The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
Embodiments according to the present invention will now be described in detail hereinafter with reference to the accompanying drawings.
The electric processing system according to this embodiment is roughly constituted of a drive control apparatus main body 1 and an electric processing instrument, e.g., bipolar type sealing forceps 2 which perform welding processing with respect to a blood vessel or the like. Distal ends 2a in which two jaws to which a high-frequency power (a power value: a high-frequency current value×a high-frequency voltage value) can be applied are formed into a double opening or single opening structure are provided at the end of the sealing forceps 2a so that a living tissue or a blood vessel is held to perform processing such as incision, coagulation, sealing, welding or the like. An insulating member such as a ceramic member or a resin member is provided on each of the two jaws so that a non-energized condition can be attained in a closed state. Additionally, manipulating an operating portion 2b provided on an operator's hand side of the sealing forceps 2 can open/close the jaws of the distal ends 2a. It should be noted that a switch which turns application of the high-frequency power on and off may be provided in this operating portion 2b.
The drive control apparatus main body 1 is comprised of: a control portion (a CPU) 3 which controls the entire apparatus and performs feedback control over a high-frequency power applied to the sealing forceps 2; a power supply 4 which supplies a direct current; a resonance circuit 5 which converts the direct current into a high-frequency current (a high-frequency power); a waveform generation circuit 6 which controls a waveform of the high-frequency current generated by the resonance circuit 5; an amplifier 7 which amplifies the high-frequency power to a desired power value; an output transformer 8 which outputs the high-frequency power from the amplifier 7 to the jaws of the sealing forceps 2; a current/voltage detecting portion 9 consisting of a current detection circuit 10 which samples the output high-frequency power to detect a current value and a voltage detection circuit 11 which detects a voltage value; analog-to-digital converters 12 and 13 which respectively digitize the current value and the voltage value detected by the current detection circuit 10 and the voltage detection circuit 11; a phase difference detection circuit 14 which detects a change in a phase difference in detection values (the current value and the voltage value) converted into digital signals; an external switch 15 such as a hood switch which turns application of the high-frequency power on and off; a key switch (including a keyboard) 16 which is provided on the exterior of the apparatus and inputs operator instructions; a display portion 17 which displays an application state of the high-frequency voltage or information required for processing; and a touch panel switch 18 which is provided on a screen of the display portion 1 in order to input operator instructions like the key switch 16.
This drive control apparatus main body 1 applies a high-frequency power to the distal ends 2a of the sealing forceps 2 which hold a living tissue or a blood vessel therebetween. As shown in
It is sufficient to set an output waveform of this high-frequency power in such a manner that it becomes substantially equivalent to an amount of an applied energy based on a product of a sum of each application time of the intermittently applied high-frequency power and a high-frequency power (a high-frequency current value or a high-frequency voltage value). That is, when the high-frequency power is reduced, prolonging the application time to allow processing can suffice.
The phase difference detection circuit 14 detects a change in a phase difference in detection values (the current value and the voltage value) converted into digital signals. It is sufficient to detect a change in a phase difference between the current and the voltage to sense occurrence of abnormal discharge. It should be noted that a waveform of the high-frequency power generated in this embodiment is basically a sine waveform, and hence a zero cross circuit may be used to detect a phase difference.
A description will now be given as to output control of the thus configured electric processing system with reference to a flowchart of
First, an operator turns on the external switch 15 to start processing (step S1). Based on this on operation, application of a high-frequency power to the sealing forceps 2 is started, and feedback control begins (step S2).
Then, a judgment is made upon whether a voltage value of the high-frequency power applied to the sealing forceps 2 has reached a preset control voltage (e.g., a constant voltage having an upper limit value of 100 V) (step S3). Voltage rising in this example has a waveform shape which is slightly inclined with respect to vertical rising of a regular pulse waveform as shown in
When the high-frequency power has not reached the control voltage yet (NO) in the judgment at step S3, the application state is maintained. On the other hand, when the high-frequency power has reached the control voltage (YES), the control voltage is maintained and an intermittent output is applied to the sealing forceps 2 in a pulse waveform with an application time of approximately one second (step S4). At this time, an intermittent time (an output stop time) is set to approximately 500 milliseconds. Of course, this output stop time is approximately set while considering a high-frequency power value in such a manner that a temperature of a held part and a temperature of its peripheral living tissue become less than a predetermined temperature.
