Abstract: Catheter systems include direction-sensitive, multi-polar tip electrode assemblies for electroporation-mediated therapy, electroporation-induced primary necrosis therapy and electric field-induced apoptosis therapy, including configurations for producing narrow, linear lesions as well as distributed, wide area lesions. A monitoring system for electroporation therapy includes a mechanism for delivering electrochromic dyes to a tissue site as well as a fiber optic arrangement to optically monitor the progress of the therapy as well as to confirm success post-therapy. A fiber optic temperature sensing electrode catheter includes a tip electrode having a cavity whose inner surface is impregnated or coated with thermochromic/thermotropic material that changes color with changes in temperature. An optic fiber/detector arrangement monitors the thermochromic or thermotropic materials, acquiring a light signal and generating an output signal indicative of the spectrum of the light signal.

Abstract: An irrigated ablation electrode assembly comprises a distal member, a first manifold, and a second manifold. The distal member includes an outer surface; an inner surface; and at least one radially extending passageway that extends from the inner surface of the distal member to the outer surface of the distal member. The first manifold includes an outer surface, an inner cavity, and at least one radially extending passageway that extends from the inner cavity to the outer surface of the first manifold. The second manifold includes an outer surface, an inner surface, and at least one radially extending passageway that extends from the inner surface of the second manifold to the outer surface of the second manifold. Other irrigated ablation electrode assemblies are also presented.

Abstract: A handle assembly is provided for use in navigating a deformable shaft within a body. The assembly includes a first guide member defining first and second linear channels and a second guide member configured for rotation relative to the first guide member. First and second connectors are disposed within, and movable within, the first and second linear channels along first and second parallel axes, respectively, and are configured for coupling to first and second steering wires, respectively. The assembly includes means, such as a flexible coupling connected to the second guide member and the connectors, for translating rotation of the second guide member into linear movement of the first connector in a first axial direction and linear movement of the second connector in a second axial direction, opposite the first axial direction such that the first and second steering wires move in opposite directions.

Abstract: A system for providing irrigation fluid during ablation of tissue includes a catheter, an electrode assembly, at least one thermal sensor adapted to be connected to the catheter, and a control system. The electrode assembly is adapted to be connected to an ablation generator. The thermal sensor is adapted to be operatively connected to an electronic control unit (ECU). The ECU receives as an input temperature measurement data from the thermal sensor; determines a power delivery rate value for the ablation generator responsive to the temperature measurement data; and outputs the power delivery rate value. The control system also delivers irrigation fluid to the irrigated catheter at a first flow rate in a first time period and at a second flow rate in a second time period that is temporally after the first time period. The second flow rate is at least half of the first flow rate.

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: An apparatus for imparting a tensile force to deflect a distal portion of a catheter while maintaining its exterior dimensions may include a handle grip including a cross-section of generally predetermined exterior dimensions, and a longitudinal axis. A flexible elongate member may include proximal and distal end portions, with the proximal end portion being coupled to the handle grip. An adjustment knob may include a cross-section of generally predetermined exterior dimensions, and is rotatably coupled to the handle grip around the longitudinal axis. An elongate deflection member may be operably coupled to the adjustment knob and to the distal end portion of the elongate member. Rotation of the adjustment knob may impart a tensile force to the deflection member thereby causing the distal end portion of the elongate member to deflect from a prior configuration while maintaining the generally predetermined exterior dimensions of the handle grip and the adjustment knob.

Abstract: A deflectable, flexible device includes an elongate body, a convoluted tip portion at a distal end of the elongate body, and a lumen to receive one or more wires. The convoluted tip portion includes an electroformed pleated region which is formed by electrodepositing a metal on a mandrel having a pleated region. The convoluted tip portion may be hermetically sealed to permit repeated sterilization. The electroformed pleated region may include one or more fluid emission orifices. The convoluted tip portion extends or bends in response to fluid pressure manipulation, contact with tissue, manipulation with an internal spring or wire, or by a user pushing, pulling, or twisting the catheter directly or via an introducer sheath or the like. The convoluted tip portion may further include an RF ablation element or other energy-driven technique to create continuous linear lesions or a sensing element.

