CA1229884A - Low-polarization low-threshold electrode - Google Patents
Low-polarization low-threshold electrodeInfo
- Publication number
- CA1229884A CA1229884A CA000452996A CA452996A CA1229884A CA 1229884 A CA1229884 A CA 1229884A CA 000452996 A CA000452996 A CA 000452996A CA 452996 A CA452996 A CA 452996A CA 1229884 A CA1229884 A CA 1229884A
- Authority
- CA
- Canada
- Prior art keywords
- electrode
- platinum
- grooves
- contact
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N1/00—Electrotherapy; Circuits therefor
- A61N1/02—Details
- A61N1/04—Electrodes
- A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
- A61N1/056—Transvascular endocardial electrode systems
- A61N1/057—Anchoring means; Means for fixing the head inside the heart
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N1/00—Electrotherapy; Circuits therefor
- A61N1/02—Details
- A61N1/04—Electrodes
- A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
- A61N1/056—Transvascular endocardial electrode systems
- A61N1/0565—Electrode heads
Abstract
ABSTRACT
Disclosed is a cardiac pacing lead employing an elec-trode which has a novel geometry and which is provided with a coating of platinum black. The electrode is generally hemispher-ical and is provided with grooving. In its preferred embodiment, the electrode is provided with circular grooves and with tines which urge the electrode into contact with the endocardial wall, in a direction roughly perpendicular to the grooves. The elec-trode may be constructed of platinum or of a conductive base metal provided with an external surface of platinum and is preferably coated over its external surface with a coating of platinum black.
The grooving of the electrode provides areas of small radius of curvature which contact the endocardial surface, resulting in lo-calized increases in current density at the edges of the grooves.
The hemispherical shape of the electrode maximizes the opportunity for contact between the groove edges and the endocardium. In its preferred embodiment, the electrode displays extremely low polar-ization following the application of a stimulation pulse and thereby displays significantly enhanced ability to sense the nat-ural electrical activity of the heart.
Disclosed is a cardiac pacing lead employing an elec-trode which has a novel geometry and which is provided with a coating of platinum black. The electrode is generally hemispher-ical and is provided with grooving. In its preferred embodiment, the electrode is provided with circular grooves and with tines which urge the electrode into contact with the endocardial wall, in a direction roughly perpendicular to the grooves. The elec-trode may be constructed of platinum or of a conductive base metal provided with an external surface of platinum and is preferably coated over its external surface with a coating of platinum black.
The grooving of the electrode provides areas of small radius of curvature which contact the endocardial surface, resulting in lo-calized increases in current density at the edges of the grooves.
The hemispherical shape of the electrode maximizes the opportunity for contact between the groove edges and the endocardium. In its preferred embodiment, the electrode displays extremely low polar-ization following the application of a stimulation pulse and thereby displays significantly enhanced ability to sense the nat-ural electrical activity of the heart.
Description
67~12-242 This invention relates generally to medical electrical leads and, in particular, to cardiac pacing leads.
During ~he past twenty years, the technology of cardiac pacing has significantly advanced, with implantable pacemakers displaying an ever-inc:reasing variety of pacing modalities, substantially broadening the indications for pacemaker use. In conjunction with this advancement) there has been extensive research and development eEfort expended to optimi3e the performance of pacing leads. As a result, a number of desirable performance characteristics for pacemaker leads have been identified.
It is generally agreed that an optimal pacing electrode will yield a low threshold of stimulation and will be responsive to the small electrical signals naturally generated by the heart. It is also known that polarization of the electrode structure by stimulation pulses may interfere with efficient delivery of these stimulat:ion pulses. The effect is discussed in detail in United States Patent No. 3,476,116 issued to Parsollett et al. Parsonett addresses -this problem by use of a large surface area electrocle withill a fluid-filled chamber provided with a small aperture tllrough which the stimulation energy must pass. A somewhat diEferen-t approach is d:isclosed in United States Patent No.3,7~19,101 issued to Williamson. l~ iamson limits the stimulation area oE the electrode to a small por-tion oE the electrode body cmd -Eabricates tha-t portion of platinum coated witll platillum black, claiDling all electrode having reduced polari3ation. ~\ -thircl apyroach is clisclosecl in Uni-tcd States Patent ~o.4,156,~12~ issued to /\nlulldsoll. Am~mdso elnploys a metallic Eilamelltous structure to produce a paci.ng e1ectrocle.
This struc-tllre is claimed to reduce the energy re(luired for st:imulatio over extended periods of time, as a result of a reduction in polariæation and of improved bicompatability~
The present invention is a cardiac pacing lead employing an electrode which has a novel geometry and which is provided with a coating of platinum black. The electrode is generally hemispherical and is provided with grooving. In its preferred embodiment, the electrode is provided with circular grooves and with tines which urge the electrode into contact with the endocardial wall, in a direction roughly perpendicular to the grooves. The electrode may be constructed of platinum or of a conduc-tive base metal provided with an external surface of platinum ancl is preferably coated over its external surface with a coating of platinum black. rhe grooving of the electrode provides arecLs of small radius of curvature which contact the endocardial surface, resulting in localizecl increases in current density at the edges of the grooves. The hemispherical shape of the electrode maximizes the opportunity for contact between the groove eclges and the endocardium. In its preferred emboclin~ellt, the electrocle displays e~ctremely low polarization following the applic~ltion of a stimulation pnlse ancl thereby displays significantly enhanced ability to sense the natural electrical act:ivity of the heart.
As discussecl above, there has been significant efort clirected to reducillg electrode pol.lri7ation to a level which cloes not inter~ere with the clelivery of stimul.ltioll ill~pulses. Ilowever, many pleselltly av.lilable electrocles knowll to nl)plicailt still clisplay some l~oliarizatioll follo~Yillg a stim~llatioll l)UISt)~ ~r~iS pol~lri7atiol~ ~lissip~lt~s ~ollowil~g tll~ st~ l.ltioil l~ulse iallcl is IlOt believecl to si~nificarltly :intertere ~Yith the delivery o~
the followi~lg stimul.lt:io~ ises. Ilowever, pol.lri7atioll ot thes~ electrocles ~Z~ 4 is believed sufficient to interfere wi~h the ability of the el-ectrode to respond to the electrical activity of the heart during the period immediately following delivery of the stimulation im-pulse. This does not prevent proper functioning of presently available pacemakers, as they are typically refractory to any nat-ural electrical activity within the heart during the period immed-iately following a stimulation pulse. However, as pacemakers having modes of operation intended to regulate tachycardias and other arrythmias are devloped, it is anticipated that the ability to sense heart activity immediately following the s-timulation pulse will be a desirable characteristic. In particular, this abili.ty would allow the development of a pacemaker capable of determining whether its stimulation puls~s have successfully trig-gered the desired heart activity. The present invention pro~ides an electrode having this desirable ability.
