to Foreseeability Estoppel: The
Federal Circuit’s Effort to Limit
the Doctrine of Equivalents
Ping-Hsun Chen*
Introduction
Under 35 U.S.C. § 271(a), a person can literally infringe a patent,1 or infringe
a patent under the doctrine of equivalents (“DOE”).2 The DOE establishes
patent infringement even when some element of the claim cannot be found on the accused product (or process).3 Under DOE, patent infringement is
found if the accused product has an equivalent element insubstantially dif-ferent from the missing element of the claim, or if such equivalent element “performs substantially the same function, in substantially the same way, and accomplishes substantially the same result” as the missing element of the claim.4
As early as Winans v. Denmead5 and O’Reilly v. Morse,6 the Supreme Court
recognized DOE. The landmark case on DOE however, is Graver Tank &
* Assistant Professor, Graduate Institute of Technology, Innovation and Intellectual Property Management, National Chengchi University; J.D. 10’ & LL.M. 08’, Washington University in St. Louis School of Law; LL.M. 07’, National Chengchi University, Taiwan; B.S. 97’ & M.S. 99’ in Chem. Eng., National Taiwan University, Taiwan. Corresponding email: [email protected]. This article is derived from a conference article that was presented in the 2013 National Technology Law Conference, National Chiao Tung University. The author thanks the audience for their comments.
1
See DeMarini Sports, Inc. v. Worth, Inc., 239 F.3d 1314, 1331 (Fed. Cir. 2001) (“Literal infringement of a claim occurs when every limitation recited in the claim appears in the ac-cused device, i.e., when ‘the properly construed claim reads on the acac-cused device exactly.’”).
2 See B. Thomas Watson, Carbons into Bytes: Patented Chemical Compound Protection in
the Virtual World, 12 Duke L. & Tech. Rev. 25, 28–30 (2014).
3 See id. at 29–30. 4
Id. at 30.
5 56 U.S. (15 How.) 330 (1853); see Graver Tank & Mfg. Co. v. Linde Air Prods. Co.,
339 U.S. 605, 608 (1950) (referring to Winans v. Denmead, 56 U.S. (15 How.) 330 (1853)).
6 56 U.S. (15 How.) 62 (1853). See Jay I. Alexander, Cabining the Doctrine of Equivalents
in Festo: A Historical Perspective on the Relationship Between the Doctrines of Equivalents and Prosecution History Estoppel, 51 Am. U.L. Rev. 553, 559 (2002) (considering O’Reilly v.
Manufacturing Co. v. Linde Air Products Co.,7
which illustrates the fundamen-tal ideas of DOE.8
In 1997, the Supreme Court in Warner-Jenkinson Co. v.
Hilton Davis Chemical Co.9
reaffirmed DOE in the post-1952 Patent Act era10
and also confirmed Graver Tank as creating the fundamental rules of DOE.11
DOE leaves the scope of an “equivalent” to an existing patent undefined because what constitutes an equivalent is adjudicated case by case.12
But, courts have imposed some limitations on the application of DOE.13
Among those limitations is prosecution history estoppel (“PHE”) that generally means what was amended or stated regarding a claim during the examina-tion within the United States Patent and Trademark Office may limit a scope of the claim.14
In 2002, the U.S. Supreme Court in Festo Corp. v. Shoketsu
Kinzoku Kogyo Kabushiki Co. (“Festo 2002”).15
finalized the basic doctrine of PHE in the context of claim amendment.16
There, the Supreme Court stated that “a narrowing amendment made to satisfy any requirement of the Patent Act may give rise to an estoppel.”17
That is, a narrowing amendment creates a presumption that a patentee surrenders all equivalents that fall between
7
339 U.S. 605 (1950).
8 See Robert P. Merges, Peter S. Menell & Mark A. Lemley, Intellectual
Prop-erty in the New Technological Age 263 (4th ed. 2006); see also Paul M. Janicke, Heat
of Passion: What Really Happened in Graver Tank, 24 AIPLA Q.J. 1, 4 (1996) (describing
that Graver Tank was the most-cited patent law case “of our time”).
9 520 U.S. 17 (1997). 10
Jeremy T. Marr, Foreseeability as a Bar to the Doctrine of Equivalents, B.C. Intell. Prop. & Tech. F., Oct. 2003, at 2, available at http://bciptf.org/wp-content/uploads/2011/07/37-MARR.pdf.
11 See Warner-Jenkinson, 520 U.S. at 21. 12
See Mark D. Janis & Timothy R. Holbrook, Patent Law’s Audience, 97 Minn. L. Rev. 72, 101 (2012).
13
See id. at 102–11; see also James Farrand et al., “Reform” Arrives in Patent Enforcement:
The Big Picture, 51 IDEA 357, 429–30 (2011) (describing the all elements rule,
prosecu-tion history estoppel, no vitiaprosecu-tion rule, express exclusion rule, disavowal or disclaimer rule, dedication rule, ensnarement rule, and all advantages rule).
14
See generally id. at 102–07.
15 535 U.S. 722 (2002) [hereinafter “Festo 2002”]. 16
Id. at 736–37. PHE can be applied based on arguments made during the prosecution.
See Cordis Corp. v. Medtronic Ave, Inc., 511 F.3d 1157, 1177 (Fed. Cir. 2008) (“[A]n
applicant can make a binding disavowal of claim scope in the course of prosecuting the patent, through arguments made to distinguish prior art references. Such argument-based disavowals will be found, however, only if they constitute clear and unmistakable surrenders of subject matter.”).
17
the original claim and amended claim.18
But, a patentee may overcome such presumption by proving any of three exceptions: the “unforeseeable” excep-tion, the “tangential” excepexcep-tion, and the “other reason” exception.19
Since
Festo 2002, the U.S. Court of Appeals for the Federal Circuit (“Federal
Circuit”) has issued several decisions about those three exceptions to PHE. This article is intended to explore the Federal Circuit case law regarding the “unforeseeable” exception. Specifically, this article discusses the standard for determining whether an accused equivalent would have been “foreseeable.”
In this Article, Part I briefly discusses the concept of DOE. Part II elaborates the PHE rules behind Festo 2002 and the following Federal Circuit decision in 2003 that describes those rules, including the definitions of those three exceptions. Part III analyzes the cases addressing the “unforeseeable” excep-tion. The review of those Federal Circuit cases indicates that any narrowing amendments more likely lead to a finding of foreseeable equivalents.20
I. Doctrine of Equivalents
A. Determination of Equivalency under Graver Tank
The Graver Tank Court developed a flexible standard of DOE,21
requiring that equivalency be “determined against the context of the patent, the prior art, and the particular circumstances of the case.”22
While recognizing the function-way-result test as a standard for proving equivalency,23
the Court did not restrict the determination of equivalency to that test because “[e]quivalence, in the patent law, is not the prisoner of a formula and is not an absolute to be considered in a vacuum.”24
The Graver Tank Court even cautioned that equivalency “does not require complete identity for every purpose and in every respect.”25
Therefore, “things equal to the same thing may not be equal to each other and, by the same token, things for most purposes different may sometimes be equivalents.”26
18
Timothy R. Holbrook, Patents, Presumptions, and Public Notice, 86 Ind. L.J. 779, 813 (2011).
19
Id.
