Trivascular, Inc. v. Samuels , 812 F.3d 1056 ( 2016 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    TRIVASCULAR, INC.,
    Appellant
    v.
    SHAUN L. W. SAMUELS,
    Appellee
    ______________________
    2015-1631
    ______________________
    Appeal from the United States Patent and Trademark
    Office, Patent Trial and Appeal Board in No. IPR2013-
    00493.
    ______________________
    Decided: February 5, 2016
    ______________________
    DAVID K.S. CORNWELL, Sterne Kessler Goldstein &
    Fox, PLLC, Washington, DC, argued for appellant. Also
    represented by PAULINE PELLETIER, RICHARD D. COLLER,
    III.
    JAMES D. PETRUZZI, Petruzzi Law Firm, Houston, TX,
    argued for appellee. Also represented by EVERETT G.
    DIEDERIKS, JR., NICHOLAS SPENCER WHITELAW, Diederiks
    & Whitelaw PC, Woodbridge, VA.
    ______________________
    Before MOORE, O’MALLEY, and WALLACH, Circuit Judges.
    2                             TRIVASCULAR, INC.   v. SAMUELS
    O’MALLEY, Circuit Judge.
    TriVascular, Inc. (“TriVascular”) appeals the judg-
    ment of the Patent Trial and Appeal Board (“the Board”)
    holding that TriVascular failed to satisfy its burden of
    proving that the challenged claims of U.S. Patent No.
    6,007,575 (“the ’575 patent”) are invalid as obvious. For
    the reasons below, we affirm.
    BACKGROUND
    The ’575 patent claims inventions in the field of in-
    traluminal stent technology. One type of intraluminal
    stent is a vascular stent. Vascular stents are used to
    treat medical conditions wherein a vascular wall is undu-
    ly constricted, as in the case of vascular stenosis, or
    unduly enlarged, as in the case of aneurysm. Either of
    these medical conditions poses an unacceptable risk of
    insufficient blood flow or vascular rupture.
    The Patent in Suit
    The ’575 patent was filed on June 6, 1997, and lists a
    sole inventor, Dr. Shaun L.W. Samuels. The ’575 patent
    generally claims intraluminal stents that can be affixed to
    a vascular wall via the use of “an inflatable and deflatable
    cuff” without penetrating the vessel wall. ’575 patent,
    col. 6 ll. 47-67. These “inflatable and deflatable cuffs” are
    depicted by the number 17 in Figure 1 of the ’575 patent
    below, and can be inflated by introduction of a fluid into
    each of the “circumferential ridges” 25.
    TRIVASCULAR, INC.   v. SAMUELS                                3
    
    Id. at fig.
    1.
    Claim 1 of the ’575 patent is illustrative and recites:
    1. An inflatable intraluminal stent adapted to be
    secured to the interior of a tubular structure with-
    in the human body comprising:
    a) an inflatable and deflatable cuff of generally
    hollow cylindrical continuation having a collapsi-
    ble lumen, an inner surface, an inlet, an outlet
    and a friction enhancing outer surface, said fric-
    tion-enhancing outer surface featuring inflatable
    protrusion(s) including at least one circumferential
    ridge disposed about the inflatable cuff, said fric-
    tion-enhancing outer surface engaging the interior
    of the tubular structure without penetration to
    prevent the cuff from moving in a longitudinal di-
    rection with respect to the tubular structure when
    said cuff is in a fully inflated condition;
    b) means for injecting an inflation material into
    said cuff to inflate it; and
    c) a valve integral with the inflatable cuff for per-
    mitting entry of the inflation material from the
    means for injecting and thereafter sealing said
    cuff to prevent deflation.
    
    Id. at col.
    6 ll. 47-67 (emphasis added). TriVascular
    disputes the Board’s construction of the claim term “cir-
    cumferential ridge,” which appears in part (a) of the
    claim.
    Procedural Background
    In 2013, Dr. Samuels sued TriVascular alleging in-
    fringement of the ’575 patent. Samuels v. TriVascular
    Corp., Case No. 3:13-cv-02261 (N.D. Cal. May 17, 2013).
