Abstract: An electrophysiology catheter includes an elongate catheter body having an elastically-deformable distal region predisposed to assume a spiral shape and a first plurality of electrodes disposed thereon. Each of the first plurality of electrodes includes an electrically active region limited to the inner surface of the spiral shape for use in non-contact electrophysiology studies. A second plurality of electrodes may also be disposed on the distal region interspersed (e.g., alternating) with the first plurality of electrodes, with each of the second plurality of electrodes having an electrically active region extending into the outer surface of the spiral shape for use in contact electrophysiology studies. The distal region may be deformed into a straight configuration for insertion into and navigation through the patient's vasculature, for example via use of a tubular introducer. As the distal region deploys beyond the distal end of the introducer, it resumes the spiral shape.

Abstract: Electrode cabling, including a core and n wires coiled on the core in an arrangement topologically equivalent to an n-start thread configuration, wherein n is an integer greater than one. The cabling also includes a sheath covering the n wires and an electrode attached through the sheath to a given wire selected from the n wires.

Abstract: Temporarily or permanently implantable medical device, having at least one longitudinally extended first electrical conductor having a functional lead, which is connected to a functional electrode pole for dispensing therapeutic signals or for detecting diagnostic signals, and including at least one second electrical conductor, which is coupled to the functional lead and is guided with it in a shared insulating sheathing, such that a coupling between the functional lead and the second electrical conductor is designed to input electromagnetic radiofrequency waves guided in the functional lead at least partially into the second electrical conductor.

Abstract: A delivery system for implanting a biostimulation device comprising a stylet extending along an axis from knob end to a threaded end configured to engage an internally threaded nut of the biostimulation device and a catheter tube configured to axially contain the stylet. The catheter tube comprises a feature that engages a corresponding feature on the biostimulation device whereby the stylet can be rotated relative to the catheter tube for disengagement of the stylet threaded end from the biostimulation device threaded end.

Abstract: An implantable medical device for electrical stimulation or sensing includes a body supporting at least one flexible elongate conductor element. The body includes an insulating structure that protects the flexible conductor element(s). The insulating structure is realized from multiple polymer layers wherein at least one of the polymer layers is formed from a polymer blend of a thermoplastic polyurethane material and an isobutylene block copolymer. In one particular embodiment, the insulating structure of the body includes at least a first polymer layer, a second polymer layer and a third polymer layer, where the second polymer layer covers and interfaces to the first polymer layer, and the third polymer layer covers and interfaces to the second polymer layer. The first polymer layer is formed from a thermoplastic polyurethane material. The third polymer layer is formed from an isobutylene block copolymer.

Abstract: A method and system for determining the mechanism of cardiac arrhythmia in a patient is disclosed. The method basically entails measuring the impedance of cardiac tissue in a portion of the patient's heart using a catheter during an episode of supraventricular tachycardia to produce an iso-impedance map of that cardiac tissue on a video display and analyzing the pattern of the iso-impedance map to differentiate focal arrhythmia caused by a circumscribed region of focal firing and reentrant arrhythmia caused by a macroreentrant circuit. The method can also be used to identify regions of coherent rapidly conducting tissue e.g., Bachman's bundle or the inferoposterior pathway insertion points, to identify focal “mother rotors” throughout the left atrium that may participate in the generation and maintenance of atrial fibrillation and to identify areas of CAFE (complex atrial/fractionated electrograms) that truly reflect these mother rotors.

Abstract: A volume of a patient can be mapped with a system operable to identify a plurality of locations and save a plurality of locations of a mapping instrument. The mapping instrument can include one or more electrodes that can sense a voltage that can be correlated to a three dimensional location of the electrode at the time of the sensing or measurement. Therefore, a map of a volume can be determined based upon the sensing of the plurality of points without the use of other imaging devices. An implantable medical device can then be navigated relative to the mapping data.

Abstract: Systems, methods and non-transient software media for performing sensing vector selection in an implantable cardiac device by assessing biphasic or monophasic characteristics of the cardiac signal in vectors under analysis. A factor associated with the biphasic or monophasic nature of the cardiac signal, as seen from a given sensing vector, can be inserted into the assessment of which of several available sensing vectors is considered “best” for purposes of cardiac signal analysis. Additional factors may be considered beyond the biphasic or monophasic nature including the quantity of turning points or inflections and amplitude variability.

