US20040133259A1 - High impedance electrode tip - Google Patents

High impedance electrode tip Download PDF

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Publication number
US20040133259A1
US20040133259A1 US10/650,207 US65020703A US2004133259A1 US 20040133259 A1 US20040133259 A1 US 20040133259A1 US 65020703 A US65020703 A US 65020703A US 2004133259 A1 US2004133259 A1 US 2004133259A1
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United States
Prior art keywords
electrode
helix
lead
tip
piston
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Abandoned
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US10/650,207
Inventor
Aaron Janke
Mary Cole
Ronald Heil
Jeffrey Bartig
Gary Goebel
Douglas Heitkamp
Randall Peterfeso
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Cardiac Pacemakers Inc
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Cardiac Pacemakers Inc
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Publication date
Application filed by Cardiac Pacemakers Inc filed Critical Cardiac Pacemakers Inc
Priority to US10/650,207 priority Critical patent/US20040133259A1/en
Publication of US20040133259A1 publication Critical patent/US20040133259A1/en
Abandoned legal-status Critical Current

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00Electrotherapy; Circuits therefor
    • A61N1/02Details
    • A61N1/04Electrodes
    • A61N1/05Electrodes for implantation or insertion into the body, e.g. heart electrode
    • A61N1/056Transvascular endocardial electrode systems
    • A61N1/057Anchoring means; Means for fixing the head inside the heart
    • A61N1/0573Anchoring means; Means for fixing the head inside the heart chacterised by means penetrating the heart tissue, e.g. helix needle or hook

