US 3868946 A
A medical electrode adapted to be placed on the skin of a patient and being disposable. The electrode is formed of a soft sheet of closed cellular material adapted to be shaped to the contour of the skin and has included therein a well having its mouth portion facing the skin with a male snap fastener element connected at the base of the well having the snap fastener projecting therefrom and the flange portion secured in the bottom of the well. The flange portion contacts a compressed sponge member saturated with a liquid electrolyte so as to carry current from the snap fastener to the skin of the patient. When stored, the sponge is compressed and the well forms a barrier to prevent leakage of the electrolyte, and a release paper is removed from the back of the sheet material allowing it to be adhesively secured to the skin.
Description (OCR text may contain errors)
United States Patent 1 Hurley 1 Mar. 4, 1975 1 MEDICAL ELECTRODE  Inventor: James S. Hurley, 120 Merwins Ln.,
Fairfield, Conn. 06430  Filed: July 13, 1973  App]. No: 379,056
 U.S. Cl. 128/2.l E, 128/DIG. 4, 128/417  Int. Cl A61b 5/04  Field of Search 128/21 E, 2.06 E, DIG. 4,
 References Cited UNITED STATES PATENTS 484.522 10/1892 McBride 128/1721 990.158 4/1911 Moses 1 128/418 3,170,459 2/1965 Phipps 128/206 E 3.340.868 9/1967 Darling 128/206 E 3.518.984 7/1970 Mason 128/417 3.545.432 12/1970 Berman 128/206 E 3.587.565 6/1971 Tatoian 128/206 E 3.701.346 10/1972 Patrick et a1 128/2.l E
FOREIGN PATENTS OR APPLICATIONS 675.494 12/1963 Canada 128/417 Primary E.raminerRichard A. Gaudet Assistant Examiner-Lee S. Cohen  ABSTRACT A medical electrode adapted to be placed on the skin of a patient and being disposable. The electrode is formed of a soft sheet of closed cellular material adapted to be shaped to the contour of the skin and has included therein a well having its mouth portion facing the skin with a male snap fastener element c0nnected at the base of the well having the snap fastener projecting therefrom and the flange portion secured in the bottom of the well. The flange portion contacts a compressed sponge member saturated with a liquid electrolyte so as to carry current from the snap fastener to the skin of the patient. When stored, the sponge is compressed and the well forms a barrier to prevent leakage of the electrolyte, and a release paper is removed from the back of the sheet material allowing it to be adhesively secured to the skin.
7 Claims, 5 Drawing Figures PATENTEB 3,868,946
MEDICAL ELECTRODE BACKGROUND OF THE INVENTION This invention relates to a medical electrode, and more particularly, to a medical electrode which is dis posable and has advantageous features.
Conventional medical electrodes as generally utilized are increasingly being manufactured as disposable items for sanitary purposes. Additionally, such disposable items eliminate expensive and difficult labor time and are finding increasing popularity. Prior art electrodes of the disposable type generally include a snap fastener element which carries an electrical signal to the skin of the patient by means of a liquid electrolyte located between the snap fastener and the skin. There are existing disposable medical electrodes in which spe cial cup members are provided to store a compressible sponge member in a non-compressed fashion prior to its utilization after which, the sponge member containing the liquid electrolyte is compressed to bear against the skin and the flange portion of the snap fastener.
These prior art electrodes have significant disadvantages. For one, they are fabricated of a number of different elements thus requiring expensive and complex machinery to assemble the same. Additionally, the cup type element is often of a rigid material and can be uncomfortable when utilized. Further, use of such a physical cup results in an unnecessarily expensive electrode thus detracting from their general utilization. Further, there can be poor conformance to patient skin surface, such as with bony prominences or infant bodies.
Other prior electrodes have been formed where the electrolyte is inserted in a cavity between the skin and snap fastener at the time of utilization. These types often are cumbersome, bulky and are difficult to activate. Further, there have been provided medical electrodes in which the storage of the liquid electrolyte is difficult often resulting in unexpected and inadvertent leaks. These leaks can be catastrophic when in hospital use since the electrolyte completing the electrical path between the patient and the monitoring apparatus or other suitable electrical apparatus is absent. Thus, in these situations, there appears to be an open circuit thus eliminating the effectiveness of the medical electrode.
