EP0879015A4 - Multi-function electrode structures for electrically analyzing and heating body tissue - Google Patents

Multi-function electrode structures for electrically analyzing and heating body tissue

Info

Publication number
EP0879015A4
EP0879015A4 EP97903022A EP97903022A EP0879015A4 EP 0879015 A4 EP0879015 A4 EP 0879015A4 EP 97903022 A EP97903022 A EP 97903022A EP 97903022 A EP97903022 A EP 97903022A EP 0879015 A4 EP0879015 A4 EP 0879015A4
Authority
EP
European Patent Office
Prior art keywords
system according
electrically
network
electrode segments
exterior wall
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP97903022A
Other languages
German (de)
French (fr)
Other versions
EP0879015A1 (en
Inventor
Dorin Panescu
David K Swanson
James G Whayne
Jerome Jackson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BOSTON SCIENTIFIC LIMITED
Original Assignee
EP Technologies Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US629014 priority Critical
Priority to US10354P priority
Priority to US1035496P priority
Priority to US1022596P priority
Priority to US1022396P priority
Priority to US10225P priority
Priority to US10223P priority
Priority to US08/629,014 priority patent/US5836874A/en
Application filed by EP Technologies Inc filed Critical EP Technologies Inc
Priority to PCT/US1997/000896 priority patent/WO1997025917A1/en
Publication of EP0879015A1 publication Critical patent/EP0879015A1/en
Publication of EP0879015A4 publication Critical patent/EP0879015A4/en
Application status is Withdrawn legal-status Critical

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00Electrotherapy; Circuits therefor
    • A61N1/02Details
    • A61N1/04Electrodes
    • A61N1/06Electrodes for high-frequency therapy
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14Probes or electrodes therefor
    • A61B18/1492Probes or electrodes therefor having a flexible, catheter-like structure, e.g. for heart ablation
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES
    • A61L29/00Materials for catheters, medical tubing, cannulae, or endoscopes or for coating catheters
    • A61L29/08Materials for coatings
    • A61L29/085Macromolecular materials
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES
    • A61L29/00Materials for catheters, medical tubing, cannulae, or endoscopes or for coating catheters
    • A61L29/14Materials characterised by their function or physical properties, e.g. lubricating compositions
    • A61L29/145Hydrogels or hydrocolloids
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES
    • A61L31/00Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
    • A61L31/08Materials for coatings
    • A61L31/10Macromolecular materials
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES
    • A61L31/00Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
    • A61L31/14Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
    • A61L31/145Hydrogels or hydrocolloids
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00059Material properties
    • A61B2018/00065Material properties porous
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00059Material properties
    • A61B2018/00071Electrical conductivity
    • A61B2018/00083Electrical conductivity low, i.e. electrically insulating
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00059Material properties
    • A61B2018/00089Thermal conductivity
    • A61B2018/00095Thermal conductivity high, i.e. heat conducting
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00107Coatings on the energy applicator
    • A61B2018/00113Coatings on the energy applicator with foam
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00107Coatings on the energy applicator
    • A61B2018/00148Coatings on the energy applicator with metal
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00214Expandable means emitting energy, e.g. by elements carried thereon
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00214Expandable means emitting energy, e.g. by elements carried thereon
    • A61B2018/0022Balloons
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00053Mechanical features of the instrument of device
    • A61B2018/00214Expandable means emitting energy, e.g. by elements carried thereon
    • A61B2018/00267Expandable means emitting energy, e.g. by elements carried thereon having a basket shaped structure
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00636Sensing and controlling the application of energy
    • A61B2018/00773Sensed parameters
    • A61B2018/00839Bioelectrical parameters, e.g. ECG, EEG
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/1206Generators therefor
    • A61B2018/1246Generators therefor characterised by the output polarity
    • A61B2018/1253Generators therefor characterised by the output polarity monopolar
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14Probes or electrodes therefor
    • A61B2018/1472Probes or electrodes therefor for use with liquid electrolyte, e.g. virtual electrodes
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2218/00Details of surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2218/001Details of surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body having means for irrigation and/or aspiration of substances to and/or from the surgical site
    • A61B2218/002Irrigation

Abstract

Systems and methods for heating body tissue places a multi-function structure (22) having an exterior wall in contact with body tissue. The structure includes an array of electrically conducting electrode segments (44) carried by the exterior wall. An electrically conductive network is coupled to the electrode segments, including at least one electrically conductive path (32) individually coupled to each electrode segment. The systems and methods operate in a first mode during which the network is electrically conditioned to individually sense at each electrode segment local electrical events in tissue, such as electrical potentials, resistivity, or impedance. The systems and methods operate in a second mode during which the network is electrically conditioned, based at least in part upon local electrical events sensed by the electrode segments, to couple at least two electrode segments together to simultaneously trasmit electrical energy to heat or ablate a region of body tissue.

Description

MULTI-FUNCTION ELECTRODE STRUCTURES FOR ELECTRICALLY ANALYZING AND HEATING BODY TISSUE Related Application

This application is a continuation-in- part of pending U.S. Application Serial No. 08/099,994, filed July 30, 1993 and entitled "Large Surface Cardiac Ablation Catheter that Assumes a Low Profile During Introduction into the Heart," which is itself a continuation-in-part of pending U.S. Application Serial No. 07/951,728, filed September 25, 1992, and entitled "Cardiac Mapping and Ablation Systems." Field of the nvention

The invention generally relates to electrode structures deployed in interior regions of the body. In a more specific sense, the invention relates to electrode structures deployable into the heart for diagnosis and treatment of cardiac conditions. Background of the Invention

Physicians examine the propagation of electrical impulses in heart tissue to locate aberrant conductive pathways. The aberrant conductive pathways constitute peculiar and life threatening patterns, called dysrhythmias. The techniques used to analyze these pathways, commonly called "mapping, " identify regions in the heart tissue, called foci, which are ablated to treat the dysrhythmia. Conventional cardiac tissue mapping techniques use multiple electrodes positioned in contact with epicardial heart tissue to obtain multiple electrograms. Digital signal processing algorithms convert the electrogram morphologies into isochronal displays, which depict the propagation of electrical impulses in heart tissue over time. These conventional mapping techniques require invasive open heart surgical techniques to position the electrodes on the epicardial surface of the heart.

Furthermore, conventional epicardial electrogram processing techniques used for detecting local electrical events in heart tissue are often unable to interpret electrograms with multiple morphologies. Such electrograms are encountered, for example, when mapping a heart undergoing ventricular tachycardia (VT) . For this and other reasons, consistently high correct foci identification rates (CIR) cannot be achieved with current multi-electrode mapping technologies.

Researchers have taken epicardial measurements of the electrical resistivity of heart tissue. Their research indicates that the electrical resistivity of infarcted heart tissue is about one-half that of healthy heart tissue.

Their research also indicates that ischemic tissue occupying the border zone between infarcted tissue and healthy tissue has an electrical resistivity that is about two-thirds that of healthy heart tissue. See, e.g., Fallert et al., "Myocardial Electrical Impedance Mapping of Ischemic Sheep Hearts and Healing Aneurysms," Circulation, Vol. 87, No. 1, January 1993, 199-207.

