Abstract: The use of an externally located dipole array mounted upon a high dielectric material for heating biological tissues is disclosed. This dipole array provides improved flexibility and adaptability to varying tissue surface contours. The adjustable dipole antenna array or other type of electromagnetic antenna applicators provides an ability to adapt the heating pattern to meet the needs of the different tissue zones, applicator positions, and applicator mechanical scanning by adjusting individual power amplitude and phase to the various elements of the applicator array for controlling the heat distribution of heat in target tissue having areas of varying power absorption and cooling effect (blood flow). The array design may also include capacitively coupled metal elements in the form of strips, patches or tubes.

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 antenna type applicator, and a microwave type temperature sensor for measuring the temperature of the prostate tissue, and an open fluid receiving tube. A microwave generator supplies electromagnetic energy to the applicator. A comparator is connected to the temperature sensor and a temperature reference potentiometer for comparing the actual tissue temperature level with a desired temperature level and outputting control signals to the microwave generator for controlling the output to the applicator. The coil type applicator is an elongated coil having a tip end connected to the center conductor of a coaxial cable and an opposite end connected to the outer conductor of the coaxial cable.

Abstract: The hyperthermia treatment apparatus includes an invasive microwave array of applicators with destructive and coherent phase. The desired power phase shift is obtained either by (1) insertion of pre-calibrated phase shift modules or cables, (2) adjustment to the phase of an in-line electronic phase shifter, (3) adjustment of mechanically movable phase shifters such as ferrite or sliding length coaxial line stretchers. A computer provides the proper selection of radiated power for each applicator using a look up table of pre-treatment planning software calculations, and the adjustment of power levels to that determined by the pre-treatment plan. At least one applicator is centrally located with respect to applicators located peripherally.

Abstract: A hyperthermia apparatus includes a hyperthermia treatment subsystem, and a receiver subsystem combined to use jointly the parts common to both subsystems. The hyperthermia and receiver subsystems include, respectively, a power source and radiometer connected to a switch controlled by a central processing unit (CPU) to selectively connect either the power source and the radiometer to the common parts to complete the subsystems as follows. A power divider having output ports for feeding electromagnetic energy through a plurality of applicator circuits each circuit including a phase shifter connected to the power divider, a power regulating switch connected to the phase shifter, and an applicator connected to the power control switches. The power regulating switches are controlled also by the CPU.

Abstract: An electromagnetic hyperthermia system for heating local regions of body tissue wherein the system includes a source of electromagnetic radiation connected to a power divider for distributing radiation to several power control devices that control the electromagnetic radiation transmission. Each of the power cotrol devices is connected to several radiation applicators. The radiation applicators include the capability for capacitively coupling radiation into body tissue and further include a sensor that provides an indication of adjacent body tissue temperature. A data processor is connected to the source, the power control apparatus and the temperature sensors and control the amount of heat in accordance with a desired heating pattern.

Abstract: A system and corresponding method for creating hyperthermia in target tissue has a computer control for applied electromagnetic radiation (EMR) in the HF, VHF and UHF microwave region. A real time thermal profile of the target and electric field readings provide feedback to the control. The frequency, amplitude, and relative phase of the EMR can be varied as necessary to create desired hyperthermia heating patterns in the target. The system utilizes controlled constructive interference between EMR emitted by several applicators in order to provide improved heating in the central regions of 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.

Abstract: An applicator for radiating electromagnetic energy to local regions of body tissue where the applicator includes a radiation apparatus that emits electromagnetic radiation into the body tissue and further includes a temperature sensing apparatus that provides an indication of the adjacent body tissue temperature. In an embodiment, the applicator includes a thermistor connected between the center conductor and an outer conductor of a coaxial cable where the center conductor extends beyond the extension of the outer conductor for radiating electromagnetic energy. In another embodiment, a method is provided for operating the radiation applicator including the temperature sensor whereby direct current is provided across the applicator and the resulting direct current voltage is measured. The applicator is then supplied intermittently with high frequency electromagnetic energy.

Abstract: A body passage or cavity insertable applicator apparatus for electromagnetic radiation (EMR) systems, particularly for medical hyperthermia use, comprises an elongate applicator having coaxial inner and outer conductors electrically conducted at an EMR input end to a conventional coaxial transmission line for transmitting high frequency EMR from a source to the applicator. The applicator outer conductor is longitudinally split on opposite sides to form first and second outer conductor segments, the inner conductor being electrically connected, at an applicator termination end to one of such segments. A dielectric media is disposed between the applicator inner and outer conductors, and the outer conductor and termination end are covered by a dielectric sheath.

Abstract: An electric field probe array including several dipole probes, each including a diode connected between two conductors with the diodes being collectively connected to at least two probe terminals. Also disclosed is a system for heating a target with electromagnetic radiation that includes a central control unit, a source coupled to the control unit with the source generating the electromagnetic energy at a frequency and power in response to the control unit, a radiation apparatus coupled to the source for transferring the electromagnetic energy from the source to the target and input circuitry connected to the control unit for indicating the status of the target whereby the operation of the system is controlled by the control unit as a function of the target's status.

Abstract: A system and corresponding method for creating hyperthermia in target tissue has a computer control for applied electromagnetic radiation (EMR) in the HF, VHF and UHF microwave region. A real time thermal profile of the target and electric field readings provide feedback to the control. The frequency, amplitude, and relative phase of the EMR can be varied as necessary to create desired hyperthermia heating patterns in the target. The system utilizes controlled constructive interference between EMR emitted by several applicators in order to provide improved heating in the central regions of 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.

Abstract: A system and corresponding method for creating hyperthermia in target tissue has a computer control for applied electromagnetic radiation (EMR) in the HF, VHF and UHF microwave region. A real time thermal profile of the target and electric field readings provide feedback to the control. The frequency, amplitude, and relative phase of the EMR can be varied as necessary to create desired hyperthermia heating patterns in the target. The system utilizes controlled constructive interference between EMR emitted by several applicators in order to provide improved heating in the central regions of 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.

Abstract: A method is described for selecting an electromagnetic radiation (EMR) frequency causing substantially uniform heating in cylindrical biological tissue specimens, having a typical cross-sectional dimension, d, and known electrical properties, by an annular applicator configured for applicator-specimen impedence matching. Accordingly, an annular applicator system (10) comprises an EMR source (32) having a selected frequency wavelength in a specimen (20) between two-thirds and twice the specimen dimension, d. Connected to the source (32) is an annular applicator apparatus (12) formed of four applicator segments (16), circumferentially arranged to form an axial specimen receiving opening (18). A composite EMR emitting aperture (22), formed around the opening (18) has an axial height to circumferential width ratio causing matching, at the selected frequency, between a characteristic impedance of the apparatus (12) and a load impedance of the specimen (20) as seen through the aperture.

Abstract: Invasive hyperthermia apparatus includes an electromagnetic energy radiation source, and a plurality of applicators. Each applicator is adapted for insertion into body tissue and radiating electromagnetic energy therein. Interconnected between the applicators and the radiation source are a power splitter and a plurality of line stretchers for providing the applicator with electromagnetic energy in a preselected frequency - phase power relationship. The applicators, power splitter and line stretchers are operative for causing constructive interference between emitted electromagnetic radiation when the applicators are inserted into body tissue in a preselected spaced apart relationship.