In Re Vaidyanathan ( 2010 )


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  •        NOTE: This disposition is nonprecedential.
    United States Court of Appeals
    for the Federal Circuit
    __________________________
    (Serial No. 10/259,203)
    IN RE RAVI VAIDYANATHAN
    __________________________
    2009-1404
    __________________________
    Appeal from the United States Patent and Trademark
    Office, Board of Patent Appeals and Interferences, No.
    2008-2867.
    ___________________________
    Decided: May 19, 2010
    ___________________________
    BRIAN M. KOLKOWSKI, Orbital Research Inc., of Cleve-
    land, Ohio, for appellant.
    RAYMOND T. CHEN, Solicitor, Office of the Solicitor,
    United States Patent and Trademark Office, of Arlington,
    Virginia, for the Director of the United States Patent and
    Trademark Office. With him on the brief were BENJAMIN
    D.M. WOOD and NATHAN K. KELLEY, Associate Solicitors.
    __________________________
    Before MICHEL, Chief Judge, NEWMAN AND DYK, Circuit
    Judges.
    Opinion for the court filed by Circuit Judge NEWMAN.
    IN RE VAIDYANATHAN                                        2
    Circuit Judge DYK concurs in the judgment.
    NEWMAN, Circuit Judge.
    Ravi Vaidyanathan (“the applicant”) appeals the rul-
    ing of the Board of Patent Appeals and Interferences of
    the United States Patent and Trademark Office, affirming
    the examiner’s rejection of claims 1–9 of application Serial
    No. 10/259,203 (“the ’203 application”), on the ground of
    obviousness, 
    35 U.S.C. §103
    (a). The Board reversed the
    rejection of claims 10–11. Ex parte Vaidyanathan, No.
    2008-2867 (B.P.A.I. March 11, 2009) (“Board Opinion”).
    For claims 1–9, we vacate the rejection and remand
    for further examination.
    DISCUSSION
    The ’203 application relates to a guidance and control
    method for controlling munitions such as missiles or
    unmanned aircraft, wherein an autonomous reflex re-
    sponse is based on a neural network model of a biological
    response. The method is designed for the “endgame”
    stage of flight when the munition is very close to the
    target, at which stage the system guides and controls the
    munition by calculating trajectory commands using a
    neural network that is trained using a genetic algorithm;
    the neural network provides “high level” guidance com-
    mands to an autopilot, which converts those commands to
    signals that direct the actual movement of the munition.
    The system is described as achieving substantial gains in
    accuracy, as compared with prior systems.
    The ’203 specification acknowledges extensive existing
    knowledge concerning guided munitions, the use of auto-
    pilots in connection with these munitions, and the devel-
    opment of neural networks.          The ’203 invention
    contemplates that known technologies are used to bring
    the munition within close range of the target, at which
    3                                         IN RE VAIDYANATHAN
    stage the neural network provides rapid-response trajec-
    tory commands for the final or endgame stage. The
    specification describes in mathematical detail a form of
    neural network that is modeled on the rapid neural
    response that is described as characteristic of the escape
    actions seen in cockroaches.
    Claim 1, the broadest claim on appeal, is as follows:
    1. A method of controlling a munition, vehicle or
    aircraft comprising the steps of:
    a) receiving information from sensors;
    b) processing the information with a neural net-
    work to obtain a desired trajectory for the muni-
    tion, vehicle or aircraft to follow;
    c) inputting the desired trajectory and the in-
    formation from internal sensor into an autopilot;
    and
    d) controlling the munition, vehicle or aircraft to
    fly the desired trajectory through the autopilot.
    Claims 2–7 include additional limitations that are not
    argued separately in this appeal, although claim 3, which
    requires that the “neural network is trained using a
    genetic algorithm,” is discussed. Claims 8 and 9 add the
    limitations that the neural network guides the munition,
    vehicle or aircraft “to avoid a target” (claim 8) or “to strike
    a target” (claim 9). Claims 10 and 11, which were allowed
    by the Board, add the limitations that the neural network
    only guides the munition “during the last less than about
    1 second” before either target avoidance (claim 10) or
    target strike (claim 11); these claims are not part of this
    appeal.
    The Board affirmed the examiner’s rejection of claims
    1, 2, and 4–9 as obvious in view of the combination of two
    references, 
    U.S. Patent No. 6,473,747
     (“Biggers”) and No.
