Abstract: An electrosurgical device for directing energy to a target volume of tissue includes a coaxial feedline having an inner conductor, an outer conductor coaxially disposed around the inner conductor, and a dielectric material disposed therebetween. An elongated electrically-conductive member is longitudinally disposed at a distal end of the inner conductor; a balun structure is disposed on the outer conductor. An electrically-conductive cylinder is coaxially disposed around a distal portion of the balun structure and a dielectric structure is disposed substantially adjacent to a distal end of the electrically-conductive cylinder and configured to extend to a distal end of the electrically-conductive member. An elongated handle assembly is coaxially disposed around a portion of the outer conductor proximal to the dielectric structure and a shell assembly is disposed at a distal end of the elongated handle assembly.

Abstract: An electrosurgical device for directing energy to a target volume of tissue includes a coaxial feedline having an inner conductor, an outer conductor and a dielectric material disposed therebetween. A proximal cylindrical dielectric sleeve is coupled to the inner conductor at a distal end of the coaxial feedline. A distal cylindrical dielectric sleeve is coupled to the inner conductor. First and second dielectric segments are coupled to the inner conductor and disposed between the proximal cylindrical dielectric sleeve and the distal cylindrical dielectric sleeve. The device also includes an elongated shaft overlying the proximal cylindrical dielectric sleeve, the first dielectric segment, the second dielectric segment and the distal cylindrical dielectric sleeve. The elongated shaft includes an opening defined therethrough, wherein the opening is at least partially aligned with the first dielectric segment.

Abstract: An electrosurgical device for directing energy to a target volume of tissue includes a coaxial feedline having an inner conductor, an outer conductor coaxially disposed around the inner conductor, and a dielectric material disposed therebetween. An elongated electrically-conductive member is longitudinally disposed at a distal end of the inner conductor. A balun structure is disposed on the outer conductor. The device also includes an electrically-conductive cylinder coaxially disposed around a distal portion of the balun structure, and a dielectric structure disposed substantially adjacent to a distal end of the electrically-conductive cylinder, wherein the dielectric structure longitudinally extends from the distal end of the electrically-conductive cylinder to a distal end of the electrically-conductive member.

Abstract: A hollow coaxial cable adapted for conduction of radio frequency (RF) energy, particularly microwave energy, has a proximal end and a distal end and comprises coaxial inner and outer conductors extending substantially the entire length of the cable from the proximal end to a distal end portion of the cable with a dielectric medium disposed between the inner and outer conductors. The inner conductor comprises an elongated electrically conductive tubular member having a hollow, axially extending lumen, and the outer conductor comprises an elongated electrically conductive tubular member disposed in a substantially coaxial relationship over at least a portion of the inner conductor. An ablating member which delivers radio frequency energy, particularly microwave energy, to body tissue is disposed at a distal end portion of the cable.

Abstract: The present disclosure relates to devices and methods for the treatment of tissue with microwave energy. The devices and methods disclosed herein utilize an antenna assembly which includes an elongate member, an outer conductor, an inner conductor, at least a portion of which is deployable, and a cooling system. The cooling system disclosed herein may significantly curtail any theoretical, or potential negative effects upon the target tissue experienced during the transmission of microwave energy to the antenna assembly due to ohmic heating.

Abstract: A microwave ablation system includes a generator operable to output energy and an antenna coupled to the generator via a coaxial cable. The antenna delivers energy to tissue and includes a proximal radiating section and a distal radiating section. The antenna also includes a feedpoint section defined by the portion of the distal radiating section that underlaps the proximal radiating section.

Abstract: A microwave ablation probe for providing microwave energy to tissue is disclosed. The probe includes a feedline having an inner conductor, a secondary inner conductor, an insulating spacer, and an outer conductor. The inner conductor is slidably disposed within the secondary inner conductor. The feedline also includes a radiating portion having an extruded portion of the inner conductor centrally disposed therein, wherein longitudinal movement of the inner conductor relative to the feedline tunes the radiating portion.

Abstract: A therapeutic microwave system comprises a support unit having two or more separable segments; a microwave power assembly positioned between two separated segments of the support unit and including two or more microwave power supply devices; position adjustment componentry; and a central processing unit. The system may further include a temperature sensor for monitoring a treated subject's exhaled air temperature in real time and adjusting microwave irradiation accordingly, and a cooling device for controlling the patient's brain temperature during treatment.