Subsequently, a phase difference signal detected by the phase difference detection circuit 14 is detected from an output signal of the high-frequency power (step S5). This phase difference signal represents a phase difference between a high-frequency power to be input and an input high-frequency power with a change in an impedance, and is detected by the phase difference detection circuit 14. The CPU 3 uses this phase difference detection signal to judge whether abnormal discharge (a spark) has been generated in the sealing forceps 2 (step S6). When it is determined that abnormal discharge is not generated in this judgment (NO), application is continued with the set control voltage and intermittent output timing (step S7). On the other hand, when such a phase difference detection signal as shown in
After the high-frequency power is applied at step S7, or after a reduction in the control voltage is set and the reduced voltage is applied at step S8, a judgment is made upon whether a preset application time (an intermittent output on time of approximately one second in this example) has been reached (step S10). If it is determined that the preset application time has not been reached in this judgment (NO), the control returns to step S5, and a change in an impedance is detected while maintaining application of the high-frequency power. On the other hand, if the preset application time has been reached (YES), output is stopped for the above-described output stop time of approximately 500 milliseconds (step S11).
Further, whether adhesion processing has been completed with respect to a blood vessel or the like is judged (step S12). As to a timing of completion of this adhesion processing, it is sufficient to use a known completion judgment method, e.g., an accumulated temperature (a sum of histories) of increases in temperature in a periphery of a held part, achievement of a preset impedance value at the time of completion or whether a phase difference has reached a specified value. If it is determined that welding processing has not been completed in the judgment (NO), the control returns to step S2 to continue the processing sequence. On the other hand, if the welding processing has been completed (YES), this processing sequence is terminated.
As described above, according to the first embodiment, a phase difference in the sequentially intermittently output high-frequency power is monitored for the feedback control over the high-frequency power applied to the bipolar type sealing forceps 2. When abnormal discharge (a spark) is produced at the distal ends, the high-frequency power is reduced and the application time is extended. As a result, the abnormal discharge can be terminated (the spark can be extinguished), a reduction in quality of processing can be avoided, and end of processing can be readily judged.
Furthermore, since abnormal discharge is avoided on the drive control apparatus main body 1 side in this embodiment, even if the sealing forceps 2 are changed over, the present invention can be applied by just changing a set value on the drive control apparatus main body 1 side, and the equivalent effect can be obtained, thereby providing high general versatility.
A second embodiment will now be described.
The electric processing system according to this embodiment is constituted of a drive control apparatus main body 1 and an electric processing instrument, e.g., bipolar type sealing forceps 2 which perform welding processing with respect to a blood vessel or the like.
The sealing forceps 2 hold a living tissue or a blood vessel between distal ends 2a to carry out processing of incision and coagulation (sealing and welding) by using a high-frequency power. In this embodiment, a treatment concerning welding processing of a blood vessel or the like is performed. This embodiment provides a structure in which an impedance detection circuit 21 which detects a change in an impedance of a held living tissue based on a fluctuation in a high-frequency power is provided in place of the phase difference detection circuit 14 according to the first embodiment.
The drive control apparatus main body 1 is comprised of a control portion (a CPU) 3 which performs control over the entire apparatus and feedback control over a high-frequency power, a power supply 4, a resonance circuit 5 which generates a high-frequency power, a waveform generation circuit 6 which controls a waveform when generating a high-frequency power, an amplifier 7 which amplifies the high-frequency power, an output transformer 8 which outputs the high-frequency power to the sealing forceps 2, a current/voltage detecting portion 9 have a current detection circuit 10 and a voltage detection circuit 11, analog-to-digital converters 12 and 13 which respectively digitize a detected current value and voltage value, an impedance detection circuit 21 which samples the generated high-frequency power (a current value and a voltage value) to detect an impedance, an external switch 15 such as a hood switch, a key switch (including a keyboard) provided on the exterior of the apparatus, a display portion 17 which displays an application state of the high-frequency voltage or information required for processing, and a touch panel switch 18 which inputs operator instructions like the key switch 16.
