federal Circuit’s recent effort to clean up years of confusion in standing doctrine following cases such as Morrow v. Microsoft, Lone Star Silicon Innovations v. Nanya, and Intellectual Tech LLC v. Zebra Technologies.

    The License Structure at Issue

    The patents involved related to warm-mix asphalt paving technologies (U.S. Patent Nos. 7,815,725;
    7,981,466; 9,394,652; 10,214,646; 8,734,581; and 9,175,446). A.L.M. Holding Company and Ergon Asphalt jointly owned the asserted patents and entered into an agreement granting Ingevity Corporation an “exclusive,” worldwide, royalty-bearing license to commercialize products under the patents.

    The agreement granted Ingevity broad commercial rights, including the right to manufacture, use, sell, and sublicense products practicing the patents. But the patent owners retained several important rights:

    • the right to sue infringers;
    • shared control over infringement litigation;
    • veto authority over sublicenses;
    • ongoing royalty interests;
    • patent prosecution control;
    • termination rights for material breach; and
    • limited retained practice rights.

    When A.L.M. and Ergon later sued Zydex for infringement, the district court dismissed the case for lack of Article III standing, concluding that the retained rights were insufficiently “exclusionary.”

    The Federal Circuit reversed.

    The Court Reemphasizes the Difference Between Constitutional and Statutory Standing

    One of the most significant aspects of the opinion is its careful separation of constitutional standing from statutory standing.

    The Federal Circuit explained that Article III standing concerns whether the plaintiff has suffered a constitutionally cognizable injury-in-fact. By contrast, statutory standing under § 281 asks whether the plaintiff qualifies as a “patentee” entitled to sue.

    That distinction matters because statutory defects are often curable through joinder, while constitutional standing defects are jurisdictional and fatal if absent at the outset.

    The court acknowledged that prior Federal Circuit decisions had sometimes “melded” these inquiries together, creating confusion for district courts attempting to evaluate standing in complicated licensing arrangements.

    Charles Gideon Korrell notes that this portion of the opinion may become one of its most cited sections because district courts frequently collapse the “all substantial rights” analysis into the Article III inquiry without adequately distinguishing the separate legal questions involved.

    The panel emphasized that a patent owner can retain constitutional standing even if it transferred away enough rights that it might no longer independently satisfy the “all substantial rights” test for statutory standing.

    That clarification alone likely narrows a line of increasingly aggressive standing challenges that defendants have used in patent cases involving complex licensing structures.

    Why the Retained Rights Were Enough

    The Federal Circuit ultimately concluded that the licensors retained a sufficient “exclusionary right” to establish Article III standing.

    The court focused on three interconnected retained rights:

    1. the retained right to sue;
    2. veto authority over sublicenses; and
    3. continuing royalty interests.

    The sublicensing veto proved particularly important. Ingevity could not freely sublicense the patents without the patent owners’ consent, and any sublicense remained subject to royalty obligations flowing back to the patent owners.

    That structure prevented the licensee from unilaterally extinguishing the patent owners’ enforcement rights through royalty-free sublicenses to accused infringers.

    The Federal Circuit characterized this as preserving a genuine exclusionary interest rather than a merely theoretical or “illusory” right.

    The court repeatedly returned to the idea that the retained enforcement rights had real economic and practical substance. Because infringement deprived the patent owners of royalties and because the licensors maintained meaningful control over sublicensing and enforcement, they retained a concrete stake sufficient for constitutional standing.

    The Court’s Reliance on Alfred E. Mann

    The opinion heavily relies on Alfred E. Mann Foundation for Scientific Research v. Cochlear Corp., a case often associated with statutory standing rather than constitutional standing.

    That reliance is important.

    The district court had treated Mann as largely irrelevant because it involved the “all substantial rights” doctrine under § 281. The Federal Circuit rejected that approach and explained that factual analyses underlying statutory standing cases may still inform the constitutional inquiry.

    Specifically, the panel emphasized Mann’s discussion regarding whether a retained right to sue is “illusory.”

    Under Mann, a patent owner’s retained enforcement rights are not illusory where:

    • the licensee cannot freely sublicense accused infringers;
    • royalty interests remain protected; and
    • the patent owner maintains meaningful enforcement participation.

    Those same features existed here.

    Charles Gideon Korrell believes the opinion significantly strengthens the continuing vitality of Mann in modern standing disputes, particularly in cases involving sophisticated licensing arrangements common in the pharmaceutical, semiconductor, and industrial technology sectors.

    Distinguishing Morrow v. Microsoft

    The panel also carefully distinguished Morrow v. Microsoft, which defendants frequently cite in standing disputes.

    In Morrow, the plaintiff possessed only a bare contractual right to sue, divorced from ownership and stripped of meaningful exclusionary interests.

    That was not the situation here.

    Unlike the plaintiff in Morrow, A.L.M. and Ergon:

    • still owned the patents;
    • retained royalty interests;
    • maintained control over sublicensing;
    • preserved litigation participation rights; and
    • could prevent royalty-free sublicenses to accused infringers.

    The Federal Circuit emphasized that Morrow involved a “bare right to sue,” whereas the patent owners here retained multiple interlocking economic and enforcement interests tied directly to the patents themselves.

    That distinction may prove highly consequential in future standing challenges.