    TriVascular filed a petition for inter partes review (“IPR”)
    on August 5, 2013. The Board instituted review on Feb-
    ruary 4, 2014. Joint Appendix (“JA”) 168. In its Institu-
    4                             TRIVASCULAR, INC.   v. SAMUELS
    tion Decision, the Board explained that it was instituting
    IPR on the following two grounds: (1) obviousness over
    Samuel’s U.S. Patent No. 5,423,851 (“Samuels ’851”) and
    U.S. Patent No. 5,423,745 to Todd et al. (“Todd”); and (2)
    obviousness over U.S. Patent No. 5,693,088 to Lazarus et
    al. (“Lazarus”) and Todd. JA 184. In its Institution
    Decision, the Board construed the phrase “circumferential
    ridge disposed about the inflatable cuff” to mean “raised
    strip disposed circumferentially about the outer surface of
    the inflatable cuff.” JA 175-76. Applying its claim con-
    struction, the Board then found that “on the present
    record,” Samuels had not demonstrated that the Samuels
    ’851 reference teaches away from the substitution of the
    penetrating anchoring barbs taught in the reference, nor
    did Samuels establish that removing the barbs would
    destroy the objective of the reference. JA 183. According-
    ly, the Board explained that TriVascular had established
    a reasonable likelihood of success on two potential
    grounds.
    The parties subsequently introduced their respective
    expert reports regarding the instituted grounds. The IPR
    proceeded to trial, and the Board issued a final decision
    on December 13, 2014, holding that TriVascular failed to
    meet its burden of demonstrating that the challenged
    claims were unpatentable over the applied art. JA 24. In
    its Final Written Decision, the Board adopted Samuels’
    construction of “inflatable protrusions,” as “protrusions
    that are themselves inflatable, i.e., expandable by being
    filled with fluid.” JA 10. The Board found that, inter alia,
    the ’575 patent’s “inflatable protrusions” were not dis-
    closed by the prior art, nor would a skilled artisan have
    been motivated to combine the prior art in a manner that
    would read on the claims of the ’575 patent. The Board
    also found that the prior art did not teach the “circumfer-
    ential ridges” taught in the ’575 patent at issue, based on
    its claim construction at institution, which did not permit
    the “circumferential ridges” to be made up of a series of
    TRIVASCULAR, INC.   v. SAMUELS                           5
    discontinuous inflatable protrusions formed circumferen-
    tially about the cuff. JA 18-19.
    After issuance of the Final Written Decision, Tri-
    Vascular filed a petition for rehearing, which the Board
    denied. JA 34.
    TriVascular timely appealed.       We have jurisdiction
    under 28 U.S.C. § 1295(a)(4)(A).
    DISCUSSION
    TriVascular argues that the Board erred in its con-
    struction of the term “circumferential ridges,” and in its
    holding that TriVascular failed to demonstrate that the
    challenged claims of the ’575 patent are invalid as obvi-
    ous. Because we find no reversible error in the Board’s
    holdings, we affirm.
    A. Standard of Review
    When reviewing claim construction by the Board,
    “[w]e review underlying factual determinations concern-
    ing extrinsic evidence for substantial evidence and the
    ultimate construction of the claim de novo.” In re Cuozzo
    Speed Techs., LLC, 
    793 F.3d 1268
    , 1280 (Fed. Cir. 2015),
    cert. granted sub nom., Cuozzo Speed Techs., LLC v. Lee,
    No. 15-446, 
    2016 WL 205946
    (U.S. January 15, 2015).
    Obviousness is a question of law based on underlying
    facts. In re Gartside, 
    203 F.3d 1305
    , 1316 (Fed. Cir.
    2000). The Board’s legal conclusion of obviousness is
    reviewed de novo; its factual findings concerning extrinsic
    evidence are reviewed for substantial evidence. 
    Cuozzo, 793 F.3d at 1280
    .
    Substantial evidence “means such relevant evidence
    as a reasonable mind might accept as adequate to support
    a conclusion.” Consol. Edison Co. v. NLRB, 
    305 U.S. 197
    ,
    229 (1938); see In re Morsa, 
    713 F.3d 104
    , 109 (Fed. Cir.
    2002).
    6                            TRIVASCULAR, INC.   v. SAMUELS
    B. Claim Construction
    TriVascular argues that the Board erred in its claim
    construction requiring the term “circumferential ridges”
    to mean a “raised strip disposed circumferentially about
    the outer surface of the inflatable cuff.” Instead, Tri-
    Vascular contends that the Board should have construed
    the term to mean “an elevated part of the outer surface
    disposed about the inflatable cuff that can be either con-
    tinuous or discontinuous.” Appellant’s Br. 3 (emphasis
    added). TriVascular argues that the Board’s construction
    is inconsistent with the plain meaning of the term “cir-
    cumferential ridges.” TriVascular further contends that
    the Board erred in failing to apply prosecution history
    disclaimer to bar Samuels from arguing for a narrower
    construction.