Definitions

  • the present invention relates generally to leads for conducting electrical signals to and from the heart. More particularly, it pertains to electrode tips for delivering electrical charges to the heart, and to tips which tend to reduce power consumption from cells without reducing the effective level of each pace.
  • Leads implanted in the body for electrical cardioversion or pacing of the heart are generally known in the art.
  • electrically transmissive leads may be implanted in or about the heart to reverse (i.e., defibrillate or cardiovert) certain life threatening arrhythmias or to stimulate contraction (pacing) of the heart.
  • Electrical energy is applied to the heart via the leads to return the heart to normal rhythm.
  • Leads have also been used to sense conditions, materials or events (generally referred to as “sense” or “sensing”) in the body, such as in the atrium or ventricle of the heart and to deliver pacing pulses to the atrium or ventricle.
  • Tachy leads generally can at least sense, pace, and deliver defibrillation shocks. Brady leads can at least perform the combination functions of pacing and sensing the heart.
  • One of the available functions of the pacemaker or the automatic implantable cardioverter defibrillator (AICD) is to receive signals from a lead and interpret signals. In response to these signals, the pacemaker can decide to pace or not pace. The AICD can decide to pace or not pace, and shock or not shock.
  • a pulse generator produces pacing or defibrillation pulses to correct the condition. The same lead used to sense the condition is sometimes also used in the process of delivering a corrective pulse or signal from the pulse generator of the pacemaker.
  • Sick sinus syndrome and symptomatic AV (atrial-ventricular) block constitute two of the major reasons for insertion of cardiac pacemakers today.
  • Cardiac pacing may be performed by the transvenous method or by leads implanted directly onto the ventricular epicardium. Most commonly, permanent transvenous pacing is performed using a lead positioned within one or more chambers of the heart.
  • a lead sometimes referred to as a catheter, may be positioned in the right ventricle or in the right atrium through a subclavian vein or other vascular port, and lead terminal pins are attached to a pacemaker which is implanted subcutaneously.
  • the lead may also be positioned in both chambers, depending on the lead, as when a lead passes through the atrium to the ventricle.
  • Sense electrodes may be positioned within the atrium or the ventricle of the heart as appropriate for the particular condition or the choice of the medical practitioner.
  • Pacemaker leads represent the electrical link between the pulse generator and the heart tissue which is to be excited.
  • These pacemaker leads include single or multiconductor coils of insulated wire having an insulating sheath.
  • the coils provide a cylindrical envelope or tube, many times referred to as a lumen, which provides a space into which a stiffening stylet can be inserted.
  • the conductive coil is connected to an electrode in an electrode assembly at a distal end of a pacing lead.
  • a terminal member is molded within a flexure sleeve at the proximal end of the pacing lead and connected to the proximal end of the conductive coil.
  • Electrode assembly After the electrode assembly is positioned at a desired location within the heart, it is desirable to provide some method for securing the electrode assembly at that location.
  • Mechanical fixation devices are used to firmly anchor the electrodes in the heart.
  • One type of mechanical fixation device used is a corkscrew, or a helix electrode connector.
  • the tip of the lead travels intravenously through veins and the heart. While traveling through the veins, the helix electrode connector at the tip of the lead may snag or attach to the side wall of the vein. Since this is highly undesirable as it may cause damage or other complications to a patient, retractable helixes are one of the optional constructions which have been provided for leads.
  • temporary caps over the helix such as an aqueous soluble cap, particularly a water soluble, innocuous organic material such as a sugar, starch or other biologically inert, or digestible material such as sugars, starches and the like (e.g., mannitol, sorbitol)
  • aqueous soluble cap particularly a water soluble, innocuous organic material such as a sugar, starch or other biologically inert, or digestible material such as sugars, starches and the like (e.g., mannitol, sorbitol)
  • these materials are at least soluble or dispersible and preferably are inert or even digestible.
  • the helix When using a retractable helix, the helix is extended and screwed into the heart muscle by applying a torque to the other end of the conductor without use of any further auxiliary device or with a special fixation stylet.
  • a fixed or non-retractable helix electrode connector needs only to be positioned and secured to the heart muscle by the application of torque. If a soluble/dispersible cap is present on the helix, the cap must be given sufficient time to dissolve or disperse before complete securement of the helix electrode connector is attempted.
  • a lead must be capable of being firmly secured into the wall of the cardiac tissue to prevent dislodgement therefrom, while avoiding perforation of the electrode completely through the cardiac tissue.
  • the pulse generator circuitry and power supply work in concert with the electrodes as a system which provides electrical pulses to the heart tissue.
  • a low impedance electrode design may increase power delivery to the heart tissue, but at the same time, this higher energy usage results in shorter battery life. Shorter battery life is undesirable, since it increases the average number of surgical procedures to perform battery replacement for a patient.
  • a separate desirable feature in body-implantable leads is for a lead having an electrode for positioning within the atrium or ventricle that allows for tissue in growth. Tissue in growth further enhances the electrical performance of the lead. The lead and electrode are further stabilized within the heart as a result of tissue in growth. Furthermore, there is a need for a relatively high pacing impedance electrode design which offers reasonable average voltage threshold with sufficient signal amplitude so that the pacing function would be effectively provided with reduced energy utilization and consequently extend battery life.
  • a body-implantable lead assembly comprising a lead, one end of the lead being adapted to be connected to electrical supply for providing or receiving electrical pulses.
  • the other end of the lead comprises a distal tip which is adapted to be connected to tissue of a living body.
  • the lead is characterized by having either a) a porous electrode at the base of the helix and/or b) an insulating coating over a portion of the helix so that the impedance is increased for the helix as compared to a helix of the same size and materials without an insulating coating.
  • the lead also has an increased impedance or high impedance which can act to extend the life of the battery.
  • the high or at least the increased impedance may be effected in any of a number of ways, including, but not limited to one or more of the following structures: 1) a fully insulated tissue-engaging tip with an electrode at the base of the insulated tip, 2) a partially insulated engaging tip (only a portion of the surface area of the engaging tip being insulated), 3) a mesh or screen of material at the distal end of the lead, at the base of an extended engaging tip (whether a fixed or retractable tip), 4) the selection of materials in the composition of the mesh and/or tip which provide higher impedance, 5) the partial insulative coating of a mesh or screen to increase its pacing impedance, and 6) combinations of any of these features.
  • helical tips with smaller surface areas (e.g., somewhat shorter or thinner tips).
  • sheath of material inert to body materials and fluids and at least one conductor extending through the lead body The use of these various constructions in the tip also allows for providing the discharge from the tip in a more highly resolved location or area in the tip.
  • a body-implantable lead assembly comprising a lead, one end being adapted to be connected to electrical supply for providing or receiving electrical pulses.
  • the lead further comprises a distal tip which is adapted to be connected to tissue of a living body.
  • the lead also has a high impedance to extend the life of the battery. There may be various constructions to effect the high impedance.
  • the distal tip electrode is adapted, for example, for implantation proximate to the heart while connected with a system for monitoring or stimulating cardiac activity.
  • the distal tip electrode includes an electrode tip (preferably with only a percentage of its entire surface area being electrically conductively exposed—only a portion of the surface is insulated—to increase its impedance), preferably a mesh screen disposed at a distal end of the electrode tip, a fixation helix disposed within the electrode tip, and a helix guiding mechanism.
  • the mesh screen preferably is electrically active, and the area of the mesh screen and the percentage of electrically exposed surface area of the electrode tip can be changed to control electrical properties.
  • the mesh screen can entirely cover an end surface of the electrode tip, or a portion of the end surface in the form of an annular ring.
  • the helix guiding mechanism includes a hole punctured within the mesh screen.
  • the helix guiding mechanism can include a guiding bar disposed transverse to a radial axis of the electrode.
  • the helix is retractable, and is in contact with a movement mechanism.
  • the movement mechanism provides for retracting the helix, such as during travel of the electrode tip through veins.
  • the helix is aligned with the radial axis of the electrode and travels through the guiding mechanism.
  • the mesh may be tightly woven or constructed so that there are effectively no openings, or the mesh can be controlled to provide controlled porosity, or controlled flow through the mesh.
  • the electrode tip includes a mesh screen forming a protuberance on the end surface of the electrode tip.
  • the protuberance is axially aligned with the radial axis of the electrode.
  • the helix travels around the protuberance as it passes through the mesh while traveling to attach to tissue within the heart.
  • the helix also travels around the protuberance as it is retracted away from the tissue within the heart. If the mesh screen is insulated around the protuberance, then a high impedance tip is created.
  • the protuberance allows for better attachment to the cardiac tissue without having the electrode tip penetrating therethrough.
  • a distal tip electrode including an electrode tip, a mesh screen disposed at a distal end of the electrode tip, a fixation helix disposed within the electrode tip, and a helix guiding mechanism.
  • the electrode tip further may include a piston for moving the helix.
  • the piston further may include a slot for receiving a bladed or fixation stylet. When engaged and rotated, the piston provides movement to the helix.
  • the base provides a mechanical stop for the helix and piston when retracted back into the electrode tip.
  • the distal tip assembly is adapted for implantation proximate to the heart while connected with a system for monitoring or stimulating cardiac activity.
  • a fixation helix/piston assembly is housed by an electrode collar, housing, and base assembly. Attached to the proximal end of the helix is a piston which includes a proximal slot for receiving a bladed or fixation stylet. When a stylet is engaged in the slot and rotated, the piston provides movement to the helix.
  • the fixation helix/piston assembly may be electrically active or inactive.
  • the electrode collar, housing, and base all house the fixation helix/piston assembly.
  • the proximal end of the electrode collar is attached to the distal end of the housing. Furthermore, the proximal end of the housing is attached to the distal end of the base, and the proximal end of the base is directly attached to the conductor coils of the lead.
  • a mesh screen may be attached to the distal tip of the electrode collar.
  • the mesh screen in another embodiment, is electrically active and serves as the electrode on the distal tip assembly.
  • the tip may then be fully insulated to increase the impedance of the tip or may be partially insulated (with preselected areas of the helix tip being insulated and other areas being non-insulated) to adjust the impedance of the tip to the specific or optimal levels desired.
  • the area of the mesh screen can be modified to cover differing portions of the end surface of the distal tip assembly to control electrical properties of the lead.
  • the fixation helix travels through a guiding mechanism, where the guiding mechanism allows the fixation helix to be extended and retracted.
  • the helix guiding mechanism includes a hole formed within the mesh screen.
  • the helix guiding mechanism can include a guiding bar disposed transverse to a radial axis of the electrode collar.
  • the mesh screen and/or guiding bar also serve as a full extension stop when the helix is fully extended.
  • the base serves as a stop when the fixation helix/piston assembly is fully retracted.
  • the provided electrode tip supplies a retractable helix and a mesh screen which advantageously allows for sufficient tissue in-growth.
  • the guide mechanism provides a convenient way to direct the rotation of the helix.
  • a further advantage of the electrode tip is the provided mechanical stop. The mechanical stop aids in preventing over-retraction of the helix during the installation or removal of the electrode tip.
  • the electrode uses a partially insulated fixation helix to provide a relatively high pacing impedance electrode.
  • the fixation helix is insulated using insulating coatings over a portion of the fixation helix.
  • FIG. 1 is a first side elevational view illustrating a lead constructed in accordance with one embodiment of the present invention.
  • FIG. 2A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention.
  • FIG. 2B is an end view of the electrode tip of the lead shown in FIG. 2A.
  • FIG. 3A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention.
  • FIG. 3B is an end view of the electrode tip of the lead shown in FIG. 3A.
  • FIG. 4A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention
  • FIG. 4B is an end view of the electrode tip of the lead shown in FIG. 4A.
  • FIG. 5A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention
  • FIG. 5B is an end view of the electrode tip of the lead shown in FIG. 5A.
  • FIG. 6 shows a partially insulated helical tip according to the present invention which increases the impedance of the tip as compared to a fully non-insulated helical tip.
  • Atrial/ventricular implantable catheters include at least the following: 1) a fully insulated tissue engaging tip (at least with respect to all surfaces that are in electrical contact or electrically active physical relationship to heart muscles so that a pace would be effective if discharged at that portion of the tip), 2) a partially insulated engaging tip (only a portion of the surface area of the engaging tip being insulated, preferably there is sufficient coating so that there is at least 5%, or at least 10%, or at least 20 or 30%, or at least 40, 50 or 60%, or at least 70, 75, 80 or 90% of the surface area of the tip which can discharge to heart muscle [or as percentages of the entire tip or as percentages of the entire tip that extends physically beyond the end plane of the catheter and which may therefore penetrate tissue or muscle]), 3) a porous, electrically conductive element, such as a mesh or screen of material at the proximal
  • catheter and/or leads there may be various constructions to effect the increased or high impedance, including the use of helical tips with smaller surface areas (e.g., somewhat shorter or thinner tips).
  • helical tips with smaller surface areas (e.g., somewhat shorter or thinner tips).
  • other elements associated with the catheter and/or leads such as a sheath of material inert to body materials and fluids, circuitry, microcatheters, and at least one conductor extending through the lead body.
  • One aspect of the present invention comprises an implantable electrode with a helical tip comprising:
  • an electrode having a distal end and a proximal end
  • a helix disposed within the electrode, which helix is aligned along a radial axis of the electrode towards the distal end, and which helix is either retractable or fixed;
  • the implantable electrode having at least one feature selected from the group consisting of:
  • the helix having a coating of an insulating material on its surface which covers at least 5% of its surface area but less than 95% of its surface area (which is exposed beyond the distal end of the electrode),
  • a porous conductive element such as a screen or mesh at a base of the helix, which is retractable/extendable, with the helix being either active or inactive (electrically), and
  • a partially insulated (partially insulation coated) porous conductive element e.g., screen or mesh
  • a partially insulated (partially insulation coated) porous conductive element e.g., screen or mesh
  • the implantable electrode preferably has the helix with a coating of insulating material on its surface which covers from 5-100% (to 100% where there is an additional electrode element within the system) or 5-95% of surface area of the helix beyond the distal end of the electrode.
  • the surface of the helix is that which is considered to be in electrically discharge-functional physical relationship with tissue or muscle into which it is embedded.
  • the tip extends beyond a tubular or cylindrical housing or structural portion which is considered the electrode, and the tip is an engaging portion that extends beyond the housing portion of the electrode.
  • the distal end of the electrode is usually characterized as the end of the cylindrical housing or tubing carrying the tip, circuits, conductive elements, guides, etc. It is more preferred that the helix of the implantable electrode has a coating of insulating material on it surface which covers from 5-95% or 10-90% of the surface area of said helix beyond the distal end of the electrode.
  • a lead 10 is illustrated in FIG. 1.
  • the lead 10 comprises a lead body 11 , an elongate conductor 13 contained within the lead body, and a lead tip 20 with an optional retractable tip assembly 24 contained in the lead tip 20 .
  • a stylet 14 is shown inserted into the lead body 11 .
  • a helix 100 (FIGS. 2 A- 5 A), which consists of an electrical conductor coil, is contained in the retractable lead tip 24 .
  • the helix 100 extends and retracts by rotation of the stylet 14 , as will be discussed further below.
  • a Brady lead body is shown, although the invention could be incorporated with other leads, such as Tachy leads.
  • the lead body 11 consists of electrical conductors 13 which are covered by a biocompatible insulating material 22 .
  • Polymers such as silicone rubber, fluorinated resins, polyacrylates, polyamides ceramic or composite materials or other insulating material can be used for covering the lead body 11 .
  • the helix 100 is formed of electrically conductive material offering low electrical resistance and also resistant to corrosion by body fluids.
  • a biocompatible metal such as titanium or platinum-iridium alloy is an example of a suitable material.
  • the helix 100 is electrically inactive or insulated.
  • the helix 100 may be coated with an insulative material (not shown) or may be constructed of a rigid, corrosion resistant, non-electrically-conductive material (e.g., a ceramic).
  • a housing 182 described in further detail below, is made from an electrically conductive material and covered with an insulating material such as a synthetic or natural polymer such as a silicone rubber. The housing 182 is directly connected to an electrical conductor within the lead 120 . These materials are additionally suitable because they tend to be biologically inert and well tolerated by body tissue.
  • the helix 100 defines a lumen and thereby is adapted to receive a stiffening stylet 14 that extends through the length of the lead.
  • the stylet 14 stiffens the lead 120 , and can be manipulated to introduce an appropriate curvature to the lead, facilitating the insertion of the lead into and through a vein and through an intracardiac valve to advance the distal end of the lead 120 into the right ventricle of the heart (not shown).
  • a stylet knob 154 is coupled with the stylet 14 for rotating the stylet 14 and advancing the helix 100 into tissue of the heart.
  • a lead 310 has an electrode tip 320 which is provided with a mesh screen 330 .
  • the mesh screen 330 completely encapsulates the diameter of the lead, and may serve, at least in part, as a pacing/sensing interface with cardiac tissue. If the helix 100 is electrically active, it too can help serve as a portion of a pacing or sensing interface.
  • the mesh screen 330 is of a porous construction, preferably made of electrically conductive, corrosion resistant material. Using a mesh screen 330 having a porous construction allows for fibrotic ingrowth.
  • the mesh screen 330 may be attached to an electrode collar 40 , which is electrically active.
  • a housing 380 which is electrically conductive, encapsulates the piston 350 and the fixation helix 100 .
  • Insulation 382 is disposed about the housing 380 and collar 40 .
  • a lead fastener 100 for securing the lead 310 to cardiac tissue.
  • the lead fastener 100 can be disposed along the radial axis 15 of the electrode lead 310 .
  • the lead fastener comprises a fixation helix 100 .
  • the fixation helix 100 can be made electrically active or inactive as discussed above.
  • Attached to the fixation helix 100 in a retractable tip system is a piston 350 .
  • the piston 350 is configured to mate with a bladed locking stylet 14 at a stylet slot 354 , and acts as an interface between the stylet 14 and the helix 100 .
  • the stylet 14 coupled with the piston 350 at the stylet slot 354 , extends and retracts the fixation helix 100 when the stylet 14 is rotated.
  • the piston 350 can either be electrically active or inactive.
  • the piston 350 also has a slot 352 , which allows the piston 350 to mate with a base 360 .
  • the base 360 mates with the slot 352 of the piston 350 .
  • the base 360 serves as a stop once the fixation helix 100 is fully retracted.
  • the electrically conductive base 360 also allows passage of a bladed locking stylet 14 and attachment of electrode coils (not shown).
  • the lead 310 has a guide groove 370 .
  • the groove 370 is formed by puncturing a hole (not shown) within the mesh screen 330 , although the guide groove 370 can be formed by other methods known by those skilled in the art. Having a circular cross-section, the guide groove 370 may have a diameter greater than that of the conductor forming the helix 100 .