Abstract: A method for providing a localization system with detailed information regarding a catheter's construction, while at the same time preventing operator input errors, for use in a three-dimensional localization field, including providing a catheter having at least one feature, providing a catheter catalog for use by the localization system, wherein the catheter catalog comprises reference data relating to features of the catheter, placing the catheter into the localization field, creating a map with the localization field, locating the catheter on the map, and correlating features of the catheter within the localization field with measurements made by the localization system when the feature is at various locations.

Abstract: A method of detecting dislodgement of a navigational reference for a localization system includes securing a reference catheter, including at least one reference localization element, at an initial reference location within a localization field. The positions of one or more of the reference localization elements are monitored for a perceived displacement that suggests that the reference catheter has become dislodged from the initial reference location (e.g., a displacement above a certain threshold, such as about 4 mm). The direction of this perceived displacement may then be further analyzed (e.g., compared to a predicted or most likely direction of displacement) to determine whether there has been an actual dislodgement of the reference catheter, and, if so, an appropriate signal (e.g., an audible or visual warning) may be generated. Upon dislodgement, guidance may be provided to aid the practitioner in restoring the reference catheter to its initial location.

Abstract: Systems for detecting when catheter electrodes enter into and exit from an introducer are disclosed. In one form, a system detects a relative position of a catheter (comprising a marker band and an electrode) and an introducer (comprising a proximity sensor adapted to sense the marker band), while the catheter and introducer are in a human body. The system may comprise an electronic control unit to analyze signals from the catheter and/or the introducer, to determine whether the catheter electrode is within the introducer; and to disregard data collected from the electrode when that electrode is in the introducer. The sensor may be on the catheter and the sensed element may be on the introducer. The sensed element may comprise one or several marker bands. A marker band may be applied during the manufacture of a medical device or during its use and is any element capable of electromagnetic detection.

Abstract: An electrophysiology catheter is provided. In one embodiment, the catheter includes an elongate, deformable shaft having a proximal end and a distal end and a basket electrode assembly coupled to the distal end of the shaft. The basket electrode assembly has a proximal end and a distal end and is configured to assume a compressed state and an expanded state. The electrode assembly further includes one or more tubular splines having a plurality of electrodes disposed thereon and a plurality of conductors. Each of the plurality of conductors extends through the tubular spline from a corresponding one of the plurality of electrodes to the proximal end of the basket electrode assembly. The tubular splines are configured to assume a non-planar (e.g., a twisted or helical) shape in the expanded state.

Abstract: A method of operating a positioning system by registering a first coordinate system of a first positioning system in a second coordinate system of a second positioning system includes determining an interpolation function configured to register the first, non-orthonormal coordinate system in the second, orthonormal coordinate system. Fiducial pairs are collected by the respective positioning systems, each of which contain a respective coordinate in the respective coordinate system, both of which refer to the same physical point in three dimensional space. Establishing a working interpolation function involves an analysis of the fiducial pairs using a thin-plate spline algorithm. The method further includes repeatedly obtaining a first coordinate in the first coordinate system and determining a corresponding second coordinate in the second coordinate system in accordance with the interpolation function.

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 saline flow out of an inner cavity of the electrode. This fluid flow is pulsatile to increase turbulence, reducing areas of stagnant flow, and produces a desired cooling effect.