20 One 2007 article has suggested that the Federal Circuit favors the application of PHE
in many circumstances. See Michael Strapp, Prosecution History Estoppel in a Post-Festo World:
How Flexible is the Supreme Court’s “Flexible Bar”?, 25 No. 2 Intell. Prop. L. Newsl. 10,
10–12 (2007).
21 See Graver Tank, 339 U.S. at 609. 22 Id. 23 See id. at 608–09. 24 Id. at 609. 25 Id. 26 Id.
While Professor Timothy R. Holbrook calls the Graver Tank standard “a messy, fact-intensive endeavor[,]”27
the Court did offer four factors for deter-mining equivalency.28
The first three factors include “the purpose for which an ingredient is used in a patent, the qualities it has when combined with the other ingredients, and the function which it is intended to perform.”29
Most importantly, the fourth factor requires courts to consider “whether persons reasonably skilled in the art would have known of the interchangeability of an ingredient not contained in the patent with one that was.”30
B. Additional Rules under Warner-Jenkinson
In 1997, the Warner-Jenkinson Court created two additional rules for ap-plying DOE. The first rule is called the “all-elements rule.”31
As the
Warner-Jenkinson Court noted, “[t]he determination of equivalence should be applied
as an objective inquiry on an element-by-element basis.”32
The rational is that “[e]ach element contained in a patent claim is deemed material to defining the scope of the patented invention[.]”33
So, “the doctrine of equivalents must be applied to individual elements of the claim, not to the invention as a whole.”34
However, the Court also cautioned that “[i]t is important to ensure that the application of the doctrine, even as to an individual element, is not allowed such broad play as to effectively eliminate that element in its entirety.”35
In fact, the all-elements rule was originally created by the Federal Circuit and then adopted by the Supreme Court.36
The modern view is that “courts must consider the totality of the circumstances of each case and determine whether the alleged equivalent can be fairly characterized as an insubstantial change
27 Timothy R. Holbrook, Equivalency and Patent Law’s Possession Paradox, 23 Harv. J.L.
& Tech. 1, 16 (2009).
28 Richard A. Kamprath, Note, Patent Pleading Standards After Iqbal: Applying
Infringe-ment Contentions as a Guide, 13 SMU Sci. & Tech. L. Rev. 301, 313 (2010).
29 Graver Tank, 339 U.S. at 609. 30
Id.
31 See Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 29 (1997); see also
Ethicon Endo-Surgery, Inc. v. U.S. Surgical Corp., 149 F.3d 1309, 1316 (Fed. Cir. 1998); see
also Daniel H. Shulman & Donald W. Rupert, “Vitiating” the Doctrine of Equivalents: A New Patent Law Doctrine, 12 Fed. Circuit B.J. 457, 462–63 (2003) (citing Warner-Jenkinson,
520 U.S. 17, 29 (1997) (describing the background of the All Elements Rule).
32 Warner-Jenkinson, 520 U.S. at 40. 33 Id. at 29. 34 Id. 35 Id. 36
See Nystrom v. Trex Co., 580 F.3d 1281, 1286 (Fed. Cir. 2009) (Rader J., additional views) (“In Warner-Jenkinson, the Supreme Court adopted this court’s established ‘all-elements’ rule.”).
from the claimed subject matter without rendering the pertinent limitation meaningless.”37
The second rule is called “claim vitiation.”38
The Warner-Jenkinson Court mentioned in a footnote that “if a theory of equivalence would entirely vitiate a particular claim element, partial or complete judgment should be rendered by the court, as there would be no further material issue for the jury to resolve.”39
Claim vitiation ensures that DOE “will not vitiate the central functions of the patent claims themselves.”40
Recently, the Federal Circuit in Deere & Co.
v. Bush Hog, LLC41
provided its view on claim vitiation, considering it as “not an exception to the doctrine of equivalents, but instead a legal determina-tion that the evidence is such that no reasonable jury could determine two elements to be equivalent.”42
Therefore, courts can satisfy the determination by “simply noting that an element is missing from the claimed structure or process because the doctrine of equivalents, by definition, recognizes that an element is missing that must be supplied by the equivalent substitute.”43
In addition to those two rules, the Warner-Jenkinson Court provided the proper timing for evaluating equivalency or interchangeability which Graver
Tank did not address. The Warner-Jenkinson Court held that the proper timing
is “the time of infringement, not at the time the patent was issued.”44
Moreover, the Warner-Jenkinson Court expressed its open mind on the case law development of DOE. While cautioning that either the function-way-result test (or, triple identity test45
) or the insubstantial differences test may have its limits,46
without “micromanaging the Federal Circuit’s particular word choice for analyzing equivalence[,]”47
the Warner-Jenkinson Court showed its
37 Freedman Seating Co. v. Am. Seating Co., 420 F.3d 1350, 1359 (Fed. Cir. 2005). 38
See James E. Hanft & Dominic A. Chiarelli, The Doctrine of Claim Vitiation: Have the
Constraints on Patent Rights Gone Too Far?, 1 No. 5 Landslide 14, 15 (2009).
39
Warner-Jenkinson, 520 U.S. at 39 n.8.
40 Id. at 30. 41
703 F.3d 1349 (Fed. Cir. 2012).
42 Id. at 1356 (quotation omitted). 43
Id. at 1356–57.
44 Warner-Jenkinson, 520 U.S. at 37. 45
See id. at 19.
46 See id. at 39–40. The court states:
There seems to be substantial agreement that, while the triple identity test may be suit-able for analyzing mechanical devices, it often provides a poor framework for analyzing other products or processes. On the other hand, the insubstantial differences test offers little additional guidance as to what might render any given difference “insubstantial.”
Id.
47
expectation “that the Federal Circuit will refine the formulation of the test for equivalence in the orderly course of case-by-case determinations[.]”48
Since Warner-Jenkinson, the Federal Circuit has held that the “insubstantial differences” test simply requires that “[a]n element in the accused device is equivalent to a claim limitation if the only differences between the two are insubstantial.”49
But, the Warner-Jenkinson Court has commented that “the insubstantial differences test offers little additional guidance as to what might render any given difference ‘insubstantial.’”50
On the other hand, under the “triple identity” test51
or “function-way-result” test,52
the Federal Circuit requires a patentee to show “on a limitation by limitation basis that the ac-cused product performs substantially the same function in substantially the same way with substantially the same result as each claim limitation of the patented product.”53
The “function-way-result test is particularly suitable for analyzing the equivalence of mechanical devices[.]”54
C. Question of Fact
The Graver Tank Court and Warner-Jenkinson Court both have held that infringement under DOE is a question of fact.55
With respect to evidence, the Graver Tank Court has held, “[p]roof can be made in any form: through testimony of experts or others versed in the technology; by documents, includ-ing texts and treatises; and, of course, by the disclosures of the prior art.”56
Thus, courts are required to balance “credibility, persuasiveness and weight of evidence” to make a “final determination.”57
48
Id.
49 Voda v. Cordis Corp., 536 F.3d 1311, 1326 (Fed. Cir. 2008) (alteration in original). 50
Warner-Jenkinson, 520 U.S. at 40.
51 See TIP Sys., LLC v. Phillips & Brooks/Gladwin, Inc., 529 F.3d 1364, 1376 (Fed.
Cir. 2008).
52 Crown Packaging Tech., Inc. v. Rexam Beverage Can Co., 559 F.3d 1308, 1312 (Fed.
Cir. 2009).
53 Id. 54
Id.