  • the groove 370 is disposed within the mesh screen 330 , and directs the fixation helix 100 from its retracted position, as illustrated in FIG. 2A, to an extended position (not shown).
  • the groove 370 also reversibly directs the fixation helix 100 from an extended position to the retraction position.
  • a lead 110 has an electrode tip 120 which is provided with a mesh screen 130 .
  • the mesh screen 130 completely encapsulates the diameter of the lead or electrode tip 120 , and serves as the pacing/sensing interface with cardiac tissue.
  • the screen 130 is of a porous construction, made of electrically conductive, corrosion resistant material. Using a mesh screen 130 having a porous construction allows for fibrotic ingrowth. This provides for a further anchoring of the lead tip 120 to tissue and also increases the sensing capability of the lead 110 . The sensing capability is enhanced because the mesh screen 130 has more surface area than corresponding solid material.
  • the ingrowth of fibrotic tissue into the mesh screen 130 increase the sensing capability of the lead 110 by increasing the surface area in contact with the cardiac tissue. Furthermore, the geometry of the mesh screen 130 , particularly any protuberance, as will be discussed below, creates a high pacing impedance tip.
  • the mesh screen 130 may form a protuberance 135 from a flat edge portion 137 of the mesh screen 130 in a generally central portion of the electrode tip 120 .
  • the protuberance 135 may be generally circular in cross-section, but may be any shape (e.g., truncated cylindrical, truncated pyramidal, oval, ellipsoidal, etc.) as a result of design or circumstance which provides a flat or conformable surface (preferably not a rigid, sharp face which will not conform to tissue) abutting tissue, and preferably has a diameter smaller than a diameter of the lead 110 .
  • the protuberance 135 is aligned with the radial axis 15 of the lead 110 .
  • the mesh screen 130 is attached to the electrode tip 120 .
  • the electrode collar 40 is electrically active.
  • a lead fastener for securing the electrode lead 110 to cardiac tissue.
  • the lead fastener can be disposed along the radial axis 15 of the electrode lead 110 .
  • the lead fastener comprises a fixation helix 100 .
  • the fixation helix 100 can be made electrically active or inactive to change sensing and pacing characteristics, as discussed above.
  • Attached to the fixation helix 100 is a piston 150 .
  • the piston 150 is configured to mate with a bladed locking stylet 14 , thereby providing a movement assembly.
  • the stylet 14 extends and retracts the fixation helix 100 when the stylet 14 is rotated.
  • the piston 150 can either be electrically active or inactive.
  • the piston 150 also has a slot 152 .
  • the slot 152 of the piston 150 allows the piston 150 to mate with a base 160 upon full retraction.
  • the base 160 is modified with a knob 162 to mate with the slot 152 of the piston 150 .
  • the knob 162 mates with the piston 150 to prevent over-retraction once the helix 100 has been fully retracted.
  • the stylet 14 operates to advance the fixation helix 100 .
  • the stylet 14 engages the piston 150 at the stylet slot 154 and rotates the piston 150 , which moves the fixation helix 100 through a guide groove 170 .
  • the guide groove 170 is for ensuring that the fixation helix 100 is properly guided out of and into the end of the electrode.
  • the base 160 serves as a mechanical stop.
  • the base 160 also allows passage of a bladed locking stylet 14 and attachment of electrode coils. Additionally, the base 60 is electrically active.
  • the electrode lead 110 also has a guide groove 170 .
  • the groove 170 is formed by puncturing a hole within the mesh screen. Having a circular cross-section, the groove 170 has a diameter greater than that of the conductor forming the helix 100 .
  • the groove 170 is disposed within the mesh screen 130 , and directs the fixation helix 100 from its retracted position, as illustrated in FIG. 2A, to an extended position (not shown).
  • the stylet 14 is rotated which causes the piston to advance the fixation helix out of the groove 170 .
  • the fixation helix 100 As the fixation helix 100 is placed in an extended position, the helix 100 travels through groove 170 and circles around the protuberance 135 . The groove 170 also directs the fixation helix 100 from an extended position to the retracted position.
  • the mesh screen 130 prevents the implanter from overextension and advancing the helix 100 too far into the tissue.
  • An electrically conductive housing 180 encapsulates both the piston 50 and the fixation helix 100 . Insulation 182 covers the housing 180 , the collar 40 , and a portion of the mesh screen 130 . The insulation 182 over the mesh screen 130 controls the impedance of the electrode tip 120 .
  • a lead 10 has an electrode tip 20 which is provided with a mesh screen 30 .
  • the mesh screen 30 completely encapsulates the diameter of the lead tip.
  • Sintered to an electrode collar 40 the mesh screen 30 is attached to the electrode tip 20 .
  • the electrode collar 40 is electrically active.
  • a housing 80 is disposed about the helix 100 , and is electrically active. Insulation 82 , encompasses the housing 80 and collar 40 .
  • a lead fastener for securing the lead 10 to cardiac tissue.
  • the lead fastener can be disposed along the radial axis 15 of the lead 10 .
  • the lead fastener comprises a fixation helix 100 .
  • the fixation helix 100 can be made electrically active or inactive to change sensing and pacing characteristics.
  • the helix 100 is of a well known construction. Using a conductor coil such as helix 100 has been shown to be capable of withstanding constant, rapidly repeated flexing over a period of time which can be measured in years. The helix 100 is wound relatively tightly, with a slight space between adjacent turns. This closely coiled construction provides a maximum number of conductor turns per unit length, thereby providing optimum strain distribution. The spirally coiled spring construction of helix 100 also permits a substantial degree of elongation, within the elastic limits of the material, as well as distribution along the conductor of flexing stresses which otherwise might be concentrated at a particular point.
  • Attached to the fixation helix 100 is a piston 50 .
  • the piston 50 is configured to mate with a bladed locking stylet 14 .
  • the piston 50 advances the fixation helix 100 once the lead is placed in position within the heart.
  • the piston 50 can either be electrically active or inactive.
  • the piston 50 also has a slot 52 and a stylet slot 54 .
  • the stylet 14 couples with the stylet slot 54 and extends or retracts the fixation helix 100 when the stylet 14 is rotated.
  • the slot 52 of the piston 50 allows the piston 50 to mate with a base 60 when the helix 100 is retracted to prevent over retraction.
  • the base 60 is configured with a knob 62 to mate with the slot 52 of the piston 50 . Once the fixation helix 100 is fully retracted, the base 60 serves as a stop at full retraction.
  • the base 60 also allows passage of a bladed locking stylet 14 and attachment of electrode coils. In addition, the base
  • the lead 10 also includes a guiding bar 70 .
  • the guiding bar 70 Extending across the diameter of the tip, the guiding bar 70 is generally cylindrical in shape.
  • the guiding bar 70 directs the fixation helix 100 from its retracted position, as illustrated in FIG. 2A, to an extended position (not shown) as the piston 52 advances the helix 100 .
  • the guiding bar 70 also directs the fixation helix 100 as it is retracted from an extended position to the retraction position through the mesh screen.
  • a guiding bar 70 is described, other types of guiding mechanisms can be used such as helical passageways, threaded housings, springs, and are considered within the scope of the invention.
  • the lead 10 is provided with a seal (not shown) for preventing entry of body fluids and tissue from entering the lead through the opening therein.
  • the seal could be a puncture seal between the piston 50 and the base 60 .
  • O-rings could be used to seal the electrode.
  • a lead 210 has an electrode tip 220 which is provided with a mesh screen 230 .
  • the mesh screen 230 forms an annular ring having an open center, where the annular ring is centered at a radial axis 15 of the electrode lead 210 .
  • the mesh screen 230 provides more surface area than a smooth tipped electrode which aids in sensing. The removal of the center portion of the mesh screen creates a high impedance pacing tip due to the nature of the surface geometry.
  • Sintered, fused, bonded, adhesively secured or mechanically attached to an electrode collar 40 the mesh screen 230 is attached to the electrode tip 220 .
  • the electrode collar 40 is electrically active.
  • a lead fastener for securing the lead 210 to cardiac tissue.
  • the lead fastener can be disposed along the radial axis 15 of the electrode lead 210 .
  • the lead fastener comprises a fixation helix 100 .
  • the fixation helix 100 can be made electrically active or inactive as discussed above.
  • Attached to the fixation helix 100 is a piston 250 .
  • the piston 250 has a stylet slot 254 and is configured to mate with a bladed locking stylet 14 .
  • the stylet 14 coupled with the piston 250 at the stylet slot 254 , extends and retracts the fixation helix 100 when the stylet 14 is rotated.
  • the piston 250 can either be electrically active or inactive.
  • the base 260 serves as a stop once the fixation helix 100 is fully retracted.
  • the base 260 also allows passage of a bladed locking stylet 14 and attachment of electrode coils.
  • the base 60 is electrically active.
  • the electrode lead also has a guiding bar 270 .
  • the guiding bar 270 directs the fixation helix 100 from its retracted position, as illustrated in FIGS. 5 A and 5 B, to an extended position (not shown).
  • the guiding bar 270 also directs the fixation helix 100 from an extended position to the retracted position.
  • a housing 280 encapsulates the piston 250 and the fixation helix 100 , and insulation 282 is disposed over the housing 280 and collar 40 .
  • Insulation generally covers the housing, the collar, and a portion of the electrical discharge surface (e.g., the cathode, the helix and/or the porous material or mesh).
  • the insulation over the mesh screen further controls the impedance of the electrode tip.
  • the insulated coating whether present on the helix or the mesh or other elements which are potentially electrically active or on which electrical activity is to be suppressed, should be biocompatible, non-thrombogenic, and otherwise safe for implantation.
  • the insulation coating should be of dimensions which effect the insulation, increase the impedance (where desired), but which dimensions do not interfere with the performance of the tip, the lead or the helix or the health of the patient.
  • the insulation is present as a coating ( a material which tends to conform to the surface rather than completely reconfigure it, as would a lump of material).
  • the coating usually should be at least 0.5 microns in thickness, usually between 0.5 and 100 microns, preferably between 1.0 and 30 or 50 microns, more preferably between 1 and 20 microns, still more preferably between 1.5 and 15 microns, and most preferably between 1.5 or 2.0 microns and 10 or 15 microns.
  • the coating may be provided by any convenient process, such as electrophoretic deposition, dip coating, spin coating, in situ polymerization, vapor deposition, sputtering and the like.
  • Any insulating material is useful, such as polymers, ceramics, glasses, and the like, but because of their convenience in application, flexibility and availability, polymers are preferred.
  • Polymers from such classes as polyesters, polyamides, polyurethanes, polyethers, polysiloxanes, polyfluorinated resins, polyolefins, polyvinyl polymers, polyacrylates (including polymethacrylates), and the like may be used with various leads and tips according to the practice of the present invention.
  • PARYLENE is a preferred material, as described herein, with a thickness of between 1.5 and 10 microns.
  • a partially insulated fixation helix is used to provide a relatively high impedance electrode design.
  • Leads comprising a distal or electrode end and a proximal or connector end may be used.
  • a “miniature” wire-in-basket porous electrode may be sintered upon the distal end of a metallic pin, provided with a blind hole.
  • a sharpened wire fixation helix may be positioned and attached at a general location proximal to the electrode by any convenient means which allows electrical continuity.
  • This attachment includes, but is not limited to, crimping, spot welding, laser welding, the use of grooves upon the surface of the pin, the use of thin metallic overband (also not shown) or any combination thereof.
  • a portion of this fixation helix is provided with an extremely thin layer of a biostable, biocompatible polymer, which, inter alia, provides electrical insulation between the fixation helix and the cardiac tissue.
  • the insulated portion is the majority of the fixation helix, leaving a relatively small uninsulated region of fixation helix. This approach offers increased impedance to reduce energy dissipation in pulsing functions, such as pacing functions.
  • varying embodiments include, but are not limited to, a portion which is approximately or substantially equal to half of the fixation helix, and a portion which is approximately or substantially equal to a minority of the fixation helix.
  • Such embodiments provide different amounts of uninsulated region and different amounts of impedance.
  • the thin coating of electrically insulating coating must usually be at least 1 micron in thickness to provide a significant insulating effect, depending upon its insulating ability and properties. The thickness of the coating is limited primarily by physical limitations on the system. The coating can not be so thick as to interfere with the fastening ability of the helix or to increase the size of the helix beyond that which is tolerable for the use of the helix and the patient.
  • the coating is at least one micron up to about 100 microns, more typically the coating is between 1 and 30 microns, preferably between 1.5 and 20 microns, more preferably between 1.5 and 15 microns, and most preferably between 2 and 10 microns.
  • the material used for the coating should, of course, be biocompatible and even more preferably non-thrombogenic. Materials such as PARYLENETM, polyurethanes, polyacrylates (including polymethacrylates), polyesters, polyamides, polyethers, polysiloxanes, polyepoxide resins and the like can be used.
  • PARYLENE material includes a thermoplastic film polymer base upon para-xylylene. Crosslinked polymers within these classes may be preferred for their resistance to breakdown and their physical durability.
  • the coating composition should not be water-soluble or aqueous soluble within the parameters and environment encountered within animal bodies (e.g., it should not be soluble within blood, serum or other body fluids with which it might come into contact).
  • a metallic conductor coil may be conveniently attached to provide electrical connection to the implantable pacemaker (not shown) by means of a connector.
  • local (e.g., steroid or other medicinal) therapy is provided by a (e.g., circumferential) steroid/polymer matrix positioned immediately proximal to the porous electrode.
  • the circumferential steroid/polymer matrix is provided with a distal taper.
  • Other embodiments include other distal configurations, including, but not limited to, non-tapered or “inflated” configurations.
  • an internalized, medicinal or biologically active (e.g., steroid) releasing matrix is used.
  • a generally cylindrical polymeric tubing (this is the preferred shape, but the shape is a matter of choice) 820 is used to provide electrical insulation of this entire assembly.
  • the lead is “unipolar.”
  • an ablative protective covering positioned over the entirety of distal end is used (not shown).
  • a “bipolar” lead is provided with the distal electrode features described.
  • the PARYLENE coating is extremely thin ( ⁇ 3 ⁇ ), providing a coating with uniform coverage which is adherent to the metallic substrate, and which is controllable to provide an abrupt margin.
  • the silicone rubber coating is known to be somewhat thicker ( ⁇ 10 ⁇ ), uniform in coverage, somewhat less adherent to the metallic substrate, and controllable to an abrupt margin.
  • Other coatings may be used without departing from the spirit and scope of the present invention.
  • the PARYLENE or other insulative coating effectively increases in vitro “pacing impedance.”
  • Application of a non-continuous or partially extensive coating of an electrically insulating polymer such as PARYLENE to the metallic fixation helix produces the desired increase in impedance compared to an uninsulated helix as well as other existing designs.
  • PARYLENE electrically insulating polymer
  • one embodiment using a coated fixation helix provides a pacing impedance of over approximately 800 ohms which is larger than the impedance of some electrodes using an uncoated fixation helix.
  • the post-implant pacing impedance of an embodiment using a coated fixation helix remains higher than that of typical electrodes using an uncoated fixation helix.
  • a coated fixation helix using PARYLENE as an insulating layer provided over 1200 ohms average pacing impedance on the day of implantation and over 900 ohms ten days after the implant.
  • post-implant average voltage threshold of the PARYLENE insulated miniaturized electrode is less than the other high impedance electrodes. Such performance is considered to be desirable.
  • an embodiment with a coated fixation helix 802 having a voltage threshold of approximately 0.2 volts on the day of implant was measured at about 0.7 volts at ten days after the implant (using a 0.5 ms pulse width).
  • An electrode with an uncoated fixation helix demonstrated over 0.8 volts average voltage threshold at ten days after the implant, illustrating the benefits of the coated fixation helix.
  • coated fixation helix embodiments may provide an improvement in both the implant as well as post-implant average S-wave amplitude detection.
  • the coated fixation helix embodiments provide an electrode where the benefits of high impedance pacing are realized through downsizing the porous electrode and insulating the fixation helix. Downsizing of the porous electrode may be accomplished, for example, by having a smaller porous (e.g., mesh) electrode supported on a non-conductive surrounding support element (e.g., a polymeric or composite film with a mesh central area, particularly a mesh truncated conical or pyramidal area of flexible, conductive mesh).
  • a non-conductive surrounding support element e.g., a polymeric or composite film with a mesh central area, particularly a mesh truncated conical or pyramidal area of flexible, conductive mesh.
  • An area of the completely conductive mesh may also be discontinuously coated leaving a conductive central or conductive raised area, particularly surrounding a contact, engaging element, or helix.
  • an external steroid collar provides a fabrication advantage since such a component can be readily mass produced compared to smaller components with elaborate profiles. Still further, fabrication of a lead with this external collar is streamlined. The higher impedance design conserves battery power to provide longer battery life with fewer battery replacements. Other benefits exist which are not described in detail herein, however, which those skilled in the art will appreciate.
  • FIG. 6 shows a high impedance catheter tip 800 with a partially insulated tip 802 and a partially insulated mesh 808 .
  • the partially insulated tip (or helix) 802 extends from a base, proximal end 830 to a distal, pointed end 834 with a middle portion 836 lying between proximal end 830 and distal end 834 .
  • Helix 802 comprises one fully insulated section 804 which begins at distal, pointed end 834 and extends to, and ends with, middle portion 836 and one uninsulated section 806 which extends from the end of the fully insulated section within middle portion 836 to base, proximal end 830 .
  • the partially insulated mesh 808 comprises a first area 810 of the mesh 808 which is insulated and second are 812 of the mesh 808 which is not insulated.
  • the impedance of the catheter tip can be readily controlled by the amount of surface area of the helical tip itself and the area of the mesh (if present) which is insulated. With a fixed conductivity in the tip and the mesh (if present), the impedance can be increased by increasing the percentage of the surface area of the tip or mesh which is insulated.
  • a hole 820 is shown in the mesh 808 .
  • the mesh 808 may be flat and flush with the end 822 of the catheter 816 or may be partially wrapped (not shown) over the end 820 or inside the end 820 to affix the mesh to the catheter 816 .
  • the mesh 808 may also be hemispherical, truncated conical, truncated pyramidal or any other shape which may assist in allowing the mesh 808 to more compliantly contact tissue (not shown) surface to transmit the pacing signal or discharge.
  • Within the catheter 816 may be a soluble, elutable or dispersible material which carries medication or biologically active material along with the catheter.
  • anti-inflammatants may be transmitted to the attachment site along with the catheter by inclusion within a material 814 carried within or on the catheter 816 .
  • the coating of insulation on the helical tip or mesh may be applied by any convenient method, including, but not limited to coating (e.g., dip coating), printing, spraying, brush application, resist application and removal and the like.
  • the insulation may also contain active ingredients (such as those recited within material 814 ) to benefit the patient.
  • the insulation carrying the active material must not be soluble, so a polymer or other material that is porous or has elutable materials must be used.
  • the material delivery does not have to be coextensive with the life of the implant or the tip, and delivery of the material may be desirable only over a short time period after insertion of the helical tip and catheter.
  • a soluble or dispersible protective cap may also be placed over the helical tip to reduce the possibility of any incidental damage while catheterizing or moving the tip within a patient.
  • the cap material should preferably be biocompatible or even digestible and may include such materials as natural and synthetic materials such as sugars, starches, gelation (unhardened), gums, resins, polymers, and the like. All components of the catheter and tip which are exposed to the tissue or fluids within a patient should be non-thrombogenic, and bio-acceptable. There are extensive classes of commercially available materials which meet these needs for metal, polymeric, composite and other materials described within the practice of the present invention.