Abstract: A multi electrode catheter for non contact mapping of the heart having independent articulation and deployment features.

Abstract: In various examples, an apparatus includes an apparatus configured for implantation within a body of a patient. The apparatus, in some examples, includes a housing. At least one antenna extends from the housing, the antenna being flexible such that the antenna conforms to the body of the patient. In some examples, the apparatus includes at least three electrodes, wherein at least a first electrode is disposed on the antenna and at least a second electrode is disposed on the housing. The at least three electrodes are disposed in a non-linear configuration, allowing for differential processing of signals recorded by the at least three electrodes.

Abstract: Systems, devices and methods described herein can be used to monitor and treat cardiovascular disease, and more specifically, can be used to determine heart rate (HR), determine respiration rate (RR) and classify cardiac rhythms based on atrial intracardiac electrogram (IEGM) and atrial pressure (AP) signals. The atrial IEGM and AP signals are subject to spectrum transforms to obtain an atrial IEGM frequency spectrum and an AP frequency spectrum. Based on peaks in the atrial IEGM and AP frequency spectrums measures of HR and RR are determined, and arrhythmias are detected and/or arrhythmia discrimination is performed.

Abstract: A sacrificial catheter assembly and method of use for placing a functional catheter within the body of a patient, such as into the patient's vasculature, is disclosed. In one embodiment, the sacrificial catheter assembly comprises a sacrificial catheter including an elongate body that defines a longitudinally extending lumen. A stylet is removably received within the lumen of the sacrificial catheter such that the catheter and stylet can be advanced together to a target destination within the body of the patient. The sacrificial catheter is configured so as to then be proximally slid over the stylet to remove the sacrificial catheter from the body while the stylet remains in place at the target destination. A functional catheter can then be distally slid over the stylet to place the functional catheter at the target destination. The stylet can then be removed from the body of the patient.

Abstract: The present disclosure provides methods and techniques associated with a planar transformer for an apparatus. The planar transformers include a substrate carrying electronic components and a continuous core that is formed by distributing the encapsulant material uniformly around the substrate unit to define a consistent cross-sectional area for the magnetic path. The electronic components include primary windings and secondary windings associated with the transformer. In some embodiments, the encapsulant material is molded to seals air gaps to the substrate unit.

Abstract: A medical device can be localized by providing at least three non-colinear localization elements (e.g., electrodes) thereon. Once placed in a non-ionizing localization field, three adjacent localization elements, at least one of which will typically be a spot electrode, may be selected, and the non-ionizing localization field may be used to measure their locations. A cylinder is defined to fit the measured locations of the selected localization elements. The cylinder is rotationally oriented using the measured location of a spot electrode. Location and rotational attitude information may be used to construct a three-dimensional representation of the medical device within the localization field. The electrodes may be provided on the medical device or on a sheath into which the medical device is inserted. The invention also provides systems and methods for identifying and calibrating deflection planes where the medical device and/or sheath are deflectable.

Abstract: A closed-ended catheter assembly that includes an electrically conductive pathway is disclosed. The conductive pathway enables electrical signals, such as ECG signals produced by a patient's heart, to pass through the closed-ended tip of the indwelling catheter while still preventing unintended fluid flow. In one embodiment, therefore, a catheter assembly is disclosed and comprises an elongate catheter tube including a closed distal end. The catheter tube defines at least one lumen and includes a valve defined in the catheter tube that is configured to selectively enable fluids to pass therethrough. The catheter tube includes a conductive element that provides an electrically conductive pathway between the at least one lumen and an exterior portion of the catheter. The conductive element includes a porous material extending between the at least one lumen and the exterior portion of the catheter, the porous material being transmissive to electrical signals and non-permeable to blood.

Abstract: An implantable cardiac monitoring device includes first and second arms, pivotably attached to one another; electronic circuitry and an associated power source of the device are hermetically sealed in a housing formed by one of the arms. A first electrode is carried by the first arm, a second electrode by the second arm, and a third electrode by one of the two arms. The device further includes a tether element, preferably a strut, pivotably attached between the arms and movable between a folded state and an expanded state. When the strut is in the folded state, the device, in a relatively compact form, can be inserted through a relatively small incision and into subcutaneous tissue, after which, the strut is moved to the expanded state where ends of the arms are spaced apart from one another and supported by the strut, and the three electrodes form dual sensing vectors.

