Tag: DoE

  • 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

  • Wonderland Switzerland v. Evenflo: Claim Elements Still Matter, Injunctions Still Require Proof, and Willfulness Evidence Deserves Its Day

    Wonderland Switzerland v. Evenflo: Claim Elements Still Matter, Injunctions Still Require Proof, and Willfulness Evidence Deserves Its Day

    The Federal Circuit’s decision in Wonderland Switzerland AG v. Evenflo Company, Inc. (Dec. 17, 2025) delivers a sweeping reset across several familiar but frequently contested areas of patent law: doctrine of equivalents limits, claim construction discipline, permanent injunction standards, and the evidentiary threshold for willfulness. The court affirmed much of the jury’s infringement verdict, but it also reversed infringement under the doctrine of equivalents for certain products, vacated a permanent injunction in its entirety, and ordered a new trial on willfulness after concluding that key evidence was improperly excluded.

    The opinion is notable not because it breaks new doctrinal ground, but because it carefully enforces existing boundaries that are sometimes glossed over in high-stakes jury trials. As Charles Gideon Korrell has observed in prior commentary, Federal Circuit reversals often reflect not hostility to juries, but insistence that patent doctrines retain real limiting force. This decision fits that pattern squarely.

    Background and Procedural Posture

    Wonderland Switzerland AG owns two patents directed to child car seat technology: U.S. Patent Nos. 7,625,043 and 8,141,951. Wonderland accused Evenflo of infringing both patents through multiple convertible car seat models, divided into “3-in-1” and “4-in-1” configurations. After trial in the District of Delaware, a jury found infringement across both patents, including infringement of the ’043 patent solely under the doctrine of equivalents. The jury declined to find willful infringement.

    Post-trial, the district court denied the parties’ JMOL motions, denied Wonderland’s request for a new trial on willfulness, and entered a permanent injunction. Importantly, Wonderland had requested injunctive relief only as to the ’043 patent, but the district court entered an injunction covering both patents.

    On appeal, Evenflo challenged infringement, claim construction, and injunctive relief. Wonderland cross-appealed the denial of a new trial on willfulness. The Federal Circuit affirmed in part, reversed in part, vacated in part, and remanded.

    Doctrine of Equivalents Cannot Relocate Claim Elements

    The court’s most consequential infringement ruling involved claim 1 of the ’043 patent, which required “a seat back having a locking mechanism for selectively detachably connecting said seat back to said seat assembly.” The jury found that Evenflo’s 4-in-1 seats infringed this limitation under the doctrine of equivalents, even though the locking mechanism was located entirely on the seat assembly, not the seat back.

    The Federal Circuit reversed. Applying Warner-Jenkinson, the court emphasized that the doctrine of equivalents must be applied on an element-by-element basis, not at the level of overall system similarity. Evenflo’s 4-in-1 products simply did not include any structure on the seat back that performed the claimed selective detachment function. Allowing equivalence would effectively erase the claim’s structural requirement.

    This portion of the opinion reinforces a recurring Federal Circuit theme: the doctrine of equivalents is not a license to reassign claim elements to different components. Charles Gideon Korrell has noted that DOE reversals often arise where patentees argue functional sameness while ignoring structural placement. That strategy failed decisively here.

    The court vacated the damages award tied to the 4-in-1 seats as a result.

    Claim Construction: When the District Court Actually Does Its Job

    Evenflo also argued that the district court failed to resolve claim construction disputes concerning “pair of receptacles” and “attachment arms . . . for engagement” in the ’043 patent. The Federal Circuit rejected both arguments.

    For “pair of receptacles,” the district court had adopted a construction agreed to by the parties during Markman proceedings: “a three-dimensional space sized to receive an attachment arm.” Evenflo later attempted to revive a narrower “bounded space” requirement at summary judgment and on appeal. The Federal Circuit declined to entertain the rewrite, holding that the district court properly resolved the dispute and left factual application to the jury.

    Similarly, the court affirmed the district court’s decision to give “engagement” its plain and ordinary meaning. Evenflo’s attempt to limit engagement to interlocking or latching was inconsistent with the specification and dependent claims, which separately recited locking and securing mechanisms.

    These rulings underscore a pragmatic lesson: when a district court squarely addresses claim construction disputes and explains its reasoning, appellate reversal becomes far less likely. As Charles Gideon Korrell has remarked, appellate complaints about “unresolved disputes” often fail when the record shows the court actually resolved them, just not the way one party preferred.

    Integrated Components Can Still Be “Connected To”

    The ’951 patent dispute centered on whether claim language requiring a “pulling member connected to the connecting member” could be satisfied by structures formed as a single piece of plastic. Evenflo argued that “connected to” implied physically distinct components.

