Abstract: A deflectable medical device incorporates a strut that is configured to reduce or eliminate axial shortening of the deflectable portion of the medical device, for example, the deflectable distal end portion of a catheter or access sheath. The strut may is coaxially disposed in the medical device in the section that is contemplated to undergo the repeated deflection. The strut provides improved column strength and axial restoration. The strut may be stent-like device, an elongate device having opposing ends coupled by a connecting lattice involving a plurality of helical connecting elements or a tube having a plurality of circumferentially-extending slots arranged in longitudinally-extending rows.

Abstract: The invention relates to electrodes used in ablation catheter devices, where the electrodes contain two or more thermal sensors at different positions within the electrode that are capable of detecting temperature differences along the external surface of the electrode. In preferred embodiments, the thermal sensors are separated by one or more thermal insulating members and the thermal sensors are positioned near the external surface of the electrode at about the same distance from the end of the electrode, so that temperature measurements can indicate the position of the electrode with respect to the tissue desired to be ablated.

Abstract: A conforming electrode for delivering ablative energy to tissue generally includes a plurality of flexible metal tubes, each having a longitudinal axis, a proximal end, and a distal end. The flexible metal tubes are arranged in a bundle with their longitudinal axes aligned parallel to each other. In addition, the flexible metal tubes are electrically coupled to a conductor for transferring ablative energy to the flexible metal tubes. The conductor may be a loop around the flexible metal tubes and to which the flexible metal tubes may be secured. The proximal ends of the flexible metal tubes may be secured to the distal end of a catheter shaft.

Abstract: An electrophysiology catheter includes a tubular body having a proximal region, a neck region, and a distal region predisposed into a loop and including electrodes. A first deflection wire extends through at least a portion of the proximal region of the catheter body and includes a first flattened section, while a second deflection wire extends through the neck region and at least a portion of the distal region and includes a second flattened section within the neck region. A first activation wire is joined to the flattened section of the first deflection wire, while a second activation wire is joined to the flattened section of the second deflection wire. Thus, forces acting on the first and second activation wires, such as forces imposed by a handle-based actuator, are respectively transmitted to the first and second deflection wires, thereby deflecting the proximal and neck regions, respectively.

Abstract: Deflectable catheter systems, apparatuses and methods utilizing thermal expansion to influence catheter deflection. A representative embodiment includes a catheter having one or more pull wires or other tensioning elements. One end of the tensioning element(s) is connected at a distal portion of the catheter to facilitate shaft deflection upon pulling the tensioning element(s). A heat-sensitive control member(s) is coupled to a proximal portion of the tensioning element(s). The elongate tensioning element(s) is pulled in a proximal direction to deflect the distal portion of the catheter in response to a temperature change applied to the heat- sensitive control member.

Abstract: A system and method for assessing effective delivery of ablation therapy to a tissue in a body is provided. A three-dimensional anatomical map of the tissue is generated and displayed with the map defining a corresponding volume. An index is generated corresponding to a location within the volume with the index indicative of a state of ablation therapy at the location. The index may be derived from one or more factors such as the duration an ablation electrode is present at the location, the amount of energy provided, the degree of electrical coupling between an ablation electrode and the tissue at the location and temperature. A visual characteristic (e.g., color intensity) of a portion of the anatomical map corresponding to the location is then altered responsive to the index.

Abstract: A system for mapping a tissue surface includes a probe for mapping a tissue surface, a localization system to measure a location data point indicative of the probe's location, a memory in which to store the location data point, a servo mechanism to move the probe along at least a portion of the tissue surface, a controller to move the probe to a plurality of locations and to record in the memory a plurality of location data points, and a contact-sensing processor to analyze the plurality of location data points and to identify a subset thereof on the tissue surface. A modeling processor generates a model of the tissue surface using the subset of location data points. The contact-sensing processor utilizes probe velocity, or a rate of change in the distance moved by the probe, to determine contact between the probe and the tissue surface.

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 system and method for assessing a degree of coupling between an electrode and tissue in a body is provided. Values for first and second components of a complex impedance (e.g., resistance and reactance or impedance magnitude and phase angle) between the electrode and the tissue are obtained. From these values, a coupling index is calculated that is indicative of a degree of coupling between the electrode and the tissue. The coupling index may be displayed to a clinician in a variety of ways to indicate the degree of coupling to the clinician. The system and method find particular application in ablation of tissue by permitting a clinician to create lesions in the tissue more effectively and safely.

Abstract: The present invention pertains to multiple piece irrigated ablation electrode assemblies wherein the irrigation channels are insulated or separated from at least one temperature sensing mechanism within the distal portion of the electrode assembly. The present invention further pertains to methods for improved assembly and accurate measurement and control of the electrode temperatures while effectively irrigating the device and target areas.

Abstract: An ablation catheter is provided for ablating internal tissue of a patient. The catheter includes a distal end that is adapted to be inserted into a body cavity relative to a desired location therein (e.g., within the heart). An ablation electrode is connected relative to the distal end of the catheter for providing ablation energy to patient tissue. A heat sink is provided that is in thermal contact with the ablation electrode. The heat sink, in addition to being in thermal contact with the ablation electrode, is electrically isolated from the ablation electrode. This allows the heat sink to conduct heat away from the ablation electrode without dissipating electrical energy from the electrode. In this regard, the heat sink may prevent build-up of excess heat within the electrode that may result in blood coagulation and/or tissue charring.

