Gyrus Medical Limited

Gyrus Group Plc

Plasmogen Inc.

Energist Limited

Colin Charles Owen Goble

Nigel Mark Goble

Mark George Marshall

Keith Penny

Scott T Latterell

Michael David Newton

Francis Amoah

Douglas S Wahnschaffe

Andrew John Ford

Kester J Batchelor

Scott R Sanders

Scott Thomas Latterell

Douglas Scott Wahnschaffe

An electrosurgical generator has output terminals for connection to active and return electrodes respectively of an electrosurgical instrument and, connected to the output terminals via at least one isolation capacitor, a radio frequency (r.f.) source which may be pulsed by a pulsing circuit. To permit tissue removal at a high rate, the source and the pulsing circuit are arranged so as to generate a pulsed r.f. output signal having a peak-to-peak voltage of at least 1250V, a mark-to-space ratio not more than 1:1, and a pulse length not more than 100 &#x3bc;s.

Electrosurgery system and method

A tissue treatment system has a radio frequency generator and a handheld treatment instrument that generates a gas plasma jet for delivering thermal energy to a tissue surface to be treated. Incorporated in the housing for the generator is a calibration device for adjusting the energy output of the generator, if necessary, at the beginning of a treatment session. The calibration device has a target element with a target surface, a transducer for sensing changes in temperature of the target element with respect to the temperature of a reference element, and an energy output adjuster for adjusting the radio frequency energy output of the generator in response to a calibration signal generated by the transducer. The generator housing has a receptacle for locating the nozzle of the handheld instrument in juxtaposition with the target element so that when a plasma burst is generated as part of a calibration sequence it is incident on the target surface. The generator output is automatically adjusted to compensate for any deviation of a calibration value, produced from the calibration signal, from a reference value. Also disclosed is a method of regenerating the reticular architecture of tissue, the method including calibrating the energy delivery of a tissue treatment system.

Tissue treatment system

An electrosurgical system includes a generator () for generating radio frequency power, an electrosurgical instrument () including at least two electrodes, and an identification element () representative of at least the number of electrodes present on the instrument. The generator () comprises an RF output stage having three or more output connections (A,B,C), and a power supply () coupled to the output stage for supplying power to the output stage. The generator () also includes a controller () capable of varying the RF signal supplied to at least one of the three or more output connections (A,B,C), and a switching circuit () for varying the connections between the power supply () and the three or more output connections. The generator () also includes a sensing circuit capable of sensing the identification element () carried by the instrument, and of sending a signal to the switching circuit () to set the switching circuit to a mode of operation depending on the number of electrodes present on the instrument ().

Electrosurgical system

An electrosurgical cutting blade () comprises a first electrode (), a second electrode (), and an electrical insulator () separating the first and second electrodes. The first and second electrodes have dissimilar characteristics (cross-sectional area, thermal conductivity etc.) such that the first electrode () is encouraged to become an active electrode and the second electrode () is encouraged to become a return electrode. The spacing between the first and second electrodes (between 0.25 mm and 3.0 mm) and the peak voltage supplied to the electrodes (and) are both selected such that arcing does not occur directly between the electrodes, but between the first electrode and the tissue at the target site. The arrangement is such that, in use, a thermal differential of at least 50&#xb0; C. is established between the first and second electrodes (and), such that the second electrode is maintained below a temperature of 70&#xb0; C. This is achieved either by thermally insulating the second electrode from the first electrode, and/or by transferring heat away from the second electrode, e.g. by conduction, forced cooling, or by means of a heat pipe ().

Surgical system

A bipolar electrosurgical instrument comprises a handle (), a body () joined to the handle, and a jaw assembly () joined to the body and arranged such that manipulation of the handle allows the opposed jaws of the jaw assembly to be opened and closed with respect to one another. A first of said opposed jaws () has at least a first coagulating electrode, and the other of said opposed jaws () has at least a second coagulating electrode and a cutting electrode () separated from the second coagulating electrode by an insulating member (). The instrument is manipulated at the surgical site such that the jaws of the jaw assembly () are open with respect to one another, with the cutting electrode () and at least one of the first and second coagulating electrodes contacting tissue at the surgical site. A radio frequency electrosurgical signal is supplied between the cutting electrode and the at least one coagulating electrode, and the electrosurgical instrument is moved while maintaining the jaws () in their open position so as to cut tissue at the surgical site.

Surgical instrument

An electrosurgical instrument for use in cutting and/or coagulating tissue includes one or more electrode surfaces (and) at least partly coated with tungsten disulphide. The tungsten disulphide coating acts to reduce the incidence of tissue becoming adhered to the or each electrode surface (). Examples of electrosurgical instruments employing such coated electrodes include forceps, scissors or scalpel blade instruments.