Abstract: A method of detecting whether a localization element is within or outside of an introducer sheath generally includes obtaining a localization signal from the localization element and detecting the state of the localization element relative to the sheath based upon the quadrature component of the localization signal. A baseline quadrature component is typically established with the localization element outside of the sheath. When the quadrature component deviates from this baseline value, it is indicative of the localization element being within the sheath. Conversely, when the quadrature component remains relatively close to the baseline value, it is indicative of the localization element being outside of the sheath. In an electrophysiology study, the state information can be used to take corrective action with respect to the data being collected.

Abstract: Cardiac valve events are monitored by recording a left atrial pressure (LAP) representing signal using an implantable pressure sensor (50). The LAP signal is processed in order to generate a derivative LAP signal representative of the first time derivative of the LAP signal. The opening of the aortic valve of the heart is then identified to coincide in time with a minimum in the derivative LAP signal following ventricular depolarization in a cardiac cycle.

Abstract: An volume of a patient can be mapped with a system operable to identify a plurality of locations and save a plurality of locations of a mapping instrument. The mapping instrument can include one or more electrodes that can sense a voltage that can be correlated to a three dimensional location of the electrode at the time of the sensing or measurement. Therefore, a map of a volume can be determined based upon the sensing of the plurality of points without the use of other imaging devices. An implantable medical device can then be navigated relative to the mapping data.

Abstract: A system and method for localizing a catheter is provided. Distance values are determined between a plurality of reference electrodes and a catheter electrode. At least two circles are identified based on the distance values. The catheter electrode is located at a position where the at least two circles substantially coincide or within a minimum distance between the at least two circles. A transformation is applied to the at least two circles to express the at least two circles in a global coordinate system. An image is displayed as a function of the catheter electrode position.

Abstract: An electrode support structure assembly is provided comprising an electrode support structure including a plurality of splines. Each of the plurality of splines can have a proximal end portion and a distal end portion. The assembly further comprises a first element defining an axis and comprising an outer surface. The outer surface comprises a plurality of slots configured to receive the distal end portion of each of the plurality of splines. The first element is configured such that the distal end portion of each of the plurality of splines may move with respect to each slot. In accordance with some embodiments, the distal end portion of each of the plurality of splines comprises a section configured for engagement with the first element, wherein the section comprises a shoulder.

Abstract: An accessory and system to provide a medical device with mapping and ablation functionality. The system may include an ablation device with a handle, a treatment element, and an elongate body. The ablation element may be located on the elongate body distal portion, and a mapping sleeve may be disposable about at least part of the distal portion of the ablation device and may include mapping electrodes disposed on the outer surface. The mapping sleeve proximal region may include a retraction element defining a proximal end and a distal end, the distal end being coupled to the proximal region of the mapping sleeve, such that retracting the retraction element toward the elongate body proximal portion pulls the mapping sleeve away from the treatment element of the ablation device.

Abstract: A method and system of electroanatomical mapping comprises bringing a patient's image such as a fluoroscopic image and intracardiac signals into a computer based mapping system. Electroanatomical mapping or superimposing of cardiac electrical activity on fluoroscopic image is provided by placing visual indicators on electrode pairs of various catheters including standard catheters and ablation catheter. Visual indicators are coupled or linked to underlying electric signals from those electrode pairs via software coding, whereby electrical activity sequence of the heart is provided and updated in real-time on fluoroscopic image. A combination of fluoroscopic image and CT or MRI may also be used. The mapping system further comprises various algorithms for aiding in cardiac mapping and ablation of cardiac arrhythmias.

Abstract: A system (10) can localize an object in a patient's body. The system (10) can include a pulse generator (18 or 30) configured to provide a localization signal to at least one electrode that is fixed to the object in the patient's body. A sensor array (22) can be configured to detect an electrical field produced in response to the localization signal and provide respective sensor signals. A map generator (42) can be configured to reconstruct electrical signals based on the respective sensor signals and geometry data representing a geometric relationship between patient anatomy and the sensor array. A location calculator (50) can determine a location where the localization signal was applied based on the reconstructed electrical signals.

