Patent Protection for Medical Technology: Implications of In re Bilski

Medtech companies employ a broad range of patent claim strategies to protect their technology. At a basic level, these strategies include pursuing claims directed to medical devices (both the overall device and individual components), systems for delivering medical treatment and diagnostic test kits.

Companies may also utilize different types of method claims, including, for example, claims directed to methods of delivering medical treatment or therapy and claims directed to diagnostic methods. Whether these medical method claims define patent-eligible subject matter is assessed under the standards set forth in In re Bilski, which was decided by the U.S. Court of Appeals for the Federal Circuit on October 30, 2008.

While Bilski has received much attention for its impact on the patentability of business methods and software, the decision also has important implications for medtech companies working to protect diagnostic and therapeutic methods.

In re Bilski: Court Articulates Definitive Patent Eligibility Test

Bilski involved a patent claim by inventors Bernard L. Bilski and Rand A. Warsaw for a "method of hedging risk in the field of commodities trading." In its much-anticipated decision, the Federal Circuit articulated a new test for determining whether a process is eligible for patent protection under U.S. patent law. In Bilski, the court relied heavily on Supreme Court precedent to overturn its previous "useful, concrete, and tangible result" test. In its place, the court adopted a more narrow "machine-or-transformation" test, which requires that a process (1) be "tied to a particular machine" or (2) "transform a particular article to a different state or thing."

Section 101 of the U.S. patent law provides that "any new and useful process, machine, manufacture or composition of matter" is eligible for patent protection. In its last two decisions addressing the contours of section 101, Diamond v. Diehr (decided in 1980) and Diamond v. Chakrabarty (1981), the Supreme Court stated that patentable subject matter includes "anything under the sun that is made by man." And the Supreme Court set forth three categories of inventions that are not patentable subject matter: "laws of nature, natural phenomena, and abstract ideas."

Processes that Preempt Use of a Fundamental Principle Not
Patent Eligible

In Bilski, a decision joined by nine of 12 judges, the Federal Circuit explained that patents should not "pre-empt substantially all uses of a fundamental principle" such as a law of nature or a mathematical formula. Thus, the court explained that the question before it was whether the applicant's claim "recites a fundamental principle and, if so, whether it would pre-empt substantially all uses of that fundamental principle if allowed."

The court further recognized, however, that "this inquiry is hardly straightforward." And, explained the majority, a claimed process "wherein all of the process steps may be performed entirely in the human mind is obviously not tied to any machine and does not transform any article into a different state or thing," and thus "would not be patent-eligible under § 101."

Accordingly, after canvassing Supreme Court decisions on the patent-eligibility of process claims, the Bilski majority determined that the Supreme Court had "enunciated a definitive test," under which a claimed process "is surely patent-eligible under § 101 if: (1) it is tied to a particular machine or apparatus, or (2) it transforms a particular article into a different state or thing." The Federal Circuit further explained that the machine-or-transformation test requires that the use of a specific machine or transformation of an article "must impose meaningful limits on the claim's scope," and "must not merely be insignificant extra-solution activity." Thus, merely adding a "data-gathering" step to a mathematical algorithm "is insufficient to convert that algorithm into a patent-eligible process."

Bilski Method Claim Did Not "Transform an Article"

The particular claims evaluated in Bilski, for a "method of hedging risk in the field of commodities trading," admittedly did not limit any process step to any specific machine or apparatus. Thus, the court did not apply the "specific machine or apparatus" test to Bilski's claims. Notably, the court stated, "We leave to future cases the elaboration of the precise contours of machine implementation, as well as the answers to particular questions, such as whether or when recitation of a computer suffices to tie a process claim to a particular machine."

The court did, however, apply the "transformation" test to Bilski's claim, and in doing so, elaborated on "what sorts of things constitute ‘articles' such that their transformation is sufficient to impart patent-eligibility under § 101." The court stated it is "virtually self-evident that a process for a chemical or physical transformation of physical objects or substances is patent-eligible subject matter." Additionally, a transformation of electronic signals or data that "represent[s] physical and tangible objects" can be patent-eligible.

The court concluded, however, that Bilski's claims did not "transform any article to a different state or thing." According to the court, "Purported transformations or manipulations simply of public or private legal obligations or relationships, business risks, or other such abstractions cannot meet the test because they are not physical objects or substances, and they are not representative of physical objects or substances."

Impact on Medtech Companies

Although interest in Bilski has largely centered around its anticipated effect on so-called "business method" patents, the machine-or-transformation test for patentability applies to all process or method claims and is not limited to any particular class of technology. Accordingly, in formulating a patent strategy, medtech companies must consider the impact of the machine-or-transformation test on claims directed to medical diagnostics or methods of medical treatment.

Medical Diagnostic Methods

Claims directed purely to diagnostic methods may be most susceptible to challenge under Bilski. Indeed, in his dissenting opinion, Judge Randall R. Rader recognized the potential impact of the Bilski decision on medical technology. Specifically, he noted that denial of patent protection for medical diagnostics would "undermine and discourage future research for diagnostic tools" by undermining the ability to protect such innovations.

