Patent Publication Number: US-2019183372-A1

Title: Multiple Configuration Electrophysiological Mapping Catheter, and Systems, Devices, Components and Methods Associated Therewith

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of, and claims priority and other benefits from, the following U.S. patent applications: (a) U.S. patent application Ser. No. 15/258,410 filed on Sep. 7, 2016 entitled “Systems, Devices, Components and Methods for Detecting the Locations of Sources of Cardiac Rhythm Disorders in a Patient&#39;s Heart” to Ruppersberg (the ‘410 patent application”); (b) U.S. patent application Ser. No. 15/577,924 filed on Nov. 29, 2017 entitled “Optical Force Sensing Assembly for an Elongated Medical Device” to Ruppersberg (the ‘924 patent application”); and (c) U.S. patent application Ser. No. 15/793,594 filed on Oct. 25, 2017 entitled “Improved Electrophysiological Mapping Catheter” to Ruppersberg (the ‘594 patent application”). The respective entireties of the &#39;410, &#39;924, and &#39;594 patent applications are hereby incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     Various embodiments described and disclosed herein relate to the field of medicine generally, and more particularly to diagnosing and treating cardiac rhythm disorders in a patient&#39;s heart using electrophysiological (EP) mapping systems, EP mapping devices such as ablation catheters and EP mapping catheters, and EP mapping components and techniques, procedures and methods. 
     BACKGROUND 
     Atrial fibrillation (or AF) is the most common type of heart arrhythmia or cardiac rhythm disorder. In atrial fibrillation, normal beating in the atria of the heart is irregular, and blood flow from the atria to the ventricles is compromised. Millions of people in the United States have AF. With the aging of the U.S. population, even more people will develop AF. Approximately 2% of people younger than age 65 have AF, while about 9% of people aged 65 years or older have AF. In some cases AF is treated with drugs. In other cases, external electrical shocks (electrical cardioversion) are delivered to the patient&#39;s heart. Open heart surgery can also be performed on a patient to treat AF. 
     Persistent atrial fibrillation (AF) is often caused by structural changes in atrial tissue, which can manifest themselves as multiwavelet re-entry and/or stable rotor mechanisms (see, e.g., De Groot M S et al., “Electropathological Substrate of Longstanding Persistent Atrial Fibrillation in Patients with Structural Heart Disease Epicardial Breakthrough,” Circulation, 2010, 3: 1674-1682). Radio frequency (RF) ablation targeting such host drivers of AF is generally accepted as one of the best therapeutic approaches to treating AF. RF ablation success rates in treating AF cases are currently limited, however, by a lack of sufficiently accurate and cost-effective diagnostic tools that are capable of quickly, cost-effectively, and precisely determining the source (or type), and location, of such AF drivers. Better diagnostic tools would help reduce the frequency and extent of cardiac ablation procedures to the minimum amount required to treat AF, and would help balance the benefits of decreased fibrillatory burden against the morbidity of increased lesion load. 
     What is needed are medical systems, devices, components and methods that can be employed to more quickly, efficiently, cost-effectively, and accurately diagnose and treat patients who have AF using intravascular techniques, where cardiac or pulmonary vein tissue is likely to be ablated, and where accurate and enhanced EP mapping of the heart can be carried out. What is also needed are improved means and methods of acquiring intracardiac electrogram signals that quickly, reliably and accurately yield the precise locations and sources of cardiac rhythm disorders in a patient&#39;s heart. Doing so would enable cardiac ablation procedures to be carried out with greater speed, greater locational precision, lower risk to the patient, reduced cost, and higher rates of success in treating cardiac rhythm disorders such as AF. 
     SUMMARY 
     In one embodiment, there is provided a multiple configuration electrophysiological (EP) mapping catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable multiple configuration electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into any two or more of the following configurations: (a) a first initial deployment configuration suitable for pulmonary vein isolation (PV) EP mapping; (b) a second intermediate deployment fan or paddle configuration suitable for high-resolution EP mapping; and (c) a third fully or nearly fully deployed basket configuration suitable for medium-resolution EP mapping, the basket configuration having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein: (i) in the first configuration the electrode mapping assembly is deployed by the user a first distance from the distal portion of the catheter body; (ii) in the second configuration the electrode mapping assembly is deployed by the user a second distance from the distal portion of the catheter body; and (iii) in the third configuration the electrode mapping assembly is deployed by the user a third distance from the distal portion of the catheter body, and further wherein the first distance is less than the second distance, the second distance is less than the third distance, an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening. 
     In another embodiment, there is provided a method of deploying a multiple configuration EP mapping catheter in a patient, the catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable multiple configuration electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into any two or more of the following configurations: (a) a first initial deployment configuration suitable for pulmonary vein isolation (PV) EP mapping; (b) a second intermediate deployment fan or paddle configuration suitable for high-resolution EP mapping; and (c) a third fully or nearly fully deployed basket configuration suitable for medium-resolution EP mapping, the basket configuration having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein: (i) in the first configuration the electrode mapping assembly is deployed by the user a first distance from the distal portion of the catheter body; (ii) in the second configuration the electrode mapping assembly is deployed by the user a second distance from the distal portion of the catheter body; and (iii) in the third configuration the electrode mapping assembly is deployed by the user a third distance from the distal portion of the catheter body, and further wherein the first distance is less than the second distance, the second distance is less than the third distance, an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening, the method comprising two or more of: (1) deploying the electrode mapping assembly into the first configuration inside or near the patient&#39;s heart; (2) deploying the electrode mapping assembly into the second configuration inside or near the patient&#39;s heart, and (3) deploying the electrode mapping assembly into the third configuration inside or near the patient&#39;s heart. 
     In yet another embodiment, there is provided an EP mapping basket catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into a basket configuration, the basket configuration having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening. 
     In still another embodiment, there is provided a method of deploying an EP mapping basket catheter in a patient, the catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into a basket configuration, the basket configuration having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening, the method comprising deploying the electrode mapping assembly into the basket configuration inside or near the patient&#39;s heart. 
     In another embodiment, there is provided a multiple configuration EP mapping catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable multiple configuration electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into the following configurations: (a) a first circular, semi-circular, oval, elliptical, or lasso-like configuration suitable for pulmonary vein isolation (PV) EP mapping; and (b) a second basket configuration, the basket having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein: (i) in the first configuration the electrode mapping assembly is deployed by the user a first distance from the distal portion of the catheter body, and (ii) in the second configuration the electrode mapping assembly is deployed by the user a second distance from the distal portion of the catheter body; and further wherein the first distance is less than the second distance, an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening. 
     In yet another embodiment, there is provided a method of deploying a multiple configuration EP mapping catheter in a patient, the catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable multiple configuration electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into the following configurations: (a) a first circular, semi-circular, oval, elliptical, or lasso-like configuration suitable for pulmonary vein isolation (PV) EP mapping; and (b) a second basket configuration, the basket having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein: (i) in the first configuration the electrode mapping assembly is deployed by the user a first distance from the distal portion of the catheter body, and (ii) in the second configuration the electrode mapping assembly is deployed by the user a second distance from the distal portion of the catheter body; and further wherein the first distance is less than the second distance, an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening, the method comprising at least one of (1) deploying the electrode mapping assembly into the first configuration inside or near the patient&#39;s heart, and (2) deploying the electrode mapping assembly into the second configuration inside or near the patient&#39;s heart. 
     In still another embodiment, there is provided a multiple spatial resolution EP mapping catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable multiple configuration electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into any two or more of the following configurations: (a) a first fan-shaped configuration of the mapping electrode assembly wherein electrodes mounted on or attached to central portions of adjoining spines are separated from one another by distances ranging between about 0.25 cm and about 2 cm such that the EP mapping electrode assembly is configured to provide high spatial resolution EP data; and (b) a second basket configuration of the mapping electrode assembly wherein electrodes mounted on or attached to central portions of adjoining spines are separated from one another by distances ranging between about 1 cm and about 4 cm such that the EP mapping electrode assembly is configured to provide medium spatial resolution EP data, the basket configuration having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein: (i) in the first configuration the electrode mapping assembly is deployed by the user a first distance from the distal portion of the catheter body; (ii) in the second configuration the electrode mapping assembly is deployed by the user a second distance from the distal portion of the catheter body; and further wherein the first distance is less than the second distance, an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening. 
     In yet another embodiment, there is provided a method of deploying a multiple spatial resolution EP mapping catheter in a patient, the catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable multiple configuration electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of pairs of splines, each spline having a proximal end and a distal end, the splines of each pair being connected at their distal ends by connecting members to form distal arms, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, some but not all adjoining pairs of splines and the arms formed thereby being connected to one another by tendons or chords located at or near the distal ends thereof, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into any two or more of the following configurations: (a) a first fan-shaped configuration of the mapping electrode assembly wherein electrodes mounted on or attached to central portions of adjoining spines are separated from one another by distances ranging between about 0.25 cm and about 2 cm such that the EP mapping electrode assembly is configured to provide high spatial resolution EP data; and (b) a second basket configuration of the mapping electrode assembly wherein electrodes mounted on or attached to central portions of adjoining spines are separated from one another by distances ranging between about 1 cm and about 4 cm such that the EP mapping electrode assembly is configured to provide medium spatial resolution EP data, the basket configuration having an imaginary central longitudinal axis associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein: (i) in the first configuration the electrode mapping assembly is deployed by the user a first distance from the distal portion of the catheter body; (ii) in the second configuration the electrode mapping assembly is deployed by the user a second distance from the distal portion of the catheter body; and further wherein the first distance is less than the second distance, an opening is located between at least portions of two adjoining splines in the electrode mapping assembly, no chord or tendon is located within at least portions of the opening such that portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket in a direction of the opening, the method comprising at least one of (1) deploying the electrode mapping assembly into the first configuration inside or near the patient&#39;s heart, and (2) deploying the electrode mapping assembly into the second configuration inside or near the patient&#39;s heart. 
     In still yet another embodiment, there is provided an EP mapping catheter comprising an elongated catheter body comprising a proximal portion, a distal portion, and a distal tip, an electrode deployment and control mechanism located near or at the proximal portion of the catheter body, a deployable electrode mapping assembly operably connected to the electrode deployment and control mechanism, the electrode mapping assembly comprising a plurality of electrodes and a plurality of splines, each spline having a proximal end and a distal end, the electrodes being mounted on or connected to at least some of the splines, at least some of the splines comprising a shape memory material, at least the distal end of each spline being configured to bend or be bent backwardly from the distal tip towards more proximal portions of the catheter body as the plurality of splines is deployed from or near the distal tip, wherein at least major portions of the electrode mapping assembly are configured to fit within the distal portion of the catheter body when the electrode assembly is in an undeployed configuration, the electrode assembly further being configured to be controllably deployed and advanced from the distal tip of the catheter by a user operating the electrode deployment and control mechanism into at least one of the following configurations: (a) a first circular, semi-circular, oval, elliptical, or lasso-like configuration suitable for pulmonary vein isolation (PV) EP mapping; (b) a second fan-shaped configuration of the mapping electrode assembly suitable for acquiring high-resolution EP data; and (c) a third basket configuration suitable for acquiring medium-resolution EP data. In such an embodiment, an opening between splines may—or may not—be included or provided in the catheters described herein. Methods of deploying and using the catheter according to such embodiments are also contemplated, as are catheters capable of assuming only one of the aforementioned three configurations (e.g., circular, fan-shaped, and basket configurations). 
     In still further embodiments, any of the above- or below-described catheters and corresponding methods can be modified such that there is no opening located between adjoining splines where portions of the catheter body located proximally from the distal tip can be moved by a user away from the longitudinal axis of the basket through such an opening. 
     The foregoing embodiments may further comprise one or more of: the catheter being configured to permit portions of the catheter body located proximally from the distal tip to be moved by the user away from the longitudinal axis of the basket in the direction of and through the opening; the catheter being configured to permit portions of the catheter body located proximally from the distal tip to be moved by the user away from the longitudinal axis of the basket in the direction of and outside the opening; the distal tip of the catheter being configured to be steerable or bent by the user; an outer slidable sheath configured to permit deployment of the electrode mapping assembly from the distal tip of the catheter; an outer slidable sheath that is steerable; a steerable sheath comprising a steerable distal end; an electrode mapping assembly comprising between 4 splines and 12 splines; each spline having attached thereto, mounted thereon or formed therein between 1 and 16 electrodes; distal ends of adjoining splines forming pairs of splines that are joined or connected to one another; one or more navigation elements, navigation coils, navigation markers or navigation electrodes; a shape memory material comprising one or more of Nitinol, a shape memory metal, a shape memory alloy, a shape memory polymer, a shape memory composite, or a shape memory hybrid; at least one spline in the electrode mapping assembly comprising laminated materials; the mapping electrode assembly being deployed by pushing the mapping electrode assembly out of the distal end of the catheter using the electrode deployment and control mechanism; a tissue ablation mechanism located at or near the distal tip of the catheter; spatial resolution provided by the electrodes in the electrode mapping assembly and an associated spacing between splines changing in accordance with the first, second and third configurations thereof; a diameter of the arms of the electrode mapping assembly ranging between about 6 mm and about 14 mm when the electrode mapping assembly is deployed in the first configuration; a diameter of the arms of the electrode mapping assembly ranging between about 6 mm and about 14 mm when the electrode mapping assembly is deployed in the first configuration; a diameter of the arms of the electrode mapping assembly ranging between about 10 mm and about 20 mm when the electrode mapping assembly is deployed in the first configuration; a length of each tendon or chord ranging between about 6 mm and about 20 mm; the electrodes being one or more of unipolar electrodes and bipolar electrodes; spacing between adjoining electrodes located on the same spline ranging between about 0.5 mm and about 1 mm, between about 0.25 mm and about 2 mm, between about 6 mm and about 20 mm, between about 8 mm and about 18 mm, or between about 10 mm and about 15 mm; the third basket structure having an outer diameter ranging between about 20 mm and about 200 mm, between about 30 mm and about 100 mm in diameter, between about 40 mm and about 80 mm in diameter, or between about 50 mm and about 70 mm, or is about 50 mm, about 60 mm or about 70 mm. 
