CA2179512A1 - Biomedical conductor containing inorganic oxides and biomedical electrodes prepared therefrom - Google Patents

Abstract

A biomedical electrical conductor (16) having a thin, conformable layer (28) of an inorganic oxide of low polarizability is disclosed. The inorganic oxide (28) can be a mamganese oxide preferably manganese dioxide. The biomedical electrical conductor (16) as a multi-layered composite also is disclosed, using the inorganic oxide layer (28) in mechanical and electrical association with an electrically conductive component (26) which is mechanically in association with a nonconductive polymeric film (24). The composite forms an essentially x-ray transparent, flexible conductor (16) of low polarizability. Biomedical electrodes (10 and 40) using the biomedical electrical conductor and methods of making and using the conductors and the electrodes are also disclosed.

Description

W095/20350 _ 2 1 79 5 1 2 ~ SS
IllOlUlANIC O~ID--D8 s AND I~T. P JSPARED
FIT Tn OF T~ INVYNTTr~N
This invention relates to D~ r;rAl C~ dU~ ~CLD
10 rrni-A;n~ng inorg_nic oxides for use in hi- ~;r~
p~rT~rOr,Tl,ND or T~iE INV~ TTr'N
Modern medicine uses m_ny fi~r~nAI~;r y~O~cJ~.L~_ where 15 electricAl sign_ls or currents ~re received from _ 1 l ~n patient's body. N~7nl imi--in~ exampleg of ~iir~nn~t ic ~L~eJ~.Lc3 include electrocardiographic (ECG or E~CG) di_gnosis or monitoring of electric_l wave patterns of A 1 l An he_rt, irrespective of duration or CiL nnre The poLnt of contact between medical equipment used in these ~ .cJuL~ And the skin of the p_tient i3 usu_lly some sort of hi- ';rAl electrode. Such _n electrode typic_lly includes a conductor which must be connected ~lectrically to the ecuipment, and a conductive medLum Adhered tc or otherwise c~ni-r~ l inq skin of ~ patient.
Among diAgnostic ~L~,~cluLL8 using hi ~ ; rA 1 electrodes _re mon$tors of electrical output fro~m body functlons, uch as el__LL ~,.DL~Iiogr_phs (ECG) for i;--rri nrJ heArt _ctLvity ~nd f or ii 1 1 _ - i n~ heA rt ~ - 1 i t i ~o .
For each ~ qnn~ r procedure, at least one bLI '~
30 electrode having An ionically ive medium rrnl J~;n;n~ an electrolyte io Adhered to or otherwise crn~ ~i-i~q skin At a loc_tion of interest and also electric_lly connected to electricnl g~ r eguipment. A critic_l component of the hil ir~l lectrode is the electric_l conductor in ~l~rtrirAl irAi-;rn 35 with the ionicall~ ` ive medium and the Dl~ri-r;r~l ii;r ~;r _ _;
T~lDci-r;rJ~ u.~JLD require excellent electrical conductivity and minimal electric~ll ro~ AnrD for h;. ~;rAl ~lectrodeD, especi_lly when fAint electric_l signals nre received 40 from the patient. For this reaDon, metals or c_rbon (especiAlly graphite) Are used. Among metals, silver is preferred because of its optim_l conductivity. But h;- `;rJ l electrodeD which monitor A patient ' s crn~ ; rn~ must be able to withst~nd the polari~ing effects of ~I defibrillation procedure for ~ heArt. For this 45 reDson, A metal h_lide, such A8 sLlver chloride, iD preferably W0 95/20350 2 1 7 9 5 1 2 P~ t ~ lss used wLth _ metal conductor, _uch as silver, to creato a depol~rizable electrical conductor in h;~ ~;oAl electrodes which can monitor a heart.
There aro two princip_l difficultie_ with a hll 'irAl 5 electrode ~-ontAIn~ng silver/silver chlorido: expense of 3ilver and x-ray detection of metallic silver.
Others hQve attempti d to reduce the cost of silver in hl~ '~cAl electrode_ by using graphite or other galvanically inactive mQ~teriA lg in r ~ at I on with silver pQrticleD or 10 ailver/-ilver chloride lA~yers . See, for ex~mple, U . S . P_t . Nos .
3,976,055 (Monter et _1.) and 4,852,571 (Gadsby et al.).
Y -_ dioxide h~s been i~ ' for use with h~ irnl electrodeg as _ nonpol~rizable m_teriAl when prepAred as a thick pellet and placed in aQ~ iAtion with graphite. See Nencini et al., Mr - - Dioxide Electrodes For St i 1 At i on and Recordinq" in M~tiirAl and BioloGi~Al Fn~nCl~rinr~ Vol. 6, pp. 193--197 (1968) and Nencini et al., Y _ Dioxide Depol~rizer For oi. ~ A1 Electrodegr in MA~j jOA1 An~i Fiir~lrl-irAl FnflinrQrin., Vol.
8, pp. 137-143 11970). But no b~ ';orl electrode is known to have been .~ ed using MnO~ in a manner that permits the electrode to conform to the contours of the skin of a patient.
Other uses of manganese dioxide in electrical app~ratus include uses in batterieQ. where electrical energy is gathered and stored for later release. See, for example, U.S.
Pat. No. 4,466,470 (Alan et al. ) .
oY OF T~F INv--FNTloN
The present invention providea A hil `ir~l eleCtric conductor comprising _ thin, conformable layer of an inorganic oxide of low polA~rizability cnntr^t~n~ an electrically conductive component which is capable of becoming in ~ ctrlrAl ~atirn with ii ~ agnoQi- i c _ i The present invention ~180 provides the use of that ,h,;l 'ionl electrical conductor in a hi~ 'ir~l ~lectrode.
"Low polQrizability" meAns that the inorg~nic oxide is capable of retaining an equilibrium potential after bi~ing exposed to a high volt~ge of ~lQrtri~-lty used to defibrill te the heart of _ patient.
The thin layer of the inorganic oxide permits the h,i~ `ir~ electrical conductor to hQve a flexible structure and a low profile. Thus, the conductor is capable of bending to conform to the contours of skin to which a bl ~ A1 electrode using the conductor cQn contact.

