Apr 15, 2020Legal
Infringement Need Not Be Ex Ante Determinable for Claim to Be Definite

Written by: James Yang & Mark Kachner


Before Moore, Taranto, and Chen. Appeal from U.S. District Court for the Northern District of California.

Summary:  Functional claim term directed at avoiding a side effect is sufficiently definite, despite infringement being determinable only after using the device or system.

Nevro sued Boston Scientific for patent infringement related to an improvement on spinal cord stimulation therapy using high frequency wave forms. The district court held inter alia, twelve asserted claims were indefinite. The Federal Circuit reversed for all twelve claims.  Significantly, the district court construed “paresthesia-free,” to mean “does not produce a sensation usually described as tingling, pins and needles, or numbness.”  The district court found this term indefinite, in that infringement depended on the effect of systems and devices on a patient, rather than the parameters of the system or device itself.  The Federal Circuit rejected this reasoning, stating that a claim may be definite, despite infringement varying case-by-case, so long as the claim term informs “about the scope of the invention with reasonable certainty.”  A wave form’s elimination of paresthesia in “some patients, but not others, does not render the claims indefinite."  Definiteness does not require infringement to be ex ante determinable.

Editor: Paul Stewart

Written by: James Yang & Mark Kachner

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