Systems, methods and apparatuses for an electrosurgical RF generator for electrosurgical cutting
A radiofrequency (RF) generator for use with an electrosurgical system includes a shifted, transformed LCLC bandpass filter, configured for allowing the RF generator to operate using a single electrosurgical power setting while preventing overheating of the electrosurgical system. The LCLC bandpass filter may be configured to operate with a specified power curve such that an operating current generated by the RF generator is folded back when approaching short circuit conditions. The RF generator may include a fixed, medical power supply, wherein the specified power curve is modified by switching frequency modulation of the LCLC bandpass filter. Further a method for designing a RF generator for electrosurgical application is disclosed.
1 . A radiofrequency (RF) generator for use with an electrosurgical system, the RF generator comprising:
a shifted, transformed LCLC bandpass filter, wherein the shifted, transformed LCLC bandpass filter is configured for allowing the RF generator to operate using a single electrosurgical power setting while preventing overheating of the electrosurgical system.
2 . The RF generator of claim 1 , wherein the LCLC bandpass filter is configured to operate with a specified power curve such that an operating current generated by the RF generator is folded back when approaching short circuit conditions.
3 . The RF generator of claim 2 , further comprising a fixed, medical power supply,
wherein the specified power curve is modified by switching frequency modulation of the LCLC bandpass filter.
4 . The RF generator of claim 1 , wherein the LCLC bandpass filter is configured for ensuring the RF generator remains within International Electrotechnical Commission (IEC) limits for medical devices over a range of load levels.
5 . The RF generator of claim 1 , wherein the shifted, transformed LCLC bandpass filter is further configured to provide a lossless narrowband filtering of an input signal over a load range about a center frequency.
6 . The RF generator of claim 1 , wherein the shifted, transformed LCLC bandpass filter is further configured to exhibit an input impedance with a power factor of zero to the RF generator with substantially no phase lead and phase lag at a center frequency.
7 . The RF generator of claim 1 , wherein the LCLC bandpass filter is further configured for implementing a pulse width modulation (PWM) scheme.
8 . The RF generator of claim 6 , further comprising:
a first stage power factor correction (PFC) alternating current (AC)—direct current (DC) conversion;
at least one of a secondary DC-DC buck stage and a secondary DC-DC boost stage
configured for adjusting an input voltage to the LCLC bandpass filter.
9 . The RF generator of claim 1 , wherein the LCLC bandpass filter is configured for maintaining zero-voltage switching (ZVS) over a load range substantially from short circuit to open circuit, meeting a selected, near-ideal, characteristic output impedance over the load range, and limiting a harmonic frequency content of RF generated over the load range to levels within International Electrotechnical Commission (IEC) limits.