CA2077318A1

CA2077318A1 - Suction electrode

Info

Publication number: CA2077318A1
Application number: CA002077318A
Authority: CA
Inventors: Heinz Eilentropp
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-09-12
Filing date: 1992-09-01
Publication date: 1993-03-13
Also published as: FR2681252A1; NO923541L; SE9202621D0; FI924015A; NO923541D0; SE9202621L; NL9201512A; FI924015A0; DE4205994A1; DE4205994C2

Abstract

ABSTRACT OF THE DISCLOSURE

A suction electrode arrangement for medical diagnostic and/or therapeutic purposes and for connection to a source of vacuum, comprises an elastic suction cup for placement onto the skin of a patient; an adapter traversing the cup; and a flexible electrode which is releasably fastened.
preferably off center to the suction cup, so that upon application of vacuum to the suction cup the electrode will contour fittingly and be urged against the skin of the patient. Certain bosses space the electrode from the cup to establish vacuum chambers in-between.

Description

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BACKGROUND OF T~E INVENTION

lhe present invention relates to suction electrodes to be used in medical diagnostics and/or therapeutics and including in each instance an elastic suction cup to be evacuated and an exchangeable, electrically conductive electrode.
Generally speaking, modern medicine makes extensive use of electrodes for the application or detection of higll or low frequency currents.
A typical example is electrocardiography wherein the activity of the heart is detected on the basis of a known relation of heart activity to electric currentson the skin. Another use of such electrodes is the relaxation of muscles and the furtherance of blood flow produced by the vibrations produced by the electrodes. Owing to the inherent choice of material for the electrodes~
namely metal, the electrode contour cannot in an optimum fashion follow the contour of the body; this is particularly noticeable when a local concentration is desired. Aside from the foregoing, the currently used suction electrodes has proven to be cumbersome and time consuming as far as their phy~ical placement and attachmcnt is concerned.
European Patent EP 0 289 905 Al discloses a suction electrode with a suction cup that may receive differently curved elastic electrodes. In this manner, the electrode being used is thus adapted to a speci-fic body part and different electrodes thus serve the pulpose of being adapted to different body parts. Moreover the electrodes can be pivotally mounted, and sponges and fleeces may be provided to further irnprove the trans-fer of electric currents.
Tt is apparent that on the one hand a very large number of different electrodes is needed to accommodate all possible body curvatures and that :

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m;lilin~ 06.1~1,7.~. 1IEW 111 still some compromise is inevi~;lbl~ in tll~t in some c~ses th~ reqllirc(l curvatllre and si7,e is not availahle wi'll tlle re(lllisite degree of acclIracy.
This is further complicated in that reproduction of results may be compromised through different choices~ For furtl1er references to the state of the art see German application DE-OS 32 28 143; AT-PS 248 608; DE-OS
25 48 805; DE-PS 40 35 820.
DESCRTPTTON OF TI-TE TNVENT~ON

It is an object of the present invention to provide a new and improvecl suction electrode to be applied withollt undue delay to any palt of a human body irrespective of the particular contour and curvature. Moreover the electrode once positioned must remain firrnly in place and the results mllst be generally reproducible.
~t is another object of the invcntion to provide a new and improved suction electrode structure that does not unduly load the skin o-f, e.g.
sensitive patients.
Tt is a specific object of the invention to provide a new and improved combination of an elastic suction cup for use of medical therapeutic and/or 20 diagnostic purposes and to which exchangeable electrodes may be connected.
In accordance with the preferred embodiment of the invention the objects~ particularly the specific object, is attained by providing the electrode as a flexible component, preferably of the rubber-elastic variety.
25 Thus the invention is to be seen in the combination of an elastic suction cupand of a flexible electrode in the Cllp. This combination permits short term (i.e. speedy) placelment of the electrode on the body and affixing the structure thereto but in an easily releasable fashion while contact malcing is . .