    IN RE VAIDYANATHAN                                        4
    5,435,503 (“Johnson”). Claim 3 was rejected in view of
    Biggers, Johnson, and 
    U.S. Patent No. 6,449,603
    (“Hunter”). The applicant argues that these rejections
    were based on a misunderstanding of the Biggers and
    Johnson references, and lacked sufficient findings by the
    Board. The applicant states that the Board misinter-
    preted claims 8 and 9, leading the Board to conclude
    erroneously that the additional limitations in these claims
    were taught by Biggers. The applicant complains that
    neither the examiner nor the Board made sufficient
    findings or adequately explained their reasoning. The
    PTO, through the Solicitor on this appeal, now seeks to
    substitute new reasoning for that supplied by the Board
    concerning how the asserted references should be inter-
    preted. The applicant attempted to respond to these new
    arguments in his Reply Brief.
    I
    The obviousness inquiry is decided as a matter of law,
    based on four general factual inquiries as explained in
    Graham v. John Deere Co., 
    383 U.S. 1
    , 17–18 (1966), and
    reaffirmed in KSR International, Inc. v. Teleflex, Inc., 
    550 U.S. 398
    , 406–07 (2007). The patent examiner is respon-
    sible for marshalling the references whose teachings are
    most relevant to the claimed invention, and evaluating
    the claimed invention against these teachings, from the
    viewpoint of a person of ordinary skill in the field of
    invention. See Graham, 
    supra;
     In re Kubin, 
    561 F.3d 1351
    , 1355 (Fed. Cir. 2009); see generally In re Oetiker,
    
    977 F.2d 1443
    , 1445–47 (Fed. Cir. 1992).
    The applicant challenges the Board’s legal and factual
    analyses. He argues that the Board committed legal error
    by failing to follow the Court’s requirement that the
    factual findings on which the legal conclusion of obvious-
    ness rests should be set forth explicitly. See KSR, 
    550 U.S. at 418
     (“To facilitate review, this analysis should be
    5                                        IN RE VAIDYANATHAN
    made explicit.”); see also In re Gartside, 
    203 F.3d 1305
    ,
    1314 (Fed. Cir. 2000) (“We have expressly held that the
    Board’s opinion must explicate its factual conclusions,
    enabling us to verify readily whether those conclusions
    are indeed supported by ‘substantial evidence’ contained
    within the record.”); In re Grasselli, 
    713 F.2d 731
    , 739
    (Fed. Cir. 1983) (“It is fundamental that rejections under
    
    35 U.S.C. §103
     must be based on evidence comprehended
    by the language of that section.”).
    The applicant points to the Board’s interpretation of
    the Biggers and Johnson references as examples of the
    Board’s failure accurately to ascertain the differences
    between the prior art and the claimed invention, as
    required by Graham. He also states that the Board failed
    to establish, or even to address at all, the level of ordinary
    skill in the field of the invention, as required by Graham.
    He also states that the Board erred in its interpretation of
    claims 8 and 9, further undermining the conclusion of
    obviousness. He contends that these errors so infect the
    Board’s legal analysis of obviousness that the rejections
    cannot stand.
    A
    The applicant first argues that the Board’s interpreta-
    tion of the Biggers reference lacks support by substantial
    evidence. The applicant points out that the Board viewed
    Biggers differently than did the examiner, and that the
    PTO Solicitor has attempted yet a third interpretation on
    this appeal. We agree that the PTO has offered divergent
    views of what Biggers describes and means in relation to
    the ’203 application.
    Biggers is directed to the control of a guided missile
    using a neural network that processes information re-
    ceived from onboard sensors to determine desired trajec-
    tory commands. Unlike the ’203 application’s emphasis
    on the endgame stage of flight, Biggers uses the neural
    IN RE VAIDYANATHAN                                      6
    network at an intermediate stage of flight, and then
    switches to an independent guidance control system for
    the late-stage approach to the target. Figures 3 and 4 of
    Biggers illustrate the method: Figure 3 is a “data flow
    diagram” showing the information received by and pro-
    duced by a neural network (20), and Figure 4 is a “flow-
    chart” depicting the sequence of steps by which the
    system operates: 1
    1    In these figures “N.N.” stands for neural network,
    “MSL” for missile, “A/C” for aircraft, and “A of A” for
    angle of attack.
