77results about How to "Remove Motion Artifacts" patented technology

Real time, high-speed image stabilization with a retinal tracking scanning laser ophthalmoscope (TSLO) enables new approaches to established diagnostics. Large frequency range (DC to 19 kHz), wide-field (40-deg) stabilized Doppler flowmetry imaging is described for human subjects. The fundus imaging method is a quasi-confocal line-scanning laser ophthalmoscope (LSLO). The retinal tracking system uses a confocal reflectometer with a closed loop optical servo system to lock onto features in the ocular fundus and automatically re-lock after blinks. By performing a slow scan with the laser line imager, frequency-resolved retinal perfusion and vascular flow images can be obtained free of eye motion artifacts.

An optical coherence tomography (OCT) system including a polarizing splitter disposed to direct light in an interferometer such that the OCT detector operates in a noise-optimized regime. When scanning an eye, the system detector simultaneously produces a low-frequency component representing a scanning laser ophthalmoscope-like (SLO-like) image pixel and a high frequency component representing a two-dimensional (2D) OCT en face image pixel of each point. The SLO-like image is unchanging with depth, so that the pixels in each SLO-like image may be quickly realigned with the previous SLO-like image by consulting prominent image features (e.g., vessels) should lateral eye motion shift an OCT en face image during recording. Because of the pixel-to-pixel correspondence between the simultaneous OCT and SLO-like images, the OCT image pixels may be remapped on the fly according to the corresponding SLO-like image pixel remapping to create an undistorted 3D image data set for the scanned region.

A system, method and medical tool are presented for use in non-invasive in vivo determination of at least one desired parameter or condition of a subject having a scattering medium in a target region. The measurement system comprises an illuminating system, a detection system, and a control system. The illumination system comprises at least one light source configured for generating partially or entirely coherent light to be applied to the target region to cause a light response signal from the illuminated region. The detection system comprises at least one light detection unit configured for detecting time-dependent fluctuations of the intensity of the light response and generating data indicative of a dynamic light scattering (DLS) measurement. The control system is configured and operable to receive and analyze the data indicative of the DLS measurement to determine the at least one desired parameter or condition, and generate output data indicative thereof.

The present invention provides for a data acquisition system for EEG and other physiological conditions, preferably wireless, and method of using such system. The wireless EEG system can be used in a number of applications including both studies and clinical work. These include both clinical and research sleep studies, alertness studies, emergency brain monitoring, and any other tests or studies where a subject's or patient's EEG reading is required or helpful. This system includes a number of features, which enhance this system over other systems presently in the marketplace. These features include but are not limited to the having multiple channels for looking at a number of physiological features of the subject or patient, a built in accelerometer for looking at a subject's or patient's body motion, a removable memory for data buffering and storage, capability of operating below 2.0 GHz, which among other things allows for more channels, movement artifact correction including video, pressure sensors capable of measuring or determining airflow, tidal volume and ventilation rate, and capability of manual and automatic RF sweep.

The present invention relates to a signal processing method and system for correcting organ motion artifacts for cardiac and brain imaging. A plurality of sets of MRI measurement data indicative of at least an image of an object is received. Each set corresponds to one row k_x of a k-space matrix of at least a k-space matrix. For each set a k-space matrix of the at least a k-space matrix is determined for allocation thereto based on motion information of the object occurring during acquisition of the plurality of sets of the MRI measurement data. In a following step a location within the allocated k-space matrix corresponding to a row of the k-space matrix allocated thereto is determined for each set. At least a k-space matrix is then generated by re-arranging the plurality of sets. Each of the at least a k-space matrix comprises the sets of the plurality of sets of the MRI measurement data allocated thereto. Inverse Fourier transforming of the plurality of k-space matrices provides at least a reconstructed image. Through careful selection of the phases of the cardiac and respiratory cycles and corresponding ranges MRI data acquisition periods are of the order of seconds or a few minutes. Furthermore, integration of motion artifact free MRI images of different phases of organ motion using the coherent k-space synthesis according to the invention allows provision of an animation showing different phases of a cardiac or lung cycle. In an embodiment for correcting motion artifacts for brain imaging a motion vector describing translational and rotational motion of a patient's head is tracked during the MRI data acquisition process. The motion artifacts are then corrected based on coherent k-space synthesis using the motion vector data.

