Abstract: A method and apparatus for endoscopic removal of compliant biological tissues utilizing an endoscopic ultrasonic aspirator comprising irrigation and aspiration means, a piezoelectric ultrasonic transducer, a first resonator such as a half-wave stepped velocity transformer, a probe including a second resonator such as a constant-stress velocity transformer, a blunt or modified working tip of open channel means or restricted tubular means for application of ultrasonic energy to cellular material, and a capacitive fluid sensor to detect the presence of irrigation fluid adjacent these transformers within the instrument. The surgery is advantageously performed by operating the transducer in the 10-20 kHz range to achieve maximum cavitation of the intracellular fluids in the tissues to be removed.

Abstract: A scanning apparatus and method for scanning an object including a frame, a transducer for obtaining information from an object and a motor oscillating the transducer. The motor comprises a spring/solenoid combination driven at the resonant frequency of the spring/motor system. The actual displacement of the transducer is measured and compared to a desired displacement to provide a control signal to the motor. The scanning apparatus is at least partially enclosed by a housing containing a heat transfer fluid for damping the resonant vibration of the apparatus.

Abstract: A method and apparatus for endoscopic removal of compliant biological tissues utilizing an endoscopic ultrasonic aspirator comprising irrigation and aspiration means, a piezoelectric ultrasonic transducer, a first resonator such as a half-wave stepped velocity transformer, a probe including a second resonator such as a constant-stress velocity transformer, a blunt or modified working tip of open channel means or restricted tubular means for application of ultrasonic energy to cellular material, and a capacitive fluid sensor to detect the presence of irrigation fluid adjacent these transformers within the instrument. The surgery is advantageously performed by operating the transducer in the 10-20 kHz range to achieve maximum cavitation of the intracellular fluids in the tissues to be removed.

Abstract: A method and apparatus for endoscopic removal of compliant biological tissues utilizing an endoscopic ultrasonic aspirator comprising irrigation and aspiration means, a piezoelectric ultrasonic transducer, a first resonator such as a half-wave stepped velocity transformer, a probe including a second resonator such as a constant-stress velocity transformer, a blunt or modified working tip of open channel means or restricted tubular means for application of ultrasonic energy to cellular material, and a capacitive fluid sensor to detect the presence of irrigation fluid adjacent these transformers within the instrument. The surgery is advantageously performed by operating the transducer in the 10-20 kHz range to achieve maximum cavitation of the intracellular fluids in the tissues to be removed.