    7                                          IN RE VAIDYANATHAN
    As depicted in Figure 4, after missile launch (62) the
    neural network receives missile position and velocity
    information (64), target position and velocity information
    (66), and time elapsed since launch information (68). At
    decision block (70) the system determines whether the
    missile is a safe distance from the aircraft; if it is not, a
    zero signal is sent to the autopilot (72) and the autopilot
    controls flight. If so, the neural network outputs a calcu-
    lated angle-of-attack command that guides the missile
    (78), unless, at decision block (76), it is determined that
    the missile is close enough to its target to be transferred
    to a separate guidance system (82). In that case, the
    neural network ceases to provide commands and the
    guidance system controls the missile’s flight. Thus the
    Biggers neural network controls flight only during the
    intermediate stage when the missile is a safe distance
    away from the launching aircraft but not yet within close
    range of its target.
    The applicant especially criticizes the Board’s third
    Finding of Fact (“FF3”), which relates to the interplay
    between the neural network component and the autopilot
    component of the Biggers system. The Board stated:
    FF3 Biggers teaches sending angle of attack
    commands to the auto pilot system of the
    missile. Biggers, col. 4, l. 66 to col. 5, l. 2.
    Although flow diagram box 44 in fig. 3 of
    Biggers is not explicitly discussed by Big-
    gers, a person of ordinary skill in the art
    would understand that box to denote the
    auto pilot alluded to by Biggers.
    Board Opinion at 6. This finding is relevant to step (c) of
    claim 1 of the ’203 application, where the desired trajec-
    tory calculated by the neural network in step (b) is input
    into an autopilot. The Board found that the trajectory or
    “angle of attack” commands generated by the Biggers
    neural network are sent to the autopilot for implementa-
    IN RE VAIDYANATHAN                                            8
    tion, and thus that this aspect of step (c) is taught by
    Biggers. The Board did not discuss Biggers Figure 4, or
    the Biggers specification (apart from the cited sentence at
    col.4 l.66 to col.5 l.2, which makes no reference to the
    neural network), but cited box (44) of Figure 3 as provid-
    ing implicit support for this aspect, although “not explic-
    itly discussed.” See FF3, supra. Box (44) shows “angle of
    attack” trajectory commands as output of the neural
    network, but makes no mention of an autopilot.
    The Board thus recognized that the relay of trajectory
    commands from the neural network to the autopilot is not
    described explicitly in Biggers, but stated that “a person
    of ordinary skill in the art of missile guidance would
    understand that trajectory angle of attack commands, by
    whatever means they are produced, are transmitted to a
    missile auto pilot, which specifies angle changes to the
    missile necessary to maintain the velocity vector of the
    missile along the specified trajectory and transmits these
    changes to an alignment/control system to effect the
    changes.” Board Opinion at 9–10. The Board cited no
    other evidence indicating the level of ordinary skill in the
    relevant art, or explaining why a person of ordinary skill
    would view this autopilot aspect as an implicit teaching of
    Biggers.
    The applicant states that Biggers teaches the use of
    three independent, discrete elements or systems to guide
    the missile in different stages of flight. The applicant
    refers to the specific portions of the Biggers specification
    that he states describe these three distinct elements and
    stages: (1) an autopilot used only to maintain the initial
    trajectory after launch and until the missile is a safe
    distance from the aircraft that launched it (Biggers, col. 4
    l.66 to col. 5 l.2); (2) a neural network apparatus for
    taking over control of the trajectory of the missile after it
    is a safe distance from the aircraft until it reaches a non-
    final position (id. col. 4 ll.13–17; col. 6 ll.43–44); and (3) a
    9                                         IN RE VAIDYANATHAN
    terminal guidance system for guiding the missile from
    that non-final position to a final position (id. col. 4 ll. 15–
    17; col. 4 ll.35–38; col. 5 ll.14–17).
    The applicant states that when it is understood that
    Biggers teaches these separate and independent systems
    for guiding the missile at different stages, it cannot rea-
    sonably be concluded that Biggers teaches that the neural
    network sends its trajectory commands to the autopilot.
    He states that Biggers only refers to the autopilot in
    connection with the initial stage, before the neural net-
    work begins to control flight. He argues that the Biggers
    specification never states that the neural network sends
    its commands to the autopilot, and that this path would
    be incompatible with the purpose of the Biggers inven-
    tion. He states that Figure 3, cited by the Board, provides
    no support for the Board’s interpretation, for it makes no
    mention of an autopilot, and box (44) represents informa-
    tion that is produced by the neural network rather than a
    separate autopilot component of the system. The appli-
    cant argues that the flowchart in Figure 4 clarifies the
    independent operation of the autopilot and the neural
    network at different temporal stages. He states that
    Figure 4 shows that the Biggers autopilot controls flight
    only in the initial stage, when the missile is not yet a safe
    distance from the launching aircraft, and that the provi-
    sion of “zero A of A command” during this stage, at step
    (72), indicates that the autopilot does not guide flight
    based on information received from the neural network.
