137 results about "Doppler imaging" patented technology

Methods and apparatus for the remote coagulation of blood using high-intensity focused ultrasound (HIFU) are provided. A remote hemostasis method comprises identifying a site of internal bleeding and focusing therapeutic ultrasound energy on the site, the energy being focused through an intervening tissue. An apparatus for producing remote hemostasis comprises a focused therapeutic ultrasound radiating surface and a sensor for identifying a site of internal bleeding, with a registration means coupled to the radiating surface and the sensor to bring a focal target and the bleeding site into alignment. The sensor generally comprises a Doppler imaging display. Hemostasis enhancing agents may be introduced to the site for actuation by the ultrasound energy.

A system and method for improved imaging is disclosed. An exemplary system provides a peripheral ultrasound system connected to a host computer with a plug-and-play interface such as a USB. An exemplary system utilizes a dedicated graphics processing unit such as a graphics card to analyze data obtained from a region of interest to produce an image on one or more output units for the user's viewing. Based on the image displayed on the output units, the user can determine the velocity of the moving tissue and fluid. The system of the present invention can be used to produce a Doppler color flow map or for power Doppler imaging.

A method of full-field or “ping-based” Doppler ultrasound imaging allows for detection of Doppler signals indicating moving reflectors at any point in an imaging field without the need to pre-define range gates. In various embodiments, such whole-field Doppler imaging methods may include transmitting a Doppler ping from a transmit aperture, receiving echoes of the Doppler ping with one or more separate receive apertures, detecting Doppler signals and determining the speed of moving reflectors. In some embodiments, the system also provides the ability to determine the direction of motion by solving a set of simultaneous equations based on echo data received by multiple receive apertures.

A system and method for real-time quantitative analysis of heart wall motion is provided. A Doppler imaging system is used to monitor the movement of a heart, or other organ. A B-mode reference image of the target organ is made and then a region-of-interest is defined through the use of a gate. Then pulsed wave spectral tissue Doppler data of the region-of-interest is formed and used to determine the velocity of a region of the target organ. The system may be used for determining appropriate biventricular pacemaker settings for patients suffering from heart disease.

In an ultrasound imaging system that applies a beamformer to received ultrasound signal samples to form one or more beams represented by arrays of beamformed samples, a method and an apparatus compress each array of beamformed samples independently of the other arrays to form compressed beams. A plurality of analog to digital converters sample multiple analog ultrasound signals produced by a transducer array to provide multiple streams of ultrasound signal samples to the beamformer. The compressed beams are transferred via a digital interface to a signal processor. At the signal processor, the compressed beams are decompressed to form decompressed beams. The signal processor further processes the decompressed beams for diagnostic imaging, such as for B-mode and Doppler imaging, and scan conversion to prepare the resulting ultrasound image for display. This abstract does not limit the scope of the invention as described in the claims.

The inventive implantable Doppler tomography system allows, for the first time, the use of Doppler shift for purposes of tracking cardiac wall motion. The present inventive Doppler tomography system methods and devices provide a critical new tool in the physician's armamentarium which provides accurate, real time monitoring of the mechanical performance of the heart.

A hand held ultrasonic instrument is provided in a portable unit which performs both B mode and Doppler imaging. The instrument includes a transducer array mounted in a hand-held enclosure, with an integrated circuit transceiver connected to the elements of the array for the reception of echo signals. A digital signal processing circuit performs both B mode and Doppler signal processing such as filtering, detection and Doppler estimation, as well as advanced functions such as assembly of multiple zone focused scanlines, synthetic aperture formation, depth dependent filtering, speckle reduction, flash suppression, and frame averaging.

Vector Doppler Imaging (VDI) improves on conventional Color Doppler Imaging (CDI) by giving speed and direction of blood flow at each pixel of a display generated by a computing system. Multiple angles of Plane wave transmissions (PWT) via an ultrasound transducer conveniently give projected Doppler measurements over a wide field of view, providing enough angular diversity to identify velocity vectors in a short time window while capturing transitory flow dynamics. A fast, aliasing-resistant velocity vector estimator for PWT is presented, and VDI imaging of a carotid artery with a 5 MHz linear array is shown using a novel synthetic particle flow visualization method.

