Methods for detection of cardiac rhythm disorders using basket style cardiac mapping catheter

A method for sensing multiple local electric voltages from endocardial surface of a heart, includes: providing a system for sensing multiple local electric voltages from endocardial surface of a heart, including: a first elongate tubular member having a lumen, a proximal end and a distal end; a basket assembly including: a plurality of flexible splines for guiding a plurality of exposed electrodes, the splines having proximal portions, distal portions and medial portions therein between, wherein the electrodes are substantially flat electrodes and are substantially unidirectionally oriented towards a direction outside of the basket.

FIELD OF THE INVENTION

The present invention is related to methods for the detection of cardiac rhythm disorders by use of basket style cardiac mapping catheters. The present invention is further related to a method for sensing multiple local electric voltages from endocardial surface of a heart by using a basket with substantially flat and unidirectionally oriented electrodes on the basket.

BACKGROUND OF THE INVENTION

Heart rhythm disorders are very common in the United States, and are significant causes of morbidity, lost days from work, and death. Heart rhythm disorders exist in many forms, of which the most complex and difficult to treat are atrial fibrillation (AF), ventricular tachycardia (VT) and ventricular fibrillation (VF). Other rhythms may be easier to treat, but may also be clinically significant including supraventricular tachycardia (SVT), atrial tachycardia (AT), atrial flutter (AFL), premature atrial complexes/beats (PAC, APC) and premature ventricular complexes/beats (PVC). Under certain conditions, rapid activation of the normal sinus node can even cause a heart rhythm disorder such as inappropriate sinus tachycardia or sinus node reentry.

Definitive diagnosis has often been performed using electrode-bearing catheters placed within the heart chambers. Electrodes have been positioned along a catheter shaft or basket splines in an attempt to analyze or map the electrical activity within a heart chamber. Mapping typically involves the use or formation external (patches on skin) of electrograms and internal (catheters with electrodes) electrograms. A typical electrocardiogram of the cardiac cycle (heartbeat) consists of a P wave, a QRS complex and a T wave. During normal atrial depolarization, the main electrical vector is directed from the SA node, and spreads from the right atrium to the left atrium. Atrial depolarization is represented by the P wave on the electrocardiogram. The QRS complex reflects the rapid depolarization of the right and left ventricles. The T wave represents the repolarization (or recovery) of the ventricles.

Devices of the prior art, however, often do not provide a complete and stable map of the electrical activity within a heart chamber (recording electrograms). In particular, electrical activity in certain portions of the right atrium and the left atrium (e.g. atrial septum, region of right pulmonary veins) are often difficult to map because of the inability of devices of the prior art to adequately conform to the irregular shape of the atria and their varying shapes during beating of the heart. Further, devices of the prior art do not provide dimensionally and/or spatially stable and complete electrograms as the prior art devices often move as the heart beats, thereby moving some or all of the electrodes away from the heart tissue and making the relative position of the electrodes variable to corresponding position of atrial tissue.

Thus, there is a need in the art for a cardiac mapping catheter that is capable of providing improved and dimensionally and/or spatially stable signals for diagnosis, and more complete coverage of the heart tissue, typically in the form of electrograms.

SUMMARY OF THE INVENTION

The present invention provides devices, systems and methods for the detection of cardiac rhythm disorders by use of a percutaneous catheter designed to permit acquisition of numerous, simultaneous endocardial electrograms from a three dimensional array of surface electrodes, herein referred to as “a basket style cardiac mapping catheter.”

In one embodiment of the present invention, a method for sensing multiple local electric voltages from endocardial surface of a heart, includes: providing a system for sensing multiple local electric voltages from endocardial surface of a heart, including: a first elongate tubular member having a lumen, a proximal end and a distal end; a basket assembly including: a plurality of flexible splines for guiding a plurality of exposed electrodes, the splines having proximal portions, distal portions and medial portions therein between, wherein the electrodes are substantially flat electrodes and are substantially unidirectionally oriented towards a direction outside of the basket; a proximal anchor for securably affixing the proximal portions of the splines; the proximal anchor being secured at the distal end of the first elongate tubular member; a distal tip for securably affixing the distal portions of the splines, the proximal anchor and the distal tip defining a longitudinal axis therein between about which the splines are disposed; wherein the splines approach the distal tip at an angle of about 90° or less than about 90° as measured from a line segment between the proximal anchor and the distal tip along the longitudinal axis; wherein the splines comprise a superelastic material such that the basket assembly exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; and wherein each of the splines in the radially expanded non-spherical shape contain a proximal recurve in the proximate portion of the spline at a location near to the proximal anchor of the basket assembly, the proximal recurve includes a proximal excurvate outward bend and a proximal incurvate inward bend between the proximal excurvate outward bend and the proximal anchor, where an apex of the proximal incurvate inward bend is disposed in a direction toward the distal tip and is further disposed inwardly closer toward the distal tip than the proximal excurvate outward bend; delivering the system to the heart so that the basket assembly is disposed within the right atrium of the heart; contacting proximal atrial tissue with the electrodes disposed on the proximal spline portions to detect multiple local electric voltages from endocardial surface thereat; and contacting atrial tissue with the electrodes disposed on the medial spline portions and the distal spline portions to detect multiple local electric voltages from endocardial surface thereat.

Desirably, the splines of the basket assembly are flexible to match the contours of the right atrium, and substantially all of the electrodes contact atrial tissue.

Further, substantially all of the electrodes may remain substantially spatially fixed with respect to atrial tissue.

Moreover, a substantial portion of atrial signals detected by the system have larger amplitudes than ventricular signals detected by the system.

These and other features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. Corresponding reference element numbers or characters indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a perspective view of basket style cardiac mapping system or assembly10of the present invention, andFIG. 2is a side elevation view of the catheter system or assembly10ofFIG. 1. As depicted inFIGS. 1 and 2, the catheter system or assembly10consists of three subassemblies: the mapping catheter assembly8, including hemostat penetrator assembly25, and the extension cable assembly31. The mapping catheter assembly8includes a spline basket12, which includes splines14with spline tube assemblies (not shown) having electrodes (not shown); a catheter body or shaft20; a hemostat penetrator assembly25(comprised of a hemostat penetrator tube22and hemostat penetrator handles24); a handle strain relief26; a handle28, with an integral connector (not shown). The extension cable assembly31includes a mating connector30and an extension cable32; interrelated as shown. The catheter assembly8allows ease of operation and precise positioning and control of the basket12within a patient. Desirably, connector30is round so there is no rotational bias as the basket12is disposed within a patient. A non-round connector grip, for example a rectangular connector grip (not shown) may provide a rotational bias which, if desired, may be used with the present invention. The mating connector cable assembly31is useful for connecting the catheter assembly8to external devices (not shown), such as devices that receive and analyze electrical signals from the catheter system10. The strain relief section26is useful in providing kink resistance to the catheter body20especially when the catheter assembly8is disposed within a patient.

The splines14of the spline basket12are secured by a distal tip16at one end, i.e. the distal end, of the basket12, and are further secured by a proximal anchor18at an opposed end, i.e. the proximal end, of the basket12. The anchor18is secured to a distal end20B of the catheter body20and/or within a lumen20C of the catheter body20of the catheter8of the present invention. The proximal end20A of the catheter body20is secured to the strain relief section26of the handle28.

The spline basket12is deliverable through and into bodily organs, such as but not limited to the right atrium of a heart. One useful delivery technique includes the Seldinger delivery technique. The Seldinger techniques uses a short introducing catheter, such as the introducing catheter34as depicted inFIG. 3, and a longer catheter, such as the catheter46, which may also be referred to as an guide catheter or delivery sheath when described with the system10of the present invention, as depicted inFIG. 4. The introducing catheter or introducer34is typically fairly short at about six inches in length and is used to navigate through muscle and into a desired vein. The catheter46is typically a long guide sheath, typically 60 mm to 80 long. In a typical Seldinger technique, a vessel or cavity is punctured with a sharp hollow needle or trocar (not shown). If desired, a guidewire (not shown) may be then advanced through the lumen of the trocar, and the trocar is withdrawn. The introducing catheter34may then be passed over the guidewire into the cavity or vessel. The introducing catheter34includes a hollow introducer lumen36. The distal end42of the introducing catheter34is positioned with a vessel or cavity. The proximal end44of the introducing catheter34remains outside of the patient so as to allow a practitioner to control the position of the distal end of the introducing catheter42. The proximal end44of the introducing catheter34may include a hemostat valve38and a saline flush lumen40. The catheter lumen48of the guide catheter46is deliverable through the lumen36of the introducing catheter34to a desired bodily site. The guide catheter46includes a distal end54and a proximal end56. The guide catheter46may also include a proximal hemostat valve50and a saline flush lumen52.

As used herein the term “proximal” generally refers to a location or direction towards the practitioner. The term “distal” generally refers to a location or direction away from the practitioner. Further, the terms inner, inward and the like generally refer to a direction toward the inside of the basket12, for example towards a longitudinal axis L between the distal tip16and the proximal anchor18. The terms outer, outward and the like generally refer to a direction away from the inside of the basket12, for example away from a longitudinal axis L between the distal tip16and the proximal anchor18.

In preparation for insertion of the basket catheter8, the basket12is collapsed within the hemostat penetrator tube22of the hemostat penetrator assembly25. The distal end23of the hemostat penetrator is insertable through the hemostat valve50of the Guide catheter46. The basket12and a portion of the catheter body20are advanced and deliverable through lumen48and past the distal end54of the catheter46. Typically, the strain relief portion26, the handle28, the mating connector30and the connector32of the system10of the present invention remain outside of the body or proximally past the proximal end56of the catheter46. Upon withdrawal of the hemostat penetrator tube22from the guide sheath hemostat valve50, the guide sheath hemostat valve with create a leak-proof seal against the outer wall of the catheter body20, preventing the loss of blood through the introducer system.

FIGS. 5 and 6depict an embodiment of the distal end of the basket style cardiac mapping catheter8of the present invention. As depicted inFIG. 5the spline basket12is deliverable through and past the distal end54of the lumen48of the catheter46and deliverable through and past the distal end23of the hemostat penetrator25, which also has an open lumen. The distal end23of the hemostat penetrator25is useful for penetrating the hemostat valve56on the proximal end of the guide catheter46.

As depicted inFIG. 5, the splines14of the spline basket12are in an expanded state, such as a radially expanded state. The overall shape of the expanded basket14is depicted as being an expanded, non-cylindrical shape. While the expanded splines14are depicted in a spherical or somewhat spherical orientation, the present invention is not so limited. Indeed, in preferred embodiments of the present invention the expanded splines14assume a non-spherical or substantially non-spherical shape, preferably asymmetric, especially but not limited to the spline portions near the distal tip16and/or the spline portions near the proximal anchor18. Such overall shapes are non-limiting, and other overall basket shapes, including substantially spherical shapes, asymmetric spherical shapes, non-spherical shapes, non-spherical asymmetric shapes and the like may suitably be used.

As depicted inFIG. 6, the splines14of the spline basket12may be in a compressed state within the lumen48of the guide catheter46and/or of the lumen of the hemostat penetrator tube22. The splines14are depicted inFIG. 6as being in a compressed approximate or substantial elongate cylindrical shape. In such a compressed state the effective length of the splines14between the distal tip16and the proximal anchor18are substantially the same. Effective spline lengths between the distal tip16and the proximal anchor18in the expanded basket shape of, for example,FIG. 5are not so limited and, if desired, may vary as described in further detail below.

FIG. 7is an expanded side view of a portion of the basket12of the system8ofFIG. 1showing M-shaped, symmetric distal splines, according to the present invention. The distal basket portion70has distal spline portions66secured to one and the other by the distal tip16. The proximal basket portion68contains proximal spline portions62. The proximal spline ends60are secured by the proximal anchor18(not shown). Medial basket portions72and medial spline portions64are disposed between the respective ends.

As depicted inFIG. 7, the splines14, including medial portions64of the splines14, expand or bow outwardly to assume an expanded, non-cylindrical shape, with the basket12having a proximal basket portion68, a distal basket portion70and a medial basket portion72there between. While the expanded splines are depicted in a spherical or somewhat spherical orientation, the present invention is not so limited. Indeed, in preferred embodiments of the present invention the expanded splines14assume a non-spherical or substantially non-spherical shape, preferably asymmetric.

FIG. 8is a perspective view of the basket14ofFIG. 7. Although eight splines14are depicted, the basket14of the present invention may have any useful number of splines.FIG. 9is a right side view of the M-shaped basket embodiment ofFIG. 7depicting symmetric spline angles. As depicted inFIG. 9, the angles, θ1through θ8, are all approximately equal at 45°. Such a relationship is a predetermined angular relationship to offer a symmetric or substantially symmetric basket14as viewed from a cross-sectional plane of the basket14.

The present invention, however, is not so limited. For example, as depicted inFIGS. 10 and 11, a predetermined angular relationship where the angles, θ1through θ8, may vary may suitably be used. As depicted inFIG. 11, the angles θ1and θ5are approximately 90°, and the angles θ2through θ4and θ6through θ8are approximately 30°. These angles are non-limiting and any suitable arrangement of angles may be used. Such a non-symmetric angular relationship as depicted inFIGS. 10 and 11may be useful, if desired, to concentrate a greater number of splines14at a particular location within the body, for example the right atrium of the heart.

FIG. 12a side elevational view of one of the splines14ofFIG. 7showing the M-shaped distal curve74of basket12at the distal spline portion66. The spline14also contains a proximal recurve76at the proximal spline portion62. Further the spline14is also depicted as being symmetric in its expanded state about a longitudinal axis L, which is determined by the line segment axis from the proximal anchor18to the distal tip16.FIG. 13is a perspective view of the spline14ofFIG. 12, further depicting the spline curvatures at the proximal spline portion62and the distal spline portion66.

FIG. 14is an exploded view of the distal M-shaped spline curve74. The M-shaped spline curve74contains distal incurvate inward bends78and excurvate outward bends80. Bend78is described as incurvate and/or inward because an apex79is directed towards the interior of the basket12. Bend80is described as excurvate and/or outward because apex81is directed away from the interior of the basket12. Bends78are useful in controlling angles from which splines14exit from or emerge into the distal tip16, i.e., directed toward the exterior of basket12. The bends80turn the splines14back in a proximal direction towards the proximal anchor18.

