Abstract: Various embodiments are directed to a method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument. The method comprises generating at least one electrical signal. The at least one electrical signal is monitored against a first set of logic conditions. A first response is triggered when the first set of logic conditions is met. A parameter is determined from the at least one electrical signal.

Abstract: A method for determining motional branch current in an ultrasonic transducer of an ultrasonic surgical device over multiple frequencies of a transducer drive signal. The method may comprise, at each of a plurality of frequencies of the transducer drive signal, oversampling a current and voltage of the transducer drive signal, receiving, by a processor, the current and voltage samples, and determining, by the processor, the motional branch current based on the current and voltage samples, a static capacitance of the ultrasonic transducer and the frequency of the transducer drive signal.

Abstract: A method for aligning at least one machine unit (36) on a base (42) comprises the steps of installing alignment markers (28) on the parts (12, 14) of a machine unit (36) to be aligned, and correcting the locations of the alignment markers (28) to effect a correction in the locations of the parts (12, 14) on which they are installed. The alignment markers (28) are installed in positions which have precise relationships to the positions of function specific openings (20) in the parts (12, 14) which are preferably formed in metal cutting machining. A correction in the locations of the alignment markers (28) thus effects a correction in the locations of the function specific openings (20). The alignment markers (28) enable an alignment of parallel parts (12, 14) of a single machine unit (36) as well as alignment of several machine units (36, 38, 40) arranged one after the other in series.