Abstract: Methods and apparatuses for providing simultaneous viewing of an instrument in two ultrasound imaging planes. An ultrasound imaging probe is provided which can generate at least two ultrasound imaging planes. In one embodiment, the two imaging planes are not parallel (i.e., the planes intersect). An instrument path is positioned with respect to the planes such that an instrument may be simultaneously viewed in both imaging planes. In one embodiment, the instrument path is provided at an intersection that, at least partially, defines the intersection of the two imaging planes.

Abstract: A forward-scanning ultrasound catheter probe. An ultrasound catheter probe includes a forward-scanning transducer positioned at the tip of the probe. As such, the forward-scanning transducer may provide images of structures that may lie ahead of the tip of the probe. Furthermore, the forward-scanning transducer is repositioned by a drive mechanism coupled to the front-scanning transducer to provide a sector scan. In one embodiment, a bimorph piezoelectric drive is utilized to sweep the forward-scanning transducer across an arc to provide an imaging area associated with a sector scan.

Abstract: A system is disclosed for measuring volume flow through vessel. A longitudinal area of a vessel in a body is scanned using a color Doppler imaging method, such that an imaging plane is formed approximately through the center of said vessel. A number of color pixels in a scanned cross-section of the vessel in which volume flow is detected are counted and tabulated. From this number of pixels, an observed cross-sectional area of the vessel is determined. Frequency shift information for each of the counted pixels is determined and these frequency shifts are spatially averaged. The instantaneous volume flow through the vessel is then computed from the cross-sectional area and frequency shift information. The volume flow for several different samples is computed. The instantaneous volume flows from each color Doppler imaging frame are temporally averaged over one or more integral cardiac cycles to compute a temporally-averaged volume flow.

Abstract: A method and apparatus for determining resistance and pulsatility indices of a flow of material, such as the flow of blood in the human body. This may be implemented, for example, in a color flow module in an ultrasonic imaging system for display of the pulsatility or resistance index in two dimensions and in different colors to allow discrimination between veins and arteries and detection of pathologic elevation of vascular resistance in a clinical survey mode of the system. The resistance index is determined from the ratio of a unipolar variation estimate of a velocity of the flow material divided by a peak velocity. The variation estimate may be one of the following: a difference between a peak velocity of the flow of material and a second minimum (if unipolar) or negative (if bipolar) velocity of the flow of material, a standard deviation .rho.

Abstract: A method and apparatus for generating three-dimensional (3D) images of flow structures and their flow lumen using ultrasound techniques. According to one aspect of the invention, a border between a flow region and a non-flow region is used to render a three-dimensional image of the flow lumen of the flow structure. The images may be viewed in real-time and/or stored on a machine-readable medium. In one embodiment, the three-dimensional images may be manipulated in a number of viewing directions/angles/distances/positions/styles. In one embodiment, a flow lumen may be displayed using a virtual angioscopic view.

Abstract: A two-dimensional ultrasonic transducer for forming images. The transducer has a plurality of transducer elements for producing ultrasonic bursts in a predetermined manner, and receiving reflected ultrasound from the subject under examination due to the ultrasonic bursts. The plurality of transducer elements are arranged in an array into columns and rows, the columns of the transducer elements arranged in a scanning plane for scanning the subject under examination in order to form a two-dimensional profile of the subject, and the rows of the transducer elements having groups of symmetrically arranged transducer elements being oriented in a elevational plane. Each of the groups of symmetrically arranged transducer elements are mechanically arranged to have a focus at specified locations distant from the transducer which is within the subject under examination.

Abstract: A method and apparatus for automatically measuring the circumference of a first region enclosed in a second region internal to a living organism, wherein the first and second regions consist of different cellular matter. One embodiment of the present invention includes generating a point inside an interior of the first region. A set of radial vectors are then generated, which emanate from the point in the interior of the first region. A path is then selected which intersects the set of radial vectors. The path is selected by identifying a distinguishable ultrasonic measurement along the respective radial vectors. A length of the selected path is then measured to generate the circumference of the first region.

Abstract: A method and apparatus for automated measuring of a diameter of a first region enclosed in a second region internal to a living organism, wherein the first and second regions consist of different cellular matter. One embodiment of the invention includes generating a plurality of trial diameters, wherein each trial diameter includes an inner and outer region and has a different length. An ultrasonic measurement is taken of the inner region and the outer region for each trial diameter. The difference is determined for the ultrasonic measurements corresponding to the inner and outer regions of each trial diameter. The trial diameter which most closely corresponds to the diameter of the first region is then selected, wherein the difference of the ultrasonic measurements corresponding to the inner and outer regions is greatest for the trial diameter which most closely corresponds to the diameter of the first region.

Abstract: A computer implemented method and apparatus for generating a vascular volume flow measurement in a living subject using an ultrasonic system by determining a velocity measurement and an area measurement at the same location in a blood vessel. The present invention generates an angle correct cursor on a display indicating where in a vessel a velocity measurement is being obtained. A diameter measure cursor is fixed perpendicular to the angle correct cursor to determine a diameter of the vessel at the same location of the vessel where the velocity measurement is obtained. The diameter is multiplied with the time averaged means velocity to accurately generate the volume flow. In one embodiment, the length of the diameter measure cursor is adjustable to extend a first end and an opposing second end of the diameter measure cursor, approximately to the walls of the vessel.