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guarantee~l. As low pressllre is ar)plied. the electrocle ancl skin are ~orced against each other and now the desirecl measurement and /or treatment (e.g.
by means of hi~gh frequency pulsating d.c. currents) can take place. The re-sul~s are reproducible and repeatable because contact making cloes not 5 depend on the particulars of the electrode contour nor on any factor of accuracy in the application by the medical technician. As low pressure is applied to the suction cup the tlexible electrode adapts itself automatically tothe body contour. The electrocle is preferably a sllction plate or dish which rests on the body as low pressure is applie(l to the suction cup.
The electrode is made of a Flexible material (e.g. a rubber elastic - material such as silicon ruhbcr or caoutchouc) which is very flexible ancl snugly fits the body in intimate surface to surface contact. The material sllollld have a suital)lc clectrically conductive filler such as soot or carbon black in order to establish the reqllisite electric conductivity. In lieu of a 15 filler of that kind, the flexible carrier material may include electric inserts to be electrically connected externally and with each other. Wire or ~llament pieces, ribbons, tapes, foils, webs, or mesh can be used here; all these kinds of inserts are predestined ~or placement in an areal configuration and thus inherently adapt themselves to the surFace configuration of the 20 electrode and its contour variation on account of the Flexibility. Wires or filaments may be provided and positioned in a radial pattern with a common contact serving as the common point of origin of that pattern. This arrangement ensures good flexibility. Whenever the electrode is o~ a simple configuration, a one - time use ~i.e. a throw-away approach may be the safest 2S and the one that also avoids also cleaning).
Another variant is the Following. A flat flexible structure part (electrode carrier) is provided with a metal coating, and on account of the m;li'inP, label l~n 20fi,1~1,755 2 0 ~ 7 3 ~ IEW 1 1 I

flexibili~y of th~t carrier the coati~lL~ thereon will ~It snllgly in surF~Ice to s~ ce contact a~inst the ~kin a~ low l~res~ure is appliecl to the suc~ion cup.
The metal coating may be established by a metal foil placed on a thermoplastic caolltchouc or other rubber elastic carrier material.
S Another advantageolls featllle is to bring abollt an increase in what could be termed the hold down pressure of the electrode by means of which the electrode is urged against the skin. For this the electrode sho~lld be contollred where it is facing the cup. Contouring may be pro(lucecl by means of protrusions such as ribs, bars or rid~es arrangecl in a reglllar or an 10 irregular pattern. These protmsions (e.g. ribs) may "racliate" from a common point of origin. This simple feature was found to increase the hold- down pressure significalltly, all other conditions being equal.
Another wav of increasing the hold-down pressure is to provide knohs~ short pin like protrusions or bosses on the flexible electrode whcre 15 facing the cup. On application of low pressure the suction cup bears against the bosses so that a multitlide of chambers obtains with low pressurc content.
These provide for a snugly fitting intimate surface to surface contact between electrode and skin, independent from the skin's consistency (other than surface geometry). If the electrode is circularly rollnd the bosses should 20 be arranged in a conc.ntric circle pattern.
P~lterna~iYel~ to ths foregoing, protrusions such as bosses ribs etc.
may be placed on the surface of the suction cup where it faces the electrode.
This feature simplilles the making of the electrode. For e,Yample, one may provide a ribbon or foil of flexihle material with concluctive fi]ling inserts or 25 coating and then the electrodes are punched out of that ribbon; the making ofthe suction cup requires a special shaping operation in any case, so that the ' ~ ' 73~$
m.lilin~ 2(16,191,75~ rw adding of bos~e~, ri~s, ridges, etc. is not a ~urdensome suppletnent in the making of a suction cup.
The invention is not limited to a circlllar contour of s-lction C~lp and electrode, nor do they have to be unifotm, but different combinations may in 5 cases be advisable. Here then one may use rectangularly shaped, square-shape, rod-like or kidney-shaped CUpS and electrodes. Also, the cup contour may differ from the contour of ~he inserted electrode. For example, a kidney shaped electrode may be placed into a rectangular cup. Owing to elasticity of the cup and the flexibility of the electrode, the very different surface 10 contours can be accommodated.
The known circular suction electrodes as per the state of the art listed in the introduction, use stiff electrodes together with low pressure nozzles, current feed lines, and holders which are all crowded in a narrow region surrounded by the flow of evacuated air. Dirt that is carried in the air and can15 readily and almost inevitably adhere, mingled with perspiration droplets, so that immediate soiling of the contact-making parts can introduce measllring errors even if the skin of the patient is meticulollsly cleaned beforehand.
This problem is avoided by the invention. The Fastening of the electrode in the suction cup is off center in the case of a ce.ntral contour for20 these parts. A separate fastening structure can be avoided here if the aforementioned bosses or ribs are used in addition as fastening elements. It was found that this feature renders the contact-making function substantially immune to soiling.
The invention provides in principle a tri - part con~lguration; elastic 25 (or flexible) suction cup, flexible electrode and adapter -for current and hose connection. This assembly permits individual cleaning and sterilization; this is a very important lFeahlre in medicine~ If, as already stated, the fastening for m;~ilin~ l~b~l Hn 206,191,755 2 0 7 7 3 ~ ~3 1 IEW l l l .

