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 balloon angioplasty device includes a microwave antenna, a catheter and a transmission line disposed through the catheter and coupled to the antenna. The device further includes a balloon coupled to the catheter and a mode filter disposed about the antenna.

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 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 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: The invention relates to a bipolar radio-frequency surgical instrument with a rigid tube shaft (11) and a working tip (12) which preferably has substantially the same cross-section as the adjoining part of the tube shaft (11) and is preferably centrally provided with at least one working electrode, such as a cutting electrode (13, 13") or a coagulating electrode (13') which can be energized with a radio-frequency voltage, and a neutral electrode (14) which preferably has a significantly larger surface. The working tip (12) is connected with the rigid tube shaft (11) near the distal end of the instrument in a hinged or flexible manner in such a way that the working tip (12) can be pivoted from a position which is axially aligned with the tube shaft (11) to a position which forms an angle relative to the tube shaft (11), and such that means (17, 18, 19) are provided to pivot and return the working tip (12).

Abstract: An R.F. hyperthermia phased array applicator uses adaptive nulling and focusing with non-invasive electric field probes to control the electric field intensity at selected positions in and around a target body to provide improved heating of solid tumors during hyperthermia treatment. A gradient search or matrix inversion algorithm is used to control the amplitude and phase weighting for the phased array transmit elements of the hyperthermia applicator. A 915 MHz monopole phased array hyperthermia applicator for heating brain tumors has an enclosed vessel including a plurality of monopole transmit antenna elements disposed as a circular arc array on a ground plane which has an aperture for positioning the tumor in proximity to the monopole antenna elements. Adaptive focusing with non-invasive electric field probes is used to maximize the electric field at the tumor site. Parallel plate microwave waveguides are used to direct R.F. energy from the monopole phased array to the tumor site.

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 ablation catheter is disclosed that include a mechanism for altering the impedance of the antenna during use in a controlled manner to tune the catheter. The impedance tuning may be accomplished in a variety of manners including altering the electromechanical configuration of the antenna and moving a material relative to the antenna or vice versa in order to vary the effective impedance during use. In a preferred embodiment, the ablation catheter transmits energy in the microwave frequencies and uses a coaxial transmission line as its waveguide. The antenna is preferably helical in nature and is carried by the distal end of the transmission line.

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 method and apparatus for determining accurately, both during and after insertion, the full length position of catheters (including implanted ports (64)), tubes (30) and placement guidewires (22) within biological tissue is disclosed including a transmitter/detector unit (2) having an alternating current (AC) radio-frequency (RF) transmitter with antenna (14), and a radio signal transmitter in the form of a continuous or segmented fine wire receiving antenna (28, 32, 74) situated along the full length of the catheter, guidewire, and implanted port assemblies (22, 30, 64). The guidewire apparatus also includes a tip antenna. These antennae are connected by a removable clip (18) to a wide-band RF detector circuit, situated within the transmitter/detector unit (2). The RF transmitter/detector circuit provides a voltage output that is a direct function of the relative spatial proximity of the transmitting antenna.

Abstract: The invention relates to a device for application of hyperthermia in a particular body using microwaves. The device comprises a wire antenna (1) supplied with microwave energy or, upon switching, acting as a radiometric probe, a sleeve (2) enabling the wire antenna to be thermostatted and a Foley-type catheter (3) removably mounted so as to encompass the assembly thus constituted, the catheter enabling this assembly to be positioned in relation to an opening for insertion into the particular body and being the sole disposable part in order to ensure good hygiene of the hyperthermia session. A connection module (4) allows the interconnection both of the wire antenna, from the radio-frequency point of view, and of the sleeve and the catheter, from the hydraulic point of view. Application to thermotherapy or to the thermal treatment of certain bodies is thus provided.

Abstract: A cardiac ablation apparatus including a solenoidal antenna, monitoring electrodes, and a coupling network at a distal end of a catheter transmission line, and another coupling network at the proximal end of the catheter transmission line to connect the catheter to the source of radiofrequency (RF) power and to an intracardiac electrogram monitor. Solenoidal antenna design includes single and multiple windings with varying geometrical features. Plated plastic tri-axial design of a transmission line offers unitary fabrication. A catheter with variable impedance electrode and gap coatings has features useful for both ablation and for hyperthermia applications.

Abstract: In an electromagnetic-wave-operated heating apparatus in which, with a body to be heated such as a living body inserted into the cavity resonator incorporating at least one reentrant, an electromagnetic wave produced by high frequency energy supplied into the cavity resonator is used to heat the body; an electric field concentrating member is provided between the reentrant and the body in such a manner that the electric field concentrating member is provided to be electrically disconnected to the reentrant, whereby, under an ordinary condition that the body held in the apparatus is not in parallel with the end face of the reentrant, a deep portion of the body can be heated with high efficiency.

Abstract: An antenna assembly has an energy propagating region that is encapsulated in a material having a high dielectric constant for minimizing the loss of energy while having a high thermal conductivity for dissipating conductive heat patterns about the energy propagating region.

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: Method and apparatus for in vivo or in vitro selective deposition of microwave power patterns in lossy dielectric materials, particularly biological tissue. Configured as a needle-like probe, a miniature coaxial cable (1) having a circumferential gap (12) in the shield (2) is wrapped with an electrically thin dielectric substrate (18). The cable center conductor (6) extends immediately past gap (12) and is shorted to cable shield (2). A thin conductive dipole resonator (21) is positioned on substrate (18) and over gap (12) to achieve inductive coupling between the cable center conductor (6) and the dipole resonator (21) through gap (12). The ends of the dipole resonator (21) are capacitively (22) loaded so as to make the current on resonator (37) more uniform and to greatly reduce and stabilize the resonant frequency to be essentially insensitive to the dielectric properties of the surrounding material.

