Court Opinion

ID: 6326330
Source: CourtListenerOpinion
Date Created: 2022-03-24 14:00:39.60345+00
Date Added: 2024-06-11T09:22:11.300233
License: Public Domain

Case: 20-2163   Document: 59    Page: 1   Filed: 03/24/2022

   United States Court of Appeals
       for the Federal Circuit
                 ______________________

                HUNTING TITAN, INC.,
                     Appellant

                           v.

        DYNAENERGETICS EUROPE GMBH,
                Cross-Appellant

   ANDREW HIRSHFELD, PERFORMING THE
    FUNCTIONS AND DUTIES OF THE UNDER
       SECRETARY OF COMMERCE FOR
 INTELLECTUAL PROPERTY AND DIRECTOR OF
 THE UNITED STATES PATENT AND TRADEMARK
                   OFFICE,
                   Intervenor
             ______________________

                  2020-2163, 2020-2191
                 ______________________

     Appeals from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in No. IPR2018-
 00600.
                  ______________________

                Decided: March 24, 2022
                ______________________

    JASON SAUNDERS, Arnold & Saunders, LLP, Houston,
 TX, argued for appellant. Also represented by GORDON
 ARNOLD, CHRISTOPHER MCKEON.
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 2       HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

    BARRY J. HERMAN, Womble Bond Dickinson (US) LLP,
 Baltimore, MD, argued for cross-appellant. Also repre-
 sented by WILLIAM R. HUBBARD; CHRISTINE H. DUPRIEST,
 PRESTON HAMILTON HEARD, Atlanta, GA; LISA MOYLES,
 JASON ROCKMAN, Moyles IP, LLC, Shelton, CT.

     SARAH E. CRAVEN, Office of the Solicitor, United States
 Patent and Trademark Office, Alexandria, VA, argued for
 intervenor. Also represented by THOMAS W. KRAUSE,
 ROBERT J. MCMANUS, MAUREEN DONOVAN QUELER,
 FARHEENA YASMEEN RASHEED.
                 ______________________

     Before PROST, REYNA, and HUGHES, Circuit Judges.
     Opinion for the court filed by Circuit Judge HUGHES.
      Concurring opinion filed by Circuit Judge PROST.
 HUGHES, Circuit Judge.
     Hunting Titan, Inc. petitioned for inter partes review
 of claims 1–15 of U.S. Patent No. 9,581,422, asserting 16
 grounds of unpatentability based on theories of anticipa-
 tion and obviousness, including allegations that the claims
 were anticipated by Schacherer, U.S. Patent No. 9,689,223.
 The Board instituted trial on all grounds and ultimately
 agreed with Hunting Titan, finding all of the original
 claims unpatentable.
     After the petition was instituted, DynaEnergetics Eu-
 rope GmbH, the patent owner, moved to amend the ’422 pa-
 tent to add proposed substitute claims 16–22. Hunting
 Titan opposed the motion to amend, advancing only obvi-
 ousness grounds. Although Hunting Titan did not assert
 that Schacherer anticipated the proposed substitute
 claims, the Board determined that the original and pro-
 posed substitute claims alike were unpatentable as antici-
 pated by Schacherer. DynaEnergetics requested rehearing
 and Precedential Opinion Panel review of the Board’s
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH         3

 denial of the motion to amend. The Panel granted
 DynaEnergetics’s request for rehearing, vacated the
 Board’s decision denying DynaEnergetics’s motion to
 amend, and then—after concluding that Hunting Titan
 had not proven by a preponderance of the evidence that
 proposed substitute claims 16–22 are unpatentable—
 granted the motion to amend the ’422 patent to add the
 proposed substitute claims.
      Hunting Titan appeals the Precedential Opinion
 Panel’s vacatur of the Board’s decision denying the motion
 to amend, and DynaEnergetics cross-appeals the Board’s
 decision finding the original claims of the ’422 patent an-
 ticipated by Schacherer. We affirm on both grounds.
                               I
     DynaEnergetics owns the ’422 patent, which is di-
 rected to a perforating gun used in an oil wellbore to pene-
 trate the well lining and surrounding rock formation in
 order to provide a flow path for oil into the wellbore from
 the surrounding rock formation. ’422 patent, 1:15–44. The
 perforating gun’s key feature is a “wireless” and “selective”
 detonator assembly for detonating an explosive projectile
 charge within the perforating gun “without the need to at-
 tach wires to the detonator.” Id. 2:24–34. Claim 1 is repre-
 sentative and is reproduced below.
     1. A wireless detonator assembly configured for be-
     ing electrically contactably received within a perfo-
     rating gun assembly without using a wired
     electrical connection, comprising:
         a shell configured for housing components
         of the detonator assembly;
         more than one electrical contact compo-
         nent, wherein at least one of the electrical
         contact components extends from the shell
         and further wherein the electrical contact
         component comprises an electrically
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 4      HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

        contactable line-in portion, an electrically
        contactable line-out portion and an electri-
        cally contactable ground portion, the
        ground portion in combination with the
        line-in portion and the line-out portion be-
        ing configured to replace the wired electri-
        cal connection to complete an electrical
        connection merely by contact;
        an insulator positioned between the line-in
        portion and the line-out portion, wherein
        the insulator electrically isolates the line-
        in portion from the line-out portion; and
        means for selective detonation housed
        within the shell, wherein the detonator as-
        sembly is configured for electrically con-
        tactably forming the electrical connection
        merely by the contact.
 Id. 8:39–61.
                               A
     Hunting Titan petitioned for inter partes review of
 claims 1–15 of the ’422 patent, asserting 16 grounds of un-
 patentability based on theories of anticipation and obvious-
 ness. The Board instituted on the petition. Appx246.
 DynaEnergetics opposed the petition. It also filed a contin-
 gent motion to amend the ’422 patent to add new claims
 16–22, in the event the Board were to find original claims
 5–11 unpatentable.
                               1
     Relevant to this appeal is Hunting Titan’s first as-
 serted ground of unpatentability that Schacherer, U.S. Pa-
 tent No. 9,689,223, anticipates all of the ’422 patent’s
 original claims. DynaEnergetics maintained, in its Patent
 Owner Response, that Schacherer lacks several limitations
 of the claimed detonator assembly.
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH           5

