GB446660A - Improvements in electrodes for high frequency treatment - Google Patents

Abstract

446,660. Electro-medical apparatus. SIEMENS - REINIGER - WERKE AKT.- GES., 31, Karlstrasse, Berlin. Aug. 1, 1934, Nos. 22451 and 22452. Convention dates, March 20 and June 15. [Class 81 (ii)] Electro-medical apparatus for treatment in condenser fields comprises a generator of very high frequency oscillations, e.g. over 3 x 10<6>, one or more metal electrodes connected to the generator and a layer, preferably more than 10 mm. thick, of solid or liquid insulating material having a dielectric constant greater than 10 covering the face of the electrode applied to the object treated. Suitable insulating materials may consist of a mixture of water and glycerine (dielectric constant 20-30); the material known as Condensa or Condensa C (dielectric constant 40-80): distilled water (dielectric constant 80) or the material known as Kerfar (dielectric constant about 100). The layer is preferably deformable, in which case liquids or powdered solids are used, enclosed in an insulating casing, e.g. of rubber, the walls of which are thin in comparison with the powder or liquid layer. Solid deformable materials, such as wax, may be used in admixture with sufficient material of higher dielectric constant, e.g. Condensa C, to give the desired dielectric constant. The mean dielectric constant of materials such as oil may be similarly increased, or by the admixture of metal powder. Various constructional forms of electrodes are described, e.g. as shown in Fig. 1, the metal electrode 1 and its attached stem 2 are covered with insulating material 3 and union between the electrode and layer of insulating material is effected by spraying the upper surface 4 of the layer 5 with metal. Alternatively, the stem 2 may be prolonged below the surface of the electrode 1 and be embedded in the insulating material 5, or the surface of the electrode in contact with the layer 5 may be ribbed or corrugated. In this case, the insulating layer may be a deformable solid. Fig. 3 shows an arrangement in which the whole of the electrode 1 and stem 2 are covered with insulating material 3 and a deformable insulating casing 7, filled with powdered solid or liquid insulating material 5, is placed between the electrode and the subject treated. In the construction shown in Fig. 6, the insulating material 5 is enclosed within a rigid container 10, the metal electrode 1 resting on the insulation. The container 10 is closed by a cover 8 secured to the stem 2. The Specification as open to inspection under Sect. 91 describes also the use of insulating materials having a dielectric constant below 10 for example, oil, wax or the materials known under the name Calan or Registered Trade Mark, " Calit," " Frequentite," or " Mycalex." This subject-matter does not appear in the Specification as accepted.