Abstract: A tuner system for a microwave power supply used in an ablation catheter system is disclosed. The tuner system includes a tuner arranged to facilitate matching the impedance of a power generator side portion of the catheter system with the impedance of a catheter side portion of the catheter system. A reflected power monitor is also provided for monitoring the amount of power that is reflected from the catheter during use. In a preferred aspect of the invention, the tuner is used in a power supply that includes a microwave power source and is used in conjunction with a catheter having a coaxial transmission line and a helical antenna. In a method aspect of the invention, a method for medical treatment using a microwave ablation catheter system is disclosed.

Abstract: A microwave radiator formed of a radioactive substance and adapted to simultaneously deliver microwave energy and nuclear radiation to living tissue. The radiator is incorporated into an interstitial or intracavitary probe. The radiator is a helical electrical conductor, formed of a radioactive substance such as iridium.sup.192, and electrically connecting a central electrical conductor to a coaxial electrically-conducting jacket.

Abstract: The antenna system of the invention is insulated on the outside and when inserted in a dissipative medium has a fixed complex resistance. When the antenna is supplied with HF energy through a coaxial cable, only that area of the medium immediately around the antenna is heated. The area surrounding the insulated HF feed line is not heated, or such heating is negligible, since, owing to the fixed complex resistance of the antenna in the medium, any return of energy along the feed line is prevented. The antenna system of the invention is suitable for use in the tumor-therapy field as a hyperthermic microwave applicator for limited local heating of cancerous tissue.

Abstract: The invention discloses an antenna arrangement with a supply line in the form of a coaxial cable arrangement suitable for high frequencies, in particular for medical applications of heat in hollow parts of the body, an extrusion process for the production thereof, a dilatation catheter with the antenna arrangement and a procedure for a dilatation treatment. The coaxial cable arrangement comprises a continuous inner conductor, an insulator arranged cylindrically around the inner conductor, a shielding device applied around the insulator in a first section of the coaxial cable arrangement which begins at the proximal end of the coaxial cable arrangement, a second section beginning at the distal end of the first section of the coaxial cable arrangement and ending at the distal end of the coaxial cable arrangement, said second section serving as an antenna and being designed without an insulator or a shielding device around the continuous inner conductor.

Abstract: A method for the treatment of the prostate gland which heats the tissues which would otherwise be surgically removed with a trans-urethral resection of the prostate. This method is accomplished by combining a radiating energy device integrated with a urinary drainage Foley type catheter, which is modified to provide cooling along the urethra surfaces. The radiating device also serves as a means to measure the tissue radiated thermal energy for the control or monitoring of temperature of the prostate tissues being heated. A urethral inserted applicator for prostate hyperthermia includes a multi-tube, balloon type catheter. The catheter includes a fluid dry tube for an energy radiator antenna applicator which also serves as a radiometric temperature sensor for measuring the temperature of the prostate tissue, and an open fluid receiving tube. An electromagnetic energy generator supplies electromagnetic energy to the applicator.

Abstract: A method of selectively treating interstitial tissue following microwave thermal therapy includes an intraurethral Foley-type catheter shaft. The catheter shaft contains a microwave antenna which is capable of generating a cylindrically symmetrical thermal pattern in tissue, within which temperatures are capable of exceeding 45.degree. C. The antenna is surrounded by means within the shaft for asymmetrically absorbing electromagnetic energy emitted by the antenna so as to concentrate thermal energy on a first side of the shaft. This asymmetrical absorption alters the thermal pattern generated by the microwave antenna, making it possible to focus microwave thermal therapy toward undesirous tissue and away from healthy tissue. The absorption means is also capable of absorbing heat from adjacent tissue by thermal conduction. Operation of the absorption means upon the conclusion of microwave thermal therapy aids in reducing edema of the treated tissues caused by the elevated temperatures of those tissues.

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 improved assembly for steering and orienting a functional element at the distal end of a catheter tube holds the functional element with its major axis aligned with the axis of the catheter tube for convenient steering to a tissue site. The mechanism can also pivot the functional element in response to an external force to orient the major axis of the functional element generally parallel to the plane of the tissue site, without bending the catheter tube.

Abstract: A radiant heating apparatus for deployment within an animal body to radiate heat-producing electromagnetic energy into the body includes an antenna mounted on a catheter element and connected to an electrical transmission line having first and second conductors for feeding electrical current from a source to the antenna. The apparatus has the improvement in which the antenna comprises a first radiating element carried on the catheter element and extending from an antenna feed junction in a first direction along a first elongation axis. The first radiating element is connected to the first transmission line conductor at the feed junction and presents a first selected impedance to the feed junction. A second radiating element is carried on the catheter element and extends from the feed junction in a second direction opposite to the first direction along the first axis.

Abstract: A urethral inserted applicator for prostate hyperthermia includes a multi-tube, balloon type catheter. The catheter includes first and second closed end fluid dry tubes, respectively, for a helical coil electrode type applicator, and an electromagnetic field compatible temperature sensor for measuring the temperature of the prostate tissue, and an open fluid receiving tube enabling urine drainage from the bladder. A radiofrequency source supplies electromagnetic energy to the applicator. A control unit contains a comparator which is connected to the temperature sensor and a temperature reference device for comparing the actual tissue temperature level with a desired temperature level and output control signals to the radiofrequency generator for controlling the output to the applicator. The coil type applicator is an elongated coil connected to the center conductor of a coaxial cable.

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