Abstract: A device for directing energy to a target volume of tissue includes an antenna assembly and an elongated body member. The elongated body member includes a proximal end portion and a distal end portion, wherein the proximal and distal end portions define a longitudinal axis. The elongated body member has a chamber defined therein that extends along the longitudinal axis, and a body wall surrounding the chamber. An antenna assembly is disposed in the chamber. The elongated body member also includes an opening in the body wall to allow energy radiated from the antenna assembly to transfer into the target volume of tissue.

Abstract: Provided is a coagulation apparatus using cold plasma. In the coagulation apparatus, the cold plasma is generated by a microwave resonator with low power consumption in the atmosphere, and the cold plasma is vented on a bleeding portion of a wound. Accordingly, it is possible to accelerate coagulation process, to reduce unfavorable side effect such as burns on the wound, and to efficiently sterilize the wound, simultaneously. In addition, it is possible to implement a small-sized portable coagulation apparatus.

Abstract: A system and corresponding method for irradiating a target with electromagnetic radiation to produce a heated region. The system comprises a coupling device operable to couple electromagnetic radiation from a magnetic resonance imaging system. A plurality of energy radiator applicators are connected to the coupling device to receive electromagnetic radiation energy from the coupling device. Each of the radiator applicators is operable to emit a radio frequency heating signal using the electromagnetic radiation energy from the coupling device. A bolus filled with a dielectric fluid is positioned within the inner area of the MRI system. The bolus is operable to receive the radio frequency heating signals from the plurality of energy radiator applicators and direct the radio frequency heating signals into a section of the body to produce a heated region within the body.

Abstract: A microwave antenna assembly comprising an elongate shaft having proximal and distal ends and a lumen defined therebetween, a conductive member at least partially disposed within the inner lumen of elongate shaft, conductive member being selectively deployable relative to a distal end of elongate shaft from a first condition wherein a distal end of conductive member at least partially abuts the distal end of elongate shaft to a second condition wherein the distal end of conductive member is spaced relative to the distal end of elongate shaft and a first dielectric material disposed between elongate shaft and conductive member, wherein a portion of conductive member is distal to the distal end of elongate shaft and adapted to penetrate tissue.

Abstract: The invention provides a microwave heating method and apparatus for evenly heating an object, such as a person's body. The methods and apparatus involve use of microwave source (or sources) that outputs multiple microwaves that are non-correlated with each other in phase; an array of antennas that radiate substantially plane microwaves to form a pseudo uniform microwave electromagnetic field, where the microwaves are not phase-correlated, in order to eliminate non-uniform heating caused by interference. Each of the antenna array consists of multiple antenna units, each antenna unit consists of at least one microwave radiator and at least one converter that converts the spherical microwave to plane microwave. A computer based control system and a temperature monitoring subsystem can be used to adjust the output of each antenna, in order to enhance the uniform heating effect. The apparatus and method can be used to perform whole-body hyperthermia or regional hyperthermia.

Abstract: A microwave antenna assembly including an elongated cooling jacket having proximal and distal ends and an inner lumen defined therebetween and a helical microwave antenna member disposed within at least a portion of the elongated cooling jacket and having an inner and outer conductor, the inner conductor disposed within the outer conductor, wherein at least a portion of the inner conductor extends distally from the outer conductor and forms at least one loop; and wherein the inner conductor is configured to deliver microwave energy.

Abstract: An RF diathermy coil assembly, including a generally elastically deformable patient conforming garment and a conductive coil secured to the garment. The conductive coil having a woven wire construction such that the coil can deform as the garment elastically deforms. The RF diathermy coil assembly can be used for wound healing in conjunction with muscle stimulation.

Abstract: Devices and methods for cooling microwave antennas are disclosed herein. The cooling systems can be used with various types of microwave antennas. One variation generally comprises a handle portion with an elongate outer jacket extending from the handle portion. A microwave antenna is positioned within the handle and outer jacket such that cooling fluid pumped into the handle comes into contact directly along a portion of the length, or a majority of the length, or the entire length of the antenna to allow for direct convective cooling. Other variations include cooling sheaths which form defined cooling channels around a portion of the antenna. Yet another variation includes passively-cooled systems which utilize expandable balloons to urge tissue away from the surface of the microwave antenna as well as cooling sheaths which are cooled through endothermic chemical reactions. Furthermore, the microwave antennas themselves can have cooling lumens integrated directly therethrough.

