Abstract: An apparatus, system and method for controlling parameters attending the emission of a vaporized material from a source in a HV environment utilizes at least one shutter which is rotatably mounted over an exit opening through which vaporized material must exit the source. The shutter has a closure portion and is mounted adjacent the exit opening associated with the source for rotation about an axis so that by rotating the shutter about the rotation axis, the closure portion repeatedly covers and uncovers the exit opening in an intermittent fashion to prevent the emission of a vaporized material from the source during the periods of shutter rotation during which the exit opening is covered by the closure portion and to permit the emission of a vaporized material from the source during the periods of shutter rotation during which the exit opening is uncovered by the closure portion.

Abstract: A method and apparatus for the treatment of tumors by heating with ultrasonic energy. A transducer assembly is provided in a housing having a refractive assembly disposed between the tumor and the transducer. The refractive assembly moves with respect to the transducer assembly. The refractive assembly includes one or more refractive elements. The refractive assembly is interchangeable to provide treatment of different types of tumors using the same transducer assembly and housing. The refractive assembly may focus, deflect or diffuse the ultrasonic energy depending on the arrangement of elements. Motion of the refractive assembly relative to the tumor results in a time-averaging spatial deposition pattern which is more highly uniform due to the averaging of maxima and minima which occurs in the near field.