Abstract: Disclosed is an ultrasonic surgical instrument that includes a blade end-effector having a curved geometry. The curved geometry creates a curved surface with multiple asymmetries causing multiple imbalances within the blade. Imbalance due to the asymmetries of the blade is corrected by the appropriate selection of the volume and location of material removed from a functional asymmetry.

Abstract: A surgical instrument for excising a targeted tissue mass to be biopsied from adjacent bodily tissue on a surgical patient is disclosed. The instrument has an elongated tube and a tissue penetrating spiral having a spiral lumen therethrough mounted within the elongated tube for rotational movement. When the spiral is rotated, it penetrates distally into the targeted tissue mass. The mass is received in the spiral lumen for subsequent excision of the mass to be biopsied. A large biopsy sample can be obtained because of the ample space within the lumen of the tissue penetrating spiral. Since a large biopsy sample can be taken, the number of samples which need to be taken is minimized, and the consequent trauma to the patient is significantly reduced.