    Samuels responds that the Board correctly interpret-
    ed “circumferential ridges” because the plain language
    and specification support the construction of continuous
    raised ridges disposed radially around the inflatable cuff.
    Samuels further asserts that the Board did not err in
    rejecting TriVascular’s interpretation of the prosecution
    history in construing the term. For the reasons below, we
    agree with Samuels.
    1. Broadest Reasonable Interpretation Standard
    In construing claim terms, the Board must determine
    the scope of the claims by giving them their broadest
    reasonable construction in light of the specification as
    they would be interpreted by one of ordinary skill in the
    art. 
    Cuozzo, 793 F.3d at 1279-80
    ; compare Phillips v.
    AWH Corp., 
    415 F.3d 1303
    , 1316 (Fed. Cir. 2005) (en
    banc). Under a broadest reasonable interpretation, words
    of the claim must be given their plain meaning, unless
    such meaning is inconsistent with the specification and
    prosecution history. Straight Path IP Grp., Inc. v. Sipnet
    EU S.R.O., 
    806 F.3d 1356
    , 1362 (Fed. Cir. 2015).
    TRIVASCULAR, INC.   v. SAMUELS                             7
    While the broadest reasonable interpretation stand-
    ard is broad, it does not give the Board an unfettered
    license to interpret the words in a claim without regard
    for the full claim language and the written description.
    In re Suitco Surface, Inc., 
    603 F.3d 1255
    , 1260 (Fed. Cir.
    2010); see In re Abbott Diabetes Care, Inc., 
    696 F.3d 1142
    ,
    1148-50 (Fed. Cir. 2012) (finding the Patent Office’s
    construction unreasonably broad because it was “unrea-
    sonable and inconsistent with the language of the claims
    and the specification”). Construing individual words of a
    claim without considering the context in which those
    words appear is simply not “reasonable.” Instead, it is the
    “use of the words in the context of the written description
    and customarily by those of skill in the relevant art that
    accurately reflects both the ‘ordinary’ and ‘customary’
    meaning of the terms in the claims.” Ferguson Beaure-
    gard/Logic Controls, Div. of Dover Res., Inc. v. Mega Sys.,
    LLC, 
    350 F.3d 1327
    , 1338 (Fed. Cir. 2003).
    2. The Board’s Claim Construction
    The Board determined that the plain meaning of “cir-
    cumferential ridges” under the broadest reasonable
    interpretation standard does not encompass discontinu-
    ous points arranged in a circular pattern on the surface of
    a stent. The Board found support for its construction in
    the written description, noting that it described a circum-
    ferential ridge as a raised strip “disposed about [the]
    circumference of outer surface 23 of inflatable cuff 17.”
    JA 175-76 (citing ’575 patent, fig. 1). The Board also
    relied on a general purpose dictionary, finding the defini-
    tion of “ridge” as “a raised strip (as of plowed ground)” to
    be in accord with the specification’s description of a raised
    strip. JA 176. Finally, the Board found that TriVascu-
    lar’s proposed construction of “circumferential” that would
    encompass discontinuous raised sections “does not inform
    the meaning of the term ‘circumferential ridge.’” JA 30.
    8                            TRIVASCULAR, INC.   v. SAMUELS
    TriVascular alleges that the Board’s construction is
    contrary to the plain meaning of the claim term. In
    support of its argument, TriVascular asserts that the
    Board’s construction is unreasonably narrow in light of
    the common definition of a topological “ridge.” TriVascu-
    lar points to the Blue Ridge Mountains in the Appalachi-
    an Mountain Range, which TriVascular alleges constitute
    “discontinuous” protrusions that collectively form the
    mountain ridge. Appellant’s Br. 31-32. We find Tri-
    Vascular’s arguments to be unpersuasive. First, we note
    that TriVascular does not explain why the Board should
    have resorted to a topological or cartographical definition
    of “ridge,” over a general dictionary definition that is
    consistent with both the specification’s teachings and the
    remaining claim limitations. And, even resorting to the
    topological definition of ridge, TriVascular has failed to
    explain why such a topological definition would encom-
    pass discontinuous peaks in a mountain range, when
    mountain ranges typically consist of adjacent, continuous
    mountain peaks. 1 To adopt TriVascular’s definition and
    construe “circumferential” to include discontinuous points
    would be to adopt an unreasonably broad construction.