Panescu U.S. Patent 5,487,391 and Panescu et al U.S. Patent 5,485,849 demonstrate that this observed physiological phenomenon, when coupled with effective, non-intrusive measurement techniques, can lead to cardiac mapping systems and procedures with a CIR better than conventional mapping technologies. The Panescu '391 and '849 Patents use a multiple electrode structure and signal processing methodologies to examine heart tissue morphology quickly, accurately, and in a relatively non-invasive manner. The systems and methods disclosed in the Panescu '391 and ,849 Patents transmit electrical current through a region of heart tissue lying between selected pairs of the electrodes, at least one of the electrodes in each pair being located within the heart. Based upon these current transmissions, the systems and methods derive the electrical characteristic of tissue lying between the electrode pairs. This electrical characteristic (called the "E-Characteristic") can be directly correlated to tissue morphology. A low relative

E-Characteristic indicates infarcted heart tissue, while a high relative E-Characteristic indicates healthy heart tissue. Intermediate E-Characteristic values indicate the border of ischemic tissue between infarcted and healthy tissue.

The treatment of cardiac arrhythmias also requires electrodes capable of creating tissue lesions having a diversity of different geometries and characteristics, depending upon the particular physiology of the arrhythmia to be treated.

For example, a conventional 8F diameter/4mm long cardiac ablation electrode can transmit radio frequency energy to create lesions in myocardial tissue with a depth of about 0.5 cm and a width of about 10 mm, with a lesion volume of up to 0.2 cm3. These small and shallow lesions are desired in the sinus node for sinus node modifications, or along the A-V groove for various accessory pathway ablations, or along the slow zone of the tricuspid isthmus for atrial flutter (AFL) or AV node slow pathways ablations.

However, the elimination of ventricular tachycardia (VT) substrates is thought to require significantly larger and deeper lesions, with a penetration depth greater than 1.5 cm, a width of more than 2.0 cm, with a lesion volume of at least 1 cm3.

There also remains the need to create lesions having relatively large surface areas with shallow depths.

One proposed solution to the creation of diverse lesion characteristics is to use different forms of ablation energy. However, technologies surrounding microwave, laser, ultrasound, and chemical ablation are largely unproven for this purpose.

The use of active cooling in association with the transmission of DC or radio frequency ablation energy is known to force the electrode-tissue interface to lower temperature values, As a result, the hottest tissue temperature region is shifted deeper into the tissue, which, in turn, shifts the boundary of the tissue rendered nonviable by ablation deeper into the tissue. An electrode that is actively cooled can be used to transmit more ablation energy into the tissue, compared to the same electrode that is not actively cooled. However, control of active cooling is required to keep maximum tissue temperatures safely below about 100° C, at which tissue desiccation or tissue boiling is known to occur.

Another proposed solution to the creation of larger lesions, either in surface area and/or depth, is the use of substantially larger electrodes than commercially available. Yet, larger electrodes themselves pose problems of size and maneuverability, which weigh against a safe and easy introduction of large electrodes through a vein or artery into the heart.

A need exists for multi-purpose cardiac ablation electrodes that can both examine the propagation of electrical impulses in heart tissue and also create lesions of different geometries and characteristics. Multi-purpose electrodes would possess the requisite flexibility and maneuverability permitting safe and easy introduction into the heart. Once deployed inside the heart, these electrodes would possess the capability to map cardiac tissue and to emit energy sufficient to create, in a controlled fashion, either large and deep lesions, or small and shallow lesions, or large and shallow lesions, depending upon the therapy required. 3unnτmτ»γ of the Invention

One aspect of the invention provides multi-function systems and methods for use in association with body tissue. The systems and methods employ a structure including an exterior wall adapted to contact tissue, which carries an array of electrically conducting electrode segments. An electrically conductive network is coupled to the electrode segments, including at least one electrically conductive path individually coupled to each electrode segment. A controller is coupled to the electrically conductive network. The controller operates in a first mode during which the network is electrically conditioned to individually sense at each electrode segment local electrical events in tissue, such as electrical potentials, resistivity, or impedance. The controller further operates in a second mode during which the network is electrically conditioned, based at least in part upon local electrical events sensed by the electrode segments, to couple at least two electrode segments together to simultaneously transmit electrical energy to create a physiological effect upon a region of body tissue, such as heating or ablating the tissue region.

According to another aspect of the invention, the controller operates in conjunction with the array of electrode segments in a first mode during which the network is electrically conditioned to individually transmit through each electrode segment electrical energy creating a local physiological effect upon body tissue, such as electrically stimulating localized tissue. The controller further operates in a second mode during which the network is electrically conditioned to couple at least two electrode segments together to simultaneously transmit electrical energy creating a regional physiological effect upon body tissue, such as heating or ablating the tissue region.

Another aspect of the invention provides systems and methods for pacing heart tissue. The systems and methods make use of a structure including an exterior wall adapted to contact heart tissue. The exterior wall is adapted to selectively assume an expanded geometry having a first maximum diameter and a collapsed geometry having a second maximum diameter less than the first maximum diameter. The exterior wall carries electrically conducting electrodes. An electrically conductive network is coupled to the electrodes, including at least one electrically conductive path individually coupled to each electrode. According to this aspect of the invention, a controller is coupled to the electrically conductive network. The controller operates in a first mode during which the network is electrically conditioned to transmit electrical energy through the electrodes to pace heart tissue. The controller further operates in a second mode during which the network is electrically conditioned to sense electrical events through the electrodes. Other features and advantages of the in¬ ventions are set forth in the following Description and Drawings, as well as in the appended Claims. Brief Description of the Drawings Fig. 1 is a view of a system for analyzing the morphology of heart tissue that embodies the features of the invention;

Fig. 2 is an enlarged side view of an expandable-collapsible electrode structure associated with the system shown in Fig. 1, shown in the expanded geometry;

Fig. 3 is an enlarged side view of the expandable-collapsible electrode structure shown in Fig. 2, shown in the collapsed geometry; Fig. 4 is an enlarged and somewhat diagrammatic view of the surface of the electrode structure shown in Figs. 2 and 3, showing the high density pattern of electrode segments;

Fig. 5 is a side elevation view of an expandable-collapsible electrode structure associated with the system shown in Fig. 1, with an interior spline support structure shown in its expanded geometry;

Fig. 6 is a side elevation view of the expandable-collapsible electrode structure shown in Fig. 5, with its interior spline support structure shown in its collapsed geometry;

Fig. 7 is a side elevation view of an expandable-collapsible electrode structure associated with the system shown in Fig. 1, with an interior mesh support structure shown in its expanded geometry;

Fig. 8 is a side elevation view of an expandable-collapsible electrode structure associated with the system shown in Fig. l, the structure having an electrically conductive body;

Fig. 9 is a side elevation view of an expandable-collapsible electrode structure with a bull's eye pattern of electrode zones; Fig. 10 an expandable-collapsible electrode structure with a circumferentially spaced pattern of electrode zones; and

Fig. 11 is an expandable-collapsible electrode structure suitable for noncontact mapping of the interior of the heart.

