43 results about "Spectral doppler" patented technology

An ultrasound imaging system with pixel oriented processing is provided in which a method of producing a Doppler velocity image is accomplished by emitting unfocused acoustic signals into a medium over substantially an entire field; receiving scattered and reflected ultrasonic signals on a transducer array in response to the emission; processing the received ultrasonic signals to extract information to construct a Doppler velocity signal corresponding to at least one point in the medium; and generating on a display device the Doppler velocity image from the processed Doppler velocity signal. Acquisition sequences and signal processing algorithms are described that provide improved quantification of fluid flow parameters, including improved discrimination between regions of blood flow and tissue. Very high frame rate Spectral Doppler and Vector Doppler acquisition modes for real-time and post-acquisition visualization over a large field of view are described.

A method of initializing a spectral Doppler mode of operation for an ultrasonic system includes acquiring ultrasound-based data during a two-dimensional mode of operation for a particular examination session and includes automatically establishing settings for the Doppler mode operation parameters based upon the ultrasound-based data. That is, the ultrasound-based data is processed during the session to select spectral Doppler mode settings that are specific to the ongoing session. The session-specific settings are invoked when the system is switched to the spectral Doppler mode. If the two-dimensional mode is a colorflow mode, the Doppler sample volume can be based upon detecting the location of maximum velocity in the colorflow image, the angle correct setting can be based upon maximum velocities in colorflow vectors, the pulse repetition frequency setting can be based upon the maximum frequency shift detected in the colorflow data, and the gain setting can be based upon the amplitude of colorflow data. On the other hand, if the two-dimensional mode is a power mode, the Doppler sample volume is based upon detecting the region of the power mode image having the strongest signals, the angle correct setting can be based upon detecting the direction of flow, the Doppler pulse repetition frequency can be based upon a scale setting for the power mode data acquisition, and a gain setting can be based upon the amplitude of power mode data. Lastly, if the two-dimensional mode is the grey-scale imaging mode, the selection of a Doppler sample volume can be based upon identifying a dark region near the center of the grey-scale image, the angle correct setting can be based upon the orientation of the boundaries of the identified dark region, and the gain setting can be based upon the amplitude of image data.

In an adaptive clutter filter for spectral Doppler imaging using an ultrasound system, the stopband center frequency and / or bandwidth of the clutter filter are effectively adjusted on a short time scale to better eliminate moving clutter while allowing low velocity bloodflow signals to pass through.

Method and apparatus for automatically adjusting a parameter used in the display of a Doppler spectral image comprises acquiring a plurality of spectral lines of Doppler data. A subset of Doppler data is determined from the plurality of spectral lines of Doppler data. A noise characteristic of the subset of Doppler data is calculated, and a signal characteristic of the subset of Doppler data is identified. The noise and signal characteristics are compared, and a system parameter is adjusted based on a result of the comparing step.

The invention provides an ultrasonic diagnostic equipment, an ultrasonic diagnostic method and a control process of the ultrasonic diagnostic equipment. A multi-thresholding unit performs a multi-thresholding on the volume data of the blood flow speed on the basis of a reference value related to the blood flow speed. A surface extraction unit extracts a surface of the blood flow on the basis of the multi-threshold volume data. A weighting unit performs a weighting used for calculating the position of the center of gravity for the blood flow region formed by the blood flow surface. A center of gravity position calculation unit calculates a position of the center of gravity of the blood flow region the Doppler sample marker position setting unit sets the position of the Doppler sample marker to the position of the center of gravity for the blood flow region. A Doppler sample marker movement control unit controls movement of the Doppler sample marker on the basis of the Doppler sample marker position setting data. The invention makes a sample marker of a spectrum Doppler method to follow three-dimensional movement of a desired blood vessel accurately and easily.

A method and system for detecting spectral Doppler blood flow velocity are disclosed. The method comprises the steps of: obtaining Doppler signals of the flow by demodulating, filtering, and analog-to-digital converting RF ultrasonic echoes; analyzing the spectrum of the Doppler signals to obtain each of the power spectral lines of the Doppler signal varying with time; determining a threshold; and determining the frequency shift parameters or the blood flow velocity corresponding to the current power spectral line based on the threshold and the current power spectral line.

A method and apparatus for extracting an envelope curve of a spectrogram, for use in measurement of blood flow velocity by using spectral Doppler techniques, the method comprising steps of: processing RF ultrasound echo signals to obtain Doppler signals; performing spectral analysis on the Doppler signals, to obtain a corresponding power spectrum P(f); estimating a forward maximum frequency fmax+ and a backward maximum frequency fmax− for the Doppler signals at a predetermined moment, according to the power spectrum P(f) of the Doppler signals at the predetermined moment; determining a noise frequency range according to the two maximum frequencies, so as to estimate an average noise power E; and correcting the forward maximum frequency and the backward maximum frequency by using the average noise power E. With the method of the invention, influence from the SNR and bandwidth on the envelope curve may be reduced, so as to be useful for accurate computation of blood flow parameters.

