Abstract: An electrode circuit has a distal region for carrying at least one electrode, a proximal region for connection to external apparatus, and an intermediate region electrically coupling the distal region with the proximal region. At least one, and preferably all, of the regions comprises flexible ribbon cable having two or more adjacent tracks of electrical conduction material and adjoining electrical insulating material. Use of ribbon cable make possible highly dense, extremely reliable electrical connections. Its reliability and density obviate the need for complicated multiplexing schemes at the distal region. Instead, less complicated, proximal multiplexing schemes can be used.

Abstract: Electrode assemblies and associated systems employ a nonporous wall having an exterior for contacting tissue. The exterior peripherally surrounds an interior area. The wall is essentially free of electrically conductive material. The wall is adapted to 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 assemblies and systems include a lumen that conveys a medium containing ions into the interior area. An element free of physical contact with the wall couples the medium within the interior area to a source of electrical energy to enable ionic transport of electrical energy from the source through the medium to the wall for capacitive coupling to tissue contacting the exterior of the wall.

Abstract: Elongated spline members are threaded through a hub to form depending spline legs. In one embodiment, the spline members are threaded through a puncturable material on the hub. In another embodiment, the spline members are threaded through a slotted hub, which is then encapsulated by a sealing, elastomeric material. In another embodiment, multiple spline members are looped and woven together beyond a distal end of the hub, and the distal end of the hub serves to exert a force that maintains the woven relationship of the spline members. The spline legs, which radiate from the hub, preferable carry one or more diagnostic or therapeutic elements, such as electrodes. Preferably, a base constrains the terminal ends of the spline legs in a normally expanded geometry between the hub and base.

Abstract: An ablation catheter having self assembling large surface area distal component provided with one or more energy emitting surfaces for thermally destroying tissue. The distal component is oriented to present a compact, low profile for introduction into the heart, and after introduction is reconfigured to present a large surface area distal ablation tip assembly. The distal tip component is subsequently returned to the low profile configuration for removal from the heart. Once introduced, the energy emitting surfaces are thus carried by a distal component having significantly enlarged surface area. The enlargable distal component is produced using a plurality of pivoting sections capable of alignment into a compact profile for introduction into and removal from a living body. When reconfigured by pivoting of the sections into contact with each other, the distal component has an significantly enlarged dimension.

Abstract: An electrode support structure comprises a distal hub and a proximal base aligned along a major axis with the distal hub. An array of generally flexible spline elements extend between the hub and the base. The spline elements each have an elongated axis that, at the base, extends generally parallel to the major axis and, at the hub, extends at an angle, measured relative to the major axis, of between 45.degree. and 110.degree.. The spline elements collectively define a distal surface lying within an envelope that approximates the curvature of endocardial tissue and within which envelope the distal hub lies. According to this aspect of the invention, the distal surface, when contacting endocardial tissue, increases in surface area in response to force applied generally along the major axis to mediate tissue pressure.

Abstract: An electrode support structure has a slotted hub and an integral body with a mid-section and opposed pair of spline elements that extend from the mid-section. The mid-section is captured within the slot, securing the integral body to the hub with the opposed spline elements radiating free of the slot for carrying one or more electrodes.

Abstract: A collapsible electrode body is assembled to an end of a catheter tube. A generally rigid stem element having an exterior diameter is connected to the catheter tube. A flexible tube, which has an initial interior diameter smaller than the exterior diameter of the stem element, is deformed into a desired geometry for the electrode body, including a neck region with an enlarged interior diameter greater than the exterior diameter of the stem element. The neck region is slipped about the stem element. Heat is applied to shrink the neck region about the stem element and form a first interference fit junction therebetween. A sleeve is fitted about the first interference fit junction, and heat is applied to shrink the sleeve about the interference fit junction and form a second interference fit junction therebetween. Preferably, after the first interference fit junction is formed, additional heat is applied to thermally fuse the neck region to the stem region.

Abstract: Collapsible electrode assemblies and associated methods employ an array of filaments assembled to form a mesh structure. The mesh 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. Preferably, at least one of the filaments includes an electrically conductive material adapted for coupling to a source of ablation energy for transmitting ablation energy.

Abstract: An electrode assembly for use in interventricular cardiac mapping includes one or more elongated splines each of which carries a plurality of spaced apart electrodes thereon. The body of each spline is formed of a plurality of alternating electrically conductive layers and the electrically non-conductive layers. A separate electrically conductive pathway is provided to connect each of the electrodes to a different one of the conductive layers. Each of the layers is electrically connected to an electrical signal processing device so that signals provided by each of the electrodes can be processed.