    1    TriVascular’s utilization of the Blue Ridge Moun-
    tains as an exemplary mountain ridge is particularly
    unsupportive of their position. In fact, the National Park
    Service has noted that the Blue Ridge Mountains were so
    named because “hydrocarbons released into the atmos-
    phere by the forest contribute to the characteristic haze
    on these mountains and to their distinctive color.” Na-
    tional Park Service, Blue Ridge Mountains, Frequently
    Asked Questions, at http://www.nps.gov/blri/faqs.htm
    (last visited January 8, 2016). The eponymous blue haze
    of the mountain range constitutes a continuous ridge
    bridging the range’s mountain peaks. Thus the word
    “Blue” modifies the term “Ridge”; the term “Ridge” is not
    intended to modify the word “Mountains.”
    TRIVASCULAR, INC.   v. SAMUELS                            9
    See Microsoft Corp. v. Proxyconn, Inc., 
    789 F.3d 1292
    ,
    1300 (Fed. Cir. 2015) (finding that the Board’s construc-
    tion of key claim terms was unreasonably broad in light of
    the broadest reasonable interpretation standard, and on
    that basis vacating and remanding the Board’s finding of
    unpatentability). We find the Board’s reliance on the
    dictionary definition of ridge when considered in the
    context of the written description and plain language of
    the claims was proper. 2
    3. Prosecution History Disclaimer
    TriVascular’s other alleged basis of error was that the
    Board should have applied prosecution history disclaimer
    to prohibit a construction of “circumferential ridges” that
    is limited to continuous ridges. Appellant’s Br. 33.
    The same general tenets that apply to prosecution
    history estoppel apply to prosecution history disclaimer.
    Regents of Univ. of Minnesota v. AGA Med. Corp., 
    717 F.3d 929
    , 942 (Fed. Cir. 2013) (drawing a parallel between
    prosecution history estoppel barring an equivalence
    argument under the doctrine of equivalents and prosecu-
    tion history disclaimer barring a position on claim con-
    struction under § 112, ¶ 6 that is inconsistent with one
    taken before the PTO, and noting that “prosecution histo-
    2    Because TriVascular argues for a broader con-
    struction than the one the Board employed rather than a
    narrower one, the Supreme Court’s grant of certiorari to
    consider the propriety of the broadest reasonable inter-
    pretation standard in IPRs will not impact our decision to
    affirm the Board’s claim construction and non-
    obviousness conclusion here. Cuozzo, 
    793 F.3d 1268
    , cert.
    granted, Cuozzo Speed Techs., LLC v. Lee, No. 15-446,
    
    2016 WL 205946
    (U.S. Jan. 15, 2016). Accordingly, we
    need not delay deciding this case pending the Supreme
    Court decision in Cuozzo.
    10                            TRIVASCULAR, INC.   v. SAMUELS
    ry disclaimer may limit the range of equivalent structures
    that fall within the scope of a means-plus-function limita-
    tion.”). Both doctrines require that the claims of a patent
    be interpreted in light of the proceedings in the PTO
    during the application process. See Festo Corp. v. Sho-
    ketsu Kinzoku Kogyo Kabushiki Co., 
    535 U.S. 722
    , 733
    (2002). As applied to a disclaimer analysis, “the prosecu-
    tion history can often inform the meaning of the claim
    language by demonstrating how the inventor understood
    the invention.” 
    Phillips, 415 F.3d at 1317
    . “Any explana-
    tion, elaboration, or qualification presented by the inven-
    tor during patent examination is relevant, for the role of
    claim construction is to ‘capture the scope of the actual
    invention’ that is disclosed, described, and patented.”
    Fenner Invs., Ltd. v. Cellco P’ship, 
    778 F.3d 1320
    , 1323
    (Fed. Cir. 2015) (citing Retractable Techs., Inc. v. Becton,
    Dickinson & Co., 
    653 F.3d 1296
    , 1305 (Fed. Cir. 2011)).
    Accordingly, disclaimer “ensures that claims are inter-
    preted by reference to those ‘that have been cancelled or
    rejected.’” Festo 
    Corp., 535 U.S. at 733
    (citing Schriber-
    Schroth Co. v. Cleveland Trust Co., 
    311 U.S. 211
    , 220
    (1940)). The party seeking to invoke prosecution history
    disclaimer bears the burden of proving the existence of a
    “clear and unmistakable” disclaimer that would have been
    evident to one skilled in the art. See Elbex Video, Ltd. v.
