Abstract: The present invention relates generally to systems and methods for assessing blood flow in blood vessels, for assessing vascular health, for conducting clinical trials, for screening therapeutic interventions for adverse effects, and for assessing the effects of risk factors, therapies and substances, including therapeutic substances, on blood vessels, especially cerebral blood vessels, all achieved by measuring various parameters of blood flow in one or more vessels and analyzing the results in a defined manner. The relevant parameters of blood flow include mean flow velocity, systolic acceleration, and pulsatility index. By measuring and analyzing these parameters, one can ascertain the vascular health of a particular vessel, multiple vessels and an individual. Such measurements can also determine whether a substance has an effect, either deleterious or advantageous, on vascular health. The present invention further provides an expert system for achieving the above.

Abstract: Valvular regurgitation is assessed by identifying a characteristic regurgitation jet in a colorflow image. An M-line is placed over the region of regurgitation and Doppler M-mode information is acquired from the flow convergence region adjacent the regurgitant orifice. The Doppler M-mode information, acquired at a higher acquisition rate than the colorflow frame rate, is used to produce a measure of the regurgitant flow rate and volume through the orifice. The flow rate can be used with velocity data acquired during the regurgitation event to produce a dynamic estimate of the size of the regurgitant valve orifice.

Abstract: A probe device is presented for use in an ultrasound-based measurement device for blood flow measurements in a patient's body. The probe comprises a housing containing a transducer arrangement. An outer surface of the housing, by which the probe is brought to a measurement location in the patient's body, is patterned so as to have at least one projecting portion. The design of the probe enables correct orientation of the transducers with respect to a blood vessel under measurements. The probe device is associated with an operation means for operating the probe, and an indication means for generating output data indicative of measurement results, which are incorporated in a common housing of a hand-held measurement device.

Abstract: A flow probe has been described which includes a sensor housing and a coupling member. The sensor housing with one or more sensors mated together with the coupling member form the flow probe. The sensor housing accepts a variety of different sized coupling members to form flow probes of different sizes. The sensor housing is adapted to house one or more transducers. Additionally, a version of the flow probe includes strategically located positioning elements for ease in placement and retrieval of the flow probe.

Abstract: A guiding catheter includes a Doppler sensor disposed at a distal end of a flexible shaft. The Doppler sensor can sense a blood flow turbulence level within a chamber of the heart or a blood vessel of the heart. Detecting changes in a blood flow turbulence level is used to assist guiding of the distal end of the flexible shaft. The Doppler sensor may include a piezoelectric sensor or an optical sensor. The sensor readings may be processed to show turbulence through a time domain or frequency domain presentation of velocity. The sensor readings can be used to modulate an audible waveform to indicate turbulence. The guiding catheter may further include steering apparatus enabling deflection of the distal tip.

Abstract: The present invention relates generally to systems and methods for assessing blood flow in blood vessels, for assessing vascular health, for conducting clinical trials, for screening therapeutic interventions for adverse effects, and for assessing the effects of risk factors, therapies and substances, including therapeutic substances, on blood vessels, especially cerebral blood vessels, all achieved by measuring various parameters of blood flow in one or more vessels and analyzing the results in a defined manner. The relevant parameters of blood flow include mean flow velocity, systolic acceleration, and pulsatility index. By measuring and analyzing these parameters, one can ascertain the vascular health of a particular vessel, multiple vessels and an individual. Such measurements can also determine whether a substance has an effect, either deleterious or advantageous, on vascular health. The present invention further provides an expert system for achieving the above.

Abstract: The present invention relates generally to systems and methods for assessing blood flow in blood vessels, for assessing vascular health, for conducting clinical trials, for screening therapeutic interventions for adverse effects, and for assessing the effects of risk factors, therapies and substances, including therapeutic substances, on blood vessels, especially cerebral blood vessels, all achieved by measuring various parameters of blood flow in one or more vessels and analyzing the results in a defined matter. The relevant parameters of blood flow include mean flow velocity, systolic acceleration, and pulsatility index. By measuring and analyzing these parameters, one can ascertain the vascular health of a particular vessel, multiple vessels and an individual. Such measurements can also determine whether a substance has an effect, either deleterious or advantageous, on vascular health. In one of many embodiments, the present invention further provides an expert system for achieving the above.