     The foregoing embodiments may further comprise one or more of: the distal tip of the catheter being configured to be steerable or bent by the user, and the user bends or steers the distal tip of the catheter inside or near the patient&#39;s heart; acquiring EP signals from the patient using electrodes in the deployed electrode mapping assembly; processing the acquired EP signals so that the signals may be interpreted by the user; redeploying the electrode mapping assembly into a different configuration or location within or near the patient&#39;s heart based upon results provided by the processed EP signals; changing the configuration of the electrode mapping assembly from one of the first, second and third configurations to a different configuration; deploying the mapping electrode assembly by pushing the mapping electrode assembly out of the distal end of the catheter using the electrode deployment and control mechanism; ablating tissue at a location in or near the patient&#39;s heart, the location being identified using the processed EP signals. 
     Further embodiments are disclosed herein or will become apparent to those skilled in the art after having read and understood the claims, specification and drawings hereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. 
       Different aspects of the various embodiments will become apparent from the following specification, drawings and claims in which: 
         FIG. 1( a )  shows one embodiment and example of a combined cardiac electrophysiological mapping (EP), pacing and ablation system  100 ; 
         FIG. 1( b )  shows one embodiment and example of computer system  300 ; 
         FIG. 2  illustrates some of the problems that can arise with conventional basket catheters, such as spline bunching and inadequate electrode coverage; 
         FIG. 3  shows an illustrative view of one embodiment of a distal portion of catheter  110  inside a patient&#39;s left atrium  14 ; 
         FIGS. 4( a ) through 4( d )  illustrate one embodiment of an EP mapping catheter  110 ; 
         FIGS. 5( a ) through 5( d )  illustrate another embodiment of an EP mapping catheter  110 ; 
         FIGS. 6( a ) and 6( b )  illustrate one embodiment of distal portion  108  of catheter  110  having mapping electrode assembly  120  initially deployed in a restricted or mushroom-shaped configuration, in two circular-shaped configurations and stages; 
         FIG. 7  illustrates one embodiment of distal portion  108  of catheter  110 , where mapping electrode assembly  120  has been deployed in an intermediate fan- or paddle-shaped configuration extending further outwardly and backwardly from distal tip  112  with respect to the deployments of mapping electrode assemblies  120  shown in  FIGS. 6( a ) and 6( b ) . 
         FIG. 8  illustrates one embodiment of mapping electrode assembly  120  of  FIGS. 6( a ), 6( b )  and  7  in a fully or nearly fully deployed basket configuration, where splines  126  have been pushed outwardly and backwardly fully from distal tip  112 ; 
         FIGS. 9 and 10  show front and side perspective views according to one embodiment of fully deployed mapping electrode assembly  120  of  FIG. 8 . 
         FIG. 11  shows one embodiment of distal portion  108  of catheter  110 , where mapping electrode assembly  120  is in a fully deployed configuration, and where splines  126  have been pushed outwardly and backwardly fully from distal tip  112 . 
         FIG. 12  illustrates one embodiment of mapping electrode assembly  120  fully deployed and electrically coupled to the walls of patient&#39;s left atrium  14 ; 
         FIG. 13  illustrates a conventional basket catheter mapping electrode assembly fully deployed inside a patient&#39;s atrium  14 , and 
         FIG. 14  illustrates one method  200  of using the configurable multi-application electrophysiological mapping catheter  110 . 
     
    
    
     The drawings are not necessarily to scale. Like numbers refer to like parts or steps throughout the drawings. 
     DETAILED DESCRIPTIONS OF SOME EMBODIMENTS 
     Disclosed herein are various embodiments of systems, devices, components and methods for diagnosing and treating cardiac rhythm disorders in a patient&#39;s heart using EP mapping and ablation catheters, as well as EP imaging, navigation, and other types of medical systems, devices, components, and methods. Various embodiments described and disclosed herein also relate to systems, devices, components and methods for discovering with enhanced precision the location(s) of the source(s) of different types of cardiac rhythm disorders and irregularities. Such cardiac rhythm disorders and irregularities, include, but are not limited to, arrhythmias, atrial fibrillation (AF or A-fib), atrial tachycardia, atrial flutter, paroxysmal fibrillation, paroxysmal flutter, persistent fibrillation, ventricular fibrillation (V-fib), ventricular tachycardia, atrial tachycardia (A-tach), ventricular tachycardia (V-tach), supraventricular tachycardia (SVT), paroxysmal supraventricular tachycardia (PSVT), Wolff-Parkinson-White syndrome, bradycardia, sinus bradycardia, ectopic atrial bradycardia, junctional bradycardia, heart blocks, atrioventricular block, idioventricular rhythm, areas of fibrosis, breakthrough points, focus points, re-entry points, premature atrial contractions (PACs), premature ventricular contractions (PVCs), and other types of cardiac rhythm disorders and irregularities. 
     Also described herein is an EP mapping catheter that is capable of assuming multiple configurations within or near a patient&#39;s heart. These multiple configurations permit a single catheter to electrographically image a patient&#39;s atrium and portions of the PV near the atrium at different resolutions, all using the same EP mapping catheter. Following initial EP mapping of a patient&#39;s atrium and/or PV with the EP mapping catheter, the same EP mapping catheter can be then used to detect PV isolation and extra PV sources following ablation, and can also be used to provide high resolution recordings from major portions of the atrium. In some embodiments, the EP mapping catheter includes or operates in conjunction with an ablation catheter. 
     In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of example embodiments or aspects. It will be evident, however, to those skilled in the art that an example embodiment may be practiced without necessarily using all of the disclosed specific details, and that other embodiments not specifically or wholly disclosed are also contemplated and fall within the scope of the various inventions. 
     Before discussing in detail some of the various embodiments of the unique configurable multi-application electrophysiological mapping catheter disclosed and described herein, several aspects of systems, devices, components and methods that may be employed in conjunction with catheters are first described and disclosed. 
     Referring now to  FIG. 1( a ) , there is illustrated one embodiment of a combined cardiac electrophysiological mapping (EP), pacing and ablation system  100 . Note that in some embodiments system  100  may not include ablation module  150  and/or pacing module  160 . Among other things, the embodiment of system  100  shown in  FIG. 1( a )  is configured to detect and reconstruct cardiac activation information acquired from a patient&#39;s heart relating to cardiac rhythm disorders and/or irregularities, and is further configured to detect and discover the location of the source of such cardiac rhythm disorders and/or irregularities with enhanced precision relative to prior art techniques and devices. In some embodiments, system  100  is further configured to treat the location of the source of the cardiac rhythm disorder or irregularity, for example by ablating the patient&#39;s heart at the detected location. 
     The embodiment of system  100  shown in  FIG. 1( a )  comprises five main functional units: electrophysiological mapping (EP mapping unit)  140  (which is also referred to herein as data acquisition device  140 ), ablation module  150 , pacing module  160 , imaging and/or navigation system  70 , and computer or computing device  300 . A data acquisition, processing and control system can be configured to comprise data acquisition device  140 , ablation module  150 , pacing module  160 , control interface  170  and computer or computing device  300 . In one embodiment, at least one computer or computing device or system  300  is employed to control the operation of one or more of systems, modules and devices  140 ,  150 ,  160 ,  170  and  70 . Alternatively, the respective operations of systems, modules or devices  140 ,  150 ,  160 ,  170  and  70  may be controlled separately by each of such systems, modules and devices, or by some combination of such systems, modules and devices. 
     Computer or computing device  300  may be configured to receive operator inputs from an input device  320  such as a keyboard, mouse and/or control panel. Outputs from computer  300  may be displayed on display or monitor  324  or other output devices (not shown in  FIG. 1( a ) ). Computer  300  may also be operably connected to a remote computer or analytic database or server  328 . At least each of components, devices, modules and systems  60 ,  110 ,  140 ,  146 ,  148 ,  150 ,  170 ,  300 ,  324  and  328  may be operably connected to other components or devices by wireless (e.g., Bluetooth) or wired means. Data may be transferred between components, devices, modules or systems through hardwiring, by wireless means, or by using portable memory devices such as USB memory sticks. 
     During electrophysiological (EP) mapping procedures, multi-electrode catheter  110  is typically introduced percutaneously into the patient&#39;s heart  10 . Catheter  110  is passed through a blood vessel (not shown), such as a femoral vein or the aorta, and thence into an endocardial site such as the atrium or ventricle of the heart  10 , or nearby pulmonary vein(s). 
     It is contemplated that other catheters, including other types of mapping or EP catheters, lasso catheters, pulmonary vein isolation (PVI) ablation catheters (which can operate in conjunction with lasso and other types of sensing catheters), ablation catheters, navigation catheters, and still other types of EP mapping catheters such as EP monitoring catheters and spiral catheters, may also be introduced into the heart, and that additional surface electrodes may be attached to the skin of the patient to record electrocardiograms (ECGs). 
     When system  100  is operating in an EP mapping mode, multi-electrode catheter  110  functions as a detector of intra-electrocardiac signals, while optional surface electrodes may serve as detectors of surface ECGs. In one embodiment, the analog signals obtained from the intracardiac and/or surface electrodes are routed by multiplexer  146  to data acquisition device  140 , which comprises an amplifier  142  and an A/D converter (ADC)  144 . The amplified or conditioned electrogram signals may be displayed by electrocardiogram (ECG) monitor  148 . The analog signals are also digitized via ADC  144  and input into computer  300  for data processing, analysis and graphical display. 
     In one embodiment, catheter  110  is configured to detect cardiac activation information in the patient&#39;s heart  10 , and to transmit the detected cardiac activation information to data acquisition device  140 , either via a wireless or wired connection. In one embodiment that is not intended to be limiting with respect to the number, arrangement, configuration, or types of electrodes, catheter  110  includes a plurality of 64 electrodes, probes and/or sensors A 1  through H 8  arranged in an 8×8 grid that are included in electrode mapping assembly  120 , which is configured for insertion into the patient&#39;s heart through the patient&#39;s blood vessels and/or veins. Other numbers, arrangements, configurations and types of electrodes in catheter  110  are, however, also contemplated, such as by way of non-limiting example, 8, 16, 24, 32, 48, 96 and/or 124 electrodes being included in electrode mapping assembly  120 . In many embodiments, at least some electrodes, probes and/or sensors included in catheter  110  are configured to detect cardiac activation or electrical signals, and to generate electrocardiograms or electrogram signals, which are then relayed by electrical conductors from or near the distal end of catheter  110  to proximal portion  116  of catheter  110  to data acquisition device  140 . 
     Note that in many embodiments of system  100 , multiplexer  146  acting as an arbiter between sub-systems or modules  60 ,  140 ,  150 ,  160 , and  300  is not employed for various reasons. In some embodiments of system  100 , separate sub-systems are provided for each of EP data acquisition device  140 , ablation module  150 , pacing module  160 , imaging and/or navigation system  60 , computer system  300 , and so on. The embodiment shown in  FIG. 1( a )  is can thus be viewed as an illustrative overview of how the various sub-systems may function and work together. Thus, and by way of non-limiting example, in some embodiments, multiplexer  146  is separate from catheter  110  and data acquisition device  140 . In other embodiments, multiplexer  146  is combined in catheter  110  or data acquisition device  140 . In still other embodiments, multiplexer  146  is not employed at all. 
     In one embodiment, a medical practitioner or health care professional employs catheter  110  as a roving catheter to locate the site of the location of the source of a cardiac rhythm disorder or irregularity in the endocardium quickly and accurately, without the need for open-chest and open-heart surgery. In one embodiment, this is accomplished by using multi-electrode catheter  110  in combination with real-time or near-real-time data processing and interactive display by computer  300 , and optionally in combination with imaging and/or navigation system  70 . In one embodiment, multi-electrode catheter  110  deploys at least a two-dimensional array of electrodes against a site of the endocardium at a location that is to be mapped, more about which is said below. The intracardiac or electrogram signals detected by the catheter&#39;s electrodes provide data sampling of the electrical activity in the local site spanned by the array of electrodes. 
     In one embodiment, the electrogram signal data are processed by computer  300  to produce a display showing the locations(s) of the source(s) of cardiac rhythm disorders and/or irregularities in the patient&#39;s heart  10  in real-time or near-real-time, further details of which are provided below. That is, at and between the sampled locations of the patient&#39;s endocardium, computer  300  may be configured to compute and display in real-time or near-real-time an estimated, detected and/or determined location(s) of the site(s), source(s) or origin)s) of the cardiac rhythm disorder(s) and/or irregularity(s) within the patient&#39;s heart  10 . This permits a medical practitioner to move interactively and quickly the electrodes of catheter  110  towards the location of the source of the cardiac rhythm disorder or irregularity. 
     In some embodiments of system  100 , one or more electrodes, sensors or probes detect cardiac activation from the surface of the patient&#39;s body as surface ECGs, or remotely without contacting the patient&#39;s body (e.g., using magnetocardiograms). In another example, some electrodes, sensors or probes may derive cardiac activation information from echocardiograms. In various embodiments of system  100 , external or surface electrodes, sensors and/or probes can be used separately or in different combinations, and further may also be used in combination with intracardiac electrodes, sensors and/or probes inserted within the patient&#39;s heart  10 . Many different permutations and combinations of the various components of system  100  are contemplated having, for example, reduced, additional or different numbers of electrical sensing and other types of electrodes, sensors and/or transducers. 
