In three recent decisions, the Federal Circuit reiterated the importance of determining estoppel in PTAB proceedings on a claim-by-claim basis. In the earlier related decisions, In re Affinity Labs of Texas, LLC [1] , 856 F.3d 883 (Fed. Cir. 2017) and In re Affinity Labs of Texas, LLC [2], 856 F.3d 902 (Fed. Cir. 2017), … Continue Reading