March 23, 2012

Lessons from Mayo v. Prometheus: Assessing Patentability and Obtaining Patent Protection for "Laws of Nature" Inventions

It is well established that “laws of nature, natural phenomena, and abstract ideas,” themselves, are not patentable subject matter under §101 of the Patent Act, while an application of a law of nature, phenomena or abstract idea may be patentable.  However, it isn’t enough to simply state the law of nature in the patent claims while adding the words, “apply it.” 

Where a patent claim involves the application of a law of nature, the appropriate question at issue is whether the patent claim adds enough to its recitation of the mathematical formula, correlation or other law of nature to qualify as a patent-eligible process.  The recent, unanimous Supreme Court ruling in Mayo v. Prometheus raises the bar significantly on how much the claim must add to the law of nature in order to satisfy §101 of the Patent Act.

In light of Mayo v. Prometheus, it may be tempting to throw in the towel and forgo pursuit of patent protection for inventions that involve applying a law of nature, correlation or mathematical equation – for example, inventions in the diagnostics field.  While the ruling does call for a renewed look at trade secret law for protection of diagnostics innovations as an alternative to patents, all is not lost in the patent arena for protection of these innovations.

So, what is still considered patentable subject matter, in light of Mayo v. Prometheus?  The Court identifies what it finds wrong with the patents licensed to Prometheus, but also provides some guidance regarding how a claimed process involving the application of a law of nature could still be considered patent-eligible subject matter, even in light of its decision on the Prometheus patents. 

The following are representative patent claims for inventions that apply a law of nature or mathematical formula, which are referenced in the Mayo v. Prometheus decision and are discussed in more detail below (“good claim” means the subject matter requirement is met, while “bad claim” means the subject matter requirement is not met):

Diamond v. Diehr case – good claim:

A method of operating a rubber-molding press for precision molded compounds with the aid of a digital computer, comprising:

  • providing said computer with a data base for said press including at least,
    • natural logarithm conversion data (ln),

    • the activation energy constant (C) unique to each batch of said compound being molded, and

    • a constant (x) dependent upon the geometry of the particular mold of the press;

  • initiating an interval timer in said computer upon the closure of the press for monitoring the elapsed time of said closure;

  • constantly determining the temperature (Z) of the mold at a location closely adjacent to the mold cavity in the press during molding;

  • constantly providing the computer with the temperature (Z);

  • repetitively calculating in the computer, at frequent intervals during each cure, the Arrhenius equation for reaction time during the cure, which is ln v=CZ+x, where v is the total required cure time;

  • repetitively comparing in the computer at said frequent intervals during the cure each said calculation of the total required cure time calculated with the Arrhenius equation and said elapsed time; and

  • opening the press automatically when a said comparison indicates equivalence.

Parker v. Flook case – bad claim:

A method for updating the value of at least one alarm limit on at least one process variable involved in a process comprising the catalytic chemical conversion of hydrocarbons wherein said alarm limit has a current value of Bo + K, wherein Bo is the current alarm base and K is a predetermined alarm offset which comprises:

  1. determining the present value of said process variable, said present value being defined as PVL:

  2. determining a new alarm base B1 using the following equation - B1 = Bo (1.0-F) + PVL (F) - where F is a predetermined number greater than zero and less than 1.0;

  3. determining an updated alarm limit value which is defined as B1 + K; and, thereafter

  4. adjusting said alarm limit to said updated alarm limit value.

Neilson case (English case) – good claim:

[A blowing apparatus for the improved application of air to produce heat in fires, forges, and furnaces, where the invention was to be applied as follows.]  “The blast or current of air produced by the blowing apparatus was to be passed from it into an air-vessel or receptacle made sufficiently strong to endure the blast; and through or from that vessel or receptacle by means of a tube, pipe, or aperture into the fire, the receptacle be kept artificially heated to a considerable temperature by heat externally applied.”

Mayo v. Prometheusbad claim:

A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:

  1. administering a drug providing 6-thioguanine to a subject having said immune-mediated gastrointestinal disorder; and
  2. determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder, wherein the level of 6-thioguanine less than [a specified amount] indicates a need to increase the amount of said drug subsequently administered to said subject and wherein the level of 6-thioguanine greater than [another specified amount] indicates a need to decrease the amount of said drug subsequently administered to said subject.

