138 results about "Cardiac Ablation" patented technology

A tissue ablation device has a handle and an ablation head coupled to the handle. The ablation head has a first jaw, a second jaw, and an ablative element coupled to at least one of the first and second jaws. A thickness measurement device may be coupled to the ablation device to indicate the distance separating the first and second jaws. Further, a force measurement device may be coupled to the ablation device to measure the force being applied by the first and second jaws to a piece of tissue. Further, a strain measurement device may be coupled to the ablation device to indicate the strain resulting in a piece of tissue disposed between the first and second jaws when a stress is applied to the tissue.

Guided ablation instruments are disclosed for creating lesions in tissue, especially cardiac tissue for treatment of arrhythmias, including atrial fibrillation. In one aspect of the invention, a percutaneous catheter is disclosed with an endoscope positionable in the instrument's distal end region to obtain an image. The image allows the clinician to determine whether contact has been achieved (or blood has been cleared from an ablative energy transmission path) before ablation begins or while ablation is occurring. In one embodiment, percutaneous ablation catheters are disclosed having at least one central lumen and one or more balloon structures at the distal end region of the instrument. Also disposed in the distal end region are an illuminating light source and an endoscope capable of collecting sufficient light to relay an image to the user. The instruments can further include an ablation element. The ablation element can be a contact ablation element, or a radiant energy emitter, which is preferably independently positionable within the lumen of the instrument and adapted to project ablative energy through a transmissive region of the instrument body (and/or balloon) to a target tissue site proximate to the pulmonary veins. The energy can delivered without the need for contact between the energy emitter and the target tissue so long as a clear transmission pathway is established. The endoscope element of the instrument allows the clinician to determine the position of the instrument and, if radiant energy is to be employed, see if such a pathway is clear. Moreover, because the position of the radiant energy emitter can be varied, endoscopic guidance permits the clinician to select a desired location and dose for the lesion.

Ablation methods and instruments are disclosed for creating lesions in tissue, especially cardiac tissue for treatment of arrhythmias and the like. Percutaneous ablation instruments in the form of coaxial catheter bodies are disclosed having at least one central lumen therein and having one or more balloon structures at the distal end region of the instrument. The instruments include an energy emitting element which is independently positionable within the lumen of the instrument and adapted to project radiant energy through a transmissive region of a projection balloon to a target tissue site. The instrument can optionally include at least one expandable anchor balloon disposed about, or incorporated into an inner catheter body designed to be slid over a guidewire. This anchor balloon can serve to position the device within a lumen, such as a pulmonary vein. A projection balloon structure is also disclosed that can be slid over the first (anchor balloon) catheter body and inflated within the heart, to define a staging from which to project radiant energy. An ablative fluid can also be employed outside of the instrument (e.g., between the balloon and the target region) to ensure efficient transmission of the radiant energy when the instrument is deployed. In another aspect of the invention, generally applicable to a wide range of cardiac ablation instruments, mechanisms are disclosed for determining whether the instrument has been properly seated within the heart, e.g., whether the device is in contact with a pulmonary vein and/or the atrial surface, in order to form a lesion by heating, cooling or projecting energy. This contact-sensing feature can be implemented by an illumination source situated within the instrument and an optical detector that monitors the level of reflected light. Measurements of the reflected light (or wavelengths of the reflected light) can thus be used to determine whether contact has been achieved and whether such contact is continuous over a desired ablation path.

A cardiac ablation apparatus for producing a circumferential ablation that electrically isolates a heart chamber wall portion from vessel such as a pulmonary vein extending into said wall portion comprises (a) an elongate centering catheter having a distal end portion; (b) an expandable centering element connected to said centering catheter distal end portion and configured for positioning within said vessel when in a retracted configuration, and for securing said elongate centering catheter in a substantially axially aligned position with respect to said vessel when said centering element is in an expanded configuration; (c) an ablation catheter slidably connected to said centering catheter said ablation element having a distal end portion, and (d) an expandable ablation element connected to said ablation catheter distal end portion. The ablation element is configured to form a circumferential ablation on the wall around the elongate centering catheter when the centering catheter is axially aligned with respect to the vessel. In a further embodiment, a non-expandable, compliant centering element is employed, such as an elastic finger. Systems incorporating such an apparatus and methods of use thereof are also disclosed.