A hand held ultrasonic instrument is provided in a portable unit which performs both B mode and Doppler imaging. The instrument includes a transducer array mounted in a hand-held enclosure, with an integrated circuit transceiver connected to the elements of the array for the reception of echo signals. A digital signal processing circuit performs both B mode and Doppler signal processing such as filtering, detection and Doppler estimation, as well as advanced functions such as assembly of multiple zone focused scanlines, synthetic aperture formation, depth dependent filtering, speckle reduction, flash suppression, and frame averaging.

The invention discloses an inverse synthetic aperture radar imaging method for maneuvering targets on the basis of the sparse aperture. The inverse synthetic aperture radar imaging method for the maneuvering targets on the basis of the sparse aperture comprises the implementation steps that (1) original echo data, with the sparse aperture, of an inverse synthetic aperture radar are received; (2) distance compression and envelope alignment processing are carried out; (3) phase correction is accurately carried out; (4) sparse aperture echo signals are reconstructed; (5) fast Fourier transform is carried out to achieve distance-Doppler imaging. According to the inverse synthetic aperture radar imaging method for the maneuvering targets on the basis of the sparse aperture, accurate phase compensation and accurate data reconstruction can be carried out on ISAR imaging processing under the conditions of the maneuvering targets and the sparse aperture, and a more focused high-quality ISAR imaging result is obtained.

An ultrasonic Doppler probe is provided for use in connection with non-invasive Doppler imaging of fluid flow within the human body. The Doppler probe can be selectively operated at more than one frequency during the course of a Doppler imaging examination thereby enhancing the resolution of the image obtained while also increasing the effective depth of the image. The probe of the present invention employs piezo-electric materials for the formation of acoustic transmitting and receiving transducers that are positioned within the probe to allow the probe to be selectively operated at a number of different frequencies spanning no more than one octave in frequency range.

Methods and systems for a user to create a custom menu for medical imaging are provided. To maximize the ease of use and increase user efficiency, the user interface is tailored to a particular user or for a certain application. The user selects from various imaging parameters in a preprogrammed user interface displayed on a monitor or other display device. The selection is by collecting the desired items or by discarding undesired items. After selection, the desired items are displayed in a customized display state. This customized display state can be labeled and stored for later use. An assignable key is also provided. Imaging functions, such as a type of B-mode or Doppler imaging, are assigned to the key. Different or new functions may be later assigned to the key as the most used imaging functions change. Any customization may be different for different users of the same system, such as by saving the customization related to a log-on procedure.

The invention discloses a non-convex optimization based MIMO radar moving object detection method. The method comprises the following steps: according to radar parameters, performing distance-angle-Doppler grid dividing on an observation area; according to radar emission, the position of a receiving array, and radar observation area parameters, calculating emission and reception guiding vectors; according to emission signal waveforms, the guiding vectors and a distance unit time delay transformation matrix, constructing a sparse dictionary matrix; performing serialization on echo signals received by an antenna array; and according to an aforementioned model, constructing MIMO radar moving object detection to be an optimization problem of an L[1 / 2] norm minimizing constraint; and using a heavy weight determining L[1] norm regularization method to solve the optimization problem, obtaining distance-angle-Doppler imaging of a MIMO radar moving object, and detecting a moving object in the observation area. By using the method provided by the invention, a moving object detection result more accurate than a result by use of a convex optimization algorithm can be obtained, and the detection result is higher in resolution.

The invention discloses a simulation method of a bistatic synthetic aperture radar sea wave direction spectrum, which comprises the following steps of calculating a JONSWAP sea wave spectrum and a sea wave vertical displacement according to sea wave parameters; obtaining BiSAR echo signals comprising sea wave orbital velocity and accelerated velocity according to a radar wave modulation principle and BiSAR system parameters; carrying the matched filtering on the echo signals according to a BiSAR distance and Doppler imaging algorithm to obtain an analysis formula of a BiSAR sea wave image; working out the BiSAR sea wave image by adopting a numerical integration method; and at last, carrying out two-dimensional FFT operation on the BiSAR sea wave image to obtain the BiSAR sea wave direction spectrum. The BiSAR sea wave image can be worked out by adopting the numerical integration method without producing the echo signals and processing the image in a time domain, therefore, the invention has higher operation efficiency.