Abstract: A method for adaptive filtering of clutter from a sample stream having a blood signal component and a clutter signal component comprises the steps of (a) estimating a signal strength of the sample stream, and (b) determining an order of a filter based on a relationship between the signal strength estimate and a signal strength threshold. The filter receives the sample stream and provides an output stream having a reduced level of the clutter signal component relative to the blood signal component.

Abstract: A method to measure spatial fluid flow components and their velocity profiles in a number of locations in a cross-sectional area of a lumen or other body cavity by using ultrasound in which the cross-sectional area is interrogated by a plurality of ultrasonic beams; the estimation of the spatial flow components is obtained from a combination of estimations of axial, lateral and total flow; the estimation of one or more flow components is obtained through any combination of time-shift and decorrelation analysis of two or more beam-signals of the interrogating ultrasound transducer; and the estimation accuracy is further improved by the use of a reference decorrelation curve obtained from experiments or beam-theory or both.

Abstract: Methods for obtaining biometric identification data for an individual using a sensor and a processor coupled to the sensor are presented. In an embodiment, the present invention involves placing a portion of a biological object such as a finger, thumb, palm or foot of the individual proximate to piezo ceramic elements of the sensor and generating an output signal with the sensor that is representative of at least one feature of the biological object. The output signal is processed using the processor to produce biological data useful for identifying the individual. In an embodiment of the present invention, the sensor includes at least fifty thousand piezo ceramic elements arranged in an array. These piezo ceramic elements are spaced on a pitch equal to or less than approximately two hundred microns. A multiplexer couples the output of the sensor to the processor.

Abstract: Provided herein is a method for use in medical applications that permits (1) affordable three-dimensional imaging of blood flow using a low-profile easily-attached transducer pad, (2) real-time blood-flow vector velocity, and (3) long-term unattended Doppler-ultrasound monitoring in spite of motion of the patient or pad. The pad and associated processor collects and Doppler processes ultrasound blood velocity data in a three dimensional region through the use of a planar phased array of piezoelectric elements. The invention locks onto and tracks the points in three-dimensional space that produce the locally maximum blood velocity signals. The integrated coordinates of points acquired by the accurate tracking process is used to form a three-dimensional map of blood vessels and provide a display that can be used to select multiple points of interest for expanded data collection and for long term continuous and unattended blood flow monitoring.

Abstract: An ultrasonic imaging apparatus having a depth range setter 28 for setting a threshold value of detection level for a Doppler signal in an ultrasonic circuit unit 2, a unit for extracting a time at which the Doppler signal exceeds the set detection level and a signal level in excess of the set detection level, and a ROI depth data generator 29 for determining, for an adaptive phase controller 3, a ROI depth range for correction necessary to make echo signals of neighboring channels be in phase by using the extracted time and signal level, whereby the focal point can follow the ROI region in an object to be inspected by correcting echo signals from the region where the intensity of the Doppler signal reaches the detection level or its neighboring region so as to make them be in phase between adjacent transducers.

Abstract: A method for treating myomas or tumors having a pedicle includes the steps of locating the pedicle of a myoma or a tumor using Doppler echography and delivering focused ultrasound to the pedicle.

Abstract: To accurately measure wave intensity as an evaluation value using an ultrasonic diagnostic apparatus, a measurement line is set in a tomogram and anterior and posterior walls of a blood vessel are tracked on the measurement line, so that a change waveform concerning a blood vessel diameter is prepared. A tracking gate S is set on the measurement line, so that a blood velocity change waveform is prepared based on echo data concerning a part within the tracking gate S, the change waveform indicating averaged blood velocity. Wave intensity is calculated based on the blood vessel diameter change waveform and the blood velocity change waveform. Prior to the calculation of wave intensity, the blood vessel diameter change waveform is calibrated based on the maximum and minimum blood pressure values into a blood pressure waveform. A beam for Doppler measurement may be set intersecting with the displacement measurement beam.

