Electrosurgical generator and system

• US 20030163124A1
• Filed: 03/05/2003
• Published: 08/28/2003
• Est. Priority Date: 08/27/2001
• Status: Active Grant

• Current Assignee: Gyrus Medical Incorporated (Olympus Corporation)
• Original Assignee: Gyrus Medical Incorporated (Olympus Corporation)
• Inventors: Goble, Coliin C.O.
• Granted Patent: US 6,966,907 B2
• Time in Patent Office: Days
• US Class Current: 606/37
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1442 Probes having pivoting end effectors, e.g. forceps
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2017/00212 using remote controls
• CPC Class Codes: A61B 2018/00404 Blood vessels other than those in or around the heart
• CPC Class Codes: A61B 2018/00601 Cutting
• CPC Class Codes: A61B 2018/00607 Coagulation and cutting with the same instrument
• CPC Class Codes: A61B 2018/0066 without feedback, i.e. open loop control
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00892 Voltage
• CPC Class Codes: A61B 2018/124 switching the output to different electrodes, e.g. sequentially
• CPC Class Codes: A61B 2018/1273 including multiple generators in one device
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe

Abstract

An electrosurgical system includes a generator for generating radio frequency power, and an electrosurgical instrument including at least three electrodes and. The generator includes a radio frequency output stage having at least a pair of RF output lines, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to limit the radio frequency output voltage developed across the output lines to at least a first predetermined threshold value to produce a cutting RF waveform, and a second threshold value to produce a coagulating RF waveform. In a combined mode, the controller delivers both cutting and coagulating waveforms, either simultaneously or by alternating constantly between the first and second threshold values to form a blended signal. The system also includes means for feeding the waveform to the three or more electrodes such that the cutting RF waveform is delivered between a first pair of the electrodes, and the coagulating waveform is delivered between a second pair of the electrodes.

Claims

1. An electrosurgical system including a generator system for generating radio frequency (RF) power, and an electrosurgical instrument including at least three electrodes, the generator system comprising

(i) one or more sources of RF output power, and

(ii) a controller operable to control the generator system such that it is capable of delivering a first cutting RF waveform to the electrosurgical instrument or a second coagulating RF waveform to the electrosurgical instrument, and, in a combined mode, to deliver both first and second RF waveforms,

the system also including means for feeding the waveforms to the three or more electrodes such that, in the combined mode, the cutting RF waveform is delivered between a first pair of the three or more electrodes, and the coagulating RF waveform is delivered between a second pair of the electrodes.

2. An electrosurgical system according to claim 1, wherein the generator system comprises a single source of RF power, and, in the combined mode, the controller is operable to cause the generator system to alternate constantly between delivering the first cutting RF waveform and the second coagulating RF waveform.

3. An electrosurgical system according to claim 2, wherein the means for connecting the waveform comprises a selection arrangement for varying the coupling between the source and the three or more electrodes such that, in the combined mode, a first part of the combined signal that is the cutting RF waveform is delivered between a first pair of the three or more electrodes, and a second part of the combined signal that is the coagulating RF waveform is delivered between a second pair of the three or more electrodes.

4. An electrosurgical system according to claim 3, wherein the selection arrangement is a switching circuit comprising first and second input connections, first second and third output connections, and an electronic switch connected between the first and second output connections, and being adapted to open and close in order to connect the first and second output connections periodically one to the other.

5. An electrosurgical system according to claim 4, wherein the electronic switch opens and closes at a frequency of between 5 and 100 Hz.

6. An electrosurgical system according to claim 4, wherein the second and third output connections are connected one to the other via a capacitor.

7. An electrosurgical system according to claim 6, wherein the capacitor has a value of between 1 and 10 nF.

8. An electrosurgical system according to claim 3, wherein the selection arrangement is housed within the electrosurgical instrument.

9. An electrosurgical system according to claim 3, wherein the selection arrangement is housed within the electrosurgical generator.

10. An electrosurgical system according to claim 3, wherein the controller is adapted to determine the timing of the changes between the first and second parts of the combined signal, and the selection arrangement is synchronised to operate in response thereto.

11. An electrosurgical system according to claim 3, wherein the selection arrangement is adapted to determine the timing of the changes between the first and second parts of the combined signal, and the controller is adapted to operate in response thereto.