Abstract

An implantable lead, being either a fixed or retractable/extendable lead, having a distal tip electrode is adapted for implantation on or about the heart and for connection to a system for monitoring or stimulating cardiac activity. The electrode includes a mechanical fastener such as a fixation helix for securing the electrode to cardiac tissue, which may or may not be electrically active. The implantable electrode with a helical tip includes an electrode which has a distal end and a proximal end. A helix is disposed within the electrode, where the helix is aligned along a radial axis of the electrode. The electrode further includes one or more of the following features: the helix having a coating of an insulating material on a surface of the helix, a porous conductive surface at a base of the helix, or a porous conductive element at the end of the electrode having an insulating coating covering from 5-95% of the surface of the porous conductive element. The electrode may further include an electrode tip having a porous electrical conductive element, such as a mesh screen, disposed on a surface at the distal end of the electrode tip, which can be used as a sensing or pacing interface with the cardiac tissue.

Description

    CROSS-REFERENCE TO RELATED APPLICATION(S)
  • This patent application is a division of U.S. patent application Ser. No. 10/288,155, filed on Nov. 5, 2002, which is a division of U.S. patent application Ser. No. 09/121,288, filed on Jul. 22, 1998, now issued as U.S. Pat. No. 6,501,994, which is a continuation-in-part of U.S. patent application Ser. No. 08/998,174, filed on Dec. 24, 1997, entitled “RETRACTABLE LEAD WITH MESH SCREEN”, now abandoned, the specifications of which are incorporated by reference herein.[0001]
  • FIELD OF THE INVENTION
  • The present invention relates generally to leads for conducting electrical signals to and from the heart. More particularly, it pertains to electrode tips for delivering electrical charges to the heart, and to tips which tend to reduce power consumption from cells without reducing the effective level of each pace. [0002]
  • BACKGROUND OF THE INVENTION
  • Leads implanted in the body for electrical cardioversion or pacing of the heart are generally known in the art. In particular, electrically transmissive leads may be implanted in or about the heart to reverse (i.e., defibrillate or cardiovert) certain life threatening arrhythmias or to stimulate contraction (pacing) of the heart. Electrical energy is applied to the heart via the leads to return the heart to normal rhythm. Leads have also been used to sense conditions, materials or events (generally referred to as “sense” or “sensing”) in the body, such as in the atrium or ventricle of the heart and to deliver pacing pulses to the atrium or ventricle. Tachy leads generally can at least sense, pace, and deliver defibrillation shocks. Brady leads can at least perform the combination functions of pacing and sensing the heart. One of the available functions of the pacemaker or the automatic implantable cardioverter defibrillator (AICD) is to receive signals from a lead and interpret signals. In response to these signals, the pacemaker can decide to pace or not pace. The AICD can decide to pace or not pace, and shock or not shock. In response to a sensed bradycardia or tachycardia condition, a pulse generator produces pacing or defibrillation pulses to correct the condition. The same lead used to sense the condition is sometimes also used in the process of delivering a corrective pulse or signal from the pulse generator of the pacemaker. [0003]
  • Sick sinus syndrome and symptomatic AV (atrial-ventricular) block constitute two of the major reasons for insertion of cardiac pacemakers today. Cardiac pacing may be performed by the transvenous method or by leads implanted directly onto the ventricular epicardium. Most commonly, permanent transvenous pacing is performed using a lead positioned within one or more chambers of the heart. A lead, sometimes referred to as a catheter, may be positioned in the right ventricle or in the right atrium through a subclavian vein or other vascular port, and lead terminal pins are attached to a pacemaker which is implanted subcutaneously. The lead may also be positioned in both chambers, depending on the lead, as when a lead passes through the atrium to the ventricle. Sense electrodes may be positioned within the atrium or the ventricle of the heart as appropriate for the particular condition or the choice of the medical practitioner. [0004]
  • Pacemaker leads represent the electrical link between the pulse generator and the heart tissue which is to be excited. These pacemaker leads include single or multiconductor coils of insulated wire having an insulating sheath. The coils provide a cylindrical envelope or tube, many times referred to as a lumen, which provides a space into which a stiffening stylet can be inserted. The conductive coil is connected to an electrode in an electrode assembly at a distal end of a pacing lead. Typically, a terminal member is molded within a flexure sleeve at the proximal end of the pacing lead and connected to the proximal end of the conductive coil. [0005]
  • After the electrode assembly is positioned at a desired location within the heart, it is desirable to provide some method for securing the electrode assembly at that location. Mechanical fixation devices are used to firmly anchor the electrodes in the heart. One type of mechanical fixation device used is a corkscrew, or a helix electrode connector. During placement of the lead, the tip of the lead travels intravenously through veins and the heart. While traveling through the veins, the helix electrode connector at the tip of the lead may snag or attach to the side wall of the vein. Since this is highly undesirable as it may cause damage or other complications to a patient, retractable helixes are one of the optional constructions which have been provided for leads. In addition, temporary caps over the helix (such as an aqueous soluble cap, particularly a water soluble, innocuous organic material such as a sugar, starch or other biologically inert, or digestible material such as sugars, starches and the like (e.g., mannitol, sorbitol)) may be formed over the helix or tip. Preferably these materials are at least soluble or dispersible and preferably are inert or even digestible. [0006]
  • When using a retractable helix, the helix is extended and screwed into the heart muscle by applying a torque to the other end of the conductor without use of any further auxiliary device or with a special fixation stylet. A fixed or non-retractable helix electrode connector needs only to be positioned and secured to the heart muscle by the application of torque. If a soluble/dispersible cap is present on the helix, the cap must be given sufficient time to dissolve or disperse before complete securement of the helix electrode connector is attempted. A lead must be capable of being firmly secured into the wall of the cardiac tissue to prevent dislodgement therefrom, while avoiding perforation of the electrode completely through the cardiac tissue. [0007]
  • The pulse generator circuitry and power supply work in concert with the electrodes as a system which provides electrical pulses to the heart tissue. A low impedance electrode design may increase power delivery to the heart tissue, but at the same time, this higher energy usage results in shorter battery life. Shorter battery life is undesirable, since it increases the average number of surgical procedures to perform battery replacement for a patient. [0008]
  • There is a need for a body-implantable lead that has a helix for fixation to the wall of the atrium or ventricle of the heart. A separate desirable feature in body-implantable leads is for a lead having an electrode for positioning within the atrium or ventricle that allows for tissue in growth. Tissue in growth further enhances the electrical performance of the lead. The lead and electrode are further stabilized within the heart as a result of tissue in growth. Furthermore, there is a need for a relatively high pacing impedance electrode design which offers reasonable average voltage threshold with sufficient signal amplitude so that the pacing function would be effectively provided with reduced energy utilization and consequently extend battery life. [0009]
  • SUMMARY OF THE INVENTION
  • According to the present invention, there is provided a body-implantable lead assembly comprising a lead, one end of the lead being adapted to be connected to electrical supply for providing or receiving electrical pulses. The other end of the lead comprises a distal tip which is adapted to be connected to tissue of a living body. The lead is characterized by having either a) a porous electrode at the base of the helix and/or b) an insulating coating over a portion of the helix so that the impedance is increased for the helix as compared to a helix of the same size and materials without an insulating coating. The lead also has an increased impedance or high impedance which can act to extend the life of the battery. The high or at least the increased impedance may be effected in any of a number of ways, including, but not limited to one or more of the following structures: 1) a fully insulated tissue-engaging tip with an electrode at the base of the insulated tip, 2) a partially insulated engaging tip (only a portion of the surface area of the engaging tip being insulated), 3) a mesh or screen of material at the distal end of the lead, at the base of an extended engaging tip (whether a fixed or retractable tip), 4) the selection of materials in the composition of the mesh and/or tip which provide higher impedance, 5) the partial insulative coating of a mesh or screen to increase its pacing impedance, and 6) combinations of any of these features. There may be various constructions to effect the high impedance, including the use of helical tips with smaller surface areas (e.g., somewhat shorter or thinner tips). There may also be a sheath of material inert to body materials and fluids and at least one conductor extending through the lead body. The use of these various constructions in the tip also allows for providing the discharge from the tip in a more highly resolved location or area in the tip. [0010]
  • According to the present invention, there is provided a body-implantable lead assembly comprising a lead, one end being adapted to be connected to electrical supply for providing or receiving electrical pulses. The lead further comprises a distal tip which is adapted to be connected to tissue of a living body. The lead also has a high impedance to extend the life of the battery. There may be various constructions to effect the high impedance. There may also be a sheath of material at the distal end of the lead assembly, with the sheath being inert to body materials and fluids and at least one conductor extending through the lead body. [0011]
  • The distal tip electrode is adapted, for example, for implantation proximate to the heart while connected with a system for monitoring or stimulating cardiac activity. The distal tip electrode includes an electrode tip (preferably with only a percentage of its entire surface area being electrically conductively exposed—only a portion of the surface is insulated—to increase its impedance), preferably a mesh screen disposed at a distal end of the electrode tip, a fixation helix disposed within the electrode tip, and a helix guiding mechanism. The mesh screen preferably is electrically active, and the area of the mesh screen and the percentage of electrically exposed surface area of the electrode tip can be changed to control electrical properties. Further, the mesh screen can entirely cover an end surface of the electrode tip, or a portion of the end surface in the form of an annular ring. In one embodiment, the helix guiding mechanism includes a hole punctured within the mesh screen. Alternatively, the helix guiding mechanism can include a guiding bar disposed transverse to a radial axis of the electrode. The helix is retractable, and is in contact with a movement mechanism. The movement mechanism provides for retracting the helix, such as during travel of the electrode tip through veins. The helix is aligned with the radial axis of the electrode and travels through the guiding mechanism. The mesh may be tightly woven or constructed so that there are effectively no openings, or the mesh can be controlled to provide controlled porosity, or controlled flow through the mesh. [0012]
  • In another embodiment, the electrode tip includes a mesh screen forming a protuberance on the end surface of the electrode tip. The protuberance is axially aligned with the radial axis of the electrode. The helix travels around the protuberance as it passes through the mesh while traveling to attach to tissue within the heart. The helix also travels around the protuberance as it is retracted away from the tissue within the heart. If the mesh screen is insulated around the protuberance, then a high impedance tip is created. Advantageously, the protuberance allows for better attachment to the cardiac tissue without having the electrode tip penetrating therethrough. [0013]
  • Additionally, a distal tip electrode is provided including an electrode tip, a mesh screen disposed at a distal end of the electrode tip, a fixation helix disposed within the electrode tip, and a helix guiding mechanism. The electrode tip further may include a piston for moving the helix. The piston further may include a slot for receiving a bladed or fixation stylet. When engaged and rotated, the piston provides movement to the helix. The base provides a mechanical stop for the helix and piston when retracted back into the electrode tip. [0014]
  • In another embodiment, the distal tip assembly is adapted for implantation proximate to the heart while connected with a system for monitoring or stimulating cardiac activity. A fixation helix/piston assembly is housed by an electrode collar, housing, and base assembly. Attached to the proximal end of the helix is a piston which includes a proximal slot for receiving a bladed or fixation stylet. When a stylet is engaged in the slot and rotated, the piston provides movement to the helix. Depending on the embodiment, the fixation helix/piston assembly may be electrically active or inactive. The electrode collar, housing, and base all house the fixation helix/piston assembly. The proximal end of the electrode collar is attached to the distal end of the housing. Furthermore, the proximal end of the housing is attached to the distal end of the base, and the proximal end of the base is directly attached to the conductor coils of the lead. [0015]
  • A mesh screen may be attached to the distal tip of the electrode collar. The mesh screen, in another embodiment, is electrically active and serves as the electrode on the distal tip assembly. The tip may then be fully insulated to increase the impedance of the tip or may be partially insulated (with preselected areas of the helix tip being insulated and other areas being non-insulated) to adjust the impedance of the tip to the specific or optimal levels desired. The area of the mesh screen can be modified to cover differing portions of the end surface of the distal tip assembly to control electrical properties of the lead. The fixation helix travels through a guiding mechanism, where the guiding mechanism allows the fixation helix to be extended and retracted. In one embodiment, the helix guiding mechanism includes a hole formed within the mesh screen. Alternatively, the helix guiding mechanism can include a guiding bar disposed transverse to a radial axis of the electrode collar. The mesh screen and/or guiding bar also serve as a full extension stop when the helix is fully extended. The base serves as a stop when the fixation helix/piston assembly is fully retracted. [0016]
  • The provided electrode tip supplies a retractable helix and a mesh screen which advantageously allows for sufficient tissue in-growth. The guide mechanism provides a convenient way to direct the rotation of the helix. A further advantage of the electrode tip is the provided mechanical stop. The mechanical stop aids in preventing over-retraction of the helix during the installation or removal of the electrode tip. [0017]
  • In yet another embodiment, the electrode uses a partially insulated fixation helix to provide a relatively high pacing impedance electrode. The fixation helix is insulated using insulating coatings over a portion of the fixation helix.[0018]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a first side elevational view illustrating a lead constructed in accordance with one embodiment of the present invention. [0019]
  • FIG. 2A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention. [0020]
  • FIG. 2B is an end view of the electrode tip of the lead shown in FIG. 2A. [0021]
  • FIG. 3A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention. [0022]
  • FIG. 3B is an end view of the electrode tip of the lead shown in FIG. 3A. [0023]
  • FIG. 4A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention [0024]
  • FIG. 4B is an end view of the electrode tip of the lead shown in FIG. 4A. [0025]
  • FIG. 5A is a cross-sectional view of an electrode tip of a lead for monitoring and stimulating the heart constructed in accordance with one embodiment of the present invention [0026]
  • FIG. 5B is an end view of the electrode tip of the lead shown in FIG. 5A. [0027]
  • FIG. 6 shows a partially insulated helical tip according to the present invention which increases the impedance of the tip as compared to a fully non-insulated helical tip.[0028]
  • DETAILED DESCRIPTION OF THE INVENTION
  • In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which specific aspects of the broader invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice both the broad concepts of the invention as well as more limiting specific constructions, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the spirit and scope of the present invention as disclosed herein. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. [0029]
  • As noted previously, there are a number of ways in which increased impedance may be effected for mechanically fastened electrode connections in atrial/ventricular implantable catheters (AVIC) systems. These include at least the following: 1) a fully insulated tissue engaging tip (at least with respect to all surfaces that are in electrical contact or electrically active physical relationship to heart muscles so that a pace would be effective if discharged at that portion of the tip), 2) a partially insulated engaging tip (only a portion of the surface area of the engaging tip being insulated, preferably there is sufficient coating so that there is at least 5%, or at least 10%, or at least 20 or 30%, or at least 40, 50 or 60%, or at least 70, 75, 80 or 90% of the surface area of the tip which can discharge to heart muscle [or as percentages of the entire tip or as percentages of the entire tip that extends physically beyond the end plane of the catheter and which may therefore penetrate tissue or muscle]), 3) a porous, electrically conductive element, such as a mesh or screen of material at the proximal end of the helix or the distal end of the lead (excluding the helix), at the base of an extended engaging tip, 4) the selection of materials in the composition of the mesh and/or tip which provide higher impedance, 5) the partial insulative coating of a porous conductive element, such as the mesh or screen to increase its impedance, and 6) combinations of any of these features. There may be various constructions to effect the increased or high impedance, including the use of helical tips with smaller surface areas (e.g., somewhat shorter or thinner tips). There may also be other elements associated with the catheter and/or leads, such as a sheath of material inert to body materials and fluids, circuitry, microcatheters, and at least one conductor extending through the lead body. [0030]
  • One aspect of the present invention comprises an implantable electrode with a helical tip comprising: [0031]
  • an electrode having a distal end and a proximal end; and [0032]
  • a helix disposed within the electrode, which helix is aligned along a radial axis of the electrode towards the distal end, and which helix is either retractable or fixed; and [0033]
  • the implantable electrode having at least one feature selected from the group consisting of: [0034]
  • a) the helix having a coating of an insulating material on its surface which covers at least 5% of its surface area but less than 95% of its surface area (which is exposed beyond the distal end of the electrode), [0035]
  • b) the helix extending beyond the distal end of the electrode and the distal end of the electrode having a porous conductive surface at a base of the helix, [0036]
  • c) a porous conductive element such as a screen or mesh at a base of the helix, which is retractable/extendable, with the helix being either active or inactive (electrically), and [0037]
  • d) a partially insulated (partially insulation coated) porous conductive element (e.g., screen or mesh) at the base of an active or inactive, retractable/extendable or fixed helix. [0038]
  • The implantable electrode preferably has the helix with a coating of insulating material on its surface which covers from 5-100% (to 100% where there is an additional electrode element within the system) or 5-95% of surface area of the helix beyond the distal end of the electrode. Alternatively, the surface of the helix is that which is considered to be in electrically discharge-functional physical relationship with tissue or muscle into which it is embedded. For purposes of measuring or determining the distal end of the electrode, the tip extends beyond a tubular or cylindrical housing or structural portion which is considered the electrode, and the tip is an engaging portion that extends beyond the housing portion of the electrode. The distal end of the electrode is usually characterized as the end of the cylindrical housing or tubing carrying the tip, circuits, conductive elements, guides, etc. It is more preferred that the helix of the implantable electrode has a coating of insulating material on it surface which covers from 5-95% or 10-90% of the surface area of said helix beyond the distal end of the electrode. [0039]
  • A [0040] lead 10 is illustrated in FIG. 1. The lead 10 comprises a lead body 11, an elongate conductor 13 contained within the lead body, and a lead tip 20 with an optional retractable tip assembly 24 contained in the lead tip 20. In addition, a stylet 14 is shown inserted into the lead body 11. A helix 100 (FIGS. 2A-5A), which consists of an electrical conductor coil, is contained in the retractable lead tip 24. In an alternative practice of the invention, the helix 100 extends and retracts by rotation of the stylet 14, as will be discussed further below. A Brady lead body is shown, although the invention could be incorporated with other leads, such as Tachy leads. The lead body 11 consists of electrical conductors 13 which are covered by a biocompatible insulating material 22. Polymers, such as silicone rubber, fluorinated resins, polyacrylates, polyamides ceramic or composite materials or other insulating material can be used for covering the lead body 11.
  • In one embodiment shown in FIGS. 3 and 3A, the [0041] helix 100 is formed of electrically conductive material offering low electrical resistance and also resistant to corrosion by body fluids. A biocompatible metal, such as titanium or platinum-iridium alloy is an example of a suitable material. Alternatively, the helix 100 is electrically inactive or insulated. In one embodiment, the helix 100 may be coated with an insulative material (not shown) or may be constructed of a rigid, corrosion resistant, non-electrically-conductive material (e.g., a ceramic). A housing 182, described in further detail below, is made from an electrically conductive material and covered with an insulating material such as a synthetic or natural polymer such as a silicone rubber. The housing 182 is directly connected to an electrical conductor within the lead 120. These materials are additionally suitable because they tend to be biologically inert and well tolerated by body tissue.
  • The [0042] helix 100 defines a lumen and thereby is adapted to receive a stiffening stylet 14 that extends through the length of the lead. The stylet 14 stiffens the lead 120, and can be manipulated to introduce an appropriate curvature to the lead, facilitating the insertion of the lead into and through a vein and through an intracardiac valve to advance the distal end of the lead 120 into the right ventricle of the heart (not shown). A stylet knob 154 is coupled with the stylet 14 for rotating the stylet 14 and advancing the helix 100 into tissue of the heart.
  • In one embodiment, as shown in FIGS. 2A and 2B, a [0043] lead 310 has an electrode tip 320 which is provided with a mesh screen 330. The mesh screen 330 completely encapsulates the diameter of the lead, and may serve, at least in part, as a pacing/sensing interface with cardiac tissue. If the helix 100 is electrically active, it too can help serve as a portion of a pacing or sensing interface. The mesh screen 330 is of a porous construction, preferably made of electrically conductive, corrosion resistant material. Using a mesh screen 330 having a porous construction allows for fibrotic ingrowth. This provides for a further anchoring of the lead tip 320 and also increases the sensing capability of the lead 310 by increasing the surface area in contact with the cardial tissue. The mesh screen 330 may be attached to an electrode collar 40, which is electrically active. In a retractable catheter system, a housing 380, which is electrically conductive, encapsulates the piston 350 and the fixation helix 100. Insulation 382 is disposed about the housing 380 and collar 40.
