Abstract: A resonant radio frequency diathermy heat applicator, including a flexible pad, an inductive coil with moderate defined resistance, fixed tuning capacitors, connecting cable and shielding that is broadly tuned to the signal source in a manner that eliminates the requirement for variable tuning elements.

Abstract: The present invention pertains to the field of medical diathermy and addresses issues of incidental undesired radiation in the prior art. The invention uses a multitude of pairs of intentional radiators with each pair driven with an identical but out-of-phase signal. The pairs or radiators are spaced near the target tissue in close proximity to the target but sufficiently distant from each other so as not to cancel the nearby tissue heating effects. Local heating of tissue is achieved by the high electric and magnetic field intensities coupling and inducing electric currents in conductive tissue.

Abstract: A therapeutic diathermy applicator is proposed which minimizes the common problem of burning of patients' skin. The heat distribution arising as a result of unwanted capacitive effects is modeled as a manifestation of ‘conservative’ energy. A specific spatial characteristic of RF stimulation is determined and incorporated into the design of the applicator in order to achieve these goals.

Abstract: A diathermy apparatus includes a cylindrical coil (24) defining an opening (42), a pair of capacitors of substantially similar capacitance (20 and 22), each capacitor connected to one end of the coil, an RF signal source (26), and a balun (28) connected between the RF signal source (26) and the pair of capacitors (20 and 22). The balun (28) is operative for converting an unbalanced signal received from the RF signal source (26) into a balanced signal supplied to coil (24) via the pair of capacitors (20 and 22). Desirably, the cylindrical coil is a conical cylindrical (or cone-shaped) spiral coil.

Abstract: A resonant radio frequency diathermy heat applicator, including a flexible pad, an inductive coil with moderate defined resistance, fixed tuning capacitors, connecting cable and shielding that is broadly tuned to the signal source in a manner that eliminates the requirement for variable tuning elements.

Abstract: A therapeutic diathermy applicator is proposed which minimizes the common problem of burning of skin patient. The heat distribution arising as a result of unwanted capacitive effects is modeled as a manifestation of ‘conservative’ energy. A specific spatial characteristic of RF stimulation is determined and incorporated into the design of the applicator in order to achieve these goals.

Abstract: An applicator supplying RF power for therapeutic diathermic treatment of a patient includes a radiation shielding device for shielding the applicator against misapplication of radiation to objects in the surroundings and unintended areas of the patient's body, and a coupling device for electrically coupling the radiation shielding device to at least one point of the body of a patient in a low impedance manner that reduces the potential drop from the grounded radiation shield to the body tissue.

Abstract: A diathermy apparatus includes a cylindrical coil (24) defining an opening (42), a pair of capacitors of substantially similar capacitance (20 and 22), each capacitor connected to one end of the coil, an RF signal source (26), and a balun (28) connected between the RF signal source (26) and the pair of capacitors (20 and 22). The balun (28) is operative for converting an unbalanced signal received from the RF signal source (26) into a balanced signal supplied to coil (24) via the pair of capacitors (20 and 22). Desirably, the cylindrical coil is a conical cylindrical (or cone-shaped) spiral coil.

Abstract: An applicator supplying RF power for therapeutic diathermic treatment of a patient includes a radiation shielding device for shielding the applicator against misapplication of radiation to objects in the surroundings and unintended areas of the patient's body, and a coupling device for electrically coupling the radiation shielding device to at least one point of the body of a patient in a low impedance manner that reduces the potential drop from the grounded radiation shield to the body tissue.

Abstract: Disclosed is a method and apparatus for combining a plurality of television signal channels which are immediately adjacent in frequency to each other. A main transmission line transmits a plurality of television signals therethrough in a predetermined direction of transmission. The visual signal of a first of the television channels is inserted into the main transmission line in the predetermined direction. The visual signal of a second, immediately adjacent television channel is then inserted into the main transmission line in the predetermined direction, using a frequency band otherwise occupied by the aural signal of the first television channel as a guard band to separate the combined visual signals of the first and second television channels.

Abstract: A high power tube in applications requiring reduced AC hum in the amplified signal, utilizes a direct current heated filament. In order to reduce the incidence of tube failure and maintain a stable mode of operation, the direct current is produced by a regulated source of DC voltage. The regulated source includes a transformer having a primary winding coupled to a source of alternating line voltage and also includes a secondary winding at which a transformed low voltage is generated. A rectifier is coupled to the secondary winding for rectifying the transformed voltage to produce a pulsating direct voltage which is applied to the tube filament by a filter. The primary winding of the transformer is coupled to the AC source by means of a saturable reactor. A control circuit senses the voltage across the filament and controls the reactor in a feedback manner.