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Patent Law: The Patent Prospector
By Gary Odom and Jordan Kuhn
Halliburon sued M-I for infringing 6,887,832, claiming oil drilling using fragile gels for drilling fluid. The problem was that "fragile gel" was ill-defined, leading to invalidity under 35 U.S.C. § 112, ¶ 2. Irresolvable ambiguity to one skilled in the art is the yardstick of indefiniteness. The CAFC pens a claim construction classic on delineation of claim term definiteness.
Halliburon Energy Services v. M-I (CAFC 2007-1149)
Indefiniteness defined by clarity of metes and bounds.
35 U.S.C. § 112, ¶ 2 requires that the specification of a patent ?conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.? Because claims delineate the patentee?s right to exclude, the patent statute requires that the scope of the claims be sufficiently definite to inform the public of the bounds of the protected invention, i.e., what subject matter is covered by the exclusive rights of the patent. Otherwise, competitors cannot avoid infringement, defeating the public notice function of patent claims. Athletic Alternatives, Inc. v. Prince Mfg., Inc., 73 F.3d 1573, 1581 (Fed. Cir. 1996) (?[T]he primary purpose of the requirement is ?to guard against unreasonable advantages to the patentee and disadvantages to others arising from uncertainty as to their [respective] rights.??) (quoting Gen. Elec. Co. v. Wabash Appliance Corp., 304 U.S. 364, 369, (1938)). The Supreme Court has stated that ?[t]he statutory requirement of particularity and distinctness in claims is met only when [the claims] clearly distinguish what is claimed from what went before in the art and clearly circumscribe what is foreclosed from future enterprise.? United Carbon Co. v. Binney & Smith Co., 317 U.S. 228, 236 (1942).
This court has applied the definiteness requirement of 35 U.S.C. § 112, ¶ 2 in numerous circumstances. For example, we have held claims indefinite where a claim recites means-plus-function elements without disclosing corresponding structure in the specification, Biomedino, LLC v. Waters Techs. Corp., 490 F.3d 946, 950 (Fed. Cir. 2007), includes a numeric limitation without disclosing which of multiple methods of measuring that number should be used, Honeywell Int?l, Inc. v. Int?l Trade Comm?n, 341 F.3d 1332, 1340 (Fed. Cir. 2003), and contains a term that is ?completely dependent on a person?s subjective opinion,? Datamize, 417 F.3d at 1350. We have also stated that a claim could be indefinite if a term does not have proper antecedent basis where such basis is not otherwise present by implication or the meaning is not reasonably ascertainable. Energizer Holdings, Inc. v. Int?l Trade Comm?n, 435 F.3d 1366, 1370-71 (Fed. Cir. 2006). The common thread in all of these cases is that claims were held indefinite only where a person of ordinary skill in the art could not determine the bounds of the claims, i.e., the claims were insolubly ambiguous.
Of course, claims are not indefinite merely because they present a difficult task of claim construction. Instead, ?[i]f the meaning of the claim is discernible, even though the task may be formidable and the conclusion may be one over which reasonable persons will disagree, we have held the claim sufficiently clear to avoid invalidity on indefiniteness grounds.? Exxon Research & Eng?g Co. v. United States, 265 F.3d 1371, 1375 (Fed. Cir. 2001) (citations omitted). Proof of indefiniteness requires such an exacting standard because claim construction often poses a difficult task over which ?expert witnesses, trial courts, and even the judges of this court may disagree.? Id. Nevertheless, this standard is met where an accused infringer shows by clear and convincing evidence that a skilled artisan could not discern the boundaries of the claim based on the claim language, the specification, and the prosecution history, as well as her knowledge of the relevant art area.
What drilling fluid is good for in oil wells -
In the process of drilling such wells, drilling fluid is used for a variety of purposes, such as ?removing drill cuttings from the wellbore, cooling and lubricating the drill bit, aiding in support of the drill pipe and drill bit, and providing a hydrostatic head to maintain the integrity of the wellbore walls and prevent well blowouts.? ?832 patent col.1 ll.27-31.
The term "fragile gel," though appearing only in the preamble of the claims, was crucial.