Abstract: A two-dimensional ultrasonic transducer for forming images. The transducer has a plurality of transducer elements for producing ultrasonic bursts in a predetermined manner, and receiving reflected ultrasound from the subject under examination due to the ultrasonic bursts. The plurality of transducer elements are arranged in an array into columns and rows, the columns of the transducer elements arranged in a scanning plane for scanning the subject under examination in order to form a two-dimensional profile of the subject, and the rows of the transducer elements having groups of symmetrically arranged transducer elements being oriented in a elevational plane. Each of the groups of symmetrically arranged transducer elements are mechanically arranged to have a focus at specified locations distant from the transducer which is within the subject under examination.

Abstract: A method and apparatus in an ultrasonic system for determining an optimum cardiac cycle of a living subject, and for performing vascular measurements. Peak velocities of a spectra of echoes over a period of time due to pulses emitted into a subject under examination are determined. Based upon the peak velocities of the spectra over the period of time, a time series of the peak velocities are determined representing an optimum cardiac cycle. In addition, vascular measurements of the peak velocities for the optimum cardiac cycle can be determined from the optimum cardiac cycle. The peak velocities of the spectra can be performed by dividing the spectra in a plurality of regions according to ranges of the velocity information. A threshold magnitude of the peak velocities is determined by adding a predetermined value to a minimum magnitude.

Abstract: A direct digital demodulator for demodulating ultrasound signals. The demodulator includes a baseband demodulator, a magnitude and differential phase generator, and a Doppler preprocessor. The demodulator further includes an interface for receiving a signal from an analog front end. The baseband demodulator utilizes a Hilbert transform to convert received ultrasound signals into analytic signals. The present invention compensates phase and frequency of the analytic signal in order to process the signal. The phase information in the signal is then extracted.

Abstract: A method and apparatus for displaying an image representing the flow of a substance in a scanned area. An Angio scanner scans a region of tissue and generates Ultrasound Angio data representing the flow of blood in the region of tissue. Relatively small blood flows are difficult to detect in images based solely on Angio data. To enhance the visibility of small blood flows, spatial derivative values are calculated from the Angio data. A fraction of the original Angio data plus a bias is summed with the spatial derivative values to generate composite values. An image of the scanned region is displayed with colors or grayscale shades based on the composite values. The resulting image depicts blood vessels in an edge-enhanced format, giving a three-dimensional appearance.

Abstract: A direct digital modulator for demodulating ultrasound signals. The demodulator includes a baseband demodulator, a magnitude and differential phase generator, and a Doppler preprocessor. The demodulator further includes an interface for receiving a signal from an analog front end. The baseband demodulator utilizes a Hilbert transform to convert received ultrasound signals into analytic signals. The present invention compensates phase and frequency of the analytic signal in order to process the signal. The phase information in the signal is then extracted.

Abstract: A method and apparatus of processing signals in an ultrasonic imaging system for imaging a living subject. The ultrasonic imaging system including an ultrasonic emitter, receptor and display. N temporally-spaced signals from ultrasound produced by a plurality of temporally-spaced referenced pulses are obtained and the amplitude (power) of each of the N temporally-spaced signals is determined. In various embodiments, N is an odd integer, usually, 1, 3, 5 or 7, depending on a user-setting. A median temporal signal of the N amplitude signals is then obtained. In implemented embodiments, the median is obtained by sorting a list of the N amplitude signals until (N+1)/2 signals have been sorted. The median is temporally filtered with a previous signal displayed on the display of the ultrasonic imaging system, wherein the temporal filtering including a filtering coefficient having a magnitude approximating a cardiac cycle of the living subject.

Abstract: Method and apparatus for performing angiography of a subject under examination in an ultrasonic imaging apparatus. A set of ultrasonic reference pulses along each of a series of parallel vectors is emitted into the subject under examination, echoes are received, and a plurality of data samples are obtained. From each of the plurality of data samples a plurality of basis functions are removed to remove clutter and generate a plurality of processed samples. The processed samples are averaged and temporally filtered with signals displayed in a previous time period to generate a second averaged signals. The temporal filtering is performed using a filter coefficient which approximates a full cardiac cycle of the subject under examination.

Abstract: An ultrasound imaging system for performing dynamic focusing of ultrasonic waves during transmit and receive. The present invention includes a method and a means for transmitting ultrasonic waves to a multiple depths within a body. The present invention optimizes the transmit frequency for each of the multiple depths to localize the energy of the ultrasonic waves. The present invention also includes a method and means for performing dynamic receive focusing of the reflected ultrasonic waves produced by discontinuities in the body, such that it is focused to receive ultrasonic waves from the depth at which the transmitted ultrasonic waves are focused.

Abstract: An apparatus for temporal filtering in an ultrasonic imaging system. The apparatus has a means for storing previous imaging information from a previous time period and a means for storing current imaging information from a current time period. Means for determining the larger of the current and previous imaging information is provided and a means is provided for generating an alpha value responsive to the larger information. The alpha value ranges between a minimum and maximum values and has the maximum value when the larger information has a large frequency and has the minimum value when the larger information has a small frequency. Means for generating output imaging information is provided, the output imaging information generated by multiplying the current imaging information by alpha and summing it with the product of the maximum value minus alpha and the previous imaging information.