By Donald Zuhn —

On Tuesday, the U.S. Patent and Trademark Office issued a memorandum providing guidance for determining subject matter eligibility of process claims involving laws of nature in view of the Supreme Court's decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc.  The memo, entitled "2012 Interim Procedure for Subject Matter Eligibility Analysis of Process Claims Involving Laws of Nature," was released some three and a half months following the Court's decision in Mayo, and sets forth an examination procedure that supersedes the preliminary guidance provided in the Office's March 21 memo on the Mayo decision (see "USPTO Issues Preliminary Guidance on Mayo v. Prometheus").

The Office notes that the examination procedure set forth in the memo is "an interim measure" intended "to provide instruction to examiners in technology areas impacted by the Mayo decision" while the Federal Circuit rehears the Association for Molecular Pathology v. Myriad Genetics and WildTangent v. Ultramercial cases.  The Office also notes that "comprehensive updated guidance" will be issued following resolution of those cases, which the Office expects will "provide insight regarding the full reach of Bilski and Mayo."

The examination procedure set forth in the guidance memo consists of three "essential" inquiries:

1. Is the claimed invention directed to a process, defined as an act, or a series of acts or steps?

2. Does the claim focus on use of a law of nature, a natural phenomenon, or naturally occurring relation or correlation (collectively referred to as a natural principle herein)? (Is the natural principle a limiting feature of the claim?)

3. Does the claim include additional elements/steps or a combination of elements/steps that integrate the natural principle into the claimed invention such that the natural principle is practically applied, and are sufficient to ensure that the claim amounts to significantly more than the natural principle itself? (Is it more than a law of nature + the general instruction to simply "apply it"?)

According to the memo, these three inquiries are to be conducted "on the claim as a whole" after the claims have been reviewed "to determine the boundaries of patent protection sought by the applicant and to understand how the claims relate to and define what the applicant has indicated is the invention."  In establishing the broadest reasonable interpretation of the claims when read in light of the specification and from the view of one of ordinary skill in the art, the memo states that:

Claim analysis begins by identifying and evaluating each claim limitation and then considering the claim as a whole.  It is improper to dissect a claimed invention into discrete elements and then evaluate the elements in isolation because it is the combination of claim limitations functioning together that establish the boundaries of the invention and limit its scope.

Once the broadest reasonable interpretation of the claims has been determined, an examiner should proceed to the three inquiries.

The first inquiry is relatively straightforward — if an examiner determines that a claim is directed to a process (i.e., an act or series of acts or steps), then the examiner proceeds to the second inquiry.  With respect to the second inquiry, the memo defines a natural principle as "the handiwork of nature [that] occurs without the hand of man," and provides three examples:  the disinfecting property of sunlight; the relationship between blood glucose levels and diabetes; and a correlation that occurs naturally when a man-made product, such as a drug, interacts with a naturally occurring substance, such as blood.  According to the memo, "a claim focuses on a natural principle when the natural principle is a limiting element or step."  The memo notes that "a claim that recites a correlation used to make a diagnosis focuses on a natural principle and would require further analysis" under the third and final inquiry.

With respect to the third inquiry, the memo begins by stating that "[t]o show integration, the additional elements or steps must relate to the natural principle in a significant way to impose a meaningful limit on the claim scope," adding that "[t]he analysis turns on whether the claim has added enough to show a practical application."  Such additional elements or steps will be deemed insufficient if they "simply amount to insignificant extra-solution activity that imposes no meaningful limit on the performance of the claimed invention."  Thus:

[A] claim to diagnosing an infection that recites the step of correlating the presence of a certain bacterium in a person's blood with a particular type of bacterial infection with the additional step of recording the diagnosis on a chart would not be eligible because the step of recording the diagnosis on the chart is extra-solution activity that is unrelated to the correlation and does not integrate the correlation into the invention.

