IP Law Essentials

What is Patentable Subject Matter?


Patent eligibility is the first of three hurdles to be cleared in obtaining a patent (the other two are novelty and non-obviousness). This post is the first of a series that provides a digest of the law of patent-eligibility that is what makes an invention patentable subject matter.

So what types of inventions are patent-eligible? If you ask Congress, the answer is "any type." The Patent Act broadly identifies "any new and useful process, machine, manufacture, or composition of matter." Ask a patent lawyer, however, and the answer is naturally more complicated. First, there is the statutory rule. Then there are judge-made exceptions to the rule. And then there is an exception to the exceptions. More recently, the courts have fashioned a two-part test for sorting it all out. We briefly address each below.

Anything Under the Sun that Is Made by Man

Section 101 of the Patent Act (35 U.S.C. 101) defines the realm of "[i]nventions patentable." It provides, "Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title." Section 101 was originally meant to set a low bar. Indeed, the legislative history of 101 reveals that Congress intended it to "include anything under the sun that is made by man." S. Rep. No. 1979, 82d Cong., 2d Sess., 5 (1952); H. R. Rep. No. 1923, 82d Cong., 2d Sess., 6 (1952). The Supreme Court, however, has imposed limitations on the expansive scope of 101.

But Not Laws of Nature, Physical Phenomena, or Abstract Ideas

The Supreme Court has long held that "laws of nature, physical phenomena, and abstract ideas" are not patentable. Diamond v. Diehr, 450 U.S. 175, 185 (1981). The rationale is that these concepts "are the basic tools of scientific and technological work," Gottschalk v. Benson, 409 U.S. 63, 67 (1972), "[a]nd monopolization of those tools through the grant of a patent might tend to impede innovation more than it would tend to promote it," Mayo Collaborative Servs. v. Prometheus Labs., Inc., 566 U.S. 66, 71 (2012).

One of the earliest applications of this judge-made exception to 101 is found in O'Reilly v. Morse, 56 U.S. 62 (1853). There, the Supreme Court invalidated the following claim of Samuel Morse's patent on the telegraph:

I do not propose to limit myself to the specific machinery or parts of machinery described in the foregoing specification and claims; the essence of my invention being the use of the motive power of the electric or galvanic current, which I call electro-magnetism, however developed for marking or printing intelligible characters, signs, or letters, at any distances...

Id. at 112 (emphasis added). The Court invalidated this claim because it encompassed all possible applications of an idea (i.e., using electromagnetism to send messages) and therefore monopolized the idea itself, disassociated from any particular machine or process. By analogy, the Court explained that "[n]o one, we suppose will maintain that Fulton could have taken out a patent for his invention of propelling vessels by steam, describing the process and machinery he used, and claimed under it the exclusive right to use the motive power of steam, however developed, for the purpose of propelling vessels." Id. at 113. In short, an inventor could not patent the idea of a steam engine, no matter how it was implemented such an idea is abstract and ineligible for patenting.

A Specific Application of a Law of Nature, Physical Phenomenon, or Abstract Idea Is Patentable

The Supreme Court has cautioned, however, that "too broad an interpretation of this exclusionary principle could eviscerate patent law ... [f]or all inventions at some level embody, use, reflect, rest upon, or apply laws of nature, natural phenomena, or abstract ideas." Mayo, 566 U.S. at 71. Accordingly, the Supreme Court has explained that an invention "is not [rendered] unpatentable simply because it contains a law of nature or a mathematical algorithm." Parker v. Flook, 437 U.S. 584, 590 (1978) (emphasis added). Instead, the analysis turns on whether the invention is limited to "an application of [an unpatentable principle] to a known structure or process." Diehr, 450 U.S. at 187 (emphasis in original); see also Funk Brothers Seed Co. v. Kalo Inoculant Co., 333 U.S. 127, 130 (1948) ("If there is to be invention from [a discovery of a law of nature], it must come from the application of the law of nature to a new and useful end.") (emphasis added). Diehr is instructive on this point. There, the Supreme Court held that although the claims at issue contained a law of nature (namely, the Arrhenius equation), they were nonetheless patentable because they applied that law of nature to improve conventional methods of curing synthetic rubber, and they further advanced the state of the art by disclosing the use of embedded thermocouples in the mold press to constantly measure temperature even when the press is closed. 450 U.S. at 178 n.3, 187.