     Continuing to refer to  FIG. 1( a ) , in one embodiment EP mapping system or data acquisition device  140  is configured to condition the analog electrogram signals delivered by catheter  110  from electrodes A 1  through H 8  in amplifier  142 . Conditioning of the analog electrogram signals received by amplifier  142  may include, but is not limited to, low-pass filtering, high-pass filtering, bandpass filtering, and notch filtering. The conditioned analog signals are then digitized in analog-to-digital converter (ADC)  144 . ADC  144  may further include a digital signal processor (DSP) or other type of processor which is configure to further process the digitized electrogram signals (e.g., low-pass filter, high-pass filter, bandpass filter, notch filter, automatic gain control, amplitude adjustment or normalization, artifact removal, etc.) before they are transferred to computer or computing device  300  for further processing and analysis. 
     In some embodiments, the rate at which individual electrogram and/or ECG signals are sampled and acquired by system  100  can range between about 0.25 milliseconds and about 8 milliseconds, and may be about 0.5 milliseconds, about 1 millisecond, about 2 milliseconds or about 4 milliseconds. Other sample rates are also contemplated. While in some embodiments system  100  is configured to provide unipolar signals, in other embodiments system  100  is configured to provide bipolar signals. 
     In one embodiment, system  100  can include a BARD® LABSYSTEM™ PRO EP Recording System, which is a computer and software driven data acquisition and analysis tool designed to facilitate the gathering, display, analysis, pacing, mapping, and storage of intracardiac EP data. Also in one embodiment, data acquisition device  140  can include a BARD® CLEARSIGN™ amplifier, which is configured to amplify and condition electrocardiographic signals of biologic origin and pressure transducer input, and transmit such information to a host computer (e.g., computer  300  or another computer). 
     As shown in  FIG. 1( a ) , and as described above, in some embodiments system  100  includes ablation module  150 , which may be configured to deliver RF ablation energy through catheter  110  and corresponding ablation electrodes disposed near distal end  112  thereof, and/or to deliver RF ablation energy through a different catheter (not shown in  FIG. 1( a ) ). Suitable ablation systems and devices include, but are not limited to, cryogenic ablation devices and/or systems, radiofrequency ablation devices and/or systems, ultrasound ablation devices and/or systems, high-intensity focused ultrasound (HIFU) devices and/or systems, chemical ablation devices and/or systems, and laser ablation devices and/or systems. 
     When system  100  is operating in an ablation mode, multi-electrode catheter  110  fitted with ablation electrodes, or a separate ablation catheter, is energized by ablation module  150  under the control of computer  300 , control interface  170 , and/or another control device or module. For example, an operator may issue a command to ablation module  150  through input device  320  to computer  300 . In one embodiment, computer  300  or another device controls ablation module  150  through control interface  170 . Control of ablation module  150  can initiate the delivery of a programmed series of electrical energy pulses to the endocardium via catheter  110  (or a separate ablation catheter, not shown in  FIG. 1( a ) ). One embodiment of an ablation method and device is disclosed in U.S. Pat. No. 5,383,917 to Desai et al., the entirety of which is hereby incorporated by reference herein. 
     In an alternative embodiment, ablation module  150  is not controlled by computer  300 , and is operated manually directly under operator control. Similarly, pacing module  160  may also be operated manually directly under operator control. The connections of the various components of system  100  to catheter  110 , to auxiliary catheters, or to surface electrodes may also be switched manually or using multiplexer  146  or another device or module. 
     When system  100  is operating in an optional pacing mode, multi-electrode catheter  110  is energized by pacing module  160  operating under the control of computer  300  or another control device or module. For example, an operator may issue a command through input device  320  such that computer  300  controls pacing module  160  through control interface  170 , and multiplexer  146  initiates the delivery of a programmed series of electrical simulating pulses to the endocardium via the catheter  110  or another auxiliary catheter (not shown in  FIG. 1( a ) ). One embodiment of a pacing module is disclosed in M. E. Josephson et al., in “VENTRICULAR ENDOCARDIAL PACING II, The Role of Pace Mapping to Localize Origin of Ventricular Tachycardia,” The American Journal of Cardiology, vol. 50, November 1982. 
     Computing device or computer  300  is appropriately configured and programmed to receive or access the electrogram signals provided by data acquisition device  140 . Computer  300  is further configured to analyze or process such electrogram signals in accordance with the methods, functions and logic disclosed and described herein so as to permit reconstruction of cardiac activation information from the electrogram signals. This, in turn, makes it possible to locate with at least some reasonable degree of precision the location of the source of a heart rhythm disorder or irregularity. Once such a location has been discovered, the source may be eliminated or treated by means that include, but are not limited to, cardiac ablation. 
     In one embodiment, and as shown in  FIG. 1( a ) , system  100  also comprises a physical imaging and/or navigation system  70 . Physical imaging and/or navigation device  60  included in system  70  may be, by way of example, a 2- or 3-axis fluoroscope system, an ultrasonic system, a magnetic resonance imaging (MRI) system, a computed tomography (CT) imaging system, and/or an electrical impedance tomography EIT) system. Operation of system  70  be controlled by computer  300  via control interface  170 , or by other control means incorporated into or operably connected to imaging or navigation system  70 . In one embodiment, computer  300  or another computer triggers physical imaging or navigation system  60  to take “snap-shot” pictures of the heart  10  of a patient (body not shown). A picture image is detected by a detector  62  along each axis of imaging, and can include a silhouette of the heart as well as a display of the inserted catheter  110  and its sensing electrodes, which is displayed on imaging or navigation display  64 . Digitized image or navigation data may be provided to computer  300  for processing and integration into computer graphics that are subsequently displayed on monitor or display  64  and/or  324 . 
     In one embodiment, system  100  further comprises or operates in conjunction with catheter or electrode position transmitting and/or receiving coils or antennas located at or near the distal end of an EP mapping catheter  110 , or that of an ablation or navigation catheter  110 , which are configured to transmit electromagnetic signals for intra-body navigational and positional purposes. 
     In one embodiment, imaging or navigation system  70  is used to help identify and determine the precise two- or three-dimensional positions of the various electrodes included in catheter  110  within patient&#39;s heart  10 , and is configured to provide electrode position data to computer  300 . Electrodes, position markers, and/or radio-opaque markers can be located on various portions of catheter  110 , mapping electrode assembly  120  and/or distal end  112 , or can be configured to act as fiducial markers for imaging or navigation system  70 . 
     Medical navigation systems suitable for use in the various embodiments described and disclosed herein include, but are not limited to, image-based navigation systems, model-based navigation systems, optical navigation systems, electromagnetic navigation systems (e.g., BIOSENSE® WEBSTER® CARTO® system), and impedance-based navigation systems (e.g., the St. Jude® ENSITE™ VELOCITY™ cardiac mapping system), and systems that combine attributes from different types of imaging AND navigation systems and devices to provide navigation within the human body (e.g., the MEDTRONIC® STEALTHSTATION® system). 
     In view of the structural and functional descriptions provided herein, those skilled in the art will appreciate that portions of the described devices and methods may be configured as methods, data processing systems, or computer algorithms. Accordingly, these portions of the devices and methods described herein may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware, such as shown and described with respect to computer system  300  illustrated in  FIG. 1( b ) . Furthermore, portions of the devices and methods described herein may be a computer algorithm or method stored in a computer-usable storage medium having computer readable program code on the medium. Any suitable computer-readable medium may be utilized including, but not limited to, static and dynamic storage devices, hard disks, optical storage devices, and magnetic storage devices. 
     Certain embodiments of portions of the devices and methods described herein are also described with reference to block diagrams of methods, systems, and computer algorithm products. It will be understood that such block diagrams, and combinations of blocks diagrams in the Figures, can be implemented using computer-executable instructions. These computer-executable instructions may be provided to one or more processors of a general purpose computer, a special purpose computer, or any other suitable programmable data processing apparatus (or a combination of devices and circuits) to produce a machine, such that the instructions, which executed via the processor(s), implement the functions specified in the block or blocks of the block diagrams. 
     These computer-executable instructions may also be stored in a computer-readable memory that can direct computer  300  or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture including instructions which implement the function specified in an individual block, plurality of blocks, or block diagram. The computer program instructions may also be loaded onto computer  300  or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on computer  300  or other programmable apparatus provide steps for implementing the functions specified in the an individual block, plurality of blocks, or block diagram. 
     In this regard,  FIG. 1( b )  illustrates only one example of a computer system  300  (which, by way of example, can include multiple computers or computer workstations) that can be employed to execute one or more embodiments of the devices and methods described and disclosed herein, such as devices and methods configured to acquire and process sensor or electrode data, to process image data, and/or transform sensor or electrode data and image data associated with the analysis of cardiac electrical activity and the carrying out of the combined electrophysiological mapping and analysis of the patient&#39;s heart  10  and ablation therapy delivered thereto. 
     Computer system  300  can be implemented on one or more general purpose computer systems or networked computer systems, embedded computer systems, routers, switches, server devices, client devices, various intermediate devices/nodes or standalone computer systems. Additionally, computer system  300  or portions thereof may be implemented on various mobile devices such as, for example, a personal digital assistant (PDA), a laptop computer and the like, provided the mobile device includes sufficient processing capabilities to perform the required functionality. 
     In one embodiment, computer system  300  includes processing unit  301  (which may comprise a CPU, controller, microcontroller, processor, microprocessor or any other suitable processing device), system memory  302 , and system bus  303  that operably connects various system components, including the system memory, to processing unit  301 . Multiple processors and other multi-processor architectures also can be used to form processing unit  301 . System bus  303  can comprise any of several types of suitable bus architectures, including a memory bus or memory controller, a peripheral bus, or a local bus. System memory  302  can include read only memory (ROM)  304  and random access memory (RAM)  305 . A basic input/output system (BIOS)  306  can be stored in ROM  304  and contain basic routines configured to transfer information and/or data among the various elements within computer system  300 . 
     Computer system  300  can include a hard disk drive  303 , a magnetic disk drive  308  (e.g., to read from or write to removable disk  309 ), or an optical disk drive  310  (e.g., for reading CD-ROM disk  311  or to read from or write to other optical media). Hard disk drive  303 , magnetic disk drive  308 , and optical disk drive  310  are connected to system bus  303  by a hard disk drive interface  312 , a magnetic disk drive interface  313 , and an optical drive interface  314 , respectively. The drives and their associated computer-readable media are configured to provide nonvolatile storage of data, data structures, and computer-executable instructions for computer system  300 . Although the description of computer-readable media above refers to a hard disk, a removable magnetic disk and a CD, other types of media that are readable by a computer, such as magnetic cassettes, flash memory cards, digital video disks and the like, in a variety of forms, may also be used in the operating environment; further, any such media may contain computer-executable instructions for implementing one or more parts of the devices and methods described and disclosed herein. 
     A number of program modules may be stored in drives and RAM  303 , including operating system  315 , one or more application programs  316 , other program modules  313 , and program data  318 . The application programs and program data can include functions and methods programmed to acquire, process and display electrical data from one or more sensors, such as shown and described herein. The application programs and program data can include functions and methods programmed and configured to process data acquired from a patient for assessing heart function and/or for determining parameters for delivering a therapy and/or assessing heart function, such as shown and described herein with respect to  FIGS. 1-10 ( f ). 
     A health care provider or other user may enter commands and information into computer system  300  through one or more input devices  320 , such as a pointing device (e.g., a mouse, a touch screen, etc.), a keyboard, a microphone, a joystick, a game pad, a scanner, and the like. For example, the user can employ input device  320  to edit or modify the data being input into a data processing algorithm or method (e.g., only data corresponding to certain time intervals). These and other input devices  320  may be connected to processing unit  301  through a corresponding input device interface or port  322  that is operably coupled to the system bus, but may be connected by other interfaces or ports, such as a parallel port, a serial port, or a universal serial bus (USB). One or more output devices  324  (e.g., display, a monitor, a printer, a projector, or other type of display device) may also be operably connected to system bus  303  via interface  326 , such as through a video adapter. 
     Computer system  300  may operate in a networked environment employing logical connections to one or more remote computers, such as remote computer  328 . Remote computer  328  may be a workstation, a computer system, a router, or a network node, and may include connections to many or all the elements described relative to computer system  300 . The logical connections, schematically indicated at  330 , can include a local area network (LAN) and/or a wide area network (WAN). 
     When used in a LAN networking environment, computer system  300  can be connected to a local network through a network interface or adapter  332 . When used in a WAN networking environment, computer system  300  may include a modem, or may be connected to a communications server on the LAN. The modem, which may be internal or external, can be connected to system bus  303  via an appropriate port interface. In a networked environment, application programs  316  or program data  318  depicted relative to computer system  300 , or portions thereof, may be stored in a remote memory storage device  340 . 
     Further information and details regarding acquisition, processing and interpretation of EP mapping data are disclosed and described in the co-pending &#39;410 patent application. At least portions of the disclosure of the &#39;410 patent application find application in catheter  110  disclosed and described herein. 
     Turning now to considerations relating specifically to the various embodiments of the unique, configurable, multiple application, electrophysiological mapping catheter described and disclosed herein, conventional surgical techniques and catheters for diagnosing and treating AF in a patient often involve using a series of different intravascular EP mapping catheters, in addition to an intravascular ablation catheter. These different intravascular EP mapping catheters are often employed in multiple successive procedures performed one after the other during a single surgical session. 
