CardioNet’s Signal Transform Invention is Ineligible

by Dennis Crouch

CardioNet v. InfoBionic (Fed. Cir. 2021)

CardioNet lost at the district court with a summary judgment of non-infringement. On appeal, the Federal Circuit has shifted its judgment–now finding the heart monitor claims ineligible under Section 101.  U.S. Patent Number 7,941,207.

The patent covers a heart monitor that includes a “T wave filter” that helps make sure the signal processor does not confuse the T-wave with the R-wave.

Asserted claim 20 is directed to a “cardiac monitoring apparatus” with the T wave filter.   In particular, the claim requires four elements:

  • a communications interface;
  • a real-time heart beat detector;
  • a frequency domain T wave filter; and
  • a selector that activates the T wave filter.

The claim also has a resulting wherein clause: “wherein the activated frequency domain T wave filter preprocesses a cardiac signal provided to the real-time heart beat detector.”

The district court found an abstract idea of “filtering raw cardiogram data to optimize its output;” but concluded that the claim also included a curative “something more” and so survived under Alice step two. In particular, the district court found that the claim was “tied to a machine” and therefore satisfied “the machine-or-transformation test.” On appeal, the Federal Circuit found this to be the wrong test.

The Federal Circuit agreed that the claims are directed to an abstract idea.  In particular, the court effectively held that any computational signal transformation is an abstract idea:

At bottom, filtering the data requires only basic mathematical calculations, such as “decompos[ing] a T wave into its constituent frequencies and multipl[ying] them by a filter frequency response.” And such calculations, even if “[g]roundbreaking,” are still directed to an abstract idea.

Slip Op.   At step two, the Federal Circuit disagreed with the lower court and found that the claimed invention lacked any inventive concept beyond the excluded abstract idea.  On this point, the court noted the existence of prior art for attenuating the T-wave.  In other cases, the court has held that such a comparison with prior art is not relevant to the eligibility inquiry.

Machine or Transformation: In Bilski, the Supreme Court explained that the machine-or-transformation test was an important “clue” to patent eligibility.  However, the court there was clear that machine-or-transformation was not the test.

This Court’s precedents establish that the machine-or-transformation test is a useful and important clue, an investigative tool, for determining whether some claimed inventions are processes under §101. The machine-or-transformation test is not the sole test for deciding whether an invention is a patent-eligible “process.”

Bilski v. Kappos (2010).   In this case, the court found that the claim is “technically tied to a machine” but its focus is actually the abstract signal transformation. The court explained that merely “formulating a claim in the form of an apparatus” does not protect it from eligibility challenge.

To the extent that formulating a claim in the form of an apparatus insulates it from an ineligibility attack if it only recites conventional components for performing an abstract idea, the Supreme Court has closed that door, at least for now.

Slip Op.

This is the third CardioNet case before the Federal Circuit and so the trio offers a good set of comparisons.  Although all three relate to heart monitor patents, the patents and claims differ from one another.

CardioNet v. InfoBionic: Patenting a Diagnostic Tool

41 thoughts on “CardioNet’s Signal Transform Invention is Ineligible

  1. 9

    “This is the third CardioNet case before the Federal Circuit and so the trio offers a good set of comparisons. Although all three relate to heart monitor patents, the patents and claims differ from one another.”

    But that’s not the only difference. I submit that this difference is more meaningful:

    * Case #1 (2019-1149), decided April 17, 2020 by Dyk, Plager, and Stoll: Claims held patent-eligible (reversing district court finding of patent-ineligibility)

    * Case #2 (2020-1018), decided July 1, 2020 by Lourie, Dyk, and Chen: Claims held patent-ineligible (affirming district court finding of patent-ineligibility)

    * Case #3 (2020-2123, 2020-2150), decided October 29, 2021 by Lourie, Dyk, and O’Malley: Claims held patent-ineligible (reversing district court finding of patent-eligibility)

    I strongly suspect that the selected panel is at least as important as the claims and subject matter, and possibly more so, in the determined outcome.

    1. 9.1

      I suppose I’ll do a further bit of legwork about this trio of cases.

      Patent-eligible claim from Case #1 (U.S. Patent No. 7,941,207):

      > 1. A device, comprising:

      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.

      First patent-ineligible claim from Case #2 (U.S. Patent No. 7,212,850):

      > 31. A system for reporting information related to arrhythmia events comprising:

      > a monitoring system configured to process and report physiological data, including heart rate data, for a living being and configured to identify arrhythmia events from the physiological data;

      > a monitoring station for receiving the physiological data from the monitoring system; [and]

      > a processing system configured to receive arrhythmia information from the monitoring system and configured to receive human-assessed arrhythmia information from the monitoring station,

      > wherein the human-assessed arrhythmia information derives from at least a portion of the physiological data and

      > wherein the processing system is capable of pictographically presenting, using a common time scale, information regarding the heart rate data during a defined time period and regarding duration of arrhythmia event activity, according to the identified arrhythmia events, during the defined time period such that heart rate trend is presented with arrhythmia event burden.

      Second patent-ineligible claim from Case #2 (U.S. Patent No. 7,907,996):

      > 12. An article comprising a machine-readable medium embodying information indicative of instructions that when performed by one or more machines result in operations comprising:

      > identifying atrial fibrillation events in physiological data obtained for a living being, wherein identifying atrial fibrillation events comprises examining the physiological data in multiple time intervals, and identifying intervals in which at least one atrial fibrillation event has occurred;

      > obtaining heart rate data for the living being; receiving a human assessment of a subset of the identified atrial fibrillation events; and

      > based on the human assessment of the subset of the identified atrial fibrillation events, pictographically presenting, using a common time scale, information regarding the heart rate data for the multiple time intervals during a defined time period in alignment with indications of atrial fibrillation activity for the identified intervals, according to the identified atrial fibrillation events, during the defined time period such that heart rate trend is presented with atrial fibrillation burden, wherein pictographically presenting information regarding the heart rate data comprises displaying for each of the multiple time intervals a range of heart rates and a heart rate average.

      1. 9.1.1

        Seems to me those last two have 101 problems that go well beyond those that might be identified in the first.

    2. 9.2

      You know what they say about the Princess and the Pea. Yah I finally found it.

      1. 9.2.1

        And now Tucker has been now involved. this is why he told me I’d get nothing, and why there is an Atty. that I never hired blocking my representation in court right now as I post. But not anymore. This was a criminal enterprise that is now in the light and a case for my constitutional right to be heard in many courts!

    3. 9.3

      I strongly suspect that the selected panel is at least as important as the claims…

      In general I agree with this, but these three cases are a poor example of this maxim. Neither Plager nor Stoll are particularly given to narrow construction of Alice invalidity principles.

      1. 9.3.1

        Greg, please stay on point. What about the princess and the pea?

        1. 9.3.1.1

          Ha!

  2. 8

    Bruhs who else is Elon droppin paychecks on here today?

    1. 8.1

      You mean Soros, right?

      (Isn’t Elon more known for using his own voice — and not spending voi€e$)…?

      1. 8.1.1

        dude elon is on track for trillionaire status in his lifetime, and I’m along for the profitable ride, to oppress MM with my evil capitalist ways.

        link to google.com

        1. 8.1.1.1

          LOL – but you missed the point that your post of “droppin paychecks on people here today” was off-kilter.

          There is “evi1 capitalist” and then there is “droppin paychecks” (and what that connotation brings – which is certainly NOT limited to the capitalist vein, and even the capitalist that elon is, does not apply to elon — you miss in BOTH aspects).

          1. 8.1.1.1.1

            anon, 6’s comment was fine. The meaning was clear. 6 is making lots of money from his Tesla stock.

            1. 8.1.1.1.1.1

              White,
              My son had about as much legal say so as Ed Bryant, who was put on the bench to block my rights while he managed this criminal conspiracy, and wasn’t even the congress to have allowed this illegal enterprise, let alone close my cases. Now congress will surely know when it goes before the real judges, nor the ones that did this illegally.
              And for you John White to have my mail going to Eugene Quinn sent to you, stopping it from being delivered to the NH disciplinary Bar and then making a decision on the conspiracy that I was unaware of, and act on it to continue it is hogwash.
              There is no way that this conspiracy that I am now aware of can be put under a statute.

            2. 8.1.1.1.1.2

              Night Writer,

              That was ONLY part of his message, and clearly not the main intonation.

              That part I take no issue with.

              I am happy for him that he is finding success in the market, based at least in part on leveraging the work and ‘progress’ of one elon musk.

              But you may want to do more than grasp only that thin surface item from his post. He errs exactly as I have laid out.

              1. 8.1.1.1.1.2.1

                “and clearly not the main intonation”

                In other words, anon is a tar d.

                1. You seem to like to use that phrase as a signal that I have nailed you.

                  We both know that your post was aimed at Tr011ing Malcolm.

  3. 7

    For reference – the court’s decision primarily focuses on claim 20:

    > 20. A cardiac monitoring apparatus comprising:

    > a communications interface;

    > a real-time heart beat detector;

    > a T wave filter frequency domain; and

    > a selector that activates the T wave filter frequency domain with respect to the real-time heart beat detector in response to a message,

    > wherein the activated T wave filter frequency domain preprocesses a cardiac signal provided to the real-time heart beat detector.