55 Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 609 (1950) (“A
finding of equivalence is a determination of fact.”); Warner-Jenkinson Co., 520 U.S. at 37 (“[W]ith regard to the objective nature of the doctrine, a skilled practitioner’s knowledge of the interchangeability between claimed and accused elements is not relevant for its own sake, but rather for what it tells the factfinder about the similarities or differences between those elements.”).
56 Graver Tank, 339 U.S. at 609. 57
II. Prosecution History Estoppel Triggered by Claim
Amendment
Prosecution History Estoppel (PHE) is a limitation on DOE. In 2002, the Supreme Court in Festo 2002 established clear guidance on PHE trig-gered by claim amendment. The Festo 2002 Court answered two questions: what kind of claim amendment may trigger PHE and whether PHE may be overcome.58
In 2003, the Federal Circuit in Festo Corp. v. Shoketsu Kinzoku
Kogyo Kabushiki Co. (“Festo 2003”),59
responded to Festo 2002 and provided clear rules for implementing Festo 2002.60
Both Festo 2002 and Festo 2003 decisions provide useful guidelines of applying PHE.
A. What Triggers Prosecution History Estoppel
Considering that DOE “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[,]”61
the Supreme Court in
Festo 2002 reaffirmed the necessity of PHE by stating that “[w]hen, however,
the patentee originally claimed the subject matter alleged to infringe but then narrowed the claim in response to a rejection, he may not argue that the surrendered territory comprised unforeseen subject matter that should be deemed equivalent to the literal claims of the issued patent.”62
Under Festo
2002, a patentee may make a narrowing amendment to meet “any
require-ment of the Patent Act.”63
A narrowing amendment used to overcome any rejection issued by patent examiners under 35 U.S.C. § 101 (usefulness and patent-eligibility requirements), § 102 (novelty requirement), § 103 (non-obviousness requirement), or § 112 (disclosure requirements) may trigger PHE.64
Even for a narrowing amendment “unrelated to patentability,” the Festo
2002 Court restated that “the court might consider whether it was the kind
of reason that nonetheless might require resort to the estoppel doctrine.”65
58
See Festo 2002, 535 U.S. 722, 735, 737 (2002).
59 344 F.3d 1359 (Fed. Cir. 2003) [hereinafter “Festo 2003”] (en banc). 60
See id.
61 Festo 2002, 535 U.S. at 733. 62
Id. at 733–34.
63 Id. at 736 (“[A] narrowing amendment made to satisfy any requirement of the Patent
Act may give rise to an estoppel.”).
64 See id. (“The claimed subject matter must be useful, novel, and not obvious. 35 U.S.C.
§§ 101–103 (1994 ed. and Supp. V). In addition, the patent application must describe, enable, and set forth the best mode of carrying out the invention.”).
65
But, the Supreme Court cautioned that “[i]f a § 112 amendment is truly cosmetic, then it would not narrow the patent’s scope or raise an estoppel.”66
To clarify which amendment triggers PHE under Festo 2002, the Federal Circuit in Festo 2003 (en banc) provided several rules. First, the court held that “a narrowing amendment made to comply with any provision of the Patent Act, including § 112, may invoke an estoppel.”67
Second, the court clarified that “a ‘voluntary’ amendment may give rise to prosecution history estoppel.”68
Third, the court introduced a presumption that “a narrowing amendment [is treated] as having been made for a ‘substantial reason related to patentability’ when the record does not reveal the reason for the amendment[.]”69
In 2004, the Federal Circuit in Honeywell International, Inc. v. Hamilton Sundstrand
Corp.70
further clarified that “rewriting a dependent claim into independent form, coupled with the cancellation of the original independent claim, constitutes a narrowing amendment when the dependent claim includes an additional claim limitation not found in the cancelled independent claim or circumscribes a limitation found in the cancelled independent claim.”71
Moreover, the Federal Circuit in Festo 2003 answered a series of questions asked prior to the application of PHE. The first inquiry is “whether an amend-ment filed in the [USPTO] has narrowed the literal scope of a claim.”72
If the answer is yes, the second inquiry is “whether the reason for that amendment was a substantial one relating to patentability.”73
“When the prosecution his-tory record reveals no reason for the narrowing amendment,”74
it is presumed that “the patentee had a substantial reason relating to patentability[.]”75
The patentee must rely only on “the evidence in the prosecution history record” to “show that the reason for the amendment was not one relating to patentability[.]”76
If the answer to the second question is yes or the patentee fails to rebut that presumption, the third question relates to “the scope of the subject matter surrendered by the narrowing amendment.”77
It is presumed that “the patentee has surrendered all territory between the original claim
66 Id. at 736–37. 67
Festo 2003, 344 F.3d 1359, 1366 (Fed. Cir. 2003) (en banc).
68 Id. 69
Id.
70 370 F.3d 1131 (Fed. Cir. 2004) [hereinafter “Honeywell 2004”]. 71 Id. at 1141. 72 Festo 2003, 344 F.3d at 1366. 73 Id. 74 Id. at 1366–67. 75 Id. at 1367. 76 Id. 77 Id.
limitation and the amended claim limitation.”78
“The patentee may rebut that presumption of total surrender by demonstrating” any of those three exceptions created by Festo 2002.79
Finally, if the rebuttal succeeds, PHE does not apply.80
Otherwise, the patentee is barred from asserting DOE against the alleged equivalent in question.81
B. Three Exceptions
Because language imperfection makes it impossible to draft an amended claim to cover a legitimate scope of the invention,82
the Festo 2002 Court did not expect that “a narrowing amendment should be deemed to relin-quish equivalents unforeseeable at the time of the amendment and beyond a fair interpretation of what was surrendered”83
or should “foreclose claims of equivalence for aspects of the invention that have only a peripheral rela-tion to the reason the amendment was submitted.”84
The question is “what equivalents were surrendered during the prosecution of the patent, rather than [to impose] a complete bar that resorts to the very literalism the equivalents rule is designed to overcome.”85
To avoid a complete bar of DOE in the context of PHE triggered by claim amendment, the Festo 2002 Court created three exceptions. The first excep-tion, or “unforeseeable” excepexcep-tion, is that “[t]he equivalent may have been unforeseeable at the time of the application[.]”86
The second exception, or “tangential” exception, is that “the rationale underlying the amendment may bear no more than a tangential relation to the equivalent in question[.]”87
The third exception, or “other reason” exception, is that “there may be some other reason suggesting that the patentee could not reasonably be expected to have described the insubstantial substitute in question.”88
Proving any of 78 Id. 79 Id. 80 See id. 81 See id.
82 See Festo 2002, 535 U.S. 722, 738 (2002) (“After amendment, as before, language
remains an imperfect fit for invention.”). While the Festo 2002 Court recognized that “[b]y amending the application, the inventor is deemed to concede that the patent does not extend as far as the original claim[,]” the Supreme Court worried that “[t]he narrowing amend-ment may demonstrate what the claim is not; but it may still fail to capture precisely what the claim is.” Id.