    Sensormatic Elecs. Corp., 
    508 F.3d 1366
    , 1371 (Fed. Cir.
    2007).
    TriVascular’s argument on prosecution history dis-
    claimer proceeds in several steps. First, TriVascular
    notes that the examiner initially rejected the claims at
    issue by interpreting Samuels ’851 as having “inflatable
    protrusions” that form a “circumferential ridge.” Appel-
    lant’s Br. 34. Second, TriVascular observes that Samuels
    responded to this rejection by (a) stating that Samuels
    ’851 did not disclose “continuous” circumferential ridges
    and (b) introducing an “Amendment B” adding the word
    “continuously” to the claim phrase “at least one circum-
    TRIVASCULAR, INC.   v. SAMUELS                           11
    ferential ridge continuously disposed about said inflatable
    cuff.” JA 707. Third and finally, TriVascular notes that
    Samuels did not expressly include the term “continuous”
    in the final issued claims. TriVascular argues that this
    series of events triggers prosecution history disclaimer
    that bars Samuels from now arguing for a construction
    limited to “continuous” circumferential ridges, which was
    not claimed in the final issued claims. Appellant’s Br. 34.
    The Board rejected TriVascular’s prosecution history
    disclaimer argument, explaining in relevant part as
    follows:
    TriVascular’s arguments focus on the patent ap-
    plicant’s “Amendment B” in isolation, and are un-
    persuasive in view of the subsequent prosecution
    history, which shows that the positions of the Ex-
    aminer and the patent applicant changed follow-
    ing a telephone interview. . . . Ultimately, an
    Examiner’s Amendment was entered deleting
    claim 26 [introduced in Amendment B] and sub-
    stituting a new claim (which issued as patent
    claim 23) and included the limitation “at least one
    circumferential ridge disposed about the inflatable
    cuff” and omitted the “continuously” language of
    Amendment B.
    JA 30-31. The Board found it significant that other
    amendments were made to the relevant claim, which
    apparently convinced the examiner of the patentability of
    the claimed invention over the prior art, without regard to
    the proposed addition of the word “continuously” to the
    claims.
    We find no error in the Board’s conclusion that Tri-
    Vascular has failed to meet its burden of demonstrating
    the existence of a “clear and unmistakable” disclaimer
    that would have been evident to one skilled in the
    art. Elbex 
    Video, 508 F.3d at 1371
    . Though Samuels
    offered the “continuously circumferential ridges” limita-
    12                            TRIVASCULAR, INC.   v. SAMUELS
    tion as one of several possible bases for distinguishing the
    prior art, the Examiner never adopted Samuels’ proposed
    amendment as a reason for allowing the claims over the
    prior art. Since the Examiner ultimately allowed the
    claims over the prior art without the proposed amend-
    ment, it is difficult to see how a skilled artisan could
    interpret the proposed amendment as a disclaimer re-
    quired for patentability. Indeed, Samuels offered several
    other amendments as possible bases for distinguishing
    the prior art: (1) a requirement that the stent use “inflat-
    able protrusion(s) without rigid components”; (2) a re-
    quirement that the cuff of the stent have “a collapsible
    lumen”; and (3) a requirement that the cuff contain a
    friction-enhancing outer surface preventing “movement of
    the cuff in a longitudinal direction with respect to the
    tubular structure.” JA 707-08 (italics added to show
    proposed amendments to claims).
    Following the proposed amendment, Samuels and the
    Examiner engaged in an interview. Subsequently, Samu-
    els submitted new claims “[i]n accordance with the Exam-
    iner’s instructions provided during [the] telephone
    interview,” and further noted that “the appropriate claims
    have been canceled to omit redundancy.” JA 721. The
    examiner then allowed the final submitted claims to
    issue, over the prior art, without the “continuously cir-
    cumferential ridges” limitation. JA 722. During the IPR,
    the Board found that this subsequent prosecution history
    “shows that the positions of the Examiner and the patent
    applicant changed following a telephone interview,”
    regarding the allowability of the claims without the
    “continuously” limitation. We find no error in the Board’s
    finding that the examiner was convinced by these alter-
    nate claim amendments rather than the “continuously”
    circumferential ridges amendment. This finding is sup-
    ported in the record, which shows that the Examiner
    entered the alternate amendments, while omitting the
    TRIVASCULAR, INC.   v. SAMUELS                           13
    “continuously” amendment. JA 721-22. Thus, the Board
    did not err in finding that no disclaimer applied.
