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: Apparatus and methods for ablating tissue surrounding a tubular anatomical structure such as the wall of a blood vessel or prostatic tissue surrounding the urethra. The apparatus includes an ultrasonic emitter such as a cylindrical emitter and an inflatable annular lens balloon surrounding the ultrasonic emitter. The lens balloon is inflated with a liquid having acoustic velocity different than that of the surrounding medium, so as to form an annular refracting surface. The acoustic energy from the emitter is focused into an annular focal region.

Abstract: A collapsible ultrasonic reflector incorporates a gas-filled reflector balloon, a liquid-filled structural balloon an ultrasonic transducer disposed within the structural balloon. Acoustic energy emitted by the transducer is reflected by a highly reflective interface between the balloons. In a cardiac ablation procedure, the ultrasonic energy is focused into an annular focal region to ablate cardiac tissue extending in an annular path along the wall. Devices for stabilizing the balloon structure and for facilitating collapse and withdrawal of the balloon structure are also disclosed.

Abstract: A balloon catheter is provided with a sleeve and a flexible material where, upon inflation of the balloon, the sleeve is slid over a ball joint, preventing the flexible material and tube from moving through a range of motion in order to prevent the tube from kinking and misaligning.

Abstract: A collapsible ultrasonic reflector incorporates a gas-filled reflector balloon, a liquid-filled structural balloon an ultrasonic transducer disposed within the structural balloon. Acoustic energy emitted by the transducer is reflected by a highly reflective interface between the balloons. In a cardiac ablation procedure, the ultrasonic energy is focused into an annular focal region to ablate cardiac tissue extending in an annular path along the wall. Devices for stabilizing the balloon structure and for facilitating collapse and withdrawal of the balloon structure are also disclosed.

Abstract: A balloon catheter is provided with engagement elements disposed within the balloon so that, upon inflation of the balloon, the engagement elements move in the proximal to distal direction of the catheter so as to abut one another and form a substantially rigid column to maintain alignment of the distal end of the balloon with the proximal end of the balloon and with the catheter.

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 lens for focusing an ultrasound wave having a wavelength, includes a plurality of substantially concentric rings disposed about a central point, at least one of the rings having a substantially triangular cross-section defined by first, second, and third sections, the first section extending from a proximal end radially away from the central point to a distal end, the second section extending from the distal end of, and substantially perpendicular to, the first section and terminating at a peak, and the third section smoothly sloping from the proximal end of the first section to the peak of the second section, and wherein the first, second and third sections have lengths with respect to the wavelength of the ultrasound wave such that (i) phases of the ultrasound wave are substantially additive at a focal point located on an axis perpendicular to the lens that passes through the central point, and (ii) aggregate focused ultrasound energy would not be predicted at the focal point by Snell's law refractio

Abstract: A compact, high-power ultrasonic emitting transducer has an active element such as a piezoelectric element and structure defining a reflective backing interface such as an air interface behind the rear surface of the active element. A liquid is provided in the resonant unit between the backing interface and the active element.

Abstract: A balloon catheter is provided with a sleeve and a flexible material where, upon inflation of the balloon, the sleeve is slid over a ball joint, preventing the flexible material and tube from moving through a range of motion in order to prevent the tube from kinking and misaligning.

Abstract: A balloon catheter is provided with engagement elements disposed within the balloon so that, upon inflation of the balloon, the engagement elements move in the proximal to distal direction of the catheter so as to abut one another and form a substantially rigid column to maintain alignment of the distal end of the balloon with the proximal end of the balloon and with the catheter.

Abstract: A collapsible ultrasonic reflector incorporates a gas-filled reflector balloon, a liquid-filled structural balloon an ultrasonic transducer disposed within the structural balloon. Acoustic energy emitted by the transducer is reflected by a highly reflective interface between the balloons. In a cardiac ablation procedure, the ultrasonic energy is focused into an annular focal region to ablate cardiac tissue extending in an annular path along the wall. Devices for stabilizing the balloon structure and for facilitating collapse and withdrawal of the balloon structure are also disclosed.

