CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 1 of 54
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`UNITED STATES DISTRICT COURT
`DISTRICT OF MINNESOTA
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`
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`Oxygenator Water Technologies, Inc.,
`
`
`Plaintiff,
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`
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`v.
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`Tennant Company,
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`
`Defendant.
`
`File No. 20-cv-358 (ECT/HB)
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`OPINION AND ORDER
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`
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`Nathan Louwagie, Aaron W. Pederson, Hannah Mosby O’Brien, J. Derek Vandenburgh,
`Philip P. Caspers, and Todd S. Werner, Carlson Caspers Vandenburgh & Lindquist, P.A.,
`Minneapolis, MN, for Plaintiff Oxygenator Water Technologies, Inc.
`
`Lora M. Friedemann, Adam R. Steinert, and Timothy O’Shea, Fredrikson & Byron, P.A.,
`Minneapolis, MN; Cara S. Donels, R. Scott Johnson, and Thomas M. Patton, Fredrikson
`& Byron, P.A., Des Moines, IA, for Defendant Tennant Company.
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`Plaintiff Oxygenator Water Technologies, Inc. owns three patents on an invention
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`that generates tiny oxygen bubbles in water in order to increase the water’s oxygen content.
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`Defendant Tennant Company manufactures and sells commercial floor scrubbers that use
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`a similar process to oxygenate water. Oxygenator believes that Tennant’s floor scrubbers
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`infringe its patents.
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`
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`The Parties seek construction of numerous claim terms in Oxygenator’s patents. See
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`Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996). The Parties agree on
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`constructions for seven claim terms. Those agreed constructions, which are shown in the
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`

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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 2 of 54
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`following table, will be adopted because they are consistent with the claims and the
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`intrinsic record, and nothing more will be said about them in this opinion.
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`Term(s)/Phrase(s)
`“a suspension comprising
`oxygen microbubbles and
`nanobubbles”
`
`Agreed Constructions
`Patent Claim(s)
`’415 Patent, Claim 13
`
`“microbubble”
`
`“critical distance”
`
`’415 Patent, Claims 13, 19,
`20, 21, 22, 25; ’092 Patent,
`Claim 23
`
`’415 Patent, Claim 13
`
`“aquarium reservoir
`container”
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`’415 Patent, Claim 20
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`“supersaturate”
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`’415 Patent, Claim 21
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`“concave”
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`“radial direction relative to
`the longitudinal center
`axis”
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`’092 Patent, Claim 64
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`’092 Patent, Claim 65
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`
`
`
`2
`
`Construction
`A mixture including
`microbubbles and
`nanobubbles that are
`dispersed within but
`undissolved in the water.
`
`A bubble with a diameter
`less than 50 microns.
`
`The distance separating the
`anode and cathode at
`which evolved oxygen
`forms microbubbles and
`nanobubbles.
`
`A container designed for
`keeping fish or other live
`aquatic creatures.
`
`Causing water to have
`oxygen at a higher
`concentration than normal
`calculated oxygen
`solubility at a particular
`temperature and pressure.
`
`Curved inward.
`
`A direction perpendicular
`to the longitudinal center
`axis.