    In contrast, Figure 4 shows that the neural network
    calculates and outputs angle of attack commands in the
    intermediate stage when it guides flight, as indicated in
    step (78).
    The PTO Solicitor on this appeal simply states that
    “substantial evidence supports the Board’s finding that
    block 44 of Figure 3 denotes the missile’s autopilot sys-
    tem.” PTO Brief at 18. This statement is not tied to any
    IN RE VAIDYANATHAN                                       10
    description within Figure 3, or any language in the speci-
    fication, or any other source of “substantial evidence.”
    Apparently recognizing this gap, the Solicitor also pre-
    sents an explanation of Biggers that differs from that
    provided by the Board. The Solicitor now states that
    Biggers’ Figure 4 provides support for finding that Big-
    gers teaches the input of trajectory information produced
    by the neural network into an autopilot, which then
    controls the missile to fly the desired trajectory. Contra-
    dicting the applicant’s explanation of Biggers, the PTO
    reasons that the “zero A of A command” sent to the auto-
    pilot in step (72) is itself a “trajectory command” provided
    by the neural network in the sense required by the appli-
    cant’s claim 1 step (c). However, neither the Board nor
    the Examiner made such findings regarding step (72), and
    the Board’s opinion states that the Board found Biggers’
    autopilot teaching not in Figure 4, but in block (44) of
    Figure 3. The PTO Solicitor now argues, for the first
    time, that Figure 4 is sufficient to show that commands
    from the neural network are input into the autopilot in at
    least one phase of the Biggers method.
    The PTO also argues that the Johnson reference de-
    scribes an autopilot that receives and implements guid-
    ance commands from a guidance function, and that this is
    evidence of how traditional autopilots were known to
    function. The Solicitor states, citing the “Background”
    discussion in the ’203 specification, that autopilots have
    operated in this way for over sixty years, since the Pro-
    portional Navigation (“ProNav”) algorithm for terminal
    stage missile guidance was introduced publicly in 1948.
    The Solicitor states that while the Biggers reference lacks
    detail in its description of the autopilot, nothing in Big-
    gers suggests that these known autopiloting techniques
    were set aside, or that the autopilot plays no role in
    effectuating the trajectory commands calculated by the
    Biggers neural network. The Solicitor argues: “Because
    11                                      IN RE VAIDYANATHAN
    the focus of Biggers is on what generates the guidance
    commands—the neural network trajectory controller—
    and not on how a missile converts these commands into
    actual course changes, it is not particularly surprising
    that Biggers does not discuss the autopilot in greater
    detail.” PTO Brief at 21.
    The applicant addresses these new PTO arguments in
    his Reply Brief. He states that Figure 4 of Biggers and
    the general background knowledge of autopilots do not
    show what the Solicitor states is shown. The applicant
    points out that while the Solicitor states that in Biggers
    “the neural network sends a zero angle of attack to the
    autopilot” in step (72), nothing in either Figure 4 or the
    accompanying description states that it is the neural
    network that sends this zero angle of attack. Biggers
    describes this step of Figure 4 as follows: “If [the missile]
    is not a safe distance, then block 72 is processed wherein
    a zero angle of attack command is sent to the auto pilot
    system of the missile, and subsequently block 74 is exe-
    cuted wherein the neural network waits a predetermined
    amount of time . . . .” Biggers, col.4 l.67 – col.5 l.4. The
    applicant contends that this description shows that the
    neural network does not participate in guiding flight
    during the initial stage. He argues that in contrast, step
    (78) expressly shows the role played by the neural net-
    work when it participates in flight guidance. He states
    that there is no evidence supporting the Solicitor’s new
    argument that the neural network’s participation is
    inherent at step (72).
    The Solicitor states that the applicant has not ex-
    plained where else the zero angle of attack in step (72)
    could come from, but the applicant responds that he does
    not bear the burden of proving what Biggers teaches. The
    applicant points to the conflicting views of the Examiner,
    the Board, and now the PTO Solicitor as indications that
    the Biggers reference does not present the clarity of
    IN RE VAIDYANATHAN                                        12
    disclosure that the Solicitor now suggests. For example,
    the Examiner’s Answer stated that “Biggers . . . explicitly
    teaches that the path from the non-final position to the
    final position should be calculated by the ‘neural network
    apparatus’ and should be provided (or inputted) from the
    neural network apparatus to the guidance system.”
