Mayo/Alice Test : CAFC Alert

Software Patents Demand Specific, Technologically Grounded Claims

| May 3, 2024

AI Visualize, Inc. vs. Nuance Communications, Inc. and Mach7 Technologies, Inc.

Decided: April 4, 2024

Before: MOORE, Chief Judge, REYNA, and HUGHES, Circuit Judges.


      The Federal Circuit upheld a district court decision that dismissed AI Visualize’s patent infringement lawsuit against Nuance Communications and Mach7 Technologies. The court agreed with the lower court’s finding that the patents claimed patent-ineligible subject matter under 35 U.S.C. § 101, focusing on abstract ideas without enough inventive concept to warrant patent protection.


      AI Visualize asserted that Nuance Communications and Mach7 Technologies had infringed on its patents related to the visualization of medical scans through a web-based portal. The patents at issue include four patents: U.S. Patent Nos. 8,701,167; 9,106,609; 9,438,667; and 10,930,397. All these patents share a common specification that describes systems and methods aimed at improving the access and visualization of volumetric medical data, such as that obtained from MRI and CT scans, through a web-based portal. The patented technology demonstrates a centralized system that processes medical scan data and visualizes it remotely, allowing efficient transmission of three-dimensional views over low-bandwidth connections, thus facilitating better diagnostic capabilities across diverse medical environments.

      The central dispute revolved around whether the patented methods and systems constituted an abstract idea under the Alice two-step framework. Nuance and Mach7 argued that the patent claims failed to transform this abstract idea into a patent-eligible application due to lack of an inventive concept. The district court agreed, finding that the patents were directed to the basic concept of manipulating and displaying data, a task it considered routine and conventional in the field.

Claim 1 of the ‘609 patent, representing the first group of claims, was central to this dispute.

1.            A system for viewing at a client device at a remote location a series of three-dimensional virtual views over the Internet of a volume visualization dataset contained on at least one centralized database comprising:

at least one transmitter for accepting volume visualization dataset from remote location and transmitting it securely to the centralized database;

at least one central data storage medium containing the volume visualization dataset;

a plurality of servers in communication with the at least one centralized database and capable of processing the volume visualization dataset to create virtual views based on client request;

a resource manager device for load balancing the plurality of servers;

a security device controlling the plurality of communications between a client device, and the server; including resource manager and central storage medium;

at least one physically secured site for housing the centralized database, plurality of servers, at least a resource manager, and at least a security device;

a web application adapted to satisfy a user’s request for the three-dimensional virtual views by: a) accepting at a remote location at least one user request for a series of virtual views of the volume visualization dataset, the series of views comprising a plurality of separate view frames, the remote location having a local data storage medium for storing frames of views of the volume visualization dataset, b) determining if any frame of the requested views of the volume visualization dataset is stored on the local data storage medium, c) transmitting from the remote location to at least one of the servers a request for any frame of the requested views not stored on the local data storage medium, d) at at least one of the servers, creating the requested frames of the requested views from the volume visualization dataset in the central storage medium, e) transmitting the created frames of the requested views from at least one of the servers to the client device, f) receiving the requested views from the at least one server, and displaying to the user at the remote location the requested series of three-dimensional virtual views of the volume visualization dataset by sequentially displaying frames transmitted from at least one of the servers along with any frames of the requested series of views stored on the local data storage medium.


      The Federal Circuit’s analysis focused on whether the district court was correct in its application of the Alice two-step test for patent eligibility. This two-step framework is critical for determining whether a patent’s claims involve patent-eligible subject matter under Section 101.

      In the first step of the Alice analysis, the court examines whether the claims at issue are directed to an abstract idea. For AI Visualize’s patents, the Federal Circuit assessed whether the system and method for visualizing medical scans, as claimed, merely recited an abstract concept without applying or using it in a uniquely technological manner.

      The court found that the patents were primarily directed to the abstract idea of manipulating and displaying data, specifically the storage, retrieval, and graphical representation of medical imaging data. The court referenced their conclusion in Hawk Tech. Sys., LLC v. Castle Retail, LLC, 60 F.4th 1349 (Fed. Cir. 2023), noting that “converting information from one format to another . . . is an abstract idea.”