  • Disposed within the [0044] lead 310 is a lead fastener 100 for securing the lead 310 to cardiac tissue. The lead fastener 100 can be disposed along the radial axis 15 of the electrode lead 310. In this embodiment, the lead fastener comprises a fixation helix 100. The fixation helix 100 can be made electrically active or inactive as discussed above. Attached to the fixation helix 100 in a retractable tip system is a piston 350. The piston 350 is configured to mate with a bladed locking stylet 14 at a stylet slot 354, and acts as an interface between the stylet 14 and the helix 100. The stylet 14, coupled with the piston 350 at the stylet slot 354, extends and retracts the fixation helix 100 when the stylet 14 is rotated. The piston 350 can either be electrically active or inactive. The piston 350 also has a slot 352, which allows the piston 350 to mate with a base 360.
  • Fitted with a [0045] knob 362, as shown in FIG. 2A, the base 360 mates with the slot 352 of the piston 350. The base 360 serves as a stop once the fixation helix 100 is fully retracted. The electrically conductive base 360 also allows passage of a bladed locking stylet 14 and attachment of electrode coils (not shown).
  • In addition, the [0046] lead 310 has a guide groove 370. The groove 370 is formed by puncturing a hole (not shown) within the mesh screen 330, although the guide groove 370 can be formed by other methods known by those skilled in the art. Having a circular cross-section, the guide groove 370 may have a diameter greater than that of the conductor forming the helix 100. The groove 370 is disposed within the mesh screen 330, and directs the fixation helix 100 from its retracted position, as illustrated in FIG. 2A, to an extended position (not shown). The groove 370 also reversibly directs the fixation helix 100 from an extended position to the retraction position.
  • In a second embodiment, as shown in FIGS. 3A and 3B, a [0047] lead 110 has an electrode tip 120 which is provided with a mesh screen 130. The mesh screen 130 completely encapsulates the diameter of the lead or electrode tip 120, and serves as the pacing/sensing interface with cardiac tissue. The screen 130 is of a porous construction, made of electrically conductive, corrosion resistant material. Using a mesh screen 130 having a porous construction allows for fibrotic ingrowth. This provides for a further anchoring of the lead tip 120 to tissue and also increases the sensing capability of the lead 110. The sensing capability is enhanced because the mesh screen 130 has more surface area than corresponding solid material. The ingrowth of fibrotic tissue into the mesh screen 130 increase the sensing capability of the lead 110 by increasing the surface area in contact with the cardiac tissue. Furthermore, the geometry of the mesh screen 130, particularly any protuberance, as will be discussed below, creates a high pacing impedance tip.
  • The [0048] mesh screen 130 may form a protuberance 135 from a flat edge portion 137 of the mesh screen 130 in a generally central portion of the electrode tip 120. The protuberance 135 may be generally circular in cross-section, but may be any shape (e.g., truncated cylindrical, truncated pyramidal, oval, ellipsoidal, etc.) as a result of design or circumstance which provides a flat or conformable surface (preferably not a rigid, sharp face which will not conform to tissue) abutting tissue, and preferably has a diameter smaller than a diameter of the lead 110. In addition, the protuberance 135 is aligned with the radial axis 15 of the lead 110. Sintered to an electrode collar 40, a process known by those skilled in the art, the mesh screen 130 is attached to the electrode tip 120. The electrode collar 40 is electrically active.
  • Disposed within the [0049] electrode lead 110 is a lead fastener for securing the electrode lead 110 to cardiac tissue. The lead fastener can be disposed along the radial axis 15 of the electrode lead 110. In this embodiment, the lead fastener comprises a fixation helix 100. The fixation helix 100 can be made electrically active or inactive to change sensing and pacing characteristics, as discussed above. Attached to the fixation helix 100 is a piston 150. The piston 150 is configured to mate with a bladed locking stylet 14, thereby providing a movement assembly. The stylet 14 extends and retracts the fixation helix 100 when the stylet 14 is rotated. The piston 150 can either be electrically active or inactive. The piston 150 also has a slot 152. The slot 152 of the piston 150 allows the piston 150 to mate with a base 160 upon full retraction.
  • The [0050] base 160 is modified with a knob 162 to mate with the slot 152 of the piston 150. The knob 162 mates with the piston 150 to prevent over-retraction once the helix 100 has been fully retracted. The stylet 14 operates to advance the fixation helix 100. As the implanter rotates the stylet 14, the stylet 14 engages the piston 150 at the stylet slot 154 and rotates the piston 150, which moves the fixation helix 100 through a guide groove 170. The guide groove 170 is for ensuring that the fixation helix 100 is properly guided out of and into the end of the electrode. Once the fixation helix 100 is fully retracted, the base 160 serves as a mechanical stop. The base 160 also allows passage of a bladed locking stylet 14 and attachment of electrode coils. Additionally, the base 60 is electrically active.
  • The [0051] electrode lead 110 also has a guide groove 170. The groove 170 is formed by puncturing a hole within the mesh screen. Having a circular cross-section, the groove 170 has a diameter greater than that of the conductor forming the helix 100. The groove 170 is disposed within the mesh screen 130, and directs the fixation helix 100 from its retracted position, as illustrated in FIG. 2A, to an extended position (not shown). During implantation, after the electrode is in contact with tissue at the desired location in the heart, the stylet 14 is rotated which causes the piston to advance the fixation helix out of the groove 170. As the fixation helix 100 is placed in an extended position, the helix 100 travels through groove 170 and circles around the protuberance 135. The groove 170 also directs the fixation helix 100 from an extended position to the retracted position. Advantageously, the mesh screen 130 prevents the implanter from overextension and advancing the helix 100 too far into the tissue. An electrically conductive housing 180 encapsulates both the piston 50 and the fixation helix 100. Insulation 182 covers the housing 180, the collar 40, and a portion of the mesh screen 130. The insulation 182 over the mesh screen 130 controls the impedance of the electrode tip 120.
  • In a third embodiment as shown in FIGS. 4A and 4B, a [0052] lead 10 has an electrode tip 20 which is provided with a mesh screen 30. The mesh screen 30 completely encapsulates the diameter of the lead tip. Sintered to an electrode collar 40, the mesh screen 30 is attached to the electrode tip 20. The electrode collar 40 is electrically active. A housing 80 is disposed about the helix 100, and is electrically active. Insulation 82, encompasses the housing 80 and collar 40.
  • Disposed within the [0053] lead 10 is a lead fastener for securing the lead 10 to cardiac tissue. The lead fastener can be disposed along the radial axis 15 of the lead 10. In this embodiment, the lead fastener comprises a fixation helix 100. The fixation helix 100 can be made electrically active or inactive to change sensing and pacing characteristics.
  • The [0054] helix 100 is of a well known construction. Using a conductor coil such as helix 100 has been shown to be capable of withstanding constant, rapidly repeated flexing over a period of time which can be measured in years. The helix 100 is wound relatively tightly, with a slight space between adjacent turns. This closely coiled construction provides a maximum number of conductor turns per unit length, thereby providing optimum strain distribution. The spirally coiled spring construction of helix 100 also permits a substantial degree of elongation, within the elastic limits of the material, as well as distribution along the conductor of flexing stresses which otherwise might be concentrated at a particular point.
  • Attached to the [0055] fixation helix 100 is a piston 50. The piston 50 is configured to mate with a bladed locking stylet 14. The piston 50 advances the fixation helix 100 once the lead is placed in position within the heart. The piston 50 can either be electrically active or inactive. The piston 50 also has a slot 52 and a stylet slot 54. The stylet 14 couples with the stylet slot 54 and extends or retracts the fixation helix 100 when the stylet 14 is rotated. The slot 52 of the piston 50 allows the piston 50 to mate with a base 60 when the helix 100 is retracted to prevent over retraction. The base 60 is configured with a knob 62 to mate with the slot 52 of the piston 50. Once the fixation helix 100 is fully retracted, the base 60 serves as a stop at full retraction. The base 60 also allows passage of a bladed locking stylet 14 and attachment of electrode coils. In addition, the base 60 is electrically active.
  • The [0056] lead 10 also includes a guiding bar 70. Extending across the diameter of the tip, the guiding bar 70 is generally cylindrical in shape. The guiding bar 70 directs the fixation helix 100 from its retracted position, as illustrated in FIG. 2A, to an extended position (not shown) as the piston 52 advances the helix 100. The guiding bar 70 also directs the fixation helix 100 as it is retracted from an extended position to the retraction position through the mesh screen. Although a guiding bar 70 is described, other types of guiding mechanisms can be used such as helical passageways, threaded housings, springs, and are considered within the scope of the invention. Additionally, the lead 10 is provided with a seal (not shown) for preventing entry of body fluids and tissue from entering the lead through the opening therein. The seal could be a puncture seal between the piston 50 and the base 60. Alternatively, O-rings could be used to seal the electrode.
  • In a fourth embodiment as shown in FIGS. 5A and 5B, a [0057] lead 210 has an electrode tip 220 which is provided with a mesh screen 230. The mesh screen 230 forms an annular ring having an open center, where the annular ring is centered at a radial axis 15 of the electrode lead 210. The mesh screen 230 provides more surface area than a smooth tipped electrode which aids in sensing. The removal of the center portion of the mesh screen creates a high impedance pacing tip due to the nature of the surface geometry. Sintered, fused, bonded, adhesively secured or mechanically attached to an electrode collar 40, the mesh screen 230 is attached to the electrode tip 220. The electrode collar 40 is electrically active.
  • Disposed within the [0058] lead 210 is a lead fastener for securing the lead 210 to cardiac tissue. The lead fastener can be disposed along the radial axis 15 of the electrode lead 210. In this embodiment, the lead fastener comprises a fixation helix 100. The fixation helix 100 can be made electrically active or inactive as discussed above. Attached to the fixation helix 100 is a piston 250. The piston 250 has a stylet slot 254 and is configured to mate with a bladed locking stylet 14. The stylet 14, coupled with the piston 250 at the stylet slot 254, extends and retracts the fixation helix 100 when the stylet 14 is rotated. The piston 250 can either be electrically active or inactive. The base 260 serves as a stop once the fixation helix 100 is fully retracted. The base 260 also allows passage of a bladed locking stylet 14 and attachment of electrode coils. The base 60 is electrically active.
  • Additionally, the electrode lead also has a guiding [0059] bar 270. The guiding bar 270 directs the fixation helix 100 from its retracted position, as illustrated in FIGS. 5A and 5B, to an extended position (not shown). The guiding bar 270 also directs the fixation helix 100 from an extended position to the retracted position. Although a guiding bar 270 has been described, other types of mechanisms could be used to extend the helix, and are considered within the scope of the invention. A housing 280 encapsulates the piston 250 and the fixation helix 100, and insulation 282 is disposed over the housing 280 and collar 40.
  • Insulation generally covers the housing, the collar, and a portion of the electrical discharge surface (e.g., the cathode, the helix and/or the porous material or mesh). The insulation over the mesh screen further controls the impedance of the electrode tip. The insulated coating, whether present on the helix or the mesh or other elements which are potentially electrically active or on which electrical activity is to be suppressed, should be biocompatible, non-thrombogenic, and otherwise safe for implantation. The insulation coating should be of dimensions which effect the insulation, increase the impedance (where desired), but which dimensions do not interfere with the performance of the tip, the lead or the helix or the health of the patient. The insulation is present as a coating ( a material which tends to conform to the surface rather than completely reconfigure it, as would a lump of material). The coating usually should be at least 0.5 microns in thickness, usually between 0.5 and 100 microns, preferably between 1.0 and 30 or 50 microns, more preferably between 1 and 20 microns, still more preferably between 1.5 and 15 microns, and most preferably between 1.5 or 2.0 microns and 10 or 15 microns. The coating may be provided by any convenient process, such as electrophoretic deposition, dip coating, spin coating, in situ polymerization, vapor deposition, sputtering and the like. Any insulating material is useful, such as polymers, ceramics, glasses, and the like, but because of their convenience in application, flexibility and availability, polymers are preferred. Polymers from such classes as polyesters, polyamides, polyurethanes, polyethers, polysiloxanes, polyfluorinated resins, polyolefins, polyvinyl polymers, polyacrylates (including polymethacrylates), and the like may be used with various leads and tips according to the practice of the present invention. PARYLENE is a preferred material, as described herein, with a thickness of between 1.5 and 10 microns. [0060]
  • In yet another embodiment, a partially insulated fixation helix is used to provide a relatively high impedance electrode design. Leads comprising a distal or electrode end and a proximal or connector end may be used. A “miniature” wire-in-basket porous electrode may be sintered upon the distal end of a metallic pin, provided with a blind hole. Circumferential to this subassembly, a sharpened wire fixation helix may be positioned and attached at a general location proximal to the electrode by any convenient means which allows electrical continuity. This attachment includes, but is not limited to, crimping, spot welding, laser welding, the use of grooves upon the surface of the pin, the use of thin metallic overband (also not shown) or any combination thereof. A portion of this fixation helix is provided with an extremely thin layer of a biostable, biocompatible polymer, which, inter alia, provides electrical insulation between the fixation helix and the cardiac tissue. In one embodiment, the insulated portion is the majority of the fixation helix, leaving a relatively small uninsulated region of fixation helix. This approach offers increased impedance to reduce energy dissipation in pulsing functions, such as pacing functions. Other varying embodiments include, but are not limited to, a portion which is approximately or substantially equal to half of the fixation helix, and a portion which is approximately or substantially equal to a minority of the fixation helix. Such embodiments provide different amounts of uninsulated region and different amounts of impedance. The thin coating of electrically insulating coating must usually be at least 1 micron in thickness to provide a significant insulating effect, depending upon its insulating ability and properties. The thickness of the coating is limited primarily by physical limitations on the system. The coating can not be so thick as to interfere with the fastening ability of the helix or to increase the size of the helix beyond that which is tolerable for the use of the helix and the patient. Typically, the coating is at least one micron up to about 100 microns, more typically the coating is between 1 and 30 microns, preferably between 1.5 and 20 microns, more preferably between 1.5 and 15 microns, and most preferably between 2 and 10 microns. The material used for the coating should, of course, be biocompatible and even more preferably non-thrombogenic. Materials such as PARYLENE™, polyurethanes, polyacrylates (including polymethacrylates), polyesters, polyamides, polyethers, polysiloxanes, polyepoxide resins and the like can be used. PARYLENE material includes a thermoplastic film polymer base upon para-xylylene. Crosslinked polymers within these classes may be preferred for their resistance to breakdown and their physical durability. As the coating is to be maintained within the body of a recipient, the coating composition should not be water-soluble or aqueous soluble within the parameters and environment encountered within animal bodies (e.g., it should not be soluble within blood, serum or other body fluids with which it might come into contact). [0061]
  • To the proximal end of this pin, a metallic conductor coil may be conveniently attached to provide electrical connection to the implantable pacemaker (not shown) by means of a connector. In one embodiment, local (e.g., steroid or other medicinal) therapy is provided by a (e.g., circumferential) steroid/polymer matrix positioned immediately proximal to the porous electrode. In one embodiment, the circumferential steroid/polymer matrix is provided with a distal taper. Other embodiments include other distal configurations, including, but not limited to, non-tapered or “inflated” configurations. In one embodiment, an internalized, medicinal or biologically active (e.g., steroid) releasing matrix is used. Proximal to this biologically active (e.g., steroid) eluting matrix, a generally cylindrical polymeric tubing (this is the preferred shape, but the shape is a matter of choice) [0062] 820 is used to provide electrical insulation of this entire assembly. In one embodiment, the lead is “unipolar.” In one embodiment, an ablative protective covering positioned over the entirety of distal end is used (not shown). One example of such a covering is the mannitol “Sweet Tip”® electrode of Guidant Corporation's Cardiac Rhythm Management Group. In one embodiment, a “bipolar” lead is provided with the distal electrode features described.
  • During an in vitro evaluation of this electrode design, polymeric coatings intended to partially insulate the fixation helix were prepared and evaluated. In one embodiment, the PARYLENE coating is extremely thin (˜3μ), providing a coating with uniform coverage which is adherent to the metallic substrate, and which is controllable to provide an abrupt margin. The silicone rubber coating is known to be somewhat thicker (˜10μ), uniform in coverage, somewhat less adherent to the metallic substrate, and controllable to an abrupt margin. Other coatings may be used without departing from the spirit and scope of the present invention. [0063]
  • The PARYLENE or other insulative coating effectively increases in vitro “pacing impedance.” Application of a non-continuous or partially extensive coating of an electrically insulating polymer such as PARYLENE to the metallic fixation helix produces the desired increase in impedance compared to an uninsulated helix as well as other existing designs. For example, it has been demonstrated that one embodiment using a coated fixation helix provides a pacing impedance of over approximately 800 ohms which is larger than the impedance of some electrodes using an uncoated fixation helix. The post-implant pacing impedance of an embodiment using a coated fixation helix remains higher than that of typical electrodes using an uncoated fixation helix. In one experiment, a coated fixation helix using PARYLENE as an insulating layer provided over 1200 ohms average pacing impedance on the day of implantation and over 900 ohms ten days after the implant. [0064]
  • Additionally, post-implant average voltage threshold of the PARYLENE insulated miniaturized electrode is less than the other high impedance electrodes. Such performance is considered to be desirable. In one experiment, an embodiment with a [0065] coated fixation helix 802 having a voltage threshold of approximately 0.2 volts on the day of implant was measured at about 0.7 volts at ten days after the implant (using a 0.5 ms pulse width). An electrode with an uncoated fixation helix demonstrated over 0.8 volts average voltage threshold at ten days after the implant, illustrating the benefits of the coated fixation helix.
  • An additional benefit is that the coated fixation helix embodiments may provide an improvement in both the implant as well as post-implant average S-wave amplitude detection. [0066]
  • The miniaturized high impedance, positive fixation porous electrode technology described here provides the following advantages over the prior art. For one example, the coated fixation helix embodiments provide an electrode where the benefits of high impedance pacing are realized through downsizing the porous electrode and insulating the fixation helix. Downsizing of the porous electrode may be accomplished, for example, by having a smaller porous (e.g., mesh) electrode supported on a non-conductive surrounding support element (e.g., a polymeric or composite film with a mesh central area, particularly a mesh truncated conical or pyramidal area of flexible, conductive mesh). An area of the completely conductive mesh may also be discontinuously coated leaving a conductive central or conductive raised area, particularly surrounding a contact, engaging element, or helix. Further, an external steroid collar provides a fabrication advantage since such a component can be readily mass produced compared to smaller components with elaborate profiles. Still further, fabrication of a lead with this external collar is streamlined. The higher impedance design conserves battery power to provide longer battery life with fewer battery replacements. Other benefits exist which are not described in detail herein, however, which those skilled in the art will appreciate. [0067]
  • FIG. 6 shows a high [0068] impedance catheter tip 800 with a partially insulated tip 802 and a partially insulated mesh 808. The partially insulated tip (or helix) 802 extends from a base, proximal end 830 to a distal, pointed end 834 with a middle portion 836 lying between proximal end 830 and distal end 834. Helix 802 comprises one fully insulated section 804 which begins at distal, pointed end 834 and extends to, and ends with, middle portion 836 and one uninsulated section 806 which extends from the end of the fully insulated section within middle portion 836 to base, proximal end 830. The partially insulated mesh 808 comprises a first area 810 of the mesh 808 which is insulated and second are 812 of the mesh 808 which is not insulated. The impedance of the catheter tip can be readily controlled by the amount of surface area of the helical tip itself and the area of the mesh (if present) which is insulated. With a fixed conductivity in the tip and the mesh (if present), the impedance can be increased by increasing the percentage of the surface area of the tip or mesh which is insulated.
  • A [0069] hole 820 is shown in the mesh 808. The mesh 808 may be flat and flush with the end 822 of the catheter 816 or may be partially wrapped (not shown) over the end 820 or inside the end 820 to affix the mesh to the catheter 816. The mesh 808 may also be hemispherical, truncated conical, truncated pyramidal or any other shape which may assist in allowing the mesh 808 to more compliantly contact tissue (not shown) surface to transmit the pacing signal or discharge. Within the catheter 816 may be a soluble, elutable or dispersible material which carries medication or biologically active material along with the catheter. For example, anti-inflammatants, antibiotics, analgesics, pain-reducing medication, vitamins, anti-viral medication, or the like may be transmitted to the attachment site along with the catheter by inclusion within a material 814 carried within or on the catheter 816.
  • The coating of insulation on the helical tip or mesh may be applied by any convenient method, including, but not limited to coating (e.g., dip coating), printing, spraying, brush application, resist application and removal and the like. The insulation may also contain active ingredients (such as those recited within material [0070] 814) to benefit the patient. The insulation carrying the active material must not be soluble, so a polymer or other material that is porous or has elutable materials must be used. The material delivery does not have to be coextensive with the life of the implant or the tip, and delivery of the material may be desirable only over a short time period after insertion of the helical tip and catheter.
  • A soluble or dispersible protective cap may also be placed over the helical tip to reduce the possibility of any incidental damage while catheterizing or moving the tip within a patient. As previously noted, the cap material should preferably be biocompatible or even digestible and may include such materials as natural and synthetic materials such as sugars, starches, gelation (unhardened), gums, resins, polymers, and the like. All components of the catheter and tip which are exposed to the tissue or fluids within a patient should be non-thrombogenic, and bio-acceptable. There are extensive classes of commercially available materials which meet these needs for metal, polymeric, composite and other materials described within the practice of the present invention. [0071]
  • It is to be understood that the above description is intended to be illustrative, and not restrictive. Although the use of the lead has been described for use in a cardiac pacing system, the lead could as well be applied to other types of body stimulating systems. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. [0072]