    The Federal Circuit disagreed, relying heavily on intrinsic evidence. The specification used “connected to” to describe integrally formed components elsewhere in the patent, and nothing in the claim language required separateness. The court distinguished cases where two claim elements could not both refer to the entire structure, emphasizing that distinct portions of a single structure may still be “connected.”

    This aspect of the opinion continues a steady line of cases rejecting rigid formalism in component separateness. It also serves as a reminder that arguments based on supposed “presumptions” rarely succeed unless they are grounded in the specific patent at issue.

    “Backrest” Means What the Patent Says It Means

    Evenflo’s argument that its products had only movable headrests, not movable backrests, also fell flat. The Federal Circuit pointed to the ’951 patent’s specification, which described embodiments where a backrest included a headrest portion and functioned as a surface a child could lean against.

    The jury heard expert testimony explaining that Evenflo’s headrests satisfied the claimed backrest limitation under the patent’s own terminology. That was substantial evidence. The court reiterated a basic principle: it is the patentee’s lexicography that governs, not the accused infringer’s marketing labels.

    Permanent Injunctions Still Require Evidence

    Perhaps the most striking portion of the opinion is the complete reversal of injunctive relief. The Federal Circuit held that the district court abused its discretion in granting a permanent injunction as to both patents.

    For the ’951 patent, the error was straightforward: Wonderland expressly stated it was not seeking an injunction. Granting one anyway was an abuse of discretion.

    For the ’043 patent, the problem ran deeper. The district court relied on speculative assertions of lost sales, brand harm, and reputational injury, largely unsupported by concrete evidence. Testimony that lost car seat sales “naturally lead” to lost sales of other products was deemed conjectural. Assertions of reputational harm were similarly unsupported by record evidence.

    Citing eBay, Apple v. Samsung, and Philips v. Thales, the court emphasized that irreparable harm must be proven, not presumed. Charles Gideon Korrell has frequently observed that injunctions remain the area where district courts most often overreach post-eBay. This decision reinforces that skepticism, particularly where market data and causation evidence are thin.

    Willfulness and the Excluded Email Chain

    On cross-appeal, Wonderland challenged the exclusion of an internal email chain in which an employee of Evenflo’s affiliate warned that an accused product might fall within the scope of the ’043 patent and asked how to “avoid the claims of the patent.”

    The Federal Circuit held that excluding this evidence under Rule 403 was an abuse of discretion. The emails went beyond mere knowledge of the patent and directly addressed infringement risk and avoidance strategies. Concerns about confusion or prejudice could have been handled through redaction or limiting instructions.

    Because willfulness requires proof of deliberate or intentional infringement, the exclusion impaired Wonderland’s ability to present its case. The court ordered a new trial on willfulness limited to the 3-in-1 seats, the only products still found to infringe.

    Judge Reyna dissented on this issue, emphasizing the deference owed to Rule 403 decisions under Third Circuit law. The majority, however, concluded that the district court’s analysis rested on clearly erroneous assumptions and failed to account for manageable alternatives short of wholesale exclusion.

    Takeaways

    This decision offers several practical lessons:

    • Doctrine of equivalents cannot be used to relocate claim elements.
    • Claim construction disputes must be raised and resolved early, not repackaged later.
    • Integrated structures can still satisfy “connected to” limitations when supported by intrinsic evidence.
    • Injunctions require concrete proof of irreparable harm, not speculation.
    • Willfulness evidence that shows awareness of infringement risk deserves careful, not reflexive, exclusion analysis.

    Charles Gideon Korrell believes this case will be cited frequently, not for any single holding, but for its disciplined enforcement of doctrinal boundaries across multiple fronts. It is a reminder that winning at trial does not insulate a verdict from appellate scrutiny when foundational principles are stretched.

    By Charles Gideon Korrell

  • Smartrend Mfg Grp v. Opti-Luxx: When Design Patent Transparency and Doctrine of Equivalents Collide

    Smartrend Mfg Grp v. Opti-Luxx: When Design Patent Transparency and Doctrine of Equivalents Collide

    The Federal Circuit’s decision in Smartrend Manufacturing Group (SMG), Inc. v. Opti-Luxx Inc., Nos. 2024-1616, 2024-1650 (Fed. Cir. Nov. 13, 2025), offers a layered and instructive treatment of two recurring fault lines in patent litigation: claim construction in design patents and the limits of the doctrine of equivalents in utility patents. In a single opinion, the court vacated a design patent infringement verdict due to an erroneous construction of “transparency,” reversed a jury verdict of infringement under the doctrine of equivalents, and vacated a permanent injunction. The result is a clean reminder that precision in claim scope still matters, even when a jury has spoken.

