Apparatus for generating ultrasonic oscillation

An apparatus for generating an ultrasonic oscillation comprising:

• an ultrasonic transducer having an ultrasonic vibrating element which produces an ultrasonic oscillation and a probe which transmits the oscillation produced by the ultrasonic vibrating element;
• a driving circuit having a voltage controlled amplifier which supplies a driving power to said ultrasonic vibrating element;
• a feedback loop connected between said ultrasonic transducer and said driving circuit which detects a current of said driving power supplied to said ultrasonic transducer and applies a control voltage corresponding to said current of the driving power to said voltage controlled amplifier to control an amplification of the voltage controlled amplifier to thereby maintain said current of said driving power supply at a constant level;
• and
• a voltage limiting means connected in said feedback loop for limiting an amplitude of said control voltage.

An apparatus for generating an ultrasonic oscillation comprising:

• an ultrasonic transducer having an ultrasonic vibrating element which produces an ultrasonic oscillation and a probe which transmits the oscillation produced by the ultrasonic vibrating element;
• a driving circuit having a voltage controlled amplifier which supplies a driving power to said ultrasonic vibrating element;
• a feedback loop connected between said ultrasonic transducer and said driving circuit which detects a current of said driving power supplied to said ultrasonic transducer and applies a control voltage corresponding to said current of the driving power to said voltage controlled amplifier to control an amplification of the voltage controlled amplifier to thereby maintain said current of said driving power supply at a constant level;
• a voltage limiting means having a plurality of voltage limiting elements connected in said feedback loop for limiting an amplitude of said control voltage;
• probe identifying means for identifying a kind of said ultrasonic transducer to generate a probe identification signal;
• and
• controlling means for automatically switching said plurality of voltage limiting elements of the voltage limiting means in accordance with the probe identification signal produced by the probe identifying means.

An apparatus for use in driving an ultrasonic surgical knife, wherein a plurality of probes having different impedances are selectively detachably coupled with said apparatus, said apparatus comprising:

• an ultrasonic vibrating element, having a selected one of said plurality of probes coupled thereto, which applies an ultrasonic vibration to said selected probe;
• an electric power supply source means for supplying a constant current to said ultrasonic vibrating element to vibrate the element;
• a matching means provided between said ultrasonic vibrating element and said electric power supply source means for effecting impedance matching therebetween and including at least two transformers having different winding ratios;
• a probe identifying means for detecting a voltage applied to said matching means to identify a kind of said selected probe coupled with the ultrasonic vibrating element;
• and
• a switching means coupled with said matching means for selecting one of said transformers on the basis of an output signal supplied from said probe identifying means, said one of said transformers being suitable for the selected probe.

A method of driving an ultrasonic vibrating apparatus comprising an ultrasonic vibrating element which applies an ultrasonic vibration to a probe coupled to the ultrasonic vibrating element, an electric power supply source means for supplying a constant current to said ultrasonic vibrating element to vibrate the ultrasonic vibrating element, a matching means provided between said ultrasonic vibrating element and said electric power supply source means for effecting impedance matching therebetween and including at least two kinds of impedance members, a probe identifying means for identifying a kind of the probe coupled with the ultrasonic vibrating element, and a switching means coupled with said matching means for selecting one of said impedance members on the basis of an output signal supplied from said probe identifying means, said one of said impedance members being suitable for the probe, comprising the steps of:

• supplying a low current from said electric power supply source means for a time period during which the kind of the probe coupled with the ultrasonic vibrating element is identified;
• operating said switching means, after the kind of the probe has been identified, to select said one of said impedance members which is suitable for the probe;
• and
• supplying a high constant current from said electric power supply source means to drive the ultrasonic vibrating element to generate an ultrasonic vibration.