Abstract: An ultrasonic diagnostic imaging system is provided which calibrates and quantifies colors of a color power Doppler display to produce quantified measurements of Doppler power intensity. The colors of a color power Doppler image are divided into discrete colors and each color assigned a quantified measure of the Doppler power intensity indicated by that color. When a user moves a cursor over the image the system compares the color of the pixel where the cursor is located with the range of colors and their quantified measures and produces a quantified measure of the Doppler power intensity at the location of the cursor. A line of such measures across a blood vessel can be used to plot a profile of Doppler power intensity across the vessel, and an index number which is a measure of perfusion in a region of the body is determined from an area of a color power Doppler image.

Abstract: An ultrasonic diagnostic imaging system is provided in which a portion of an ultrasonic image can be selected for enlarged display as a "zoom" image. When the image portion is displayed in its enlarged format, the bandwidth of a filter in the ultrasonic information path is extended to increase the information content of the image portion when displayed in its enlarged format. The bandwidth is continuously optimized to maximize information content in consideration of the characteristics of the display while preventing the generation of scintillation artifacts caused by attempts to display information of an excessive bandwidth.

Abstract: An ultrasonic diagnostic system is provided which detects the presence of coated microbubble contrast agents in the body of a patient by transmitting ultrasonic energy which causes the destruction of the coated microbubbles and detects the microbubble destruction through phase insensitive detection and differentiation of echoes received from two consecutive ultrasonic transmissions. The destruction of a microbubble can also be used as a point source of acoustic energy for aberration correction, whereby the timing of the beamformer is adjusted from an analysis of beamformer signals resulting from a detected microbubble destruction event.

Abstract: An ultrasonic probe assembly in which an ultrasonic transducer is mechanically scanned in response to a drive motor which is located in a housing spaced from the transducer such that the transducer can be positioned in a body cavity of a patient while the housing containing the drive motor remains outside the body of the patient.

Abstract: A technique for scanning an image field with adjacent beams of ultrasonic energy is provided in which initially transmitted beams are transmitted along beam directions down the center of the image field. Subsequent beams are alternately transmitted on either side of the initially transmitted beams and at increasing lateral locations in said field with respect to the locations of the initially transmitted beams until the full image field has been scanned. In a preferred embodiment a waiting period is added to the pulse repetition interval of each transmission to allow time for multipath reflections to dissipate. The waiting periods are longer during initial transmissions in the vicinity of the center of the image field, and decline as beams are transmitted at increasing lateral locations of the field. The scanning technique provides a reduction in multipath reflection artifacts while maintaining a smoothly varying or uniform temporal disparity in the transmission times of adjacent beams.

Abstract: A multiplane TEE probe is provided in which rotation of the ultrasonic transducer is motor controlled. The motor is controlled to rotate the transducer either clockwise or counterclockwise, and at either a high rotational speed or a low rotational speed. The motor is also automatically controlled to drive the transducer to a predetermined home position. The transducer tip of the probe is detachably connected to the gastroscope tube. An aluminum sheet is embedded in the acoustic lens in front of the transducer to dissipate heat which accumulates in the lens. The gastroscope tube includes an articulating section formed of a plurality of matching cylindrical links which form alternating pivot axes from one link to the next. The pivot range of each link with respect to an adjoining link is controlled by opposing limit stops orthogonally located with respect to the pivot points of the links.

Abstract: An ultrasonic diagnostic imaging system is provided which scans an image region to receive a plurality of spatially arranged lines of ultrasonic image information signals. These ultrasonic line information signals are used in an interpolater to interpolate one or more lines which are spatially interlineated between each pair of spatially adjoining received lines. These interpolated lines are produced using either the received RF or demodulated IF ultrasonic image information signals. The interpolated lines are produced prior to scan conversion, and preferably prior to nonlinear processing such as detection or log compression to reduce spatial aliasing artifacts. In one preferred embodiment the interpolater comprises a transversal filter of four taps which is responsive to received line information signals from a common range or depth.