FIG. 15is an exploded view of the proximal spline portion62of the spline14ofFIG. 12. The proximal spline portions62contain proximal recurves76. The proximal recurves76include proximal incurvate bends82having apices83and proximal excurvate bends84having apices85. The proximal recurves76impart several important features to the basket12of the present invention. The proximal recurves76allow for the geometry and flexibility of individual splines14to vary at the proximal end62which allows the basket12to become asymmetric and to better conform to the contours of the right atrium, as described in conjunction withFIG. 42Abelow. Further, the proximal recurves76allow for better placement of electrodes (not shown) at the proximal atrial tissue. Baskets common in the prior art do not often have good contact with proximal atrial tissue, thereby adversely effecting electrical activity detection thereat. Furthermore, the flexibility and geometry of the recurves76also permit enhanced electrode-tissue contact for the electrodes placed not only on the proximal spline portions62, but also on the medial spline portions64and distal spline portions66.

FIG. 16is an exploded view of the distal spline portion66. The splines14may contain portions of reduced spline widths88as compared to normal or non-reduced spline widths86. Here the reduce spline widths88are depicted as being near the distal spline portion66. Such reduced widths88may increase spline flexibility, as these spline portions are proximal to the distal tip16(not shown). The distal spline portion66may also include an alignment member89which, as described further below, is useful for aligning and/or securing the splines14within the distal tip16(not shown). The reduced width portions88at the spline distal portions also allows for less force to compress the basket12, as depicted inFIG. 6, during removal of the basket12from the patient. Further, the reduced spline widths88aid in the basket12in achieving the substantially cylindrical shape, as depicted inFIG. 6. In other words, as compression of the basket12within a lumen22,48goes from the medial basket portions72towards the distal basket portions70, the reduced spline widths88allows the distal incurvate bends78to flex outward or away from the compression force so that the distal spline portions66do not retain the inward bends78, or simply stated the bends78pop outward during radial compression of the basket12. Another advantage of the distal M-Shaped spline curve74is that the distal tip16is directed towards the interior of the basket12when the basket12is deployed or is in its radially expanded state. This feature, if desired, keep the distal tip16away from distal heart tissue as the distal spline portions66may extend beyond the distal tip16in the longitudinal direction of the basket14.

FIG. 17is another embodiment of the spline14ofFIG. 12. The spline14ofFIG. 17contains proximal tangential curves90. While the tangential curve90may not offer the same degree of spline flexibility and basket stability as offered by the proximal spline recurve76, such a proximal tangential curve90may be preferred by some practitioners in certain atrial procedures.

FIG. 18is a side elevational view of another spline14useful with the present invention. The spline14inFIG. 18has a similar proximal spline recurve76as the spline14ofFIG. 12. However, the spline14ofFIG. 18has a D-shaped92distal end portion66. Such a D-shaped distal end92is useful with certain embodiments of distal tips16that are described below.FIG. 19is a perspective view of the spline ofFIG. 18showing spline curvatures in further detail.FIG. 20is an exploded view of the D-shaped spline portion92ofFIG. 18. The distal spline portion66has substantially flat portions94followed by the curved portions96. The curved portions96merge into the normal curvature of the overall basket shape. The substantially straight portion94are useful with certain distal tip14designs and where spline emergence or entrance angles at the distal tip14are desired to be about 90°.

FIG. 21depicts yet another spline14embodiment. The spline14ofFIG. 21contains D-shaped distal portions94,96at the distal spline portion66and proximal tangential curves90at the proximal spline portion62. Thus, the assembly10of the present invention may use any combination of the above-described spline geometries.

Splines14may be flattened splines through the body of the spline14having a substantial rectangular shape with rounded sides (see, e.g.,FIG. 34C). Throughout at least a major portion of the splines14, the splines14may be about 0.013 to about 0.035 inches wide (W1) and about 0.002 to about 0.012 inches thick (T1), as depicted inFIGS. 22A through 22D. A preferred width (W1) is about 0.022 inches. Spline thickness (T1) may depend on the overall size of the basket12with small sized baskets, for example less than 60 mm in nominal diameter, the thickness may range from about 0.002 inches to about 0.010 inches, with 0.004 inches being preferred. For larger size baskets, for example greater than 60 mm in nominal diameter, the thickness may range from about 0.002 inches to about 0.012 inches, with 0.006 inches being preferred. These dimensions are not limiting and represent normal or typical spline width portions86and spline thickness portions98.

Some portions of the splines14may have reduced with portions88and/or reduced thickness potions100. Typically, these portions88,100are disposed at distal spline portions66near or at the distal tip16. However, the present invention is not so limited at these reduced portions88,100may be present in proximal spline portions62and medial spline portions64. The thinned spline portions88,100may have a reduction in width and or thickness of several thousands of an inch. For example, the thickness (T2) of certain spline portions100may be thinned down to several thousands of an inch or to a thickness of about 0.003 inches to 0.004 inches, or less. Such thinning of the distal spline segments66near the membrane tip14reduces stresses during capture of the splines14within the guide catheter34. Low stress is an advantageous feature during collapse for introduction, repositioning and withdrawal of the spline basket. The width (W2) of the narrowed spline segments88may be narrowed from about 0.013 to 0.035 inches to about 0.008 to 0.014 inches. Such thinning aids the splines14, when they fold up or collapse into the guide catheter34, to overcome their tendency to push themselves apart and avoid them occupying more space in the catheter34. Thus, a low profile catheter system10may be provided according to the present invention.

FIGS. 23A and 23Bdepict a spline portion, such as spline portion86, having a buckle point102. The buckle point102may be ground into the spline14or formed by any other suitable technique. The buckle point102is depicted as an inwardly curved notch, but other designs may suitably be used. As depicted inFIGS. 23A and 23B, the buckle points102provide the splines14with curvature inflection points, which provide the basket12with improved matching of the contours of the interior of the heart. The buckle points102may be disposed at any location along the proximal spline portions62, the medial spline portions64and/or the distal spline portions66shown inFIG. 21. Further, the number or frequency of buckle points102may also vary.

As depicted inFIGS. 24 and 25, the splines14may emerge from the distal tip16at any useful emergence angle, α, with respect to the longitudinal axis L, which is defined by a line segment from the proximal anchor18to the distal tip16. For example, as depicted inFIG. 24, the emergence angle α may be about 45° or less than about 45°. As depicted inFIG. 25, the emergence angle α may be about 90°. The splines14may include a bend78which is useful for, among things, controlling the shape of the expanded splines14or basket12. The distal tip16shown inFIGS. 24 and 25is merely a schematic depiction of a general tip. Any of the below-described distal tips of the present invention may be used with any of the emergence angles described in conjunction withFIGS. 24 to 25. The angles are non-limiting, and any suitable emergence angle or combination of emergence angles may be used.

FIGS. 26A through 26Fdepict a two-part welded distal tip16, according to the present invention.FIG. 26Ais a front perspective of distal tip16;FIG. 26Bis a back or rear perspective of distal tip16;FIG. 26Cis perspective view of a top part of the distal tip16;FIG. 26Dis a bottom view of the top part of the distal tip16;FIG. 26Eis a top perspective view of the bottom part of distal tip16; andFIG. 26Fdepicts an alternate embodiment of the distal tip16.

As depicted inFIGS. 26A through 26E, distal tip16may include a top part104and a bottom part108. The distal portions66of the splines14are securably disposed within the distal tip16. The top surface106of the top part104may have any suitable shape, such as a substantially flat surface106with rounded edges so that the distal tip16is an atraumatic tip, i.e., a tip that will not cause damage to atrial tissue. The bottom part108likewise should be free of any sharp edges or projections to avoid atrial tissue damage. The top part104and the bottom part108are secured to one and the other by any suitable means. One non-limiting means and useful means is welding the two parts together to provide a unitary distal tip16. Such securement is typically performed after proper placement of the distal spline portions66within the distal tip16.

As depicted inFIGS. 26C through 26D, the top part104of the distal tip16may include spline alignment posts110. The spline alignment posts110are spaced apart so that the splines14may fit between the spline alignment channels112. The spline alignment posts110do not extend completely into the center of the distal tip16, but terminate to provide a center spline alignment portion114of the top part104of the distal tip16. The center spline alignment portion114is useful for receiving the spline alignment members89of the distal portions66of the splines14into that region114of the distal tip16. The combination of the center spline alignment portion114and the spline alignment channels112provide for, among other things, securably holding the splines14in any desired predetermined angular relationship. The number of spline alignment posts110may vary as the number of splines14may vary within the distal tip16. The bottom part108of the distal tip16may contain flat top and inner surface116. The surface116may generally correspond to the bottom surfaces of the spline alignment posts110. The bottom part108may also include a raised central; portion118. Desirably this raised central portion118is substantially flat. The raised portion118is sized so that it can be disposed within the center spline alignment portion114of the top part104of the distal spline16.

While the splines are securably held within the distal tip16, the spline alignment channels112allow some movement of the spline14. For example, spline portions may move upward and or downward with the spline alignment channel112to provide flexibility of the splines14at the distal tip16. If desired, an elastomeric material may also be placed within the two-part distal tip16to minimize tip voids and open spaces.

Ad depicted inFIG. 26F, the two-part distal tip16may include a rounded or domed upper106′ of the top part104′. Such a rounded or domed design may be useful in providing more rounded surfaces for the atraumatic distal tip16.

The distal tip16ofFIGS. 26A through 26Fmay be made of any suitable biocompatible material. Although metal materials are preferred, plastic materials may be used.

FIGS. 27A through 27Cdepict an alternate embodiment of the distal tip16of the present invention, i.e., a filament wound and encapsulated distal tip120, in whichFIG. 27Ais a front perspective view of the filament wound and encapsulated distal tip120;FIG. 27Bis a side view of the filament wound and encapsulated distal tip120; andFIG. 27Cis a back or rear perspective view of the filament wound and encapsulated distal tip120.FIGS. 27D and 27Eare exploded views of the filament wrapping for the filament wound and encapsulated distal tip120, in whichFIG. 27Dis a top perspective view thereof andFIG. 27Eis a back or rear perspective view thereof. The filament124is wrapped over, under and between the splines14and over and under the spline alignment members89to secure the splines14in any desired predetermined angular relationship.

The splines14are secured to each other at the filament wound and encapsulated distal tip120. Tip120may be described as being a “filament wrapped and encapsulated” or a “suture wrapped and encapsulated” tip16. Tip120is not limited to the use of suture materials and any suitable filaments, threads, wires and the like may be suitably used. Advantageously, the filament wound and encapsulated distal tip120is a low profile tip. Further, filament wound and encapsulated distal tip120has no open spaces, such as slots or holes, common with some basket catheters of the prior art. Such open spaces or holes present in tips of the prior art allow for entry of blood cells, thereby causing or having the potential to cause blood clot formation or thrombogenesis. As described below, the splines14are secured to each other at their circular alignment members89by the use of a suture(s)124, filament(s)124, wire(s)124or thread(s)124. Multiple sutures124, filaments124, wires124or threads124may be used. After the splines14are so secured, the circular alignment members89of the splines14, including the securing suture(s)124, filament(s)124, wire(s)124or thread(s)124are fully or substantially or partially encapsulated with an encapsulant122to provide the filament wound and encapsulated distal tip120.

As depicted inFIG. 27D and 27E, the circular tip spline alignment portions89of the splines14are aligned or substantially aligned with each other. Filaments(s)124are laced, looped or wound between, over and under the splines14at the circular tip spline alignment portions89. A single filament or multiple filaments124may be used. Advantageously, the filament(s)124is laced, looped or wound between every adjacent spline portion. As depicted inFIGS. 27D and 27E, the filament(s)124is laced, looped or wound about opposite spline intersections or alternating spline intersections and then is crisscrossed in a similar fashion until all or substantially all of the spline intersection locations are secured

The filament124may include any suitable material. The use high tensile strength fibers, such as electrospun, braided or monofilament may be used. Some non-limiting examples include, but are not limited to, for example: Dyneema Purity® (Ultra High Molecular Weight Polyethylene or UHMWPE), Spectra® fiber (UHMWPE), Polyethyleneterephthalate or PET, polypropylene, etc. Metallic wires, such as stainless steel or nitinol, may also be used, but non-metallic fibers are preferred for their greater flexibility. The filament(s)124may be tied or twisted together to secure the circular tip or alignment portions89of the splines14. The filament(s)124may be twisted or tied together at locations interior to the spline basket12. The tied together circular tip or alignment portions89and the filament(s)124are then encapsulated with an encapsulant122. One useful encapsulant122is polyurethane, but other biocompatible encapsulants may suitably be used. The encapsulant122is also disposed between the spline intersection points to provide the tip120of the present invention.

Some advantages of the filament wound and encapsulated distal tip120of the present invention include, but are not limited to improved flexibility over tips of the prior art; reduced thrombogenicity; significantly smaller overall tip size; transparency under fluoroscopy; no MR artifacts; superior strength, i.e., equal to or greater than15times the strength of steel of the same diameter; superior adhesive bond strength; resistance to cutting (scissor action); and very small diameters, as low as 25 decitex (dtex).

As depicted inFIGS. 27A through 27C, the filament wound and encapsulated distal tip120has an atraumatic profile with a smooth, somewhat rounded upper surface, an inwardly contoured bottom surface and smooth side surfaces. The amount of encapsulant122may be minimized to provide maximum spline flexibility.

FIG. 28Adepicts another embodiment of the distal tip16in which two-part welded distal tip126with half splines is provided. As depicted inFIG. 28A, two-part tip126includes a top portion128insertable through a bottom portion130. A space or detent is provided in either or both portions128,130so that distal ends67of the splines14may be securably inserted therein. The portions128,130of the two-part tip126are securably joined together to securably affix the distal spline ends67therein. The portions128,130of the two-part tip126may be secured to each other by spot welds132, but other securing techniques may suitably be used. Although the splines14are depicted as emerging from the sidewall of the two-part tip126, the present invention is not so limited. If desired, the splines14may emerge from the top portion128(not shown) and/or the bottom portion130(not shown). The emergence angle of the splines14from the two-part tip126may include any of the above-described emergence angles. The splines14depicted inFIG. 28Amay be referred to as half-splines because these splines have both distal spline ends67and proximal spline ends60.

FIG. 28Bdepicts another embodiment of the distal tip16, in which a nitinol shrink ring tip134according to another aspect of the present invention. Spline ends67may be disposed within the tip134. The tip134has a compression ring138and a core post136. The spline ends67are disposed within and secured by the tip134. The ring138may be made from metallic, nitinol shape memory metal, shrink tubes. It may be machined at room temperature to design specifications, and then chilled so it can be expanded and stored. One may slip the ring138over the mated spline ends67and post136and assemble quickly. As the ring138comes up to room temperature it shrinks and provides a very strong compression fitting to secure the spline14within the tip134.