But "Token Postsolution Components" Are Not Enough

Predictably, the exception to the exception invited artful drafting around the rule. Patent applicants attempted (often successfully) to steer clear of 101 rejections by dressing up their claims with generic, conventional components or steps that gave the appearance of a specific machine or process. In reality, however, such components merely limit the unpatentable principle to a particular technological environment, or they are the components that would be necessary in all practical applications of the unpatentable principle. The Supreme Court denounced this practice as early as 1978, when it rejected "[t]he notion that post-solution activity, no matter how conventional or obvious in itself, can transform an unpatentable principle into a patentable process [or apparatus]." Flook, 437 U.S. at 590. In that case, the claim at issue covered the use of a particular mathematical formula to update alarm limits in a catalytic conversion process. The Court held that the formula was an unpatentable law of nature, and the added step of updating alarm limits was merely post-solution activity because it was already a known practice. Id.. at 585-86, 594. The rationale is that post-solution activity fails to provide any "practical assurance that the process [or apparatus] is more than a drafting effort designed to monopolize the [unpatentable principle] itself." Mayo, 566 U.S. at 77.

Enter Alice's Two-Part Test for Determining Patent-Eligibility

In the 2010s, due in large part to the wave of software patents stemming from the earlier proliferation of computers, the Supreme Court has had occasion to revisit 101 law. In Bilski v. Kappos, the Court reaffirmed the holding from Flook that "the prohibition against patenting abstract ideas cannot be circumvented by attempting to limit the use of the [ideas] to a particular technological environment or adding insignificant postsolution activity." 561 U.S. 593, 610-11 (2010). Applying that rule, Bilski held the claims at issue unpatentable because they recited the abstract idea of hedging risk in commodities trading and then merely "instruct[ed] the use of well-known random analysis techniques to help establish some of the inputs into the [risk hedging] equation." Id. at 611-12. And in Mayo, the Court illustrated the principle with two practical examples: "Einstein, we assume, could not have patented his famous law by claiming a process consisting of simply telling linear accelerator operators to refer to the law to determine how much energy an amount of mass has produced (or vice versa). Nor could Archimedes have secured a patent for his famous principle of flotation by claiming a process consisting of simply telling boat builders to refer to that principle in order to determine whether an object will float." 566 U.S. at 78.

The Court's focus on 101 culminated in Alice Corp. v. CLS Bank International, 573 U.S. 208 (2014). There, a unanimous Court laid out a two-part test for weeding out abstract claims. First, the analysis asks whether the claim at issue is "directed to" a law of nature, physical phenomenon, or abstract idea. Id. at 217. If so, then the analysis proceeds to the second step to determine whether the claim contains an "inventive concept," as distinct from "well-understood, routine, conventional activities previously known to the industry." Id. at 221, 225. Under Alice step one, claims that "focus on a specific means or method that improves the relevant technology" (such as "an improved cardiac monitoring device" that uses unconventional techniques to detect atrial fibrillation and atrial flutter) typically pass, and claims that "are instead directed to a result or effect that itself is the abstract idea and merely invoke generic processes and machinery" (such as a method "for detecting fraud in financial transactions during a payment clearing process" using a computer) do not. See CardioNet, LLC v. InfoBionic, Inc., 955 F.3d 1358 (Fed. Cir. 2020); Bozeman Fin. LLC v. Fed. Reserve Bank of Atlanta, 955 F.3d 971, 978-980 (Fed. Cir. 2020). As for Alice step two, claims in which the only non-abstract elements are "conventional, off-the-shelf computer components" are usually doomed to fail. Id.

For more information on the Alice test, as well as an index of significant cases applying it, please check out Fish's Alice Tracker.

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