  United States Court of Appeals
      for the Federal Circuit
                 ______________________

             IN RE: JEFF H. VERHOEF,
                       Appellant
                ______________________

                       2017-1976
                 ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 13/328,201.
                  ______________________

                  Decided: May 3, 2018
                 ______________________

   THOMAS E. LOOP, Loop Intellectual Property Law
PLLC, Seattle, WA, argued for appellant.

   MEREDITH HOPE SCHOENFELD, Office of the Solicitor,
United States Patent and Trademark Office, Alexandria,
VA, argued for appellee Andrei Iancu. Also represented
by NATHAN K. KELLEY, THOMAS W. KRAUSE, BRIAN
RACILLA.
                ______________________

  Before NEWMAN, MAYER, and LOURIE, Circuit Judges.
LOURIE, Circuit Judge.
    Jeff H. VerHoef (“VerHoef”) appeals from the decision
of the Patent Trial and Appeal Board (the “Board”) affirm-
ing the examiner’s rejection of all claims of VerHoef’s
2                                           IN RE: VERHOEF




pending application 13/328,201 (the “’201 application”) as
unpatentable under 35 U.S.C. § 102(f) (2006). 1 Ex parte
VerHoef, No. 2015-005270, 2017 WL 745052 (P.T.A.B.
Feb. 23, 2017) (“Decision”). Because the Board correctly
concluded that VerHoef did not solely invent the claimed
subject matter of the ’201 application on which he claimed
sole inventorship, we affirm.
                      BACKGROUND
    VerHoef filed the ’201 application, generally relating
to a dog mobility device, at the U.S. Patent and Trade-
mark Office (“the PTO”), naming himself the sole inven-
tor. The only question on appeal is whether VerHoef
“himself invent[ed] the subject matter sought to be pa-
tented,” as required by § 102(f).
    In response to the examiner’s initial rejection of the
’201 application under § 102(f), VerHoef submitted an
affidavit describing the origins and conception of the
claimed invention. We summarize the affidavit here in
relevant part.
    VerHoef’s dog Reilly developed difficulty walking after
undergoing surgery. VerHoef Aff. ¶ 3; J.A. 122. Reilly
would drag his hind paw and put weight on his paw’s
knuckles, called “knuckling.” Id. Consequently, VerHoef
met with a veterinarian, Dr. Alycia Lamb (“Lamb”), to
begin rehabilitative therapy for Reilly. Id. ¶¶ 4–5.
     Initial results using an underwater treadmill were
disappointing and appeared to exacerbate the knuckling
problem. Id. ¶ 5. Lamb then suggested trying a commer-
cially available harness that would provide support to the



    1   Because the ’201 application was filed before
March 16, 2013, the pre-Leahy-Smith American Invents
Act version of § 102 applies. See Pub. L. No. 112-29, 125
Stat. 284 (2011); 35 U.S.C. § 102 (2006).
IN RE: VERHOEF                                            3



hind leg. Id. The harness similarly did not fix the knuck-
ling problem. Id. ¶ 6; J.A. 122. Consequently, VerHoef
constructed a homemade harness modeled on the com-
mercial one, but this yielded similar results. Id. ¶¶ 7–8;
J.A. 123. VerHoef then recognized that the harness would
work better if connected to the dog’s toes. Id. ¶ 8.
    After mentioning this idea to Lamb during a therapy
session, the following discussion occurred:
   I said to Dr. Lamb, “There has to be a way to con-
   nect the cord to the toes.” At the end of our ap-
   pointment, Dr. Lamb suggested that a strap
   configured in a figure ‘8’ that fit around the toes
   and wrapped around the lower part of the leg,
   above the paw, might be something to consider. In
   response, I said that I would try to figure out a
   way to make that work.”
Id. (emphasis added). VerHoef then implemented Lamb’s
figure eight idea, and, after further adjustments, had a
working device that reduced the knuckling problem. Id.
¶¶ 9–10, 17–18; J.A. 123–25.
     VerHoef contacted a patent attorney who then filed a
patent application directed to the homemade dog harness
listing both VerHoef and Lamb as joint inventors. Id.
¶ 28; J.A. 126. The application included a single inde-
pendent claim that expressly recited a figure eight loop
that engages the dog’s toes, reading as follows:
   1. A dog mobility device for assisting with a for-
        ward movement of a hind leg of a dog and
        with an upward movement of the dog’s toes,
        the dog mobility device comprising:
   at least one elastic cord connectable to a dog har-
        ness, wherein the at least one elastic cord in-
        cludes an upper forward end portion and a
        lower rearward end portion; and
4                                             IN RE: VERHOEF