Thus, in accordance with one broad aspect of the in-vention, there is provided an implantable lead, comprising:
an electrical conductor having a proximal end and a distal end;
an insulative sheath covering said conductor, an electrical connector coupled to the proximal end of said conductor; and an electrode means having a surface exposed to the exterior of said insulative sheath, for directly contacting the endocard-ium of a human heart at said exposed surface, ~herein substantial-ly all of said exposed 5urface is provided with a coating of plat-inum black and wherein said electrode means is coupled to the distal end of said conductor.
The details of the present invention and of its ad-vantages may be rnore fully understood in conjunction with the attached drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
_ Figure 1 shows a side plan view of a pacing lead accord-ing to the present invention.
Figure 2 shows a cross sectional view of the distal tip of the electrode of the lead shown in Figure 1~
E'igure 3 shows a front plan view of the distal tip of the electrode of -the lead shown in Figure 1.
Figure 4 shows a cross sectional view of the distal portion of the pacing lead shown in Figure 1.
Figure 5 illustrates an oscilloscope tracing which depicts the performance of the presently available pacing elec-trode.
Figure 6 illus-trates an oscilloscope~ tracing which de-pic-ts the performance o~ an electrode constructed according to the
During ~he past twenty years, the technology of cardiac pacing has significantly advanced, with implantable pacemakers displaying an ever-inc:reasing variety of pacing modalities, substantially broadening the indications for pacemaker use. In conjunction with this advancement) there has been extensive research and development eEfort expended to optimi3e the performance of pacing leads. As a result, a number of desirable performance characteristics for pacemaker leads have been identified.
It is generally agreed that an optimal pacing electrode will yield a low threshold of stimulation and will be responsive to the small electrical signals naturally generated by the heart. It is also known that polarization of the electrode structure by stimulation pulses may interfere with efficient delivery of these stimulat:ion pulses. The effect is discussed in detail in United States Patent No. 3,476,116 issued to Parsollett et al. Parsonett addresses -this problem by use of a large surface area electrocle withill a fluid-filled chamber provided with a small aperture tllrough which the stimulation energy must pass. A somewhat diEferen-t approach is d:isclosed in United States Patent No.3,7~19,101 issued to Williamson. l~ iamson limits the stimulation area oE the electrode to a small por-tion oE the electrode body cmd -Eabricates tha-t portion of platinum coated witll platillum black, claiDling all electrode having reduced polari3ation. ~\ -thircl apyroach is clisclosecl in Uni-tcd States Patent ~o.4,156,~12~ issued to /\nlulldsoll. Am~mdso elnploys a metallic Eilamelltous structure to produce a paci.ng e1ectrocle.
This struc-tllre is claimed to reduce the energy re(luired for st:imulatio over extended periods of time, as a result of a reduction in polariæation and of improved bicompatability~
The present invention is a cardiac pacing lead employing an electrode which has a novel geometry and which is provided with a coating of platinum black. The electrode is generally hemispherical and is provided with grooving. In its preferred embodiment, the electrode is provided with circular grooves and with tines which urge the electrode into contact with the endocardial wall, in a direction roughly perpendicular to the grooves. The electrode may be constructed of platinum or of a conduc-tive base metal provided with an external surface of platinum ancl is preferably coated over its external surface with a coating of platinum black. rhe grooving of the electrode provides arecLs of small radius of curvature which contact the endocardial surface, resulting in localizecl increases in current density at the edges of the grooves. The hemispherical shape of the electrode maximizes the opportunity for contact between the groove eclges and the endocardium. In its preferred emboclin~ellt, the electrocle displays e~ctremely low polarization following the applic~ltion of a stimulation pnlse ancl thereby displays significantly enhanced ability to sense the natural electrical act:ivity of the heart.
As discussecl above, there has been significant efort clirected to reducillg electrode pol.lri7ation to a level which cloes not inter~ere with the clelivery of stimul.ltioll ill~pulses. Ilowever, many pleselltly av.lilable electrocles knowll to nl)plicailt still clisplay some l~oliarizatioll follo~Yillg a stim~llatioll l)UISt)~ ~r~iS pol~lri7atiol~ ~lissip~lt~s ~ollowil~g tll~ st~ l.ltioil l~ulse iallcl is IlOt believecl to si~nificarltly :intertere ~Yith the delivery o~
the followi~lg stimul.lt:io~ ises. Ilowever, pol.lri7atioll ot thes~ electrocles ~Z~ 4 is believed sufficient to interfere wi~h the ability of the el-ectrode to respond to the electrical activity of the heart during the period immediately following delivery of the stimulation im-pulse. This does not prevent proper functioning of presently available pacemakers, as they are typically refractory to any nat-ural electrical activity within the heart during the period immed-iately following a stimulation pulse. However, as pacemakers having modes of operation intended to regulate tachycardias and other arrythmias are devloped, it is anticipated that the ability to sense heart activity immediately following the s-timulation pulse will be a desirable characteristic. In particular, this abili.ty would allow the development of a pacemaker capable of determining whether its stimulation puls~s have successfully trig-gered the desired heart activity. The present invention pro~ides an electrode having this desirable ability.
Thus, in accordance with one broad aspect of the in-vention, there is provided an implantable lead, comprising:
an electrical conductor having a proximal end and a distal end;
an insulative sheath covering said conductor, an electrical connector coupled to the proximal end of said conductor; and an electrode means having a surface exposed to the exterior of said insulative sheath, for directly contacting the endocard-ium of a human heart at said exposed surface, ~herein substantial-ly all of said exposed 5urface is provided with a coating of plat-inum black and wherein said electrode means is coupled to the distal end of said conductor.
The details of the present invention and of its ad-vantages may be rnore fully understood in conjunction with the attached drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
_ Figure 1 shows a side plan view of a pacing lead accord-ing to the present invention.
Figure 2 shows a cross sectional view of the distal tip of the electrode of the lead shown in Figure 1~
E'igure 3 shows a front plan view of the distal tip of the electrode of -the lead shown in Figure 1.