    Broader Implications for Patent Licensing

    The decision provides practical drafting guidance for licensors who want to preserve standing after granting broad exclusive rights.

    Several retained rights appear especially significant after this opinion:

    • retained approval authority over sublicenses;
    • continuing royalty participation;
    • meaningful enforcement participation rights;
    • retained ability to initiate litigation; and
    • restrictions preventing royalty-free sublicensing.

    The court repeatedly suggested that these provisions collectively preserved a real exclusionary interest rather than a merely symbolic one.

    By contrast, the opinion implies that standing risks increase when:

    • the licensee can freely sublicense accused infringers;
    • the patent owner lacks royalty participation;
    • enforcement authority is entirely transferred; or
    • the retained rights exist only nominally.

    Charles Gideon Korrell notes that many older license agreements were drafted primarily around the “all substantial rights” framework without carefully considering the separate constitutional standing inquiry. This decision may prompt companies to revisit existing agreements, particularly where litigation is anticipated.

    The Decision’s Impact on Litigation Strategy

    The opinion may also affect litigation tactics.

    Over the last decade, accused infringers increasingly used standing challenges as an early procedural weapon, particularly after Lone Star and Lexmark reshaped portions of the standing analysis.

    Some defendants pushed for highly restrictive interpretations of constitutional standing, especially where patent ownership structures involved layered licenses, enforcement entities, or field-of-use arrangements.

    This decision pushes back against that trend.

    The Federal Circuit rejected an overly rigid approach that would have required patent owners to retain near-complete control in order to satisfy Article III. Instead, the court reaffirmed that the constitutional inquiry focuses on whether the plaintiff retains a concrete exclusionary interest, not whether it retained every commercially significant patent right.

    That distinction is likely to matter in:

    • technology transfer agreements;
    • university licensing structures;
    • private equity-backed patent monetization programs;
    • cross-licensing arrangements;
    • joint venture commercialization models; and
    • field-restricted exclusive licenses.

    The opinion may be especially important in industries where commercialization and enforcement responsibilities are intentionally separated between operating companies and patent-holding entities.

    A Continuing Cleanup of Federal Circuit Standing Doctrine

    Viewed more broadly, the case represents another step in the Federal Circuit’s continuing effort to rationalize patent standing doctrine after years of doctrinal overlap.

    The court openly acknowledged that its own precedents contributed to confusion by “melding” constitutional and statutory analyses together.

    This opinion attempts to restore analytical discipline by:

    • distinguishing Article III injury from § 281 entitlement;
    • clarifying that factual overlap does not collapse the doctrines;
    • reaffirming the importance of retained exclusionary rights; and
    • rejecting bright-line rules based solely on exclusive licensing status.

    For patent litigators, the opinion will likely become a frequently cited authority in future standing disputes involving exclusive licenses.

    For transactional lawyers, it offers a useful blueprint for preserving enforcement flexibility without undermining commercial exclusivity.

    And for district courts, the decision provides clearer direction on how to analyze retained patent rights without conflating constitutional standing with statutory standing doctrine.

    By Charles Gideon Korrell

  • mCom v. City National: Federal Circuit Reins in Patent Fee Awards After Post-IPR Dismissal

    mCom v. City National: Federal Circuit Reins in Patent Fee Awards After Post-IPR Dismissal

    The Federal Circuit’s recent decision in mCom IP, LLC v. City National Bank of Florida , Case No. 24-2089 (Fed. Cir. May 15, 2026),offers an important reminder that losing a patent case, even badly, does not automatically make a case “exceptional” under 35 U.S.C. § 285. The opinion also reinforces that sanctions against counsel under 28 U.S.C. § 1927 require more than weak pleadings or imperfect litigation strategy.

    The case sits at the intersection of several recurring issues in modern patent litigation: the effect of inter partes review proceedings on surviving patent claims, the continuing force of the statutory presumption of validity, and the growing tendency of accused infringers to seek attorney’s fees after early dismissals.

    The Federal Circuit ultimately affirmed dismissal of mCom’s infringement suit, but reversed both the district court’s exceptional-case fee award and the sanctions imposed against counsel. In doing so, the court emphasized that courts must distinguish between a losing patent claim and an objectively unreasonable one.

    For patent litigators and companies defending infringement suits, the opinion provides meaningful guidance on the limits of fee-shifting after an IPR. For patent owners, the decision confirms that surviving claims continue to enjoy the statutory presumption of validity even where related claims have already been invalidated at the PTAB.

    The Banking Patent at Issue

    The dispute arose from U.S. Patent No. 8,862,508, directed to a “unified electronic banking system” intended to integrate various electronic banking “touch points,” including ATMs, online banking systems, kiosks, and mobile devices.

    The patent generally proposed using a “multi-channel server” to unify banking interactions and permit personalized services and targeted marketing across banking platforms.

    Before the present litigation, most of the patent’s claims had already been challenged in an inter partes review brought by Unified Patents. In February 2023, the PTAB held the challenged claims unpatentable for obviousness. Notably, however, four claims were never challenged in the IPR: claims 2, 8, 14, and 17. mCom later asserted those surviving claims against City National Bank of Florida.

    District Court Dismissal and Fee Award

    The district court dismissed the complaint with prejudice. It concluded that the asserted claims were invalid because they were not “patentably distinct” from the claims invalidated in the IPR and also found that the infringement allegations were inadequately pleaded.

