Westerngeco L.L.C. v. Ion Geophysical Corp. (876 F. Supp. 2d 857, 2012)

United States District Court for the Southern District of Texas 2012-06-26

Citations

Full opinion text

AMENDED MEMORANDUM AND ORDER

KEITH P. ELLISON, District Judge.

A number of motions for summary judgment are pending before the Court. Broadly, those motions can be divided into two categories: (1) motions addressing patent invalidity; and (2) motions addressing patent infringement. In this Memorandum and Order, the Court considers first the invalidity motions, including Defendants’ Motion for Summary Judgment of Patent Invalidity of the Bittleston Patents (Doc. No. 273), and Defendants’ Motion for Summary Judgment of Patent Invalidity of the Zajac Patent (Doc. No. 270). The Court also considers, in examining invalidity, the portion of Plaintiffs Motion for Summary Judgment of Willful Infringement of the '520 Patent (Doc. No. 276) in which Plaintiff moves for summary judgment on patent validity. After considering these three motions, all responses thereto, and the applicable law, the Court concludes that each motion must be denied.

The second category of motions at issue, those that address patent infringement, includes Defendants’ Motion for Summary Judgment of Non-Infringement of the Bittleston Patents’ Apparatus Claims (Doc. No. 272); Defendants’ Motion for Summary Judgment of Non-Infringement of the '038 Patent’s Systems Claims (Doc. No. 269); and (3) Plaintiffs Motion for Summary Judgment of Willful Infringement of the '520 Patent. After considering these motions, all responses thereto, and the applicable law, the Court concludes that Defendants’ Motion for Summary Judgment of Non-Infringement of the Bittleston Patents’ Apparatus Claims must be denied. Plaintiffs Motion for Summary Judgment of Willful Infringement of the '520 Patent must be granted in part and denied in part. Defendants’ Motion for Summary Judgment of Non-Infringement of the '038 Patent’s Systems Claims also must be granted in part and denied in part.

INVALIDITY MOTIONS

I. BACKGROUND

Plaintiff WesternGeco, L.L.C. (‘WesternGeco”) brings claims against Defendants under 35 U.S.C. § 271 based on the alleged infringement of a number of claims in the following WesternGeco patents: (1) U.S. Patent No. 6,932,017 (the “017 patent”); (2) U.S. Patent No. 7,080,607 (the “607 patent”); (3) U.S. Patent No. 7,162,-967 (the “967 patent”); (4) U.S. Patent No. 7,293,520 (the “520 patent”); and (5) U.S. Patent No. 6,691,038 (the “038 patent” or the “Zajac patent”). Defendants in this case, ION Geophysical Corporation (“ION”), and Fugro-Geoteam, Inc.; Fugro Geoteam AS; Fugro Norway Marine Services AS; Fugro, Inc.; Fugro (USA), Inc.; and Fugro Geoservices, Inc. (collectively, “Fugro” or “the Fugro Defendants”), jointly have filed four motions for summary judgment. Two of these motions address patent invalidity. (Doc. Nos. 270, 273.) The other two address patent infringement. (Doc. Nos. 269, 272.) Plaintiffs pending motion for summary judgment addresses both invalidity and infringement. (Doc. No. 276.) As the Court has addressed the factual background in this case in considering a number of prior motions, it does not do so again here.

II. LEGAL STANDARDS

A. Summary Judgment

Summary judgment is appropriate where the pleadings and evidence show that no genuine issue of material fact exists, and that the movant therefore is entitled to judgment as a matter of law. Fed. R.Civ.P. 56. The party moving for summary judgment must demonstrate the absence of any genuine issue of material fact; however, that party need not negate the elements of the nonmovant’s case. Little v. Liquid Air Corp., 87 F.3d 1069, 1075 (5th Cir.1994). If the moving party meets this burden, the nonmoving party then must go beyond the pleadings to identify specific facts showing there is a genuine issue for trial. Id. “A fact is ‘material’ if its resolution in favor of one party might affect the outcome of the lawsuit under governing law.” Sossamon v. Lone Star State of Tex., 560 F.3d 316, 326 (5th Cir.2009) (citation omitted).

Factual controversies should be resolved in favor of the nonmoving party. Liquid Air Corp., 37 F.3d at 1075. However, “summary judgment is appropriate in any case where critical evidence is so weak or tenuous on an essential fact that it could not support a judgment in favor of the nonmovant.” Id. at 1076 (internal quotations omitted). Importantly, .“[t]he nonmovant cannot satisfy his summary judgment burden with conclusional allegations, unsubstantiated assertions, or only a scintilla of evidence.” Diaz v. Superior Energy Servs., LLC, 341 Fed.Appx. 26, 28 (5th Cir.2009) (citation omitted). A court should not, in the absence of proof, assume that the nonmoving party could or would provide the necessary facts. Liquid Air Corp., 37 F.3d at 1075.

The Federal Circuit has made clear that “summary judgment is as appropriate in a patent case as in any other.” Barmag Barmer Maschinenfabrik AG v. Murata Machinery, Ltd., 731 F.2d 831, 835 (Fed. Cir.1984). That is, “[wjhere no issue of material fact remains and the movant is entitled to judgment as a matter of law,” the court should grant summary judgment in order “to avoid unnecessary expense to the parties and wasteful utilization of the jury process and judicial resources.” Id.

B. Patent Invalidity under 35 U.S.C. § 112

An issued patent is presumed valid, 35 U.S.C. § 282, and an accused infringer has the burden of proving invalidity by clear and convincing evidence. Aero Products Int’l, Inc. v. Intex Recreation Corp., 466 F.3d 1000, 1015 (Fed.Cir.2006) (citation omitted); Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 962 (Fed.Cir.2001). Section 112 of Title 35 of the United States Codé governs what must be included in a patent specification. The requirements of Section 112 include the written description requirement, the enablement requirement, the distinctiveness or definiteness requirement, and, for cases filed prior to September 2011 — as this one was — the “best mode” requirement.

1. Definiteness

Section 112 ¶ 2 requires a patent to “point[] out and distinctly claim[] the subject matter which the applicant regards as his invention.” 35 U.S.C. § 112 ¶2. Claims are considered indefinite when they are “not amenable to construction or are insolubly ambiguous.” Young v. Lumenis, Inc., 492 F.3d 1336, 1346 (Fed.Cir.2007). The Federal Circuit has explained:

[T]he definiteness of claim terms depends on whether those terms can be given any reasonable meaning. Indefiniteness requires a determination whether those skilled in the art would understand what is claimed.' The purpose of the definiteness requirement is to ensure that the claims, as interpreted in view of the written description, adequately perform their function of notifying the public of the scope of the patentee’s right to. exclude.