     In such a typical surgical session, a series of different types of EP mapping catheters and an ablation catheter are used first to sense or map the electrical signals in a patient&#39;s atrium with sensing electrodes, next to ablate or otherwise treat tissue in the atrium or at or near the pulmonary vein at locations where electrical anomalies have been detected, and then to confirm that ablation has disrupted or destroyed the electrical sources of the AF. During the surgical session, additional intravascular EP mapping and ablation procedures may be required so that the precise location(s) of sources of still-remaining errant AF signals may be determined, such remaining sources may be ablated, and the locations of sources of errant AF signals may be confirmed to have been ablated successfully. 
     One way to treat some forms of AF is carry out RF or cryogenic ablation that results in pulmonary vein isolation (PVI), which is carried out by performing multiple ablations in a circular path or pattern around the pulmonary veins (PVs) of the patient. Usually both PVs are ablated, with access being provided by the right and left atria, which are adjacent to the PVs. To validate that ablation has produced sufficient PVI in a patient, in many instances a LASSO® mapping catheter specifically designed to sense signals in or near the PVs, or an EP mapping basket catheter, such as a Boston Scientific CONSTELLATION catheter or a TOPERA FIRMap® catheter, is introduced into or near the PVs after the ablation procedure has been completed so as to detect any remaining channels of excitation indicated by atrial signals still arriving in the PVs (or arriving in the atrium from the PVs). Sometimes these catheters provide insufficient spatial resolution to map the precise locations of the sources of errant AF signals. 
     If still greater spatial resolution of errant AF signals is to be obtained, a different type of EP mapping catheter (e.g., a star-shaped, fan- or grid-type catheter) with decreased inter-electrode spacing can be guided to a target inserted site after the LASSO or basket catheter has been withdrawn from the patient. Once PVI has been confirmed to have been accomplished successfully, ablation in the right or left atria may be required if errant arrhythmias are still detected. EP mapping basket catheters are often employed to map the patient&#39;s atria following PVI. However, conventional basket catheters often do not optimally fit into or conform to the walls of the irregularly-shaped atria, and also are frequently incapable of providing high resolution recordings owing to irregular spacing of the splines containing the sensing electrode once the basket assembly has been positioned within the patient&#39;s heart. Additionally, medium resolution basket catheters are often difficult or impossible to position in a desired orientation and placement within a patient&#39;s atrium owing, among other things, to the steep angle of entrance into the atrium by the tip of the basket catheter through a trans-septal puncture, the long paths to the right and left atria (and consequent difficulty in adjusting or tweaking the position of the tip of a catheter and its electrodes therein), and the oblong and generally irregular geometries of the left and right atria As a result, EP mapping results obtained using conventional basket catheters can be suboptimal owing to insufficient and/or uneven electrode coverage, and to electrodes not being positioned in the locations required to acquire useful signals. In such instances, a star-shaped PENTARAY® or other high-resolution EP mapping catheters can be used to obtain higher resolution EP recordings. This, of course, requires the use and deployment of yet another type of EP mapping catheter, which as a result is often not done. 
     In the above-described intravascular surgical techniques, the following different types of intravascular catheters may thus be employed: (a) a lasso-type or circular electrode electrophysiological (EP) mapping catheter configured to sense electrical activity in and around the pulmonary veins; (b) a basket EP mapping catheter configured to sense electrical activity in and around the atrium at medium resolution; (c) a star-shaped, fan- or grid-type EP mapping catheter configured to sense electrical activity in and around the atrium at higher resolution; and (d) an RF, cryogenic or other type of ablation catheter configured to ablate tissue in the atria or pulmonary veins at locations that have been identified as the source(s) of the AF. Oftentimes an ablation catheter is deployed in the patient&#39;s heart at the same time that an EP mapping catheter is deployed therein. 
     According to the above-described surgical techniques, multiple different EP mapping catheters are thus inserted into and then withdrawn from the patient&#39;s heart, typically via the femoral vein. Up to four or more different catheters may be employed one after the other in a single surgical session to treat a patient&#39;s AF. Each catheter used in the session has a purchase price associated with it; most EP mapping catheters are used once only, and are thrown away after the session has ended. In addition, the greater the number of intravascular procedures performed on a patient, the greater the risk to the patient. 
     Problems that can and do occur using conventional basket catheters, such as spline bunching and poor electrode coverage, are described in considerable detail in the following publications: (a) “Basket-Type Catheters: Diagnostic Pitfalls Caused by Deformation and Limited Coverage” to Oesterlein et al., BioMed Research International, Volume 2016, Article ID 5340574 (“the Oesterlein publication”); (b) “Practical Considerations of Mapping Persistent Atrial Fibrillation With Whole-Chamber Basket Catheters” to Laughner et al., JACC: Clinical Electrophysiology, Volume 2, Issue 1, February 2016, Pages 55-65 (“the first Laughner publication”); and (c) “Atrial Mapping With Basket Catheters—A Basket Case?” to Hummel et al., JACC: Clinical Electrophysiology, Volume 2, Issue 1, February 2016, Pages 66-68 (“the Hummel publication”). The respective entireties of the Oesterlein, Laughner and Hummel publications, complete copies of which were submitted on the filing date corresponding to the present patent application, are incorporated by reference herein. 
       FIG. 2  illustrates some of the problems that can arise with conventional prior art basket catheters, and more particularly problems that can arise from spline bunching and inadequate electrode coverage. Shown in  FIG. 2  are anterior (left side of  FIG. 2 ) and posterior (right side of  FIG. 2 ) views of a patient&#39;s left atrium with a prior art TOPERA FIRMap basket catheter deployed therein. The two images shown in  FIG. 2  were acquired using a TOPERA RhythmView 3D mapping workstation. In  FIG. 2 , the eight splines of the FIRMap basket catheter are labelled A through H, and the eight electrodes on each spline are numbered  1  through  8  according to conventional nomenclature and practice. As shown, splines E and F are widely spaced from one another, while the other splines are more closely (or too closely) spaced from one another. A significant gap in EP mapping coverage resulted between splines E and F, as well as uneven electrode coverage in the remainder of the patient&#39;s left atrium. Once the catheter shown in  FIG. 2  was emplaced within the patient&#39;s left atrium, moving it into a different position to obtain more even or better electrode coverage was difficult or impossible, as movement of the basket was effectively limited to minor adjustments of the basket forwards and backwards, or spinning or rotation of the basket within the patient&#39;s left atrium. 
     Referring now to  FIG. 3 , there is shown an illustrative view of one embodiment of a distal portion of catheter  110  inside a patient&#39;s left atrium  14 . As shown in  FIG. 2 , heart  10  includes right atrium  12 , left atrium  14 , right ventricle  18 , and left ventricle  20 . Mapping electrode assembly  120  is shown in a fully deployed, expanded or open state inside left atrium  14  after it has been inserted through the patient&#39;s inferior vena cava and foramen ovalen (“IVC” and “FO” in  FIG. 2 ), and in one embodiment is configured to obtain electrogram signals from left atrium  12  via electrodes  122  included in mapping electrode assembly  120 . Mapping electrode assembly and catheter  110  may also be positioned within the patient&#39;s right atrium  12 , left ventricle  18 , and/or right ventricle  20 . In  FIG. 2 , distal tip  112  of catheter  110  is punched through the FO and/or the trans-septal wall into the left atrium from the right atrium. The location and steep angle of approach provided by the resulting trans-septal puncture typically significantly restrict the freedom of movement and positionability that is possible using a conventional basket catheter after it has been deployed inside the left atrium. Contrariwise, owing to the unique structural attributes and configuration of the multi-configuration and application EP mapping catheter  110  described and disclosed herein, such as splines  126  bending backwardly from tip  112  in the proximal direction, positionability and maneuvering of distal portion  108  of catheter  112  are much enhanced. 
       FIGS. 4( a ) through 4( d )  illustrate one embodiment of EP mapping catheter  110  comprising mapping electrode assembly  120  located at the distal portion  108  of catheter  110 , where portions of catheter body  106  are covered by outer slidable sheath  104 . In  FIGS. 4( a ) through 4( d ) , once distal end  112  of EP mapping catheter  110  has been guided to a desired location within patient&#39;s heart  10 , mapping electrode assembly  120  can be deployed in one or more configurations within patient&#39;s heart  10  according to the physician&#39;s objective at hand (e.g., obtain EP recordings at or near the PV or inside atrium  12  or  14 , and/or obtain low, medium or high resolution EP recordings at desired locations with patient&#39;s heart  10 ). 
       FIG. 4( a )  shows one embodiment of EP mapping catheter  110  in a configuration where mapping electrode assembly  120  has not yet been deployed by the physician, and does not extend outwardly from tip  112  or outside slidable sheath  104 . Handle or electrode deployment and control mechanism  102  remains outside the patient while the distal tip  112  of catheter is advanced towards the desired target inside or near patient&#39;s heart  10 . 
       FIG. 4( b )  shows the embodiment of EP mapping catheter  110  of  FIG. 3( a )  where mapping electrode assembly  120  is partially deployed such that 16 electrodes  122  on splines  126  are exposed at or near tip  112 . (In the embodiment of EP mapping catheter  110  shown in  FIGS. 4( a ) through 4( b ) , mapping electrode assembly  120  comprises 8 splines  126 , and each spline  126  has a total of 8 sensing or other electrodes  122  disposed or mounted thereon. Other numbers of splines and electrodes in catheter  110  are also contemplated, as described elsewhere herein.) 
     In  FIG. 4( b ) , outer slidable sheath  108  has been withdrawn backwardly by the physician in the direction of handle  102  a distance D 1  from initial position W of  FIG. 4( a )  to position X of  FIG. 4( b ) . As slidable sheath  104  is withdrawn from tip  112  towards position X, the initially distal-most portions of splines  126  of mapping electrode assembly  120  become exposed gradually. Representative but non-limiting examples of distance D 1  between W and X in  FIG. 4( b )  range between about 0.5 cm and about 2 cm. 
     In the configuration of partially deployed mapping electrode assembly  120  shown in  FIG. 4( b )  at distal portion  108  of catheter  110 , a total of 16 electrodes  122 , two on each spline, are exposed and available to take EP recordings. In the partially deployed configuration of  FIG. 4( b ) , sufficient electrodes  122  are exposed, and electrodes  122  may be configured according to inter-electrode spacing and the size or surface area of the electrodes, to permit high-quality EP recordings to be taken, by way of non-limiting example, at or near a pulmonary vein (PV), in a manner similar to that obtained using a LASSO catheter as described above. Note that mapping electrode assembly  120  may also be deployed, and sheath  104  withdrawn a distance less than D 1 , such that, for example, only the first 8 electrodes  112  mounted on or attached to splines  126  are exposed and available to make EP recordings. 
     Continuing to refer to  FIG. 4( b ) , mapping electrode assembly  120  further comprises flexible (and in some embodiments extendible and/or elastic) tendons or chords  115  that connect adjoining splines  126 . Tendons or chords  115  are configured to hold the ends of splines  126  in predetermined positions relative to one another as mapping electrode assembly  120  is progressively deployed. Tendons or chords  115  may be formed of any suitable biocompatible material, such as an elastic material, a wound, braided, stranded, twisted or thread-like material (such as KEVLAR or metal or metal alloy wires), a polymer, a metal or metal alloy, or a polymer- or otherwise biocompatible-material-coated metal, metal alloy, stranded, braided or twisted metal or metal alloy wires, polymeric fibers or threads, carbon fibers or the like, and may be attached or connected to splines  126  via tendon attachment points or structures  118  comprising a suitable adhesive such as epoxy, or may be crimped, swaged, stapled, or welded thereto at tendon or chord connection points or structure  118 . Proximal portion  116  of catheter  110  shown in  FIG. 4( b )  includes external electrical connector  128 , which permits electrical connections to be established between electrodes  122  of mapping electrode assembly  120  and the various modules of system  100 , such as data acquisition device  140  and ablation module  150 . Electrical conductors are provided within catheter  110  between distal and proximal portions  108  and  116  thereof such that signals sensed by electrodes  112  can be routed to from such electrodes  122  to connector  128  and thence system  100 . The number of such electrical conductors included in catheter body  106  may be reduced (or effectively increased) by including suitable multiplexing electronic circuitry (e.g., a multiplexer ASIC) within catheter  110  (e.g., in handle  102 , in catheter body  106 , or near or at distal tip  112  in cap  111 ). Note that in some embodiments, catheter  110  includes one or more ablation electrodes or other devices configured to ablate or treat tissue from distal end  112 , and may also include pacing electrodes. Sensing electrodes  122  may also be configured to serve as pacing electrodes. In some embodiments, catheter  110  includes navigation elements, coils, markers and/or electrodes so that the precise positions of the sensing, pacing and/or ablation electrodes inside the patient&#39;s heart  10  can be determined. 
     In some embodiments, splines  126  disclosed and described herein comprise a biocompatible shape memory alloy (e.g., nickel titanium, or Nitinol), and have been treated and configured during the process of manufacturing splines  126  and catheter  110  such that splines  126  will curl backwardly in the direction of proximal portion  116  of catheter as they are progressively exposed by the withdrawal of sheath  104  (or as spines  126  are advanced from distal end  112  of catheter  110 , more about which is said below). 