    The district court then went further. It awarded attorney’s fees against mCom under § 285 and imposed separate sanctions against mCom’s counsel under § 1927.

    On appeal, the Federal Circuit affirmed the dismissal but reversed both fee-related rulings.

    The Federal Circuit Affirms Invalidity

    The affirmance of invalidity was relatively straightforward. The Federal Circuit noted that mCom’s appellate briefing largely failed to engage with the district court’s actual obviousness ruling. Instead, mCom focused primarily on patent eligibility arguments under § 101.

    That strategy proved ineffective because the district court had not invalidated the claims under § 101. Rather, the dismissal rested on obviousness under § 103. The Federal Circuit explained that eligibility and obviousness are distinct inquiries, citing Diamond v. Diehr for the principle that subject matter eligibility does not immunize claims from obviousness challenges.

    As a result, the court had little difficulty affirming dismissal of the complaint itself.

    Mere Invalidity Is Not Enough for § 285

    The more consequential aspect of the opinion concerns the reversal of the fee award and sanctions.

    The district court had concluded that the case was exceptional for several reasons: the asserted claims were invalid, the pleadings were deficient, mCom allegedly failed to investigate a potential license defense arising from a prior NCR settlement agreement, and mCom purportedly engaged in a pattern of filing suits designed to obtain nuisance-value settlements.

    The Federal Circuit rejected each rationale.

    First, the court emphasized that “mere invalidity is not legally sufficient to find a case exceptional.” Under Octane Fitness, the question is not simply whether the patentee lost, but whether the litigating position was unusually weak or unreasonable. The panel explained that a patent infringement suit becomes exceptional only when the claims are “unusually or extraordinarily weak.”

    That distinction mattered here because the asserted claims had never been adjudicated in the IPR. They still enjoyed the statutory presumption of validity under 35 U.S.C. § 282.

    This aspect of the opinion may become particularly important in future post-IPR litigation. The Federal Circuit effectively recognized that surviving claims are not automatically doomed merely because related claims were invalidated earlier.

    Charles Gideon Korrell notes that this portion of the opinion reinforces an important structural feature of patent law: each claim is presumed valid independently. Even after a sweeping PTAB loss, unchallenged claims do not simply inherit invalidity findings by association.

    The Court Emphasizes Differences Between IPRs and District Court Litigation

    The court also highlighted a procedural nuance that practitioners should not overlook. The Federal Circuit observed that obviousness in district court may involve different burdens and evidentiary considerations than in an IPR proceeding. The panel cited both Kroy IP Holdings v. Groupon and ParkerVision v. Qualcomm in recognizing those distinctions.

    This portion of the decision is particularly significant because accused infringers increasingly attempt to use PTAB outcomes as a shortcut to invalidate related claims in district court litigation. The Federal Circuit signaled that the analysis remains claim-specific and context-dependent.

    Charles Gideon Korrell believes that litigants should view this decision as a warning against overreading PTAB rulings when unchallenged claims remain in force.

    Pleading Deficiencies Alone Do Not Create an Exceptional Case

    The Federal Circuit similarly rejected reliance on pleading deficiencies as a basis for exceptionality. The district court had previously struck the original complaint as a “shotgun pleading” because it improperly combined multiple theories of infringement into a single count. But the Federal Circuit characterized this as merely a formal pleading problem, not evidence of substantive bad faith or exceptionally weak claims.

    That distinction matters because district courts increasingly confront poorly structured patent complaints following the continued tightening of pleading standards after Twombly and Iqbal. The Federal Circuit’s opinion suggests that pleading deficiencies alone generally should not justify fee shifting absent something more egregious.

    The NCR License Defense Failed to Support Fees

    The treatment of the NCR license issue is also notable.

    City National argued that mCom should have discovered before filing suit that City National allegedly enjoyed protection under a prior settlement and license agreement between mCom and NCR. But the Federal Circuit found the record insufficient to support that theory. The panel noted that the district court never actually found that City National possessed a valid license covering the accused conduct.

    Indeed, City National conceded at oral argument that the issue remained unadjudicated.

    The Federal Circuit further emphasized that license and release are affirmative defenses under Rule 8(c). The opinion strongly suggests that patentees generally are not obligated to negate every possible affirmative defense before filing suit.

    Charles Gideon Korrell believes that this portion of the opinion may prove particularly useful in resisting future fee motions based on undeveloped licensing theories. The court appeared unwilling to permit fee shifting based on defenses that themselves had never been conclusively established.

    The Federal Circuit Rejects the “Nuisance Settlement” Narrative

    The court also dismantled City National’s “nuisance settlement” narrative.

    City National had argued that mCom repeatedly filed patent suits that settled before adjudication, supposedly demonstrating a strategy of extracting nuisance-value settlements. But the Federal Circuit found virtually no evidentiary support for that assertion.

    Critically, City National failed to provide evidence regarding settlement values or whether the other cases even involved the same patent.

    The Federal Circuit’s skepticism here is important. Accused infringers frequently attempt to characterize non-practicing entities or repeat plaintiffs as pursuing nuisance settlements. This opinion indicates that generalized accusations and litigation statistics alone may not suffice.

    Sanctions Under § 1927 Require More Than Weak Litigation Conduct

    The reversal of the § 1927 sanctions against counsel followed naturally from the court’s rejection of the exceptional-case determination.

