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CACF's Opinion in CardioNet v. InfoBionic Highlights the Importance of Patent Drafting in Defeating Potential Section 101 Challenges

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Since the Supreme Court’s decision in Alice v. CLS Bank, the Federal Circuit has issued a number of opinions addressing what is patent-eligible subject matter.  In an opinion issued in April 2019, the Federal Circuit relied heavily on the written description of the patent-at-issue, and found the asserted claims to be directed to patent-eligible subject matter in the form of an improved cardiac monitoring device.[1]  This article addresses the potential importance of intrinsic evidence in defeating potential Section 101 challenges. 

Section 101 provides that “any new and useful process, machine, manufacture, or composition of matter” is patent-eligible.[2]  The Supreme Court has identified certain subject matter (also known as “judicial exceptions”) that are not patent-eligible, i.e., laws of nature, natural phenomena, and abstract ideas.[3] The Supreme Court further articulated a two-step test in Alice to examine patent eligibility when a patent claim may involve one of the three judicial exceptions.[4] At step one, courts consider the claim in its entirety to determine whether the claim as a whole is directed to a judicial exception.  If the claim is not directed to a judicial exception, the claim satisfies Section 101 and courts need not proceed further.[5]

The Federal Circuit has found in a number of cases that when the claimed invention improves the functioning of a computer or another technical field, the claim as a whole is not directed to a judicial exception.[6]  In view of the Federal Circuit’s decisions, the United States Patent and Trademark Office (USPTO) amended the Ninth Edition of the Manual of Patent Examination Procedure (MPEP) in June 2020 to provide further guidance to Examiners in evaluating whether a claim that includes a judicial exception may nonetheless be patent-eligible.[7]

District Court’s Decision
In CardioNet v. InfoBionic, CardioNet sued InfoBionic for infringement of U.S. Patent No. 7,941,207 (“the ’207 patent”), which describes certain cardiac monitoring systems and techniques for detecting and distinguishing atrial fibrillation and atrial flutter from other various forms of cardiac arrhythmia.

The asserted claim 1 of the ’207 patent recited:

A device, comprising the:

a beat detector to identify a beat-to-beat timing of cardiac activity;

a ventricular beat detector to identify ventricular beats in the cardiac activity;

variability determination logic to determine a variability in the beat-to-beat timing of a collection of beats; relevance determination logic to identify a relevance of the variability in the beat-to-beat timing to at least one of atrial fibrillation and atrial flutter; and

an event generator to generate an event when the variability in the beat-to-beat timing is identified as relevant to the at least one of atrial fibrillation and atrial flutter in light of the variability in the beat-to-beat timing caused by ventricular beats identified by the ventricular beat detector.

The district court quickly dismissed the case under Fed. R. Civ. Proc. 12(b)(6) on the ground that the asserted claims were directed to patent-ineligible subject matter under § 101.[8]  While the district court recognized that “idea of using a machine to monitor and analyze heartbeat variability and interfering beats so as to alert the user of potential [atrial fibrillation or atrial flutter] events may well improve the field of cardiac telemetry,” it nevertheless found that CardioNet “did not identify improvements to any particular computerized technology.”[9]

Federal Circuit’s Opinion
The Federal Circuit reversed and remanded.  The Court held that the asserted claims are “directed to an improved cardiac monitoring device and not to an abstract idea.”[10]  The Court based its holding on the claim language and the written description of the patent.  First, the Court found that the language of claim 1 focuses on “a specific means or method that improves cardiac monitoring technology [and is not] directed to a result or effect that itself is the abstract idea and merely invoke generic processes and machinery.”[11]

Second, the Court looked to the written description of the patent and found that it confirmed that the claimed invention claimed improvements to cardiac monitoring technology.[12]  The Summary section of the patent included about 40 lines to describe the purported advantages of the disclosed cardiac monitoring systems and techniques, including improved sensitivity and positive predictivity in detecting atrial fibrillation (“AF”), the ability to identify sustained AF episodes, well-adapted to monitor cardiac signal of ambulatory patients, well-adapted to real-time monitoring of arrhythmia patients, requiring minimal computational resources, and requiring no training before different types of cardiac arrhythmia can be distinguished.[13]   For example, the ‘207 patent stated that:

The described systems and techniques are well-adapted to monitoring cardiac signals of ambulatory patients who are away from controlled environments such as hospital beds or treatment facilities. [] The described systems and techniques are also well-adapted to real-time monitoring of arrhythmia patients, where minimal delays in distinguishing between different types of cardiac arrhythmia can speed the delivery of any urgent medical care. The described systems and techniques also require minimal computational resources. Further, the described systems and techniques do not require training before different types of cardiac arrhythmia can be distinguished.[14]

 Even though they may not be improvements to computerized technology per se, the Court “consider[ed] them important in [the Court’s] determination that the claims are drawn to a technological improvement.”[15]