     Nitinol is a metal alloy of nickel and titanium, where the two elements are typically present in roughly equal atomic percentages, e.g., Nitinol  55 , Nitinol  60 . The properties of the Nitinol or other suitable shape memory alloy employed in splines  126  are particular to the precise composition of the alloy used and its processing, and in some embodiments exhibit shape memory effect (SME) and superelasticity (SE; also called pseudoelasticity, PE). Nitinol is highly biocompatible, and has properties suitable for use in medical devices inserted or implanted within the human body. Due to Nitinol&#39;s unique properties, finds application in catheters, stents, and superelastic needles. In embodiments where the shape memory alloy selected for use in catheter  110  is Nitinol, tight compositional control of the Nitinol is required during the manufacturing process due to the high reactivity of titanium. By way of example, melting methods of the Nitinol employed to form splines  126  may include vacuum arc remelting (VAR) or vacuum induction melting (VIM). High vacuums may be required during a Nitinol spline manufacturing process. Alternatives to VAR and VIM include, but are not limited to, plasma arc melting, induction skull melting, and e-beam melting. Physical vapor deposition may also be employed. Some methods of working Nitinol for use in splines  126  include, but are not limited to, grinding, abrasive cutting, electrical discharge machining (EDM), and laser cutting. Heat treating of Nitinol employed in splines  126  can include varying aging time and temperature controls to obtain a desired Ni-rich phase and transformation temperature of splines  126 , and thus control how much nickel resides in the resulting NiTi lattice. With respect to catheter  110  and splines  126  thereof, Nitinol is worked, treated and formed so that it will consistently and reliably behave and assume one or more of the various configurations shown and described herein as mapping electrode assembly  120  is progressively deployed from distal end  112  of catheter  110 . 
     In alternative embodiments, splines  126  comprise a biocompatible material having shape memory characteristics and attributes, but are not formed of Nitinol or other shape memory alloys (or at least are not formed primarily or solely of one or more shape memory alloys). By way of non-limiting example, in such alternative embodiments splines  126  are formed of biocompatible shape memory materials such as shape-memory polymers, laminated 3D printed splines comprising shape memory materials, shape memory composites, and/or shape memory hybrids. 
     Referring now to  FIG. 4( c ) , there is shown the embodiment of EP mapping catheter  110  of  FIG. 4( a ) , where mapping electrode assembly  120  has been more fully deployed such that 32 electrodes  122  on eight splines  126  are exposed backwardly from tip  112 . In  FIG. 4( c ) , outer slidable sheath  108  has been withdrawn by the physician in the direction of handle  102  a distance D 2  from initial position W of  FIG. 4( a )  to position Y of  FIG. 4( c ) . As slidable sheath  104  is withdrawn from position X to position Y, further portions of splines  126  of mapping electrode assembly  120  become exposed. Representative but non-limiting examples of distance D 2  between W and Y in  FIG. 4( c )  range between about 2 cm and about 10 cm. In the configuration of partially deployed mapping electrode assembly  120  shown in  FIG. 4( c ) , a total of 32 electrodes  122 , four on each spline, are exposed and available to take EP recordings. In the partially deployed configuration of  FIG. 4( c ) , sufficient electrodes  122  are exposed, and electrodes  122  may be configured according to inter-electrode spacing and the size or surface area of the electrodes, to permit high resolution EP recordings to be taken in a patient&#39;s atrium or ventricle, in a manner similar to that obtained, for example, using a PENTARAY catheter as described above, or similar to the ADVISOR HD GRID mapping catheter manufactured by St. Jude. 
     Referring now to  FIG. 4( d ) , there is shown the embodiment of EP mapping catheter  110  of  FIG. 4( a )  where mapping electrode assembly  120  has been fully deployed to form a basket catheter such that 64 electrodes  122  on eight splines  126  are exposed rearwardly from tip  112 . In  FIG. 4( d ) , outer slidable sheath  108  has been withdrawn backwardly by the physician in the direction of handle  102  a distance D 3  from initial position W of  FIG. 4( a )  to position Z of  FIG. 4( d ) . As slidable sheath  104  is withdrawn from position Y to position Z, further portions of splines  126  of mapping electrode assembly  120  become exposed. Representative but non-limiting examples of distance D 4  between W and Z in  FIG. 4( d )  range between about 3 cm and about 20 cm. In the configuration of fully deployed mapping electrode assembly  120  shown in  FIG. 4( d ) , a total of 64 electrodes  122 , eight on each spline, are exposed and available to take EP recordings. In the fully deployed configuration of  FIG. 4( d ) , sufficient electrodes  122  are exposed, and electrodes  122  may be configured according to inter-electrode spacing and the size or surface area of the electrodes, to permit medium resolution EP recordings to be taken in a patient&#39;s atrium or ventricle, in a manner somewhat similar, by way of non-limiting example, to that obtained using a Boston Scientific CONSTELLATION catheter (excepting, of course, the increased maneuverability and positionability of catheter  110 ). 
     Fully deployed mapping electrode assembly  120  of  FIG. 4( d )  further comprises and forms a basket having an interior open space  129  formed by fully expanded splines  126 , which in some embodiments are spaced apart from one another along the circumference forming the basket at regular or fairly regular intervals. Moreover, also shown in  FIG. 4( d )  is opening  125 , where no tendon or connector is disposed between two adjoining splines  126 , which permits catheter body  106  and outer sheath  104  in distal portion  108  of catheter  110  to swing away from the longitudinal axis of, and partially outside, the basket, more about which is said below. This feature allows fully deployed mapping electrode assembly  120  to be positioned inside a patient&#39;s atrium or ventricle with improved accuracy and enhanced electrode coupling to the atrial or ventricular wall relative to that which can be achieved with a conventional basket catheter, and enables extra degrees of freedom, movement and positioning to be attained relative to a conventional prior art basket catheter. 
     Thus, and in reference to  FIGS. 4( a ) through 4( d ) , it will now be seen that in some embodiments mapping electrode assembly  120  of catheter  110  is capable of assuming different configurations while positioned within or near patient&#39;s heart  10  according to the particular application at hand. For example, EP recordings of the PVs, atria and ventricles at different spatial resolutions and in different locations within and near the heart  10  and PV16 can be made, all using the same catheter  110 . 
     Referring now to  FIGS. 5( a ) through 5( d ) , there is shown another embodiment of EP mapping catheter  110  comprising mapping electrode assembly  120  located at the distal portion  108  of catheter  110 , where no outer sheath  104  is provided, and where mapping electrode assembly  120  is instead deployed by pushing mapping electrode assembly  120  out of the distal end  112  of catheter  110  by advancing one or more wires, stylets, or other suitable pushing mechanisms in the distal direction of catheter  100  through the control and operation, by the physician, of deployment mechanism  130  located in handle  102 . In  FIGS. 5( a ) through 5( d ) , once distal end  112  of EP mapping catheter  110  has been guided to a desired location within patient&#39;s heart  10 , mapping electrode assembly  120  can be deployed in one or more configurations within patient&#39;s heart  10  according to the physician&#39;s objectives at hand (e.g., obtain EP recordings at or near the PV or inside atrium  12  or  14 , and/or obtain low, medium or high resolution EP recordings at desired locations with patient&#39;s heart  10 ). 
       FIG. 5( a )  shows one embodiment of EP mapping catheter  110  in a configuration where mapping electrode assembly  120  has not yet been deployed by the physician, and does not extend outwardly from tip  112 . 
       FIG. 5( b )  shows the embodiment of EP mapping catheter  110  of  FIG. 5( a )  where mapping electrode assembly  120  is partially deployed such that 16 electrodes  122  on splines  126  are exposed at or near tip  112 . (In the embodiment of EP mapping catheter  110  shown in  FIGS. 5( a ) through 5( b ) , mapping electrode assembly  120  comprises 8 splines  126 , and each spline  126  has a total of 8 sensing or other electrodes  122  disposed or mounted thereon. Other numbers of splines and electrodes in catheter  110  are also contemplated, as described elsewhere herein.) 
     In  FIG. 5( b ) , EP mapping electrode assembly  120  has been advanced by the physician outside distal end  112  of catheter  110 , and in the direction of handle  102  a distance D 1  from initial position W of  FIG. 5( a )  to position X of  FIG. 5( b ) . As mapping electrode assembly  120  is pushed out of distal end  112  towards position X, the initially distal-most portions of splines  126  of mapping electrode assembly  120  become exposed gradually. Representative but non-limiting examples of distance D 1  between W and X in  FIG. 5( b )  range between about 0.5 cm and about 2 cm. 
     In the configuration of partially deployed mapping electrode assembly  120  shown in  FIG. 5( b )  at distal portion  108  of catheter  110 , a total of 16 electrodes  122 , two on each spline, are exposed and available to take EP recordings. In the partially deployed configuration of  FIG. 5( b ) , sufficient electrodes  122  are exposed, and electrodes  122  may be configured according to inter-electrode spacing and the size or surface area of the electrodes, to permit high-quality EP recordings to be taken, by way of non-limiting example, at or near a pulmonary vein (PV), in a manner similar to that obtained using a LASSO catheter as described above. Note that mapping electrode assembly  120  may also be deployed such that, for example, only the first 8 electrodes  112  mounted on or attached to splines  126  are pushed out of the distal end of catheter  110  to make EP recordings. 
     Continuing to refer to  FIG. 5( b ) , mapping electrode assembly  120  further comprises flexible (and in some embodiments extendible and/or elastic) tendons or chords  115  that connect adjoining splines  126 . Tendons or chords  115  are configured to hold the ends of splines  126  in predetermined positions relative to one another as mapping electrode assembly  120  is progressively deployed. Tendons or chords  115  may be formed of any suitable biocompatible material, such as an elastic material, a wound, braided, stranded, twisted or thread-like material (such as KEVLAR or metal or metal alloy wires), a polymer, a metal or metal alloy, or a polymer- or otherwise biocompatible-material-coated metal, metal alloy, stranded, braided or twisted metal or metal alloy wires, polymeric fibers or threads, carbon fibers or the like, and may be attached or connected to splines  126  via tendon attachment points or structures  118  comprising a suitable adhesive such as epoxy, or may be crimped, swaged, stapled, or welded thereto at tendon or chord connection points or structure  118 . Proximal portion  116  of catheter  110  shown in  FIG. 5( b )  includes external electrical connector  128 , which permits electrical connections to be established between electrodes  122  of mapping electrode assembly  120  and the various modules of system  100 , such as data acquisition device  140  and ablation module  150 . Electrical conductors are provided within catheter  110  between distal and proximal portions  108  and  116  thereof such that signals sensed by electrodes  112  can be routed to from such electrodes  122  to connector  128  and thence system  100 . The number of such electrical conductors included in catheter body  106  may be reduced (or effectively increased) by including suitable multiplexing electronic circuitry (e.g., a multiplexer ASIC) within catheter  110  (e.g., in handle  102 , in catheter body  106 , or near or at distal tip  112  in cap  111 ). Note that in some embodiments, catheter  110  includes one or more ablation electrodes or other devices configured to ablate or treat tissue from distal end  112 , and may also include pacing electrodes. Sensing electrodes  122  may also be configured to serve as pacing electrodes. In some embodiments, catheter  110  includes navigation elements, coils, markers and/or electrodes so that the precise positions of the sensing, pacing and/or ablation electrodes inside the patient&#39;s heart  10  can be determined. 
     Referring now to  FIG. 5( c ) , there is shown the embodiment of EP mapping catheter  110  of  FIG. 5( a ) , where mapping electrode assembly  120  has now been more fully deployed such that 32 electrodes  122  on eight splines  126  are exposed backwardly from tip  112 . In  FIG. 5( c ) , mapping electrode assembly  120  has been pushed further out of distal tip  112  by the physician in the direction of handle  102  a distance D 2  from initial position W of  FIG. 5( a )  to position Y of  FIG. 5( c ) . As slidable sheath  104  is withdrawn from position X to position Y, further portions of splines  126  of mapping electrode assembly  120  become exposed. Representative but non-limiting examples of distance D 2  between W and Y in  FIG. 5( c )  range between about 2 cm and about 10 cm. In the configuration of partially deployed mapping electrode assembly  120  shown in  FIG. 5( c ) , a total of 32 electrodes  122 , four on each spline, are exposed and available to take EP recordings. In the partially deployed configuration of  FIG. 5( c ) , sufficient electrodes  122  are exposed, and electrodes  122  may be configured according to inter-electrode spacing and the size or surface area of the electrodes, to permit high resolution EP recordings to be taken in a patient&#39;s atrium or ventricle, in a manner similar to that obtained using, for example, a PENTARAY catheter as described above, or similar to the ADVISOR HD GRID mapping catheter manufactured by St. Jude. 
     Referring now to  FIG. 5( d ) , there is shown the embodiment of EP mapping catheter  110  of  FIG. 5( a )  where mapping electrode assembly  120  has been fully deployed to form a basket catheter such that 64 electrodes  122  on eight splines  126  are exposed rearwardly from tip  112 . In  FIG. 5( d ) , mapping electrode assembly  120  has been fully advanced towards and then outside and backwardly from distal tip  112  of catheter  110  a distance D 3  by the physician through the action of deployment mechanism  130  located on handle  102  from initial position W of  FIG. 5( a )  to position Z of  FIG. 5( d ) . As mapping electrode assembly  120  is pushed further out of distal end  112  of catheter  110 , from position Y to position Z, further portions of splines  126  of mapping electrode assembly  120  become exposed. Representative but non-limiting examples of distance D 4  between W and Z in  FIG. 5( d )  range between about 3 cm and about 20 cm. In the configuration of fully deployed mapping electrode assembly  120  shown in  FIG. 5( d ) , a total of 64 electrodes  122 , eight on each spline, are exposed and available to take EP recordings. In the fully deployed configuration of  FIG. 5( d ) , sufficient electrodes  122  are exposed, and electrodes  122  may be configured according to inter-electrode spacing and the size or surface area of the electrodes, to permit medium resolution EP recordings to be taken in a patient&#39;s atrium or ventricle, in a manner similar, by way of non-limiting example, to that obtained using a Boston Scientific CONSTELLATION catheter. 
