An elongate endovascular element for crossing through an obstruction in a blood vessel comprises: a proximal section; a distal tip section of smaller diameter than the proximal section; and a distally-tapering intermediate section extending between the proximal and distal tip sections; wherein the tapered intermediate section has a length that is substantially ?/2 or a multiple of ?/2, where ? is a wavelength of a driving frequency that will produce longitudinal resonance in the element.

A method for controlling a system, comprising repeatedly monitoring a resonant frequency of a system that includes an ultrasonic transducer, wherein the ultrasonic transducer is powered by an ultrasonic generator and is configured to drive a device at a predetermined level of resonant frequency, and wherein the ultrasonic generator includes a controller configured to monitor operational parameters of the system; detecting a change in resonant frequency based on a comparison of the monitored resonant frequency against a predetermined threshold for resonant frequency; inferring a system-use criteria based on the detected change in the resonant frequency; and adapting system control by using the controller to alter the operational parameters of the system based on the inferred use criteria.

This disclosure disclosed an ultrasonic needle and apparatus used for removal of the vitreous body and other tissues. An ultrasonic vitrectomy needle, comprising: a connector, a connected inner needle, and an outer sheath. The length of the outer sheath at the distal end is slightly longer than that of the inner needle; the sheath distal end is of blind with smooth surface, but there is an open cut at the side of the distal end used for aspirating the vitreous body. The benefits of this disclosure: due to the difficulty if not impossible in the prior arts making a slim long center bore needle for ultrasonic surgical system, this disclosure clears the way to make the ultrasonic vitrectomy a practical reality; the ultrasonic vibration inherent advantages of the quietness, minuscule displacement, liquid repulsion and viscosity reduction improve safety of the surgery; the possibility of integrating ultrasonic vitrectomy and ultrasonic phaco emulsification procedures simplifies the complexity from prior arts, thus brings ease to the ophthalmic surgeries and reduces the cost.

An endovascular apparatus for crossing through an obstruction in a blood vessel comprises an elongate endovascular element such as a wire. The element has a proximal section, a distal tip section of smaller diameter than the proximal section; and a distally-tapering intermediate section extending between the proximal and distal tip sections. The apparatus comprises an ultrasonic transducer, mechanically coupled to the proximal section of the element for ultrasonically activating the element, hence exciting the distal tip section to facilitate crossing through the obstruction. A catheter surrounds the element, leaving at least part of the distal tip section of the element protruding distally beyond a distal end of the catheter.

An elongate endovascular element for crossing through an obstruction in a blood vessel comprises: a proximal section; a distal tip section of smaller diameter than the proximal section; and a distally-tapering intermediate section extending between the proximal and distal tip sections; wherein the tapered intermediate section has a length that is substantially /2 or a multiple of /2, where is a wavelength of a driving frequency that will produce longitudinal resonance in the element.

The present disclosure relates to ultrasonic catheters including vibration wires that are positionable in a retracted position and an extended position, and their methods of use. In operation, catheters according to the present disclosure are operable in an occlusion crossing mode, in which the catheter emits ultrasonic energy with the vibration wires in the retracted position and in an atherectomy mode, in which the catheter emits ultrasonic energy with the vibration wires in the extended position, causing the vibration wires to oscillate. The vibration wires may directly or indirectly engage plaque within an artery, causing the plaque to break free from the artery wall. The oscillation of the vibration wires may be less abrasive than conventional cutting elements used in atherectomy procedures, such that catheters according to the present disclosure may cause less trauma to artery walls as compared to conventional atherectomy devices.