Majority — GINSBURG J.
I
Authorized by the Constitution "[t]o promote the Progress of Science and useful Arts, by securing for limited Times to ... Inventors the exclusive Right to their ... Discoveries," Art. I, § 8, cl. 8, Congress has enacted patent laws rewarding inventors with a limited monopoly. "Th[at] monopoly is a property right," and "like any property right, its boundaries
II
The patent in dispute, U.S. Patent No. 5,337,753 ('753 patent), issued to Dr. Gregory Lekhtman in 1994 and assigned to respondent Biosig Instruments, Inc., concerns a heart-rate monitor for use during exercise. Previous heart-rate monitors, the patent asserts, were often inaccurate in measuring the electrical signals accompanying each heartbeat (electrocardiograph or ECG signals). The inaccuracy was caused by electrical signals of a different sort, known as electromyogram or EMG signals, generated by an exerciser's skeletal muscles when, for example, she moves her arm, or grips an exercise monitor with her hand. These EMG signals can "mask" ECG signals and thereby impede their detection. App. 52, 147.
Dr. Lekhtman's invention claims to improve on prior art by eliminating that impediment. The invention focuses on a key difference between EMG and ECG waveforms: while ECG signals detected from a user's left hand have a polarity opposite to that of the signals detected from her right hand,[2] EMG signals from each hand have the same polarity. The patented device works by measuring equalized EMG signals detected at each hand and then using circuitry to subtract the identical EMG signals from each other, thus filtering out the EMG interference.
2 This difference in polarity occurs because the heart is not aligned vertically in relation to the center of the body; the organ tilts leftward from apex to bottom. App. 213.
Claim 1 of the '753 patent, which contains the limitations critical to this dispute, refers to a "heart rate monitor for use by a user in association with exercise apparatus and/or exercise procedures." Id., at 61 . The claim "comprise[s]," among other elements, an "elongate member" (cylindrical bar) with a display device; "electronic circuitry including a difference amplifier"; and, on each half of the cylindrical bar, a live electrode and a common electrode "mounted ... in spaced relationship with each other." Ibid.[3] The claim sets forth additional elements, including that the cylindrical bar is to be held in such a way that each of the user's hands "contact[s]" both electrodes on each side of the bar. Id., at 62 . Further, the EMG signals detected by the two electrode pairs are to be "of substantially equal magnitude and phase" so that the difference amplifier will "produce a substantially zero [EMG] signal" upon subtracting the signals from one another. Ibid.
B
The dispute between the parties arose in the 1990's, when Biosig allegedly disclosed the patented technology to StairMaster Sports Medical Products, Inc. According to Biosig, StairMaster, without ever obtaining a license, sold exercise machines that included Biosig's patented technology, and petitioner Nautilus, Inc., continued to do so after acquiring the StairMaster brand. In 2004, based on these allegations, Biosig brought a patent infringement suit against Nautilus in the U.S. District Court for the Southern District of New York.
3 As depicted in figure 1 of the patent, id., at 41 , reproduced in the Appendix to this opinion, the live electrodes are identified by numbers 9 and 13, and the common electrodes, by 11 and 15.
4 Dr. Lekhtman's declaration also referred to an expert report prepared by Dr. Henrietta Galiana, Chair of the Department of Biomedical Engineering at McGill University, for use in the infringement litigation. That report described how Dr. Galiana's laboratory technician, equipped with a wooden dowel, wire, metal foil, glue, electrical tape, and the drawings from the '753 patent, was able in two hours to build a monitor that "worked just as described in the ... patent." Id., at 226 .
Nautilus moved for summary judgment, arguing that the term "spaced relationship," as construed, was indefinite under § 112, ¶ 2. The District Court granted the motion. Those words, the District Court concluded, "did not tell [the court] or anyone what precisely the space should be," or even supply "any parameters" for determining the appropriate spacing. Id., at 72a.