~ W095/20350 21 7951 2 r~ ss Thin~ mezms th~t the l~yer of inorg~m$c oxide is less th~n ~bout 100 llm thick.
~ Conformable" means that the l~yer of inorganic oxlde can flex ~nd bend to permit a hi~ 'tral electrode rrntAlnln~ the 5 l~yer to contact A ufficient ~rea of Okin of _ patient to perm$t ~ccur~te and pr~cille reception of h; 'ir~l elsctrical signals em~n~ting from the p~tient in the location of olectrode cont~ct.
Of possible inorganic oxides, vnriouli oxides of ~re preferred. Oxides of m~nganese, particularly _ dioxlde in its various commercially available forms, ~re suitable for the r~pid reactions which are required to maintain low polArizAbility of ~n oloc~r1r-1 conductor within a hi~ lrAl electrode on ~ patient aSter an eiectrical defibrillation ~L~ du~e of th~t p~tient ig lei-o~i As r^rr7n;~oA by Nencini lAont-lfloA ~bove, little is known how oxides of , operate to maintain low pol~riz~bility. While not being limited to A particular theory, dioxide in commercially available forms nre believed to hAve oxides of _ - having more than one oxidntion ~t~lte, 20 such that low polnriz~bility for the electrical conductor is ~chieved by either reduction reactions or oxid~tion reactions of the various oxides of ~;n.~ __ present in commercially available dioxide. These reduction/oxidation (REDOX) reactions ;Ire rapid and permlt -lni-on~nre of low polnrizability of the 25 electr$cal conductor after being expoDed to n high volt~ge of lectricity used to defibrillAte the heart of A patient.
The prel~ent invention A150 ~chieveg a hi 'ir~l electrode comprising a hl~ 'lr-l oloc~rlr~l conductor described herein. The h~ ~lrAl electrode comprigeg A hi~ 'lrAl 30 electrical ~ L described herein and ~n ionically-conductive medium r"ni-~-tlnq the conductor ~nd also rrntari-ln~ the Dkin of a patient .
A feoture of the present invention is that, when comp~red to a ~ilver/silver chloride hl- lr~l electrical 35 conductor, the hi~ lrJ l olortrlrAl conductor of the present invention is ~Ally x-ray L-o.~ L-Another feature of the present invention is thAt, whenoompared to ~ silver/silver chloride hl~ lral eleCtriCAl lu~L~ the hl 'lr~l olori-rlr~l conductor of the present 40 invention is relatively inexpensive because of the A~ fforonre in material cost of I dioxide compared with silver.
An ~dvantage of the present inventLon is that a h~ 'lr~l electrical conductor described herein has all of the properties of ~.~r.,....l Oilver/silver chloride electrodes with the WO 9S/20350 ' 2 1 7 9 5 1 2 r~ [ lss ~
bDJnefit~ of ~ lly x-rDy ~LC~ y and low mDteri~ls cost.
For a greater appreclatLon of the invention,: ~1 D of the inventlon Are described in relation to the drawings.
pRTF!lr DESCRIPTION OF TH~ PRAWINGS ,, FIG. 1 i_ a top plan view of a bi~ ';rAl electrode rnnt~;n~nq a b;~ irAl Dl~r~rlrAl conductor of the present invention .
FIG. 2 is a section~1 viow of the bi~ IrAl electrode of FIG. 1.
FIG. 3 is a top plan view of another hi- 'irAl electrode rnnl J~;ninq a biomedical electrical conductor of the present invontion.
FIG. 4 is a section view of the h;' ;rAl electrode of FIG. 3 .
~....h..l~ . OF TH~ INV~NTION
20 R;nmD~l;rAl electrical conductor A h;l ir~l electrical conductcr of the present invention comprises a thin~ conformable depolarizing layer of an inorganic oxide rnnLr^~;nq an l-lertr;rAlly conductive ccmponent which c2~p~ble cf beccming in electrical ; rnt; nn with 25 ,i; ~nnrL; r equipment .
~ nl;m;1 ;nq examples of electrically conductLve include ~ rDd snaps, eyelets, pcsts, thln layers on D~LDLL~IL~ and DlDrLr;r~lly conductive particles ;nLorm;~r~e in the thin, rnrfnrr~~lD depolarizing layer of 30 inorganic cxide.
Preferably, the electric_lly conductive component is a layer in contllct with the thin, cnnfnrr~~l D depol~rizing layer.
Preferably, the lDyer is flexible, cnnfnr--'lD, and ~ ;~lly x-rny i ~..L.
N~nl;m;t;nq exDmples of materials suitable for the olDrLr;rAlly conductive ccmponent include intrinsically conductive polymers and various forms of carbon, especially graphite, such as C~LL~ o;n;nq inks, ~;~LL.... ' fibers, carbon-loaded woven and nonwoven webs, carbon-loaded membranes, and other 40 Graphite is preferred, especially when applied in the form of a graphite ink to a ~ I ;ve, thin, flexible polymer film (e.g., a polyester film).
Altern_tively, particles of the ol~c~-r;r lly conductive component can be; n~ nrm; YD~l with particles of the ~ W095l20350 - 21 795 ~ 2 r~ l~u~5'~rl55 inorgOnic oxides to form a blended, thin, conformable, ;Ally x-ray LL~ OL_.~L layer.
The thin layer of inorganic oxide provides a dopolarizing layer as a part of the hi~ .l electrical 5 conductor and preferably covors the area of contact b~tween an electricnlly conductive lnyer and nn ionicnlly conductive medium in a hi- 'irAl electrode.
The thin lnyer of inorganic oxidc either c~n be a gel ~ ntJIlning the inorganic oxide covering the ~ ctr~c~lly 10 conductive layer or can be a thin film coOted on the ~AlCl~.triC.Al ly conductive lnyer using a binder.
OS possible inorganic oxides, dioxide is readily nvailable commercially in a variety of crystalline forms, has low polarizability, nnd is inexpensively priced compared with 15 silver.
Because commercially available J~ dioxide can oxidize other ~ _ ~t;~no, depending on the rYir~-tinn state(s) of the oxides of --- J~ present in commercially available - dioxide, some care must be taken in the selection of it;~no c~nt~-t;ns it to avoid undesirable 1~ _ ;ti~n Graphite i8 an excellent choice as an electrically conductive component for contact with, dioxide. The graphite can contact oxides of mangnnese as either particles to be ;nt~rm; YD~I in the thin depolarizing layer or formed as a separate 25 ~ ctri~nlly conductive layer which contnctA the thin depolarizing layer .
Graphite hns a high electrical conductivity, is x-rny L~ L~ and is inert to oxidative effects of oxides of To form n thin, ~1", c-.~ntin.~ O film of d~polDrizing layer on ~n electric~lly conductive layer, particles of oxides of "J- ~ require a binder and can be applied ns an ink to the electrically conductive layer. In this manner, the thin, ~ ~,.,r ~1 A depolarizing lOyer is sandwiched between the 35 electrically conductive layer nnd the ionically conductive medium.
Alternatively, particles of oxides of and particles of ~ tr;rAlly conductive component can be int-rm;
with a binder and applied as nn ink to an electrically ive gubgtrate in a blended layer to provide a thin, 40 . r hl e, electrically conductive and depolarizing l~yer.
A binder relatively resist~nt to ~.Y;8.t;~n by inorgnnic oxideAA, especially oxides of .u~ C, can be a water-oluble polymer. N~nl;m;t;n~ exDmples include ~11..1. such asmethyl CAl 1..1. , polyethylene oxide, poly(vinyl alcohol), and W095l~0350 21 7951 2 I~I/I),J5/ -155 poly(N-vinyl lActOm), such o8 poly~N-vlnyl-2-pyrrolldone). of these polymers, methyl cellulose wlth a limltod number of unreO-cted hydroxy groups thereon (l.e., less thAn fully h~lLV~I
t~.rminJtoA) and poly~vlnyl alcohol) aro preferred.
S The partlcles of inorgO-nlc oxlde can rango ln slzo from obOut 0.1 Il:n to about 50 llm, O-nd proferO-bly about 1 I~m.
Whon the lnorg~nlc oxlde are oxldes of manglmese, the crystOlllne structure cOn bo ~ny structuro that result in A low pol~rlz~blllty. Nnnl~mil 1ng examples lnclude a-MnO~ inO2, and r-MnO2, with y-MnO2 beLng preferred.
Tho solids contont of inorganlc oxlde ln the thin, COnfnr ~ A dopolarlzlng lOyor can r~ngo ln O-n amount from obOut 10 to about 99.99 wolght porcent of the layer, preferably about 40 to ~Ibout 99 weight peroent, O-nd most preferably about 97 welght5 percent . The blndor cnno~ i t~ltC~o the balanco of tho thln, t~lo dopolarizlng lAyer when tho layor 18 ~V~LLU~.L~ to contO-ct a sepilrOte, electrically conductive lAyer.
In the: ` 'i where particles of inorganic oxlde and electrically conductivo componont aro i ntorml YoA to form a 20 blendod 10-yer, the solids content of Lnorganic oxide in the blended lAyor r~mgos from about 1 to about 99 woight percont of tho layer; the sollds content of the electrlcally conductlve component ri~nges from about 1 to about 99 welght percent of the layer; O-nd blnder cnnRtii-~t^o the bOlance of the welght.
25 Pr~ferably, the weight percent of inorgimlc oxldo, ole~trir~l ly conductive component, Ond bindor rAngos fr obOut SO to ~bout 90;
from about 10 to obOut SO; and tho balance; respectively.
A volatllo liquid 18 used to dissolvo tho blnder.
PO-rtlcles of lnorg~nlc oxlde, ~nd optlon~lly Also p~rticles of 30 electrically conductive component are mixed in the volOtile liquld to form an ink. The volOtile liauid i8 prefi~rO-bly wO-~ter. After ~pplying tho ink, the volatilo lLquid is L. VL~L~d upon coOting onto a substr~to. In O multi-l~yer 'i , the substr~te i~
the electrically conductive layor. In tho blended layer 35 - ` i , the substrAte is an eloctrically n- - l I ive film th~t serves A8 O- backlng for tho olo~ trj Al conductor.
other _ o optlonally can be lncludod in the ink. To O~sist the water-soluble polymer bind particles of the dioxide, an inorganic salt, such as calcium chloride or 40 potzlssium chloride, can be added in an ~mount ranging from about 0.1 to AboYt 3 weight percent of the solids content of the lnk Ond preferably about 1 weLght percent of solids content of the ink. When poly~vinyl alcohol) l8 u ed as the binder, calcium -~ WOg5/20350 21 79512 r~
chlorLde acts an LcnLc crosslLnker for poly(vLnyl chlorLde), increasing binding ef~ect.
Al~o op~ r~lly, a commercially nvaLlable surf~ctant, nuch as sorbLtAn 1 ~At~ commercLally AvaLlable frcm WAko Co .
5 of Tokyo, Japan or polyoxyethylene sorbLtan 1 OAte commercLally avaLlable also from Wako Co. can be Lncluded Ln the ink up to about 0 . 5 weight percent of tho sollds content of the ink but can decre~se adhesLcn o~ the depolarLzLng layer to the electrLcally conductLve layer. Preferably, surf_ctant L~ not 10 needed for the ink used to prepare the depolarizLng layer.
Also optLonally, to achLeve hLgher electrLcal conductLvity in the depolarLzLng layer Ln the multi-layer ~i , carbon or graphLte partLcles cAn be included in the ink in AmountD r_nging from About 1 to about 90 weLght percent of the solids content of the ink.
Also optLonally, to Lncrease adhesLveness cf the depoldrLzing layer to the electrically conductLve l~yer, a water .ylLc emulsLon adhesLve can be added Ln the ink in _mounts ranging from About 0 to about 90 weLght percent of the Lnk.
The acrylLc emulsLcn adhesLve can be a rsactLon product of the polymerLzatLon of at least one A monomer And at leaat one B monomer to yLeld a copolymer hnvLng an Lnherent viscosLty of about 1. 0 dl/g to about 2 . 0 dl/g . The A monomer Ls a polymerL7_ble monomer comprLsLng ~n AcrylAte or meth_cryl-te ester 25 of a non-tertLary alcohol or A mLxture of non-tertLAry alcohols with the _lcohols h_vLng from 1 to 14 cArbon atoms and desLr_bly averagLng about 4 to 12 carbon atoms.
The B monomer Ls An ethylenLcally uns_turAted compound _nd de~Lrably may be acrylic acid, meth_cyrlLc acLd, itaconic 30 _cid, acrylamLde, methAcryl_mide, acrylonitrile, meth_crylonitrile, vinyl acetate, N-vinyl pyrrolidone, or ' ir-1-ir~n~ thereof.
The A monomer is polymerLz~ble and contributes the V; ~'Cn~l A~ ` propertLes of the presliure sensLtLve adhesLve 35 copolymer. Non-limLtLng examples of such A monomers Lnclude the ~sters of _crylic acid or methacrylic acid with non-terti_ry alkyl alcohol nuch as l-butAnol, l-pent_nol, 2 ~ 1, 3 ~ A~l, 2-methyl-l-butAnol, l-methyl-l-butAnol, l-methyl-l-pentanol, 2-methyl-l-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol, 2-40 ethyl-l-hexanol, 3,5,5-trimethyl-1-hexanol, ~ ', 1, 2-octanol, l-decanol, l-dodec~nol, and the lLke. Such monomerLc acrylLc or methacrylLc esters are known Ln the art, and many are commercially available .

