35results about How to "Suppresses Motion Artifacts" patented technology

In diffusion weighted imaging, motion monitoring navigation echoes are measured at every measurement of data after applying an RF excitation pulse, and one of them is set as a reference navigation echo. The reference navigation echo and other navigation echoes are one-dimensionally Fourier-transformed, a linear phase gradient thereof is calculated from those data, a linear phase gradient of the reference navigation echo is compared with those of other navigation echoes, and it is judged whether a difference therebetween is within an acceptable value or not. An echo signal corresponding to a navigation echo having the above difference being larger than the acceptable value is judged that correction based on the navigated motion correction is not applicable therein, and the image is produced by using an echo signal measured along with a navigation echo having the difference being the acceptable value or less. In this manner, a motion component included in the echo signal used for producing the image is made uniform and motion artifacts are eliminated.

In order to prevent the occurrence of motion artifacts and improve image quality, the first displacement N1 of the diaphragm before the scanning part (2) has performed the imaging sequence and the second displacement N2 of the diaphragm after the scanning part (2) has performed the imaging sequence are detected by the body motion detection part (25) Detection is performed as displacement caused by breathing motion of the subject (SU). Thereafter, based on the first displacement N1 and the second displacement N2 detected by the body motion detection section (25), imaging data is selected as raw data by a raw data selection section (26). Then, according to the imaging data selected as raw data by the raw data selection part (26), the slice image of the subject (SU) is generated by the image generation part (31).

In a method and device for suppressing residual motion artifacts, k-space is divided into a snapshot segment, an alternate sampling segment and a high frequency segment in a phase encoding direction; then phase encoding lines are respectively sampled within each of the segments; and a magnetic resonance image is reconstructed according to the phase encoding lines within k-space.

The invention relates to an ultrasonic doppler blood flow imaging method and system. The imaging method comprises the steps of obtaining a blood flow speed measuring interest region and the quantity of launching sub-hole diameters; according to the quantity of the launching sub-hole diameters, determining the inclination angle of a plane wave in each launching sub-hole diameter; according to the inclination angle, determining array element excitation delay time in each launching sub-hole diameter; according to the array element excitation delay time, controlling all the launching sub-hole diameters to synchronously emit plane waves, and receiving echo signals through a full hole diameter; generating a radio frequency signal sequence according to the echo signals; extracting blood flow doppler signals of the blood flow speed measuring interest region according to the radio frequency signal sequence; determining blood flow speed according to the blood flow doppler signals; and generatingdoppler blood flow images of the blood flow speed measuring interest region according to the blood flow speed. Through the adoption of the imaging method and system provided by the invention, the largest pulse repeating frequency can be realized, and besides, motion artifacts introduced by radio frequency signal compositing in ultra-high ultrasonic doppler blood flow imaging can be restrained.

In a method for performing recordings for dual absorptiometry, a high-energy radiation pulse is performed before a low-energy radiation pulse. Furthermore the high-energy radiation pulse is arranged at the end of an assigned radiation window of the detector. This temporal sequence of a high-energy radiation pulse and a low-energy radiation pulse allows the total time for performing the recordings for dual absorptiometry to be minimized.

The invention relates to a flexible dry type electrode for collecting electroencephalograms and a preparation method thereof. The flexible dry type electrode comprises an electrode body and an electric connecting piece, wherein the electrode body comprises an electrode bottom and array-structure probes arranged on the electrode bottom. The electric connecting piece is arranged at the electrode bottom, and the electric connecting piece and the array-structure probes are located on the two opposite surfaces of the electrode bottom correspondingly. The array-structure probes comprise a plurality of probe bodies annularly arranged along the electrode bottom, and the tail ends of the probe bodies in a probe array formed after the multiple probe bodies are arranged form a sunken three-dimensional arc-shaped curved surface. The flexible dry type electrode has the advantages that conductive adhesive / conductive paste is not needed, operation is easy and convenient, impedance is low, long-term stability, long-term reliability and flexibility are achieved, wearing of the flexible dry type electrode is comfortable and safe, the cost is low, and the machining technology is simple.

The invention is a graphene flexible electrocardiogram dry electrode for suppressing motion artifacts, which is composed of a base layer, a fabric conductive layer, a motion artifact suppressing layer, a contact surface layer and an insulating shielding layer, wherein the flexible fabric constitutes the base layer The conductive cloth constitutes the conductive layer of the fabric; the first buffer layer, the reinforcing layer and the second buffer layer constitute the motion artifact suppression layer, the conductive sponge constitutes the first buffer layer and the second buffer layer, and the conductive cloth constitutes the The strengthening layer; the graphene coating constitutes the contact layer; the central hollow insulating fabric constitutes the insulating shielding layer. The invention is a dry electrode, which overcomes the irritation and damage to the skin caused by the traditional wet electrode, is non-disposable, and can be worn and used for a long time.