    …for which the court states: “Filtering the data requires only basic mathematical calculations… such calculations, even if groundbreaking, are still directed to an abstract idea.”

    The patent also includes other independent claims:

    > 1. A machine-implemented method comprising

    > identifying heart beats in a sensed cardiac signal;

    > activating a T wave filter frequency domain, used in said identifying heart beats, in response to a message from a monitoring station generated at least in part based upon discovery of a predetermined characteristic in the sensed cardiac signal; and

    > outputting information corresponding to the identified heart beats to a communications channel of a distributed cardiac activity monitoring system.

    > 11. A distributed cardiac activity monitoring system comprising:

    > a monitoring apparatus including a communications interface, a real-time QRS detector, a T wave filter frequency domain, and a selector that activates the T wave filter with respect to the real-time QRS detector in response to a message, wherein the activated T wave filter frequency domain preprocesses a cardiac signal provided to the real-time QRS detector; and

    > a monitoring station that communicatively couples with the monitoring apparatus via the communications interface and transmits the message to the monitoring apparatus to activate the T wave filter frequency domain based at least in part upon a predetermined criteria.

    …which the court summarily dismissed as being “directed to substantially similar subject matter as claim 20.”

    For comparison: – in In re Abele (CCPA, 1982), the following claim (independent claim 5 + dependent claim 6) was held to be patent-eligible:

    > A method of displaying data in a field comprising the steps of

    > calculating the difference between the local value of the data at a data point in the field and the average value of the data in a region of the field which surrounds said point for each point in said field, and

    > displaying the value of said difference as a signed gray scale at a point in a picture which corresponds to said data point,

    > wherein said data is X-ray attenuation data produced in a two dimensional field by a computed tomography scanner.

    Here’s the rationale from the court:

    > The algorithm, when properly viewed, is merely applied to the “attenuation data” to eliminate what would otherwise appear as artifacts upon display of the data in the manner claimed. The algorithm does not necessarily refine or limit the earlier steps of production and detection as would be required to achieve the status of patentable subject matter by the board’s narrow reading of Walter. What appellants have done is to discover an application of an algorithm to process steps which are themselves part of an overall process which is statutory. Hence, claim 6 cannot be construed as a mere procedure for solving a given mathematical problem. As was the case in Diehr and Johnson, both supra, the algorithm is but a part of the overall claimed process.

    > We are faced simply with an improved CAT-scan process comparable to the improved process for curing synthetic rubber in Diehr. The improvement in either case resides in the application of a mathematical formula within the context of a process which encompasses significantly more than the algorithm alone.

    It is difficult, to put it mildly, to square the rationale in these cases.

    1. 7.1

      “> a T wave filter frequency domain;”

      Just as an FYI, the above gibberish was modified in a certificate of correction, and now reads: “a frequency domain T wave filter.”

      1. 7.1.1

        As an FYI, your insertion of “gibberish” entirely misses the point that you are responding to.

        If you do not like Night Writer’s characterizations of you, you would do better than not merit those characterizations.

      2. 7.1.2

        I would logically read “a T wave filter frequency domain” as either “a frequency domain _of_ a T wave filter” or “a T wave filter _applied to_ a frequency domain.” Seems like these interpretations are correct and intended. Could be just a translation issue.

        1. 7.1.2.1

          “a frequency domain _of_ a T wave filter”

          I agree that’s the right interpretation, except that it becomes incoherent in the context of the limitation about activating a “T wave filter frequency domain” or where that “T wave filter frequency domain” does preprocessing.

          “a T wave filter _applied to_ a frequency domain”

          That would be contorting English to save a claim.

          In this case, it looks like the print shop misunderstood the Examiner’s amendment and put “frequency domain” after, instead of before, “T wave filter.” It produced a unacceptable and incoherent claim, which the applicant quickly and rightly corrected.

          And yet people here are so doggedly bent on defending any claim that they need to jump to defending claim language that applicant didn’t want and never asked for.

          1. 7.1.2.1.1

            > I agree that’s the right interpretation, except that it becomes incoherent in the context of the limitation about activating a “T wave filter frequency domain” or where that “T wave filter frequency domain” does preprocessing.

            It might make more sense in isolation, but it makes less sense when substituted in the claim, which would then recite: “A cardiac monitoring apparatus comprising: a communications interface; a real-time heart beat detector; and a frequency domain for a T-wave filter.” A frequency domain of a signal cannot be a component of an apparatus.

            > That would be contorting English to save a claim.

            Eh, not so much. Consider: “A spellcheck target” vs. “spellcheck applied to a target.”