      Having determined that the claims were directed to an abstract idea, the court then proceeded to step two of the Alice test, which involves determining whether the claim elements, either individually or as an ordered combination, add something significantly more to the abstract idea to transform the claim into patent-eligible subject matter. This “something more” must be an inventive concept that is not merely an instruction to implement or apply the abstract idea on a generic computer or using generic technology.

      In reviewing AI Visualize’s claims, the court concluded that the methods described for processing and visualizing medical data did not involve an inventive concept sufficient to warrant patent protection. The claims were found to involve routine and conventional computer functions that are generic enough to be performed on any computer network. This included the creation of virtual views from medical data, transmitting these views over low-bandwidth networks, and enabling remote access via a web portal—none of which constituted a technological improvement over existing practices.

      AI Visualize cites several sections of the specification to argue that creating virtual views offers a technical solution to a technical problem. This includes a section that explains how dynamic and static virtual views are formed by selecting related image frames from a volume visualization dataset. However, the court declined to consider details from the specification that are not specifically claimed.

      Moreover, the court noted that the claimed invention did not solve a technical problem in an innovative way but rather applied a known solution (data manipulation and visualization) to a practice long prevalent in the field of computer systems.

      The decision reaffirms the strict standards imposed by the Federal Circuit for patent eligibility under Section 101, emphasizing that a patent’s claims must do more than simply apply an abstract idea using conventional and well-understood applications. They must demonstrate a specific, inventive concept that enhances the technological process in a non-obvious way. This ruling highlights the challenges patent applicants face in securing protection for software-based innovations, particularly those that could be viewed as abstract ideas without clear, specific, and technologically rooted implementations.


  • The decision reinforces the importance of demonstrating a specific, technologically rooted inventive concept in patent claims, particularly in fields involving software and data manipulation.
  • Patents that broadly claim the performance of “abstract ideas” such as data retrieval and display without a clearly defined inventive mechanism are likely to face challenges under 35 U.S.C. § 101.
  • It is essential to provide detailed technical descriptions in patent applications and include technological specificity in the patent claims to effectively present the unique contributions.

Detecting Natural Phenomena Using Conventional Techniques Found “Directed to” Natural Phenomena at Alice/Mayo Step One

| September 16, 2022


Lourie, Bryson, and Hughes.  Opinion by Lourie.


The CAFC held that genetic diagnostic method claims are ineligible for patent, finding that the claims reciting conventional laboratory techniques to perform diagnosis using a naturally occurring correlation are directed to natural phenomena under Alice/Mayo step one, and also lack additional elements to constitute enough inventive concept under Alice/Mayo step two. 


            CareDx sued Natera and Eurofins in the U.S. District Court for the District of Delaware, asserting that their products infringed one or more patents licensed to CareDx.  The district court awarded summary judgment for the defendants, holding that the patents are ineligible for patent under 35 U.S.C. §101. CareDx appealed the district court’s grant of the summary judgment motions of ineligibility.

            The patents at issue, U.S. Patents 8,703,652, 9,845,497, and 10,329,607, relate to diagnosis of organ transplant status by detecting a donor’s cell-free DNA (“cfDNA”) circulating in a recipient’s body.  The specification, common to all three patents, depicts prior findings that the existence of cfDNA in blood is mostly attributed to dead cells, and had been used for various diagnostic purposes, such as cancer diagnostics and prenatal testing.  The specification notes that the cfDNA-based diagnostic scheme is applicable to organ transplant situations, where the recipient’s immune system kills incompatible donor’s cells which in turn release their nucleic acids into the recipient’s stream, such that an increased level of the donor-derived cfDNA may allow for detection of the transplant rejection.  

            Claim 1 of ‘652 patent recites:

1. A method for detecting transplant rejection, graft dysfunction, or organ failure, the method comprising:
(a) providing a sample comprising cell-free nucleic acids from a subject who has received a transplant from a donor;
(b) obtaining a genotype of donor-specific polymorphisms or a genotype of subject-specific polymorphisms, or obtaining both a genotype of donor-specific polymorphisms and subject-specific polymorphisms, to establish a polymorphism profile for detecting donor cell-free nucleic acids, wherein at least one single nucleotide polymorphism (SNP) is homozygous for the subject if the genotype comprises subject-specific polymorphisms comprising SNPs;
(c) multiplex sequencing of the cell-free nucleic acids in the sample followed by analysis of the sequencing results using the polymorphism profile to detect donor cell-free nucleic acids and subject cell-free nucleic acids; and
(d) diagnosing, predicting, or monitoring a transplant status or outcome of the subject who has received the transplant by determining a quantity of the donor cell-free nucleic acids based on the detection of the donor cell-free nucleic acids and subject cell-free nucleic acids by the multiplexed sequencing, wherein an increase in the quantity of the donor cell-free nucleic acids over time is indicative of transplant rejection, graft dysfunction or organ failure, and wherein sensitivity of the method is greater than 56% compared to sensitivity of current surveillance methods for cardiac allograft vasculopathy (CAV).

The representative claims of the three patents recite somewhat similar procedures, which may be summarized as:

  • collecting a bodily sample from the recipient,
  • “genotyping” or identifying genetic features that allow for distinction between the donor and recipient,
  • “sequencing” or determining the makeup of cfDNA included in the sample, and
  • determining, using the genetic features, the amount of cfDNA originating from the donor in the sample.

            The specification depicts that the methods are performed using specific techniques that are “standard,” “well-established” and/or reported in prior patents and scientific articles, including sophisticated polymerase chain reaction (“PCR”), such as digital PCR and selective amplification, and next-generation sequencing (“NGS”), all of which are advanced, but already known, techniques in the field. 

            The district court held that that the asserted claims were patent ineligible as they were “directed to the detection of natural phenomena, specifically, the presence of donor cfDNA in a transplant recipient and the correlation between donor cfDNA and transplant rejection” and also, “recited only conventional techniques.”

            On appeal, the CAFC performed the two-step Alice/Mayo analysis to determine patent-eligibility.

  1. Are the claims “directed to” laws of nature or natural phenomena? – Yes.

            CareDx sought to characterize the claimed invention as directed to “improved measurement methods,” in particular, patent-eligible “use of digital PCR, NGS, and selective amplification” allowing for improved accuracy in cfDNA measurement, as opposed to “discovery of a natural correlation between organ rejection and the donor’s cfDNA levels in the recipient’s blood.” CareDx also asserted that the district court improperly considered conventionality of the claimed techniques at step one, essentially merging the two steps into a single-step analysis centered on conventionality.

            The CAFC found that the claims satisfy the step one. Two contrasting precedents are notable: Illumina, Inc. v. Ariosa Diagnostics, Inc., 952 F.3d 1367, opinion modified by 967 F.3d 1319, 1327 (Fed. Cir. 2020), and Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015).  The CAFC noted that this case is different from Illumina, where the claimed improvement was a patent-eligible “method for preparing” a cfDNA fraction that would not occur naturally without manipulation of a starting sample; rather, the asserted claims are akin to those in Ariosa, wherein the claimed diagnostic methods, including the steps of “amplifying” (i.e., making many copies of) a cfDNA sample using PCR and “detecting” a certain type of cfDNA, so as to perform diagnosis using a natural correlation between certain conditions and the level of cfDNA, were found to be “directed to a natural phenomenon.” 

            The CAFC noted that the conventionally considerations are not limited to step two, and precedents have routinely performed overlapping conventionality inquiry at both stages of Alice/Mayo.  The CAFC found that the use of specific laboratory techniques relied on by CareDx only amounts to “conventional use of existing techniques to detect naturally occurring cfDNA.”  The CAFC added that the conventionality is supported by the specification’s numerous remarks characterizing the claimed techniques as “any suitable method known in the art” and similar boilerplate language.

  • Do the claims recite additional elements, aside from the natural phenomena, which transform the nature of the claim’ into a patent-eligible application? – No.

            CareDx’s main argument at step two was that the inventive concept resides in the use of the specific advanced techniques to identify and measure donor-derived cfDNA.

            The CAFC disagreed, concluding that the claimed methods lack requisite inventive concept.  In reaching the conclusion, the CAFC again pointed to the specification’s admissions of the conventionality of the individual techniques recited in the claims.   The CAFC went on to state that “[t]he specification confirms that the claimed combination of steps … was a straightforward, logical, and conventional method for detecting cfDNA previously used in other contexts,” which adds nothing inventive to the detection of natural phenomena.


This case provides a reminder that conventionality of claimed elements may affect both steps of Alice/Mayo test.  At step one, the effort to characterize the claim as being “directed to” a patent-eligible subject matter can be thwarted where the claimed elements are undisputedly conventional, in the absence of an unconventional element that is not a judicial exception to eligibility.  And at step two, the conventionality of the individual elements and their combination prohibits finding of inventive concept.