Abstract: A base cardiac electrogram signal at a base electrode is recorded for a predetermined amount of time. A plurality of cardiac electrogram signals at a plurality of electrodes other than the base electrode are recorded for the predetermined amount of time. The base cardiac electrogram signal is compared with each of the plurality of cardiac electrogram signals. The similarities between the base cardiac electrogram signal and each of the plurality of cardiac electrogram signals is determined. A specific area of cardiac tissue where the base electrode is positioned is mapped based at least in part on the determined similarities.

Abstract: A method and system for determining activation times for electric potentials from complex electrograms to identify the location of arrhythmic sources or drivers. The method includes counting a number deflections in a recorded cardiac electrogram signal from at least one electrode for a predetermined amount of time. A deflection time is identified for each of the counted number of deflections. A most negative slope is identified between each of the identified deflections times. Each of the identified most negative slopes is correlated to a possible activation time. Each possible activation time is associated with a corresponding electrode from the at least one electrode. A spatial voltage gradient at each corresponding electrode is calculated for each possible activation time. The greatest spatial voltage gradient is identified. The greatest spatial voltage gradient is correlated to an activation time.

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

Abstract: A system for sensing multiple local electric voltages from endocardial surface of a heart, includes: an elongate tubular member having a lumen, a proximal end and a distal end; a plurality of flexible splines; an anchor for securably affixing the proximal portions of the splines, where the anchor is securably affixed within the lumen of the elongate tubular member at the distal end of the elongate tubular member; and a metallic tip for securably affixing the distal portions of the splines.

Abstract: A system and method for guiding a catheter or other medical device to a desired target destination within the vasculature of a patient via bioimpedance measurements is disclosed. The target destination in one embodiment includes placement of the catheter such that a distal tip thereof is disposed proximate the heart, e.g., the junction of the right atrium and superior vena cava. In one embodiment the method for guiding the catheter comprises introducing the catheter into a vessel of the patient, the catheter defining a lumen through which fluids can be infused into the vasculature of the patient. The catheter is advanced toward a target destination within the vasculature. A first impedance value based on intravascular detection of at least one electrical property related to a first tissue surface of the vessel is calculated to enable determination of the proximity of a distal end of the catheter to the target destination.

Abstract: A tissue electrode assembly includes a membrane configured to form an expandable, conformable body that is deployable in a patient. The assembly further includes a flexible circuit positioned on a surface of the membrane and comprising at least one base substrate layer, at least one insulating layer and at least one planar conducting layer. An electrically-conductive electrode covers at least a portion of the flexible circuit and a portion of the surface of the membrane not covered by the flexible circuit, wherein the electrically-conductive electrode is foldable upon itself with the membrane to a delivery conformation having a diameter suitable for minimally-invasive delivery of the assembly to the patient.

Abstract: The present invention provides a handy remote physiological signal detection system, comprising a sensing unit, a stimulation unit and a control unit. The sensing unit includes a detecting electrode, a first surface detection electrode, a second surface detection electrode and a sensing module. The sensing modules is used to detect the signals between the detection electrode and the first surface detection electrode to get an epicardial detection signal, and is also used to detect the signals between the second surface detection electrode and the first detection electrode to get a surface-ECG signal. The stimulus unit includes a stimulating electrode and a stimulus module used to provide a stimulus signal to the stimulating electrode. The control unit includes a user interface and a processing module used to convert the epicardial detection signal and the surface-ECG signal to digital signals and display the digital signals in the user interface.

Abstract: This invention provides a percutaneous implantable electrode array that can be deployed or repositioned though a needle insertion site. The deployable electrode apparatus, in one embodiment, is made of a fixed electrode array on a central body of the apparatus and a deployable electrode array. The deployable electrode array is actuated by at least two struts, each of the struts having a first and second end. The central body of the apparatus is configured to retain the first end of the at least two struts. Each of the side arrays are flexurally connected to the second end of each of the strut and the side arrays are connected to at least one stylet, which extends to the proximal end of the apparatus.

Abstract: An apparatus which includes a dual loop structure that carries a plurality of operative elements. A guide with a distal indentation that may be used to reorient a dual loop structure.

Abstract: An embodiment of a mapping probe assembly includes a body frame with a lumen therein. The body frame includes a catheter shaft region, a loop section and a transition region between the catheter shaft region and a loop section. A plurality of mapping electrodes are attached around the loop section. Electrical conductors extend through the lumen of the body frame to the mapping electrodes. In some embodiments, the loop section is skived, where a portion of the body frame is removed toward the interior of the loop section. The loop section has a generally planar loop, and further has a loop center. In some embodiments, the catheter shaft has an alignment generally perpendicular to the loop section where the alignment of the catheter shaft is along a line that intersects the planar loop proximate to the loop center.