In another recent opinion, Classen Immunotherapies, Inc. v. Biogen Idec, which was issued just six weeks after Bilski, the Federal Circuit evaluated the patent eligibility of a claim to a "method of determining whether an immunization schedule affects the incidence or severity of a chronic immune-mediated disorder in a treatment group of mammals."

The claim recited two method steps:

• "immunizing mammals in the treatment group of mammals with one or more doses of one or more immunogens, according to [an] immunization schedule"; and
•  "comparing the incidence, prevalence, frequency or severity of said chronic immune-mediated disorder or the level of a marker of such a disorder, in the treatment group, with that in the control group."

In a one-paragraph, non-precedential opinion, the Federal Circuit, quoting Bilski, found that the Classen claims were not directed to patentable subject matter, as they were "neither ‘tied to a particular machine or apparatus,'" nor did "they ‘transform[] a particular article into a different state or thing.'" While the Classen panel provided no explanation or analysis, the court's decision presumably turned on the "transformation" test, as the claim is not expressly tied to any particular machine or apparatus.

In another case currently on appeal before the Federal Circuit, Prometheus Labs, Inc. v. Mayo Collaborative Services, a California district court struck down patent claims directed to a "method of optimizing therapeutic efficacy" of a Crohn's disease therapy by (a) administering a drug providing a metabolite and (b) determining the level of the metabolite in the subject, wherein the level indicates a need to increase or decrease the amount of drug subsequently administered to the subject.

The district court held that the claims "wholly pre-empt" the correlation and thus fail to define patent-eligible subject matter. It further found that the consumption of the drug and physical transformation into metabolites were merely "necessary data gathering steps," which likewise did not satisfy section 101.

Medical Treatment Methods

While the Federal Circuit has not recently addressed the patent eligibility of claims directed to medical treatment methods, the Board of Patent Appeals and Interferences recently considered this issue, in July 2008.

In Ex parte Roberts, the board evaluated a claim that included the following steps: (a) obtaining a first measurement of a cornea; (b) determining a first ablation specification based on this first measurement; (c) obtaining perturbation data from the cornea to obtain biodynamic response data; (d) obtaining a second measurement of the cornea, (e) correlating the perturbation data with the biodynamic response data; and (f) establishing an individualized, customized ablation specification for that individual cornea. The board characterized steps (a), (c) and (d) as data gathering steps, and steps (b), (e) and (f) as mental steps in forming an individualized ablation specification.

Although Roberts was decided before Bilski, the board applied a version of the machine-or-transformation test. It found that the claim requires "no transformation of subject matter" and further noted that even assuming the data gathering steps are performed by a machine, such steps are not sufficient to satisfy section 101.

After Bilski: Craft Claims to Satisfy Machine-or-Transformation Test

Medtech companies should carefully evaluate their patent strategy relating to medical diagnostic and medical treatment claims in view of Bilski. While these claims continue to be a valuable tool for protecting medical technology, they should be carefully crafted to satisfy the machine-or-transformation test.

Further, courts analyzing section 101 issues will likely continue to scrutinize the extent of the preemptive effect of the claims. In other words, claims that appear to preempt a broad range of applications of a particular concept or algorithm are more likely to fail a section 101 analysis than claims that are expressly directed to a particular application. Thus, medtech companies should consider expressly tying medical diagnostic and therapy process claims to a particular purpose or application.

Diagnostic Method Claims

Claims drawn primarily to diagnostic methods should be scrutinized to ensure they are either appropriately tied to a specific diagnostic device or recite a complete "transformation" of data into a different state. One possible strategy for strengthening the section 101 position of medical diagnostic claims is to avoid trigger words such as "compare" or "correlate," which appear in many of the claims that courts and the Board of Patent Appeals have deemed to be ineligible for patent protection under section 101.

At a minimum, applicants should avoid claims that only recite limitations directed to "comparison" or "correlation" steps. Rather, claims should require additional steps or actions either before or, preferably, after these steps. For example, claims requiring visually displaying the results of such comparisons or correlations will likely satisfy the "transformation" test.

Medical Treatment Method Claims

Claims directed to treatment methods performed by a medical device, for example, should be drafted to expressly include a nexus or tie between the method of treatment and a specific medical device. For example, a claim that expressly requires method steps to be carried out by or using a particular medical device (e.g., an implantable pacemaker or a catheter) should satisfy the "machine" aspect of the test.

Moreover, courts may be more likely to find that certain medical treatment methods satisfy the "transformation" branch of the Bilski test, which requires a physical transformation of an article to a different state or thing.

The Bilski court stated that a qualifying transformation includes a "physical transformation of physical objects or substances." The Federal Circuit has previously stated, in In re Abele, that "physical objects" includes the "structure of bones, organs, and other body tissues."

Courts may determine that a transformation of a person from a "diseased" state to a "healthy" state satisfies the transformation branch of the test. Accordingly, consider crafting medical treatment claims to expressly recite steps resulting in such a transformation.

Supreme Court Will Review Bilski Decision

Bernard Bilski and Rand Warsaw have asked the Supreme Court to review the Federal Circuit's decision, and on June 1, 2009, the court issued an order granting the inventors' petition for writ of certiorari. Briefing will take place over the next several months, with a decision likely in 2010. Stay tuned, as it is quite possible the Supreme Court will decide to broaden or narrow the machine-or-transformation test, or even to articulate an entirely different test.