     Fully deployed mapping electrode assembly  120  of  FIG. 5( d )  further comprises and forms a basket having an interior open space  129  formed by fully expanded splines  126 , which in some embodiments are spaced apart from one another along the circumference forming the basket at regular or fairly regular intervals. Moreover, also shown in  FIG. 5( d )  is opening  125 , where no tendon or connector is disposed between two adjoining splines  126 . Similar to the embodiment of catheter  110  shown in  FIGS. 3( a ) through 3( d )  and discussed above, opening  125  permits catheter body  106  of distal portion  108  of catheter  110  to swing away from the longitudinal axis of, and partially outside, the basket, more about which is said below. This feature allows fully deployed mapping electrode assembly  120  to be positioned inside a patient&#39;s atrium or ventricle with improved accuracy and enhanced electrode coupling to the atrial or ventricular wall relative to that which can be achieved with a conventional basket catheter, and enables extra degrees of freedom, movement and positioning to be attained relative to a conventional prior art basket catheter. 
     Thus, and in reference to  FIGS. 5( a ) through 5( d ) , it will now be seen that in some embodiments mapping electrode assembly  120  of catheter  110  is capable of assuming different configurations while positioned within or near patient&#39;s heart  10  according to the particular application at hand. For example, EP recordings of the PVs, atria and ventricles at varying spatial resolutions and in different locations within and near the heart  10  and PV16 can be made, all using the same catheter  110 . 
     Referring now to  FIGS. 4( a ) through 5( d ) , electrodes  122  on splines  126  can be assigned electrode labels or addresses such as, by way of non-limiting example, A 1  through H 8 . Catheter body  106  needs to be flexible so that it can be advanced through the patient&#39;s blood vessels towards the target site or location. Electrodes  122  are configured to sense electrical activity (e.g., activation signals, rotors, re-entry points, exit points, and the like) in tissue, such as heart tissue and pulmonary vein tissue. As described above, sensed signals provided by catheter  110  and electrodes  122  are processed by system  100  to assist the physician in identifying the specific site or sites where cardiac heart rhythm disorders or other pathologies originate or are manifested in heart, vein or other tissue. This information can then be used to determine an appropriate location for applying an appropriate therapy, such as ablation, to the identified sites, and also to navigate the one or more ablation or treatment electrodes to the identified sites. As discussed above, in some embodiments splines  126  are made of a shape memory alloy such as Nitinol. Other metals, metal alloys, combinations or laminations of metal or other materials such as KEVLAR, silicone, rubber, suitable polymers, may also be employed to form splines  126  to form resilient, pre-tensioned members (including shape-memory members) that are configured to bend and conform to the tissue surface with which they come into contact. In the embodiments illustrated in  FIGS. 4( d ) and 5( d ) , eight splines  126  form a basket structure. As discussed above, additional or fewer splines  126  can be employed in other embodiments. As illustrated in  FIGS. 4( d ) and 5( d ) , each spline  126  carries  8  mapping electrodes  122 . In other embodiments, additional or fewer mapping electrodes  122  may be disposed on each spline  126 . 
     While an arrangement of 64 mapping electrodes  122  is shown in  FIGS. 4( d ) and 5( d ) , mapping electrodes  122  in mapping electrode assembly  120  may be arranged in different numbers (more or fewer splines and/or more or fewer electrodes), on different structures, in different positions, or arranged at varying spacing along splines  126 . In addition, in some embodiments multiple circular, fan-like or basket structures can be deployed in the same or different anatomical structures to simultaneously obtain signals from different anatomical structures or portions of tissue. 
     After electrodes  122  of catheter  110  have been deployed in the desired configuration, and positioned adjacent to a target anatomical structure (e.g., a pulmonary vein, the left atrium, the left ventricle, the right atrium, or the right ventricle of heart  10 ) whose electrical activity is to be measured, or which is to be treated (e.g., ablated), system  100  is configured to record electrical signals from each electrode  122  situated near the target anatomical structure. As described above, and as shown in  FIGS. 4( a ) through 5( d ) , mapping electrode assembly  120  can be deployed in myriad different configurations, where different spatial resolutions between electrodes are employed, and where different numbers of electrodes  122  are employed to sense electrical signals. For example, in the embodiments of catheter  110  shown in  FIGS. 4( d ) and 5( d ) , where mapping electrode assembly  120  is shown fully deployed, the spacing between electrodes can be twice that of the embodiments shown in  FIGS. 4( c ) and 5( c ) . Thus, in fully expanded configurations of  FIGS. 4( d ) and 5( d ) , catheter  110  can be configured to provide half the spatial resolution but cover a greater surface area than the higher spatial resolution configurations of  FIGS. 4( c ) and 5( c ) . In a fully deployed basket configuration, mapping electrode assembly  120  may vary in size from a small basket (capable of mapping a small, localized section of the cardiac chamber) to a large basket (capable of mapping most or all of a cardiac chamber). Utilizing a small basket structure may result in system  100  having to combine localized recordings together. Localized recordings may overlap one another, and therefore, to achieve a “global” representation of the cardiac chamber, it may be necessary to combine, or “stitch,” local recordings together. 
     The arrangement, size, spacing and location of electrodes  122  along a spline  126 , in combination with the specific geometry of the targeted anatomical structure, may contribute to the ability (or inability) of electrodes  122  to be electrically coupled adequately to cellular tissue. Because splines  126  are flexible and bendable, they are configured to permit substantial conformance to and physical coupling to differently-shaped and configured anatomical regions. In at least some embodiments, and according to the inevitable particularities of the geometry of a given patient&#39;s heart or pulmonary vein, in many cases catheter  110  permits good coupling of most or all electrodes  122  to the patient&#39;s heart or vein tissue at or near the target site owing to the flexibility and shape memory of splines  126 , the configurability and variable geometry mapping electrode assembly  120  is capable of assuming under the control of the physician, and the off-axis movement of the resulting electrode sensing array permitted by opening  125  of mapping electrode assembly  120  (more about which is said below). 
     Mapping electrode assembly  120  may also be employed to facilitate the assessment of entrainment, conduction velocity studies, and refractory periods in patient&#39;s heart  10 . In some embodiments, mapping electrode assembly  120  further permits the simultaneous acquisition of longitudinal and circumferential signals along splines  126  for accurate 3-D mapping, and provides a flexible circular, fan-shaped, or basket geometry that is configured to conform to atrial or ventricular anatomy, and which permits greater accuracy in positioning and placement within patient&#39;s heart  10 . Sixty-four electrodes A 1  through H 8  (or individual electrodes  122 ) can provide comprehensive, real-time 3-D information over a single heartbeat. 
     Continuing to refer to  FIGS. 4( a ) through 5( d ) , it will be seen that distances W-X (D 1 ), W-Y (D 2 ) and W-Z (D 3 ) correspond approximately to the respective lengths of mapping electrode assembly  120  that is exposed and available to sense electrical or other signals in a patient&#39;s internal organ (such as patient&#39;s heart  10 ). Moreover, the overall length of catheter  110  can be configured for applications in different types of patient&#39;s and applications, such as pediatric applications (where shorter overall lengths are preferred), applications in persons who have large frames (where longer overall lengths are preferred), gastric and esophageal applications (where lengths different from catheters configured for intra-cardiac applications are preferred), different access points for the catheter (e.g., femoral vein, femoral veins, internal jugular vein, subclavian vein, etc.). By way of non-limiting example, in intra-cardiac applications an overall length of catheter  110  between handle  102  and distal tip  112  can range between about 40 cm and about 200 cm, and in some embodiments the overall length is about 145 cm. 
     In respect of the terms “high resolution,” “high spatial resolution,” “medium resolution,” and “medium spatial resolution” as they are employed herein, note the following. In some embodiments, electrodes  122 / 127  are located along splines  126  at distances from one another ranging between about 1.2 cm to about 1.6 cm (see electrode spacing E 2  described below in connection with fan-shaped mapping electrode assembly  120  of  FIG. 7 ). Closer electrode spacing of about 0.25 mm to about 2 mm along splines  126  may be employed for bipolar electrodes  122 / 123  used in a circular or lasso-like configuration (see electrode spacing E 1  described below in connection with mushroom-shaped mapping electrode assembly  120  of  FIGS. 6( a ) and 6( b ) ). In the mushroom-shaped configurations of mapping electrode assembly  120  shown in  FIGS. 6( a ) and 6( b ) , the finest and highest spatial resolution between electrodes is achieved by catheter  110  (which may be on the order of millimeters, e.g., about 0.25 mm to about 2 mm). In fan-shaped configurations of mapping electrode assembly  120  (such as that shown in  FIG. 7 ), high spatial resolution is achieved by catheter  110 , which in some embodiments, and depending on the manner and particular configuration in which mapping electrode assembly  120  is deployed and pressed and coupled against a patient&#39;s heart or other tissue, can range between nothing (splines touching) and about 2 cm. In basket configurations of mapping electrode assembly  120  (such as that shown in  FIGS. 8-11 and 13 ), medium spatial resolution is achieved by catheter  110 , which in some embodiments, and depending on the manner and particular configuration in which mapping electrode assembly  120  is deployed and pressed and coupled against a patient&#39;s heart or other tissue, can range between nothing (squished splines touching) to as much as 4 or 5 cm. Averaged spacings between electrodes in fine, high and medium resolution configurations that reduce the effects of touching splines can thus range, respectively, between about 0.25 mm and about 2 mm (fine spatial resolution), between about 0.25 cm and about 2 cm (high spatial resolution), and between about 1 cm and about 4 cm (medium spatial resolution). 
     Referring now to  FIGS. 6( a ) and 6( b ) , there is shown one embodiment of distal portion  108  of catheter  110  having mapping electrode assembly  120  initially deployed in a restricted or mushroom-shaped configuration, in two circular-shaped configurations and stages. In  FIG. 6( a ) , mapping electrode assembly  120  is partially deployed such that only small pairs of bipolar electrodes  122 / 123  located on four arms  121  have been pushed outwardly from distal tip  112  beneath distal cap  111 , for a total of 8 deployed sets of bipolar sensing electrodes. (Note that in some embodiments, bipolar pairs of electrodes  122 / 123  can be replaced with unipolar single electrodes  122 , and vice-versa). In the embodiment shown in  FIGS. 6( a ) and 6( b ) , each of arms  121  comprises two splines  126  joined at tendon or chord connection point or structure  118  (although other numbers of splines  126  may be joined together or connected by structures  118 ). In  FIGS. 6( a ) and 6( b ) , tendons or chords  115  connect adjoining arms  121  comprising pairs of splines, and are likewise attached to tendon or chord connection points or structures  118 . Tendons or chords  115  hold the ends of splines  126  in predetermined positions relative to one another as mapping electrode assembly  120  is progressively deployed. 
     As further shown in  FIGS. 6( a ) and 6( b ) , opening  125  disposed between two adjoining arms  121  located between arrow  125  in  FIGS. 6( a ) and 6( b )  has no tendon or chord  115  disposed thereacross. Such a configuration permits distal portion  108  of catheter body  106  to swing or move outwardly away from the central longitudinal axis of deployed mapping electrode assembly  120  between two adjoining arms  121  through opening  125  (more about which is said below). This ability to partially decouple distal portion  108  of catheter  110  from mapping electrode assembly  120  permits more accurate, different and quicker placement, and better electrode coupling, of mapping electrode assembly near or at a target site than may be achieved with conventional basket catheters. 
     In the embodiment of catheter  110  shown in  FIG. 6( a ) , splines  126 , arms  121  and bipolar pairs of electrodes  122 / 123  extend but a small distance from distal end  112  of catheter  110 . In one embodiment, a representative diameter of arms  121  in the configuration of distal portion  108  of catheter  110  shown in  FIG. 6( a )  is about 10 mm, or between about 8 mm and about 12 mm. Distal portion  108  of catheter  110  of  FIG. 6( a )  finds particularly efficacious application in EP mapping of small structures, such as, by way of non-limiting example, portions of tissue located at or near a pulmonary vein. As shown in  FIG. 6( a ) , splines  126  and the shape memory material included therein may be configured and manufactured such that arms  121  of mapping electrode assembly  120  project mostly outwardly and only slightly downwardly when partially deployed in the circular fashion and configuration shown in  FIG. 6( a ) . As shown in  FIG. 6( a ) , spacing E 2  may be employed to separate each pair bipolar electrodes. In some embodiments, spacing E 2  ranges between about 0.5 mm and about 1 mm, or between about 0.25 mm and about 2 mm. 
     In the embodiment of catheter  110  shown in  FIG. 6( b ) , splines  126 , arms  121 , and bipolar pairs of electrodes  122 / 123  extend a further distance from distal end  112  of catheter  110  than is shown in  FIG. 6( a ) , and also finds particularly efficacious application in EP mapping of small structures, such as, by way of non-limiting example, portions of tissue located at or near a pulmonary vein. In one embodiment, a representative diameter of arms  121  in the configuration of distal portion  108  of catheter  110  shown in  FIG. 6( b )  is about 15 mm, or between about 12 mm and about 20 mm. Splines  126  and the shape memory material included therein may be configured such that arms  121  of mapping electrode assembly  120  project outwardly but further downwardly than is shown in  FIG. 6( a )  when partially deployed in the circular fashion and configuration shown in  FIG. 6( b ) . In  FIG. 6( b ) , in one embodiment, a representative but non-limiting length of tendon or chord  115  ranges between about 10 mm and about 15 mm. Consequently, the distance between adjoining splines  126  at the bottom portions thereof is set by the length of tendons or chords  115 . 
