Abstract: A catheter for contact force sensing includes a catheter body, a deflectable section, and a distal section having a tip electrode and a contact force sensor for sensing a 3D contact force vector applied to the tip electrode. The contact force sensor has a body and at least one sensor with an electrical characteristic responsive to deformation of the body resulting from the force vector. The sensor receives an electrical current and outputs an electrical signal indicative of a change in the electrical characteristic. The sensor may be a strain gage responsive to tension and compression of at least a portion of the body of the force sensor, and the electrical characteristic may be electrical resistivity of the strain gage. Alternatively, the sensor may be responsive to strain and stress of at least a portion of the body, and the electrical characteristic is inductance or hysteresis loss.

Abstract: A system and method for determining on a continuous, real-time basis the proximity of the esophagus to an endocardial catheter during mapping, ablation or other endocardial catheter-based procedures, comprising an esophagus probe catheter and an endocardial catheter adapted for proximal signal transmission between each other. A signal processing unit is included to process and compare a characteristic of the proximity signal that is changes or attenuates with distance between the two catheters, such as impedance, amplitude and/or phase. Audio and/or optical outputs are provided to alert an operator when the distance between the catheters changes or is below a baseline measurement to avoid damage to the esophagus by the endocardial catheter. The system and method may include adaptations of the catheters with location sensor, and a mapping/navigational system for nonfluoroscopic location determination of the catheters.

Abstract: The present invention provides a bi-directional catheter with nearly double the throw in its catheter tip deflection. In particular, the travel path of each the puller wire includes a U-turn or doubling-back around a pulley which minimizes the offset angle between the puller wire and the longitudinal axis of the control handle while maximizing the travel distance of that puller wire for any given distance traveled by the pulley drawing the puller wire. In one embodiment, the catheter has an elongated catheter body, a catheter tip section with first and second diametrically-opposed off-axis lumens, and a control handle which includes a steering assembly having a lever structure carrying a pair of pulleys for simultaneously drawing and releasing corresponding puller wires to deflect the tip section of the catheter.

Abstract: An irrigated ablation catheter provides improved distribution of irrigation fluid across its tip electrode surface resulting in improved cooling and flushing of blood and proteins from the tip region. An axially directed flow of irrigation provides improved heat transfer from the tip electrode to the irrigation fluid allowing for a cooler tip electrode and larger lesions. The irrigation fluid is introduced to the catheter with improved flow by means of a standard constant flow pump. A lumen or tube within a shaft of the catheter transfers the irrigation fluid to a proximal end of the tip electrode where it exits the catheter via a flow directing member mounted on the tip electrode. In one embodiment, the flow directing member is a thin walled tube that surrounds the proximal end of the tip electrode and directs the irrigation fluid distally along an outer surface of the tip electrode.

Abstract: A method for tracking a position of an object includes generating alternating current (AC) magnetic fields at two or more frequencies in a vicinity of the object using at least one field generator. The AC fields are sensed using a field sensor associated with the object. Corresponding AC data points that are indicative of amplitudes and directions of the AC fields at the field sensor are produced, wherein at least some of the sensed AC fields are subject to a distortion. A dependence of the AC data points on the frequencies of the AC fields is extrapolated to a target frequency so as to determine the amplitudes and directions of the AC fields with a reduced level of the distortion. Position coordinates of the object relative to the at least one field generator are calculated responsively to the extrapolated data points.

Abstract: A method of medical imaging includes creating an anatomical map of an inner wall of a cavity in a body of a subject by inserting a probe into the body and collecting data using the probe. A three dimensional (3-D) contour is delineated in a 3-D image of the cavity based on the map.

Abstract: The present invention is directed to a method of securing a puller member in a control handle for a deflectable catheter. The method comprises preforming an end of the puller member, placing the preformed end in an insert mold, filling the insert mold with thermoplastic material to form a molded member, and positioning the molded member encasing the end of the puller member in a control handle. The method may also include shaping the thermoplastic material into a screw configuration and fastening the molded member to a wall in the control handle. The method may further include joining the end of the puller member with an end of a second puller member, and placing joined ends of the puller members in the insert mold.

Abstract: The invention is directed to a catheter that creates enhanced lesions using a needle electrode and can simultaneously map electrical activity at a plurality of points using an enhanced mapping assembly. The catheter comprises an elongated catheter body having at least one lumen extending longitudinally therethrough. A needle control handle is provided at the proximal end of the catheter body. A needle electrode assembly extends through the catheter body and needle control handle and has a proximal end attached to the needle control handle and a distal end within the distal end of the catheter body. A mapping assembly is mounted at the distal end of the catheter body and comprises at least two flexible spines. Each spine has a proximal end attached at the distal end of the catheter body and a free distal end. Each spine carries at least one electrode. The distal end of the needle electrode assembly is extendable past the proximal end of the mapping assembly upon manipulation of the needle control handle.

Abstract: A catheter adapted for mapping and ablating epicardial tissue from the pericardial cavity includes a catheter body and an electrode assembly that has a tip section and a loop member lying generally within a plane, wherein the tip section includes an ablation electrode exposed on one side of the loop member and an insulation member exposed on an opposite side of the loop member. The catheter also includes a intermediate section between the catheter body and the electrode assembly, wherein the intermediate deflects the loop member and the tip section bi-directionally within the same plane. So arranged, the catheter can be safely maneuvered in the pericardial sac and swept in a side to side motion over the epicardium with the ablation electrode reliably facing and making contact with the epicardium. The tip section can include a balloon that is inflatable to push away surrounding pericardial tissue.