The Federal Circuit reversed and remanded. A claim is indefinite, the majority opinion stated, "only when it is 'not amenable to construction' or 'insolubly ambiguous.' " 715 F.3d 891 , 898 (2013) (quoting Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342 , 1347 (C.A.Fed.2005) ). Under that standard, the majority determined, the '753 patent survived indefiniteness review. Considering first the "intrinsic evidence"- i.e., the claim language, the specification, and the prosecution history-the majority discerned "certain inherent parameters of the claimed apparatus, which to a skilled artisan may be sufficient to understand the metes and bounds of 'spaced relationship.' " 715 F.3d, at 899 . These sources of meaning, the majority explained, make plain that the distance separating the live and common electrodes on
In a concurring opinion, Judge Schall reached the majority's result employing "a more limited analysis." Id., at 905 . Judge Schall accepted the majority's recitation of the definiteness standard, under which claims amenable to construction are nonetheless indefinite when "the construction remains insolubly ambiguous." Ibid. (internal
III
Although the parties here disagree on the dispositive question-does the '753 patent withstand definiteness scrutiny-they are in accord on several aspects of the § 112, ¶ 2 inquiry. First, definiteness is to be evaluated from the perspective of someone skilled in the relevant art. See, e.g., General Elec. Co. v. Wabash Appliance Corp., 304 U.S. 364 , 371, 58 S.Ct. 899 , 82 L.Ed. 1402 (1938). See also § 112, ¶ 1 (patent's specification "shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same" (emphasis added)). Second, in assessing definiteness, claims are to be read in light of the patent's specification and prosecution history. See, e.g., United States v. Adams, 383 U.S. 39 , 48-49, 86 S.Ct. 708 , 15 L.Ed.2d 572 (1966) (specification); Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722 , 741, 122 S.Ct. 1831 , 152 L.Ed.2d 944 (2002) (prosecution history). Third, "[d]efiniteness is measured from the viewpoint of a person skilled in [the] art at the time the patent was filed ." Brief for Respondent 55 (emphasis added). See generally Sarnoff & Manzo, An Introduction to, Premises of, and Problems With Patent Claim Construction, in Patent Claim Construction in the Federal Circuit 9 (E. Manzo ed. 2014) ("Patent claims ... should be construed from an objective perspective of a [skilled artisan], based on what the applicant actually claimed, disclosed, and stated during the application process.").
The parties differ, however, in their articulations of just how much imprecision § 112, ¶ 2 tolerates. In Nautilus' view, a patent is invalid when a claim is "ambiguous, such that readers could reasonably interpret the claim's scope differently." Brief for Petitioner 37. Biosig and the Solicitor General would require only that the patent provide reasonable notice of the scope of the claimed invention. See Brief
Section 112, we have said, entails a "delicate balance." Festo, 535 U.S., at 731 , 122 S.Ct. 1831 . On the one hand, the definiteness requirement must take into account the inherent limitations of language. See ibid. Some modicum of uncertainty, the Court has recognized, is the "price of ensuring the appropriate incentives for innovation." Id., at 732, 122 S.Ct. 1831 . One must bear in mind, moreover, that patents are "not addressed to lawyers, or even to the public generally," but rather to those skilled in the relevant art. Carnegie Steel Co. v. Cambria Iron Co., 185 U.S. 403 , 437, 22 S.Ct. 698 , 46 L.Ed. 968 (1902) (also stating that "any description which is
To determine the proper office of the definiteness command, therefore, we must reconcile concerns that tug in opposite directions. Cognizant of the competing concerns, we read § 112, ¶ 2 to require that a patent's claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty. The definiteness requirement, so understood, mandates clarity, while recognizing that absolute precision is unattainable. The standard we adopt accords with opinions of this Court stating that "the certainty which the law requires in patents is not greater than is reasonable, having regard to their subject-matter." Minerals Separation, Ltd. v. Hyde, 242 U.S. 261 , 270, 37 S.Ct. 82 , 61 L.Ed. 286 (1916). See
7 Online at http://www.ftc. gov/sites/default/files/documents/reports/evolving-ip-marketplace-aligning-patent-notice-and-remedies-competition-report-federal-trade/110307 patentreport.pdf (as visited May 30, 2014, and available in Clerk of Court's case file).
B
In resolving Nautilus' definiteness challenge, the Federal Circuit asked whether the '753 patent's claims were "amenable to construction" or "insolubly ambiguous." Those formulations can breed lower court confusion,[8] for they lack the precision § 112, ¶ 2 demands. It cannot be sufficient that a court can ascribe some meaning to a patent's claims; the definiteness inquiry trains on the understanding of a skilled artisan at the time of the patent application, not that of a court viewing matters post hoc . To tolerate imprecision just short of that rendering a claim "insolubly ambiguous" would diminish the definiteness requirement's public-notice function and foster the innovation-discouraging "zone of uncertainty," United Carbon, 317 U.S., at 236 , 63 S.Ct. 165 , against which this Court has warned.
Appreciating that "terms like 'insolubly ambiguous' may not be felicitous," Brief for Respondent 34, Biosig argues the phrase is a shorthand label for a more probing inquiry that the Federal Circuit applies in practice. The Federal Circuit's fuller explications of the term "insolubly ambiguous," we recognize, may come closer to tracking the statutory prescription. See, e.g., 715 F.3d, at 898 (case below) ("[I]f reasonable efforts at claim construction result in a definition that does not provide sufficient particularity and clarity to inform skilled artisans of the bounds of the claim, the claim is
8 See, e.g., Every Penny Counts, Inc. v. Wells Fargo Bank, N. A., --- F.Supp.2d ----, ----, 2014 WL 869092 , *4 (M.D.Fla., Mar. 5, 2014) (finding that "the account," as used in claim, "lacks definiteness," because it might mean several different things and "no informed and confident choice is available among the contending definitions," but that "the extent of the indefiniteness ... falls far short of the 'insoluble ambiguity' required to invalidate the claim").