2 1 7 ~ 5 1 2 The B monomer i~ an ethylenLcAlly u~ sLl~L~L~d compound copolymerized with the A monomer to affect the physical propertieu of the resulting pressure sensitlve ndhesive copolymer. In gener~l, the pre~ience of the B monomer will reduce the flexibility 5 of the rntiulting pres~ure ~ensitive ndhe-ive copolymer.
Thu8, the weight percentAges of the A monomer And the B monomer should be balanced in order to provide a pressure ~n~Ltive adhesive copolymer hAving an inherent viscosity of from About 1. 0 dl/g to About 2 . 0 dl/g . The weight percentAge rAtio of A
10 monomer: B monomer ranges from About B5:15 to about 98:2 And desirably from about 90:10 to 97:3.
PreferAbly, the Adhe3Lve can be a copolymer of i-ooctyl acrylAte And acrylic ncid in A weight percentAge rAtio of About 95:5 ~nd cAn be prepAred ~ccording to U.S. Pat. No. PE24,906 15 ( Ulrich ) .
If electrolytic mangAneae dioxide i~i used in the ink, then addition of ~n alkaline agent to control pF is also needed to get rjood dispersion stAbLlity. For exAmple, potAssium hydroxide cAn be Added in ~n ~mount of about 1. 5 weight percent of the 20 ~olids content of the ink.
Ri~ irAl Ell~r~rode~
B~ -irAl electrodes employing hi~ ~lr~l electricAl . of the present invention nre useful for monitoring or 25 ~ r~ r purpo~les. In its most bnsic form, A h,i~ ''r~l lectrode comprises an ionicAlly conductive medium cnn' r~in7 skin nd A menns for electrical ~rA~nn ~nt~Arr-l inrJ between the ionic~lly conductive medium And elnc~r~r~l fi~qnr~ r equipment.
FIGS. 1 And 2 8how 11 ri~ -hl n ~ n~gl ~ r 30 electrocardiograph (ECG or EI~G~ electrode 10 on a release liner 12. Electrode 10 includes a field 14 of ~ h~ hlf~, dhesive, ionic~lly conductiYe medium for rnnl ~-tinr, skin of A
pationt upon removal of protective release liner 12. Electrode 10 includeD means for electrical ~ ~rAt~nn of the present invention comprising A hil irAl electrical conductor 16 h~ving a conductive interface portion 18 rnr~r~ing field 14 of ionicAlly conductive medium and a tab portion 20 not rnnt~r~ ~ n~ field 14 of conductive medium for .n~rAl and electricAl cont~ct with electrical eriuipment (not shown).
In this multi-layer: ~ , conductor 16 is shown in ~ multi-lAyered construction of n n. - - l ~ ive, flexible polymeric film 24, an electric~lly conductive lnyer 26, And A
thin, conformAble depol~rizing lAyer 28. The conductive interfAce portion 18 of member 16 comprises an electric~lly conductive layer ~ W095120350 21 7q 512 r~ l55 26 coAted on At least the side of polymeric film 24 f~cing field 14 of conductlve medium and the thin, depolAriziny l~yer 28 co~ted on the olor-rjr~lly conductLve layer 26 and cnn-~-;n~ field 14.
Because depolarizing is not needed for the in~l and S electrical contact with electrical equipment, depolArizing l~yer 28 need not extend to tab portion 20.
In the blended layer ;~ , conductor 16 is a multi-layered construction of film 24 with layers 26 And 28 blended together.
It is foreseen that a typical EICG conductor member 16 be thin, flexible, ~md ~nnfnr~ 1o Polymeric film 24 typically h~s a thickness r~mging from ~bout 10 llm to about 200 ym, And preferably has a thickness of about 75 /~m. Electrically conductive layer 26, ~ ~ graphite layer applied from an ink, has a dried thickness ranging from about 1 /~m to about 100 ,um, ~nd preferably h~s a thickness of about 12 /~m. Depolarizing layer 28, as a ~ J_ ~ A~ dioxide lAyer applied from an lnk, has dried thickness ranging from about 1 llm to about 100 llm, ~nd prefer~bly ~ thickness of about 50 ~m. L~yer 26 And layer 28 total in thickness from about 2 to about 200 ~Im, and preferably About 72 ym, whether ln the: '; of separate l~yers shown ln Fig. 1 or blended together. Thi~ cumulative thickness permits the electric~l conductor 16 to cnnfnrr-'7lo to contours to skin of a p~tlent .
Presently preferred for polymeric film 24 Are a polyester film commercially available as "Mellinex" 505-300, 329, or 339 film from ICI Americas of Eopewell, VA and ~ polyester (polyethylene tororh~ te) film commerciAlly available as "EMBLET T-100" or "EMBLET T-75" film from Unitika Co. of OsAka, 30 Jap~n .
Presently preferred for electric~llly conductive layer 26 is a graphite ink commercially available in Japan as "JEF-120"
from Acheson Jap~n Co. Ltd. of ~obe, J~pan. It is believed that this gr~phite ink h~s a polyester binder cont~ined therein. This 35 commerciA1 gr~phite ink is particularly useful when used dis~olved in a butylacetate solvent in a mix of about 80 weight percent gr~phite ink ~md about 20 weight percent solvent.
A preferred depolarizing layer 28 is ~ _ dioxide film comprising 93.2 weight percent of ~ J- dioxide 40 powder (0.8 llm ~verage p~rticle size~ from Johnson M~tthey of L5, USA, 5.8 weight percent of methyl cellulose binder commercially Available as "Marpolose EM 4000" from Matsumoto Chemical Co. of Osaka, Jap~n, and 1.0 weight percent of pot~sium chloride. An alternate preferred depolarizing layer 28 is a _ g _ W0 951Z0350 2 1 7 9 5 1 2 ~ SS
dLoxide f$1m comprising zlbout 25.6 weight percent of lectrolytic dioxide powder commercially available from Tosoh Co. of Tokyo, Japan, 6.4 weight percent acidic furn~ce cOrbon block commerciOlly avail~ble from Vii~ h; '; Chemicol Co.
of Tokyo, Japnn, 28.8 weight percent of methy7re~ binder - A
~tock ( a 2 . 3 weight percent solution of methyl cellulose commercially ovOllAble a~ "EM 4000 from Ml-t~ ~ ChemicOl CO. of OsOkO, JOp~n, 7.0 weight percent of an acrylic emulsion ndhesive comprisLng about 95 we$ght percent isooctyl acrylate ~nd ~bout 5 10 weight percent ~crylic acLd prepOred ~ccording to U. 5 . Pot . No .
PE24,906 (Ulrlch), Olkaline agent of either 9.6 weight percent of KO}I or 1. 6 weight percent of ~1 259~ Oqueous ammoni~ solution, Ond 0.13 welght percent of KCl, with the bal~mce being deionized water. The solids content of the ink is about 369.
To enhOnce ir:~l contact between an electrode clip (not shown) Ond tab portion 20 of conductor member 16, an Adhesively-backed polyethylene tOpe can be ~pplied to t~b portion 20 on the side opposite side 22 having the electrically conductive l~yer 26. A surg$c~1 tOpe commercL~lly OvallAble from 3M CompOny o8 "Blenderm tOpe can be employed for thls purpose.
As stOted prevlously, some care muat be tOken when electlng an ionic~lly conductive medium for contact with the dopolOrizing l~yer 28.
The ionically conductive medium should be resistOnt to the oxid~tive effect of the inorganic oxide, espeoi~lly '~ in~ effects on hydroxyl group density on terminol groups of ionic~lly-conductive ~ _ ~ i- i nno . For the ionic~lly conductive medium 14, ionically-conductive gels and adhesives whlch ~re minim~lly reActive with m~ng~nese dioxide ~re preferred.
Nnnl ~m~ nrJ exomples of ionic~lly-conductive pressure ensltlve ~dhesive, _ ~-;nn~ Ore commerciOlly ovailOble a8 disclo~ed in U.S. Pot. No. 4,855,077 (ShikinOmi et nl.). Other uteful, _ ~tinn^ include solld stOte conductlve polymer ~1 ~nn~2 dlgcloged in European Patent Puhl;r~i-1nn 0 542 294 (Uy et Oal. ), ionically conductive pressure sensitive ~dhesive '-;nno di8cl0ged in U.S. Pat. No. 5,276,079 (Duan et ~1.), except that . ;A11Y non-volatlle E~lr~iri7nr present in any of ~uch ionically conductive ~inno 18 preferably a rlr iri7nr whlch hns a higher molecular welght than obOut 200 or has hydroxyl 40 s~roups comprising less th~n ~Ibout 3 percent of the molecular weight of the pl~- iri70r. It h~s been found thot limiting hydroxyl group content in the L71no~r;70r to less th~n about 3 percent c~uses a b~ ~ r~l electrode 10 to h~ve appropriOte aging ~.I.o~ lstics during storOge of the electrode 10 prior to use.

~ . .