Abstract: A catheter assembly includes an inner liner made of flexible material and an outer layer having a steering mechanism. The steering mechanism includes at least one flat wire and a corresponding lumen through which the flat wire may travel. The steering mechanism may also include at least one pull ring to which the flat wires are attached. A layer of heat shrink material may encompass the outer layer. A braided wire assembly may also be provided in the outer layer, and may be formed by braiding a plurality of flat wires into a wire mesh. The overall cross-section of the catheter assembly is preferably substantially circular. A catheter shaft may include a plurality of segments of differing hardness characteristics. The outer layer typically comprises a melt processing polymer such that the catheter assembly may be laminated using heat.

Abstract: An ablation device for creating linear lesions comprises a flexible support structure defining at least a partial curve; and an electrode disposed on the flexible support structure. The electrode comprises a pressure sensitive conductive composite that is configured for electrical communication with an electrical conductor and a flexible conductive outer covering that covers at least a portion of the pressure sensitive conductive composite. Electrical resistance of the pressure sensitive conductive composite varies inversely in proportion to pressure that is applied to the pressure sensitive conductive composite. Methods of creating linear lesions are also provided.

Abstract: An elongate medical device with independently-deflectable segments and a handle for manually deflecting those segments can include a shaft having a distal segment and proximal segment, at least one proximal segment deflection wire adapted to deflect the proximal segment, at least one distal segment deflection wire adapted to deflect the distal segment independent of the proximal segment, and a handle portion. The handle portion may comprise a first manual actuation mechanism coupled to the at least one distal segment deflection wire and a second manual actuation mechanism coupled to the at least one proximal segment deflection wire. Actuation of the first manual actuation mechanism may impart a tensile force on the distal segment deflection wire to cause the distal segment to deflect, and actuation of the second manual actuation mechanism may impart a tensile force on the proximal segment to cause the proximal segment to deflect.

Abstract: An apparatus for detecting deformation of an elongate body may comprise a light source configured to sequentially provide light of multiple frequencies, an optical receiver configured to receive light from the light source, and a filter disposed between the light source and the optical detector. The filter may comprise multiple segments, each of the segments configured to filter light at one of the frequencies so as to alter the amount of light incident on said optical receiver. A total amount of light detected by the optical receiver may change during the sequence so as to be indicative of deformation of the elongate body.

Abstract: A method of monitoring contact between a probe and a tissue surface includes placing the probe in proximity to the surface, robotically moving the probe, measuring a tissue parameter at the distal end of the probe, calculating an amount of change in the measured tissue parameter between measurements thereof, and indicating a change in proximity or degree of contact between the probe and the surface based upon the amount of change. The indication of change may be based directly upon the calculated amount of change in the measured parameter or upon a calculated rate of change in the parameter. The rate of change may be relative to the time between measurements or the distance traveled by the probe between measurements, and may be calculated as a first, second, or other derivative of the tissue parameter.

Abstract: Systems and methods are disclosed for assessing tissue contact, e.g., for mapping, tissue ablation, or other procedures. An exemplary tissue contact sensing system comprises a flexible tip device. At least one piezoelectric sensor is housed within the flexible tip device. The at least one piezoelectric sensor is responsive to contact stress of the flexible tip device by generating electrical signals corresponding to the amount of contact stress. An output device is electrically connected to the at least one piezoelectric sensor. The output device receives the electrical signals for assessing tissue contact by the flexible tip device. Methods for assembling and using the flexible tip device are also disclosed.

Abstract: A method is provided for ablating a portion of the myocardium. The method includes inserting an occlusion catheter into a vessel on a heart, occluding the vessel using the occlusion catheter, inserting an ablation catheter into a chamber of the heart, positioning the ablation catheter against the myocardium, and ablating a portion of the myocardium while the vessel is occluded. The system includes an occlusion catheter having a catheter body including a tubular member having a distal portion and a bend located in the distal portion, a balloon located proximal of the bend and configured to contact an inner surface of the CS when positioned therewithin, a plurality of marker bands positioned on the catheter body, and a plurality of electrodes positioned on the catheter body. One or more electrodes or coils can be used as a reference for an electroanatomical system and can be disposed on the occlusion catheter.