Claims (7)

What is claimed:
1. A distal tip electrode adapted for implantation on or about the heart and for connection to a system for monitoring or stimulating cardiac activity, said electrode comprising:
an electrode tip;
a mesh screen disposed at a distal end of the electrode tip;
a surface at the distal end of the electrode tip;
a fixation device disposed within said electrode, said fixation device adapted for travel along radial axis of the electrode through said surface;
a guiding mechanism for directing movement of the fixation device during travel; and
a movement assembly, said movement assembly for providing movement to said fixation device.
2. The distal tip electrode as recited in claim 1, wherein said fixation device comprises a helix.
3. The distal tip electrode as recited in claim 1, wherein said movement assembly comprises a piston.
4. The distal tip electrode as recited in claim 3, wherein the piston has a slot therein, and the base further comprises a knob, said slot for mating with said knob.
5. The distal tip electrode as recited in claim 3, wherein the slot is mated with said knob to form a stop mechanism for said fixation device.
6. The distal tip electrode as recited in claim 1, wherein the mesh screen has a groove guide disposed therein.
7. The distal tip electrode as recited in claim 3, wherein said distal tip electrode further comprises a seal, said seal disposed between said piston and said base.
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040142607A1 (en) * 2002-12-11 2004-07-22 Yazaki Corporation Method of connecting and structure of connecting electric wire and connection terminal
WO2007100277A1 (en) 2006-03-02 2007-09-07 St.Jude Medical Ab A medical implantable lead and a method for manufacturing of the same
WO2007123443A1 (en) * 2006-04-25 2007-11-01 St. Jude Medical Ab A medical implantable lead and a method for manufacturing the same
WO2009025597A1 (en) * 2007-08-22 2009-02-26 St. Jude Medical Ab Medical lead with a cover
US20090259272A1 (en) * 2008-04-15 2009-10-15 Reddy G Shantanu Bundle of his stimulation system
EP2150309A1 (en) * 2007-05-15 2010-02-10 St. Jude Medical AB Medical implantable lead with pivoting segments
US7711437B1 (en) 2006-11-22 2010-05-04 Pacesetter, Inc. Lead fixation device
US20110218604A1 (en) * 2010-03-02 2011-09-08 Sen Ji Cardiac Lead for Epicardial, Endocardial and Trans-Coronary Sinus Placement
US20120330122A1 (en) * 2011-06-24 2012-12-27 Sen Ji Cardiac Lead for Epicardial, Endocardial and Trans-Coronary Sinus Placement

Families Citing this family (61)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6463334B1 (en) 1998-11-02 2002-10-08 Cardiac Pacemakers, Inc. Extendable and retractable lead
US6862480B2 (en) * 2001-11-29 2005-03-01 Biocontrol Medical Ltd. Pelvic disorder treatment device
US7142928B2 (en) * 2001-12-03 2006-11-28 Medtronic, Inc. Field stimulation about a discontinuity of the myocardium to capture the heart at reduced pacing thresholds
US20030199938A1 (en) * 2002-04-22 2003-10-23 Karel Smits Precise cardiac lead placement based on impedance measurements
US7027852B2 (en) * 2002-05-21 2006-04-11 Pacesetter, Inc. Lead with distal tip surface electrodes connected in parallel
US7106043B1 (en) * 2002-09-17 2006-09-12 Bioluminate, Inc. Low capacitance measurement probe
US8246974B2 (en) 2003-05-02 2012-08-21 Surmodics, Inc. Medical devices and methods for producing the same
AU2004237774B2 (en) 2003-05-02 2009-09-10 Surmodics, Inc. Implantable controlled release bioactive agent delivery device
US7945337B2 (en) * 2003-08-27 2011-05-17 Medtronic, Inc. High impedance and low polarization electrode
US7953499B2 (en) * 2003-09-30 2011-05-31 Cardiac Pacemakers, Inc. Drug-eluting electrode
US7197362B2 (en) * 2003-12-11 2007-03-27 Cardiac Pacemakers, Inc. Cardiac lead having coated fixation arrangement
US9463313B2 (en) * 2004-11-24 2016-10-11 Flea Street Translational, Llc Sensor-assisted catheter-based procedures
US7720550B2 (en) * 2004-12-03 2010-05-18 Medtronic, Inc. High impedance active fixation electrode of an electrical medical lead
US20070179582A1 (en) * 2006-01-31 2007-08-02 Marshall Mark T Polymer reinforced coil conductor for torque transmission
US9901731B2 (en) * 2006-01-31 2018-02-27 Medtronic, Inc. Medical electrical lead having improved inductance
US8195296B2 (en) 2006-03-03 2012-06-05 Ams Research Corporation Apparatus for treating stress and urge incontinence
US20070282411A1 (en) * 2006-03-31 2007-12-06 Brian Franz Compliant electrical stimulation leads and methods of fabrication
WO2007114875A1 (en) * 2006-04-04 2007-10-11 Ams Research Corporation Apparatus for implanting neural stimulation leads
US8160710B2 (en) * 2006-07-10 2012-04-17 Ams Research Corporation Systems and methods for implanting tissue stimulation electrodes in the pelvic region
US8311606B2 (en) * 2006-09-20 2012-11-13 Cardiac Pacemakers Inc. Conductive polymer patterned electrode for pacing
US7610101B2 (en) 2006-11-30 2009-10-27 Cardiac Pacemakers, Inc. RF rejecting lead
US8250753B2 (en) 2007-01-31 2012-08-28 St. Jude Medical Ab Method for manufacturing an active fixation electrode
US20100049289A1 (en) * 2007-07-10 2010-02-25 Ams Research Corporation Tissue anchor
US9427573B2 (en) 2007-07-10 2016-08-30 Astora Women's Health, Llc Deployable electrode lead anchor
EP2227289B1 (en) 2007-12-06 2015-07-22 Cardiac Pacemakers, Inc. Implantable lead having a variable coil conductor pitch
WO2009100003A1 (en) 2008-02-06 2009-08-13 Cardiac Pacemakers, Inc. Lead with mri compatible design features
US8103360B2 (en) 2008-05-09 2012-01-24 Foster Arthur J Medical lead coil conductor with spacer element
DE102008028410B4 (en) 2008-06-17 2011-04-07 W.C. Heraeus Gmbh Selective parylene coating for pacemaker electrodes
US7904177B2 (en) * 2008-06-25 2011-03-08 Cardiac Pacemakers, Inc. Lead interconnect using a capured fixation member
CA2743824A1 (en) * 2008-11-26 2010-06-03 Surmodics, Inc. Implantable ocular drug delivery device and methods
US9084883B2 (en) 2009-03-12 2015-07-21 Cardiac Pacemakers, Inc. Thin profile conductor assembly for medical device leads
WO2010114429A1 (en) * 2009-03-31 2010-10-07 St. Jude Medical Ab A medical implantable lead and a method for manufacturing of such a lead
US20100305672A1 (en) * 2009-05-28 2010-12-02 Felling Michael A Tip assembly for medical electrical lead
JP5542926B2 (en) 2009-06-26 2014-07-09 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 Medical instrument lead comprising a conductor assembly consisting of a single wire coil with improved torque transfer performance and reduced heating by MRI
WO2011028949A1 (en) * 2009-09-03 2011-03-10 Mayo Foundation For Medical Education And Research Pacing, sensing or defibrillator leads for implantation into the myocardium
US8335572B2 (en) * 2009-10-08 2012-12-18 Cardiac Pacemakers, Inc. Medical device lead including a flared conductive coil
WO2011049684A1 (en) 2009-10-19 2011-04-28 Cardiac Pacemakers, Inc. Mri compatible tachycardia lead
US8812134B2 (en) * 2009-11-12 2014-08-19 Cardiac Pacemakers Inc. Helix fixation mechanism
US8903514B2 (en) 2009-11-30 2014-12-02 St. Jude Medical Ab Medical implantable lead with fixation detection
WO2011081709A1 (en) * 2009-12-30 2011-07-07 Cardiac Pacemakers, Inc. Mri-conditionally safe medical device lead
WO2011081713A1 (en) 2009-12-31 2011-07-07 Cardiac Pacemakers, Inc. Mri conditionally safe lead with multi-layer conductor
US8391994B2 (en) * 2009-12-31 2013-03-05 Cardiac Pacemakers, Inc. MRI conditionally safe lead with low-profile multi-layer conductor for longitudinal expansion
US8380312B2 (en) 2009-12-31 2013-02-19 Ams Research Corporation Multi-zone stimulation implant system and method
WO2011143233A2 (en) 2010-05-10 2011-11-17 Spinal Modulation, Inc. Methods, systems and devices for reducing migration
US8825181B2 (en) 2010-08-30 2014-09-02 Cardiac Pacemakers, Inc. Lead conductor with pitch and torque control for MRI conditionally safe use
US9220887B2 (en) 2011-06-09 2015-12-29 Astora Women's Health LLC Electrode lead including a deployable tissue anchor
WO2013036399A2 (en) 2011-09-08 2013-03-14 Ams Research Corporation Implantable electrode assembly
WO2013066505A1 (en) 2011-11-04 2013-05-10 Cardiac Pacemakers, Inc. Implantable medical device lead including inner coil reverse-wound relative to shocking coil
EP2825255A2 (en) * 2012-03-15 2015-01-21 Krishnan, Subramaniam, Chitoor Mechanism, system, method for in vivo lead fixation
AU2013249088B2 (en) 2012-04-20 2015-12-03 Cardiac Pacemakers, Inc. Implantable medical device lead including a unifilar coiled cable
JP6549482B2 (en) 2012-06-01 2019-07-24 サーモディクス,インコーポレイテッド Device and method for coating a balloon catheter
US9827401B2 (en) 2012-06-01 2017-11-28 Surmodics, Inc. Apparatus and methods for coating medical devices
US8954168B2 (en) 2012-06-01 2015-02-10 Cardiac Pacemakers, Inc. Implantable device lead including a distal electrode assembly with a coiled component
US10905884B2 (en) 2012-07-20 2021-02-02 Cardialen, Inc. Multi-stage atrial cardioversion therapy leads
WO2014036529A1 (en) 2012-08-31 2014-03-06 Cardiac Pacemakers, Inc. Mri compatible lead coil
WO2014062966A1 (en) 2012-10-18 2014-04-24 Cardiac Pacemakers, Inc. Inductive element for providing mri compatibility in an implantable medical device lead
US11090468B2 (en) 2012-10-25 2021-08-17 Surmodics, Inc. Apparatus and methods for coating medical devices
CN106029162A (en) 2014-02-26 2016-10-12 心脏起搏器股份公司 Construction of an MRI-safe tachycardia lead
US11911623B2 (en) * 2018-03-02 2024-02-27 Medtronic, Inc. Implantable medical electrode assemblies, devices, systems, kits, and methods
US11628466B2 (en) 2018-11-29 2023-04-18 Surmodics, Inc. Apparatus and methods for coating medical devices
US11819590B2 (en) 2019-05-13 2023-11-21 Surmodics, Inc. Apparatus and methods for coating medical devices