a circular el~ctrode is located off center as far as the suction cup is concerned and also away from the vacmlm connection, then the contact elements involved shoul(l have some form of hinge or pivot mounting, and there may also he a valve function included. In either case, there is contact pressure to be provided for.

DESCRIPTTON OF T~E DRAWINC;S

While the specification conclu(les with claims particularly 10 pointing out and distinctly claiming the sub ject matter which is regarded asthe invention, it is believed that the invention, the objects and features of the invention and further ob jects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a skle view of an example of the preferred embodiment of the invention but shown in a somewhat simplified manner;
Fig. 2 is a bottom view o-f a rnodified electrode;
Fig~ 3 is a cross-section through a more sophisticated version of the 20 preferred e~bodiment for practicing the invention in accordance with the best mode aspec~ of the invention;
Fig. 4 and 5 are respectively section and plan views of the electrode component in the embodiment of Fig. 3;
Fig. 6 is a cross-section through the suction cup in the embodiment of 25 Fig~ 3;
Figs. 7a,b,c,d,e are plan views of four different electrode con~lgurations; and : . ..

u~ Ut~ ,t'~5 llrw 141 2 ~ 3 ~ ~3 Fig.8 is a r~lan view of a circlllar cul~ and kidneyshaped electrode;an(l Figs. 9a and 9b are pian views of different electrodes with line shaped protrusions.
Proceeding now to ~he detailcd descriplion of the drawings, Fig. 1 S shows an elastic suction cup 1 which could also be terrned a suction dish because of its rather flat configuration. The cup is elastic and because of thatelasticity it can also be terrned to be a flexible dish using the term flexible more generally. However the shape restorability of an e]astic cup /dish is the preferred form of cup flexibility. Next, there is provided an as yet lo unconnected flat flexible electrode 2 and there is a connecting hose 3. The suction cup / dish 1 is circularly rollnd and is made, for example, of silicon caolltchollc which material establishes the elasticity. A flat rib, ridge or rim/lip 4 is provided at and along thc outer periphery of the cup I in order to improve the effect of suction. A duct S is placcd on the cup/dish 1 for 1~ connection to thc hosc 3. Thc dllct S is surroundcd by cast or spray on material Sa. The duct itself opens centrally as far as cup/clish 1 is concerne(lat location or mouth 11; an additional casting or soldering 8 fastens the hose to the duct S. P~ cable or conducts)r with or without insulation is run through the hose and is elcctrically connected to a lirling of, or to the duct 5 itself, the 20 latter be;ng preferably electrically conductive.
As stated ~a is a material that is sprayed or cast around the angled off duct 5, so is 8 for fastening of the hose. The material may all be the same.
Reference numeral 9 refers to a tubu1ar connecting end with a tubular connecting stud 14 to establish the connection to a low pressure source and 25 also to electrical equipment with which the suction electrode is to co-operate.