Figure 4 shows a cross sectional view of the distal portion of the pacing lead shown in Figure 1.
Figure 5 illustrates an oscilloscope tracing which depicts the performance of the presently available pacing elec-trode.
Figure 6 illus-trates an oscilloscope~ tracing which de-pic-ts the performance o~ an electrode constructed according to the
2~ present invention.
Figure 1 shows a side plan view o~ a pacing lead accord--ing to the present inventiorl. The lead is provided with an elon-gated lead body 10 which is covered with an insulation sheath 12, which may be fabricated of silicone rubber, polyurethane or other suitable plastic. At the yroximal end of lead body 10 is connector assembly 16, which is provided with sealing rings 18 and which carries connector pin 20. Connector assembly 16 may be constructed using techniques known to the art, and may be fabricated of silicone rubber, polyurethane or other suitable plastic. Connector pin 20 may be fabricated of stainless steel or other conductive material. At the distal end of lead body 10 is electrode 26 which is discussed in more detail below. Immediately proximal to the exposed portion of electrode 26 is tine sheath 22 which bears four tines 24, of which three are visible.
Tines 24 engage with heart tissue and urge electrode 26 into contact with the endocardium, in a direction parallel ~o the lead a~is. Tines 22 are more fully described in United States Patent No.3,902,501~ issued to Citron et al.
Slideably mounted aro~md lead body 10 is fixation sleeve 14, which serves to stabilize the lead at the site of venous insertion. Sleeve 14 is more fully described in commonly assigned ~ited States Patent No. 4,437,475 of White.
Figure 2 S~lOWS a cross sectional view of the distal end of electrode 26 shown in Figure l. Electrode 2LS is generally hemlspherical and is provided with two circular) v-shaped grooves 28 and 30 and with an a.~ial bore 32. Grooves 28 and 30 and bore 32 divide the outermost sur~ace vf electrode 26 into three anllular areas 34, 36 and 38. Central bore ~ ~nd g-roove 28 define all angle 4~, wh:ich may be 70 degrees. Central bore 32 alld groove 3() define an angle L~2 "~hich may be 40 degrees. Grooves 28 arld 30 are Cllt havillg all angle 40 which may be 60 degrees. The edges defined by the grooves ancl annular areas of electrode 26 are seen to provide areas of small radius of curvature, which are believed to ~rovide localized increases in current 7 ~3~
density and to thereby redwce stimulation thresholds. Precise adherence to the dimensions given above is not believed necessary to practice the invention.
~1owever, it is desirable that the edges defined by the grooves and annular areas display a small radius of curvature, for the reasons discussed above.
Arranging the grooving generall~- perpendicular to the direction in which the tines urge the electrode is believed to be beneficial. In the preferred embodiment this is accomplished using circular grooves. ~le grooves are believed to assist in fixation of the electrode to the endocardiwn by providing invaginations into which tissue may grow. Such -Ei~ation is believed to reduce the possibility o micro-dislodgmen-ts, whic}l can cause an increase in threshold due to irritation of the endocardi~m1, increased fibrotic growth, or simply due to the displacement of the electrode from the endocardium.
Figure 3 shows a front plan view of the distal tip of electrode 26.
In this view, the form of annular areas 36 and 38 is more clearly apparent, along with the circular form of grooves 28 and 30.
Figure 4 shows a cross sectional vie~ of the clistal end of the lead of Figure l. In this view, electrode 26 is seen to be provided Wit]l an elongated tubular portion 46 W}liCil has a central lumell 56. ~loullted within lumen 56 are swaging pin ~18 and coiled conductor 54. Crimps 50 mai1ltai11 coiled conductor 54 tightly fixed between swaging pin 48 anc1 tubular portion 46 of electrode 26. This structure provides n1echa1lical and electrical coupling oE conductor 54 to electrode 26. Coiled conductor 5~ extends proximally within insulating sheath 12 to the proximal enc1 of the lead and is coupled to connec-tor pin 20 ~1:igure 1). Swaging pin 48 is provic1ed with a central lumen 52 into which a style-t may be inserted. Coiled conductor 5~1 may be fabricated of ~35N alloy or other suitable conductive material, and is preferably a m~lltifilar coil. Swaging pin 48 may be fabricated of stainless steel or other appropriate metal. Electrode 26 is preferably constructed of or provided with a coating of platinum or of a platinllm alloy, but may also be constructed of ti-tanium, rhodi~lm, irrid~un, or alloys thereof.
Tile exterior surface of electrode 26 is preferably completely covered with a coating of platinwn black, which allo~s for a substa]ltial reduction in e~lectrode polarization. In order to assure good adhesion of the pla-tin~ml black to the preferred platinwn electrode s~lrface~ the electrode should be cleaned by first soaking the electrode in aqua regia, subsequently boilinv the electrode in fuming hydroc}lloric acid, and finally sandblastillg the exterior surface of the electrode to remove any oxidation. After sUCil Clealling, the electrode may be platinized by i~ne-rsing the electrode, as ca-thode, in a platinizing solution consistillg of 3% platin~l~. chloricle dissolveci in .025"~
lead acetate sol~ltion. ~n anode of inert metal may then be placed into the platini~ing solution and a sufficient current passed through -the cell so that small bubbles are visible at the elec~rode. The process should be continued until a layer of platinllm black is cieposited over tile entire electrode. 'I'he above p-rocess for cleaning alld platinizing proci~lces a platillulu black surt'ace which is sufficielltly cdurable for use on tile e.~cposed clllllular portions 3~1, 36, and 38 ol' the electrode, which clirectly contact the enclocarcliwll as ~ell as withill grooves 28, 30 and hole 31 I-t is believed that pLatinu~n blac~, whicil h~ls a Illicroporous surface of sublnicroll size ;~articles, is less easily recognizecl by thc body's :imlllullological sys-tem ;ls a foreigll body ailowillg ~for the formatioll of a thillller tibrotic capsule surrollllclillg the electlode. 1~ thin~ler caps-lle allows the electrode to remain in close proximity to stimulatable heart tiss-ue which is believed to increase the current density -to the stimulatable tissue and thereby lower stimulation thresholds. In the ~preferred embodiment of the invention, the entire exterior of electrode 26 is coa-ted, although coating only the grooves of the electrode is also believed to offer some benefits.