A cardiac ablation system including an ablation catheter having an anchor adapted to support the ablation catheter within an atrium of a heart and an ultrasound emitter disposed radially outward from a rotation axis and from the anchor, and a control mechanism adapted to rotate the ultrasound emitter about the rotation axis and to provide ablation energy to the ultrasound emitter to ablate heart tissue.

A cardiac ablation catheter includes a coil-like ablating element that is deployable from an elongate, flexible sheath. The ablating element, while in the deployed position, has a shape with at least one revolution oriented in a plane that is orthogonal to a longitudinal axis of the sheath. The catheter system is well-suited to ablate a circumferential region of tissue about a pulmonary vein or the posterior wall of the left atrium proximate the pulmonary vein os. The treated tissue region electrically isolates the atria from the pulmonary vein.

A cardiac ablation method including the following steps: inserting a treatment catheter into an atrium of a heart, the treatment catheter including an ultrasound emitter; positioning the ultrasound emitter to face heart tissue within the left atrium outside of a pulmonary vein; emitting ultrasound energy from the ultrasound emitter while rotating the ultrasound emitter about a rotation axis; and ablating heart tissue with the ultrasound energy to form a lesion outside of a pulmonary vein.

A cardiac ablation device treats atrial fibrillation by directing and focusing ultrasonic waves into a ring-like ablation region (A). The device desirably is steerable and can be moved between a normal disposition, in which the ablation region lies parallel to the wall of the heart for ablating a loop-like lesion, and a canted disposition, in which the ring-like focal region is tilted relative to the wall of the heart, to ablate only a short, substantially linear lesion. The ablation device desirably includes a balloon reflector structure (18, 1310) and an ultrasonic emitter assembly (23, 1326), and can be steered and positioned without reference to engagement between the device and the pulmonary vein or ostium. A contrast medium (C) can be injected through the ablation device to facilitate imaging, so that the device can be positioned based on observation of the images.

A novel medical probe assembly, system, and methods for the use thereof to treat tissue are described. The system optionally comprises an energy source, two probe assemblies, and one or more cooling devices to provide cooling to at least one of the probe assemblies. The probe assemblies may be configured in a bipolar mode, whereby current flows preferentially between the probe assemblies. The probe assemblies and system described herein are particularly useful to deliver radio frequency energy to a patient's body. RF energy delivery may be used for various applications, including the treatment of pain, tumor ablation and cardiac ablation.

A system and method for cardiac mapping and ablation include a multi-electrode catheter introduced percutaneously into a subject's heart and deployable adjacent to various endocardial sites. The electrodes are connectable to a mapping unit, an ablation power unit a pacing unit, all of which are under computer control. Intracardiac electrogram signals emanated from a tachycardia site of origin are detectable by the electrodes. Their arrival times are processed to generate various visual maps to provide real-time guidance for steering the catheter to the tachycardia site of origin. In another aspect, the system also include a physical imaging system which is capable of providing different imaged physical views of the catheter and the heart. These physical views are incorporated into the various visual maps to provide a more physical representation. Once the electrodes are on top of the tachycardia site of origin, electrical energy is supplied by the ablation power unit to effect ablation.

The present invention provides devices and methods for the treatment of atrial fibrillation. In one embodiment method for treatment of atrial fibrillation is provided that includes positioning a sheath catheter having a deflectable distal end segment in the left atrium of a heart, orienting said sheath catheter such that an ablation instrument can be delivered through the sheath catheter to a position proximal to a first pulmonary vein, activating the ablation instrument to form a circumferential lesion around the first pulmonary vein, repositioning the sheath catheter by deflecting the distal end segment to another orientation, and activating the ablation instrument to form a circumferential lesion around at least one additional pulmonary vein.

The present invention provides devices and methods for the treatment of atrial fibrillation. In one embodiment a method for ablating tissue about an ostium of a right inferior vein of a heart includes positioning a sheath catheter having a deflectable distal end segment with a bent tip element in the left atrium of a heart, causing the distal end segment to deflect in a compound curve as the catheter is advanced towards an ostium of a right inferior vein, orienting said sheath catheter such that an ablation instrument can be delivered through the sheath catheter to a position proximal to the right inferior vein, and activating the ablation instrument to form at least one lesion about the right inferior vein.