    TriVascular nonetheless argues that there must be
    “written evidence” to contradict an applicant’s concessions
    made in an amendment, and that “[w]here the record is
    devoid of any written documentation, no inferences can be
    made as to what the examiner relied upon or understood.”
    Appellant’s Br. 36. TriVascular contends that this propo-
    sition flows from three cases, Litton Systems, Inc. v.
    Whirlpool Corp., 
    728 F.2d 1423
    (Fed. Cir. 1984), Genzyme
    Corp. v. Transkaryotic Therapies, Inc., 
    346 F.3d 1094
    (Fed. Cir. 2003), and Rohm & Haas Co. v. Crystal Chemi-
    cal Co., 
    722 F.2d 1556
    (Fed. Cir. 1983). TriVascular’s
    reliance on these cases is misplaced.
    First, TriVascular argues that this court explained in
    Litton that failure to document the results of an interview
    with the examiner estopped the applicant from later
    contending that the “prosecution record is not true.”
    Appellant’s Br. 37 (citing 
    Litton, 728 F.2d at 1439
    ). Litton
    involved a case where an applicant elected to continue
    prosecution by filing a continuation application. Litton
    then had an examiner interview, the results of which
    were not documented. After the examiner interview,
    Litton filed an amendment clarifying that the continua-
    tion application was a continuation in part (“CIP”).
    Subsequently in litigation, Litton attempted to argue
    that, in the undocumented examiner interview, the exam-
    iner accepted Litton’s explanation that the continuation
    application did not contain new matter, and therefore
    should be entitled to the continuation application’s filing
    date. A review of the prosecution history in each case is
    necessarily context-specific. Unlike the present case, the
    examiner in Litton accepted Litton’s written filing, which
    characterized the application as a CIP. Furthermore, this
    court considered the prosecution history as a whole to find
    that Litton should be estopped from arguing that the
    record was “not true.” In contrast, here the examiner
    14                           TRIVASCULAR, INC.   v. SAMUELS
    never required the claim amendment upon which Tri-
    Vascular hinges its prosecution history disclaimer argu-
    ment. Accordingly, Litton does not control the facts of
    this case.
    Genzyme is similarly distinguishable. In Genzyme,
    the issue was whether an applicant’s attempted last-
    minute amendment could omit a limitation that had been
    repeatedly emphasized throughout the prosecution histo-
    ry. In particular, “the deposit requirement, the specifica-
    tion, the applicant’s arguments to distinguish prior art,
    the examiner’s responses, and [applicant’s expert’s]
    declaration repeatedly stressed that the invention envi-
    sioned” inclusion of the claim limitation at issue. Gen-
    
    zyme, 346 F.3d at 1103
    . This court held that “[a]
    clarifying amendment at the last moment could not
    negate th[e] extensive public record” in which the appli-
    cant had repeatedly argued that a limitation was neces-
    sary to distinguish the claimed invention from the prior
    art. 
    Id. Similarly, Genzyme
    supports the Board’s rejec-
    tion of prosecution history disclaimer in the present case,
    in which the Board considered the proper claim construc-
    tion in view of “the complete prosecution history.” JA 31.
    Finally, unlike the present case, Rohm involved a
    claim of inequitable conduct based on a patent applicant’s
    intentional misrepresentations in certain affidavits.
    
    Rohm, 722 F.2d at 1557
    . The central issue was whether
    the applicant was able to show that it had “cured” its
    prior misrepresentations during an examiner interview.
    
    Id. at 1572-73.
    In Rohm, the applicant provided “lengthy
    interview summaries” of the examiner interview, but the
    summaries failed to note whether the applicant informed
    the PTO “that any misrepresentations had been made or
    precisely where they had been made.” 
    Id. We held
    that
    “[s]uch express disclosure was necessary to meet [the
    applicant]’s duty, and would have alerted the PTO to the
    necessity of reconsidering rejections which had been
    withdrawn as a result of those submissions.” 
    Id. Rohm TRIVASCULAR,
    INC.   v. SAMUELS                            15
    clearly does not control or even inform the question of
    prosecution history disclaimer we consider in this case.
    For the above reasons, we find no error in the Board’s
    construction of the “circumferential ridges” claim limita-
    tion requiring the ridges to be continuous.
    C. Obviousness
    TriVascular next argues that the Board should have
    found the ’575 patent’s claims invalid under the instituted
    ground of obviousness over Samuels ’851 in view of Todd.