Regarding the district court’s decision, the Federal Circuit identified three errors.  First, the Court found that “[a]t the heart of the district court's erroneous step one analysis is the incorrect assumption that the claims are directed to automating known techniques.”[16]  The Court reasoned that nothing in the record, in particular the writing description, supports the district court’s finding.[17]  Second, the Court found that “the district court erred by disregarding the written description's recitation of the advantages of the claimed invention.”[18]  Finally, the Court found that the district court erred in “oversimplifying the claims by looking at them generally and failing to account for the specific requirements of the claims.”[19]

In the last part of the opinion, the Federal Circuit held that remand was unnecessary to assess the state of the art because “Alice step one presents a legal question that can be answered based on the intrinsic evidence.”[20]  The Court stated that in determining whether a claim is directed to a technological improvement, “a court may well consult the intrinsic evidence, including the plain claim language, written description, and prosecution history” and “need not consult the prior art to see if, in fact, the assertions of improvement in the patent's written description are true.”[21]  The Court reasoned that “the § 101 patent-eligibility inquiry is only a threshold test,” and “we reserve for §§ 102 and 103 purposes our comparison of the prior art and the claims to determine if the claims are, in fact, an improvement over the prior art.”[22]

Judge Dyk dissented on the last part of the opinion, and opined that the majority erred in “limiting the use of extrinsic evidence to establish that a practice is longstanding."[23]  The majority, however, responded that courts are still allowed, within their discretion, to “look outside the intrinsic evidence as part of their Alice step one inquiry.”[24]  The majority further stated that, however, “there is no basis for requiring, as a matter of law, consideration of the prior art in the step one analysis in every case.”[25] 

The case is currently on remand pending in the U.S. District Court for the District of Massachusetts. 

The Federal Circuit’s decision in CardioNet v. InfoBionic highlights the importance of intrinsic evidence in defeating potential Section 101 challenges.  Similarly, in a recent opinion, Simio, LLC v. FlexSim Software, the Federal Circuit relied heavily on the specification of the patent-at-issue to reach its decision that the asserted claim was directed to a patent ineligible abstract idea.  The Federal Circuit repeatedly quoted the specification and found that the purported advance of the claimed computer-based system “[s]imply appl[ied] the already widespread practice [] to the environment of object-oriented simulations” and the asserted claim was “directed to the use of conventional or generic technology….”[26]

Patent owners should consider drafting claims that focus on a specific technique that improves a technology or technical field, and avoiding language that merely invokes generic processes and machinery.  Patent owners should also consider including into the specification a description of specific advantages of the claimed invention, for example, a paragraph specifically identifying the “practical applications” achieved by the invention; concrete language of technical improvements that could be amended into the claims if it were ever necessary to overcome a 101 rejection; data showing specific improvements (e.g., improved sensitivity, accuracy, or efficacy) over the existing technologies. 


See CardioNet, LLC v. InfoBionic, Inc, 955 F.3d 1358, 1368 (Fed. Cir. 2020).
2 35 U.S.C. § 101.
3 See Alice Corp. v. CLS Bank Int'l, 573 U.S. 208, 216 (2014).
4 See id. at 216.
5 See Data Engine Techs. LLC v. Google LLC, 906 F.3d 999, 1007 (Fed. Cir. 2018).
6 See Enfish, LLC v. Microsoft Corp., 822 F.3d 1327, 1339 (Fed. Cir. 2016); McRO, Inc. v. Bandai Namco Games Am. Inc., 837 F.3d 1299, 1315 (Fed. Cir. 2016); Visual Memory LLC v. NVIDIA Corp., 867 F.3d 1253,1259-60 (Fed. Cir. 2017).
7 M.P.E.P. § 2106.04(d)(1)(“A claim reciting a judicial exception is not directed to the judicial exception if it also recites additional elements demonstrating that the claim as a whole integrates the exception into a practical application. One way to demonstrate such integration is when the claimed invention improves the functioning of a computer or improves another technology or technical field.”)
 See CardioNet, LLC v. InfoBionic, Inc., 348 F. Supp. 3d 87, 93 (D. Mass. 2018), rev'd and remanded sub nom. CardioNet, LLC v. InfoBionic, Inc, 955 F.3d 1358 (Fed. Cir. 2020).
9 Id.
 CardioNet, LLC v. InfoBionic, Inc, 955 F.3d 1358, 1368 (Fed. Cir. 2020).
11 Id. at 1368-1369.
12 Id.
13 The ’207 patent col. 3 ll 6-43.
14 Id. at col.3 ll 27-43.
15 CardioNet, 955 F.3d at 1370.
16 Id.
17 Id.
18 Id. at 1371.
19 Id.
20 Id. at 1372.
21 Id. at 1372-1373.
22 Id. at 1373.
23 Id. at 1375.
24 Id. at 1373.
25 Id.
26 Simio, LLC v. FlexSim Software Prod., Inc., No. 2020-1171, 2020 WL 7703014, at *4 (Fed. Cir. Dec. 29, 2020).


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