In contrast, the memo notes that:

Claims that do not include a natural principle as a limitation do not raise issues of subject matter eligibility under the law of nature exception.  For example, a claim directed to simply administering a man-made drug that does not recite other steps or elements directed to use of a natural principle, such as a naturally occurring correlation, would be directed to eligible subject matter.  Further, a claim that recites a novel drug or a new use of an existing drug, in combination with a natural principle, would be sufficiently specific to be eligible because the claim would amount to significantly more than the natural principle itself.

In conducting the third inquiry, the memo notes that the weighing factors outlined in the Office's "Interim Guidance for Determining Subject Matter Eligibility for Process Claims in View of Bilski v. Kappas" may assist in the analysis.  The memo then sets forth a number of relevant factors that may be useful in completing the third inquiry.  For example, the memo states that "[a] claim that covers known and unknown uses of a natural principle and can be performed through any existing or future-devised machinery, or even without any apparatus, would lack features that are sufficient for eligibility."  The memo also indicates that "[a] particular machine or transformation recited in more than general terms may be sufficient to limit the application to just one of several possible machines or just one of several possible changes in state, such that the claim does not cover every substantial practical application of a natural principle."  In contrast, the memo notes that "[a] machine or transformation that is merely nominally, insignificantly, or tangentially related to the steps or elements, e.g., data gathering or data storage, would not show integration."  Lastly, the memo suggests that "[c]omplete absence of a machine-or-transformation in a claim signals the likelihood that the claim is directed to a natural principle and has not been instantiated (e.g., is disembodied or can be performed entirely in one's mind[])."

Following the description of relevant factors, the memo provides a sample analysis.  The first two parts of this section discuss claims that were at issue in Diamond v. Diehr and Mayo, while the last three parts provide examples that practitioners and examiners may find to be more helpful.  In a subsection entitled "Making A Rejection," the memo provides an exemplary claim:

Claim 1. A method of determining effective dosage of insulin to a patient, comprising the steps of administering a dose of insulin to a patient, testing the patient’s blood for the blood sugar level, and evaluating whether the insulin dosage is effective based on the blood sugar level.

The memo then applies the three inquiries to this claim, concluding that:

The claim does not pass Inquiry 3 because, although the additional steps integrate or make use of the correlation in the process by administering insulin in one step and testing for the correlation in another step, the steps are not sufficient to ensure that the claim amounts to significantly more than the correlation itself since every application of the correlation would require an administration of insulin and testing of blood to observe the relationship between insulin and blood glucose levels.

In the next subsection, entitled "Evaluating a Response," the memo notes that a "proper" response to a rejection based on failure to claim patent-eligible subject matter could involve the presentation by the applicant of "persuasive arguments that the additional steps add something significantly more to the claim than merely describing the natural principle," or a "showing that the steps are not routine, well-known or conventional."  Returning to its disinfecting property of sunlight and blood glucose levels/diabetes examples, the memo states, with respect to the latter example, that:

A claim that sets forth the relationship between blood glucose levels and the incidence of diabetes would require additional steps that do significantly more to apply this principle than conventional blood sample testing or diagnostic activity based on recognizing a threshold blood glucose level.  Such additional steps could involve a testing technique or treatment steps that would not be conventional or routine.

The last section of the memo provides an analysis of two sets of exemplary claims:  one set directed to a method for treating a psychiatric behavioral disorder using sunlight (claim 1), white light (claim 2), or UV light (claim 3); and another set directed to a method of determining the increased likelihood of having or developing rheumatoid arthritis using an anti-IgM antibody (claim 1), providing a positive control (claim 2), using a specific IgM antibody (claim 3), or using two specific assays (claim 4).  In the first example, the memo finds only claim 3 to be a patent-eligible practical application, stating that "the additional step of filtering the UV rays from the white light manipulates the white light; and the additional step of positioning the patient relates to the conditions under which the patient is exposed to the light."  In the second example, the memo finds both claims 3 and 4 to be patent-eligible practical applications.  With respect to claim 3, the memo notes that "use of the particularly claimed antibody does transform the claim to a patent-eligible practical application as it does not cover substantially all practical applications of the correlation because it is limited to those applications that use the antibody XYZ."  As for claim 4, the memo points out that the claim "uses assays M and N, which are not routinely used together."