    (Emphasis in original.) The Board contradicted the
    Examiner, and stated “We find no teaching in Biggers
    that the trajectory data produced by the neural network
    are sent to the missile guidance system.” Board Opinion
    at 6. The Board instead relied on FF3, which also de-
    parted from the Examiner’s fact finding, for the Examiner
    had concluded that the “guidance system” of Biggers
    “should be reasonably understood as an autopilot system,”
    whereas the Board viewed the autopilot and guidance
    systems of Biggers as separate functionalities. The PTO
    Solicitor now retreats from the Board’s finding that
    Biggers teaches that the trajectory commands produced
    by the neural network are input into a separate autopilot
    function; the Solicitor instead argues that autopilot
    functions were well known, and that neither Biggers nor
    the claimed invention altered the basic understanding of
    autopilot functions.
    Thus the PTO has now provided a third explanation of
    why Biggers teaches the input of trajectory commands
    from the neural network into the autopilot—one to which
    the applicant had no opportunity to respond or provide
    rebuttal evidence before the Board, although he has
    attempted to respond in his Reply Brief on this appeal.
    This third retooling of the PTO position, without addi-
    tional development of the record, casts serious doubt upon
    the sufficiency of the support for any set of findings relat-
    ing to the teachings of Biggers. Although the Solicitor
    argues that the court must defer to the PTO’s latest
    position, the agency’s contradictory findings of technologi-
    cal facts based on shifting perceptions of the prior art
    13                                      IN RE VAIDYANATHAN
    impeach the deference normally owed to administrative
    findings of fact. See Universal Camera Corp. v. NLRB,
    
    340 U.S. 474
    , 496 (1951) (“evidence supporting a conclu-
    sion may be less substantial when an impartial, experi-
    enced examiner who has observed the witnesses and lived
    with the case has drawn conclusions different from the
    Board’s than when he has reached the same conclusion”).
    Further, the PTO’s new explanation cannot of itself
    provide substantial evidence for the Board’s findings, for
    our review is constrained by the facts that were developed
    during the Board proceeding. While the PTO Solicitor’s
    argument is new as to what portion of Biggers provides
    support for the Board’s findings, we have occasionally
    permitted the Solicitor to support the Board, on appeal to
    the court, by reference to additional portions of the refer-
    ences of record, provided that the applicant has had a fair
    opportunity to respond. See In re Hedges, 
    783 F.2d 1038
    ,
    1039 (Fed. Cir. 1986); see also In re Wesslau, 
    353 F.2d 238
    , 241 (CCPA 1965) (prior art reference should be
    considered in its entirety for what it fairly suggests to one
    skilled in the art). Nonetheless, the reviewing court must
    review the decision of the Board on the basis of the
    Board’s findings, rather than on “post hoc rationalizations
    for agency action.” In re Hounsfield, 
    699 F.2d 1320
    , 1324
    (Fed. Cir. 1983) (quoting Burlington Truck Lines, Inc. v.
    United States, 
    371 U.S. 156
    , 168 (1962)).
    We conclude, on the evidence and arguments pre-
    sented, that the Board did not persuasively explain how a
    person of ordinary skill in the art would conclude that
    Biggers taught that the trajectory commands produced by
    the neural network are to be input into a separate autopi-
    lot function. The PTO’s shifting positions do not assist in
    appellate review. See In re Thrift, 
    298 F.3d 1357
    , 1366
    (Fed. Cir. 2002) (citing SEC v. Chenery Corp., 
    332 U.S. 194
    , 196 (1947)) (“a reviewing court, in dealing with a
    determination or judgment which an administrative
    IN RE VAIDYANATHAN                                         14
    agency alone is authorized to make, must judge the
    propriety of such action solely by the grounds invoked by
    the agency”). However, we are not prepared to hold that
    all three of the PTO’s conflicting interpretations of Big-
    gers and other teachings with respect to autopilot func-
    tionality are incorrect.       We remand for further
    development of the record, and full reconsideration by the
    agency.
    B
    The applicant next argues that the Board erred as a
    matter of law by failing to make any findings at all as to
    some aspects of the obviousness analysis. He stresses
    that the Board did not establish the level of ordinary skill
    in the field of the invention, a necessary Graham factor.
    He acknowledges that “the absence of specific findings on
    the level of skill in the art does not give rise to reversible
    error ‘where the prior art itself reflects an appropriate
    level and a need for testimony is not shown,’” Okajima v.