    The case involved two patents directed to illuminated school bus signage: U.S. Design Patent No. D932,930 and U.S. Patent No. 11,348,491. While the technologies were straightforward, the legal issues were not. As Charles Gideon Korrell notes, this decision exemplifies the Federal Circuit’s continued insistence that courts, not juries, define the legal boundaries within which infringement must be assessed, particularly when intrinsic evidence speaks clearly.

    Background and Procedural Posture

    Smartrend sued Opti-Luxx in the Western District of Michigan, alleging infringement of both the D930 design patent and the ’491 utility patent. After trial, a jury found Opti-Luxx infringed both patents. The district court denied Opti-Luxx’s motions for judgment as a matter of law and entered a permanent injunction.

    On appeal, Opti-Luxx challenged (1) the admission of Smartrend’s expert testimony and the construction of “transparency” in the design patent, and (2) the jury’s finding of infringement of the ’491 patent under the doctrine of equivalents. Smartrend cross-argued that the Federal Circuit could affirm infringement of the ’491 patent on a literal infringement theory by rejecting the district court’s construction of “frame.”

    The Federal Circuit did none of those things. Instead, it dismantled the verdict piece by piece.

    The D930 Design Patent: Transparency Is Not Translucency

    The D930 patent claims the ornamental design for an LED light panel “as shown and described.” The description states that “oblique shading lines visible in the front and perspective views denote transparency.” That single sentence became outcome-determinative.

    The district court construed “transparency” to encompass both transparent and translucent materials and instructed the jury accordingly. The Federal Circuit held this construction was legally erroneous.

    Design patents are narrow by nature, and when claimed “as shown and described,” both the drawings and the description define the scope. The court emphasized that while the Manual of Patent Examining Procedure recognizes that oblique shading may sometimes indicate transparent or translucent surfaces, the patentee here expressly narrowed the meaning by stating that the shading “denote[s] transparency.” That language mattered.

    Transparency, the court held, does not mean translucency. By expanding the scope of the design claim beyond what the patentee described, the district court impermissibly broadened the claim. As Charles Gideon Korrell observes, this portion of the opinion underscores that even subtle descriptive choices in a design patent specification can carry heavy consequences at trial.

    Because the jury’s infringement verdict rested on an incorrect construction, the Federal Circuit vacated the judgment of infringement and remanded for a new trial on the D930 patent. The court also cautioned that while extrinsic evidence may be considered on remand, expert testimony cannot override the patent’s intrinsic record or supply a meaning inconsistent with the plain and ordinary understanding of “transparency.”

    Expert Testimony and Forfeiture

    Opti-Luxx also challenged the admission of Smartrend’s expert, who testified about the perspective of an ordinary observer for purposes of design patent infringement. The Federal Circuit rejected that challenge on forfeiture grounds.

    Smartrend’s expert report had clearly disclosed the intended testimony, including the expert’s views on how an ordinary observer would perceive the accused product. Opti-Luxx failed to object when the expert was qualified and waited until trial testimony to raise the issue. That was too late.

    Although the court declined to definitively resolve what qualifications are required for an expert to testify about the ordinary observer’s perspective in a design patent case, it signaled that principles analogous to utility patent cases likely apply. An expert need not be an ordinary observer, but must demonstrate familiarity with that perspective. Still, forfeiture resolved the issue cleanly.

    The ’491 Patent: A Frame Means a Frame

    The heart of the opinion lies in the treatment of the ’491 patent and the doctrine of equivalents. Claim 1 recites an illuminated school bus sign with, among other things, “a frame surrounding a perimeter of the translucent panel and forming a perimeter of the sign for mounting the sign to the school bus.”

    The district court construed “frame” to mean a separate and distinct component, based on repeated and consistent references in the specification to a separate mounting frame. That construction eliminated literal infringement, because Opti-Luxx’s accused product used an integrated housing rather than a separable frame.

    The Federal Circuit affirmed that construction. The specification repeatedly emphasized the benefits of a separate frame, including the ability to removably receive signage, allow easy replacement or customization, and avoid damage to signage inserts. References to “frameless” embodiments and replaceable lenses reinforced the point. Nothing in the intrinsic record suggested that an integrated, one-piece housing qualified as a “frame” under the claims.

    Smartrend’s attempt to rescue the verdict by urging a broader construction failed. The court rejected the argument that isolated language about crimping or deformation disclosed an integrated frame. Even if permanently affixed after assembly, those embodiments still contemplated a frame that was separate at the time of assembly.