    a paw loop connectable to the lower rearward end
        portion of the elastic cord, wherein the paw
        loop is configured to engage one of the dog’s
        paws, and wherein the paw loop is defined by
        a material strip looped into a figure eight
        configuration, and wherein the material strip
        figure eight configuration further defines a
        metatarsal strap section and a toe strap sec-
        tion, and wherein the metatarsal strap sec-
        tion is configured to receive and fit about the
        dog’s metatarsus, and wherein the toe strap
        section is configured to receive and fit about
        the dog’s two innermost toes.
J.A. 53 (emphasis added).
     Relations between VerHoef and Lamb soured thereaf-
ter. In December 2011, VerHoef’s patent attorney aban-
doned VerHoef’s and Lamb’s joint application and filed a
substantially identical application, the ’201 application,
listing VerHoef as the sole inventor. VerHoef Aff. ¶¶ 40–
43; J.A. 128. That same day Lamb also filed a substan-
tially identical application listing herself as sole inventor.
Id. ¶ 44. Each application recites the same independent
claim reproduced above. J.A. 32; J.A. 101; J.A. 53.
    The examiner issued a final rejection under § 102(f)
after VerHoef had submitted the affidavit. The rejection
stated that VerHoef “did not invent the claimed subject
matter.” J.A. 151. VerHoef then appealed to the Board.
The Board held that the paw loop configured in a figure
eight was an essential element of the claimed invention,
Decision, 2017 WL 745052, at *4, and conception was thus
not complete until Lamb suggested the figure eight loop,
id. at 6. In addition, the Board determined that VerHoef
did not maintain “intellectual domination” over the in-
ventive process. Id. Accordingly, the Board concluded
that Lamb was a joint inventor of the claimed invention
IN RE: VERHOEF                                             5



and sustained the examiner’s rejection of the ’201 applica-
tion naming only VerHoef as inventor under § 102(f). Id.
   VerHoef appealed.       We have jurisdiction under 28
U.S.C. § 1295(a)(4)(A).
                          DISCUSSION
    Under 35 U.S.C. § 102(f) (2006), one cannot obtain a
valid patent if “he did not himself invent the subject
matter sought to be patented.” This provision requires
that a patent accurately name the correct inventors of a
claimed invention. 2 Pannu v. Iolab Corp., 155 F.3d 1344,
1349 (Fed. Cir. 1998); see City of Milwaukee v. Activated
Sludge, 69 F.2d 577, 587 (7th Cir. 1934) (“When a number
of persons make an invention jointly, a valid patent can
not be taken out in the name of one of them.”). “[F]ailure
to name them renders a patent invalid.” Pannu, 155 F.3d
at 1350.
    One court has said that the “exact parameters of what
constitutes joint inventorship are quite difficult to define.
It is one of the muddiest concepts in the muddy meta-
physics of patent law.” Mueller Brass Co. v. Reading
Indus., Inc., 352 F. Supp. 1357, 1372 (E.D. Pa. 1972). But
this court has stated that “[d]etermining ‘inventorship’ is
nothing more than determining who conceived the subject
matter at issue, whether that subject matter is recited in
a claim in an application or in a count in an interference.”
Sewall v. Walters, 21 F.3d 411, 415 (Fed. Cir. 1994).
Whether such a determination is “nothing more than” or
“quite difficult,” a valid patent requires correct inventor-
ship.
    Conception and inventorship are ultimately questions
of law that we review de novo, but they are premised on



    2   Although we note that 35 U.S.C. § 256 does pro-
vide for correction of inventorship of a patent.
6                                            IN RE: VERHOEF




