PTO Guidelines: Computer Programs and Mathematical Algorithms

Citation: U.S. Patent & Trademark Office, Computer Programs and Mathematical Algorithms (Sept. 1989).

In September 1989, the U.S. Patent & Trademark Office published a set of guidelines on the patentability of mathematical algorithms. In these guidelines, the PTO interpreted the law to encourage greater consistency in examination procedures among the different groups which handled patent applications that include mathematical algorithms.

The PTO relied upon the two-part test of In re Freeman72 as modified by In re Walter73 and In re Abele 74 as the proper legal analysis of mathematical algorithm-statutory subject matter cases. Part 1 of the test is to determine whether a mathematical algorithm is recited, directly or indirectly, in the claims. The guidelines warn that, since mathematical algorithms have been determined not to fall within the section 101 statutory class of a "process," applicants may attempt to circumvent the nonstatutory subject matter rejection by drafting mathematical algorithms as "apparatus" claims.75 The guidelines require that the claims first be inspected to determine whether the claim recites a mathematical algorithm.76 Noting that such a determination is not always possible by inspection of the claim, the guidelines indicate "careful interpretation of each claim in light of its supporting disclosure."77

Part 2 of the test is to determine whether the mathematical algorithm is "applied in any manner to physical elements or process steps." The guidelines suggest that the Abele rule be followed, wherein the claim is viewed without the mathematical algorithm to determine whether what remains is “otherwise statutory.” If it is, the claim does not become nonstatutory simply because it includes a mathematical algorithm. Citing Flook, and recognizing that the line between a patentable ‘‘process’ and an unpatentable ‘‘principle’ is not always clear, the PTO suggests some “useful guidelines” synthesized from the court decisions, that should aid in drawing the line between a patentable process and an unpatentable ‘‘principle. ” The PTO issued guidelines resulting from leading court decisions:


 * 1. If the only limitation other than the mathematical algorithm is insignificant or nonessential “post solution activity,” the claimed subject matter is nonstatutory.78


 * 2. A mathematical algorithm is not rendered statutory by "attempting to limit the use of the formula to a particular technological environ-

ment," so that "field of use” or “end use” limitation in the claim preamble do not suffice to constitute statutory subject matter.79


 * 3. If the only claim limitations in addition to the mathematical algorithm are data gathering steps which ‘merely determined values for the variables used in the mathematical formulae used in making the calculations, such steps are insufficient to change a nonstatutory method of calculation into a statutory process.80


 * 4. The PTO suggests that it is useful to analyze whether there is transformation of something physical into another form. A distinction is

made between transformation of matter in one