Abstract: An intraurethral catheter includes an microwave antenna and a cooling lumen structure substantially surrounding the antenna. A cooling balloon partially surrounds the cooling lumens on one side of the catheter adjacent the microwave antenna. The cooling balloon improves wall contact between the catheter and a wall of the urethra to improve cooling of the urethra. The cooling balloon communicates with the cooling lumen structure to permit circulation of cooling fluid through the cooling balloon.

Abstract: A microwave-heatable therapeutic exercise putty mass is packaged in a microwaveable container having at least one transparent wall. The putty mass within the container is in heat transfer proximity with transparent wall of the container. A thermochromic heat sensitive semiconductor material (strip, label or coating) is affixed to the transparent wall in intimate heat transfer contact with the putty mass. The thermochromatic material provides a visual first indication through the transparent wall when the putty mass has been microwave heated to a heat exercise therapy acceptable temperature range of about 40 to about 47 degrees C. and a visual second indication through the transparent wall when the putty mass has been microwave heated to a temperature range of about 54 to about 60 degrees C. or above which is non-acceptable for heat exercise therapy.

Abstract: An electrophysiology catheter suitable for radiofrequency ablation of cardiac tissue endocardially or epicardially comprises a catheter shaft whereby a distal tip section having multiple steerable curved portions, multiple long electrodes and multiple temperature sensors, further comprising a close-loop control mechanism for each electrode with a temperature sensor.

Abstract: An ablation apparatus includes an energy source producing an ablation energy output. A multiple antenna device is included and has a primary antenna with a longitudinal axis, a central lumen and a distal end, and a first secondary antenna with a distal end. The first secondary antenna is deployed from the primary antenna central lumen in a lateral direction to the longitudinal axis. The primary antenna is coupled to the energy source to receive the ablation energy output, and the first secondary antenna is coupled to the primary antenna to receive ablation energy from the primary antenna. A sensor is positioned at one or both of the primary or secondary antennas. A feedback control system is coupled to the energy source and the sensor. The feedback control system is responsive to a detected characteristic from the sensor to provide a delivery of ablation energy output from the energy source to the antennas.

Abstract: An intraurethral, Foley-type catheter shaft contains a microwave antenna capable of generating a cylindrically symmetrical thermal pattern, within which temperatures are capable of exceeding 45.degree. C. The antenna, which is positioned within the shaft, is surrounded by means within the shaft for absorbing thermal energy conducted by the tissue and asymmetrically absorbing electromagnetic energy emitted by the antenna--a greater amount of electromagnetic energy being absorbed on one side of the shaft. This asymmetrical absorption alters the thermal pattern generated by the microwave antenna, making it cylindrically asymmetrical, which effectively focuses microwave thermal therapy toward undesirous benign tumorous tissue growth of a prostate anterior and lateral to the urethra, and away from healthy tissue posterior to the urethra.

Abstract: Systems and methods employ an energy emitting electrode to heat tissue. The systems and methods follow a prescribed temperature set curve, in which a setpoint temperature changes over time, to control the application of energy to the electrode.

Abstract: A cardiac ablation system and method employs an ablation electrode having an energy emitting body. A temperature sensing element senses the temperature of the tissue being ablated by the electrode. The system monitors tissue temperature using the temperature sensing element. A control element controls the therapeutic characteristics of the ablated lesion based upon sensed tissue temperature conditions.

Abstract: Systems and methods ablate body tissue using an electrode for contacting tissue at a tissue-electrode interface to transmit ablation energy at a determinable power level. The systems and methods include an element to remove heat from the electrode at a determinable rate. The systems and methods employ a processing element to derive a prediction of the maximum tissue temperature condition occurring beneath the tissue-electrode interface. The processing element controls the power level of ablation energy transmitted by the electrode, or the rate at which the electrode is cooled, or both, based, at least in part, upon the maximum tissue temperature prediction.

