In Defense of M-S-T: The Federal Circuit’s Decision in Dyestar v. C.H. Patrick
The U.S. Court of Appeals for the Federal Circuit issued an opinion in the Dystar Textilfarben v. C.H. Patrick Co. and Bann Quimica decision that defended the use of the “motivation-suggesting teaching” (hereinafter: “M-S-T”) test in order to determine a finding of obviousness in the matter of patented inventions. The opinion is of particular interest because it is seemingly drafted in direct response to the Supreme Court granting certiorari for the KSR v. Teleflex appeal, which has now been decided in favor of KSR and perhaps has forever altered the application of the M-S-T test.
In Dystar v. C.H. Patrick, the plaintiff patent holder had patented an improvement to the process of dyeing textile materials with catalytically hydrogenated leuco. The improvement centered on the removal of two of the six steps traditionally used in the process: stabilizing the leuco indigo solution into a paste or powdered form, and then reconstituting the solution in a preparation tank. The patent holder successfully alleged that the defendants had infringed on 4 claims of the patent as the jury declined to hold the patent claims invalid for lack of enablement, anticipation or obviousness. The defendants then filed a motion for judgment as a matter of law asserting the patent should be held invalid for issues of obviousness. This motion was denied by the district court, upon which defendants appealed.
In its analysis of the case, the Federal Circuit notes that pursuant to 35 U.S.C. §103(a), a determination of obviousness rests on “if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains”. The Supreme Court interpreted the issue in Graham v. John Deer and determined that there were four factors upon which obviousness depended: (1) the scope and content of the prior art; (2) the differences between the claimed invention and the prior art; (3) the level of ordinary skill in the art; and (4) any relevant secondary considerations. The Federal Circuit articulated a secondary requirement to the first factor when it stated that “when all claim limitations are found in a number of prior art references, the fact finder must determine what the prior art teaches, whether it teaches away from the claimed invention, and whether it motivates a combination of teachings from different references”. The M-S-T test, the Court explained, was its way of evaluating the “motivation to combine”, factor. The Court acknowledged the criticism of the test— that it is seen by some as a rigid categorical rule —but was quick to point out that it explained in Motorola, Inc. v. Interdigital Tech Corp., that “there is no requirement that the prior art contain an express suggestion to combine known elements to achieve the claimed invention. Rather the suggestion to combine may come from prior art, as filtered through the knowledge of one skilled in the art”.
Richard Ito
Patent Attorney