  United States Court of Appeals
      for the Federal Circuit
                 ______________________

                IBORMEITH IP, LLC,
                  Plaintiff-Appellant,

                            v.

 MERCEDES-BENZ USA, LLC, AND DAIMLER AG,
            Defendants-Appellees.
           ______________________

                       2013-1007
                 ______________________

    Appeal from the United States District Court for the
District of New Jersey in No. 10-CV-5378, Judge Faith S.
Hochberg.
                 ______________________

                Decided: October 22, 2013
                 ______________________

    PATRICK F. SOLON, Niro, Haller & Niro, of Chicago, Il-
linois, argued for plaintiff-appellant. With him on the
brief was OLIVER D. YANG.

    SCOTT W. DOYLE, Shearman & Sterling, LLP, of
Washington, DC, argued for defendants-appellees. With
him on the brief were JONATHAN R. DEFOSSE and MICHEL
E. SOUAYA.
                 ______________________

    Before LOURIE, PROST, and TARANTO, Circuit Judges.
2                     IBORMEITH IP, LLC   v. MERCEDES-BENZ USA



TARANTO, Circuit Judge.
    Ibormeith IP, LLC, the assignee of U.S. Patent No.
6,313,749, appeals a district court’s grant of summary
judgment of indefiniteness in favor of defendants Mer-
cedes-Benz USA, LLC, and Daimler AG (collectively,
“Mercedes”). We affirm.
                        BACKGROUND
     U.S. Patent No. 6,313,749, entitled “Sleepiness Detec-
tion for Vehicle Driver or Machine Operator,” addresses
the monitoring of conditions affecting, or behavior reflect-
ing, a vehicle driver’s sleepiness and the issuing of a
warning to the driver before the driving is unduly im-
paired. ’749 patent, col. 1, lines 5-17; id. at col 2, lines 55-
62. The monitor disclosed in the patent may take into
account multiple factors associated with sleepiness,
including natural body-clock (circadian) rhythm, the
magnitude and number of corrective steering actions the
driver is taking, the cabin temperature, the monotony of
the road, and how long the driver has been driving. Id. at
col. 2, lines 55-62; see id. at col. 12, line 25 through line
39. Some factors involve actions or conditions at the
moment, like steering behavior and light conditions,
which are measured by sensors in the vehicle. See id. at
col. 3, lines 43-45; id. at col. 6, lines 14-17; id. at col. 6,
lines 61-64. Others involve general or driver-specific
background information, such as circadian rhythm or a
driver’s recent sleep patterns and alcohol consumption,
which are not measured by sensors but must be input into
the monitor by other means (e.g., by the programmer or
the driver). Id. at col. 3, lines 45-49. The factors are
“individually weighted, according to contributory im-
portance, and combined in a computational decision
algorithm or model, to provide a warning indication of
sleepiness.” Id. at col. 3, lines 39-42.
   Claims 1 and 9 of the ’749 patent are the two inde-
pendent claims at issue. Both claims contain a “computa-
IBORMEITH IP, LLC   v. MERCEDES-BENZ USA                 3



tional means” element that is undisputedly subject to the
requirements of 35 U.S.C. § 112(f) for claims to means of
performing specified functions. 1 Claim 1 requires that the
means take account of sleepiness-related time-of-day
information to determine the likelihood of driver sleepi-
ness and to produce an output that, according to a sepa-
rate claim element, triggers a warning. ’749 patent, col.
16, lines 21-30. Claim 1 reads:
   A sleepiness monitor for a vehicle driver, or ma-
   chine operator, comprising:
       a sensor for sensing a driver or operator
       control input;
       a memory for storing an operational model
       that includes a physiological reference
       model of driver or operator circadian
       rhythm pattern(s) and a vehicle or ma-
       chine operating model or algorithm;
       computational means for weighting the
       operational model according to time of day
       in relation to the driver or operator circa-
       dian rhythm pattern(s) and for deriving,
       from the weighted model, driver or opera-
       tor sleepiness condition and producing an
       output determined thereby; and
       a warning indicator triggered by the com-
       putational means output, to provide a




