US 2943628 A
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Description (OCR text may contain errors)
July 5, 1960 w. L. HOWELL 2,943,628
ELECTRODE ASSEMBLY Filed Feb. 27, 1957 2 Sheets-Sheet 1 ZET:- 5 5- 1N VENTOR Mlm E Hum@ BY @am ATTORNEYS July 5, -1960 w. L. HOWELL ELECTRODE ASSEMBLY 2 Sheets-Sheet 2 FledKFeb. 27, 1957 @EL m ATTORNEYS United States Patent O ELECTRODE ASSEMBLY William L. Howell, 3562 Macomb St. NW., Washington, D.C.
Filed Feazl, 11957, ser. No. 642,706 s claims. (ci. 12s-41s) This invention relates broadly to electrode assemblies and in its more specic aspects it relates to such assemblies which are especially designed for application to the human bodies yas a component of an electrocardiagraph apparatus used for making electrocardiagrams; and the nature and objects of the invention will be readily recognized and understood by those skilled in the Iarts to which i-t relates in the light of the following explanation vand detailed description of the accompanying drawings illustrating what I at present believe to be preferred embodiments or mechanical expression of my invention from among various other forms, arrangements, combinations and constructions, of which the invention is capable within the spirit and scope thereof.
Broadly speaking, Ianelectrocardiagraph apparatus records the changes of electrical potential initiating the heart beat and such apparatus includes means for putting the heart in connection with the apparatus either by means of contacts or electrodes from the chest wall and a hand or foot, or, by three electrodes which may be connected to both hands and one foot. The apparatus produces a graphic curve of the electrical variations associated with each heart beat together with appropriate time marks.
It has been found desirable for a variety of reasons to make tests from a plurality of chest points, usually six.
It is -usual practice to use one electrode for the chest contact which is moved from one test point to the other while the circuit is opened and a reading taken from each test point. The electrode must be positioned against the chest properly in order to provide a good contact and there are several methods now in use for fastening the electrode tov thehuman body. They may, for instance, be held by hand, by a strap or by suction cups. There are objections to all such methods, for instance, suction cups may bruise the body which causes ecchymosis. It will also be appreciated that thetransferring and attaching of the one electrode at the six chest locations is time consuming and not always a pleasant procedure for the patient.
It has been found that highly advantageous diagnostic results may be had by serial testing by electrocardiagraph and it is now common practice to run a series of tests on a patient, for example, from day to day. In this manner a plurality of serial tracings is obtained and their comparison is essential in order to obtain a definitive diagnosis.
It is desirable in practicing the serial testing technique to have the electrode or electrodes placed at the same chest locations for each test of the series of tests and I have found that a slight change of location of the electrode may make -a significant change in the Q.R.S.T. complex. Under prior procedures where one electrode was moved from one chest location to another and was not attached to the particular test point or chest location for the duration of the series of tests it was unlikely that each time the electrode was positioned on the chest that it would be positioned -at the same location as previously positioned, and due to this 'the value of the results obtained from serial testing underprior procedures may be questionable.
I have evolved `au electrode assemblywhich overcomes Patented July 5, i960 the above mentioned and other disadvantages which are inherent in present day procedures and electrocardiagraph apparatus.
I have devised an electrode assembly which involves a mounting means -for a plurality of electrodes, usually six, wherein the electrodes are properly and permanently spaced so that upon application of the assembly to the chest each electrode will be disposed at the desirable test point. p
The supporting base for the electrodes comprises a flexible strip of the proper proportions having an adhesive side upon which the electrodes are caused to firmly adhere and which will adhere to the body of the patient when the assembly is applied thereto. The highly advantageous characteristics of my assembly will be recognized when it is appreciated that by aixing each electrode in the desired spaced relation on the supporting base they will maintain such positions, and by providing an adhesive surface on the base it may be easily and quickly applied to the body of the patient. When the assembly has been adhesively applied to the body it may remain thereon for a series of tests, and a highly advantageous result of this is that each electrode will remain in the same body location for each test of a series of tests to thereby eliminate the possibility of the test results being untrue.