Abstract: An ablation apparatus includes a multiple antenna device coupled to an electromagnetic energy source that produces an electromagnetic energy ablation output. The multiple antenna device includes a primary antenna with a lumen and a longitudinal axis, and a secondary antenna deployable from the lumen in a lateral direction relative to the longitudinal axis. At least a distal end of each secondary antenna is structurally less rigid than the primary antenna, and the primary antenna is sufficiently rigid to be introduced through tissue. At least one cable coupling the multiple antenna device to the energy source. A cooling element is coupled to the primary antenna. A variety of energy sources can be used including RF, microwave and laser.

Abstract: A method of providing thermal therapy to prostate tissue of a patient. The method includes: inserting a mechanical separator or infusing a fluid to separate human tissue to be treated from nontarget tissue, thereby providing thermal insulation and other beneficial effects, and applying the thermal therapy to the target tissue.

Abstract: A multiple antenna ablation apparatus includes an electromagnetic energy source, a trocar including a distal end, and a hollow lumen extending along a longitudinal axis of the trocar, and a multiple antenna ablation device with three or more antennas. The antennas are initially positioned in the trocar lumen as the trocar is introduced through tissue. At a selected tissue site the antennas are deployable from the trocar lumen in a lateral direction relative to the longitudinal axis. Each of the deployed antennas has an electromagnetic energy delivery surface of sufficient size to, (i) create a volumetric ablation between the deployed antennas, and (ii) the volumetric ablation is achieved without impeding out any of the deployed antennas when 10 to 50 watts of electromagnetic energy is delivered from the electromagnetic energy source to the multiple antenna ablation device. At least one cable couples the multiple antenna ablation device to the electromagnetic energy source.

Abstract: An electrode catheter is provided for ablation of arrhythmogenic tissue in a malperforming heart and includes an elongated catheter tube having longitudinally spaced apart proximal and distal ends. At least one electrode for ablation of the arrhythmogenic tissue in a targeted region of the patient is carried on the catheter tube, preferable at or proximate the distal end of the catheter tube. One such electrode may be located at the distal tip of the catheter and configured in the shape of a generally flat disk that substantially conforms to the contour of the targeted region and such that the ratio of the surface area of the tissue-contacting end face to that of a side wall portion of the electrode is greater than 1.0.

Abstract: Systems and methods employ an energy emitting electrode to heat tissue. The systems and methods control the application of energy to the electrode using adjustments that take into account, in a non-linear fashion, changes in monitored operating conditions.

Abstract: Multi-phase RF ablation employing a two-dimensional or three-dimensional electrode array produces a multitude of currents paths on the surface of the ablation zone. This results in a uniform lesion with a size defined by the span of the electrode array. An orthogonal electrode catheter array suitable for cardiac ablation is used in conjunction with a two-phase RF power source to produce uniform square-shaped lesions of size 1.2 cm.sup.2. Lesions of larger size are created by successive adjacent placement of the square-shaped lesions. A temperature sensor at the electrode tip allows monitoring of ablation temperature and regulation of thereof to minimize the electrode tips from being fouled by coagulum.

Abstract: Systems and methods for ablating body tissue use an electrode for contacting tissue to form a tissue-electrode interface. The electrode is adapted to be connected to a source of ablation energy to conduct ablation energy for transmission by the electrode into tissue at the tissue-electrode interface. The electrode is preferably cooled. The systems and methods include multiple temperature sensing elements. One element senses tissue temperature. A second element senses electrode temperature. A third element senses the rate at which the electrode is cooled. The systems and methods control the supply of ablation energy to the electrode based, at least in part, upon the multiple temperatures sensed by the different temperature sensing elements.

Abstract: A microwave apparatus for warming of a liquid such as blood or IV fluids in which the warming occurs in-line by means of a microwave heating cavity having a source of microwave energy coupled thereto. A support element in the form of a bobbin forms an assembly with an IV tube wound about the bobbin. This tubing-bobbin assembly is inserted into the microwave heating cavity. A non-invasive, non-perturbing microwave temperature monitor is provided coupled to the microwave heating cavity for monitoring the temperature of liquid flowing in the IV tube. Controls are provided including a desired operating selector for combining signals representative of, not only cavity temperature, but also inlet and outlet temperatures to control the power level of microwave energy delivered to the heating cavity.

