Apparatus and methods for deactivating renal nerves extending along a renal artery of a mammalian subject to treat hypertension and related conditions. An ultrasonic transducer (30) is inserted into the renal artery (10) as, for example, by advancing the distal end of a catheter (18) bearing the transducer into the renal artery. The ultrasonic transducer emits unfocused ultrasound so as to heat tissues throughout a relatively large impact volume (11) as, for example, at least about 0.5 cm.sup.3 encompassing the renal artery to a temperature sufficient to inactivate nerve conduction but insufficient to cause rapid ablation or necrosis of the tissues. The treatment can be performed without locating or focusing on individual renal nerves.

The present disclosure relates generally to thrombectomy devices. An exemplary catheter comprises: a central tube; an emitter assembly mounted over the central tube, wherein the emitter assembly comprises: a conductive sheath; a first insulated wire having a first curved distal portion; and a second insulated wire having a second curved distal portion, wherein the first curved distal portion and the second curved distal portion are positioned within the conductive sheath, and wherein the emitter assembly is configured to generate a plurality of cavitation bubbles or shockwaves when a pulsed voltage is applied to the emitter assembly; and an outer tube housing the emitter assembly, wherein the outer tube is configured to receive a conductive fluid, wherein the outer tube comprises a distal opening for releasing the plurality of cavitation bubbles or shockwaves and the conductive fluid in a forward direction to treat thrombus at a treatment site.

A tip at the distal end of a catheter is designed to vibrates vigorously in order to break up a blood clot. Broken-up, the blood clot avoids “corking,” thus allowing it to be directly aspirated into the catheter. Unlike devices in minimally invasive surgery, where access to the organs to be removal are achieved through conveniently located small incisions, access to a location in the vascular space is achieved through a long flexible catheter, often 100 cm or more in length. An electroactive polymer (EAP) in at the tip of the distal end enables the vibration that breaks up the blood clot to be actuated from the proximal end of the catheter, without transferring mechanical action over substantially the entire length of the catheter.

Described herein are low-profile electrodes for use with an angioplasty shockwave catheter. A low-profile electrode assembly may have an inner electrode, an insulating layer disposed over the inner electrode such that an opening in the insulating layer is aligned with the inner electrode, and an outer electrode sheath disposed over the insulating layer such that an opening in the outer electrode sheath is coaxially aligned with the opening in the insulating layer. This layered configuration allows for the generation of shockwaves that propagate outward from the side of the catheter. In some variations, the electrode assembly has a second inner electrode, and the insulating layer and outer electrode may each have a second opening that are coaxially aligned with the second inner electrode. An angioplasty shockwave catheter may have a plurality of such low-profile electrode assemblies along its length to break up calcified plaques along a length of a vessel.

Apparatus and methods for deactivating renal nerves extending along a renal artery of a mammalian subject to treat hypertension and related conditions. An ultrasonic transducer (30) is inserted into the renal artery (10) as, for example, by advancing the distal end of a catheter (18) bearing the transducer into the renal artery. The ultrasonic transducer emits unfocused ultrasound so as to heat tissues throughout a relatively large impact volume (11) as, for example, at least about 0.5 cm.sup.3 encompassing the renal artery to a temperature sufficient to inactivate nerve conduction but insufficient to cause rapid ablation or necrosis of the tissues. The treatment can be performed without locating or focusing on individual renal nerves.

The present invention provides a catheter for treating an occlusion in a body lumen. The catheter includes an elongated tube, a first electrode pair and a second electrode pair each configured to generate shock waves. The catheter also includes a flexible polymer enclosure that is fillable with conductive fluid and wrapped circumferentially around at least a portion of the elongated tube such that it surrounds the first and second electrode pairs. The first and second electrode pairs can be arranged relative to one another to promote interference between shock waves generated at the electrode pairs when voltage is delivered across the electrodes of each pair. Electrode pairs can be longitudinally adjacent (spaced a relatively small longitudinal distance apart), longitudinally aligned (at the same longitudinal location), circumferentially offset (offset about the circumference of the catheter), circumferentially aligned (at the same circumferential location), or any combination of any of the above.

A system for breaking obstructions in body lumens includes a catheter including an elongated carrier, a balloon about the carrier in sealed relation thereto, the balloon being arranged to receive a fluid therein that inflates the balloon, and an arc generator including at least one electrode within the balloon that forms a mechanical shock wave within the balloon. The system further includes a power source that provides electrical energy to the arc generator.

The invention provides a device for generating shock waves. The device may comprise an elongated tube and a conductive sheath circumferentially mounted around the elongated tube. The device may further comprise first and second insulated wires extending along the outer surface of the elongated tube. A portion of the first insulated wire is removed to form a first inner electrode, which is adjacent to a first side edge of the conductive sheath. A portion of the second insulated wire is removed to form a second inner electrode, which is adjacent to a second side edge of the conductive sheath. Responsive to a high voltage being applied across the first inner electrode and the second inner electrode, a first shock wave is created across the first side edge and the first inner electrode, and a second shock wave is created across the second side edge and the second inner electrode.

A flexible ultrasonic wave generating device (2) is inserted into a flexible tube (10) having flexibility, and an inductor (15), a discharge resistor (21), an FET (22), and an SBD (23) constituting a drive circuit (25) are mounted on first to third flexible substrates (11) to (13). An actuator (14) is connected to the distal end portion of the flexible ultrasonic wave generating device (2). An active blade (30) is attached to the actuator (14).

A system for breaking obstructions in body lumens includes a catheter including an elongated carrier, a balloon about the carrier in sealed relation thereto, the balloon being arranged to receive a fluid therein that inflates the balloon, and an arc generator including at least one electrode within the balloon that forms a mechanical shock wave within the balloon. The system further includes a power source that provides electrical energy to the arc generator.