~ WO 9S120350 2 1 7 9 5 1 2 r~L~~ ss N~nllm~inq examples of rlAotiri7~r8 useful ln ionically conductive ~ i t t I are polyethylene glycol methyl ether, 550 molecular weight, commercially available under the C~rbowax" br~md from UnLon Carbide Corporation, polyethylene 5 glyool 2000 moleculnr weight commercially available also under the "C ' ~ - brond from Union Carbide Corporation, ~nd t_~ ' 2 leneglycol dimethyl ether commerci~lly avaLlable under the ~E}ysolve" br~nd from Tohou Chemical Co. of Tokyo, J~p~n. Of these rlr lr~ r~ polyethylene glycol methyl ther, 550 10 moleculnr weight is preferred.
Another type of ~iirgnr~tlr procedure which cnn employ ~ hl. '~rJ l electrode of the pre~ent invention iD the longer term monitoring of ~ ri-rirAl wave patterns of the heart of a patient to detect patterns of ~hnrrr~-l ;ty. Monitoring h~ r~l 15 electrode ~LL~ UL~3 are disclosed in U.S. Pat. No. 5,012,810 (Str~nd et al.), U.S. Pat. No. 4,848,353 (Engel). The hi~
electrical ov...lu~ ~v. of the present invention can be used ns the conductor member in nny of the ~ shown therein, with the depolOrizing layer of the present invention covering the pnd 20 portion of the conductor member thnt contncts a field of conductive adhesive but not covering either side of the tob portion of the conductor member that ~ Jnlr.lly nnd eleotrically cont~cts n clip leading to the ~ ri-rir~l equipment. Preferably, the h~ rAl electrical conductor of the present invention is 25 used as the c ' member in the hi' ';r~l electrode of the ' '~ ' shown in Figs. 2, 3, Ond 4 of U.8. PAt. No. 5,012,810.
Figs. 3 and 4 s--hr~ni-i-~lly ~.vLLe rv~d to Figs. 2 and

3, respectively, of U.S. Pat. No. 5,012,810. Electrode 40 includes an insulator construction 41, and n conductor member 42.
30 The insul~tor construction 41 includes first ~nd second sections 44 ~nd 45 which, together, define opposite ~ides 46 ~nd 47 of the insulntor construction 41. As seen in Fig. 4, each section 44 nnd 45 includes ~m elongate edge portion 50 nnd 51, respectively. The e~dge portions 50 and 51 eOch include a border portion 52 and 53, 35 respectively, which comprise n peripheral portion of each section 44 and 45, respectively, nnd extending along edges 50 ~nd 51, respectively. In th~t manner, secticns 44 nnd 45 are oriented to xtend ~h~tAn~ y parallel to one ~nother, with edge portions 50 And 51 overl~pping one Onother such that border portions 52 and 40 53 overlap. A seam 60 is created between edge portions 50 nnd 51.
S~lhAIAn~ lly pnrnllelr does not mean that the sections 44 and 45 are necessarily precisely parallel. They may be out of precise coplanar alignment due, for example, to the thickness of the CV~.d~C~VL member 42.

W0 95120350 p.~ ss Conductor member 42 is ~hl~An~i~lly l~imilar to h;~ ';rAl electrLcal conductor 16 described above, having a tab portion 61 ~ D~..ding to tab portion 20 delicribed above ~nd pad portion 62 ~ .,L~ ~.,ding to conductivo interface portion 18 5 descrlbed above. Like hi~ 'irnl ~AlArtrirAl conductor 16, conductor member 42 i~ ~ multi-lnyered conttruction of a n.. l.. I ive~ flexible polymeric film 63, ~n Al~ 'r-mly conductLve layer 64, and a thLn, ~-rn' ' le, depolllrizing layer 65. Altermltively, layer 64 and layer 65 can be A blended layer.
The pAd portion 62 of member 42 comprises ~n ~.1. rAl ly conductive layer 64 coated on at le~st the tiide of polymeric film 63 f~cing field 70 of conductLve adhesive, and the thLn, depol~rLzLng layer 65 coated on the ~l~A~A~r;rAl ly conductLve layer 64 And ~ 1 ng fLeld 70. Because depolarLzLng Ls not 15 needed for the ;rAl and electrLcal contact wLth electrLcal e-yuLpment, depolarLzLng layer 65 does not extend to tab portLon 61. Alt~-rn~l ;vely, layers 64 _nd 65 c~m be a blended l~yer ~nd co_ted Ln a 3Lngle step. OptLonally, an adheaLvely-backed polyethylene tape can be ~pplLed to tab portLon 61 Ln the Dame 20 manner ~8 thnt for the '; of Figff. 1 and 2, in order to ~nhance i r~- 1 contact .
In general, electrode 40 i8 conAtructed such that t_b portion 61 of conductor member 42 pro~ects through ~e~m 60 and ov~r ~ portLon of surface or sLde 46. As a result, ~8 seen Ln 25 Figs. 3 ~nd 4, pad portLon 62 of conductor member 42 Ls ro~
on on- sLde 47 of Ln-ul~tor constructLon 41, and the t~b portLon 61 of conductor member 42 Ls p^~ on ~n opposLte sLde 46 of insulator conatruction 41. It will be, ~.Lo~.d that except where t~b portion 61 extends through tieam 60, the seam may be 30 soAled by me~ns of An adhesive or the like.
It mny be desired to provLde an outsLde ~eal over seam 60. OptLonally a8 seen Ln FLg. 3, thLs can be ~ h~r'~ by placement of A strLp 66 of adhesLve tape or the lLke Ln overlap of ~e~m 60, And partly extendLng over tab portLon 61, t ._.~_ly to 35 ~ lr~ m ~vt~n~ n thereof. It Ls ~l-o desLrable to place an ~dhesLve p.,oi~; ' between surf~ce 47 ~nd upper urface 67 of tab portLon 61 rrn~ l ;ng; sectLon 44. AlternatLvely, as seen Ln lrLg. 4, lower surface 68 of tab portLon 61 Ls shown adhered Ln posLtLon to tiection 45, by means of double-stick tape strip 69.
40 That is, ndhesion in Fig. 4 between the tab portLon 61 and sectLon 45 Ls by means of adhesLve 69 lln~ nAAth tab portLon 61, rather than on top ns shown Ln FLg. 3.
In FLg. 4, a fLeld 70 of conductive adhesLve Ls shown n~ri generally underneath conductLve member 42. It wLll be .

~ W095l~0350 21 7q 51 2 r~ s5 ul~d~ ~oc,d th_t in general the field 70 of conductive adhesive will be nu~ ullded by a fleld 71 of skin Adhesive Also _pplicd to insul~tor construction 41 the side thereof h_ving pAd portion 62 ther-on .
In FLg. 4, a layer of release liner 75 is shown r~; t i nn--ri agninst th_t gide of electrode 40 which has skin ~dhesive 71, conductive Adhesive 70 _nd pad portion 62 thereon.
optionally as shown in Fig. 4, a spacer 76 or tab 76 can be r~itinn~ti between rele~ge liner 75 and ~ portion of insulator 10 construction 41, to fJ~il;t~t~ the separ_tion.
A variety of release liners 75 m_y be utilized; for example, il liner comprising a polymer such as _ polyester or polypropylene material, coated with a silicone release type co~ting which is reAdily 15 ep_rAble from the skin _dhesive and conductive _dhesive.
A variety of m_terials may be utilized to form the ~ections 44 and 45 of the insulator construction 41. In gener_l, a flexible material is preferred which will be comfortable to the user, _nd is relatively strong ~nd thin. Preferred materiA 18 Are0 polymer foamû, especially polyethylene foams, non-woven pads, ~ A 1 1 y polye8ter ~ .l.., various types of paper, And LL~ aL~ films. ~r~nl imlting examples of transparent films include polyester film such as ~ 0.05mm polyester film commerci_lly _v~ilable as Mellinex polyester film from ~C~5 Americ_s, }iopewell, VA having A thickness of 0.05 mm.
The most preferred materials _re non-woven p~ds m_de from melt blown polyurethAne fibre, which exhibit ~ rti~
1m~ h; 1 ity, gtretch recovery and bro10 I~ ty. Nelt blown polyurethane materi~ls usable in insulator construction 41 in Dl -~tro ~ according to the present invention ~re generally 9~ in U.S. Pat. No. 5,230,701 (Meyer et ~1. ) .
Preferably the insulator construction hAs a skin ndhesive on its surface ~nt~tin~ the remainder of the electrode 40 .
Preferred web materials (melt blown polyureth2mes~ for ulie in insulator construction 41 h~ve a web basis weight of about 60-140 g/m2 ~prefer_bly about 120 g/m~). Such materials have an appropri_te tensile strength ~nd moisture vapor LL~ n rate.
A ~ moiDture vapor L~ i ,,n rate is about 500-3000 grAms water/m2/24 hours (preferably 500-1500 grams water/m~/24 hours) when tested according to ASTM E96--80 ~t 21C And 50~i rel~tive humidity. An advantage to such materi~ls i~ that webs formed from them can be made which exhibit good el~sticity ~nd ~tretch recovery. This means that the electrode can stretch well, ~1 7951 ~
in ~11 dlr-ction~, wlth movement of the s~ub~ect, wlthout lo-- of electrode lntegrlty and/or fallure of the HeAl provided by the kin adheslve Materlal wlth a i3tretch recovery of at leait ~bout - 85%, ln all dlrectlon~, after ~tretch of 50'~ l~ preferred It will bo ~ ood that a varlety of 1~ ~rn~ may be utllized for the h~l 'ir~l electrod- di-clo~led hereln Gener~lly an ln~ulator construction of about 3 5-4 5 cm by 5 5-10 cm wlll be rlulte uLtabl- for typlc-l for-~een ~rrl~r~ n~ A
thLckne-- of about 200 to 600 mm provldels for adequat- ~trength 10 And a deslred low rel$ef or proflle, in typlCAl Arpl ~r~ ,rn~, It wlll allio~be ~__ -ood th~t a varlcty of mat-rials may be utllLzed - the skin ~dh-slve q~ypic~lly, acrylat- ester adhesives will be preferr-d Acrylate e~ter copolymer adhe~ivec ~r- particularly pr-ferred Such material are gener~lly described $n U S P~t Nos Re 24,906i R- 33,353; 3,389,827; 4,112,213;

4,310,509; 4,323,557; 4,732,808; 4,917,928; 4,917,929; and Europe~n Patent pl.hl ~ r~-t i rn O 051 935 In particul~r, an ~dh Rlve copolym r h~ving from about 95 to ~bout 97 weight percent l-o-octyl acryl~t- ~nd from Aboilt S
to ~bout 3 perc-nt ~cryl mld- and h~vlng an lnher-nt vl-coslty of 1 1-1 25 dl/q l- prenently pref-rred Adhe~iv- useful a- for adhe~ive 69 c~n b- any of the acrylat~ ~tor adhesiv-- d -cribed abov in double tick tape form A pr~s-ntly prei-rred adhe~ive i~ the same ~Idhesive as prel~ently pr-frrred for the ~kin adhesiv- except having an inher-nt visco-ity of bout 1 3-1 45 dllg For th- fi-ld 70 of conductlv~ adhesive, conductlve Adheslv-s such a- tho~r descrlb~d abov~ as u~eful for field 14 of conductlve medlum are pref-rr-d It wLll be under~itood that the ri i rn~ of the v~rlous layer-, and th-ir, ~ ; rn during ~ n~ are shown somewhat . ,, ' Ln FLg 4, to fari 1 it-At~ an underst ndLng of the con-tructLon In general, an overall sub~tantLally flat _, wlth only a very mLnor ~8~ type bend Ln th- conductLv~ memb-r 42 Ls - 1 by the ~r~A-desplte the multl-l~yer~d constructlon of member 42 Other ~x~mple~ of hi. 'ir~l electrode~ whlch c~n u-e the pre-ent lnventLon a- hi~ '~r~l electrLcal .~, L Lo~ lnclude lectrodes dlsclosed ln U S Pat No 4,539,996; 4,554,924;
4,848,353 (all l}ngel~; 4,846,185 (Carlm); 4,715,382 (Strand~;

5,133,356 (Bryan t ~1 ); and IJ S Pat No 5,215,087 IAnder~on et ~1 ) Ifethods of makLng ~uch ~ rtroe~ ar~ dl-clo-ed in uch p~tent~, except that the hi~ ir~l electrLcal conductor of the pre~ent LnventLon can be AMENDED Si~EET
.. . . . . .. ..... . ..

