Abstract: A system for improving vector Doppler velocity measurements by using information about the constancy of the velocity's angle to reduce the errors caused by the intrinsic variability in power of Doppler signals.

Abstract: An apparatus and method for detecting the highest velocity of fluid flow with in a volume having multiple sources of fluid flow with different velocities. There are multiple pairs of receiving transducers arranged about a region wherein each transducer in a pair is positioned on the same axis with respect to the region. A transmitting transducer is positioned at the region to provide an output frequency signal, which frequency signal is transmitted to the fluid flow area volume. This causes Doppler shifted frequency signals to be reflected, with the Doppler shift being a function of the fluid flow velocity. Each of the receiving transducers receive the Doppler shifted signals. Signal processing means are responsive to the Doppler shifted signals and the original transmitted output frequency signal to process those signals to provide a velocity signal for each pair of transducers. One then selects the maximum velocity signal obtained from the pair.

Abstract: An apparatus and method for detecting the highest velocity of fluid flow with in a volume having multiple sources of fluid flow with different velocities. There are multiple pairs of receiving transducers arranged about a region wherein each transducer in a pair is positioned on the same axis with respect to the region. A transmitting transducer is positioned at the region to provide an output frequency signal, which frequency signal is transmitted to the fluid flow area volume. This causes Doppler shifted frequency signals to be reflected, with the Doppler shift being a function of the fluid flow velocity. Each of the receiving transducers receive the Doppler shifted signals. Signal processing means are responsive to the Doppler shifted signals and the original transmitted output frequency signal to process those signals to provide a velocity signal for each pair of transducers. One then selects the maximum velocity signal obtained from the pair.

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 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 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.

Abstract: A scanning system that is forward looking that uses ultrasound for intraluminal imaging. A transducer that emits ultrasonic signals is nutatably mounted on the tip of a probe. The front mounted transducer enables intraluminal scanning of an oncoming area or volume as the probe moves to a selected position in a lumen or body cavity. Cables are used to nutate the transducer so as to provide spiral or raster scanning patterns. The cables are driven by programmable electromagnetic drives. Three dimensional images are then obtained from the reflected ultrasonic signals.

Abstract: A VIBER vibrating mechanism is coupled to a cannula or needle and operates to provide flexural vibrations to move the needle and to enable detection of the position of a needle within a body of interest by a color ultrasound imaging system. The VIBER mechanism exhibits multiple modes of oscillation when energized. The VIBER mechanism is excited to exhibit predetermined oscillations at a given frequency in the X plane, a predetermined oscillation at another frequency in the Y plane and still another frequency of oscillation in the Z plane. In this manner, the VIBER mechanism device exhibits motion in all three planes, which motion is detectable by a conventional color ultrasound imaging system. The frequency of oscillation is a function of the entire system, namely the VIBER mechanism, the needle or cannula which is attached to the VIBER mechanism and the tissue. The resonant frequency is preferred as it provides larger vibrational amplitudes.

Abstract: A VIBER vibrating mechanism is coupled to a cannula or needle and operates to provide flexural vibrations to move the needle and to enable detection of the position of a needle within a body of interest by a color ultrasound imaging system. The VIBER mechanism exhibits multiple modes of oscillation when energized. The VIBER mechanism is excited to exhibit predetermined oscillations at a given frequency in the X plane, a predetermined oscillation at another frequency in the Y plane and still another frequency of oscillation in the Z plane. In this manner, the VIBER mechanism device exhibits motion in all three planes, which motion is detectable by a conventional color ultrasound imaging system. The frequency of oscillation is a function of the entire system, namely the VIBER mechanism, the needle or cannula which is attached to the VIBER mechanism and the tissue. The resonant frequency is preferred as it provides larger vibrational amplitudes.

Abstract: An ultrasonic imaging system employs a processing circuit which enables the imaging system to accurately display the location of an element in a body by utilizing a transducer which provides an electric signal when an ultrasonic wave impinges thereon. The electric signal is processed to determine the maximum amplitude signals during an entire frame of the ultrasonic imaging system. The signals are characterized in terms of the line at which the signal appears or the ray at which the signal appears and the pixel or location along that line. This information regarding ray and pixel serves as X-Y coordinates enabling one to accurately locate the element and transducer on the displayed image by intensifying the display at that location or by adding color or by producing some other visual effect such as blinking, and so on. Thus the disclosed apparatus in its various forms provides ultrasonic position indication without adjustment whereby one shows the exact location of the localizing transducer.

Abstract: An ultrasonic transducer for use in locating devices with an ultrasonic imaging system which is sensitive over a broad range of angles of incident acoustic beams, such as those beams emitted in ultrasonic systems, has a curved surface, and is an annular member in shape. The elongated catheter or other device passes through the opening of the annular transducer. Based on the shape of such transducers and the wavelength used, the response of the transducers is a function of the angle of the insonifying beam to the catheter axis. The particular response of such transducers is shown to depend on the curvature of the annular marker, with the radius of curvature chosen on the basis of the wavelength used in the ultrasonic scanning system; between 2-50 wavelengths.

Abstract: There is disclosed an ultrasonic scanning apparatus for directing ultrasonic energy towards a body under investigation, such as the body of a person. The scanning apparatus consists of a focussed ultrasonic transducer which is capable of radiating a beam of ultrasonic energy in a given direction. The beam emanating from the transducer impinges upon at least one surface of a rotating reflector where the rotating reflector directs the beam relatively perpendicular to the direction of the beam as propagated from the transducer. The redirected beam can then be further focussed or reflected to further shape the beam prior to directing the beam towards the body under investigation.