EP0237316A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Cardiac pacing device
Assignee: Intermedics Inc
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Filing: 1987-03-10
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Granted: —
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Expires: 2007-03-10
Abstract
Abstract An electrode (10, 35, 50, 65) for use in cardiac pacing has a substrate (15, 87) composed of a material conventionally employed for pacing electrodes, and a surface layer or film (20, 75, 85, 95) of iridium oxide overlying the substrate. For use as a stimulating cathodic electrode and a sensing electrode, the iridium oxide layer is arranged to be in cardiac tissue stimulating relationship when the electrode is in proper position with respect to the patient's heart. The electrode impresses electrical stimuli on the excitable myocardial tissue to provide pacing at very low stimulation thresholds. At the completion of each stimulus, the electrode is capable of abruptly sensing, within an interval less than 100 ms thereafter, the electrical activity of the heart in response to the stimulus to reliably verify capture. The surface of the electrode may be provided with recesses (65) to which the iridium oxide layer may be confined. An iridium oxide layer may be provided on both the cathode and the anode for effecticient transduction at the electrode-electrolyte interface formed by the surface of the iridium oxide layer and the surrounding body fluid and tissue.
Inventors
- 👤 G. Baker Ross Jr
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 04:23
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/02; A61N1/04; A61N1/05; A61N1/056; A61N1/057; A61N1/0573
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
116 words
A cardiac pacing lead assembly, comprising an electrode having an exposed surface layer of iridium oxide situated to be in electrically coupled relationship with excitable cardiac tissue of the heart when said lead assembly is implanted in a human patient, for stimulating said cardiac tissue when said electrode is electrically energized and sensing electrical activity of the heart in response to said stimulation when said electrode is de-energized, and an electrical conductor means electrically connected at one end thereof to said electrode for delivering electrical energization thereto and for conducting signals representing said electrical activity therefrom, and having terminal means at the other end for connection to electrical generating and detecting circuitry of a cardiac pacemaker.
Claim 2
Dependent Claim
116 words
A cardiac pacing lead assembly, comprising an electrode having an exposed surface layer of iridium oxide situated to be in electrically coupled relationship with excitable cardiac tissue of the heart when said lead assembly is implanted in a human patient, for stimulating said cardiac tissue when said electrode is electrically energized and sensing electrical activity of the heart in response to said stimulation when said electrode is de-energized, and an electrical conductor means electrically connected at one end thereof to said electrode for delivering electrical energization thereto and for conducting signals representing said electrical activity therefrom, and having terminal means at the other end for connection to electrical generating and detecting circuitry of a cardiac pacemaker.
Claim 3
Dependent Claim
32 words
The pacing lead assembly of Claim 1, in which the electrode senses electrical activity of the heart within less than 100 milliseconds after being de-energized, to verify capture from the evoked potential.
Claim 4
Dependent Claim
29 words
The pacing lead assembly of Claim 1, in which the surface of the electrode is porous and said iridium oxide surface layer follows the interstices of said porous surface.
Claim 5
Dependent Claim
21 words
The pacing lead assembly of Claim 1, in which said surface layer of iridium oxide has a thickness exceeding 100 nanometers.
Claim 6
Dependent Claim
72 words
The pacing lead assembly of Claim 1, further including a second electrode having an iridium oxide surface layer and insulatively spaced from the first-mentioned electrode in fixed relationship therewith, for bipolar stimulation of the patient's heart, and a second electrical conductor means electrically connected at one end to said second electrode and having further terminal means at the other end thereof for connection to a point of reference potential of said circuitry.
Claim 7
Dependent Claim
99 words
A cardiac pacemaker for stimulating and sensing electrical activity of a human heart, comprising a pulse generator means, means for supplying electrical power to said pulse generator means, an electrode means having a surface layer of iridium oxide to electrically interact with excitable cardiac tissue of said heart when a stimulating pulse is applied thereto, and a conductor means having a distal end and a proximal end, said distal end electrically connected to said electrode means and said proximal end electrically connected to said pulse generator means, for applying stimulating pulses from said generator means to said electrode means.