     DynaEnergetics asserted that Schacherer does not
 teach or disclose the claimed “wireless detonator assem-
 bly.” Appx320 (emphasis added). According to DynaEner-
 getics, Schacherer “incorporate[s] an electrically wired
 detonator (38) into a tandem sub or connector,” id., while
 the claimed detonator assembly “replace[s] [the] electri-
 cally wired detonator . . . with a wireless detonator 10 and
 house[s] the components of the detonator, including the
 means for selective detonation, within a shell (12).”
 Appx321. DynaEnergetics also argued that “Schacherer
 does not teach or suggest incorporating the selecting firing
 module (32) into the wired detonator (38),” but instead “de-
 scribes a [tandem] sub for housing such components.”
 Appx322–23. Thus, according to DynaEnergetics,
 “Schacherer does not teach or suggest a shell configured for
 housing components of the detonator assembly.” Appx323.
     Because these limitations, among others not relevant
 to this appeal, are allegedly not taught by Schacherer,
 DynaEnergetics argued that Hunting Titan failed to
 “show[] that Schacherer anticipates [any] of the challenged
 claims of the ’422 [p]atent.” Appx333. The Board disagreed
 with DynaEnergetics, concluding that each original claim
 is unpatentable as anticipated by Schacherer. Appx24.
     Significant to this appeal, the Board first considered
 claim 1’s uncontested limitations and found these limita-
 tions fully supported by the record and “effectively admit-
 ted” by DynaEnergetics. Appx9. The Board accordingly
 concluded that Hunting Titan had met its burden of prov-
 ing that Schacherer discloses a “detonator assembly” that
 is:
    (1) “received with a perforating gun,”
    (2) has “more than one electrical contact compo-
    nent, wherein at least one of the electrical contact
    components . . . comprises an electrically contacta-
    ble line-in portion, . . . line-out portion[,] and . . .
    ground portion,” and
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 6      HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

     (3) has “means for selective detonation,” as recited
     in representative claim 1.
 Appx9–10. The Board then addressed whether Schacherer
 teaches or suggests the remaining limitations that are pur-
 portedly missing from the prior art reference.
     Beginning with claim 1’s “wireless detonator assem-
 bly” limitation, the Board said that “DynaEnergetics [had]
 oversimplifie[d] what constitutes Schacherer’s detonator
 assembly and ignore[d] the express language of the [repre-
 sentative] claim” in the ’422 patent. Appx13. The Board ex-
 plained that, “consistent with the claim language and
 specification, the ‘wireless’ and ‘merely by the contact’ lim-
 itations speak expressly to how one assembly forms an elec-
 trical connection with the other assembly—through bodily
 contact as opposed to connection of physical wires.” Id. But
 “nowhere does the ’422 patent preclude the use of wired
 connections internal to the detonator assembly.” Id.
      Still, the Board observed, DynaEnergetics attempted to
 fall back on a third, related limitation—i.e., “without using
 a wired connection”—when it “distort[ed] the [clarifying]
 testimony of Hunting Titan’s expert,” Appx15, and
 “fault[ed] Schacherer for using a wired connection between
 subcomponents of the detonator assembly,” Appx13–14.
 “What DynaEnergetics fail[ed] to acknowledge,” however,
 was “that the claimed ‘wireless,’ ‘without using a wired con-
 nection,’ and ‘merely by the contact’ limitations pertain
 solely to how the detonator assembly as a whole forms an
 electrical connection with the perforating gun assembly as
 a whole, irrespective of how any subcomponents with each
 assembly are connected.” Appx15. And because “the claims
 require only the absence of a wired connection between the
 detonator assembly and the perforating gun assembly,” the
 Board “conclude[d] that Schacherer is a ‘wireless’ detona-
 tor assembly in the manner recited by claim 1” since its
 “detonator assembly achieves an electrical connection with
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH       7

 the perforating gun assembly merely by contact of one with
 the other.” Appx16.
     The Board also determined that Schacherer discloses
 claim 1’s “shell configured for housing components of the
 detonator assembly.” In reaching this determination, the
 Board construed “shell” to mean “a shell, housing, or casing
 for housing any component of the detonator assembly, in-
 cluding but not limited to a detonator head plug, a fuse
 head, an electronic circuit board, or explosive components.”
 Appx17. It then found that this construction “matches ex-
 actly the structure and function” of Schacherer’s con-
 nector 30. Appx19. The Board thus dismissed
 DynaEnergetics’s arguments “as nothing more than se-
 mantics.” Id.
     Having determined “that a skilled artisan would have
 understood Schacherer as disclosing each and every limi-
 tation of claim 1,” the Board then determined the same
 with respect to each limitation of independent claims 5
 and 12 as well as the claims depending therefrom.
 Appx24–25.
                               2
     Contingent on the Board finding original claims 5–11
 unpatentable, DynaEnergetics also moved the Board to
 amend the ’422 patent to add proposed substitute
 claims 16–22. The substitute claims would retain all the
 limitations of the original claims and further add the fol-
 lowing new limitations:
    1) “a perforating gun housing” having “a detonator
    assembly contained entirely within the perforating
    gun housing,”
    2) “a carrying device positioned within the perfo-
    rating gun housing to hold at least one shaped
    charge,” and
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 8      HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

