6,371,977 was Aquatex's hammer.

AquaTex contends that Techniche’s evaporative cooling garments and products infringe the ’977 patent either literally or under the doctrine of equivalents.

The ’977 patent claims a method of cooling a person through evaporation by providing a multi-layered, liquid-retaining composite material comprising a fiberfill batting, and either hydrophilic polymeric fibers or hydrophilic polymeric particles. The technology is suited for use in a wide variety of items such as protective garments, blankets, and compresses. In general terms, practice of the patented method involves soaking a composite material in a liquid for a matter of minutes, wringing out the excess liquid, and then placing the material or garment against a person for cooling by evaporation.

Because the ’977 patent claims the use of evaporative cooling garments, rather than the actual multi-layer fabric itself, AquaTex’s cause of action is one for contributory infringement under 35 U.S.C. § 271(c). Although not directly infringing, a party may still be liable for inducement or contributory infringement of a method claim if it sells infringing devices to customers who use them in a way that directly infringes the method claim. R.F. Del., Inc. v. Pac. Keystone Techs., Inc., 326 F.3d 1255, 1267 (Fed. Cir. 2003). “Liability for either active inducement of infringement or for contributory infringement is dependent upon the existence of direct infringement.” Joy Techs., Inc. v. Flakt, Inc., 6 F.3d 770, 774 (Fed. Cir. 1993).

“An infringement analysis entails two steps. First, the meaning and scope of the asserted patent claims is determined, and then the properly construed claims are compared to the accused product or process.” Ranbaxy Pharms., Inc. v. Apotex, Inc., 350 F.3d 1235, 1239-40 (Fed. Cir. 2003) (citing Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed. Cir. 1998) (en banc)).

Claim Scope

Phillips v AWH again acted as the touchstone for preferring intrinsic evidence over extrinsic.

To ascertain the meaning of a disputed claim term “the words of a claim are generally given their ordinary and customary meaning,” as would be understood by “a person of ordinary skill in the art in question at the time of the invention, i.e., as of the effective filing date of the patent application.” Phillips v. AWH Corp., 415 F.3d 1303, (Fed. Cir. 2005) (en banc). The specification is of central importance in construing claims because “the person of ordinary skill in the art is deemed to read the claim term not only in the context of the particular claim in which the disputed term appears, but in the context of the entire patent, including the specification.” Id. at *24. Where, as here, the disputed claim term is technical or a term of art, “[t]he best source for understanding [it] is the specification from which it arose, informed, as needed, by the prosecution history.” Id. at *30 (quoting Multiform Desiccants, Inc. v. Medzam Ltd., 133 F.3d 1473, 1478 (Fed. Cir. 1998)). Along with the intrinsic evidence of record, including the prosecution history, extrinsic evidence can be useful in claim construction and “technical dictionaries may provide [help] to a court ‘to better understand the underlying technology’ and the way in which one of skill in the art might use the claim terms.” Id. at *38 (quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1584 (Fed. Cir. 1996)).

Techniche’s accused products used the fiberfill Vizorb®.

The claim limitation disputed by the parties is “fiberfill batting material,” and the primary issue is whether it should be construed to encompass only synthetic fibers as the trial court held. Resolution of the claim construction issue then controls whether Vizorb® constitutes “fiberfill” as required by the ’977 patent for literal infringement because Vizorb® contains a combination of natural and synthetic fibers. Whether Techniche is liable for contributory infringement depends upon this issue.

In the detailed description of the invention, AquaTex dictated that “[t]he particular fiberfill is not known to be critical. That is, any commercial fiberfill may be used as long as it does not adversely affect the performance of the end composite.” ’977 patent, col. 3, ll. 47-50. From this statement, the patentee has informed the public that any commercial fiberfill that is capable of performing the claimed functions will suffice.

Three patents had been incorporated into the specification. These patents indicated fiberfill as being comprised of synthetic fibers.

Because AquaTex chose to incorporate by reference the teachings of three United States Patents to define the scope of the term “fiberfill,” these publications are highly relevant to one of ordinary skill in the art for ascertaining the breadth of the claim term... None of the patents discusses the possibility of using natural fibers as commercial fiberfill batting.

“In addition to consulting the specification . . . a court ‘should also consider the patent’s prosecution history, if it is in evidence.’” Phillips, 415 F.3d at __ (quoting Markman v. Westview Instr., Inc., 52 F.3d 967, 980 (Fed. Cir. 1995) (en banc)).

The CAFC disagreed with the district court, finding the prosecution history ambiguous about defining fiberfill, but technical dictionaries agreed with Techniche's preferential definition of fiberfill.

