Transducer assembly and method for coupling ultrasonic energy to a body for thrombolysis of vascular thrombi

Ultrasonic medical apparatus comprising:

• a housing;
• means, including a piezoelectric element, enclosed in said housing for generating ultrasonic waves;
• front mass means, disposed in said housing, for radiating the ultrasonic waves into a medical target in a patient;
• a fluid conductive medium;
• reservoir means including a flexible membrane containing the fluid conductive medium between the front mass means, the flexible membrane providing an interface between said fluid conductive medium and the body surface of the patient,
• flow management means, defined by an outlet through the front mass means, for removing expelled gasses from the reservoir means in order to enhance the transmission of the ultrasonic waves into the medical target, said front mass means including a sloped surface comprising concavity means, including a concavity apex, for enabling gasses expelled from the fluid conductive medium to accumulate at the concavity apex, and outlet means, in fluid communication with said reservoir means and disposed generally at said concavity apex, for passing fluid conductive medium and accumulated gasses out of the reservoir.

A method for coupling ultrasonic energy to a body for dissolution or treatment of a medical target the method comprising the steps of:

• positioning an ultrasonic transducer having a radiator comprising a front mass having an arcuate or sloped surface onto a body surface over the medical target;
• radiating ultrasound waves from the ultrasonic transducer into the medical target beneath the body surface to thereby dissolve or treat the medical target;
• containing a fluid conductive medium in the transducer by confining the fluid conductive medium in a reservoir between the arcuate or sloped surface of the radiator and the body surface;
• circulating the fluid conductive medium between a replenishing source of fluid conductive medium and the transducer;
• accumulating, in the transducer reservoir, gasses expelled from the circulating fluid conductive medium;
• and
• removing the accumulating gasses from the transducer reservoir through outlet means disposed generally at the apex of said sloped or arcuate surface of the radiator.