Abstract: A velocity estimation technique is provided for a pulse-echo ultrasonic diagnostic system in which a two dimensional array of samples is acquired from a sample volume. The two dimensions of the array are depth, in which echo signal samples are acquired in response to transmission of a pulse to the sample volume, and pulse time, in which samples are acquired in response to transmission of the pulses in the pulse ensemble to the sample volume. Two autocorrelation calculations are performed on the array, one in the depth dimension and another in the pulse time dimension to yield two correlation functions, the first related to echo frequency and the second related to the Doppler frequency. The two correlation functions are then employed in a Doppler velocity estimation to determine the velocity of motion at the sample volume.

Abstract: An intraoperative ultrasonic transducer probe is described comprising a handle section and a transducer section which resemble a tiny leg and foot. The two sections are obtusely angled relative to each other so that the physician may continue to clearly view the surgical site while holding and manipulating the probe. The extension of the transducer section away from its point of attachment to the handle section results in the toe of the foot being insertable under unincised tissue, enabling the surgeon to ultrasonically examine organs and tissue peripheral to the surgical site and to follow a vessel even beyond the incision. The transducer section is completely encapsulated in a rubberlike material which electrically insulates the transducer from the patient, enables the probe to be easily sterilized, and further provides an inherent standoff between the transducer and the contact surface of the probe.

Abstract: An ultrasonic diagnostic system simultaneously monitors the Doppler signal of a plurality of sample volumes within the body of a patient which are aligned around a point of diagnostic interest within the body. The Doppler signal of the sample volume which best satisfies a predetermined criterion, such as that exhibiting the greatest Doppler signal power, is displayed to the user. When a different sample volume meets the criterion the Doppler signal display changes to display the Doppler signal of the newly identified sample volume. In one embodiment the spectral Doppler displays of a number of sample volumes are displayed concurrently and that which best satisfies the chosen criterion is identified to the user. In another embodiment the identified sample volume is identified in a B mode display of the sample volume area while the spectral Doppler display from the identified sample volume is displayed.

Abstract: An ultrasonic imaging system is disclosed which produces a sequence of images of planes of a subject including both image and spatial positional information of the image plane. In one embodiment the positional information is developed from a plurality of accelerometers located within a scanhead. The second integrals of the acceleration signals are used to determine positional information of the image plane. In a second embodiment a transmitter transmits a magnetic field and a receiver attached to the scanhead detects the position of the scanhead in relation to the transmitted magnetic field. Spatially related images are displayed by displaying one image plane in the plane of the display and a second image plane projected in relation thereto. Either of the displayed planes may be displayed in outline form, and the outline may be modulated to depict depth.

Abstract: An ultrasonic transducer is provided for producing two-dimensional projection images of the interior of the body. The transducer may comprise an array of elements, acuated to produce scanning beams which are focused in the azimuthal direction and divergent in the elevation direction. The elements will, when actuated, emit fan-shaped beams which will insonify a volumetric region in front of the transducer. Echoes returning from structures within the volumetric region are acoustically integrated and projected onto a plane within the region. An image display of this plane will represent a two-dimensional projection of the volumetric region.

Abstract: A technique for continuously determining and displaying the peak and mean velocities of spectral Doppler information is disclosed. Received spectral Doppler data is examined over a predetermined period to determine the signal to noise ratio of the Doppler signals. Individual instantaneous measurements, or lines, of Doppler spectral information are analyzed in the power versus frequency domain to compare the line information against a noise threshold determined by the signal to noise ratio. The maximum frequency signal component is thereby identified as the peak velocity of the spectral line. Mean velocity is calculated as an intensity weighted mean about the maximum power frequency of the line data. The identified peak and mean velocities are displayed in contrasting colors or shades on a continuously updated and displayed flow velocity versus time spectral display.