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`

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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 3 of 54
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`The Parties dispute the meaning of seventeen claim terms. For the reasons discussed
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`below, those disputed terms will be construed as follows:
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`Claim Term
`“water”
`
`Constructions of Disputed Terms
`Claim
`Recommendation
`’415 Patent,
`Any aqueous medium that can
`Claims 13, 18, 19,
`support the electrolysis of water
`20, 21, 25, 29;
`’092 Patent,
`Claims 13, 27, 60;
`’665 Patent,
`Claims 13, 55
`
`’415 Patent, Claim
`13
`
`No construction
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`“conductivity produced by
`the presence of dissolved
`solids such that the water
`supports plant or animal
`life”
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`“aqueous medium”
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`“oxygenated aqueous
`composition”
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`“tubular housing”
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`“flowing water . . . through
`an electrolysis emitter”
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`“a flow-through
`oxygenator”
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`“deliver electrical current
`to the electrodes while
`water flows through the
`tubular housing”
`
`’665 Patent, Claim
`55
`
`’415 Patent, Claim
`13
`
`’415 Patent, Claims
`13 and 26
`
`’415 Patent, Claim
`13
`
`’092 Patent, Claim
`13
`
`’665 Patent, Claim
`13
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`No construction
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`No construction
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`An enclosure shaped like a
`cylinder, hose, or tube
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`Moving water through an
`electrolysis emitter by means other
`than electrolysis
`
`A device that oxygenates water as
`the water passes through it
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`Deliver electrical current to the
`electrodes while moving water
`through the electrolysis emitter by
`means other than electrolysis
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`
`3
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 4 of 54
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`“passing water through the
`tubular housing”
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`’092 Patent, Claim
`13
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`Moving water through an
`electrolysis emitter by means other
`than electrolysis.
`
`Electrical and mechanical
`equipment and their
`interconnections used to generate
`and/or convert power
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`A bubble with a diameter less than
`that necessary to break the surface
`tension of water
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`No construction
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`
`’415 Patent, Claim
`13;
`’092 Patent, Claims
`13 and 27;
`’665 Patent, Claim
`13
`
`’415 Patent, Claims
`13, 19, 20, 21, 22,
`25;
`’092 Patent, Claim
`26
`
`’415 Patent, Claim
`25
`
`’415 Patent, Claim
`18
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`The method uses water
`temperature as a factor in forming
`the suspension
`
`’415 Patent, Claim
`19
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`No construction.
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`’415 Patent, Claim
`20
`
`Wherein the water with
`microbubbles and nanobubbles is
`contained in a two and one half
`gallon aquarium reservoir
`container to determine the period
`for which the microbubbles and
`nanobubbles at least in part
`remain in the water
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`“an electrical power
`source”
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`and
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`“a power source”
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`“nanobubble”
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`“incapable of breaking the
`surface tension of the
`water”
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`“the water temperature is a
`factor for formation of the
`suspension”
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`“the microbubbles and
`nanobubbles remain in the
`water at least in part for a
`period up to several hours”
`
`“wherein the period for
`which microbubbles and
`nanobubbles at least in part
`remain in the water is
`determined by containing
`the water with
`microbubbles in a two and
`one half gallon aquarium
`reservoir container”
`
`
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`
`4
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 5 of 54
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`“a first anode electrode
`portion that is non parallel
`to a second anode electrode
`portion”
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`“tubular flow axis from the
`inlet to the outlet”
`
`’665 Patent, Claim
`61
`
`No construction
`
`’415 Patent, Claim
`13
`
`A main line of flow through the
`tubular housing from the inlet to
`the outlet
`
`
`I
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`This case involves three patents owned by Oxygenator: U.S. Patent Nos. RE45,415
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`(“the ’415 patent”), RE47,092 (“the ’092 patent”), and RE47,665 (“the ’665 patent”)
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`(collectively, “the patents-in-suit”). All three patents-in-suit are part of the same lineage.
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`The ’092 patent is a continuation of the ’665 patent, which is itself a continuation of the
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`’415 patent. The ’415 patent began as a reissue application for U.S. Patent No. 7,670, 495
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`(“the ’495 patent”). The ’495 patent issued from a divisional application of U.S. Patent
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`No. 7,396,441 (“the ’441 patent”). The ’441 patent was a continuation-in-part of U.S.
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`Patent No. 6,689,262 (“the ’262 patent”). And the ’262 patent claims priority to U.S.
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`Provisional Application 60/358,534, which was filed by a man named James A. Senkiw in
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`2002. See Donels Decl. ¶ 2, Ex. A [ECF Nos. 77, 77-1]. The upshot is that the patents-in-
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`suit share the same parent patent and the same specification.1
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`
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`The patents-in-suit disclose devices and methods for using a process known as
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`electrolysis to form tiny bubbles of oxygen gas in water. Joint Appendix (“JA”) 11 at 1:23–
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`30, 2:66–3:3 [ECF Nos. 74, 74-1]. Essentially, this works by situating two electrodes with
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`Citations to the specification in this opinion will refer to the pages of the ’415 patent.