FIG. 28Cdepicts a tip140which may also be used with the present invention. A cap144and a base146may be secured to each other, by for example spot welding, via a square rivet142. The square rivet142is passed through alignment square holes148punched in splines14, as depicted inFIG. 28D. The splines14do not directly pass through the distal tip members144,146. In other words, the splines14do not pass through a sidewall of tip140, as no sidewall is present between the distal tip members144,146.

In another embodiment of the present invention, the tips of the present invention may include a magnetic tip (not shown). With previously described constraining tips spline lengths should be about identical in order for the basket to collapse evenly into guide catheter. If atrium outline shape deviates from approximately cylindrical or oval, then equal length splines may not contact all endocardial surfaces. A way to circumvent this problem is to allow the splines to be of different lengths (to match the atria), and allow the tip to “assemble” itself in situ when deploying. The tip may also “disassemble” itself when being captured into the guide catheter. This design may be achieved by using a small magnetic portion on each spline that “self assemble” themselves into a tip when deployed from the guide catheter, and disassemble themselves (i.e., magnets pull apart) when the basket is collapsed into the guide catheter. It may be necessary to place an elastic thread between each magnet, pulling them close enough for magnetic force to pull into assembly. If the splines follow the inside wall of the heart during diastole, then the splines need to buckle or deform during systole. The buckling will bring parts of the spline out of contact with the endocardium. Deformation will move the electrodes to different locations on the endocardium, confusing the mapping software. Note that, during atrial fibrillation, the heart remains close to its diastolic dimensions during its entire contraction cycle. This reduces the significance of this effect, making the basket design easier. In order for the basket to collapse into the guide catheter the splines need to be the same length but would need to be different lengths in order to follow locally distended parts of the atrium. A magnetic tip would disassemble as the catheter goes into the guide catheter. An elastic thread could be used between them so that the magnetic field then grabs them the rest of the way.

FIG. 29depicts another embodiment of a distal tip14, in which an encapsulated tip150is provided. The encapsulated tip may include any suitable flexible and/or elastomeric material. The overall profile of the tip150may be larger than for the filament and encapsulated tip120as tip150may not contain any filament wrapping or securement means. The encapsulated or molded tip150may be made from any suitable material. In one embodiment of the present invention, the encapsulated or molded tip150may be made from polyurethane, polyester block amide or silicone.

FIGS. 30A and 30Bdepict another embodiment of the distal tip16, in which a membrane distal tip152is provided. The membrane tip152may include an inner membrane or film156and an outer membrane or film154for securing the distal portions66of the splines14. The distal portions66of the splines14may simply cross each other between the two membranes154,156. The membranes154,156may be bonded, for example adhesive bonding, thermal bonding, and the like, together to provide the membrane tip152.

The splines14may simply cross within the membrane tip152. No separate connection between the splines14within the membrane152is needed. If desired, a connection (not shown) between the splines14may be provided. The inner membrane156and the outer membrane154may be adhesively bonded to all splines14within the membrane tip152. Further, the inner membrane156and outer membrane154may be adhesively bonded to each other at locations between the splines14. All elements may then be placed into fixture (not shown) so as to ensure the proper linear and angular orientation of the elements and then heat bonded together.

The present invention is not limited to the use of the inner membrane156and outer membrane154to form the membrane tip152. Additional membrane layers or films may be used. The membrane tip152may have any suitable shape, for example a circular shape, an octagonal shape, and the like. Further, matched diameter adhesive pads (not shown) may be placed between splines14to add additional support beyond just membranes154,156. The adhesive pads between the splines14at the membrane tip152may fill in gaps between splines14, thereby providing a slightly larger area for adhesive bonding, if desired. Thus, in either embodiment the width and/or thickness of the tip membrane152is minimal, i.e., less than the thickness of the splines14, or about the same thickness of the splines14or even just slightly larger than the thickness of the splines14. In any case, the tip membrane152does not have an appreciable sidewall as compared to the tips of the prior art.

Further, the tip membrane152, including the inner membrane156and outer membrane154, may be made from any suitable polymeric material, preferably non-elastic polymeric material, including flexible non-elastic polymeric material. In one embodiment the membranes154,156may be made from a polyimide material. Desirably, the membranes154,156are not made from polytetrafluoroethylene, i.e., PTFE, including expanded polytetrafluoroethylene, i.e., ePTFE.

FIGS. 31A through 31Ddepict an embodiment of the proximal anchor18of the present invention, in which a slotted proximal anchor is provided.FIG. 31Ais a perspective view of the proximal end160of the slotted anchor158.FIG. 31Bis a cross-section view of the distal end162of the slotted anchor158taken along the31B-31B axis. Slotted anchor158has an open diameter or open lumen164. The open diameter or lumen164allows wires, flex circuits, etc from the spline basket12to pass through the anchor158. The proximal end160of the slotted anchor158presses into an inner diameter or lumen of a catheter shaft20C or is otherwise connected to the catheter shaft20. Anchor158also includes spline-receiving slots168. The number of spline-receiving slots168typically is equal to the number of proximal spline end portions60, and is shown in these drawings as a quantity of eight. As depicted inFIGS. 31A and 31B, the spline-receiving slots168may be evenly spaced to allow for the basket splines14to be equally spaced in the desired angular position. The present invention, however, is not so limited, and any number of proximal spline end portions60and spline-receiving slots168, oriented at any desired relative angles may suitably be used.

One function of the anchor158is to attach the basket splines14to the catheter20and orient the splines14to give the basket12the proper shape and ensure it remains straight (not bent) upon collapse into the guide catheter46. The anchor device158is a means by which to orient the basket splines14on the proximal end68of the spline basket12and to fasten them together. Additionally, the anchor158affixes the basket splines14to the catheter shaft20. The anchor158may be fabricated from a single piece of material, e.g., a hypotube, or multiple sections that are attached (i.e. welded, glued, etc.) together. The slots168are sized to fit the basket splines14and the slot length ensures splines14are positioned accurately, which aids in even collapsing of the basket12. The slots168have adequate length to allow for the variable positioning of the basket splines14. The basket splines14may be attached to the anchor158by adhering with glue, welding, crimping or the like. Additionally, a ring (not shown) may be slid over the anchor158to hold the basket splines14in place. The outer ring (not shown) may be crimped, swaged, welded, glued, etc. to the outside of the anchor158or the outside of the catheter shaft20. The angular spacing of the slots168may be varied to accommodate the amount or number of basket splines14to be attached as well as to get the desired spacing of basket splines14. As depicted inFIG. 31B, one typical angular spacing is 45° degrees. The proximal end160of the anchor158is sized to press fit into a catheter shaft. It can be changed to accommodate any desired catheter dimensions. Additionally, the proximal end160can have geometry to mechanically lock the anchor into the catheter shaft (i.e., barb(s), serrated edges, ribs, etc). The inner diameter or lumen164of the anchor158is open to allow for catheter wiring, flex circuits, etc. to pass through the catheter shaft. Additionally, the wiring, flex circuits, etc. could be, if desired, run on the outer diameter of the anchor device158. Additionally, when the splines14are inserted into the anchor158and it is press fitted into the catheter shaft20C, the anchor158locks into the catheter shaft20C to enable the shaft20to be rotated without the basket12slipping inside the catheter shaft20C. Some non-limiting advantages of the anchor158of the present invention include, but are not limited to, ease of allowing fastening or gathering of basket splines14made of any material; may be fabricated from any suitable material or multiple materials; allows for variable positioning (length and angular) of the basket splines14to ensure even collapsing into the recovery sheath device; and provides sufficient clearance for device wiring. Further, as depicted inFIG. 31D, the anchor158may include a hemostat plug170into which a spline tube172, which may contain a spline14, passes to provide a sealed proximal spline tube lumen. The hemostat plug170may also be useful in securing the slotted anchor158to the catheter shaft20.

FIGS. 32A through 32Cdepict another embodiment of a proximal anchor18of the present invention, in which an anchor176is provided. The spline14may contain a notch174at the spline proximal end60. The anchor176includes an inner ring181having spline alignment slots180through which the spline ends60may pass. The spline ends60are interlocked with the anchor176via the spline notch174and alignment detent184. This interlock provides both excellent pull out retention and automatic, accurate alignment of all splines14with respect to each other so that they collapse neatly and reliably into the guide catheter46during introduction and removal of the catheter20. Once the splines14interlock with the anchor176, a second thin-walled tubing178is inserted over the anchor176. This tube178prevents the splines14from disengaging their interlocks in the anchor181. A complete lack of applicable forces on the internal anchor ring, adhesive and a slight interference fit between the external anchor and internal anchor rings prevents pull out of the inner anchor during use.

FIGS. 33Ais a perspective view of the basket12showing spline tubes172having spline tube assemblies185and exposed electrodes186.FIG. 33Bis a side elevational view of the basket12ofFIG. 33A. The spline tubes172are disposed over the splines14except at distal basket portion70where the splines14emerge from the distal tip16. The exposed electrodes186are spaced along spline distal portions66, spline medial portions64and spline proximal portions62. The number of exposed electrodes186may vary. The electrodes186are part of a flex electrode circuit188, which will be described in further detail below.

FIGS. 34A and 34Bare exploded partial cross-sectional views of the spline tubes172and spline tube assemblies185. The splines are disposed within a lumen208of the spline tubes172. As depicted inFIGS. 34A and 34Bthe splines14are not fixed to lumen208of the spline tube172. The spline tube172may be slidingly assembled over the spline14to provide some interference there between. The spline tube172may desirably includes a flexible material so that the lumen208of the spline tube172takes an elliptical shape substantially matching the cross-sectional extents of the spline14.

FIG. 34Cdepicts a cross-section of the spline14of the present invention. As depicted inFIG. 10, spline14may have a flat or substantially flat upper surface190, a flat or substantially flat lower surface192, and rounded sidewalls194,196. The present invention, however is not so limited, and the upper surface190and/or the lower surface192may be rounded or otherwise have curvature, including concave and/or convex curvatures. The splines14desirably include and/or are made of a super-elastic material so that the splines bow outwardly into the basket shape12, including asymmetric basket shapes. Any suitably super-elastic material may be used. Preferably, the splines include or are made of nitinol. If desired, the spline material may also be a shape memory material, such as but not limited to shape memory nitinol. Further, the splines14may be about 0.013 to about 0.025 inches wide and about 0.002 to about 0.010 inches thick. These dimensions are non-limiting and other dimensions may suitably be used.

FIGS. 34D through 34Fdepict radiopaque markers198useful with the spline tubes172and spline tube assemblies185of the present invention. As depicted in these figures, the radiopaque marker198may be disposed over a portion of the spline14that is near an electrode186. Desirably, the radiopaque marker198is securably fixed to the spline14. A significant useful feature of the current design over prior art is the radiotransparency of the flex circuit electrodes186(described below). This feature allows the separation of the fluoroscopic images of the splines and electrodes provided by the radiopaque markers198from the signal gathering function of the electrodes. This feature allows distinguishable patterns of electrode markings to be produced under fluoroscopy without modifying or compromising the electrogram gathering performance of the electrodes186.

FIGS. 34G through 34Hdepict a non-limiting arrangement of radiopaque markers198with the spline basket12of the present invention. The number of radiopaque markers198may vary along each spline14and may vary from spline to spline. These figures represent the two-dimensional shadowgraphs produced by fluoroscopy.FIG. 34Gis a side perspective view of the basket12under fluoroscopy. Each spline14has four radiopaque markers198identifying a particular electrode on a particular spline14. For example, the four radiopaque markers198at S1E8refers to the unique combination set of {spline1, electrode8}; at S2E7refers to {spline2, electrode7}; at S3E6refers to {spline3, electrode6}; at S4E5refers to {spline4, electrode5}; at S5E4refers to {spline5, electrode4}; at S6E3refers to {spline6, electrode3}; at S7E2refers to {spline7, electrode2}; and at S8E1refers to {spline8, electrode1}. In addition other electrodes186are marked with one marker198or two markers198. Generally, even numbered splines have two markers198at each electrode position, and the odd numbered splines have one marker198at each electrode position not marked with the four markers. Such an arrangement, as depicted inFIG. 34Hallows a practitioner to easily note the orientation of the basket12under fluoroscopy, including the location of the distal tip16and all of the electrodes198.FIG. 34Idepicts that when the basket12ofFIG. 34Gis rotated, individual splines14and electrodes186become apparent with the placement of the radiopaque markers198. For example, inFIG. 34I, the identity of each pair of crossed splines (S7& S8, S1& S6, S2& S5, S3& S4) would be ambiguous on one side of the crossing if each electrode were marked with a single RO marker. Further, a portion of the catheter body20(not shown) may also include radiopaque markers (not shown) to further aid the practitioner under fluoroscopy.

FIGS. 35A through 35Hdepict the spline tubes172with the spline tube assemblies185of the present invention. As depicted inFIG. 35A, the spline tube172is an elongate tubular member. The spline tube172or spline tube assembly185includes a proximal end200and a distal end202. As depicted inFIG. 35A, a portion of the spline14may emerge from the tube distal end202, where it may engage the distal tip16. The present invention, however, is not limited to flexible tube assemblies185only with the use of the basket12. The flexible spline tube assemblies185may be used by them themselves or with any other device where electrical activity within a body is to be monitored. In some cases spline tube assembly185amay not need to have a spline portion14or similar component exiting from the distal end202. The spline tube assembly185ofFIG. 35Ahas two flex circuits188, each with four electrodes186, mounted sequentially on the spline tube172, while the spline tube assembly ofFIG. 35Bhas one flex circuit188with eight electrodes186. These numbers of flex circuits and electrodes are non-limiting.

FIG. 35Cis a partial exploded view of the spline tube assemblies185,185aofFIGS. 35A and 35B. As depicted inFIG. 35C, the spline tube assemblies185,185amay include a first flex circuit188ahaving electrodes186and a second flex circuit188calso having electrodes186. The first flex circuit188amay have a transition portion188bwhere the first flex circuit188atransitions to a position on the tube173below that of the second flex circuit188c. In such a manner, multiple flex circuits may be places on the tubes172, while still orienting the electrodes186in substantially one direction, typically in an outward direction from the spline basket12.

As depicted inFIGS. 35D and 35E, the proximal end200of the spline tube172may be sealed with a plug204of material. The material may be an adhesive, polymer or any other useful material having sealing characteristics. The distal end202of the tube172may also be sealed with a plug206of material. Such sealing closes the internal lumen208of the spline tune172against the flow of fluids, including body fluids, such as blood. Such sealing also secures the spline tube172to the spline14. The present invention, however, is not limited to having just the proximal end and/or distal end so sealed or secured and intermediate portions may also be so sealed or secured.

