The Supreme Court Passes on a § 101 Patentability Case: A Recap of CardioNet v. InfoBionic

By Alistair McIntyre, J.D. Candidate, 2021

On January 25, 2021, the Supreme Court denied a petition for writ of certiorari in CardioNet, LLC v. InfoBionic, Inc.,¹ passing up an opportunity to clarify patent eligibility under 35 U.S.C. § 101. Cases involving § 101 patentability remain unpredictable,² perhaps because the doctrine has been difficult for courts like the Federal Circuit to apply consistently.³

The difficulty of applying § 101 doctrine is evident in CardioNet. Patent No. 7,941,207 (“’207 Patent”), at issue, describes a cardiac monitoring system and associated techniques for “detecting and distinguishing atrial fibrillation and atrial flutter from other various forms of cardiac arrythmia.”⁴ According to CardioNet’s patent application and relevant parts of the claim, the system tracks these abnormal heart rhythms by determining variability over a series of measured heartbeats.⁵ The district court dismissed the case on the grounds that the ’207 patent was ineligible under § 101, and CardioNet appealed.⁶ The Federal Circuit reversed and remanded, concluding that CardioNet’s claims were actually patent eligible.⁷

Courts use the Alice test to determine whether an invention is patentable under § 101.⁸ First, a court determines if the patent claims are directed to a patent-ineligible concept, such as an abstract idea.⁹ If so, the court proceeds to the second prong, which asks whether the claims’ additional limitations contain an “inventive concept” that is “sufficient to ensure that the patent . . . amounts to significantly more than a patent [than] the [ineligible concept] itself.”¹⁰ Further limitations that are “well-understood, routine, conventional activit[ies] previously engaged in by researchers in the field” are insufficient to make claims directed to a patent-ineligible concept eligible.¹¹

In CardioNet, the district court applied the first step of the Alice test to find that CardioNet’s claims were directed to an abstract idea: distinguishing atrial fibrillation and atrial flutter by focusing on heartbeat variability.¹² The district court further found that the claims failed the Alice test’s second step, because CardioNet had not claimed anything beyond basic steps that doctors already employ, despite the company’s claims that its invention was a medical device that improved cardiac monitoring and led to “more accurate and clinically significant detection.”¹³

The Federal Circuit overturned this ruling, concluding that CardioNet’s claims were actually directed to a patent-eligible “improved cardiac monitoring device,” satisfying step one of the Alice test.¹⁴ The court reasoned that because the claims “focus[ed] on a specific means or method that improves” the monitoring of heartbeats, they were not directed to an abstract idea.¹⁵ Additionally, the Federal Circuit found the patent’s written description valuable in providing evidence that the claimed invention was a significant improvement over existing methodology.¹⁶

Where did the district court’s Alice analysis go wrong? According to the Federal Circuit, the lower court assumed that “the claims [were] directed to automating known techniques.”¹⁷ Despite no support in the record, the district court found that claim 1 of the ’207 patent merely automated diagnostic techniques that had long been used by doctors.¹⁸ Further, the district court failed to consider the patent’s written description when making this determination.¹⁹ The written description’s recitation of the claimed invention’s advantages was important to the Federal Circuit’s conclusion that the ’207 patent represented a technological improvement to cardiac monitoring.²⁰

It is unclear why the Supreme Court denied certiorari.²¹ It seems that the disagreement between the district court and Federal Circuit in CardioNet is simply another example of courts struggling with § 101 patentability and Alice doctrine.