Electrocardiograph Electrode

Abstract

An electrode for an electrocardiograph comprising a reinforced base sheet having the underside thereof coated with a pressure sensitive adhesive and protected by a thin layer of removable paper. A snap fastener comprising a male and female portion extends through the center of the base sheet with the male portion of the snap fastener being firmly attached to the base sheet. The contacting surfaces of the male and female portion of the snap fastener are provided with a plurality of alternating grooves and ridges to increase the contact area and to prevent relative rotation of the respective male and female portions. A screen or sponge is attached to the underside of the male portion of the fastener and may be the fastener and may be impregnated with an electrically conductive jelly. The female portion of the fastener is mounted into a housing designed for easy gripping with the fingers.

Description

This invention relates in general to the art of electrocardiography and in particular to a new and improved electrode to be attached to the human body in order to pick up and convey electrical impulses to the recording instrument generally referred to as an electrocardiograph.

The electrocardiograph is an instrument designed to record the electromotive force generated by the heart muscle preliminary by the physical contraction of the muscle.

In recording the graph the differences in electrical potential of two points on the surface of the body are measured. This is accomplished by electrodes which may be placed on the extremities of the body and on the chest. The electrode on the right leg usually acts as a ground while other electrodes are utilized in a definite sequence to record the various sections of the completed tracing. Normally, the highest potential difference or the peak of the highest wave recorded by the electrocardiograph is in the order of from 0.70 to 1.80 millivolts.

It will thus be appreciated that the electrodes employed to pick up and convey the small potential differences, as above indicated, must be extremely accurate and ensure good contact with the human body as well as provide for good electrical conduction within the electrode.

It is accordingly an important object of the present invention to provide for an electrocardiograph electrode which ensures positive contact with the human body.

Another object of the instant invention is to provide for an electrode of the above type which has substantially improved electrical conductivity between its constituent parts.

A more specific object of the instant invention is to provide an electrode wherein the leads can be quickly and effectively disconnected from the portion of the electrodes attached to the body by means of a snap fastener.

Yet another object of the instant invention is to provide an electrode including a quick disconnect snap fastener and in which the connecting conductive surfaces of the snap fastener are provided with a plurality of alternating minute grooves and ridges to ensure complete electrical conductivity between the male and female parts of the snap fastener and to prevent relative rotation therebetween.

A further object of the present invention is to provide an electrode for an electrocardiograph including a snap fastener and in which the female part of the fastener is mounted into relatively heavy housing to accommodate easy gripping by the fingers of an operator.

A still further object of the present invention is to provide an electrode for an electrocardiograph including a snap fastener in which the electrical current is transmitted from the human body to the snap fastener by means of a screen member of electrically conductive material or combined with or replaced by a sponge impregnated with an electrically conductive jelly.

These and other objects of the present invention will appear from time to time particularly when reference is made to the accompanying drawings and specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of the electrode of the present invention;

FIG. 2 is a plan view of the structure indicated in FIG. 1;

FIG. 3 is a plan view taken substantially along lines A-A of FIG. 1;

FIG. 4 is a plan view taken substantially along the lines B-B of FIG. 1; and

FIG. 5 is a bottom plan view taken in the direction of the arrow C as shown in FIG. 1.

As shown in FIG. 1, the device of the instant invention comprises a circular sheet of paper 10 having a predetermined relatively large diameter 11. Concentrically attached to the sheet of paper 10, on the upper side thereof, is a sheet of reinforcing paper 12 having an outer diameter 13. Both sheets of paper 10 and 12 have a central common circular opening of equal diameter as indicated by the numeral 14.

The two sheets of paper 10 and 12 are clamped between the metal portions 15 and 16 which form the male portion of the snap fastener 17 which is of generally circular configuration. The portion 15 of the male portion of the snap fastener protrudes through the central opening 14 and through the sheets of paper 10 and 12 and is firmly clamped to the portion 16 of the male portion of the snap fastener 17. In this manner, both sheets of paper 10 and 12 are firmly secured at their center to the male portion 15--16 of the snap fastener 17. The snap fastener 17 also comprises a female portion 18 which may be snapped over the male portion 15--16 of the fastener 17 in a manner well known to those skilled in the art.

Fixedly attached to the female portion 18 of the snap fastener 17 is a relatively heavy metal housing 19 which is of sufficiently large size to enable easy gripping with the fingers. This relatively heavy housing 19 is preferably made of brass to ensure good electrical conductivity. Attached to the gripping portion 19 is an electrical connector means 20 to which electrical cables may be suitably connected for conveying electrical currents to the electrocardiograph recording device.

As shown in FIG. 2, the sheets of paper 10 and 12 are preferably of circular configuration but it should be understood that any desirable configuration may be employed. Also, the gripping piece 19 is preferably made of circular configuration but square or hexagonal configurations may also be employed.

As further shown in FIG. 1, the underside of the circular sheet of paper 10 has attached thereto, an annular sheet of paper 21 which has an outer diameter equal to the diameter 11 of the sheet of paper 10 and an inner diameter 22 having a diameter of approximately one-half of the outer diameter 11.

The underside of the sheet of paper 10 is coated with a pressure sensitive adhesive and the annular sheet of paper 21 merely performs the function of protecting the pressure sensitive adhesive coated to the underside of the sheet of paper 10. As shown in FIG. 5, the annular sheet of paper 21 is cut along the line 23 so that it may be easily stripped from the underside of the sheet of paper 10 whereupon the sheet of paper 10 may be firmly adhered to the human body.

As further shown in FIG. 1, a screen 24 is mounted to the underside of the sheet of paper 10. Screen 24 has an outer diameter approximating the inner diameter 22 of the annular sheet of paper 21 and is firmly attached to the underside of the paper sheet 10 by means of the pressure sensitive adhesive previously discussed in connection with paper sheet 10.

The screen 24 serves the important function of conducting the electrical current from the human body through the snap fastener 17 and the gripping portion 19 to the electrocardiograph instrument. The screen 24 is urged into firm contact with the human body by means of the sheet of paper 10 the underside of which is coated with a pressure sensitive adhesive as previously described. In order to increase the conductivity of the screen 24 the screen may be impregnated or coated with an electrically conductive jelly or may be made of metal with or without the electrically conductive jelly.

Other devices may be substituted for the screen 24 such as, for example, a sponge pad impregnated with an electrically conductive jelly. Additionally, such a sponge pad may be used in connection with the screen 24 to increase the electrical conductivity of the entire device.

It will thus be seen that with the use of the screen 24 or its corresponding substitute in the form of a sponge proper electrical conductivity is obtained between the human body and the male portion of the snap fastener 17. It will, of course, be appreciated the connection between the male portion 15--16 of the snap fastener 17 and the female portion 18 thereof, must be equally effective in order to ensure proper recording of the electrical impulses generated by the human body. It is therefore extremely important that the connection between the male and female portions of the fasteners 17 are made in such a manner to ensure the greatest possible amount of electrical conductivity obtainable.

Accordingly, as shown in FIGS. 3 and 4, the contacting surfaces of the male and female portions of the snap fastener 17 are provided with a plurality of alternating grooves and ridges, the grooves being indicated by the numeral 25 and the ridges being indicated by the numeral 26. The grooves and ridges perform a dual function in that they provide for additional surface area between the male and the female contacting portions of the snap fastener 17 and more importantly they prevent the male and the female portions from rotating with respect to one another. The increased contact area provided by the grooves and ridges 25 and 26, respectively, increases the amount of electrical conductivity between the male and female portions of the snap fastener 17, while their function of preventing the respective male and female portions from rotating with respect to one another ensures electrical conductivity of the same degree at all times.

As will be appreciated by those skilled in the art, it is important to be able to remove one electrode from the human body and attach it to another part of the human body. For example, it may be desirable to shift the electrode attached to the left leg over to the right leg. In that instance, one would merely disconnect the snap fastener on the right leg and left leg respectively, and interchange the female portion to which the electrical leads leading to the recording instrument are connected. The heavy metal housing 19 provides for easy gripping as a result of which a change of electrodes may be easily accomplished.

While reference has herein been made to circular sheets of paper it will, of course, be understood that other materials such as plastics or textiles can also be used and that suitable substitutions may be made depending upon the particular type of application.

It is also to be understood that while the device of the present invention may be used with a "human body" as used herein, the device may also be used with other animals and other objects.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

Claims

I claim:

1. An electrode for an electrocardiograph comprising in combination;

a base sheet having the underside thereof coated with a pressure sensitive adhesive,

a snap fastener comprising an electrically conductive male portion and an electrically conductive female portion, said male portion and said female portion having opposed contacting surfaces pressed into engagement with each other to provide an electrical connection therebetween,

said male portion of said snap fastener being firmly attached to and having a shank portion and a portion thereof extending through the underside of said base sheet,

conductive means secured to said male portion extending through the underside of said base sheet and adapted to be placed in contact with an object to be tested by said electrocardiograph,

a housing partially surrounding and secured to said female portion of said snap fastener and adapted for easy manual gripping, said housing being oriented to permit said female portion to receive said male portion of said snap fastener, and

said opposed contacting surfaces of said male and female portions of said snap fastener being provided with a plurality of closely spaced alternating grooves and ridges, said grooves and ridges on the shank portion of said male portion extending in a generally spiral direction.

2. The structure of claim 1 in which said grooves and ridges extend spirally radially along said contacting surfaces.