As depicted inFIGS. 35F and 35G, the flex circuit portions188a,188band188exiting the spline tubes172may be embedded into the wall of the spline tube172. The present invention is, however, not so limited and as depicted inFIG. 35H, a portion of the flex circuit188may transition from the outer surface208A and past the inner surface208B so that it is disposed within the lumen208of the tube172. The spline tube172and the spline tube assembly185may comprise a biocompatible polymer such as a polyether block amide material, such as Pebax®. Other flexible biocompatible polymers, such as polyesters, silicones (e.g. Silastic®), silicone rubber, urethanes (e.g. Texin® and Pellethane®), and the like may suitably be used.

FIGS. 36A through 36Edepict an embodiment of the flex circuit188as a flex circuit strip212of the present invention. The flex circuit212includes a proximal end214and a distal end216. Towards the distal end216is an electrode-containing portion218. The medial portion220may be free of electrodes. The flex circuit strip212may contain wings222. These wings are useful in securing the flex circuit212to tubular members, such as spline tubes172, especially where it is desirable to keep the electrodes186as substantially unidirectional flat electrodes. The flex circuit or electrode assembly strip188may have a thickness from about 0.001 inches to about 0.010 inches, more desirably from about 0.005 inches to about 0.008 inches.

FIG. 36Ais a top view of the flex circuit strip212showing electrodes186disposed on the upper surface224of the flex circuit substrate236. The flex circuit substrate or polymeric substrate236may comprise a polyamide material, such as KAPTON polyimide available from DuPont, which is suitable for short term (single use medical device) or long term (medical implant) contact with skin, tissue or blood, depending on the intended application, but other suitable materials may be used, such as the above-described materials for the spline tube172or the spline tube assembly185. At the proximal end214electrical pads are disposed on the upper surface224.FIG. 36Bis a bottom view of the flex circuit strip212. Electrical traces228are disposed on the bottom surface226of the substrate236. The traces run from location underneath the electrodes185to locations underneath the electrical pads232. As depicted inFIGS. 36C through 36E, metal plated holes or vias230electrically connect individual traces to individual electrodes186. In a similar fashion vias234connect individual electrical traces228to individual electrical pads232.

As depicted inFIG. 36F, the flex circuit212may contain upper surface coverlays238to cover those areas of the upper substrate surface236A not having electrodes186or connection pads232. Likewise, if desired, bottom surface coverlays240may cover part or all of the electrical traces228. Upper coverlays238and lower coverlays240are bonded to the substrate236with the use of suitable adhesive239, usually acrylic adhesive. Desirably, the upper flex circuit axis S is substantially smooth, i.e., the coverlays238and the electrodes186being substantially the same height. The present invention, however, is not so limited, and electrodes may be raised slightly above the substrate surface with the use, for example, of strips of material disposed between the substrate236and the electrodes186. Alternatively, the electrodes may be depressed slightly below the substrate surface, as shown inFIG. 36F. The coverlays228,240may comprise a similar material as the substrate236, but different materials may suitably be used.

FIGS. 37A through 37Cdepict an alternate embodiment of the flex circuit188. As depicted, electrical traces may run on both sides of the flex circuit substrate236. For example, four electrodes,186a,186b,186cand186dare depictured inFIG. 37A. In the top view ofFIGS. 37A and 37Bno electrical traces run on the upper surface224between the electrodes186. However, proximal to the electrodes, electrical traces228for two electrodes186c,186drun on the upper surface224, and the electrical traces for the other electrodes186a,186brun on the bottom surface226of the flex circuit substrate. The electrical trace228for electrode186ctransitions from the bottom surface226to the upper surface224by means of a trace-to-trace via244. Such as arrangement of electrical traces228as depicted inFIGS. 37A through 37Cmay make for a more overall compact flex circuit.

FIGS. 38A and 38Bdepict a flexible electrode assembly strip247. The flexible electrode assembly strip includes a flex circuit or electrode assembly strip188,236pressed into the substrate246of a flexible polymeric material, such as any of the above-described materials for the spline tube172or the spline tube assembly185. The flex circuit or electrode assembly strip188,236may also be thermally, compressively and/or adhesively bonded onto or into the substrate246. While the substrate246is depicted as being a strip or being planar, the present invention is not so limited. The substrate could be tubular with or without an open lumen. As depicted inFIG. 38Bthe electrode assembly strip188,236is pressed into the substrate wall246bwhile leaving a substantially smooth upper surface246A and lower surface246C. If desired portions of the flex circuit188,236, for example those portions not containing electrodes, may be disposed between multiple two or more substrates246, either in planar or tubular form. When covering the electrodes with a cover or substrate of polymeric material, it is desirable to remove cover or substrate material so that the electrodes186remain exposed.

All components, i.e., splines, electrode flex circuits, electrode elevation strips (used to raise the surface of the electrodes above the substrate, if desired; not shown), radiopaque marker strips are desirably thin, flat, planar elements. In a simple design, these elements may be stacked and adhesively bonded to each other. Alternately, a length of flexible tubing or membrane can be slid over the bonded spline/radiopaque marker/flex circuit/electrode elevation strip in order to contain all parts within a single body. This tube or membrane can be shrunk in place for a tight, contained fit using either heat shrink tubing or tubing that is chemically expanded (e.g., by absorption of alcohol or other chemical) for assembly, and then contracts when the chemical evaporates.

FIG. 39depicts yet another alternate embodiment of a flex circuit188having laterally staggered electrodes186.

FIGS. 40A and 40Bdepict the use of quad wires248which connect proximal end214of the flex circuit188. Individual quad wires248are connected to individual electrical pads232at the proximal ends214of the flex circuits. The quad wires248then are routed through the catheter body20and handle28to the catheter connector located at the proximal end of the handle28.

FIGS. 41A and 41Bdepict a portion of the catheter shaft20as having a braided shield that minimizes possible electro-magnetic interference from outside sources. The catheter20may also have anti-kink beading sections252or254, which provide greater support to prevent kinking of the catheter20. Flexibility of the catheter body20may also be controlled which advantageously aids in having the basket12more closely match the contours of the heart.

FIGS. 42A through 42Cfurther depict asymmetric basket shapes for basket12.FIG. 42Ais a side view of the asymmetric basket shape is depicted. The basket shape is asymmetric in this view in that, among other things, the basket shape is not spherical and/or the proximal spline portions62may contain different degrees of curvature of bends82,84. These bends82,84, also know as a dimple end and/or a puckered end, allows the basket12to compress when the heart contracts. In other words, the proximal portion68of the basket12is designed with greater flexibility to ensure, among other things, improved contact of the splines14with interior surfaces of the heart wall.

While one overall basket shape is depicted inFIG. 42A, it may be desirable to have different basket shapes, for example, a right atrial basket shape and a left atrial basket shape. These different baskets may have different basket outline shapes and therefore different compliances of the individual splines. These differences may allow each shape to optimally conform to the differently shaped left atrium and right atrium. In addition, each shape may come in several different overall sizes. Note that the specific shape shown inFIG. 42is not intended to represent an “atrial shaped basket”, but is instead an arbitrary shape that illustrates the design features required to fabricate an asymmetric basket that will successfully collapse within a guide catheter.

FIGS. 42B and 42Care an end views of the basket12ofFIG. 42A. As depicted inFIG. 42B, all spline portions are substantially equidistant from the center longitudinal axis L and/or tip16or are substantially in the center of the overall basket outline C as depicted. As depicted inFIG. 42C, all spline portions are not substantially equidistant from the center longitudinal axis L and/or tip16or are not substantially in the center of the overall basket outline C as depicted. Such asymmetry provides for improved basket performance by more closely matching the shape of the atria of the heart. The splines14inFIG. 42Ahave an equal or substantially equal longitudinal length. The varying distances of the medial portions64of the splines from the center longitudinal axis L results from, in part, the flexibility of the splines14at the proximal spline portions62due to the inclusion of the bends82,84. While the longitudinal lengths of the splines14are equal or substantially equal inFIG. 42Aif the basket12is in its compressed state, the present invention is not so limited, and splines14of varying lengths may be suitably used. Such varying lengths may be achieved by imparting geometries to different bends82,84. For example, some bends may have greater inward longitudinal extents than other bends such that, when compressed with the guide catheter46, all the splines14of the basket12have an equal or substantially equal net line segment between the anchor18and the tip16. When the basket12is expanded, the bends82,84may “relax” and provide a basket assembly12with splines14of net different lengths, for example spline14ahaving an effective longer length than spline14b. Such asymmetry provided by, in part, splines14of varying lengths provide for a closer matching of the shape of the basket12with interior portions of the heart, i.e., the atria, as the heart is beating.

In a similar fashion, the bends78,80at the distal basket portion70also provide for asymmetry, if desired. As depicted, both proximal and distal spline portions62,66may have different recurves or incurvate bends to more effectively match the shape of a typical atrium. Different proximal recurves with different lengths and/or angles compensate for different spline lengths so that the basket may be disposed within the guide catheter where the splines would have the same or about the same effective length when the basket in compressed, but will have different effective lengths when the basket is expanded

The apparatus, system or devices of the present invention may include electrodes are configured as Monophasic Action Potential (MAP) electrodes, where a single electrode at each site is configured to intimately contact the tissue, and a second electrode at each site is configured to face away from the tissue, acting as an MAP “reference” electrode. An electronic Data Acquisition System may be configured to record the electrograms produced by the catheter as MAP electrograms. The electronics Data Acquisition System may also be selected to record the electrograms produced by the catheter as either standard unipolar electrograms, bipolar electrograms or as MAP electrograms. Further, the electrodes may be configured as Modified Monophasic Action Potential (m-MAP) electrodes, where a single electrode at each site is configured to intimately contact the tissue, and a second electrode placed intermediate between two or more sensing (i.e., tissue facing) electrodes, which is configured to face away from the tissue, acting as an MAP “reference” electrode for multiple sensing electrodes. The curvature of the splines is specifically chosen to match the curvature of a “typical” atrium for the purpose of enhancing electrode to tissue contact, producing the contact force required for quality MAP mapping. The splines may be curved at the proximal end with different length segments in order to compensate for the different spline lengths that result from matching the splines to the shape of a typical atrium; where equal spline total length (tissue contact segment plus recurve segment) is required to allow collapsibility for introduction and withdrawal of the catheter through the second elongate tube.

FIGS. 43A and 43Bare bipolar electrograms obtained from animal studies. InFIG. 43Athe electrograms were obtained from the use of the system10of the present invention. InFIG. 43A, the atrial signals258are much larger than the ventricular signals260on electrodes A3, A5, A7, B7and C3. Further inFIG. 43A, the atrial signals258are approximatel equal to the ventricular signals260on electrodes B5, C1and C5. Moreover. inFIG. 43A, the electrogram traces I, aVF and V1are not basket signals. In general the atrial signals258are much larger than or equal to the ventricular signals260. This allows a practitioner to more easily map the atrial signals within the heart to locate heart tissue causing heart fibrillations. The practitioner may suitably ablate such areas.

FIG. 43Bdepicts electrograms obtained from animal studies using a commercially available prior art basket catheter. InFIG. 43B, atrial signals258are absent on electrodes A1, A5and A7. Also inFIG. 43B, the atrial signals258are smaller than the ventricular signals260on electrodes A3, B5and B7. Further inFIG. 43B, the atrial signals258are approximately equal to the ventricular signals260on electrode B3. Still further inFIG. 43B, the atrial signal258are larger then ventricular signals260on electrodes B1, C1, C3and C5. Moreover, inFIG. 43B, the electrogram traces I, aVF and V1are not basket signals. In general, the atrial signals258, when present, are much smaller than ventricular signals260on some electrodes, but may also be larger on other electrodes. The recorded signals ofFIGS. 43Arepresent a significant improvement over the recorded signals ofFIG. 34B. While not being bound by any theory, it is believed that the substantially flat, single sided flex electrodes186of the present invention with the described flex circuits and spline tube assemblies, superior contact and contact force generate higher atrial signals from the heart while reducing the ventricular signals from the heart.

Further, the improved basket geometries of the present invention also contribute to improve mapping of the atrial signals as the baskets of the present invention are not only more stable within the atrium of the beating heart, but also can flex and contour to the varying complexities of the beating heart.

The devices, systems and assemblies of the present invention are useful in overcoming the problems or deficiencies associated with mapping of the right atria and the left Atria, especially when used in conjunction with atrial fibrillation ablation. Problems or deficiencies with typical prior art or presently available commercial devices include (a) positional instability of basket during mapping and data analysis times, (b) positional instability of basket during ablation, (c) lack of proximal basket electrodes, (d) poor electrode contact with atrial tissue typically yields poor signal (atrial) to noise (ventricular) ratios, (e) lack of electrode contact (no measurable atrial signals), (f) radiofrequency (RF) noise interfering with atrial signals recording, (g) spline lateral bunching, (h) electrode sliding (i.e., changing position) during heart contraction, (i) poor spline/electrode identification under fluoroscopy, and/or (j) poor performance in left atrial (LA) transeptal procedures.

Positional instability of basket during mapping and data analysis times typically involves movement of shifting of the catheter basket. Different types of shifting include, but may not be limited to: rotation of the basket about its basket tip to anchor central axis; rotation of the basket about its axis normal to basket tip to anchor central axis; a linear shift of the basket along its catheter axis; a lateral shift of individual splines; and a combination thereof. As a result of shifting, some electrodes may come out of contact with endocardium, thereby providing an inadequate or incomplete map and data analysis of electrical signals from the heart. The basket electrodes are the “frame of reference” for all the maps generated from the electrical signals. The maps are typically produced by the software are “with respect to the basket electrode positions at the time the electrograms were recorded.” As an example, the map may tell the practitioner to ablate heart tissue midway between, for example, Spline C, Electrode5and Spline D, Electrode4. The practitioner will attempt to place an ablation catheter at this location, using the basket splines and electrodes as reference points. Any shift of the basket from its position at the time of recording to a different position at the time of ablation produces errors (rotational or linear) or distortions in the maps. The magnitudes of these errors are proportional to amount of shift of the electrodes. Such errors or distortions are problematic to the practitioner.

Positional instability of basket during ablation is another area of concern for a practitioner. Electrogram maps will indicate to the practitioner or clinician where to ablate “with respect to the spline and electrode positions at the time the map electrograms were recorded.” The practitioner or clinician must insert an ablation catheter between splines of mapping basket and direct its steerable tip to various locations on the endocardium, using the splines and electrodes of the mapping basket as reference points within the heart. In order for the information on the electrogram maps to be useful, the spline and electrode positions of the mapping basket during ablation must be substantially equivalent to their positions during recording. Otherwise, practitioner or clinician will be relying on inaccurate reference locations.

