GB429486A - Improvements in and relating to electrodes for therapeutic purposes, in particular for short wave treatment - Google Patents

Abstract

429,486. Electro-medical appliances. LAST, E., 32, Schottenring, Vienna. Nov. 30, 1934, Nos. 34443 and 34444. Convention dates, Jan. 10. [Class 81 (ii)] An electrode for therapeutic purposes, particularly for short-wave treatment, consists of an insulating intermediate layer of approximately uniform thickness moulded to conform to the surface treated and a metal coating fitted to outer surface of the insulating layer, the whole, together with an outer protective coating if desired, forming a stiff mask. The insulating layer may consist of a mass capable of being moulded and hardened, such as plaster of Paris, rubber &c. A mixture of fibrous material with hardening binders which forms a porous unbreakable body like stiff felt may also be used, e.g. a mixture of gypsum, fibrous matter, rubber, hair and colophony is suitable. Textile layers may be incorporated in the layer to reinforce it. The electrode itself consists of metal foil, e.g. tin, lead, aluminium, of wire gauze or a thicker sheet of metal if the configuration of the surface permits. If it is desired to produce a greater or lesser heating effect in certain areas, the insulating layer may be made of materials of differing dielectric constants, or its thickness may be varied. The insulating layer may also be separated from the treated surface by an air space, and the layer and air-space may be of non-uniform thickness, provided that the metal electrode is uniformly spaced from the surface to be treated. Fig. 1 shows an electrode with a solid intermediate layer, which is formed by applying a layer 2 of suitable material upon the surface 1 to be treated or on a positive cast thereof. After hardening, a metal coating 3 is applied to its outer surface. The metal coating can then be covered by an insulating lacquer, textile &c., or may be provided with a thicker coating 4 to protect it from mechanical injury. Fig. 2 shows an electrode in which the insulating layer 2 is separated from the treated surface 1 by distance pieces 5 leaving an air space 9 between, and is made in a similar manner, except that the insulating material 2 is deposited on an auxiliary layer of easily removable material such as wax or gelatine, the thickness of which corresponds to the thickness a of the air space. If the insulating layer is thin, the whole structure is strengthened by an outer coating 4 in which the distance pieces 5 may be embedded. In the construction shown in Fig. 4, the distance pieces 1 required for the air space 9 are fo:rmed by continuing the marginal portion 5<1> of outer protective layer 4 right up to the surface to be treated. The recesses 7 which allow access of air may be formed during the moulding of the layer 4 or by removal of material from the hardened margins of the layer 4. The studs 11 left between the recesses 7 thus act as distance pieces for the intervening air space.