Abstract: An apparatus for determining the velocity of a fluid flowing through a lumen comprises a first diffraction grating transducer (DGT) responsive to a continuous wave (CW) input and operable in a first mode for producing a first signal beam at a first frequency and first phase, and in a second mode for producing a second signal beam at the first frequency and a second phase; a second diffraction grating transducer (DGT) operating as a receiver and coupled to the first diffraction grating transducer at a predetermined angle, the second diffraction grating transducer producing a first beam which intersects the first DGT first beam for receiving a first reflected signal associated with the first signal beam, and for producing a second beam which intersects the first DGT second beam for receiving a second reflected signal associated with the second signal beam; the first beams adapted to intersect in a first predetermined region through which dynamic particles are undergoing velocity analysis, and the second beams a

Abstract: An ultrasonic imaging apparatus comprising a transducer operative for receiving a pulse of energy containing multiple frequencies and generating a plurality of beams at different angles corresponding to a plurality of frequencies toward an object to be imaged; means for focusing said beams to produce an array of focused points at spatial positions on the object; a receiver for receiving reflected signals from the object having frequencies corresponding to the spatial positions and simultaneously filtering the reflected signals to produce sample image data sets corresponding to spatial positions at particular time intervals; and means for producing rotational motion between the transducer and the object to enable generation of sample image data sets at other predetermined spatial positions; and means for summing the sample image data sets at each of the predetermined spatial positions to produce an image of the object.

Abstract: A disposable interventional medical device assembly for use with a color ultrasonic imaging system or other ultrasonic systems sensitive to motion. The assembly includes an interventional medical device having an elongated member for insertion into an interior region of a body under investigation, and piezo driver assembly coupled to the member of the interventional medical device. The driver assembly produces a vibratory oscillation which causes the member to exhibit a flexural motion in response thereto, the flexural motion having a zero amplitude point and a maximum amplitude point, wherein the driver assembly is coupled to the member at a point located between the zero amplitude point and the maximum amplitude point of the member's flexural motion. In one embodiment of the present invention, the interventional medical device can be a biopsy needle wherein the elongated member is the shaft of the biopsy needle.

Abstract: A higher-order quadrature driven diffraction grating ultrasonic transducer and mode of operation, useful for determining the velocity of a fluid under investigation. The diffraction grating of the transducer is easier to fabricate compared to prior art first order quadrature driven diffraction grating ultrasonic transducers because the higher order design allows the grating to be expanded. The higher order design also eliminates the need to vary the frequency or phase of pulse generator used to drive the transducer in order to produce multiple beams needed for fluid velocity measurements.

Abstract: An apparatus and method is disclosed for locating a desired blood vessel within a predetermined volume of tissue. The apparatus and method includes a plurality of transducers which are operable to be positioned over the tissue. Each of the transducers when driven produces an output signal indicative of a characteristic of a blood vessel located under each transducer. A control system for selectively driving the transducers in order to produce a plurality of output signals and for comparing the plurality of output signals in order to determine the output signal having the largest amplitude which corresponds to the transducer positioned over the desired blood vessel.

Abstract: An ultrasonic transducer apparatus of variable frequency including a diffracting structure adapted for emitting and receiving a plurality of diffracted ultrasonic beams of calculable different angles for determining the velocity of a fluid flowing through a lumen, and flow volume. Velocity and flow volume are determined from at least two equations in the two unknowns of the velocity, and the angle between the ultrasonic transducer apparatus and the direction of the fluid flow, and from a determination of the diameter of the lumen.

Abstract: An ultrasonic imaging system for guiding a user in the placement of an interventional medical device within the body includes a vibrating element which transmits vibratory mechanical oscillation at a predetermined frequency of vibration to the interventional medical device. The medical device oscillates in accordance with the vibratory oscillation so that the interventional medical device completes an oscillation during each vibratory period. An imaging transducer sequentially transmits ultrasonic waves down a selected image line into the imaging region in pulses which are separated by a time interval determined as a function of the vibratory period so that they coincide with maximum displacement of a given point on the interventional device. Return signals received after each pulse are processed to eliminate static and non-static tissue components so that a bright image of the vibrating element is obtained.