In adclition, coating of the entire exposed surface of the electrode is believed to ofEer benefits for electrode geometries other than that of the preferred embodiment.
Figure 5 illustrates an oscilloscope trace depicting the actual performance of a currently available pacing lead, the ~ledtronic ~lodel 6971 Tined Pacing lead. This lead is similar to the leacl illustrated in Figure 1 i.n all respects except for the elec-trode, which is a platin~lm ring tip electrode of the type widely used for cardiac pacing. The tracillg is -taken ~rom such a lead implanted within a living dog heart, and illustrates the electrical potential across the electrode following a stimulation impulse by an external~ A-V sequential pacemaker. In this tracing, the scale is such that the screen encompasses a range of 160 millivolts vertically, and 500 milliseconds horizontally. The stimulation impulse, not visible in the tracing, occurs at point a, after l~hich the electrode can be seen to gradually clepolarize. Althoug}l the clog heart does responcl to the stimulus pulse, no evidence of that response is prese-lt in the trac;ng, because the natural electr:ical activi-ty of the dog heart whicll woulcl o-therwise indic.l-te the response is overwllelllled by the repo1arization of the electrocle. The artifact at point b is due to the atrial output of the pacerllakcr.
iigure 6 illustrates an oscilloscope trace depicting the actual ~ ~ ~ d ~
performance of the preferred embodiment of the present invention, as shown in Figures 1 through 4, in which the electrode is completely covered with platinum black. The tracing is taken from a lead implan-ted within a living dog heart and illustrates the electrical potential across the electrode following a stimulation pulse by an external, A-V sequential pacemaker.
In this tracing, the scale is such that the screen encompasses a range of ~0 millivolts vertically and 500 milliseconds horizontally. Clearly discernable at e is the QRS complex indicative of the ventricular contraction of the dog heart, followed at f by the T-wave indicating repolarizatioll of the dog :L0 heart. The stimulation pulse, located at point c, is not visible in this tracing. This tracing clearly depicts the ability of an electrode according to the present invention to sense the natural electrical heart activity generated in response to a stimulation pulse. This ~bility to sense immecliatelyfollowing a stimulation pulse is believed to result from the extremely lo-~
polarization of the electrode~ and -the resultant very rapid discharge of tllat polarization. As such, the invention provides an electrode which is capable of sensing whetiler a stimulatioll pulse has actl~ally resulted in a h~rt beat.
The artifact at point d is causecl by the atrial outpu-t of the pacema~er.
The invention has been described in detail with particular reference 20 ~o the yreferrecL embodiment thereof, but it will be l~clerstood that variations and modi:fications can be effected within the scope of the invelltioll.
9 _
Figure 1 shows a side plan view o~ a pacing lead accord--ing to the present inventiorl. The lead is provided with an elon-gated lead body 10 which is covered with an insulation sheath 12, which may be fabricated of silicone rubber, polyurethane or other suitable plastic. At the yroximal end of lead body 10 is connector assembly 16, which is provided with sealing rings 18 and which carries connector pin 20. Connector assembly 16 may be constructed using techniques known to the art, and may be fabricated of silicone rubber, polyurethane or other suitable plastic. Connector pin 20 may be fabricated of stainless steel or other conductive material. At the distal end of lead body 10 is electrode 26 which is discussed in more detail below. Immediately proximal to the exposed portion of electrode 26 is tine sheath 22 which bears four tines 24, of which three are visible.
Tines 24 engage with heart tissue and urge electrode 26 into contact with the endocardium, in a direction parallel ~o the lead a~is. Tines 22 are more fully described in United States Patent No.3,902,501~ issued to Citron et al.
Slideably mounted aro~md lead body 10 is fixation sleeve 14, which serves to stabilize the lead at the site of venous insertion. Sleeve 14 is more fully described in commonly assigned ~ited States Patent No. 4,437,475 of White.
Figure 2 S~lOWS a cross sectional view of the distal end of electrode 26 shown in Figure l. Electrode 2LS is generally hemlspherical and is provided with two circular) v-shaped grooves 28 and 30 and with an a.~ial bore 32. Grooves 28 and 30 and bore 32 divide the outermost sur~ace vf electrode 26 into three anllular areas 34, 36 and 38. Central bore ~ ~nd g-roove 28 define all angle 4~, wh:ich may be 70 degrees. Central bore 32 alld groove 3() define an angle L~2 "~hich may be 40 degrees. Grooves 28 arld 30 are Cllt havillg all angle 40 which may be 60 degrees. The edges defined by the grooves ancl annular areas of electrode 26 are seen to provide areas of small radius of curvature, which are believed to ~rovide localized increases in current 7 ~3~
density and to thereby redwce stimulation thresholds. Precise adherence to the dimensions given above is not believed necessary to practice the invention.
~1owever, it is desirable that the edges defined by the grooves and annular areas display a small radius of curvature, for the reasons discussed above.
Arranging the grooving generall~- perpendicular to the direction in which the tines urge the electrode is believed to be beneficial. In the preferred embodiment this is accomplished using circular grooves. ~le grooves are believed to assist in fixation of the electrode to the endocardiwn by providing invaginations into which tissue may grow. Such -Ei~ation is believed to reduce the possibility o micro-dislodgmen-ts, whic}l can cause an increase in threshold due to irritation of the endocardi~m1, increased fibrotic growth, or simply due to the displacement of the electrode from the endocardium.
Figure 3 shows a front plan view of the distal tip of electrode 26.
In this view, the form of annular areas 36 and 38 is more clearly apparent, along with the circular form of grooves 28 and 30.
Figure 4 shows a cross sectional vie~ of the clistal end of the lead of Figure l. In this view, electrode 26 is seen to be provided Wit]l an elongated tubular portion 46 W}liCil has a central lumell 56. ~loullted within lumen 56 are swaging pin ~18 and coiled conductor 54. Crimps 50 mai1ltai11 coiled conductor 54 tightly fixed between swaging pin 48 anc1 tubular portion 46 of electrode 26. This structure provides n1echa1lical and electrical coupling oE conductor 54 to electrode 26. Coiled conductor 5~ extends proximally within insulating sheath 12 to the proximal enc1 of the lead and is coupled to connec-tor pin 20 ~1:igure 1). Swaging pin 48 is provic1ed with a central lumen 52 into which a style-t may be inserted. Coiled conductor 5~1 may be fabricated of ~35N alloy or other suitable conductive material, and is preferably a m~lltifilar coil. Swaging pin 48 may be fabricated of stainless steel or other appropriate metal. Electrode 26 is preferably constructed of or provided with a coating of platinum or of a platinllm alloy, but may also be constructed of ti-tanium, rhodi~lm, irrid~un, or alloys thereof.