    Bourdeau, 
    261 F.3d 1350
    , 1355 (Fed. Cir. 2001) (quoting
    Litton Industrial Prods., Inc. v. Solid State Systems Corp.,
    
    775 F.2d 158
    , 163 (Fed Cir. 1985)), but he complains that
    the Board made repeated reference to what a “person of
    ordinary skill” would have understood or inferred, without
    ever explaining that level of ordinary skill or citing evi-
    dence to support these findings. As this court has ob-
    served, “Skill in the art does not act as a bridge over gaps
    in the substantive presentation of an obviousness case,
    but instead supplies an important guarantee of objectivity
    in the process.” 
    Id.
    The PTO responds that the Board is not required to
    make express findings as to the level of ordinary skill in
    the field of the invention. The PTO states that reversal
    on this basis is appropriate only when the Board’s failure
    to make an express finding on this factor reasonably may
    15                                      IN RE VAIDYANATHAN
    have distorted the ultimate conclusion on obviousness.
    See Custom Accessories, Inc. v. Jeffrey-Allan Industries,
    Inc., 
    807 F.2d 955
    , 963 (Fed. Cir. 1986) (vacating obvious-
    ness holding and remanding because the district court’s
    failure to make specific findings on the level of ordinary
    skill, along with failure to address other Graham factors,
    suggested that the court had not properly applied the
    Graham analysis). The PTO argues that the applicant
    “has not attempted to show how the lack of an express
    finding influenced the Board’s conclusion on obviousness,
    or that the prior art in the record is inadequate to demon-
    strate the appropriate level of skill.” PTO Brief at 28.
    The applicant replies that his argument is not simply
    that the Board failed to make express findings as to the
    level of skill; he states that the issue is uniquely relevant
    because the examiner’s statements apparently reflect
    personal experience in the field of the invention, but are
    unaccompanied by explanation or reasoning. He states
    that the Board, like the examiner, made conclusory state-
    ments that it would have been obvious to a person of
    ordinary skill to select and combine certain parts of
    certain references; the Board’s analysis of this aspect
    reads:
    To combine the feature of a neural network for de-
    termining the optimal trajectory as taught by
    Biggers with the missile guidance system of John-
    son to attain the advantages of each would have
    been obvious to a person of ordinary skill in the
    art, as this would involve nothing more than the
    predictable use of prior art elements according to
    their established functions.
    Board Opinion at 10. The applicant argues that to sup-
    port this conclusion it is necessary to explain how the
    knowledge and competence of the ordinary skilled person
    in this field would have led to this combination of previ-
    ously uncombined elements.
    IN RE VAIDYANATHAN                                         16
    We agree with the Solicitor that an explicit statement
    of the level of ordinary skill is not always necessary in
    evaluating the obviousness of a new technologic advance.
    But whether or not stated explicitly, the perspective of a
    person of ordinary skill must frame the obviousness
    inquiry, and assertions of what such a person of ordinary
    skill would have found to be obvious require sufficient
    explanation to permit meaningful appellate review. In
    this case, not only the Board but also the examiner an-
    nounced their conclusions of obviousness without provid-
    ing any evidentiary support or reasoning for why a person
    of ordinary skill in the field of the invention would have
    deemed it obvious to select and combine various steps
    from different references, in the manner of the applicant.
    This court explained in In re Zurko, 
    258 F.3d 1379
     (Fed.
    Cir. 2001), that the entry of the PTO into the deferential
    review of the Administrative Procedure Act requires the
    agency to provide support for its findings:
    With respect to core factual findings in a determi-
    nation of patentability, . . . the Board cannot sim-
    ply reach conclusions based on its own
    understanding or experience—or on its assess-
    ment of what would be basic knowledge or com-
    mon sense. Rather, the Board must point to some
    concrete evidence in the record in support of these
    findings. To hold otherwise would render the
    process of appellate review for substantial evi-
    dence on the record a meaningless exercise.
    
    Id. at 1386
    .
    The PTO Solicitor argues that the Court in KSR held
    that a combination of elements from different prior art
    references is likely to be unpatentable if it would involve
    nothing more than “the predictable use of prior art ele-
    ments according to their established functions,” KSR, 
    550 U.S. at 417
    , and that the Board applied this reasoning to
    the combination of Biggers and Johnson. KSR also clari-
    17                                      IN RE VAIDYANATHAN
    fied that recourse to “common sense,” viewed through the
    perspective of a person of ordinary skill, is not barred in
    the obviousness inquiry. As the applicant states, while
    KSR relaxed some of the formalism of earlier decisions
    requiring a “teaching, suggestion, or motivation” to com-
    bine prior art references, it did not remove the need to
    anchor the analysis in explanation of how a person of
    ordinary skill would select and apply the teachings of the
    references. See, e.g., 
    id. at 417
     (“If a person of ordinary
    skill can implement a predictable variation, §103 likely
    bars its patentability. For the same reason, if a technique
    has been used to improve one device, and a person of
    ordinary skill in the art would recognize that it would
    improve similar devices in the same way, using the tech-
    nique is obvious unless its actual application is beyond his
    or her skill.”).