     3) “a detonator assembly contained entirely within
     the perforating gun housing.”
 Appx419, 429. DynaEnergetics asserted that these “contin-
 gent amendments further clarify that the detonator assem-
 bly includes a means for selective detonation within the
 shell, in addition to at least one electrically contactable
 component extending from the shell, all designed in a way
 that replaces wires and instead completes an electrical con-
 nection within the perforating gun housing merely by con-
 tact.” Appx419; see also Appx429. These proposed
 substitute claims are therefore patentable and not antici-
 pated by Schacherer, according to DynaEnergetics, be-
 cause Schacherer’s detonator assembly is not wireless and
 its “selective detonator assembly . . . is clearly not con-
 tained within its perforating gun housing.” Appx430–31.
 So DynaEnergetics argued that Schacherer “does not teach
 or disclose a ‘wirelessly connectable selective detonator as-
 sembly’ that is ‘contained entirely within the perforating
 gun housing without using a wired electrical connection’ as
 recited in” its proposed substitute claims. Appx431.
     Hunting Titan opposed the motion to amend, asserting
 that the proposed substitute claims “d[id] not overcome the
 previously cited prior art in the Petition.” Appx524. Hunt-
 ing Titan identified two publications—U.S. Patent
 No. 10,077,641 (Rogman) and U.S. Patent Application
 No. 14/888,882 (Harrigan)—that, it contended, “disclose all
 of the additional claim limitations in proposed amended
 claims 16–22 and would have been obvious to combine with
 the previously cited prior art.” Appx524. It also identified
 as pertinent several previously cited prior art references—
 including Schacherer—and asserted that each of these ref-
 erences discloses or teaches every claim limitation of the
 proposed substitute claims. Appx524–44. Based on these
 assertions, Hunting Titan maintained that the proposed
 substitute claims are obvious and therefore unpatentable.
 Hunting Titan “presented only obviousness arguments,
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH         9

 without alleging that the proposed substitute claims were
 anticipated by the prior art of record.” Appx33.
      “In [the Board’s] view, none of [DynaEnergetics’s] ad-
 ditional limitations render[ed] the proposed substitute
 claims novel or non-obvious over the prior art of record. In-
 stead,” the Board held, “each of [the additional] limitations
 is taught by the prior art, either as admitted in the ’422 pa-
 tent itself or as disclosed by Schacherer.” Appx26. The
 Board thus decided that “Hunting Titan ha[d] carried its
 burden in showing that DynaEnergetics’[s] proposed
 amendments d[id] not overcome the anticipatory nature of
 Schacherer’s disclosure,” and it denied DynaEnergetics’s
 motion to amend. Appx29. In reaching this decision, the
 Board “addresse[d] only Hunting Titan’s anticipation chal-
 lenge based on Schacherer . . . . [It] render[ed] no findings
 or conclusions as to Hunting Titan’s numerous obviousness
 challenges.” 1 Appx34.
                               B
     DynaEnergetics requested rehearing and Precedential
 Opinion Panel review of the Board’s denial of the motion to
 amend. The Panel granted DynaEnergetics’s request for re-
 view to address “[u]nder what circumstances and at what
 time during an inter partes review . . . the Board [may]
 raise a ground of unpatentability that a petitioner did not
 advance or insufficiently developed against substitute pro-
 posed claims in a motion to amend[.]” Appx34.
     The Panel acknowledged that our decision in Nike, Inc.
 v. Adidas AG, 955 F.3d 45 (Fed. Cir. 2020), had “resolve[d]

     1   In a footnote and without further explanation, the
 Board found “persuasive” Hunting Titan’s argument that a
 particular modification to Schacherer would have been ob-
 vious as “within the purview of Schacherer and the general
 knowledge of a skilled artisan.” Appx29 n.5; see also
 Appx34 n.2.
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 10     HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

 the question of whether the Board may advance a ground
 of unpatentability that a petitioner does not advance, or in-
 sufficiently develop[s], against substitute claims proposed
 in a motion to amend,” and it agreed that Nike had an-
 swered this question in the affirmative. Appx39. But the
 Panel said, Nike “d[id] not address the circumstances in
 which the Board should advance such a ground of un-
 patentability in relation to substitute claims proposed in a
 motion to amend.” Appx40. And the Panel “conclude[d] that
 only under rare circumstances should the need arise for the
 Board to advance grounds of unpatentability to address
 proposed substitute claims that the petitioner did not ad-
 vance, or insufficiently developed, in its opposition to the
 motion.” Appx40.
      The Panel believed that “the better approach, in most
 instances, is to rely on the incentives the adversarial sys-
 tem creates, and expect that the petitioner will usually
 have an incentive to set forth the reasons why the proposed
 substitute claims are unpatentable.” Appx43. Still, the
 Panel left open the possibility for the Board to sua sponte
 raise a ground of unpatentability, but “only . . . under rare
 circumstances,” such as when a petitioner “cease[s] to par-
 ticipate in the proceeding altogether” or “chooses not to op-
 pose the motion to amend.” Appx43–44. The Panel further
 accepted that “there may be circumstances where certain
 evidence of unpatentability has not been raised by the pe-
 titioner, but is readily identifiable and persuasive such
 that the Board should take it up in the interest of support-
 ing the integrity of the patent system, notwithstanding the
 adversarial nature of the proceedings.” Appx44. Although
 the Panel chose not “to delineate [every situation] with par-
 ticularity,” it did put forth one exemplary situation: “where
 the record readily and persuasively establishes that substi-
 tute claims are unpatentable for the same reasons that cor-
 responding original claims are unpatentable.” Appx44. In
 addition, it noted that “[s]uch situations are usually fact-
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH      11