`5
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`1
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 6 of 54
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`opposite charges at a “critical distance” from (i.e., very close to) one another and
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`surrounding them with water. JA12 at 3:13–16. The resulting electrical charge breaks
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`apart some of the water molecules, leaving behind hydrogen gas and oxygen gas. JA11 at
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`2:3–18. The hydrogen immediately forms large bubbles and escapes into the atmosphere.
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`JA12 at 4:38–41. But if the oxygen bubbles are small enough, they will remain suspended
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`in the water for some period of time instead of floating up and breaking the water’s surface
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`tension. JA12 at 4:27–37. This leaves water that is “supersaturated with oxygen.” JA12
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`at 4:38.
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`
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`The record shows several potential applications for oxygenated water. A heightened
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`concentration of oxygen can be beneficial to aquatic creatures living in aquariums or bait
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`buckets. See JA13 at 5:24–25. It can aid the hydroponic growth of plants. See JA14 at
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`7:48–67. And it can be used for other agricultural purposes like watering hoses and
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`irrigation systems. JA15 at 9:9–67. Tennant uses electrolysis to oxygenate water in
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`commercial floor scrubbers. Am. Compl. ¶ 13 [ECF No. 9]. According to its
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`advertisements, oxygenated water can be used to clean floors without using potentially
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`harmful chemicals. Id. Oxygenator believes that Tennant’s floor scrubbers infringe the
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`patents-in-suit.
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`II
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`The basic standards governing claim construction are easy to recite, if sometimes
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`difficult to apply. Courts, not juries, construe patent claims. Markman, 517 U.S. at 391.
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`In general, claim language means whatever it would have meant to a person of ordinary
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`skill in the relevant art at the time the patent application was filed. Phillips v. AWH Corp.,
`6
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 7 of 54
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`415 F.3d 1303, 1312–13 (Fed. Cir. 2005) (en banc). Construction is most necessary when
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`a claim uses “technical terms for which the jury may not appreciate an ‘ordinary’ meaning.”
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`Fed. Judicial Ctr., Patent Case Management Judicial Guide § 5.1.4.3 (3d ed. 2016); accord
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`Eli Lilly & Co. v. Aradigm Corp., 376 F.3d 1352, 1360 (Fed. Cir. 2004) (citing U.S.
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`Surgical Corp. v. Ethicon, Inc., 103 F.3d 1554, 1568 (Fed. Cir. 1997)). Sometimes,
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`however, the ordinary and customary meaning of claim language to a person of ordinary
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`skill in the art may be identical to the meaning of that language to a lay person who is not
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`skilled in the art. See Phillips, 415 F.3d at 1314 (acknowledging that claim construction
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`sometimes “involves little more than the application of widely accepted meaning of
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`commonly understood words”). When the meaning of a claim term is clear and there is no
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`genuine dispute as to its scope, a court may decline to issue a construction. See O2 Micro
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`Int’l Ltd. v. Beyond Innovation Tech. Co., 521 F.3d 1351, 1362 (Fed. Cir. 2008); Patent
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`Case Management Judicial Guide § 5.1.4.3 (explaining that construing a term under such
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`circumstances “could well encroach upon the fact-finder’s domain”); see also, e.g.,
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`QXMédical, LLC v. Vascular Sols., LLC, No. 17-cv-1969 (PJS/TNL), 2018 WL 5617568,
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`at *6 (D. Minn. Oct. 30, 2018). Courts depart from the plain and ordinary meaning of a
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`claim term only “when a patentee acts as his own lexicographer” or “when the patentee
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`disavows the full scope of the claim term in the specification or during prosecution.” Poly-
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`Am., L.P. v. API Indus., Inc., 839 F.3d 1131, 1136 (Fed. Cir. 2016).