83 Id. 84 Id. 85 Id. 86 Id. at 740. 87 Id. 88 Id. at 740–41.
those three exceptions can help the patentee “overcome the presumption that prosecution history estoppel bars a finding of equivalence.”89
The Federal Circuit in Festo 2003 further elaborated several applicable rules for each exception. Regarding the “unforeseeable” exception, the Federal Cir-cuit held that it is “an objective inquiry, asking whether the alleged equivalent would have been unforeseeable to one of ordinary skill in the art at the time of the amendment.”90
The determination of unforeseeability “depends on underlying factual issues relating to, for example, the state of the art and the understanding of a hypothetical person of ordinary skill in the art at the time of the amendment.”91
Courts “may hear expert testimony and consider other extrinsic evidence relating to the relevant factual inquiries.”92
In addition, the Federal Circuit provided an absolute rule that “if the alleged equivalent were known in the prior art in the field of the invention, it certainly should have been foreseeable at the time of the amendment.”93
Regarding the “tangential” exception, the Federal Circuit in Festo 2003 held that it “asks whether the reason for the narrowing amendment was peripheral, or not directly relevant, to the alleged equivalent.”94
The inquiry focuses on “the patentee’s objectively apparent reason for the narrowing amendment”95
and “the context in which the amendment was made[.]”96
When “the public notice function of a patent and its prosecution history is to have significance,”97
the Federal Circuit required that courts must look to “the prosecution his-tory record without the introduction of additional evidence, except, when necessary, testimony from those skilled in the art as to the interpretation of that record.”98
So, courts must rely on the prosecution history record mainly. But, it is unclear under what circumstance courts may consult with expert testimony. Moreover, while admitting that it “cannot anticipate the instances of [the second exception],”99
the Federal Circuit provided an exclusionary rule that “an amendment made to avoid prior art that contains the equivalent in question is not tangential[, because] it is central to allowance of the claim.”100
89 Id. at 741. 90
Festo 2003, 344 F.3d 1359, 1369 (Fed. Cir. 2003).
91 Id. 92 Id. 93 Id. 94 Id. 95 Id. 96 Id. at 1370. 97 Id. at 1369. 98 Id. at 1370. 99 Id. at 1369. 100 Id.
Regarding the “other reason” exception, the Federal Circuit in Festo 2003 did not create another phrase for this inquiry. The original phrase for the inquiry used by the Supreme Court was “some other reason suggesting that the patentee could not reasonably be expected to have described the insub-stantial substitute in question.”101
This phrase was considered “vague” by the Federal Circuit which, therefore, held that the “other reason” exception “must be a narrow one.”102
The only situation the Federal Circuit can imagine is “shortcomings of language” which prevents the patentee from “describing the alleged equivalent when it narrowed the claim.”103
In addition, the Federal Circuit required courts to limit the determination to the prosecution history record.104
One example is that “a patentee may not rely on the third [excep-tion] if the alleged equivalent is in the prior art[.]”105
However, the Federal Circuit showed its unwillingness to foreclose evidence outside the prosecution history record.106
Those three exceptions to PHE now can be determined according to the Federal Circuit’s guidelines. Those guidelines, however, are not absolute. As the Federal Circuit held, “[b]ecause we cannot anticipate all of the circumstances in which a patentee might rebut the presumption of surrender, we believe that discussion of the relevant factors encompassed by each of the rebuttal criteria is best left to development on a case-by-case basis.”107
Therefore, the rules of each exception may be changed from time to time, depending on the specific fact pattern of a case.
C. Question of Law
Prior to 1997, PHE had been considered a question of law by the Federal Circuit.108
The Warner-Jenkinson Court seemed to agree because it mentioned that courts may grant a summary judgment of no infringement under DOE if PHE is established.109
While the Supreme Court has never reviewed the issue,
101 Id. at 1370 (quoting Festo 2002, 535 U.S. 722, 741 (2002)). 102
Id.
103 Id. 104
Id.
105 Id. (citing Pioneer Magnetics, Inc. v. Micro Linear Corp., 330 F.3d 1352 (Fed. Cir.
2003)).
106 See id. (“We need not decide now what evidence outside the prosecution history
record, if any, should be considered in determining if a patentee has met its burden under this third rebuttal criterion.”).
107
Id. at 1368.
108 See Mark I Mktg. Corp. v. R.R. Donnelley & Sons Co., 66 F.3d 285, 291 (Fed. Cir.
1995).
109 See Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 39 n.8 (“[U]nder
the Federal Circuit has treated PHE as a question of law ever since.110
In Festo
2003, the Federal Circuit reaffirmed that PHE is a question of law.111
First, the Federal Circuit recognized PHE as “equitable in nature,” so the application should be “guided by equitable and public policy principles.”112
Second, the Federal Circuit held that it has treated PHE as a question of law, which was recognized by the Supreme Court in Warner-Jenkinson.113
In Festo 2002, the Supreme Court addressed PHE and three exceptions, but did not mention whether the determination of PHE or three exceptions should be a question of law or question of fact. When the case was remanded, the Federal Circuit decided to answer whether the determination of any ex-ception is a question of law or question of fact.114
The Federal Circuit in Festo
2003 held that any exception to PHE is a “question of law to be determined
by the court, not a jury”115
because it is a question related to PHE.116
III. Foreseeability Rules under Federal Circuit Case Law
The Federal Circuit in Festo 2003 clarified the applicable rules of each exception. Because the case-by-case analysis is a basis for the application of those three exceptions to PHE, the application in reality is shown through Federal Circuit case law. This section further examines the Federal Circuit’s decisions regarding the “unforeseeable” exception. Unfortunately, the Federal Circuit has never had a case where the “unforeseeable” exception was met. The following analysis will demonstrate that the Federal Circuit has transformed the “unforeseeable” exception into foreseeability rules for showing PHE should be applied. The Federal Circuit case law could be summarized as follows:• An alleged equivalent that falls within the original version of the claim or other canceled claim would be held foreseeable.
equivalence would entirely vitiate a particular claim element, partial or complete judgment should be rendered by the court, as there would be no further material issue for the jury to resolve.”).
110
See Philippe Signore, On the Role of Juries in Patent Litigation (Part 1), 83 J. Pat. & Trademark Off. Soc’y 791, 807–08 (2001).
111
See Festo 2003, 344 F.3d at 1367–68.
112 Id. at 1367 (internal quotation marks omitted). 113
See id. at 1368 (“The Supreme Court has recognized that, as a legal limitation on the application of the doctrine of equivalents, prosecution history estoppel is a matter to be determined by the court.” (citing Warner-Jenkinson, 520 U.S. at 39 n.8)).
114 See id. at 1365. 115
Id. at 1367.
116 See id. at 1368 (“Questions relating to the application and scope of prosecution history
• An alleged equivalent disclosed by any prior art document cited by the examiner or submitted by the applicant would be held foreseeable. • An alleged equivalent would be held foreseeable if the applicant had
admitted or known the existence of such equivalent during the prosecu-tion or had used such equivalent in another relevant patent.
• An alleged equivalent would be held foreseeable because it is covered by a broad claim interpretation made in the argument related to literal infringement.
• The original version of the claim at dispute governs the determination of the field of the invention; the particular function of the disputed element is irrelevant.
• An alleged equivalent is not required to exist as a suitable substitute of the disputed element at the time of the amendment.