 specific” and gave the Board discretion to “address them as
 they arise.” Appx44.
      The Panel then observed that Hunting Titan had
 “never mentioned anticipation as a ground” of unpatenta-
 bility against the proposed substitute claims. Appx48. It
 further rejected Hunting Titan’s assertion that its antici-
 pation arguments against the original claims, found in its
 petition, were “sufficient to also raise arguments regarding
 anticipation of the proposed substitute claims by
 Schacherer.” Appx48. And because “raising a ground of un-
 patentability in a petition against original claims in a pa-
 tent does not provide a patent owner with sufficient notice
 that new arguments would be asserted using that same ref-
 erence against new substitute claims proposed in a motion
 to amend,” the Panel concluded that “the anticipation
 ground based on Schacherer . . . was not advanced, much
 less sufficiently developed, by [Hunting Titan] against pro-
 posed substitute claims 16–22.” Appx49.
      Although anticipation based on Schacherer was not
 raised by Hunting Titan, the Panel asked “whether the
 Board should [still] have raised that ground against the
 proposed substitute claims in the Final Written Decision.”
 Appx49–50. It decided that the circumstances of this case
 did not “qualify as one of the rare circumstances necessi-
 tating the Board to advance a ground of unpatentability
 that Petitioner did not advance or sufficiently develop.”
 Appx50. In doing so, the Panel faulted Hunting Titan for
 its strategic choice “to oppose the motion to amend on dif-
 ferent grounds,” holding that “an unsuccessful strategy
 alone does not reflect a failure of the adversarial process
 here that might otherwise support the Board’s decision to
 exercise its discretion to sua sponte raise a new ground of
 unpatentability.” Appx50–51.
     The Panel further rejected Hunting Titan’s and sup-
 porting amici’s arguments that “the public interest w[ould]
 be harmed by the issuance of substitute claims that the
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 12     HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

 []PTO knows to be unpatentable” “if the Board cannot raise
 the Schacherer anticipation ground” here. Appx51. “The
 public interest is preserved,” the Panel claimed, “by a well-
 functioning adversarial system, which, in contrast to reex-
 amination, is the basic set-up Congress envisioned for inter
 partes reviews.” Id. So in a case like this one, where Hunt-
 ing Titan “vigorously prosecuted its case but made a tacti-
 cal decision not to raise anticipation arguments,” the Panel
 explained, “the adversarial system has not failed” and
 “[t]he public interest [wa]s not well-served by the [PTO]
 filling in gaps intentionally left void by” the petitioner. Id.
 The Panel therefore “conclude[d] that, as a policy matter,
 the Board should not have raised the Schacherer anticipa-
 tion ground.” Appx50. Moreover, the Panel stated, this case
 was not one that “present[ed] the potential for issuing sub-
 stitute claims the [PTO] ‘knows to be unpatentable’” be-
 cause the PTO “d[id] not have sufficient information on the
 record of this case . . . to make requisite findings on antici-
 pation.” Appx52. According to the Panel, this case did not
 contain “the sort of readily identifiable and persuasive evi-
 dence of anticipation in the record that would justify the
 Board raising its own grounds of unpatentability.” Id.
     Having determined that the Board should not have it-
 self advanced the ground of anticipation based on
 Schacherer when Hunting Titan raised this ground of un-
 patentability only against the original claims and not the
 proposed substitute claims, the Panel proceeded to con-
 sider in the first instance Hunting Titan’s obviousness “ar-
 guments and cited evidence” raised in its opposition to
 DynaEnergetics’s motion to amend. Appx54. The Panel
 “conclude[d] that [Hunting Titan] ha[d] not set forth an ad-
 equate case of obviousness.” Id. Rather, the Panel ob-
 served, Hunting Titan had “merely present[ed] how one or
 more of the various asserted prior art references separately
 teaches the various limitations of proposed substitute
 claims 16–22.” Appx56. It had “provide[d] no discussion of
 a reason to combine or modify the prior art,” and the Panel
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH        13

 “decline[d] to piece together [its] arguments” and “develop
 a persuasive theory of unpatentability” on Hunting Titan’s
 behalf. Id. Thus, following its holding that “the obviousness
 grounds that [Hunting Titan] purport[ed] to have raised
 [we]re facially insufficient to support a finding of unpatent-
 ability,” the Panel granted the motion to amend.
 Appx56–57.
     Hunting Titan timely appealed the Panel’s decision va-
 cating the Board’s denial of DynaEnergetics’s motion to
 amend. DynaEnergetics timely cross-appealed the Board’s
 decision invalidating its original claims. We have jurisdic-
 tion under 28 U.S.C. § 1295(a)(4)(A).
                               II
     We review the Board’s decisions in accordance with the
 Administrative Procedure Act, 5 U.S.C. § 706. HTC Corp.
 v. Cellular Commc’ns Equip., LLC, 877 F.3d 1361, 1367
 (Fed. Cir. 2017). We therefore “review the Board’s legal
 conclusions de novo and its factual findings for substantial
 evidence.” Id. Because “[a]nticipation is a question of fact,”
 we consider whether substantial evidence supports the
 Board’s determination holding the original claims un-
 patentable as anticipated by Schacherer. SynQor, Inc. v.
 Artesyn Techs., Inc., 709 F.3d 1365, 1373 (Fed. Cir. 2013).
 “Substantial evidence review asks ‘whether a reasonable
 fact finder could have arrived at the agency’s decision’ and
 requires examination of the ‘record as a whole, taking into
 account evidence that both justifies and detracts from an
 agency’s decision.’” Intelligent Bio-Systems, Inc. v. Illumina
 Cambridge Ltd., 821 F.3d 1359, 1366 (Fed. Cir. 2016) (cita-
 tion omitted). “Where two different conclusions may be
 warranted based on the evidence of the record, the Board’s
 decision to favor one conclusion over the other is the type
 of decision that must be sustained by this court as sup-
 ported by substantial evidence.” In re Chudik, 851 F.3d
 1365, 1371 (Fed. Cir. 2017) (citation omitted).
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 14     HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