~ W095l20350 217q512 r~ tl~
Q..hQ i t~tDfi for the various meanD of electrical i rA~; nn dLDclosed in such p_tents .
Among these vQrious electrode constructions iD an electrode construction particularly preferred as that shown in 5 FIGS. 1-2 of U.S. Pat. No. 4,539,g96 (Engel) in which backing 13 having electrical conductor 12 is replaced by the h~ rnl -Qlectrical conductor of the present invention.
Electrodes discloDed in U.S. Patent NoD. 4,539,996 4,848,353; 5,012,810~ and 5,133,356 are preferred.
In some instances, h;- ~irAl electrical oonductor can be an electricQlly conductive tab extending from the periphery of the hi~ 'IrJ-l DlDrtrn~lDo ~uch as that Qeen in U.S. Pat. No.
4,84a,3s3 or can be a conductor member extending through a Dlit or Qeam in a ~ ;nq backing member, such aD that seen in U.S.5 Patent No. 5,012,810. otherwise~ the meang for DlDci-rir~l i r~i- i nn can be an eyelet or other Dnap-type connector such as th~t ~liorl~ ' in U.S. Pat. No. 4,846,185 with the depolarizing layer coated on a graphite coated snap electrode. Alternatively, an DlDci-rir~lly conductive tQb Duch as that seen in U.S. Pat. No.
20 5,012,810 oan have an eyelet or other snap-type connector secured thereto .
Method of M71rinn Bi: ~iCDl ElectrirAl Cv~lJu~L~L~
The hi' 'irAl electrical ~ J~.~.L~Q of the preDent 25 invention can be made by convention~l coating I D, rhn i ~ .
~`Prl irA~inn of an ink rnntA~n;nq electrically conductive component particles, an ink rnni-Aininq inorganic oxide particles, or a blended ink cnn~ln~nq particles of both electrically oonductive component and lnorganic oxide, can employ screen printing or knife 30 coating methods, followed by drying to evaporate solvent, e.g.
water, from the ink applied. when knife coating is employed, ~
gap of about 25 to 100 ~m is ..".~ innAl ly uged, preferably about 50 llm. To minimize surface defects in the coating, a web speed of less than about 7 m/min. is possible with 2 m/min. preferred when 35 coating is made on a ubDtrate in a rnnt 1 process .
Drying of the ink on the ~ ve, polymeric film subDtrate 80 coated can take up to about 10 minutes at 145C he_t to yield a thickness of about 10 to 15 ~Im. Alternatively, the drying can be rnn~ rtQd at about 150-160C with a relatively high 40 air velocity of about 0 . 8-4 . 6 m/secs above and below the substr_te being coated. Preferably the drying occurs in two zones with the air velocity in the first zone ranging from about 1.4 to about 2.8 m/secs. above and below the subDtrate, with a web speed below about 2 m/min.

wog5no3so 2 1 795 1 2 F~ 5s Co~ting of depolarlzing Lnorg~nic oxide-b~sed ink on that portion of the graphite l~yer intended to overlay ~n ionic~lly conductiYe medium is followed by drying for About 10 minut~s at about 40-70C heat to yield a co~t~d thickness of ~bout 5 40-60 /~m.
A lot fed knife is preferably used to coat the depol~rlzing inorg_nic oxide-based Lnk, where the slot width iff pr~ferably about 40-50 mm when the coating width is about 50-60 mm. Preferably the contact ~mgle is About 0. To minimize air 10 ~ntr~l in the coating, a web speed of less than about 5 m/min. is possible with 2 m/min. preferred when coAting is made on a ub-trate in A rrnl ir..~ a process.
Alternatively, drying of the depolarizing layer can be conducted at ~bout 65-75C with a relatively lower Air velocity of 15 ~bout 0 .1-1. 2 m/secs . Preferably the drying occurs in two zones with the Air velocity in the fir t zone ranging from about 1.4 to ~bout 2.8 m/secs. above and below the substrate being coated, with the web speed during drying less than about 2 m/min.
After the hi- irAl electrical conductor is 20 ..~..DL,~_ 1, it c~n be used in A~sembly with other disclosed in the electrode p~tentti Lef~ bove to make a variety of b1- irAl electrode_ suited for a variety of purpose~.
Using an inexpensive, ~ iA11Y x-ray ~ ...L, thin, flexible, rrnfrr~~ hi- ir~l electrical conductor of the 25 present invention, one skilled in the art can repl~ce more expentiive, x-ray op~r~ue sllver/silver chloride L~ without louing the beneflt~ of low-polilrizing electrode p~
The following teit methods and examples further expl;lin the scope of the present invention.
The 7- 'Ai-inn for the AiY. of Medic~l InsL,_ A~l~n (AAMI) hag adopted the following standArds and tosting methods to determine proper ~eLf for a hi- 'irAl eleotrode used for ECG Disposable Electrodes. See the ~Americ~n National St~nd_rd for Pregelled ECG ni orr~~~le Electrodes~
35 r- 'Ai-irn for the AiY_ of Medical IrLr. A~irn (1984), for testing method-A ~md ronr~;t1rn~ for minimum standards for D.C.
Offset (l00 mV), A.C. Impedance (2 kOhms), And Defibrillation OverloAd Recovery ( less than l00 mV 5 seconds after 4 capacitor discharges And a rate of change of residual polariz~tion potential ~0 ~ -e~ tll-n I ~/--~ ~