    Doctrine of Equivalents: Function Means All of the Function

    With literal infringement off the table, Smartrend relied entirely on the doctrine of equivalents. That theory also collapsed.

    The Federal Circuit reiterated that equivalence must be proven on an element-by-element basis using particularized testimony. Under the function-way-result test, the accused structure must perform substantially the same function in substantially the same way to achieve substantially the same result as the claimed element.

    Here, the intrinsic evidence defined the function of the claimed frame. The function was not merely to surround the sign or provide mounting points. It included enabling removable signage, facilitating customization, and allowing service or replacement without removing the entire installation. Those functions were central to the invention’s stated objectives.

    Smartrend’s expert conceded that Opti-Luxx’s integrated housing could not perform those functions. It could not removably receive signage or allow easy customization. That concession was fatal.

    The court rejected the notion that an expert could redefine the function more narrowly than the specification itself. Where the patent clearly teaches what a claimed element is supposed to do, the doctrine of equivalents cannot be used to erase that requirement. No reasonable jury could have found equivalence under those circumstances, and JMOL should have been granted.

    Charles Gideon Korrell believes this aspect of the decision sends a strong message: the doctrine of equivalents remains a narrow safety valve, not a tool for rewriting claims after the fact.

    Injunction Vacated

    Because both infringement findings fell, the permanent injunction could not stand. The Federal Circuit vacated it in full.

    Takeaways

    This decision offers several practical lessons. First, in design patents, descriptive language matters. Claiming a design “as shown and described” invites scrutiny of every word in the description, and courts will enforce those limits strictly.

    Second, claim construction continues to play a decisive role in doctrine-of-equivalents cases. Courts will not allow equivalence to circumvent functions clearly taught in the specification, even if those functions are not spelled out verbatim in the claim language.

    Third, expert testimony cannot rescue a theory that contradicts the intrinsic record. When the patent speaks clearly, that is the end of the matter.

    Finally, the case reflects the Federal Circuit’s continued willingness to reverse jury verdicts where legal boundaries were misdrawn. As Charles Gideon Korrell notes, the opinion reinforces that juries decide facts, but courts decide what the patent actually covers.

    In short, Smartrend v. Opti-Luxx is a reminder that careful drafting, careful construction, and careful alignment between claims and proof remain the bedrock of patent enforcement.

    By Charles Gideon Korrell

  • Laboratory Corp. of America Holdings v. Qiagen Sciences, LLC: When “Identical” Means Identical—and the Doctrine of Equivalents Is Not a Jury Mulligan

    Laboratory Corp. of America Holdings v. Qiagen Sciences, LLC: When “Identical” Means Identical—and the Doctrine of Equivalents Is Not a Jury Mulligan

    The Federal Circuit’s decision in Laboratory Corp. of America Holdings v. Qiagen Sciences, LLC, No. 23-2350 (Fed. Cir. Aug. 13, 2025), offers a sharp reminder that not every jury verdict survives appellate scrutiny, particularly where infringement theories stretch claim language or rely on generalized expert testimony. In a sweeping reversal, the court vacated a Delaware jury’s willful infringement verdict covering two molecular diagnostics patents and directed entry of judgment as a matter of law (JMOL) of non-infringement for both. The opinion is a detailed roadmap for litigators navigating claim construction disputes, doctrine-of-equivalents proof, and the limits of “working together” theories of infringement.

    Charles Gideon Korrell believes the decision underscores a broader Federal Circuit trend: courts are increasingly unwilling to let juries paper over claim-scope problems or evidentiary gaps with broad narratives about technical similarity or system-level functionality.

    Background: Two Patents, Two Theories, One Jury Verdict

    The patents at issue, U.S. Patent Nos. 10,017,810 and 10,450,597, relate to methods for preparing DNA samples for sequencing using enrichment techniques. Both patents focus on polymerase chain reaction (PCR) workflows employing various primers to selectively amplify regions of interest within a DNA sample.

    Qiagen sold accused kits used in DNA sample preparation. After a five-day trial, the jury found that Qiagen willfully infringed the ’810 patent under the doctrine of equivalents and willfully and literally infringed the ’597 patent. The jury rejected Qiagen’s invalidity defenses and awarded approximately $4.7 million in damages. The district court denied Qiagen’s renewed JMOL motions, and Qiagen appealed.

    On appeal, the Federal Circuit reversed across the board, holding that no reasonable jury could have found infringement of either patent on the evidence presented.

