NOTE: This disposition is nonprecedential.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 Cleveland, 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 ruling 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 response 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 commands 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 autopilots in connection with these munitions, and the development 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 trajectory 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 network to obtain a desired trajectory for the munition, vehicle or aircraft to follow; 

c) inputting the desired trajectory and the information 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 misinterpreted 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 interpreted. 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 responsible 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 obviousness 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 interpretation 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 received from onboard sensors to determine desired trajectory 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 produced by a neural network (20), and Figure 4 is a “flowchart” depicting the sequence of steps by which the 

system operates:1

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 calculated angle-of-attack command that guides the missile 

(78), unless, at decision block (76), it is determined that 

 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

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 Biggers, 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 trajectory 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 implementation, 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 providing implicit support for this aspect, although “not explicitly 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. 
IN RE VAIDYANATHAN 8

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 nonfinal position (id. col. 4 ll.13–17; col. 6 ll.43–44); and (3) a 

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 reasonably 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 
9 IN RE VAIDYANATHAN

connection with the initial stage, before the neural network 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 invention. 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 information that is produced by the neural network rather than a 

separate autopilot component of the system. The applicant 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 provision 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 system.” PTO Brief at 18. This statement is not tied to any 

description within Figure 3, or any language in the specification, or any other source of “substantial evidence.” 

Apparently recognizing this gap, the Solicitor also presents 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 Biggers 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-
IN RE VAIDYANATHAN 10

dicting the applicant’s explanation of Biggers, the PTO 

reasons that the “zero A of A command” sent to the autopilot in step (72) is itself a “trajectory command” provided 

by the neural network in the sense required by the applicant’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 describes an autopilot that receives and implements guidance 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 Proportional 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 Biggers 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 

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 
11 IN RE VAIDYANATHAN

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 executed 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 network 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 explained 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 

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 
IN RE VAIDYANATHAN 12

are sent to the missile guidance system.” Board Opinion

at 6. The Board instead relied on FF3, which also departed 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 additional development of the record, casts serious doubt upon 

the sufficiency of the support for any set of findings relating 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 technological facts based on shifting perceptions of the prior art 

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 conclusion may be less substantial when an impartial, experienced 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 
13 IN RE VAIDYANATHAN

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 references 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 presented, 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 autopilot 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 

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 Biggers and other teachings with respect to autopilot functionality are incorrect. We remand for further 

development of the record, and full reconsideration by the 

agency. 
IN RE VAIDYANATHAN 14

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 evidence to support these findings. As this court has observed, “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 

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 obviousness 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, 
15 IN RE VAIDYANATHAN

or that the prior art in the record is inadequate to demonstrate 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 

statements 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 determining the optimal trajectory as taught by 

Biggers with the missile guidance system of Johnson 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 support 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 previously uncombined elements. 

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-
IN RE VAIDYANATHAN 16

nounced their conclusions of obviousness without providing 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 determination of patentability, . . . the Board cannot simply reach conclusions based on its own 

understanding or experience—or on its assessment of what would be basic knowledge or common 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 evidence 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 elements 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 clarified 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 combine 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 
17 IN RE VAIDYANATHAN

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 technique is obvious unless its actual application is beyond his 

or her skill.”). 

The applicant complains that the Board simply reasoned 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 

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 rejections should be backed up by the best other art rejections 

available.”). If it is not possible for the examiner to provide 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 
IN RE VAIDYANATHAN 18

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 application 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 employee, 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 themselves 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 require 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 insulated 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 

must be some articulated reasoning with some rational 

underpinning to support the legal conclusion of obviousness.”). 

Because there is insufficient elaboration of the examiner’s or the Board’s reasoning in this record, we vacate 

the Board’s rejection of claims 1–7. We remand for redetermination of the question of obviousness. On remand, 

the PTO should determine obviousness based on evidence 
19 IN RE VAIDYANATHAN

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 network to obtain a desired trajectory for the munition, vehicle or aircraft to follow; 

c) inputting the desired trajectory and the information 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 information related to a target position; 

wherein the neural network determines a desired 

trajectory for the munition, vehicle or aircraft; 

and] 

wherein the neural network is guiding the munition, vehicle or aircraft to strike a target. 
IN RE VAIDYANATHAN 20

The Board found that “Biggers does not teach using the 

neural network to guide the missile all the way to intercept.” 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 missile guidance system can take control and guide the 

missile 47 to intercept the target (FF1), the neural network 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 construed in light of the specification, requires actual participation 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, 

to be replaced by a different terminal guidance system 

before intercept. 

The PTO Solicitor responds that the broadest reasonable claim interpretation that is supported by the specification is adopted during examination, for the claims can 

readily be amended during examination, to impart precision if needed. We agree with this protocol as an exami-
21 IN RE VAIDYANATHAN

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” interpretation 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 interpretation under the rules of claim construction. The description in the specification consistently indicates that the 

neural network guides the munition all the way intercept. 

The ’203 specification uses the word “strike” synonymously with “intercept,” foreclosing the divergent meanings the Board seeks to attach to these terms. The 

Board’s rejection of claims 8 and 9 was based on an incorrect 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 example 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 

either allowance or rejection.2 They may be considered on 

remand if relevant to the issues. 

 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 
IN RE VAIDYANATHAN 22

VACATED AND REMANDED 

DYK, Circuit Judge, concurs in the judgment. 

 

appealed claims are too broadly drawn to distinguish the 

invention from the combination of Biggers and Johnson. 

This aspect may warrant attention on remand.