       FIG. 7  shows one embodiment of distal portion  108  of catheter  110 , where mapping electrode assembly  120  has been deployed in an intermediate fan- or paddle-shaped configuration extending further outwardly and backwardly from distal tip  112  with respect to the deployments of mapping electrode assemblies  120  shown in  FIGS. 6( a ) and 6( b ) . In  FIG. 7 , mapping electrode assembly  120  has been further partially deployed from distal end  112  into a fan-shaped configuration such that two further rows of larger unipolar electrodes  122 / 127  (with respect to the first row of smaller pairs of bipolar electrodes  122 / 123  shown in  FIGS. 6( a ) and 6( b ) ). Electrodes  122 / 123  and  122 / 127  are deployed on four arms  121  that have been pushed outwardly from distal tip  112  beneath distal cap  111 . (Note that in some embodiments, bipolar pairs of electrodes  122 / 123  can be replaced with unipolar single electrodes  122 , and vice-versa). 
     In the embodiment shown in  FIG. 7 , each of arms  121  comprises two splines  126  joined at tendon or chord connection point or structure  118  (although other numbers of splines  126  may be joined together or connected by structures  118 ). In  FIG. 7 , tendons or chords  115  connect three of adjoining arms  121  comprising pairs of splines  126 , and are likewise attached to tendon or chord connection points or structures  118 . Tendons or chords  115  hold the ends of splines  126  in predetermined positions relative to one another as mapping electrode assembly  120  is progressively deployed. 
     In  FIG. 7 , opening  125  shown in  FIGS. 6( a ) and 6( b )  has become a large space located between the outer edges of fan-shaped mapping electrode assembly  120 . The fan-shaped configuration of mapping electrode assembly  120  shown in  FIG. 7  is a result of utilizing and implementing the shape memory effects of splines  126  and arms  121 , and of the particular, customized, shape memory treating and manufacturing process that has been employed to make splines  126  and arms  121 . That is, splines  126  and arms  121  are pre-bent, shaped, formed, and/or treated, and utilize one or more shape memory materials such as a shape memory metal alloy that will assume progressively different geometric configurations as mapping electrode assembly  120  is deployed ever further from distal end  120  of catheter  110 . 
     As shown in  FIG. 7 , spacing E 1  may be employed to separate each row of electrodes  122 / 127  and  122 / 123  from one another. Note that electrode E 1  and E 2  may be varied according to the desired application. In some embodiments, spacing E 1  ranges between about 6 mm and about 20 mm, or between about 8 mm and about 18 mm, or between about 10 mm and about 15 mm. In some embodiments, inter-electrode spacing E 1  is varied in accordance with the maximum diameter obtained by mapping electrode assembly  120  in its fully deployed configuration, more about which is said below. 
     Referring now to  FIG. 8 , there is shown one embodiment of mapping electrode assembly  120  of  FIGS. 6( a ), 6( b )  and  7  in a fully or nearly fully deployed basket configuration, where splines  126  have been pushed outwardly and backwardly fully from distal tip  112  from beneath cap  111 . Again owing to the particular utilization and implementation of the shape memory effects inherent in splines  126  and arms  121 , and the particular customized shape memory material or metal alloy treating and manufacturing process that has been employed to make splines  126  and arms  121 , mapping electrode assembly  120 , and arms  121  and splines  126  thereof, wrap around distal portion  108  of catheter  110  to form a distinct opening  125 . Such a configuration of opening  125  permits distal portion  108  of catheter body  106  to swing or move outwardly away from a central longitudinal axis of deployed mapping electrode assembly  120  between two adjoining arms  121  through opening  125  (more about which is said below in connection with  FIGS. 10 and 10 ( a )). In some embodiments, strong bending forces and characteristics may be employed in the shape memory materials forming the portions of splines  126  located near distal tip  112 , while relatively weaker bending forces and characteristics are employed in the shape memory materials forming more centrally-located portions of splines  126  located in the equatorial regions of the resulting basket catheter. Employing disparate bending forces along splines  126  permits mapping electrode assembly  120  to switch from the fan-shaped configuration shown in  FIG. 7  to the basket configuration shown in  FIG. 8   
     In some embodiments, the resulting basket structure may have a diameter ranging between about 20 mm and about 200 mm, between about 30 mm and about 100 mm in diameter, between about 40 m and about 80 mm in diameter, and/or between about 50 mm and about 70 mm in diameter. In still other embodiments, the resulting basket structure is smaller or larger (e.g., less than 20 mm in diameter or greater than 200 mm in diameter). Basket diameters of about 50 mm, about 60 mm, and about 70 mm are also contemplated in the resulting basket structure. As discussed above, inter-electrode spacing E 1  may also be varied according to the resulting basket diameter. For example, in a 50 mm diameter embodiment, inter-electrode spacing E 1  may be about 10 mm, in a 60 mm diameter embodiment, inter-electrode spacing E 1  may be about 13 mm, and in a 70 mm diameter embodiment may be about 15 mm. 
       FIGS. 9 and 10  show front and side perspective views according to one embodiment of fully deployed mapping electrode assembly  120  of  FIG. 8 . For simplicity, electrodes are not shown on splines  126  mapping electrode assembly  120  of  FIGS. 9 and 10 .  FIGS. 9 and 10  shows opening  125  through which catheter body  106  may move or swing away from central and bottom (or distally disposed) portions of mapping electrode assembly  120 . 
       FIG. 11  shows one embodiment of distal portion  108  of catheter  110  where mapping electrode assembly  120  is in a fully deployed configuration, and where splines  126  have been pushed outwardly and backwardly fully from distal tip  112  from beneath cap  111 . For simplicity, and as in  FIGS. 9 and 10 , electrodes are not shown on splines  126  mapping electrode assembly  120  of  FIG. 11 . As shown in  FIG. 11 , the basket formed by fully deployed mapping electrode assembly  120  has a first imaginary central longitudinal axis A-A′ associated therewith, around which splines  126  are evenly or fairly evenly arranged, opened and deployed. Also shown in  FIG. 9  is a second imaginary axis B-B′ associated with portions of catheter body  106  located proximally from distal tip  112 . The first and second imaginary axes A-A′ and B-B′ of  FIG. 9  intersect one another at an angle θ. Opening  125  permits more proximally-located portions of catheter body  106  to be swung and moved outwardly away from central longitudinal axis A-A′ of the basket formed by fully deployed mapping electrode assembly  120  for alignment with axis B-B′. Being able to partially decouple catheter body  106  of catheter  110  from mapping electrode assembly  120  permits more accurate, different and quicker placement, and superior electrode coupling, of mapping electrode assembly  120  near or at a target site inside or near patient&#39;s heart  10  than may be achieved with a conventional basket catheter. 
     As further shown in  FIG. 11 , portions of catheter body  106  located just proximally from distal tip  112  may be configured such that tip  112  can be bent at location  119  and then steered in a desired direction by the physician. Such bending at location  119  of catheter body  106  and steering of tip  112  may be accomplished using a pull wire or stylet disposed inside catheter body  106 , as is well known in the art. 
     The combination of a mapping electrode assembly  120  that can be decoupled from catheter body  106  and the ability to steer or bend tip  112  in catheter  110  results, relative to prior art EP mapping catheters, in substantial improvement of mapping electrode assembly  120  being placed in optimum EP mapping positions, and electrodes having optimum coupling to tissue, inside patient&#39;s heart  10 . These desirable results are illustrated in  FIG. 12 , where one embodiment of football-shaped mapping electrode assembly  120  is shown fully deployed and electrically coupled inside patient&#39;s left atrium  14 . In the example shown in  FIG. 12 , once fully deployed inside atrium  14 , the combination of a bendable or steerable tip  112  and the decoupling mechanism enabled by opening  125  permits all or most portions of mapping electrode assembly  120  to be electrically coupled to the walls of atrium  14 , including portions of the atrial walls that are actually located behind and to the left of the entry point of distal end  112 . This may be accomplished, for example, by the physician pulling backwardly on catheter body  106  once electrode assembly  120  has been fully deployed in atrium  14 . Given the steep entry angle of distal tip  112  into patient&#39;s atrium  14  via the foramen ovalen and trans-septal puncture, such optimal positioning and electrode coupling cannot be achieved using a conventional basket catheter (as illustrated in  FIG. 13 , where it is shown that a conventional basket catheter cannot be positioned, at least not without great difficulty, leftwardly from the atrial entry point of distal tip  112 ). 
     In other embodiments, catheter  110  is a basket catheter 
       FIG. 14  shows one method  200  of using the configurable multi-application electrophysiological mapping catheter described above and shown in  FIGS. 2 through 12 . At step  202 , configurable multi-application EP mapping catheter  110  is guided to a selected or desired site within or near patient  10 &#39;s heart  10  (e.g., to the right or left atrium, or one of the pulmonary veins or arteries)). In some embodiments, imaging and/or navigation system  60  is employed help guide catheter  110  to the site. At step  203 , and after being guided to the desired or selected site, configurable multi-application EP mapping catheter  110  is deployed into a desired electrode configuration (e.g., the mushroom-shaped electrode configuration of  FIGS. 6( a )  or  6 ( b ), the fan-shaped electrode configuration of  FIG. 7 , or the basket-shaped electrode configuration of  FIG. 8 ). EP data are then acquired, processed, displayed at step  206  using system  100 , which are then interpreted by the physician or other health care professional. At step  208 , the physician or other health care professional determines whether additional or different EP data are required to identify treatment locations within or near patient&#39;s heart  10 . If so, steps  204  and  206  are repeated. If not, at step  210  patient&#39;s heart  10  is treated at the identified locations by, for example, ablating heart or pulmonary vein or artery tissue at the desired location identified in step  208 . At step  212 , configurable multi-application EP mapping catheter  110  is redeployed into a desired electrode configuration at a desired step, and at step  214  EP data are once again acquired, processed, and displayed using system  100 . The results obtained in step  214  are then interpreted by the physician or other health care professional. At step  216 , the physician or other health care professional determines whether additional or different EP data are required to identify additional treatment locations within or near patient&#39;s heart  10 . If so, steps  212  and  214  are repeated. If not, at step  218  patient&#39;s heart  10  is treated at the additional identified locations by, for example, ablating heart or pulmonary vein or artery tissue at the desired location identified in step  216 . At step  220 , the efficacy and success of the treatment and surgery can be confirmed by redeploying configurable multi-application EP mapping catheter  110  to a desired site, and acquiring, processing, displaying and interpreting EP data. 
     Provided now are some illustrative details regarding the composition, materials, and manufacture of some embodiments of catheter  110 . 
     Depth markers on proximal portion  116  of lead body  106  and/or on outer sheath  104  may be used by a physician to gauge the extent to distal tip  112  of catheter  110  has been inserted inside the patient. By way of example, depth markers may be formed of polyethylene heat shrink, or printed on lead body  15  using medical grade ink. 
     An electrically insulative material may be employed inside catheter body  106  to protect electrical conductors disposed within catheter body  106  from the corrosive effects presented by body fluids, and may be formed of a biocompatible material such as a suitable polyurethane, silastic compound, a fluoro-copolymer such as fluorinated ethylene propylene (FEP) or TEFLON 100™, nylon, or any other suitable electrically insulative material. 
     Outer sheath  104  and portions of catheter body  106  may comprise a biocompatible material such as polyethylene, or any other suitable polymer or polymeric compound such as PEBAX. 
     Catheter  110 , catheter body  106 , and outer sheath  104  (if used) may be configured to have lengths appropriate for pediatric use, use in persons having different body sizes, or implantation through different entry points such as the left or right subclavian vein, the internal jugular vein, or the right or left femoral veins. Additionally, catheter body  106  and catheter  110  may be configured to have lengths appropriate for implantation in the right atrium, the left atrium, the right ventricle, and/or the left ventricle. 
     In some embodiments, electrical conductors disposed within lead body  106 , and that are operably attached to electrodes  122  and external connector  115 , comprise one or more suitable flexible electrically conductive materials such as metal or metal alloy wires, or stranded, wound, braided and/or twisted metal or metal alloy wires that are capable of reliably conducting electrical current after having been subjected to numerous, repeated bending and torquing stresses. Such conductors may be formed, by way of non-limiting example, of wires comprising a nickel-titanium alloy such as NITINOL™, stainless steel, platinum, gold, silver, palladium, other noble metals, and other alloys or metals suitable for use in the human body. 
     In some embodiments, catheter body  106  has a diameter ranging between about 2 French and about 10 French, or between about 3 French and about 8 French, or between about 4 French and about 6 French. Other diameters of catheter body  106  are also contemplated. In addition, catheter  110  may have incorporated therein tissue ablation mechanisms and/or components, and/or force sensing mechanisms, such as those described in the aforementioned &#39;924 patent application. 