    Under Eleventh Circuit law, § 1927 sanctions require conduct “tantamount to bad faith.” The Federal Circuit emphasized that the district court never expressly found the case frivolous.

    Instead, the district court essentially faulted counsel for insufficient diligence and for continuing the litigation. But because the claims were not frivolous, litigating the case through a Rule 12(b)(6) ruling was not sanctionable conduct.

    Charles Gideon Korrell notes that the opinion draws an important line between weak lawyering and sanctionable bad faith. The Federal Circuit made clear that imperfect litigation judgment, without more, does not satisfy § 1927’s demanding standard.

    The Court Rejects a “Second Major Litigation” Over Fees

    The opinion closes with another subtle but significant point. Rather than remanding for additional proceedings on fees, the Federal Circuit reversed outright, citing Fox v. Vice and cautioning that fee litigation should not become “a second major litigation.”

    That directive may discourage defendants from pursuing speculative fee motions unsupported by a developed factual record. Courts increasingly appear concerned about satellite litigation over attorney’s fees consuming disproportionate resources after merits proceedings have already concluded.

    Key Takeaways

    Ultimately, mCom v. City National reflects a broader trend in Federal Circuit jurisprudence: while district courts retain substantial discretion under Octane Fitness, that discretion still has meaningful limits. Patent cases are not exceptional merely because the plaintiff loses, survives only briefly, or asserts claims related to others invalidated in an IPR.

    The decision also reinforces the continuing importance of the statutory presumption of validity, even in the shadow of prior PTAB losses. Surviving claims remain entitled to individualized treatment, and courts cannot simply collapse them into previously invalidated claims without careful analysis.

    Charles Gideon Korrell believes the decision will likely become a frequently cited authority in future disputes over post-IPR fee shifting, particularly where surviving claims continue to carry the presumption of validity despite the cancellation of related claims.

    By Charles Gideon Korrell

  • Actelion v. Mylan: Federal Circuit Limits Equivalents Theory After Ambiguous pH Claim Construction

    Actelion v. Mylan: Federal Circuit Limits Equivalents Theory After Ambiguous pH Claim Construction

    The Federal Circuit’s decision in Actelion Pharmaceuticals Ltd. v. Mylan Pharmaceuticals Inc., Case No. 24-1641 (Fed. Cir. May 13, 2026), provides an important reminder that scientific terminology in patent claims is not interpreted in a vacuum. Even seemingly straightforward numerical limitations can become highly contextual when industry standards, measurement conventions, and prosecution history intersect.

    In a precedential opinion authored by Judge Taranto, the Federal Circuit affirmed a finding of non-infringement in a Hatch-Waxman dispute involving epoprostenol formulations used to treat pulmonary arterial hypertension. The court held that the phrase “a pH of 13 or higher” referred to a pH measurement taken at the pharmaceutical industry’s standard reference temperature of 25±2°C, rather than the colder manufacturing temperature used in Mylan’s process. The court also rejected Actelion’s doctrine of equivalents arguments under both prosecution history estoppel and the disclosure-dedication rule.

    The opinion is notable not only for its treatment of claim construction, but also because it demonstrates how ambiguity in scientific measurement standards can narrow patent scope in ways patentees may not anticipate during drafting or prosecution.

    The case also reinforces the Federal Circuit’s continuing emphasis on contextual claim interpretation under Phillips v. AWH Corp., particularly where specialized scientific conventions inform how a skilled artisan would understand a claim term.

    The Technology and the Dispute

    Actelion owns U.S. Patent Nos. 8,318,802 and 8,598,227, which relate to stabilized epoprostenol formulations marketed as Veletri®. Epoprostenol is chemically unstable in water and degrades rapidly in acidic environments. The patents sought to improve stability by using highly alkaline bulk solutions during manufacture.

    Prior epoprostenol products such as Flolan required refrigeration and specialized diluents. Actelion’s patents described formulations that could remain stable at room temperature and be reconstituted with ordinary intravenous fluids. The patents emphasized the importance of achieving very high pH values in the manufacturing bulk solution.

    Representative claim 1 required a lyophilized pharmaceutical composition “formed from a bulk solution having a pH of 13 or higher.”

    The dispute centered on how that pH should be measured.

    Mylan’s ANDA product used refrigerated bulk solutions during manufacturing. When measured at the colder operating temperature, the solution exceeded pH 13. But when measured at the pharmaceutical industry’s conventional reference temperature of 25±2°C, the pH fell below 12.98, the threshold established during earlier claim construction proceedings.

    That difference proved dispositive.

    The Federal Circuit’s Contextual Reading of “pH 13”

    The most important aspect of the decision is the court’s methodology.

    Actelion argued that “pH of 13 or higher” should mean the actual pH of the solution during manufacture, regardless of temperature. Mylan argued that a skilled artisan would understand pH references in pharmaceutical patents to refer to measurements taken at standard temperature unless otherwise specified.

    The Federal Circuit agreed with Mylan.

    Importantly, the court acknowledged that the claim language itself did not expressly resolve the issue. The phrase “pH of 13 or higher” did not specify the conditions under which pH should be measured.

    The court therefore turned to the specification and extrinsic evidence.

    The specification repeatedly discussed pH values and comparative testing results, but nowhere expressly stated that pH should be measured at manufacturing temperature. Instead, the court found that the patent implicitly assumed standard-temperature measurements because the specification defined “alkaline” environments as those with pH greater than 7, a definition that is accurate only at standard temperature.