Abstract: An endocardial ablation and mapping apparatus is introduced into a heart chamber for mapping to detect arrhythmogenic foci, and ablate endocardium at the arrhythmogenic foci. An inflatable, flexible porous membrane is adapted to receive an electrolytic solution, and become inflated to substantially conform a conductive surface of the membrane to the wall of the heart chamber. A membrane support is surrounded by the membrane, and includes a sealed proximal end and a sealed distal end. Each end has an aperture formed therein defining a central lumen in the membrane support that permits blood flow through the support member and the heart chamber. The membrane support is attached to the membrane and is expanded to a non-distensible state when the membrane is inflated. A catheter, with a distal end, is attached to the membrane or the membrane support.

Abstract: An ablation treatment apparatus has a multiple antenna device. The multiple antenna device includes a primary antenna with a lumen, a longitudinal axis and an ablative surface area of length L.sub.1. The multiple antenna device also includes a secondary antenna that is positioned in the primary antenna as the primary antenna is introduced through tissue. A secondary antenna distal end is deployed at a selected tissue site from the primary antenna lumen in a lateral direction relative to the longitudinal axis. A sensor is at least partially positioned at an exterior of the secondary antenna distal end at a distance L.sub.2 from the primary antenna along the secondary antenna distal end. L.sub.2 is at least equal to 1/3 L.sub.1. An energy source is coupled to the primary antenna.

Abstract: An ablation treatment apparatus has a multiple antenna device with a primary antenna and a secondary antenna. The secondary antenna is positioned in a lumen of the primary antenna as the primary antenna is introduced through tissue to a selected tissue site. At the tissue site the secondary antenna is deployed from the primary antenna in a lateral direction relative to a longitudinal axis of the primary antenna. At least a portion of a distal end of the secondary antenna is structurally less rigid than the primary antenna. The primary antenna is constructed to be rigid enough to be introduced and advanced through tissue. A cable couples the energy source to one or more of the antennas.

Abstract: A method for performing thermotherapy treatment of patient prostate tissue, comprising the steps of inserting a thermotherapy probe in a urethral passageway, the probe having a fluid volume containing portion and an energy source inserted therein for generating radiation to heat the patient prostate tissue by the tissue absorbing the radiation; generating a pressurized fluid flow in the probe within the fluid volume containing portion and cooling the energy source by enveloping at least a portion of the energy source to direct the pressurized fluid flow to come into direct contact with and circulate around and over all energy radiating portions of the energy source simultaneously with energy radiation by the energy source, thereby preventing thereby preventing thermal damage to the energy source; and providing an inflatable nondistensible structure as part of the probe inserted into the urethral passageway and inflating the nondistensible structure with the pressurized fluid flow to cool tissue contacting the

Abstract: A system for treatment of benign prostatic hyperplasia within intraprostatic tissue surrounding a urethra is disclosed. The system includes an intraurethral catheter having an intraurethral catheter shaft. An antenna is located within the catheter shaft for delivering heat to the intraprostatic tissue surrounding the urethra. Coolant fluid is circulated through a chamber located between the catheter shaft and the urethral wall.

Abstract: A thermatological device comprising an applicator and a main body. The applicator has a microwave-applying section, a first temperature sensor and a second temperature sensor. The main body contains a control unit. The microwave-applying section applies microwaves to an affected part, thereby treating the part. The first temperature sensor detects the temperature of the affected part being treated. The, the second temperature sensor detects a part located adjacent to the affected part. The control unit controls the microwave-applying section to render the temperature detected by the first temperature sensor equal to a preset target temperature. The control unit causes the microwave-applying section to stop or reduce the emission of microwaves when the temperature detected by the second temperature sensor reaches a preset burn temperature.