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`
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`“The intrinsic record in a patent case is the primary tool to supply the context for
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`interpretation of disputed claim terms.” V-Formation, Inc. v. Benetton Grp. SpA, 401 F.3d
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`1307, 1310 (Fed. Cir. 2005) (citing Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576,
`7
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 8 of 54
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`1582 (Fed. Cir. 1996)). Such intrinsic evidence includes “the words of the claims
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`themselves, the remainder of the specification, [and] the prosecution history,” which
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`“consists of the complete record of the proceedings before the [Patent and Trademark
`
`Office (“PTO”)] and includes the prior art cited during the examination of the patent.”
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`Phillips, 415 F.3d at 1314, 1317 (citations omitted). The prosecution history of a parent
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`application also constitutes intrinsic evidence that may be useful in construing claim terms.
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`Elkay Mfg. Co. v. Ebco Mfg. Co., 192 F.3d 973, 980 (Fed. Cir. 1999). “[T]he specification
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`‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it
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`is the single best guide to the meaning of a disputed term.’” Phillips, 415 F.3d at 1315
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`(quoting Vitronics Corp., 90 F.3d at 1582).
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`
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`Courts also may rely on “extrinsic evidence”—that is, “all evidence external to the
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`patent and prosecution history, including expert and inventor testimony, dictionaries, and
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`learned treatises.” Phillips, 415 F.3d at 1317 (citations omitted). Extrinsic evidence “can
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`shed useful light on the relevant art,” but it “is less significant than the intrinsic record in
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`determining the legally operative meaning of disputed claim language.” C.R. Bard, Inc. v.
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`U.S. Surgical Corp., 388 F.3d 858, 862 (Fed. Cir. 2004) (internal quotation marks and
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`citation omitted); see Phillips, 415 F.3d at 1317. Extrinsic evidence is “less reliable” than
`
`intrinsic evidence and may not be used to contradict intrinsic evidence. Phillips, 415 F.3d
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`at 1318; see Mantech Env’t Corp. v. Hudson Env’t Servs., Inc., 152 F.3d 1368, 1373 (Fed.
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`Cir. 1998).
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`
`
`8
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 9 of 54
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`III
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`The Parties dispute the meaning of seventeen claim terms. See Joint Claim
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`Construction Statement at 2–5 [ECF No. 75]. Most of these disputed terms appear in one
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`of four independent claims in the patents-in-suit.
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`The first independent claim is Claim 13 of the ’415 patent, which provides in its
`
`entirety:
`
`13. A method for producing an oxygenated aqueous
`composition comprising:
`
`
`flowing water at a flow rate no greater than 12 gallons
`per minute through an electrolysis emitter comprising
`an electrical power source electrically connected to an
`anode electrode and a cathode electrode contained in a
`tubular housing,
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
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`causing electricity to flow from the power source to the
`electrodes, and,
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`producing the composition comprising a suspension
`comprising oxygen microbubbles and nanobubbles
`having a bubble diameter of less than 50 microns,
`wherein:
`
`
`the anode electrode is separated at a critical
`distance from the cathode such that the critical
`distance is from 0.005 inches to 0.140 inches;
`
`
`
`
`
`
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`the power source produces a voltage no greater
`than about 28.3 volts and an amperage no greater
`than about 13 amps,
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`the tubular housing has an inlet and an outlet and
`a tubular flow axis from the inlet to the outlet;
`
`the water flows in the inlet, out the outlet, is in
`fluid connection with the electrodes, and the
`water flowing into the inlet has a conductivity
`9
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`

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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 10 of 54
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`produced by the presence of dissolved solids
`such that the water supports plant or animal life.
