37 results about "Ultrasound scattering" patented technology

The measuring device comprises a computer used for data process, a signal process circuit connected to the computer, a pulse wave transmitting/receiving circuit connected to the signal processing circuit; a bandwidth transmitting/receiving transducer assembly connected to the pulse transmitting/receiving circuit. The data process program compares the measuring signal with the preset standard substance; the actually measured acoustic attenuation spectrum is combined with the acoustic attenuation spectrum obtained based on the scattering formula computational theory to construct the matrix and linear equation; using dual frequency attenuation ratioing to realize the calculation of average particle size; according to the particle size, inversely computes the particle concentration.

Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements. A modified TR-MUSIC imaging algorithm is used to account for ultrasound scattering from both density and compressibility contrasts. The phase response of ultrasound transducer elements is accounted for in a PC-MUSIC system.

The invention relates to an ultrasonic scattering coefficient optimal computation method for crack direction recognition, belonging to the field of nondestructive examination. According to the method, an ultrasonic phased array detection system is used for acquiring full-matrix data of a crack defect; firstly, the acquired data are used for performing full-focusing imaging on the defect to determine the position of the defect and then a scattering coefficient space distribution of the crack defect is computed to determine an angle of the crack; the quantity of wafers included in a sub array and the quantity of wafers between adjacent sub arrays greatly affect the measurement precision of the crack angle. A plurality of evaluation indexes are used for evaluating the quantity of a crack angle measurement result according to the quantities of the wafers included in different sub arrays and the wafers between the adjacent sub arrays, and the measurement result is comprehensively evaluated by a main component analysis method to obtain an optimal measurement result; corresponding parameters, namely the quantities of the wafers included in the sub arrays and the quantity of the wafers between the adjacent sub arrays, are optimal detection parameters.

A treatment instrument system according to the present invention includes: an endoscope having a treatment instrument channel; an ultrasound probe inserted through the treatment instrument channel of the endoscope; an ultrasound observing apparatus having a blood flow display function and a distance measuring function; a treatment instrument having, at a distal end portion, an ultrasound scattering portion for scattering ultrasound; and an over tube having an endoscope insertion path through which the endoscope can be inserted and a treatment instrument insertion path through which the treatment instrument can be inserted, and having, at a distal end portion, an ultrasound scattering portion for scattering ultrasound.

A method for characterizing ultrasound scatterers in soft tissue, wherein scattered signals are used to eliminate the absorption attenuation of an ultrasound wave from estimated parameters and to obtain directional scattering information. The scattered signals are obtained from either multiple regions where one region is used as a reference or multiple scattering directions, creating known reference signals from the same scattering region. The method provides new ultrasound parameters for the characterization and contrast enhancement of tissue structures in ultrasound imaging, such as tumor structures, ischemia of a myocardial wall and/or plaque compositions in vascular atheroma. The method of the invention can be used with various arrangements of ultrasound transducers, particularly switched linear arrays.

The velocity of fluids containing particles that scatter ultrasound can be measured by determining the Doppler shift of the ultrasound scattered by the particles in the fluid. Measuring fluid flow in cylindrical vessels such as blood vessels is an important use of Doppler ultrasound. This invention teaches using various configurations of cylindrical diffraction-grating transducers and cylindrical non-diffraction-grating transducers that suppress the Doppler shift from non-axial components of fluid velocity while being sensitive to the Doppler shift produced by axial velocity components. These configurations thus provide accurate measurement of the net flow down the vessel, even when the fluid flow is curved or not parallel to the vessel wall.