The assembly which I have provided being exible will conform to body curvature and body movements and will cause no distress to the patient wearing it for the period of time necessary to complete the series of tests.
lt will be evident that a good electrical contact must be made between the electrode and the body 4if the apparatus is to operate eiliciently and produce the proper results. With this requirement in -mind I have not only produced the supporting base of a ilexible material but I have also formed each electrode of a ilexible material having a relatively large plane surface for contact with the body of the patient. Thus, the electrode itself will conform to the configuration of the part of the body to which it is at tached and its entire conductive surface will be in close engagement with the body. The proper contactof each electrode of the assembly with the body is also ensured by the supporting base which being held in tau-t condition when applied to the body Will constantly urge and maintain each electrode in flat full electrical contact with the patients body.
In the use of certain types of electrodes such as those Iformed of brass, silver or the like .the conductive surface of each electrode may be coated with a water soluble paste including an electrolyte and this paste must be maintained in condition and must not be permitted to dry. The electrode arrangements of which I am aware -are not designed to keep the paste from, drying and hence would be inoperative if left on thev patients body for the duration of testing in a serial testing procedure. The assembly which l have devised is of such construction and the electrodes are mounted thereon in such a manner that the coated conductive surface is substantially protected from the :air so that thepaste coating will not dry and become useless.
It is also within my contemplation to form the electrodes of any suitable metallized cloth or any fabric which is treated to provide for electrical conductivity. I have found that when such metallized cloth is used it is unnecessary to use the aforementioned paste in order to obbase may be supplied as an independent unit. The indes pendent electrode units may be used in generally the same manner as when a plurality on the same base are used. Thus, a unit may be caused to adhere to each test poi-nt. onv the. chest'of a. patient and wilL, of course, remain thereon during the seriesof tests and such independent units may be applied to other parts of the body.
The electrodey assembly of this invention may he supplied tothe user in rolls to thereby reducel shipment. and storageA problems. The spacing, of the. electrodes on the, supporting base and the length` of the. base may be varied toA fit different sized` chests. and tocause each electrode. to be properly located at a chest point.
It has. been one of my purposes to provide, an electrode assembly which may be produced inexpensively so 'that an assembly may be disposed of after it hasV been used on a patient.
For an assembly of this nature to be practical and efhcient means must be provided for the easy attachment and detachment of the electric; circuit leads to the electrodes and to ensure a good electrical contact between the electrode and the lead. My electrode assembly has these necessary attributes for I. have provided attachment means which are positive intheir action and make the connection of the lead to an electrode a simple and easy operation I have also devised a package organization for the. i11- dependent electrode. units which provides for ease of. handling and dispensing of one unit at a time from. the package. h
It will be: evident that my invention is versatile 1nV its uses and adaptations and, while L shall describey its use as a component of anA electrocardiagraph it is to be distinctly understood that it is within my contemplation that it may be used in other than the medical field. It will alsoy be understood that in its medicali use my assembly may be used equally well on other parts of the body than those mentioned.
With the foregoing general objects, features and results in view, as well as certain others which will be apparent from the following explanation, the invention consists, in certain novel features in design, construction, mounting and arrangement and combination of elements, as. will be more fully and particularly referred to and specified hereinafter.
Referring to the accompanying drawings:
Fig. l is a view of my electrode. assembly' in operative position on. the chest of a patient.
Fig. 2 is a view in perspective of my electrode assembly rolled on a spool, with a section thereof unrolled.
Fig. 3 is a plan view of the operative surface of a portion of an electrode assembly;
Fig. 4 is a view in section through an electrode and the supporting base and illustrating a connection attached to the assembly.
Fig. 5 is a view in section through an electrode and the supporting base, the electrode being a modified, form.
Fig. 6 isV a view in perspective ofv a modified form of electrode assembly rolled on a spool, with a section thereof unrolled.
Fig. 7 is a view in section through an electrode and supporting base ot" the assembly illustrated in Fig. 6 and illustrating a connector attached to the assembly.
Fig. 8 is a plan view of the operative surface of the electrode assembly illustrated in Fig. 6.
Pig. 9 is a view in perspective with the supporting base and they electrode of Fig. 6 in separated positions.
Fig. l0 is a view in perspective of a package of' independent electrode units.
Referring to the accompanying drawings and particularly Figs. 1 through 4 thereof wherein I have used the numeral 1' to designate inv its entirety the supporting base of my electrode assembly. The supporting base may be formed' of any suitable flexible fabric material or of any other suitable material and maybe of any desired length and preferably though not necessarily the base is approximately 1" in width. The supporting base may, if desired, be not only flexible but also elastic. Consideration of the drawings clearly indicates that the supporting base of the assembly is in the nature of a tape and on the operative face of the tape or supporting base I provide a layer or coating of any suitable adhesive 3, the other or outer surface` 5 of the base being uncoated. The adhesive coating 3 is preferably a pressure sensitive adhesive and one which willY adhere tothe skin of the human body and to. metal foils and. metallic fabrics for reasons which will hereinafter be made clear.