    As explained above, we find no error in the Board’s claim
    construction of “circumferential ridges.” For the reasons
    below, the Board did not err in finding that TriVascular
    failed to satisfy its burden of proving that the challenged
    claims of the ’575 patent are invalid as obvious.
    A patent is invalid “if the differences between the sub-
    ject matter sought to be patented and the prior art are
    such that the subject matter as a whole would have been
    obvious at the time the invention was made to a person
    having ordinary skill in the art to which said subject
    matter pertains.” 35 U.S.C. § 103(a) (2012); see generally
    Graham v. John Deere Co., 
    383 U.S. 1
    , 17-18 (1966).
    Thus, a patent may be found invalid as obvious if “there
    are a finite number of identified, predictable solutions,
    [and] a person of ordinary skill has good reason to pursue
    the known options within his or her technical grasp.”
    KSR Int’l Co. v. Teleflex Inc., 
    550 U.S. 398
    , 421 (2007).
    Although the KSR test is flexible, the Board “must still be
    careful not to allow hindsight reconstruction of references
    . . . without any explanation as to how or why the refer-
    ences would be combined to produce the claimed inven-
    tion.” Kinetic Concepts, Inc. v. Smith & Nephew, Inc., 
    688 F.3d 1342
    , 1368 (Fed. Cir. 2012) (emphases added) (inter-
    nal quotations omitted).
    The prior art forming the ground of the Board’s deci-
    sion being appealed are Samuels ’851 in view of Todd, two
    16                           TRIVASCULAR, INC.   v. SAMUELS
    references directed at stent technology. Samuels ’851
    taught the use of inflatable protrusions containing pene-
    trating spikes capable of securing the stent within the
    vessel wall. Figures 3 and 4 of Samuels ’851 show the
    disclosed protrusions in both inflated and deflated form:
    JA 512, Samuels ’851, figs. 3 & 4.
    Todd taught the use of non-penetrating “gripping pro-
    tuberances” on the outer surface of the stent. The “grip-
    ping protuberances” disclosed in Todd are solid, however,
    in contrast to the hollow inflatable ridges taught in the
    ’575 patent at issue.
    TRIVASCULAR, INC.   v. SAMUELS                           17
    JA 581, Todd, fig. 7.
    Thus, a key point of distinction between the ’575 pa-
    tent and the prior art is that the ’575 patent teaches the
    use of inflatable, circumferential ridges that do not pene-
    trate the vessel wall.
    TriVascular argues that the Board’s conclusion on
    nonobviousness was erroneous because the Board improp-
    erly required the references to be physically “bodily incor-
    porated” into each other, and because the Board ignored
    the state of the art and its predictability. TriVascular
    also argues that, contrary to the Board’s findings, a
    skilled artisan would have been motivated to combine
    Samuels ’851 and Todd by replacing the barbs of Samuels
    ’851 with the gripping protuberances of Todd to obtain the
    desirable result of non-penetrating stent fixation. Thus,
    TriVascular argues, it would have been obvious for a
    skilled artisan to substitute the inflatable, penetrating
    barbs of Samuels ’851 with the noninflatable, nonpene-
    trating protuberances of Todd. Appellant’s Br. 45.
    Samuels responds that the Board did not err in con-
    cluding that TriVascular failed to carry its burden of
    proving invalidity based on the combination of Samuels
    ’851 and Todd. Samuels contends that TriVascular’s
    arguments on obviousness are misguided because the
    Board did not require that TriVascular explain how Todd
    must be bodily incorporated into Samuels ’851. Samuels
    further notes that the Board’s findings that a skilled
    artisan would neither have had the motivation to combine
    nor a reasonable likelihood of success in combining Samu-
    els ’851 with Todd further supports the Board’s conclusion
    on nonobviousness. We agree with Samuels that the
    Board’s findings are supported by substantial evidence.
    We find no error in the Board’s rejection of TriVascu-
    lar’s argument that it would have been obvious to substi-
    tute the recessed barbs of Samuels ’851 with the
    protuberances of Todd, since TriVascular’s proposed
    18                            TRIVASCULAR, INC.   v. SAMUELS
    substitution would destroy the basic objective of the
    barbs, which is to penetrate surrounding tissue. See JA 18
    (Board finding that the “recesses 12 of Samuels ’851
    function to project barbs 18 into surrounding tissue when
    inflatable balloon cuff 10 is filled fully with fluid.”).