Hearing Components, Inc. v. Shure Inc., 600 F.3d 1357, 1366-67 (Fed.Cir.2010) (citations omitted). This distinctiveness or definiteness requirement is met if “one skilled in the art would understand the bounds of the claim when read in light of the specification.” Exxon Research & Eng’g Co. v. United States, 265 F.3d 1371, 1375 (Fed.Cir.2001) (citing Miles Labs., Inc. v. Shandon, Inc., 997 F.2d 870, 875 (Fed.Cir.1993)). Indefiniteness is a question of law. IGT v. Bally Gaming Int’l, Inc., 659 F.3d 1109, 1119 (Fed.Cir.2011).

Section 112, ¶ 6 provides that “[a]n element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.” 35 U.S.C. § 112 ¶ 6. Such a “means-plus-function” claim format allows a patentee to “describe an element of his invention by the result accomplished or the function served, rather than describing the item or element to be used.” Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 27, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997). If a claim element that recites a function uses the word “means,” it creates a presumption that the element is drafted in means-plus-function format. Id.; TriMed, Inc. v. Stryker Corp., 514 F.3d 1256, 1259 (Fed.Cir.2008). The means-plus-function presumption can be rebutted if the claim itself recites a structure to accomplish the functions identified in the claim. Welker Bearing Co. v. PHD, Inc., 550 F.3d 1090, 1096 (Fed.Cir.2008).

If a patentee uses means-plus-function language, he “must set forth in the specification an adequate disclosure showing what is meant by that language. If an applicant fails to set forth an adequate disclosure, the applicant has in effect failed to particularly point out and distinctly claim the invention as required by the second paragraph of section 112.” Tech. Licensing Corp. v. Videotek, Inc., 545 F.3d 1316, 1338 (Fed.Cir.2008) (quoting In re Donaldson Co., 16 F.3d 1189, 1195 (Fed. Cir.1994) (en banc)). Such a failure results in invalidity for indefiniteness. In re Dossel, 115 F.3d 942, 946 (Fed.Cir.1997).

If a court determines that the means-plus-function analysis applies, it must decide what the claimed function is, and then determine whether a structure corresponding to that function is disclosed in the specification. Welker Bearing, 550 F.3d at 1097; Minks v. Polaris Indus., Inc., 546 F.3d 1364, 1377 (Fed.Cir.2008). If the patent does not contain an adequate disclosure of the structure that corresponds to the claim elements, the patentee will have “failed to particularly point out and distinctly claim the invention as required by the second paragraph of section 112.” Blackboard, Inc. v. Desire2Learn, Inc., 574 F.3d 1371, 1382 (Fed.Cir.2009). Whether the written description adequately sets forth structure corresponding to the claimed function must be considered from the perspective of a person skilled in the art. Intel Corp. v. VIA Techs., Inc., 319 F.3d 1357, 1365-66 (Fed.Cir.2003) (citing Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376 (Fed.Cir.2001)). However, “the question is not whether one of skill in the art would be capable of implementing a structure to perform the function, but whether that person would understand the written description itself to disclose such a structure.” Brown v. Baylor Health Care Sys., 662 F.Supp.2d 669, 677 (S.D.Tex.2009), aff'd sub nom. Brown v. Baylor Healthcare Sys., 381 Fed.Appx. 981 (Fed. Cir.2010) (citing Biomedino, LLC v. Waters Techs. Corp., 490 F.3d 946, 953 (Fed. Cir.2007)).

2. Written description

The specification of a patent “shall contain a written description of the invention, and of the manner and process of making and using it.” 35 U.S.C. § 112 ¶ 1. The purpose of the “written description” requirement “is to ensure that the scope of the right to exclude, as set forth in the claims, does not overreach the scope of the inventor’s contribution to the field of art as described in the patent specification.” Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1353-54 (Fed.Cir.2010) (citing University of Rochester v. G.D. Searle & Co., Inc., 358 F.3d 916, 920 (Fed.Cir.2004)). “The test for sufficiency of a written description is ‘whether the disclosure of the application relied upon reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date.’ ” Bard Peripheral Vascular, Inc. v. W.L. Gore & Assocs., Inc., 670 F.3d 1171, 1188 (Fed.Cir.2012) (quoting Aviad, 598 F.3d at 1351). This test “requires an objective inquiry into the four corners of the specification from the perspective of a person of ordinary skill in the art. Based on that inquiry, the specification must describe an invention understandable to that skilled artisan and show that the inventor actually invented the invention claimed.” Ariad, 598 F.3d at 1351.

“What is required to meet the written description requirement ‘varies with the nature and scope of the invention at issue, and with the scientific and techno-logic knowledge already in existence.’ ” Id. at 1363 (quoting Capon v. Eshhar, 418 F.3d 1349, 1357 (Fed.Cir.2005)). A means-plus-function claim does not meet the written description requirement unless there is a known or disclosed correlation between the function and the corresponding structure. Boston Sci. Corp. v. Johnson & Johnson, 647 F.3d 1353, 1366 (Fed.Cir.2011). Compliance with the written description requirement is a question of fact. Hynix Semiconductor Inc. v. Rambus Inc., 645 F.3d 1336, 1351-52 (Fed.Cir.2011).

3. Enablement

In addition to requiring a written description of the invention, Section 112 requires that the written description be “in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same.” 35 U.S.C. § 112 ¶ 1. The test for enablement is whether a person “skilled in the • art, after reading the specification, could practice the claimed invention without undue experimentation.” Sitrick v. Dreamworks, LLC, 516 F.3d 993, 999 (Fed.Cir.2008) (citation omitted).

In determining whether a disclosure requires undue experimentation, courts may consider the following factors: (1) the quantity of experimentation necessary, (2) the amount of direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, (6) the relative skill of those in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims. ALZA Corp. v. Andrx Pharm., LLC, 603 F.3d 935, 940 (Fed.Cir.2010) (quoting In re Wands, 858 F.2d 731, 737 (Fed.Cir.1988)).

To satisfy the enablement requirement, the full scope of the claimed invention must be enabled, Sitrick, 516 F.3d at 999, but unclaimed elements need not be enabled, DeGeorge v. Bernier, 768 F.2d 1318, 1324 (Fed.Cir.1985). An inventor therefore need not enable the commercial embodiment of' his invention in cases where the commercial embodiment contains unclaimed elements. CFMT, Inc. v. Yieldup Inter. Corp., 349 F.3d 1333, 1338 (Fed.Cir.2003). As the Federal Circuit has recognized:

Improvement and selection inventions are ubiquitous in patent law; such developments do not alone cast doubt on enablement of the original invention. In general, few patented inventions are an immediate commercial success. Rather, most inventions require further development to achieve commercial success. Thus, additional inventive work does not alone show nonenablement.

