Lack of Standard for Measuring “Substantial” Interference Renders Wireless Transmission Claims Indefinite

The court granted defendant's motion for summary judgment that plaintiff's wireless data transmission patent was invalid as indefinite because of the term, "substantially prevent communication interference between the first and second pairs." "It is clear that the use of the word "substantially" does not necessarily make a claim term indefinite. . . . But when a word of degree is used in a patent, the court must determine whether the patent’s specification provides a standard for measuring that degree. It is not enough to identify some standard for measuring the scope of a phrase. . . . [Defendant] correctly notes that the intrinsic evidence does not offer any objective boundaries for the term 'substantial.' The fact that the specification and prosecution history lack evidence that would inform a person skilled in the art as to how much interference prevention the patent contemplates sets it apart from patents that have overcome indefiniteness challenges to terms of degree."

Fairfield Industries Incorporated v. Wireless Seismic, Inc., 4-14-cv-02972 (TXSD March 10, 2015, Order) (Ellison, J.)