For Biotech, “Method of Preparation” Claims May Survive §101

| April 15, 2020

Illumina, Inc. v. Ariosa Diagnostics, Inc.

March 17, 2020

Lourie, Moore, and Reyna (Opinion by Lourie; Dissent by Reyna)


In a patent infringement litigation between the same parties that were involved in the earlier case, Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015) (diagnostic patent deemed patent ineligible under 35 U.S.C. §101), the United States Court of Appeals for the Federal Circuit (“Federal Circuit”) found the claimed “method of preparation” of a fraction of cell-free fetal DNA (“cff-DNA”) enriched in fetal DNA to be patent eligible, reversing the district court’s grant of summary judgment of patent ineligibility.  A dissent by J. Reyna (author of the earlier Ariosa decision) asserts that there is nothing new and useful in the claims, other than the discovery that cff-DNA tends to be shorter than cell-free maternal DNA, and that use of known laboratory techniques and commercially available testing kits to isolate the naturally occurring shorter cff-DNA does not make the claims patent eligible.


Illumina and Sequenom (collectively, “Illumina”) appealed a summary judgment ruling of patent ineligibility by the United States District Court for the Northern District of California.  The two patents at issue, USP 9,580,751 (the ‘751 patent) and USP 9,738,931 (the ‘931 patent), are unrelated to the diagnostic patent held ineligible in the 2015 Ariosa decision.  While the earlier litigated patent claimed a method for detecting the small fraction of cff-DNA in the plasma and serum of a pregnant woman that were previously discarded as medical waste, the present ‘751 and ‘931 patents claim methods for preparing a fraction of cff-DNA that is enriched in fetal DNA.  A problem with maternal plasma is that it was difficult, if not impossible, to determine fetal genetic markers (e.g., for certain diseases) because the proportion of circulatory extracellular fetal DNA in maternal plasma was tiny as compared to the majority of it (>90%) being circulatory extracellular maternal DNA. The inventor’s “surprising” discovery was that the majority of circulatory extracellular fetal DNA has a relatively small size of approximately 500 base pairs or less, as compared to the larger circulatory extracellular maternal DNA.  With this discovery, they developed the following claimed methods for preparing a DNA fraction that separated fetal DNA from maternal DNA from the maternal plasma and serum, to create a DNA fraction enriched with fetal DNA.

‘931 Patent:

1.         A method for preparing a deoxyribonucleic acid (DNA) fraction from a pregnant human female useful for analyzing a genetic locus involved in a fetal chromosomal aberration, comprising:

            (a) extracting DNA from a substantially cell-free sample of blood plasma or blood serum of a pregnant human female to obtain extracellular circulatory fetal and maternal DNA fragments;

            (b) producing a fraction of the DNA extracted in (a) by:

                        (i) size discrimination of extracellular circulatory DNA fragments, and

                        (ii) selectively removing the DNA fragments greater than approximately 500 base pairs, wherein the DNA fraction after (b) comprises a plurality of genetic loci of the extracellular circulatory fetal and maternal DNA; and

            (c) analyzing a genetic locus in the fraction of DNA produced in (b).

‘751 Patent:

1.         A method, comprising:

            (a) extracting DNA comprising maternal and fetal DNA fragments from a substantially cell-free sample of blood plasma or blood serum of a pregnant human female;

            (b) producing a fraction of the DNA extracted in (a) by:

                        (i) size discrimination of extracellular circulatory fetal and maternal DNA fragments, and

                        (ii) selectively removing the DNA fragments greater than approximately 300 base pairs, wherein the DNA fraction after (b) comprises extracellular circulatory fetal and maternal DNA fragments of approximately 300 base pairs and less and a plurality of genetic loci of the extracellular circulatory fetal and maternal DNA fragments; and

            (c) analyzing DNA fragments in the fraction of DNA produced in (b).