Abstract: A method and apparatus for ultrasound imaging of a biopsy needle or the like during an ultrasound imaging examination, including the steps of alternately performing one or more imaging scans with ultrasound transmit and receive parameters which are adapted for optimized imaging and visualization of the needle and one or more imaging scans with ultrasound transmit and receive parameters adapted for optimized imaging and visualization of the body, in which the needle is inserted, injecting contrast agents in the region to be examined before imaging, and setting ultrasound transmit and receive parameters adapted for optimized imaging and visualization of the body.

Abstract: The present invention relates generally to systems and methods for assessing blood flow in blood vessels, for assessing vascular health, for conducting clinical trials, for screening therapeutic interventions for adverse effects, and for assessing the effects of risk factors, therapies and substances, including therapeutic substances, on blood vessels, especially cerebral blood vessels, all achieved by measuring various parameters of blood flow in one or more vessels and analyzing the results in a defined matter. The relevant parameters of blood flow include mean flow velocity, systolic acceleration, and pulsatility index. By measuring and analyzing these parameters, one can ascertain the vascular health of a particular vessel, multiple vessels and an individual. Such measurements can also determine whether a substance has an effect, either deleterious or advantageous, on vascular health. In one of many embodiments, the present invention further provides an expert system for achieving the above.

Abstract: A method of estimating the volume flow in a vessel utilizing ultrasound techniques including the steps of imaging the vessel utilizing an ultrasonic transducer array so as to produce fluid velocity information for the vessel, the plane formed by the beams emitted by the transducers having a direction which is offset from an axis of the vessel such that the beam plane forms an elliptical section within the vessel, and utilizing the velocity information for points within the vessel and the elliptical section to calculate a mean velocity for the fluid flow through the elliptical section. The improvement of the volume flow estimation is achieved by utilizing average velocity information and Doppler signal power, and mean velocity calculation based on a weighted summation of the velocity values a multiple measurement points with weighting factors determined by the Doppler signal power at the measurement points.

Abstract: The present invention is related to cerebral blood flow velocity monitoring method and system, specifically a transcranial Doppler device for odor matching and odor selection in canine and human subjects. The method and system is non-invasive with high temporal resolution, user-friendly and portable, including steps of obtaining a subject's baseline mean blood flow velocity in cerebral arteries using transcranial Doppler instrument with sample volume focused on cerebral vessels on both sides using two probes placed on the temples and calculating laterality index for both arteries. Simultaneously, testing the subject with odors while monitoring mean blood flow velocity during each odor in real-time. The acquired data is processed using an operatively attached microprocessor and using a cellular telephone to communicate the results to a computer workstation for further data analysis and storage.

Abstract: An ultrasound system is disclosed that includes a method and apparatus to automatically adjust certain parameters that affect visualization of a Doppler spectral image. The ultrasound system acquires spectral lines of Doppler data generated by the ultrasound system. A data processor within the ultrasound system determines the presence of aliasing and estimates noise levels from the spectral lines of Doppler data. The data processor then automatically adjusts system parameters such as pulse repetition frequency (PRF), baseline shift, and spectrum orientation in response to aliasing and noise levels. The data processor of the ultrasound system also determines positive and negative signal boundaries for each spectral line of Doppler data and a display architecture processes the signal boundary data to display a spectral trace corresponding to the edges of the spectral lines.

Abstract: An ultrasound machine measures coronary intima-medial thickness and relates it to a statistically derived vascular age. Quantitative risk of coronary heart disease may be calculated using vascular age to substitute for chronological age in publicly available risk assessment data.

Abstract: The present invention relates generally to systems and methods for assessing blood flow in blood vessels, for assessing vascular health, for conducting clinical trials, for screening therapeutic interventions for adverse effects, and for assessing the effects of risk factors, therapies and substances, including therapeutic substances, on blood vessels, especially cerebral blood vessels, all achieved by measuring various parameters of blood flow in one or more vessels and analyzing the results in a defined matter. The relevant parameters of blood flow include mean flow velocity, systolic acceleration, and pulsatility index. By measuring and analyzing these parameters, one can ascertain the vascular health of a particular vessel, multiple vessels and an individual. Such measurements can also determine whether a substance has an effect, either deleterious or advantageous, on vascular health. The present invention further provides an expert system for achieving the above.