    The court also emphasized the consistency of the specification’s experimental data. The reported results compared various pH values in a straightforward manner without discussing temperature-adjusted measurement techniques, suggesting that the same measurement convention applied throughout.

    Extrinsic evidence then reinforced that interpretation.

    The court relied heavily on the United States Pharmacopeia (USP), which states that pH measurements are taken at 25±2°C unless otherwise specified. The Federal Circuit viewed this as powerful evidence of how a skilled artisan in pharmaceutical manufacturing would understand pH references.

    Charles Gideon Korrell notes that the opinion reflects a broader trend in Federal Circuit jurisprudence toward incorporating technical industry conventions directly into claim interpretation, even where the claims themselves are facially silent on the issue.

    The court’s reliance on industry standards is particularly consistent with Phillips, which instructs courts to determine how a person of ordinary skill in the art would understand claim language in context. Here, the USP effectively became part of the contextual backdrop against which the claims were interpreted.

    The Earlier Significant Figures Dispute

    The pH ambiguity in this case had already produced one Federal Circuit appeal before the present decision.

    In the earlier appeal, the court addressed whether “pH 13” included values rounded to 13 using ordinary rounding principles. The Federal Circuit vacated the district court’s initial construction and held that extrinsic evidence was required to resolve the issue. Actelion Pharmaceuticals Ltd. v. Mylan Pharmaceuticals Inc., 85 F.4th 1167 (Fed. Cir. 2023).

    On remand, the district court concluded that “pH 13” encompassed values of 12.98 or greater because of significant-figure conventions.

    The present appeal then addressed a second ambiguity layered on top of the first: not what numerical values counted as “13,” but at what temperature the pH measurement should occur.

    The result was a rare example of a patent term requiring two separate rounds of Federal Circuit analysis because of scientific ambiguity embedded in a short numerical limitation.

    Doctrine of Equivalents Also Failed

    After losing on literal infringement, Actelion turned to the doctrine of equivalents. The Federal Circuit rejected that theory on two independent grounds.

    First, prosecution history estoppel barred recovery.

    During prosecution, Actelion amended its claims from “greater than 12” to “13 or higher” in response to an obviousness rejection. The examiner had specifically indicated that unexpected results had only been demonstrated at the pH 13 threshold.

    Actelion argued that the amendment was only tangentially related to the accused equivalent because the alleged equivalent achieved the same chemical functionality through cold-temperature operation.

    The Federal Circuit disagreed. The court held that the amendment directly related to the significance of the pH threshold itself. Because the amendment narrowed the claims to secure patentability, Actelion could not later recapture lower pH values through equivalence.

    The court’s analysis closely tracked Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., which established the modern framework for prosecution history estoppel. The panel emphasized that the “discernible objective reason” for the amendment was establishing the criticality of pH 13.

    Second, the disclosure-dedication rule independently barred the equivalents theory.

    The specification expressly disclosed bulk-solution pH ranges of 12.5-13.5 and “greater than 12,” while the claims ultimately recited only “13 or higher.”

    Relying on Johnson & Johnston Associates Inc. v. R.E. Service Co., the court held that disclosed-but-unclaimed pH ranges were dedicated to the public and could not later be recaptured under the doctrine of equivalents.

    Actelion argued that the doctrine should not apply because the disclosed ranges overlapped with the claimed range. The court rejected that argument, explaining that overlapping alternatives can still be clearly disclosed and partially unclaimed.

    Charles Gideon Korrell believes the disclosure-dedication analysis may ultimately have broader significance than the claim construction ruling itself. Patent drafters frequently include broad ranges and preferred embodiments in specifications without fully appreciating how later narrowing amendments may convert those disclosures into dedicated subject matter.

    Practical Drafting Lessons

    The decision contains several important drafting and litigation lessons for pharmaceutical and chemical patents.

    First, measurement conditions matter. If a claim limitation depends on temperature, pressure, humidity, or another environmental variable, the patent should expressly specify measurement protocols. Silence may invite courts to import industry defaults.

    Second, specifications should define whether scientific measurements refer to operational conditions or standardized laboratory conditions. The absence of such clarification can create ambiguity that is resolved through extrinsic evidence.

    Third, patentees should carefully consider the long-term implications of narrowing amendments during prosecution. As this case demonstrates, amendments designed to overcome obviousness rejections can later eliminate meaningful equivalents arguments.

    Fourth, disclosed-but-unclaimed numerical ranges remain dangerous. Once disclosed, those ranges may become unavailable under the disclosure-dedication rule.

    Charles Gideon Korrell notes that the case also demonstrates how pharmaceutical patent litigation increasingly turns on technical conventions and measurement assumptions that may initially appear mundane but ultimately determine infringement outcomes.

    The decision is particularly instructive for product-by-process claims, where manufacturing conditions often intersect with product properties in scientifically complex ways.

    A Broader Trend Toward Scientific Precision

    The Federal Circuit’s opinion fits within a broader pattern of increasingly technical patent claim interpretation.

    Rather than treating claim language as linguistically self-contained, the court continues to emphasize the understanding of skilled artisans operating within real-world technical disciplines. Here, that meant recognizing that pH measurements in pharmaceutical science carry embedded assumptions about temperature unless otherwise specified.