The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims. Fig. 1 shows the components of a system

10 for examining heart tissue morphology.

The system 10 includes a flexible catheter tube 12 with a proximal end 14 and a distal end 16. The proximal end 14 carries a handle 18. The distal end 16 carries an electrode structure 20, which embodies features of the invention.

The physician uses the electrode structure 20 in association with a process controller 40 to take multiple, sequential measurements of the transmission of electrical current through heart tissue. Based upon these current transmissions, the controller 40 derives the electrical characteristic of tissue lying between the electrode pairs, called the

"E-Characteristic". The E-Characteristic can be directly correlated to tissue morphology.

The electrode structure 20 can be also used to ablate tissue in the system 10. As Figs. 2 and 3 best show, the electrode structure 20 includes an expandable-collapsible body 22. The geometry of the body 22 can be altered between a collapsed geometry (Fig. 3) and an enlarged, or expanded, geometry (Fig. 2) . In the illustrated and preferred embodiment, fluid pressure is used to inflate and maintain the expandable-collapsible body 22 in the expanded geometry.

In this arrangement (see Fig. 2) , the catheter tube 12 carries an interior lumen 34 along its length. The distal end of the lumen 34 opens into the hollow interior of the expandable- collapsible body 22. The proximal end of the lumen 34 communicates with a port 36 (see Fig. 1) on the handle 18. The fluid inflation medium

(arrows 38 in Fig. 2) is conveyed under positive pressure through the port 36 and into the lumen 34. The fluid medium 38 fills the interior of the expandable-collapsible body 22. The fluid medium 38 exerts interior pressure to urge the expandable-collapsible body 22 from its collapsed geometry to the enlarged geometry.

This characteristic allows the expandable-collapsible body 22 to assume a collapsed, low profile (ideally, less than 8

French diameter, i.e., less than about 0.267 cm) when introduced into the vasculature. Once located in the desired position, the expandable- collapsible body 22 can be urged into a significantly expanded geometry of, for example, approximately 7 to 20 ram.

As Figs. 5 to 7 show, the structure 20 can include, if desired, a normally open, yet collapsible, interior support structure 43 to apply internal force to augment or replace the force of fluid medium pressure to maintain the body 22 in the expanded geometry. The form of the interior support structure 43 can vary. It can, for example, comprise an assemblage of flexible spline elements 25, as shown in Fig. 5, or an interior porous, interwoven mesh or open cell foam structure 26, as shown in Fig. 7.

In these arrangements (see Fig. 6) , the internally supported expandable-collapsible body 22 is brought to a collapsed geometry, after the removal of the inflation medium, by outside compression applied by an outer sheath 28 (see Fig. 6), which slides along the catheter tube 12. As Fig. 6 shows, forward movement of the sheath 28 advances it over the expanded expandable- collapsible body 22. The expandable-collapsible body 22 collapses into its low profile geometry within the sheath 28. Rearward movement of the sheath 28 (see Figs. 5 or 7) retracts it away from the expandable-collapsible body 22. Free from the confines of the sheath 48, the interior support structure 43 springs open to return the expandable-collapsible body 22 to its expanded geometry to receive the fluid medium. The expandable-collapsible body 22 can be formed about the exterior of a glass mold. In this arrangement, the external dimensions of the mold match the desired expanded geometry of the expandable-collapsible body 22. The mold is dipped in a desired sequence into a solution of the body material until the desired wall thickness is achieved. The mold is then etched away, leaving the formed expandable-collapsible body 22.

Alternatively, the expandable-collapsible body 22 may also be blow molded from extruded tube. In this arrangement, the body 22 is sealed at one end using adhesive or thermal fusion. The opposite open end of the body 22 is left open. The sealed expandable-collapsible body 22 is placed inside the mold. An inflation medium, such as high pressure gas or liquid, is introduced through the open tube end. The mold is exposed to heat as the tube body 22 is inflated to assume the mold geometry. The formed expandable-collapsible body 22 is then pulled from the mold. Various specific geometries, of course, can be selected. The preferred geometry is essentially spherical and symmetric, with a distal spherical contour, as Fig. 2 shows. However, nonsymmetric or nonspherical contours can be used, depending upon the contour of the underlying tissue to be contacted during use. For example, when used in the ventricle, the body 22 should have a generally spherical contour. When used in the atrium, the body 22 should have a generally elongated contour. When used epicardially, the body 22 should have a generally concave contour. As Fig. 4 best shows, the structure 20 includes an array of small electrode segments 44 overlying all or a portion of the expandable-collapsible body 22. The array orients the small electrode segments 44 in a high density, closely spaced relationship. The resistivity of each electrode segment 44 is low relative to the resistivity of the body 22 spacing the segments 44 apart.

The electrode segments 44 comprise metal, such as gold, platinum, platinum/iridium, among others, deposited upon the expandable-collapsible body 22 by sputtering, vapor deposition, ion beam deposition, electroplating over a deposited seed layer, photo-etching, multi-layer processes, or a combination of these processes.

A signal path 32 made from a highly conductive metal, like copper, leads from each electrode segment 44. The signal paths 32 are deposited on the body using conventional photo- etching or multi-layer processes. The signal paths 32 communicate with wires 33, which extend through catheter tube 12 for coupling to connectors 38 carried by the handle 18.

When deployed inside the heart chamber in its expanded geometry, the body 22 holds the array of electrodes segments 44 in intimate contact against the endocardial surface of the heart chamber. In the illustrated and preferred embodiment, a distal steering mechanism 52 (see Fig. 1) enhances the manipulation of the electrode structure 20 both during and after deployment. The steering mechanism 52 can vary. In the illustrated embodiment (see Fig. 1) , the steering mechanism 52 includes a rotating cam wheel 56 coupled to an external steering lever 58 carried by the handle 18. The cam wheel 56 holds the proximal ends of right and left steering wires 60. The wires 60 pass with the signal wires 33 through the catheter tube 12 and connect to the left and right sides of a resilient bendable wire or leaf spring (not shown) adjacent the distal tube end 16. Further details of this and other types of steering mechanisms are shown in Lundquist and Thompson U.S. Patent 5,254,088, which is incorporated into this Specification by reference. When deployed, the array of electrode segments 44 functions in both a diagnostic mode and a therapeutic mode.

In the diagnostic mode, each segment 44 is conditioned by the controller 40 to transmit electrical current through tissue. The electrode segments 44 can transmit electrical current in either a unipolar mode or a bipolar mode. When operated in a unipolar mode, the current return path is provided by an exterior indifferent electrode attached to the patient. When operated in a bipolar mode, the current return path is provided by an electrode segment located immediately next to or spaced away from the selected transmitting electrode segment 44.

