What constitutes evidence of experimental activity for patent purposes?
Evidence of experimental activity for patent purposes typically involves modifications or refinements to the invention. The MPEP provides guidance on this matter: The fact that alleged experimental activity does not lead to specific modifications or refinements of an invention is evidence, although not conclusive evidence, that such activity is not within the realm permitted by the statute.
(MPEP 2133.03(e)(3))
Furthermore, any modifications resulting from experimental activity must be related to the claimed invention: Nevertheless, any modifications or refinements which did result from such experimental activity must at least be a feature of the claimed invention to be of any probative value.
This means that ongoing changes or improvements to the invention can support claims of experimental use, but these changes should be relevant to the patent claims to be considered valid experimental activity.
To learn more: