  United States Court of Appeals
      for the Federal Circuit
                ______________________

          TRITON TECH OF TEXAS, LLC,
               Plaintiff-Appellant,

                           v.

          NINTENDO OF AMERICA, INC.,
                Defendant-Appellee.
              ______________________

                      2013-1476
                ______________________

    Appeal from the United States District Court for the
Western District of Washington in No. 13-CV-0157, Judge
Richard A. Jones.
                 ______________________

                Decided: June 13, 2014
                ______________________

   JAMES F. MCDONOUGH, III, Heninger Garrison Davis,
LLC, of Atlanta, Georgia, argued for plaintiff-appellant.
With him on the brief were JACQUELINE KNAPP BURT; and
TIMOTHY C. DAVIS, of Birmingham, Alabama.

    GRANT KINSEL, Perkins Coie, LLP, of Los Angeles,
California, argued for defendant-appellee. With him on
the brief were JOSEPH HAMILTON, of Los Angeles, Califor-
nia; JONATHAN L. MCFARLAND, of Seattle, Washington;
and DAN L. BAGATELL, of Phoenix, Arizona.
                 ______________________
2    TRITON TECH OF TEXAS, LLC   v. NINTENDO OF AMERICA, INC.




    Before MOORE, REYNA, and HUGHES, Circuit Judges.
MOORE, Circuit Judge.
    Triton Tech of Texas, LLC (“Triton”) appeals from the
district court’s judgment that the means-plus-function
term “integrator means” renders the asserted claims of
Triton’s U.S. Patent No. 5,181,181 invalid for indefinite-
ness. We affirm.
                      BACKGROUND
    Triton sued Nintendo of America, Inc. (“Nintendo”),
alleging that the Wii Remote™ used in combination with
a related accessory infringes the ’181 patent. The ’181
patent is directed to an input device for a computer. ’181
patent col. 1 ll. 9–10. It discloses that a user can com-
municate with a computer by moving the input device—
much like using a mouse, but in three dimensions. Id. col.
2 ll. 50–67. The input device sends commands to the
computer based on the input device’s three-dimensional
position, attitude (i.e., orientation), and motion. Id.
Abstract. For example, a user may be able to manipulate
an object that is represented graphically on the computer
by moving the input device in a manner in which the user
wishes to manipulate the object. Id. col. 1 ll. 15–22.
    The input device includes components for determining
its position, attitude, and motion. In the preferred em-
bodiment, these components include three accelerometers
and three rotational rate sensors for measuring linear
acceleration along, and rotational velocity about, three
orthogonal axes. Id. col. 3 ll. 3–29, Fig. 1(d). The pre-
ferred embodiment also includes a conventional micropro-
cessor that is programmed to periodically read and
numerically integrate over time digitized acceleration and
rotational rate values to calculate the position, attitude,
and motion values for the input device. Id. col. 7 ll. 15–
TRITON TECH OF TEXAS, LLC   v. NINTENDO OF AMERICA, INC.      3



25. The ’181 patent does not further explain how the
numerical integration is performed, only that it is per-
formed in a “conventional manner.” Id. col. 10 ll. 7–9.
The input device then outputs these values to the com-
puter to facilitate the user’s interaction with the comput-
er. Id. col. 11 ll. 14–42.
    Claim 4 is representative of the asserted claims:
    An input device for providing information to a
    computing device, comprising: . . .
    a first acceleration sensor . . . ; a second accelera-
    tion sensor . . . ; a third acceleration sensor [each
    producing analog acceleration sensor signals];
    a first rotational rate sensor . . . ; a second rota-
    tional rate sensor . . . ; a third rotational rate sen-
    sor . . . ; . . .
    an analog-to-digital converter associated with said
    input device which quantizes said analog acceler-
    ation sensor signals to produce digital acceleration
    sensor values;
    a first-in, first-out buffer memory which tempo-
    rarily stores said digital acceleration sensor val-
    ues from said analog-to-digital converter in
    sequential order for later processing;
    integrator means associated with said input device
    for integrating said acceleration signals over time
    to produce velocity signals for linear translation
    along each of . . . first, second and third axes; and
    communication means associated with said input
    device for communicating information between
    said input device and said computing device.
Id. col. 12 l. 42 – col. 13 l. 15 (emphases added).
4       TRITON TECH OF TEXAS, LLC   v. NINTENDO OF AMERICA, INC.