A medical probe assembly, system, and methods for the use thereof to treat tissue are described. The system optionally comprises an energy source, two internally-cooled probe assemblies, and one or more cooling devices to provide cooling to at least one of the probe assemblies. The probe assemblies may be configured in a bipolar mode, whereby current flows preferentially between the probe assemblies. The probe assemblies and system described herein are particularly useful to deliver radio frequency energy to a patient's body. RF energy delivery may be used for various applications, including the treatment of pain, tumor ablation and cardiac ablation.

Devices, systems, and methods for the localization of body lumen junctions and other intraluminal structure are disclosed. Various embodiments permit clinicians to identify the locations of intraluminal structures and medical devices during non-surgical medical techniques, such as cardiac ablation, by determining the intralumen conductance and/or cross-sectional area at a plurality of locations within the body lumen.

A cardiac ablation device, including a steerable catheter (10) and an expandable ablation element (18) incorporating one or more balloons (20, 22) at the distal end of the catheter, has a continuous passageway (28, 30) extending through it from the proximal end of the catheter to the distal side of the expandable ablation element. A probe (72) carrying electrodes is introduced through this passageway and deploys, under the influence of its own resilience, to a structure incorporating a loop (82) which is automatically aligned with the axis of the expandable ablation device, so that minimal manipulation is required to place the sensor probe.

A microwave antenna suitable for cardiac ablation, in particular for catheter ablation, and a method for making such an antenna. The antenna comprises a transmission line having an inner conductor, an outer conductor, and a dielectric insulator to provide insulation between the inner and outer conductors. An energy emitting antenna element is located at the distal end of the transmission line. The antenna element has an inner conductor which is electrically coupled to the inner conductor of the transmission line, and, around the inner conductor, a sheath of dielectric insulator continuous with the insulator of the transmission line. At its distal end, a hollow metallic cap is electrically connected to the inner conductor, surrounding a length of the insulator.

A catheter includes a cryoablation tip with an electrically-driven ablation assembly for heating tissue. The cryoablation tip may be implemented with a cooling chamber through which a controllably injected coolant circulates to lower the tip temperature, and having an RF electrode at its distal end. The RF electrode may be operated to warm cryogenically-cooled tissue, or the coolant may be controlled to conductively cool the tissue in coordination with an RF treatment regimen, allowing greater versatility of operation and enhancing the lesion size, speed or placement of multi-lesion treatment or single lesion re-treatment cycles. In one embodiment a microwave energy source operates at a frequency to extend beyond the thermal conduction depth, or to penetrate the cryogenic ice ball and be absorbed in tissue beyond an ice boundary, thus extending the depth and/or width of a single treatment locus. In another embodiment, the cooling and the application of RF energy are both controlled to position the ablation region away from the surface contacted by the electrode, for example to leave surface tissue unharmed while ablating at depth or to provide an ablation band of greater uniformity with increasing depth. The driver or RF energy source may supply microwave energy at a frequency effective to penetrate the ice ball which develops on a cryocatheter, and different frequencies may be selected for preferential absorption in a layer of defined thickness at depth in the nearby tissue. The catheter may operate between 70 and minus 70 degrees Celsius for different tissue applications, such as angioplasty, cardiac ablation and tissue remodeling, and may preset the temperature of the tip or adjacent tissue, and otherwise overlay or delay the two different profiles to tailor the shape or position where ablation occurs or to speed up a treatment cycle.

A system provides heart ablation unit control. The system includes an input processor for acquiring electrophysiological signal data from multiple tissue locations of a heart and data indicating tissue thickness at the multiple tissue locations. A signal processor processes the acquired electrophysiological signal data to identify location of particular tissue sites of the multiple tissue locations exhibiting electrical abnormality in the acquired electrophysiological signal data and determines an area of abnormal tissue associated with individual sites of the particular sites. An ablation controller automatically determines ablation pulse characteristics for use in ablating cardiac tissue at an individual site of the particular tissue sites in response to the acquired data indicating the thickness of tissue and determined area of abnormality of the individual site.