    Moreover, in order to meet the claimed limitations, not
    only the barbs but also the underlying recesses in Samu-
    els ’851 would need to be replaced with inflatable non-
    penetrating protrusions. And, it would not have been
    obvious to substitute the inflatable barbed recesses with
    the non-penetrating protuberances of Todd because the
    protuberances taught in Todd were not inflatable, as
    recited in the asserted claims. JA 15-17 (“TriVascular,
    however, has not provided a declaration, or any other
    evidence, to establish that a person of ordinary skill in the
    art would understand Todd to disclose protuberances that
    are hollow, and themselves inflatable.”).        Thus, the
    Board’s findings regarding the lack of a motivation to
    combine are supported by substantial evidence.
    TriVascular next contends that the Board’s conclusion
    of nonobviousness is inconsistent with the Board’s find-
    ings in its Institution Decision, since the Board found that
    TriVascular had initially demonstrated a reasonable
    expectation of success in demonstrating obviousness.
    TriVascular argues that the Board should not have
    changed its view of the patent’s validity without clearly
    explaining why it had done so. In fact, this misguided
    theme pervades TriVascular’s briefs. Contrary to Tri-
    Vascular’s assertions, the Board is not bound by any
    findings made in its Institution Decision. At that point,
    the Board is considering the matter preliminarily without
    the benefit of a full record. The Board is free to change its
    view of the merits after further development of the record,
    and should do so if convinced its initial inclinations were
    wrong. To conclude otherwise would collapse these two
    very different analyses into one, which we decline to do.
    If those determinations were somehow binding with
    TRIVASCULAR, INC.   v. SAMUELS                           19
    respect to the Board’s final decision, as TriVascular urges,
    the patentee’s appeal rights as to that second determina-
    tion would be close to illusory. TriVascular’s argument
    also fails to appreciate that there is a significant differ-
    ence between a petitioner’s burden to establish a “reason-
    able likelihood of success” at institution, and actually
    proving invalidity by a preponderance of the evidence at
    trial. Compare 35 U.S.C. § 314(a) (standard for institu-
    tion of inter partes review), with 35 U.S.C. § 316(e) (bur-
    den of proving invalidity during inter partes review). The
    Board’s findings in its Final Written Decision were thus
    not inconsistent with those in its Institution Decision;
    they were made under a qualitatively different standard.
    After considering Samuels’ expert’s testimony, the
    Board found that, while a skilled artisan might have had
    a reasonable expectation of success in replacing the entire
    recesses of Samuels ’851 with the protuberances of Todd,
    there was an insufficient motivation to substitute just the
    barbs of Samuels ’851 with the protuberances of Todd.
    The Board’s reasoning is supported by the teachings of
    Samuels ’851 and Todd regarding the underlying purpos-
    es of the inventions claimed in each reference. First,
    Samuels ’851 taught away from substituting only the
    barbs, since the barbs were the primary objective of the
    reference, allowing the stent to be anchored to the vessel.
    Second, replacing just the barbs of Samuels ’851 would
    not have satisfied the “circumferential ridge” limitation,
    since the barbs were individual, discontinuous points,
    rather than a continuous circumferential ridge. Third,
    the gripping protuberances of Todd, even if substituted,
    would not satisfy the “inflatable protrusions” limitations
    of the challenged claims. JA 19-20. TriVascular has not
    met its burden of showing that the Board’s findings are
    not supported by substantial evidence.
    Though TriVascular asserts that the Board required it
    to prove how the references could be physically “bodily
    incorporated” within each other, we see no evidence
    20                            TRIVASCULAR, INC.   v. SAMUELS
    supporting TriVascular’s assertion. Instead, the Board
    merely requested that TriVascular explain why it would
    have been obvious to replace just the barbs of Samuels
    ’851 with the circumferential ridges of Todd, in view of
    the Board’s findings regarding the stated purposes of each
    prior art reference. JA 440-41, Trial Transcript. Accord-
    ingly, we find TriVascular’s assertions to be without
    merit.
    As discussed above, the Board’s findings regarding
    the lack of a sufficient motivation to combine and the lack
    of a reasonable expectation of success in combining the
    prior art are supported by substantial evidence. In view
    of these findings, we see no error in the Board’s conclusion
    that TriVascular failed to satisfy its burden of proving
    that the challenged claims are invalid.
    CONCLUSION
    For the above reasons, we find no error in the Board’s
    claim construction or its judgment that TriVascular has
    failed to meet its burden of demonstrating that the as-
    serted claims are invalid as obvious. Accordingly, we
    affirm.
    AFFIRMED