Id. at 1340 (internal citations omitted).

The requirements of written description and enablement “usually rise and fall together. That is, a recitation of how to make and use the invention across the full breadth of the claim is ordinarily sufficient to demonstrate that the inventor possesses the full scope of the invention, and vice versa.” Am. Med. Sys., Inc. v. Laser Peripherals, LLC, 712 F.Supp.2d 885, 912-13 (D.Minn.2010) (quoting LizardTech, Inc. v. Earth Resource Mapping, Inc., 424 F.3d 1336, 1345 (Fed.Cir.2005)) (internal quotation marks omitted). Enablement is a question of law involving underlying factual inquiries. Id. (citing Falko-Gunter Falkner v. Inglis, 448 F.3d 1357, 1363 (Fed.Cir.2006)).

4. Best mode

Section 112 also requires that a patent specification “set forth the best mode contemplated by the inventor of carrying out his invention.” 35 U.S.C. § 112 ¶ l. The best mode must be disclosed for the invention defined in each claim of the patent. Pfizer, Inc. v. Teva Pharms. USA, Inc., 518 F.3d 1353, 1365 (Fed.Cir.2008). The best mode analysis is a question of fact involving an inquiry into whether “the inventor both knew of and concealed a better mode of carrying out the claimed invention than that set forth in the specification.” Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1330 (Fed. Cir.2002). The Federal Circuit has made clear that invalidity for violation of the best mode requirement does not require intentional concealment of a better mode than was disclosed. United States Gypsum Co. v. National Gypsum Co., 74 F.3d 1209, 1215-16 (Fed.Cir.1996). A defendant moving for summary judgment based on invalidity must prove both prongs of the best mode analysis — knowledge and failure to disclose the mode — by clear and convincing evidence. Id.

III. INVALIDITY OF THE BITTLE-STON PATENTS

Defendants move for summary judgment on WesternGeeo’s apparatus claims for four patents that name Oyvind Hillesund and Simon Bittleston as their inventors (the “Bittleston patents”). These include the '017 patent (Doc. No. 273-3), the '607 patent (Doc. No. 273-9), the '967 patent (Doc. No. 287-31), and the '520 patent (Doc. No. 273-1). Defendants contend that these patents are invalid for their failure to meet the requirements of 35 U.S.C. § 112. As to the '520 patent, Plaintiff moves for summary judgment of validity.

A. Timeliness of Defenses

Before responding to the specific arguments raised in Defendants’ motion, Plaintiff first contends that Defendants’ patent invalidity arguments should be precluded on the basis of untimeliness. Plaintiff essentially argues that, because Defendants pled their Section 112 defenses very generally, those defenses should be stricken, and Defendants should not now be allowed to make specific arguments deriving from those general pleadings. While the Court agrees that these defenses were pled very generally, Plaintiff has not raised the issue of Defendants’ pleadings until now. Moreover, the cases cited by Plaintiff fail to support the argument that Defendants’ broadly pled defenses should be precluded at the summary judgment phase. The Court declines to exclude these defenses on the basis of untimeliness.

B. Definiteness Requirement

Defendants contend that the following claims in the Bittleston patents are invalid for indefiniteness: (1) claim 16 of the '017 patent; (2) claim 15 of the '607 patent; (3) claim 15 of the '967 patent; and (4) claim 18 of the '520 patent.

1. Claim 16 of the '017 patent

Claim 16 of the '017 patent lists four elements, all of which are drafted in the “means-plus-function” format: (1) “means for obtaining a predicted position of the streamer positioning devices”; (2) “means for obtaining an estimated velocity of the streamer positioning devices”; (3) “means for calculating desired changes in the orientations of the respective wings of at least some of the streamer positioning devices using said predicted position and said estimated velocity”; and (4) “means for actuating the wing motors to produce said desired changes in wing orientation.” ('017 patent at claim 16.) As noted above, courts considering means-plus-function expressions first must decide what the claimed function is, and then must determine whether a structure corresponding to that function is disclosed in the specification. Welker Bearing, 550 F.3d at 1097. Whether the written description adequately sets forth structure corresponding to the claimed function is considered from the perspective of a person skilled in the art. Intel Corp., 319 F.3d at 1365-66 (citing Budde, 250 F.3d at 1376).

Defendants challenge the first, third, and fourth of claim 16’s means-plus-function elements. Specifically, Defendants contend that claim 16 fails to provide structure by (1) failing to disclose structure for the “means for predicting”; (2) failing to disclose structure for “calculating desired changes in the orientations of the respective wings of at least some of the streamer positioning devices using said predicted position and said estimated velocity”; and (3) failing to disclose structure for the “means for actuating.”

a. Means for obtaining a predicted position of the streamer positioning devices

In construing the '017 patent, the Court has previously determined that the specification does disclose structure corresponding to this language. The Court reasoned that the global control system runs position predictor software to estimate the actual location of each of the birds and that, therefore, that position predictor software is an indisputably necessary structure to perform the disclosed function. (735 F.Supp.2d at 640-41.) On that basis, the Court construed this term as “global control system and predictor software; and equivalents thereof.” (Id. at 641.)

Defendants argue, somewhat conclusorily, that because this means-plus-function claim is computer-implemented— that is, because it uses a control system and predictor software — it must be linked to a corresponding algorithm in order to meet the definiteness requirement. (Doc. No. 273 at 2.) The Federal Circuit has held that, in cases “involving a special purpose computer-implemented means-plus-function limitation ... the structure disclosed in the specification [must] be more than simply a general purpose computer or microprocessor.” Noah Sys., Inc. v. Intuit Inc., 675 F.3d 1302, 1312 (Fed.Cir.2012). In such a situation, the specification must “disclose an algorithm for performing the claimed function.” Net MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1367 (Fed.Cir.2008); Aristocrat Techs. Australia Pty Ltd. v. Int’l Game Tech., 521 F.3d 1328, 1333 (Fed.Cir.2008) (“[I]n a means-plus-function claim ‘in which the disclosed structure is a computer, or microprocessor, programmed to carry out an algorithm, the disclosed structure is not the general purpose computer, but rather the special purpose computer programmed to perform the disclosed algorithm.’ ” (quoting WMS Gaming, Inc. v. Int’l Game Tech., 184 F.3d 1339, 1349 (Fed.Cir.1999))). If, on the other hand, a function can be performed by “any general purpose computer without special programming,” then “it [is] not necessary to disclose more structure than the general purpose processor that performs those functions.” In re Katz Interactive Call Processing Patent Litig., 639 F.3d 1303, 1316 (Fed.Cir.2011).