A. Alleged Equivalents Covered by the Original Claim
If an alleged equivalent is covered by the original claim, it would be held foreseeable. In Ranbaxy Pharmaceuticals Inc. v. Apotex, Inc,117
the patent-in-suit related to a process of making amorphous cefuroxime axetil.118
The original version of the representative claim at dispute included a “highly polar or-ganic solvent.”119
During the prosecution, the examiner rejected some claims because “highly polar organic solvent” was indefinite and because a prior art patent disclosed acetone as a “highly polar organic solvent.”120
The applicant then added dependent claims into some independent claims, and the broad limitation became “the highly polar organic solvent is selected from the group consisting of a sulfoxide, an amide and formic acid.”121
On the other hand, the accused process used “acetic acid” as a solvent.122
117 350 F.3d 1235 (Fed. Cir. 2003). 118
See id. at 1237. Cefuroxime axetil is a pharmaceutical compound used to treat the beta-lactamase positive respiratory pathogens (H. influenzae and M. catarrhalis). See
gener-ally Caroline M. Perry & Rex N. Brogden, Cefuroxime Axetil, 52 Drugs 125 (1996). After
oral administration, cefuroxime axetil is transformed into another form to be “absorbed into the bloodstream as cefuroxime moiety.” Cefuroxime has antibiotic activity against certain bacteria that cause respiratory diseases. See generally Iyad Naeem Muhammad, Muhammad Harris Shoaib, & Rabia Ismail Yousuf, Pharmacokinetic and Bioequivalence Studies of Oral
Cefuroxime Axetil 250 mg Tablets in Healthy Human Subjects, 6(5) J. Bioequivalence &
Bioavailability 149, 149 (2014), available at http://www.omicsonline.org/open-access/ pharmacokinetic-and-bioequivalence-studies-of-oral-cefuroxime-axetil-mg-tablets-in-healthy-human-subjects-jbb.10000196.pdf. 119 Ranbaxy Pharms., 350 F.3d at 1237. 120 Id. at 1238. 121 Id. 122 Id.
The patentee asserted the “unforeseeable” exception,123
but the defendant argued that “acetic acid is a foreseeable equivalent to formic acid that could have and should have been included in the original claim.”124
The Federal Circuit found that the patentee “stated that formic acid and acetic acid . . . are readily known by chemists to exhibit similar properties and are therefore equivalent.”125
The original claim would have literally included “acetic acid.”126
Therefore, the Federal Circuit held that the “unforeseeable” exception could not be established.127
Ranbaxy indicates that the use of a generic term may more likely result in a
finding of foreseeable equivalents. The same situation also exists when a claim has structural elements. In Research Plastics, Inc. v. Federal Packaging Corp.,128
although the Federal Circuit remanded the case because of incorrect claim construction, it did affirm that the district court correctly applied PHE.129
The patent-in-suit related to the structure of a caulking tube.130
Figure 1(a) shows the patented caulking tube.
(a) (b)
123
See id. at 1241.
124 Id. 125
Id. While the Federal Circuit did not disclose where it found the statement of the patentee, the appellate brief filed by the patentee did state:
Formic acid and acetic acid solvents are the first and second compounds in the series of carboxylic acids. Compounds that are related to each other as members of the same series are called “homologs.” (A1252.) When homologs are adjacent to each other in a series—as formic acid and acetic acid are—the patent law has held that they are obvious variants of one another, because chemists ordinarily expect adjacent homologs to exhibit substantially similar functional properties.
Brief for Defendant-Appellant at 50, Ranbaxy Pharms. Inc. v. Apotex, Inc., 350 F.3d 1235 (Fed. Cir. 2003) (No. 02–1429), 2002 WL 32815089.
126 Ranbaxy Pharms., 350 F.3d at 1241. 127 See id. 128 421 F.3d 1290 (Fed. Cir. 2005). 129 See id. at 1292, 1298–99. 130 See id. at 1292.
Figure 1: (a) Patented Caulking Tube131
and (b) Infringing Caulking Tube132
During the prosecution, the claim at dispute was amended to avoid a prior art.133
The amended claim included a phrase “said ribs each occupying an area that is less than 0.5% of the area of said tube, and said ribs extending to
said rear end of said hollow tube body.”134
The new limitation was intended to distinguish the claimed invention from the prior art because the ribs of the prior art were “positioned near the nozzle end of the tube.”135
On the other hand, the alleged equivalent was a rib “extending to a point short of the rear edge of the tube.”136
The infringing product is shown in Figure 1(b).
The Federal Circuit held that the alleged equivalent was foreseeable because “rib placement was a point of differentiation.”137
The holding was based on the evidence that the applicant used the rib position to distinguish the claimed invention from the prior art.138
This determination indicates that a change of the relative placement of a claimed feature is always be foreseeable.
Another example is Integrated Technology Corp. v. Rudolph Technologies,
Inc.,139
where the patent-in-suit was related to integrated circuit probe card inspection equipment.140
The claim at dispute originally recited “a window with a flat surface contacted by said probe tip.”141
Then it was amended to overcome a rejection related to patentability, and a new limitation “in a first
131
Brief for Plaintiff-Appellant at 8–9, Research Plastics, Inc. v. Fed. Packaging Corp., 421 F.3d 1290 (Fed. Cir. 2005) (No. 04-1605), 2004 WL 4977760.
As described by representative claim 10 and shown below, the ‘433 Patent recites a hollow tube body (30) and a plunger (32) received within the body. Ribs (38) are defined extending inwardly from an inner periphery (36) of the hollow tube (30). The claim recites that the tube (30) extends from a rear end (33) to a nozzle end (34). The ribs (38) extend to the rear end (33).
Id. (internal citation omitted).
132
Id. at 11.
133 See Research Plastics, 421 F.3d at 1293. 134
Id. (emphasis added).
135 Id. 136
Id. at 1299.
137 Id. 138
See id. at 1298–99. The second exception was not met because “the purpose of the amendment was to avoid rejection based on rib placement.” Id. at 1299. The third excep-tion was not established because the applicant “could have claimed ribs placed in the region between the nozzle end and the rear end of the tube, so long as it disclaimed the location adjacent to the nozzle” (emphasis added), or described “ribs placed rearward from the nozzle
end, yet not extending completely to the rear edge.” Id. at 1298 (emphasis added).
139
734 F.3d 1352 (Fed. Cir. 2013).
140 See id. at 1355. 141
state where said probe tip is driven in contact with said window with a first force” was added.142
The alleged equivalent, on the other hand, was character-ized as “in a first state when the probe tip is five microns above the viewing window, and in a second state when the probe tip touches the window.”143
Eventually, the court found that the original claim literally covered the alleged equivalent.144
Therefore, the alleged equivalent would have been foreseeable at the time of the amendment.145
B. Alleged Equivalents Covered by Another Canceled Claim
If an alleged equivalent is covered by another canceled claim, it would be held foreseeable. In Mycogen Plant Science, Inc. v. Monsanto Co.,146
the patent-in-suit related to a man-made gene that has “a pesticidal protein of the soil bacterium Bacillus thuringiensis (‘Bt’)[.]”147
The claim at dispute was not amended during the prosecution.148
Instead, another claim reciting “said DNA sequence is at least about 85% homologous to a native insecticidal protein gene of Bt [sic]”149
was canceled during the prosecution.150
The cancellation was filed to respond to the enablement rejection.151
The alleged equivalent, on the other hand, was a gene having “a level of homology with the native Bt gene of about 78 percent and a frequency of usage of plant-preferred codons of about 51 percent.”152
The Federal Circuit found that the claim in dispute was not broad enough to cover the alleged equivalent, while the cancelled claim could cover it.153
The patentee asserted that it should have been permitted to present evidence regarding the unforeseeability of the alleged equivalent.154
Nevertheless, the Federal Circuit stated that “the fact that [the applicants] originally claimed coverage of genes bearing 85 percent similarity to the native Bt gene is it-self evidence that the applicants foresaw the possibility of less homologous
142
Id. (internal quotation marks omitted).