                               A
     We first address DynaEnergetics’s cross-appeal, chal-
 lenging the Board’s decision holding the original claims of
 the ’422 patent unpatentable as anticipated by Schacherer.
      DynaEnergetics primarily takes issue with the Board’s
 finding that Schacherer teaches a detonator assembly that
 is received within a perforating gun assembly. Specifically,
 DynaEnergetics faults the Board for identifying this limi-
 tation as uncontested, fully supported by the record, or ef-
 fectively admitted, and contends that the Board’s conduct
 erroneously shifted the burden of persuasion from Peti-
 tioner to Patent Owner. But the Board identified where in
 the petition Hunting Titan had shown how Schacherer dis-
 closes the uncontested limitations. Appx9. And “[t]he
 Board, having found the only disputed limitations together
 in one reference, was not required to address undisputed
 matters.” In re NuVasive, Inc., 841 F.3d 966, 974 (Fed. Cir.
 2016).
      For the same reason, we are not persuaded by
 DynaEnergetics’s argument that the Board’s purported
 “failure to analyze the ‘received within’ feature infected its
 construction of the ‘shell’ limitation” and its determination
 that “Schacherer disclosed a shell,” such that “neither is
 supported by substantial evidence.” Cross-Appellant’s
 Opening Br. 25. Moreover, DynaEnergetics’s arguments
 addressing the wireless detonator assembly’s “shell” com-
 ponent—which fault Schacherer’s sub for its size and as-
 sert that this sub “cannot reasonably be said to be
 configured for being received within the perforating gun as-
 sembly” since it is “a large structural element or heavy
 steel tool that [instead] provides a connection between
 guns,” id. at 27—overlook the fact that the Board construed
 “shell” to include “casing for housing any component of the
 detonator assembly,” Appx16–17. So, since the shell houses
 at least part of the detonator assembly and since the deto-
 nator assembly is received within the perforating gun
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH       15

 assembly, substantial evidence supports the Board’s find-
 ing that the shell is configured to be received within the
 perforating gun assembly. See Appx15–19.
      Lastly, DynaEnergetics contends that substantial evi-
 dence does not support the Board’s findings that
 Schacherer discloses the claimed “wireless detonator as-
 sembly” because the Board did not satisfactorily explain
 why it dismissed DynaEnergetics’s evidence in favor of
 Hunting Titan’s evidence. But the Board’s explanation was
 more than satisfactory. It expressly disagreed with
 DynaEnergetics’s narrow construction of “detonator as-
 sembly,” specifically noting that “[w]hat DynaEnergetics
 fails to acknowledge is that the claimed ‘wireless,’ ‘without
 using a wired connection,’ and ‘merely by the contact’ limi-
 tations pertain solely to how the detonator assembly as a
 whole forms an electrical connection with the perforating
 gun assembly as a whole, irrespective of how any subcom-
 ponents within each assembly are connected.” Appx15.
 And, in light of its construction, the Board explicitly
 pointed to DynaEnergetics’s failure to provide evidentiary
 support or an explanation for why its position—that “a
 wired connection residing entirely within, and internal to,
 Schacherer’s detonator assembly precludes the assembly
 from being ‘wireless’”—was the correct and necessary one
 for the Board to adopt. Appx16. Substantial evidence sup-
 ports the Board’s determination that the detonator assem-
 bly’s electrical connection with the perforating gun
 assembly does not use a wired electrical connection in
 Schacherer. Appx16.
     For the foregoing reasons, substantial evidence sup-
 ports the Board’s determination that Schacherer antici-
 pates all of the ’422 patent’s original claims.
                               B
     Because we affirm the Board’s decision holding the
 original claims unpatentable, we address Hunting Titan’s
 appeal challenging the Panel’s decision to vacate the
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 16     HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

 Board’s denial of the motion to amend. Hunting Titan con-
 tends that, under Aqua Products, Inc. v. Matal, 872 F.3d
 1290, 1325–26 (Fed. Cir. 2017) (en banc) and Nike, Inc. v.
 Adidas AG, 955 F.3d 45, 51–52 (Fed. Cir. 2020), the Board
 has a duty to determine the patentability of the proposed
 substitute claims based on the entirety of the record. Hunt-
 ing Titan asserts that the Panel therefore erred in revers-
 ing the Board’s decision finding the proposed claims
 anticipated by Schacherer and further erred in determin-
 ing the patentability of the proposed substitute claims
 based only on its review of Hunting Titan’s opposition to
 the motion to amend. In other words, Hunting Titan argues
 that the Board had an obligation to sua sponte identify pa-
 tentability issues for a proposed substitute claim based on
 the prior art of record, and that the Panel committed legal
 error by vacating the Board’s decision to do so in this case.
 We disagree.
      Neither Aqua Products nor Nike established that the
 Board maintains an affirmative duty, without limitation or
 exception, to sua sponte raise patentability challenges to a
 proposed substitute claim. Nike, 955 F.3d at 51 (“We ad-
 dressed the universe of prior art that the Board should con-
 sider when reviewing a motion to amend in Aqua
 Products. . . . We expressly declined to address, however,
 whether the Board ‘may sua sponte raise patentability
 challenges of amended claims.’” (citation omitted)); id. (“We
 hold today that the Board may sua sponte identify a pa-
 tentability issue for a proposed substitute claim based on
 the prior art of record.” (emphasis added)). Indeed, as the
 Panel correctly pointed out, “Nike resolve[d] the question
 of whether the Board may advance a ground of unpatenta-
 bility that a petitioner does not advance, or insufficiently
 develop[s], against substitute claims proposed in a motion
 to amend.” Appx39. But Nike left unanswered “the circum-
 stances in which the Board should advance such a ground
 of unpatentability in relation to substitute claims proposed
 in a motion to amend.” Appx40. It was this question that
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH        17