Abstract: An intraurethral catheter shaft comprises a plurality of lumens extending between a first end and a second end of the shaft. An antenna lumen has a generally circular cross-sectional surface area and is positioned nearer a first outer surface than a second outer surface of the catheter shaft. A first and second pair of cooling lumens substantially surround the antenna lumen and have a generally arc shaped cross-sectional surface area. The cooling lumens are configured to be circumjacent to the antenna lumen about a substantial majority of the antenna lumen. A urinary drainage lumen is positioned between the second pair of cooling lumens adjacent the antenna lumen and has a generally circular cross-sectional surface area. The lumens of the catheter shaft are defined by a unitary wall having a substantially uniform thickness throughout the catheter.

Abstract: Multi-phase RF ablation employing a two-dimensional or three-dimensional electrode array produces a multitude of currents paths on the surface of the ablation zone. This results in a uniform lesion with a size defined by the span of the electrode array. An orthogonal electrode catheter array suitable for cardiac ablation is used in conjunction with a two-phase RF power source to produce uniform square-shaped lesions of size 1.2 cm.sup.2. Lesions of larger size are created by successive adjacent placement of the square-shaped lesions. A temperature sensor at the electrode tip allows monitoring of ablation temperature and regulation of thereof to minimize the electrode tips from being fouled by coagulum. In another embodiment, an external auxiliary electrode is used in combination with the catheter electrodes. This also produces lesions of greater depth. In yet another embodiment, ablation is performed with a sequence of elementary electrode-electrical configurations.

Abstract: A method for treating an individual with benign prostate hyperplasia is disclosed. The method includes inserting a catheter into a urethra so as to position an energy emitting element located within the catheter adjacent a prostatic region of the urethra. A fluid is circulated within the catheter until the fluid stabilizes at a prechilled temperature. An energy emitting element is then energized sufficient to heat prostatic tissue surrounding the energy emitting element.

Abstract: An RF treatment apparatus includes a catheter with a catheter lumen. A removable needle electrode is positioned in the catheter lumen in a fixed relationship to the catheter. The needle electrode includes a needle lumen and a needle electrode distal end. A removable introducer is slidably positioned in the needle lumen. The introducer includes an introducer distal end. A first sensor is positioned on a surface of the needle electrode or the insulator. An RF power source is coupled to the needle electrode and a return electrode. An insulator sleeve is slidably positioned around the electrode and includes a second sensor. Resources are associated with the electrodes, sensors as well as the RF power source for maintaining a selected power at the electrode independent of changes in current or voltage.

Abstract: A system for treatment of benign prostatic hyperplasia within intraprostatic tissue surrounding a urethra is disclosed. The system includes an intraurethral catheter having an intraurethral catheter shaft. An antenna is located within the catheter shaft for delivering heat to the intraprostatic tissue surrounding the urethra. Coolant fluid is circulated through a chamber located between the catheter shaft and the urethral wall.

Abstract: A system for delivering radiofrequency energy to ablate cardiac tissue comprises a radiofrequency generator and an intravascular catheter. The catheter includes both a radiofrequency ablation electrode and a temperature sensor within its distal end. Delivery of power to the ablation electrode may then be controlled based on electrode temperature using a cascade control system wherein analog temperature controller adjusts the set point to a secondary power controller. Alternatively, power delivered to the patient can be controlled directly based on a power set point. Reuse of the catheter is prevented by a fuse within the catheter which is sensed prier to power delivery and broken prior to disconnection of the catheter.

Abstract: A non-contact type of deep-diathermy apparatus comprises a microwave source (1), a microwave radiator (2), a microwave focusing device (3), a temperature-measuring device (4) and a computer based control and display device (5). An output port of the microwave radiator (2) is spaced apart from a surface of a diathermized position of a medium to be diathermized by a predetermined distance. The microwave focusing device (3) is placed in front of the output port of the radiator (2) and attached to the output port of the radiator (2) for focusing the microwave from the radiator (2) on a point within the predetermined distance. This apparatus can be used to kill cancer cells or reduce their vitality in deep parts of the medium and will not cause the surface of the medium to be burnt.