143 Id. at 1359. 144
See id.
145 See id. 146
91 F. App’x 666 (Fed. Cir. 2004).
147 Id. at 666. 148 See id. at 668. 149 Id. at 667. 150 See id. 151 See id. 152 Id. at 667. 153 See id. 154 See id. at 668.
genes.”155
Therefore, the standard for the “unforeseeable” exception could not be satisfied.156
C. Alleged Equivalents Covered by Prior Art
If an alleged equivalent had been covered by the prior art, it will be held foreseeable. In Pioneer Magnetics, Inc. v. Micro Linear Corp.,157
the patent related to a power supply.158
The claim at dispute originally recited “multiplier[,]”159
and later was amended to recite “‘switching analog’ multiplier circuit” to overcome a rejection based on novelty and indefiniteness.160
The Federal Circuit found that the prior art cited by the examiner “disclosed a power supply containing a non-switching multiplier.”161
Because “a non-switching [multiplier] was known in the art[,]”162
the Federal Circuit held that it “would have been foreseeable at the time of the amendment.”163
Another example is Talbert Fuel Systems Patents Co. v. Unocal Corp.,164
where the patent-in-suit related to a gasoline fuel composition.165
The claim at dispute originally recited no boiling temperature range.166
To reject the original claim, the examiner cited several references, one of which showed a boiling range of 390°F–420°F.167
Then, to overcome the rejection, the applicant amended the original claim to recite “a boiling range of 121°F–345°F.”168
On the other hand, the accused fuel had a boiling point ranging from 373.8°F–472.9°F.169
The Federal Circuit found that the alleged “boiling point” equivalent started at 373.8°F, which is between the 345°F upper limit of the claim at dispute and the 390°F of the prior art.170
The range of the alleged “boiling point” equivalent was partially embraced by the prior art.171
Therefore, because of
155
Id.
156 See id. 157
330 F.3d 1352 (Fed. Cir. 2003) (per curiam).
158 See id. at 1354. 159 See id. 160 Id. at 1355. 161 Id. at 1357. 162 Id. 163 Id. 164 347 F.3d 1355 (Fed. Cir. 2003). 165 See id. at 1357. 166 Id. at 1358. 167 See id. 168 Id. 169 See id. at 1360. 170 See id. at 1359. 171 See id.
the applicant’s “clear disclaimers of such higher-boiling fuels,”172
the Federal Circuit held that the alleged equivalent “cannot be deemed to have been unforeseeable when [the] amendments were made.”173
D. Alleged Equivalents Known to the Applicant
If an alleged equivalent had been known to the applicant at the time of the amendment, it would be held foreseeable. There are several scenarios. First, an information disclosure statement (“IDS”) submitted by the applicant may include some reference which describes the use of the alleged equivalent in the art. The Federal Circuit in Glaxo Wellcome, Inc. v. Impax Laboratories, Inc.174
and
Smithkline Beecham Corp. v. Excel Pharmaceuticals, Inc.175
was confronted with a patent related to “controlled sustained release tablets containing bupropion hydrochloride.”176
The specification disclosed a drug formulation containing hydroxypropylmethylcellulose (“HPMC”) which helps achieve the claimed sustained release.177
Because the examiner considered HPMC as essential to the claimed controlled release rate (a rate that shows how fast a pharmaceutical compound is released into the body), the applicant was required to amend the original claim to recite HPMC; otherwise the enablement requirement would not be met.178
The alleged equivalents, meanwhile, in Glaxo Wellcome,
Inc. and Smithkline Beecham Corp. were two hydrogel-forming polymers,
hy-droxypropyl cellulose (“HPC”), a hydrogel-forming compound, and polyvinyl alcohol (“PVA”), respectively.179
The Federal Circuit in Glaxo Wellcome, Inc. affirmed the district court’s ap-plication of PHE,180
but in Smithkline Beecham Corp. it remanded the district court’s finding of foreseeability.181
In Glaxo Wellcome, Inc., the Federal Circuit found that HPC was known as a sustained release hydrogel-forming polymer like HPMC in several prior art documents, including in those submitted by the applicant in the IDS.182
Therefore, the Federal Circuit held that the applicant knew that HPC would have been an equivalent at the time of the
amend-172 Id. 173 Id. at 1359–60. 174 356 F.3d 1348 (Fed. Cir. 2004). 175 356 F.3d 1357 (Fed. Cir. 2004). 176 Glaxo, 356 F.3d at 1349–50; Smithkline, 356 F.3d at 1359.
177 See Glaxo, 356 F.3d at 1352; see also Smithkline, 356 F.3d at 1361–62. 178
See Glaxo, 356 F.3d at 1352; see also Smithkline, 356 F.3d at 1362.
179 See Glaxo, 356 F.3d at 1351; see also Smithkline, 356 F.3d at 1360. 180
See Glaxo, 356 F.3d at 1349.
181 See Smithkline, 356 F.3d at 1359. 182
ment.183
The patentee failed to rebut PHE.184
On the other hand, in Smithkline
Beecham Corp., while considering PVA as a later-developed technology for
being used as a sustained release ingredient for bupropion hydrochloride,185
the Federal Circuit found that the patentee admitted that “PVA and HPMC are functional equivalents in retarding the release of bupropion hydrochloride from an ingested tablet.”186
With these contradictory facts, the Federal Circuit concluded that “the record does not disclose whether HPMC and PVA were recognized as interchangeable sustained release hydrogel-forming polymers used in the art of pharmaceutical formulation at the time the claims were amended.”187
In the second scenario, a finding of knowledge of a disputed equivalent may result from the patentee’s admission during the prosecution. In Amgen
Inc. v. Hoechst Marion Roussel, Inc.,188
the Federal Circuit affirmed that the alleged equivalent was foreseeable at the time of the amendment.189
The patent-in-suit related to recombinant deoxyribonucleic acid technology for producing the hormone erythropoietin (“EPO”).190
The claim at dispute had been through three preliminary amendments.191
The first preliminary amend-ment broadly covered either an isolated human EPO or monkey EPO.192
The second preliminary amendment embraced an EPO made from the amino acid sequence for EPO and a fragment thereof.193
The final preliminary amendment removed the features of a non-human monkey EPO and the use of a frag-ment. Instead, the final version was limited to “only a human EPO product having the complete amino acid sequence of [a DNA sequence drawing].”194
That is, the claim at dispute recited a human EPO made from a 166-amino acid sequence defined in such drawing.195
The alleged equivalent, however was an EPO made from a 165-amino acid sequence.196
The Federal Circuit found that during the prosecution the applicant informed the examiner that human EPO has a 165-amino acid sequence when filing
183 Id. 184 Id. at 1356. 185 See Smithkline, 356 F.3d at 1364–65. 186 Id. at 1365. 187 Id. 188 457 F.3d 1293 (Fed. Cir. 2006). 189 See id. at 1316. 190 See id. at 1295. 191 See id. at 1310. 192 See id. 193 See id. 194 Id. 195 See id. at 1299, 1313. 196 See id. at 1310.