This drive control apparatus main body 1 applies a high-frequency power to the distal ends 2a of the sealing forceps 2 which hold a living tissue or a blood vessel therebetween. As shown in
It is sufficient to set an output waveform of this high-frequency power in such a manner that it becomes substantially equivalent to an amount of an applied energy based on a product of a sum of each application time of the intermittently applied high-frequency power and a high-frequency power value (a high-frequency current value or a high-frequency voltage value). That is, when the high-frequency power value is reduced, it is sufficient to prolong an application time to enable processing.
The impedance detection circuit 21 according to this embodiment is constituted by using a differential circuit. In a differential output signal of an impedance which is output from this impedance detection circuit 21 and shown in
A description will now be given as to output control of the thus configured electric processing system with reference to a flowchart shown in
First, an operator instructs start of processing to commence application of a high-frequency power to the sealing forceps 2 and to also begin feedback control (steps S21 and S22). A judgment is made upon whether a voltage value of the high-frequency power applied to the sealing forceps 2 has reached a preset control voltage (e.g., 100 V: an upper limit value) (step S23). In this embodiment, rising of the high-frequency power is slightly inclined to avoid overshoot, thereby eliminating a factor of a reduction in quality of processing and start of abnormal discharge due to overshoot.
When it is determined that the high-frequency power has not reached the control voltage in the judgment at step S23 (NO), this application state is maintained. On the other hand, when the high-frequency power has reached the control voltage (YES), this control voltage is determined as a constant voltage and applied to the sealing forceps 2 as an intermittent output having a pulse waveform with an application time of approximately one second (step S24). At this time, an intermittent time (an output stop time) is set to approximately 500 milliseconds. These settings are the same as those in the first embodiment.
Subsequently, a detection signal obtained by differentiating a change in an impedance in the sealing forceps 2 is detected from the output signal of the high-frequency power by the impedance detection circuit 21 (step S25). Whether abnormal discharge (a spark) has been generated in the sealing forceps 2 is judged based on this detection signal (step S26). If it is determined that abnormal discharge has not been generated in this judgment (NO), application is continued with the set control voltage and intermittent output timing (step S27). On the other hand, when a pulsating signal is detected in such a differential signal of the impedance as shown in
Then, after steps S27 and S29, a judgment is made upon whether the preset application time (an intermittent output on time of approximately one second in this example) has been reached (step S30). When it is determined that the present application time has not been reached (NO), the control returns to step S25 and a change in the impedance is detected while continuing application of the high-frequency power. On the other hand, when the preset application time has been reached (YES), the output is stopped for the above-described output stop time of approximately 500 milliseconds (step S11).
Moreover, a judgment is made upon whether welding processing has been completed with respect to a blood vessel or the like (step S12). As to a timing of completion of this welding processing, it is sufficient to use a known completion judgment method, e.g., a history of an increase in a temperature in a periphery of a held part or attainment of a preset impedance value at the time of completion. If it is determined that the welding processing has not been completed yet in this judgment (NO), the control returns to step S2 to continue the processing sequence. On the other hand, if the welding processing has been completed (YES), this processing sequence is terminated.
As described above, according to the second embodiment, a differential output of the impedance of the intermittently generated high-frequency power is sequentially monitored for the feedback control with respect to the high-frequency power applied to the bipolar type sealing forceps 2. When abnormal discharge (a spark) is produced at the distal ends, the high-frequency power is reduced and the application time is extended. As a result, the abnormal discharge can be terminated, a reduction in quality of processing can be avoided, and end of processing can be readily judged.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.