Abstract: A splittable cannula includes a radiopaque marker placed at or near the distal end of the cannula. The radiopaque marker may be a unitary piece, or may consist of several portions. The cannula may include a sheath or catheter body with a grooved score line running along a portion of the sheath body and a radiopaque marker located at a distal end of the body and abutting the body. The radiopaque marker may be located within the lumen of the sheath, may be embedded in the sheath wall, or may be affixed to the external sheath wall. The radiopaque marker may be scored, notched, grooved, or contain apertures longitudinally. The notches, grooves, apertures, and/or score lines in both the sheath or catheter body and the radiopaque marker serve to provide a weakened tear path. An electrode lead may be coupled with the radiopaque marker.

Abstract: The invention discloses a system for delivering acoustic energy to a subject in connection with high intensity focused ultrasound (HIFU) systems. In an embodiment, the system comprises an optionally disposable waveguide-attached ablation applicator coupled with an optionally re-usable waveguide, and an optional acoustic power source. The systems may comprise acoustic energy exit port intensity control, waveguide heat-sinking, and transducer operational adjustments that accommodate waveguide effects on the traversing acoustic power.

Abstract: The invention relates to an ablation catheter which controls the temperature and reduces the coagulation of biological fluids on an electrode of a catheter, prevents the impedance rise of tissue in contact with the electrode, and maximizes the potential energy transfer to the tissue, thereby allowing an increase in the lesion size produced by the ablation. The electrode includes passages positioned to allow blood and other biological fluids to flow into and out of an inner cavity of the electrode. This fluid flow produced the desired cooling effect and is accomplished, for example, by a reciprocating plunger or piston, or by a balloon that is alternately inflated and deflated.

Abstract: A body-surface mapping system is disclosed that uses a plurality of electrodes to map at least a portion of a human torso without having to adjust the positions of the electrodes. The body-surface mapping system energizes groupings or regions of electrodes, then compares and adjusts the current driven through each grouping or region of electrodes to produce near-uniform fields. The electrodes of the body-surface mapping system may be interconnected by wires capable of sensing interelectrode distances, such that the system can reconstruct a detailed model of a patient's torso surface. The body-surface mapping system may also use a catheter in addition to the body surface electrodes to compute both endocardial and epicardial voltage distributions.

Abstract: A method of manufacturing a catheter shaft includes the steps of forming an inner layer of a first polymeric material, forming a plait matrix layer including a second polymeric material about the inner layer, and forming an outer layer of a third polymeric material about the plait matrix layer. The plait matrix layer includes a braided wire mesh partially or fully embedded within the second polymeric material, which is different from at least one of the first polymeric material forming the inner layer and the third polymeric material forming the outer layer. The second polymeric material has a higher yield strain and/or a lower hardness than at least the first polymeric material, and preferably both the first and the third polymeric materials. The first polymeric material and the third polymeric material may be different or the same. The catheter shaft may be formed by stepwise extrusion, co-extrusion, and/or reflow processes.

Abstract: A flexible guidewire comprising a hollow tube, having a proximal section and a distal section, the distal section having a distal tip, the outer diameter of the distal section gradually decreasing toward the distal tip, the outer diameter of the distal tip being larger than the smallest outer diameter of the distal section, the flexible guidewire further comprising a plug coupled with the distal tip of the hollow tube for creating a non-traumatic tip, and the flexible guidewire further comprising a tubular spring, being place around the distal section of the hollow tube for maintaining the outer diameter of the hollow tube over the length thereof and for supporting compressive loads.

Abstract: An imaging system is provided with an ultrasound catheter and a controller coupled to the ultrasound catheter. The catheter includes a localizer sensor configured to generate positional information for the ultrasound catheter, and an imaging ultrasound sensor having a restricted field of view. The controller co-registers images from the imaging ultrasound sensor with positional information from the localizer sensor.

Abstract: A cardiac imaging system including an imaging module including an ultrasound emitter and one or more position markers. A tracking and control system may include a position sensing system for sensing a location and orientation of the position marker relative to a predetermined reference. The tracking and control system may be operable with the imaging module to produce at least a three dimensional image of a patient's anatomy. A method of cardiac imaging may include operatively attaching one or more position markers to an imaging module including an ultrasound emitter. The method may further include sensing a location and orientation of the position marker relative to a predetermined reference, and producing at least a three dimensional image of a patient's anatomy by evaluating one or more images obtained by the imaging module and aligning the image(s) obtained by the imaging module relative to the location and orientation of the position marker.

Abstract: A method of calibrating a robotic device, such as a cardiac catheter, includes oscillating the device on an actuation axis by applying an oscillation vector at an oscillation frequency. While oscillating, a location of the device is periodically measured to generate a plurality of location data points, which may express the location of the device relative to a plurality of measurement axes. The location data points are then processed using a signal processing algorithm, such as a Fourier transform algorithm, to derive a transfer function relating a position of the device to a movement vector for the actuation axis. The transfer function may be resolved into and expressed as a calibration vector for the actuation axis, which may include one or more components, including zero components, directed along each of the measurement axes. The process may be repeated for any actuation axes on which calibration is desired.