Citations (96)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3804098A (en) * 1972-04-17 1974-04-16 Medronic Inc Body implantable lead
US3942536A (en) * 1971-03-15 1976-03-09 Mieczyslaw Mirowski Cardioverting device having single intravascular catheter electrode system and method for its use
US4010758A (en) * 1975-09-03 1977-03-08 Medtronic, Inc. Bipolar body tissue electrode
US4026303A (en) * 1975-11-17 1977-05-31 Vitatron Medical B.V. Endocardial pacing electrode
US4030508A (en) * 1976-02-04 1977-06-21 Vitatron Medical B.V. Low output electrode for cardiac pacing
US4030509A (en) * 1975-09-30 1977-06-21 Mieczyslaw Mirowski Implantable electrodes for accomplishing ventricular defibrillation and pacing and method of electrode implantation and utilization
US4082087A (en) * 1977-02-07 1978-04-04 Isis Medical Instruments Body contact electrode structure for deriving electrical signals due to physiological activity
US4136703A (en) * 1978-03-09 1979-01-30 Vitatron Medical B.V. Atrial lead and method of inserting same
US4146037A (en) * 1977-12-12 1979-03-27 Cardiac Pacemakers, Inc. Cardiac pacer electrode and lead insertion tool
US4156429A (en) * 1977-10-11 1979-05-29 Cardiac Pacemakers, Inc. Implantable electrode
US4187853A (en) * 1978-11-06 1980-02-12 Barbanel Sidney M Electrode implanting apparatus with optimum location probe
US4270549A (en) * 1979-04-30 1981-06-02 Mieczyslaw Mirowski Method for implanting cardiac electrodes
US4311153A (en) * 1980-09-30 1982-01-19 Medtronic, Inc. Screw-in lead having lead tip with membrane
US4326534A (en) * 1979-06-21 1982-04-27 Jens Axelgaard Transcutaneous electrical muscle stimulation for treatment of scoliosis and other spinal deformities
US4437474A (en) * 1982-07-16 1984-03-20 Cordis Corporation Method for making multiconductor coil and the coil made thereby
US4444206A (en) * 1982-04-29 1984-04-24 Cordis Corporation Mesh tip pacing lead assembly
US4567900A (en) * 1984-06-04 1986-02-04 Moore J Paul Internal deployable defibrillator electrode
US4570642A (en) * 1983-09-23 1986-02-18 Daig Corporation Endocardial extendable screw-in lead
US4587975A (en) * 1984-07-02 1986-05-13 Cardiac Pacemakers, Inc. Dimension sensitive angioplasty catheter
US4633880A (en) * 1984-04-06 1987-01-06 Peter Osypka Surgical electrode
US4646755A (en) * 1985-10-21 1987-03-03 Daig Corporation Introducer tool for endocardial screw-in lead
US4649937A (en) * 1985-01-28 1987-03-17 Cordis Corporation Etched grooved electrode for pacing lead and method for making same
US4649938A (en) * 1985-04-29 1987-03-17 Mcarthur William A Tissue-stimulating electrode having sealed, low-friction extendable/retractable active fixation means
US4662382A (en) * 1985-01-16 1987-05-05 Intermedics, Inc. Pacemaker lead with enhanced sensitivity
US4662377A (en) * 1985-11-07 1987-05-05 Mieczyslaw Mirowski Cardioverting method and apparatus utilizing catheter and patch electrodes
US4664113A (en) * 1984-05-30 1987-05-12 Advanced Cardiovascular Systems, Inc. Steerable dilatation catheter with rotation limiting device
US4667686A (en) * 1985-05-16 1987-05-26 Cordis Corporation Pacer lead terminal assembly
US4722353A (en) * 1985-09-16 1988-02-02 Intermedics, Inc. Stabilizer for implantable electrode
US4722351A (en) * 1981-12-21 1988-02-02 American Home Products Corporation Systems and methods for processing physiological signals
US4727877A (en) * 1984-12-18 1988-03-01 Medtronic, Inc. Method and apparatus for low energy endocardial defibrillation
US4799493A (en) * 1987-03-13 1989-01-24 Cardiac Pacemakers, Inc. Dual channel coherent fibrillation detection system
US4799486A (en) * 1987-03-13 1989-01-24 Cardiac Pacemakers, Inc. Refractoriless atrial sensing in dual chamber pacemakers
US4817608A (en) * 1987-05-29 1989-04-04 Mieczyslaw Mirowski Cardioverting transvenous catheter/patch electrode system and method for its use
US4817634A (en) * 1987-06-18 1989-04-04 Medtronic, Inc. Epicardial patch electrode
US4819661A (en) * 1987-10-26 1989-04-11 Cardiac Pacemakers, Inc. Positive fixation cardiac electrode with drug elution capabilities
US4819647A (en) * 1984-05-03 1989-04-11 The Regents Of The University Of California Intracochlear electrode array
US4819662A (en) * 1987-10-26 1989-04-11 Cardiac Pacemakers, Inc. Cardiac electrode with drug delivery capabilities
US4827932A (en) * 1987-02-27 1989-05-09 Intermedics Inc. Implantable defibrillation electrodes
US4827940A (en) * 1987-04-13 1989-05-09 Cardiac Pacemakers, Inc. Soluble covering for cardiac pacing electrode
US4830006A (en) * 1986-06-17 1989-05-16 Intermedics, Inc. Implantable cardiac stimulator for detection and treatment of ventricular arrhythmias
US4905691A (en) * 1989-04-17 1990-03-06 Everest Medical Corporation Polypectome snare with bipolar electrodes
US4919135A (en) * 1988-12-14 1990-04-24 Intermedics, Inc. Triaxial electrode
US4922927A (en) * 1987-12-30 1990-05-08 Intermedics, Inc. Transvenous defibrillating and pacing lead
US4924881A (en) * 1989-05-12 1990-05-15 Intermedics, Inc. Implantable endocardial lead with fixation device retractable by threaded stylet
US4932969A (en) * 1987-01-08 1990-06-12 Sulzer Brothers Limited Joint endoprosthesis
US4998975A (en) * 1989-10-30 1991-03-12 Siemens-Pacesetter, Inc. Travenously placed defibrillation leads
US5002067A (en) * 1989-08-23 1991-03-26 Medtronic, Inc. Medical electrical lead employing improved penetrating electrode
US5003992A (en) * 1989-08-23 1991-04-02 Holleman Timothy W Atraumatic screw-in lead
US5016645A (en) * 1987-06-18 1991-05-21 Terrell Williams Medical electrode lead
US5016646A (en) * 1988-11-29 1991-05-21 Telectronics, N.V. Thin electrode lead and connections
US5016808A (en) * 1989-09-14 1991-05-21 Cardiac Pacemakers, Inc. Implantable tapered spiral endocardial lead for use in internal defibrillation
US5020544A (en) * 1989-11-01 1991-06-04 Cardiac Pacemakers, Inc. Low energy defibrillation electrode
US5083562A (en) * 1988-01-19 1992-01-28 Telectronics Pacing Systems, Inc. Method and apparatus for applying asymmetric biphasic truncated exponential countershocks
US5085218A (en) * 1990-08-31 1992-02-04 Cardiac Pacemakers, Inc. Bipolar myocardial positive fixation lead with improved sensing capability
US5090422A (en) * 1990-04-19 1992-02-25 Cardiac Pacemakers, Inc. Implantable electrode pouch
US5105826A (en) * 1990-10-26 1992-04-21 Medtronic, Inc. Implantable defibrillation electrode and method of manufacture
US5107834A (en) * 1991-01-30 1992-04-28 Cardiac Pacemakers, Inc. Low energy multiple shock defibrillation/cardioversion discharge technique and electrode configuration
US5107734A (en) * 1987-07-22 1992-04-28 Armbruster Joseph M Electrically powered dispenser for rolled sheet material
US5111812A (en) * 1990-01-23 1992-05-12 Cardiac Pacemakers, Inc. Defilbrillation electrode having smooth current distribution
US5111811A (en) * 1985-06-20 1992-05-12 Medtronic, Inc. Cardioversion and defibrillation lead system with electrode extension into the coronary sinus and great vein
US5181526A (en) * 1990-04-20 1993-01-26 Tanaka Kikinzoku Kogyo K.K. Electrode for human heart pacemaker
US5203348A (en) * 1990-06-06 1993-04-20 Cardiac Pacemakers, Inc. Subcutaneous defibrillation electrodes
US5209229A (en) * 1991-05-20 1993-05-11 Telectronics Pacing Systems, Inc. Apparatus and method employing plural electrode configurations for cardioversion of atrial fibrillation in an arrhythmia control system
US5217028A (en) * 1989-11-02 1993-06-08 Possis Medical, Inc. Bipolar cardiac lead with drug eluting device
US5282845A (en) * 1990-10-01 1994-02-01 Ventritex, Inc. Multiple electrode deployable lead
US5300110A (en) * 1992-10-15 1994-04-05 Angeion Corporation Dirk-based epicardial defibrillation electrode
US5300108A (en) * 1993-01-05 1994-04-05 Telectronics Pacing Systems, Inc. Active fixation lead with a dual-pitch, free spinning compound screw
US5306292A (en) * 1992-05-25 1994-04-26 Siemens-Elema Ab Heart stimulation apparatus
US5324327A (en) * 1991-12-17 1994-06-28 Cohen Donald M Low threshold cardiac pacing lead
US5383908A (en) * 1993-06-16 1995-01-24 Ventritex, Inc. Defibrillation system having innominate vein electrode and method for its use
US5385574A (en) * 1990-04-25 1995-01-31 Cardiac Pacemakers, Inc. Implantable intravenous cardiac stimulation system with pulse generator housing serving as optional additional electrode
US5391200A (en) * 1992-09-30 1995-02-21 Cardiac Pacemakers, Inc. Defibrillation patch electrode having conductor-free resilient zone for minimally invasive deployment
US5397342A (en) * 1993-06-07 1995-03-14 Cardiac Pacemakers, Inc. Resilient structurally coupled and electrically independent electrodes
US5405373A (en) * 1993-02-12 1995-04-11 Siemens-Elema Ab Electrode device for intracorporeal tissue stimulation
US5411544A (en) * 1993-11-02 1995-05-02 Ventritex, Inc. Defibrillation lead with improved mechanical and electrical characteristics
US5411525A (en) * 1992-01-30 1995-05-02 Cardiac Pacemakers, Inc. Dual capacitor biphasic defibrillator waveform generator employing selective connection of capacitors for each phase
US5425756A (en) * 1992-05-27 1995-06-20 Cardiac Pacemakers, Inc. Positive fixation device
US5425755A (en) * 1992-12-04 1995-06-20 Pacesetter, Inc. Rotatable pin, screw-in pacing and sensing lead having Teflon-coated conductor coil
US5480416A (en) * 1994-09-22 1996-01-02 Intermedics, Inc. Cardiac pacemaker with universal coating
US5492119A (en) * 1993-12-22 1996-02-20 Heart Rhythm Technologies, Inc. Catheter tip stabilizing apparatus
US5496362A (en) * 1992-11-24 1996-03-05 Cardiac Pacemakers, Inc. Implantable conformal coil patch electrode with multiple conductive elements for cardioversion and defibrillation
US5500008A (en) * 1994-03-29 1996-03-19 Ventritex, Inc. Method and apparatus for delivering defibrillation shocks with improved effectiveness
US5515848A (en) * 1991-10-22 1996-05-14 Pi Medical Corporation Implantable microelectrode
US5709753A (en) * 1995-10-27 1998-01-20 Specialty Coating Sysetms, Inc. Parylene deposition apparatus including a heated and cooled dimer crucible
US5713926A (en) * 1990-04-25 1998-02-03 Cardiac Pacemakers, Inc. Implantable intravenous cardiac stimulation system with pulse generator housing serving as optional additional electrode
US5720099A (en) * 1996-01-31 1998-02-24 Cochlear Limited Thin film fabrication technique for implantable electrodes
US5725810A (en) * 1995-11-29 1998-03-10 Sulzer Chemtech Ag Packing for a counterflow high pressure column
US5725559A (en) * 1996-05-16 1998-03-10 Intermedics Inc. Programmably upgradable implantable medical device
US5728140A (en) * 1996-06-17 1998-03-17 Cardiac Pacemakers, Inc. Method for evoking capture of left ventricle using transeptal pacing lead
US5755764A (en) * 1996-09-10 1998-05-26 Sulzer Intermedics Inc. Implantable cardiac stimulation catheter
US5855594A (en) * 1997-08-08 1999-01-05 Cardiac Pacemakers, Inc. Self-calibration system for capture verification in pacing devices
US5871529A (en) * 1997-01-16 1999-02-16 Cardiac Pacemakers, Inc. Electrode for high impedance heart stimulation
US5871531A (en) * 1997-09-25 1999-02-16 Medtronic, Inc. Medical electrical lead having tapered spiral fixation
US5876431A (en) * 1997-07-30 1999-03-02 Sulzer Intermedics Inc. Small cable endocardial lead with exposed guide tube
US5902329A (en) * 1997-11-14 1999-05-11 Pacesetter, Inc. Explantable lead
US6212434B1 (en) * 1998-07-22 2001-04-03 Cardiac Pacemakers, Inc. Single pass lead system

Family Cites Families (67)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3614955A (en) 1970-02-09 1971-10-26 Medtronic Inc Standby defibrillator and method of operation
DE2319054C3 (en) * 1973-04-14 1980-03-06 Hans Dr.Med. Stockholm Lagergren Electrode arrangement
US4106512A (en) 1976-12-16 1978-08-15 Medtronic, Inc. Transvenously implantable lead
US4217913A (en) 1977-10-10 1980-08-19 Medtronic, Inc. Body-implantable lead with protected, extendable tissue securing means
JPS5554963A (en) 1978-10-18 1980-04-22 Fujiwara Akimasa Catheter that fix pacemaker electrode into atrium
US4291707A (en) 1979-04-30 1981-09-29 Mieczyslaw Mirowski Implantable cardiac defibrillating electrode
IT1147750B (en) * 1980-06-19 1986-11-26 Sorin Biomedica Spa ELECTRODE FOR CARDIAC STIMULATORS
CA1173114A (en) 1981-02-02 1984-08-21 David F. Juncker Body implantable lead with improved dcd electrode
US4548203A (en) 1982-06-01 1985-10-22 Purdue Research Foundation Sequential-pulse, multiple pathway defibrillation method
US4469104A (en) 1982-07-16 1984-09-04 Cordis Corporation Multipolar connector for pacing lead
US4458695A (en) 1982-07-16 1984-07-10 Cordis Corporation Multipolar electrode assembly for pacing lead
US4463765A (en) 1982-08-30 1984-08-07 Cordis Corporation Screw-in pacing lead assembly
US4559951A (en) 1982-11-29 1985-12-24 Cardiac Pacemakers, Inc. Catheter assembly
US4627439A (en) 1983-12-15 1986-12-09 Cordis Corporation Prebent ventricular/atrial cardiac pacing lead
US4624266A (en) 1983-12-19 1986-11-25 Daig Corporation Introducer tool for screw-in lead
US4603705A (en) 1984-05-04 1986-08-05 Mieczyslaw Mirowski Intravascular multiple electrode unitary catheter
US4624265A (en) 1985-07-24 1986-11-25 Ge. Sv. In. S.R.L. Electro-catheter used in physiological cardiac stimulation simulative of the auriculo-ventricular sequence, featuring active engagement of the cardiac muscle
US4938231A (en) 1985-10-22 1990-07-03 Telectronics N.V. Defibrillator electrode
US4784161A (en) 1986-11-24 1988-11-15 Telectronics, N.V. Porous pacemaker electrode tip using a porous substrate
US4953551A (en) 1987-01-14 1990-09-04 Medtronic, Inc. Method of defibrillating a heart
DE3708133A1 (en) 1987-03-13 1988-09-22 Bisping Hans Juergen IMPLANTABLE ELECTRODE PROBE WITH EXTENDABLE SCREW ELECTRODE
US4944300A (en) 1987-04-28 1990-07-31 Sanjeev Saksena Method for high energy defibrillation of ventricular fibrillation in humans without a thoracotomy
US4971070A (en) 1987-06-18 1990-11-20 Medtronic, Inc. Epicardial patch electrode
US4860769A (en) 1987-11-12 1989-08-29 Thomas J. Fogarty Implantable defibrillation electrode
US4865037A (en) 1987-11-13 1989-09-12 Thomas J. Fogarty Method for implanting automatic implantable defibrillator
US4967766A (en) 1989-05-16 1990-11-06 Intermedics, Inc. Implantable endocardial lead with fixation apparatus retractable by a lanyard
US4953564A (en) 1989-08-23 1990-09-04 Medtronic, Inc. Screw-in drug eluting lead
US5133365A (en) 1989-09-14 1992-07-28 Cardiac Pacemakers, Inc. Implantable tapered spiral endocardial lead for use in internal defibrillation
US5063932A (en) 1989-10-03 1991-11-12 Mieczyslaw Mirowski Controlled discharge defibrillation electrode
US5056516A (en) 1989-11-02 1991-10-15 Intermedics, Inc. Implantable endocordial lead with torque-transmitting lanyard
US5269319A (en) 1989-12-08 1993-12-14 Cardiac Pacemakers, Inc. Unitary intravascular defibrillating catheter with bipolar sensing
US5044375A (en) 1989-12-08 1991-09-03 Cardiac Pacemakers, Inc. Unitary intravascular defibrillating catheter with separate bipolar sensing
US5271417A (en) 1990-01-23 1993-12-21 Cardiac Pacemakers, Inc. Defibrillation electrode having smooth current distribution
US5076285A (en) 1990-03-30 1991-12-31 Medtronic, Inc. Screw-in lead
IT1238542B (en) 1990-04-05 1993-08-18 Enzo Borghi THREE-POLE RETRACTABLE LEAD WITH ENDOCAVITARY ANCHORAGE ACTIVE FOR CARDIAC STIMULATION.
US5050601A (en) 1990-05-29 1991-09-24 Joel Kupersmith Cardiac defibrillator electrode arrangement
US5230337A (en) 1990-06-06 1993-07-27 Cardiac Pacemakers, Inc. Process for implanting subcutaneous defibrillation electrodes
US5129404A (en) 1990-12-21 1992-07-14 Intermedics, Inc. Implantable endocardial lead with retractable fixation apparatus
FR2671010B1 (en) 1990-12-27 1993-07-09 Ela Medical Sa ENDOCARDIAC PROBE PROVIDED WITH AN ACTIVE FIXING MEMBER
US5165403A (en) 1991-02-26 1992-11-24 Medtronic, Inc. Difibrillation lead system and method of use
US5152299A (en) 1991-04-19 1992-10-06 Intermedics, Inc. Implantable endocardial lead with spring-loaded screw-in fixation apparatus
US5174303A (en) 1991-05-03 1992-12-29 Intermedics, Inc. Pacer lead with replaceable sensor
US5259395A (en) 1992-01-15 1993-11-09 Siemens Pacesetter, Inc. Pacemaker lead with extendable retractable lockable fixing helix
US5261400A (en) 1992-02-12 1993-11-16 Medtronic, Inc. Defibrillator employing transvenous and subcutaneous electrodes and method of use
US5318572A (en) 1992-06-02 1994-06-07 Siemens Pacesetter, Inc. High efficiency tissue stimulating and signal sensing electrode
US5447533A (en) 1992-09-03 1995-09-05 Pacesetter, Inc. Implantable stimulation lead having an advanceable therapeutic drug delivery system
FR2696348B1 (en) 1992-10-01 1994-12-09 Dev Et Electrode for a retractable biological screw cardiac stimulation device.
US5344439A (en) 1992-10-30 1994-09-06 Medtronic, Inc. Catheter with retractable anchor mechanism
US5358516A (en) 1992-12-11 1994-10-25 W. L. Gore & Associates, Inc. Implantable electrophysiology lead and method of making
EP0612538A3 (en) 1993-02-22 1995-04-05 Cardiac Pacemakers Inc Metallized, implantable cardiac electrode.
US5374286A (en) 1993-03-31 1994-12-20 Medtronic, Inc. Torque indicator for fixed screw leads
US5366496A (en) 1993-04-01 1994-11-22 Cardiac Pacemakers, Inc. Subcutaneous shunted coil electrode
US5342414A (en) 1993-07-01 1994-08-30 Medtronic, Inc. Transvenous defibrillation lead
US5456708A (en) 1993-10-28 1995-10-10 Pacesetter, Inc. Rotatable pin, screw-in pacing and sensing lead having improved tip and fluidic seal
ES2149241T3 (en) 1993-11-10 2000-11-01 Xomed Inc BIPOLAR ELECTRO-SURGICAL INSTRUMENT AND MANUFACTURING METHOD.
US5456706A (en) 1994-01-04 1995-10-10 Ventritex, Inc. Cardiac defibrillation lead having defibrillation and atrial sensing electrodes
ITRM940130A1 (en) 1994-03-10 1995-09-11 P A & M Spa SAFETY ELEMENT TO GUARANTEE THE ELECTRICAL RELIABILITY OF THE ELECTRODOCATHETERS FOR THE ELECTRIC STIMULATION OF THE
US5476501A (en) 1994-05-06 1995-12-19 Medtronic, Inc. Silicon insulated extendable/retractable screw-in pacing lead with high efficiency torque transfer
US5522874A (en) * 1994-07-28 1996-06-04 Gates; James T. Medical lead having segmented electrode
US5534022A (en) 1994-11-22 1996-07-09 Ventritex, Inc. Lead having an integrated defibrillation/sensing electrode
US5654030A (en) 1995-02-07 1997-08-05 Intermedics, Inc. Method of making implantable stimulation electrodes
US5545201A (en) * 1995-03-29 1996-08-13 Pacesetter, Inc. Bipolar active fixation lead for sensing and pacing the heart
US5578068A (en) 1995-05-08 1996-11-26 Medtronic, Inc. Medical electrical lead with radially asymmetric tip
US5837006A (en) 1996-09-10 1998-11-17 Medtronic, Inc. Retraction stop for helical medical lead electrode
US5935159A (en) 1996-12-19 1999-08-10 Medtronic, Inc. Medical electrical lead
JP4430744B2 (en) 1997-03-14 2010-03-10 ユニヴァーシティ・オヴ・アラバマ・アト・バーミンガム・リサーチ・ファンデイション Implantable system for patients in need of such treatment with cardiac cardioversion
US6097986A (en) * 1997-12-17 2000-08-01 Cardiac Pacemakers, Inc. Retractable lead with mesh screen