Bilksi case – bad claim:

A method for managing the consumption risk costs of a commodity sold by a commodity provider at a fixed price comprising the steps of:

  1. initiating a series of transactions between said commodity provider and consumers of said commodity wherein said consumers purchase said commodity at a fixed rate based upon historical averages, said fixed rate corresponding to a risk position of said consumer;

  2. identifying market participants for said commodity having a counter-risk position to said consumers; and

  3. initiating a series of transactions between said commodity provider and said market participants at a second fixed rate such that said series of market participant transactions balances the risk position of said series of consumer transactions.

Gottschalk v. Bensonbad claim

The method of converting signals from binary coded decimal form into binary which comprises the steps of

  1. storing the binary coded decimal signals in a reentrant shift register,

  2. shifting the signals to the right by at least three places, until there is a binary `1' in the second position of said register,

  3. masking out said binary `1' in said second position of said register,

  4. adding a binary `1' to the first position of said register,

  5. shifting the signals to the left by two positions,

  6. adding a `1' to said first position, and

  7. shifting the signals to the right by at least three positions in preparation for a succeeding binary `1' in the second position of said register.

Presented below are guidelines for determining whether a claimed invention involving a law of nature, abstract idea, or mathematical formula is amenable to patent protection in light of Mayo v. Prometheus.

The Claim Should Be Confined to a Specific, Useful Application of the Law of Nature

Patent attorneys often do their best to claim inventions in as broad a manner as possible.  However, where the invention involves the application of a law of nature, abstract idea or mathematical formula, this general approach should be reconsidered.  The existence of such a broad claim may call into question whether the subject matter requirement of §101 of the Patent Act is satisfied, thereby jeopardizing the entire claim set (a court may be reluctant to find limitations in dependent claims that overcome subject matter problems identified in the independent claims).

In Mayo v. Prometheus, the Supreme Court emphasized a concern about patents that disproportionately tie up the use of underlying natural laws, thereby inhibiting their use in the making of further discoveries, particularly in fields not contemplated by the patentees.  The Court stated, “to transform an unpatentable law of nature into a patent-eligible application of such a law, a patent must do more than simply state the law of nature while adding the words ‘apply it.’ … It must limit its reach to a particular inventive application of the law.”

Further, the Court stated, “the claimed processes are not patentable unless they have additional features that provide practical assurance that the processes are genuine application of those laws rather than drafting efforts designed to monopolize the correlations” [emphasis added].

The Court provided two contrasting examples of claims involving application of a law of nature or mathematical formula – one that it found to be directed to patent-eligible subject matter (Diehr), and one that it found to be ineligible subject matter (Flook). 

The invention in Diehr involved application of a mathematical formula in the operation of a rubber molding cure press – one of the claims at issue basically consisted of (i) continuously monitoring the temperature on the inside of the mold, (ii) feeding the resulting numbers into a computer, which would use an Arrhenius equation to continuously recalculate the mold-opening time, and (iii) configuring the computer so that at the appropriate moment it would signal a device to open the press.  In Diehr, the Court found that “the overall process was patent eligible because of the way the additional steps of the process integrated the equation into the process as a whole. … These additional steps transformed the process into an inventive application of the formula.”  The Court found these steps, or at least the combination of the steps, were not obvious, were not already in use and were not purely conventional. 

The Court stated, “the patentees did not ‘seek to pre-empt the use of [the] equation,’ but sought ‘only to foreclose from others the use of that equation in conjunction with all of the other steps in their claimed process.’  These other steps apparently added to the formula something that in terms of patent law’s objectives had significance – they transformed the process into an inventive application of the formula.”  There seems to be an uncomfortable overlap between the subject matter requirement and the non-obviousness requirement (analogous to the European “inventive step” requirement), but, so be it.

The Court contrasted the patentable claim in Diehr with the unpatentable claim in Flook.  The claimed process in Flook involved a system for updating alarm limits in the catalytic conversion of hydrocarbons, by (i) measuring the current level of the variable, e.g., temperature, (ii) using an apparently novel mathematical algorithm to calculate the current alarm limits and (iii) adjusting the system to reflect the new alarm-limit values.  The Court said that unlike the process in Diehr, the claim in Flook did not “explain how the variables used in the formula were to be selected, nor did the [claim] contain any disclosure relating to chemical processes at work or the means of setting off an alarm or adjusting the alarm limit.”  Thus, the Court found that the steps added to the mathematical algorithm step “did not limit the claim to a particular application” and, thus, the claim was found not to satisfy the subject matter requirement.

