Navigating Terms of Degree Post-Nautilus

This article appeared in the September 25, 2014 Edition of IP Law 360

At the heart of nearly every patent litigation is a dispute over the meaning of claim terms. Such disputes often arise in the form of a claim definiteness challenge by the accused infringer. Recently, in Nautilus v. Biosig1, the Supreme Court relaxed the requirements for proving a claim indefinite, but offered very little guidance as to how claim drafters might comply with its ruling.

The June 2, 2014 Nautilus ruling overturned the Federal Circuit’s “insoluble ambiguity” and “amenable to construction” tests for determining whether a patent claim is invalid for indefiniteness.2 The test for indefiniteness is now whether the “claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”3

The dispute in Nautilus turned on the patent’s claim language requiring pairs of electrodes “in spaced relationship with each other.” The term “spaced relationship” qualified as a term of degree because in the claim language itself there was no upper or lower bound as to the exact spacing between the two electrodes.4 The Federal Circuit concluded that the space had to be smaller than the human hand and large enough that the two kinds of electrodes in the claims did not effectively merge such that the electrodes could not detect separate signals from the user’s hand.5 The Supreme Court vacated that decision, however, and remanded the case to the Federal Circuit for reconsideration under the Court’s newly articulated legal standard for definiteness, casting doubt on the continued vitality of patent claims that use a term of degree, at least in the near term.6

Since Nautilus, several district courts have addressed terms of degree in evaluating indefiniteness under the new standard. While the case law on indefiniteness continues to evolve, the rulings in these recent cases offer valuable insight into how one might use Nautilus as a tool to attack and defend claim terms of degree in litigation and also provide some much needed guidance to patent prosecutors when drafting claims.

Post-Nautilus District Court Cases Involving Claim Terms of Degree

On July 9, 2014, the Middle District of Louisiana decided Broussard v. Go-Devil Mfg., where the Defendants raised the issue of indefiniteness on summary judgment in a case involving alleged infringement of an outboard motor patent.7 Following trial, the district court solicited supplemental briefing on indefiniteness in light of Nautilus.8 The claims at issue recited an “elongated drive housing” attached to a “propeller shaft,” said propeller shaft (1) “extending at least 12 inches beyond said [elongated] drive housing” in the first patent-in-suit, and (2) “extending in excess of 18 inches beyond [said elongated] drive housing” in the second patent-in-suit.9

Although the claim language did not on its face implicate term of degree issues, the patents-in-suit made contradicting term of degree type statements, such as “it is necessary to extend the length of the propeller shaft 28 and its housing assembly 26 a significant distance in excess of 18 inches from the belt drive housing 22 in accordance with the horsepower of the engine” and “the overall length of the drive assembly 12 is considerably shorter than that of other drives used for this purpose.”10The district court also noted that its construction of the term “elongated drive housing” to mean “a drive housing that is greater in measurement in one axis than in the other two axes” compounded the ambiguity of the claims.11 Presumably, this was because one axis would result in a different length measurement than the other two axes.

Invoking Nautilus, the Broussard court found that the lack of a maximum length limitation improperly expanded the claims to include traditional long-tail motors in the prior art.12 Of critical importance, the district court found that the claims and specification of the patents-in-suit failed to provide such a maximum length limitation, and pointed to the trial testimony from both sides’ experts that nothing in the patents gave a maximum length limitation to the propeller shaft.13Based on this testimony, the district court determined that the claims created precisely the type of “zone of uncertainty” that the Supreme Court warned against in Nautilus.14

On July 23, 2014, the Western District of Pennsylvania decided In re Maxim Integrated Prods., where the disputed claim term was a “substantially unique electronically readable identification number.”15 Defendants argued that this phrase was indefinite because there was no standard against which the phrase “substantially unique” could be measured.16 The Special Master disagreed with the Defendants in his report and concluded that the term was definite because “substantially unique” meant unique enough to distinguish one portable module from another portable module.17The district court subsequently adopted the Special Master’s report on this issue.18

Post-Nautilus, the Defendants appealed the court’s adoption of the Special Master’s report.19 Upon revisiting the issue of indefiniteness, the district noted that although the Nautilus patent-in-suit included the phrase “produce a substantially zero [EMG] signal,” the Supreme Court never addressed the word-of-degree issue raised by the term “substantially” in Nautilus.20 Thus, the district court found that Nautilus did not require the court to alter its prior ruling that the claim term was definite.21

