Abstract: Systems for examining heart tissue morphology deploy one or more electrodes into the heart in contact with endocardial tissue. The systems transmit electrical current from the electrodes in paths through the contacted endocardial tissue. Based upon these current transmissions, the systems derive the electrical characteristics of tissue lying in the path. This electrical characteristic can be directly correlated to tissue morphology. The systems maximize surface contact with endocardial tissue, while minimizing contact with the surrounding blood pool, to obtain accurate tissue electrical characteristic measurements.

Abstract: A coaxial cable assembly has an associated steering mechanism for maneuvering the assembly within the body.

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

Abstract: Systems and methods analyze biopotential morphologies in body tissue. The systems and methods use a template of a biopotential event of known cause in body tissue. The template comprises a plot of variations in biopotentials over time and not a spacial distribution of endocardial surface activation. The systems and methods compare this template to a sample of a biopotential event externally triggered in body tissue. The sample comprises a plot of variations in biopotentials over time and not a spacial distribution of endocardial surface activation. The systems and methods generate an output based upon the comparison. The systems and methods can be used to compare an event-specific template of a cardiac event of known diagnosis to a sample of a paced cardiac event. The comparison yields a matching factor indicating how alike the input sample is to the input template.

Abstract: Systems and related methods guide a movable electrode within an array of multiple electrodes located within the body. The systems and methods employ the movable electrode or at least one of the multiple electrodes on the array to generate and then sense electrical or sonic energy in a predetermined fashion to generates an output that locates the movable electrode within the array.

Abstract: A porous electrode assembly includes a wall having a surface capable of contacting tissue. The wall peripherally surrounds an interior area. The assembly also includes a lumen to convey a medium containing ions into the interior area, as well as an electrically conductive element, which couples the medium within the interior area to a source of electrical energy. At least a portion of the wall comprises a porous material, which is sized to pass ions contained in the medium, to thereby enable ionic transport of electrical energy through the porous material to tissue contacting the wall. An imaging element is located in the interior area, which is coupled to a source of visualizing energy for visualizing tissue. At least a portion of the wall is generally transparent to the visualizing energy.

Abstract: Systems and methods acquire electrocardiograms using a first electrode associated with a region of heart tissue and a second body surface electrode. An analog or digital processing element is coupled to the first and second electrodes for conditioning the first electrode to emit a pacing signal and for conditioning the second electrode to sense paced electrocardiograms occurring as a result of the pacing signal. The systems and methods also employ a template of an electrocardiogram of a cardiac event of known diagnosis; for example an arrhythmia that the physician seeks to treat. This event-specific template comprises a plot of biopotentials over time and not a spacial distribution of endocardial surface activation. The systems and methods compare this event-specific template to a sample of a paced electrocardiogram. The paced electrocardiogram sample comprises a plot of biopotentials over time and not a spacial distribution of endocardial surface activation.

Abstract: Systems and methods employ an energy emitting electrode to heat tissue. The systems and methods control the application of energy to the electrode using adjustments that take into account, in a non-linear fashion, changes in monitored operating conditions.

Abstract: An ablation electrode carries a temperature sensing element for measuring the temperature of the tissue being ablated. A thermal insulating element associated with the sensing element blocks the transfer of heat energy from between the temperature sensing element and the body. The temperature sensing element therefore measures temperature without being affected by the surrounding thermal mass of the electrode.

Abstract: Systems and methods for ablating body tissue use an electrode for contacting tissue to form a tissue-electrode interface. The electrode is adapted to be connected to a source of ablation energy to conduct ablation energy for transmission by the electrode into tissue at the tissue-electrode interface. The electrode is preferably cooled. The systems and methods include multiple temperature sensing elements. One element senses tissue temperature. A second element senses electrode temperature. A third element senses the rate at which the electrode is cooled. The systems and methods control the supply of ablation energy to the electrode based, at least in part, upon the multiple temperatures sensed by the different temperature sensing elements.