Using pulsed-wave (PW) ultrasonography for determining an aliasing-free radial velocity spectrum of matter moving in a region. Includes: transmitting into the region a plurality of pulse trains of sound waves at two or more different pulse repetition frequencies; spectrally analyzing each pulse train, for evaluating a Doppler frequency spectrum associated with each pulse train; combining frequency components of Doppler frequency spectrum of each pulse train, for obtaining aliasing-free instantaneous Doppler frequency spectrum for the region; using Doppler effect for translating aliasing-free frequency spectrum to aliasing-free radial velocity spectrum. Implementable using pulsed-wave Doppler (PWD), color flow Doppler (CFD), tissue Doppler imaging (TDI), or pulsed-wave (PW) ultrasonography. Applicable to liquid or / and solid forms of matter, moving in a two- or three-dimensional region. Matter is any substance or material, composed of organics or / and inorganics, which is part of a non-living object, or, part of a human or animal subject.

The invention discloses an adjustable receiving aperture digital ultrasonic beam synthesis method and a device, which relates to the medical ultrasonic field; the invention supports the synthesis of a single or a plurality of ultrasonic beam synthesis, can be combined with the different application occasions, and can change the maximum number of the receiving aperture and the position of the receiving aperture on a probe flexibly. When in observation of a static tissue structure, a transmitter scans the same physical position twice, and the number of the receiving aperture at the moment is twice the number of the physical channels, which can significantly improve the image quality. When in observation of a high-speed moving tissue or in Doppler imaging of the blood flow, the transmitter scans the same physical position once only, the center of the receiving aperture is near a emission line or coincided with the emission line, and the frame rate at the moment can be doubled. Compared with the prior art, the invention has the advantages that: the invention applies the single ultrasonic beam or multiple ultrasonic beams to support and receive the ultrasonic echo of the receiving aperture at an arbitrary position. The invention can also change the maximum number of the aperture and leads the center of the aperture to be near or coincided with the emission line; the results of ultrasonic beam synthesis can still be obtained without the synthesis of the aperture, and the frame rate under the same scanning depth can be doubled as the earlier applied patent.

The invention discloses an inverse synthetic aperture radar imaging method based on a generative adversarial network. A generative adversarial network (GAN) is composed of a generator network and a discriminator network. The generator network uses a convolution layer and a residual network module to extract feature representation and maintain low-dimensional feature information, and uses a deconvolution layer to reconstruct an ISAR target image. And the discriminator network extracts feature information from an ISAR image output by the generator network by using the convolutional layer, thereby realizing authenticity discrimination of the ISAR image. And at the network training stage, all layers of parameters of the generator network and the discriminator network are updated by using the training error output by the discriminator network. And the trained generator network is separated from the GAN and is used for under-sampling ISAR data imaging. At the imaging stage, a low-quality target image obtained by under-sampling ISAR target echo data through a distance-Doppler RD method is input into the generator network, and correspondingly, a high-quality ISAR target image is output. The imaging quality and the calculation efficiency of the method are superior to those of a traditional distance Doppler imaging method and a compressed sensing imaging result.

A method for cardiac motion estimation includes: receiving a set of echocardiographic images of a heart, the echocardiographic images including B-mode ultrasonic images and Tissue Doppler Imaging (TDI) images; and calculating, by the image processing machine, a motion field representing the motion of the heart using the B-mode ultrasonic images and applying a velocity constraint from the TDI images. A system for cardiac motion estimation, includes: an imaging device configured to acquire a set of echocardiographic images of a heart, the echocardiographic images including B-mode ultrasonic images and TDI images; a data storage device in communication with the imaging device and configured to store the set of echocardiographic images; an image processing machine in communication with the data storage device and configured to calculate a motion field representing the motion of the heart using the B-mode ultrasonic images and applying a velocity constraint from the TDI images.

