Impedance and temperature generator control

An automatic control for an electrosurgical generator responsive separately and independently to the level of tissue impedance between active and the return electrode of the electrosurgical generator during tissue desiccation comprising:

• an electrosurgical generator having an active lead and a return lead connected thereto to supply high frequency electrosurgical power;
• a pair of active electrode tissue contacting members positionable against the tissue, the active electrode tissue contacting members connected to the active lead;
• a plurality of active electrode contacts associated with each of the pair active electrode tissue contacting members, each active electrode contact in circuit with the tissue and capable of separately and independently providing high frequency power supplied to the respective active electrode tissue contacting member in order to electrosurgically effect the tissue in contact with each active electrode contact;
• a return electrode connected to the return lead of the electrosurgical generator, the return electrode in circuit with the tissue, and
• a monitor connected in circuit between each of the active electrode contacts and the return electrode, the monitor separately and independently responsive to voltage across and current flow though the active electrode contacts, the tissue and the return electrode for application in providing signals instantaneously of impedances therebetween;
• one or more temperature sensors each associated with one or more of the active electrode contacts and each temperature sensor connected for transmitting a temperature amount to the electrosurgical generator indicative of at least the temperature amount at an associated active electrode contact and the monitor connected to receive instantaneously the temperature amounts and assess temperature changes for use in separately and independently regulating the electrosurgical generator power to each of the active electrode contacts to individually electrosurgically effect the tissue between each active electrode contact and the return electrode in response to the sensed temperature amount;
• a regulator electrically linked in circuit with and associated with the power output of the electrosurgical generator for separately and independently controlling the electrosurgical generator as a function of the signalled impedance between each active electrode contact in accord with the impedance monitored and the temperature amount sensed, the regulator connected in circuit with the electrosurgical generator for changing a level of transmission of high frequency power between the electrosurgical generator and the associated active electrode contact for independent regulation of power passing between the return electrode and each active electrode contact;
• a first multiplexer electrically coupled to the active electrode contacts, the first multiplexer for providing high frequency electrosurgical power separately and independently to each active electrode contact from the active lead of the electrosurgical generator, and
• a second multiplexer electrically coupled to one or more temperature sensors, the second multiplexer for providing the temperature amounts to the electrosurgical generator indicative of the temperature at its associated active electrode contact.

A method for automatically controlling an electrosurgical generator responsive separately and independently to the level of tissue impedance between active and return electrodes of the electrosurgical generator, the active electrode having a plurality of active electrode contacts having the steps of:

• supplying electrosurgical power from an electrosurgical generator to the active and return electrodes;
• positioning against the tissue one or more of the active electrode contacts associated with the active electrode;
• supplying high frequency power separately and independently to each active electrode contact in order to produce an electrosurgically effect on the tissue thereagainst;
• monitoring separately and independently impedance between one or more of the active electrode contacts and the return electrode for providing signals of the instantaneous impedances therebetween;
• receiving signals of instantaneous impedance with a regulator for setting electrosurgical generator power to be applied by each of the active electrode contacts;
• controlling separately and independently the electrosurgical generator as a function of the impedance between each of the active electrode contacts and the return electrode with the regulator for changing the level of transmission of high frequency power between the electrosurgical generator and the associated active electrode contact for independent regulation of power passing between the return electrode and each active electrode contact, and
• providing separate and independent high frequency electrosurgical power with a first multiplexer electrically coupled to one or more of the active electrode contacts.