`
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`JA16 at 11:20–45. The next is Claim 13 of the ’092 patent, which provides as follows:
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`13. A method for treating water comprising:
`
`
`providing a flow-through oxygenator comprising an
`emitter for electrolytic generation of bubbles of oxygen,
`the emitter including:
`
`
`
`
`
`
`
`
`
`
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`a tubular housing having a water inlet, a water
`outlet, and a longitudinal water flow axis from
`the inlet to the outlet;
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`at least two electrodes comprising a first
`electrode and a second electrode, the first and
`second electrodes being positioned in the tubular
`housing,
`the first electrode opposing and
`separated from the second electrode by a
`distance of between 0.005 inches to 0.140 inches
`within the tubular housing;
`
`each electrode of the emitter is positioned so that
`substantially all points midway between all
`opposing electrodes are closer to a surface of the
`tubular housing than to a center point within the
`tubular housing and so that at least some water
`may flow from the water inlet to the water outlet
`without passing
`through a space between
`electrodes of opposite polarity separated by a
`distance of between 0.005 inches to 0.140
`inches;
`
`a power source in electrical communication with
`the electrodes, the power source configured to
`deliver a voltage to the electrodes, the voltage
`being less than or equal to 28.3 volts, the power
`source being configured to deliver a current to
`the electrodes, the current being less than or
`equal to 12.8 amps;
`
`
`
`10
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`

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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 11 of 54
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`passing water through the tubular housing while
`electrical current is applied to the electrodes producing
`oxygen in said water via electrolysis.
`
`
`JA33 at 11:53–12:17. The third is Claim 13 of the ’665 patent, which discloses:
`
`13. An emitter for electrolytic generation of bubbles of oxygen
`in water, the emitter comprising:
`
`
`a tubular housing having a water inlet, a water outlet,
`and a longitudinal water flow axis from the inlet to the
`outlet;
`
`
`
`
`
`
`
`
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`
`
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`at least two electrodes comprising a first electrode and
`a second electrode, the first and second electrodes being
`positioned in the tubular housing, the first electrode
`opposing and separated from the second electrode by a
`distance of between 0.005 inches to 0.140 inches within
`the tubular housing;
`
`each electrode of the emitter is positioned so that all
`points midway between all opposing electrodes are
`closer to a surface of the tubular housing than to a center
`point within the tubular housing and so that at least
`some water may flow from the water inlet to the water
`outlet without passing through a space between
`electrodes of opposite polarity separated by a distance
`of between 0.005 inches to 0.140 inches;
`
`a power source in electrical communication with the
`electrodes, the power source configured to deliver a
`voltage to the electrodes, the voltage being less than or
`equal to 28.3 volts, the power source being configured
`to deliver a current to the electrodes, the current being
`less than or equal to 12.8 amps;
`
`the power source being operable to deliver electrical
`current to the electrodes while water flows through the
`tubular housing and is in contact with the electrodes to
`produce oxygen in said water via electrolysis.
`
`11
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`

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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 12 of 54
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`JA54 at 11:39–67. The fourth independent claim is Claim 27 of the ’092 patent, which
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`discloses:
`
`27. An emitter for electrolytic generation of bubbles of oxygen
`in water, the emitter comprising:
`
`
`a tubular housing defining an oxygenation chamber and
`having a water inlet, a water outlet, a longitudinal water
`flow axis from the inlet to the outlet, and an inward-
`facing surface that runs parallel to the water flow axis
`and defines at least in part the oxygenation chamber;
`
`
`
`
`
`
`
`
`
`
`
`at least two electrodes comprising an outside electrode
`and an inside electrode, the outside and inside
`electrodes being positioned
`in
`the oxygenation
`chamber, said outside and inside electrodes extending
`in a direction that is parallel to the longitudinal axis, the
`outside electrode opposing and separated from the
`inside electrode by a distance of between 0.005 inches
`and 0.140 inches within the chamber,
`
`wherein the position and size of each electrode within
`the chamber defines a cross-section of the chamber that
`has a water flow area within the oxygenation chamber
`through which water may flow without passing between
`electrodes of opposite polarity that are separated by a
`distance of between 0.005 inches to 0.140 inches,
`wherein the water flow area is greater than an area at the
`cross-section equal to the total area between electrodes
`of opposite polarity that are separated by a distance of
`between 0.005 inches to 0.140 inches,
`
`wherein at least a portion of the outside electrode
`positioned in the chamber is closer to the inward-facing
`surface of
`the oxygenation chamber
`than
`to a
`longitudinal center axis of the oxygenation chamber;
`and
`
`a power source in electrical communication with the
`outside and inside electrodes, the power source
`configured to deliver a voltage to the outside and inside
`electrodes, the voltage being less than or equal to 28.3
`12
`
`

`

`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 13 of 54
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`volts, the power source being configured to deliver a
`current to the outside and inside electrodes, the current
`being less than or equal to 12.8 amps.
