# US 2012/0083779 A1 · Electrosurgical system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0083779 A1 - Document ID: US20120083779A1 - Status: Published application - Kind: A1 - Application number: 13/252,493 - Filed: 2011-10-04 - Published: 2012-04-05 - Earliest claimed: 2010-10-05 - Assignees: Gyrus Medical Limited - Inventors: John Roland HOSIER - Web page: https://patentgrep.com/patent/US20120083779A1 ## CPC - A61B 18/1233: {with circuits for assuring patient safety} - A61B 18/1206: {Generators therefor} - A61B 2018/00196: {reciprocating lengthwise} - A61B 2018/00589: {Coagulation} - A61B 2018/00601: {Cutting} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A method of controlling an electrosurgical system is described, the system including an electrosurgical generator and an electrosurgical instrument connected to the generator by means of a cable. A radio frequency signal is supplied to the electrosurgical instrument at an operating frequency, and the voltage of the radio frequency signal is monitored at a frequency corresponding to the frequency of a resonant circuit established by the electrosurgical instrument together with the cable. The monitored voltage is capable of indicating the initiation of arcing from the electrosurgical instrument, such that the voltage of the radio frequency signal can be adjusted in response to the monitored voltage at the resonant frequency. The magnitude of the monitored voltage is an indication of the degree of arcing. An electrosurgical system including an arc detector is also disclosed. ## Claims ### Claim 1 A method of controlling an electrosurgical system including an electrosurgical generator and an electrosurgical instrument connected to the generator by means of a cable, the method comprising the steps of: (i) supplying a radio frequency signal to the electrosurgical instrument at an operating frequency; (ii) monitoring the voltage of the radio frequency signal at a frequency corresponding to the frequency of a resonant circuit established by the electrosurgical instrument together with the cable, the monitored voltage being capable of indicating the initiation of arcing from the electrosurgical instrument; and (iii) adjusting the magnitude of the radio frequency voltage in response to the monitored voltage at the resonant frequency. ### Claim 2 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the step of adjusting the voltage of the radio frequency signal comprises reducing the magnitude of the voltage to a level insufficient to cause arcing from the electrosurgical instrument. ### Claim 3 (depends on 2) A method of controlling an electrosurgical system according to claim 2, wherein the voltage is temporarily reduced for a preset period of time before being re-established at its original level. ### Claim 4 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the frequency of the monitored voltage is unrelated to the operating frequency of the radio frequency signal or any of its non-zero harmonics. ### Claim 5 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the operating frequency of the radio frequency signal is below 500 kHz. ### Claim 6 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the frequency of the monitored voltage is in the range 10 MHz to 25 MHz. ### Claim 7 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the frequency of the monitored voltage is at least 30 times the operating frequency of the radio frequency signal. ### Claim 8 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the monitored voltage is the basic resonant frequency of the resonant circuit established by the electrosurgical instrument together with the cable. ### Claim 9 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the monitored voltage is a harmonic frequency of the resonant circuit established by the electrosurgical instrument together with the cable. ### Claim 10 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the electrosurgical instrument is an endoscopic instrument. ### Claim 11 (depends on 10) A method of controlling an electrosurgical system according to claim 10, wherein the arcing from the electrosurgical instrument is between the electrosurgical instrument and another endoscopic device. ### Claim 12 (depends on 11) A method of controlling an electrosurgical system according to claim 11, wherein the other endoscopic device is an endoscope. ### Claim 13 (depends on 11) A method of controlling an electrosurgical system according to claim 11, wherein the other endoscopic device is an endoscopic camera. ### Claim 14 (depends on 1) A method of controlling an electrosurgical system according to claim 1, wherein the electrosurgical instrument is a multipolar electrosurgical instrument. ### Claim 15 (depends on 14) A method of controlling an electrosurgical system according to claim 14, wherein the electrosurgical instrument is a bipolar electrosurgical instrument. ### Claim 16 (depends on 14) A method of controlling an electrosurgical system according to claim 14, wherein the arcing from the electrosurgical instrument is between the electrodes of the electrosurgical instrument. ### Claim 17 A method of controlling an electrosurgical system including an electrosurgical generator and an electrosurgical instrument connected to the generator by means of a cable, wherein the method comprises the steps of: (i) supplying radio frequency (RF) energy to the instrument as an RF output signal at a generator operating frequency; (ii) monitoring the voltage of the RF output signal at a frequency at least 30 times the generator operating frequency, the monitoring frequency being a frequency corresponding to that of a ringing signal component produced when arcing occurs at the electrosurgical instrument: and (iii) adjusting the voltage magnitude of RF output signal in response to the voltage at the monitoring frequency. ### Claim 18 An electrosurgical system comprising; an electrosurgical generator for generating radio frequency (RF) energy for delivery as an RF output signal at a generator output and at a generator operating frequency; an electrosurgical instrument including at least one treatment electrode; and a cable for connecting the instrument to the generator output to supply the RF output signal to the said electrode; wherein the system further comprises an are detector having a monitoring input coupled to the cable and the instrument, and a detection output coupled to a signalling input of the generator, the arc detector being arranged to monitor via its monitoring input the supplied RF output signal, to detect in the supplied RF output signal a ringing signal component at a frequency corresponding to the resonant frequency of a resonant circuit established by the instrument together with the cable, and to produce, in response to the detected ringing signal component a detection signal at the detection output for feeding to the generator signalling input, and wherein the arc detector and the generator are arranged such that the supplied RF output signal is adjusted in response to the detection signal fed to the generator signalling input. ### Claim 19 (depends on 18) A system according to claim 18, wherein the generator is arranged such that, in response to the said detection signal, the voltage of the supplied RF output signal is reduced to a level insufficient to cause arcing from the electrosurgical instrument. ### Claim 20 (depends on 19) A system according to claim 19, wherein the generator is arranged such that the voltage of the supplied RF output signal is temporarily reduced for a preset period of time and then re-established at its original level. ### Claim 21 (depends on 18) A system according to claim 18, wherein the generator operating frequency is below 500 kHz and the frequency at which the arc detector is operable to detect a ringing signal component is at least 10 MHz. ### Claim 22 (depends on 18) A system according to claim 18, wherein the frequency at which the arc detector is operable to detect a ringing signal component is at least 30 times the generator operating frequency. ### Claim 23 (depends on 18) A system according to claim 18, wherein the frequency at which the detector is operable to detect a ringing signal component is the fundamental resonant frequency of the said resonant circuit. ### Claim 24 An electrosurgical system comprising; an electrosurgical generator for generating radiofrequency (RF) energy for delivery as an RF output signal at a generator output and at a generator operating frequency; an electrosurgical instrument including at least one treatment electrode; and a cable for connecting the instrument to the generator output to supply the RF output signal to the said electrode; wherein the system further comprises an arc detector having a monitoring input coupled to the cable and the instrument, and a detection output coupled to a signalling input of the generator, the arc detector being arranged to monitor via its monitoring input the supplied RF output signal, to detect in the supplied RF output signal a ringing signal component at a frequency at least 30 times the generator operating frequency, and to produce, in response to the detected ringing signal component, a detection signal at the detection output for feeding to the generator signalling input, and wherein the arc detector and the generator are arranged such that to the supplied RF output signal is adjusted in response to the detection signal fed to the generator signalling input.