Abstract: A minimally-invasive fluid-cooled insertion sleeve assembly, with an attached balloon and distally-located penetrating tip, into which sleeve any of a group comprising a rigid rod, a microwave-radiator assembly and an ultrasonic-imaging transducer assembly may be inserted, constitutes a probe of the system. The sleeve assembly comprises spaced inner and outer plastic tubes with two fluid channels situated within the coaxial lumen between the inner and outer tubes. The fluid coolant input flows through the fluid channels into the balloon, thereby inflating the balloon, and then exits through that coaxial lumen. An alternative embodiment has no balloon. The method employs the probe for piercing sub-cutaneous tissue and then ablating deep-seated tumor tissue with microwave-radiation generated heat.

Abstract: Medical catheter apparatus for minimally invasive applications includes a probe for radiating electromagnetic waves of a first frequency capable of heating tissue and detecting thermal emissions from that tissue of a second frequency indicative of tissue temperature. The probe has an inner conductor extending along the probe to a conductive probe tip and a concentric tubular outer conductor having a leading end spaced rearwardly from the probe tip and a closed trailing end shorted to the inner conductor. A dielectric sheath surrounds the outer conductor which sheath has a leading end spaced rearwardly from the leading end of the outer conductor. A diplexer integrated into the probe includes a filter circuit positioned inside the outer conductor and a coupling capacitor connected between a point on the inner conductor and the input of the filter circuit such that the conductors between that point and the shorted trailing end of the outer conductor constitute a quarter wave stub at the second frequency.

Abstract: Apparatus for controlled tissue ablation includes an elongated relatively flexible antenna with a first, strip-like, conductor having opposite faces and proximal and distal ends, a dielectric spacer covering one face of the first conductor, and a second, serpentine, conductor composed of a series of similar segments positioned flush against the spacer and being coextensive lengthwise with the first conductor. The second conductor has a distal end connected to the distal end of the first conductor and a proximal end. An electrically insulating enclosure surrounds the conductors. The proximal ends of the first and second conductors may be connected via a coaxial cable to a remote microwave transmitter/receiver unit.

Abstract: An irradiation device for irradiating a living organism with electromagnetic radiation in order to influence biological structures inside the organism has a frequency generator that has a frequency synthesizer for the production of electromagnetic radiation having a defined frequency pattern, and a transmission antenna that is fashioned such that during operation the electromagnetic radiation is emitted essentially into a particular radiation volume.

Abstract: An antenna for microwave tumor ablation provides coaxial antenna conductors surrounded by an insulated sleeve of length and size promoting destructive interference of axial microwave energy passing inside and outside of the sleeve to limit the tail of SAR power toward the skin.

Abstract: As described herein vascular anchoring systems are used to position an implant in a vascular area such as a bifurcated vasculature with relatively high fluid flow, for instance, in an area of a pulmonary artery with associated left and right pulmonary arteries. Implementations include an anchoring trunk member having a first anchoring trunk section and a second anchoring trunk section. Further implementations include a first anchoring branch member extending from the anchoring trunk member. Still further implementations include a second anchoring branch member extending from the anchoring trunk member.

Abstract: A system for use with a microwave antenna includes a microwave antenna configured to deliver microwave energy from a power source to tissue and a sensor module in operative communication with the power source and configured to detect a reflectance parameter. The system further includes a jacket adapted to at least partially surround the microwave antenna to define a fluid channel between the jacket and the microwave antenna. A plurality of fluid distribution ports are defined through the jacket and are in fluid communication with the fluid channel to permit the flow of fluid through the jacket. The system further includes a fluid pumping system operably coupled to the power source and configured to selectively provide cooling fluid to the fluid channel for distribution through the fluid distribution ports based on the reflectance parameter.

Abstract: A radio-frequency based catheter system and method for ablating biological tissues within the body vessel of a patient comprises a radio-frequency (“RF”) generator for selectively generating a high frequency RF energy signal in a deployable catheter having an RF transmission line, an RF antenna mounted on the distal portion of the catheter, and a temperature sensor also mounted on a distal portion of the catheter for detecting temperature adjacent an ablation site. A control system adjusts the RF energy signal so that the detected temperature is at or close to a selected temperature setting or within a selected temperature range.

