Automatic activation of electrosurgical generator bipolar output
First Claim
1. An automatic circuit that controls a surgical instrument having a pair of bipolar electrodes, the circuit comprising:
- means for measuring the current between the pair of electrodes, said measuring means including;
means for generating a constant voltage;
a transformer having a primary winding and a secondary winding, said primary winding having a signal end for receiving a signal and a return end, said secondary winding coupled to the pair of electrodes; and
a resistive element in series with said generating means and said signal end, wherein a voltage developed across said signal end and said return end of said primary winding is representative of a measured current between the pair of bipolar electrodes;
an impedance detection circuit in electrical communication with said measuring means for calculating the impedance based on the measured current, the impedance detection circuit generating a first signal indicative of the calculated impedance;
a comparator in electrical communication with the impedance detection circuit, the comparator processing the first signal and generating an activation signal if the calculated impedance falls within a predetermined range of impedance values and generating a deactivation signal if the calculated impedance exceeds a deactivation threshold; and
a controller in electrical communication with the comparator for receiving the activation and deactivation signals and transmitting a first control signal to a radiofrequency energy output stage to activate the electrodes in response to the activation signal and transmitting a second control signal to the radiofrequency output stage to deactivate the electrodes in response to the deactivation signal.
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Accused Products
Abstract
An automatic circuit that controls a surgical instrument having a pair of bipolar electrodes. The circuit comprises means for measuring the current between the pair of electrodes, an impedance detection circuit in electrical communication with the current measuring means, a comparator in electrical communication with the impedance detection circuit and a controller electrically connected to the comparator. The impedance detection circuit calculates the impedance between the electrodes based on the measured current and generates a first signal indicative of the calculated impedance. The comparator processes the first signal and generates an activation signal if the calculated impedance falls within a predetermined range of impedance values and generates a deactivation signal if the calculated impedance exceeds a deactivation threshold. The controller receives the activation and deactivation signals and transmits a first control signal to a radiofrequency energy output stage to activate the electrodes in response to the activation signal and transmits a second control signal to the radiofrequency output stage to deactivate the electrodes in response to the deactivation signal.
325 Citations
14 Claims
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1. An automatic circuit that controls a surgical instrument having a pair of bipolar electrodes, the circuit comprising:
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means for measuring the current between the pair of electrodes, said measuring means including;
means for generating a constant voltage;
a transformer having a primary winding and a secondary winding, said primary winding having a signal end for receiving a signal and a return end, said secondary winding coupled to the pair of electrodes; and
a resistive element in series with said generating means and said signal end, wherein a voltage developed across said signal end and said return end of said primary winding is representative of a measured current between the pair of bipolar electrodes;
an impedance detection circuit in electrical communication with said measuring means for calculating the impedance based on the measured current, the impedance detection circuit generating a first signal indicative of the calculated impedance;
a comparator in electrical communication with the impedance detection circuit, the comparator processing the first signal and generating an activation signal if the calculated impedance falls within a predetermined range of impedance values and generating a deactivation signal if the calculated impedance exceeds a deactivation threshold; and
a controller in electrical communication with the comparator for receiving the activation and deactivation signals and transmitting a first control signal to a radiofrequency energy output stage to activate the electrodes in response to the activation signal and transmitting a second control signal to the radiofrequency output stage to deactivate the electrodes in response to the deactivation signal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An electrosurgical system including a generator for use with bipolar electrodes comprising:
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a current monitor for measuring the current between the bipolar electrodes including a transformer having a primary winding with a first end driven at a constant voltage through a resistive element and a second end coupled to a return, wherein the voltage across the primary winding of the transformer varies in accordance with a variation of a current between the electrodes;
an impedance detection circuit in electrical communication with the current monitor to calculate the impedance between the electrodes based on the measured current;
a comparator for comparing the calculated impedance to an activation range of impedance values; and
a controller for automatically activating the generator if the calculated impedance falls within the activation range of impedance values and deactivating the generator if the calculated impedance exceeds a deactivation threshold. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method of automatically activating and deactivating a bipolar electrosurgical radiofrequency generator comprising the steps of:
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measuring the current between a pair of bipolar electrodes electrically connected to the generator utilizing a transformer driven at a constant voltage through a resistive element and determining the voltage across a primary winding of the transformer;
calculating the impedance between the bipolar electrodes based on the measured current;
comparing the calculated impedance to an activation range of impedances;
automatically activating the generator if the calculated impedance falls within the activation range; and
automatically deactivating the generator if the calculated impedance falls above a deactivation threshold. - View Dependent Claims (14)
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Specification