During prosecution, Halliburton distinguished the claims of the ?832 patent from prior art fluids by stating that the claims were ?limited to? a ?fragile gel? drilling fluid or the method of using a ?fragile gel? drilling fluid. Thus, although the term ?fragile gel? appears only in the preamble of the asserted independent claims, Halliburton concedes that the claimed drilling fluids are limited to those that are ?fragile gels.? Pitney Bowes, Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1305 (Fed. Cir. 1999) (?If the claim preamble, when read in the context of the entire claim, recites limitations of the claim, or, if the claim preamble is ?necessary to give life, meaning, and vitality? to the claim, then the claim preamble should be construed as if in the balance of the claim.?) (citations omitted). The specification defines ?fragile gels? as follows:
A ?fragile gel? as used herein is a ?gel? that is easily disrupted or thinned, and that liquifies or becomes less gel-like and more liquid-like under stress, such as caused by moving the fluid, but which quickly returns to a gel when the movement or other stress is alleviated or removed, such as when circulation of the fluid is stopped, as for example when drilling is stopped. The ?fragileness? of the ?fragile gels? of the present invention contributes to the unique and surprising behavior and advantages of the present invention. The gels are so ?fragile? that it is believed that they may be disrupted by a mere pressure wave or a compression wave during drilling. They seem to break instantaneously when disturbed, reversing from a gel back into a liquid form with minimum pressure, force and time and with less pressure, force and time than known to be required to convert prior art fluids from a gel-like state into a flowable state.
?832 patent col.2 ll.26-42.
Lack of objective definition was killer to the district court; the CAFC affirmed.
[T]he definition of fragile gel in the specification and found that it was too subjective and unclear because it relied on terms such as ?easily transitions,? ?easily disrupted or thinned,? ?less gel-like,? ?more liquid-like,? ?quickly returns to a gel,? ?break instantaneously,? and ?minimum pressure, force, and time.?
In this case, the district court found that the asserted claims, which contained the limitation that the drilling fluid be a ?fragile gel,? were indefinite. ?Only claims ?not amenable to construction? or ?insolubly ambiguous? are indefinite.? Datamize, 417 F.3d at 1347 (citing Novo Indus., L.P. v. Micro Molds Corp., 350 F.3d 1348, 1353 (Fed. Cir. 2003); Honeywell, 341 F.3d at 1338; Exxon Research, 265 F.3d at 1375). Because we conclude that neither Halliburton?s proposed definition nor any other possible construction resolves the ambiguity in the scope of the term ?fragile gel,? we agree with the district court that claims containing that term are indefinite.
The fact that Halliburton can articulate a definition supported by the specification, however, does not end the inquiry. Even if a claim term?s definition can be reduced to words, the claim is still indefinite if a person of ordinary skill in the art cannot translate the definition into meaningfully precise claim scope. Having reviewed the remaining two parts of Halliburton?s proposed construction, both individually and in combination, in the context of the intrinsic record and the knowledge of a person of ordinary skill in the art, we hold that the ambiguity as to the scope of ?fragile gel? cannot be resolved.
Suggesting a narrow construction may help resolve ambiguity, but in this case, Halliburton's greed was its downfall.
We note that where a claim is ambiguous as to its scope we have adopted a narrowing construction when doing so would still serve the notice function of the claims. See Athletic Alternatives, 73 F.3d at 1581 (?Where there is an equal choice between a broader and a narrower meaning of a claim, and there is an enabling disclosure that indicates that the applicant is at least entitled to a claim having the narrower meaning, we consider the notice function of the claim to be best served by adopting the narrower meaning.?). In this case, however, Halliburton asks that we resolve the ambiguity in a way that gives it the broadest possible construction (i.e., that its claim covers all future improvements without regard to whether Halliburton invented such improvements); such a construction would undermine the notice function of the claims because it would allow Halliburton to benefit from the ambiguity, rather than requiring Halliburton to give proper notice of the scope of the claims to competitors. Additionally, adopting the broadest possible construction could retard innovation because cautious competitors may steer too far around that which Halliburton actually invented, neglecting improvements that otherwise might be made.
Halliburton had argued that the definition was clear enough in light of the prior art, but that prior art anticipation was altogether a different challenge. Not so: prior art differentiation can be illuminating in claim construction.
Halliburton argues, however, that whether the prior art (i.e., 12.1 SF fluid) is covered by the claim as construed is properly addressed in validity challenges of other types (anticipation, obviousness, etc.) rather than in claim construction or in evaluating definiteness. We disagree that the evaluation of a claim?s definiteness cannot include whether the patent expressly or at least clearly differentiates itself from specific prior art. Such differentiation is an important consideration in the definiteness inquiry because in attempting to define a claim term, a person of ordinary skill is likely to conclude that the definition does not encompass that which is expressly distinguished as prior art.
Of course, that is not to suggest that a claim can never be definite and yet read on the prior art. For example, a claim that recites a specific numeric range for a physical property may be definite even though prior art products fell within that range. In such a case, a person of ordinary skill in the art would know the boundaries of the claim, and the focus would properly be on other validity challenges (e.g., anticipation).
But that is an aside in this case.