Abstract: An apparatus and method are provided for control contraction of tissue that includes collagen fibers. The apparatus includes a handpiece, and an electrode with an electrode proximal end associated with the handpiece. A distal end of the electrode has a geometry that delivers a controlled amount of energy to the tissue for a desired contraction of the collagen fibers. This is achieved while dissociation and breakdown of the collagen fibers is minimized. The handpiece, with electrode, is adapted to be introduced through an operating cannula in percutaneous applications. Additionally, an operating cannula may be included in the apparatus and be attached to the handpiece. The apparatus and method provides for a desired level of contraction of collagen soft tissue without dissociation or breakdown of collagen fibers.

Abstract: An ablation apparatus has a balloon that is inserted into an organ of a body and ablates all or a selected portion of the inner layer of the organ. Electrolytic solution fills the balloon, and the balloon includes a plurality of apertures from which electrolytic solution flows from the balloon. The flow rate of electrolytic solution is dependent on the pressure applied to the balloon by the electrolytic solution. A conforming member, with a conductive surface and a back side, is made of a material that substantially conforms to a shape of the inner layer of the organ and delivers the electrolytic solution and RF energy through the conductive surface to the inner layer. Advantageously, difficult to access areas are reached with the inclusion of the conforming member. Optionally positioned between the conforming member and the balloon is a porous membrane.

Abstract: An ablation apparatus has an expandable member that is inserted into an organ of a body and ablates all or a selected portion of the inner layer of the organ. Electrolytic solution fills the expandable member, and the expandable member includes a plurality of apertures from which electrolytic solution flows from the expandable member. First and second fluid conduits, which can be first and second conforming members, are in a surrounding relationship to the expandable member. The second conforming member, including a conductive surface, is made of a material that provides substantial conformity between the conductive surface and a shape of the inner layer of the organ. A plurality of electrodes is positioned between the two conforming members. The expandable member serves as an insulator to RF energy. Each electrode includes an insulator formed on a surface of the electrode positioned adjacent to the second conforming member.

Abstract: A coaxial hyperthermia applicator for applying non-invasively electromagnetic energy to a body against which it is placed. The coaxial applicator antenna has formed integrally within it a non-invasive radiometric antenna for receiving thermoelectromagnetic emissions. The coaxial-configured applicator produces a bell-shaped radiation pattern symmetric about the axis of symmetry of the coaxial applicator. Integrating the radiometric antenna within the coaxial applicator produces a single device that performs dual functions. The first function is to transmit non-invasively energy for heating a subcutaneous tumor. The second function is to receive non-invasively thermal electromagnetic radiation from the tumor by which temperature is sensed and fed back to control the output of the coaxial applicator.

Abstract: An intraurethral, Foley-type catheter shaft contains a microwave antenna capable of generating a cylindrically symmetrical thermal pattern, within which temperatures are capable of exceeding 45.degree. C. The antenna, which is positioned within the shaft, is surrounded by means within the shaft for absorbing thermal energy conducted by the tissue and asymmetrically absorbing electromagnetic energy emitted by the antenna--a greater amount of electromagnetic energy being absorbed on one side of the shaft. This asymmetrical absorption alters the thermal pattern generated by the microwave antenna, making it cylindrically asymmetrical, which effectively focuses microwave thermal therapy toward undesirous benign tumorous tissue growth of a prostate anterior and lateral to the urethra, and away from healthy tissue posterior to the urethra.

Abstract: A balloon catheter is provided that includes a catheter shaft constructed for insertion into a blood vessel, a balloon mounted on the catheter shaft, and a heating device located within the balloon and arranged for heating fluid inside the balloon to permit heating of tissue by thermal conduction from the fluid to the tissue through a wall of the balloon. The balloon catheter is inserted into a blood vessel and the balloon is passed through the right atrium of the heart and into the coronary sinus of the heart. The balloon is inflated with the fluid, and the fluid is heated inside the balloon through use of the heating device, to cause heat to pass from the fluid to surrounding tissue by thermal conduction through the wall of the balloon.