The supporting base 1 is provided throughout its length with a pluralityi of' longitudinally spacedl openings 7 therethrough, the openings being equally spaced apart and formed through the base intermediate the longitudinal edges thereof. While I have illustrated the openings 7 as being circular they may be of a variety of configurations and still fall within. the spirit and scope of my invention.
I provide an annulus 9 at each opening 7 in the supporting base. Each annulus is. applied to the adhesively coated side of the, supporting base in such. position that it encircles the opening. The annuli may be formed. of paper or any other appropriate material and provide at. each opening an encircling area whichI is uncoated, that is` each annulus covers the coated surface of an annular area of the base. immediately adjacent to and surrounding the` opening. L provide a plurality of electrodes. indicated generally by the numeral 11, of a thin metal foil, metallized fabric or other suitable. pliant conductive material which is a good conductor of electricity, each electrode is. preferably though not necessarily' of circular configuration providing a disclike electrode. For example, shim stock of brass may be used or thin silver foil or any conductive material which is pliant. An electrode is located on and caused to adhere to the coated side of the supporting, base at each opening therein in position thereon over and covering the opening and covering. the annulus 9 and extending therebeyond- Consideration particularly of Fig. 4 of theV drawings. clearly illustrates the manner of attachment ofthe electrodes to the supporting base soy that the central free portion; 13. of each electrode is free of and not in contact with the adhesive: coating due toI the annulus and the peripheral', surface 1S' of each electrode is the portion which is attached to thel adhesive on the supporting hase. The electrodes4 are applied to the baseso.l that there. isr a degree of looseness in the. central free portion for a purpose which: will hereinafter become clear.Y The electrodes, whether of; circular or some. other suitable configuration are preferably dimensionally such that they do not entendv across the width of the supporting base but instead an adhesively coated. area. 17 extends between the edges'of the supporting base and the most: adjacent portion of the periphery orv side'Y of the electrode. The purpose and; advantages of such electrede positioning will' become clear as this. description proceeds.
The electrode assembly may be supplied tothe user in long strips, that is long strips of the supporting base with the openings therein andr the electrodes applied in permanent position as described. These strips ofthe assembly in any desirable lengths may be rolled on any suitable spool 19 as shown in. Fig. 2 of the drawings. When it is desired', to use an assembly the user merely must. unroll enough ofA the strip from the spool to fonn an assembly having the desired number of electrodes. and then cut across the strip For instance if the assembly is to be used, in a cardiagraph apparatusl yfor application to the chest a strip containing six electrodes may be cutoff the supply length, if an assembly' onlyl involving one electrode for application toy the fool or hand' or some other part of the body is to be. used ay strip containing one electrode may be cut from the supply length. Of course, for other applications and uses of the assembly strips may assenzaY be severed from the supply length which contain any vdesired number of electrodes. f
IIf it is desiredto take a series of tests for a cardiagram, the strip containing six electrodes is cut from the supply length and is applied to the chest of the patient by pressing the coated side of the supporting base against the chest in the manner of the conventional adhesive tape. It will be recognized that when the supportlng base is so applied the electrode discs will be pressed against the chest in good electrical "contact therewith, and' the base and the electrodes being formed of flexible or pliable material they wi-ll conform to the curvature of the chest land ensure `an excellent :and lastingcontact of each electrode With the chest. The supporting base is caused to adhere firmly tothe chest and all portions thereof including those edge portions 17 will be caused to adhere to the chest. It will now be apparent that the paste with which the operative face of each electrode is coated will be maintained in substantially airtight condition so that the paste will not dry during the time the assembly is left in operative positionV on the chest of the patient during the series of tests.
In using the assembly it is desirable that each electrode 4be placed lat a particular location on the chest of the user. There are normally six chest points where the physician wishesto place an electrode. In Fig. l of the drawings they are, reading from left to right as the drawing -is looked at: V-1 the fourth right inter-costal inter space; V*2 the same horizontal location as V-J1 except to the left of the sternum; V3 half way between V-Z and V4; V4 the fifth inter-costal inter space in the midc-lavicular line (approximately half way between the ends of the collar bone); V'5 the same horizontal level as V-4 where anterior axillary line bisects the horizontal plane of V-4; V-6 the same horizontal line yas V-4 and V-S where it b-isects the mid-axillary line.