The extrinsic evidence of record, in the form of technical dictionaries, supports construing “fiberfill” as a purely synthetic fiber because it is consistently defined as such.

So, with something of a mixed record as to how to define fiberfill, and the issue of literal infringement hanging in the balance...

While we adhere to the adage that limitations from the specification must not be imported into the claims, see, e.g., Nazomi Communications, Inc. v. ARM Holdings, PLC, 403 F.3d 1364, 1369 (Fed. Cir. 2005), based upon the teachings of the specification, one of ordinary skill in the textile manufacturing industry would understand that commercial “fiberfill batting material” is made of synthetic or polyester fibers. The combined teachings within the specification of the ’977 patent, the patents incorporated by reference, and the consistent interpretations in the industry publications would lead one skilled in the art to this conclusion. Therefore, we affirm the district court’s determination that the accused Techniche products do not literally infringe claims 1 and 9 of the ’977 patent.

Applying The Doctrine of Equivalents

However, “[t]he doctrine of equivalents allows the patentee to claim those insubstantial alterations that were not captured in drafting the original patent claim but which could be created through trivial changes.” Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 733 (2002) (“Festo II”). Infringement under the doctrine of equivalents requires that the accused product contain each limitation of the claim or its equivalent. Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 40 (1997). An element in the accused product is equivalent to a claim limitation if the differences between the two are insubstantial. The analysis focuses on whether the element in the accused device “performs substantially the same function in substantially the same way to obtain the same result” as the claim limitation. Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 608 (1950) (internal quotation omitted).

Prosecution history estoppel can prevent a patentee from relying on the doctrine of equivalents when the patentee relinquishes subject matter during the prosecution of the patent, either by amendment or argument. Pharmacia & Upjohn Co. v. Mylan Pharm., Inc., 170 F.3d 1373, 1376-77 (Fed. Cir. 1999). “The doctrine of prosecution history estoppel limits the doctrine of equivalents when an applicant makes a narrowing amendment for purposes of patentability, or clearly and unmistakably surrenders subject matter by arguments made to an examiner.” Salazar, 2005 U.S. App. LEXIS 13517, at *6; see Festo II, 535 U.S. at 736 (narrowing amendment for purposes of patentability); Eagle Comtronics, Inc. v. Arrow Communication Labs., Inc., 305 F.3d 1303, 1316 (Fed. Cir. 2002) (argument-based estoppel).

Techniche did not proffer the normal argument for prosecution estoppel a la Festo - limitation by claim amendment; instead, arguing that the prosecutor had overtly disavowed equivalence during prosecution. But the CAFC caught the district court out for wrongly falling for an apples-and-oranges comparison.

While at least one claim limitation was added here to overcome an anticipation rejection during the prosecution of the patent, Techniche does not allege amendment-based estoppel. Instead it asserts argument-based estoppel. To invoke argument-based estoppel, the prosecution history “must evince a clear and unmistakable surrender of subject matter.” Pharmacia, 170 F.3d at 1377 (internal quotation omitted). To determine if subject matter has been relinquished, an objective test is applied, inquiring “whether a competitor would reasonably believe that the applicant had surrendered the relevant subject matter.” Cybor Corp., 138 F.3d at 1457.

We do not see the clear and unmistakable surrender of subject matter required to invoke argument-based prosecution history estoppel. During prosecution of the ’977 patent AquaTex stated that “the ’297 Patent fails to disclose or suggest the fiberfill batting and polymeric fibers and/or particles of the composite material in the claimed method.” Techniche and the trial court believe this argument limited claim coverage of fiberfill to only synthetic fibers. The argument, however, does not address or even relate to the composition of the fiberfill batting. Rather, it was based on the ’297 patent not teaching or suggesting the overall composition of materials, or the use of the disclosed compress to cool a person through evaporation.

The arguments made during prosecution, and the corresponding addition of the claim limitation “by evaporation,” indicate that AquaTex was distinguishing the overall method of cooling of its claimed invention from that of the ’297 patent. The subject matter surrendered by the narrowing amendment bears no relation to the composition of the fiberfill batting material. There is no indication in the prosecution history whether or not AquaTex agreed or disagreed with the examiner’s statement that the fiberfill found in the prior art comprised natural fibers. Thus, the trial court erred in holding that prosecution history estoppel barred AquaTex from asserting infringement under the doctrine of equivalents.

So, the issue of claim construction and literal infringement hinging on the definition of the composition of fiberfill became moot, as Techniche is subject to contributory infringement under the doctrine of equivalents, because of the method of using the compress for evaporative cooling: how a customer would use the accused product, not the product itself per se.