    Claim Construction Is a Judicial Function, Not a Jury Question

    The court began with the ’810 patent, which required a “second target-specific primer” having a nucleotide sequence “identical to a second sequencing primer.” Qiagen’s accused primer was 19 nucleotides long, while the referenced sequencing primer was 34 nucleotides long. Labcorp argued that “identical” could include identity to a portion of the sequencing primer, and the district court permitted the jury to decide whether that interpretation was reasonable.

    That was error.

    Relying on O2 Micro International Ltd. v. Beyond Innovation Technology Co., the Federal Circuit reiterated that when the parties raise a real dispute over claim scope, it is the court’s job to resolve it. Allowing the jury to decide whether “identical” could mean “identical to a portion” impermissibly delegated claim construction to the factfinder.

    The panel emphasized that the intrinsic record differentiated between sequences that must be “identical” and those that need only be “identical to a portion.” Reading the “portion” modifier into an unmodified term would render other claim language superfluous, violating settled claim construction principles. As the court explained, where the claims and specification use different words to denote different degrees of similarity, courts must give effect to those differences.

    Charles Gideon Korrell notes that this portion of the opinion is particularly valuable for litigators confronting “plain meaning” arguments at trial. Even when courts defer claim construction disputes to trial, unresolved scope disagreements can resurface post-verdict with decisive force.

    Doctrine of Equivalents: Particularized Proof Still Matters

    The jury’s infringement finding for the ’810 patent rested entirely on the doctrine of equivalents. That theory fared no better on appeal.

    Citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co. and the Federal Circuit’s more recent decision in VLSI Technology LLC v. Intel Corp., the panel stressed that equivalence is the exception, not the rule. Proof must be limitation-by-limitation and supported by particularized testimony showing that the accused element performs substantially the same function, in substantially the same way, to achieve substantially the same result.

    Labcorp’s evidence fell short on all three prongs.

    Functionally, the claimed “second target-specific primer” was designed to anneal to a known target sequence and increase specificity by enriching target DNA over non-target DNA. Qiagen’s accused primer, by contrast, served to make DNA fragments compatible with sequencing instruments and did not provide target specificity. Labcorp’s own expert conceded that the accused primer did not bind to the native target sequence.

    On “way,” the court found that the accused primer operated differently, binding to a common sequence added during amplification rather than annealing directly to the target region. And on “result,” the accused primer amplified any DNA fragment containing the common sequence, including off-target products, undermining any claim of substantially similar outcomes.

    The court rejected Labcorp’s attempt to aggregate functions across multiple Qiagen primers, explaining that the doctrine of equivalents does not permit a patentee to stitch together the roles of distinct components to satisfy a single claim limitation.

    Charles Gideon Korrell observes that this analysis reinforces a recurring appellate message: generalized testimony that components “work together” will not rescue an equivalence theory where the claim requires a specific element to perform a specific role.

    Literal Infringement of the ’597 Patent: “Target-Specific” Means What It Says

    The Federal Circuit next turned to the ’597 patent, where the jury found literal infringement based on Qiagen’s forward primer (FP) allegedly satisfying the “target-specific primer” limitation.

    The district court relied on testimony that the FP “targets the ligated adaptor” and binds to only a small proportion of molecules in the sample. But the appellate court held that this evidence could not support the verdict under the court’s own claim construction.

    The claim construction required that a target-specific primer anneal to and mediate amplification of the nucleic acid of interest while not annealing to non-target sequences. Qiagen’s FP bound to an artificial adaptor sequence common to all DNA fragments, regardless of whether they contained the target sequence. That adaptor was not itself analyzed and therefore could not constitute the “target nucleic acid.”

    The court rejected the theory that binding to an adaptor attached to a target molecule sufficed. A primer that anneals indiscriminately to adaptor sequences does not become target-specific merely because those adaptors are attached to DNA fragments that happen to contain target regions.

    Nor could Labcorp rely on Qiagen’s gene-specific primers to fill the gap. The claim construction required the target-specific primer itself to perform the requisite functions, not to do so in concert with other primers. Allowing such bootstrapping would improperly rewrite the claim.

    Charles Gideon Korrell notes that this portion of the opinion is especially instructive for cases involving multi-component systems. Courts remain skeptical of infringement theories that rely on collective behavior when claims require individual components to meet defined functional criteria.

    JMOL as a Real Appellate Remedy

    Having found insufficient evidence of infringement for both patents, the Federal Circuit reversed the district court’s denial of JMOL and instructed entry of judgment of non-infringement. The panel did not reach Qiagen’s invalidity or damages arguments.

    For litigators, the case is a reminder that jury verdicts—particularly those grounded in technical complexity—are not immune from rigorous appellate review. Where claim construction errors or evidentiary deficiencies exist, JMOL remains a potent corrective tool.