A lack of electrodes on the proximal spline segments of the mapping basket is also a problematic for a practitioner or clinician. Mapping software gathers timing data at discrete electrode positions (a “sparse data array”) and calculates continuous interpolated timing results for all areas of the heart that reside within the electrode coverage area. The software cannot extrapolate results beyond the electrode coverage area. Directed ablation is performed using the calculated, continuous interpolated space-time maps, using the electrodes as reference points. There can be no mapping or useful directed ablation on areas of the heart outside of the area of electrode coverage. Basket catheters of the prior art generally have no electrodes on the proximal segments of their basket splines. Thus, with typical prior art devices, the proximal segments of the atria (especially areas on the septal wall during transeptal mapping and ablation of the Left Atrium) cannot be mapped. Accordingly, these proximal wall segments of the atria cannot be ablated by a practitioner or clinician with the directional control of maps or reference electrodes.

Furthermore, poor electrode contact in zones where electrodes exist yields poor signal (atrial) to noise (ventricular) ratios. In the prior art devices, poor electrode contact results in decreased atrial signals (f-waves in atrial fibrillation and p-waves in sinus rhythm) as compared to background noise (ventricular depolarizations). Such a poor signal to noise ratio makes it difficult for software to automatically determine accurate f-wave timing. This results in poor automatic mapping and the need for trained human assistance in the recognition of f-waves.

A lack of electrode contact (no measurable atrial signals) is yet another concern with devices of the prior art. Electrodes that are sufficiently displaced from the endocardial surface will record no measurable f-waves. This produces holes in the sparse data array and poor resolution in zones of dropped data. While some interpolation of the missing data will occur with software, it will not be as accurate, since more widely spaced electrodes are used for such interpolation. The difference between poor electrode signal and no electrode signal is that, in the former case, a human operator may be able to assist the software algorithms in finding f-waves. However, in the latter case, there is nothing that the software or operator assistance can do to overcome the lack of available data.

RF noise may result from, among other things, a lack of shielding of the long signal conduction wires that run from the mapping catheter to the associated recorder. In a typical electrophysiology laboratory, there are many other pieces of equipment that may generates significant RF noise, which can be picked up by the long lengths of unshielded shielded wires and superimposed upon the millivolt level signals from the mapping catheter. Radiated noise is especially problematic when one attempts to compensate for low amplitude atrial signals (due to poor electrical contact) by increasing amplifier gain, because RF noise will be amplified along with the low amplitude signals.

Spline lateral bunching is also a concern with prior art devices. With the prior technology, multiple splines frequently “bunch up” (i.e., gather together) due to varying atrial wall shapes. This often puts many electrodes in close proximity to each other, leaving large zones of the endocardium lacking in electrode coverage where the splines are not “bunched-up”. This will typically result in distortions in the calculated maps, with zones of unnecessarily high resolution (with extra splines and electrodes) adjacent to zones of poor resolution (lacking splines and electrodes).

Prior art devices typically do not guard against electrode sliding (i.e., changing position) during heart contraction. The mapping software typically assumes that the electrodes provide a signal from a single location on the endocardium. If electrodes slide during heart contraction, this assumption is violated. Fortunately, the valuable information for the detection of the f-wave during a-fib happens at the start of contraction for any given electrode. Motion that occurs after this event is not likely to negatively impact the mapping. Unfortunately, electrodes are typically ganged together in groups of eight on each spline. If one electrode starts to slide laterally during the contraction, it can (and will) drag the other seven electrodes on the same spline with it. The impact on the resultant map will be proportional to the difference between the assumed position and actual position of the electrode at the arrival of the f-wave, which is obviously problematic to a practitioner or clinician.

Poor spline/electrode identification under fluoroscopy is another concern for the practitioner or clinician with the devices of the prior art. With prior art devices, the eight splines are typically identified sequentially with the letters A through H. The electrodes are identified with the numbers one (most distal) to eight (most proximal). With prior technology, each electrode operates as its own radiopaque marker. This may be convenient for locating individual electrodes. Additionally, an extra dummy electrode is often placed adjacent to an index electrode on seven out of eight splines. For the prior art device, the index “Spline/Electrodes” are A8, B7, C6, D5, E4, F3 and G2 electrodes. (H1 is typically not identified.) In principle, this scheme should allow the clinician to identify each spline and then each electrode. In reality, however, this system frequently produces ambiguous, difficult to resolve fluoroscopic images. As described above, the electrodes are the reference map by which the practitioner or clinician will ablate heart tissue. Difficulty in unambiguously identifying each spline and each electrode will result in uncertainty in ablation locations.

Poor performance of prior art devices in LA transeptal procedures is yet another area of concern for the practitioner or clinician. It is much more difficult to achieve a high proportion of electrodes in high quality contact with the endocardium in the left atrium than it is in the right atrium. The systems, devices and assemblies of the present invention offer improved electrode contact over the prior art in both the left atrium and the right atrium.

Some non-limiting causes of problems are described below.

Positional instability of basket during mapping and data analysis times may be due to the lack of “all direction” counter-pressure. For the prior art device, pressure on distal half of a basket often produces a net compressive force on the splines that possesses a lateral component, pushing the distal end of the catheter out of touch with the endocardium. The only force counteracting this force is provided by the catheter body shaft, which is free to float in the oversized inferior vena cava (IVC). Counterforce of basket shaft, however, is unpredictable and unreliable. Further, basket electrode shapes (typically round) and radial forces (very light) often result in extremely tenuous basket anchoring to atrial walls. Very slight loads or torques will cause baskets of the prior art to shift position.

Positional instability of baskets of the prior art during ablation may also result from the tenuous anchoring of the basket to the endocardium, which results in movement of the basket during insertion and manipulation of the ablation electrode. The practitioner or clinician must attempt to compensate for this motion by constantly repositioning the basket or by using educated estimations of the locations of relevant splines and electrodes at the time of mapping. This is complicated by the lack of proximal wall electrodes in the prior art devices, i.e., with the given shape of prior devices proximal electrodes would likely not contact endocardium. Consequently, manufacturers have chosen to place no electrodes on proximal segments of splines.

Poor electrode contact may result from misalignment of basket in atrial chamber; non-spherical atrial shape; basket/atrium size mismatch; lack of “all direction” counter pressure (causing distal electrodes to withdraw from endocardium as a result of heart contractions); inability of prior splines to track discontinuities in atrial wall curvature and/or very light radial spline force preventing splines from conforming to local recesses in the atrial wall.

A lack of electrode contact often results from the same causes as “poor electrode contact” and/or lack of proximal electrodes on splines.

RF noise results from the lack of RF shielding in catheter and extension cables.

Spline lateral bunching may occur when splines expand against endocardial surface. If that surface is at an oblique angle to the plane of the spline, a “side load” will be imparted on the spline. If the spline's lateral stiffness is too weak to resist this side load, then it will deform in that direction. Further, certain spline and electrode shapes (e.g., rectangular or substantially rectangular) are better suited to resist sideward sliding than other shapes (e.g., round).

For electrode sliding (i.e., changing position) during heart contraction, the same effects that may result in spline lateral bunching may be exacerbated during heart contraction. As a result, the splines can be forced to slide laterally (or twist helically) during systole. This spline movement (which carries the spline's electrodes) can produce improper electrode position or motion artifacts in the electrograms.

Poor spline/electrode identification under fluoroscopy of prior art devices is caused because each electrode acts as its own RO marker. This limits the possible schemes that one may employ to distinguish what are otherwise identical electrodes. Even if splines are definitively identified at the location of their “index electrodes”, the splines always cross each other in the two dimensional fluoroscopic images. It is frequently difficult or impossible to identify splines after these crossings. SeeFIG. 34Ifor an example of this phenomenon. It can be readily appreciated inFIG. 34Ithat, if all electrodes appeared as a single radiopaque marker, then it would be difficult to identify each spline after such a crossing. However, by providing a distinguishable marking scheme on adjacent splines (i.e., single electrode markers versus double electrode markers on adjacent splines), then it becomes trivial to accurately identify all portions of all splines.

With regard to poor performance of prior art devices in LA transeptal procedure, a practitioner or clinician accesses the left atrium (LA) through a transeptal puncture. The practitioner or clinician pushes a specially designed needle through the septal wall separating the right atrium from the left atrium. The catheter guide sheath and mapping catheter are then advanced through this puncture site, and the mapping catheter deployed from this location. The transeptal puncture site frequently represents a very strong, misaligning constraint on the location of the proximal end of the basket. If not approximately centered in the left atrial chamber, this constraint can hold many (mostly proximal) electrodes off of the endocardium. If the transeptal puncture site is not approximately centered with respect to the left atrial chamber, the anchor portion of the basket will be drawn “off center” as well. This misalignment can have the effect of holding one sector of splines off of the proximal endocardium, while pushing the opposite sector into excess contact with its proximal endocardium. Currently, practitioners or clinicians attempt to compensate for this problem by using a “J tip” transeptal guide catheter, and directing the anchor portion of the catheter to a more centered location, or by deflecting the portion of the catheter body that is proximal to the septal wall puncture site.

The present inventions solves these problems of typical prior art devices.

Improved positional stability of basket during mapping and data analysis times is one area addressed by the present invention. First, poor solutions and non-solutions include use of larger basket, which frequently exacerbates, rather than cures, the problem; the use of inappropriate physical constraints on basket; the placing tip of basket into one of the left pulmonary veins; using J tip guide catheter to deflect distal end of catheter body, which puts an angular, as well as linear, deflection on anchor portion of basket; and/or advancing or retracting catheter body in an attempt to overcome or address the problems of the prior art. The correct solutions, as identified by the present invention, include, but are not limited to, design basket shape to fit atria; design basket shape to generate “all direction” counter pressure from its contact with endocardium; make basket slightly oversized to diastolic size of atrium; allow basket to align itself to atrial shape; and/or relax all other constraints (as much as possible) and allow basket counter pressure to determine basket position; give electrodes and splines a shape (rounded rectangular) that is advantageous to the spline anchoring itself to the endocardium without causing trauma; and/or provide baskets in sufficiently small size increments so that a size can be chosen that will be both stable and non-traumatic.

To improve positional stability of basket during ablation, all of the position stabilization techniques described above may be used. Experience has shown that, when all splines are poorly anchored, a slight force applied to one spline will move the entire basket. When the splines are well anchored, however, slight pushing of one spline will deflect only that one spline. The other splines will retain their positions and, when the side force is removed from the one spline, the single displaced spline will return to its former position.

The devices of the present invention provide proximal wall electrodes by, for example, adjusting electrode spacing or adding additional electrodes on each spline. Further, since new spline shape will put proximal spline segments into contact with endocardium, electrodes mounted in this location contribute to map.

Improve electrode contact may be achieved with the devices of the present invention by, for example, the practitioner's use of baskets that are chosen to be slightly oversized to the patient's atrium. The use of an oversized basket will force the splines and the atrium to conform to the atrial shape will produce excellent electrode contact as the endocardium deforms to conform to each other's shape, which will reduce bridging effects, giving better electrode contact. Additional design elements that will improve electrode contact include, but are not limited to, the incorporation of break points in spline, or the inclusion of assisting tension members (e.g., elastic bands) adjacent to the splines, both said elements allowing short spline segment to flex independently of each other, providing improved electrode to endocardium contact. Additional steps to improve electrogram signal quality include: the reduction of areas of electrode exposed to far field ventricular (i.e., noise) inputs but not near field atrial signal, which improves signal to noise ratio; improved atria/basket size match by providing small increment basket sizes; and/or adding proximal curve to spline shapes allows severely distorted basket shapes that will match non-spherical atria, while being able to collapse into guide catheter.

The devices of the present invention may include RF noise shielding. An RF shield incorporated into catheter and extension cable will reduce amplifier pick up of radiated noise. Moreover, excellent electrode contact of the present invention will increase atrial signal magnitude and reduce the need for high amplifier gain.

Reduce spline lateral bunching is achieved by the present invention by giving the spline sufficient lateral stiffness to resist side loads and/or using spline and electrodes shape (rectangular or substantially rectangular) better suited to taking purchase on the endocardial wall while still providing a non-traumatic anchor.

The present invention achieves reduce electrode sliding by, for example, improved positional stability of baskets, improved anchoring of splines, relaxation of inappropriate constraints.

Improving spline/electrode identification under fluoroscopy may be achieved by several aspects of the present invention. The basket design of the present invention produces a radio-transparent electrode. Separate means (radiopaque bands of metal or ink) may be varied from spline to spline, or from electrode to electrode, to produce highly distinguishable splines and electrodes, as seen inFIGS. 34G through 34I. The system described here (one marker at every electrode on odd numbered splines, two markers at every electrode on even numbered splines, and four markers on each “index electrode”) produces an unambiguous fluoroscopic image.

For improved performance in LA transeptal procedure, it is desirable that the selection of puncture site be more central to left atrial chamber. Further, a reduction of constraint of anchor imposed by transeptal puncture site is also desirable.

Increased number of basket sizes by reducing step increment is also an important aspect of the present invention. Many of the prior technology's flaws are exacerbated by poor basket to atrium size match. Atria come in a continuum of sizes. The only way to achieve an adequate size match while avoiding endocardial trauma is to offer a multitude of basket sizes in relatively small increments.