Abstract: A system and corresponding method for creating hyperthermia in a selected position in target tissue using the application of electromagnetic radiation (EMR) in the HF, VHF and UHF microwave region and phased array steering includes an array of applicators and a single channel EMR radiation energy source coupled to at least one of the applicators of the array. A variable reflective termination device is coupled to at least one of the applicators so that a user can vary the energy radiated from the coupled applicator to steer the heating region in the target to a desired position in the target. Several different applicator arrays are suitable for use with the system, and comprise generally cylindrical annuli which emit radiation toward a central axis. Parasitic applicators with variable reflective termination devices can be used in the applicator array along with at least one applicator directly coupled to the energy source.

Abstract: Method and apparatus for cellular and intracellular manipulation of cell functions with ultrashort electrical pulses and for targeted delivery of the electrical pulses into cell cultures, patients, and tissues.

Abstract: A position detecting device finds the position of a specimen arranged in a conductive structure on the basis of microwaves and includes an electrical circuit for the production and/or reception of the microwaves and a microwave antenna arrangement for emitting and/or receiving the microwaves. Said position detecting device includes a dielectric antenna body with a first pole face and a second pole face for the transmission of microwaves. The antenna body forms a component of the microwave antenna arrangement. The electrical circuit is at least in part arranged on the antenna body.

Abstract: A near-field antenna structure is described that is an effective delivery tool for radiofrequency (RF) and microwave power to achieve coagulative necrosis in metastatic tumors while reducing or eliminating thermal conduction along the structure. This tool is a probe small enough to be used safely virtually anywhere in the neck, chest, abdomen, and pelvis, and be guided by computerized tomography (CT) or ultrasonic imaging.

Abstract: A tissue-sensing adaptive radar method of detecting tumours in breast tissue uses microwave backscattering to detect tumours which have different electrical properties than healthy breast tissue. The method includes steps for reducing skin reflections and for constructing a three-dimensional image using synthetic focusing which shows the presence or absence of microwave reflecting tissues.

Abstract: A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095? (2.4 mm) but the design permits for smaller diameters.

Abstract: A medical instrument includes a pair of spaced apart and electrically isolated elongated electrodes positioned adjacent one another on a working member. The electrodes are arranged for sensing electrical activity of biological tissues inside the body of the patient. The medical instrument also includes a pair of electrically isolated electrode wires that extend through the working member and electrically couple to associated electrodes.

Abstract: A method and device delivers microwave power to an antenna through a coaxial cable utilizing air or other gases as its dielectric core. The cable includes supports made of low-loss materials to keep the inner conductor centered in the cable, and defining spaces therebetween for the air or gas. Channels in the supports allow the air or gas to circulate in the cable. The gas may be chilled or cooled to provide an addition level of heat dissipation. The device enables delivery of large amounts of power to tissue without undue heating of the feed cable or peripheral tissues, and without increasing the diameter of the feeding cable or antenna, keeping the antenna safe for percutaneous use.

Abstract: A microwave antenna assembly comprising an elongate shaft having proximal and distal ends and a lumen defined therebetween, a conductive member at least partially disposed within the inner lumen of elongate shaft, conductive member being selectively deployable relative to a distal end of elongate shaft from a first condition wherein a distal end of conductive member at least partially abuts the distal end of elongate shaft to a second condition wherein the distal end of conductive member is spaced relative to the distal end of elongate shaft and a first dielectric material disposed between elongate shaft and conductive member, wherein a portion of conductive member is distal to the distal end of elongate shaft and adapted to penetrate tissue.

Abstract: An ablation catheter apparatus with a monopole antenna that is arranged to provide a relatively uniform electric field and a method for using such an ablation catheter apparatus are disclosed. According to one aspect of the present invention, an ablation catheter includes an elongated flexible tubular member that is adapted to be inserted into the body of a patient, and a transmission line that is disposed within the tubular member. The transmission line has a distal end and a proximal end which is arranged to be connected to an electromagnetic energy source. The catheter also includes a monopole antenna with tip section and a body section that includes a distal end and a proximal end. The tip section and the body section are arranged to produce a relatively uniform electric field around the monopole antenna which is sufficiently strong to cause tissue ablation. The proximal end of the body section of the monopole antenna is arranged to be electrically coupled to the transmission line.

