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.
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.