How is unity of invention determined in national stage applications?
Unity of invention in national stage applications is determined according to PCT Rule 13 and 37 CFR 1.475. As stated in the MPEP, “unity of invention (not restriction practice pursuant to 37 CFR 1.141 – 1.146) is applicable in international applications (both Chapter I and II) and in national stage applications submitted under 35 U.S.C. 371.” The basic principle is that an application should relate to only one invention or to a group of inventions so linked as to form a single general inventive concept. This is determined by the presence of a technical relationship among the inventions involving one or more of the same or corresponding special technical features.
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