Abstract: A system for delivering radiofrequency energy to ablate tissue comprises a radiofrequency generator and an intravascular catheter. The catheter includes both a radiofrequency ablation electrode and a temperature sensor within its distal end. Delivery of power to the ablation electrode may then be controlled based on electrode temperature using a cascade control system wherein analog temperature controller adjusts the set point to a secondary power controller. Alternatively, power delivered to the patient can be controlled directly based on a power set point. A sinusoidal RF signal is provided to avoid energy attenuation and the sinusoidal RF signal may be pulsed to avoid buildup of coagulum on the catheter tip while providing high power to create large lesions. A verification circuit checks the continuity of circuits in the catheter.

Abstract: A transurethral radio frequency apparatus for ablation of the prostate gland through the urethra formed by a wall, a probe consisting of a flexible elongate tubular member with proximal and distal extremities and sized so as to be adapted to be inserted into the urethra, and an ablation electrode carried by the distal extremity of the flexible elongate member. The flexible elongate tubular member is provided with first and second flow lumens for delivering a cooled fluid to the ablation electrode to cool the same. Means are connected to the probe to supply a coolant solution to the probe, to supply radio frequency energy to the electrode while it is being cooled, and to monitor the temperature of the ablation electrode so that the ablation electrode is maintained at a temperature below a predetermined temperature to spare the urethral wall from irreversible damage from the radio frequency energy delivered to the ablation electrode.

Abstract: A urethral probe having a front part and a rear part, and a microwave antenna connected to an external device for generating microwaves. The microwave antenna has its primary active heating part arranged in the urethral probe to be directed onto the prostatic tissues located at least at the level of the bladder neck in the working position.The urethral probe constitutes an essential element of a device for the therapeutic treatment of tissues by thermotherapy, more particularly tissues of the bladder neck of the bladder of a human being.

Abstract: A method and apparatus for noninvasively locating and heating a volume of tissue, specifically a cancerous tumor, including placing a bolus in contact with the patient and substantially around an area of interest including the volume of tissue, placing an array of antennas on the bolus and substantially around the area of interest, imaging the area of interest, selecting an approximate center of the volume of tissue on said initial image, determining appropriate amplitudes and phases for the antennas, energizing each element at respective appropriate amplitudes and phases to heat the volume of tissue, repetitively imaging the area of interest to create subsequent images, and subtracting said initial image from the subsequent images to determine temperature changes in the area of interest.

Abstract: An apparatus and method for treatment of conditions in which it is desired to simultaneously hyperthermally treat diseased target tissue in a patient and dilate a lumen of a patient which is compressed and/or obstructed by the diseased target tissue and/or surrounding tissue is disclosed.

Abstract: A hyperthermia treatment apparatus includes an annular radio frequency (RF) antenna array with bolus that is compatible with a magnetic resonance imaging (MRI) machine. Antenna elements polarized parallel to the axis of the cylinder are used for forming a Specific Absorption Ratio (SAR) map as well as for directing the energy to accomplish hyperthermia. The array may be dynamically controlled to focus energy at any specified region within the cylinder. The array is positioned inside an MRI machine and is tuned to the machine's hydrogen resonant frequency. For treatment planning, the array is employed to form an SAR map via RF current density imaging. Using this map, array phase, amplitude, and temporal weighting are optimized until the SAR maxima is congruent with the treatment volume. For treatment, RF radiation is applied to the subject to induce heating of the treatment volume using these optimal array parameters. Temperature is periodically determined via noninvasive MRI methods (i.e.

