Abstract: Injector for use in ophthalmic applications, having a gas supply tube and a liquid supply tube, both supply tubes being interconnected at a junction member that is in fluid communication with an outflow cannula, characterised in that a selective flow member is placed in the gas supply tube, near the junction member, allowing gases to pass through and blocking the passage of liquid.

Abstract: This invention relates to an optimization method for driving a piezoelectric actuator by dynamic detection of its electromechanical characteristics, as well as to a device, in particular a phacoemulsifier based thereupon. The piezoelectric actuator includes a voltage driven, two-terminal piezoelectric transducer. The method for detection of its electromechanical characteristics is such that the drive of the transducer is cyclically discontinued in order to detect the characteristic parameters of its free motion by detection of the parameters of the signal generated by the transducer at the ends of the two terminals.