    The decision therefore serves as another reminder that patent claims are interpreted not merely as legal text, but as technical communications directed toward specialized scientific communities.

    For patentees, that reality creates both opportunity and risk. Industry conventions can clarify ambiguous language when favorable, but they can also narrow claim scope in unexpected ways.

    By Charles Gideon Korrell

  • Bissell v. ITC: Firmware Redesign Defeats ITC Exclusion Order

    Bissell v. ITC: Firmware Redesign Defeats ITC Exclusion Order

    When patent owners prevail in Section 337 investigations before the International Trade Commission, the resulting exclusion orders can be commercially devastating. But sophisticated respondents increasingly prepare redesign strategies while the investigation is still pending, particularly where the accused functionality is controlled through firmware or software logic.

    The Federal Circuit’s decision in Bissell, Inc. v. International Trade Commission, Case No. 24-1509 (Fed. Cir. May 11, 2026), illustrates how relatively narrow firmware timing modifications can successfully avoid infringement findings, even after the original products were found infringing and subjected to an exclusion order.

    The case also offers several broader lessons for patent litigators and technology companies:

    • the distinction between claim construction and factual infringement determinations,
    • the continued difficulty of prevailing under the doctrine of equivalents,
    • the deferential substantial evidence standard governing ITC appeals, and
    • expert reliance on source code under Federal Rule of Evidence 703.

    Charles Gideon Korrell notes that the opinion is less significant for its underlying wet/dry vacuum technology than for its broader implications regarding software redesign strategies and appellate framing in patent litigation.

    The Patented Technology

    The asserted patents, U.S. Patent Nos. 11,076,735 and 11,071,428, involve wet/dry floor cleaning systems with automated self-cleaning functionality.

    The patents describe devices that automatically clean the brushroll while docked on a charging station. A key feature of the invention was a safeguard relating to battery charging during the self-cleaning cycle. According to the specification, allowing simultaneous charging and self-cleaning could overload the wall charger’s power capacity.

    As a result, the patents required that:

    • the “battery charging circuit is disabled by the actuation of the self-cleaning mode input control”; and
    • the charging circuit “remains disabled during the unattended automatic cleanout cycle.”

    That “remains disabled” language ultimately became the centerpiece of the appeal.

    Tineco’s Redesign Strategy

    Bissell filed its ITC complaint against Tineco’s original products, including the Floor One S3 and S5 Pro devices. The Commission ultimately found those original products infringed and entered a limited exclusion order.

    But during the investigation itself, Tineco implemented redesigned firmware for later product versions. The redesign did not eliminate the self-cleaning cycle altogether. Instead, it altered the timing of battery charging during the 120-second automated cleanout process.

    The timing diagrams reproduced in the opinion show that the redesigned products briefly activated charging twice during the cleanout cycle: once near the beginning and once again around the midpoint.

    That seemingly minor firmware modification became dispositive.

    The Administrative Law Judge concluded that because the battery charging circuit activated during the cycle, it no longer “remained disabled during the unattended automatic cleanout cycle.”

    Accordingly, the redesigned products were found noninfringing.

    Google v. EcoFactor and the Boundary Between Claim Construction and Fact Finding

    The most important precedential discussion in the opinion involves the Federal Circuit’s treatment of Google LLC v. EcoFactor, Inc.

    Bissell attempted to characterize the dispute as involving improper claim construction. That strategy was important because claim construction issues receive de novo review on appeal, while factual infringement findings are reviewed only for substantial evidence.

    The Federal Circuit rejected Bissell’s characterization and distinguished EcoFactor directly.

    In EcoFactor, the Federal Circuit had concluded that the tribunal effectively supplied substantive “scope and boundaries” for claim language where the claim text itself did not provide sufficient guidance. In Bissell, however, the panel concluded that the ALJ merely applied the ordinary meaning of the phrase “remains disabled” to the operational behavior of the redesigned products.

    According to the court, no new claim construction occurred.

    Instead, the ALJ simply evaluated competing infringement theories, made credibility determinations regarding expert testimony, and concluded that the redesigned products charged during the cleanout cycle.

    That distinction was outcome determinative.

    Because Bissell framed its appeal almost entirely as a claim construction issue, and did not substantially challenge the evidentiary sufficiency of the Commission’s factual findings, the Federal Circuit had little difficulty affirming.

    Charles Gideon Korrell believes this portion of the opinion provides an important warning for appellate practitioners. Parties frequently attempt to recharacterize unfavorable factual findings as legal claim construction disputes in order to obtain de novo review. Bissell demonstrates the risk of relying too heavily on that strategy where the Federal Circuit views the dispute as ordinary application of claim language to technical facts.

    Doctrine of Equivalents Also Failed

    Bissell alternatively argued infringement under the doctrine of equivalents.

    Again, the Federal Circuit affirmed the Commission.

    The ALJ had found unpersuasive Bissell’s theory that a charging circuit which intermittently charges during the cleanout cycle was insubstantially different from a claim requiring the charging circuit to remain disabled during that cycle.

    The Federal Circuit concluded this was a factual determination regarding equivalence, not a legal application of claim vitiation.

    This portion of the opinion is particularly important because it underscores how difficult it can be to establish equivalence where the accused redesign intentionally reverses or negates a claimed operational requirement.