Abstract: Devices, systems, and methods for remotely monitoring physiologic cardiovascular data are disclosed. At least some of the embodiments disclosed herein provide access to the external surface of the heart through the pericardial space for the delivery of the sensor to the epicardial surface of the heart. In addition, various disclosed embodiments provide for a memory device capable of receiving the physiologic cardiovascular data collected by the sensors and transmitting such data wirelessly to a remote location.

Abstract: Implantable medical leads and methods of forming such leads are disclosed. An implantable medical lead includes a lead body, a swage base coupled to the lead body, and a polymeric member interposed at least in part between the swage base and at least one rigid component of the lead such as an electrode or annular ring. The swage base includes an annular-shaped body including a flange having a number of protrusions that extend radially outward from the flange. During a swaging process, the protrusions on the flange are compressed against the polymeric member, forming a number of channels in the member that mechanically bond the member to the swage base.

Abstract: Catheters, systems, and related methods for optimized for mapping, minimizing, and treating cardiac fibrillation in a patient, including an array of at least one stacked electrode pair, each electrode pair including a first electrode and a second electrode, wherein each electrode pair is configured to be orthogonal to a surface of a cardiac tissue substrate, wherein each first electrode is in contact with the surface to record a first signal, and wherein each second electrode is separated from the first electrode by a distance which enables the second electrode to record a second signal, wherein the catheter is configured to obtain one or more measurements from at least a first signal and a second signal in response to electrical activity in the cardiac tissue substrate indicative of a number of electrical circuit cores and distribution of the electrical circuit cores for a duration across the cardiac tissue substrate.

Abstract: Methods and systems for mapping cardiac fibrillation in a patient include deploying a catheter in the patient's heart, wherein the catheter includes an array of at least one stacked electrode pair having a first electrode and a second electrode. Each electrode pair is configured to be orthogonal to the surface of a cardiac tissue substrate. A plurality of measurements are obtained from the electrode array in response to electrical activity in the cardiac tissue substrate for a duration indicative of a number of electrical circuit cores and distribution of the electrical circuit cores across the cardiac tissue substrate in the patient's heart. These are processed to obtain the density and distribution of electrical circuit cores which are mapped onto a representation of the patient's heart.

Abstract: A catheter having a distal assembly with multiple spines with proximal ends affixed to the catheter and free distal ends. The spines have different lengths so distal ends of the spines trace different circumferences along an inner tissue surface of a tubular region to minimize risk of vein stenosis. The spine lengths can be configured so that the distal ends trace a helical pattern. The distal assembly may have a plunger which deflects the spines when moved longitudinally relative to the distal assembly. The catheter may include a second distal assembly distal of a first distal assembly wherein the first and second distal assemblies are separated by a fixed distanced or an adjustable distance.

Abstract: A heart support system featuring a sheath sized to fit about at least a portion of an adult human heart in a living body, an expansion sleeve disposed within the sheath and sized to fit about the heart and a sensor sleeve disposed within the sheath and sized to fit about the heart. The expansion sleeve is at least partially defining an expandable chamber. The sensor sleeve carries at least one sensor electrically responsive to a heart parameter.

Abstract: A catheter with a mechanism for omni-directional deflection of a catheter shaft includes a shaft assembly and a controller. The shaft assembly includes a first tubular component that has a preformed curvilinear distal section, a second, substantially straight tubular component with a main axis and an outer shaft. The first and second components are configured for slidable movement therebetween while preserving common rotation so that when the second component is axially moved in a distal direction, the second component deflects the preformed curvilinear section towards the main axis while orientation of the outer shaft is preserved. The controller is configured to effect relative axial movement between the first and second components as well as to effect rotation of the first and second components (and thus also of the preformed curvilinear distal section) without any rotation of the shaft relative to the handle.