Abstract: Enhanced electrical connections for electrodes are provided. In one implementation, an electrode body comprises a first electrically nonconductive layer and a second electrically nonconductive layer overlying at least a portion of the first layer. An intermediate region is formed between the first and second layers. An electrically conductive pathway extends within the intermediate region. An formed opening extends to the intermediate region, exposing a part of the electrically conductive pathway. An electrically conductive material is deposited on the second layer so that a part of the electrically conductive material passes through the opening to establish electrical contact between the electrically conductive material and the electrically conductive pathway.

Abstract: Collapsible electrode assemblies and associated methods employing a structure having an axis and a distal end. The structure comprises a wall peripherally enclosing an interior. The structure is adapted to selectively assume an expanded geometry having a first maximum diameter about the axis and a collapsed geometry having a second maximum diameter about the axis less than the first maximum diameter. An electrically conductive material is carried by the wall, forming an electrode region adapted to conform to both the normally expanded geometry and the collapsed geometry of the structure. In one implementation, a flexing element in the interior of the structure bends within the interior along the axis of the structure to displace the distal end relative to the axis. In another implementation, a stilette element within the interior of the structure imparts axial force upon the distal end along the axis of the structure, thereby axially elongating or shortening the structure.

Abstract: An electrode support structure has at least two spline leaves, each comprising an opposed pair of spline elements connected by a center web. Each web has a hole through which a pin assembly extends to join the webs of the spline leaves in a mutually stacked relationship. The spline elements radiate from the pin assembly in a circumferentially spaced relationship for carrying one or more electrodes. A hub member is over-molded about the pin assembly.

Abstract: An electrode support structure has spline elements radiating from a center hub in a circumferentially spaced relationship. The spline elements and hub are integrally formed from a single sheet of material.

Abstract: An electrode support structure has spline elements radiating from a center hub in a circumferentially spaced relationship. The spline elements include terminal ends spaced from the hub which are joined to a base member to form a three dimensional structure for supporting electrodes. The center hub lies essentially within the envelope of the spline elements to present a surface free of projections that can poke into and cause tissue trauma during use.

Abstract: A steerable first catheter directs the introduction of a guide sheath, which can otherwise be free of any onboard steering mechanism. The guide sheath, in turn, directs the introduction of the electrode-carrying second catheter, which can likewise be free of any onboard steering mechanism. Use of a guide sheath positioned by a separate, dedicated steering catheter to guide a separate, dedicated electrode-carrying catheter results in a significant reduction in the overall size of the system components.

Abstract: A method of ablating tissue in the heart to treat atrial fibrillation introduces into a selected atrium an energy emitting element. The method exposes the element to a region of the atrial wall and applies ablating energy to the element to thermally destroy tissue. The method forms a convoluted lesion pattern comprising elongated straight lesions and elongated curvilinear lesions. The lesion pattern directs electrical impulses within the atrial myocardium along a path that activates the atrial myocardium while interrupting reentry circuits that, if not interrupted, would cause fibrillation. The method emulates the surgical maze procedure, but lends itself to catheter-based procedures that do not require open heart surgical techniques. A composite structure for performing the method is formed using a template that displays in planar view a desired lesion pattern for the tissue. An array of spaced apart element is laid on the template.

Abstract: Systems and methods form curvilinear lesions in tissue within the body. The systems and methods expose tissue to electrode arrays with intersecting energy emitting elements. The systems and methods apply ablating energy for emission by the elements to create intersecting curvilinear lesion patterns in the tissue.

Abstract: A cardiac diagnosis and treatment system comprises a support carrying at least two electrodes. A conductor is associated with the support for selectively directing electrical signals to and from each electrode. The conductor includes a first buss for delivering power from an external power source, a second buss for transmitting electrode signals to an external signal processor, and a third buss for receiving control signals from an external signal source to multiplex the electrode signals from the electrodes through the second buss. A conduction line conducts power, control signals, and electrode signals from the external sources to the conductor.

Abstract: An electrode assembly for use in interventricular cardiac mapping includes one or more elongated splines each of which carries a plurality of spaced apart electrodes thereon. The body of each spline is formed of a plurality of alternating electrically conductive layers and the electrically non-conductive layers. A separate electrically conductive pathway is provided to connect each of the electrodes to a different one of the conductive layers. Each of the layers is electrically connected to an electrical signal processing device so that signals provided by each of the electrodes can he processed.

Abstract: A flexible electrode circuit laces through a slit sleeve to expose electrodes outside the sleeve while enclosing the rest of the circuit within the sleeve. A stiffener member extends through the sleeve to support the sleeve and the flexible electrode circuit. The stiffener member is preferably connected to and constrained at opposite ends by a hub and a base to urge the stiffener member, the sleeve, and the electrode circuit into a predetermined curvilinear contour.