Tile exterior surface of electrode 26 is preferably completely covered with a coating of platinwn black, which allo~s for a substa]ltial reduction in e~lectrode polarization. In order to assure good adhesion of the pla-tin~ml black to the preferred platinwn electrode s~lrface~ the electrode should be cleaned by first soaking the electrode in aqua regia, subsequently boilinv the electrode in fuming hydroc}lloric acid, and finally sandblastillg the exterior surface of the electrode to remove any oxidation. After sUCil Clealling, the electrode may be platinized by i~ne-rsing the electrode, as ca-thode, in a platinizing solution consistillg of 3% platin~l~. chloricle dissolveci in .025"~
lead acetate sol~ltion. ~n anode of inert metal may then be placed into the platini~ing solution and a sufficient current passed through -the cell so that small bubbles are visible at the elec~rode. The process should be continued until a layer of platinllm black is cieposited over tile entire electrode. 'I'he above p-rocess for cleaning alld platinizing proci~lces a platillulu black surt'ace which is sufficielltly cdurable for use on tile e.~cposed clllllular portions 3~1, 36, and 38 ol' the electrode, which clirectly contact the enclocarcliwll as ~ell as withill grooves 28, 30 and hole 31 I-t is believed that pLatinu~n blac~, whicil h~ls a Illicroporous surface of sublnicroll size ;~articles, is less easily recognizecl by thc body's :imlllullological sys-tem ;ls a foreigll body ailowillg ~for the formatioll of a thillller tibrotic capsule surrollllclillg the electlode. 1~ thin~ler caps-lle allows the electrode to remain in close proximity to stimulatable heart tiss-ue which is believed to increase the current density -to the stimulatable tissue and thereby lower stimulation thresholds. In the ~preferred embodiment of the invention, the entire exterior of electrode 26 is coa-ted, although coating only the grooves of the electrode is also believed to offer some benefits.
In adclition, coating of the entire exposed surface of the electrode is believed to ofEer benefits for electrode geometries other than that of the preferred embodiment.
Figure 5 illustrates an oscilloscope trace depicting the actual performance of a currently available pacing lead, the ~ledtronic ~lodel 6971 Tined Pacing lead. This lead is similar to the leacl illustrated in Figure 1 i.n all respects except for the elec-trode, which is a platin~lm ring tip electrode of the type widely used for cardiac pacing. The tracillg is -taken ~rom such a lead implanted within a living dog heart, and illustrates the electrical potential across the electrode following a stimulation impulse by an external~ A-V sequential pacemaker. In this tracing, the scale is such that the screen encompasses a range of 160 millivolts vertically, and 500 milliseconds horizontally. The stimulation impulse, not visible in the tracing, occurs at point a, after l~hich the electrode can be seen to gradually clepolarize. Althoug}l the clog heart does responcl to the stimulus pulse, no evidence of that response is prese-lt in the trac;ng, because the natural electr:ical activi-ty of the dog heart whicll woulcl o-therwise indic.l-te the response is overwllelllled by the repo1arization of the electrocle. The artifact at point b is due to the atrial output of the pacerllakcr.
iigure 6 illustrates an oscilloscope trace depicting the actual ~ ~ ~ d ~
performance of the preferred embodiment of the present invention, as shown in Figures 1 through 4, in which the electrode is completely covered with platinum black. The tracing is taken from a lead implan-ted within a living dog heart and illustrates the electrical potential across the electrode following a stimulation pulse by an external, A-V sequential pacemaker.
In this tracing, the scale is such that the screen encompasses a range of ~0 millivolts vertically and 500 milliseconds horizontally. Clearly discernable at e is the QRS complex indicative of the ventricular contraction of the dog heart, followed at f by the T-wave indicating repolarizatioll of the dog :L0 heart. The stimulation pulse, located at point c, is not visible in this tracing. This tracing clearly depicts the ability of an electrode according to the present invention to sense the natural electrical heart activity generated in response to a stimulation pulse. This ~bility to sense immecliatelyfollowing a stimulation pulse is believed to result from the extremely lo-~
polarization of the electrode~ and -the resultant very rapid discharge of tllat polarization. As such, the invention provides an electrode which is capable of sensing whetiler a stimulatioll pulse has actl~ally resulted in a h~rt beat.
The artifact at point d is causecl by the atrial outpu-t of the pacema~er.
The invention has been described in detail with particular reference 20 ~o the yreferrecL embodiment thereof, but it will be l~clerstood that variations and modi:fications can be effected within the scope of the invelltioll.
9 _
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An implantable lead, comprising:
an electrical conductor having a proximal end and a distal end;
an insulative sheath covering said conductor;
an electrial connector coupled to the proximal end of said conductor; and an electrode means having a surface exposed to the exterior of said insulative sheath, for directly contacting the endocardium of a human heart at said exposed surface, wherein substantially all of said exposed surface is provided with a coating of platinum black and wherein said electrode means is coupled to the distal end of said conductor.
an electrical conductor having a proximal end and a distal end;
an insulative sheath covering said conductor;
an electrial connector coupled to the proximal end of said conductor; and an electrode means having a surface exposed to the exterior of said insulative sheath, for directly contacting the endocardium of a human heart at said exposed surface, wherein substantially all of said exposed surface is provided with a coating of platinum black and wherein said electrode means is coupled to the distal end of said conductor.