The Federal Circuit has recognized two categories of cases in which defendants may challenge special purpose computer-implemented means-plus-function claims. The first includes cases in which the specification discloses no algorithm at all. The second includes cases in which the specification does disclose an algorithm, but the defendant contends that the disclosure is inadequate. Noah Sys., 675 F.3d at 1313. Defendants appear to contend that the claims at issue disclose no algorithm at all.

Before considering Defendants’ arguments on the merits, the Court acknowledges Plaintiffs contention that Defendants should be estopped from litigating indefiniteness. When the parties were before this Court on claim construction, ION argued that the only structures disclosed in the '017 patent that can perform the function of obtaining a predicted position are the global control system and the position predictor software. (See 735 F.Supp.2d at 640-41.) The Court agreed, and adopted ION’s proposed construction. (Id.) In what seems to be a complete reversal of its earlier position, ION now argues that there are no structures disclosed in the '017 patent corresponding to this function. Such a reversal, Plaintiff urges, should be subject to judicial estoppel. However, because the Court recognizes that there might be a difference between acknowledging the disclosure of some structure — which ION clearly has done — and acknowledging the existence of a sufficient algorithm, the Court proceeds to consider Defendants’ argument on the merits.

The Federal Circuit has explained that a patent’s specification can express an algorithm “in any understandable terms including as a mathematical formula, in prose, or as a flow chart, or in any other manner that provides sufficient structure.” Finisar Corp. v. DirecTV Grp., Inc., 523 F.3d 1323, 1340 (Fed.Cir.2008) (citation omitted). Simply disclosing software, “without providing some detail about the means to accomplish the function[,] is not enough.” Id. at 1340-41 (citation omitted). The critical question in considering whether an algorithm is disclosed is whether the algorithm to be implemented by the programmer could, as described in the specification, be “readily implemented by person of skill in computer programming.” Typhoon Touch Techs., Inc. v. Dell, Inc., 659 F.3d 1376, 1386 (Fed.Cir.2011).

While testimony from one skilled in the art may aid the court in interpreting the specification, “the testimony of one of ordinary skill in the art cannot supplant the total absence of structure from the specification.” Default Proof Credit Card Sys., Inc. v. Home Depot U.S.A., Inc., 412 F.3d 1291, 1302 (Fed.Cir.2005); Med. Instr. & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1212 (Fed.Cir.2003) (“The correct inquiry is to look at the disclosure of the patent and determine if one of skill in the art would have understood that disclosure to encompass software [with sufficient structure to perform the recited function], not simply whether one of skill in the art would have been able to write such a software program.”); see also Elekta AB, 344 F.3d at 1214 (“[H]ere there would be no need for a disclosure of the specific program code if software were linked to the converting function and one skilled in the art would know the kind of program to use”). Thus, if structure is disclosed in the specification, and one skilled in the art would interpret that structure as encompassing software capable of performing the recited function, then the claim is not indefinite.

■ As the Court is to approach the indefiniteness question from the position of one skilled in the art, it looks to the positions taken by the parties’ experts, bearing in mind that the burden is on Defendants to establish indefiniteness by clear and convincing evidence. The Court is persuaded by the fact that both Plaintiffs and Defendants’ experts opine that the claim is definite. When asked whether he believed that the Bittleston '636 application discloses and enables “predicting positions of streamer positioning devices,” Defendants’ expert, Robert Bruñe, answered “yes.” (Bruñe Dep., Doc. 287-16 at 128:12-15.) Plaintiffs expert, Dr. Michael Triantafyllou, states in his declaration that, as to claim 16 of the '017 patent, “there is corresponding structure disclosed, [and] the specification demonstrates to one of ordinary skill in the art that Dr. Bittleston and Mr. Hillesund were in possession of the invention at the time.” (Doc. 287-1 ¶ 17-18.). The only expert evidence contradicting this testimony is that of Defendants’ expert, Dr. Charles Garris, who states that “one of ordinary skill in the art at the time of the '017 application would be unable to find a structure or act which would satisfy this requirement.” (Garris Expert Report, Doc. No. 288-25 at 58-59.)

Although indefiniteness is a question of law, IGT, 659 F.3d at 1119, it requires a factual determination as to what one skilled in the art would have understood by looking at the patent. The expert evidence addressing what one skilled in the art would have understood by looking at this patent is in conflict. Defendants have failed to prove, by clear and convincing evidence, that such a person would not have understood the structure disclosed in the patent. As such, the determination of the factual question underlying this legal issue must be made by a jury,

b. Means for calculating desired changes in the orientations of the respective wings of at least some of the streamer positioning devices using said predicted position and said estimated velocity

As with the previous claim language, Defendants contend that there is no disclosure of a structure corresponding to this language. The Court construed this limitation and found the corresponding disclosed structures to be a “global control system; local control system and localized displacement/force conversion program using a look-up table or a conversion routine; and equivalents thereof.” (735 F.Supp.2d at 642.) The only evidence cited in support of Defendants’ indefiniteness contention is Dr. Bittleston’s testimony that “there are multiple ways” to change the orientations of respective wings, depending on the device and the implementation. (Bittleston Dep., Doc. No. 273-7 at 156:14-22.) It is not clear how this testimony, which is consistent with the teachings of the specification as construed by the Court, could possibly prove indefiniteness by clear and convincing evidence.

Further undermining Defendants’ argument is the testimony of Plaintiffs expert that “a person of ordinary skill in the art would understand the corresponding structure and would be able to implement this limitation in Claim 16 of the '017 patent without undue experimentation.” (Triantafyllou Decl. ¶¶ 19-20.) Defendants again have failed to prove indefiniteness by clear and convincing evidence. The Court concludes that the jury will have to determine, after listening to live witness testimony, whether a person of ordinary skill in the art would have understood this language to disclose a corresponding structure.

c. Means for actuating the wing motors to produce said desired changes in wing orientation

Defendants assert that there is no disclosed structure corresponding to this claim limitation. The Court construed this language to mean “motor driver; and equivalents thereof’ (735 F.Supp.2d at 642), a construction on which the parties agreed. Defendants now contend that “[n]o structure for accomplishing that function is shown.” (Doc. No. 273 at 5.) The Court cannot agree, on the limited and conclusory argument made by Defendants, that no structure for actuating wing motors is disclosed. Moreover, although the Court did not find the doctrine of judicial estoppel appropriate above, where the disclosure of an algorithm was at issue, the doctrine is far more persuasive here, where the only question is whether the specification discloses a structure that corresponds to this limitation. ION agreed, at one point in this litigation, that it does.