WO 95l20350 2 1 7 9 5 1 2 P~ ~v~ ~ . 155 ADP1~1~
r 1~ 1 A coating ~ n wag prep~red by mixing 70 per 5 cent by weight of a graphite ink with n polyester binder commerci~lly av~ilable ~n JEF-120 from Acheson JAp~n Co. of l~obe, JAp~n with 30 percent by weight of butyl c~rbitol acetate a8 a solv~nt, the solvent commerci~lly available from Waco Co.
r 1-~ 2 A series of inks according to the pre~ent invention were prep~red ~ccording to Table 1 below. All vnlues ~re in weight percent.
Table 1 15 Name MnO2 !5C I~Cl Wnter Ma8 EC Denka Ink A 24.4 1.7 0.3 70.8 2.8 Ink B 21.8 1.7 0.3 70.8 5.4 Ink C 24.4 1.7 0.3 70.8 2.8 Ink D 24.4 1.7 0.3 70.8 2.8 20 Ink E 21.8 1.7 0.3 70.8 5.4 "MnO2" .c~.~ ~ activated n.. y.. ,.___ dioxide commerci~lly ~vailable from Johnson Matthey Co.
~MC" _ ~ ~ methyl cellulose commerciAlly ~vailable A8 15M4000 from ~ - ChemlcAl Co.
"MA8" ~LC ' carbon in the form of acidic furnace bl~ck commercilllly ~v~ilable from Mit~--hi '; Chemic~l Co.
"EC" .,~.~ ~ carbon in the form of }~etjen black commercially nvnilable from Azko Chemicnl Co.
"Denk~" ...~.. ~ carbon in the form of Acetylene blAck commerciAlly ~vailable from Denkn Co.
All the inks were mixed in n high-shear mixer, and then vacuumed for the purpose of defoaming.
r 1~- 3 A conductive adhesive was prepared ~cccrding the the following formula. V~lues are in weight percent.
40 polyvinyl pyrrolidone 13.2 (commercially available from BASF and crosslinked ~ccording to IJ.S. Pat. No. 5,276,079) polyethylene glycol - (commercially avail~ble an 45 "PEG 300" from Union Carbide~ 26.0 ~ i chloride 0 . 8 w~ter - 17 - 60 . 0 WO95l20350 2 1 795 t 2 r~ r~ s The . o were mixed in a high she~r mixer, then vacuumed for defo~mLng beiore continq.
r ln 4 A conductLve adheslve was prepared ~ccording the the following formula. Values are in weight pcrcent.
Cross-l$nked polyv_ny1 pyrollidone 9.9 IcommerciOlly ~v~i_able from BASF and crosslinked O~ccording 10 to U.S. P~t. No. 5,276,C79) polyethylene glyco_ 4 . 8 ~commerciAlly ~va lable A8 "PEG 600"
from Union Carbl~e ) polyethylene glyco_ methyl ether 15(commercially Ava_lAble as "C~rbowelx 550 from Union CArbide) 14.7 potas~ium chlorlde 0. 6 water 70 . 0 The o were mixed in a high shear mixer, then 20 vAcuumed for defoaminq before coating.
r ln 5 The ink of Ex~mple l was coated on a polymeric film in order to create a conductive layer. The polymeric film was 25 polyethylene ternrh~hAlAte, lO0 micrometers in thickness, commercially available as E}IBLET T-100 film from Unitlka Co. of J~pan. The ink wns applied with a laboratory knife coOter with the knife-to-roll gap beinq set at ~5 micrometer~. The applied co~ltings were then dried ~t 145 degrees C in a static dryinq oven 30 for 6 m$nutes. The finished coatinq wa~ about 12 m1~ ., in thickness .
r ln 6 The inks of Ex~mple 2 were eAch co~ted on the5 polymeric film described in Example 5 in order to create thin, ln depolarizing ~u~ L~ILD. The inks were applied with a labor~tory knife coater with the knife-to-roll gap beinq set ~t lO0 micrometers. The applied co~tinqs were then dried ~t 70 degrees C in ~ stOtic drying oven for 6 minutes. The finished0 co~tings were between ~bout 40 to 50 micrometers in thickness.
r ln 7 The rlnrol~r~7ins ~ ,... Ex~mple 6 were eo.ch coAted with the conductive ~dhe~ive of Example 3 in order to create test 45 ~heets for evaluating properties. The adhesive was applied with a laboratory knife coater with the knife-to-roll qap being set at 800 micrometer~. The applicd coating~ were then dried at 70 wogsno350 2 1 7 9 5 1 2 F~
degrees C in ~ st~tic drying oven for 20 minutes. The finished co~ting~ were between about 200 to 250 micrometers in thickness.
o 8 The test sheets of ~xample 7 were evalu~ted for physical properties. In ~r~ble 2 below, Sheets A-E were prep~red wLth Inks A-E, re~pectLvely. ~rhe wettLng condLtLon ~nd surfaoe nA i t i ~ were evAlu~ted by visual i n~pect i nn through the ..... L conductLve adhesive. The adhesLon strength w~s 10 ev~lluated by applying and then peeling the test sheet from human ~kin; break~ge of the depol~rising layer was the crLterLIl for f Table 2 Sample wettLng surf~ce adhesion r condLtLon rl nrli tlon strenoLh sheet A good mooth good sheet 3 good smooth good 8heet C poor rough not good Sheet D poor rough good sheet E poor rough good r le 9 In order to riotQrm;ne the dry-out properties to be expected of b;oQlectrodes according to the present invention, test sheets made according to Example 7, ut;1;~in~ Ink A, but dried ~or varying lengths of time and evaluated for electrical properties 30 according to the AAMI standards d; ccllcced above. Table 3 shows the results.
Table 3 DryLrg tLme DC offset AC Lmpedance SDR of 4th pulse o' a~hesLve mV at 60 ohms at 10 Hz ~offset) (slope) 70"C~ 8 c~nds mV at sec mV 8ec 2 m n. . 392 2 .2 - .
40 4n m_n . . o 537 3 2 . 7 -n .
60 m_n. n.~ 1957 5-~.6 -_.
90 ~ mLn. -0 . 4052 13n . 7 -5, -~
(-o full dry out WO 9S/20350 P~ SS
r 1~ 10 In order to determine the effect of different depol~rizing l~yers on dry-out properties of test sheets made from all the inks of ExAmple 2 were made accordlng to Example 9, except that all the 5 test sheets were dried to dry-out. These were then evalu~ted for .lr ~-..1 propertles a~ per Example 9. Table 4 shows the r-~ults .
Table 4 10 Drying tLme DC offset AC Lmpedance SDR of 4th pulse of adheslve mV ~t 60 ohms at 10 ~3z ~offset) (slope~
(70C~ seconds mV at 5 8ec mV/aec S leet A -0 . 4052 130 . 7 -~ . `
15~eet B --h.. hl6 33.8 --0.
s leet C 3 . ~07 5 . 6 -O . ~
s~eet D .4 585 _.7 -O.h S~eet E 1~. ' 408 ,~.0 -0.3 r lr- 11 BecAuse the several examples descrlbed above LndLcate a f~vor~ble mix of propertLes when Ink B was used wLth the present LnventLon, an experLment was conducted to optLmLze and scale up 25 the f~t~re of an electrode LncorporatLng thLs ccmpound.
The coatLng ~ _ 1 f i on of Example 1 was coated on the PET film discussed in Ex~mple 5 usLng ~ knLfe coater set to a knLfe gAp of 80 micrometers and a coatLng speed of 1 meter/mLnute.
Th~ ~pplLed co~tLng was then drLed at 145 degrees C Ln a 7 . 5 meter 30 dryLng oven. The fLnlshed coatLng was about 12 mLcrometers Ln thLckness .
ThLs coAted film was then coated wLth Ink B as descrlbed Ln ExAmple 2, usLng a dle coater set to ~ dle space cf 200 mLcrometer~, ~ contLng gap of 142 mLcrometer~, and a dLe head 35 angle of 0.1 degrees. The coatLng speed was 1 meter/mlnute, and the ~pplied coatLng w~s then drLed at 57 degrees C in a 7 . 5 meter dryLng oven. The flnlshed layer was ~bout 35 mlcrometers ln thLckness .
ThLs co~ted fllm was then coated wlth conductlve 40 adhesive as descrLbed in Example 4, using a die coater set to a dle space of 500 mLcrometers, a coatLng gap of 1100 mLcrometers, ~nd ~ dLe head angle of 0.1 degrees. The co~tLng speed was 1 meter/mLnute, and the applLed co~tlng was then drled at 91 deqrees C ln ~ 7 . 5 meter drylng oven . The f lnlshed layer was about 200 45 mlcrometers in thLcknes~.
ThL~ ccAted f llm was cut to a shape sultable for forming the electrode depicted ln Flg. 1, uslng a dle cutter. It ~ W09S/20350 2179512 r_.,.,_ rl~s was observed th~t there was no breakage of the co~ted lAyera ~t the cut edges aiter this operation. 80me of the electrode~ were Applicd to hum~m skin, and a peel test was ~ '. No bre~kage of the coatings WA8 observed following the peel test. An 5 lectriczll test was ~.L, ~ according to the AAMI standards, yielding the following results a8 an ~verage of 10 tri~ls. TAble 5 Yhows the results.
T~ble 5 DC offset AC imped~nce SDR of 4th pulse mV at 60 ohms at 10 ilz (offset) (~lope~
nr'.. mV ~t 5 ~ec mV/seC
15 Example 12 2 . 3 442 33 . 5 -0 . 3 AAMI minimum ~ 100 < 2000 < 100 < 1. 0 reyuirement Examnle 12 A conductive adhesive was prepared ~ccording the the following formula. Values ~re in weight rercent.
Cross-linked polyvinyl pyrrolidone 9.4 (commerci~lly available from BASF and crosRlinked according to U.S. P~t. Ilo. 5,276,079~
polyethylene glycol methyl ether (PEGME) ~commerci~llly available as "Carbowax 550~ from Union Carbide) 18.6 potassium chloride 0 . 6 water 71. 4 The ~Cl, w~ter And PEGME were placed Lnto a mixing ves~el ~nd mixed with a screw mixer until the salt was dissolved. The cr~ --l in~ ' polyvinylpyrrolidone was added to the ve~sel, and mixed until the polymer waa ~
r 1 f' 13 The conductive adhesive of Example 12 w~s coated on a polymeric fllm ln order to test how ~dheslve propertles vary wLth dryLng time. The polymerLc film waf~ a polyethylene ter~rhl h~.lJ.I ~, 100 mLcrometers in thickness, commercially available as EMBLET T-100" film from Unitika Co. of Japan, which had been lightly corona treated by Unitik~ Co. prior to delivery. The conductive ~dhesive 45 was appliod with A l~onma brand roll coater wlth the knife-to-roll g~p being set ~t 750 micrometers. The applied coatings were then dried at 65 degrees C in ~ static dryLng oven for 20, 30, 40, 50, nd 60 mLnutes. After drying, the co~ted film was covered with a liner and cut into 25 mm by 50 mm sample pl~tes. Each sample 50 pl~te w~s ~dhered to ~ st~nd~rd Phenol pl~te and pressed down with a 1 kilogram roller twice. Each 8ample was then tested for 180 WO95/203~0 21 79512 r~ 5S
.
degree peel strength. After the peel test, finger tack wa~ tested by a trial by hand, and the presence o any residue on the Phenol plate was noted. Tablen 6-8 show the results.
Table 6 Peel test performed at 25 degrees C
Drying time Visual Finger 180 degree Imim~i oo~ _ ~ . O~ e tack 8tr~n~h (o~ Residue 20much water strong 7 yes 30soft, cle~r strong 30 yes 40hArd, clear very strong 65 no 50p~rtly hnrd, white moderate 320 no 1560hard, white weak 55 no Table 7 Peel test performed at 37 degree~i C
Drying time Visual Finger 180 degree minllte~ nr,o:~r~nr~ tack ~trenath (a~ residue 20much water strong 4 yes 2530soft, clear very strong 40 yes 40h~rd, clear very strong 120 no 50hard, clear ~ trong 185 no 60hard, clear strong 220 yes Table 8 Pael test performed at 45 degrees C
Drying time Visual Finger 180 degree 35(m;r.. ~ ea~ e t~ck strenoth (o~ residue 30soft, clear very strong 31 yes 40hard, clear very strong 120 no 50hard, clear very strong 220 yes 4060hard, clear very strong 320 yes It is therefore to be noted that drying time for the conductive O~dhesive has an influence on the final properties of the assembled electrode, and ~ t be rrtimi7od W0 95/20350 2 1 7 9 5 1 2 ~ 5 ~ c l55 r 1-~ 14 A coating . ~ n wafi prepared by mixing 70 per cent by we$ght of a graphite ink with ~ polyester binder commorcially Av~ilable as JEF-120 from Acheson J4pan Co. of lCobe, S Japan with 30 percent by weight of butyl carbitol acetate as a solvent, the solvent commercially available from ~;aco Co. Three percent by weight of the ink of a polyisocyanate cross-linking agent ~riDn~f~d D8 ~ardner commercially available from Acheson Japan Co. was added.
r 1~ lS
The ink of 3xample 14 was coated on a polymerio ~Llm in order to create a conductive layer. The polymeric film was a polyethylene tDrerhth~ , 100 micrometers in thickness, lS commercially available as EMaLET T-100 film from Unitika Co. of Japan, with which had been lightly corona treated by Unitika Co.
prior to delivery. The ink waD applied with a roll coater, and then the applied coating was then dried at 120 degrees C. The finished coating was about 13 micrometers in thickness.
E lD 16 An ink was prepared according to the following formula. Values are in parts by weight.
activated _ dioxide 39 . 7 (commercially available from J.M. ) polyvinyl alcohol (comercially available as Poval 2000 from Eishiwa Chemical Co. ) 0.8 methyl cellulose 0 . 8 (commercially available as Marpolose EM4000 from Chemical ) calcium chloride 0 . 6 water 58.1 This ink was coated on the coated film of Example 15 in order to create depolarizing ~.u~lI...,L~D. Before this ooating step, some of the coated films from Example 15 were wiped with paper to modify the surface properties. The ink was then applied 40 with a roll coater ad~usted to several gap sizes. The applied coatings were then dried at 70 degrees C in a static drying oven for 10 minutes, yielding several gampleg with layer th~
variously of 30, 35, and 45 micrometers, depending on the gap size .
ExamDle 17 The depolarizing conductor of Example 16 was each coated with the conductive adhesiv of Example 12 in order to W095/20350 2 1 79 5 1 2 ~ SS
create test m~mples for ~valuating aging propertle~. The _dhesive was appliod with a roll ao~ter and then drLed. The ,.~ u.L~
with theLr AdhesLve coatLngs wore then tested for Aging by being placed $n an oven z~t 57 degrees C, and tested for Adhesive 5 propertiea eAch week for sLx weeks. T_ble 9 hows the results.
Table 9 Conductlve ThLckness of Week 10 laver wi~ed? d~nol Arizino laver 1 2 3 4 5 6 yes 30 micrometers OX OIC OX OK 01~ NG
yes 35 OK 01~ OX OX 0~ NG
yos Ar OK 01~ 0 C OR 01~ NG
15 no `~n 01~ 01~ O,C 0}~ OK OiC
no ~ OK OIC 01~ o~ OE OIC
no 45 OE 0~ OK 0~ 0~ oX
"NGn me_ns not good.