2. An implantable lead according to claim 1 wherein said exposed surface of said electrode means in platinum.
3. An implantable lead according to claim 2 wherein said electrode means is fabricated of platinum.
4. An implantable lead according to claim 1 wherein the exposed surface of said electrode means has grooving.
5. An implantable lead according to claim 4 wherein the exposed surface of said electrode means is generally hemispherical.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/489,657 US4502492A (en) | 1983-04-28 | 1983-04-28 | Low-polarization low-threshold electrode |
| US489,657 | 1983-04-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1229884A true CA1229884A (en) | 1987-12-01 |
Family
ID=23944740
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000452996A Expired CA1229884A (en) | 1983-04-28 | 1984-04-27 | Low-polarization low-threshold electrode |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4502492A (en) |
| EP (1) | EP0126981B1 (en) |
| JP (1) | JPS59184845U (en) |
| AU (1) | AU558105B2 (en) |
| CA (1) | CA1229884A (en) |
| DE (1) | DE3472758D1 (en) |
Families Citing this family (89)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4627439A (en) * | 1983-12-15 | 1986-12-09 | Cordis Corporation | Prebent ventricular/atrial cardiac pacing lead |
| US4662382A (en) * | 1985-01-16 | 1987-05-05 | Intermedics, Inc. | Pacemaker lead with enhanced sensitivity |
| US4649937A (en) * | 1985-01-28 | 1987-03-17 | Cordis Corporation | Etched grooved electrode for pacing lead and method for making same |
| FR2582945B1 (en) * | 1985-06-11 | 1988-04-15 | Nivarox Sa | IMPLANTABLE ELECTRODE |
| FR2595253A1 (en) * | 1986-03-04 | 1987-09-11 | Amiel Alain | MYOCARDIAL ELECTRODE WITH SEPARATE CONDUCTIVE ELEMENT |
| CA1305528C (en) * | 1986-03-11 | 1992-07-21 | Ross G. Baker, Jr. | Low threshold cardiac pacing electrodes |
| US4679572A (en) * | 1986-03-11 | 1987-07-14 | Intermedics, Inc. | Low threshold cardiac pacing electrodes |
| US4762136A (en) * | 1987-02-19 | 1988-08-09 | Intermedics, Inc. | Low polarization pacing electrodes for capture verification |
| US4844099A (en) * | 1986-11-24 | 1989-07-04 | Telectronics, N.V. | Porous pacemaker electrode tip using a porous substrate |
| US4784161A (en) * | 1986-11-24 | 1988-11-15 | Telectronics, N.V. | Porous pacemaker electrode tip using a porous substrate |
| US4972847A (en) * | 1989-11-02 | 1990-11-27 | Dutcher Robert G | Pacing lead and introducer therefor |
| US5255693A (en) * | 1989-11-02 | 1993-10-26 | Possis Medical, Inc. | Cardiac lead |
| US5143090A (en) * | 1989-11-02 | 1992-09-01 | Possis Medical, Inc. | Cardiac lead |
| US5217028A (en) * | 1989-11-02 | 1993-06-08 | Possis Medical, Inc. | Bipolar cardiac lead with drug eluting device |
| EP0538368A4 (en) * | 1990-06-15 | 1995-04-19 | Medtronic Inc | Miniature steroid eluting pacing lead electrode |
| US5282844A (en) * | 1990-06-15 | 1994-02-01 | Medtronic, Inc. | High impedance, low polarization, low threshold miniature steriod eluting pacing lead electrodes |
| US5179962A (en) * | 1991-06-20 | 1993-01-19 | Possis Medical, Inc. | Cardiac lead with retractible fixators |
| DE4207368A1 (en) * | 1991-08-06 | 1993-02-11 | Biotronik Mess & Therapieg | VOICE ELECTRODE |
| DE4126363B4 (en) * | 1991-08-06 | 2004-11-04 | Biotronik Gmbh & Co. Kg | Cardiac pacemaker with means for effectiveness detection |
| FR2685640B1 (en) * | 1991-12-31 | 1998-04-10 | Ela Medical Sa | ENDOCARDIAC PROBE WITH FOLDABLE BARBULES. |
| US5231996A (en) * | 1992-01-28 | 1993-08-03 | Medtronic, Inc. | Removable endocardial lead |
| US5601607A (en) * | 1992-03-19 | 1997-02-11 | Angeion Corporation | Implantable cardioverter defibrillator housing plated electrode |
| US5318572A (en) * | 1992-06-02 | 1994-06-07 | Siemens Pacesetter, Inc. | High efficiency tissue stimulating and signal sensing electrode |
| DE4231603A1 (en) * | 1992-09-17 | 1994-03-24 | Biotronik Mess & Therapieg | Pacemaker system |
| US5326448A (en) * | 1992-10-15 | 1994-07-05 | Telectronics Pacing Systems, Inc. | Method for reducing the polarization of bioelectrical stimulation leads using surface enhancement, and product made thereby |
| AU5214193A (en) * | 1992-12-03 | 1994-06-16 | Pacesetter Ab | Implantable medical device lead assembly having high efficiency, flexible electrode head |
| US5408744A (en) * | 1993-04-30 | 1995-04-25 | Medtronic, Inc. | Substrate for a sintered electrode |
| US5347708A (en) * | 1993-09-21 | 1994-09-20 | Medtronic, Inc. | Method for fabrication of implantable electrode |
| WO1995011723A1 (en) * | 1993-10-29 | 1995-05-04 | Medtronic, Inc. | Method of manufacturing a medical electrical lead |
| US5443492A (en) * | 1994-02-02 | 1995-08-22 | Medtronic, Inc. | Medical electrical lead and introducer system for implantable pulse generator |
| US5628778A (en) * | 1994-11-21 | 1997-05-13 | Medtronic Inc. | Single pass medical electrical lead |
| US5534022A (en) * | 1994-11-22 | 1996-07-09 | Ventritex, Inc. | Lead having an integrated defibrillation/sensing electrode |
| US5578068A (en) * | 1995-05-08 | 1996-11-26 | Medtronic, Inc. | Medical electrical lead with radially asymmetric tip |
| US5779699A (en) * | 1996-03-29 | 1998-07-14 | Medtronic, Inc. | Slip resistant field focusing ablation catheter electrode |
| US5991667A (en) * | 1997-11-10 | 1999-11-23 | Vitatron Medical, B.V. | Pacing lead with porous electrode for stable low threshold high impedance pacing |
| US6240320B1 (en) * | 1998-06-05 | 2001-05-29 | Intermedics Inc. | Cardiac lead with zone insulated electrodes |