9 E.g., Hearing Components, Inc. v. Shure Inc., 600 F.3d 1357 , 1366 (C.A.Fed.2010) ("the definiteness of claim terms depends on whether those terms can be given any reasonable meaning"); Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342 , 1347 (C.A.Fed.2005) ("Only claims 'not amenable to construction' or 'insolubly ambiguous' are indefinite."); Exxon Research & Engineering Co. v. United States, 265 F.3d 1371 , 1375 (C.A.Fed.2001) ("If a claim is insolubly ambiguous, and no narrowing construction can properly be adopted, we have held the claim indefinite."). See also Dept. of Commerce, Manual of Patent Examining Procedure § 2173.02(I), p. 294 (9th ed. 2014) (PTO manual describing Federal Circuit's test as upholding a claim's validity "if some meaning can be gleaned from the language").
10 The Federal Circuit suggests that a permissive definiteness standard " 'accord[s] respect to the statutory presumption of patent validity.' " 715 F.3d 891 , 902 (2013) (quoting Exxon Research, 265 F.3d, at 1375 ). See also § 282, ¶ 1 ("[a] patent shall be presumed valid," and "[t]he burden of establishing invalidity of a patent or any claim thereof shall rest on the party asserting such invalidity"); Microsoft Corp. v. i4i Ltd. Partnership, 564 U.S. ----, ----, 131 S.Ct. 2238 , 2242, 180 L.Ed.2d 131 (2011) (invalidity defenses must be proved by "clear and convincing evidence"). As the parties appear to agree, however, this presumption of validity does not alter the degree of clarity that § 112, ¶ 2 demands from patent applicants; to the contrary, it incorporates that definiteness requirement by reference. See § 282, ¶ 2(3) (defenses to infringement actions include "[i]nvalidity of the patent or any claim in suit for failure to comply with ... any requirement of [§ 112 ]"). The parties nonetheless dispute whether factual findings subsidiary to the ultimate issue of definiteness trigger the clear-and-convincing-evidence standard and, relatedly, whether deference is due to the PTO's resolution of disputed issues of fact. We leave these questions for another day. The court below treated definiteness as "a legal issue [the] court reviews without deference," 715 F.3d, at 897 , and Biosig has not called our attention to any contested factual matter-or PTO determination thereof-pertinent to its infringement claims.
The patent laws have retained this requirement of definiteness even as the focus of patent construction has shifted. Under early patent practice in the United States, we have recounted, it was the written specification that "represented the key to the patent." Markman, 517 U.S., at 379 , 116 S.Ct. 1384 . Eventually, however, patent applicants began to set out the invention's scope in a separate section known as the "claim." See generally 1 R. Moy, Walker on Patents § 4.2, pp. 4-17 to 4-20 (4th ed. 2012). The Patent Act of 1870 expressly conditioned the receipt of a patent on the inventor's inclusion of one or more such claims, described with particularity and distinctness. See Act of July 8, 1870, § 26, 16 Stat. 201 (to obtain a patent, the inventor must "particularly point out and distinctly claim the part, improvement, or combination which [the inventor] claims as his invention or discovery").
The 1870 Act's definiteness requirement survives today, largely unaltered. Section 112 of the Patent Act of 1952, applicable to this case, requires the patent applicant to conclude the specification with "one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention." 35 U.S.C. § 112 , ¶ 2 (2006 ed.). A lack of definiteness renders invalid "the patent or any claim in suit." § 282, ¶ 2(3).[1]
1 In the Leahy-Smith America Invents Act, Pub.L. 112-29, 125 Stat. 284 , enacted in 2011, Congress amended several parts of the Patent Act. Those amendments modified §§ 112 and 282 in minor respects not pertinent here. In any event, the amended versions of those provisions are inapplicable to patent applications filed before September 16, 2012, and proceedings commenced before September 16, 2011. See §§ 4(e), 15(c), 20( l ), 125 Stat. 297 , 328, 335, notes following 35 U.S.C. §§ 2 , 111, 119. Here, the application for the patent-in-suit was filed in 1992, and the relevant court proceedings were initiated in 2010. Accordingly, this opinion's citations to the Patent Act refer to the 2006 edition of the United States Code.