Finally and persuasively, the Federal Circuit has explained that, “[i]f a claim is amenable to construction ... the claim is not indefinite.” Aero Prods., 466 F.3d at 1016 (citing Exxon Res. & Eng’g Co. v. United States, 265 F.3d 1371, 1375 (Fed.Cir.2001)). The Court construed this claim as having corresponding structure at the urging of both parties. Defendants have failed to prove the indefiniteness of this limitation, and their motion as to this limitation therefore must be denied.

2. Claim 15 of the '607 patent

Claim 15 of the '607 patent recites a “prediction unit” as one of its elements. It describes the prediction unit’s function as follows: “predict positions of at least some of the streamer positioning devices.” ('607 patent at claim 15.) Defendants argue, for essentially the reasons asserted above with regard to claim 16’s “means for obtaining a predicted position,” that claim 15 of the '607 patent fails for indefiniteness.

Plaintiff contends that this claim is not a “means-plus-function” limitation, as it does not contain the word “means.” Better Bags, Inc. v. Cont’l Poly Bags, Inc., No. H-10-608, 2011 WL 2014551, at *5 (S.D.Tex. May 23, 2011) (“[S]ince the claim does not contain the word ‘means,’ there is a strong presumption against the ‘means-plus-function’ construction.” (citing Lighting World, Inc. v. Birchwood Lighting, Inc., 382 F.3d 1354, 1358 (Fed.Cir.2004))). Defendants respond that, under WesternGeco’s theory, a clever patent drafter could avoid the disclosure requirements of Section 112 ¶ 6 by claiming a “predictor” instead of a “means for predicting.”

Ultimately, even if the Court were to construe this limitation as a means-plus-function limitation, Defendants would need to offer evidence regarding how someone skilled in the art would have interpreted the language. The only such evidence comes from Plaintiffs expert, Dr. Triantafyllou, who testifies that, “[t]o the extent it is necessary for this term to have a corresponding structure in the patent’s specification, it is my opinion that there is corresponding structure disclosed as noted above with ‘means for obtaining a predicted position of the streamer positioning devices.’ ” (Triantafyllou Deck ¶ 23.) Dr. Triantafyllou further opines that “a person of ordinary skill in the art would understand the corresponding structure for this limitation in Claim 15 of the '607 Patent.” (Id. ¶ 24.) Defendants have presented no evidence on this argument, and therefore fail to meet their burden of proving indefiniteness by clear and convincing evidence.

3. Claim 15 of the '967 patent

Defendants assert that claim 15 of the '967 patent is invalid for improper functional claiming because it creates confusion as to when it is directly infringed. Claim 15 of the '967 patent includes an element reciting “a global control system transmitting location information to at least one local control system.” ('967 patent at claim 15.) Defendants urge that this claim is invalid because it claims both a system and a method, creating confusion.

Claims directed both to systems and to actions performed by users of the systems are considered indefinite if they create confusion as to when an apparatus claim is directly infringed. See Katz, 639 F.3d at 1318; IPXL Holdings, L.L.C. v. Amazon.com, Inc., 430 F.3d 1377, 1384 (Fed.Cir.2005). The claim at issue in IPXL reads as follows:

The system of claim 2 [including an input means] wherein the predicted transaction information comprises both a transaction type and transaction parameters associated with that transaction type, and the user uses the input means to either change the predicted transaction information or accept the displayed transaction type and transaction parameters.

IPXL, 430 F.3d at 1384. The Federal Circuit held that, because this claim recites both a system and the method for using that system, it is unclear whether the claim is infringed “when one creates a system that allows the user to change the predicted transaction information or accept the displayed transaction, or whether infringement occurs when the user actually uses the input means to change transaction information or uses the input means to accept a displayed transaction.” Id. Notably, a number of district courts addressing mixed subject matter claims have found that the IPXL invalidity defense does not apply, concluding that the “suspect claims [at issue in those cases] did not cover both an apparatus and a méthod, but rather were apparatus claims containing functional limitations.” See Ricoh Co., Ltd. v. Katun Corp., 486 F.Supp.2d 395, 402 (D.N.J. 2007) (collecting cases).

The claim at issue in Katz is similar to the challenged claim in IPXL, and recites a system with. an “interface means for providing automated voice messages ... to certain of said individual callers, wherein said certain of said individual callers digitally enter data.” 639 F.3d at 1318. The court in Katz explained that, “[l]ike the language used in the claim at issue in IPXL (‘wherein ... the user uses’), the language used in the Katz claims (‘wherein ... callers digitally enter data’ and ‘wherein ... callers provide ... data’) is directed to user actions, not system capabilities.” Id.

Although functional language directed to user actions, like the language at issue in IPXL and Katz, can invalidate a claim, “functional language which merely describes the capability of the claimed invention will not render a claimed invention invalid” under IPXL. Eolas Techs., Inc. v. Adobe Systems, Inc., 810 F.Supp.2d 795, 812 (E.D.Tex.2011) (citing Microprocessor Enhancement Corp. v. Texas Instruments, Inc., 520 F.3d 1367, 1375 (Fed.Cir.2008)). Thus, in Yodlee, Inc. v. CashEdge, Inc., No. 05-01550, 2006 WL 3456610, at *4-6 (N.D.Cal. Nov. 29, 2006), the court concluded that the claims at issue were valid because they “describe what the apparatuses do, when used in a certain way. They do not claim use of the apparatuses.” Likewise, in Eolas, the court held that, notwithstanding the claim’s use of the word “wherein,” the claims at issue described the capabilities of the claimed apparatuses, and thus- did not render the claims indefinite. 810 F.Supp.2d at 813-14. In Toshiba Corp. v. Juniper Networks, Inc., No. 03-1035-SLR, 2006 WL 1788479, at *4 (D.Del. Jun. 28, 2006), the court similarly denied a motion for summary judgment of invalidity as to a claim with the phrase “wherein the control message processing unit communicates with,” holding that the claim recited only the functional capabilities of the apparatus. Ultimately, it is well-established that a functional limitation — that is, an attempt to define something by what it does rather than by what it is — is a permissible means of articulating a claim limitation. See, e.g., In re Schreiber, 128 F.3d 1473, 1478 (Fed.Cir.1997).

Unlike in Katz and IPXL, the claims of the '967 patent do not create confusion as to when infringement occurs. First, they do not attempt to cover an apparatus and a method in a single claim. Rather,' claim 1 is a method claim, and claim 15 is the corresponding apparatus claim. Claim 1 recites a method comprising “transmitting from a global control system location information to at least one local control system ....” Claim 15 includes a global control system capable of transmitting location information to a local control system, whereas claim 1 recites the method transmission. Moreover, claim 15 does not refer to actions to be taken by the user, as in IPXL and Katz. Instead, the language “a global control system transmitting location information” recites the capabilities of the apparatus, much like the claims at issue in Eolas and Toshiba. As such, this claim includes valid functional language which merely describes the capability of the claimed invention.