Abstract: An apparatus for the surgical treatment of tissues by thermal effect, in particular prostate, is disclosed comprising a urethral emitting probe having a front end and a rear end, capable of being inserted in the urethra, provided with microwave antenna located intermediate or in the vicinity of said front end, said microwave antenna being connected to an external microwave generating device, and working at a frequency and at a power effective to heat said tissues to a predetermined temperature for a period of time sufficient to treat said tissues by thermal effect.

Abstract: A system for treatment of benign prostatic hyperplasia within intraprostatic tissue surrounding a urethra is disclosed. The system includes an intraurethral catheter having an intraurethral catheter shaft. An antenna is located within the catheter shaft for delivering heat to the intraprostatic tissue surrounding the urethra. Coolant fluid is circulated through a chamber located between the catheter shaft and the urethral wall.

Abstract: An intraurethral, Foley-type catheter shaft contains a microwave antenna capable of generating a cylindrically symmetrical thermal pattern, within which temperatures are capable of exceeding 45.degree. C. The antenna, which is positioned within the shaft, is surrounded by means within the shaft for absorbing thermal energy conducted by the tissue and asymmetrically absorbing electromagnetic energy emitted by the antenna--a greater amount of electromagnetic energy being absorbed on one side of the shaft. This asymmetrical absorption alters the thermal pattern generated by the microwave antenna, making it cylindrically asymmetrical, which effectively focuses microwave thermal therapy toward undesirous benign tumorous tissue growth of a prostate anterior and lateral to the urethra, and away from healthy tissue posterior to the urethra.

Abstract: An MRI machine RF body coil is arranged so that it can also function as a hyperthermia treatment apparatus by arranging the RF body coil as an array of individual antenna element connected to each other by individually controllable switches and feedthrough elements.

Abstract: An apparatus for thermotherapy has a plurality of temperature sensors to control a temperature-elevating energy output for allowing temperature which is detected at the temperature sensors to be set to be within a predetermined temperature range. To this end, the apparatus is adapted to select one or a plurality of temperature sensors which are detected at different sites in an area including an affected region to be temperature-elevated, to compare measured data of the selected temperature sensor with predetermined temperature data and to control a temperature-elevating output on the basis of a result of comparison.

Abstract: An intraurethral, Foley-type catheter shaft contains a microwave antenna capable of generating a cylindrically symmetrical thermal pattern, within which temperatures are capable of exceeding 45.degree. C. The antenna, which is positioned within the shaft, is surrounded by means within the shaft for absorbing thermal energy conducted by the tissue and asymmetrically absorbing electromagnetic energy emitted by the antenna--a greater amount of electromagnetic energy being absorbed on one side of the shaft. This asymmetrical absorption alters the thermal pattern generated by the microwave antenna, making it cylindrically asymmetrical, which effectively focuses microwave thermal therapy toward undesirous benign tumorous tissue growth of a prostate anterior and lateral to the urethra, and away from healthy tissue posterior to the urethra.

Abstract: A device constituting a transrectal probe comprises a probe body made of a flexible self-supporting polymer material whose degree of flexibility is designed to enable it to comply with the shape of the rectum while having substantially no compression effect on the rectum when inserted therein; the degree of flexibility preferably being defined by a hardness on the Shore A scale of less than about 90. The invention makes it possible to achieve accurate, safe, and reliable positioning of an instrument for detection or therapeutic treatment level with an organ to be observed or treated, and in particular the prostate.

Abstract: A catheter shaft carries a coaxial cable, the terminal end of which contains a dipole antenna with opposing first and second helical elements. The first and second helical elements originate from a common connection to an outer conductor of the coaxial cable. The first and second helical elements are formed by winding flat wire around an outer insulator of the coaxial cable near a terminal end of the coaxial cable. A tubular-shaped capacitor is connected between an inner conductor of the coaxial cable and a point on the second helical element where the resistive component of the antenna's impedance matches the characteristic impedance of the coaxial cable. This match minimizes reflective losses of the antenna, thereby maximizing power transfer to the antenna. The antenna has an effective electrical length which is equal to one half the wavelength of the radiation emitted, independent of the physical length of the antenna.

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.