Claim 8
Dependent Claim
99 words
A cardiac pacemaker for stimulating and sensing electrical activity of a human heart, comprising a pulse generator means, means for supplying electrical power to said pulse generator means, an electrode means having a surface layer of iridium oxide to electrically interact with excitable cardiac tissue of said heart when a stimulating pulse is applied thereto, and a conductor means having a distal end and a proximal end, said distal end electrically connected to said electrode means and said proximal end electrically connected to said pulse generator means, for applying stimulating pulses from said generator means to said electrode means.
Claim 9
Dependent Claim
44 words
The cardiac pacemaker of Claim 6, further including a metal case housing said pulse generator means and said power supply means, and an indifferent electrode means affixed to said case and having a surface layer of iridium oxide thereon, for use in unipolar stimulation.
Claim 10
Dependent Claim
80 words
The cardiac pacemaker of Claim 6, further including detection circuit means, and wherein the iridium oxide surface layer of said electrode means provides rapid recovery from after-potentials at said layer upon cessation of the stimulating pulse to enable sensing of the potential evoked and verification of capture of the heart by said stimulating pulse, and said conductor means further having its proximal end electrically connected to said detection circuit means for applying evoked potentials sensed by said electrode means thereto.
Claim 11
Dependent Claim
22 words
The cardiac pacemaker of Claim 8, wherein said rapid recovery takes place less than 100 milliseconds after cessation of the stimulating pulse.
Claim 12
Independent Claim
78 words
A method of artificially pacing a heart, comprising the steps of introducing an electrode having an iridium oxide surface layer thereon into cardiac tissue stimulating relationship with said heart, impressing electrical stimuli on said electrode at a rate within the range selected to provide the desired stimulation of the heart, and sensing the electrical activity of the heart detected at the surface of said iridium oxide layer to determine whether the heart is properly responding to said stimuli.
Claim 13
Independent Claim
78 words
A method of artificially pacing a heart, comprising the steps of introducing an electrode having an iridium oxide surface layer thereon into cardiac tissue stimulating relationship with said heart, impressing electrical stimuli on said electrode at a rate within the range selected to provide the desired stimulation of the heart, and sensing the electrical activity of the heart detected at the surface of said iridium oxide layer to determine whether the heart is properly responding to said stimuli.
Claim 14
Dependent Claim
38 words
The method of Claim 10, wherein the electrical activity of the heart is sensed at the surface of the iridium oxide layer within less than 100 milliseconds after each successive stimulus, to verify capture by the respective stimulus.
Claim 15
Dependent Claim
38 words
The method of Claim 10, wherein the electrode is introduced transvenously into a selected chamber of the heart to position the iridium oxide surface layer of the electrode in cardiac stimulating relationship with the endocardium of said chamber.
Claim 16
Dependent Claim
98 words
An implantable lead assembly for electrical conduction between an electrical energy processing means and the myocardium of a human heart, said lead assembly comprising an electrode means having a size and shape configured to be positioned in proximity to the myocardium for impressing electrical stimuli thereon, said electrode means having an iridium oxide coating on at least a portion of the surface thereof adapted to be in closest proximity to the myocardium, and conductor means electrically interconnecting said energy processing means and said electrode means, for delivery of electrical stimuli from said processing means to said electrode means.
Claim 17
Dependent Claim
98 words
An implantable lead assembly for electrical conduction between an electrical energy processing means and the myocardium of a human heart, said lead assembly comprising an electrode means having a size and shape configured to be positioned in proximity to the myocardium for impressing electrical stimuli thereon, said electrode means having an iridium oxide coating on at least a portion of the surface thereof adapted to be in closest proximity to the myocardium, and conductor means electrically interconnecting said energy processing means and said electrode means, for delivery of electrical stimuli from said processing means to said electrode means.
Claim 18
Dependent Claim
60 words
The lead assembly of Claim 13, wherein said electrode means has low polarization to avoid buildup of residual voltage and thereby to permit sensing electrical signals indicative of the behavior of said heart in response to each electrical stimulus within less than 100 milliseconds after the stimulus ceases, and said conductor means delivers the sensed signals to said processing means.
Claim 19
Dependent Claim
32 words
The lead assembly of Claim 13, wherein the surface of said electrode means is dimpled and porous, and said iridium oxide coating resides within the interstices of the pores in the dimples.
Claim 20
Dependent Claim
19 words
The lead assembly of Claim 13, wherein said iridium oxide coating has a thickness of at least 100 nanometers.
References Cited (Backward Citations)
No citation records indexed.
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