The invention aims to provide a new method for ultrasonic flaw detection of a pressure-bearing cast iron device, namely a grain characteristic-based improved split spectrum method in ultrasonic flaw detection of the pressure-bearing cast iron device, wherein compared with a conventional cast iron flaw detection, the method enables a system to obtain higher signal-to-noise ratio, faster response time and higher flexibility. Because an internal organizational structure of cast iron is not uniform and the grain size is larger, when ultrasonic waves are used for flaw detection, attenuation of the ultrasonic waves is larger when in propagation, sporadic reflection is prone to generate, and forest-like or grass-like echoes are produced, resulting in poor flaw detection sensitivity. The method utilizes effects of an average grain size and an crystal orientation angle (an included angle of the acoustic wave incident direction and the grain axis) of the cast iron internal grain characteristics on ultrasonic scattering and attenuation, a noise time-frequency characteristic and a flaw echo frequency dispersion characteristic with obvious grain characteristics are caused, optimized split spectrum parameters are obtained through analysis of noise and echo signals, and thus with utilization of the split spectrum technology, the scattering noise can be well reduced and the ultrasonic echo signal sensitivity can be well improved.

Realistic ultrasound imaging simulation requires modeling of scatterers corresponding to different imaging speckle appearances. A scatterer generator acquires a plurality of ultrasound signal samples, each corresponding to a different ultrasound capture and reconstructs a scatterer representation from the ultrasound signal samples and associated Point Spread Functions. Point Spread Functions (PSFs) may be estimated from multiple image acquisitions at the same reference position resulting from beam-steering. Reconstructed scatterers may then directly be used in ultrasound simulation or an additional step of modeling the scatterers may be applied. Statistical distribution parametrization or texture synthesis may be used to model the scatterers. Different scatterer models may be used for different homogeneous regions. The reconstructed scatterers and/or the scatterer models may be registered into a library of scatterers by the scatterer generator.

The present invention provides an acceleration and enhancement methods for ultrasound scatterer structure visualization. The method includes: obtaining an ultrasonic image, calculating all values of the ultrasonic signal points in each m^th window centered at a n^th signal point to obtain a plurality of original statistical values a_nx_m, obtaining a plurality of m^th statistical values by averaging value of original statistical values in the same window, calculating a plurality of m^th weighting values based on the statistical values by different weighting formulas, multiplying each weighting value with the original statistical values corresponding to the various size of windows, summing up to obtain an ultrasound structure scatterer value of the n^th ultrasonic signal point, and generating an ultrasound scatterer structure image based on a matrix of the ultrasound scatterer values. The present invention further combined interpolation method can reduce the computation time and retain the 80% accuracy.

The invention provides a defect classification method and system based on ultrasonic phased array imaging, and belongs to the field of nondestructive detection.The method comprises the steps that ultrasonic phased array imaging is adopted for a to-be-detected sample piece to obtain ultrasonic full-matrix data; performing full-focusing processing on the ultrasonic full-matrix data, performing color coding according to the signal amplitude, and obtaining an image of the sample piece to be detected; preprocessing an image of a to-be-detected sample, inputting the preprocessed image into the classification prediction model, and obtaining defect classification of the to-be-detected sample; a method for training the classification prediction model comprises the following steps of: acquiring simulation data by simulating ultrasonic phased array imaging by utilizing a defect ultrasonic scattering data finite element simulation method; after full-focusing processing is carried out on the simulation data, a simulation image is obtained; preprocessing the simulation image and then performing data enhancement; carrying out image feature extraction on the simulation image by adopting a convolutional neural network; and inputting the image features into a full connection layer, and training a classification prediction model by taking defect classification as output. According to the invention, the accuracy of defect classification is improved.

The present application discloses an ultrasonic measurement system and a detection method for detecting deep structural fissures. By utilizing the detection method, the size of a deep sub-wavelength-scale linear micro-fissure of a material can be quantitatively detected. After being excited by ultrasonic pulses, the micro-fissure deep in the material can generate ultrasonic scattering and reflection; after being received by an ultrasonic transducer, ultrasonic signals pass through a signal amplifier and an analog-to-digital converter and are stored in a computer; and a power spectrum of the ultrasonic signals is obtained by computing. A spectrum parameter, namely a power spectrum slope, can be obtained by carrying out linear fitting on low-frequency bands of the power spectrum, the spectrum slope and the diameter of the micro-fissure are in one-to-one correspondence, and the diameter of the sub-wavelength micro-fissure can be quantitatively evaluated by computing the slope. Because the quantitative detection method needs a low working frequency, the method provides a non-invasive, non-ionizing, cheap and safe method for evaluating the scale of the deep micro-fissure.