It will be understood that the electrodes are longitudinally spaced apart substantially the same distance vas the aforementioned chest test points. It will also be understood that the assembly may be made in different sizes, to suit persons with different sized chests and in making the different sizes the spacing of the electrodes would be `slightly varied.
With the six electrode assembly applied tothe chest so that the electrodes are positioned as described, the assembly may be leftv on .for several days during the period of serial testing and it will 'be recognized that there can be no chance of any electrode not being yat the same chest location for each test of the series of tests.
In Fig. 4 of the drawings I have illustrated one form of connecting an electrode to the lead of the electric circuit of the apparatus. I provide `a connector designated `generally by the numeral 21, the connector may include a stem 23 and a hook portion 25. When it is desired to connect any electrode into the circuit lead 27 which is attached in any suitable manner to the stem of the connector element the hook of the connector is inserted through the opening 7 in the supporting base and extended between the electrode and the annulus 9. It will be understood that the free or non-adhered portion of the elect-rode permits this good electrical con` nection to be made, it will be also understood that a relatively long portion of the hook is in good contact with the electrode. Any other suitable type of connector may be used and still fall within the spirit and scope of my invention In use the connector is connected with one elect-rode for the necessary length of time and then to each succeeding electrode of the assembly and it will be apparent that I have provided a mounting arrangement for the electrodes on the supporting base which makes the attachment of any type of suitable connector an easy matter.
In Fig. of the drawings I have illustrated a modified form of electrode and I have used the same reference characters for parts which are the same as those heretofore described. trode 11 is formed with a peripheral edge which is rolled inwardly asat 29 to provide a bead about the peripheral edge of the electrode. I have done this to eliminate any small possibility of the edge of the electrode irritating or otherwise damaging the skin of the patient in the eventv that the edge of the electrode happened to be unusually sharp.
In Figs. 6 through 9 of the drawings I have illustrated a further form which my invention may take and in describing this form of my invention I shall use the same reference numerals `for parts Iwhich are the same as those described above. In this form of the invention the same type of supporting base 1 may be used as described in connection with the lform of the invention shown in Figs.,
l through 5, however I provide pairs of openings at each electrode point and in longitudinally spaced relation on Each pair of openings may corn prise triangular openings 31 with a bridge 33 extending between them `and longitudinally of the supporting base,
the supporting base.
portion 39 which I shall term a connecting portion.
The connecting portion 39 is preferably of reduced dimensions relative to portion 37. The connecting portion 39 is formed with a diametrically extending upstanding rib il for a purpose to be described. As in the case' of the electrodes described in connection with Figs. 1 through 5 the electrode 35 is formed of a very thin metal Vfoil of flexible and electrical conductive material. The Selectrode portions 37 and 39 are cemented together by means of any suitable cement which' is conductive to electricity and an electrode unit consisting of the two portions 37 and 39 is applied to the coated side 3 of the supporting base 1 at each pair of openings in such position over the openings that they are closed by the electrode and the rib 41 extends below and in alignment with the bridge 33 of the supporting base, all as clearly illustrated in Fig. 7 of the drawings. Since the contacting portion 37 of each electrode is dimensionally greater than the other portion of the electrode it is the peripheral free portion 43 of the connecting portion which will contact and adhere to the adhesive surface 3 of the supporting base. I may provide a pincerl or clamping connector designated generally by the numeral 45 for connecting the electrodes into the electric circuit of the apparatus. The working noses 47 of the connector are adapted to beinserted in `a pair of openings 31 in engagement withv the electrode to make a good electric contact therewith. It will be seen that the Working noses of the connector extend between the rib 41 and the body of the electrode so that they are in conductive relation with not only the body of the electrode but also with the rib of the connector portion of the electrode.
The electrode assembly which I have illustrated in Figs. 6 through 9 of the drawings is used in the same manner as that which is illustrated in Figs. 1 through 5 and has the same inherent advantageous characteristics.