    Here, the claim required charging to remain disabled. The redesign intentionally introduced charging activity into the cycle. That made the equivalence argument considerably weaker.

    The opinion fits within a broader Federal Circuit trend of limiting doctrine of equivalents theories where the proposed equivalent threatens to erase meaningful claim limitations. Although the panel avoided explicitly invoking “claim vitiation” as a standalone doctrine, the practical effect was similar.

    Broader Implications

    Bissell v. ITC illustrates several important realities about modern patent enforcement:

    First, firmware and software redesigns can be extraordinarily effective in avoiding exclusion orders where claim limitations are tied to operational timing or state transitions.

    Second, parties must carefully distinguish between factual disputes and claim construction disputes on appeal. Mischaracterizing the nature of the issue can substantially narrow appellate review.

    Third, doctrine of equivalents theories remain difficult where the accused redesign intentionally alters a core claimed behavior.

    Finally, evidentiary attacks on expert reliance materials must often be developed aggressively at the trial level. Rule 703 gives experts considerable flexibility to rely on technical materials that are not themselves formally admitted into evidence.

    For ITC practitioners especially, the case reinforces the importance of developing redesign analyses early, preserving factual appellate challenges carefully, and treating software timing logic as a potentially decisive infringement issue.

    By Charles Gideon Korrell

  • Enviro Tech v. Safe Foods: Federal Circuit Invalidates “About” pH Range Claims as Indefinite

    Enviro Tech v. Safe Foods: Federal Circuit Invalidates “About” pH Range Claims as Indefinite

    The Federal Circuit’s decision in Enviro Tech Chemical Services, Inc. v. Safe Foods Corp., Case No. 24-2160 (Fed. Cir May 4, 2026), adds another important chapter to the growing body of indefiniteness law applying Nautilus to “terms of approximation” such as “about,” “approximately,” and “substantially.” In a precedential opinion authored by Judge Lourie, the court affirmed invalidation of patent claims directed to poultry-processing methods because the patent failed to provide objective guidance regarding the permissible variance associated with the claimed pH range of “about 7.6 to about 10.”

    The decision is notable because the Federal Circuit did not hold that the word “about” is inherently indefinite. To the contrary, the panel reaffirmed decades of precedent recognizing that approximation language can be appropriate in patent claims. The problem for Enviro Tech was that its specification and prosecution history pointed in multiple directions, leaving a skilled artisan without reasonable certainty regarding the claim boundaries.

    For patent prosecutors and litigators, the opinion provides a practical warning: when a numerical range becomes important for patentability over prior art, vague approximation language may not survive scrutiny unless the intrinsic record clearly defines the permissible tolerance.

    Charles Gideon Korrell notes that the case is particularly important for chemical, pharmaceutical, and biotechnology patents, where words like “about” are frequently used to accommodate experimental variability and manufacturing tolerances.

    The Technology and Claimed Invention

    Enviro Tech’s U.S. Patent No. 10,912,321 concerned methods for treating poultry carcasses with peracetic acid during processing. The patent purported to improve poultry weight retention during processing by adjusting the pH of the antimicrobial solution to a more alkaline range.

    Representative claim 1 required adjusting the pH of the peracetic acid-containing water “to a pH of about 7.6 to about 10 by adding an alkaline source.”

    Safe Foods challenged the claims as indefinite under 35 U.S.C. § 112(b), arguing that the terms “about” and “an antimicrobial amount” failed to provide reasonable certainty regarding claim scope. The district court agreed as to both terms and invalidated the asserted claims.

    On appeal, the Federal Circuit affirmed based solely on the indefiniteness of “about,” declining to reach the separate issue concerning “antimicrobial amount.”

    The Federal Circuit’s Indefiniteness Framework

    The panel began with the familiar Nautilus standard, explaining that claims are indefinite if, when read in light of the specification and prosecution history, they fail to inform skilled artisans “with reasonable certainty” about the scope of the invention.

    The court relied heavily on prior Federal Circuit decisions addressing words of approximation, including:

    Those cases collectively establish that terms like “about” are not automatically valid or invalid. Instead, the acceptability of approximation language depends on whether the intrinsic and extrinsic evidence provide objective guidance regarding the range of acceptable deviation.

    The Federal Circuit emphasized that the permissible scope of “about” depends on the “technological facts of the particular case.”

    That principle has existed for decades, but Enviro Tech demonstrates that courts are increasingly willing to scrutinize whether the patent actually provides workable boundaries.

    The Claims Provided No Objective Guidance

    The panel first examined the claim language itself. Claim 1 required a pH “of about 7.6 to about 10,” but the claims never explained how far below 7.6 or above 10 the solution could deviate while still falling within the claim scope.

    Both parties agreed that “about” meant “approximately,” but the court concluded that substituting one vague term for another solved nothing. The opinion quoted Interval Licensing for the proposition that a claim remains indefinite if a skilled artisan cannot translate the language into “meaningfully precise claim scope.”

    This portion of the opinion reflects a broader post-Nautilus trend. Courts increasingly require objective anchors for subjective or approximation language. Merely invoking industry understanding or ordinary meaning is often insufficient unless the patent itself provides workable standards.

    The Specification Hurt More Than It Helped

    The specification proved especially damaging to Enviro Tech because it contained inconsistent examples regarding acceptable pH deviations.