4. Claim 18 of the '520 patent

Claim 18 of the '520 patent requires “(a) an array of streamers each having a plurality of streamer positioning devices there along; [and] (b) a control system configured to use a control mode selected from a feather angle mode, a turn control mode, a streamer separation mode, and two or more of these modes.” ('520 patent at claim 18.) As to claim 18, Defendants move for summary judgment of invalidity based on indefiniteness. In light of the Court’s construction of the '520 patent as a control system configured to use one or more of the group of four listed modes (discussed below in addressing the infringement motions), Defendants also raise concerns about invalidity based on prior art. Plaintiff cross-moves for summary judgment on the '520 patent’s validity,

a. Indefiniteness

The apparatus portion of claim 18 of the '520 patent has two elements: (1) an array of streamers; and (2) a control system “configured to use a control mode” that is selected from a list of “modes,” including “feather angle mode,” “turn control mode,” and “streamer separation mode.” (Id.) Defendants contend that the “control system” is a computer-implemented element, and therefore that it requires a corresponding algorithm in the specification to satisfy the definiteness requirement. Plaintiff responds that claim 18 is not a means-plus-function claim, so there is no requirement that a corresponding algorithm be supplied in order to make the claim definite. Plaintiff notes that ION’s claim-construction brief did not classify claim 18 of the '520 patent as a functional expression • governed by Section 112 ¶ 6; indeed, ION sought construction of this claim language, some of which the Court adopted almost verbatim. (Doc. No. 120.) Plaintiff urges that Defendants should be estopped from now arguing that this language, for which ION sought construction, is indefinite.

Putting aside Plaintiffs argument as to estoppel, the Court finds that, even if this claim were construed as a means-plus-function claim, Defendants provide insufficient evidence to meet their “clear and convincing” burden. Indeed, one of Defendants’ own experts, Mr. Bruñe, has testified that claim 18 of the '520 patent is clear and not indefinite. (Bruñe Dep. at 175:10-17.) When asked whether, in his expert opinion, Mr. Bruñe had any doubt as to what is covered by claim 18 of the '520 patent, Mr. Bruñe answered, “[n]o, it’s — it’s clear to me.” (Id. at 175:10-12.) When asked whether, in his opinion, there is anything indefinite about the scope of claim 18, Mr. Bruñe responded “[n]ot in my interpretation.” (Id. at 175:13-17.) Importantly, “[i]f one skilled in the art would understand the bounds of the claim when read in light of the specification, then the claim satisfies section 112 paragraph 2.” Exxon Research & Eng’g Co. v. United States, 265 F.3d 1371, 1375 (Fed.Cir.2001). Defendants’ unsupported attorney argument fails to prove indefiniteness by clear and convincing evidence.

As Plaintiff moves for summary judgment of validity, the Court also must consider Plaintiff s, argument that claim 18 of the '520 patent is valid under 35 U.S.C. §112. Plaintiff addresses possible challenges to claim 18 raised by Defendants’ experts, including enablement and indefiniteness. Plaintiff acknowledges that Defendants’ expert, Mr. Bruñe, has stated that claim 18 fails to enable the disclosed modes (Bruñe Expert Report, Doc. No. 276-71 at 21-22), but urges that Mr. Brune’s argument is “conclusory.” Plaintiff likewise recognizes the opinion of Defendants’ expert Dr. Edgar, who has asserted that the claim is indefinite. (Doc. No. 276-76, Edgar Expert Report at § V(D).) Plaintiff urges that both of these expert opinions are too conclusory, and therefore cannot raise triable issues of material fact on summary judgment. Dynacore Holdings Corp. v. U.S. Philips Corp., 363 F.3d 1263, 1278 (Fed.Cir.2004).- The Court disagrees. Many of the expert opinions in this case, on both sides, have been surprisingly conclusory. However, the Court has denied a number of Defendants’ summary judgment arguments in large part because of the factual dispute over the perspective of one skilled in the art, generated by the fairly conclusory opinions of Plaintiffs expert. Such a factual dispute is similarly present here; for that reason alone, the Court cannot grant Plaintiffs motion for summary judgment of validity.

b. Prior Art under 35 ■ U.S.C. §§ 102, 103

Defendants argue that claim 18 is invalid because it is anticipated under 35 U.S.C. § 102, and because it is obvious under 35 U.S.C. § 103. (Doc. No. 298 at 28-31.) As the Court has noted, patents are presumed valid, and an accused infringer must prove invalidity by clear and convincing evidence. Microsoft Corp. v. i4i Ltd. P’ship,-U.S. ——, 131 S.Ct. 2238, 2242, 180 L.Ed.2d 131 (2011). This burden is especially high where the accused infringer asserts prior art considered during prosecution, as the USPTO is entitled to the deference accorded to a government agency performing its specified function. Hewlett-Packard v. Bausch & Lomb Inc., 909 F.2d 1464, 1467 (Fed.Cir.1990). The Court considers anticipation and obviousness below.

i. Anticipation

“For a prior art reference to anticipate in terms of 35 U.S.C. § 102, every element of the claimed invention must be identically shown in a single reference.” In re Bond, 910 F.2d 831, 832 (Fed.Cir.1990). “There must be no difference between the claimed invention and the reference disclosure, as viewed by a person of ordinary skill in the field of the invention.” Scripps Clinic & Research Found. v. Genentech, Inc., 927 F.2d 1565, 1576 (Fed.Cir.1991). “Anticipation is a question of fact.” Marrin v. Griffin, 599 F.3d 1290, 1293 (Fed.Cir.2010).

Defendants argue that, under the Court’s construction of claim 18 of the '520 patent, discussed below, the claim is anticipated by U.S. Patent No. 5,790,472 (the “Workman Reference”). (Doc. No. 298-S.) The Workman Reference was filed on December 20, 1996, and issued on August 4, 1998. (Id.) Because it was filed before October 1, 1998, the priority date of the '520 patent, the Workman Reference is presumptively prior art under 35 U.S.C. § 102(e). The reference was cited to the Examiner during prosecution of the '520 patent.

Under the Court’s construction of claim 18 of the '520 patent, the Workman Reference would have to disclose only one of the modes listed in claim 18. Defendants urge that the Workman Reference discloses a control mode that performs the function of claim 18’s “streamer separation mode.” The Court has construed “streamer separation mode” as “a control mode that attempts to set and maintain the spacing between adjacent streamers.” (735 F.Supp.2d at 639.)

