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: When transesophageal echocardiography is used to obtain a transgastric short axis view of the left ventricle of the heart, the best place to position the transducer is in the fundus of the stomach, aimed up through the left ventricle. The probes disclosed herein facilitate placement of the transducer in the optimum position within the fundus, despite wide variations in the distance between the lower esophageal sphincter and the fundus among different subjects. In one preferred embodiment, the ultrasound probe uses a bending section with a series of vertebrae and stiffening that is more flexible proximally and less flexible distally, which causes the probe to bend relatively sharply at the point where the probe exits the lower esophageal sphincter. The flexibility of the proximal-most portion of the bending section is preferably greater than or equal to the flexibility of the interface between the bending section and the shaft.

Abstract: A connectorized ultrasound probe includes a distal section that is configured for insertion into a patient's body and a proximal section configured to interface the distal section with an ultrasound system. The distal section is easily attachable and detachable from the proximal section using at least one set of connectors. When connected, a user-operated actuator located on the proximal section controls the bending of the distal section, and the ultrasound system sends driving signals to and receives return signals from the ultrasound transducer via the proximal section. This arrangement is particularly advantageous for long term monitoring, because the disconnectability of the proximal section makes it possible to leave the distal section in place in the patient for longer periods of time without undue discomfort. In some preferred embodiments, the mechanical interface is made before the electrical interface when the distal section is connected to the proximal section.

Abstract: To keep the temperature of an ultrasound probe down, the probe is operated at a low frame rate (with correspondingly low heat generation) for the vast majority of time. Probe operation is only switched to the high frame rate temporarily at times when high temporal resolution is needed, preferably under operator control. The probe is only operated at the high frame rate for a short period of time, during which a burst of images with high temporal resolution is obtained. After capturing the short burst of images, the frame rate is cut back, which reduces the generation of heat.

Abstract: A connectorized ultrasound probe includes a distal section that is configured for insertion into a patient's body and a proximal section configured to interface the distal section with an ultrasound system. The distal section is easily attachable and detachable from the proximal section using at least one set of connectors. When connected, a user-operated actuator located on the proximal section controls the bending of the distal section, and the ultrasound system sends driving signals to and receives return signals from the ultrasound transducer via the proximal section. The proximal section also has a control bottom ergonomically arranged in relation to the actuator to allow actuation of the actuator and button with one hand.

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: An ultrasound probe includes a flexible shaft with a channel that runs through the shaft in a proximal-distal direction, and an ultrasound transducer disposed in a housing mounted at the distal end of the shaft. Flexible wiring is disposed within the channel and is configured to carry signals to and from the transducer. The flexible wiring includes a plurality of substantially parallel conductors that are positioned above a ground plane, and separated from the ground plane by an insulating material. The substantially parallel conductors are also insulated from one another. In some embodiments, a grounded conductive shield is provided on the opposite side of the ground plane. Preferred approaches for implementing the flexible wiring include ribbon cable with a built-in ground plane and flexible printed circuit boards (i.e., flex circuits).

Abstract: When transesophageal echocardiography is used to obtain a transgastric short axis view of the left ventricle of the heart, the best place to position the transducer is in the fundus of the stomach, aimed up through the left ventricle. The probes disclosed herein facilitate placement of the transducer in the optimum position within the fundus, despite wide variations in the distance between the lower esophageal sphincter and the fundus among different subjects. In one preferred embodiment, the ultrasound probe uses a bending section with a series of vertebrae and stiffening that is more flexible proximally and less flexible distally, which causes the probe to bend relatively sharply at the point where the probe exits the lower esophageal sphincter.

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 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: An ultrasonic emitting apparatus (10) for cauterizing and ablating tissue. Ultrasonic waves are focused at an intended region of operation by an elongated waveguide (15), thus reducing damage to adjacent unintended tissue. The waveguide (15) can be inserted into structures of the body through overlying organs. The device may be used, for example, to ablate protruding portions of spinal disks.

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 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 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: An apparatus and method for applying sonic energy within the body of the living subject. A probe for applying sonic energy within the body of a subject comprises a probe body having a proximal and a distal end adapted for insertion into the body of a subject, a spatially-distributed sonic transducer disposed adjacent to the distal end of the probe body and a device for moving one portion of the spatially-distributed transducer relative to another portion of the transducer while the distal end of the probe is disposed within the body of the subject.