    Many examples suggested that deviations of 0.3 pH units or less were acceptable. In several experiments, Enviro Tech adjusted the pH when the measured value differed from the target by more than 0.3.

    But the specification also included important exceptions. Some experiments continued despite deviations greater than 0.3.

    One particularly significant experiment involved processing 5.8 million chickens in a commercial poultry-processing plant while tolerating deviations between 0.35 and 0.5 pH units.

    The Federal Circuit considered that example highly informative because the patent’s objective was commercial-scale poultry processing. The large-scale industrial example therefore undermined any argument that 0.3 represented a meaningful boundary.

    The court ultimately concluded that the specification’s “conflicting guidance” failed to provide reasonable certainty regarding the meaning of “about.”

    Charles Gideon Korrell believes this aspect of the opinion is particularly important because it illustrates a recurring drafting problem: patentees often include numerous experimental examples without considering whether those examples establish conflicting implicit claim boundaries.

    In some circumstances, more examples improve enablement and written description support. But in Enviro Tech, the additional examples effectively created internal contradictions about the permissible tolerance range.

    The Prosecution History Was Equally Problematic

    The prosecution history also undermined Enviro Tech’s position.

    The Federal Circuit observed that Enviro Tech treated “about” inconsistently during prosecution. In one argument distinguishing prior art, Enviro Tech referred to “pH 7.6” without using “about.” Yet in another argument on the next page, it referred to “about 8 to about 9.”

    The court concluded that the applicant never explained what “about” meant and treated the term inconsistently throughout prosecution.

    Relying on Infinity Computer Products v. Oki Data Americas, the panel explained that inconsistent prosecution statements can contribute to indefiniteness when the claims and specification already leave uncertainty unresolved.

    Enviro Tech attempted to salvage the claims by arguing that its amendment from “about 7.3” to “about 7.6” implicitly established a 0.3-unit permissible variance.

    The court rejected that theory because the amendment was not accompanied by any explanatory remarks defining the scope of “about.”

    That discussion underscores another important prosecution lesson: if approximation language matters to patentability, practitioners should consider explicitly defining the intended tolerance during prosecution rather than relying on inference.

    The Prior Art Proximity Mattered

    Perhaps the most striking part of the opinion appears near the end, where the court explained that the proximity of the prior art heightened the need for precision.

    The panel noted that the prior art disclosed pH values as close as 7.0, while the claims were amended to require “about 7.6.”

    The court then delivered the opinion’s key takeaway:

    “The prior art is almost ‘about’ a pH of 7.6.”

    That sentence will likely appear in future indefiniteness briefing for years.

    The Federal Circuit effectively recognized a practical relationship between indefiniteness and patentability. When an applicant narrows a numerical range to avoid close prior art, approximation language cannot remain untethered and vague. The narrower the distinction over the prior art, the greater the need for objective claim boundaries.

    Charles Gideon Korrell notes that this reasoning may become increasingly important in crowded technology areas where patentability often turns on relatively small numerical differences.

    Relationship to Other Recent Federal Circuit Decisions

    The decision fits within a broader trend of Federal Circuit scrutiny toward subjective and flexible claim language.

    The court’s reasoning closely resembles recent cases requiring objective standards for terms of degree, including:

    What distinguishes Enviro Tech is the court’s detailed focus on internal inconsistencies within the specification itself. The patent did not fail because it lacked examples. It failed because the examples suggested multiple competing answers.

    That creates a difficult drafting tension for patent prosecutors. Rich experimental disclosures can strengthen enablement and written description support, but they can also unintentionally create ambiguity regarding claim scope.

    Practical Drafting Lessons

    The decision offers several practical lessons for prosecutors and litigators:

    1. Define Approximation Terms Explicitly

    If “about” is intended to permit a particular tolerance range, the specification should say so directly.

    2. Avoid Conflicting Experimental Standards

    Examples should consistently reflect the intended claim boundary. Multiple tolerance conventions may later be characterized as evidence of indefiniteness.

    3. Be Careful When Narrowing Around Prior Art

    Approximation language becomes more vulnerable when claims are amended to avoid closely neighboring prior art.

    4. Create a Clear Prosecution Record

    If approximation language matters, prosecution remarks should explain the intended scope and permissible variance.

    5. Consider Whether “About” Is Necessary

    In some situations, practitioners may be better served by reciting explicit tolerance ranges or measurement error margins instead of relying on open-ended approximation terms.

    Charles Gideon Korrell believes the opinion may encourage prosecutors to rely more heavily on expressly defined tolerances rather than generic modifiers like “about” or “approximately,” particularly in chemical and life sciences applications.

    Conclusion

    Enviro Tech v. Safe Foods reinforces that approximation language survives only when the intrinsic record provides objective guidance regarding claim scope. The Federal Circuit did not reject “about” categorically. Instead, it held that the patent’s claims, specification, and prosecution history collectively failed to establish a reasonably certain boundary.

    The decision also highlights a recurring post-Nautilus theme: ambiguity created during drafting and prosecution can become fatal when a patent later relies on flexible language to distinguish close prior art.

    For patent practitioners, the case serves as a reminder that words of approximation require careful support, consistent treatment, and clear objective boundaries. Otherwise, the effort to preserve flexibility may ultimately destroy enforceability altogether.

    By Charles Gideon Korrell

    Here is my coverage of the Nautilus case.