| US6134478A (en) * | 1998-06-05 | 2000-10-17 | Intermedics Inc. | Method for making cardiac leads with zone insulated electrodes |
| US6253110B1 (en) | 1999-04-27 | 2001-06-26 | Medtronic Inc | Method for tissue stimulation and fabrication of low polarization implantable stimulation electrode |
| US6405091B1 (en) | 1999-07-20 | 2002-06-11 | Pacesetter, Inc. | Lead assembly with masked microdisk tip electrode and monolithic controlled release device |
| US6389320B1 (en) | 1999-10-01 | 2002-05-14 | Pacesetter, Inc. | Implantable stimulation lead adaptable for stylet or guidewire placement |
| US6556873B1 (en) | 1999-11-29 | 2003-04-29 | Medtronic, Inc. | Medical electrical lead having variable bending stiffness |
| US6549812B1 (en) | 1999-11-29 | 2003-04-15 | Medtronic, Inc. | Medical electrical lead having bending stiffness which increase in the distal direction |
| US6430448B1 (en) | 2000-11-07 | 2002-08-06 | Pacesetter, Inc. | Stimulating electrode having low polarization and method of making same |
| US6430447B1 (en) | 2000-11-07 | 2002-08-06 | Pacesetter, Inc. | Stimulating electrode having low polarization and method of making same |
| US6999819B2 (en) * | 2001-08-31 | 2006-02-14 | Medtronic, Inc. | Implantable medical electrical stimulation lead fixation method and apparatus |
| US6687545B1 (en) | 2001-10-23 | 2004-02-03 | Pacesetter, Inc. | Cardiac stimulation system and method for performing automatic capture verification during bipolar stimulation |
| US6974533B2 (en) * | 2002-04-11 | 2005-12-13 | Second Sight Medical Products, Inc. | Platinum electrode and method for manufacturing the same |
| US8389434B2 (en) * | 2002-04-11 | 2013-03-05 | Second Sight Medical Products, Inc. | Catalyst and a method for manufacturing the same |
| US7282213B2 (en) * | 2002-09-30 | 2007-10-16 | Medtronic, Inc. | Method for applying a drug coating to a medical device |
| US7123963B2 (en) * | 2002-10-31 | 2006-10-17 | Medtronic, Inc. | Method of automatic evoked response sensing vector selection using evoked response waveform analysis |
| EP1428551A1 (en) * | 2002-12-13 | 2004-06-16 | W.C. Heraeus GmbH & Co. KG | Stimulation electrode and manufacturing and use thereof |
| US20050075709A1 (en) * | 2003-02-18 | 2005-04-07 | Medtronic, Inc. | Biomedical electrode of enhanced surface area |
| US7831303B2 (en) * | 2003-06-17 | 2010-11-09 | Medtronic, Inc. | Cardiac pacing apparatus and method for continuous capture management |
| AU2003903532A0 (en) * | 2003-07-09 | 2003-07-24 | Cochlear Limited | Conductive elements |
| US7945337B2 (en) * | 2003-08-27 | 2011-05-17 | Medtronic, Inc. | High impedance and low polarization electrode |
| US7190993B2 (en) * | 2003-11-04 | 2007-03-13 | Medtronic, Inc. | Implantable medical device having optical fiber for sensing electrical activity |
| US20050228469A1 (en) * | 2004-04-12 | 2005-10-13 | Cardiac Pacemakers, Inc. | Electrode and conductor interconnect and method therefor |
| US8155754B2 (en) * | 2005-01-25 | 2012-04-10 | Medtronic, Inc. | Method for fabrication of low-polarization implantable stimulation electrode |
| DE102005013066B4 (en) | 2005-03-18 | 2008-11-20 | W.C. Heraeus Gmbh | Pacing electrode with porous coating, use and manufacturing process |
| US20070100411A1 (en) * | 2005-10-27 | 2007-05-03 | Medtronic, Inc. | Implantable medical electrical stimulation lead fixation method and apparatus |
| US8996129B2 (en) * | 2007-01-31 | 2015-03-31 | Medtronic, Inc. | Medical electrode including an iridium oxide surface and methods of fabrication |
| US8396539B2 (en) * | 2007-02-16 | 2013-03-12 | Medtronic, Inc. | Implantable medical device having optical fiber for sensing electrical activity |
| US8688235B1 (en) * | 2008-07-22 | 2014-04-01 | Boston Scientific Neuromodulation Corporation | Lead with transition and methods of manufacture and use |
| WO2010034270A1 (en) * | 2008-09-29 | 2010-04-01 | Narcoscience Gmbh & Co. Kg | Method and apparatus for evaluating an anesthesia or intensive care eeg |
| US8461042B2 (en) * | 2009-12-01 | 2013-06-11 | Cochlear Limited | Electrode contact contaminate removal |
| US20110130815A1 (en) * | 2009-12-01 | 2011-06-02 | Peter Gibson | Contoured electrode contact surfaces |
| US8782884B2 (en) * | 2009-12-01 | 2014-07-22 | Cochlear Limited | Manufacturing an electrode assembly having contoured electrode contact surfaces |
| US10071243B2 (en) | 2013-07-31 | 2018-09-11 | Medtronic, Inc. | Fixation for implantable medical devices |
| US9393427B2 (en) | 2013-08-16 | 2016-07-19 | Cardiac Pacemakers, Inc. | Leadless cardiac pacemaker with delivery and/or retrieval features |
| US9492674B2 (en) | 2013-08-16 | 2016-11-15 | Cardiac Pacemakers, Inc. | Leadless cardiac pacemaker with delivery and/or retrieval features |
| JP6151452B2 (en) | 2013-08-16 | 2017-06-21 | カーディアック ペースメイカーズ， インコーポレイテッド | Delivery device and method for a leadless heart device |
| US9480850B2 (en) | 2013-08-16 | 2016-11-01 | Cardiac Pacemakers, Inc. | Leadless cardiac pacemaker and retrieval device |
| US10179236B2 (en) | 2013-08-16 | 2019-01-15 | Cardiac Pacemakers, Inc. | Leadless cardiac pacing devices |
| US10842993B2 (en) | 2013-08-16 | 2020-11-24 | Cardiac Pacemakers, Inc. | Leadless cardiac pacing devices |
| US9700732B2 (en) | 2013-08-16 | 2017-07-11 | Cardiac Pacemakers, Inc. | Leadless cardiac pacemaker and retrieval device |
| US10722723B2 (en) | 2013-08-16 | 2020-07-28 | Cardiac Pacemakers, Inc. | Delivery devices and methods for leadless cardiac devices |
| WO2015030738A1 (en) | 2013-08-27 | 2015-03-05 | Advanced Bionics Ag | Asymmetric cochlear implant electrodes and method |