Some electrodes are provided on the market with an insufficient amount of stored electrolyte. This can lead to premature drying and the absence of electrolyte conduction when the electrode is put into service.
An object of this invention is to provide an improved medical electrode.
Another object of this invention is to provide such an electrode which is inexpensive, easy to manufacture, and will enjoy a wide utilization.
Yet another object of this invention is to provide such a medical electrode which ensures that the liquid electrolyte does not leak from the electrode prior to use.
Another object of this invention is to provide such a medical electrode which is easily contoured to the shape of the patients body without being uncomfortable.
Yet another object of this invention is to provide such an electrode with increased storage capacity for liquid electrolyte.
Other objects, advantages and features of this invention shall become more apparent hereinafter.
SUMMARY OF THE INVENTION In accordance with the principles of the invention. the above objects are accomplished by providing a medical electrode which is formed of a non-porous sheet of material adapted to conform to the skin of a patient and having formed thereon a well in which there is placed at the bottom thereof an electrical conductor formed ofa male snap fastener with the projecting portion projecting from the top surface of the sheet of material with the flange portion of the snap fastener being fixedly secured at the bottom of the well. The well is provided with walls forming a barrier and being impervious to liquid flow and when the well is filled with a saturated compressed sponge-like material, the liquid electrolyte contained therein normally cannot leak therefrom. The rear surface of the soft sheet of material is provided with adhesive, and a release sheet is removed therefrom to allow the sponge to expand and then again be compressed when the electrode is placed on the skin of a patient, the liquid electrolyte completing the electrical path from the male snap fas tener to the skin of the patient being prevented from leaking while the electrode is being stored and prior to its time of utilization.
As a feature of this invention, the well may be formed of a plastic ring attached to the back surface of the sheet of material to form the barrier preventing leakage of the liquid electrolyte when the electrode is being stored. As an alternative embodiment, the well may be formed from facing sheets of material in which an aperture is cut through one, the aperture forming the walls of the well when the two sheets are laminated together.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the disposable electrode showing the top surface thereof;
FIG. 2 is a sectional view taken along the lines 2-2 of FIG. 1;
FIG. 3 is a view similar to FIG. 2 with the backing or release sheet removed therefrom showing the sponge like member in a non-compressed form;
FIG. 4 is a top view of another embodiment of this invention;
FIG. 5 is a sectional view taken along line 5-5 of FIG. 4
DETAILED DESCRIPTION Referring to FIGS. 1 through 3, there is shown the disposable electrode 10 comprising a sheet of soft nonporous material 12 having a certain thickness, the sheet of material being provided with a top surface 14 and a bottom surface 16. The resilient material 12 is flexible causing it to easily conform to curved and uneven skin areas of the patient. The bottom surface 16 is provided with a pressure sensitive adhesive upon which is placed a protective paper or release sheet 18, which when removed from bottom surface 16 exposes the adhesive to allow the electrode to be attached to the skin of the patient.
As a feature of this invention, there is provided a well 20 formed by a wall member 22, the wall member being an annular ring formed of a plastic material. An electrical conductor member, conventionally a male snap fastener 24 is provided with a flange portion 26 at the bottom of the well with a projecting conductor member 28 projecting from the top surface of the electrode. Within the well there is placed a compressible sponge member 30 being saturated with a conducting electrolyte so as to provide a complete electrical path from the skin of the patient to the electrical conductor 24. As shown in FIG. 2, the sponge member 30 when stored prior to its utilization, is stored in a compressed fashion and the annular ring 22 serves as a barrier around the compressed sponge to prevent leakage of the liquid electrolyte. When the disposable electrode is to beused, the release paper 18 is removed from the bottom surface 16 and the sponge 30 expands as illustrated in FIG. 3, and when the adhesive bottom surface 16 is attached to the skin of the patient, the sponge 30 again compresses, thereby forming a complete electrical path from the skin of the patient to the electrical conductor 24.