underlying factual findings, id., that we review for sub-
stantial evidence, see In re Gartside, 203 F.3d 1305, 1315
(Fed. Cir. 2000). A finding is supported by substantial
evidence if a reasonable mind might accept the evidence
as adequate to support the finding. Consol. Edison Co. v.
NLRB, 305 U.S. 197, 229 (1938).
    VerHoef concedes that the figure eight loop was “an
essential feature of the claimed invention that was con-
ceived and suggested to him by another, [Lamb],” Appel-
lant Br. 2, but argues that he should nonetheless be
declared the sole inventor on the ’201 application because
he maintained “intellectual domination and control of the
work,” id. at 17. VerHoef relies on a previous Board
decision, Morse v. Porter, 155 U.S.P.Q. 280, 1965 WL 6982
(B.P.A.I. 1965), for the proposition that a person may be
named as a sole inventor even if that person did not
conceive of each feature of the claimed invention, as long
as the person maintained “intellectual domination” and
control over the inventive process.
    The PTO responds that because Lamb contributed the
idea of the figure eight loop claimed in the ’201 applica-
tion, Lamb is a joint inventor. As VerHoef failed to name
Lamb as a joint inventor, the PTO argues that the claims
of the ’201 application are unpatentable under § 102(f).
    We agree with the PTO that Lamb is a joint inventor.
“Conception is the touchstone of invention,” Burroughs
Wellcome Co. v. Barr Labs., Inc., 40 F.3d 1223, 1227–28
(Fed. Cir. 1994) (citing Sewall, 21 F.3d at 415), and it
requires a “definite and permanent idea of an operative
invention, including every feature of the subject matter
sought to be patented,” Sewall, 21 F.3d at 415 (emphasis
added). “An idea is definite and permanent when the
inventor has a specific, settled idea, a particular solution
to the problem at hand, not just a general goal or research
plan.” Burroughs Wellcome, 40 F.3d at 1228 (emphasis
added).
IN RE: VERHOEF                                            7



    When an invention is made jointly, the joint inventors
need not contribute equally to its conception. See 35
U.S.C. § 116 (2006); Pannu, 155 F.3d at 1351. A joint
inventor must:
   (1) contribute in some significant manner to the
   conception or reduction to practice of the inven-
   tion, (2) make a contribution to the claimed inven-
   tion that is not insignificant in quality, when that
   contribution is measured against the dimension of
   the full invention, and (3) do more than merely
   explain to the real inventors well-known concepts
   and/or the current state of the art.
Pannu, 155 F.3d at 1351. As we explain below, under this
framework Lamb is a joint inventor because she contrib-
uted the idea of the figure eight loop, and the figure eight
loop is an essential feature of the claimed invention.
    VerHoef does not dispute that Lamb, not he, contrib-
uted the idea of the figure eight loop. Appellant Br. 2.
According to his affidavit, VerHoef had only recognized
the problem of connecting the cord of the harness to the
dog’s toes and discussed that problem with Lamb.
VerHoef Aff. ¶ 8; J.A. 123. Then Lamb proposed “a par-
ticular solution to the problem,” Burroughs Wellcome, 40
F.3d at 1228, the figure eight loop.
    Furthermore, there is no dispute that the figure eight
loop is an essential feature of the claimed invention
expressly recited in the claims of the ’201 application.
Claim 1 recites only two limitations, one of which is a paw
loop in a figure eight configuration. ’201 application,
claim 1. And during prosecution, VerHoef argued that the
configuration of the paw loop, which necessarily includes
the figure eight loop, distinguished the claimed invention
over the prior art. J.A. 164. Thus, measured against the
dimension of the claims, Lamb’s contribution of the figure
eight loop was not insignificant in quality, an explanation
8                                           IN RE: VERHOEF




of a well-known concept, or a summary of the prior art.
See Pannu, 155 F.3d at 1351.
     In sum, substantial evidence in the form of VerHoef’s
affidavit supports the Board’s determinations that Lamb
contributed the idea of the figure eight loop and that the
figure eight loop is an essential feature of the invention
not insignificant in quality or well-known in the art.
Because these facts establish that Lamb shared in the
conception of the claimed invention, we conclude that she
is a joint inventor with VerHoef. 3
    VerHoef cites an earlier decision by the Board, Porter,
1965 WL 6982, at *4, purportedly directing a different
outcome. While Porter is not binding on this court, it does
not support a different result. The Board in Porter decid-
ed a priority contest between putative inventors Morse
and the group of Porter, Auville, and Winch (“Winch”).
Id. at *1. The invention at issue was a sanitary napkin
with a particular stitching pattern. Id. Based on an
extensive and conflicting record, ultimately the Board
concluded that “[w]e cannot tell from the evidence which
of the two, Morse and Winch, first suggested” the stitch-
ing pattern. Id. at *4. Morse alone tested the various
napkin iterations, while Winch “knew generally what
Morse was working on” and assisted Morse in supplying
different stitching patterns. Id. at *2–3.
    The Board stated that as long as an inventor “main-
tains intellectual domination of the work of making the
invention . . . he does not lose his quality as inventor by
reason of having received a suggestion or material from
another even if such suggestion proves to be the key that
unlocks his problem.” Id. at *4. According to the Board,



