United States: Supreme Court Reverses Federal Circuit On Indefiniteness And Divided Infringement In Nautilus And Limelight

In two opinions issued on June 2, 2014, the Supreme Court rejected the Federal Circuit's claim definiteness and indirect infringement tests, and reversed the Federal Circuit's holding in each case. In Nautilus, Inc. v. Biosig Instruments, Inc., No. 13-369, the Supreme Court adopted a "reasonable certainty" test for claim definiteness under 35 U.S.C. § 112, ¶ 2, holding that the Federal Circuit's more lenient formulations "can leave courts and the patent bar at sea without a reliable compass." In Limelight Networks, Inc. v. Akamai Technologies, Inc., No. 12-786, the Court effectively abolished the doctrine of divided infringement under 35 U.S.C. § 271(b), holding that the Federal Circuit's analysis of the issue "fundamentally misunderstands what it means to infringe a method patent."

I. Nautilus, Inc. v. Biosig Instruments, Inc.: Definiteness Under 35 U.S.C. § 112 Requires "Reasonable Certainty"

Section 112, ¶ 2 requires that patent claims particularly point out and distinctly claim the invention. The Federal Circuit has long held that a claim satisfies the definiteness requirement of § 112, ¶ 2 if it is "amenable to construction," and, as construed, is not "insolubly ambiguous." Applying these formulations in Nautilus, the Federal Circuit held that the claims at issue (relating to heart-rate monitors for use during exercise) survived an indefiniteness challenge. 

Justice Ginsburg, writing for the unanimous Court, rejected the Federal Circuit's formulations and adopted a new test, which provides that "a patent is invalid for indefiniteness if its 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." The Court expressed no opinion on the validity of the patents at issue, and instead, vacated and remanded for consideration of the indefiniteness challenge under the new test.

While critical of the Federal Circuit's formulations, the Supreme Court recognized the "inherent limitations of language" and the "necessary modicum of uncertainty" in claim language. Nonetheless, the Court, citing its precedent, held that "a patent must be precise enough to afford clear notice of what is claimed" so that the public is apprised of what remains open to them. The Court further recognized that "absent a meaningful definiteness check," patent applicants have "powerful incentives to inject ambiguities into their claims." In the Court's view, its "reasonable certainty" test should eliminate "that temptation," and the test properly places the burden of resolving claim language ambiguity on the patent drafter.

The decision in Nautilus likely paves the way for more frequent and more successful claim indefiniteness challenges from accused infringers. The decision also serves as a strong caution to patent drafters of the need for precision in claim language. Debates over whether definiteness is a question of law and the level of deference due to the PTO's resolution of disputed issues of fact are likely to continue, as the Court opted to "leave[ ] these questions for another day."

II. Limelight Networks, Inc. v. Akamai Technologies, Inc.: Divided Infringement Abolished Under 35 U.S.C. § 271(b)

The Supreme Court effectively eliminated the doctrine of divided infringement under 35 U.S.C. § 271(b) in its unanimous reversal of the Federal Circuit in Limelight. In an opinion authored by Justice Alito, the Court held that a defendant cannot be liable under § 271(b) for inducing infringement unless a single entity has directly infringed the claims.

Liability for induced infringement under § 271(b) depends on the existence of an underlying act of direct infringement under § 271(a).  The Federal Circuit had developed a line of precedent holding that induced infringement may exist even where no single entity committed an act of direct infringement under § 271(a). The Supreme Court held that the Federal Circuit's doctrine of divided infringement departed from the plain language of the § 271(b). In so holding, the Court was not persuaded by the Federal Circuit's concern that a potential infringer may artfully dodge liability by dividing performance of a method patent's steps with another person who is not under the potential infringer's direction or control.

The Court noted that the patentee's lack of recourse for infringement of its method claims in Limelight was the result of the Federal Circuit's holding in Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318 (2008), that direct infringement requires that "a single party to perform every step of a claimed method" or that a single party "exercise[s] control or direction over the entire process." The Supreme Court hinted that it may not agree with Muniauction, but declined to address whether Muniauction was decided correctly. Instead, the Court reasoned that the Federal Circuit could not circumvent the consequences it created in Muniauction by altering the fundamental rules of inducement liability.

In light of Limelight, patent applicants should draft claims, particularly method claims, to permit performance by a single entity. Both patent applicants and litigants should be mindful that there may be room for the Federal Circuit or Supreme Court to reexamine Muniauction's rule that an agency relationship must exist between parties who perform the method steps in finding liability under § 271(a).

This article is intended to provide information of general interest to the public and is not intended to offer legal advice about specific situations or problems. Brinks Gilson & Lione does not intend to create an attorney-client relationship by offering this information and review of the information shall not be deemed to create such a relationship. You should consult a lawyer if you have a legal matter requiring attention. For further information, please contact a Brinks Gilson & Lione lawyer.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

In association with
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Check to state you have read and
agree to our Terms and Conditions

Terms & Conditions and Privacy Statement

Mondaq.com (the Website) is owned and managed by Mondaq Ltd and as a user you are granted a non-exclusive, revocable license to access the Website under its terms and conditions of use. Your use of the Website constitutes your agreement to the following terms and conditions of use. Mondaq Ltd may terminate your use of the Website if you are in breach of these terms and conditions or if Mondaq Ltd decides to terminate your license of use for whatever reason.

Use of www.mondaq.com

You may use the Website but are required to register as a user if you wish to read the full text of the content and articles available (the Content). You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these terms & conditions or with the prior written consent of Mondaq Ltd. You may not use electronic or other means to extract details or information about Mondaq.com’s content, users or contributors in order to offer them any services or products which compete directly or indirectly with Mondaq Ltd’s services and products.


