disclosed is an ultrasonic surgical instrument that combines end - effector geometry to best affect the multiple functions of a shears - type configuration . the shape of the blade is characterized by a radiused cut offset by some distance to form a curved geometry . the cut creates a curved surface with multiple asymmetries causing multiple imbalances within the blade . imbalance due to the curve of the instrument is corrected by a non - functional asymmetry proximal to the functional asymmetry . imbalance due to the asymmetric cross - section of the blade is corrected by the appropriate selection of the volume and location of material removed from a functional asymmetry . the shape of the blade in one embodiment of the present invention is characterized by two radiused cuts offset by some distance to form a curved and potentially tapered geometry . these two cuts create curved surfaces including a concave surface and a convex surface . the length of the radiused cuts affects , in part , the acoustic balancing of the transverse motion induced by the curved shape .