Abstract: A treatment catheter (10) carries an elongated ultrasonic emitter (20) extending in the lengthwise direction of the catheter. The array is flexible in all directions transverse to the lengthwise direction. The treatment catheter is inserted into a chamber of the heart and brought to a desired configuration such as a substantially closed loop. The treatment catheter is then biased into engagement with the wall of the heart by an expansible balloon (62) or other expansible structure, which may be carried on a separate stabilizer catheter (60). While the treatment catheter is engaged with the heart wall, the array is actuated to ablate tissue along a path having a shape corresponding to the configuration of the treatment catheter.

Abstract: A tubular anatomical structure in a mammalian subject is occluded by directing ultrasonic energy from outside of the body. For example, a male subject may be sterilized by directing ultrasonic energy through the skin of the scrotum, onto the vas deferens. The focal spot of an ultrasonic transducer may be registered with the structure to be treated by means of guide members on a probe holding the transducer. The procedure is simple and can be entirely non-invasive. Apparatus for performing this and other treatments may be provided as a disposable unit, and the guide members may be arranged to hold a fold of tissue without substantially obstructing the sonic path from the transducer to the fold.

Abstract: A collapsible ultrasonic reflector incorporates a gas-filled reflector balloon, a liquid-filled structural balloon an ultrasonic transducer disposed within the structural balloon. Acoustic energy emitted by the transducer is reflected by a highly reflective interface between the balloons. In a cardiac ablation procedure, the ultrasonic energy is focused into an annular focal region to ablate cardiac tissue extending in an annular path along the wall. Devices for stabilizing the balloon structure and for facilitating collapse and withdrawal of the balloon structure are also disclosed.

Abstract: High intensity focused ultrasound heating is provided by applying therapeutic ultrasonic waves using an array of transducers. Cavitation is detected by using some or all of the transducers in the array to detect ultrasonic waves emanating from or reflected from the patient's body or the interface. A feedback signal is generated based on such detection. If the feedback signal indicates the presence of cavitation, the therapeutic ultrasonic waves are terminated or altered. Obstacles to ultrasound transmission, such as bony structures or bubbles at the interface between the transducer array and the patient can be detected using the same transducers.

Abstract: A compact, high-power ultrasonic emitting transducer has an active element such as a piezoelectric element and structure defining a reflective backing interface such as an air interface behind the rear surface of the active element. A liquid is provided in the resonant unit between the backing interface and the active element.

Abstract: Apparatus and methods for ablating tissue surrounding a tubular anatomical structure such as the wall of a blood vessel or prostatic tissue surrounding the urethra. The apparatus includes an ultrasonic emitter such as a cylindrical emitter and an inflatable annular lens balloon surrounding the ultrasonic emitter. The lens balloon is inflated with a liquid having acoustic velocity different than that of the surrounding medium, so as to form an annular refracting surface. The acoustic energy from the emitter is focused into an annular focal region.

Abstract: A collapsible ultrasonic reflector incorporates a gas-filled reflector balloon, a liquid-filled structural balloon an ultrasonic transducer disposed within the structural balloon. Acoustic energy emitted by the transducer is reflected by a highly reflective interface between the balloons. In a cardiac ablation procedure, the ultrasonic energy is focused into an annular focal region to ablate cardiac tissue extending in an annular path along the wall. Devices for stabilizing the balloon structure and for facilitating collapse and withdrawal of the balloon structure are also disclosed.

Abstract: A lens for focusing an ultrasound wave having a wavelength, includes a plurality of substantially concentric rings disposed about a central point, at least one of the rings having a substantially triangular cross-section defined by first, second, and third sections, the first section extending from a proximal end radially away from the central point to a distal end, the second section extending from the distal end of, and substantially perpendicular to, the first section and terminating at a peak, and the third section smoothly sloping from the proximal end of the first section to the peak of the second section, and wherein the first, second and third sections have lengths with respect to the wavelength of the ultrasound wave such that (i) phases of the ultrasound wave are substantially additive at a focal point located on an axis perpendicular to the lens that passes through the central point, and (ii) aggregate focused ultrasound energy would not be predicted at the focal point by Snell's law refraction.