 the Panel answered here, and confining the circumstances
 in which the Board should sua sponte raise patentability
 issues was not itself erroneous.
      Notably, we do find problematic the Panel’s reasoning
 behind its decision to confine the Board’s discretion to sua
 sponte raise patentability issues to only rare circum-
 stances. For example, while the adversarial system proves
 useful in IPR proceedings to bring forth evidence the
 agency might not have otherwise discovered, the Panel’s
 substantial reliance on the adversarial system as the basis
 for confining its patentability determination for new claims
 overlooks the basic purpose of IPR proceedings: to reex-
 amine an earlier agency decision and ensure “that patent
 monopolies are kept within their legitimate scope.” Oil
 States Energy Servs., LLC v. Greene’s Energy Grp., LLC,
 138 S. Ct. 1365, 1374 (2018) (cleaned up). And “[t]he fact
 that Congress has enlisted the assistance of private parties
 does not change their essential character.” Regents of Univ.
 of Minn. v. LSI Corp., 926 F.3d 1327, 1338 (Fed. Cir. 2019);
 see also id. (“[A]lthough these modifications to inter partes
 reexamination make IPR [proceedings] ‘look[] a good deal
 more like civil litigation,’ fundamentally these proceedings
 continue to be a ‘second look at an earlier administrative
 grant of a patent.’” (third alteration in original) (citations
 omitted)).
     Nevertheless, the Panel’s conclusion, at least to the ex-
 tent at issue here, is not inconsistent with Nike and Aqua
 Products. The Panel identified circumstances in which the
 Board should advance “a ground of unpatentability that a
 petitioner did not advance, or insufficiently developed,
 against substitute claims in a motion to amend.” Appx44.
 And it acknowledged that “even where both a petitioner
 and patent owner participate in the motion to amend pro-
 cess, there may be situations where certain evidence of un-
 patentability has not been raised by the petitioner, but is
 readily identifiable and persuasive such that the Board
 should take it up in the interest of supporting the integrity
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 18       HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

 of the patent system” (the readily identifiable evidence ex-
 ception). Id.
      Notably, however, the Panel highlighted one example
 in which the readily identifiable evidence exception could
 apply: “where the record readily and persuasively estab-
 lishes that substitute claims are unpatentable for the same
 reasons that corresponding original claims are unpatenta-
 ble.” Id. It was on this basis that the Panel concluded that
 the Board should not have considered whether the pro-
 posed substitute claims were anticipated by Schacherer,
 and the Panel therefore confined its own consideration to
 the grounds of unpatentability advanced by Hunting Titan
 in its opposition to DynaEnergetics’s motion to amend. In
 other words, the Panel did not preclude the Board from con-
 sidering the entirety of the record, but instead determined
 that certain evidence of anticipation—evidence that Hunt-
 ing Titan contends on appeal should have been considered
 when determining patentability—was not readily identifi-
 able and persuasive. Yet, on appeal, Hunting Titan did not
 challenge the Panel’s decision as an abuse of discretion.
 That is, Hunting Titan failed to argue that the Panel mis-
 applied the readily identifiable evidence exception. Be-
 cause Hunting Titan raised no such argument, it is
 forfeited. 2

      2  It does strike us as odd, however, that the Panel
 determined that the Schacherer anticipation ground was
 not readily identifiable and persuasive such that the Board
 should have sua sponte raised this ground of unpatentabil-
 ity against DynaEnergetics’s proposed substitute claims.
 Indeed, the Board specifically found the proposed substi-
 tute claims unpatentable for the same reasons it found the
 corresponding original claims unpatentable. Moreover,
 when the Board finds an original claim unpatentable as an-
 ticipated by a prior art reference, it would seem to follow
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH      19

     We must therefore affirm the Panel’s decision granting
 the motion to amend. We emphasize, however, that this af-
 firmance is based only on this narrow ground. We are not
 determining the patentability of the proposed substitute
 claims, nor are we deciding whether the Panel abused its
 discretion in determining that the Schacherer anticipation
 ground was not readily identifiable and persuasive such
 that the Board should have sua sponte raised this ground
 of unpatentability. Likewise, we are not opining on the
 other limitations that the Panel placed on the Board’s abil-
 ity to advance patentability issues not raised by a peti-
 tioner, and whether those limitations are consistent with
 35 U.S.C. § 318. Cf. Samsung Elecs. Am., Inc. v. Prisua
 Eng’g Corp., 948 F.3d 1342, 1352 (Fed. Cir. 2020). Finally,
 we do not decide whether the Board has an independent
 obligation to determine patentability of proposed substi-
 tute claims. These questions need not be answered to re-
 solve the appeal before us.
                          CONCLUSION
     We affirm the Board’s decision holding claims 1–15 un-
 patentable, and we also affirm the Panel’s decision grant-
 ing DynaEnergetics’s motion to amend the ’422 patent to
 add new claims 16–22.
                          AFFIRMED
                             COSTS
 No costs.

 that the Board should begin by first asking if the corre-
 sponding proposed substitute claim overcomes the ground
 on which it found the original claim unpatentable.
Case: 20-2163    Document: 59     Page: 20   Filed: 03/24/2022

    United States Court of Appeals
        for the Federal Circuit
                  ______________________

                 HUNTING TITAN, INC.,
                      Appellant

                             v.