Abstract: A method for ultrasonic imaging, particularly of moving bodies, such as surgical utensils, tissues, flows, or the like, which includes the following steps:—Periodically emitting ultrasonic pulses along a predetermined view line and with a predetermined repetition rate through one or more transducers;—Receiving the echoes produced by the body and/or the tissues or flows and transforming them into echo signals;—Processing the echo signals for extracting information therefrom and for generating an image based on such information. According the invention, the following steps are additionally provided:—determining a real time vector difference between the echo signals of two pulses successively emitted at predetermined time intervals;—using said difference signal as an information signal for ultrasonic imaging.

Abstract: There is provided a pulse detecting device which resists fluctuations in the quality by locating an ultrasound transmitting piezoelectric element and an ultrasound receiving piezoelectric element with high precision. In the pulse detecting device, a detection sensitivity of the pulse is improved. A transmitting piezoelectric element and a receiving piezoelectric element are fixed onto a substrate by electrodes. The transmitting piezoelectric element is excited in response to an inputted drive voltage signal to generate an ultrasound and transmits the generated ultrasound to a living body. The receiving piezoelectric element receives an echo produced by reflecting the ultrasound transmitted into the living body by a blood flow of the living body and converts it into a voltage signal. A processing arithmetic unit compares the frequency of the ultrasound generated by the transmitting piezoelectric element with that of the echo received in the receiving piezoelectric element to thereby detect a pulse.

Abstract: Methods of scanning using a two dimensional (2D) ultrasound transducer array are disclosed. The 2D ultrasound transducer arrays include at least one row of ultrasound transducer elements that is configured to extend in a curved dimension of the array and at least one column of ultrasound transducer elements that is configured to extend in a linear dimension of the array. A 2D ultrasound transducer array can be used to scan by defining a sub-aperture of the 2D ultrasound transducer array that includes a plurality of ultrasound transducer elements in the curved dimension of the array and in the linear dimension of the array and exciting the ultrasound transducer elements included in the sub-aperture to generate a transmit/receive ultrasound beam. Related 2D ultrasound transducer arrays and elements are also disclosed.

Abstract: An apparatus, automated method technique and product for accurately determining the intima-media thickness of a blood vessel.

Abstract: A method and apparatus for combining therapeutic pulsed or continuous-wave ultrasound with diagnostic pulsed ultrasound are described. In both a therapeutic mode and in a diagnostic mode, the ultrasound is administered from a single probe to a patient suffering from thrombosis. The ultrasound can have the same or different frequency ranges in the diagnostic and therapeutic modes. The pulsed or continuous-wave ultrasound in the therapeutic mode enhances a lysing effect of a thrombolytic agent. The pulsed ultrasound in the diagnostic mode allows monitoring of blood flow to locate a thrombus, to determine an optimal window to administer the therapeutic pulsed ultrasound, and to detect when recanalization has occurred. If an operator attends the device, a graphical display operates during the diagnostic mode to display an image representative of the blood flow.

Abstract: A similarity measurement method for the classification of medical images into predetermined categories. A small set of pre-classified images is required to employ the method. The images can be real world images acquired using a camera, computer tomography, etc., or schematic drawings representing samples of different classes. The use of schematic drawings as a source of images allows a quick test of the method for a particular classification problem. The eigenvectors for each category are mathematically derived, and each image in each category is represented as a weighted linear combination of the eigenvectors. A test image is provided and projected onto the eigenvectors of each of the categories so as to reconstruct the test image with the eigenvectors. The RMS (root-mean-square) distance between the test image and each of the categories is measured.

Abstract: An image generation unit 102 generates image data of a tomographic image based on an electric signal received from a send/receive unit 12 through a control unit 101. An ROI setting unit 103 sets an ROI to the generated tomographic image. A characteristic value extraction unit 104 extracts a characteristic value (such as volume of left ventricular of a heart) to the set ROI. A synchronization generation unit 105 generates a synchronization signal based on the extracted characteristic value. A synchronization information addition unit 106 adds information that represents the generated synchronization signal to image data and stores the image data in an image data storage unit 107. A data reading unit 109 reads out the image data to which the information that represents the synchronization signal is added from the image data storage unit 107. An image display unit 111 displays a tomographic image of the read-out image data.