The Workman Reference discloses a vessel towing a plurality of streamer cables. (Workman Reference at col. 2:66— 3:5.) It states that “[sjtreamer positioning devices 14, for example birds and tail buoys, may be attached to the exterior of the streamer cables 13 for adjusting the vertical and lateral positions of the streamer cables 13.” (Id. at col. 3:14-18.) The Workman Reference also discloses a “streamer cable controller,” which is part of a “seismic data acquisition system” located on the vessel. (Id. at fig. 2, col. 3:30-45.) Defendants emphasize the following language in the Workman Reference in support of their argument that it anticipates the “streamer separation mode”:

The marine seismic data acquisition system 05 also includes a streamer control processor 40 for deciding when the streamer cables 13 should be repositioned and for calculating a position correction to reposition the streamer cables 13. Also in the present embodiment of the invention, threshold parameters are established for determining when the streamer cables should be repositioned. Threshold parameters may include a plurality of values for: minimum allowable separations between streamer cables 13 .... A terminal 32 for entering threshold parameters is connected to the streamer control processor 40. Threshold parameters may be entered into the streamer control processor 40 before or contemporaneously with the acquisition of a marine seismic survey.

(Id., at col. 3:58-4:8 (emphasis added by Defendants).) Although Defendants do not direct the Court to any expert evidence, the Court notes that Dr. Garris does opine, in his expert report, that the turn control and streamer separation modes of the '520 patent are anticipated by the Workman Reference. (Garris Report, Doc. No. 308-108 at 6.)

To the extent that Defendants intend to move for summary judgment based on the Workman Reference, this minimal evidence, not even cited by Defendants in their briefing, is insufficient to resolve the fact question of how one of ordinary skill in the art would view the Workman Reference. Defendants’ position is further weakened by the question, which Defendants fail to address, of whether the Workman Reference’s disclosure' is enabling with respect to claim 18. “Whether a pri- or art reference is enabling is a question of law based upon underlying factual findings.” Minn. Mining & Mfg. Co. v. Chemque, Inc., 303 F.3d 1294, 1301 (Fed.Cir.2002). Nonetheless, the Court does read the quoted language as potentially anticipating the streamer separation mode of the '520 patent. Thus, the Court determines that a factual issue remains, and Plaintiff is not entitled to summary judgment on validity.

ii. Obviousness

A patent claim is invalid “if the differences between the [claimed] subject matter ... and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person of ordinary skill in the art to which said subject matter pertains.” 35 U.S.C. § 103(a). “In order to render a claimed apparatus or method obvious [under § 103], the prior art must enable one skilled in the art to make and use the apparatus or method.” Beckman Instruments, Inc. v. LKB Produkter AB, 892 F.2d 1547, 1551 (Fed.Cir.1989). To avoid being obvious, claimed subject matter must be “more than the predictable use of prior art elements according to their established functions.” KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 417, 127 S.Ct. 1727, 167 L.Ed.2d 705 (2007). “Obviousness is a question of law based on underlying questions of fact.” Green Edge Enters., LLC v. Rubber Mulch Etc., 620 F.3d 1287, 1298 (Fed.Cir.2010).

Defendants contend that the Workman Reference, in combination with U.S. Patent No. 4,890,568 (the “Dolengowski Reference” or “Dolengowski”), renders claim 18 obvious, and therefore invalid. The Dolengowski Reference, titled “Steerable Tail Buoy,” was issued on January 2, 1990. (Doc. No. 298-T.) It is presumptively prior art to the '520 patent under 35 U.S.C. § 102(b). The Dolengowski Reference discloses remotely controllable tail buoys to maintain the lateral separation of the ends of streamers to avoid entanglement. (Id. at col. 2:50-58, col. 7:4-35.)

Plaintiff argues that, beyond the fact that Dolengowski was considered by the USPTO and determined not to render the '520 patent obvious, it also fails to disclose the patented invention because it does not teach control modes required by the claim. The only expert evidence provided by Defendants is that, while Dolengowski does not “explicitly use the terms ‘feather angle mode,’ ‘turn control mode,’ and ‘streamer separation mode,’ it does teach the challenges of towing multiple streamers to address these modes.” (Garris Expert Report at 70.)’ Merely teaching the challenges resolved by the patented control modes of the '520 patent, without actually solving those challenges in the same way, cannot give rise to obviousness. As Plaintiffs expert avers, “Dolengowski’s solution to the described problems was merely to use rudders to move tail buoys away from one another.” (Triantafyllou Rebuttal Report ¶ 101.) Dr. Triantafyllou further notes that Dolengowski “does not teach or suggest using a ... streamer separation mode as taught in the '520 patent and construed by the Court.” (Id. ¶ 104.) He concludes that Dolengowski “does not anticipate ... Claim 18 of the '520 Patent.” (Id. ¶ 101.) Defendants have failed to submit any evidence as to whether the Dolengowski and Workman References — both of which might fail to teach the control modes listed in claim 18 — enable one skilled in the art to make and use any method within claim 18 of the '520 patent. Until the enablement questions are sorted out at trial, substantial underlying questions of fact remain, and summary judgment of nonobviousness should be denied.

C. Written Description Requirement

Defendants contend that claim 16 of the '017 patent, considered above in the context of indefiniteness, also fails to satisfy the written description requirement. Defendants essentially reiterate their indefiniteness contentions, noting that their arguments as to indefiniteness similarly demonstrate the absence of an adequate written description.

The Workman Reference discloses a vessel towing a plurality of streamer cables. (Workman Reference at col. 2:66-3:5.) It states that “[s]treamer positioning devices 14, for example birds and tail buoys, may be attached to the exterior of the streamer cables 13 for adjusting the vertical and lateral positions of the streamer cables 13.” (Id. at col. 3:14-18.) The Workman Reference also discloses a “streamer cable controller,” which is part of a “seismic data acquisition system” located on the vessel. (Id. at fig. 2, col. 3:30-45.) Defendants emphasize the following language in the Workman Reference in support of their argument that it anticipates the “streamer separation mode”:

Although written description is a factual issue, the test for compliance with the written description requirement requires an “objective inquiry” into the four corners of the specification from the perspective of a person of ordinary skill in the art. Ariad, 598 F.3d at 1351. Based on that inquiry, the specification must describe an invention understandable to that skilled artisan and show that the inventor actually invented the invention claimed. Id. Defendants cite no evidence in support of their written description argument. The only relevant evidence that the Court has located is in the expert report of Dr. Garris, who states that “[t]here is no description of what the ‘position predictor software’ consists of.” (Garris Expert Report at 56.) Plaintiffs expert contends, in contrast, that the written description requirement is satisfied. (Triantafyllou Expert Report ¶ 327.) Dr. Triantafyllou indicates that he disagrees with Dr. Garris “because the '017 patent’s specification discusses position prediction. For example, the specification describes using a ‘distributed processing control architecture and behavior-predictive model-based control logic’ in the control system.... The specification also discusses the use of such software.” (Id.) Written description is a question of fact; where, as here, there is competing expert testimony regarding the perspective of a person of ordinary skill in the art, a genuine issue of material fact remains, and this question must be resolved by the jury.