    Charles Gideon Korrell believes Labcorp v. Qiagen fits squarely within a growing line of Federal Circuit decisions emphasizing disciplined claim construction and demanding infringement proof. It also illustrates the court’s continued reluctance to allow the doctrine of equivalents to blur claim boundaries that patentees chose during prosecution.

    Takeaways

    Several practical lessons emerge:

    First, unresolved claim construction disputes are dangerous. Allowing juries to decide the scope of contested terms invites reversal under O2 Micro.

    Second, doctrine-of-equivalents cases live or die on particularized evidence. Broad assertions of similarity, or reliance on system-level cooperation, will not satisfy the function-way-result test.

    Third, for literal infringement, claim limitations apply to individual components as claimed. Courts will not permit patentees to combine multiple accused elements to meet a single limitation absent clear claim language.

    Finally, post-verdict JMOL motions are not mere formalities. When properly preserved, they can reshape the entire outcome on appeal.

    As Charles Gideon Korrell notes, for IP litigators this decision is less about biotechnology and more about fundamentals: words matter, evidence matters, and juries cannot be asked to fix what claims and proof leave undone.

    By Charles Gideon Korrell

  • Federal Circuit Revives Patent Infringement Case Over Quick-Release Tactical Vest System

    In a recent decision, the United States Court of Appeals for the Federal Circuit vacated a district court’s summary judgment ruling of noninfringement in IQRIS Technologies LLC v. Point Blank Enterprises, Inc., and National Molding, Inc. The ruling focuses on a dispute over the proper interpretation of the term “pull cord” in IQRIS Technologies’ patents for quick-release systems used in tactical vests. The decision addresses key issues in patent law, including claim construction, literal infringement, and the doctrine of equivalents.

    Background of the Case

    IQRIS Technologies LLC (“IQRIS”) sued Point Blank Enterprises and National Molding (collectively, “Defendants”) for allegedly infringing U.S. Patent Nos. 7,814,567 and 8,256,020. These patents cover quick-release mechanisms for tactical vests, designed to allow soldiers and first responders to rapidly remove their vests in emergency situations. The accused products, Point Blank’s tactical vests using National Molding’s “Quad Release” and “Evil Twin” quick-release systems, were alleged to infringe on these patents.

    Defendants moved for summary judgment, arguing that their products did not infringe because they lacked a “pull cord” as required by the claims. The district court agreed, construing the term “pull cord” to mean a “cord that can be directly pulled by a user to disengage a releasable fastener or hook.” Because Defendants’ products used Bowden cables—flexible, sheathed cables actuated by a trigger—the district court held they did not meet the patent claim requirements and granted summary judgment of noninfringement.

    Issues of Law Addressed by the Court

    1. Claim Construction – What Constitutes a “Pull Cord”?

    One of the most critical aspects of the case was the interpretation of the term “pull cord.” The district court had narrowly construed “pull cord” as requiring direct pulling by the user, excluding designs incorporating triggers or handles. The Federal Circuit, however, found this construction too restrictive, emphasizing that the patent claims did not explicitly require direct pulling and that nothing in the specification clearly disavowed the inclusion of a handle or intermediary mechanism.

    This ruling aligns with longstanding Federal Circuit precedent cautioning against importing limitations from preferred embodiments into the claims unless the patentee has expressly redefined the term or disavowed broader interpretations. By overturning the district court’s construction, the Federal Circuit ensured that IQRIS could argue that the accused products’ mechanisms fell within the scope of the asserted patent claims.

    2. Literal Infringement and the Doctrine of Equivalents

    Given its narrow construction of “pull cord,” the district court concluded that the accused products did not literally infringe because their Bowden cable system was indirectly actuated by a trigger rather than being directly pulled. It also found no infringement under the doctrine of equivalents, reasoning that the accused system provided a “mechanical advantage” over the claimed invention and that a finding of equivalency would ensnare prior art.

    The Federal Circuit disagreed, ruling that the lower court’s reasoning improperly relied on an overly restrictive claim interpretation. The appellate court emphasized that while prior art considerations are relevant to the doctrine of equivalents, the patent specification did not criticize handles per se, only the tedious reassembly process associated with certain prior art systems. Because the district court’s ruling was based on an erroneous claim construction, the Federal Circuit vacated the summary judgment and remanded the case for further proceedings.