From this, the controller 40 acquires impedance information about the heart tissue region that the electrode segments 44 contact. The impedance information is processed by the controller 40 to derive the E-Characteristic, which assists the physician in identifying regions of infarcted tissue where ablation therapy may be appropriate. The coupled electrode segments 44, being held by the body in intimate contact with tissue and thereby shielded from contact with the blood pool, direct essentially all current flow into tissue, thereby obtaining tissue characteristic information free of artifacts. The high density of electrode segments 44 carried by the expandable-collapsible body 22 also provides superior signal resolution for more accurate identification of the potential ablation region.

Further details of specific operation of the process controller 40 in deriving the E- Characteristics are disclosed in U.S. Patents 5, 485,849 and 5,487,391, which is incorporated herein by reference.

In the therapeutic mode, the controller 40 electrically couples a grid of adjacent electrode segments 44 together overlying the identified region to a source 42 of ablation energy. The coupled electrode segments simultaneously receive ablation energy from the source 42 (see Fig. 1) , thereby serving as a large-surface area transmitter of the energy. While the type of ablation energy used can vary, in the illustrated and preferred embodiment, the coupled electrode segments 44 transmit radio frequency (RF) electromagnetic energy. The ablation energy from the coupled electrode segments pass through tissue, typically to an external patch electrode (forming a unipolar arrangement) . Alternatively, the transmitted energy can pass through tissue to a separate adjacent electrode in the heart chamber (forming a bipolar arrangement) . The radio frequency energy heats the tissue, mostly ohmically, forming a lesion.

A controller 43 preferably governs the conveyance of radio frequency ablation energy from the generator 42 to the selected coupled electrode segments 44. In the preferred embodiment (see Fig. 2) , the array of electrode segments 44 carries one or more temperature sensing elements 104, which are coupled to the controller 43. Temperatures sensed by the temperature sensing elements 104 are processed by the controller 43. Based upon temperature input, the controller 43 adjusts the time and power level of radio frequency energy transmissions by the coupled electrode segments 44, to achieve the desired lesion patterns and other ablation objectives. The temperature sensing elements 104 can take the form of thermistors, thermocouples, or the equivalent.

Various ways for attaching temperature sensing elements to an expandable-collapsible electrode body are described in copending Patent Application entitled "Expandable-Collapsible Electrode Structures" filed concurrently with this application.

Further details of the use of multiple ablation energy transmitters controlled using multiple temperature sensing elements are disclosed in copending U.S. Patent Application Serial No.08/286,930, filed August 8, 1994, and entitled "Systems and Methods for Controlling Tissue Ablation Using Multiple Temperature Sensing Elements".

In an alternative embodiment (see Fig. 8) , the body 22 can itself be electrically conductive, having a resistivity similar to the tissue it contacts (i.e., about 500 ohm-cm) , or greater or more than this amount. The body can be made conductive by the inclusion by coextrusion of an electrically conductive material, like carbon black or chopped carbon fiber. In this arrangement, the electrically conductive body 22 is used in association with an interior electrode 200, like that shown in Fig. 8. In such an arrangement, a hypertonic saline solution 204 also fills the interior of the electrically conductive body 22 (as also shown in Fig. 8) , to serve as an electrically conductive path to convey radio frequency energy from the electrode 200 to the body 22. In effect, in this arrangement, the electrically conductive body 22 functions as a "leaky" capacitor in transmitting radio frequency energy from the interior electrode 200 to tissue.

The amount of electrically conductive material coextruded into the body 22 affects the electrical conductivity, and thus the electrical resistivity of the body 22, which varies inversely with conductivity. Addition of more electrically conductive material increases electrical conductivity of the body 22, thereby reducing electrical resistivity of the body 22, and vice versa. The user selects a body 22 with a given resistivity according to a function that correlates desired lesion characteristics with the electrical resistivity values of the associated body 22. According to this function, resistivities equal to or greater that about 500 ohm*cm result in more shallow lesions, while resistivities less than about 500 ohm*cm result in deeper lesions, and vice versa.

Further details of electrode structures having electrically conductive bodies are disclosed in copending patent application entitled "Expandable-Collapsible Electrode Structures With Electrically Conductive Walls" (Attorney Docket 2458-A1) , filed concurrently with this application.

Alternatively, the body 22 can be made electrically conductive by being made porous. Used in association with the interior electrode 200 and hypertonic solution 204 within the body 22, the pores of the porous body 22 establishes ionic transport of ablation energy from the electrode 200, through the electrically conductive medium 204, to tissue outside the body.

The electrode segments 44 can be used in tandem with the electrically conductive body to convey radio frequency energy to ablate tissue. At the same time the controller 40 electrically couples a grid of adjacent electrode segments 44 together to a source 42 of ablation energy, the interior electrode 200 also receives radio frequency energy for transmission by the medium 204 through the electrically conductive body 22. The conductive body 22 extends the effective surface area of the coupled segments 44, thereby enhancing the ablation effect. If the body 22 is porous enough to actually perfuse liquid, an interior electrode 200 is not required to increase the effective electrode surface area of the segments 44. The perfusion of hypertonic liquid through the pores at the time the regions transmit radio frequency energy is itself sufficient to increase the effective transmission surface area of the segments 44. However, if the pores of porous body 22 are smaller, so that ionic transfer is not driven principally by perfusion, it is believed that it would be advantageous in increasing the effective surface area to also transmit radio frequency energy using an interior electrode 200 at the same time that radio frequency is being delivered to the segments 44 for transmission.

It should also be appreciated that, in this embodiment, the segments 44 can themselves be made from a porous, electrically conducting material. In this way, ionic transport can occur by mass transfer or perfusion through the segment 44 themselves.

Further details of a liquid filled porous electrode structure are disclosed in copending patent application entitled "Expandable- Collapsible Porous Electrode Structures" filed concurrently with this application.

The expandable-collapsible electrode structure 20 shown in Fig. 2 can also be used in association with conventional pacing apparatus (not shown) for pacing the heart to acquire electrograms in a conventional fashion. The pacing apparatus is electrically coupled to the connectors 38 to provide a pacing signal to a selected one electrode segment 44, generating depolarization foci at selected sites within the heart. The electrode segments 44 also serve to sense the resulting electrical events for the creation of electrograms. Used in this fashion, the structure 20 can accommodate both pace mapping and entrainment pacing techniques. The expanded structure 20 can also be used to convey pacing signals to confirm contact between tissue and the segments 44. The ability to carry out pacing to sense tissue contact is unexpected, given that the expanded structure 20 presents a surface area significantly greater than that presented by a conventional 4mm/8F electrode.

Other types of expandable-collapsible electrode structures are well suited for pacing the heart as well.

For example, Fig. 9 shows an expandable- collapsible body 22, as previously described, which carries an electrically conductive shell 300 that has been segmented into separate electrode zones 302 arranged in a concentric "bulls eye" pattern about the distal tip of the body 22. Alternatively, as Fig. 10 shows, the shell 300 can be segmented into axially elongated, circumferentially spaced electrode zones 302.