         DYNAENERGETICS EUROPE GMBH,
                 Cross-Appellant

    ANDREW HIRSHFELD, PERFORMING THE
     FUNCTIONS AND DUTIES OF THE UNDER
        SECRETARY OF COMMERCE FOR
  INTELLECTUAL PROPERTY AND DIRECTOR OF
  THE UNITED STATES PATENT AND TRADEMARK
                    OFFICE,
                    Intervenor
              ______________________

                   2020-2163, 2020-2191
                  ______________________

     Appeals from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in No. IPR2018-
 00600.
                  ______________________

 PROST, Circuit Judge, concurring.
     I join the majority’s opinion, agreeing that Hunting Ti-
 tan didn’t preserve a challenge to the Precedential Opinion
 Panel’s (“POP”) application of its standard for when it is
 (and isn’t) appropriate for the Board to sua sponte raise
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 2       HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

 patentability issues as to new claims. 1 I write separately
 to explain why, had that challenge been preserved, it likely
 would have succeeded—and why I’m troubled by how the
 PTO is handling this issue, including with a recently en-
 acted regulation.
                                I
     In evaluating new (i.e., proposed substitute or
 amended) claims, “the Board should not be constrained to
 arguments and theories raised by the petitioner in its peti-
 tion or opposition to the motion to amend.” Nike, Inc. v.
 Adidas AG, 955 F.3d 45, 51 (Fed. Cir. 2020) (emphasis
 added). We’ve reasoned:
     It makes little sense to limit the Board, in its role
     within the agency responsible for issuing patents,
     to the petitioner’s arguments in this context. Ra-
     ther, based on consideration of the entire record,
     the Board must determine whether the patent
     owner’s newly-presented, narrower claims are . . .
     “unpatentable in the face of the prior art cited in
     the IPR.”
 Id. at 51–52 (emphasis added) (quoting Aqua Prods., Inc.
 v. Matal, 872 F.3d 1290, 1314 (Fed. Cir. 2017) (en banc)
 (plurality opinion)). Although we haven’t delineated the
 outer bounds of any independent Board duty to ensure that
 new patent claims are, in fact, patentable before they issue,
 we have observed that “the text, structure, and history of
 the IPR [s]tatutes . . . indicate Congress’s unambiguous

     1   This preservation failure was discussed exten-
 sively at oral argument, during which Hunting Titan’s
 counsel could not—despite repeated opportunities—iden-
 tify where its opening brief made this challenge. See Oral
 Arg. at 2:31–4:49, 5:59–7:28, 11:58–15:04, 1:03:27–1:07:37,
 No. 20-2163, https://oralarguments.cafc.uscourts.gov/de-
 fault.aspx?fl=20-2163_11012021.mp3.
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH        3

 intent to permit the [Board] to review [new] claims more
 broadly than” original claims. Uniloc 2017 LLC v. Hulu,
 LLC, 966 F.3d 1295, 1304 (Fed. Cir. 2020); id. at 1306 (not-
 ing the absence of “any other context under Title 35—e.g.,
 original applications, reexaminations, reissue, etc.—in
 which the [PTO] is required or authorized to newly issue a
 patent claim without ever having determined that the par-
 ticular claim meets the statutory requirements for patent-
 ability”).
      The POP nevertheless constrained the Board’s ability
 to raise its own patentability issues as to new claims. It
 identified just three situations in which the Board could do
 so: (1) where the petitioner has ceased participating in the
 proceeding altogether; (2) where the petitioner chooses not
 to oppose the patent owner’s motion to amend; and
 (3) where, although the petitioner has opposed, it has failed
 to raise unpatentability evidence that is nonetheless “read-
 ily identifiable and persuasive.” Hunting Titan, Inc. v.
 DynaEnergetics Eur. GmbH, IPR2018-00600, 2020 WL
 3669653, at *6 (P.T.A.B. July 6, 2020). The third situa-
 tion—“readily identifiable and persuasive” evidence—is at
 issue here, given that Hunting Titan opposed DynaEner-
 getics’s motion to amend.
     Whatever the “readily identifiable and persuasive”
 standard means, it should have let the Board do what it did
 here: evaluate whether the prior-art reference that antici-
 pated the original claims also anticipated the new claims.
 Such an evaluation can hardly be deemed overly zealous or
 creative on the Board’s part. Indeed, among potential un-
 patentability bases to raise sua sponte, this would seem to
 be square one. But the POP disagreed. It forbade the
 Board from making that basic evaluation. The POP thus
 denied three administrative patent judges—who had de-
 voted extensive resources to analyzing this prior-art refer-
 ence—the ability to use that acquired expertise in making
 their own patentability determinations before letting new
 claims out the door. I don’t see how the POP’s decision in
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 4       HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

 this regard is reasonable. It also appears inconsistent with
 Nike, where we approved the Board’s sua sponte unpatent-
 ability finding based on a prior-art reference not even men-
 tioned in the petitioner’s opposition. 2 See Nike, 955 F.3d
 at 48–53.
     But, because Hunting Titan forfeited a challenge to the
 POP’s application of its new standard here, review of that
 standard’s application must await another day.
                                II
     The POP stressed the adversarial aspect of IPRs when
 justifying its “readily identifiable and persuasive” con-
 straint on the Board. Hunting Titan, 2020 WL 3669653,
 at *5–6, *9. But it acknowledged that motions to amend
 don’t always have an adversary. For example, the peti-
 tioner might have dropped out or declined to oppose. Ac-
 cordingly, the POP framed the “readily identifiable and
 persuasive” constraint as applying only to situations where
 the petitioner opposes a motion to amend:
     To be sure, there may be circumstances where the
     adversarial system fails to provide the Board with
     potential arguments for the unpatentability of the
     proposed substitute claims. As noted above, the
     Supreme Court in Cuozzo specifically addressed
     one such situation, in which the petitioner has
     ceased to participate in the proceeding altogether.
     A similar situation may exist where a petitioner
     chooses not to oppose the motion to amend. And