            Also, consider claim 22: “the T wave filter frequency domain comprises an analog T wave filter.” Or claim 23: “the T wave filter frequency domain comprises a filter that reduces signal amplitude at low frequencies.” The following dependent claims recite “the filter.”

            Also, Figure 2 includes block 230 labeled: “T Wave Filter.” And Figure 6 shows a plot of “a frequency response of an example T wave filter” – i.e., the response of the T wave filter when applied to a signal in the frequency domain.

            > people here are so doggedly bent on defending any claim that they need to jump to defending claim language that applicant didn’t want and never asked for.

            No, I’m considering the claim term in the context of the claims, specification, and figures. There is only one plain and unambiguous meaning of the claim term that would make sense in this broader context. I don’t believe that patents should be invalidated by playing games with word claims to reach a strange interpretation that the patentee clearly did not intend.

            1. 7.1.2.1.1.1

              But Ben is — as well as he is so quick to claim others are quick.

              I’ll bet that he is oblivious to his own anti-patent bias (he is rather thick that way).

              In case you need it spelled out for you, Ben, it is less about particular claims and more about the Rule of Law (cue Malcolm mumbling some incoherent attempt at denigration vis a vis Rule of Law, as if the concept is not a well understood term of art).

    2. 7.2

      Because there can be no rational application of the judicial exceptions without a definition of abstract other than “we know it when we see it”

      But there CAN be such an application: Utility reached with no human mind, no abstraction.

      Requires a human mind to reach the utility? Absolutely abstract.

      1. 7.2.1

        S I G H

        At its core, ALL utility is necessarily countenance by the human mind.

        If the utility is NOT something so appreciated, then you LACK meeting the utility requirement.

        Think: traffic light.

    3. 7.3

      It is difficult, to put it mildly, to square the rationale in these cases.

      +1

    4. 7.4

      It is difficult, to put it mildly, to square the rationale in these cases.

      One does not “square” a Gordian Knot.

      One cuts it.

      (For example, one MAY cut it with a pair of Kavanaugh Scissors)

    5. 7.5

      “square the rationale”

      The one and only way to square the rationale is to be . . . irrational.

      When it comes to eligibility, many members of the CAFC spend their time happily splish-splashing . . . in their self-filled pool of irrationality.

      “The water’s divine — jump on in everyone!”

    6. 7.6

      At one time, for 101 rejections, I would argue both the Patent Office’s 101 guidance and also the CAFC’s. Now, unless the claims are similar to a case at the CAFC where the result was patentable, I don’t attempt to argue the CAFC’s guidance, since I no longer have any idea what is patentable under 101.

      1. 7.6.1

        … and yet people** still insist on not seeing the Gordian Knot.

        **of several ilk: the willfully blind and the purposefully denigrating of strong innovation protection.

  4. 6

    The opinion appears to actually reference patent number 7,099,715.

  5. 5

    . . . and the innovation carnage continues . . .

  6. 4

    Was this en banc?

    If not, we have just another instance of the Gordian Knot (as there are precedential opinions dictating a different result.

  7. 3

    The following patent owner admission from this CardioNet v. InfoBionic decision should be noted:
    “..during oral argument, CardioNet admitted that “T wave filters, as a general proposition, existed” prior to the patent..”
    [Also, one step of the subject process seems to be required to be done by a human expert, not a machine?]
    [Otherwise, other parts of this decision might look like a far better cert candidate re 101 “abstraction” exceptions than American Axle?]

    1. 3.1

      >“..during oral argument, CardioNet admitted that “T wave filters, as a general proposition, existed” prior to the patent..”

      Check. No preemption of a fundamental principle/truth, building block of human ingenuity, or basic tool of scientific and technological work.

  8. 2

    This reminds me of that 1994 paper reporting how the author had invented an algorithm for determining the area under a glucose tolerance curve by breaking up that area into rectangles.

    So is this sophomore or junior level signal processing?

    1. 2.1

      Right. A lot of stuff that gets killed on §101 surely deserves to die on §103 grounds (but usually not on §101 grounds). If the IPR system had come online a decade earlier, Alice would likely never have happened.

  9. 1

    Is it a method? Yes

    Is the useful result of the method comprised solely of information? Yes

    Is the utility of the information result realized within a human mind? No

    This method should be eligible.

    I’ll assume the usual drivel: no, all utility is not the same. No this is not the MoT restated, because non-human use may not implicate machines- for example, a domestic animal could usefully consume information. Yes this comports with legal “terrain” since the legal terrain of eligibility is already quicksand.

    1. 1.1

      Corrected:

      “This IS the usual drivel.”

    2. 1.2

      One does not “comport” with quicksand.

      Recognizing the problem OF quicksand is a necessary predicate to fixing the problem of quicksand.

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