Patent Citations (101)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3942536A (en) * 1971-03-15 1976-03-09 Mieczyslaw Mirowski Cardioverting device having single intravascular catheter electrode system and method for its use
US3942536B1 (en) * 1971-03-15 1987-03-24
US3804098A (en) * 1972-04-17 1974-04-16 Medronic Inc Body implantable lead
US4010758A (en) * 1975-09-03 1977-03-08 Medtronic, Inc. Bipolar body tissue electrode
US4030509A (en) * 1975-09-30 1977-06-21 Mieczyslaw Mirowski Implantable electrodes for accomplishing ventricular defibrillation and pacing and method of electrode implantation and utilization
US4026303A (en) * 1975-11-17 1977-05-31 Vitatron Medical B.V. Endocardial pacing electrode
US4030508A (en) * 1976-02-04 1977-06-21 Vitatron Medical B.V. Low output electrode for cardiac pacing
US4082087A (en) * 1977-02-07 1978-04-04 Isis Medical Instruments Body contact electrode structure for deriving electrical signals due to physiological activity
US4156429A (en) * 1977-10-11 1979-05-29 Cardiac Pacemakers, Inc. Implantable electrode
US4146037A (en) * 1977-12-12 1979-03-27 Cardiac Pacemakers, Inc. Cardiac pacer electrode and lead insertion tool
US4136703A (en) * 1978-03-09 1979-01-30 Vitatron Medical B.V. Atrial lead and method of inserting same
US4187853A (en) * 1978-11-06 1980-02-12 Barbanel Sidney M Electrode implanting apparatus with optimum location probe
US4270549A (en) * 1979-04-30 1981-06-02 Mieczyslaw Mirowski Method for implanting cardiac electrodes
US4326534A (en) * 1979-06-21 1982-04-27 Jens Axelgaard Transcutaneous electrical muscle stimulation for treatment of scoliosis and other spinal deformities
US4311153A (en) * 1980-09-30 1982-01-19 Medtronic, Inc. Screw-in lead having lead tip with membrane
US4722351A (en) * 1981-12-21 1988-02-02 American Home Products Corporation Systems and methods for processing physiological signals
US4444206A (en) * 1982-04-29 1984-04-24 Cordis Corporation Mesh tip pacing lead assembly
US4437474A (en) * 1982-07-16 1984-03-20 Cordis Corporation Method for making multiconductor coil and the coil made thereby
US4570642A (en) * 1983-09-23 1986-02-18 Daig Corporation Endocardial extendable screw-in lead
US4633880A (en) * 1984-04-06 1987-01-06 Peter Osypka Surgical electrode
US4819647A (en) * 1984-05-03 1989-04-11 The Regents Of The University Of California Intracochlear electrode array
US4664113A (en) * 1984-05-30 1987-05-12 Advanced Cardiovascular Systems, Inc. Steerable dilatation catheter with rotation limiting device
US4567900A (en) * 1984-06-04 1986-02-04 Moore J Paul Internal deployable defibrillator electrode
US4587975A (en) * 1984-07-02 1986-05-13 Cardiac Pacemakers, Inc. Dimension sensitive angioplasty catheter
US4727877A (en) * 1984-12-18 1988-03-01 Medtronic, Inc. Method and apparatus for low energy endocardial defibrillation
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
US4649938A (en) * 1985-04-29 1987-03-17 Mcarthur William A Tissue-stimulating electrode having sealed, low-friction extendable/retractable active fixation means
US4667686A (en) * 1985-05-16 1987-05-26 Cordis Corporation Pacer lead terminal assembly
US5111811A (en) * 1985-06-20 1992-05-12 Medtronic, Inc. Cardioversion and defibrillation lead system with electrode extension into the coronary sinus and great vein
US4722353A (en) * 1985-09-16 1988-02-02 Intermedics, Inc. Stabilizer for implantable electrode
US4646755A (en) * 1985-10-21 1987-03-03 Daig Corporation Introducer tool for endocardial screw-in lead
US4662377A (en) * 1985-11-07 1987-05-05 Mieczyslaw Mirowski Cardioverting method and apparatus utilizing catheter and patch electrodes
US4830006B1 (en) * 1986-06-17 1997-10-28 Intermedics Inc Implantable cardiac stimulator for detection and treatment of ventricular arrhythmias
US4830006A (en) * 1986-06-17 1989-05-16 Intermedics, Inc. Implantable cardiac stimulator for detection and treatment of ventricular arrhythmias
US4932969A (en) * 1987-01-08 1990-06-12 Sulzer Brothers Limited Joint endoprosthesis
US4827932A (en) * 1987-02-27 1989-05-09 Intermedics Inc. Implantable defibrillation electrodes
US4799493A (en) * 1987-03-13 1989-01-24 Cardiac Pacemakers, Inc. Dual channel coherent fibrillation detection system
US4799486A (en) * 1987-03-13 1989-01-24 Cardiac Pacemakers, Inc. Refractoriless atrial sensing in dual chamber pacemakers
US4827940A (en) * 1987-04-13 1989-05-09 Cardiac Pacemakers, Inc. Soluble covering for cardiac pacing electrode
US4817608A (en) * 1987-05-29 1989-04-04 Mieczyslaw Mirowski Cardioverting transvenous catheter/patch electrode system and method for its use
US5016645A (en) * 1987-06-18 1991-05-21 Terrell Williams Medical electrode lead
US4817634A (en) * 1987-06-18 1989-04-04 Medtronic, Inc. Epicardial patch electrode
US5107734A (en) * 1987-07-22 1992-04-28 Armbruster Joseph M Electrically powered dispenser for rolled sheet material
US4819662A (en) * 1987-10-26 1989-04-11 Cardiac Pacemakers, Inc. Cardiac electrode with drug delivery capabilities
US4819661A (en) * 1987-10-26 1989-04-11 Cardiac Pacemakers, Inc. Positive fixation cardiac electrode with drug elution capabilities
US4922927A (en) * 1987-12-30 1990-05-08 Intermedics, Inc. Transvenous defibrillating and pacing lead
US5083562A (en) * 1988-01-19 1992-01-28 Telectronics Pacing Systems, Inc. Method and apparatus for applying asymmetric biphasic truncated exponential countershocks
US5016646A (en) * 1988-11-29 1991-05-21 Telectronics, N.V. Thin electrode lead and connections
US4919135A (en) * 1988-12-14 1990-04-24 Intermedics, Inc. Triaxial electrode
US4905691A (en) * 1989-04-17 1990-03-06 Everest Medical Corporation Polypectome snare with bipolar electrodes
US4924881A (en) * 1989-05-12 1990-05-15 Intermedics, Inc. Implantable endocardial lead with fixation device retractable by threaded stylet
US5002067A (en) * 1989-08-23 1991-03-26 Medtronic, Inc. Medical electrical lead employing improved penetrating electrode
US5003992A (en) * 1989-08-23 1991-04-02 Holleman Timothy W Atraumatic screw-in lead
US5016808A (en) * 1989-09-14 1991-05-21 Cardiac Pacemakers, Inc. Implantable tapered spiral endocardial lead for use in internal defibrillation
US4998975A (en) * 1989-10-30 1991-03-12 Siemens-Pacesetter, Inc. Travenously placed defibrillation leads
US5020544A (en) * 1989-11-01 1991-06-04 Cardiac Pacemakers, Inc. Low energy defibrillation electrode
US5217028A (en) * 1989-11-02 1993-06-08 Possis Medical, Inc. Bipolar cardiac lead with drug eluting device
US5111812A (en) * 1990-01-23 1992-05-12 Cardiac Pacemakers, Inc. Defilbrillation electrode having smooth current distribution
US5314459A (en) * 1990-01-23 1994-05-24 Cardiac Pacemakers, Inc. Defibrillation electrode system having smooth current distribution with floating electrode
US5090422A (en) * 1990-04-19 1992-02-25 Cardiac Pacemakers, Inc. Implantable electrode pouch
US5181526A (en) * 1990-04-20 1993-01-26 Tanaka Kikinzoku Kogyo K.K. Electrode for human heart pacemaker
US5385574A (en) * 1990-04-25 1995-01-31 Cardiac Pacemakers, Inc. Implantable intravenous cardiac stimulation system with pulse generator housing serving as optional additional electrode
US5713926A (en) * 1990-04-25 1998-02-03 Cardiac Pacemakers, Inc. Implantable intravenous cardiac stimulation system with pulse generator housing serving as optional additional electrode
US5603732A (en) * 1990-06-06 1997-02-18 Cardiac Pacemakers, Inc. Subcutaneous defibrillation electrodes
US5203348A (en) * 1990-06-06 1993-04-20 Cardiac Pacemakers, Inc. Subcutaneous defibrillation electrodes
US5085218A (en) * 1990-08-31 1992-02-04 Cardiac Pacemakers, Inc. Bipolar myocardial positive fixation lead with improved sensing capability
US5282845A (en) * 1990-10-01 1994-02-01 Ventritex, Inc. Multiple electrode deployable lead
US5105826A (en) * 1990-10-26 1992-04-21 Medtronic, Inc. Implantable defibrillation electrode and method of manufacture
US5107834A (en) * 1991-01-30 1992-04-28 Cardiac Pacemakers, Inc. Low energy multiple shock defibrillation/cardioversion discharge technique and electrode configuration
US5209229A (en) * 1991-05-20 1993-05-11 Telectronics Pacing Systems, Inc. Apparatus and method employing plural electrode configurations for cardioversion of atrial fibrillation in an arrhythmia control system
US5515848A (en) * 1991-10-22 1996-05-14 Pi Medical Corporation Implantable microelectrode
US5324327A (en) * 1991-12-17 1994-06-28 Cohen Donald M Low threshold cardiac pacing lead
US5411525A (en) * 1992-01-30 1995-05-02 Cardiac Pacemakers, Inc. Dual capacitor biphasic defibrillator waveform generator employing selective connection of capacitors for each phase
US5306292A (en) * 1992-05-25 1994-04-26 Siemens-Elema Ab Heart stimulation apparatus
US5425756A (en) * 1992-05-27 1995-06-20 Cardiac Pacemakers, Inc. Positive fixation device
US5391200A (en) * 1992-09-30 1995-02-21 Cardiac Pacemakers, Inc. Defibrillation patch electrode having conductor-free resilient zone for minimally invasive deployment
US5300110A (en) * 1992-10-15 1994-04-05 Angeion Corporation Dirk-based epicardial defibrillation electrode
US5496362A (en) * 1992-11-24 1996-03-05 Cardiac Pacemakers, Inc. Implantable conformal coil patch electrode with multiple conductive elements for cardioversion and defibrillation
US5425755A (en) * 1992-12-04 1995-06-20 Pacesetter, Inc. Rotatable pin, screw-in pacing and sensing lead having Teflon-coated conductor coil
US5300108A (en) * 1993-01-05 1994-04-05 Telectronics Pacing Systems, Inc. Active fixation lead with a dual-pitch, free spinning compound screw
US5405373A (en) * 1993-02-12 1995-04-11 Siemens-Elema Ab Electrode device for intracorporeal tissue stimulation
US5397342A (en) * 1993-06-07 1995-03-14 Cardiac Pacemakers, Inc. Resilient structurally coupled and electrically independent electrodes
US5383908A (en) * 1993-06-16 1995-01-24 Ventritex, Inc. Defibrillation system having innominate vein electrode and method for its use
US5411544A (en) * 1993-11-02 1995-05-02 Ventritex, Inc. Defibrillation lead with improved mechanical and electrical characteristics
US5492119A (en) * 1993-12-22 1996-02-20 Heart Rhythm Technologies, Inc. Catheter tip stabilizing apparatus
US5500008A (en) * 1994-03-29 1996-03-19 Ventritex, Inc. Method and apparatus for delivering defibrillation shocks with improved effectiveness
US5480416A (en) * 1994-09-22 1996-01-02 Intermedics, Inc. Cardiac pacemaker with universal coating
US5709753A (en) * 1995-10-27 1998-01-20 Specialty Coating Sysetms, Inc. Parylene deposition apparatus including a heated and cooled dimer crucible
US5725810A (en) * 1995-11-29 1998-03-10 Sulzer Chemtech Ag Packing for a counterflow high pressure column
US5720099A (en) * 1996-01-31 1998-02-24 Cochlear Limited Thin film fabrication technique for implantable electrodes
US5725559A (en) * 1996-05-16 1998-03-10 Intermedics Inc. Programmably upgradable implantable medical device
US5728140A (en) * 1996-06-17 1998-03-17 Cardiac Pacemakers, Inc. Method for evoking capture of left ventricle using transeptal pacing lead
US5755764A (en) * 1996-09-10 1998-05-26 Sulzer Intermedics Inc. Implantable cardiac stimulation catheter
US5871529A (en) * 1997-01-16 1999-02-16 Cardiac Pacemakers, Inc. Electrode for high impedance heart stimulation
US5876431A (en) * 1997-07-30 1999-03-02 Sulzer Intermedics Inc. Small cable endocardial lead with exposed guide tube
US5855594A (en) * 1997-08-08 1999-01-05 Cardiac Pacemakers, Inc. Self-calibration system for capture verification in pacing devices
US5871531A (en) * 1997-09-25 1999-02-16 Medtronic, Inc. Medical electrical lead having tapered spiral fixation
US5902329A (en) * 1997-11-14 1999-05-11 Pacesetter, Inc. Explantable lead
US6212434B1 (en) * 1998-07-22 2001-04-03 Cardiac Pacemakers, Inc. Single pass lead system
US6505082B1 (en) * 1998-07-22 2003-01-07 Cardiac Pacemakers, Inc. Single pass lead system

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7705265B2 (en) 2002-12-11 2010-04-27 Yazaki Corporation Method of connecting and structure of connecting electric wire and connection terminal
US20060057903A1 (en) * 2002-12-11 2006-03-16 Yazaki Corporation Method of connecting and structure of connecting electric wire and connection terminal
US20040142607A1 (en) * 2002-12-11 2004-07-22 Yazaki Corporation Method of connecting and structure of connecting electric wire and connection terminal
WO2007100277A1 (en) 2006-03-02 2007-09-07 St.Jude Medical Ab A medical implantable lead and a method for manufacturing of the same
US8099177B2 (en) 2006-03-02 2012-01-17 St. Jude Medical Ab Implantable medical lead and method for the manufacture thereof
US20090171425A1 (en) * 2006-03-02 2009-07-02 Kenneth Dahlberg Implantable medical lead and method for the manufacture thereof
WO2007123443A1 (en) * 2006-04-25 2007-11-01 St. Jude Medical Ab A medical implantable lead and a method for manufacturing the same
US7711437B1 (en) 2006-11-22 2010-05-04 Pacesetter, Inc. Lead fixation device
EP2150309A4 (en) * 2007-05-15 2010-06-09 St Jude Medical Medical implantable lead with pivoting segments
EP2150309A1 (en) * 2007-05-15 2010-02-10 St. Jude Medical AB Medical implantable lead with pivoting segments
US20100324636A1 (en) * 2007-05-15 2010-12-23 Rolf Hill MEDICAL IMPLANTABLE LEAD WITH PIVOTING SEGMENTS (As Amended)
WO2009025597A1 (en) * 2007-08-22 2009-02-26 St. Jude Medical Ab Medical lead with a cover
US20090259272A1 (en) * 2008-04-15 2009-10-15 Reddy G Shantanu Bundle of his stimulation system
WO2009129313A3 (en) * 2008-04-15 2010-01-21 Cardiac Pacemakers, Inc. Bundle of his stimulation system
US20120179221A1 (en) * 2008-04-15 2012-07-12 Reddy G Shantanu Bundle of his stimulation system
EP2526997A1 (en) * 2008-04-15 2012-11-28 Cardiac Pacemakers, Inc. Bundle of His stimulation system
AU2009236213B2 (en) * 2008-04-15 2013-01-10 Cardiac Pacemakers, Inc. Bundle of His stimulation system
AU2009236213B9 (en) * 2008-04-15 2013-01-24 Cardiac Pacemakers, Inc. Bundle of His stimulation system
US8406899B2 (en) * 2008-04-15 2013-03-26 Cardiac Pacemakers, Inc. Bundle of his stimulation system
US20110218604A1 (en) * 2010-03-02 2011-09-08 Sen Ji Cardiac Lead for Epicardial, Endocardial and Trans-Coronary Sinus Placement
US20120330122A1 (en) * 2011-06-24 2012-12-27 Sen Ji Cardiac Lead for Epicardial, Endocardial and Trans-Coronary Sinus Placement

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