As I have pointed out above each electrode mounted as described may be furnished as an independent unit and may be used as an independent unit and function in generally the same manner as when a plurality of electrodes are mounted on the same supporting base. It is to be understood that my invention is intended not only to cover the assembly of a plurality of electrodes mounted on a common supporting base but also a single electrode mounted on a supporting base providing an Y independent electrode unit. In Fig. 10 I have illustrated a convenient arrangement for packaging a plurality of independent electrode units and I have used the numeral 49 to designate each independent electrode unit. On one end of each such unit I provide a tab 51 which is caused to adhere to the adhesive on the coated side of In this form of my invention the eleci' assenza thersupportingf base ofthe unit. and to extend from and beyond the. transverse end of the unit- The` electrode. 53 which is illustrated' in Fig.. 110. is formed of metallized fabric, although I may form the package of independent which include electrodes: formed of. metal foils or anyother suitable pliant conductive material.
A plurality of independent electrode. units, are assembled into the package of Fig. 10 by placing them in an aligned pile or staclc with the adhesively coated. side. of a unit: in engagement with the uncoated surface` of the next adjacent' unit. At one end. of the unit the adhesively coated sides of the end' adjacent units are placed face, to face so that. the. end units will have their uncoated faces outermost. In assembling a plurality4 of' the units into.x a package each unit is alternately arranged so: that. adjacent unitsk havel the tabs. extending from opposite ends'. When it is desiredl to separate a unit from the package for use the tab. on anA outside unit is grasped and the. unit is peeled fromthe stack. The package may be Wrapped in any desired and convenient manner.
l. A11 electrode assembly including, in combination, an elongated eidble supporting base having an adhesive coating on one; face thereof, said supporting base-y and coating having a pluralityY of' longitudinally spaced openings therethrough, a plurality of separateV electrodes be' ing aixed to said supporting base. by said. adhesivecoating, each of said electrodes beingaixed to said supporting: hase in position covering an opening and comprising a. metal foil unitary section having a surface adapted to engage the skin ofv a patient and an opposite surface adapted to be engaged by means: forI connecting an elec# tric lead to the electrode, and means loosely and removably extended through each opening' for connecting an electrical lead to. each of said electrodes.
2.. An electrode assembly, including, inI combination, a flexible supporting base having an adhesive coating on one face thereof andv the supporting base and coating having an opening therethrough, and a unitary metal foil electrode, a portion of said electrode being aixed to. said coating and. the remainderl of said electrode being free'of the coating and the electrode extending over the opening, and. electrical conductive. means extending through the opening and between and in contact with the free portion. of the electrode. and the supporting baseY and connected to an electric lead for connecting the el'ec-y trode in an electric: circuit.
3. Arr electrodel assembly including', in combination, a. flexible supporting base havingi an adhesive coating on one face thereof' and the supporting base and coating havingl an opening therethrough, and a metal foil electrede, a portion'of. said. electrode being afiixed. tosaid coating, means being aiixed to said coating and surrounding the opening ltolcelepthe remainder of said electrode from adhering to.. said coating to. thereby provide a freeV electrode portion, said free electrode. portion extending over the opening, and electrical conductive means extending through the opening and. between the freev portions of the electrode and said first: named means and connected to an electric lead for connecting,` the electrode. in an electricl circuit.
4. An electrode assembly in accordance with claim 3 wherein said rst named means comprises. an annulus of flexible material.
5.r An electrode assembly in accordance: with claim 3 wherein said electrode. comprises a metal foil dise and:
said first named means comprises an annulusY of flexible. material and said electrodeportion is. aixed to said coating radially outwardly with respect to the outer periphery of said annulus.
6. An electrode. assembly including, in combination, an elongated exible supportingl base having, an adhesive coating on one face. thereof, said supportingA base and coating having a plurality of spaced pairs of openings. therethrough, and the openings of each pair of openings being separated by av bridgingl member integral with thev supporting base, a plurality of separateelectrodes being ai'xed to said supporting base by said adhesive. coating, each of said electrodes being aixed to said. supporting. base in position covering a pair of openings and a. bridging member, and means for connecting an References Cited in the file of this patent UNITED STATES PATENTS 496,244 Barret Apr. 25, 1893 691,820 Spalding Ian. 28, 1902, 1,262,963 McCrea Apr. 16, 1918 1,498,059 Tyler Jllue 1.7', 1924 1,662,446 Wappler Mar. 13., 1928. 1,671,825 Johnson May 29, 1928 Sullivan Dec. 2.2., 1936