Abstract: A microwave applicator for applying microwave radiation to body tissue includes a temperature sensor positioned along the applicator to measure the temperature of body tissue at a margin of the tissue to be treated. By monitoring the temperature of the tissue at the margin of the tissue to be treated, the heating of the tissue can be better controlled to ensure that the tissue to be treated is heated to the required temperature while damage to surrounding normal tissue is minimized. Treatment can include positioning one or more applicators into body tissue and applying microwave radiation to the applicators. Phase and amplitude control of the microwave radiation can be used to produce a desired heating pattern. Optimization of the number and location of microwave applicators and the phase and amplitude of microwave energy applied thereto can be determined through pretreatment simulation.

Abstract: A telemetry antenna for an implantable medical device includes one or more portions having a non-linear configuration. In some embodiments, the non-linear configuration provides an antenna having a greater antenna length than the linear lengthwise dimension of the antenna structure. In some embodiments, the non-linear configuration is a serpentine pattern.

Abstract: Medical catheter apparatus for minimally invasive applications includes a probe for radiating electromagnetic waves of a first frequency capable of heating tissue and detecting thermal emissions from that tissue of a second frequency indicative of tissue temperature. The probe has an inner conductor extending along the probe to a conductive probe tip and a concentric tubular outer conductor having a leading end spaced rearwardly from the probe tip and a closed trailing end shorted to the inner conductor. A dielectric sheath surrounds the outer conductor which sheath has a leading end spaced rearwardly from the leading end of the outer conductor. A diplexer integrated into the probe includes a filter circuit positioned inside the outer conductor and a coupling capacitor connected between a point on the inner conductor and the input of the filter circuit such that the conductors between that point and the shorted trailing end of the outer conductor constitute a quarter wave stub at the second frequency.

Abstract: A catheter based delivery system may be used for both therapeutic and diagnostic applications. The catheter based delivery system includes a catheter having a distal end. The distal end of the catheter includes several electrodes that can emit a radio frequency waveform, and may receive a signal representative of an impedance of material in the exposed to the radio frequency waveform. The radio frequency waveform may also be applied to ablate specifically targeted material exposed to the radio frequency waveform. The several electrodes may be configured as an antenna.

Abstract: A wireless communication system is provided that includes an antenna structure adapted for coupling to a medical device antenna when the medical device is not implanted in a patient's body. The antenna structure effectively extends the medical device antenna length, thereby improving the efficiency and reliability of a communication link between the medical device and a programmer or monitor outside the implanted environment. The antenna structure is fabricated from any conductive material, which may be in the form of conductive wire, tape, ink, foil, film, adhesive or the like, and is attached to a portion of a medical device packaging assembly or another accessory device or substrate such as a pouch or overlay. The antenna structure may be a monopole, dipole, slot antenna, microstrip patch, or loop antenna, and may be fixed or movable relative to the substrate on which it is implemented.

Abstract: In general, the invention is directed to a patient programmer for an implantable medical device. The patient programmer may include one or more of a variety of features that may enhance performance, support mobility and compactness, or promote patient convenience.

Abstract: Microwave hyperthermia treatment device includes a microwave generation unit, a power supply unit, and a control unit including an exposure-time actuation timer, an intermittent actuation timer, a second-device connecting terminal, and a remote switch. Two microwave hyperthermia treatment devices are connected with each other via the second terminal connecting terminals for simultaneous use flanking the torso along either side of an affected area, whereby superposed strong microwaves are irradiated. The temperature of tumor(s) in the affected area can thereby be brought to about 43° C. in about 1 minute, rendering lengthy treatment periods unnecessary and thus alleviating temperature stress on the patient. Two remote-control switches to the control unit can be provided, one of which may be given to a patient for use as an emergency stop switch, eliminating the necessity of having to insert a temperature sensor in the body, which also alleviates the burden on the patient.

Abstract: A method and device delivers microwave power to an antenna through a coaxial cable utilizing air or other gases as its dielectric core. The cable includes supports made of low-loss materials to keep the inner conductor centered in the cable, and defining spaces therebetween for the air or gas. Channels in the supports allow the air or gas to circulate in the cable. The gas may be chilled or cooled to provide an addition level of heat dissipation. The device enables delivery of large amounts of power to tissue without undue heating of the feed cable or peripheral tissues, and without increasing the diameter of the feeding cable or antenna, keeping the antenna safe for percutaneous use.