`
`JA34 at 13:40–14:9. Shorter dependent claims will be introduced below in connection
`
`with the relevant disputed term.
`
`A2
`
`
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`The first two disputed claim terms are “water” and “nanobubble.” Although the
`
`Parties’ arguments surrounding these terms do not overlap completely, the terms have
`
`
`Several times throughout its briefing, Oxygenator argues that Tennant’s claim-
`2
`construction positions are inconsistent with the positions Tennant has raised in two
`petitions for inter partes review (“IPR”) it has filed with respect to the patents-in-suit. See
`Louwagie Decl., Exs. 1, 2 [ECF Nos. 80-1, 80-2]. Oxygenator does not cite authority for
`these arguments or explain why the positions Tennant is taking before the PTAB should
`affect claim construction at this time.
`
`
`Although Oxygenator never uses the phrases, these arguments seem meant to invoke
`the concept of judicial estoppel. “[W]here a party assumes a certain position in a legal
`proceeding, and succeeds in maintaining that position, he may not thereafter, simply
`because his interests have changed, assume a contrary position, especially if it be to the
`prejudice of the party who has acquiesced in the position formerly taken by him.” Trs. in
`Bankr. of N. Am. Rubber Thread Co. v. United States, 593 F.3d 1346, 1353 (Fed. Cir. 2010)
`(quoting New Hampshire v. Maine, 532 U.S. 742, 749 (2001)). The decision whether to
`estop a party from asserting an argument depends on three non-exclusive factors: “(1)
`whether the party’s position is clearly inconsistent with its earlier position; (2) whether the
`party has succeeded in persuading a court to accept that party’s earlier position, so that
`judicial acceptance of an inconsistent position in a later proceeding would create the
`perception that either the first or the second court was misled; and (3) whether the party
`seeking to assert an inconsistent position would derive an unfair advantage or impose an
`unfair detriment on the opposing party if not estopped.” Id. at 1354 (internal quotation
`marks and citation omitted).
`
`These factors do not favor estoppel here. To be sure, Oxygenator has identified
`tension between some of Tennant’s IPR positions and some of its proposed constructions.
`Oxygenator points out that, instead of pressing its claim-construction positions in the IPR
`proceeding, Tennant raised validity arguments that seem more consistent with
`Oxygenator’s preferred constructions. See, e.g., Oxygenator Br. at 4–5 [ECF No. 78].
`13
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 14 of 54
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`something important in common: the specification purports to define both under the
`
`heading, “Definitions”:
`
`For the purpose of describing the present invention the
`following terms have these meanings:
`. . .
`
`“Nanobubble” means a bubble with a diameter less than
`that necessary to break the surface tension of water.
`Nanobubbles remain suspended in the water, giving the water
`an opalescent or milky appearance.
`. . .
`
`“Water” means any aqueous medium with resistance
`less than one ohm per square centimeter; that is, a medium that
`can support the electrolysis of water. In general, the lower
`limit of resistance for a medium that can support electrolysis is
`water containing more than 2000 ppm total dissolved solids.
`
`
`JA12 at 3:66–67, 4:12–14, 22–26.
`
`1
`
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`Start with “water.” Oxygenator argues that the construction of this term should be
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`a shorter, simpler version of the specification’s definition: “an aqueous medium that can
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`support the electrolysis of water.” Joint Claim Construction Statement at 2 [ECF No. 75];
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`Oxygenator Br. at 7–17. It asserts that the reference in the definition’s first sentence to a
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`“resistance less than one ohm per square centimeter” is “not strictly accurate” because, if
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`Whether or not this amounts to “clear[]” inconsistency, as opposed to just legitimate
`strategy, is beside the point. The record does not show that Tennant has prevailed in IPR
`based on any of these positions, and because it has not, it is hard to see how it could derive
`any unfair advantage if it were to prevail on its claim construction positions here. See Trs.