The electrode zones 302 are formed by masking regions on the body 22 which are to be free of the shell 300. A metal material having a relatively high electrical conductivity, as well as a relative high thermal conductivity, such as gold, platinum, platinum/iridium, among others, is deposited upon the unmasked regions on the body 22 by sputtering, vapor deposition, ion beam deposition, electroplating over a deposited seed layer, or a combination of these processes. Alternatively, preformed foil shells can be applied in axially spaced bands on the distal region to form the segmented zones. Still alternatively, the segmented zones can comprise signal wire snaked through the wall with noninsulated signal wire portions exposed on the exterior wall.

Regardless of the pattern, each zone 302 is coupled to a dedicated signal wire or a dedicated set of signal wires (not shown) . In this arrangement, the controller 43 can direct ablation energy differently to each zone according to prescribed criteria. Furthermore, in this arrangement, a pacing signal can be conveyed to a selected one electrode zone. The electrode zones 302 can also serve to sense the resulting electrical events for the creation of electrograms.

In the illustrated and preferred embodiment (see Figs. 9 and 10) , smaller, bipolar electrode segments 304 are placed in the regions between the zones 304. These bipolar electrode segments 304, like the zones 302 themselves, comprise metal materials, such as gold, platinum, platinum/iridium, among others, deposited upon the body 22 by sputtering, vapor deposition, ion beam deposition, electroplating over a deposited seed layer, or a combination of these processes. Alternatively, preformed foil patches can be applied to form the bipolar segments. The bipolar segments 304 are electrically coupled to signal wires (not shown) to allow bipolar electrogram acquisition, pacing, or E-Characteristic measurements. As Fig. 10 shows, the interior surface of the body 22 can also carry electrodes 306 suitable for unipolar or bipolar sensing or pacing or sensing of E-Characteristics. Different electrode placements can be used for unipolar or bipolar sensing or pacing. For example, pairs of 2-mm length and 1-mm width electrodes 306 can be deposited on the interior surface of the body 22. Connection wires (not shown) can be attached to these electrodes 306. Preferably the interelectrode distance is about 1 mm to insure good quality bipolar electrograms. Preferred placements of these interior electrodes 306 are at the distal tip and center of the structure 22. Also, when multiple zones 302 are used, it is desired to have the electrodes 306 placed in between the zones 302.

As Fig. 10 also shows, it is preferred to deposit opaque markers 308 on the interior surface of the body 22 so that the physician can guide the device under fluoroscopy to the targeted site. Any high-atomic weight material is suitable for this purpose. For example, platinum, platinum-iridium. can be used to build the markers 106. Preferred placements of these markers 308 are at the distal tip and center of the structure 22.

Fig. 11 shows a structure 310 for mapping electrical activity within the heart without physical contact between the structure and endocardial tissue. The structure 310 comprises an expandable-collapsible body that takes the form of a mesh 312 made from interwoven resilient, inert wire or plastic filaments preformed to the desired expanded geometry. A sliding sheath (as previously shown and described in conjunction with Fig. 6) advanced along the catheter tube 12 compresses the mesh structure 312 to collapse it. Likewise, retraction of the sheath removes the compression force, and the freed mesh structure 312 springs open.

By interweaving the mesh filaments close enough together, the mesh structure 312 serves as the support for the electrode segments 44, which can be deposited on the filaments as on a shell supported by the filaments. Alternatively, all or a portion of the mesh filaments could be made electrically conductive. The network of the filaments makes it possible to form electrodes whose spacial location can be determined. Alternatively, as Fig.11 also shows, the mesh structure 312 can be made to normally assume the collapsed geometry. In this arrangement, one or more interior bladders 314 can accommodate the introduction of an inflation medium to cause the mesh structure 312 to assume the expanded geometry.

If the mesh structure 312 is tightly woven enough to be essentially liquid impermeable, the interior bladder could be eliminated. In this arrangement, the introduction of a biocompatible liquid, such as sterile saline, directly into the interior of the structure 312 would cause the structure to assume the expanded geometry.

The expandable-collapsible mesh structure 312 can be positioned within the blood pool of a heart chamber. The electrode segments 44 sense electrical potentials in blood. Electrical potentials in myocardial tissue can be inferred from the sensed blood potentials, without actual contact with the endocardium. Further details of this methodology are found in Pilkington, Loftis, Thompson et al.(Ed.), High Performance Computing in Biomedical Research (Part 3) , "Inverse Problems and Computational Methods," CRC Press, Inc. (1993), and Jackman, Beatty, Scherlag et al., "New Noncontact Catheter Multiple Electrode Array Accurately Reconstructs Left Ventricular Endocardial Potentials," Pace, v.18, N.4(2), p. 898 (1995). It should be appreciated that expandable- collapsible bodies carrying deposited electrically conductive shells or electrode segments, as previously discussed and shown in Figs. 2 to 10, could also be used for noncontact mapping in the manner just described.

Further details of the structure of various expandable-collapsible electrode bodies and how to assemble them are described in copending Patent Application entitled "Expandable-Collapsible Electrode Structures" filed concurrently with this application.

Various features of the invention are set forth in the following claims.