Abstract: A method for tracking a position of an object includes using a field sensor associated with the object to measure field strengths of magnetic fields generated by two or more field generators, wherein a measurement of at least one of the field strengths is subject to a distortion. Rotation-invariant location coordinates of the object are calculated responsively to the measured field strengths. Corrected location coordinates of the object are determined by applying to the rotation-invariant location coordinates a coordinate correcting function so as to adjust a relative contribution of each of the measured field strengths to the corrected location coordinates responsively to the distortion in the measured field strengths.

Abstract: The invention is directed to a mapping catheter useful for mapping tubular regions in and around the heart. The catheter comprises an elongated tubular catheter body. A mapping assembly is provided at the distal end of the catheter body. The mapping assembly comprises a tubular structure comprising a pre-formed generally circular main region generally transverse and distal to the catheter body and having an outer circumference. The tubular structure comprises a non-conductive cover over at least the main region of the mapping assembly. A plurality of electrodes are carried by the generally circular main region of the mapping assembly. A control handle is mounted at the proximal end of the catheter body. A contraction wire extends through the catheter body and non-conductive cover of the mapping assembly for contracting the generally circular main region of the mapping assembly.

Abstract: An esophagus isolation catheter for deflecting an esophagus of a patient away from an ablation site in the left atrium of the patient's heart is provided. The catheter comprises an elongated catheter body and a deflectable section. In one embodiment, the catheter comprises a deflectable intermediate section mounted at the distal end of the catheter body and a generally straight tip section mounted at the distal end of the intermediate section. In this embodiment, the catheter comprises two puller wires, one anchored proximal the other. The intermediate section deflects to form a generally C-shaped curve. In an alternative embodiment, the catheter comprises a deflectable tip section mounted at the distal end of the catheter body. In this embodiment, the catheter comprises only one puller wire. The tip section carries a tip electrode having an atraumatic design to prevent damage to the esophagus upon deflection.

Abstract: A system for determining the proximity of the esophagus to the ablation electrode of an ablation catheter during an ablation procedure is disclosed. The system comprises an ablation catheter having at least one ablation electrode, an esophageal probe catheter having at least one electrode, and a signal processing unit. Both the ablation electrode and the esophageal probe catheter are electrically connected to the signal processing unit. The signal processing unit receives electrical signals from the ablation electrode on the ablation catheter and the electrode on the esophageal probe catheter and compares the signals to determine the proximity of the esophagus to the ablation electrode.

Abstract: A porous tip electrode catheter is provided. The porous tip electrode comprises a porous material through which fluid can pass. The porous tip electrode is covered with a thin coating of conductive metal having openings through which fluids can pass.

Abstract: A deflectable catheter comprises a catheter body, a tip section, and a control handle for affecting deflection of the tip section. The tip section comprises a flexible tubing having proximal and distal ends and at least two lumens extending therethrough. The proximal end of the tip section is fixedly attached to the distal end of the catheter body. The flexible tubing comprises a plastic core, a metal braid over the core, a plastic skin over the braid, and at least two pieces of plastic tubing in longitudinal arrangement extruded over the plastic skin, wherein the at least two pieces of plastic tubing have different stiffnesses and are arranged with the stiffer plastic being proximal the less stiff plastic. The tip section is made by extruding a plastic core over at least one mandrel and braiding a metal over the plastic core.

Abstract: Visualization of a probe when impedance-based measurement technology is being used is improved by stabilizing a displayed image of the probe or catheter. Using a model of reasonable probe shapes and a matching algorithm, an erroneous probe image is adjusted so that it assumes a realistic shape on a display. A range of positional variations is also incorporated in the model. When an apparent probe position exceeds a permissible range of motion, the probe image is constrained to a realistic position.

Abstract: A method for treating tissue is provided. The method comprises introducing into a patient the distal end of a catheter. The catheter comprises a catheter shaft comprising an elongated tubing having proximal and distal ends, and a distal shaft comprising a tubing having proximal and distal ends. The distal shaft carries a treatment device along a side of the distal shaft. A hinge is mounted between the distal end of the catheter shaft and the proximal end of the distal shaft. The hinge enhances the ability of the distal shaft to bend relative to the catheter shaft in a single predetermined plane A force is exerted on the distal shaft to cause at least a portion of the treatment device that is along a side of the distal shaft to contact the tissue. The tissue is treated with the treatment device.

Abstract: An esophageal mapping catheter enables a physician to map the location of the esophagus so as to avoid damaging the esophagus during radio frequency (RF) ablation procedures. Information from the esophageal mapping catheter is communicated to a patient information unit, communications unit and/or electroanatomic mapping system. The electroanatomic mapping system uses the information from the esophageal mapping catheter to develop a three-dimensional map of the esophagus and to monitor the temperature within the esophagus in order to prevent the creation of esophageal fistula.

Abstract: Apparatus is provided for use with a steerable catheter that includes a thumb control adapted to control a deflection of a distal tip of the catheter. The apparatus includes a robot, including an end-effector, adapted to be coupled to the thumb control, and a controller, adapted to drive the end-effector to deflect the distal tip by manipulating the thumb control.

Abstract: A mapping catheter comprises a catheter body and a mapping assembly. The catheter body has an outer wall, proximal and distal ends, and at least one lumen extending therethrough. The mapping assembly comprises a generally straight proximal region attached to the catheter body, a generally circular main region distal the proximal region having an outer circumference, and a generally straight distal region distal the main region. The mapping assembly also comprises a support member having shape-memory, a non-conductive covering over the support member, and a plurality of electrodes on the non-conductive covering along the generally circular main region.