The invention provides a method and system for realizing automatic deflection of a spectral Doppler angle. The method comprises the following steps: configuring ultrasound scanning lines of a plurality of scanning angles; transmitting the ultrasound scanning lines to a tissue to be detected; acquiring back wave data corresponding to each deflection angle; carrying out fast Fourier transform on the back wave data of each deflection angle in a pulse repetition frequency domain; and determining the deflection angle corresponding to the maximum value in each energy to be a best angle needed to be deflected in ultrasound scanning. With the adoption of the method and the system, the condition that at least one transmitting wave beam at one direction is not vertical to a bleeding direction can be satisfied through configuring transmitting wave beams of a plurality of deflection angles, an optimum deflection angle can be automatically acquired, so that automatic deflection of the spectral Doppler angle can be realized through the optimum deflection angle; and the sensitivity of spectral Doppler is improved. With the adoption of the method and the system, the working process of doctors can be simplified, and the operation is convenient.

The invention discloses an imaging method and device based on plane waves. The imaging method includes the steps that deflection angles of the plane waves are sequentially adjusted according to a preset angle of a system, and echo signals of all the deflection angles are received by selected sampling gates; the echo signals are subjected to beam forming, and IQ data of all the deflection angles is calculated; frequency spectrums of all the deflection angles of all the sampling gates are subjected to composite weighting, and a Doppler frequency spectrum is generated. The best deviation angle can be automatically obtained, and automatic deflection of spectral Doppler angles is achieved; instant blood flow velocity information of a plurality of areas can be simultaneously and quantitatively analyzed, the scanning operation procedure of the blood flow velocity is simplified, and the scanning efficiency of the blood blow velocity is improved.

An ultrasound imaging system and method includes receiving a first ultrasound image of a region-of-interest (ROI) and associated first ECG data, the first ultrasound image including an M-mode image or a spectral Doppler image. The system and method includes receiving a cine loop of B-mode images acquired from the ROI and second associated ECG data. The system and method includes selecting a first phase and displaying, at the same time, a first one of the B-mode images at the first phase, the first ultrasound image, and a marker. The marker is positioned at a first position with respect to the first ultrasound image, the first position indicating the first phase.

A method and system for estimating the volume of blood ejected from a cardiac ventricle or atrium uses spectral Doppler ultrasound while imaging a portion of the heart. The method computes the mean ejection velocity Vavg(t) at time t from the spectral Doppler data. The process may further utilize a discrete graphical technique to compute a measure of cardiac output. Further, the measure of cardiac output can yield an approximation to the mean-ejection-velocity integral, which is the area under the curve Vavg(t) for all moments t within a cardiac cycle.

The ultrasonic diagnosis system capable of tracking blood flow position automatically to obtain the spectral Doppler information has measures of setting one limited monitoring range and obtaining the Doppler information of sampling volumes inside the range. The system compares the Doppler information of the sampling volumes to select one standard sampling volume and regulates the position of the limited monitoring range around the selected sampling volume to realize the automatic tracking of the blood flow. Spectral curve is formed and displayed based on the Doppler information for the calculation of various blood flow parameters. Optimally, the system can display the limited monitoring range and the position of the central sampling volume dynamically in image of mode B or other spatial display mode.

A method and an apparatus for performing pulsed-wave spectral Doppler imaging at every color flow range gate location in a two-dimensional (or three-dimensional) region of interest. Spectral processing is necessary to determine the flow parameters. Performing this processing at every color flow range gate location creates the two-dimensional image. The method generates two-dimensional images of flow parameters such as peak velocity, pulsatility index, resistance index, etc. With the two-dimensional image, the user immediately observes where the most critical value of the flow parameter occurs and what that value is.

A method and apparatus for extracting an envelope curve of a spectrogram, for use in measurement of blood flow velocity by using spectral Doppler techniques, the method comprising steps of: processing RF ultrasound echo signals to obtain Doppler signals; performing spectral analysis on the Doppler signals, to obtain a corresponding power spectrum P(f); estimating a forward maximum frequency fmax+ and a backward maximum frequency fmax− for the Doppler signals at a predetermined moment, according to the power spectrum P(f) of the Doppler signals at the predetermined moment; determining a noise frequency range according to the two maximum frequencies, so as to estimate an average noise power E; and correcting the forward maximum frequency and the backward maximum frequency by using the average noise power E. With the method of the invention, influence from the SNR and bandwidth on the envelope curve may be reduced, so as to be useful for accurate computation of blood flow parameters.

