US1973911A - Electrode for therapeutic devices - Google Patents

Description

Sept. 18, 1934' s. RUBEN 1,973,911

ELECTRODE FOR THERAPEUTIC DEVICES Filed 001;. 28 1933 IN VENTOR ATTORNEY Patented Sept. 18, 1934 UNITED STATES PATENT OFFICE Claims.

This invention relates to electrodes for use in therapeutic devices; specifically for use in connection with the application of high frequency currents to the body.

An object is to provide such an electrode which is' highly flexible and adaptable for use with any part of the body.

Another object of the invention is to provide such an electrode at a very low cost so that it may be destroyed after a single use or application.

A further object of the invention is to provide such an electrode which is light in weight and which has an adhesive surface so that it may be used with comfort by the patient.

Other objects will be apparent from the disclosure and from the drawing in which Figure 1 shows an electrode; partly cut away in section and Figure 2 is an end view of Figure 1.

Heretofore, there have been used for such applications, electrodes generally composed of lead sheet or foil which has been bent or formed into shape. In many uses, these electrodes have not been sufficiently flexible or adaptable for the specific purposes required. Furthermore,

these electrodes have been limited in the maximum current applicable, due i localized contact and contact resistance.

I have found that by utilizing a flexible and plastic electrode composed of a non-fibrous cellulose sheet which has been rendered highly conductive by plasticization and impregnation with a conductive material such as glycol, glycerol or glycol borate and then rendered adhesive by the addition of a mucilaginous material, that a light weight and universally applicable electrode can be made, capable of allowing the application without skin burns, of currents of greater magnitude than heretofore possible.

In order tohave .minimum internal electrode resistance and to more uniformly distribute the applied current over the entire electrode area, a very thin tin foil sheet is cemented on one side of the conductive cellulose sheet.

The flexible sheet material used is preferably a non-fibrous regenerated cellulose such as is popularly designated cellophane although other materials such as Kodapak or Protectoid (cellulose acetate sheets), sheet gelatin or porous membranes may be used in combination with proper plasticizing conductive and adhesive compounds. The practically non-porous cellophane, however, has given the best results to date.

In the preparation of the material, the cellophane" is preferably plasticized by immersion in an aqueous glycol or glycerol compound. It is then passed through and impregnated with a heated conductive compound such as glycol or glycerol borate with which is combined an adhesive such as water soluble glue, gum arabic, gelatin or other mucilaginous material. Additional adhesive may be brushed on after impregnation in which event it combines with the impregnated cellophane and itself becomes conductive.

The glycol or glycerol borates are preferred as the active conductive materials because of their low vapor pressure and because of their hygroscopic character which tends to maintain the cellulose in plastic conductive condition; however, other compounds such as the chlorides, phosphates, etc., may be substituted.

On one side of this flexible conductive cellophane sheet is then cemented a very thin metal foil, preferably tinfoil of a thickness of approximately 0.00025". The cellophane itself is preferably about 0.001 thick, and its adhesive surface affords a good cement for the foil.

This combination of conductive plastic mate-' rial and adhesive, allows the electrode to be placed on any part of the body and affords an intimate contact with the skin, thus allowing a minimum contact resistance drop and maximum distribution of current over the entire contacting area. The adhesive character of the material is such that the electrode weight is easily sustained and intimate contact during treatment is obtained without the use of binding straps or other commonly used accessories.

In Figure 1 of the drawing, tin foil (1) is cemented on impregnated plasticized cellophane (2) the adhesive surface of which (3) makes contact with the body of the patient (not shown).

In Figure 2, like numbers indicate like parts.

What I claim as new and desire to secure by Letters Patent, is

1. A flexible surface electrode for therapeutic purposes comprising an electrically conductive non-fibrous organic sheet plasticized with a ma-' terial chosen from the glycol and glycerol compounds, said sheet being adapted to be directly applied to the human body, and a metal backing conductively cemented on said sheet.

2. A flexible surface electrode for therapeutic purposes comprising an electrically conductive non-fibrous organic sheet plasticized with a material chosen from the glycol and glycerol borate compounds, said sheet being adapted to be directly applied to the human body, and a metal backing cemented on said sheet.

pounds, said sheet being adapted to be directly applied to the human body, and a metal backing conduct-ively cemented on said sheet.

5. A flexible electrode for therapeutic purposes comprising an electrolyte impregnated membrane sheet material having a metal foil backing conductively cemented to one surface thereof and having on its other surface a water soluble mucilaginous adhesive adapted to be directly applied to the human body.

SAMUEL RUBEN.

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