Abstract: An acoustic transducer assembly is provided in which the signal and reference potential contacts of the elements of the transducer are electrically connected to external circuitry by means of tape automated bonding conductors. At least a first array of TAB conductors is provided for the signal leads to the transducer elements and a second array is provided for the reference potential leads. In a preferred embodiment a uniform reference potential is maintained across the reference potential contacts of the transducer by utilizing TAB conductors connected to each end of the reference potential contacts and leading to a source of reference potential.

Abstract: Ultrasonic diagnostic scanheads are described which include a lighting mechanism located at the transducer end of the scanhead. The scanhead includes an integral light which is illuminated when the scanhead is connected to an imaging system. The light is color-coded in a manner which clearly identifies a particular characteristic of the scanhead such as frequency of operation. In the preferred embodiment the integral light is located in a position on the scanhead which also informs the user of the orientation of the image plane in relation to the scanhead. In accordance with a further aspect of the present invention, the light of a selected scanhead is modulated by the imaging system when the clinician selects the scanhead for use.

Abstract: A method for accentuating the differences in blood perfusion between normal and tumorous tissue is provided which comprises the steps of measuring the blood perfusion in a local area of the body, heating the local area, then measuring the blood perfusion for variations or inhomogenieties in blood perfusion after the local area has been subjected to heating. As a result of heating normal tissue will generally exhibit increased blood perfusion compared with its preheated condition and as compared with blood perfusion in tumorous tissue, rendering the tumorous tissue more susceptible to detection by techniques such as ultrasonic Doppler blood flow measurement. Apparatus for performing the inventive method is described, including an ultrasonic scanhead which includes a high intensity transducer for heating tissue to be scanned, and an array transducer for performing Doppler measurements of the tissue before and after it has been heated.

Abstract: A transesophageal echocardiographic scanner includes a rotatable transducer for rotating the image plane of the scanner. The transducer is a circular shaped array of parallel oriented elements which may be operated as a phased or linear array. The transducer is mounted on a bell-shaped backing box with a conical interior surface that directs reverberations from the back of the transducer into damping material which fills the box. The transducer is located in a fluid compartment which is divided by a cover member into an ultrasonic transmission region between the emitting surface of the transducer and the cover, and an adjacent bubble trap region into which bubbles may pass and preferentially remain.

Abstract: An ultrasonic color flow information processing system receives ultrasonic Doppler information signals which are used to develop a map of color flow display information of fluid flow. The system processes the Doppler information through autoregressive spectral estimation, which models the Doppler information as the output of an all-pole filter driven by white noise. For real-time utilization, the estimation of poles of the filter model is restricted to the estimation of two poles, one representative of tissue and one representative of fluid flow. The two poles and the white noise power parameter of the model are analyzed in accordance with certain criteria to select for display one of the poles as that representative of fluid flow.

Abstract: An ultrasonic diagnostic imaging system is described which enhances the presentation of flow velocity images through asymmetric persistence of visually displayed changes in fluid velocity. Preferably the asymmetric persistence employs a shorter (i.e., faster) time constant for increases in fluid velocity and a longer (i.e., slower) time constant for decreases in fluid velocity. In a preferred embodiment of the present invention, increases in fluid velocity are displayed at their rate of occurrence, and decreases in fluid velocity are displayed with a longer, user-selectable time constant. In the preferred embodiment the persistence enhancement is determined as a function of displayed image frame rate so that the persistence time constant remains fixed as a function of time despite user changes affecting the frame rate.

Abstract: An ultrasonic transesophageal scanhead is provided which enables a physician to easily and quickly change the orientation of the image plane during a scanning procedure. Means are provided on either the scanhead or the ultrasound system for selecting the imaging plane. As the imaging plane selector is actuated, an indication of the orientation of the selected plane appears concurrently on the monitor of the system along with a display of ultrasonic information of the selected plane. In a preferred embodiment the indication of the selected plane is displayed both graphically and numerically. A recording of the displayed information will thus capture both the ultrasonic information as well as the image plane orientation. A physician reviewing the recording will thereby know the exact orientation of the image being viewed, leading to a better informed and more precise diagnosis of medical conditions of the body.