Abstract: A sacrificial catheter assembly and method of use for placing a functional catheter within the body of a patient, such as into the patient's vasculature, is disclosed. In one embodiment, the sacrificial catheter assembly comprises a sacrificial catheter including an elongate body that defines a longitudinally extending lumen. A stylet is removably received within the lumen of the sacrificial catheter such that the catheter and stylet can be advanced together to a target destination within the body of the patient. The sacrificial catheter is configured so as to then be proximally slid over the stylet to remove the sacrificial catheter from the body while the stylet remains in place at the target destination. A functional catheter can then be distally slid over the stylet to place the functional catheter at the target destination. The stylet can then be removed from the body of the patient.

Abstract: The present disclosure relates to acquiring image data of a subject and selecting image data to be displayed. The image data can include a plurality of frames that relate to a specific location of a tracking device positioned within the subject. The determined location of the tracking device can be used to determine which frame of the image data to display at a selected time.

Abstract: An anatomical mapping system includes a plurality of mapping electrodes each having an electrode location and configured to detect activation signals of intrinsic physiological activity within an anatomical structure. A mapping processor is associated with the plurality of mapping electrodes and is configured to record the detected activation signals and associate one of the plurality of mapping electrodes with each recorded activation signal. The mapping processor is further configured to analyze the recorded activation signals to identify at least one recurring pattern based on a relationship between a timing of the detected activation signals and the electrode locations of the mapping electrode associated with each detected activation signal.

Abstract: An electrode coupling output system associated with an electrode catheter that provides indication to the physician via the navigation system, concerning the electrical coupling of an electrode, such as an ablative or mapping electrode, with a patient. The indication may be provided by changing the color or other display characteristics of the electrode on the navigation system display or by way of providing a waveform indicating the electrode coupling. In this manner, electrode coupling information is provided to a physician in a manner that minimizes physician distraction.

Abstract: A multi electrode catheter for non contact mapping of the heart having independent articulation and deployment features.

Abstract: A medical device including a catheter having a shaft with a distal portion; a first plurality of substantially hemispherical electrodes coupled to the distal portion; a second plurality of substantially hemispherical electrodes coupled to the shaft proximal of the first plurality, where the second plurality of electrodes are oriented substantially orthogonal to the first plurality of electrodes; and an additional electrode coupled to the shaft. A console may have a processor in electrical communication with the first and second plurality of electrodes and the reference electrode, the processor programmed to obtaining a monophasic action potential recording from at least one of the first and second plurality of electrodes.

Abstract: Catheter systems for measuring at least one electrical property, e.g., impedance, of cardiac tissue of a living being are disclosed. The system includes a catheter having a tip with a sensing electrode, a guard electrode and an electrical shield. The sensing electrode is arranged to engage the cardiac tissue and is coupled to circuitry for measuring the at least one electrical property of the cardiac tissue, shielding the sensing electrode from bulk blood adjacent the cardiac tissue. The measurement can gated to the cardiac cycle. Additional embodiments include multi-electrode sensor catheter tips for high density mapping. Moreover, such tips may be dynamically configurable, i.e., their electrodes can be variably assigned as sensor electrodes or guard electrodes by associated circuitry. Such multi-electrode configuration and reconfiguration can be gated to the cardiac cycle.

Abstract: A system and method are provided for determining characteristics of a device electrode disposed on a medical device within a body. A plurality of measurement electrodes are coupled to an external surface of the body and establish transmission paths for current through the body. An electronic control unit (ECU) is configured to cause transmission of current between a pair of active electrodes selected from the measurement electrodes and thereby generate a voltage on the device electrode. The ECU receives impedance signals from a plurality of passive electrodes among the measurement electrodes other than the active electrodes. The ECU establishes a virtual reference electrode at a reference position within the body responsive to the impedance signals and computes a position of the device responsive to the voltage on the device electrode and the reference position of the reference electrode. The ECU may also compute impedances at the device and measurement electrodes.

Abstract: The present invention is directed to a high density mapping catheter including a number of shape memory electrode fibers and associated methods of construction and operation. The invention ensures good electrical contact between a large number of mapping electrodes and cardiac tissue in relation to a number of cardiac tissue approach angles, including head-on approaches. In addition, the invention allows for a reduced range of deflection angles in relation to deployment and retraction of the electrode fibers, thereby reducing resistance to retraction and reducing stress on the fibers and associated concerns regarding patient safety. The catheter of the present invention allows for rapid acquisition of a large amount of mapping data and allows for a variety of different geometries in relation to sweeping of the catheter across the cardiac tissue.