United States Patent 3826245

This invention relates to disposable electrode pads which may be used with cardiac devices, such as ECG, defibrillator or pacemaker devices. The pads are in the form of a foil bag containing an electrolyte. The bags are easily rupturable so that the electrolyte is applied to the surface of the human body.

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International Classes:
A61B5/0408; A61N1/04; (IPC1-7): A61B5/04; A61N1/18
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US Patent References:
1849745Electrode device1932-03-15Hoffman

Primary Examiner:
Gaudet, Richard A.
Assistant Examiner:
Cohen, Lee S.
I claim

1. An electrode for electrocardiac machine comprising a metallic sheet, a handle to which said sheet is mounted, an electrical connection insulated from said handle and electrically connected to said metallic sheet, a closed foil bag having two sides, one side being mounted on said metallic sheet, an electrolyte in said bag, and a sponge connected to the side of the bag opposite to the aforementioned side adhesively connected on said metallic sheet, a retractable punch mounted on said handle adjoining said foil bag, and means connected to said punch for moving said punch through both sides of said foil bag, whereby said punch punctures said bag to permit electrolyte to escape from said bag into said sponge.


In all of the cardiac devices such as E.C.G. defibrillator or pacemaker devices, it is necessary to connect the device to the body of the patient by electrodes spaced from each other on the body. This requires that the electrodes make electrical contact with the body of the patient. It is usual, in this connection, to use creams and sometimes saline salt gauze pads applied to the electrodes to insure adequate electrical contact between the electrodes and the patient and to prevent localized points of contact between the electrodes on the body. This requires preparation of the patient, when under some circumstances, time may be extremely critical as for example when defibrillation or pacemaker pulses must be applied.


It is the object of this invention to provide an electrode whereby it will be unnecessary to prepare the patient for application of the electrodes.

The electrodes of my invention consist of pads which are applied to the electrode. They include a pad in the form of a foil bag containing an electrolyte which may be mounted on the paddle of the electrode and are easily removed and replaced when once used. The electrolyte may be a saline water or saline viscous of paste-like material or other conductive material used in this art. The pads are attached to the paddle surface by means of an adhesive backing on the side of the foil bag to be placed against the electrode paddle.

Various methods could be used for rupturing the foil bag; for example, the bag could have weak spots such as scoring formed in the foil so that when the paddle places a pressure upon the pad the bag will rupture and apply the electrolyte so that good electrical contact is made with the patient. Alternatively, a mechanical device may be attached to the paddle so that the foil bag is ruptured and the electrolyte issues to create the conductive path.

In order to insure the successful application of the electrolyte between the electrode surface and the body provide I may and preferably do provide a sponge, which may be of plastic foam, which is saturated by the electrolyte and which is placed between the foil bag and the body member when the electrode is applied. This may be and preferably is attached to the side of the bag opposite to that to be placed against the electrode paddle.


This and other objects of my invention will be further understood by reference to the figures of which:

FIG. 1 is a schematic of a circuit which is one possible application of my invention.

FIG. 2 shows one form of the electrode of my invention carrying the disposable pad of my invention.

FIG. 3 is a fragmentary view of FIG. 2.

FIG. 4 shows a section of another and preferred form of electrode showing the application of the disposable pad of my invention.

FIG. 5 is an exploded view of the disposable pad of my invention.

FIG. 1 shows a circuit for application of my invention to an E.C.G unit or a defibrillation unit or a combination of the two illustrating that combination. Other types of cardiac systems may be employed, for example, the form described in Public Health Reports No. 11 November 1966 at page 1,042 and 1,043.

The switch 1 may be placed in any position but is conveniently mounted upon the electrode, for example, electrode 8 of the electrode pair 7 and 8. The closing of the switch 1 actuates the relay 2 which actuates the switches 3 and 4. As shown, the switches are in position to connect the high voltage source to the condenser 5 to charge the condenser. When switch 1 is closed, the relay pulls the contact from position contacts 3 and 4 to contact 6 and a pulse is applied to the electrodes 7 and 8. The E.C.G. unit 9 is connected to the electrodes 7 and 8 so that the heart is monitored at all times and is protected by the capacitor and diodes and resistor system in junction box 10. Since the aforesaid system is not a portion of my invention but merely illustrates one possible use of my invention, it need not be described further. It will be seen that at all times after the electrodes are applied the heart is being monitored and the defibrillation pulse may be applied when it becomes necessary, if contact has been established between the body of the patient and the electrodes by the use of the pads of my invention. But because of the nature of the heart malfunction, in such cases, the time taken in applying the electrodes to the body is of critical importance. The use of pads of my invention will reduce the time and make the preparation of the patient more convenient.

FIG. 2 shows one illustration of an electrode using the disposable pad of my invention. The pads 13 consists of a bag formed of a metallic foil sheet 11 and 12 which are sealed at the edges at 14 by cementing, crimping or welding the outer edges together. The bag filled with an electrically conductive material 15 such as a saline solution or with a conductive jelly or other equivalent electrically conductive liquid or semi-liquid conductive material for example such as has been used to insure electrical contact between the electrode and the body. Methods of filling foil bags with material for example, ketchup or mustard, are well known and may be used for this purpose.

The side to be placed against the electrode may be and preferably is coated with an adhesive material for example, a pressure sensitive adhesived for attachment of the bag to the underneath side of the paddle of the electrode. The lower side of the lower foil 12 is adhesively connected to a sponge 16. The sponge 16 may be of any sponge sheet material and in my preferred embodiment is a urethane foam or a similar rubber foam sheet. While not essential to my invention, a sponge saturated with the conductive fluid may be placed inside the bag formed at the foil sheets 11 and 12 with the edges of the foil sheets sealed to each other.

As is illustrates in FIGS. 2 and 3, the pad may be adhesively mounted in the electrode 7 or 8 which are formed of insulating material such as a synthetic plastic material conveniently connected to a handle 17. Mounted on the underneath side of the paddle is a metallic member 18 to which the upper foil 12 may be adhesively connected. The paddle carries a terminal 19 which makes electrical contact with a metallic plate 18 which is supported in the paddle. The metallic member 18 is bored with a bore 21 and the punch 22 is mounted in the ring 20 and carries a needle 23 mounted in the punch 22. A needle limit motion stop is provided in the form of a slot 23' which is mounted a stop pin 24 connected to the needle 23 so that when the head 24' is depressed against the spring 25 the needle punctures the foil sheet 11 and 12 of the bag permitting the material in the bag to saturate the sponge 16 when the electrode is pressed against the body compressing the bag. On release of pressure on head 24' the needle retracts. The needle having retracted, it will not injure the patient when pressure is applied. As shown in the form illustrated in FIG. 2 the electrode is provided with a handle 17.

The form in FIG. 4 shows an alternative form. The electrode 8 is a hollow member made of plastic or other insulating material with a guard disc 26 and carrying the switch 1 with the suitable electrical connections connected to the terminal 28. The electrode is connected by means of the electrode terminal 28 which makes contact with the metallic plate 29 to which foil bag is connected. In this case, the foils of the bag may be sufficiently weakened at suitable localities as by scoring so that when pressure is applied to the electrode plate 30 the envelope is compressed and stretched and ruptured at the weakened portions on the surface. Rupture will occur in the foil 12 and permit the fluid to escape to saturate the sponge 16.