    Each asserted claim recites an “integrator means.”
The district court held that this term rendered the assert-
ed claims indefinite. Triton Tech of Texas, LLC v. Nin-
tendo of Am., Inc., C.A. No. 13-cv-0157 (W.D. Wash. June
4, 2013), ECF No. 153 (“Claim Construction Order”). It
determined that the corresponding structure for perform-
ing the recited integrating function was a “conventional
microprocessor having a suitably programmed read-only
memory.” Id. at 14. It found that the ’181 patent did not
disclose any algorithm for performing the recited integrat-
ing function. Id. at 15–16. It noted that the ’181 patent
broadly discloses using “numerical integration,” but
determined that this alone was not a sufficient disclosure
because “‘[n]umerical integration’ . . . is not a single
algorithm, but rather a whole class of algorithms that can
be used to calculate definite integrals . . . .” Id. at 16. The
district court thus concluded that the asserted claims
were indefinite. 1 Id. at 15–16 (citing Aristocrat Techs.
Austr. Pty Ltd. v. Int’l Gaming Tech., 521 F.3d 1328, 1334
(Fed. Cir. 2008)). Triton appeals. We have jurisdiction
under 28 U.S.C. § 1295(a)(1).
                          DISCUSSION
    We review de novo a district court’s decision regarding
indefiniteness. Function Media, L.L.C. v. Google Inc., 708
F.3d 1310, 1316 (Fed. Cir. 2013). Section 112 ¶ 6 allows a
patentee to express an element of a claim as a means for


    1   The district court similarly determined that “pro-
cessing means,” recited only in dependent claim 13, was
indefinite and also construed several claim terms adverse-
ly to Triton. On appeal, Triton also challenges the indefi-
niteness of “processing means” and the district court’s
claim construction. In light of our affirmance of indefi-
niteness based on “integrator means,” we need not reach
these issues.
TRITON TECH OF TEXAS, LLC   v. NINTENDO OF AMERICA, INC.    5



performing a specified function. 35 U.S.C. § 112 ¶ 6
(2006). In exchange for using this form of claiming, the
patent specification must disclose with sufficient particu-
larity the corresponding structure for performing the
claimed function and clearly link that structure to the
function. Ibormeith IP, LLC v. Mercedes-Benz USA, LLC,
732 F.3d 1376, 1379 (Fed. Cir. 2013). If the function is
performed by a general purpose computer or microproces-
sor, then the specification must also disclose the algo-
rithm that the computer performs to accomplish that
function. Aristocrat, 521 F.3d at 1333. Failure to disclose
the corresponding algorithm for a computer-implemented
means-plus-function term renders the claim indefinite.
Ergo Licensing LLC v. CareFusion 303, Inc., 673 F.3d
1361, 1363 (Fed. Cir. 2012).
    Triton concedes that the structure corresponding to
“integrator means” is a conventional microprocessor, and
contends that the ’181 patent discloses an algorithm for
performing the integrating function with enough specifici-
ty to render the claims discernible to a person of ordinary
skill. First, Triton argues that merely using the phrase
“numerical integration” is sufficient disclosure of an
algorithm because numerical integration was well known
to those skilled in the art. Second, Triton argues that the
’181 patent discloses a two-step algorithm for accomplish-
ing the integrating function: (1) sampling measured
values over time and (2) accumulating by continuously
summing areas defined by the sampled values. Triton
asserts that the ’181 patent discloses the sampling step as
acquiring instantaneous values from the different sensors,
formatting them to digital values, and then storing them
for further processing. Appellant’s Br. 20–21 (citing ’181
patent col. 3 ll. 30–38, col. 9 ll. 2–6, 28–37, 49–59). Triton
contends that the ’181 patent discloses the accumulating
step as “clearing all numeric integration accumulators”
and continually performing numerical integration to
6     TRITON TECH OF TEXAS, LLC   v. NINTENDO OF AMERICA, INC.



