Claims drafting will employ new or adjusted strategies in the wake of the US Supreme Court’s decision in Bilski v Kappos.1 Bilski rejected the machine-or-transformation test as the exclusive test of patentable subject matter, but maintained the machine-or-transformation test as one test. In situations where the machine-or-transformation test is not met, patent practitioners will seek to establish that their claims nevertheless recite patentable subject matter.

One further impact of the Supreme Court’s decision is that there is great uncertainty about the viability of prior Federal Circuit case law. While the Supreme Court did not specifically disclaim any prior Federal Circuit precedent, it also did not endorse any.

Accordingly, rather than looking to Federal Circuit precedent, patent practitioners will need to scrutinize Supreme Court precedent. Diehr, Benson and Flook, in particular, provide principles that may assist in getting beyond the machine-or-transformation test.

Principle 1: Solving a Practical Problem

The patent at issue in Diamond v. Diehr2 involved a process for molding cured precision synthetic rubber products from raw, uncured synthetic rubber. The particular facts of Diehr, therefore, fall squarely within the “transformation” branch of the machine-or-transformation test.

What is easily overlooked is the broader issue that the Supreme Court decided. As Justice Rehnquist explained: “We granted certiorari to determine whether a process for curing synthetic rubber which includes in several of its steps the use of a mathematical formula and a programmed digital computer is patentable subject matter under 35 U.S.C. §101” (emphasis added).

During prosecution of the claims, the examiner at the United States Patent and Trademark Office had based his rejection on the fact that the claims were carried out by a computer under control of a stored program. The Court of Customs and Patent Appeals (CCPA) eventually reversed the examiner’s rejection noting that a claim, which is otherwise drawn to statutory subject matter, is not rendered unstatutory simply because a computer is involved.

In describing the CCPA’s rationale, the Supreme Court noted an important distinction: “The respondent’s claims were not directed to a mathematical algorithm or an improved method of calculation but rather recited an improved process for molding rubber articles by solving a practical problem which had arisen in the molding of rubber products” 3 (emphasis added). This seems to suggest the idea of appealing to a solution to a practical problem as one way of identifying patentable subject matter. There is at least a reasonable argument to be made that if a process solves a practical problem, it should constitute patentable subject matter, as opposed to being merely an abstract idea.

The key precedent upon which the Diehr’s decision hung was the following:

That a process may be patentable, irrespective of the particular form of the instrumentalities used, cannot be disputed. * * * A process is a mode of treatment of certain materials to produce a given result. It is an act, or a series of acts, performed upon the subject matter to be transformed and reduced to a different state or thing. If new and useful, it is just as patentable as is a piece of machinery. In the language of the patent law, it is an art. The machinery pointed out as suitable to perform the process may or may not be new or patentable; whilst the process itself may be altogether new, and produce an entirely new result. The process requires that certain things should be done with certain substances, and in a certain order; but the tools to be used in doing this may be of secondary consequence. Cochrane v. Deener, 94 U.S. 780, 787-788 (1876).4

One may reasonably argue that a patentable process is defined as one or more acts performed on subject matter to be changed.

The significance of this definition is that the patentability of a process does not hang on the machine or tools used. Thus, one may reasonably argue that a patentable process is defined as one or more acts performed on subject matter to be changed.

Principle 2: Particular End Use

Connected with the citation from Cochrane, Gottschalk v. Benson5 explained: “Transformation and reduction of an article ‘to a different state or thing’ is the clue to the patentability of a process claim that does not include particular machines.” While this transformation may be connected with the machine-or-transformation test, the case also provided some indication of why the claims at issue in Benson were not directed to statutory subject matter. Specifically, the Court indicated that “[t]he claims were not limited to any particular art or technology, to any particular apparatus or machinery, or to any particular end use”6 (emphasis added). The implication in the Court’s statement is that if the claims had been limited to a particular end use, they would apparently have been patentable subject matter.

Principle 3: Integrating Process and Solution

After Benson but before Diehr, the Supreme Court provided the particularly challenging precedent of Parker v. Flook.7 The Court took the position that a claim arguably addressed to a particular end use was not directed to patentable subject matter. The Court recognized what many people doubtless are beginning to see is true: “The line between a patentable ‘process’ and an unpatentable ‘principle’ does not always shimmer with clarity.”8

The Court explained that its decision was consistent with the approach of considering a claim as a whole, stating that “[r]espondent’s process is unpatentable under §101 not because it contains a mathematical algorithm as one component, but because once that algorithm is assumed to be within the prior art, the application, considered as a whole, contains no patentable invention.”9 The Court specifically defined algorithm to mean a “procedure for solving a given type of mathematical problem.”10

The Court appeared to focus on the idea that the entire “solution” in Flook was an algorithm – a different way of calculating a given type of mathematical problem. The lesson here is that care should be taken to avoid drafting claims that have the appearance of differing from the prior art only by using a different algorithm, the different algorithm having the same input and output as the prior art. In other words, to avoid a situation like Flook, the algorithm should be integrated, as much as possible, into the process and the solution so that even if the algorithm were assumed to be part of the prior art, the process would still be novel and nonobvious.


Undoubtedly, the primary approach for drafting claims going forward will be to attempt to make the claims fall within the machine-or-transformation test. However, for claims that do not naturally fall within the limits of that test for whatever reason, the above principles may help guide the drafter.

In particular, an emphasis on solving a particular practical problem with a particular end use identified, while integrating the process and solution together as much as possible, should help to assist the patent practitioner, both in obtaining an allowance of the claims and subsequently defending those claims against challenges in the course of litigation.