Abstract: Systems and methods sense electrical events about a selected annulus region of the heart to identify the location of an accessory pathway. The systems and methods establish a contact site between heart tissue along the selected annulus and a multi-electrode array having a generally circular shape that conforms to the circumferential geometry of the selected annulus region. The systems and methods maintain the site of contact between the electrode array and heart tissue, while conveying signals representing electrical events sensed by bipolar pairs of the electrodes in the selected annulus region. The systems and methods display the signals as graphic information that represents the time differences between the atrial and ventricular electrogram complexes sensed by bipolar pairs of the electrodes on the selected annulus region. The bipolar pair of electrodes displaying the least time separation between the atrial and ventricular complexes identifies the region of the accessory pathway.

Abstract: A catheter carries a functional component, like an ablating electrode, having a predetermined operating characteristic. The catheter also electronically retains an identification code that uniquely identifies the predetermined operating characteristic. The catheter is capable of transmitting the identification code to an external reader in response to a predetermined prompt. An associated apparatus, like an ablating energy source, reads the identification code and compares it to predetermined operating criteria. The apparatus will not permit interaction with the functional catheter component, if the identification code indicates that the functional characteristics of the catheter are not suited for the intended interaction. The catheter can also store usage information, to prevent reuse.

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

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

Abstract: Systems and methods sense electrical events in heart tissue to identify the location of an arrhythmogenic focus for ablation. The systems and methods establish a contact site between heart tissue and a curvilinear electrode array. The systems and methods monitor signals representing electrical events sensed by the electrodes in the contact site. The signals are displayed as graphic information that represents the time sequence in which the electrodes sense a given electrical event. By moving the electrode array to one or additional contact sites in the general direction of the electrode that first sensed the electrical event, the physician homes in on a contact site in which all electrodes on the array sense the given electrical event at generally the same time. This contact site contains the arrhythmogenic focus. The systems and methods convey ablating energy to bipolar pairs of the electrodes to form large bipolar lesions in heart tissue.

Abstract: Analog or digital systems or methods filter an artifact from a signal derived from a biological event comprising sample values arranged with respect to time. The systems and methods generate a variable expressing a template of the artifact and reduce the derived biological signal by the variable to derive a filtered derived biological signal. The systems and methods change the variable over time based upon the energy of the filtered derived biological signal to minimize the energy of the artifact remaining in the filtered derived biological signal over time. The systems and methods output the filtered derived biological signal. The systems and methods remove artifacts from signals derived from a biological event; for example, electrograms, electrocardiograms, electroencephalograms, electrogastrograms, electromyograms, and respiratory signals.

Abstract: A flexible bond is formed between the exterior sleeve of a catheter guide tube and the exterior sleeve of the steerable electrode tip of the catheter. The flexible bond holds the sleeves in fluid tight abutment during twisting of the guide tube and bending of the electrode tip.

Abstract: Systems and methods analyze biopotential morphologies in myocardial tissue by comparing a template of a cardiac event of known diagnosis to one or more samples of a paced cardiac event. The systems and methods generate an output based upon the comparison. The comparison yields an output, which indicates how alike the input sample is to the input template. The output can be used by the physician, for example, to aid in the location of sites that are potentially appropriate for ablation. The systems and methods employing different pacing and/or comparative techniques to provide multiple outputs. The pacing techniques that the systems and methods employ can comprise entrainment pacing or pace mapping. Various alternative comparison techniques include matched filtering, cross correlation, norm of the difference, and symmetry matching.

Abstract: Systems and methods provide non-linear, non-median filters for signals derived from biological events. The systems and methods select a set of n sample values arranged with respect to time from the derived biological signal input. The systems and methods arrange the n sample values of the set into ordered positions following a predetermined permutation. The systems and methods select one of the ordered positions, z, within the permutation, where z is an odd positive integer greater or equal to one but less than or equal to n. The systems and methods generate a processed output comprising the sample value occupying the ordered position, z, in the permutation.

Abstract: Analog or digital systems and methods filter an artifact from a composite signal, which comprises sample values arranged with respect to time. The systems and methods select sets of WL sample values in time-sequence along the composite signal and arrange the WL sample values of each set into ordered positions following a predetermined permutation. The systems and methods select one of the ordered positions, z, within each permutation. The systems and methods generate a filter output comprising the sample values occupying the ordered position, z, of each permutation in time-sequence with the composite signal. The systems and methods remove artifacts from signals derived from a biological event; for example, electrograms, electrocardiograms, electroencephalograms, electrogastrograms, electromyograms, and respiratory signals.