The invention provides a phased array ultrasonic evaluation method for grain size. The method comprises the following steps: obtaining an experimental longitudinal wave scattering attenuation coefficient by using primary bottom surface echo and secondary bottom surface echo; deriving a radiation sound field of the linear phased array probe according to the Huygens principle, receiving average sound pressure through the probe, defining a diffraction correction coefficient of the linear phased array probe, and calculating a final diffraction correction coefficient; obtaining a theoretical relationship between the grain size and the longitudinal wave scattering attenuation coefficient according to a Weaver ultrasonic scattering model, and obtaining an agent model of the grain size and the theoretical longitudinal wave scattering attenuation coefficient by using polynomial fitting based on a nonlinear least square method; and substituting the experimental longitudinal wave scattering attenuation after the diffraction loss is eliminated into the proxy model, and inverting a grain size value. According to the method, diffraction loss interference is eliminated, multi-angle acoustic beam information is fused, compared with a traditional method, relative errors are greatly reduced, and a feasible and reliable means is provided for grain size estimation of polycrystalline materials.

The invention provides a novel composite fiber based on sweet sorghum skin fiber and a preparation method thereof. The preparation method comprises the following steps: (1) removing leaves of sweet sorghum stalks which are about 15-20 cm long, cleaning the sweet sorghum stalks, obtaining sweet sorghum skin and flesh pith containing normal juice through a separator, performing squeezing separation on the flesh pith containing the normal juice to obtain stalk flesh residue, cleaning and drying the stalk flesh residue, and obtaining stalk residue powder after smashing and filtration; (2) refining the sweet sorghum skin into skin fiber strips, placing the skin fiber strips in a solvent to undergo ultrasound scattering, washing and drying to obtain the skin fiber; (3) evenly mixing the stalk residue powder and the skin fiber; after distilled water is added for swelling for a period of time, adding chitosan and sodium alginate, performing high-speed stirring at a high temperature, performing vacuum defoamation, and performing filtration to obtain spinning solution; (4) causing the spinning solution to form nascent fiber through a wet spinning technology, and obtaining the composite fiber based on the sweet sorghum skin fiber through drafting, washing and winding. The fiber is a composite fiber integrating toughness, antibiosis, anti-inflammation and greenness.

The invention discloses a power spectrum based ultrasonic scattering particle diameter imaging method. Based on ultrasonic radio frequency signals, the method calculates a power spectrum, calculates an ultrasonic scattering particle diameter parameters and calculates an ultrasonic scattering particle diameter parameter image. The method is as below: sliding a sliding window over an ultrasonic RF signal; calculating ultrasonic scattering particle parameters in each sliding window based on the power spectrum to obtain a matrix of ultrasonic scattering particle parameter values; interpolating thematrix of the ultrasonic scattering sub-parameter values into the size of the ultrasonic RF signal; and performing color mapping to obtain an ultrasound scattering particle diameter parameter image.The ultrasonic scattering particle diameter imaging method of the present invention can be used for ultrasonic tissue characterization of biological tissues such as mammary gland, liver and the like.

The present invention provides an ultrasonic phased array detection device and method for an automobile third-generation hub bearing outer ring, a phased array probe is arranged on the side wall of the hub bearing outer ring, and a six-degree-of-freedom mechanical arm with the probe is used for conducting ultrasonic phased array detection on the hub bearing outer ring along the section of the hub bearing outer ring, and a phased array probe array element self-transmitting and self-receiving mode is adopted to obtain a reflection echo signal of the hub bearing outer ring defect and transmit the reflection echo signal to a computer. Computer writing software carries out data storage and signal processing on the received reflection echo signals, and finally, a frequency domain synthetic aperture focusing imaging algorithm is used for carrying out defect imaging on the hub bearing outer ring. According to the method, a water immersion ultrasonic phased array detection method is adopted, and the problems are solved that ultrasonic scattering of a small-angle, small-size, thin-wall and complex curved surface of the hub bearing is serious, and the defect detection blind area is large, and the defect detection capability of the hub bearing is improved.