r 1 e 18 A conductive adhe~ive was prepared from a monomeric ~solution cnnoi~l 1n~ of 71.25 9 of Isooctyl Acrylate, 0.795 g of 25 1 i l~ii hylketal (commercially available as IrgAcure 651 from Cib_ Geigy), 12.31 9 of ~Icrylic acid, 16.60 9 of a 4', I~Cl aqueous solution, 25.29 g of polyethylene glycol acrylate (750,000 M.W. ), and 24.99 g of alkylene polyalkoxy sulfate surfactant ~SAM 211 ~1~+) commercially avail~ble as from PPG Industries, Inc. ) . This 30 monomeric solution was cured using ultrAviolet light of 350 nm for ufficient time to provide About 680 mJ/cm~ of nergy between two ilicone coated release liners ~the upper release liner being silicone coAted polyester release liner). The resulting conductivo adhesive was made into ~m electrode ~hown in Fig. 1 35 ~having adhegive ~ Inn~ of 2.54 cm X 2.54 cm) by 1- In~inn onto ~ piece of the conductor ~h~ving Ai inn~ of 2.54 cm X
3.175 cm) produced according to Example 11 above. A second olectrode w_s similarly made. These two electrodes were then evaluat~d for electrical propertiell according to the AAMI
40 ~tandards discussed above at various time incr~ments. Table 10 shows the results.
Table 10 45 DC Offset AC Impedence SDR of 3rd Pulse mV Ohm~ ~ of f set ) ~ 8 lope ) mV mV/s -2.0 461 @ 5 sec. 8.4 --@ 15 sec. 7 . 3 -O.1 @ 25 sec . 6 . 8 -O . O
@ 35 sec . 6 . 4 -O . O

WO 9Sl20350 r~ l5 r 1~ 19 Ex~mple 18 was repeated except thAt polyethylene glycol acrylate 750 was replaced with polyethylene glycol acrylate Hter commercLally avaLlable from Shin ~T~h _ Chemical Co. of S Wakay~ma, Japan. AaMI test~ reRulted in the following values wLth SDR measured At 5 secs. Table 11 flhows the results.
Table 11 DC Offset AC }mredence 8DR of 3rd Pulse 10 mV Ohms ~offset) Islope) mV ~t 5 sec. mV/s 3 . 7 403 9 . 3 -O . 1 r 1~. 20 ExAmple 19 wa8 repe~ted under ~m Aging test by being placed in a moisture barrier pouch in an oven heated to 49C and removed for testing ~t 1, 2, 4, and 8 weeks. AaMI tests resulted in the following values with SDR measured at 5 secs. Table 12 shows the results.

Table 12 Week DC offaet Ac Imredence SDR of 3rd Pulse 25 mV Ohms (offset) (slope) mV mV/ 8 2.3 713 4.6 -0.1 2 -0.8 906 15 3 -0.1 4 -1 . 4 547 14 . 7 -O . 1 8 -2 . 5 614 15 . 4 -O . 2 r 1~,- 21 An~ 22 Two different conductor l~heets were prepared using the s~me graphite ink f lAfir~n~ the game polyester b~se film, but different depolcrizing layer f~ n-m The base film was ~5 40 llm polyethylene ter~rh~ film (Emblet T-75 film commerci~lly available from Unitika Co. of Osaka, Japan), which was tre~ted on the co~ting side by a corona discharge by Unitika Co. prior to delivery .
The graphite ink was prepared from JEF-120 branded 45 gr~phite ink (commercially AvailAble from Acheson J~p~n Co. of Kobe, Japan) at 80 weight rercent and butylacetate solvent at 20 weight percent.
The graphite ink and solvent were mixed by air mixer until in a well-mixed ~rn~ n After mixing, the mixture was 50 filtered with two sheets of gauze cloth and stored.

WO 95/20350 2 1 7 9 5 1 2 ~ F~~ ss ~
The depolarizing layer was prep~red by elther of two formul~e In both formulAe, ~m acrylic emull3ion Adhel3ive wa~3 added for strong Adhesion, and an alkaline agent was ~dded for rnrF;r~n stability. One used ROH as the alkaline agent; the 5 other u-ed NH~ as the ~lkaline agent. The solid depolarizing layer by tha Example 21 ink contained the Active I~OH of ~Ibout 0.1 wt.~,.
The ~olld depolarizing layer of Example 22 cont~ined no ~lkaline ~gent by the ev~por~tlon of NH3. Their formul~e are l~hown in Table 13.
Table 13: Formulae of MnOz ink or depolarizing l~yer ~wt.9~) Materi~l Example 21 Example 22 Electrolytic MnOz powder 2S.6 25.6 15MA8 AcLdic FurnAce carbon bl~ck 6 . 4 6 . 4 Methylcnll~ binder stock 28.3 28.8 Acrylic emulsion adhesive 7.0 7.0 I~Cl 0 . 13 0 . 13 lli-l~OH 9 . 6 -----2025~ ammonia water --- 1.6 Ion exchanged water 22.47 30.47 (Solidi) (36.6) (36.6) * Electrolytic MnO~ powder :FMH- MnOz of Tosoh Co., J~p~n 25 * MA8 Acidic Furnace carbon bl~ck: Mi~ h; Chem Co., J~pan * Acryl_c ( I-~ooctyl acrylate/Acrylic acid 95/5 ) emulsion prepared accoruing to U.8. Pat. No. RE 24,906 * Hethy ~ 1 t binder stock : 2 . 3 wt . ~ solution of EM4000 Methy_ cellulo-e: Mat~umoto Chem Co., Japan The pH of the ink w~s 12 for the Example 21 ink and 11 for the Example 22 ink. The ink without binder stock or emulsion adhesive was mixed in the plastic can by air mixer and stored.
35 Mixing occurred in the order of XCl, then carbon black, then MnOz powder, then alkaline agent. In order to keep dispersion tability of ink, the stored ink was mixed Again before coating, and methylcnl 11ll. binder stock and ~crylic emul-ion adhesive were mLxed into the stored ink by air mixer until well-mixed. The 40 mixture was filtered by 2 sheetD of gauze cloth ~nd poured into the hopper of a Moyno pump, commercially available from Heishin Engineering and Equipment Co. of Eobe, Japan.
The pot life of the inks of Example~3 21 and 22 were over 6 hours. The coating ink in the hopper was c~m~ir~lly mixed ~ W095/20350 2 1 7 9 5 1 2 _J~u~ ~ ccls~
by a minL mixer to minimize sep~r~tion of the adheaive emulsion.
For the ~x mple 22 ink, the hopper was sealod to minimize ev~r~ nn of NH3 f rom the ink.
The co Ating of graphite ink and NnO2 ink were cArried 5 out ~ccording to the ~ inn~ identified in Table 14 for both ~Sxamples 21 And 22.