A spectral tissue Doppler processor for an ultrasound system produces Doppler phase shift estimates of sequences of signal samples from a sample volume with a short-lag autocorrelator. The autocorrelation products are summed and an arc tangent taken of each sum to produce angle estimates. The angle estimates, which are proportional to the tissue motion velocity, are plotted, smoothed, and displayed as a spectral tissue Doppler display. The angle estimates are also used to produce the audio Doppler signal which is frequency-adjustable by a user. The spectral Doppler display exhibits good time and velocity resolution for motion which is less than that of blood flow such as myocardial motion. Major causes of blurring, unevenness, and distortion are reduced or eliminated.

The invention provides a device for adjusting the measuring range of the movement velocity on the basis of spectral Doppler, which comprises: a measuring range receiving unit for receiving the input measuring range of the movement velocity; a sampling clock providing unit for providing a sampling clock signal, wherein the frequency of the sampling clock signal is different along with the difference of the received measuring range; and a digital-to-analog conversion unit for sampling Doppler frequency shift signals that reflect the movement velocity according to the frequency of the sampling clock signal so as to obtain Doppler frequency shift data within the received measuring range. According to the device, a simple and easily-actualized method is adopted to achieve the fine change within the measuring range of the movement velocity on the basis of the spectral Doppler and achieve precise measurement effect.

The present invention relates to an ultrasound system. The ultrasound system includes: an image processing unit for forming at least one 3-dimensional ultrasound image based on ultrasound echoes reflected from a target object; an input unit for receiving a setup instruction; and a control unit for outputting a first control signal for setting at least one predefined sample volume on the 3-dimensional ultrasound image in response to the setup instruction. The image processing unit is further configured to form at least one spectral Doppler image corresponding to the sample volume in response to the first control signal.

The present invention is directed to an ultrasound diagnostic system for displaying an enhanced Doppler spectrum image. The ultrasound diagnostic system includes: a period setting unit operable to set a period for computing spectral Doppler components from ultrasound data obtained by transmitting / receiving ultrasound signals to / from a target object; a Doppler spectrum data acquiring unit operable to compute the spectral Doppler components at the set period from the ultrasound data for acquiring Doppler spectrum data; a storage unit operable to store the acquired Doppler spectrum data; a user input unit operable to receive sweep speed information from a user for selecting a sweep speed; a data adjusting unit operable to compare the set period with the selected sweep speed and adjust the Doppler spectrum data based on the comparison result; and a display unit operable to display a Doppler spectrum image based on the adjusted Doppler spectrum data.

A method for controlling a spectral Doppler ultrasound imaging device adapted for operating both in a spectrum-live Doppler measurement mode (S3) and in an image-live measurement mode (S1, S6) is proposed. In accordance with the present invention, the method comprises automatically switching to the image-live measurement mode (S6) upon detection (S5) of a change of a sampled region. A change of a sampled region may be indicated by an operator by actuating a sampled region control device such as a trackball, angle knob or sample gate controller and, upon such actuation, the spectral Doppler ultrasound imaging device may automatically switch to the image-live measurement mode (S6) to allow for adapting or correcting of a position and / or orientation of the sampled region. After the sampled region has been positionally stable for a predetermined duration, the spectral Doppler ultrasound imaging device may be switched back (S7) to the spectrum-live measurement mode (S3). Thereby, unnecessary manual toggling between different measurement modes may be avoided and quantitative spectrum-live Doppler measurement (S3) is enabled being interrupted only when necessary, i.e. when a sampled region is changed.

The invention discloses a hemodynamic visualization method based on ultrasonic spectral Doppler and a system for implementing the same. The method and the system have low calculation quantity, low consumption of storage resources and high accuracy of measurement results and allow specific hemodynamic parameters to be visually and quickly presented. The method comprises: acquiring sampling gate data, and performing ultrasonic scanning according to selected sampling gate depth; subjecting echo signals to beam forming according to the position of a sampling gate so as to obtain an RF (radiofrequency) signal; dividing the sampling gate into multiple sub-sampling gates; calculating spectral data in each sub-sampling gate to obtain three-dimensional spectral data; processing each voxel in a volume data field formed by the three-dimensional spectral data, acquiring an iso-surface of each voxel, and calculating a normal vector of each iso-surface; using a set lighting model to calculate lightintensity; performing three-dimensional surface drawing and rendering according to the calculated light intensity to generate a three-dimensional surface image.