Biosig thereafter reinstituted its infringement suit, which the parties had voluntarily dismissed without prejudice while PTO reexamination was underway. In 2011, the District Court conducted a hearing to determine the proper construction of the patent's claims, see Markman v. Westview Instruments, Inc., 517 U.S. 370 , 116 S.Ct. 1384 , 134 L.Ed.2d 577 (1996) (claim construction is a matter of law reserved for court decision), including the
We granted certiorari, 571 U.S. ----, 134 S.Ct. 896 , 187 L.Ed.2d 702 (2014), and now vacate and remand.
At the same time, a patent must be precise enough to afford clear notice of what is claimed, thereby " 'appris[ing] the public of what is still open to them.' " Markman, 517 U.S., at 373 , 116 S.Ct. 1384 (quoting McClain v. Ortmayer, 141 U.S. 419 , 424, 12 S.Ct. 76 , 35 L.Ed. 800 (1891) ).[6] Otherwise there would be "[a] zone of uncertainty
5 See also Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45 , 58, 65-66, 43 S.Ct. 322 , 67 L.Ed. 523 (1923) (upholding as definite a patent for an improvement to a paper-making machine, which provided that a wire be placed at a "high" or "substantial elevation," where "readers ... skilled in the art of paper making and versed in the use of the ... machine" would have "no difficulty ... in determining ... the substantial [elevation] needed" for the machine to operate as specified).
6 See also United Carbon Co. v. Binney & Smith Co., 317 U.S. 228 , 236, 63 S.Ct. 165 , 87 L.Ed. 232 (1942) ("The statutory requirement of particularity and distinctness in claims is met only when they clearly distinguish what is claimed from what went before in the art and clearly circumscribe what is foreclosed from future enterprise."); General Elec. Co. v. Wabash Appliance Corp., 304 U.S. 364 , 369, 58 S.Ct. 899 , 82 L.Ed. 1402 (1938) ("The limits of a patent must be known for the protection of the patentee, the encouragement of the inventive genius of others and the assurance that the subject of the patent will be dedicated ultimately to the public.").
IV
"[M]indful that we are a court of review, not of first view," Cutter v. Wilkinson, 544 U.S. 709 , 718, n. 7, 125 S.Ct. 2113 , 161 L.Ed.2d 1020 (2005), we decline to apply the standard we have announced to the controversy between Nautilus and Biosig. As we have explained, the Federal Circuit invoked a standard more amorphous than the statutory definiteness requirement allows. We therefore follow our ordinary practice of remanding so that the Court of Appeals can reconsider, under the proper standard, whether the relevant claims in the '753 patent are sufficiently definite. See, e.g., Johnson v. California, 543 U.S. 499 , 515, 125 S.Ct. 1141 , 160 L.Ed.2d 949 (2005) ; Gasperini v. Center for Humanities, Inc., 518 U.S. 415 , 438, 116 S.Ct. 2211 , 135 L.Ed.2d 659 (1996).
* * *
For the reasons stated, we vacate the judgment of the United States Court of Appeals for the Federal Circuit and remand the case for further proceedings consistent with this opinion.
It is so ordered.
APPENDIX
11 Notably, however, all three panel members found Nautilus' arguments unavailing.
Cases cited
- 715 F.3d 891 715 F.3d 891 p. 901, p. 906
- Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. 535 U.S. 722 at 731 p. 902, p. 908, p. 909
- Markman v. Westview Instruments, Inc. 517 U.S. 370 at 389, at 379, at 373 p. 902, p. 904, p. 911, p. 2125, p. 2127, p. 2128, p. 2129
- 417 F.3d 1342 417 F.3d 1342 at 905 p. 906, p. 907
- General Electric Co. v. Wabash Appliance Corp. 304 U.S. 364 p. 908
- United States v. Adams 383 U.S. 39 p. 908
- Carnegie Steel Co. v. Cambria Iron Co. 185 U.S. 403 p. 909
- United Carbon Co. v. Binney & Smith Co. 317 U.S. 228 at 236 p. 910, p. 911
- 514 F.3d 1244 514 F.3d 1244 p. 910
- 904 F.2d 1558 904 F.2d 1558 p. 910
- Minerals Separation, Ltd. v. Hyde 242 U.S. 261 p. 910
- Warner-Jenkinson Co. v. Hilton Davis Chemical Co. 520 U.S. 17 p. 912
- 134 S.Ct. 896 134 S.Ct. 896 p. 2128
- McClain v. Ortmayer 141 U.S. 419 p. 2129
- Cutter v. Wilkinson 544 U.S. 709 p. 2131
- Johnson v. California 543 U.S. 499 p. 2131
- Gasperini v. Center for Humanities, Inc. 518 U.S. 415 p. 2131