12. An electrosurgical system according to claim 1, wherein the generator system comprises at least first and second sources of RF power, operating at different frequencies, the first source of RF power being adapted to deliver the first cutting RF waveform, and the second source of RF power being adapted to deliver the second coagulating RF waveform, and, in the combined mode, the controller is operable to cause the generator system to deliver both the first and second RF waveforms simultaneously.

13. An electrosurgical system according to claim 12, wherein the first and second sources of RF power have respective pairs of output lines, and wherein the output lines of the first source are connected to a first pair of the three or more electrodes and the output lines of the second source are connected to a second pair of the three or more electrodes.

14. An electrosurgical system according to claim 13, wherein the pairs of output lines have a common line which is connected to one of the three or more electrodes.

15. An electrosurgical system according to claim 12, wherein the means for feeding the waveforms to the electrodes comprise one or more output stages arranged such that the cutting RF waveform from the first RF source is at least mainly delivered between a first pair of the three or more electrodes, and the coagulating waveform from the second RF source is at least mainly delivered between a second pair of the three or more electrodes.

16. An electrosurgical system according to claim 15, wherein the output stages comprise first and second resonant output circuits tuned respectively to the first and second frequencies and connected respectively to the first and second pairs of electrodes.

17. An electrosurgical system according to claim 1, having an RF power source operable in response to the controller to generate on a common pair of output lines an RF power signal which, in the combined mode, alternates constantly between delivering a first cutting RF waveform at a first frequency and delivering a second coagulating RF waveform at a second frequency, wherein the means for feeding the waveform to the electrodes comprises first and second resonant output circuits coupled to said output lines and tuned respectively to the first and second frequencies, the first resonant output circuit being connected to the first pair of electrodes and the second resonant output circuit being connected to the second pair of electrodes.

18. An electrosurgical system according to claim 17, wherein the controller and the RF power source are operable together to limit the peak RF output voltage to a first predetermined threshold when delivering the cutting RF waveform and to a second predetermined threshold when delivering the coagulating RF waveform.

19. An electrosurgical system including a generator system for generating radio frequency (RF) power, and an electrosurgical instrument including at least three electrodes, the generator system comprising

(i) at least one RF output stage,

(ii) means for supplying power to the at least one output stage, and

(iii) a controller operable to limit the RF output voltage developed by the at least one output stage to at least a first predetermined threshold value for cutting or vaporisation and a second threshold value for coagulation and, in a combined mode, to deliver waveforms limited to both first and second threshold values,

the electrosurgical system also including means for coupling the waveform to the three or more electrodes such that, in the combined mode, a waveform limited to the first threshold value for cutting or vaporisation is delivered between a first pair of the three or more electrodes, and a waveform limited to the second threshold value for coagulation is delivered between a second pair of the three or more electrodes.

20. An electrosurgical generator for supplying radio frequency power (RF) to an electrosurgical instrument, the generator comprising

(i) at least one RF output stage,

(ii) three more output connections for the delivery of RF power to the electrosurgical instrument,

(iii) means for supplying power to the at least one output stage, and

(iv) a controller operable to limit the RF output voltage developed by the at least one output stage to at least a first predetermined threshold value for cutting or vaporisation and a second threshold value for coagulation and, in a combined mode, to deliver waveforms limited to both first and second threshold values, and

(v) means for feeding the waveforms to the three or more output connections such that, in the combined mode, the waveform that is limited to the first threshold value for cutting or vaporisation is delivered between a first pair of the three or more output connections, and the waveform that is limited to the second threshold value for coagulation is delivered between a second pair of the three or more output connections.

21. An electrosurgical system including a generator for generating radio frequency (RF) power, and an electrosurgical instrument including at least two electrodes, the generator comprising

(i) an RF output stage having two or more output connections, each in electrical connection with a respective one of the at least two electrodes,

(ii) a power supply coupled to the output stage for supplying power to the output stage,

(iii) a controller operable to limit the RF output voltage developed across the output connections to at least a first predetermined threshold value for cutting or vaporisation and a second threshold value for coagulation and, in a blend mode, to alternate constantly between the first and second threshold values, and

(iv) adjustment means, operable by a user of the electrosurgical system, for varying the ratio of the blend mode so as to vary the part of the blend signal that is limited to the first threshold value for cutting or vaporisation, as compared with the part of the blend signal that is limited to the second threshold value for coagulation.

22. An electrosurgical system according to claim 21, wherein the adjustment means is carried by the electrosurgical instrument.

23. An electrosurgical system according to claim 21, wherein the adjustment means is mounted on the generator.