A sparse angle X-ray captive test (CT) imaging method comprises the following steps: (1) system parameters, all angle projection data scanned previously and sparse angle projection data scanned previously in different periods are obtained; (2) image reconstruction is respectively performed to the all angle projection data scanned previously and the sparse angle projection data scanned previously which are obtained in step (1) so that a previously scanned CT image and a currently reconstructed CT image are obtained; (3) weighting even filtering processing is performed to the previously scanned CT image and the currently reconstructed CT image which are obtained in the step (2) so that a prior image is obtained; (4) a sparse angle CT image reconstruction model is constructed by the prior image obtained in the step (3); and (5) a final reconstructed image is obtained through optimization solution. According to the sparse angle X-ray CT imaging method, motion artifact caused by mismatching of imaging positions between the previously scanned CT image and the currently reconstructed CT image is removed so that high quality reconstruction of a low dose CT image is achieved.

The present invention relates to systems and methods of performing magnetic resonance imaging (MRI) in awake animals. The invention utilizes head and body restrainers to position an awake animal relative to a radio frequency dual coil system operating in a high field magnetic resonance imaging system to provide images of high resolution without motion artifact.

A method for eliminating motion artifacts in digital subtraction angiography comprises the following steps: step 1, reading; step 2, selecting points; step 3, constructing a DSA space body; step 4, carrying out space slicing; step 5, connecting tracks; step 6, analyzing the space motion characteristics of DSA pixel; step 7, carrying out triangulation; step 8, carrying out affine transformation; step 9, carrying out space winding; step 10, optimizing; step 11, registering; step 12, carrying out grey correction; step 13, carrying out logarithmic subtraction angiography. The invention belongs to the technology of image processing. The method of space analysis is used so that the registering of DSA image is more accurate, thereby efficiently eliminating motion artifacts and obtaining clear angiography images. Thus, the diagnostic accuracy of a doctor is improved, and the working efficiency is increased.

A computer-implemented method of correcting for motion of a sample during OCT imaging obtains a series of cross-sectional volume scans through the sample at different positions on a first coordinate axis, obtains at least two cross-sectional alignment scans in planes intersecting said volume scans at an angle, and stores the alignment scans and the volume scans in memory. The alignment scans are matched to the volume scans at lines of intersection thereof to determine the relative displacement of the volume scans to the sample due to sample motion. The relative displacement is used to correct for motion of the sample between successive volume scans.

The invention provides a multi-excitation magnetic resonance diffusion imaging method based on multilayer simultaneous excitation. The method comprises steps: multilayer simultaneous excitation pulses are used for carrying out multiple excitations on a measured object, and during each excitation process, signal acquisition is carried out on the measured object through multichannel coils so as to acquire multi-excitation multichannel sample-reducing k space data; according to the multi-excitation multichannel sample-reducing k space data, each-excitation complete multichannel k space data are restored; inverse Fourier transform is carried out on the each-excitation complete multichannel k space data respectively to obtain multi-excitation multichannel image domain data; and the multi-excitation multichannel image domain data are combined to generate a needed image. According to the multi-excitation magnetic resonance diffusion imaging method based on multilayer simultaneous excitation provided by the embodiment of the invention, the image resolution can be improved, image deformation can be reduced, and the imaging speed is improved.

The invention discloses a magnetic resonance diffusion imaging method based on multiple excitation. The method comprises the steps of activating a tested object, and collecting signals of the tested object in every excitation process, so as to obtain reduced k space data activated for multiple times; recovering the k space data of a data point to be restored according to the reduced k space data activated for multiple times collected in a preset scope where the data point to be restored, so as to obtain k space data activated for multiple times; carrying out inverse Fourier change on the k space data activated for multiple times, so as to obtain images or data activated for multiple times; and combining the images or data activated for multiple times to generate a needed image. According to the method provided by the embodiment of the invention, the motion artifacts among different activations cannot be effectively eliminated, the images can be diffused in multiple collecting way, the high resolution of the images can be provided, the deformation of the images can be reduced, and the rebuilding process can be simplified.