The Court cited Flook, Benson and Bilski as illustrating the danger posed by pre-empting the use of a particular natural law, correlation or formula over a broad range of fields or applications.  The Court stated that the danger “becomes acute when a patented process amounts to no more than an instruction to ‘apply the natural law,’ or otherwise forecloses more future invention than the underlying discovery could reasonably justify.”  The court continued, “the more abstractly their claims are stated, the more difficult it is to determine precisely what they cover.  They risk being applied to a wide range of situations that were not anticipated by the patentee.”

The narrowness of the natural law or mathematical formula itself is irrelevant – it is the narrowness of the application of the natural law or mathematical formula that is important.

The Court acknowledged that the correlations at issue in the Prometheus patents are narrow laws that may have limited applications, but this was deemed irrelevant.  It is the narrowness of the application of the law or formula that is deemed relevant to the question of whether the claimed use of the law or formula is patent eligible subject matter.  In the Prometheus patent, the Court pointed to the “determining” step as being “set forth in highly general language covering all processes that make use of the correlations after measuring metabolites, including later discovered processes that measure metabolite levels in new ways.”  The Court was concerned that the claim would threaten to inhibit the development of more refined treatment recommendations that combine Prometheus’ correlations with later discovered features of metabolites, human physiology or individual patient characteristics.

The Court said the added steps in Prometheus “add nothing of significance to the natural laws themselves.  Unlike, say, a typical patent on a new drug or a new way of using an existing drug [which the Court finds satisfies the subject matter requirement], the patent claims do not confine their reach to particular applications of those laws.”  The Court stated, “the underlying functional concern here is a relative one:  how much future innovation is foreclosed relative to the contribution of the inventor.”

Limiting the use of the natural law or mathematical formula to a particular technological environment is not sufficient.

In Bilski, it was determined by the Court that a “prohibition against patenting abstract ideas cannot be circumvented by attempting to limit the use of the formula to a particular technological environment.”  In Prometheus, the Court explained that the “administering step” was analogous to Bilski in that it simply confined application of a particular formula or natural law to a particular technological environment, namely, doctors who treat patients with thiopurine drugs.  Thus, the Court found that the “administering step” in Prometheus did not suffice to satisfy the subject matter requirement.

The Claim Should Include Unconventional Steps

The claims in Diehr were found to include steps whose combination was not purely conventional.  Likewise, the claims in Neilson were found to include several unconventional steps such as inserting a receptacle, applying heat to the receptacle externally and blowing air into a furnace.  These steps were found to confine the claims to “a particular, useful application of the principle” and contributed to the finding that the claims satisfy the subject matter requirement.

Simply appending conventional steps, specified at a high level of generality, to laws of nature is not sufficient.

The “determining” step in Prometheus was found by the Court to simply tell doctors to engage in well-understood, routine, conventional activity previously engaged in by scientists who work in the field.  This was not found to be an added step that elevated the recitation of the law of nature to patent-eligible subject matter.

Adding ‘insignificant post-solution activity’ is not sufficient.

Likewise, attempting to elevate a law of nature to patent-eligible subject matter by adding conventional, ‘insignificant post-solution activity’ was also found by the Court to be insufficient.  The claim in Flook was cited as an example of a claim in which “token post-solution components” were added (e.g., adjusting an alarm limit to a newly computed value).

Simply implementing a mathematical principle on a physical machine, e.g., a computer, is not sufficient

Similarly, the Court cited Benson, in which the patent claim simply recited that a novel mathematical principle be implemented on a physical machine, namely a computer.  This was deemed insufficient to elevate the principle to a patentable invention.

The Machine-of-Transformation Test Is a "Clue" to Patentability, but Is Not Determinative

The Federal Circuit applied the “machine-or-transformation” test from Bilski in its determination of whether the subject matter requirement of §101 of the Patent Act was satisfied by the Prometheus patent claims.  In the “machine-or-transformation” test, a claim to a process satisfies the subject matter requirement if it is (i) implemented with a particular machine that is configured to carry out the process in a non-trivial, not concededly conventional way, or (ii) transforms an article from one thing or state to another.

The Federal Circuit reasoned that the claimed processes in Prometheus were patent eligible because they involved “transforming the human body by administering a thiopurine drug and transforming the blood by analyzing it to determine metabolite levels.”  The Supreme Court, however, found that this transformation was irrelevant because the “administering” step simply identifies individuals who are likely interested in applying the law of nature. 

The Supreme Court emphasized that the “machine-or-transformation” test merely provides a “clue” to patentability, but that it is not determinative.  More important is the determination of whether or not the claim at issue is confined to a specific, useful application of the recited law of nature.