A device for therapeutic ablative treatment of residual plaque on, in, and/or surrounding a stent within a blood vessel of a subject includes a jacket configured for insertion within a stent within a blood vessel of a subject. The device further includes an ultrasound transducer located within the jacket and having at least one active element oriented to deliver ultrasound energy in a radial and/or axial direction of the jacket from within the stent to ablate the residual plaque.

A surgical instrument and method, for example to accomplish phacoemulsification, are disclosed. The surgical instrument includes a handpiece that includes a piezoelectric transducer. A hollow titanium needle having a substantially cylindrical portion and a free distal tip is attached to the handpiece by way of a threaded supported end structure. The piezoelectric transducer is driven by a circuit to periodically expand and contract at a high-ultrasound frequency that rings the hollow titanium needle with a high-ultrasonic frequency standing wave having a node of minimum amplitude residing in the substantially cylindrical portion between the supported end structure and the free distal tip, and to periodically expand and contract at an ultrasound frequency that rings the hollow titanium needle with an ultrasonic frequency standing wave, the circuit adapted to between the high-ultrasonic frequency and the ultrasonic frequency.