    The applicant complains that the Board simply rea-
    soned from the hindsight knowledge of his successful
    invention; he stresses that, unlike the facts in KSR, the
    various steps that he combined were not known to be
    combinable, and the result of increased precision in
    missile guidance to the target was not previously known
    or predictable.
    Obviousness is determined as a matter of foresight,
    not hindsight. See id. at 421 (citing Graham, 
    383 U.S. at 36
    ). KSR did not free the PTO’s examination process
    from explaining its reasoning. In making an obviousness
    rejection, the examiner should not rely on conclusory
    statements that a particular feature of the invention
    would have been obvious or was well known. Instead, the
    examiner should elaborate, discussing the evidence or
    reasoning that leads the examiner to such a conclusion.
    Generally, the examiner cites prior art references to
    demonstrate the state of knowledge. See 
    37 C.F.R. §1.104
    (c)(2) (“In rejecting claims for want of novelty or
    obviousness, the examiner must cite the best references at
    IN RE VAIDYANATHAN                                        18
    his or her command.”); Manual of Patent Examining
    Procedure (MPEP) §706.02 (8th ed., rev. July 2008)
    (“Prior art rejections should ordinarily be confined strictly
    to the best available art. [citing exceptions] Such rejec-
    tions should be backed up by the best other art rejections
    available.”). If it is not possible for the examiner to pro-
    vide this type of information, the examiner might choose
    instead to provide an affidavit detailing the examiner’s
    own personal knowledge (as a person approximating one
    of ordinary skill in the art) of the technology in question.
    See 
    37 C.F.R. §1.104
    (d)(2) (“When a rejection in an appli-
    cation is based on facts within the personal knowledge of
    an employee of the Office, the data shall be as specific as
    possible, and the reference must be supported, when
    called for by the applicant, by the affidavit of such em-
    ployee, and such affidavit shall be subject to contradiction
    or explanation by the affidavits of the applicant and other
    persons.”). Where, as here, prior art references are cited
    to support an obviousness rejection, the references them-
    selves need not in every case provide a “specific hint or
    suggestion” of the alteration needed to arrive at the
    claimed invention; the examiner’s analysis “may include
    recourse to logic, judgment, and common sense available
    to a person of ordinary skill that do not necessarily re-
    quire explication in any reference or expert opinion.”
    Perfect Web Techs. v. InfoUSA, Inc., 
    587 F.3d 1324
    , 1329
    (Fed. Cir. 2009). In these cases the examiner should at
    least explain the logic or common sense that leads the
    examiner to believe the claim would have been obvious.
    Anything less than this results in a record that is insu-
    lated from meaningful appellate review. Zurko, 
    258 F.3d at 1386
    . If the examiner is able to render a claim obvious
    simply by saying it is so, neither the Board nor this court
    is capable of reviewing that determination. See KSR, 
    550 U.S. at 418
    , citing In re Kahn, 
    441 F.3d 977
    , 988 (Fed.
    Cir. 2006) (“[R]ejections on obviousness grounds cannot be
    sustained by mere conclusory statements; instead, there
    19                                      IN RE VAIDYANATHAN
    must be some articulated reasoning with some rational
    underpinning to support the legal conclusion of obvious-
    ness.”).
    Because there is insufficient elaboration of the exam-
    iner’s or the Board’s reasoning in this record, we vacate
    the Board’s rejection of claims 1–7. We remand for rede-
    termination of the question of obviousness. On remand,
    the PTO should determine obviousness based on evidence
    of record or on the examiner’s detailed and articulated
    reasoning. If there is neither record evidence nor detailed
    examiner reasoning, the Board should not conclude that
    Vaidyanathan’s claims are obvious.