compute the position and attitude values. Id. at 21–22
(citing ’181 patent col. 7 l. 65 – col. 8 l. 3, col. 10 ll. 51–62,
col. 7 ll. 21–36, col. 8 ll. 11–12).
    We affirm the district court’s determination that the
asserted claims of the ’181 patent are indefinite because
the specification does not disclose an algorithm for per-
forming the claimed integrating function of the “integra-
tor means.” It is certainly true that an algorithm can be
expressed in many forms, including flow charts, a series of
specific steps, mathematical formula, prose, and so on.
Finisar Corp. v. DirecTV Grp., Inc., 523 F.3d 1323, 1340
(Fed. Cir. 2008). However, merely using the term “nu-
merical integration” does not disclose an algorithm—i.e.,
a step-by-step procedure—for performing the claimed
function. Ergo Licensing, 673 F.3d at 1365 (“Even de-
scribed in prose, an algorithm is still a step-by-step proce-
dure for accomplishing a given result.”) (quotations
omitted). As the district court correctly determined,
numerical integration is not an algorithm but is instead
an entire class of different possible algorithms used to
perform integration. Claim Construction Order at 16.
Disclosing the broad class of “numerical integration” does
not limit the scope of the claim to the “corresponding
structure, material, or acts” that perform the function, as
required by section 112. Indeed, it is hardly more than a
restatement of the integrating function itself. Disclosure
of a class of algorithms “that places no limitations on how
values are calculated, combined, or weighted is insuffi-
cient to make the bounds of the claims understandable.”
Ibormeith, 732 F.3d at 1382.
    The fact that various numerical integration algo-
rithms may have been known to one of ordinary skill in
the art does not rescue the claims. “[A] bare statement
that known techniques or methods can be used does not
disclose structure.” Biomedino, LLC v. Water Techs.
Corp., 490 F.3d 946, 953 (Fed. Cir. 2007); see also ePlus,
TRITON TECH OF TEXAS, LLC   v. NINTENDO OF AMERICA, INC.   7



Inc. v. Lawson Software, Inc., 700 F.3d 509, 519 (Fed. Cir.
2012).    The district court correctly recognized that
“[a]lthough a person of skill in the art might be able to
choose an appropriate numerical integration algorithm
and program it onto a microprocessor, the [p]atent dis-
closes no algorithm at all.” Claim Construction Order at
16. We thus conclude that the district court correctly
found that the ’181 patent’s disclosure of “numerical
integration” does not satisfy the disclosure requirement of
section 112 ¶ 6; “numerical integration” is not an algo-
rithm.
    We hold that Triton has waived its second argument
that the ’181 patent discloses a two-step algorithm that
consists of sampling and accumulating. Triton did not
make this argument to the district court. Instead, it
argued that the corresponding structure for “integrator
means” is a conventional microprocessor “that performs
integration.”   Plaintiff’s Opening Claim Construction
Brief, Triton Tech of Texas, LLC v. Nintendo of Am. Inc.,
No. 10-cv-328, at 14 (E.D. Tex. Nov. 30, 2012), ECF No.
115. 2 It explained that “[the position, velocity, and atti-
tude values] are computed and numerically integrated in
a ‘known manner,’” and that “[n]umerical integration
describes the ways in which a numerical value is reached
from the integration of definite integrals.” Plaintiff’s
Reply Claim Construction Brief, Triton Tech of Texas,
LLC v. Nintendo of Am. Inc., No. 10-cv-328, at 7 (E.D.
Tex. Dec. 21, 2012), ECF No. 122. It did not argue that
the ’181 patent discloses a two-step numerical algorithm.
It argued only that the term “numerical integration” was
sufficient.



   2     This case was transferred from the Eastern Dis-
trict of Texas to the Western District of Washington after
the parties finished their claim construction briefing.
8    TRITON TECH OF TEXAS, LLC   v. NINTENDO OF AMERICA, INC.



    To the extent that Triton now argues that one of skill
in the art would have understood the bare disclosure of
“numerical integration” as disclosing a particular two-step
algorithm, we find that it also waived that argument.
Triton argued to the district court that “numerical inte-
gration describes the ways in which a numerical value is
reached from . . . integration,” that “the method of numer-
ical integration would [have been] obvious” and that the
specification disclosed “numerical integration” such that
“one of ordinary skill in the art could identify a preferred
mathematical equation with which to perform the func-
tion of integrating.” Id. at 7–8. Thus, at best, Triton
argued to the district court that one of skill in the art
would have been able to identify a preferred integration
algorithm because different methods for performing
numerical integration were well known. Triton did not
argue below that one of skill in the art would have under-
stood the disclosure of “numerical integration” as describ-
ing a particular two-step algorithm. It cannot make that
argument for the first time on appeal.
    In exchange for expressing “integrator means” as a
means-plus-function term, Triton was required to disclose
an algorithm for performing the claimed integrating
function. Because it did not do so, the asserted claims are
indefinite.
                       CONCLUSION
    We affirm the district court’s judgment that the as-
serted claims of the ’181 patent are invalid for indefinite-
ness.
                       AFFIRMED