Graphite NnO2 Col-ting coAting Type of S~ho' ~ PET GrAphite on PIST
0 SubOtrate Thi.' Alo.61m] 86 Co~ting Width [mm~ 135 54 Coating C~liper~10~[m] 11 60 Cooting C'~n~ nn Type of Co~ter Die (FB) Die (SF}C) 15Slot G~p [mm] 0.2 Slot Width [mm] 130 46 Co~ting Speed [m/min. ] 2 2 FB Upstream Roll [mm] 290 D -- ~ Roll [mm] 521 20SFK Die to Web di~t~nce~ 10~[m] 289 Die Angle tdegreel 0 Type of Pump Zenith Noyno Pump Size 1 cc/rev. ] 0 . 58 0.1 Pump Speed [rpm] 23 108 Filter Roki Techno Co., Ltd. SL-700 Tension [~g/Substratc width]
Unwinder ¦ 2 ¦ 2 Winder ¦ 2 ¦ 2 Drying r , ~ nn 30 Blower Revolution [Hz~
Zone 1 Supply 24 12 Zone 2 Supply 18 9 Exhaust 55 55 Recirculation Y N
35B~Ack 8ide He~ting N Y
Oven ~ , ~Lu~e: [ C ]

W0 95/20350 2 ~i 7 9 5 1 2 P~ IS5 ~
zone 1 2~ax 154 71 Zone 2 Min 152 67 zone 2 Mox 159 72 Zone 2 Min 158 67 FEI ~ Fluid Bearing Die SFIC - Slot Fed }~nife Die Durlnq ~, i n~ it was Lmportant to a) U~e ~lot fed knife coating die head or MnO2 ink coating without air r~ ~ ;
b) Provide a drying condition for MnO2 ink to keep ~mooth urface Ond ~trcng adhesion on the graphite ~urface c) U~e Moyno pump for MnOl ink d) Mix and seal ~n~ on the hopper for MnO~ ink ) Avoid u~e of MnOl ink which was stored for long time f ) Filter the mixed ink before u~e The coated conductor sheets of Examples 21 and 22 were 20 evaluated for physical properties and olor~r~rAl properties The co~ted grOphite sheet w~s evaluated for thicknes~, co~ting weight and surface resistance Table 15 ahow~ the rel~ult~
Table 15 ~valuation of the coOted graphic sheet Eloth Example 21 and Ex~mple 22 Thicknel;s (solid) 11 to 12~m Coated weight (solid) 0 204 g/10 cm surface .~ ~ol lre 40 to 50 n/8q The co~ted MnOl layer wa~ evaluated for coated weight, ~oftness, edge break, '-1 'r-t~rn and electricOl ~L r~ A~
the coated ~urface was very rough, it was difficult to measure the 35 coated thickness So, the co~ted weight was mea~ured The ~oftness was evaluated with the coated sheet bent 180 to d~ttermine how much of the depol~rizing loyer came of the graphite layer The edge break wa~ evaluated to determine if the depolarizing layer ot the edge of electrode came off the gr~phite 40 layer The ~iol ~ ~ nnt ~ rn wa~ evaluated if the depolarizing layer was off from the graphite layer, when the ccnductive adhesive of the electrode was peeled off The olec~r~r~l ~L_r wa~
~valuated on the AAMI ~tandOrds de~2cribed above ~ W095/20350 2 1 7 q 5 1 2 1 l/ 'I 155 T~ble 16 Evaluation of the coated depol_rizing l_yer Example 21 Example 22 Co_ted weight (solld) 0.987 g/lOOcm2 0.793 g/lOOcm~
5 Softne~s No off No off - Edge Break No break No break r 1J ~nAt~rn No No AAMI st_ndards S_tisfied SAI ~rfin~' Example~ 23A, 23B, 24A, and 24B
Two types of hi~ 'irAl electrodes were f_bricnted with co_ted conductor heets of Ex_mples 21 _nd 22 _nd conductive 15 adhesive b_cking electrode (2RG) film _nd lLner film. One w_s in the form of Figs. 1 and 2 _nd the other electrode (ECG) was in the form of Figs. 3 ~nd 4. For the electrode of Figs 1 and 2, five 1- were _dhered on the s_me liner sheet, and two sheets were p_cked in a moisture bnrrier pouch and stored. For the 20 ~1~ of Fig~. 3 and 4, ten electrodes were adhered on the u_me liner sheet, and packed in a moisture b_rrier pouch nnd stored. The conductive ~dhesive used wa~ a solid state conductive dhesive sheet m_de of polyureth~ne _nd LLC10~ salts (commerci~lly Av~il_ble A8 No.--VIII from TARIRON Co., JAPAN) . This _dhesive w_s 25 ~ opeci_l ' lA~irn conductive _dheAive and cont_ined less free polyole and had suit_ble tack for the skin adhesion.
Over 40 pouches for each kind of electrode were f_bricated for the sever_l evalu_tions including ~n aging study.
The f~bric_ted electrodes were evalu_ted using A~lI
tandards, initi_l _dhesive strength, _nd _dhesion strength after i hour, tr_ce r~u_lity lmd the i~l nAtirn after peeling from the skin. AAMI standards were carried out as bove. Adhesion strength was me_sured by 180~ peeling test on the fore _rm of _n indiv$duz~1 .
Table 17 shows the electrical peL~ on AAMI
~tand_rds. All electrode~ satisfied _11 AAMI st_nd_rds.

W095r20350 2179512 r~ .. 't-lS~ ~
T~ble 17 Electrical p~ ~ i on AA~I l~t-~nd-lrdn 3Sx. Electrode DC Off~et AC SDR-4th Pulse (mv) e60 Impedance Offset MAX
sec. ~It 10 Hz e5 noc Slope (n) (mV) (mV/s) 23A ECG --l.9 473 15.9 --0.4 electrode (Figs. l and ~xample 21 -1.1 504 15.4 -0.3 conductor 1;~ 1.3 548 21.3 -0.5 TAlURON VIII Ave. 508 Ave.-0.4 ~dhesive 5 23B EKG 0.1 297 10.7 --0.2 eloctrode (Pigs. 3 And 4) Ex~mple 21 0.0 311 10.1 -0.1 conductor & 0.2 327 10.8 -0.2 TAKIRON VIII Ave. 312 Ave.-0.2 ~dhesive 24A ECG -0 . 2 411 17 . 5 -0 . 2 electrode (FLgn. 1 And 2) Example 22 - l . 2 48 7 17 . 2 -0 . 3 conductor h -2 .1 476 16 . 5 -0 . 3 TAICIRON VIII Ave. 458 Ave.-0.3 o.dhesive 24B E~G --0.1 254 11.8 --0.1 electrode ( Figs . 3 and 4) Example 22 0 . 2 279 12 . 7 -0 .1 conductor -0 . 4 302 12 . 9 -0 . 2 TAXIRON VIII Ave. 278 Ave.-0.1 adhesive T~ble 18 ~hows the physical and clinic~l pc.-10 on skLn ~dhesion ~trength, the ' l ' n~ n of MnO~ depolarizing ll~yer from the graphite layer, and trace quality of Lead(I).

~, ~ 2 1 7 9 5 1 2 ; ~
TAbl~l 18 PhyGical and clLnlc~l p~_~
Ex Electrode Skln adh--lon Av D-lami- Tr~lce I~ ) natlon form 180 p~l~
lnltlal Ql hour Z3A ECC electrod~ 218 1~0 No Cood Example 21 conductor G
TA~IRON No VIII
23B ERG electrode 60 133 No A
Ex~mpl-- 21 llttle conductor & B--se TAEIRON No VIII llne Nol6e 24A ECC electrod-- 308 305 No Good Ex~mpl-- 22 conductor &
TAEIRON No YIII
24B ERC electrode 94 183 No Good ExAmpl-- 22 conductor &
TANIRON No VIII
S ~ Peellng 6peed 0 3 m/mln Example6 23A, 23B, 24A, and 24B w r- rep-~ted under ~n aging t-~t by belng placed ln a mol6tur~ b~rrl-r pouch ln an oven he~ted to 57C and removed for testlng ~ft~ r 10 week- All !lample 10 el LL~_- I atlsfled the AA!lI st ndard6 AMENDED SHEE~

Claims (11)

What is claimed is:

1. A biomedical electrical conductor (16), comprising a thin, conformable film of an inorganic oxide of low polarizability. and a binder relatively resistant to oxidation by the inorganic oxide.

2. A biomedical electrode (10 or 40), comprising the biomedical electrical conductor (16) of Claim 1.

3. The biomedical electrical conductor, according to Claim 1, further comprising an electrically conductive layer (26) in mechanical and electrical association with the thin layer of the inorganic oxide of low polarizability.

4. The biomedical electrical conductor, according to Claim 3, wherein the conductor (16) is a multi-layered composite of a nonconductive, flexible polymeric film (24), the electrically conductive layer (26) comprising a thin layer in mechanical association with the polymeric film, and the thin, conformable layer (28) of the inorganic oxide of low polarizability in mechanical and electrical association with at least a portion of the electrically conductive layer.

5. The biomedical electrical conductor, according to Claim 4, wherein the inorganic oxide comprises an oxide of manganese.

6. The biomedical electrical conductor, according to Claim 1, wherein the binder comprises a water-soluble polymer comprising naturally and synthetically modified celluloses, polyethylene oxide, poly(vinyl alcohol), or poly(N-vinyl lactam), an acrylic emulsion adhesive and an alkaline agent, or combinations thereof.

7. The biomedical electrical conductor, according to Claim 6, wherein the inorganic oxide comprises from about 0.01 to about 90 weight percent of the film and wherein the binder comprises from about 0.01 to about 90 weight percent of the film.

8. The biomedical electrical conductor, according to Claim 6, wherein the inorganic oxide comprises dioxide.
and wherein the binder comprises methyl cellulose.

9. The biomedical electrical conductor, according to Claims 3-8, wherein the electrically conductive layer is essentially x-ray transparent and comprises a conductive polymer or carbon-containing layer.

10. The biomedical electrical according to Claim 2, further comprising an ionically-conductive medium contacting the conductor, wherein the ionically-conductive medium comprises an ionically-conductive pressure sensitive adhesive and wherein the ionically-conductive pressure sensitive comprises an essentially nonvolatile plasticizer having hydroxy group comprising less than about 3 percent of the molecular weight of the plasticizer.

11. The biomedical electrode according to Claim 2, wherein the conductor comprises a tab portion (61) and pad portion (62) and wherein the electrode further comprises an insulator construction (41) having opposing sides contacting the conductor in a manner whereby the tab portion is positioned on one side of the insulator construction and the pad portion is positioned on an opposing side of the insulator construction.