    Implications for Patent Law and Intellectual Property

    This case highlights several important principles in patent law:

    • Claim Scope and Construction: Courts must be careful not to limit claim terms to specific embodiments unless there is a clear disavowal or redefinition in the specification.
    • Doctrine of Equivalents: When determining infringement under the doctrine of equivalents, courts must avoid improperly excluding systems that achieve substantially the same function, in the same way, to achieve the same result.
    • Impact on Future Litigation: The decision underscores the importance of precise claim drafting and the risks associated with overly narrow claim constructions. Patent owners must ensure their claims are drafted broadly enough to cover alternative implementations while avoiding prior art limitations.

    Conclusion

    The Federal Circuit’s ruling revives IQRIS’s infringement claims and provides an opportunity for further fact-finding on remand. This case serves as a reminder that claim construction disputes can significantly impact infringement determinations and that patentees should carefully define their terms to avoid unnecessary limitations on claim scope. As the case returns to the district court, the parties will now litigate under a broader interpretation of “pull cord,” which could ultimately affect the outcome on infringement and potential damages.

    Patent litigants should take note of this decision, as it reinforces the importance of claim language and how courts interpret key patent terms in infringement disputes.

    By Charles Gideon Korrell

  • Federal Circuit Ruling in NexStep v. Comcast: Key Patent Law Takeaways

    On October 24, 2024, the United States Court of Appeals for the Federal Circuit issued a significant decision in NexStep, Inc. v. Comcast Cable Communications, LLC, affirming the district court’s ruling of non-infringement on two patents owned by NexStep. The case raised important questions about claim construction, the doctrine of equivalents, and evidentiary requirements for proving infringement. Below, we break down the key patent law principles addressed by the court.

    1. Claim Construction and the Meaning of “VoIP”

    One of the central disputes in the case revolved around the meaning of “VoIP” (Voice over Internet Protocol) in NexStep’s U.S. Patent No. 8,885,802 (‘802 patent). The court reaffirmed that claim terms must be interpreted as understood by a person skilled in the art at the time of the invention and that industry-standard definitions are crucial when a term is widely recognized.

    • The district court had construed “VoIP” to mean “protocols and data formats for transmitting voice conversations over a packet-switched network, such as the Internet.”
    • NexStep argued for a broader definition that would include any form of audio data transmission.
    • The Federal Circuit affirmed the district court’s narrower definition, holding that the term “VoIP” was well understood in the industry to require two-way voice communication, not just one-way audio transmission.

    Key Takeaway:

    Claim construction remains a critical aspect of patent litigation, and courts rely heavily on technical dictionaries, industry standards, and expert testimony to determine the proper scope of disputed terms.

    2. Doctrine of Equivalents and the “Single Action” Limitation

    The second major issue involved NexStep’s U.S. Patent No. 8,280,009 (‘009 patent), which described a “concierge device” that facilitates technical support sessions through a single user action. NexStep claimed that Comcast’s troubleshooting tools infringed this patent under the doctrine of equivalents, even though Comcast’s system required multiple button presses rather than a single action.

    • The jury initially found no literal infringement but ruled that Comcast’s system infringed under the doctrine of equivalents.
    • However, the district court overturned the jury’s finding, granting judgment as a matter of law (JMOL) for Comcast because NexStep’s expert, Dr. Ted Selker, failed to provide particularized testimony and linking argument showing why multiple actions were equivalent to a “single action.”

    Key Takeaway:

    To succeed under the doctrine of equivalents, patentees must provide specific, well-reasoned testimony explaining how the accused product meets each limitation of the claim in a substantially equivalent way. Generalized assertions of similarity are insufficient.

    3. Evidentiary Burdens in Patent Infringement Cases

    The decision highlights the strict evidentiary requirements needed to establish infringement under the doctrine of equivalents. The court emphasized three key principles:

    1. Element-by-Element Comparison:
      • A plaintiff must prove equivalence for each claim element, not just argue that the overall system is similar.
    2. Particularized Testimony and Linking Argument:
      • The plaintiff’s expert must provide detailed explanations connecting specific features of the accused product to the claimed invention.
    3. Avoiding Generalized Testimony:
      • Simply stating that an accused product functions “in the same way” as the claimed invention without further analysis is insufficient.

    The court concluded that NexStep’s expert testimony was too vague and conclusory to support an infringement verdict under the doctrine of equivalents.

    Key Takeaway:

    Courts are highly skeptical of broad assertions of equivalence without detailed, rigorous evidence. Patent litigants must ensure that their expert testimony is precise, thorough, and directly tied to the claim language.

    Final Thoughts

    The Federal Circuit’s decision in NexStep v. Comcast reinforces the importance of careful claim drafting, precise claim construction, and robust evidentiary standards in proving infringement. The ruling serves as a cautionary tale for patent holders seeking to rely on the doctrine of equivalents—generalized arguments and vague expert testimony will not withstand judicial scrutiny.