On June 23, 2014, the Eastern District of Texas decided Endo Pharm. v. Watson Labs., where the Defendants argued that the term “with increased penetration” was a term of degree and invalid under Nautilus.22 The district court rejected the Defendants’ contention that the term “with increased penetration” was a term of degree because there was nothing subjective about the phrase.23 According to the district court, one skilled in the art would understand that “any amount of increase in penetration would meet this limitation, if it constituted a separate limitation of the claims.”24

In a similar vein, the Defendants argued that the term “reducing inflammation” was a term of degree.25 The district court also rejected this argument because “[a]ny amount of reduction would meet this limitation if it were a separate limitation of the claims.”26

Litigation and Claim Drafting Strategies

Given the different district court interpretations of Nautilus, litigators should be prepared to distinguish Nautilus or use it to their advantage, where appropriate. When defending a term of degree, patentees may point to In re Maxim Integrated Prods. to frame an argument that Nautilus did not address terms of degree directly and then explain why the claim language on its face favors a particular claim construction. In view of Endo Pharm., Defendants should be cautious in advancing a term of degree argument when the disputed claim term is facially clear.

Conversely, when the specification contains contradictory statements or litigants advance claim constructions that turn seemingly clear claim language into a term of degree as in Broussard, an indefiniteness argument may be framed. In these circumstances, defendants, if feasible, should seek to analogize a claim term to the “spaced relationship” limitation at issue in Nautilus.

To minimize the likelihood of an indefiniteness finding, claim drafters might consider adding upper and lower bounds in dependent claims. For example, in Nautilus, several dependent claims could have been added that specified the spacing dimensions of the “spaced relationship.” However, it seems that even when bounds are provided in the specification, as in Broussard, a court may be reluctant to read in limitations from the specification where there are conflicting dimensions given.

In Broussard, a chain of dependent claims could have been added to specify the maximum length limitation or upper bounds of the claim scope. This might have presented the patentee in Broussard with a claim differentiation argument that the independent claims at issue were simply the combined scope of the dependent claims even though the upper bound was not explicit.

On September 10, 2014, the Federal Circuit decided Interval Licensing LLC v. AOL, Inc., where the district court found the disputed term of degree “unobtrusive manner” indefinite under the pre-Nautilus standard.27 The Federal Circuit affirmed the district court’s finding of indefiniteness because the claim language lacked objective boundaries and the example from the specification would leave a skilled artisan wondering what other forms of display are unobtrusive and non-distracting.28 However, the Federal Circuit warned that “[w]e do not understand the Supreme Court to have implied in Nautilus, and we do not hold today, that terms of degree are inherently indefinite.”29

Since Nautilus, both the accused infringer, Nautilus, and the patentee, Biosig, have filed briefs in the remanded case. In its brief, Nautilus has argued that the Federal Circuit must find Biosig’s patent indefinite and that not doing so would “defeat the Supreme Court’s stated goal of eliminating the powerful incentives to draft unclear, imprecise claims.”30 Biosig argued that the Supreme Court’s new test does not merit a change in the Federal Circuit’s previous ruling that found its patent definite.31 The Federal Circuit has yet to decide whether Biosig’s patent satisfies the Supreme Court’s new test for indefiniteness.


1Nautilus, Inc. v. Biosig Instruments, Inc., 134 S.Ct. 2120 (2014).
2See id. at 2124.
3See id.
4See id. at 2127.
5See id.
6See Nautilus at 2131.
7Broussard v. Go-Devil Mfg. Co., No. 3:08-cv-00124, slip op. at 93 n.2 (M.D. La. July 9, 2014).
8See id.
9See id. at 95.
10See id. at 96.
11See id. at 95.
12See id. at 97.
13See id at 96-97.
14See id. at 97.
15In re Maxim Integrated Prods., Inc., Misc. No. 12-244, slip op. at 18 (W.D. Pa. July 23, 2014).
16See id.
17See id. at 18-19.
18See id. at 19.
19See id.
20See id.
21See id.
22Endo Pharm., Inc. v. Watson Labs., Inc., No. 2:13-cv-192, slip op. at 7 (E.D. Tex. June 23, 2014).
23See id. at 15.
24See id.
25See id. at 18.
26See id.
27Interval Licensing LLC v. AOL, Inc., Appeal No. 2013-1282, slip op. at 8 (Fed. Cir. Sept. 10, 2014).
28See id. at 13.
29See id. at 11.
30See Supp. Br. of Nautilus, Inc. at 1, filed Aug. 15, 2014 (Appeal No. 2012-1289).
31See Supp. Br. of Biosig Instruments, Inc. at 1, filed Aug. 15, 2014 (Appeal No. 2012-1289).