An electrosurgical cutting blade ( ) comprises a first electrode ( ), a second electrode ( ), and an electrical insulator ( ) separating the first and second electrodes. The first and second electrodes ( and ) have dissimilar characteristics (cross-sectional area, thermal conductivity etc.) such that the first electrode ( ) is encouraged to become an active electrode and the second electrode ( ) is encouraged to become a return electrode. The spacing between the first and second electrodes (between 0.25 mm and 3.0 mm) and the peak voltage supplied to the electrodes are both selected such that arcing does not occur directly between the electrodes, but between the first electrode and the tissue at the target site. The arrangement is such that, in use, a thermal differential of at least 50&deg; C. is established between the first and second electrodes, such that the second electrode is maintained below a temperature of 70&deg; C. This is achieved either by thermally insulating the second electrode from the first electrode, and/or by transferring heat away from the second electrode, e.g. by conduction, forced cooling, or by means of a heat pipe.

In an electrosurgery system having a radio frequency generator and an instrument with a treatment electrode, the generator includes a circuit for sensing thermionic emission from the electrode as means of controlling the supply of radio frequency power to the electrode. Thermionic emission is sensed by detecting d.c. voltage at the output of the generator, or an a.c. representation of the d.c. voltage, using a detector with an isolated output, and generator output power is controlled so as to limit the d.c. voltage or the a.c. representation to a predetermined threshold. Accordingly, the temperature of the electrode can be limited to avoid electrode destruction. The invention also has application to reducing nerve stimulation due to electrosurgical treatment.

Electrosurgery system and instrument

An electrosurgical system including an electrode assembly having two electrodes for use immersed in an electrically conductive fluid has a generator with control circuitry for rapidly reducing the delivered radio frequency output power by at least 50% within at most a few cycles of the peak radio frequency output voltage reaching a predetermined threshold limit. In this way, tissue coagulation can be performed in, for example, saline without significant steam generation. The same peak voltage limitation technique is used in a tissue vaporization or cutting mode to limit the size of the steam pocket at the electrodes and to avoid electrode burning. In a blended mode, the output voltage is alternately limited to a value appropriate for coagulation and a value appropriate for cutting or vaporization.

Electrosurgical generator and system

An electrosurgical instrument has coaxial inner and outer tubular members ( ) made of a conductive material to form a coaxial transmitting line. The inner member ( ) is preferably dimensioned to receive a laparoscopic tool with the working elements of the tool projecting beyond a distal end ( D) of the inner member ( ). Alternatively, the inner member ( ) may, itself, incorporate a working element at its distal end. The outer member ( ) is connected to the inner member ( ) at a distance from the distal end ( D) of the later, and a radio frequency (r.f.) feed ( ) is connected to the inner member ( ) distally of the connection ( ) between the inner and outer members. Between the connections there is an r.f. isolating structure formed by or associated with the inner member ( ) to present a series impedance between the connections ( ) at an operating frequency of the instrument.

Electrosurgical instrument

An electrosurgical system including an electrode assembly having two electrodes for use immersed in an electrically conductive fluid has a generator with control circuitry for rapidly reducing the delivered radio frequency output power by at least 50% within at most a few cycles of the peak radio frequency output voltage reaching a predetermined threshold limit. In this way, tissue coagulation can be performed in, for example, saline without significant steam generation. The same peak voltage limitation technique is used in a tissue vaporisation or cutting mode to limit the size of the steam pocket at the electrodes and to avoid electrode burning.

An electrosurgical system including an electrode assembly having two electrodes for use immersed in an electrically conductive fluid has a generator with control circuitry for rapidly reducing the delivered radio frequency output power by at least 50% within at most a few cycles of the peak radio frequency output voltage reaching a predetermined threshold limit. In this way, tissue coagulation can be performed in, for example, saline without significant steam generation. The same peak voltage limitation technique is used in a tissue vaporization or cutting mode to limit the size of the steam pocket at the electrodes and to avoid electrode burning.

Electrosurgical generator method

An electrosurgical system including an electrode assembly having two electrodes for use immersed in an electrically conductive fluid has a generator with control circuitry for rapidly reducing the delivered radio frequency output power by at least 50% within at most a few cycles of the peak radio frequency output voltage reaching a predetermined threshold limit. In this way, tissue coagulation can be performed in, for example, saline without significant steam Generation. The same peak voltage limitation technique is used in a tissue vaporisation or cutting mode to limit the size of the steam pocket at the electrodes and to avoid electrode burning.

An electrosurgical instrument is disclosed for the treatment of tissue in the presence of an electrically-conductive fluid. The instrument comprises an instrument shaft, and a tissue treatment electrode at one end of the shaft, the tissue treatment electrode being constructed to define a plurality of pockets for trapping electrically-conductive fluid. Alternatively, the tissue treatment electrode is made from an electrically-conductive material and is coated with a resistive inert material which is effective to increase the local power density within the tissue treatment electrode.

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South Glamorgan, United Kingdom

Colin Charles Owen Goble