Halliburton?s failure to distinguish the fragileness of the drilling fluids of the invention from the close prior art (the 12.1 SF fluid that exhibited the L-shaped curve behavior) is fatal. Amgen, Inc. v. Chugai Pharm. Co., Ltd., 927 F.2d 1200, 1218 (Fed. Cir. 1991) (holding that the term ?at least about? was indefinite because the patent provided no guidance as to where the line should be drawn between the numerical value of the prior art cited in the prosecution history and the close numerical value in the patent); see also Verve, LLC v. Crane Cams, Inc., 311 F.3d 1116, 1119-20 (Fed. Cir. 2002) (recognizing that guidance as to measurement of a term of degree can come from the intrinsic record or from the knowledge of a person of ordinary skill in the art).
By failing to identify the degree of the fragility of its invention, Halliburton?s proposed definition would allow the claims to cover not only that which it invented that was superior to the prior art, but also all future improvements to the gel?s fragility. While patentees are allowed to claim their inventions broadly, they must do so in a way that distinctly identifies the boundaries of their claims.
Halliburton also tried functional definition, to no effect. There is nothing wrong with functional definition, as long as the definition is clear.
We also note that the two parts of Halliburton?s proposed definition discussed above (ability of the fluid to transition quickly from gel to liquid, and the ability of the fluid to suspend drill cuttings at rest) are functional, i.e., the fluid is defined ?by what it does rather than what it is.? In re Swinehart, 439 F.2d 210, 212 (CCPA 1971). The Supreme Court in two early cases identified the dangers of using only functional claim limitations to distinguish the claimed invention from the prior art. In General Electric, the Court held that a vice of functional claiming occurs ?when the inventor is painstaking when he recites what has already been seen, and then uses conveniently functional language at the exact point of novelty.? General Electric, 304 U.S. at 371 (holding claims invalid where the grains of the claimed lighting filament were distinguished from the prior art only because they were ?of such size and contour as to prevent substantial sagging and offsetting? of the filament during the commercially useful life of the lamp). Likewise, in United Carbon, the Court held indefinite claims that recited only ?inaccurate suggestions of the functions of the product.? United Carbon, 317 U.S. at 234 (holding indefinite patent claims that recited, for example, ?sustantially (sic) pure carbon black in the form of commercially uniform, comparatively small, rounded smooth aggregates having a spongy or porous exterior?).
Although our predecessor court later recognized that ?there is nothing intrinsically wrong with? using functional language in claims, it noted that in some instances, use of functional language can fail ?to provide a clear-cut indication of the scope of subject matter embraced by the claim? and thus can be indefinite. Swinehart, 439 F.2d at 212-13 (holding that the term ?transparent? was definite because the disclosure, which showed that a substantial amount of infrared radiation was always transmitted even though the precise degree of transparency varied depending on certain factors, was sufficiently clear).
When a claim limitation is defined in purely functional terms, the task of determining whether that limitation is sufficiently definite is a difficult one that is highly dependent on context (e.g., the disclosure in the specification and the knowledge of a person of ordinary skill in the relevant art area). We note that the patent drafter is in the best position to resolve the ambiguity in the patent claims, and it is highly desirable that patent examiners demand that applicants do so in appropriate circumstances so that the patent can be amended during prosecution rather than attempting to resolve the ambiguity in litigation.
A patent drafter could resolve the ambiguities of a functional limitation in a number of ways. For example, the ambiguity might be resolved by using a quantitative metric (e.g., numeric limitation as to a physical property) rather than a qualitative functional feature. The claim term might also be sufficiently definite if the specification provided a formula for calculating a property along with examples that meet the claim limitation and examples that do not. See Oakley, Inc. v. Sunglass Hut Int?l, 316 F.3d 1331, 1341 (Fed. Cir. 2003) (holding that, at the preliminary injunction stage, the accused infringer had not shown a substantial question of indefiniteness, where the claims and specification linked the claim term ?vivid colored appearance? to a calculation for differential effect and then provided examples of when differential effect values were and were not sufficient for a ?vivid colored appearance?); see also In re Marosi, 710 F.2d 799, 803 (Fed. Cir. 1983) (finding claims definite where the applicant?s disclosure provided ?a general guideline and examples sufficient? to teach an artisan when the claim limitation was satisfied).
In this case, Halliburton differentiated its invention from the prior art because it was a ?fragile gel.? As discussed above, Halliburton?s proposed definition of that term is not sufficiently definite because it does not adequately distinguish the fragileness of the invention from disclosed prior art, it is ambiguous as to whether an upper bound of fragileness is contemplated, and it is ambiguous as to its requisite ability to suspend drill cuttings. In other words, Halliburton?s proposed construction of ?fragile gel? as used in the claims of the ?832 patent is indefinite because it is ambiguous as to the requisite degree of the fragileness of the gel, the ability of the gel to suspend drill cuttings (i.e., gel strength), and/or some combination of the two. We discern no other construction that can properly be adopted that would render the claims definite.
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