.' 2, ~ 7 7 3 1'3 The electrocle 2 is placcd in the ol~en p~lrt of cup/disll 1 but is shown external to it. As indicatcd by the arrow, 'I connecting stud of the electrode 2permits insertive connection Or a stud 10 into and with a -flared tmmpet shaped portic)n of duct 5 at the openin~ 11 thereof. This simple plug - in step completes the assembly and renders the arrangement operational as a suction electrode. The stud 10 is simply unplugged, that is, just pulled Ollt o-f the duct S after the device has been u.sed.
The stud 10 is provided with a bore 12. The vacuum produced in hose

3 and duct 5 by a connection to a pump is transmitted through the bore 12 into the space delineated by the cup/dish I Thc stud is made of metal and thus makes electric contact with the duct 5. On the other hand, an embedded electrical configuration such as wires, fi]aments, mesh, etc., 13 is in electrical contact with the stud 10. If the material of thc electrode includes an electrically conductiYe filler, then the contact making situation with stud 10 is immediately present. As stated~ at the other end there is a short metallic stud 14 which is hollow for connection to the pump while also being connected with the other end of the wire 6. All in all this establishes a rathercompact unit as long as it is disconnected and can be carried around like a stethoscope by a physician.
In summary of operational preparedness, the electrode is p]aced inside cup 1, the stud is Inserted and thu~s provides gas and electrical conductive connection to duct S, the embedding in the electrode, e.g. wires 13, etc., is established therewith. Now the cup with insertetl electrode is placed onto the skin of a patient. Plug end 9 - 14 is connected to the equipment that provides 2s vacuum and supportive electrical CitCllit connection. As suction is applied the skin is sucked against the electrode 2 and because of its flexibility the .

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contact is established as a goocl surf~ce to sul-face contact that is uniform ~nd areally.
Fig. 2 shows an electrode 15 whicll may be inserted into ~hc SUCtiOIl Cllp of Fig 1. The electrode 15 cliffers frorn 2 in that radially extencling h~r~, 5 ribs, or ridges 17 ~re provided on the surf~ce that will face the cup I when inserted. These ribs, etc., extend from the centrally located stud 16. These ribs establish a signi~lcantly larger hokl-down pressure of the electrode on the skin.
Proceeding now to the description of Fig. 3 et seq., the suction 10 electrode is comprised of an adapter 18, an elastic / flexible sllction cup /dish 19 and the fle:sible electrode 20. The electrode is preferably made of conductive silicon caoutchouc. Owing to that material, the flexibily of the elcctrode is also realized here by elasticity. The adapter itself includes essenti~lly a connecting stud 21 ~ora hose which leads to the vacuum pump.
15 An electr;cal conductor 23 is run through the hose 22. As before, the conductor may l~e provided for passing a therapeutic energization clllTent to the electrode or the conductor may conduct a diagnostic measurement current that was piclced up from the skin, to the external equipment.
A contact piece 24 connects the conductor 23 to the electrode 20. For 20 this, 24 rests on a contact 25 which is inserted in electrode 20. The contactpiece 24 serves in addition as a valve. A sealing ring 28 tightly pressure seals the chamber 26 in the adapter 18 vis-a-vis the chamber or space 27 in the suction cup 19. The adapter 1~ has a groove 18a in which is inserted a beaded rim portion of the cup 19. This clamps the adapter to the cup but 2s perrnits easy removal simply through pull-out.
The flexible electrode 20 is connected to the cup / dish 19 by means of two or more bosses or pins 29 in order to facilitate handling and to improve ~ ~

