Electrosurgical generator
First Claim
1. A system for tissue ablation including:
- a generator of high-frequency electrical signal output;
an electrode including an shaft portion adapted to be inserted into a body and adapted to be connected to the generator, the shaft portion having a tip portion so adapted such that when said shaft portion is inserted into the body, the signal output is delivered through the tip portion to the bodily tissue to be ablated, said shaft portion having an inner space that can accept circulation of a coolant to cool said tip portion;
a coolant system adapted to connect to said electrode and supply circulation of the coolant to the electrode inner space to cool the electrode tip portion;
a measuring system adapted to measure in real time at least two signal output parameters from the list of impedance, current, voltage, and power;
a control system including an automatic controller adapted to control at least one of the measured signal output parameters, including modulating the signal output to maintain the controlled signal output parameter at a desired level, wherein the control system repeatedly switches the level of the signal output between an ablation range configured to heat tissue substantially, and a cooling range configured to allow for cooling of the heated tissue, wherein the control system performs the switching in response to the controlled signal output parameter in accordance with the automatic controller; and
a computer graphic display adapted to plot in real time the controlled signal output parameter and at least one other measured signal output parameter on the same time scale axis.
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Accused Products
Abstract
This invention relates to high-frequency ablation of tissue in the body using a cooled high-frequency electrode connected to a high frequency generator including a computer graphic control system and an automatic controller for control the signal output from the generator, and adapted to display on a real time graphic display a measured parameter related to the ablation process and visually monitor the variation of the parameter of the signal output that is controlled by the controller during the ablation process. In one example, one or more measured parameters are displayed simultaneously to visually interpret the relation of their variation and values. In one example, the displayed one or more parameters can be taken from the list of measured voltage, current, power, impedance, electrode temperature, and tissue temperature related to the ablation process. The graphic display gives the clinician an instantaneous and intuitive feeling for the dynamics and stability of the ablation process for safety and control. This invention relates to monitoring and controlling multiple ground pads to optimally carry return currents during high-frequency tissue ablation, and to prevent of ground-pad skin burns. This invention relates to the use of ultrasound imaging intraoperatively during a tissue ablation procedure. This invention relates to the use of nerve stimulation and blocking during a tissue ablation procedure.
80 Citations
52 Claims
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1. A system for tissue ablation including:
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a generator of high-frequency electrical signal output; an electrode including an shaft portion adapted to be inserted into a body and adapted to be connected to the generator, the shaft portion having a tip portion so adapted such that when said shaft portion is inserted into the body, the signal output is delivered through the tip portion to the bodily tissue to be ablated, said shaft portion having an inner space that can accept circulation of a coolant to cool said tip portion; a coolant system adapted to connect to said electrode and supply circulation of the coolant to the electrode inner space to cool the electrode tip portion; a measuring system adapted to measure in real time at least two signal output parameters from the list of impedance, current, voltage, and power; a control system including an automatic controller adapted to control at least one of the measured signal output parameters, including modulating the signal output to maintain the controlled signal output parameter at a desired level, wherein the control system repeatedly switches the level of the signal output between an ablation range configured to heat tissue substantially, and a cooling range configured to allow for cooling of the heated tissue, wherein the control system performs the switching in response to the controlled signal output parameter in accordance with the automatic controller; and a computer graphic display adapted to plot in real time the controlled signal output parameter and at least one other measured signal output parameter on the same time scale axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system for tissue ablation that includes a radiofrequency generator, a controller, and a graphic display, wherein the radiofrequency generator is configured to apply a radiofrequency signal to an ablation electrode that is in contact with bodily tissue;
- wherein the controller is configured to automatically alternate the signal level between a first range configured to heat tissue, and a second range configured to allow for cooling of heated tissue;
wherein the controller switches the signal level from the first range to the second range based in whole or in part on an indication of boiling or impending boiling in tissue heated by the ablation electrode, and wherein the controller switches the signal level from the second range to the first range after a duration configured to allow for dissipation of gas bubbles formed in the tissue due to boiling, wherein the controller automatically performs the switching;
wherein the graphic display is configured plot in real time and on one time axis, two or more different types of parameters of the signal delivered to the ablation electrode;
wherein each parameter is selected from the list;
impedance;
voltage;
current;
power;
a measurement of the signal;
mathematical functions taking one or more of the arguments impedance, voltage, current, power, and a measurement of the signal. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
- wherein the controller is configured to automatically alternate the signal level between a first range configured to heat tissue, and a second range configured to allow for cooling of heated tissue;
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44. A system for tissue ablation that includes a radiofrequency generator;
- a controller;
a graphic display;
an electrode configured to be inserted into bodily tissue; and
a coolant configured to be supplied to, and to thereby to cool, the electrode;
wherein the radiofrequency generator is configured to deliver a radiofrequency signal output to the electrode when inserted into bodily tissue;
wherein the controller automatically alternates between a first state and a second state;
wherein in the first state, the controller maintains the signal output at a higher level configured to raise the temperature of a substantial portion of the bodily tissue to a destructive temperature;
wherein in the second state, the controller maintains the signal output at a lower level configured to allow the temperature of heated bodily tissue to cool substantially;
wherein the controller switches from the first state to the second state when a measurement indicates the presence of high-temperature vapor in the tissue near the electrode;
wherein the duration for which the controller remains in the second state before switching to the first state is configured to provide for dissipation of high-temperature vapor in the tissue near the electrode, wherein the controller automatically performs the switching;
wherein the graphic display plots one or more parameters as a function of time;
wherein each parameter can be selected from the list impedance, current, power, voltage, duty cycle, temperature, time, a signal output level, a measurement of the signal output, a parameter of the signal output, a time average of a parameter of the signal output, the RMS value of a parameter of the signal output over a time window, a mathematical function of one or more parameters of the signal output. - View Dependent Claims (45, 46, 47, 48, 49, 50, 51, 52)
- a controller;
Specification