In Nature Simulation Systems Inc. v. Autodesk, Inc., [2020-2257] (January 27, 2022), the Federal Circuit reversed the district court’s judgement that U.S. Patent Nos. 10,120,961 and 10,109,105, both entitled “Method for Immediate Boolean Operations Using Geometric Facets,” were not invalid for indefiniteness.

The patents are for data structures and algorithms for the claimed method, which is described as a modification of the Watson method, a Boolean operation published in 1981 for analyzing and representing three-dimensional geometric shapes.

There were two claim elements that the district court determined made the claims indefinite: “searching neighboring triangles of the last triangle pair that holds the last intersection point”; and “modified Watson method.” The district court held the claims indefinite based on the “unanswered questions” that were suggested by Autodesk’s expert.

In finding the claims indefinite, the district court declined to consider information in the specification that was not included in the claims. The Federal Circuit found that the district court misperceived the function of patent claims. The Federal Circuit also found that the applicant, in consultation with the examiner, amended the claim to add the disputed language. The Federal Circuit noted that the district court gave no weight to the prosecution history showing the resolution of indefiniteness by adding the designated technologic limitations to the claims. The court did not discuss the Examiner’s Amendment, and held that since Dr. Aliaga’s questions were not answered, the claims are invalid.

The Federal Circuit said that “[a]ctions by PTO examiners are entitled to appropriate deference as official agency actions, for the examiners are deemed to be experienced in the relevant technology as well as the statutory requirements for patentability.”

The Federal Circuit added, “[t]he subject matter herein is an improvement on the known Watson and Delaunay methods, and partakes of known usages for established technologies. Precedent teaches that when ‘the general approach was sufficiently well established in the art and referenced in the patent’ this ‘render[ed] the claims not indefinite.’”

The Federal Circuit concluded that ‘[I]ndefiniteness under 35 U.S.C. § 112 was not established as a matter of law,” and reversed the district court.