     2    Here, Hunting Titan cited and discussed the
 Schacherer reference throughout its opposition to
 DynaEnergetics’s motion to amend. J.A. 518–47. But it
 argued obviousness (not anticipation), and as to one of the
 newly added claim elements, the Board found a disclosure
 in Schacherer that Hunting Titan’s opposition did not spe-
 cifically identify.
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH          5

     even where both a petitioner and patent owner par-
     ticipate in the motion to amend process, there may
     be situations where certain evidence of unpatenta-
     bility has not been raised by the petitioner, but is
     readily identifiable and persuasive such that the
     Board should take it up in the interest of support-
     ing the integrity of the patent system, notwith-
     standing the adversarial nature of the proceedings.
 Id. at *6 (emphasis added) (citation omitted). 3 The clear
 implication was that the Board would not be so constrained
 when a motion to amend is unopposed. Id.; see Nike,
 955 F.3d at 51 (expressing concern over limiting the PTO’s
 “ability to examine the new claims” in cases where the pe-
 titioner has not opposed).
      The PTO, however, has since enacted a regulation that
 seemingly applies the “readily identifiable and persuasive”
 constraint to all motions to amend—opposed or not. The
 following provision now applies 4:
     (d) Burden of Persuasion. On a motion to amend:
         (1) A patent owner bears the burden of per-
         suasion to show, by a preponderance of the
         evidence, that the motion to amend com-
         plies with the requirements of paragraphs
         (1) and (3) of 35 U.S.C. § 316(d), as well as

     3      The PTO’s brief in this appeal adopted this same
 framing. E.g., Intervenor’s Br. 17 (“These circumstances
 include where the petitioner ceases to participate in the
 proceeding altogether or does not oppose the motion to
 amend; and, even when the petitioner opposes, where the ev-
 idence of unpatentability is readily identifiable and persua-
 sive . . . .” (emphasis added)).
     4      This provision applies to all motions to amend filed
 on or after January 20, 2021, so it doesn’t apply in this case.
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 6      HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

         paragraphs (a)(2), (a)(3), (b)(1), and (b)(2) of
         this section;
         (2) A petitioner bears the burden of persua-
         sion to show, by a preponderance of the ev-
         idence, that any proposed substitute claims
         are unpatentable; and
         (3) Irrespective of paragraphs (d)(1) and (2)
         of this section, the Board may, in the inter-
         ests of justice, exercise its discretion to
         grant or deny a motion to amend only for
         reasons supported by readily identifiable
         and persuasive evidence of record. In doing
         so, the Board may make of record only
         readily identifiable and persuasive evi-
         dence in a related proceeding before the
         [PTO] or evidence that a district court can
         judicially notice. Where the Board exer-
         cises its discretion under this paragraph,
         the parties will have an opportunity to re-
         spond.
 37 C.F.R. § 42.121(d) (emphasis added); see Rules of Prac-
 tice to Allocate the Burden of Persuasion on Motions to
 Amend in Trial Proceedings Before the Patent Trial and
 Appeal Board, 85 Fed. Reg. 82,923, 82,924 (Dec. 21, 2020)
 (setting forth the effective date).
      The PTO’s remarks accompanying this regulation’s en-
 actment note some situations where the “readily identifia-
 ble and persuasive” constraint would apply. For example,
 if the patent owner’s briefing fails to expressly address or
 establish every statutory and regulatory requirement for a
 motion to amend (as 37 C.F.R. § 42.121(d)(1) mandates),
 the Board may nonetheless determine that such require-
 ments are met—but “only when there is readily identifiable
 and persuasive evidence” showing as much. 85 Fed. Reg.
 at 82,927. Likewise, where a petitioner opposes a motion
 to amend “but fails to raise certain evidence of
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 HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH       7

 unpatentability that is [nonetheless] readily identifiable
 and persuasive,” the Board may take up that evidence,
 “notwithstanding the adversarial nature of the proceed-
 ings.” Id.
      The prospect of applying the “readily identifiable and
 persuasive” constraint to unopposed motions to amend,
 however, is what particularly troubles me. Although the
 POP indicated that the constraint wouldn’t apply in such
 circumstances, see Hunting Titan, 2020 WL 3669653, at *6,
 and although the PTO maintains that this regulation “cod-
 ifie[s]” or “embod[ies] the policy determination articulated
 by the POP here,” Intervenor’s Br. 17–18, 29–30, the regu-
 lation appears to apply the constraint to all motions to
 amend—opposed or not. Indeed, the PTO’s counsel at oral
 argument adopted that view, maintaining that the regula-
 tion imposes the “readily identifiable and persuasive” con-
 straint even in unopposed situations. Oral Arg. at
 21:03–13; see id. at 19:39–59. According to counsel, the
 reason for doing so is “to encourage the parties to remain
 in and oppose the motion [to amend].” Oral Arg. at
 19:48–57. But an adverse petitioner needs no extra encour-
 agement to oppose a motion. And if the petitioner is no
 longer adverse—e.g., having settled or satisfied itself that
 an amendment removes the threat of infringement—it’s
 unclear how the PTO’s policy would affect the petitioner’s
 incentive to oppose.

     Because the regulation makes no caveat for unopposed
 motions, the Board may find its hands tied (or its head
 forced into the sand) even when no one is around to oppose
 a new patent monopoly grant.

                           *   *   *
      The “basic purpose[]” of IPRs is “to reexamine an ear-
 lier agency decision,” thus “help[ing] protect the public’s
 paramount interest in seeing that patent monopolies are
 kept within their legitimate scope.” Cuozzo Speed Techs.,
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 8      HUNTING TITAN, INC.   v. DYNAENERGETICS EUROPE GMBH

 LLC v. Lee, 579 U.S. 261, 279–80 (2016) (cleaned up). That
 purpose is particularly salient here, given that the Board
 usually evaluates the patentability of new claims only after
 it has recognized the PTO’s original error in issuing un-
 patentable claims. I don’t see the reasonableness of a pol-
 icy that seriously hinders the Board’s basic efforts to avoid
 making the same error twice.