The invention discloses a high-precision moving target imaging and recognition method based on target tracking. The method comprises the following steps: acquiring a SAR video by an SAR platform working in a bunching mode; using the Probability Hypothesis Density multi-target tracking method to perform tracking, and estimating motion parameters of moving targets; using the acquired motion parameters of the moving targets to correct a Doppler imaging coefficient, and acquiring SAR images that are accurately imaged after defocusing and displacement; and detecting and recognizing the moving targets in the acquired accurate SAR images. The technical effects of the method are that the motion parameters of the moving targets in the SAR video can be acquired through the multi-target tracking method in the video, the Doppler imaging coefficient and the problems of defocusing and offsetting in the images are corrected according to the acquired motion parameters of the moving targets so as to obtain high-precision images; and a support is provided for high-precision recognition.

The invention discloses a method for tracking features of an ultrasound pattern and a system thereof. The method comprises the following steps: setting an initial region of features of interest; calculating the regional gray-scale similarity to obtain a regional gray-scale similarity parameter; reading Doppler velocity information in the region of features of interest, and establishing a constraint condition; and constructing a similarity measurement by combining the regional gray-scale similarity parameter and the constraint condition, and calculating the extreme value of the similarity measurement to obtain the position of a tracked track point. By combining the features of color Doppler tissue imaging, the invention effectively improves the accuracy and the robustness of tracking of the region of features.

The invention provides an ultrasonic color Doppler image post-processing method, which comprises the following steps of 1) setting a blood parameter estimation module in an ultrasonic color Doppler imaging system; 2) correspondingly receiving a blood flow variance signal and a blood flow velocity signal by a blood flow signal processing module; 3) setting a parameter pre-processing module in the ultrasonic color Doppler imaging system; 4) comparing and judging whether a signal is a blood flow signal or not by the parameter pre-processing module; 5) setting a spatial processing module for processing an image. Based on the above method, the generation of anomalous points is lowered maximally.

The invention discloses an automatic aliasing judgment and Doppler imaging adjusting method and an ultrasonic system thereof. The method comprises the following steps of: acquiring a Doppler spectrogram; comparing strong and weak parameters of the whole field signals of the spectrogram with a threshold value and judging whether the spectrogram performs vein aliasing for multiple times or not; according to the characteristics of the spectrogram area signals, judging whether the spectrogram performs artery aliasing for multiple times or not; and if the vein aliasing judgment result and the artery aliasing judgment result perform aliasing for multiple times, judging that the Doppler spectrogram does not perform aliasing for multiple times. In the method, the influence of spectrogram forms on the judgment is taken into full consideration, so the aliasing judgment of a vein spectrogram is added, the probability of erroneous judgment is reduced, and the accuracy of the aliasing judgment is improved.

The invention provides a ship target ISAR imaging method based on fractional Fourier transform. The ship target ISAR imaging method comprises the steps of: acquiring a radar echo signal of a scattering point of a ship target in each distance unit; modeling the acquired radar echo signals in the distance units into multi-component secondary frequency modulation signals through pulse compression andmotion compensation; determining estimated parameters of scattering point echo signals in the distance units according to the secondary frequency modulation signals; updating radar echo signals in the distance units by adopting the estimated parameters of the scattering point echo signals in the distance units; and acquiring an ISAR image of a ship target by utilizing the updated radar echo signals. The ship target ISAR imaging method adopts a symmetrical correlation function, fractional Fourier transform and multi-product processing for the radar echo signals in sequence, avoids the couplingof time and time delay, estimates a quadratic term phase coefficient and a cubic term phase coefficient with high precision, adopts a range-instantaneous-Doppler imaging technology combining with parameter estimation, and obtains a high-quality and high-precision ISAR image of a moving target.

Vector Doppler Imaging (VDI) improves on conventional Color Doppler Imaging (CDI) by giving speed and direction of blood flow at each pixel of a display generated by a computing system. Multiple angles of Plane wave transmissions (PWT) via an ultrasound transducer conveniently give projected Doppler measurements over a wide field of view, providing enough angular diversity to identify velocity vectors in a short time window while capturing transitory flow dynamics. A fast, aliasing-resistant velocity vector estimator for PWT is presented, and VDI imaging of a carotid artery with a 5 MHz linear array is shown using a novel synthetic particle flow visualization method.