The Federal Circuit had consistently found diagnostic claims patent ineligible (as directed to natural phenomenon) (Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, 927 F.3d 1333 (Fed. Cir. 2019); Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, 915 F.3d 743 (Fed. Cir. 2019); Cleveland Clinic Found. v. True Health Diagnostics LLC, 859 F.3d 1352 (Fed. Cir. 2017)).  In contrast, the Federal Circuit had also held that method of treatment claims are patent eligible (Endo Pharm. Inc. v. Teva Pharm. USA, Inc., 919 F.3d 1347 (Fed. Cir. 2019); Natural Alternative Int’l, Inc. v. Creative Compounds, LLC, 918 F.3d 1338 (Fed. Cir. 2019); and Vanda Pharm. Inc. v. West-Ward Pharm. Int’l Ltd., 887 F.3d 1117 (Fed. Cir. 2018)).  However, this is not a diagnostic case, nor a method of treatment case.  This is a method of preparation case – which the Federal Circuit found to be patent eligible.

The natural phenomenon at issue is that cell-free fetal DNA tends to be shorter than cell-free maternal DNA in the mother’s bloodstream.  However, under the Alice/Mayo Step 1, the Federal Circuit held that these claims are not directed to a natural phenomenon.  Instead, the claims are directed to a method that utilizes that phenomenon.  The claimed method recites specific process steps – size discrimination and selective removal of DNA fragments above a specified size threshold.  These process steps change the composition of the normal maternal plasma or serum, creating a fetal DNA enriched mixture having a higher percentage of cff-DNA fraction different from the naturally occurring fraction in the normal mother’s blood.  “Thus, the process achieves more than simply observing that fetal DNA is shorter than maternal DNA or detecting the presence of that phenomenon.”

In distinguishing the earlier Ariosa case, the Federal Circuit stated, “the claims do not merely cover a method for detecting whether a cell-free DNA fragment is fetal or maternal based on its size.” 

In distinguishing the Supreme Court decision in Association for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. 576 (2013), the Federal Circuit noted that the “Supreme Court in Myriad expressly declined to extend its holding to method claims reciting a process used to isolate DNA” and that “in Myriad, the claims were ineligible because they covered a gene rather than a process for isolating it.”  Here, the method “claims do not cover cell-free fetal DNA itself but rather a process for selective removal of non-fetal DNA to enrich a mixture in fetal DNA.”  This is the opposite of Myriad.

As for whether the techniques for size discrimination and selective removal of DNA fragments were well-known and conventional, those considerations are relevant to the Alice/Mayo Step 2 analysis, or to 102/103 issues – not for Alice/Mayo Step 1.  The majority concluded patent eligibility under Step 1 and did not proceed to Step 2.

J. Reyna’s dissent focused on the claims being directed to a natural phenomenon because the “only claimed advance is the discovery of that natural phenomenon.”  In particular, referring to a “string of cases reciting process claims” since 2016, the “directed to” inquiry under Alice/Mayo Step 1 asks “whether the ‘claimed advance’ of the patent ‘improves upon a technological process or is merely an ineligible concept.’” citing Athena, 915 F.3d at 750 and Genetic Techs., 818 F.3d at 1375.  “Here, the claimed advance is merely the inventors’ ‘surprising[]’ discovery of a natural phenomenon – that cff-DNA tends to be shorter than cell-free maternal DNA in a mother’s bloodstream.”  J. Reyna criticizes the majority for ignoring the “claimed advance” inquiry altogether.

Under the claimed advance inquiry, one looks to the written description.  Here, the written description identifies the use of well-known and commercially available tools/kits to perform the claimed method.  Checking for 300 and 500 base pairs using commercially available DNA size markers and kits does not constitute any “advance.”  There is no improvement in the underlying DNA processing technology, but for checking the natural phenomenon of sizes indicative of cff-DNA.

J. Reyna also criticized the majority’s “change in the composition of the mixture” justification.  “A process that merely changes the composition of a sample of naturally occurring substances, without altering the naturally occurring substances themselves, is not patent eligible.”  Here, one begins and ends with the same naturally occurring substances – cell-free fetal DNA and cell free maternal DNA.  There is no creation or alteration of any genetic information encoded in the cff-DNA.  Therefore, the claims are directed to a natural phenomenon under Alice/Mayo Step 1. 

J. Reyna also found no inventive concept under Alice/Mayo Step 2.

Take Away

  • Until there is an en banc rehearing or a Supreme Court review of this case, this case is an example of a patent eligible method of preparation claim.
  • For defendants, the “claimed advance” inquiry could help sink a claimed method under Alice/Mayo Step 1. 

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