Abstract: A non-invasive method and system to determine face and object processing in a human subject, said method with high temporal resolution, user-friendly and portable, including steps of obtaining a subject's baseline cerebral blood flow velocity in cerebral arteries using a transcranial Doppler ultrasound instrument with sample volumes focused on cerebral vessels on both sides using two probes placed on the temples and calculating laterality index for both arteries. Simultaneously, testing the subject with face and object processing tasks presented on the screen of a digital computer and using a computer input peripheral device while simultaneously monitoring the mean blood flow velocity during each stage of the task in real-time. Processing the acquired data using a microprocessor operatively connected to a computer workstation for image retrieval.

Abstract: The present invention relates to an infrared sensor adapted to be stabilized in temperature and an infrared thermometer with an infrared sensor adapted to be stabilized in temperature, more particularly, a clinical thermometer for temperature measurement in the ear. The infrared sensor has a casing (14) with a window (12) transparent to infrared radiation which are made of materials with a good thermal conduction and are thermally connected to a heating and/or cooling element (16). Further, the infrared sensor includes a temperature sensor (18) which may be identical with the heating and/or cooling element (16).

Abstract: A strobed blood flow meter provides periodic measurements of blood flow velocity or volumetric blood flow over a cardiac cycle at reduced average power consumption, which is advantageous for reducing battery size, and extending device battery life, such as in an implantable application. Continuous wave Doppler, pulsed Doppler, laser Doppler, transit time, electromagnetic flow, and thermal dilution techniques are included. Strobing provides higher level excitation during active periods, which improves signal-to-noise ratio, and provides a low power standby mode during an idle time between active periods. The invention may be used for chronic or acute applications. Doppler or other signals may be telemetered from an implanted portion of the flow meter for further signal processing to extract velocity or volumetric flow. Alternatively, such signal processing is also implanted, such that the velocity signal can be telemetered to an remote monitor.

Abstract: A pulse Doppler ultrasound system and associated methods are described for monitoring blood flow. A graphical information display includes simultaneously displayed depth-mode and spectrogram displays. The depth-mode display indicates the various positions along the ultrasound beam axis at which blood flow is detected. These positions are indicated as one or more colored regions, with the color indicating direction of blood flow and varying in intensity as a function of detected Doppler ultrasound signal amplitude or detected blood flow velocity. The depth-mode display also includes a pointer whose position may be selected by a user. The spectrogram displayed corresponds to the location identified by the pointer. Embolus detection and characterization are also provided.

Abstract: A method and an apparatus for imaging blood motion by displaying an enhanced image of the fluctuating speckle pattern. The first step in the blood motion image processing is high-pass filtering of the signal vector from each range gate. Following high-pass filtering, a speckle signal is formed. The speckle signal is then subjected to a nonlinear scale conversion. The resulting speckle signal is displayed as the desired blood motion image concurrently with a corresponding tissue image.

Abstract: A method and apparatus of blood flow imaging is disclosed. The method comprises receiving a beamformed signal indicative of an ultrasound signal reflected from a target within a body, based upon the beamformed signal, imaging tissue within the body, generating thereby a tissue signal, based upon the beamformed signal, detecting blood flow within the body, generating thereby a blood flow signal and combining the tissue signal and the blood flow signal generating thereby a composite image of tissue and blood flow.

Abstract: A system for controlling the point spread function of an ultrasound signal transmitted into a patient. In accordance with one embodiment of the invention, only a selected number of the transducer elements transmit a transmit pulse. The elements which do not transmit the pulse are selected in accordance with an apodization probability density function. In accordance with another aspect of the present invention, each transducer element transmits a variable portion of a transmit pulse in order to control the acoustic power of the signal transmitted from each element.

Abstract: An ultrasonic Doppler flow phantom is described which is formed of tissue-mimicking material containing a plurality of fluid flow paths through which fluid is pumped. The fluid flow paths are made of tubing and each extends over a different portion of the depth of the phantom and at a different angle. Each path is individually accessible by a probe located on the simulated skin surface at the top of the phantom, enabling the performance of the probe to be evaluated over a wide range of depths from shallow to very deep and over several flow angles.