The present invention relates to an adaptive correction method for magnetic resonance diffusion weighted imaging, comprising the following steps: step 1, repeating acquisition of diffusion weighted images N times with the same scanning parameters, N≥3; step 2, based on the original image or compressed image point by point Construct a correlation matrix; step 3, perform principal component analysis on the correlation matrix after smoothing and filtering, and obtain the eigenvector corresponding to the largest eigenvalue of each correlation matrix; step 4, calculate the weight according to the eigenvector; step 5, according to Weighting performs weighted synthesis on the original image to obtain a corrected diffusion-weighted image. On the basis of multiple acquisition average technology, the present invention adopts principal component analysis method to adaptively detect and correct data from redundant data, suppress motion artifacts, radio frequency ignition artifacts, etc., and improve image quality; no need to increase Hardware device, and the image quality is better than multiple acquisition direct averaging technology.

The invention discloses a capacitor electrode for detecting electrocardiogram signals of a motorist. The capacitor electrode for detecting the electrocardiogram signals of the motorist comprises a supporting component, a signal detecting component and a buffer component, wherein the supporting component is composed of a metal plate; the signal detecting component is composed of a double-sided PCB (printed circuit board) with a voltage snubber circuit, the voltage snubber circuit is arranged on the bottom surface of the PCB and comprises CMOS (Complementary Metal-Oxide-Semiconductor Transistor) type double precision operational amplifiers with high input impedance and low noise; and the buffer component is composed of springs and is used for connecting the supporting component and the signal detecting component. The capacitor electrode for detecting the electrocardiogram signals of the motorist utilizes the double-sided PCB as the signal detecting component so that the structure is simple and the cost is low; utilizes springs as the buffer component so that the motion artifact caused by the body movement of a detected object during a signal detecting process is effectively restrained; and utilizes the mental plate as the supporting component so that not only a supporting function is achieved, but also an electromagnetic shielding function for the signal detecting component is achieved.

An active noise cancellation device (2) for medical equipment comprises an active circuit having a first input connection (8), a second input connection (10) and an output connection (12). The second input connection (10) is connected to at least one predetermined reference signal. The active noise canceling device (2) further comprises a low-impedance body-connected electrode (4) adapted to be in electrical contact with the subject's blood flow, wherein the low-impedance body-connected electrode (4) is connected to said first input connection (8), and a feedback branch (14) connects the output connection (12) with the first input connection (8). The feedback branch (14) includes a current limiting circuit (18) for limiting the current through said feedback branch (14) to below a predetermined current.

The invention relates to a method and a device for eliminating motion artifact of K spacial sampled data in a magnetic resonance imaging (MRI) system. The method comprises the following steps of: sampling data; preprocessing the data, namely ensuring the consistency of echo signal intensity, and moving the echo maximum to the center; estimating rotary motion, namely searching echo reference pairsbetween a rotary data tape and a basis data tape by utilizing frequency domain similarity, calculating relative angle offset among the reference pairs, establishing a rotary motion equation set, and introducing a constraint condition to solve rotary motion parameters; estimating translational motion, namely establishing a translational equation set to solve translational motion parameters according to a data consistency principle equivalent equation and the rotation angle obtained in the last step; compensating motion parameters, namely performing motion compensation on the motion parameters solved in the step 3 and the step 4; and performing filtered backprojection weighted reestablishment, namely adopting a filtered backprojection method for weighted reestablishment. The method or the device can effectively inhibit motion artifact.

The invention relates to a method for measuring three-dimensional morphological parameters of a blood vessel in an intracoronary ultrasound (ICUS) image sequence, which is used for improving the measurement accuracy of the morphological parameters of the blood vessel of a coronary artery. The technical scheme comprises the following steps of: completing three-dimensional reconstruction of the blood vessel by using the ICUS image sequence which is obtained by continuously withdrawing an ultrasound catheter and covers a plurality of cardiac cycles and cross information between two approximatelyvertical X-ray coronary arteriography images which are acquired at a starting point of a withdrawing path of the ultrasound catheter; and measuring and calculating the morphological parameters of theblood vessel which are important to clinical medicine by a geometric method by using a three-dimensional blood vessel model. Experiments prove that the measurement result of the morphological parameters of the blood vessel by the method is more accurate than that of the prior art, so that a reliable basis for visual diagnosis and treatment of coronary heart diseases and evaluation of interventional therapy effect is provided.