Methods and apparatus are described for facilitating the extraction of cleaner biometric signals from biometric monitors. A motion reference signal is generated independently from a biometric signal and then the motion reference signal is used to remove motion artifacts from the biometric signal.

The invention discloses a magnetic resonance imaging method and device. The magnetic resonance imaging method comprises collecting through a PROPELLER (Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction) algorithm to obtain a plurality of K-space bars; performing Fourier transformation on the K-space bars to obtain temporary reconstructed images which are corresponding to the K-space bars respectively; enabling the temporary reconstructed image which is corresponding to one K-space bar to be served as a reference image, enabling the temporary reconstructed images which are corresponding to other temporary reconstructed images to be served as images to be performed registration and working out optimal motion parameters of the images to be performed registration relative to the reference image through image registration; correcting the K-space bars which are obtained before the temporary reconstructed images according to obtained optimal motion parameters; rearranging the corrected K-space bars, performing the Fourier transformation on a rearranged result and obtaining imaging images. The magnetic resonance imaging method is less influenced by acquisition parameters such as the echo train length and provides possibilities for eliminating motion artifacts due to the fact that estimation of motion parameters is performed based on registration of image fields.

The invention discloses a respiratory and ECG gating device used in a MRI system, relating to the MRI technology, wherein an information processing system is an embedded system taking a singlechip as the processing core; a sensor is used to capture respiratory and electrocardio signals which are amplified and subject to analog-to-digital conversion and input into the singlechip to be processed, and used as well to input the respiratory and electrocadio signals into a computer through a serial port for displaying the essential information on the screen of the computer which returns the information of the threshold preset in a man-computer interaction way to the device through the serial pore; the singlechip operates the threshold signal, i.e., control pulses, according to the generation sequence of the threshold and transmit the threshold signal to an alpha spectrometer. The device of the invention is simple, flexible, reliable and low in cost, and ensures the real timing and accuracy of the captured signals and clear image of the MRI system.

The invention provides a voice transmission method, device and system based on MRL (magnetic resonance imaging). The voice transmission method comprises the following steps: a scanning position and a scanning sequence of a patient are obtained; an instruction is generated according to the scanning position and the scanning sequence; language and voice matching processing is performed on the instruction, and a voice prompt corresponding to the instruction is obtained; the voice prompt is send to a first playing device in a scanning room, so that the first playing device plays the voice prompt to the patient conveniently, and the patient cooperates for scanning according to the requirement in the voice prompt. According to the embodiment of the invention, the corresponding voice prompt is obtained after the generated instruction is subjected to language and voice variety matching processing, the voice prompt is sent to the patient,, the patient is prompted to cooperate for scanning according to the requirement in the voice prompt, so that motion artifact is eliminated, the quality of scanned images is improved, and the scanning efficiency is increased.

The invention is applicable to the field of communication, and provides a background phase extracting method. The method includes the steps of selecting and collecting any TE of a plurality of time of echo (TE) of a gradient echo sequence; calculating the phase diagram phi(x,y) of any TE filtering out magnetic susceptibility interference; fitting the phase diagram phi(x,y) of a polynomial to obtain the coefficient, substituting the coefficient to a phase diagram expression to obtain an expression of the phase diagram phi(x,y), and calculating to obtain the reference phase phi(x,y) of a fitted area according to the expression; calculating the complex difference delta phi between the original phase of the fitted area in the phase diagram at any TE and the reference phase; calculating to obtain the temperature change value delta T through delta phi, wherein the delta T is the final temperature image. The background phase extracting method has the advantages of eliminating impact from motion artifact, magnetic susceptibility artifact and the like, and being high in measurement accuracy.