   1    When this case arose, what is now section 112(f)
was designated paragraph 6 of 35 U.S.C. § 112.        The
Leahy–Smith America Invents Act, Pub. L. No. 112-29,
125 Stat. 284 (2011), changed the internal organization of
section 112. It made no other change of relevance to this
appeal. For convenience we refer to section 112(f).
4                     IBORMEITH IP, LLC   v. MERCEDES-BENZ USA



        warning indicator of driver or operator
        sleepiness.
Id. at col. 16, lines 13-30.
    Whereas claim 1 does not specify what driver conduct
or other conditions may factor into the determination
along with sleepiness-related time-of-day information,
claim 9 focuses on the driver’s steering. Claim 9 reads:
    A sleepiness monitor for a driver and vehicle,
    comprising:
        a sensor for sensing a steering movement,
        about a reference position;
        a memory, for storing a circadian rhythm
        pattern or time-of-day physiological refer-
        ence profile of pre-disposition to sleepi-
        ness; and
        computational means for computing steer-
        ing transitions and weighing that compu-
        tation according to time of day, to provide
        a warning indication of driver sleepiness.
Id. at col. 16, lines 50-61.
    Ibormeith sued Mercedes for infringing claims 1, 5, 8,
and 9 of the ’749 patent. Before and at a claim-
construction hearing held on April 25, 2012, Mercedes
argued that the means-plus-function “computational
means” limitations in independent claims 1 and 9 were
indefinite. (If so, the dependent claims 5 and 8 would also
be invalid, because they incorporate the elements of
independent claim 1.) The district court reserved its
ruling on claim construction and indicated that a motion
for summary judgment concerning indefiniteness should
be pursued as a threshold issue. With the parties’ agree-
ment, the court directed that expert discovery take place
on that issue.
IBORMEITH IP, LLC   v. MERCEDES-BENZ USA                   5



    That process occurred, and Mercedes moved for sum-
mary judgment of indefiniteness. On September 5, 2012,
after receiving the parties’ briefs, the district court ruled
that the asserted claims were invalid because the “compu-
tational means” limitations were indefinite. Ibormeith IP,
LLC v. Mercedes-Benz USA, LLC, 889 F. Supp. 2d 677
(D.N.J. 2012). The court granted summary judgment for
Mercedes.
    To comply with section 112(f), the specification of
Ibormeith’s patent has to disclose a structure for perform-
ing the functions claimed in the “computational means”
limitation, the statute providing that the claim limitation
covers that disclosed structure and its equivalents. If
there is no such structure, the claim limitation is indefi-
nite, i.e., fails to “particularly point[] out and distinctly
claim[]” the invention, because there is insufficient defini-
tion of something that, by virtue of section 112(f), is
incorporated into the claim. See, e.g., Function Media,
LLC v. Google, Inc., 708 F.3d 1310, 1319 (Fed. Cir. 2013);
Blackboard, Inc. v. Desire2Learn Inc., 574 F.3d 1371,
1382-83 (Fed. Cir. 2009). Ibormeith argued that the
required structure is an algorithm, or any of several
algorithms, it said could be found in three portions of the
specification: (1) column 2, lines 55-62; (2) column 3, lines
5-30; and (3) Table 10. Ibormeith, 889 F. Supp. 2d at 685.
The district court held that those passages are inadequate
to disclose the needed structure.
    As to claim 1, the district court concluded that the cit-
ed passages did not disclose an algorithm for “weighting
the operational model according to time of day in relation
to the driver or operator circadian rhythm pattern(s) and
for deriving from the weighted model, driver or operator
sleepiness condition and producing an output determined
thereby.” Id. at 685-91. The court explained that column
2, lines 55-62, and column 3, lines 5-30, described the
claimed functions but did “not disclose the algorithm by
which the computational means performs those func-
6                    IBORMEITH IP, LLC   v. MERCEDES-BENZ USA



tions.” Id. at 685-86. The court also concluded that Table
10 did not disclose an algorithm for performing all of
claim 1’s “computational means” functions. Id. at 686-90.
It reasoned that, although one skilled in the art might
understand Table 10, along with Figures 3 and 17, to
disclose a structure corresponding to the “weighting the
operational model” function, Table 10 does not disclose an
algorithm for deriving a score for “driver . . . sleepiness
condition” or an “output.” See id. at 687-90. Even putting
aside Ibormeith’s insistence that the various elements
listed in Table 10 are merely options for inclusion in a
calculation, the district court concluded: “Neither Table
10 nor any other clearly identified portion of the specifica-
tion states the steps to obtain the listed elements’ scores,
or how to weight them according to their relative im-
portance.” Id. at 687-88.
    The district court also concluded that claim 9’s “com-
putational means” limitation was indefinite because the
specification does not contain an algorithm that adequate-
ly provides structure for the claimed functions. Id. at 691-
93. The court reasoned that, although Table 10 appears
to disclose an algorithm for the “computing steering
transitions” function of claim 9, the specification “fails to
disclose the steps necessary to actually perform that
suggested algorithm.” Id. at 692. The court rejected
Ibormeith’s argument that no algorithm is required for
the “providing a warning indication” function because
that function is intended to be carried out by a visual
display panel (hardware) and not the computational
means. Id. at 693. The court stated: the specification
does “not explain how the monitor determines when the
computation of steering transitions and time of day
weighing leads to the issuance of a warning.” Id.
   Ibormeith appeals.     We have jurisdiction under 28
U.S.C. 1295(a)(1).
IBORMEITH IP, LLC   v. MERCEDES-BENZ USA                    7



                         DISCUSSION
    Ibormeith recognizes that the structure required for
“computational means” in claims 1 and 9 must be an
algorithm—a sequence of computational steps to follow—
that must be found in the specification. See Typhoon
Touch Techs., Inc. v. Dell, Inc., 659 F.3d 1376, 1384 (Fed.
Cir. 2011); In re Freeman, 573 F.2d 1237, 1245 (C.C.P.A.
1978). It is clear, as the district court ruled, that the only
substantial question is whether such an algorithm is
found in Table 10, along with Figures 3 and 17 and any
other specification material that may clarify the meaning
of Table 10. As Ibormeith agrees, whether there is ade-
quate disclosure is a question of law that we decide de
novo. Typhoon Touch, 659 F.3d at 1383.
    Section 112(f) allows patentees to put structural de-
tails into the specification and build into the literal cover-
age of the claim a certain scope for equivalents in
performing a defined function. See Chiuminatta Concrete
Concepts, Inc. v. Cardinal Indus., Inc., 145 F.3d 1303,
1310 (Fed. Cir. 1998). The price of using this form of
claim, however, is that the claim be tied to a structure
defined with sufficient particularity in the specification.
E.g., id. at 1308; Functional Media, 708 F.3d at 1317;
Typhoon Touch, 659 F.3d at 1383-84. For a claim to be
definite, a recited algorithm, or other type of structure for
a section 112(f) claim limitation, need not be so particu-
larized as to eliminate the need for any implementation
choices by a skilled artisan; but it must be sufficiently
defined to render the bounds of the claim—declared by
section 112(f) to cover the particular structure and its
equivalents—understandable by the implementer. See
AllVoice Computing PLC v. Nuance Comm’cns, Inc., 504
F.3d 1236, 1245-46 (Fed. Cir. 2007). Here, we conclude,
the disclosed algorithm does not adequately define the
structure.
IBORMEITH IP, LLC   v. MERCEDES-BENZ USA                9



    Related to the algorithm are Figures 3 and 17 of the
’749 patent. Figure 3 is a graph depicting the likelihood
of falling asleep at different times during the day. ’749
patent at Fig. 3; id. at col. 5, lines 25-27. Figure 17,
shown below, appears to reflect the same reference mod-
els as Figure 3. It too depicts how sleepiness varies
depending on time of day, but it includes three warning
lines meant to represent warning threshold levels.




   Id. at Fig. 17; id. at col. 5, lines 50-52.
    In Ibormeith’s view, Table 10 identifies factors that
may be related to driver drowsiness, but there is no
disclosure of even a single concrete relationship between
the various factors that are used to compute an outcome
to warn of driver drowsiness. Ibormeith’s expert, Dr.
Jochem, opined that the algorithm is not based on simple
adding of already weighted inputs. In his expert report,
Dr. Jochem described the disclosed computational means
as an algorithm “template.” J.A. 617-18 ¶ 54 (“I believe
that the patent authors meant for Table 10 to be used as a
template for constructing a specific formula(s) or equa-
tion(s) to compute sleepiness.”); see also J.A. 618 ¶ 57
(explaining that while circadian rhythm pattern and
corrective steering actions are mandatory factors for
10                   IBORMEITH IP, LLC   v. MERCEDES-BENZ USA



claims 1 and 9, respectively, “[t]he other terms are op-
tional” and that “some terms are less important than
others”); J.A. 621 ¶ 70 (“it is very important to note that it
is obvious in the patent specification that the examples
given are meant to be just that—examples of a possible
way to implement the described algorithm”). He further
stated that the ’749 patent requires one who implements
the drowsiness detection system to determine which
factors to use in the algorithm, how to obtain them, how
to weight them (for example, by multiplication or addi-
tion), how to combine them, and when to issue the warn-
ing. See, e.g., J.A. 621 ¶ 71 (“the use of specific numerical
values in the context of the algorithm description does not
limit the algorithm to use only those values”); J.A. 662
(testifying that the method of weighting, either by adding
or multiplying, is determined by the implementer); J.A.
686 (testifying at his deposition that the claim terms are
optional); J.A. 660 (Dr. Jochem testifying that weighting
could be performed by multiplication or a function that
has some linear or nonlinear terms); J.A. 666 (Dr. Jochem
testifying that weighting can mean “the value you would
[as]sign to a constant value in an algorithm,” “the output
of a function that has some linear and nonlinear terms,”
or multiplication).
    In determining that the specification does not suffi-
ciently disclose an algorithm providing the structure for
“computational means,” we take Ibormeith and its expert
at their word in insisting on the breadth, rather than
specificity, of what Table 10 discloses. With means-plus-
function claiming, the narrower the disclosed structure in
the specification, the narrower the claim coverage. To
succeed ultimately in proving that the “computational
means” elements cover the accused Mercedes products
(vehicles with a feature called Attention Assist),
Ibormeith’s argument therefore needs to be based on a
reading of Table 10 that is broad enough to reach the
accused products. With consequences of such importance,
IBORMEITH IP, LLC   v. MERCEDES-BENZ USA                 11



Ibormeith’s position as to Table 10’s breadth is fairly
treated as a binding admission.
    That position, however, fails in the necessary attempt
to steer a course that permits proof of infringement yet
avoids invalidity. Even if Table 10 could be read as
providing a single, definite algorithm that simply adds all
of the disclosed variables—a possibility we need not rule
on—Ibormeith and its expert assert that it does not so
provide, but instead equally covers all ways of taking into
account the listed variables, or some subset of the varia-
bles, that a skilled artisan would find appropriate. Such a
reading of Table 10 leaves the disclosure without an
algorithm whose terms are defined and understandable.
If, as Dr. Jochem testified, the algorithm in the ’749
patent is not disclosing addition, then the S circ factor in
Table 10 merely indicates that weighting based on circa-
dian patterns occurs. Neither Table 10 nor the associated
tables disclose how to perform the weighting of the S circ
or any other factor. Table 10 merely lists inputs without
specifying any single formula or function or algorithm
defining the contribution of any of the inputs to a compu-
tation. As recognized by Mercedes’s expert Dr. Knipling,
a person of ordinary skill in the art “would need to devise
his or her own method for determining driver drowsiness
based on the factors generally disclosed in Tables 10, 11
and 12.” J.A. 805 ¶ 19.
    With its insistence that Table 10 does not disclose ar-
riving at a warning threshold by simply adding the dis-
closed factors—e.g., S circ (circadian-rhythm factor), S
zerox (steering direction changes), and S rms (magnitude
of corrective steering actions)—Ibormeith cannot rely on
Figures 3 and 17 to supply the structure that Table 10
does not. Ibormeith does not argue that the weighting
function of claim 1 is limited to a structure allegedly
disclosed in Figures 3 and 17, which in any event do not
specify anything about other inputs. At best, the two
figures provide raw circadian information that a person of
12                  IBORMEITH IP, LLC   v. MERCEDES-BENZ USA



ordinary skill in the art could use to design his or her
own method of weighting. A description of an algorithm
that places no limitations on how values are calculated,
combined, or weighted is insufficient to make the bounds
of the claim understandable.
     Ibormeith’s argument that the disclosed algorithm
provides as much specificity as the patents in Typhoon
Touch, 659 F.3d 1376, and WMS Gaming, Inc. v. Int’l
Game Tech., 184 F.3d 1339 (Fed. Cir. 1999), is incorrect.
In Typhoon Touch, the claim term at issue was “means for
cross-referencing said responses with one of said libraries
of said possible responses.” 659 F.3d at 1383. This court
found the disclosed algorithm sufficient because the
specification stated that “cross-referencing entails the
steps of data entry, then storage of data in memory, then
the search in a library of responses, then the determina-
tion if a match exists, and then reporting action if a match
is found.” Id. at 1386. The described process of straight-
forward matching of user-entered data with data in
memory was a routine, concrete algorithm.
    In WMS Gaming, the claim term at issue—concerning
slot machines that use a reel for generating responses to
what in a traditional slot machine is a user’s pull of the
lever—was “means for assigning a plurality of numbers
representing said angular positions of said reel, said
plurality of numbers exceeding said predetermined num-
ber of radial positions such that some rotational positions
are represented by a plurality of numbers.” 184 F.3d at
1346-47. A figure in the patent depicted a series of con-
centric circles (like a dart board) that showed the rela-
tionship between 44 stop positions on a virtual reel with
22 stop positions on a physical reel. See id. at 1347-48;
see also U.S. Patent No. 4,448,419 at Fig. 6. This court
found that an algorithm was sufficiently disclosed because
the relationship between the virtual stop positions and
the physical stop positions was limited by the figure. See
id. at 1349-50. WMS Gaming, like Typhoon Touch, did
IBORMEITH IP, LLC   v. MERCEDES-BENZ USA                  13



not rely on a specification passage like the one in the ’749
patent, which, Ibormeith itself insists, does not indicate
which factors should be used and in what combination
and with what relative weights.
     For these reasons, the judgment of the district court is
affirmed.
                         AFFIRMED