| WO2015030739A1 (en) | 2013-08-27 | 2015-03-05 | Advanced Bionics Ag | Implantable leads with flag extensions |
| WO2015030734A1 (en) | 2013-08-27 | 2015-03-05 | Advanced Bionics Ag | Thermoformed electrode arrays |
| US9795781B2 (en) | 2014-04-29 | 2017-10-24 | Cardiac Pacemakers, Inc. | Leadless cardiac pacemaker with retrieval features |
| WO2015168153A1 (en) | 2014-04-29 | 2015-11-05 | Cardiac Pacemakers, Inc. | Leadless cardiac pacing devices including tissue engagement verification |
| US10743960B2 (en) | 2014-09-04 | 2020-08-18 | AtaCor Medical, Inc. | Cardiac arrhythmia treatment devices and delivery |
| US10328268B2 (en) | 2014-09-04 | 2019-06-25 | AtaCor Medical, Inc. | Cardiac pacing |
| US11097109B2 (en) | 2014-11-24 | 2021-08-24 | AtaCor Medical, Inc. | Cardiac pacing sensing and control |
| US10463853B2 (en) | 2016-01-21 | 2019-11-05 | Medtronic, Inc. | Interventional medical systems |
| US10099050B2 (en) | 2016-01-21 | 2018-10-16 | Medtronic, Inc. | Interventional medical devices, device systems, and fixation components thereof |
| US11759632B2 (en) | 2019-03-28 | 2023-09-19 | Medtronic, Inc. | Fixation components for implantable medical devices |
| WO2020243534A1 (en) * | 2019-05-29 | 2020-12-03 | AtaCor Medical, Inc. | Implantable electrical leads and associated delivery systems |
| CN113368391B (en) * | 2021-07-08 | 2022-07-22 | 杭州神络医疗科技有限公司 | Nerve stimulation electrode and stimulation device |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3476116A (en) * | 1967-11-09 | 1969-11-04 | Victor Parsonnet | Nonpolarizing electrode for physiological stimulation |
| US3749101A (en) * | 1972-02-09 | 1973-07-31 | Cordis Corp | Nonpolarizable muscle stimulating electrode |
| DE2334049C3 (en) * | 1973-07-04 | 1988-12-22 | Hans Dr Med Lagergren | ENDOCARD ELECTRODE ARRANGEMENT |
| DE2613086B2 (en) * | 1976-03-26 | 1979-10-11 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Endocardial electrode |
| WO1980002231A1 (en) * | 1979-04-24 | 1980-10-30 | J Donachy | Long-life flexible electrode lead |
| IT1147750B (en) * | 1980-06-19 | 1986-11-26 | Sorin Biomedica Spa | ELECTRODE FOR CARDIAC STIMULATORS |
| IT1128813B (en) * | 1980-06-19 | 1986-06-04 | Sorin Biomedica Spa | ELECTRODE FOR HEART STIMULATORS AND PROCEDURE FOR ITS MANUFACTURE |
| US4325389A (en) * | 1980-09-22 | 1982-04-20 | Cordis Corporation | Tip assembly for a carbon fiber implantable lead |
| US4407302A (en) * | 1981-04-06 | 1983-10-04 | Telectronics Pty., Ltd. | Cardiac pacemaker electrode tip structure |
| JPS57193852U (en) * | 1981-05-04 | 1982-12-08 | ||
| US4409994A (en) * | 1981-06-02 | 1983-10-18 | Telectronics Pty., Ltd. | Lap joint molding member for a pacemaker electrode lead |
| US4437474A (en) * | 1982-07-16 | 1984-03-20 | Cordis Corporation | Method for making multiconductor coil and the coil made thereby |
-
1983
- 1983-04-28 US US06/489,657 patent/US4502492A/en not_active Expired - Lifetime
-
1984
- 1984-04-18 AU AU27074/84A patent/AU558105B2/en not_active Ceased
- 1984-04-26 EP EP84104654A patent/EP0126981B1/en not_active Expired
- 1984-04-26 DE DE8484104654T patent/DE3472758D1/en not_active Expired
- 1984-04-26 JP JP1984062156U patent/JPS59184845U/en active Granted
- 1984-04-27 CA CA000452996A patent/CA1229884A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59184845U (en) | 1984-12-08 |
| EP0126981B1 (en) | 1988-07-20 |
| AU2707484A (en) | 1984-11-01 |
| US4502492A (en) | 1985-03-05 |
| AU558105B2 (en) | 1987-01-15 |
| JPH0216768Y2 (en) | 1990-05-09 |
| DE3472758D1 (en) | 1988-08-25 |
| EP0126981A1 (en) | 1984-12-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1229884A (en) | Low-polarization low-threshold electrode | |
| US4762136A (en) | Low polarization pacing electrodes for capture verification | |
| US6263250B1 (en) | Ring electrode with porous member | |
| EP1324804B1 (en) | Biostable small french lead | |
| US5534022A (en) | Lead having an integrated defibrillation/sensing electrode | |
| US7139614B2 (en) | Leads for pacing and/or sensing the heart from within the coronary veins | |
| EP0129875B1 (en) | Body implantable lead and method for imparting a curve to such a lead | |
| CA1173114A (en) | Body implantable lead with improved dcd electrode | |
| EP0191238B1 (en) | Pacemaker lead with enhanced sensitivity | |
| US5342414A (en) | Transvenous defibrillation lead | |
| US4355646A (en) | Transvenous defibrillating lead | |
| US4125116A (en) | Human tissue stimulation electrode structure | |
| JPS60249972A (en) | Intravascular multiple electrode single catheter | |
| JPS62270172A (en) | Heart conditioning lead wire assembly and method | |
| US20080243200A1 (en) | Methods and apparatus for enhancing specificity of arrhythmia detection using far-field sensing and intracardiac sensing of cardiac activity | |
| US20090204194A1 (en) | Medical system including a novel bipolar pacing pair | |
| EP0024913A1 (en) | Electrodes for cardiac pacemakers | |
| US7191016B2 (en) | Medical system including a novel bipolar pacing and sensing pair | |
| US20050075709A1 (en) | Biomedical electrode of enhanced surface area | |
| US20050049665A1 (en) | High impedance and low polarization electrode | |
| US20070156215A1 (en) | Dilating lead tip | |
| Schaldach | Fractal coated leads: Advanced surface technology for genuine sensing and pacing | |
| EP0057451B1 (en) | Body implantable cushioned lead | |
| CA1305528C (en) | Low threshold cardiac pacing electrodes | |
| Stopczyk | Electrodes, Leads and Interface Problems |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |