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, Illinois, 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 Mercedes-Benz USA, LLC, and Daimler AG (collectively, 

“Mercedes”). We affirm.

BACKGROUND

U.S. Patent No. 6,313,749, entitled “Sleepiness Detection for Vehicle Driver or Machine Operator,” addresses 

the monitoring of conditions affecting, or behavior reflecting, a vehicle driver’s sleepiness and the issuing of a 

warning to the driver before the driving is unduly impaired. ’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 importance, 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 independent 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 sleepiness and to produce an output that, according to a separate claim element, triggers a warning. ’749 patent, col. 

16, lines 21-30. Claim 1 reads:

A sleepiness monitor for a vehicle driver, or machine 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 machine operating model or algorithm;

computational means 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; and

a warning indicator triggered by the computational 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 reference profile of pre-disposition to sleepiness; and

computational means for computing steering transitions and weighing that computation 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 claimconstruction 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’ agreement, 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 summary judgment of indefiniteness. On September 5, 2012, 

after receiving the parties’ briefs, the district court ruled 

that the asserted claims were invalid because the “computational 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 performing 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 indefinite, i.e., fails to “particularly point[] out and distinctly 

claim[]” the invention, because there is insufficient definition 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 cited 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 specification states the steps to obtain the listed elements’ scores, 

or how to weight them according to their relative importance.” Id. at 687-88.

The district court also concluded that claim 9’s “computational means” limitation was indefinite because the 

specification does not contain an algorithm that adequately 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 adequate 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 details into the specification and build into the literal coverage 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 particularized 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 models 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 equation(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 optional” 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 addition), how to combine them, and when to issue the warning. 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 sufficiently 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-plusfunction 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 variables, 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 circadian 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 computation. 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 arriving at a warning threshold by simply adding the disclosed 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 determination if a match exists, and then reporting action if a match 

is found.” Id. at 1386. The described process of straightforward 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 number 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 concentric circles (like a dart board) that showed the relationship 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