Abstract: Ablation apparatus such as a catheter carrying an ultrasonic ablation device including an ablation transducer and a balloon reflector structure for directing ultrasonic energy from the ablation transducer into a ring-like ablation region is provided with an imaging ultrasonic transducer mounted on an imaging probe which may be inserted into or through a passageway extending through the catheter and into or through the ablation device to image the ablation region or neighboring regions. Alternatively, the imaging transducer may be mounted within the balloon reflector structure or distal to this structure.

Abstract: Ablation device including a probe structure 10 having a proximal end 12 and a distal end 14. Probe structure 10 includes a tubular first catheter 16, a tubular second catheter 18 surrounding the first catheter and a tubular guide catheter extending within the first catheter 16. The first catheter 16 carries a cylindrical ultrasonic transducer 20 adjacent its distal end. The transducer 20 is connected to a source of electrical excitation. The ultrasonic waves emitted by the transducer are directed at the heart wall tissue. Once the tissue reaches the target temperature, the electrical excitation is turned on and off to maintain the tissue at the target temperature. Alternatively, the transducer 20 is subjected to continuous excitation at one power level and upon the tissue reaching the target temperature, the power level of the continuous excitation is switched to a second lower power level.

Abstract: Ablation apparatus such as a catheter carrying an ultrasonic ablation device including an ablation transducer and a balloon reflector structure for directing ultrasonic energy from the ablation transducer into a ring-like ablation region is provided with an imaging ultrasonic transducer mounted on an imaging probe which may be inserted into or through a passageway extending through the catheter and into or through the ablation device to image the ablation region or neighboring regions. Alternatively, the imaging transducer may be mounted within the balloon reflector structure or distal to this structure.

Abstract: Ablation apparatus such as a catheter (10) carrying an ultrasonic ablation device (20) including an ablation transducer (42) and a balloon reflector structure (22, 24) for directing ultrasonic energy from the ablation transducer into a ring-like ablation region (A) is provided with an imaging ultrasonic transducer (86) mounted on an imaging probe (80) which may be inserted into or through a passageway (18, 65) extending through the catheter and into or through the ablation device to image the ablation region or neighboring regions. Alternatively, the imaging transducer (102, 202) may be mounted within the balloon reflector structure or distal to this structure.

Abstract: 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.

Abstract: A system having a catheter having a distal pressure sensitive capacitive element providing an impedance and phase shift which varies responsive to the amount of pressure from blood external the catheter, a detector having electronics for determining the impedance and/or phase shift. This impedance and or phase shift corresponds to the pressure of the blood about the distal end of the catheter. When the catheter is inserted into a patient's body, the impedance or phase shift is detected quasi wirelessly without special signal communication means like optical fibers or electrical wires from outside the patient's body utilizing the patient as a ground path and the catheter shaft as an electrical conductor.

Abstract: Mitral valve insufficiency is treated by introducing an expansible device such as a balloon bearing an ultrasonic transducer into the heart so that the transducer is positioned adjacent the mitral annulus but spaced from the mitral annulus, and actuating the transducer to heat the mitral annulus, denature collagen in the annulus and thereby shrink the annulus.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Mitral valve insufficiency is treated by introducing an expansible device such as a balloon bearing a an ultrasonic transducer into the heart so that the transducer is positioned adjacent the mitral annulus but spaced from the mitral annulus, and actuating the transducer to heat the mitral annulus, denature collagen in the annulus and thereby shrink the annulus.

Abstract: Ablation device including a probe structure 10 having a proximal end 12 and a distal end 14. Probe structure 10 includes a tubular first catheter 16, a tubular second catheter 18 surrounding the first catheter and a tubular guide catheter extending within the first catheter 16. The first catheter 16 carries a cylindrical ultrasonic transducer 20 adjacent its distal end. The transducer 20 is connected to a source of electrical excitation. The ultrasonic waves emitted by the transducer are directed at the heart wall tissue. Once the tissue reaches the target temperature, the electrical excitation is turned on and off to maintain the tissue at the target temperature. Alternatively, the transducer 20 is subjected to continuous excitation at one power level and upon the tissue reaching the target temperature, the power level of the continuous excitation is switched to a second lower power level.

Abstract: Apparatus for treating cardiac arrhythmias includes an ultrasonic ablation device incorporating an ultrasonic emitter (22, 400), means (10, 14, 402, 404) for positioning the ablation device outside of the heart but adjacent the epicardial surface of the heart, and means (26, 28, 30) for focusing the ultrasonic energy emitted by the emitter into an ablation region, so that the ablation region is disposed within the wall of the heart.

Abstract: Ablation apparatus such as a catheter (10) carrying an ultrasonic ablation device (20) including an ablation transducer (42) and a balloon reflector structure (22, 24) for directing ultrasonic energy from the ablation transducer into a ring-like ablation region (A) is provided with an imaging ultrasonic transducer (86) mounted on an imaging probe (80) which may be inserted into or through a passageway (18, 65) extending through the catheter and into or through the ablation device to image the ablation region or neighboring regions. Alternatively, the imaging transducer (102, 202) may be mounted within the balloon reflector structure or distal to this structure.

Abstract: 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.

Abstract: Ultrasound energy originating from an emitter at a number of predetermined positions is sensed by a plurality of duplex transducers in a predefined arrangement. Each transducer produces a sensor signal representing ultrasound energy sensed by it, and the sensor signals of each transducer are stored in association with the predetermined position producing the sensor signal. Thereafter, an ablation pattern corresponding to a group of the predetermined positions may be generated by actuating each transducer with a time-reversed version of the sensor signals stored in association with the group of positions. By placing the transducers in a predetermined spatial relationship to the heart, the ablation pattern may be formed on the ostium of a pulmonary artery. Preferably the predetermined positions correspond to a grid of dots that may be used to approximate virtually any shape.