One method according to the present for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: providing a system (10) for sensing multiple local electric voltages from endocardial surface of a heart, comprising: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the electrodes (186) are substantially flat electrodes and are substantially unidirectionally oriented towards a direction outside of the basket assembly (12); a proximal anchor (18) for securably affixing the proximal portions (62) of the splines (14); said anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16) for securably affixing the distal portions (66) of the splines (14), said proximal anchor (18) and said distal tip (16) defining a longitudinal axis (L) about which the splines (14) are disposed; wherein the splines (14) approach the distal tip (16) at an angle (α) of about 90° or less than about 90° as measured from a line segment between the proximal anchor (18) and the distal tip (16) along the longitudinal axis (L); wherein the splines (14) comprise a superelastic material such that the basket assembly (12) exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; and wherein each of the splines (14) in the radially expanded non-spherical shape contain a proximal recurve (76) in the proximate portion (62) of the spline (14) at a location near to the proximal anchor (18) of the basket assembly (12), the proximal recurve (76) comprises a proximal excurvate outward bend (84) and a proximal incurvate inward bend (82) between said proximal excurvate outward bend (84) and said proximal anchor (18), where an apex (83) of the proximal incurvate inward bend (82) is disposed in a direction toward the distal tip (16) and is further disposed inwardly closer toward the distal tip (16) than the proximal excurvate outward bend (84); delivering the system (10) to the heart so that the basket assembly (12) is disposed within the right atrium of the heart; contacting proximal atrial tissue with the electrodes (186) disposed on the proximal spline portions (62) to detect multiple local electric voltages from endocardial surface thereat; and contacting atrial tissue with the electrodes (186) disposed on the medial spline portions (64) and the distal spline portions (66) to detect multiple local electric voltages from endocardial surface thereat. The splines (14) of the basket assembly (12) may be flexible to match the contours of the right atrium. Substantially all of the electrodes (186) may contact atrial tissue. Substantially all of the electrodes (186) may remain substantially spatially fixed with respect to atrial tissue. A substantial portion of atrial signals detected by the system (10) may have larger amplitudes than ventricular signals detected by the system (10). The splines (14) in the radially expanded non-spherical shape may contain an distal excurvate outward bend (80) disposed at the distal portion (66) of the spline (14) at a location near to the distal tip (16) of the basket assembly (12) to bend the splines (14) back towards the proximal anchor (18); and wherein the splines (14) have an distal incurvate inward bend (78) between said distal tip (16) and said distal excurvate outward bends (80). The splines (14) of the basket assembly (12) may be flexible to match the contours of the right atrium.

The devices of the present invention may suitably be used to detect or map cardiac rhythm disorders. Details of methods for detecting or mapping cardiac rhythm disorders may be found in U.S. Provisional Application No. 61/342,016, filed on Apr. 8, 2010, entitled “Methods, System And Apparatus For The Detection, Diagnosis And Treatment Of Biological Rhythm Disorders”, which published as U.S. Patent Application Publication No. 2011/0251505 A1 for its corresponding Non-Provisional application Ser. No. 13/081,411, the contents of all which are incorporated herein by reference.

The following aspects, embodiments, and the like are part of the detailed description for the present invention. Embodiments directed to distal tip embodiments include, but are not limited to, as follows:

In one embodiment, a system (10) for sensing multiple local electric voltages from endocardial surface of a heart is provided. The system may comprise a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); and a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62) and distal portions (66); an anchor (18) for securably affixing the proximal portions (62) of the splines (14); said anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); an encapsulated and filament-wrapped distal tip (16,120) comprising an encapsulant (122) and a filament (124) for securably affixing the distal portions (66) of the splines (14) in a predetermined angular relationship at said distal tip (16,120); wherein the splines (14) comprise a superelastic material; and wherein the basket assembly (12) has a radially expanded non-cylindrical shape. The system (10) of may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has a substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-cylindrical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). The encapsulant may have a smooth, non-thrombogenic outer surface free of voids and slots which would permit the passage or entry of blood thereinto. The encapsulant (122) may comprise a thermoplastic material. The encapsulant (122) may also comprise a polyurethane material. The filament (124) may comprise a polymeric filament, a metallic filament or combinations thereof. The filament (124) may be laced, looped or wound between, over and under the splines (14) to substantially align and secure the distal portions (66) of the splines (14) in said predetermined angular relationship. The flexible splines (14) may further comprise alignment members (89) at the distal portions (66) of the splines (14); and wherein the filament (124) is also laced, looped or wound between, over and under the alignment members (89). The alignment members (89) may comprise circular portions at the distal spline portions (66). The angles (θ1-θ8) between said splines (14) at said distal tip (16,120) forming said predetermined angular relationship may be all substantially equal to each other. Alternatively, at least one angle (θ1-θ8) between said splines (14) at said distal tip (16,120) forming said predetermined angular relationship may be different from another angle (θ1-θ8) between said splines (14) at said distal tip (16,120). When basket assembly (12) is in said radially expanded non-cylindrical shape, the splines (14) may extend beyond the distal tip (16,120) and may comprise excurvate bends (80) beyond the distal tip (16) to bend the splines (14) back towards the anchor (18).

In one embodiment, a system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); and a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62) and distal portions (66); an anchor (18) for securably affixing the proximal portions (62) of the splines (14); said anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16,150) comprising an elastomeric material for securably affixing the distal portions of the splines (14) in a predetermined relationship at said distal tip (16,150); wherein the splines (14) comprise a superelastic material; and wherein the basket assembly (12) has a radially expanded non-cylindrical shape. The system may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has a substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-cylindrical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). The distal tip (16,150) may have a smooth, non-thrombogenic outer surface free of voids and slots which would permit the passage or entry of blood there into. Angles (θ1-θ8) between said splines (14) at said distal tip (16,150) forming said predetermined angular relationship may be all substantially equal to each other. Alternatively, at least one angle (θ1-θ8) between said splines (14) at said distal tip (16,150) forming said predetermined angular relationship is different from another angle (θ1-θ8) between said splines (14) at said distal tip (16,150). The elastomeric material may comprise polyurethane, silicone and combinations thereof.

In one embodiment, a system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62) and distal portions (66); an anchor (18) for securably affixing the proximal portions (62) of the splines (14); said anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16,150) comprising a flexible material for securably affixing the distal portions of the splines (14); wherein the basket assembly (12) has a radially expanded non-cylindrical shape; wherein the splines (14) comprise a superelastic material; wherein said flexible material comprises a material selected from the group consisting of an elastomeric material, a non-elastic polymeric material, a thermoplastic material and combinations thereof; and wherein the splines (14) approach the tip (16) at an angle (α) of less than about 45° as measured from a line segment between the anchor (18) and the tip (16) along a longitudinal axis (L) between the proximal anchor (18) and the distal tip (16,150). The system (10) of embodiment19, may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has a substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-cylindrical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). When basket assembly (12) is in said radially expanded non-cylindrical shape, the splines (14) may extend beyond the distal tip (16,150) and may comprise excurvate bends (80) beyond the distal tip (16) to bend the splines (14) back towards the anchor (18). The angles (θ1-θ8) between said splines (14) at said distal tip (16,150) forming said predetermined angular relationship may be all substantially equal to each other. Alternatively, at least one angle (θ1-θ8) between said splines (14) at said distal tip (16) forming said predetermined angular relationship may be different from another angle (θ1-θ8) between said splines (14) at said distal tip (16,150).

In one embodiment, a system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62) and distal portions (66); an anchor (18) for securably affixing the proximal portions (62) of the splines (14); said anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16,104,104′,126,134,140,152) for comprising a first part and a second part that are securably affixed to one and the other; wherein the distal portions (66) of the splines (14) are securably and non-slidingly disposed within said distal tip (16) in a predetermined angular relationship; wherein the splines (14) approach the distal tip (16) at an angle (α) of about 90° or less than about 90° as measured from a line segment between the anchor (18) and the tip (16) along the longitudinal axis (L); wherein the basket assembly (12) has a radially expanded non-cylindrical shape; and wherein the splines (14) comprise a superelastic material. The system (10) may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has a substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-cylindrical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). Angles (θ1-θ8) between said splines (14) at said distal tip (16,104,104′,126,134,140,152) forming said predetermined angular relationship may be all substantially equal to each other. Alternatively, at least one angle (θ1-θ8) between said splines (14) at said distal tip (16) forming said predetermined angular relationship may be different from another angle (θ1-θ8) between said splines (14) at said distal tip (16,104,104′,126,134,140,152). When basket assembly (12) is in said radially expanded non-cylindrical shape, the splines (14) may extend beyond the distal tip (16,104,104′,126,134,140,152) and may comprise excurvate bends (80) beyond the distal tip (16,104,104′,126,134,140,152) to bend the splines (14) back towards the anchor (18). The splines (14) may have distal end portions (67); and further wherein the distal spline end portions (67) may be securably and non-slidingly disposed within said distal tip (16,104,104′,126,134,140). The splines (14) may approach said distal tip (16) at an angle (α) of less than 45° as measured from a line segment between said anchor (18) and said distal tip (16,104,104′,126,134,140) along the longitudinal axis (L).

Embodiments directed to spline bends and recurves embodiments include, but are not limited to, as follows:

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between; a proximal anchor (18) for securably affixing the proximal portions (62) of the splines (14); said proximal anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16) for securably affixing the distal portions (66) of the splines (14), said proximal anchor (18) and said distal tip (16) defining a longitudinal axis (L) therein between about which the splines (14) are disposed; wherein the splines (14) approach the distal tip (18) at an angle (α) of about 90° or less than about 90° as measured from a line segment between the proximal anchor (18) and the distal tip (16) along the longitudinal axis (L); wherein the splines (14) comprise a superelastic material such that the basket assembly (12) exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; and wherein at least some of the splines (14) in the radially expanded non-spherical shape contain a distal excurvate outward bend (80) disposed at the distal portion (66) of the spline (14) at a location near to the distal tip (16) of the basket assembly (12) to bend the splines (14) back towards the proximal anchor (18). The system may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has said substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-spherical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). When basket assembly (12) is in said radially expanded non-spherical shape, the splines (14) may extend beyond the distal tip (16); and, when basket assembly (14) is in said radially expanded non-spherical shape, apices (81) of the distal excurvate bends (80) may be disposed beyond the distal tip (16). The distal spline portions (66) may be securably and non-slidingly disposed within said distal tip (16). The distal spline portions (66) may be securably and non-slidingly disposed within said distal tip (16) in a predetermined angular relationship, wherein angles (θ1-θ8) between said splines (14) at said distal tip (16) forming said predetermined angular relationship may be all substantially equal to each other; or wherein at least one angle (θ1-θ8) between said splines (14) at said distal tip (16) forming said predetermined angular relationship may be different from another angle (θ1-θ8) between said splines (14) at said distal tip (16). The splines (14) have distal end portions (67); and further wherein the distal spline end portions (67) may be securably and non-slidingly disposed within said distal tip (16). The splines (14) may approach said distal tip (16) at an angle (α) of less than about 45° as measured from the line segment between said proximal anchor (18) and said distal tip (16) along the longitudinal axis (L). The splines (14) may have a distal incurvate inward bend (78) between said distal tip (16) and said distal excurvate outward bends (80). The distal tip (16) may have a non-thrombogenic outer surface free of voids and slots that would permit the passage or entry of blood thereinto. The splines (14) may have reduced widths at said distal portions (66) near the tip (16) as compared to spline widths at said medial portions (64).

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between; a proximal anchor (18) for securably affixing the proximal portions (62) of the splines (14); said anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16) for securably affixing the distal portions (66) of the splines (14), said proximal anchor (18) and said distal tip (16) defining a longitudinal axis (L) about which the splines (14) are disposed; wherein the splines (14) approach the distal tip (16) at an angle (α) of about 90° or less than about 90° as measured from a line segment between the proximal anchor (18) and the distal tip (16) along the longitudinal axis (L); wherein the splines (14) comprise a superelastic material such that the basket assembly (12) exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; and wherein each of the splines (14) in the radially expanded non-spherical shape contain a proximal recurve (76) in the proximate portion (62) of the spline (14) at a location near to the proximal anchor (18) of the basket assembly (12), the proximal recurve (76) comprises a proximal excurvate outward bend (84) and a proximal incurvate inward bend (82) between said proximal excurvate outward bend (84) and said proximal anchor (18), where an apex (83) of the proximal incurvate inward bend (82) is disposed in a direction toward the distal tip (16) and is further disposed inwardly closer toward the distal tip (16) than the proximal excurvate outward bend (84). The system (10) may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has said substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-spherical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). The splines (14) may approach said distal tip (16) at an angle (α) of less than about 45° as measured from the line segment between said proximal anchor (18) and said distal tip (16) along the longitudinal axis (L). The splines (14) in the radially expanded non-spherical shape may contain an distal excurvate outward bend (80) disposed at the distal portion (66) of the spline (14) at a location near to the distal tip (16) of the basket assembly (12) to bend the splines (14) back towards the proximal anchor (18); wherein the splines (14) may have an distal incurvate inward bend (78) between said distal tip (16) and said distal excurvate outward bends (80); and wherein, when basket assembly (12) is in said radially expanded non-spherical shape, the splines (14) may extend beyond the distal tip (16) and, when basket assembly (12) is in said radially expanded non-spherical shape, apices (81) of the distal excurvate bends (80) may be disposed beyond the distal tip (16). The distal tip (16) may have a non-thrombogenic outer surface free of voids and slots that would permit the passage or entry of blood thereinto. The splines (14) may have reduced widths at said distal portions near the distal tip (16) as compared to spline widths at said medial portions (64). Each of the splines (14) have a length between said apex (83) of said proximal incurvate inward bend (82) and said proximal excurvate outward bend (84); and further wherein said length of at least one spline (14) may be different from said length of another of said splines (14). Alternatively, each of the splines (14) may have a substantially equal overall length between said proximal anchor (18) and said distal tip (16). Alternatively, each of the splines (14) may have a substantially equal overall length from said proximal anchor (18) and to said distal tip (16); and further wherein a length from said proximal excurvate outward bend (84) to said distal tip (16) for at least one of said splines (14) may be different from said length for another one of said splines (14).

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62) and distal portions (66); a proximal anchor (18) for securably affixing the proximal portions (62) of the splines (14); said proximal anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16) for securably affixing the distal portions (66) of the splines (14), said proximal anchor (18) and said distal tip (16) defining a longitudinal axis (L) about which the splines (14) are disposed; wherein the splines (14) approach the distal tip (16) at an angle (α) of less than about 45° as measured from a line segment between the proximal anchor (18) and the distal tip (16) along the longitudinal axis (L); wherein the splines (14) comprise a superelastic material such that the basket assembly (12) exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; wherein the splines (14) in the radially expanded non-spherical shape contain an distal excurvate outward bend (80) disposed at the distal portion of the spline (14) at a location near to the distal tip (16) of the basket assembly (12) to bend the splines (14) back towards the proximal anchor (18); wherein the splines (14) have a distal incurvate inward bend (78) between said distal tip (16) and said distal excurvate outward bends (80); wherein, when basket assembly (12) is in said radially expanded non-spherical shape, the splines (14) extend beyond the distal tip (16) and, when basket assembly (12) is in said radially expanded non-spherical shape, apices (80) of the distal excurvate bends (80) are disposed beyond the distal tip (16); and wherein each of the splines (14) in the radially expanded non-spherical shape contain a proximal recurve (76) in the proximate portion (62) of the spline (14) at a location near to the proximal anchor (18) of the basket assembly (12), the proximal recurve (76) comprises a proximal excurvate outward bend (84) and a proximal incurvate inward bend (82) between said proximal excurvate outward bend (84) and said proximal anchor (18), where an apex (83) of the proximal incurvate inward bend (82) is disposed in a direction toward the distal tip (16) and is further disposed inwardly closer toward the distal tip (16) than the proximal excurvate outward bend (84). The system (10) may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has said substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-spherical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). The distal spline portions (66) may be securably and non-slidingly disposed within said distal tip (16). The splines (14) may have distal end portions (67); and further wherein the distal spline end portions (67) may be securably and non-slidingly disposed within said distal tip (16). Each of the splines (14) may have a substantially equal overall length from said proximal anchor (18) and to said distal tip (16); and further wherein a length from said proximal excurvate outward bend (84) to said distal tip (16) is for at least one of said splines (14) is different from said length for another one of said splines (14).