    II
    The Board addressed claims 8 and 9 separately, with
    claim 9 agreed to be representative. Claim 9, in multiple
    dependent form, may be rewritten in independent form as
    follows:
    9. [A method of controlling a munition, vehicle or
    aircraft comprising the steps of:
    a) receiving information from sensors;
    b) processing the information with a neural net-
    work to obtain a desired trajectory for the muni-
    tion, vehicle or aircraft to follow;
    c) inputting the desired trajectory and the in-
    formation from internal sensor into an autopilot;
    and
    d) controlling the munition, vehicle or aircraft to
    fly the desired trajectory through the autopilot;
    wherein the information is received from external
    and internal sensors;
    wherein the external sensor information is infor-
    mation related to a target position;
    IN RE VAIDYANATHAN                                         20
    wherein the neural network determines a desired
    trajectory for the munition, vehicle or aircraft;
    and]
    wherein the neural network is guiding the muni-
    tion, vehicle or aircraft to strike a target.
    The Board found that “Biggers does not teach using the
    neural network to guide the missile all the way to inter-
    cept.” However, the Board concluded that the “to strike a
    target” limitation does not adequately distinguish claim 9
    from Biggers because it does not require that the neural
    network guide the missile or munition all the way to
    “intercept,” but instead merely requires that the neural
    network guide the munition “to strike a target.” The
    Board viewed the words “to strike a target” as a recitation
    of intended purpose, rather than a step of a claimed
    method. On this view, the Board held that because the
    purpose in Biggers is also a target strike, Biggers teaches
    this limitation and thus describes the same method as
    claim 9. The Board stated: “In guiding the missile toward
    the target to the optimum point in space where the mis-
    sile guidance system can take control and guide the
    missile 47 to intercept the target (FF1), the neural net-
    work in the method taught by Biggers guides the missile
    to strike a target.” Board Opinion at 11.
    The applicant argues that claim 9, when properly con-
    strued in light of the specification, requires actual partici-
    pation by the neural network until the point of intercept,
    unlike the Biggers method. He argues that the Board
    misconstrued the “to strike a target” limitation of claim 9,
    and thereby misapplied Biggers. The applicant states
    that the ’203 application describes for the first time the
    use of a neural network in connection with the final stage
    of flight leading to intercept, whereas Biggers describes
    the use of a neural network only at an intermediate stage,
    21                                      IN RE VAIDYANATHAN
    to be replaced by a different terminal guidance system
    before intercept.
    The PTO Solicitor responds that the broadest reason-
    able claim interpretation that is supported by the specifi-
    cation is adopted during examination, for the claims can
    readily be amended during examination, to impart preci-
    sion if needed. We agree with this protocol as an exami-
    nation expedient, for its purpose is to aid in sharpening
    the claims in order to avoid ambiguity or uncertainty in
    the issued patent. See e.g., In re Skvorecz, 
    580 F.3d 1262
    ,
    1267 (Fed. Cir. 2009); In re Buszard, 
    504 F.3d 1364
    ,
    1366–67 (Fed. Cir. 2007); In re Prater, 
    415 F.2d 1393
    ,
    1396 (CCPA 1969). However, the PTO’s “broadest” inter-
    pretation must be reasonable, and must be in conformity
    with the invention as described in the specification.
    The Board’s interpretation of claim 9 finds no support
    in the ’203 specification, and is not a reasonable interpre-
    tation under the rules of claim construction. The descrip-
    tion in the specification consistently indicates that the
    neural network guides the munition all the way intercept.
    The ’203 specification uses the word “strike” synony-
    mously with “intercept,” foreclosing the divergent mean-
    ings the Board seeks to attach to these terms. The
    Board’s rejection of claims 8 and 9 was based on an incor-
    rect interpretation of these claims. That rejection is
    vacated and remanded for reconsideration under the
    correct interpretation of the claims, and in further view of
    the issues with respect to obviousness as discussed in
    connection with claims 1–7.
    III
    Both sides have raised additional arguments, for ex-
    ample with respect to the impact of the Johnson reference
    on the “sensor” aspect of step 1(c). In view of our remand
    for further prosecution of claims 1–9, we need not reach
    the additional issues, for none appears to be dispositive of
    IN RE VAIDYANATHAN                                     22
    either allowance or rejection. 2 They may be considered on
    remand if relevant to the issues.
    VACATED AND REMANDED
    DYK, Circuit Judge, concurs in the judgment.
    2    In its Statement of Facts, the PTO points out that
    the appealed claims do not limit the ’203 application’s
    invention to a specific use of a neural network based on
    the specific reflex response that is the primary matter
    described in the specification, and thus suggests that the
    appealed claims are too broadly drawn to distinguish the
    invention from the combination of Biggers and Johnson.
    This aspect may warrant attention on remand.