The invention provides a method and a device for automatically optimizing Doppler imaging parameters. The method comprises: an acquiring step used for acquiring at least two characteristic spectral lines under a predetermined pulse repetition frequency; a storage step used for storing the at least two characteristic spectral lines; and an optimizing step used for optimizing at least one of the Doppler imaging parameters based on the stored at least two characteristic spectral lines and a predetermined noise average power. In the predetermined time, the acquiring step acquires the at least twocharacteristic spectral lines by acquiring Doppler spectral lines under the predetermined pulse repetition frequency in real time and processing the acquired Doppler spectral lines in real time without storage. Compared with the prior art, the method and the device realize automatic optimization of the Doppler imaging parameters only by storing and processing the two characteristic spectral linesand the predetermined noise average power, thereby having the advantages of few occupied resource, low complexity and good stability.

The device comprises: a laser, a first / second spectroscope, a polarization beam-splitter piece, a 1 / 4 wave plate, a telescope, a full-reflection mirror on reflection beam of the first spectroscope, a switch, and an optical Doppler imaging detector on the output light direction of second spectroscope. Wherein, arranging the first spectroscope and beam-splitter piece both as 45Deg, 1 / 4 wave plate and telescope on the OA of output beam of the laser in turn; arranging with 45Deg the second spectroscope on the cross point of switch light path and reflection light path of laser echo of beam-slitter piece. This invention can determine the position, height, velocity and direction.

The invention discloses an inverse synthetic aperture radar imaging method based on time-phase derivative distribution. Under the situation of very complicated object motion, the Doppler frequency of echo signals of scatter points is time-varying, and an image obtained by using a traditional distance-Doppler imaging method is vague at the moment so that an object is difficult to identify. In the invention, the echo signals of the scatter points are described to be multi-component quartic-phase signals, and a parameter evaluation method based on the time-phase derivative distribution is proposed in specific to the situation of single-component signals; and a parameter evaluation method in which product type time-phase derivative distribution is adopted and a clean technology is combined, is proposed in specific to the situation of multi-component signals. Finally, a transient image with a clear object is obtained by combining a distance-transient Doppler imaging method.

The invention provides an ISAR (Inverse Synthetic Aperture Radar) imaging method for a complex moving target. Through polynomial phase optimization estimation on each dominant scatterer distance unitecho signal after translational compensation and polynomial phase signal time frequency decomposition, each signal component obtained by decomposition is a single component only corresponding to one frequency point at any time, the defect that cross terms exist in a non-signal component corresponding to multiple frequency points at one time in the traditional time frequency transform is overcome,each dominant scatterer distance unit echo signal has no any cross term interference and building of time frequency distribution with good time frequency joint resolution is realized finally, and range-instantaneous Doppler imaging is thus obtained. The principle is simple, the operation is convenient, bad influences of cross term interference in the classical time frequency analysis method and losses of the time frequency joint resolution are overcome effectively, the quality and the benefits of nonstationary polynomial phase signal time frequency analysis are effectively enhanced, and a target image with good quality and good resolution is obtained.

The invention discloses a full-aperture imaging method for multi-channel wave beam-pointing synthetic aperture radar (SAR), and mainly solves the problem of low imaging resolution in a wide scene. The full-aperture imaging method comprises the following implementation processes of: (1) receiving original SAR echo signals in a full-aperture way in a one-transmitting multi-receiving channel mode; (2) performing azimuth bandwidth compressing processing and wave beam compressing processing on the echo signals; (3) recovering and reconstructing the compressed echo signals by a Doppler space-time adaptive post-processing method; (4) transforming the recovered and reconstructed echo signals into a two-dimensional frequency domain; and (5) performing distance migration correction and pulse compression on the echo signals in the two-dimensional frequency domain by utilizing a Doppler imaging algorithm to realize imaging. According to the method, the azimuth resolution is improved by utilizing the wave beam-pointing SAR; the problem that the bandwidth of the wave beam-pointing SAR is over-wide is solved by compressing a wave beam domain and an angle domain; simultaneously, an imaging processing flow is simplified; the imaging processing efficiency is improved; and the method can be used in the SAR imaging of a space-borne platform under the requirements of wide scene and high resolution.