`of Columbia Univ. v. NortonLifeLock, Inc., No. 3:13cv808, 2019 WL 7040931, at *4–6
`(E.D. Va. Dec. 20, 2019) (applying judicial estoppel when litigant prevailed on one claim
`construction in IPR proceedings before raising a contrary proposed construction in district
`court). For these reasons, it is unnecessary to address Oxygenator’s estoppel arguments
`with any greater specificity.
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`taken literally, that limitation would exclude “ordinary tap water”—an “absurd result” that
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`is inconsistent with the rest of the intrinsic record. Id. at 7–9. Oxygenator argues that the
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`second sentence of the specification’s definition has no place in the construction of “water”
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`because it is “not definitional.” Id. at 15–16.
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`Tennant’s primary position is based on the principle that “[w]hen a patentee defines
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`a claim term, the patentee’s definition governs, even if it is contrary to the conventional
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`meaning of the term.” Honeywell Int’l v. Universal Avionics Sys. Corp., 493 F.3d 1358,
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`1361 (Fed. Cir. 2007). According to Tennant, Oxygenator’s decision to locate its definition
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`of “water” under the “Definitions” heading means that Oxygenator is stuck with its chosen
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`definition no matter what. Tennant Br. at 10–11 [ECF No. 76]; see Joint Claim
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`Construction Statement at 2, 4. At the claim-construction hearing, Tennant seemed to
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`characterize this rule as nearly absolute.
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`Tennant has cited, and research has disclosed, no case or other authority expressing
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`the rule as Tennant advances it. The better understanding is that the law is not so rigid and
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`that, when a patentee’s chosen definition (even if it appears under the heading
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`“Definitions”) is, to a person of ordinary skill in the art, ambiguous, vague, or perhaps even
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`indecipherable, a court must look beyond the chosen definition to construe the term. This
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`is because a patentee must “define the specific terms used to describe his or her invention
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`. . . with reasonable clarity, deliberateness, and precision.” In re Paulsen, 30 F.3d 1475,
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`1480 (Fed. Cir. 1994); see also Typhoon Touch Techs., Inc. v. Dell, Inc., 659 F.3d 1376,
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`1383 (Fed. Cir. 2011). Courts have rejected a patentee’s definition for failing to meet this
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`standard when the definition is “ambiguous,” Merck & Co. v. Teva Pharm. USA, Inc., 395
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`CASE 0:20-cv-00358-ECT-HB Doc. 162 Filed 08/18/21 Page 16 of 54
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`F.3d 1364, 1370–71 (Fed. Cir. 2005), or internally inconsistent, Abbott Labs. v. Syntron
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`Bioresearch, Inc., 334 F.3d 1343, 1354–55 (Fed. Cir. 2003); see also, e.g., Taro Pharm.
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`Indus. Ltd. v. Novitium Pharma, LLC, No. 19-01028 (FLW), 2020 WL 1673045, at *9
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`(D.N.J. Apr. 6, 2020).
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`Deciding whether the patentee defined “water” with “reasonable clarity,
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`deliberateness, and precision” requires the consideration of some extrinsic evidence for
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`context. See Phillips, 415 F.3d at 1317–18. The ability of an aqueous medium to support
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`electrolysis depends on two related features of the medium: conductivity and resistivity.
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`“Conductivity is a measure of how easily electrical current can flow through” the medium.
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`White Decl. ¶ 29 [ECF No. 88]. “Resistivity is the inverse of conductivity and is a measure
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`of the resisting power of” the medium “to the flow of an electrical current.” Id. It is easy
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`for a medium with a high conductivity and a low resistivity to support electrolysis.
