Marine Polymer Technologies, Inc. v. HemCon, Inc.

Marine Polymer Technologies, Inc. (Marine Polymer) (defendant) held United States Patent No. 6,864,245 (the 245 patent). Marine Polymer sued HemCon, Inc. (defendant) in federal court for infringement of the 245 patent. Marine Polymer and HemCon disagreed on the proper construction of the patent term biocompatibility. Each party proposed a construction of the term, but the district court rejected both and imposed its own construction. The district court granted Marine Polymer’s motion for summary judgment that HemCon literally infringed seven claims of the 245 patent. HemCon filed a request with the United States Patent and Trademark Office (PTO) for ex parte reexamination of the 245 patent. The PTO granted the reexamination request and issued a nonfinal judgment that applied a construction of biocompatibility that differed from the district court’s construction, explaining that the district court’s construction conflicted with dependent claims in the patent. The examiner rejected all claims of the 245 patent under the new construction of biocompatibility. In response, Marine Polymer canceled the conflicting dependent claims, which eliminated the inconsistencies noted by the examiner. Marine Polymer argued that because the conflict was resolved, the district court’s construction of biocompatibility should apply. The examiner agreed and found that under the district court’s construction, the remaining claims were patentable. The language of the seven asserted claims never changed. HemCon appealed. The court of appeals reversed the district court’s judgment because it determined that HemCon obtained intervening rights in the 245 patent. Marine Polymer filed a motion for reconsideration, arguing that the claims were not amended or new. HemCon argued that Marine Polymer’s acts of canceling claims and convincing the patent examiner to apply the district court’s construction of biocompatibility constituted amendment because it led to significant change in the scope of the seven asserted claims.