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: a first elongate tubular (20) member having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62) and distal portions (66); a proximal anchor (18) for securably affixing the proximal portions (62) of the splines (14); said proximal anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16) for securably affixing the distal portions (66) of the splines (14), said proximal anchor (18) and said tip (16) defining a longitudinal axis (L) about which the splines (14) are disposed; wherein the splines (14) comprise a superelastic material such that the basket assembly (12) exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; wherein each of the splines (14) in the radially expanded non-spherical shape contain a proximal recurve (76) in the proximate portion of the spline (14) at a location near to the anchor (18) of the basket assembly (12), the proximal recurve (76) comprises a proximal excurvate outward bend (84) and a proximal incurvate inward bend (82) between said proximal excurvate outward bend (84) and said proximal anchor (18), where an apex (83) of the proximal incurvate inward bend (82) is disposed in a direction toward the distal tip (16) and is further disposed inwardly closer toward the distal tip (16) than the proximal excurvate outward bend (84); and wherein the proximal incurvate inward bends (82) of some splines (14) have a different geometry from the proximal incurvate inward bends (82) of other splines (14); and wherein one or more tissue-contacting portions of the individual splines (14) are of unequal length with respect to each other, and each of the proximal incurvate inward bend portions (82) of the splines (14) possess compensating lengths such that the sum of the tissue facing portion plus proximal incurvate inward bend portion (82) of all splines (14) are substantially the same. The system (10) may further comprise: a second elongate tubular member (46) having a lumen (48), a proximal end (56) and a distal end (54); wherein the basket assembly (12) is slidingly compressible to fit within the lumen (48) of the second elongate tubular member (46); wherein the basket assembly (12) has said substantially cylindrical shape when compressed within the lumen (48) of the second elongate tubular member (46); and wherein the basket assembly (12) has said radially expanded non-spherical shape when not compressed within the lumen (48) of the second elongate tubular member (46) and disposed past the distal end (54) of the second elongate tubular member (46). The splines (14) may have distal end portions (67); and further wherein the distal spline end portions (67) may be securably and non-slidingly disposed within said distal tip (16). The splines (14) in the radially expanded non-spherical shape may contain an distal excurvate outward bend (80) disposed at the distal portion (66) of the spline (14) at a location near to the distal tip (16) of the basket assembly (12) to bend the splines (14) back towards the proximal anchor (18); wherein the splines (14) may have a distal incurvate inward bend (78) between said distal tip (16) and said distal excurvate outward bends (80); and wherein, when basket assembly (12) is in said radially expanded non-spherical shape, the splines (14) may extend beyond the distal tip (16) and, when basket assembly (12) is in said radially expanded non-spherical shape, apices (81) of the distal excurvate bends (80) are disposed beyond the distal tip (16).

Embodiments directed to spline assemblies for basket catheters include, but are not limited to, as follows:

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: an elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a plurality of flexible splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the splines (14) comprise an outer surface (190), an inner surface (192) and two side surfaces (194,196); an anchor (18) for securably affixing the proximal portions (62) of the splines (14), wherein the anchor (18) is securably affixed within the lumen (20C) of the elongate tubular member (20) at the distal end (20B) of the elongate tubular member (20); a tip (16) for securably affixing the distal portions (66) of the splines (14); and a polymeric member (185) comprising opposed a first open end (202) and a second open end (200) defining an open lumen (208) therein between and an inner member surface (208B) and an outer member surface (208A), wherein at least one of the plurality of flexible splines (14) is at least partially disposed within the lumen (208) of said polymeric member; a flexible electrode assembly strip (188) with one or more exposed electrodes (186) disposed on at least a portion of the outer surface (208A) of said polymeric member (185); wherein the flexible electrode assembly strip (188) comprises: a polymeric substrate (236) having an inner surface (236B) and an opposed outer surface (236A); said one or more exposed electrodes (186) disposed over at least part of the outer surface (236A) of the polymeric substrate (236); and one or more electrical traces (228) disposed over at least a portion of the inner surface (236B) of the polymeric substrate (236) or over at least a portion of the outer surface (236A) of the polymeric substrate (236), said one or more electrical traces (228) being in electrical communication with said one or more exposed electrodes (186); wherein a portion of the flexible electrode assembly (188) transitions from the outer surface (208A) of said polymeric member (185) towards the inner surface (208B) of said polymeric member (185) prior to said anchor (18); and wherein another portion of the flexible electrode assembly (188) extends through at least a portion of said anchor (18) and into said lumen (20C) of said elongate tubular member (20). The system (10) may further comprise: a plurality of polymeric members (185) each comprising said flexible electrode assembly strip (188); wherein each of said plurality of flexible splines (14) are at least partially disposed within a different one of said plurality of polymeric members (185). The one or more electrical traces (228) may be disposed over at least a portion of the inner surface (236B) of the polymeric substrate (236) and may further comprise vias (230) to provide said electrical communication between said one or more electrical traces (228) and said one or more exposed electrodes (186). The one or more electrical traces (228) may be disposed over at least a portion of the outer surface (236A) of the polymeric substrate (236) and further comprising a polymeric covering (238,240) over the outer surface (236A) of the polymeric substrate (236) and said electrical traces (228) with the one or more exposed electrodes (186) being substantially free of the polymeric covering (238,240). The first opposed open end (202) of the polymeric member (185) may be secured to the distal spline portion (66) of said at least one of the plurality of flexible splines (14) at a position near to the distal tip (16) and the second opposed open end (200) of the polymeric member (185) may be secured to the proximal spline portion (62) of said at least one of the plurality of flexible splines (14) at a position near to the anchor (18). The first opposed open end (202) of the polymeric member (185) may be sealingly secured to the distal spline portion (66) at the position near to the distal tip (16) by a seal (206). Medial portions of the polymeric member (185) between said first opposed open end (202) and said second opposed open end (200) of the polymeric member (185) may not be secured to said medial portions (64) of said at least one of the plurality of flexible splines (14). At least one intermediate medial portion of the polymeric member (185) between said first opposed open end (202) and said second opposed open end (200) of the polymeric member (185) may be secured to at least one intermediate portion of said medial portions (64) of said at least one of the plurality of flexible splines (14). The one or more exposed electrodes (186) may comprise copper, gold, platinum, platinum black, platinum-iridium and combinations thereof. The the outer surface (190) and the inner surface (192) of said plurality of flexible splines (14) may be substantially flat surfaces and the two side surfaces (194,196) of said plurality of flexible splines (14) may be convexly rounded surfaces. The one or more exposed electrodes (186) may have a substantially flat upper surface.

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: an elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a plurality of flexible splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the splines (14) comprise an outer surface (190), an inner surface (192) and two side surfaces (194.196); an anchor (18) for securably affixing the proximal portions (62) of the splines (14), wherein the anchor (18) is securably affixed within the lumen (20C) of the elongate tubular member (20) at the distal end (20B) of the elongate tubular member (20); a tip (16) for securably affixing the distal portions (66) of the splines (14); and a polymeric member (185) comprising opposed first (202) and second (200) open ends defining an open lumen (208) therein between and an inner member surface (208B) and an outer member surface (208A), wherein at least one of the plurality of flexible splines (14) is at least partially disposed within the lumen (208) of said polymeric member (185); a flexible electrode assembly strip (188) with one or more exposed electrodes (186) disposed on at least a portion of the outer surface (208A) of said polymeric member (185); wherein the flexible electrode assembly strip (188) comprises: a polymeric substrate (236) having an inner surface (236B) and an opposed outer surface (236A); said one or more exposed electrodes (186) disposed over at least part of the outer surface (236A) of the polymeric substrate (236); and one or more electrical traces (228) disposed over at least a portion of the inner surface (236B) of the polymeric substrate (236) or over at least a portion of the outer surface (236A) of the polymeric substrate (236), said one or more electrical traces (228) being in electrical communication with said one or more exposed electrodes (186); wherein the first opposed open end (202) of the polymeric member (185) is secured to the distal spline portion (66) of said at least one of the plurality of flexible splines (14) at a position near to the distal tip (16) and the second opposed open end (200) of the polymeric member (185) is secured to the proximal spline portion (62) of said at least one of the plurality of flexible splines (14) at a position near to the anchor (18); and wherein medial portions of the polymeric member (185) between said first opposed open end (202) and said second opposed open end (200) of the polymeric member (185) are not secured to said medial portions (64) of said at least one of the plurality of flexible splines (14). The system (10) may further comprise a seal (206) for sealingly engaging said first opposed open end (202) of the polymeric member (185) and said distal spline portion (66). A portion of the flexible electrode assembly (188) may extend through at least a portion of said anchor (18) and into said lumen (20C) of said elongate tubular member (20). The system (10) may further comprise: a plurality of polymeric members (185) each comprising said flexible electrode assembly strip (188); wherein each of said plurality of flexible splines (14) may be at least partially disposed within a different one of said plurality of polymeric members (185). The one or more electrical traces (228) may be disposed over at least a portion of the inner surface (236B) of the polymeric substrate (236) and may further comprise vias (230) to provide said electrical communication between said one or more electrical traces (228) and said one or more exposed electrodes (186). The one or more electrical traces (228) may be disposed over at least a portion of the outer surface (236A) of the polymeric substrate (236) and may further comprise a polymeric covering (238,240) over the outer surface (236A) of the polymeric substrate (236) and said electrical traces (228) with the one or more exposed electrodes (186) being substantially free of the polymeric covering (238,240). The one or more exposed electrodes (186) may comprise copper, gold, platinum, platinum black, platinum-iridium and combinations thereof. The outer surface (190) and the inner surface (192) of said plurality of flexible splines (14) may be substantially flat surfaces and the two side surfaces (194,196) of said plurality of flexible splines (14) may be convexly rounded surfaces. The one or more exposed electrodes (186) have a substantially flat upper surface.

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: an elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a plurality of flexible splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the splines (14) comprise an outer surface (190), an inner surface (192) and two side surfaces (194,196), wherein said inner and outer spline surfaces (190,192) have a substantially flat portion with the substantially flat portions being parallel to one and the other, and further wherein the two side spline surfaces (194,196) are convexly rounded to define a rounded-rectangular shape; an anchor (18) for securably affixing the proximal portions (62) of the splines (14), wherein the anchor (18) is securably affixed within the lumen (20C) of the elongate tubular member (20) at the distal end (20B) of the elongate tubular member (20); a tip (16) for securably affixing the distal portions (66) of the splines (14); and a plurality of polymeric members (185) each having opposed first (202) and second (200) open ends defining an open lumen (208) therein between, wherein the polymeric members (185) comprise an outer surface (208A), an inner surface (208B) and two side surfaces where a cross-sectional profile of the polymeric members is elliptical to match a cross-sectional profile of the rounded-rectangular shape of the splines (14) and is slightly larger than the cross-sectional profile of the rounded-rectangular shape of the splines (14) and wherein each of the plurality of flexible splines (14) is at least partially disposed within the lumen (208) of a different one of said plurality of polymeric members (185); a flexible electrode assembly strip (188) with one or more exposed electrodes (186) disposed on at least a portion of the outer surface (208A) of said polymeric members (185); wherein the flexible electrode assembly strip (188) comprises: a polymeric substrate (236) having an inner surface (236B) and an opposed outer (236A) surface; said one or more exposed electrodes (186) disposed over at least part of the outer surface (236A) of the polymeric substrate (236); and one or more electrical traces (228) disposed over at least a portion of the inner surface (236B) of the polymeric substrate (236) or over at least a portion of the outer surface (236A) of the polymeric substrate (236), said one or more electrical traces (228) being in electrical communication with said one or more exposed electrodes (186); wherein a portion of said e flexible electrode assembly strip (188) extends through at least a portion of said anchor (18) and into said lumen (20C) of said elongate tubular member (20). The one or more electrical traces (228) may be disposed over at least a portion of the inner surface (236B) of the polymeric substrate (236) and may further comprise vias (230) to provide said electrical communication between said one or more electrical traces (228) and said one or more exposed electrodes (186). The one or more electrical traces (228) may be disposed over at least a portion of the outer surface (236A) of the polymeric substrate (236) and may further comprise a polymeric covering (238,240) over the outer surface (236A) of the polymeric substrate (236) and said electrical traces (228) with the one or more exposed electrodes (186) being substantially free of the polymeric covering (238,240). The first opposed open end (202) of the polymeric member (185) may be sealingly secured to the distal spline portion (66) of said at least one of the plurality of flexible splines (14) at a position near to the distal tip (16) and the second opposed open end (200) of the polymeric member (185) may be secured to the proximal spline portion (62) of said at least one of the plurality of flexible splines (14) at a position near to the anchor (18). Medial portions of the polymeric member between said first opposed open end (202) and said second opposed open end (200) of the polymeric member (185) may not be secured to said medial portions (64) of said at least one of the plurality of flexible splines (14). At least one intermediate medial portion of the polymeric member (185) between said first opposed open end (202) and said second opposed open end (200) of the polymeric member (185) may be secured to at least one intermediate portion of said medial portions (64) of said at least one of the plurality of flexible splines (14). The one or more exposed electrodes (186) may comprise copper, gold, platinum, platinum black, platinum-iridium and combinations thereof. The one or more exposed electrodes (186) may have a substantially flat upper surface.