Mondaq Ltd and/or its respective suppliers make no representations about the suitability of the information contained in the documents and related graphics published on this server for any purpose. All such documents and related graphics are provided "as is" without warranty of any kind. Mondaq Ltd and/or its respective suppliers hereby disclaim all warranties and conditions with regard to this information, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. In no event shall Mondaq Ltd and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of information available from this server.

The documents and related graphics published on this server could include technical inaccuracies or typographical errors. Changes are periodically added to the information herein. Mondaq Ltd and/or its respective suppliers may make improvements and/or changes in the product(s) and/or the program(s) described herein at any time.


Mondaq Ltd requires you to register and provide information that personally identifies you, including what sort of information you are interested in, for three primary purposes:

  • To allow you to personalize the Mondaq websites you are visiting.
  • To enable features such as password reminder, newsletter alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our information providers who provide information free for your use.

Mondaq (and its affiliate sites) do not sell or provide your details to third parties other than information providers. The reason we provide our information providers with this information is so that they can measure the response their articles are receiving and provide you with information about their products and services.

If you do not want us to provide your name and email address you may opt out by clicking here .

If you do not wish to receive any future announcements of products and services offered by Mondaq by clicking here .

Information Collection and Use

We require site users to register with Mondaq (and its affiliate sites) to view the free information on the site. We also collect information from our users at several different points on the websites: this is so that we can customise the sites according to individual usage, provide 'session-aware' functionality, and ensure that content is acquired and developed appropriately. This gives us an overall picture of our user profiles, which in turn shows to our Editorial Contributors the type of person they are reaching by posting articles on Mondaq (and its affiliate sites) – meaning more free content for registered users.

We are only able to provide the material on the Mondaq (and its affiliate sites) site free to site visitors because we can pass on information about the pages that users are viewing and the personal information users provide to us (e.g. email addresses) to reputable contributing firms such as law firms who author those pages. We do not sell or rent information to anyone else other than the authors of those pages, who may change from time to time. Should you wish us not to disclose your details to any of these parties, please tick the box above or tick the box marked "Opt out of Registration Information Disclosure" on the Your Profile page. We and our author organisations may only contact you via email or other means if you allow us to do so. Users can opt out of contact when they register on the site, or send an email to unsubscribe@mondaq.com with “no disclosure” in the subject heading

Mondaq News Alerts

In order to receive Mondaq News Alerts, users have to complete a separate registration form. This is a personalised service where users choose regions and topics of interest and we send it only to those users who have requested it. Users can stop receiving these Alerts by going to the Mondaq News Alerts page and deselecting all interest areas. In the same way users can amend their personal preferences to add or remove subject areas.


A cookie is a small text file written to a user’s hard drive that contains an identifying user number. The cookies do not contain any personal information about users. We use the cookie so users do not have to log in every time they use the service and the cookie will automatically expire if you do not visit the Mondaq website (or its affiliate sites) for 12 months. We also use the cookie to personalise a user's experience of the site (for example to show information specific to a user's region). As the Mondaq sites are fully personalised and cookies are essential to its core technology the site will function unpredictably with browsers that do not support cookies - or where cookies are disabled (in these circumstances we advise you to attempt to locate the information you require elsewhere on the web). However if you are concerned about the presence of a Mondaq cookie on your machine you can also choose to expire the cookie immediately (remove it) by selecting the 'Log Off' menu option as the last thing you do when you use the site.

Some of our business partners may use cookies on our site (for example, advertisers). However, we have no access to or control over these cookies and we are not aware of any at present that do so.

Log Files

We use IP addresses to analyse trends, administer the site, track movement, and gather broad demographic information for aggregate use. IP addresses are not linked to personally identifiable information.


This web site contains links to other sites. Please be aware that Mondaq (or its affiliate sites) are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of these third party sites. This privacy statement applies solely to information collected by this Web site.

Surveys & Contests

From time-to-time our site requests information from users via surveys or contests. Participation in these surveys or contests is completely voluntary and the user therefore has a choice whether or not to disclose any information requested. Information requested may include contact information (such as name and delivery address), and demographic information (such as postcode, age level). Contact information will be used to notify the winners and award prizes. Survey information will be used for purposes of monitoring or improving the functionality of the site.


If a user elects to use our referral service for informing a friend about our site, we ask them for the friend’s name and email address. Mondaq stores this information and may contact the friend to invite them to register with Mondaq, but they will not be contacted more than once. The friend may contact Mondaq to request the removal of this information from our database.


From time to time Mondaq may send you emails promoting Mondaq services including new services. You may opt out of receiving such emails by clicking below.

*** If you do not wish to receive any future announcements of services offered by Mondaq you may opt out by clicking here .


This website takes every reasonable precaution to protect our users’ information. When users submit sensitive information via the website, your information is protected using firewalls and other security technology. If you have any questions about the security at our website, you can send an email to webmaster@mondaq.com.

Correcting/Updating Personal Information

If a user’s personally identifiable information changes (such as postcode), or if a user no longer desires our service, we will endeavour to provide a way to correct, update or remove that user’s personal data provided to us. This can usually be done at the “Your Profile” page or by sending an email to EditorialAdvisor@mondaq.com.

Notification of Changes

If we decide to change our Terms & Conditions or Privacy Policy, we will post those changes on our site so our users are always aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it. If at any point we decide to use personally identifiable information in a manner different from that stated at the time it was collected, we will notify users by way of an email. Users will have a choice as to whether or not we use their information in this different manner. We will use information in accordance with the privacy policy under which the information was collected.

How to contact Mondaq

You can contact us with comments or queries at enquiries@mondaq.com.

If for some reason you believe Mondaq Ltd. has not adhered to these principles, please notify us by e-mail at problems@mondaq.com and we will use commercially reasonable efforts to determine and correct the problem promptly.