D. Lack of Enablement

With regard to enablement, Defendants argue (1) that claim 16 of the '017 patent is invalid because the full scope of the claim is not enabled; and (2) that all of the Bittleston patents are invalid because each contains claims having a “steamer positioning device,” which Defendants contend is not enabled.

1. Claim 16 of the '017 patent

Defendants again reassert their indefiniteness arguments in the context of enablement. They urge that there is no disclosure for three of the four elements of claim 16: (1) obtaining a predicted position, (2) calculating the desired changes in the orientation of the wings, using estimated velocity and predicted position, and (3) actuating the wing motors. Here, as in the context of indefiniteness, Defendants provide insufficient evidence regarding whether one of skill in the art, after reading the specification, could practice the claimed invention without undue experimentation. Sitrick, 516 F.3d at 999. Thus, like their indefiniteness argument, Defendants’ enablement argument as to claim 16 of the '017 patent must fail.

2. All of the Bittleston patents

Defendants also contend that the phrase “streamer positioning device,” used in all of the Bittleston patents, is not enabled, rendering claims in each of the Bittleston patents invalid. Defendants urge that, aside from one figure and one block diagram reciting the results to be obtained, no streamer positioning device is disclosed in the patents.

First, Defendants argue that the Bittleston patents’ specifications fail to enable stability in the streamer positioning devices, despite the inventors’ knowledge that stability was critical. In an attempt to prove that the inventors knew of the importance of stability in the streamer positioning devices, Defendants point to the fact that the inventors hired an expert outside contractor to develop software to make the steering device stable. (Hillesund Dep., Doc. No. 273-14 at 286:11-287:6; 412:15-22.) Defendants also cite to Mr. Hillesund’s explanation that one method of ensuring stability was to update the angles of the wings on the bird “several times every second” to prevent the bird from “twisting.” (Hillesund Dep., Doc. No. 273-15 at 363:15-364:17.) Notwithstanding Mr. Hillesund’s recognition of the importance of rapid updating to stability, Defendants argue, the Bittleston patents do not disclose this need. (Hillesund Dep., Doc. No. 273-16 at 365:2-365:12.) Defendants also emphasize the fact that Mr. Hillesund and Dr. Bittleston knew, before filing their patent applications, that the spinning of the bird could become so violent that the wings might need to be blown off the bird body. (Hillesund Dep., Doe. No. 273-20 at 380:13-381:15; Doc. No. 273-21 at WG00024668.)

Defendants’ evidence on the “twisting” issue consists entirely of inventor testimony having nothing to do with the Bittleston patents’ text. The credibility of these witnesses, which inherently is at issue, should be judged at trial. As with a number of Defendants’ arguments, no expert testimony is cited, and the Court has been unable to find any that is persuasive on this issue. On the other hand, Plaintiffs expert has opined that the Bittleston patents do enable streamer positioning devices. (Triantafyllou Decl. ¶ 27.) Defendants’ own expert, Mr. Bruñe, similarly has affirmed that the Bittleston '895 application discloses and enables an active streamer positioning device or a master controller. (Bruñe Dep., Doc. No. 287-16 at 66:25-67:6.) Mr. Brune’s report mentions nonenablement only as to the '038 and '607 patents, but gives no rationale whatsoever for his opinion. (Bruñe Expert Report at 20-21.) Dr. Garris does not discuss enablement of a streamer positioning device at all. As to the Bittleston patents’ enablement of a streamer positioning device, the expert evidence is conflicting, and Defendants fail to demonstrate that a person of ordinary skill in the art, after reading the specification, could not practice the claimed invention without undue experimentation. Sitrick, 516 F.3d at 999.

Defendants also argue that the Bittleston patents fail to disclose a system for locating the positions of the streamer positioning devices. Defendants highlight Mr. Hillesund’s testimony that the lack of an accurate system for locating the positions of the streamer positioning devices would have made the use of lateral steering “possibly impossible to implement.” (Hillesund Dep., Doc. No. 287-36 at 296:9-297:15.) Again, Defendants offer no expert testimony in support of their argument, and fail to prove that the claimed “streamer positioning device” requires a system for locating the positions of the streamer positioning devices. The burden to prove non-enablement is on Defendants, and they have failed to meet it at this juncture.

E. Best Mode Requirement

Finally, Defendants claim that the inventors of the Bittleston patents knew, but did not disclose, better modes of carrying out the Bittleston patents. Defendants proffer essentially the same arguments used to challenge the enablement of the Bittleston patents. Defendants first contend that streamer positioning devices need modes that the inventors did not disclose. Specifically, Defendants point to the importance, acknowledged by Mr. Hillesund, of preventing streamer positioning devices from twisting. Defendants also contend that WesternGeeo’s later-completed acoustic positioning system for measuring the locations of streamer positioning devices is not mentioned in the patents, despite the fact that the inventors “knew what positioning system they were going to try to use.” (Doc. No. 273 at 22.) Defendants also offer evidence that the inventors worked on addressing these two problems — the need for additional modes and the need for an acoustic positioning system — as late as 2005. What Defendants fail to prove is that Dr. Bittleston or Mr. Hillesund knew of a better mode in 1998 and failed to disclose it.

Perhaps even more problematically, Defendants also fail to prove that the functionality of the alleged best modes — anti-twist methods, fail-safe explosives, and an acoustic positioning system for measuring the locations of streamer positioning devices — is within the scope of Bittleston patents. Cf. AllVoice Computing PLC v. Nuance Communications, Inc., 504 F.3d 1236, 1248 (Fed.Cir.2007) (“Because the functionality of the alleged best mode falls outside the scope of claim 73, this court detects no violation of the best mode requirement with respect to claim 73.”). The “best mode” analysis is a question of fact, and Defendants have failed to meet their burden of proving, by clear and convincing evidence, that the inventors of the Bittleston patents “knew of and concealed a better mode of carrying out the claimed invention than that set forth in the specification.” Teleflex, 299 F.3d at 1330.

IV. INVALIDITY OF APPARATUS CLAIMS OF THE ZAJAC PATENT

Defendants move for summary judgment of invalidity as to claims 1, 3, 4, 11, and 14 of the Zajac patent on the basis that these claims fail to meet the written description and enablement requirements of 35 U.S.C.