Electrosurgical system employing multiple electrodes
First Claim
1. A system for heat ablation of tissue in a patient comprising:
- a radiofrequency source configured to supply radiofrequency energy to at least two electrodes for treating tissue;
at least one return electrode configured to return the radiofrequency energy to the radiofrequency source;
a controller configured to sequentially apply the radiofrequency energy to each of the at least two electrodes for a pre-determinable period of time, wherein the pre-determinable period of time is determined by a surgical procedure or the number of electrodes, the controller further including;
a determiner configured to determine an off time for a next electrode in a sequence;
a comparator configured to compare the off time for the next electrode in the sequence to a predetermined minimum off time wherein the controller applies the radiofrequency energy to the next electrode in the sequence when the off time is greater than the predetermined minimum off time;
current and voltage measuring circuitry operably connected to at least one of the at least two electrodes, wherein an impedance is calculated based on the measured current and voltage; and
circuitry that restricts the flow of radiofrequency energy to at least one of the at least two electrodes when the calculated impedance exceeds a threshold impedance and that allows the flow of radiofrequency energy to at least one of the at least two electrodes when the calculated impedance does not exceed a threshold impedance, wherein the threshold impedance relates to a baseline impedance and a predetermined differential impedance wherein the predetermined differential impedance is about 30 ohms if the baseline impedance is less than about 100 ohms.
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Accused Products
Abstract
A system for heat ablation of tissue in which energy is sequentially applied to at least two electrodes inserted into tissue, the system comprising a radiofrequency source configured to supply radiofrequency energy to two or more electrodes, at least one return electrode for returning the RF energy to the RF source, and a controller configured to sequentially apply the RF energy to each of the two or more electrodes for a predetermined period of time. The controller includes a determiner configured to determine an off time for a next electrode in a sequence and a comparator configured to compare the off time for the next electrode in the sequence to a predetermined minimum off time. The controller applies the radiofrequency energy to the next electrode in the sequence when the off time is greater than the predetermined minimum off time.
225 Citations
28 Claims
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1. A system for heat ablation of tissue in a patient comprising:
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a radiofrequency source configured to supply radiofrequency energy to at least two electrodes for treating tissue; at least one return electrode configured to return the radiofrequency energy to the radiofrequency source; a controller configured to sequentially apply the radiofrequency energy to each of the at least two electrodes for a pre-determinable period of time, wherein the pre-determinable period of time is determined by a surgical procedure or the number of electrodes, the controller further including; a determiner configured to determine an off time for a next electrode in a sequence; a comparator configured to compare the off time for the next electrode in the sequence to a predetermined minimum off time wherein the controller applies the radiofrequency energy to the next electrode in the sequence when the off time is greater than the predetermined minimum off time; current and voltage measuring circuitry operably connected to at least one of the at least two electrodes, wherein an impedance is calculated based on the measured current and voltage; and circuitry that restricts the flow of radiofrequency energy to at least one of the at least two electrodes when the calculated impedance exceeds a threshold impedance and that allows the flow of radiofrequency energy to at least one of the at least two electrodes when the calculated impedance does not exceed a threshold impedance, wherein the threshold impedance relates to a baseline impedance and a predetermined differential impedance wherein the predetermined differential impedance is about 30 ohms if the baseline impedance is less than about 100 ohms. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for heat ablation of tissue in a patient comprising:
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a radiofrequency source configured to supply radiofrequency energy to at least two electrodes for treating tissue; at least one return electrode configured to return the radiofrequency energy to the radiofrequency source; a controller configured to sequentially apply the radiofrequency energy to each of the at least two electrodes for a pre-determinable period of time, wherein the pre-determinable period of time is determined by a surgical procedure or the number of electrodes, the controller further including; a determiner configured to determine an off time for a next electrode in a sequence; a comparator configured to compare the off time for the next electrode in the sequence to a predetermined minimum off time wherein the controller applies the radiofrequency energy to the next electrode in the sequence when the off time is greater than the predetermined minimum off time; current and voltage measuring circuitry operably connected to at least one of the at least two electrodes wherein an impedance is calculated based on the measured current and voltage; and circuitry that restricts the flow of radiofrequency energy to at least one of the at least two electrodes when the calculated impedance exceeds a threshold impedance and that allows the flow of radiofrequency energy to at least one of the at least two electrodes when the calculated impedance does not exceed a threshold impedance, wherein the threshold impedance relates to a baseline impedance and a predetermined differential impedance wherein the predetermined differential impedance is about 30% of the baseline impedance if the baseline impedance is greater than about 100 ohms. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A system for heat ablation of tissue in a patient comprising:
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a radiofrequency source configured to supply radiofrequency energy to at least two electrodes for treating tissue; at least one return electrode configured to return the radiofrequency energy to the radiofrequency source; an internal load; circuitry configured to switch the radiofrequency energy to the internal load; and a controller configured to sequentially apply the radiofrequency energy to each of the at least two electrodes for a pre-determinable period of time, wherein the pre-determinable period of time is determined by a surgical procedure or the number of electrodes, the controller further including; a determiner configured to determine an off time for a next electrode in a sequence; a comparator configured to compare the off time for the next electrode in the sequence to a predetermined minimum off time; wherein the controller applies the radiofrequency energy to the next electrode in the sequence when the off time is greater than the predetermined minimum off time and radiofrequency energy is applied simultaneously to the internal load and one of the at least two electrodes. - View Dependent Claims (24, 25, 26, 27, 28)
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Specification