As can be appreciated from the above, the disposable electrode, according to this invention, will enable the liquid electrolyte to remain within the well 20, the well being formed by the annular ring 22, the flange portion 26, and the backing or release paper 18. Elimination of the prior leakage problem is achieved with this simple, yet effective, construction. As can further be seen, the electrode of this invention is relatively easily to manufacture, inexpensive yet extremely effective in achieving its desired function. Use of the conventional male snap fastener 24 enables the present invention to be utilized with conventional electrical and electronic apparatus uutilized in hospitals and doctors offices, although the present invention is not limited to only a male type snap fastener. Other electrical conductors carrying current from such an electrical apparatus through the saturated sponge 30 to the skin of the patient may be effectively utilized, as appropriate.
Referring now to FIG. 4, there is shown an alternate form of this invention in which the well is formed of a pair of similar non-porous sheets of material designated 40 and 42, with sheet 42 being similar to sheet 12 in the above embodiment. An aperture 44 is formed in sheet 40, and when the sheets are placed in a laminated or facing relationship, a well or recess is formed behind the flange portion 26. The well thus formed comprises the wall formed by the aperture area 44 as well as the flange portion 26', and during storage, when the release sheet 18 is applied to the bottom surface 46 of the second sheet of material 40, the sponge 30' is stored in its compressed fashion. When the release paper 18 is removed from the rear surface 46 of sheet 40, the sponge 30 expands and thereafter is compressed upon the skin of the subject patient.
Preferably, the thickness of sheets 40 and 42 is approximately equal, while the sponge member 30 is slightly thicker than sheet 40, in its non-compressed state. With regard to FIGS. l-3, the annular ring may be of a resilient plastic material and has a height of approximately half the thickness of sheet 12. The ring can comprise a closed cell foam material. The sponge member 30 in its non-compressed state has a thickness greater than and approximately twice that of the annulat ring 22.
It may be seen that the disposable electrode of the present invention achieves the above enumerated objects, and while preferred embodiments of the present invention have been disclosed above, it will be understood that the invention is not limited thereto but may be otherwise embodied within the scope of protection sought.
1. A medical electrode comprising a non-porous soft sheet of material having top and bottom surfaces and being adapted to be placed on the skin, an electrical conductor member embedded with said sheet of material and having a flange portion forming the bottom of a well, a recess formed between said bottom surface of said sheet of material and said flange forming a portion of the walls of said well and a non-porous wall member attached to and depending from said bottom surface, said wall member encircling said recess to form a barrier and form the remainder of the wall portion of said well, said electrical conductor member having a male electrical connector member projecting outwardly from the top surface of said sheet, a compressible sponge member saturated with an electrically conductive liquid located within said well and having a thickness greater than the depth of said well, said sponge member being in contact with said flange, said sheet of material having a self-stick adhesive on said bottom surface, and release paper means covering said bottom surface and compressing said sponge member totally in said well when said electrode is being stored prior to utilization, said well serving to form a barrier and contain said liquid to prevent said liquid from leaking when said electrode is stored.
2. A medical electrode as set forth in claim 1, wherein said wall member comprises an annular ring secured to said bottom surface and being concentric with said flange portion.
3. A medical electrode as set forth in claim 2, wherein said annular ring comprises a resilient plastic material.
4. A medical electrode as set forth in claim 2, wherein said annular ring comprises a closed cell foam material, said ring having a height of approximately half the thickness of said sheet.
5. A medical electrode as set forth in claim 4, wherein said sponge member has a thickness approximately twice that of the height of said annular ring.
6. A medical electrode as set forth in claim 1, wherein said wall member comprises a second sheet of non-porous material having an aperture cut therein, said sheets of non-porous material being secured together in a facing relationship, said well being formed by the recess formed at the apertures when said sheets are secured together.
7. A medical electrode as set forth in claim 6, wherein said facing sheets are approximately of equal thickness.