摘要:
A method and system for detecting microbubble formation during a radiofrequency ablation procedure. The method includes measuring an impedance of a pair of electrodes, at least one electrode in the pair of electrodes being coupled to a treatment assembly of a medical device. Radiofrequency ablation energy is transmitted between the pair of electrodes. The transmission of radiofrequency ablation energy between the pair of electrodes is terminated when after a predetermined period of time the measured impedance in either of the electrodes in the pair of electrodes is a predetermined percentage above a measured minimum impedance and a measured power is above a predetermined power threshold. An alert is generated indicating at least one of the formation and release of microbubbles proximate the pair of electrodes.
摘要:
A method of assessing a tissue ablation treatment, including positioning a medical device adjacent a target tissue; measuring a first impedance magnitude a first frequency with the medical device; measuring a first impedance phase at a second frequency with the medical device; ablating at least a portion of the target tissue with the medical device; measuring at second impedance magnitude at a third frequency with the medical device; measuring a second impedance phase at a fourth frequency with the medical device; comparing at least one of (i) the first and second impedance magnitudes and (ii) the first and second impedance phases; and providing an indication of the efficacy of the ablation treatment based at least in part on the comparison.
摘要:
Systems and methods for assessing electrode position, including positioning a plurality of electrodes within a heart and proximate a pulmonary vein; obtaining an impedance measurement from each of the plurality of electrodes; determining whether any of the plurality of electrodes is located within the pulmonary vein based at least in part on the obtained impedance measurements; and generating an indication if at least one of the plurality of electrodes is determined to be located within the pulmonary vein.
摘要:
A medical system, including a catheter body, an elongate body disposed in the catheter body; an expandable element having a proximal portion coupled to the catheter body and a distal portion coupled to the elongate body, the distal portion of the expandable element defining the distal-most portion of the medical device; a mesh or array of longitudinal splines substantially surrounding the expandable element, at least a portion of the mesh or splines being electrically conductive; and a coolant source in fluid communication with the expandable element.
摘要:
A medical method is provided, including a medical device having a distal assembly including at least one electrode and at least one treatment element, the medical device generating information regarding at least one of a physiological measurement and an operational parameter of the medical device; a plurality of surface electrodes affixable to a skin of the patient, wherein the surface electrodes are in electrical communication with the distal assembly to obtain position information of the medical device; and a processor pairing the position information and the at least one of a physiological measurement and an operational parameter of the medical device.
摘要:
Catheters and methods for obtaining monophasic action potential (“MAP”) electrograms include a flexible catheter body defining a longitudinal axis, and a distal assembly affixed to the catheter body distal end defining a distal tip. The distal assembly has at least three MAP recording electrodes, and at least one reference electrode for determining reference potential. The recording electrodes are each positioned a radial distance from the longitudinal axis in at least three different radial directions, defining a recording geometry substantially having radial symmetry. The reference electrode is a longitudinal distance from the recording geometry. Optional features include a steerable catheter shaft, one or more radio-frequency ablation electrodes, and a dedicated pacing electrode. Different possible embodiments include a dome housing having the recording electrodes in a fixed spatial arrangement, and a distal loop assembly having an array of electrodes on at least three flexible loop elements.
摘要:
Device, system and method for evaluating the effectiveness of tissue ablations of a heart of a patient. The tissue is clamped between a pair of opposing jaws. A portion of the tissue is ablated at a first generally linear position on the tissue by applying ablative energy to two of a plurality of elongate electrodes, each of the two of the plurality of elongate electrodes being coupled in opposing relationship to each other and the pair of opposing jaws, respectively. An effectiveness of the ablation is sensed at a second generally linear position on the tissue with at least one of the plurality of elongate electrodes positioned on one of the pair of opposing jaws. The second linear position on the tissue is laterally distal to the first linear position on the tissue with respect to the atrium of the heart.
摘要:
A medical device having retention means extending along a length of an elongate body of the medical device including a plurality of projections adapted to interfere with a wall of a generally tubular vessel to retain the body within the vessel.
摘要:
Steerable electrophysiology catheters for use in mapping and/or ablation of accessory pathways in myocardial tissue of the heart wall and methods of use thereof are disclosed. The catheter comprises a catheter body and handle, the catheter body having a proximal section and a distal section and manipulators that enable the deflection of a distal segment of the distal tip section with respect to the independently formed curvature of a proximal segment of the distal tip section through a bending or knuckle motion of an intermediate segment between the proximal and distal segments. A wide angular range of deflection within a very small curve or bend radius in the intermediate segment is obtained. At least one distal tip electrode is preferably confined to the distal segment which can have a straight axis extending distally from the intermediate segment. The curvature of the proximal segment and the bending angle of the intermediate segment are independently selectable. The axial alignment of the distal segment with respect to the nominal axis of the proximal shaft section of the catheter body can be varied between substantially axially aligned (0° curvature) in an abrupt knuckle bend through a range of about −90° to about +180° within a bending radius of between about 2.0 mm and 7.0 mm and preferably less than 5.0 mm. The proximal segment curve can be independently formed in a about +180° through about +270° with respect to the axis of the proximal shaft section to provide an optimum angular orientation of the distal electrode(s). The distal segment can comprise a highly flexible elongated distal segment body and electrode(s) that conform with the shape and curvature of the heart wall.
摘要:
A delivery catheter for delivering an intra-bodily medical device to an internal bodily site. The delivery catheter includes an elongated shaft defining a proximal section and a distal section. A delivery lumen is formed by the shaft, extending from the proximal section and terminating at an opening formed proximal the distal section. Finally, a locator is formed by the distal section, and is configured to locate a target site. In one preferred embodiment, the locator is elongated, having a diameter less than that of a remainder of the shaft. In another preferred embodiment, the delivery catheter includes a steering device capable of effectuating a bend both proximal and distal the opening for steering the locator to a target site.