Abstract: The invention here described relates to monitoring the effect of angiogenesis inhibiting drugs used to treat cancer in breast and testicular tissues. A probe combining electromagnetic radiation in the red and infra-red part of the spectrum is physically combined with a series of Ultrasound Doppler transducers arranged to monitor blood flow over one hemisphere of the tumour. This arrangement overcomes the major difficulty with conventional Doppler blood flow probes that the signals vary more from area to area of the cancer than the changes induced by the drugs acting on the neovascularisation over short time intervals. The invention envisages using probes with transducers of different frequencies and where the piezoelements are angled to cover such an area of angiogenesis that inhomogeneities become insignificant, by virtue of the fact that signals from all the vessels in a hemispherical volume of the tumour's advancing front are collected and processed electronically to produce the observed spectra.

Abstract: An ultrasound machine that generates a color representation of moving structure, such as cardiac wall tissue within a region of interest, and is displayed on a monitor. The color representation is generated by displaying at least one color characteristic related to a set of signal values of the structure, such as velocity or strain rate. The related feature of the set of signal values is mapped to the color characteristic by an apparatus comprising a front-end that generates received signals in response to backscattered ultrasound waves. A Doppler processor generates a set of signal values representing a spatial set of values of the moving structure. A host processor embodies a tracking function and a time integration function to generate tracked movement parameter profiles and displacement parameter values over a time period corresponding to sampled anatomical locations within the region of interest. The displacement parameter values are then mapped to color characteristic signals.

Abstract: An ultrasonic imaging system uses a specially configured scanhead to provide ultrasound return signals that are processed by an imaging unit to generate a three-dimensional Doppler ultrasound image. One embodiment of the scanhead includes a first pair of apertures aligned along a first axis, and a second pair of apertures aligned along a second axis that is perpendicular to the first axis. All of the apertures lie in a common plane. Respective signals from the apertures along each axis are processed to generate two-dimensional Doppler motion vectors. The resulting pairs of two-dimensional Doppler motion vectors are then processed to generate three-dimensional Doppler motion vectors that are used to generate a three-dimensional Doppler image. In another embodiment, three co-planar apertures are arranged equidistantly from each other about a common center, and the three-dimensional Doppler image is generated from respective signals from the apertures.

Abstract: In order to properly discern a plurality of streams of blood flow having different contrast agent arrival times or blood concentration properties, an ultrasonic diagnostic apparatus 200 comprises: an ultrasonic probe 1; a transceiver section 2; a quadrature detector section 3; a power calculating section 4 for calculating the power P of blood flow; a power peak holding section 21 for comparing the latest power P and a predecessor peak value Po, and outputting the larger one as a peak value P′ and an elapsed time t′ corresponding to the peak value P′; a predecessor power/elapsed time keeping section 22 for keeping the predecessor peak value Po and the corresponding elapsed time ‘to’ and outputting these values to the power peak holding section 21; a timer 11 for measuring an elapsed time t from a reference time; a blood flow image producing section 25 for producing a power peak hold blood flow image G2 in which the hue is changed before and after the elapsed time t′ reaches

Abstract: A method of cardiac physiologic monitoring is disclosed comprising the steps of: (a) utilizing an external ultrasonic transducer element attached to a patient to determine an information signal indicating of blood floe within a patient's heart; (b) processing the information signal to determine physiologic parameters associated with the heart. The physiologic parameters can include at least one of transaortic peak velocity, mean transvalvular pressure gradient, time velocity integral, stroke volume, cardiac output or any other product as an analogue of output. The method can preferably include monitoring the change in time of the physiologic parameters through continual monitoring of the information signal. The monitoring step preferably can include determining an alarm state if the parameters are preferably outside a predetermined range.

Abstract: A system for automatic manipulation of a transcranial Doppler probe device designed for placement on a patient's head comprising a bi-temporal probe hanger, a cylindrical probe housing having an inner electrical wiring, an ultrasound transducer with cable affixed on the probe cylindrical base having a coil, said probe cylindrical base placed within the cylindrical probe housing, a spring system affixed to provide perpendicular pressure on the probe cylindrical base, a system of roller balls, a locking system to affix the cylindrical probe housing to the frame of the bi-temporal probe hanger, a system software program and microprocessor for controlling the probe position, and a removable handle attached to the said probe cylindrical base. The system software ‘learns’ probe angulations after initial manual manipulations and then performs cerebral vessel insonation using electromotive force independent of operator.

