Power source device for an electric surgical knife

• US 3,897,787 A
• Filed: 12/27/1973
• Issued: 08/05/1975
• Est. Priority Date: 12/29/1972
• Status: Expired due to Term

• Current Assignee: Yuji Ikuno, Yutaka Kato
• Original Assignee: Yuji Ikuno, Yutaka Kato
• Inventors: Kato, Yutaka, Ikuno, Yuji
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Cohen, Lee S.
• Application Number:
  US05/428,892
• Time in Patent Office: 586 Days
• Field of Search: 128/303.14,303.13,303.17,303.18,2.1P 317/27R
• US Class Current: 606/35
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• CPC Class Codes: A61B 18/16 Indifferent or passive electrodes for grounding

Abstract

Power source device for an electric surgical knife for use with an endoscope comprising, means for supplying a high frequency signal to an electric surgical knife, a selector for determining whether or not the high frequency signal is attenuated before it is supplied to the knife, a level detecting circuit for detecting the voltage level of the high frequency signal which is attenuated and supplied to the treatment electrode of the knife, a level difference detecting circuit for detecting different voltages between the high frequency signal supplied to the treatment electrode and that supplied to the fixed electrode of the knife, and means for determining whether the conductive state of the knife is normal or abnormal using output signals from the level detecting circuit and level difference detecting circuit.

Claims

1. A power source device for supplying high frequency electrical signals on first and second output lines which are respectively adapted to be connected to active and fixed electrodes of an electrosurgical knife, comprising:

means for generating a high frequency signal;

means for supplying a high frequency signal to first and second output lines;

selector means connected to said supplying means for selectively passing said high frequency signal to said supplying means or for attenuating said high frequency signal before passing same to said supplying means;

level detecting means coupled to said supplying means for detecting the voltage level of the high frequency signal supplied to said first output line;

level difference detecting means coupled to said supplying means and to said level detecting means for detecting a difference between the voltage levels of output signals corresponding to the signals appearing on said first and second output lines;

level comparison means fro comparing the voltage level of an output signal from said level detecting means with a first fixed voltage level;

level difference comparison means for comparing the voltage level of an output signal from said level difference detecting means with a second fixed voltage level;

determining means responsive to the output signals from both said level comparison means and said level difference comparison means for determining whether or not the signals supplied to said first and second output lines are '"'"''"'"''"'"''"'"'normal'"'"''"'"''"'"''"'"' so as to render an electric knife in a normal conduction state; and

indicating means responsive to the output of said determining means for indicating whether or not said signals supplied to said first and second output lines are '"'"''"'"''"'"''"'"'normal'"'"''"'"''"'"''"'"'.

2. A power source device according to claim 1 wherein said means for supplying a high frequency signal comprises means for amplifying the voltage and power of the high frequency signal;

and an output circuit means for eliminating a direct current component from the amplified high frequency signal.

3. A power source according to claim 2 wherein said high frequency signal supplying means further comprises a low frequency signal generator for generating a square wave signal of low frequency;

a clamping and differentiating circuit means connected to said low frequency signal generator so as to form a damped wave signal by repeating damping at a repititive frequency equal to the frequency of said low frequency signal; and

means for amplitude modulating said high frequency signal with said damped low frequency signal.

4. A power source according to claim 3 wherein said selector means comprises means coupled to said low frequency signal generator for forming a pulse signal from a low frequency signal generated by said low frequency signal generator;

a first gate means connected to said determining means and to the output of said modulating means so as to supply said high frequency signal without attenuation when an output signal from said determining means which indicates a normal state is delivered to said first gate means;

a second gate means connected to said pulse signal forming means and to said high frequency signal generator and enabled intermittently each time a pulse signal formed by said pulse signal forming means is supplied to said second gate means; and

a signal forming circuit means connected to the output terminal of said second gate means so as to cause said high frequency signal to be attenuated when said second gate means is enabled, thereby causing the attenuated high frequency signal to be supplied by said supplying means to the first and second output lines.