     In one embodiment electrode assembly  120  is configured to be controllably deployed and advanced from distal tip  112  of catheter  110  by a user operating electrode deployment and control mechanism  102  into any two or more of the following configurations: (a) a first initial deployment configuration suitable for pulmonary vein isolation (PV) EP mapping (see, e.g.,  FIGS. 4( b ), 5( b ), 6( a ), and 6( b ) ); (b) a second intermediate deployment fan or paddle configuration suitable for high-resolution EP mapping (see, e.g.,  FIGS. 4( c ), 5( c ) , and  7 ); and (c) a third fully or nearly fully deployed basket configuration suitable for medium-resolution EP mapping, the basket configuration having imaginary central longitudinal axis A-A′associated therewith when the basket is deployed in an unobstructed and unconfined space (see, e.g.,  FIGS. 4( d ), 5( d ) ,  8 ,  9 ,  10 ,  11 , and  13 ), and further wherein: (i) in the first configuration electrode mapping assembly  120  is deployed by the user a first distance from distal portion  108  of catheter body  106  (see, e.g., distance D 1  of  FIGS. 4( b ) and 5( b ) ); (ii) in the second configuration electrode mapping assembly  120  is deployed by the user a second distance from distal portion  108  of catheter body  106  (see, e.g., distance D 2  of  FIGS. 4( c ) and 5( c ) ); and (iii) in the third configuration electrode mapping assembly  120  is deployed by the user a third distance from distal portion  108  of catheter body  106  (see, e.g., distance D 3  of  FIGS. 4( d ) and 5( d ) ), and further wherein the first distance is less than the second distance, the second distance is less than the third distance, opening  125  is located between at least portions of two adjoining splines in electrode mapping assembly  120 , no chord or tendon is located within at least portions of opening  125  such that portions of catheter body  108  located proximally from distal tip  112  can be moved by a user away from longitudinal axis A-A′ of the basket in a direction of opening  125  (see, e.g.,  FIG. 11 ). In such an embodiment, corresponding methods can comprise two or more of: (1) deploying electrode mapping assembly  120  into the first configuration inside or near patient&#39;s heart  10 ; (2) deploying electrode mapping assembly  120  into the second configuration inside or near patient&#39;s heart  10 , and (3) deploying electrode mapping assembly  120  into the third configuration inside or near patient&#39;s heart  10 . 
     In another embodiment electrode assembly  120  is configured to be controllably deployed and advanced from distal tip  112  of catheter  110  by a user operating electrode deployment and control mechanism  102  into a basket configuration, the basket configuration having an imaginary central longitudinal axis A-A′ associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein opening  125  is located between at least portions of two adjoining splines in electrode mapping assembly  120 , no chord or tendon  115  is located within at least portions of opening  125  such that portions of catheter body  106  located proximally from distal tip  112  can be moved by a user away from longitudinal axis A-A′ of the basket in a direction of opening  125 . In such an embodiment, corresponding methods can comprise deploying the electrode mapping assembly into the basket configuration inside or near the patient&#39;s heart. 
     In yet another embodiment electrode assembly  120  is further configured to be controllably deployed and advanced from distal tip  112  of catheter  110  by a user operating electrode deployment and control mechanism  102  into the following configurations: (a) a first circular, semi-circular, oval, elliptical, or lasso-like configuration suitable for pulmonary vein isolation (PV) EP mapping (see, e.g.,  FIGS. 4( b ), 5( b ), 6( a ), and 6( b ) ); and (b) a second basket configuration, the basket having imaginary central longitudinal axis A-A′ associated therewith when the basket is deployed in an unobstructed and unconfined space (see, e.g.,  FIGS. 4( d ), 5( d ) ,  8 ,  9 ,  10 ,  11 , and  13 ), and further wherein: (i) in the first configuration electrode mapping assembly  120  is deployed by the user a first distance from distal portion  108  of the catheter body  106  (see, e.g., distance D 1  of  FIGS. 4( b ) and 5( b ) ), and (ii) in the second configuration electrode mapping assembly  120  is deployed by the user a second distance from distal portion  108  of catheter body  106  (see, e.g., distance D 3  of  FIGS. 4( d ) and 5( d ) ); and further wherein the first distance is less than the second distance, opening  125  is located between at least portions of two adjoining splines in electrode mapping assembly  120 , no chord or tendon  115  is located within at least portions of opening  125  such that portions of catheter body  106  located proximally from distal tip  112  can be moved by a user away from longitudinal axis A-A′ of the basket in a direction of opening  125 . In such an embodiment, corresponding methods can comprise at least one of: (1) deploying the electrode mapping assembly into the first configuration inside or near the patient&#39;s heart, and (2) deploying the electrode mapping assembly into the second configuration inside or near the patient&#39;s heart. 
     In still another embodiment electrode assembly  120  is configured to be controllably deployed and advanced from distal tip  112  of catheter  110  by a user operating electrode deployment and control mechanism  102  into any two or more of the following configurations: (a) a first fan-shaped configuration of mapping electrode assembly  120  wherein electrodes mounted on or attached to central portions of adjoining spines are separated from one another by distances ranging between about 0.25 cm and about 2 cm such that mapping electrode assembly  120  is configured to provide high spatial resolution EP data; and (b) a second basket configuration of mapping electrode assembly  120  wherein electrodes mounted on or attached to central portions of adjoining spines are separated from one another by distances ranging between about 1 cm and about 4 cm such that mapping electrode assembly  120  is configured to provide medium spatial resolution EP data, the basket configuration having imaginary central longitudinal axis A-A′ associated therewith when the basket is deployed in an unobstructed and unconfined space, and further wherein: (i) in the first configuration electrode mapping assembly  120  is deployed by the user a first distance from distal portion  108  of catheter body  106 ; (ii) in the second configuration electrode mapping assembly  120  is deployed by the user a second distance from distal portion  108  of catheter body  106 ; and further wherein the first distance is less than the second distance, opening  125  is located between at least portions of two adjoining splines in electrode mapping assembly  120 , no chord or tendon  115  is located within at least portions of opening  125  such that portions of catheter body  106  located proximally from distal tip  112  can be moved by a user away from longitudinal axis A-A′ of the basket in a direction of opening  125 . In such an embodiment, corresponding methods can comprise at least one of: (1) deploying electrode mapping assembly  120  into the first configuration inside or near patient&#39;s heart  10 , and (2) deploying electrode mapping assembly  120  into the second configuration inside or near patient&#39;s heart  10 . 
     In yet a further embodiment, EP mapping catheter  120  comprises elongated catheter body  106  comprising proximal portion  116 , distal portion  108 , and distal tip  112 , electrode deployment and control mechanism  102  located near or at proximal portion  116  of catheter body  108 , deployable electrode mapping assembly  120  operably connected to electrode deployment and control mechanism  102 , electrode mapping assembly  120  comprising a plurality of electrodes  122 / 123 / 127  and a plurality of splines  126 , each spline  126  having a proximal end and a distal end, electrodes  122 / 123 / 127  being mounted on or connected to at least some of splines  126 , at least some of splines  126  comprising a shape memory material, at least the distal end of each spline  126  being configured to bend or be bent backwardly from distal tip  112  towards more proximal portions of catheter body  106  as the plurality of splines  126  is deployed from or near distal tip  112 , wherein at least major portions of electrode mapping assembly  120  are configured to fit within distal portion  108  of catheter body  106  when electrode assembly  120  is in an undeployed configuration, electrode assembly  120  further being configured to be controllably deployed and advanced from distal tip  112  of catheter  110  by a user operating electrode deployment and control mechanism  102  into at least one of the following configurations: (a) a first circular, semi-circular, oval, elliptical, or lasso-like configuration suitable for pulmonary vein isolation (PV) EP mapping; (b) a second fan-shaped configuration of the mapping electrode assembly suitable for acquiring high-resolution EP data; and (c) a third basket configuration suitable for acquiring medium-resolution EP data. In such embodiments, opening  125  between splines  126  may—or may not—be included or provided in catheters  110  described herein. Methods of deploying and using catheter  110  according to such embodiments are also contemplated, as are catheters  110  capable of assuming only one of the aforementioned three configurations (e.g., circular, fan-shaped, and basket configurations). 
     In still further embodiments, any of the above- or below-described catheters  110  and corresponding methods can be modified such that there is no opening  125  located between adjoining splines  126  where portions of catheter body  106  located proximally from distal tip  112  can be moved by a user away from the longitudinal axis A-A′ of the basket through such opening  125 . In such embodiments, movement of catheter body  106  outside proximally-located portions of a fully deployed or nearly fully-deployed basket-shaped mapping electrode assembly  120  may not be possible owing to the presence of chords or tendons  115  in the path of catheter body  106 . 
     The foregoing embodiments may further comprise one or more of: catheter  110  being configured to permit portions of catheter body  106  located proximally from distal tip  112  to be moved by the user away from longitudinal axis A-A′ of the basket in the direction of and through opening  125 ; catheter  110  being configured to permit portions of catheter body  106  located proximally from distal tip  112  to be moved by the user away from longitudinal axis A-A′ of the basket in the direction of and outside opening  125 ; distal tip  112  of catheter  110  being configured to be steerable or bent by the user; outer slidable sheath  104  being configured to permit deployment of electrode mapping assembly  120  from distal tip  112  of the catheter; outer slidable sheath  104  being steerable or having a tip thereof that is steerable; a steerable sheath  104  comprising a steerable distal end; electrode mapping assembly  120  comprising between 4 splines and 12 splines  126 ; each spline  126  having attached thereto, mounted thereon or formed therein between 1 and 16 electrodes  122 / 123 / 127 ; distal ends of adjoining splines  126  forming pairs of splines  126  that are joined or connected to one another; one or more navigation elements, navigation coils, navigation markers or navigation electrodes; a shape memory material comprising one or more of Nitinol, a shape memory metal, a shape memory alloy, a shape memory polymer, a shape memory composite, or a shape memory hybrid; at least one spline  126  in electrode mapping assembly  120  comprising laminated materials; mapping electrode assembly  120  being deployed by pushing mapping electrode assembly  120  out of distal end  112  of catheter  110  using the electrode deployment and control mechanism; a tissue ablation mechanism located at or near distal tip  112  of catheter  110 ; spatial resolution provided by electrodes  122 / 123 / 127  in electrode mapping assembly  120  and an associated spacing between splines  126  changing in accordance with the first, second and third configurations thereof; a diameter of arms  121  of electrode mapping assembly  120  ranging between about 6 mm and about 14 mm when electrode mapping assembly  120  is deployed in the first configuration; a diameter of arms  121  of electrode mapping assembly  120  ranging between about 6 mm and about 14 mm when electrode mapping assembly  120  is deployed in the first configuration; a diameter of arms  121  of electrode mapping assembly  120  ranging between about 10 mm and about 20 mm when electrode mapping assembly  120  is deployed in the first configuration; a length of each tendon or chord  115  ranging between about 6 mm and about 20 mm; electrodes  122 / 123 / 127  being one or more of unipolar electrodes and bipolar electrodes; spacing between adjoining electrodes  122 / 123 / 127  located on the same spline  126  ranging between about 0.5 mm and about 1 mm, between about 0.25 mm and about 2 mm, between about 6 mm and about 20 mm, between about 8 mm and about 18 mm, or between about 10 mm and about 15 mm; the third basket structure having an outer diameter ranging between about 20 mm and about 200 mm, between about 30 mm and about 100 mm in diameter, between about 40 mm and about 80 mm in diameter, or between about 50 mm and about 70 mm, or is about 50 mm, about 60 mm or about 70 mm. 
     The foregoing embodiments may further comprise one or more of: distal tip  112  of catheter  110  being configured to be steerable or bent by the user, and the user bends or steers distal tip  112  of catheter  110  inside or near patient&#39;s heart  10 ; acquiring EP signals from the patient using electrodes  122 / 123 / 127  in deployed electrode mapping assembly  120 ; processing the acquired EP signals so that the signals may be interpreted by the user; redeploying electrode mapping assembly  120  into a different configuration or location within or near patient&#39;s heart  10  based upon results provided by the processed EP signals; changing the configuration of electrode mapping assembly  120  from one of the first, second and third configurations to a different configuration; deploying mapping electrode assembly  120  by pushing mapping electrode assembly  120  out of the distal end  112  of catheter  110  using electrode deployment and control mechanism  102 ; ablating tissue at a location in or near the patient&#39;s heart  10 , the location being identified using the processed EP signals. 
     It will now become apparent to those skilled in the art that configurable multi-application EP mapping catheter  110  provides a significant advantage to physicians and patients alike, in that only a single EP mapping catheter need be employed to carry out all the steps of method  200  illustrated in  FIG. 14 , and that multiple EPO catheters need not be inserted within and withdrawn from the patient&#39;s heart and vasculature to obtain EP mapping data and information required to inform and guide the treatment process. It will now be seen that the various systems, devices, components and methods disclosed and described herein are capable of detecting with considerable accuracy and precision the locations of the sources of cardiac rhythm disorders in and near a patient&#39;s heart. 
     The various systems, devices, components and methods described and disclosed herein may also be adapted and configured for use in EP mapping and/or neurological sensing and mapping applications other than those involving the interior of a patient&#39;s heart or the pulmonary veins or arteries. These alternative applications include, but are not limited to, EP mapping and diagnosis, or other forms, means or methods of electrically sensing, a patient&#39;s stomach, colon, esophagus, veins, arteries, aorta, or any other suitable portion of a patient&#39;s body such as a patient&#39;s brain. The various embodiments further include within their scope methods of implanting, using and making the leads described hereinabove. 
     What have been described above are examples and embodiments of the devices and methods described and disclosed herein. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the devices and methods described and disclosed herein are possible. Accordingly, the devices and methods described and disclosed herein are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims. In the claims, unless otherwise indicated, the article “a” is to refer to “one or more than one.” 
     The foregoing outlines features of several embodiments so that those skilled in the art may better understand the detailed description set forth herein. Those skilled in the art will now understand that many different permutations, combinations and variations of hearing aid  10  fall within the scope of the various embodiments. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure. 
     After having read and understood the present specification, those skilled in the art will now understand and appreciate that the various embodiments described herein provide solutions to long-standing problems, both in the use of electrophysiological mapping systems and in the use of cardiac ablation systems.