Abstract: A medical probe device comprises a catheter having a stylet guide housing with one or more stylet ports in a side wall thereof and a stylet guide for directing a flexible stylet outward through the stylet port and through intervening tissue at a preselected, adjustable angle to a target tissue. The total catheter assembly includes a stylet guide lumen communicating with the stylet port and a stylet positioned in said stylet guide lumen for longitudinal movement from the port through intervening tissue to a target tissue. The stylet can be an electrical conductor enclosed within a non-conductive layer, the electrical conductor being a radiofrequency electrode. Preferably, the non-conductive layer is a sleeve which is axially moveable on the electrical conductor to expose a selected portion of the electrical conductor surface in the target tissue. The stylet can also be a microwave antenna. The stylet can also be a hollow tube for delivering treatment fluid to the target tissue.

Abstract: A medical probe device comprises a catheter having a stylet guide housing with one or more stylet ports in a side wall thereof and a stylet guide for directing a flexible stylet outward through the stylet port and through intervening tissue at a preselected, adjustable angle to a target tissue. The total catheter assembly includes a stylet guide lumen communicating with the stylet port and a stylet positioned in said stylet guide lumen for longitudinal movement from the port through intervening tissue to a target tissue. The stylet can be an electrical conductor enclosed within a non-conductive layer, the electrical conductor being a radiofrequency electrode. Preferably, the non-conductive layer is a sleeve which is axially moveable on the electrical conductor to expose a selected portion of the electrical conductor surface in the target tissue. The stylet can also be a microwave antenna. The stylet can also be a hollow tube for delivering treatment fluid to the target tissue.

Abstract: A method for calculating the impedance in a first circuit coupling a first radio frequency electrode to a radio frequency controller where the first electrode is disposed in tissue in the vicinity of a second radio frequency electrode coupled to a second circuit. The impedance IMP of the first circuit is measured when energy is being supplied to both electrodes. The impedance IMP0 of the first circuit is also measured when energy is being supplied to the first electrode but not to the second electrode, and subtracted from the impedance value IMP to determine a delta value IMP&Dgr;. The impedance IMP2 of the first circuit is then measured when energy is being supplied to both electrodes. The impedance delta value IMP&Dgr; is subtracted from the impedance value IMP2 to arrive at a calculated impedance value for the first circuit. A computer-readable memory and apparatus utilizing the method are provided.

Abstract: A method for treating tissue of a mammalian body in which the conductivity of the tissue is characterized. The amount of a conductive liquid to supply to the tissue is determined as a function of the conductivity of the tissue and injected into the tissue over an interval of time. Electromagnetic energy is supplied to the tissue to form a lesion in the tissue. A computer-readable memory and a radio frequency generator and controller utilizing such method are further provided.

Abstract: A method for monitoring the impedance in a circuit coupling a radio frequency electrode to a radio frequency generator to control the power supplied by the generator to the electrode during a treatment procedure. In the method, the impedance in the circuit is monitored over a length of time. An expected impedance at the end of the treatment procedure is calculated from the monitored impedance and compared to a predetermined maximum impedance. The power supplied to the circuit is reduced if the expected impedance is greater than the predetermined maximum impedance. A computer-readable memory and apparatus utilizing the method are provided.

Abstract: A method for calculating the impedance in a first circuit coupling a first radio frequency electrode to a radio frequency controller where the first electrode is disposed in tissue in the vicinity of a second radio frequency electrode coupled to a second circuit. The impedance IMP of the first circuit is measured when energy is being supplied to both electrodes. The impedance IMP0 of the first circuit is also measured when energy is being supplied to the first electrode but not to the second electrode, and subtracted from the impedance value IMP to determine a delta value IMP. The impedance IMP2 of the first circuit is then measured when energy is being supplied to both electrodes. The impedance delta value IMP is subtracted from the impedance value IMP2 to arrive at a calculated impedance value for the first circuit. A computer-readable memory and apparatus utilizing the method are provided.

Abstract: An electrosurgical device comprising an elongate probe member having proximal and distal extremities and a passage extending from the proximal extremity to an opening at the distal extremity. The elongate probe member is provided with an elongate cutout adjacent the opening so that the elongate probe member is formed with an elongate extension projecting alongside the cutout beyond the opening. A guide canula is mounted in the passage of the elongate probe member and has proximal and distal extremities and a lumen extending therethrough. A radio frequency electrode is disposed in the lumen and an insulating sleeve is coaxially disposed on the radio frequency electrode. A handle is secured to the proximal extremity of the guide canula for advancing and retracting the radio frequency electrode and the insulating sleeve with respect to the guide canula and for causing bending of the distal extremity of the guide cannula into the cutout.