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tl~e conditions for cleanin~. In~lcnls :3() con1plete the connection in that thepins or bosses a?e claml~ed tl1erclo. Thi~ r)roced~lre (i.e. this ~ccentric fastening of the electrocle to ~lle suction cup 19) keeps the area or zone of electrical connecti~n and suction free from this fastening fllnction.
The electrode 20 is furtl1er provided with additional short pins or bosses 31. The pins 29 are part of tl1e hoss-pattern but are larger (at least a few tin1es as largc) as the bosses 31. As the vacuum is applied to the hose 22~ the cup sllcks and the bosses 31 establish many chambers 32. These chambers assure that the electrocle 20 does indeed uniformly sit and is held against the skin 33. Figs 4 and 5 show the electrocle in greater detail. There are shown two pin / bosses 29 for thc above described releasable fastening funclion. Jn addition Fig 5 sl1ows that the bosses 29 are a part of a pattern ofbosses whicl1 is established hy way of concentric circular arrangemcnts.
Fig. 6 on the other hand shows the sllction cup / dish 19 by itself Wit}1 an opening 34 ~or faslening the adapter 18. Opening 30 with rc-enforced beaded rim 35 reccives and claml-s one of the pins 29. The inner surface of tl1e cup 19 may be provided with ~osses in which case the bosses 31 will be omittcd from the electrode. In other words, it makes no difference whether the spacing function as provided by the bosses is established frorn the electrode or from the Cllp.
As mentioned above, the contour of the parts as such is not very important; overriding is the flexibility of the electrode and the elasticity (with inherent flexibility) of the suction cup / dish. Figs 7a,b,c,d,e show circll~ar, quadrilateral, rod and bar shaped and kidney-shaped electrodes 2s 36a,b,c,d,e respectively with electrical connections at 37a,b,c,d,e resp. Fig 8 shows a circular flexible e1astic suction cup 38 and a kidney shaped e]ectrode 39 with contact making featllre 4Q.

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~ enerally speaking, the electro(lcs sl~lP~b$~ay be madc of a rllhl er clastic material with emhedcled electrically conductive fillens, or there may be a conduetive coating on the sicle facing the body of the patient.
Alternatively there may be inserts as shown in Figs. 9a and 9b. These inserts must not impede the flexibility of the electrode as a whole. Fig. 9a shows a circular electrode 41 with embedded wires or ~llaments arS extending from the central contact point 43. A quadrilateral electrode 42 is shown to have wires or filaments 46 emanating from an ofr-center but common point of origin.
The invention is not limited to the embodiments described above but all change~ and modi~lcations thereof, not constituting departures from the spirit and scope of the invention, are intended to he included.

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Claims

mailing HB 206,191,755 HEW 141

Claim 1. Suction electrode arrangement for medical diagnostic and/or therapeutic purposes and for connection to a source of vacuum, comprising;
an elastic suction cup for placement onto the skin of a patient;
a flexible electrode; and means for releasably fastening the flexible electrode in the suction cup so that upon application of vacuum to the suction cup the electrode will contour fittingly to and be urged against the skin of the patient.
Claim 2 . arrangement as in claim 1 the electrode being of rubber elastic material .
Claim 3. Arrangement as in claim 1 the suction cup being a flexible dish.
Claim 4. Arrangement as in claim 2 there being a conductive filler in the rubber elastic material.
Claim 5. Arrangement as in claim 2 the electrode being coated with metal.
Claim S. Arrangement as in claim 1 the means being off center as far as the suction cup is concerned.
Claim 7. Arrangement as in claim 1 the cup and the electrodes having mutually facing surfaces one of the surfaces being provided with protrusions.
Claim 8. Arrangement as in claim 7 said protrusions providing a radial pattern.
Claim 9. Arrangement as in claim 7 said protrusions providing an annular pattern
Claim 10. Arrangement as in claim 7 at least one of the protrusions provided for fastening the cup to the electrode.
12 mailing label HB 206,191,755 HEW 141 Claim l l. Arrangement as in claim 10, the fastening protrusions being pins on the electrode, the suction cup having commensurate openings for clampingly receiving the fastening protrusion
Claim 12. Arrangement as in claim 1 and including an adapter for connection to the cup as far as a vacuum application is concerned and to the electrode for electrical connection thereto
Claim 13. Arrangement as in claim 2, there being inserts in the electrode.
Claim 14. Arrangement as claim 13, the inserts being of wire-like configuration.
Claim 15. Arrangement as in claim 13, the inserts being arranged in the electrode in a radial pattern.
Claim 16. Arrangement as in claim 1, there being a contact piece in the electrode, there being a connection traversing the suction cup leading to the contact piece.