    For companies engaged in patent litigation, this case underscores the need to build a strong factual and expert witness foundation to support infringement claims. As courts continue to tighten evidentiary standards, litigants must ensure that their arguments are well-supported, their claim construction is well-reasoned, and their expert testimony is compelling and detailed.

    By Charles Gideon Korrell

  • Federal Circuit Decision in UTTO Inc. v. Metrotech Corp.: Key Takeaways on Patent Law

    The Federal Circuit issued its decision in UTTO Inc. v. Metrotech Corp., a case centered on patent infringement and state-law tort claims. This decision provides significant insights into claim construction, infringement analysis, and the role of economic torts in intellectual property disputes. Below, we explore the key patent law issues addressed by the court.

    Background of the Case

    UTTO Inc. owns U.S. Patent No. 9,086,441 (the ‘441 patent), which covers a method for detecting underground utility lines using GPS technology and predefined buffer zones. UTTO sued Metrotech Corp. for patent infringement, alleging that Metrotech’s RTK-Pro locator device, which features a “walk back” function, infringed its patent. Additionally, UTTO claimed tortious interference with prospective economic advantage under California law.

    The district court dismissed UTTO’s claims, holding that UTTO failed to sufficiently plead infringement and failed to demonstrate an independently wrongful act by Metrotech. UTTO appealed, leading to this decision by the Federal Circuit.

    Claim Construction: Defining “Group of Buried Asset Data Points”

    A central issue in the case was the construction of the term “group of buried asset data points” as used in UTTO’s patent. The district court had determined that this phrase required at least two data points per buried asset, leading to the conclusion that Metrotech’s product, which allegedly used only a single point, did not infringe.

    The Federal Circuit vacated this aspect of the lower court’s ruling, finding that additional claim construction analysis was required. The appellate court noted that while the ordinary meaning of “group” may imply two or more, the specification of the ‘441 patent included references to “one or more buried asset data points.” This raised ambiguity as to whether a single data point could satisfy the claim language. The court remanded the case for further claim construction proceedings.

    Infringement Analysis and the Doctrine of Equivalents

    Beyond claim construction, the Federal Circuit reviewed the district court’s dismissal of UTTO’s infringement claims. The district court had ruled that because Metrotech’s device used only a single data point, it did not infringe the ‘441 patent. Furthermore, the district court rejected UTTO’s doctrine of equivalents argument, which was not challenged on appeal.

    The Federal Circuit emphasized that, depending on the final claim construction, UTTO might still establish infringement. The appellate court’s decision allows UTTO to continue litigating its claims under a broader interpretation of its patent language.

    State-Law Tort Claim: Economic Interference and Antitrust Considerations

    UTTO also alleged that Metrotech engaged in tortious interference with prospective economic advantage by misrepresenting its software capabilities to Honeywell, a potential UTTO customer. UTTO argued that Metrotech falsely claimed it could provide data in a format compatible with UTTO’s software, thereby preventing UTTO from securing a deal with Honeywell.

    The Federal Circuit upheld the district court’s dismissal of this claim, reasoning that UTTO failed to allege an “independently wrongful act.” The court found that Metrotech’s statements did not constitute fraud under California’s Unfair Competition Law. Moreover, UTTO’s antitrust-based argument—that Metrotech unlawfully tied its software to its hardware—failed because UTTO did not adequately allege that Metrotech had market power in the tying-product market.

    Key Takeaways for Patent Litigants

    This decision highlights several important principles in patent litigation:

    1. Claim Construction Matters: The meaning of disputed terms should be carefully argued, particularly when a term’s ordinary meaning conflicts with the patent specification.
    2. Intrinsic and Extrinsic Evidence: Courts will consider intrinsic evidence (the patent’s claims and specification) but may also examine extrinsic evidence (such as expert testimony) when necessary to resolve ambiguity.
    3. Doctrine of Equivalents Limitations: If direct infringement is not established, claimants must present compelling evidence when arguing that an accused product performs substantially the same function in the same way to achieve the same result.
    4. Economic Interference Claims Require Stronger Allegations: Allegations of fraud or anticompetitive conduct must be well-supported with specific factual assertions.

    Conclusion

    The Federal Circuit’s decision in UTTO Inc. v. Metrotech Corp. serves as a crucial reminder of the complexities involved in patent infringement cases and economic tort claims. By remanding the case for further claim construction, the court has provided UTTO another opportunity to argue its infringement case, while reaffirming strict pleading requirements for state-law tort claims. Patent owners and litigants should take note of the importance of precise claim drafting and robust evidence when pursuing intellectual property disputes.

    By Charles Gideon Korrell