An ultrasound system with a matrix array (500) probe (10) operable in the biplane mode is used to assess stenosis of a blood vessel by simultaneously displaying two color Doppler biplane images (60a, 60b) of the vessel, one a longitudinal cross-sectional view (60a) and the other a transverse cross-sectional view (60b). The two image planes intersect along a Doppler beam line (68) used for PW Doppler. A sample volume graphic (SV) is positioned over the blood vessel at the peak velocity location in one image, then positioned over the blood vessel at the peak velocity location in the other image. As the sample volume location is moved in one image, the plane and / or sample volume location of the other image is adjusted correspondingly. Spectral Doppler data (62) is then acquired and displayed from the sample volume location.

A method and system for detecting spectral Doppler blood flow velocity are disclosed. The method comprises the steps of: obtaining Doppler signals of the flow by demodulating, filtering, and analog-to-digital converting RF ultrasonic echoes; analyzing the spectrum of the Doppler signals to obtain each of the power spectral lines of the Doppler signal varying with time; determining a threshold; and determining the frequency shift parameters or the blood flow velocity corresponding to the current power spectral line based on the threshold and the current power spectral line.

The invention discloses a method for optimizing an ultrasonic image. The method comprises the following steps: acquiring blood flow data, blood flow related parameters and spectral Doppler parameters; analyzing the blood flow data and acquiring related information of blood vessels in the blood flow data; and in accordance with the related information of the blood vessels, optimizing the blood flow related parameters and spectral Doppler parameters of the blood vessels, so as to obtain the ultrasonic image. The invention also discloses a device for optimizing the ultrasonic image. With the application of the method and the device provided by the invention, complexity of user operation is reduced; and meanwhile, the obtained ultrasonic image can effectively express human body information.

To reduce speckle is spectral Doppler imaging, any oversampling relative to the velocity scale is used to create different data sets for the location at a given time. The different data sets have at least partially independent noise. Spectra are estimated from the different data sets and the resulting spectra combined into a spectrum with less speckle. To improve signal-to-noise ratio, the samples acquired for a given velocity scale are band-limited into different narrower bands. The portion of the spectrum estimated for each narrow band has a higher signal-to-noise ratio than a spectrum estimated for the entire band. The parts of the spectrum estimated for the different narrow bands are stitched together to provide a spectrum for the entire band with greater signal-to-noise ratio. In another approach, the user may input a narrow band relative to the velocity scale so that the corresponding part of the spectrum is provided with greater signal-to-noise ratio. Similar approaches may be used for color or flow imaging.

An ultrasound imaging system with pixel oriented processing is provided in which a method of producing a Doppler velocity image is accomplished by emitting unfocused acoustic signals into a medium over substantially an entire field; receiving scattered and reflected ultrasonic signals on a transducer array in response to the emission; processing the received ultrasonic signals to extract information to construct a Doppler velocity signal corresponding to at least one point in the medium; and generating on a display device the Doppler velocity image from the processed Doppler velocity signal. Acquisition sequences and signal processing algorithms are described that provide improved quantification of fluid flow parameters, including improved discrimination between regions of blood flow and tissue. Very high frame rate Spectral Doppler and Vector Doppler acquisition modes for real-time and post-acquisition visualization over a large field of view are described.

The embodiment of the invention relates to a method and a device for processing a two-dimensional spectrum Doppler echocardiography image. The method comprises the following steps: acquiring the two-dimensional spectrum Doppler echocardiography image; performing region-of-interest image extraction processing to generate a second image; performing Gaussian blurred image processing to generate a third image; performing binarization processing to generate a fourth image; frequency spectrum envelope line identification is carried out to mark a first envelope line; performing peak point identification on the first envelope line to mark a plurality of first peak points; performing left and right baseline point identification on each first peak point to mark a corresponding first left baseline point and a first right baseline point; measuring and calculating blood flow parameters to generate a corresponding blood flow parameter group sequence; and calculating an average value of all similar parameters in the blood flow parameter group sequence. According to the invention, the problem that the measurement accuracy is reduced or the measurement quality is unstable due to artificial factors can be solved.

In spectral pulsed wave Doppler imaging, spatial variance in signal and / or noise are reduced by combination of multiple spectra with at least partially decorrelated noise. Rather than requiring oversampling in time, the multiple spectra for one Doppler gate are created from different spatial signals. The Doppler gate is divided into sub-gates, the beamformed sample locations in the Doppler gate are grouped into two or more groups using any selection criterion, and / or different receive apertures are used to simultaneously sample the Doppler gate. Spectra for the gate are estimated from the samples with the different spatial content and then combined.