Apparatus for generating ultrasonic oscillation

• US 5,425,704 A
• Filed: 06/09/1992
• Issued: 06/20/1995
• Est. Priority Date: 04/28/1989
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Gotanda, Masakazu, Sakurai, Tomohisa
• Primary Examiner(s): Pfaffle, Krista M.
• Application Number:
  US07/895,839
• Time in Patent Office: 1,106 Days
• Field of Search: 128/24 AA, 128/660.01, 604/22, 606/169-171, 310/313 R, 310/314-317
• US Class Current: 604/22
• CPC Class Codes: A61B 2017/0003 of parts of the instruments
• CPC Class Codes: A61B 2017/32007 with suction or vacuum means
• CPC Class Codes: A61B 2017/320071 with articulating means for working tip
• CPC Class Codes: A61B 8/546 involving monitoring or regulation of device temperature

Abstract

The apparatus includes an ultrasonic transducer having a hand piece, an ultrasonic vibrating element secured to the hand piece and a probe coupled with the hand piece for propagating the ultrasonic oscillation produced by the ultrasonic vibrating element, a driving circuit for producing a driving signal for the ultrasonic vibrating element, a voltage controlled amplifier for amplifying the driving signal, an impedance matching transformer having a plurality of primary windings connected to the output of the voltage controlled amplifier via a switching circuit and a secondary winding connected to the ultrasonic vibrating element, a probe identification circuit for detecting the probe connected to the hand piece to produce a probe identification signal, a feedback control loop for generating a control voltage which is applied to the voltage controlled amplifier for controlling the amplification factor thereof in accordance with a driving current of the driving signal, an impedance detecting circuit for detecting the impedance of the ultrasonic transducer and controlling, the switching circuit such that a given primary winding is connected to attain the impedance matching between the driving circuit and the ultrasonic transducer, and a voltage limiter arranged in the feedback control loop such that the maximum value of the control voltage is limited in accordance with the probe identification signal.

Claims

1. 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, said ultrasonic transducer having an impedance;

a driving circuit which supplies a driving power to said ultrasonic vibrating element, said driving circuit having an output impedance;

an impedance matching means connected between said ultrasonic transducer and said driving circuit for matching the output impedance of the driving circuit to the impedance of said ultrasonic transducer;

a probe identifying means for identifying a kind of said ultrasonic transducer to generate a probe identification signal; and

controlling means for automatically controlling said impedance matching means in accordance with said probe identification signal supplied from said probe identifying means such that the output impedance of said driving circuit is matched to the impedance of said ultrasonic transducer.

2. An apparatus according to claim 1, wherein said impedance matching means comprises a matching transformer having a plurality of primary windings and a secondary winding connected to the ultrasonic transducer, a switching circuit which selectively connects one of said primary windings into the circuit, and a control circuit which controls said switching circuit in accordance with said probe identification signal supplied from said probe identifying means such that the output impedance of said driving circuit is matched with the impedance of the ultrasonic transducer.

3. An apparatus according to claim 2, wherein said switching circuit comprises a relay driven by said control circuit.

4. An apparatus according to claim 1, wherein said probe identifying means comprises a circuit which detects the impedance of said ultrasonic transducer to generate said probe identification signal.

5. An apparatus according to claim 4, wherein said circuit which detects the impedance of the ultrasonic transducer is constructed to detect the impedance of the ultrasonic transducer by detecting a voltage of said driving power.

6. An apparatus according to claim 5, wherein said circuit which detects the voltage of the driving power to detect the impedance of the ultrasonic transducer is provided on an input side of said impedance matching means.

7. An apparatus according to claim 6, wherein said probe identifying means comprises a voltage detection circuit which detects an absolute value of the voltage of said driving power, a plurality of comparators whose outputs are inverted when the absolute value of the detected voltage exceeds different reference voltages, and a logic circuit which generates said probe identification signal in accordance with conditions of the outputs of said comparators.

8. An apparatus according to claim 1, wherein said ultrasonic transducer is constructed such that said probe includes a base portion which is detachably coupled with a front end portion of said ultrasonic vibrating element, and said probe identifying means comprises a first means provided in said base portion of the probe for identifying the kind of the probe and a second means provided in said front end portion of the ultrasonic vibrating element for detecting the kind of the probe in co-operation with said first means.

9. 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.

10. An apparatus according to claim 9, wherein said feedback loop comprises a current detector connected between said driving circuit and said ultrasonic transducer, a current-voltage converter which converts a current detected by said current detector into a voltage, and a low pass filter which passes a low frequency component of the voltage output from the converter, whereby an output signal from the low pass filter is supplied to said voltage limiting means.

11. An apparatus according to claim 10, wherein said current detector includes a current transformer having a primary winding connected in a line which supplies the driving power to the ultrasonic transducer and a secondary winding which produces the driving current, and said current-voltage converter includes a differential amplifier having positive and negative input terminals connected across said secondary winding.

12. An apparatus according to claim 9, wherein said voltage limiting means comprises at least one zener diode.

13. 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.

14. An apparatus according to claim 13, wherein said probe identifying means comprises an impedance detection circuit which detects an impedance of said ultrasonic transducer to generate the probe identification signal for identifying the kind of the ultrasonic transducer.

15. An apparatus according to claim 13, wherein said impedance detection circuit is constructed to detect a voltage of the driving power for the ultrasonic transducer.

16. An apparatus according to claim 15, wherein said probe identifying means comprises a voltage detection circuit which detects an absolute value of the voltage of said driving power, a plurality of comparators whose outputs are inverted when the absolute value of the detected voltage exceeds different reference voltages, and a logic circuit which generates said probe identification signal in accordance with conditions of the outputs of said comparators.

17. An apparatus according to claim 13, wherein said plurality of voltage limiting elements are formed by zener diodes having different threshold voltages, and said controlling means comprises a plurality of switches which are driven by the probe identification signal supplied from said logic circuit, each of said zener diodes being connected to a respective one of said switches.

18. 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.

19. An apparatus according to claim 18, wherein said apparatus further comprises a display means for displaying the kind of the selected probe which has been identified by said probe identifying means.

20. An apparatus according to claim 18, wherein said electric power supply source means is constructed to have a first operation mode in which a low constant current is generated during a time in which the kind of the selected probe is identified and a second operation mode in which the ultrasonic surgical knife is driven.

21. 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.

22. A method according to claim 21, wherein said probe identifying means includes a voltage comparing means for detecting a voltage of the electric power supply source means and comparing the voltage thus detected with a predetermined voltage, and said step of identifying the kind of the probe is carried out by detecting and comparing the voltage of the electric power supply source means with said predetermined voltage.