    3  We note that VerHoef’s attorney apparently
thought similarly when he filed a joint application nam-
ing Lamb as a co-inventor on the device.
IN RE: VERHOEF                                            9



“at most [Winch] could only be a joint inventor with
Morse.” Id. at *5. However, in the context of their priori-
ty contest where the origin of the final stitching pattern
was heavily disputed, the Board held that “we can not see
Porter, Auville and Winch as the inventors of the napkin
in issue to the exclusion of Morse.” Id.
    Under the reasoning of Porter, VerHoef is not the sole
inventor to the exclusion of Lamb. First, in the present
case there is no factual dispute or conflicting testimony.
Unlike the parties’ testimony concerning the stitching
pattern at issue in Porter, VerHoef’s affidavit conclusively
establishes that Lamb, not VerHoef, contributed the idea
of the claimed figure eight loop.
     Second, while we do not necessarily endorse the “in-
tellectual domination” language of Porter, as it is vague
and subject to variable meanings, the point here is that
the key idea of the figure eight loop was Lamb’s, not
VerHoef’s. Lamb “freely volunteered” the idea of the
figure eight loop during a therapy session for Reilly.
Appellant Br. 21; VerHoef Aff. ¶ 8; J.A. 123. VerHoef’s
theory is that Lamb’s “naked idea was emancipated when
she freely gave it to VerHoef.” Appellant Br. 22. But
VerHoef cites no case adopting his “emancipation” theory,
nor could we locate any. And for good reason, as it would
be paradoxical to regard VerHoef as having solely con-
ceived the invention when he admits to appropriating
Lamb’s freely-given idea constituting an essential feature
of the claimed invention. 4 Consequently, the Board’s
reasoning in Porter does not disturb our conclusion that



   4    The fact that Lamb joined the initial patent appli-
cation as a joint inventor and then filed an application
asserting her own claim to the invention indicates that
she did not purport to surrender whatever rights she had
in the invention to VerHoef.
10                                            IN RE: VERHOEF




Lamb is a joint inventor of the invention claimed in the
’201 application.
      We next address whether the Board properly affirmed
the examiner’s rejection of the claims under 35 U.S.C.
§ 102(f) given its joint inventorship determination. Under
§ 102(f), a person is not entitled to a patent if “he did not
himself invent the subject matter sought to be patented.”
This provision “makes the naming of the correct inventor
or inventors a condition of patentability; failure to name
them renders a patent invalid.” Pannu, 155 F.3d at 1349–
50. Accordingly, “[e]xaminers are required to reject
applications under 35 U.S.C. § 102(f) on the basis of
improper inventorship” when the facts so indicate. Per-
Septive Biosystems, Inc. v. Pharmacia Biotech, Inc., 225
F.3d 1315, 1321 (Fed. Cir. 2000); see Leviton Mfg. Co. v.
Universal Sec. Instruments, Inc., 606 F.3d 1353, 1360
(Fed. Cir. 2010) (“Even if one application had an earlier
priority date, the examiner would have to evaluate which
set of inventors actually conceived of the invention.”).
Consistent with statutory command and our precedent,
the Manual of Patent Examining Procedure (“MPEP”)
instructs examiners that “[i]n the rare situation it is clear
the application does not name the correct inventorship
and the applicant has not filed a request to correct inven-
torship . . . , the examiner should reject the claims under
. . . pre-AIA 35 U.S.C. [§] 102(f) for applications subject to
pre-AIA 35 U.S.C. [§] 102.” MPEP § 706.03(a) (9th ed.
Jan. 2018).
    This case presents the “rare situation,” or at least an
uncommon one, where the ’201 application and VerHoef’s
affidavit make clear that he did not himself solely invent
the subject matter sought to be patented, as those materi-
als establish that Lamb was a joint inventor improperly
omitted from the application. We therefore conclude that
the Board properly sustained the examiner’s rejection of
the claims under § 102(f).
IN RE: VERHOEF                                           11



                       CONCLUSION
     For the foregoing reasons, the decision of the Board is
affirmed.
                       AFFIRMED
