Negative functional limitations can recite structural elements and be directly infringed by product sales

LifeNet Health v. LifeCell Corporation, No. 2015-1549 (Fed. Cir. Sept. 16, 2016)

The accused infringer appealed a jury verdict of infringement and validity. The Federal Circuit affirmed. The asserted claim called for a “soft tissue graft suitable for transplantation,” in which certain preservative “plasticizers are not removed … prior to transplantation.” The accused infringer, which sells plasticized tissue grafts but does not perform transplants, argued that it did not directly infringe the claim because “the non-removal limitation cannot be met until a surgeon actually prepares and uses the accused product.”

However, “functional limitations recited in the negative may describe a capability or structural element,” and in this case “[t]he non-removal limitation simply provides a negative limitation that those plasticizers remain… prior to transplantation.” “This limitation is met without action by a third party,” so sales of the accused tissue grafts infringe even before any transplant takes place.

Likewise, the claim was not indefinite “for covering both an apparatus [i.e., the graft] and a method of using that apparatus [i.e., not removing the plasticizer].” Because “the non-removal limitation defines a property of the recited plasticizer in that it does not need to be removed,” “no later action is necessary.”