the third preliminary amendment.197
Because “the patentee admittedly knew about the 165-amino acid [sequence] at the time of the third preliminary amendment[,]”198
the Federal Circuit held that the alleged equivalent would have been foreseeable at the time of the third preliminary amendment.199
Under the third scenario, a finding of knowledge of an equivalent at dispute may be based on the patentee’s argument during the litigation. In Cross Medical
Products, Inc. v. Medtronic Sofamor Danek, Inc.,200
the patent-in-suit related to a fixation device for bone connection.201
The claim at dispute originally recited a “seat means including a vertical axis and first threads.”202
When the examiner rejected the claim on several grounds including obviousness and novelty,203
the applicant responded by amending the original claim to recite “said seat means including a vertical axis and first threads which extend in the direction of said vertical axis toward said lower bone interface to a depth below the diameter of the rod when it is in the rod receiving channel.”204
As the applicant explained to the examiner, the claim was limited to “seat threads extend[ing] toward the channel to a depth below the top of the stabilizer when it is in the channel.”205
On the other hand, the alleged equivalent referred to as an undercut, or recess, was treated by the Federal Circuit as not including “threads extending to a depth below the top of the stabilizer.”206
The Federal Circuit agreed with the district court’s holding that the al-leged equivalent was foreseeable.207
First, the evidence showed that the use of an undercut or recess was “an old and well known fundamental of basic machining” at the time of the amendment.208
Second, when arguing literal infringement, the patentee suggested that “an ‘undercut’ was known in the art to serve effectively as a thread.”209
Therefore, the patentee did not rebut PHE with the “unforeseeable” exception.210
Regarding the fourth scenario, the infringer’s activity may cause a finding of knowledge. In Honeywell International, Inc. v. Hamilton Sunstrand Corp.
197 See id. at 1313. 198 Id. 199 Id. 200 480 F.3d 1335 (Fed. Cir. 2007). 201 See id. at 1339. 202
Id. at 1340 (internal quotation marks omitted).
203 See id. 204
Id. (emphasis omitted).
205 Id. at 1343 (emphasis omitted). 206
Id. (internal quotation marks omitted).
207 Id. 208 Id. 209 Id. 210 See id. at 1344.
(“Honeywell 2008”),211
the patents-in-suit related to compressor technology that implements a surge control system to maintain a minimum level of airflow through a compressor during the operation.212
The patented technol-ogy applied to aircrafts.213
The patented invention used a set of adjustable inlet guide vanes (“IGV”) to control the minimum flow in the compressor to prevent surges.214
The disputed limitation, which was not included in the original claim, described a mechanism applying IGVs and using “the position of these guide vanes in the surge control system.”215
On the other hand, the alleged equivalent was characterized as using a “static pressure differential” as an indicator of surge only if the engine is in a low flow, and “IGV position” as an indicator of whether the engine is in a high or low flow.216
The “foreseeability” question was “whether the use of IGV position to detect high flow and low flow was later-developed technology and thus un-foreseeable at the time of the amendments during the prosecution process.”217
The Federal Circuit held that the use was foreseeable, basing its decision on the product development history of the infringer.218
While recognizing that the infringing product was developed after the claim amendment,219
the Federal Circuit affirmed the district court’s finding of foreseeability.220
The infringer’s product development showed that the use of IGV position as a low flow indicator had been known in the art.221
One old patent suggested that IGVs “were routinely used in surge control systems and affected the air flow rate.”222
Finally, the experts from both parties demonstrated that using IGV position was known as a solution in the 1970s, or at least at the time of the amendment.223
Lastly, a term used by the applicant in other relevant patents may suggest that the alleged equivalent was known to the applicant. In Energy Transportation
Group, Inc. v. William Demant Holding A/S,224
the Federal Circuit upheld that
211 523 F.3d 1304 (Fed. Cir. 2008) [hereinafter “Honeywell 2008”]. 212 See id. at 1307. 213 See id. 214 See id. 215 Id. at 1308. 216 Id. at 1313. 217 Id. 218 See id. at 1314. 219 See id. at 1313. 220 See id. at 1314. 221 Id. at 1313. 222 Id. at 1313–14. 223 Id. at 1314. 224 697 F.3d 1342 (Fed. Cir. 2012).
the district court applied PHE to limit DOE.225
Two patents, No. 4,731,850 (“the ‘850 Patent”) and No. 4,879,749 (“the ‘749 Patent”), were involved,226
both relating “to technology for reducing acoustic feedback in a program-mable digital hearing aid.”227
The ‘749 Patent was a division of application of the ‘850 Patent.228
However, only the ‘749 Patent related to the issue of PHE.229
The process claim at dispute originally recited “means for receiving signals indicative of the frequency gain and feedback characteristics.”230
To overcome the examiner’s rejection, the claim was amended to replace the “means for receiving” limitation with “means for receiving signals from the hearing aid and measuring phase and amplitude.”231
On the other hand, the alleged equivalent was characterized as “determining the effect of phase and amplitude.”232
The Federal Circuit found that the applicant knew the use of “determin-ing” at the time of the amendment.233
Both the ‘850 Patent and ‘749 Patent shared a common specification.234
Because the applicant used the “determin-ing” language in the ‘850 Patent, the Federal Circuit held that the alleged equivalent was foreseeable at the time of the amendment.235
E. Foreseeability Determination under the Original Claim
In 2007, the Federal Circuit in Festo Corp. v. Shoketsu Kinzoku Kogyo
Ka-bushiki Co. (“Festo 2007”)236
rejected a “foreseeability test [which] requires application of the function/way/result or insubstantial differences test.”237
The Federal Circuit clarified that an alleged equivalent “is foreseeable if it is disclosed in the pertinent prior art in the field of the invention.”238
The Federal Circuit also held that an alleged equivalent “is foreseeable if it is known in
225
See id. at 1347.
226 Id. 227
Id.
228 See U.S. Patent No. 4,879,749, col. 1 l. 5 (filed Feb. 12, 1988). A divisional
ap-plication is a patent apap-plication divided from its parent apap-plication. See David V. Radack,
Understanding “Related” U.S. Patent Applications, http://www.tms.org/pubs/journals/JOM/
matters/matters-0406.html (last visited Aug. 14, 2015).
229 See Energy Transp. Group, 697 F.3d at 1358. 230
Id. at 1359 (internal quotation marks omitted).
231 Id. (emphasis omitted). 232
Id. at 1360 (internal quotation marks omitted).
233 See id. 234
See id. at 1347.
235 See id. at 1360. 236
493 F.3d 1368 (Fed. Cir. 2007) [hereinafter “Festo 2007”].
237 Id. at 1379. 238
the field of the invention as reflected in the claim scope before amendment.”239
This rule applies “even if the suitability of the alternative for the particular purposes defined by the amended claim scope were unknown.”240
In Festo 2007, the patent-in-suit related to a motor assembly.241
The claim at dispute originally did not include a sleeve bearing (or “sleeve” as a term used in the patent), however, it was included in a dependent claim.242
When submitting to the USPTO a German patent as a prior art, showing the use of a sleeve [bearing] made of non-magnetic material, the applicant amended the claim at dispute to recite “a cylindrical sleeve made of a magnetizable material.”243
On the other hand, the alleged equivalent was a sleeve made of “a non-magnetizable material, aluminum alloy.”244
The Federal Circuit held that “use of non-magnetizable sleeves (including aluminum sleeves) was foreseeable under the original broader claim[.]”245
The patentee argued that “sleeve” was used to “shield against magnetic field leakage[,]”246
but the Federal Circuit found that the claimed sleeve “was not designed to shield the magnetic field but rather to enclose the magnets.”247
The German patent that the applicant submitted also indicated that a sleeve bearing could be made of a non-magnetic material.248
In addition, the speci-fication of the patent-in-suit showed “the possibility of using a non-magnetic material for the sleeve.”249
While describing that the use of magnetic material for the sleeve could reduce undesirable braking forces, the specification did not mandate such use.250
Therefore, the Federal Circuit concluded that “use of an aluminum alloy sleeve was foreseeable at the time of amendment” and, therefore, PHE applied.251
Under Festo 2007, whether a field relates to unforeseeability should be determined in view of the original claim. However, the technology in Festo
2007 could not show the difference between the fields of the original claim
and amended claim because the claimed sleeve bearings in the original form and amended form were in the same or similar field.
239
Id. (emphasis added).
240 Id. at 1382. 241
See id. at 1371–72.
242 See id. at 1372. 243
Id. at 1373 (internal quotation marks omitted).
244 Id. at 1374. 245 Id. at 1382. 246 Id. 247 Id. 248 See id. 249 Id. 250 See id. at 1383. 251 Id.
Schwarz Pharma, Inc. v. Paddock Laboratories, Inc.252
may be a good example for illustrating the determination of unforeseeability under “the field of the invention as reflected in the claim scope before amendment.” There, the patent-in-suit related to pharmaceutical compositions containing Angiotensin Converting Enzyme (‘ACE’) inhibitors as an active ingredient and certain stabilizers as an ingredient that can prevent certain types of degradation of ACE inhibitors.253
Two claims were involved, and each claim recited a stabilizer limitation.254
One claim recited a “metal containing stabilizer” and the other claim recited “an alkali or alkaline earth-metal salt[.]”255
During the prosecu-tion, because of the examiner’s rejecprosecu-tion, those two stablizer limitations were amended as “an alkali or alkaline earth metal carbonate.”256
On the other hand, the alleged equivalent was magnesium oxide (“MgO”).257
Eventually, the Federal Circuit found that MgO fell within the definition of a “metal containing stabilizer” and that the patentee’s expert described “an alkali or alkaline earth-metal salt” as embracing MgO.258
Therefore, the Federal Circuit held that MgO clearly fell within “the territory between the language of the original and the amended claims.”259
Moreover, the Federal Circuit rejected the patentee’s argument that MgO was unforeseeable because MgO was not known as a stabilizer against one of those claimed degradations or was not used for the claimed ACE inhibitors.260
The ultimate question was whether the alleged equivalent was within the field of the invention.261
The Federal Circuit cautioned that “care must be taken not to sweep too broadly in defining the field of an invention[.]”262
That is, if the field of the invention is defined broadly, many objects may be considered as an equivalent. However, the Federal Circuit concluded that the patentee offered a very narrow definition of the field of the claimed invention.263
Re-ferring to the claim language, the Federal Circuit found that before being amended, the claims at dispute began with the phrase“[a] pharmaceutical composition which contains[.]”264
So, the Federal Circuit upheld that the
252
504 F.3d 1371 (Fed. Cir. 2007).
253 See id. at 1372. 254
See id. at 1372–73.
255 Id. at 1373 (internal quotation marks omitted). 256
Id. (internal quotation marks omitted).
257 See id. 258 Id. at 1376. 259 Id. at 1376–77. 260 See id. at 1377. 261 See id. 262 Id. 263 Id. 264
field of invention should be “pharmaceutical compositions” in general rather than “pharmaceutical stabilizers that inhibit cyclization in ACE inhibitors.”265
Therefore, the Federal Circuit concluded that “MgO was known as a stabilizer in the field of pharmaceutical compositions,”266
and that the patentee failed to rebut the presumption.267
F. Foreseeability and Suitability
An alleged equivalent does not have to be a promising choice of equivalents at the time of the amendment. In Duramed Pharmaceuticals, Inc. v. Paddock
Laboratories, Inc.,268
the patented technology related to “conjugated estrogen pharmaceutical compositions for use in hormone replacement therapies.”269
The claim at dispute originally recited “a moisture barrier coating.”270
A “moisture barrier coating” (“MBC”) was used “to inhibit the absorption of moisture and reduce storage-related degradation.”271
The claim was then re-jected by the examiner because of obviousness.272
After an interview with the examiner, the examiner agreed that the claim would overcome the rejection if it recites “ethylcellulose” as an MBC.273
The final version recited “a moisture barrier coating comprising ethylcellulose.”274
On the other hand, the alleged equivalent as an MBC was a “polyvinyl alcohol” (“PVA”).275
The Federal Circuit relied on a Patent Cooperation Treaty (“PCT”) ap-plication to find that PVA had been used as an MBC for pharmaceutical compositions.276
The PCT application disclosed drug “formulations of PVA-based MBCs,”277
but also indicated some “technical drawbacks of using PVA as an MBC.”278
The patentee asserted that a PVA had to be known as an MBC for conju-gated estrogen.279
Relying on Schwarz Pharma, Inc., the Federal Circuit
af-265 Id. 266 Id. 267 See id. 268 644 F.3d 1376 (Fed. Cir. 2011). 269 Id. at 1378. 270 Id. 271 Id. 272 Id. 273 See id.
274 Id. (internal quotation marks omitted). 275 Id. 276 See id. at 1380–82. 277 Id. at 1379. 278 Id. 279 Id. at 1380.
firmed its rule for the definition of the field of the invention.280
As the Federal Circuit held, “when the language of both original and issued claims begins with the words ‘[a] pharmaceutical composition,’ that language defines the field of the invention for purposes of determining foreseeability.”281
So, the ultimate question was whether PVA MBCs had “been known in the field of pharmaceutical compositions as of the time of [the applicant’s] narrowing amendment.”282
Because the PCT application disclosed “PVA MBCs for use with pharmaceutical compositions[,]”283
the Federal Circuit held that PVA MBCs were foreseeable.284
Alternatively, the patentee argued that the PCT application failed to disclose that PVA was suitable as an MBC because the application provided “only conclusory statements that the inventors had solved the technical drawbacks of PVA MBCs and lacks any data on the stability of the pharmaceutical compounds coated with [PVA MBCs].”285
The Federal Circuit disagreed.286
The Federal Circuit clarified that “foreseeability does not require such precise evidence of suitability”287
or “flawless perfection to create an estoppel.”288
Instead the court found, “even if the PCT disclosure indicates that PVA is less than ideal in some pharmaceutical uses as an MBC, it is still disclosed to be use-ful as such[.]”289
Thus, PVA was foreseeable at the time of the amendment.290
G. Foreseeability Estoppel
Professor Peter Lee has commented that “the foreseeability inquiry is highly factually intensive.”291
But, several rules can still be drawn from those Federal Circuit cases. Though, the Federal Circuit in Festo 2003 accepted various sources of evidence showing unforeseeability. Ironically, the Federal Circuit has relied on prior art documents, expert testimony, defendant’s activities, and the patentee’s admission or arguments to determine that an alleged equivalent was foreseeable at the time of claim amendment. The standard for
280
See id. (citing Schwarz Pharma, Inc. v. Paddock Labs., Inc., 504 F.3d 1371, 1377 (Fed. Cir. 2007)).
281
Id. at 1380–81 (alteration in original) (citing Schwarz Pharma, 504 F.3d at 1377).
282 Id. at 1381. 283 Id. 284 See id. 285 Id. 286 Id. 287 Id. 288 Id. 289 Id. 290 See id. 291