Abstract: A microwave antenna having a curved configuration is described herein. The antenna portion is formed into various shapes whereby the antenna substantially encloses, by a partial or complete loop or enclosure, at least a majority of the tissue to be irradiated. When microwave energy is delivered through the antenna, the curved configuration forms an ablation field or region defined by the curved antenna and any tissue enclosed within the ablation region becomes irradiated by the microwave energy. The microwave antenna is deployed through one of several methods, and multiple curved antennas can be used in conjunction with one another. Moreover, RF energy can also be used at the distal tip of the antenna to provide a cutting tip for the antenna during deployment in tissue.

Abstract: Disclosed is an electrode device for microwave surgery which is provided with a marker securely fixed to the central electrode, which marker can provide a magnetic susceptibility artifact of a uniform size and shape free of fluctuation among electrode devices. The electrode device comprise a central conductor body, a tubular insulator body which covers the central conductor body except its distal end, a tubular external electrode which covers the tubular insulator body except its distal end part, and a central electrode which covers the distal end part of the central conductor body. The central conductor body, the insulator body, the external electrode and the central electrode are made of a nonmagnetic material, and a cylindrical member made of a magnetic material is fit around the distal end part of the central conductor body.

Abstract: A medical instrument is disclosed. The medical instrument includes a pair of spaced apart and electrically isolated elongated wire electrodes positioned adjacent one another on a working member. The wire electrodes are arranged for sensing electrical activity of biological tissues inside the body of the patient. The medical instrument also includes a pair of electrically isolated electrode wires that extend through the working member. Each of the electrode wires are electrically coupled to an associated wire electrode.

Abstract: The present invention relates to minimally invasive surgery techniques. It provides a method for manufacturing an antenna for percutaneous acute hyperthermia microwave applications of the monopole or dipole co-axial type provided with trap, commonly called choke, for blocking the propagation of the backwards reflecting wave towards the generator. The miniaturization of the device allows a use minimally invasive for interstitial hyperthermia in medicine and surgery, in particular for oncology. The method of manufacturing the antenna provides a metal needle (1) for the introduction of the antenna (2,3,4) in the target tissue.

Abstract: An improved antenna for microwave ablation uses a triaxial design which reduces reflected energy allowing higher power ablation and/or a smaller diameter feeder line to the antenna.

Abstract: An external transmitter circuit drives an implantable neural stimulator having an implanted coil from a primary coil driven by a power amplifier. For efficient power consumption, the transmitter output circuit (which includes the primary coil driven by the power amplifier inductively coupled with the implanted coil) operates as a tuned resonant circuit. When operating as a tuned resonant circuit, it is difficult to modulate the carrier signal with data having sharp rise and fall times without using a high power modulation amplifier. Sharp rise and fall times are needed in order to ensure reliable data transmission. To overcome this difficulty, the present invention includes an output switch that selectively inserts a resistor in the transmitter output coil circuit in order to de-tune the resonant circuit only during those times when data modulation is needed. Such de-tuning allows sharp rise and fall times in the data modulation without the need for using a high power modulation amplifier.

Abstract: A RF catheter system includes a catheter with a proximal portion, a distal portion having a distal end and a lumen extending from the proximal portion to the distal portion. Inner and outer coaxially aligned conductors extend within the catheter and are coaxial with the lumen. A deflectable catheter guide is disposed within the catheter lumen and extends proximally within the catheter lumen and terminates distally of the distal end of the catheter to define a biological ablation pathway. A radio-frequency antenna is disposed at the distal portion of the catheter and is in electrical communication with the inner and outer coaxially aligned conductors. The radio-frequency antenna is adaptable to receive and transmit radio-frequency energy for ablating biological tissue along the ablation pathway.

Abstract: A medical instrument is disclosed. The medical instrument includes a pair of spaced apart and electrically isolated elongated wire electrodes positioned adjacent one another on a working member. The wire electrodes are arranged for sensing electrical activity of biological tissues inside the body of the patient. The medical instrument also includes a pair of electrically isolated electrode wires that extend through the working member. Each of the electrode wires are electrically coupled to an associated wire electrode.