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`Conversely, it is difficult for a medium with a low conductivity and a high resistivity to
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`support electrolysis. See id.
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`
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`A medium’s conductivity and resistivity depend, at least in part, on the level of
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`dissolved solids in the medium. More dissolved solids means a higher conductivity (and a
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`lower resistivity). Id. For electrolysis to work, however, there must be a Goldilocks-like
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`level of dissolved solids. Too few dissolved solids, and the resistivity will be too high to
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`support electrolysis; too many, and the resistivity will be too low. Id. ¶¶ 31–32. Although
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`these background facts come from Oxygenator’s expert, the Parties do not seem to dispute
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`them.
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`
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`With that background, it becomes clear that a person of ordinary skill in the art
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`would understand the first sentence of the specification’s definition of “water” to contain
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`a mistake and a potential inconsistency. To recap, that sentence reads as follows: “‘Water’
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`means any aqueous medium with resistance less than one ohm per square centimeter; that
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`is, a medium that can support the electrolysis of water.” JA12 at 4:22–23. There are a
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`couple of problems with this clause. First, there is a difference between “resistance” and
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`“resistivity.” White Decl. ¶ 35 n.4. Tennant does not dispute that resistivity, not resistance,
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`is the relevant measure in determining water’s utility for electrolysis. Second, “ohms per
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`square centimeter” are not the units used to express resistivity or resistance; instead, an
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`appropriate unit would be “ohms-centimeters.” Id. ¶ 35; Suppl. Donels Decl., Ex. B at
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`66:18–25 [ECF No. 144-1]. These discrepancies at best introduce a degree of ambiguity—
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`and at worst, meaninglessness—to the first clause.
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`
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`Tennant suggests “correcting” the mistakes as follows:
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`Water means any aqueous medium with resistivity less than
`one ohm-centimeter, that is, a medium that can support the
`electrolysis of water.
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`Tennant Resp. Br. at 4 [ECF No. 143]. Tennant’s proposal introduces an internal
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`inconsistency in the first sentence. Extrinsic evidence shows that an aqueous medium with
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`a resistivity below 1 ohm-centimeter could not support the electrolysis of water, and it
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`would exclude most everyday forms of water, including lake, river, tap, and ocean water.
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`See Oxygenator Resp. Br. at 4 [ECF No. 145]. In other words, under Tennant’s proposal,
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`the first and second clauses of the first sentence would contradict each other.
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`Given this context, the specification and prosecution history support leaving the first
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`clause out of the construction of “water.” The examples in the specification contemplate
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`increasing the oxygen content of water used to water plants and support aquatic life. See
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`JA12–JA15. A person of ordinary skill in the art would not understand the word “water”
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`as used therein to exclude tap water and other forms of natural freshwater in favor of a
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`specialized form of water with extremely low resistivity. Indeed, at least one example in
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`the specification describes the use of “plain tap water” as a control used to test the
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`effectiveness of “oxygenated water.” JA14 at 8:21. The patentee’s statements during the
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`prosecution of the ’415 patent are consistent with this understanding. When discussing the
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`phrase “water[] having a conductivity produced by dissolved solids so that the . . . water[]
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`is capable of supporting plant or animal life”—logically, a subset of the general term
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`“water”—the applicant stated that the phrase was meant to “cover[] potable water delivered
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`by a municipal water treatment plant in addition to well water, lake water and irrigation
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`water,” as well as “[w]ater used to clean clothes, wash floors and water plants[.]” JA 1142–
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`43.
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`
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`The remaining question is whether the construction of “water” should include the
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`second sentence of the specification’s definition: “In general, the lower limit of resistance[3]
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`for a medium that can support electrolysis is water containing more than 2000 ppm total
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`dissolved solids.” JA12 at 4:24–26. The correct answer is not obvious. After all, the
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`patentee included the sentence in a set-off section of definitions under the heading,
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`If the second sentence were included, then it would seem appropriate to change the
`3
`word “resistance” to “resistivity” for the reasons discussed above.
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`CASE 0:20-cv-00358-ECT-HB Do