A system (10) for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: an elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a plurality of flexible splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the splines (14) comprise an outer surface (190), an inner surface (192) and two side surfaces (194,196); an anchor (18) for securably affixing the proximal portions (62) of the splines (14), wherein the anchor (18) is securably affixed within the lumen (20C) of the elongate tubular member (20) at the distal end (20B) of the elongate tubular member (20); a tip (16) for securably affixing the distal portions (66) of the splines (14); and a plurality of polymeric members (185) each having opposed first (202) and second (200) open ends defining an open lumen (208) therein between and an outer surface (208A) and an inner surface (208B), wherein each of the plurality of flexible splines (14) is at least partially disposed within the lumen (208) of a different one of said plurality of polymeric members (185); a flexible electrode assembly strip (188) with one or more exposed electrodes (186) disposed on at least a portion of the outer surface (208A) of said polymeric members (185); wherein the flexible electrode assembly strip (188) comprises: a polymeric substrate (236) having an inner surface (236B) and an opposed outer surface (236A); said one or more exposed electrodes (186) disposed over at least part of the outer surface (236A) of the polymeric substrate (236); and one or more electrical traces (228) disposed over at least a portion of the inner surface (236B) of the polymeric substrate (236) or over at least a portion of the outer surface (236A) of the polymeric substrate (236), said one or more electrical traces (228) being in electrical communication with said one or more exposed electrodes (186); wherein the flexible electrode assembly strip (188) is compressed into the outer surface (208A) of the polymeric member (185); and wherein the flexible electrode assembly strip (188) is thermally or adhesively bonded to the outer surface (208A) of the polymeric member (185).

Embodiments directed to flex circuits and flexible electrode assemblies include, but are not limited to, as follows:

A device for insertion into a body lumen, may comprise: an electrode assembly strip (188) with exposed electrodes (186) comprising: a polymeric substrate (236) having an upper surface (236A) and an opposed lower surface (236B); one or more electrodes (186) disposed over a portion of the upper surface (236A) of the polymeric substrate (236); one or more electrical traces (228) disposed over a portion of the lower surface (236B) of the polymeric substrate (236) in electrical communication with the one or more electrodes (186) by way of metal plated holes (230) through the substrate (236); and a flexible polymeric substrate (246) having a substrate surface (246A) and a substrate wall (246C); wherein the electrode assembly strip (188) is compressingly and thermally bonded to the substrate surface (246A) of the flexible polymeric substrate (246) to define a flexible electrode assembly strip (247); and wherein the electrode assembly strip (188) has a thickness from about 0.0005 inches to about 0.008 inches. The electrode assembly strip (188) may have a thickness from about 0.002 inches to about 0.004 inches. The device may further comprise: a first polymeric covering (238) disposed portions of the substrate surface (236A) of the polymeric substrate (236) not having the one or more electrodes (186) thereon, said first polymeric covering (238) having holes disposed over the one or more electrodes (186) thereby defining one or more exposed electrodes (186); and a second polymeric covering (240) disposed over the one or more electrical traces (228) and portions of the lower surface (236B) of the substrate (236) not having the one or more electrical traces (228) thereon. The polymeric substrate (236), the first polymeric covering (238) and the second polymeric covering (240) may comprise a biocompatible polyimide material. The flexible polymeric substrate (236) may comprise a biocompatible polyether block amide material. The flexible polymeric substrate (236) may comprise a biocompatible polymer selected from the group consisting of polyesters, silicones, silicone rubbers, urethanes and combinations thereof. The flexible polymeric substrate (236) may be a sheet. Alternatively, the flexible polymeric substrate (236) may be an extruded tube having an open lumen.

A device for insertion into a body lumen, may comprise: an electrode assembly strip (188) with exposed electrodes (186) comprising: a polymeric substrate (236) having an upper surface (236A) and an opposed lower surface (236B); at least two electrodes (186) disposed over a portion of the upper surface (236A) of the polymeric substrate (236); at least two electrical traces (228) disposed over a portion of the lower surface (236B) of the polymeric substrate (236) in electrical communication with the at least two electrodes by way of metal plated holes (230) through the substrate (236); a first polymeric covering (238) disposed portions of the upper surface (236A) of the polymeric substrate (236) not having the at least two of said electrodes (186) thereon, said first polymeric covering (238) having holes disposed over the at least two of said electrodes (186) thereby defining at least two exposed electrodes (186); a second polymeric covering (240) disposed over the at least two of the electrical traces (228) and portions of the lower surface of the substrate not having the at least two electrical traces (228) thereon; a first flexible polymeric tube (185) having opposed open ends (200,202) defining an open lumen (208) therein between and an inner tubular surface (208B) and an outer tubular surface (208A); wherein the electrode assembly strip (188) is disposed over the outer surface (208A) of the first flexible polymeric tube (185); and a second flexible polymeric tube (185) having opposed open ends (200,202) defining an open lumen (208) therein between and an inner tubular surface (208B) and an outer tubular surface (208A), wherein the second flexible polymeric tube (185) is disposed over portions of the electrode assembly strip (188) not having the exposed electrodes (186); wherein the electrode assembly strip (188), the first flexible polymeric tube (185) and the second flexible polymeric tube (185) are compressingly and thermally bonded to each other to define a flexible electrode assembly strip (247); and wherein the electrode assembly strip (188) has a thickness from about 0.0005 inches to about 0.008 inches. The polymeric substrate (236), the first polymeric covering (238) and the second polymeric covering (240) may comprise a biocompatible polyimide material. The first and second flexible polymeric tubes (185) may comprise a polyether block amide material. The first flexible polymeric tube (185) may be an extruded tube. The flexible electrode assembly strip (247) may have a substantially smooth and atraumatic overall outer surface (246A). The device may further comprise: an elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a plurality of flexible splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the splines (14) comprise an outer surface (190), an inner surface (192) and two side surfaces (194,196); an anchor (18) for securably affixing the proximal portions (62) of the splines (14), wherein the anchor (18) is securably affixed within the lumen (20C) of the elongate tubular member (20) at the distal end (20B) of the elongate tubular member (20); and a tip (16) for securably affixing the distal portions (66) of the splines (14); wherein the flexible electrode assembly strip (247) is disposed over at least one of the plurality of splines (14). The device may further comprise a plurality of flexible electrode assembly strips (247), wherein each of said plurality of splines (14) has at least one of said plurality of flexible electrode assembly strips (247) disposed there over.

A device for insertion into a body lumen, may comprise: an electrode assembly strip (188) with exposed electrodes (186) comprising: a polymeric substrate (236) having an upper surface (236A) and an opposed lower surface (236B); one or more of substantially flat electrodes (186) disposed over a portion of the upper surface (236A) of the polymeric substrate (236); one or more of electrical traces (228) disposed over a portion of the lower surface (236B) of the polymeric substrate (236) in electrical communication with the one or more electrodes (186) by way of metal plated holes (230) through the substrate (236); a first polymeric covering (238) disposed portions of the upper surface (236A) of the polymeric substrate (236) not having the one or more of the electrodes (186) thereon, said first polymeric covering (238) having holes disposed over the one or more electrodes (186) thereby defining one or more exposed electrodes (186); a second polymeric covering (240) disposed over the over the one or more electrical traces (228) and portions of the lower surface (236B) of the substrate (236) not having the one or more electrical traces (228) thereon; and a flexible polymeric tube (185) having opposed open ends (200,202) defining an open lumen (208) therein between and an inner tubular surface (208B) and an outer tubular surface (208A) defining a tubular wall (210) therein between; wherein the electrode assembly strip (188) is compressingly and thermally bonded to the outer surface (208A) of the flexible polymeric tube (185) to define a flexible electrode assembly strip (247); wherein substantial portions of the substantially flat electrodes (186) remain substantially flat to provide substantially flat exposed electrodes (186); and wherein the electrode assembly strip (188) has a thickness from 0.0005 inches to about 0.008 inches. The polymeric substrate (236) may comprise a polyimide material. The first polymeric covering (238) and the second polymeric covering (240) may comprise a polyimide material. The flexible polymeric tube (185) may comprise a polyether block amide material. The flexible polymeric tube (185) may be an extruded tube. The electrode assembly strip (188) may be compressed into the tubular wall (210) of the flexible polymeric tube (185) to provide a substantially smooth and atraumatic overall outer surface for the flexible electrode assembly strip. The device may further comprise: an elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); one or more flexible splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the one or more splines (14) comprise an outer surface (190), an inner surface (192) and two side surfaces (194,196); an anchor (18) for securably affixing the proximal portions (62) of the one or more splines (14), wherein the anchor (18) is securably affixed within the lumen (20C) of the elongate tubular member (20) at the distal end (20B) of the elongate tubular member (20); and a tip (16) for securably affixing the distal portions (66) of the one or more splines (14); wherein the flexible electrode assembly strip (247) is disposed over at least one of the one or more splines (14). The device may further comprise one or more of flexible electrode assembly strips (247), wherein each of said one or more of the splines (14) may have at least one of said one or more of the flexible electrode assembly strips (247) disposed there over.

A device for insertion into a body lumen, may comprise an electrode assembly strip (188) with exposed electrodes (186) comprising: a polymeric substrate (236) having an upper surface (236A) and an opposed lower surface (236B); at least two substantially flat electrodes (186) disposed over a portion of the upper surface (236A) of the polymeric substrate (236); at least two electrical traces (228) disposed over a portion of the lower surface (236B) of the polymeric substrate (236) in electrical communication with the at least two electrodes (186) by way of metal plated holes (230) through the substrate (236); a first polymeric covering (238) disposed portions of the upper surface (236A) of the polymeric substrate (236) not having the at least two of said electrodes (186) thereon, said first polymeric covering (238) having holes disposed over the at least two of said electrodes (186) thereby defining at least two exposed electrodes (186); a second polymeric covering (240) disposed over the over the plurality of electrical traces (228) and portions of the lower surface (236B) of the substrate (236) not having electrical traces (228) thereon; a first flexible polymeric tube (185) having opposed open ends (200,202) defining an open lumen (208) therein between and an inner tubular surface (208B) and an outer tubular surface (208A); wherein the electrode assembly strip (188) is disposed over the outer surface (208A) of the first flexible polymeric tube (185); and a second flexible polymeric tube (185) having opposed open ends (200,202) defining an open lumen (208) therein between and an inner tubular surface (208B) and an outer tubular surface (208A), wherein the second flexible polymeric tube (185) is disposes over portions of the electrode assembly strip (188) not having the exposed electrodes (186), wherein the electrode assembly strip (186), the first flexible polymeric tube (185) and the second flexible polymeric tube (185) are compressingly and thermally bonded to each other to define a flexible electrode assembly strip (247); wherein substantial portions of the at least two substantially flat electrodes (186) remain substantially flat to provide at least two substantially flat exposed electrodes (186); and wherein the electrode assembly strip (188) has a thickness from about 0.0005 inches to about 0.008 inches. The polymeric substrate (236) may comprise a polyimide material. The first polymeric covering (238) and the second polymeric covering (240) may comprise a polyimide material. The first and second flexible polymeric tubes (185) may comprise a polyether block amide material. The first flexible polymeric tube (185) may be an extruded tube. The flexible electrode assembly strip (247) may have a substantially smooth and atraumatic overall outer surface. The device may further comprise: an elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); one or more flexible splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the splines (14) comprise an outer surface (190), an inner surface (192) and two side surfaces (194,196); an anchor (18) for securably affixing the proximal portions (62) of the splines (14), wherein the anchor (18) is securably affixed within the lumen (20C) of the elongate tubular member (20) at the distal end (20B) of the elongate tubular member (20); and a tip (16) for securably affixing the distal portions (66) of the one or more splines (14); wherein the flexible electrode assembly strip (247) is disposed over at least one of the one or more of the splines (14).

Embodiments directed to methods for sensing multiple local electric voltages from endocardial surface of a heart include, but are not limited to, as follows:

A method for sensing multiple local electric voltages from endocardial surface of a heart, may comprise: providing a system (10) for sensing multiple local electric voltages from endocardial surface of a heart, comprising: a first elongate tubular member (20) having a lumen (20C), a proximal end (20A) and a distal end (20B); a basket assembly (12) comprising: a plurality of flexible splines (14) for guiding a plurality of exposed electrodes (186), the splines (14) having proximal portions (62), distal portions (66) and medial portions (64) therein between, wherein the electrodes (186) are substantially flat electrodes and are substantially unidirectionally oriented towards a direction outside of the basket assembly (12); a proximal anchor (18) for securably affixing the proximal portions (62) of the splines (14); said anchor (18) being secured at the distal end (20B) of the first elongate tubular member (20); a distal tip (16) for securably affixing the distal portions (66) of the splines (14), said proximal anchor (18) and said distal tip (16) defining a longitudinal axis (L) about which the splines (14) are disposed; wherein the splines (14) approach the distal tip (16) at an angle (α) of about 90° or less than about 90° as measured from a line segment between the proximal anchor (18) and the distal tip (16) along the longitudinal axis (L); wherein the splines (14) comprise a superelastic material such that the basket assembly (12) exhibits a substantially cylindrical shape when radially compressed and exhibits a radially expanded non-spherical shape when not radially compressed; and wherein each of the splines (14) in the radially expanded non-spherical shape contain a proximal recurve (76) in the proximate portion (62) of the spline (14) at a location near to the proximal anchor (18) of the basket assembly (12), the proximal recurve (76) comprises a proximal excurvate outward bend (84) and a proximal incurvate inward bend (82) between said proximal excurvate outward bend (84) and said proximal anchor (18), where an apex (83) of the proximal incurvate inward bend (82) is disposed in a direction toward the distal tip (16) and is further disposed inwardly closer toward the distal tip (16) than the proximal excurvate outward bend (84); delivering the system (10) to the heart so that the basket assembly (12) is disposed within the right atrium of the heart; contacting proximal atrial tissue with the electrodes (186) disposed on the proximal spline portions (62) to detect multiple local electric voltages from endocardial surface thereat; and contacting atrial tissue with the electrodes (186) disposed on the medial spline portions (64) and the distal spline portions (66) to detect multiple local electric voltages from endocardial surface thereat. The splines (14) of the basket assembly (12) may be flexible to match the contours of the right atrium. Substantially all of the electrodes (186) may contact atrial tissue. Substantially all of the electrodes (186) may remain substantially spatially fixed with respect to atrial tissue. A substantial portion of atrial signals detected by the system (10) may have larger amplitudes than ventricular signals detected by the system (10). The splines (14) in the radially expanded non-spherical shape may contain an distal excurvate outward bend (80) disposed at the distal portion (66) of the spline (14) at a location near to the distal tip (16) of the basket assembly (12) to bend the splines (14) back towards the proximal anchor (18); and wherein the splines (14) have an distal incurvate inward bend (78) between said distal tip (16) and said distal excurvate outward bends (80). The splines (14) of the basket assembly (12) may be flexible to match the contours of the right atrium

While various embodiments of the present invention are specifically illustrated and/or described herein, it will be appreciated that modifications and variations of the present invention may be effected by those skilled in the art without departing from the spirit and intended scope of the invention. Further, any of the embodiments or aspects of the invention as described in the claims or in the specification may be used with one and another without limitation.