5. A power source according to claim 1 wherein said selector means comprises a signal generator means for generating a gate signal;

a detecting switch means connected to said gate signal generator means and provided with a normally open contact and normally closed contact;

a first gate means connected to said gate signal generator means so as to supply the high frequency signal to said output lines without attenuation when said first gate means is supplied with a signal from the normally closed contact of the detecting switch means;

a second gate means connected to said gate signal generator means and enabled when supplied with a gate signal through the normally open contact of the detecting switch means; and

an output adjusting circuit means connected to the output terminal of said second gate means and to said means for supplying so as to cause said high frequency signal to be attenuated

6. A power source according to claim 5 wherein said means for supplying a high frequency signal includes an output circuit means for eliminating a direct current component from the high frequency signal;

and wherein said voltage level detecting means comprises a first detector electrically coupled to said output circuit means for detecting the amount of current supplied by said supplying means to the said first output line;

a first converter and rectifier circuit means coupled to the output of the first detector;

a third gate means coupled to the normally open contact of the detecting switch means and to an output of the first converter and rectifier circuit means, the operation of the third gate means being controlled by a gate signal supplied thereto through the normally open contact of the detecting switch means; and

a first amplifier means coupled to the third gate means for amplifying an output signal from the third gate means.

7. A poWer source according to claim 6 wherein said voltage level difference detecting means comprises a second detector electrically coupled to said output circuit means for detecting the amount of current supplied by said supplying means to said second output line;

a second converter and rectifier circuit means coupled to the output of the second detector;

a fourth gate means coupled to the normally open contact of the detecting switch means and to the output of the second converter and rectifier circuit means, the operation of the fourth gate means being controlled by a gate signal supplied to the fourth gate means through the normally open contact of the detecting switch means;

a second amplifier mena connected to the output terminal of the fourth gate; and

a differential amplifier coupled to the outputs of the first and second amplifier means.

8. A power source according to claim 5 wherein said determining means comprises a first flip-flop coupled to the output of said level comparison means;

a second flip-flop coupled to the output of said level difference comparison means, said first and second flip-flops being coupled to said selector means and being controlled by a gate signal from said selector means; and

an AND gate means coupled to the outputs of both said first and second flip-flops; and

wherein said indicating means includes a display means coupled to the output of said AND gate means.

9. A power source according to claim 1 wherein said selector means comprises a signal generator means for generating a gate signal;

a detecting switch means connected to said gate signal generator means and provided with a single contact;

a first gate means connected to said means for generating a high frequency signal and to an output of said determining means for supplying said high frequency signal without attenuation when an output signal from said determining means which indicates a normal condition is supplied to said first gate means;

a second gate means connected to said gate signal generator means and enabled when the contact of the detecting switch means is closed; and

a signal forming circuit means connected to the output terminal of said second gate means so as to cause said high frequency signal to be attenuated when said second gate means is enabled, thereby causing an attenuated high frequency signal to by supplied by said supplying means to the first and second output lines.

10. A power source device according to claim 1 wherein said level comparison means comprises a standard voltage level setting circuit means for generating said first fixed voltage level;

and a first Schmitt circuit means coupled to the output of the level detecting means and to the output of the standard voltage level setting circuit means, for producing an output signal of its own when the voltage level of an output signal from the level detecting means is higher than said first fixed voltage level.

11. A power source device according to claim 1 wherein said level difference comparison means comprises a standard voltage level difference setting circuit means for generating said second fixed voltage level representing a preset standard difference;

and a second Schmitt circuit means coupled to an output of the level difference detecting means and to the output of the standard voltage level difference setting circuit means, for producing an output signal of its own when the voltage level of an output signal from the level difference detecting means is lower than said second fixed voltage level.

12. A power source according to claim 1 wherein said determining means comprises a first bistable multivibrator coupled to the output of said level comparison means;

a second bistable multivibrator coupled to the output of said level difference comparison means; and

gating means coupling the outputs of said first and second bistable multivibrators to said indicating means.

13. An electric surgical knife device comprising:

an electric surgical knife provided witH an active electrode and a fixed electrode whose contact area is larger than that of said active electrode;

a high frequency signal generator for generating a high frequency signal;

means for supplying the high frequency signal to the active and fixed electrodes of the electric surgical knife;

selector means connected to said supplying means for selectively passing said high frequency signal to said supplying means or for attenuating said high frequency signal before passing same to said supplying means;

level detecting means coupled to said supplying means for detecting the voltage level of the high frequency signal supplied to the active electrode of the knife;

level difference detecting means coupled to said supplying means and to said level detecting means for detecting a difference between the voltage levels of output signals corresponding to the signals supplied to the active electrode and to the fixed electrode;

level comparison means for comparing the voltage level of an output signal from said level detecting means with a first fixed voltage level;

level difference comparison means for comparing the voltage level of an output signal from said level difference detecting means with a second fixed voltage level;

determining means responsive to the output signals from both said level comparison means and said level difference comparison means for determining whether or not the signals supplied to said electric knife are such as to render said electric knife in a normal conductive state; and

indicating means responsive to the output of said determining means for indicating whether or not said signals supplied to said electric knife are such as to render said electric knife in a normal conductive state.