Claims

CLAIMS We Claim:
1. A system comprising a structure including an exterior wall adapted to contact body tissue, an array of electrically conducting electrode segments carried by the exterior wall of the structure, an electrically conductive network coupled to the electrode segments, including at least one electrically conductive path individually coupled to each electrode segment, and a controller coupled to the electrically conductive network, the controller operating in a first mode during which the network is electrically conditioned to individually sense at each electrode segment local electrical events in tissue, the controller further operating in a second mode during which the network is electrically conditioned, based at least in part upon local electrical events sensed by the electrode segments, to couple at least two electrode segments together to simultaneously transmit electrical energy to create a physiological effect upon a region of body tissue.
2. A system according to claim 1 wherein, in the first mode, the controller electrically conditions the network to sense local electrical potentials in body tissue with individual electrode segments.
3. A system according to claim 1 wherein, in the first mode, the controller electrically conditions the network to sense local resistivity in body tissue with individual electrode segments.
4. A system according to claim 1 wherein, in the first mode, the controller electrically conditions the network to sense local impedance in body tissue with individual electrode segments.
5. A system according to claim 1 and further including at least one temperature sensing element carried by the exterior wall in association with the array of electrically conducting electrode segments.
6. A system comprising a structure including an exterior wall adapted to contact body tissue, an array of electrically conducting electrode segments carried by the exterior wall of the structure, an electrically conductive network coupled to the electrode segments, including at least one electrically conductive path individually coupled to each electrode segment, and a controller coupled to the electrically conductive network, the controller operating in a first mode during which the network is electrically conditioned to individually transmit through each electrode segment electrical energy creating a local physiological effect upon body tissue, the controller further operating in a second mode during which the network is electrically conditioned to couple at least two electrode segments together to simultaneously transmit electrical energy creating a regional physiological effect upon body tissue.
7. A system according to claim 6 wherein, in the first mode, the controller electrically conditions the network to locally stimulate body tissue with electrical energy individually transmitted by the electrode segments.
8. A system according to claim 6 wherein the controller further operates in a third mode during which the network is electrically conditioned to individually sense at each electrode segment local electrical events in tissue.
9. A system according to claim 8 wherein, in the third mode, the controller electrically conditions the network to sense local electrical potentials in heart tissue with individual electrode segments.
10. A system according to claim 8 wherein, in the third mode, the controller electrically conditions the network to sense local resistivity in heart tissue with individual electrode segments.
11. A system according to claim 8 wherein, in the third mode, the controller electrically conditions the network to sense local impedance in heart tissue with individual electrode segments.
12. A system according to claim 1 or 6 wherein, in the second mode, the controller electrically conditions the network to heat a region of body tissue with electrical energy simultaneously transmitted by at least two electrode segments.
13. A system according to claim 1 or 6 wherein, in the second mode, the controller electrically conditions the network to ablate a region of body tissue with electrical energy simultaneously transmitted by at least two electrode segments.
14. A system according to claim 6 and further including at least one temperature sensing element carried by the exterior wall in association with the array of electrically conducting electrode segments.
15. A system for ablating heart tissue comprising a structure including an exterior wall adapted to contact heart tissue, an array of electrically conducting electrode segments carried by the exterior wall of the structure, an electrically conductive network coupled to the electrode segments, including at least one electrically conductive path individually coupled to each electrode segment, and a controller coupled to the electrically conductive network, the controller operating in a first mode during which the network is electrically conditioned to individually sense at each electrode segment a local electrical event in heart tissue, the controller further operating in a second mode during which the network is electrically conditioned, based at least in part upon local electrical events individually sensed by the electrode segments, to couple at least two electrode segments together to simultaneously transmit radio frequency electrical energy to ablate a region of heart tissue.
16. A system according to claim 15 wherein, in the first mode, the controller electrically conditions the network to sense local electrical potentials in heart tissue with individual electrode segments.
17. A system according to claim 15 wherein, in the first mode, the controller electrically conditions the network to sense local resistivity in heart tissue with individual electrode segments.
18. A system according to claim 15 wherein, in the first mode, the controller electrically conditions the network to sense local impedance in heart tissue with individual electrode segments.
19. A system according to claim 15 and further including at least one temperature sensing element carried by the exterior wall in association with the array of electrically conducting electrode segments.
20. A system for ablating heart tissue comprising a structure including an exterior wall adapted to contact heart tissue, an array of electrically conducting electrode segments carried by the exterior wall of the structure, an electrically conductive network coupled to the electrode segments, including at least one electrically conductive path individually coupled to each electrode segment, and a controller coupled to the electrically conductive network, the controller operating in a first mode during which the network is electrically conditioned to individually transmit through each electrode segment electrical energy to pace heart tissue, the controller further operating in a second mode during which the network is electrically conditioned to couple at least two electrode segments together to concurrently transmit radio frequency electrical energy to ablate a region of heart tissue.
21. A system according to claim 20 wherein the controller further operates in a third mode during which the network is electrically conditioned to individually sense at each electrode segment local electrical events in heart tissue.
22. A system according to claim 21 wherein, in the third mode, the controller electrically conditions the network to sense local electrical potentials in heart tissue with individual electrode segments.
23. A system according to claim 21 wherein, in the third mode, the controller electrically conditions the network to sense local resistivity in body tissue with individual electrode segments.
24. A system according to claim 21 wherein, in the third mode, the controller electrically conditions the network to sense local impedance in body tissue with individual electrode segments.
25. A system according to claim 20 and further including at least one temperature sensing element carried by the exterior wall in association with the array of electrically conducting electrode segments.
26. A system according to claim 1 or 6 or 15 or 20 wherein the exterior wall peripherally surrounds an interior area, and further including a lumen to convey a medium containing ions into the interior area, and wherein at least a portion of the exterior wall comprises a porous material sized to pass ions contained in the medium.
27. A system according to claim 26 wherein the porous material comprises an ultrafiltration membrane.
28. A system according to claim 26 wherein the porous material comprises a microporous membrane.
29. A system according to claim 26 and further including an electrically conductive element contacting the medium within the interior area to transmit electrical energy for ionic transport through the medium and porous material.
30. A system according to claim 26 wherein the porous wall has an electrical resistivity of equal to or greater than about 500 oh •cm.
31. A system according to claim 26 wherein the porous wall has an electrical resistivity of less than about 500 ohm*cm.
32. A system according to claim 1 or 6 or 15 or 20 wherein the exterior wall is electrically conductive and peripherally surrounds an interior area, and further including a lumen to convey a medium containing ions into the interior area, and an electrically conductive element contacting the medium within the interior area to transmit electrical energy for ionic transport through the medium.
33. A system according to claim 32 wherein the exterior wall has an electrical resistivity of equal to or greater than about 500 ohm*cm.
34. A system according to claim 32 wherein the exterior wall has an electrical resistivity of less than about 500 ohm•cm.
35. A system according to claim 32 and wherein at least a portion of the exterior wall comprises a porous material sized to pass ions contained in the medium.
36. A system according to claim 35 wherein the porous material has an electrical resistivity of equal to or greater than about 500 ohm*cm.
37. A system according to claim 35 wherein the porous material has an electrical resistivity of less than about 500 ohm•cm.
38. A system according to claim 35 wherein the porous material comprises an ultrafiltration membrane.
39. A system according to claim 35 wherein the porous material comprises a microporous membrane.
40. A system according to claim 1 or 6 or 15 or 20 wherein the exterior wall is adapted to selectively assume an expanded geometry having a first maximum diameter and a collapsed geometry having a second maximum diameter less than the first maximum diameter.
41. A system according to claim 1 or 6 or 15 or 20 wherein the exterior wall peripherally surrounds an interior area, and further including a support structure underlying the wall.
42. A system according to claim 41 wherein the support structure is adapted to selectively assume an expanded geometry having a first maximum diameter and a collapsed geometry having a second maximum diameter less than the first maximum diameter.
43. A system according to claim 1 or 6 or 15 or 20 wherein the electrode segments comprise a coating deposited on the exterior wall.
44. A system according to claim 1 or 6 or 15 or 20 wherein the electrode segments comprise foil affixed to the exterior wall.
45. A system according to claim 1 or 6 or 15 or 20 wherein the electrically conductive electrode segments comprise noninsulated signal wire exposed on the exterior wall.
46. A system according to claim 1 or 6 or 15 or 20 wherein the exterior wall includes a distal region and a proximal region, and wherein the array of electrically conducting electrode segments occupies more of the distal region than the proximal region.
47. A system according to claim 46 wherein at least l/3rd of the proximal region is free of the array of electrically conducting electrode segments. 48. A system according to claim 46 wherein the array of electrically conducting electrode segments occupies at least l/3rd of the distal region.
49. A system according to claim 1 or 6 or 15 or 20 wherein the array of electrically conducting electrode segments is arranged in radially spaced zones.
50. A system according to claim 1 or 6 or 15 or 20 wherein the array of electrically conducting electrode segments is arranged in circumferentially spaced zones.
51. A system for pacing heart tissue comprising a structure including an exterior wall adapted to contact heart tissue, the exterior wall adapted to selectively assume an expanded geometry having a first maximum diameter and a collapsed geometry having a second maximum diameter less than the first maximum diameter, electrically conducting electrodes on the exterior wall of the structure, an electrically conductive network coupled to the electrodes, including at least one electrically conductive path individually coupled to each electrode, and a controller coupled to the electrically conductive network, the controller operating in a first mode during which the network is electrically conditioned to transmit electrical energy through the electrodes to pace heart tissue, the controller further operating in a second mode during which the network is electrically conditioned to sense electrical events through the electrodes.
52. A system according to claim 51 wherein, in the first mode, the network is electrically conditioned to carry out pacing mapping.
53. A system according to claim 51 wherein, in the first mode, the network is electrically conditioned to carry out entrainment pacing.
54. A system according to claim 51 wherein the controller further operates in a third mode during which the network is electrically conditioned to transmit radio frequency electrical energy through at least two of the electrodes to ablate heart tissue.
55. A system according to claim 51 wherein the exterior wall includes a distal region and a proximal region, and wherein the electrodes occupy more of the distal region than the proximal region.
56. A system according to claim 51 wherein at least l/3rd of the proximal region is free of the electrodes.
57. A system according to claim 51 wherein the electrodes occupy at least l/3rd of the distal region.
58. A system according to claim 51 wherein the electrodes are arranged in radially spaced segments.
59. A system according to claim 51 wherein the electrodes are arranged in circumferentially spaced segments.
60. A system according to claim 51 wherein the electrodes comprise a coating deposited on the exterior wall.
61. A system according to claim 51 wherein the electrodes comprise foil affixed to the exterior wall.
62. A system according to claim 51 wherein the electrodes comprise noninsulated signal wire exposed on the exterior wall.
63. A system according to claim 51 and further including at least one temperature sensing element carried by the exterior wall in association with the array of electrically conducting electrodes.
64. A method for heating body tissue comprising the steps of placing a structure having an exterior wall in contact with body tissue, the structure including an array of electrically conducting electrode segments carried by the exterior wall and an electrically conductive network coupled to the electrode segments, including at least one electrically conductive path individually coupled to each electrode segment, operating in a first mode during which the network is electrically conditioned to individually sense at each electrode segment local electrical events in tissue, and operating in a second mode during which the network is electrically conditioned, based at least in part upon local electrical events sensed by the electrode segments, to couple at least two electrode segments together to simultaneously transmit electrical energy to heat a region of body tissue.
EP97903022A 1996-01-19 1997-01-17 Multi-function electrode structures for electrically analyzing and heating body tissue Withdrawn EP0879015A4 (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
US629014 1984-07-09
US1035496P true 1996-01-19 1996-01-19
US1022596P true 1996-01-19 1996-01-19
US1022396P true 1996-01-19 1996-01-19
US10225P 1996-01-19
US10354P 1996-01-19
US10223P 1996-01-19
US08/629,014 US5836874A (en) 1996-04-08 1996-04-08 Multi-function electrode structures for electrically analyzing and heating body tissue
PCT/US1997/000896 WO1997025917A1 (en) 1996-01-19 1997-01-17 Multi-function electrode structures for electrically analyzing and heating body tissue