Abstract: A pulse Doppler ultrasound system and associated methods are described for monitoring blood flow and detecting emboli. A graphical information display includes simultaneously displayed depth-mode and spectrogram displays. The depth-mode display indicates the various positions along the ultrasound beam axis at which blood flow is detected. These positions are indicated as one or more colored regions, with the color indicating direction of blood flow and varying in intensity as a function of detected Doppler ultrasound signal amplitude or detected blood flow velocity. The depth-mode display also includes a pointer whose position may be selected by a user. The spectrogram displayed corresponds to the location identified by the pointer. Embolus detection and characterization are also provided.

Abstract: A method for adaptive filtering of clutter from a sample stream having a blood signal component and a clutter signal component comprises the steps of (a) estimating a signal strength of the sample stream, and (b) determining an order of a filter based on a relationship between the signal strength estimate and a signal strength threshold. The filter receives the sample stream and provides an output stream having a reduced level of the clutter signal component relative to the blood signal component.

Abstract: Techniques are provided for obtaining selected instantaneous area measurements for a dynamic orifice through which blood is flowing in at least one direction, for obtaining instantaneous flow rates of blood passing through such a dynamic orifice and for obtaining flow volume for blood passing through a dynamic orifice. All of these techniques involve ensonifying a thin sample volume of blood flow exiting at the orifice, which volume is in a region of flow which is substantially laminar, such region normally being the vena contracta for the orifice, with an ultrasonic pulsed Doppler signal, receiving backscattered signal from blood within the sample volume and forming a power-velocity spectrum from the received backscattered signal. Techniques are disclosed for assuring that only laminar flow is looked at in forming the power-velocity spectrum.

Abstract: Strain rate analysis is performed for ultrasonic images in which the spatial gradient of velocity is calculated in the direction of tissue motion. Strain rate is calculated for cardiac ultrasound images in the direction of motion which, for myocardial images, may be either in the plane of the myocardium or across the myocardium. Strain rate information is calculated for a sequence of images of a heart cycle and displayed for an automatically drawn border such as the endocardial border over the full heart cycle.

Abstract: A medical diagnostic ultrasonic imaging system analyzes receive signals generated by the system to adaptively set the interline delay and/or the transmit power to optimize frame rate while reducing or eliminating the wraparound artifact associated with transmit events that are too closely spaced in time for currently prevailing imaging conditions.

Abstract: A method is provided to simultaneously acquire two ultrasound images. A first set of ultrasound pulses are transmitted at a first frame rate utilizing a first mode of operation. The echoes from the first set of ultrasound pulses are received. A second set of ultrasound pulses are transmitted at a second frame rate utilizing a second mode of operation. The first and second frame rates are different. The first set of ultrasound pulses defines an entire image, while the second set of ultrasound pulses defines a partial image. The echoes from the second set of ultrasound pulses are received, and the echoes from the first and second sets of ultrasound pulses are displayed as a single image.

Abstract: An ultrasound diagnostic apparatus and method for measuring a blood flow velocity effectively select one of the positive frequency range and the negative frequency range to compute noise threshold, and determine a reliability of the computed noise threshold. A sample data generator samples a reflected signal of the ultrasound signal transmitted into a human body. A frequency distribution data generator processes the sample data, and generates a frequency distribution data including a number of frequency components. A first determiner selects one of a positive frequency range and a negative frequency range of the frequency distribution data. A second determiner determines a noise threshold by using a predetermined number of frequency components within the frequency range selected by the first determiner. A third determiner determines a peak frequency component having the highest frequency among the frequency components.

Abstract: A pulse Doppler ultrasound system and associated methods are described for monitoring blood flow and detecting emboli. A graphical information display includes simultaneously displayed depth-mode and spectrogram displays. The depth-mode display indicates the various positions along the ultrasound beam axis at which blood flow is detected. These positions are indicated as one or more colored regions, with the color indicating direction of blood flow and varying in intensity as a function of detected Doppler ultrasound signal amplitude or detected blood flow velocity. The depth-mode display also includes a pointer whose position may be selected by a user. The spectrogram displayed corresponds to the location identified by the pointer. Embolus detection is also provided.