Publications (2)

Publication Number Publication Date
EP0879015A1 EP0879015A1 (en) 1998-11-25
EP0879015A4 true EP0879015A4 (en) 1999-11-17

Family

ID=27485982

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97903022A Withdrawn EP0879015A4 (en) 1996-01-19 1997-01-17 Multi-function electrode structures for electrically analyzing and heating body tissue

Country Status (4)

Country Link
EP (1) EP0879015A4 (en)
JP (1) JP2000504242A (en)
CA (1) CA2243595A1 (en)
WO (1) WO1997025917A1 (en)

Families Citing this family (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6892091B1 (en) 2000-02-18 2005-05-10 Biosense, Inc. Catheter, method and apparatus for generating an electrical map of a chamber of the heart
US6496712B1 (en) * 2000-05-01 2002-12-17 Biosense Webster, Inc. Method and apparatus for electrophysiology catheter with enhanced sensing
US6400981B1 (en) 2000-06-21 2002-06-04 Biosense, Inc. Rapid mapping of electrical activity in the heart
US7756583B2 (en) 2002-04-08 2010-07-13 Ardian, Inc. Methods and apparatus for intravascularly-induced neuromodulation
US8347891B2 (en) 2002-04-08 2013-01-08 Medtronic Ardian Luxembourg S.A.R.L. Methods and apparatus for performing a non-continuous circumferential treatment of a body lumen
US20040226556A1 (en) 2003-05-13 2004-11-18 Deem Mark E. Apparatus for treating asthma using neurotoxin
US20050059963A1 (en) * 2003-09-12 2005-03-17 Scimed Life Systems, Inc. Systems and method for creating transmural lesions
US7438714B2 (en) * 2003-09-12 2008-10-21 Boston Scientific Scimed, Inc. Vacuum-based catheter stabilizer
US7771420B2 (en) 2004-03-05 2010-08-10 Medelec-Minimeca S.A. Saline-enhanced catheter for radiofrequency tumor ablation
WO2005112812A1 (en) * 2004-05-14 2005-12-01 Medtronic, Inc. Method and devices for treating atrial fibrillation by mass ablation
US20060089637A1 (en) 2004-10-14 2006-04-27 Werneth Randell L Ablation catheter
US8617152B2 (en) 2004-11-15 2013-12-31 Medtronic Ablation Frontiers Llc Ablation system with feedback
US7429261B2 (en) 2004-11-24 2008-09-30 Ablation Frontiers, Inc. Atrial ablation catheter and method of use
US7468062B2 (en) 2004-11-24 2008-12-23 Ablation Frontiers, Inc. Atrial ablation catheter adapted for treatment of septal wall arrhythmogenic foci and method of use
AU2006262447A1 (en) 2005-06-20 2007-01-04 Medtronic Ablation Frontiers Llc Ablation catheter
WO2007008954A2 (en) 2005-07-11 2007-01-18 Ablation Frontiers Low power tissue ablation system
US8657814B2 (en) 2005-08-22 2014-02-25 Medtronic Ablation Frontiers Llc User interface for tissue ablation system
US8641704B2 (en) 2007-05-11 2014-02-04 Medtronic Ablation Frontiers Llc Ablation therapy system and method for treating continuous atrial fibrillation
US8103327B2 (en) 2007-12-28 2012-01-24 Rhythmia Medical, Inc. Cardiac mapping catheter
US8538509B2 (en) 2008-04-02 2013-09-17 Rhythmia Medical, Inc. Intracardiac tracking system
CN102014779B (en) 2008-05-09 2014-10-22 赫莱拉公司 A system, components and methods for treating bronchial tree
JP5649573B2 (en) * 2008-08-22 2015-01-07 コーニンクレッカ フィリップス エヌ ヴェ Sensing device for sensing an object
US8295902B2 (en) * 2008-11-11 2012-10-23 Shifamed Holdings, Llc Low profile electrode assembly
US9655677B2 (en) 2010-05-12 2017-05-23 Shifamed Holdings, Llc Ablation catheters including a balloon and electrodes
US9717557B2 (en) 2008-11-11 2017-08-01 Apama Medical, Inc. Cardiac ablation catheters and methods of use thereof
US9795442B2 (en) 2008-11-11 2017-10-24 Shifamed Holdings, Llc Ablation catheters
US10098694B2 (en) 2013-04-08 2018-10-16 Apama Medical, Inc. Tissue ablation and monitoring thereof
EP3106116B1 (en) 2009-06-30 2018-08-01 Boston Scientific Scimed, Inc. Map and ablate open irrigated hybrid catheter
CA2779135C (en) 2009-10-27 2018-09-04 Innovative Pulmonary Solutions, Inc. Delivery devices with coolable energy emitting assemblies
US8911439B2 (en) 2009-11-11 2014-12-16 Holaira, Inc. Non-invasive and minimally invasive denervation methods and systems for performing the same
AU2010319477A1 (en) 2009-11-11 2012-05-24 Holaira, Inc. Systems, apparatuses, and methods for treating tissue and controlling stenosis
CN105105844B (en) 2010-05-12 2017-12-15 施菲姆德控股有限责任公司 Low profile electrode assembly
US9687196B2 (en) * 2011-04-07 2017-06-27 Sanovas, Inc. Electrically conductive balloon catheter
EP2694150A1 (en) 2011-04-08 2014-02-12 Covidien LP Iontophoresis drug delivery system and method for denervation of the renal sympathetic nerve and iontophoretic drug delivery
CN103917185A (en) * 2011-09-14 2014-07-09 波士顿科学西美德公司 Ablation device with ionically conductive balloon
WO2013040201A2 (en) 2011-09-14 2013-03-21 Boston Scientific Scimed, Inc. Ablation device with multiple ablation modes
EP2802282A1 (en) 2012-01-10 2014-11-19 Boston Scientific Scimed, Inc. Electrophysiology system
WO2014047071A1 (en) 2012-09-18 2014-03-27 Boston Scientific Scimed, Inc. Map and ablate closed-loop cooled ablation catheter with flat tip
EP2897544B1 (en) * 2012-09-18 2018-12-12 Boston Scientific Scimed, Inc. Map and ablate closed-loop cooled ablation catheter
US20140121657A1 (en) * 2012-10-26 2014-05-01 Biosense Webster (Israel) Ltd. Irrrigated ablation catheter with deformable head
US9398933B2 (en) 2012-12-27 2016-07-26 Holaira, Inc. Methods for improving drug efficacy including a combination of drug administration and nerve modulation
WO2014164847A1 (en) * 2013-03-12 2014-10-09 Boston Scientific Scimed, Inc. Retrieval device and related methods of use
CN105592778A (en) 2013-10-14 2016-05-18 波士顿科学医学有限公司 High resolution cardiac mapping electrode array catheter
WO2015171921A2 (en) * 2014-05-07 2015-11-12 Mickelson Steven R Methods and apparatus for selective tissue ablation
WO2015187386A1 (en) 2014-06-03 2015-12-10 Boston Scientific Scimed, Inc. Electrode assembly having an atraumatic distal tip
CN106413539A (en) * 2014-06-04 2017-02-15 波士顿科学医学有限公司 Electrode assembly
US9743854B2 (en) 2014-12-18 2017-08-29 Boston Scientific Scimed, Inc. Real-time morphology analysis for lesion assessment
WO2017087740A1 (en) * 2015-11-20 2017-05-26 St. Jude Medical, Cardiology Division, Inc. Multi-electrode ablator tip having dual-mode, omni-directional feedback capabilities

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993016632A1 (en) * 1992-02-24 1993-09-02 Boaz Avitall Deflectable loop electrode array and method
US5462545A (en) * 1994-01-31 1995-10-31 New England Medical Center Hospitals, Inc. Catheter electrodes

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5334193A (en) * 1992-11-13 1994-08-02 American Cardiac Ablation Co., Inc. Fluid cooled ablation catheter
US5598848A (en) * 1994-03-31 1997-02-04 Ep Technologies, Inc. Systems and methods for positioning multiple electrode structures in electrical contact with the myocardium
US5505730A (en) * 1994-06-24 1996-04-09 Stuart D. Edwards Thin layer ablation apparatus

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993016632A1 (en) * 1992-02-24 1993-09-02 Boaz Avitall Deflectable loop electrode array and method
US5462545A (en) * 1994-01-31 1995-10-31 New England Medical Center Hospitals, Inc. Catheter electrodes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9725917A1 *

Also Published As

Publication number Publication date
EP0879015A1 (en) 1998-11-25
WO1997025917A1 (en) 1997-07-24
JP2000504242A (en) 2000-04-11
CA2243595A1 (en) 1997-07-24

Similar Documents

Publication Publication Date Title
US5860974A (en) Heart ablation catheter with expandable electrode and method of coupling energy to an electrode on a catheter shaft
US6246914B1 (en) High torque catheter and methods thereof
EP0573311B1 (en) Endocardial mapping and ablation system utilising a separately controlled ablation catheter
US9566113B2 (en) Low power tissue ablation system
US6471696B1 (en) Microwave ablation instrument with a directional radiation pattern
US5871483A (en) Folding electrode structures
EP1568331B1 (en) Radio-frequency based catheter system with hollow co-axial cable for ablation of body tissues
ES2210403T3 (en) System that emits high-energy frencuencia for multi-electrode catheter.
US6029091A (en) Catheter system having lattice electrodes
CA2499223C (en) Methods and devices for ablation
US6740080B2 (en) Ablation system with selectable current path means
US6033402A (en) Ablation device for lead extraction and methods thereof
US8475450B2 (en) Dual-purpose lasso catheter with irrigation
US5853411A (en) Enhanced electrical connections for electrode structures
JP4873816B2 (en) Tip flexible catheter having a guide wire tracking mechanism
EP1663043B1 (en) Systems and apparatus for creating transmural lesions
US6033403A (en) Long electrode catheter system and methods thereof
US5718241A (en) Apparatus and method for treating cardiac arrhythmias with no discrete target
US6165169A (en) Systems and methods for identifying the physical, mechanical, and functional attributes of multiple electrode arrays
US6241692B1 (en) Ultrasonic ablation device and methods for lead extraction
US6264654B1 (en) Ablation catheter
US6972016B2 (en) Helically shaped electrophysiology catheter
US6016437A (en) Catheter probe system with inflatable soft shafts
JP4131414B2 (en) Tissue ablation apparatus using the slide ablation instrument
US6259941B1 (en) Intravascular ultrasound locating system

Legal Events

Date Code Title Description
17P Request for examination filed

Effective date: 19980818

AK Designated contracting states:

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AK Designated contracting states:

Kind code of ref document: A4

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

A4 Despatch of supplementary search report

Effective date: 19991004

RAP1 Transfer of rights of an ep published application

Owner name: BOSTON SCIENTIFIC LIMITED

17Q First examination report

Effective date: 20021210

18D Deemed to be withdrawn

Effective date: 20030918