31 results about "Velocity waveform" patented technology

A method and apparatus for determining the mean arterial blood pressure (MAP) of a subject during tonometric conditions. In one embodiment, the apparatus comprises one or more pressure and ultrasound transducers placed over the radial artery of a human subject's wrist, the latter transmitting and receiving acoustic energy so as to permit the measurement of blood velocity during periods of variable compression of the artery. During compression, the ultrasound velocity waveforms are recorded and processed using time-frequency analysis. The time at which the mean time-frequency distribution is maximal corresponds to the time at which the transmural pressure equals zero, and the mean pressure read by the transducer equals the mean pressure within the artery. In another aspect of the invention, the ultrasound transducer is used to position the transducer over the artery such that the accuracy of the measurement is maximized. In yet another aspect of the invention, a wrist brace useful for measuring blood pressure using the aforementioned apparatus is disclosed. A method of continuously estimating systolic and diastolic pressure is also described.

A method and apparatus for determining the mean arterial blood pressure (MAP) of a subject during tonometric conditions. In one embodiment, the apparatus comprises one or more pressure and ultrasound transducers placed over the radial artery of a human subject's wrist, the latter transmitting and receiving acoustic energy so as to permit the measurement of blood velocity during periods of variable compression of the artery. During compression, the ultrasound velocity waveforms are recorded and processed using time-frequency analysis. The time at which the mean time-frequency distribution is maximal corresponds to the time at which the transmural pressure equals zero, and the mean pressure read by the transducer equals the mean pressure within the artery. In another aspect of the invention, the ultrasound transducer is used to position the transducer over the artery such that the accuracy of the measurement is maximized. In yet another aspect of the invention, a wrist brace useful for measuring blood pressure using the aforementioned apparatus is disclosed.

An embodiment of a method of predicting maternal hypertension during pregnancy is disclosed. The method may include measuring a maternal blood velocity waveform and measuring a fetal blood velocity waveform. The method may further include the calculation of a coherence value using a magnitude-squared coherence function between the maternal and fetal blood velocity waveforms and comparing the coherence value to a predetermined threshold value.

The invention discloses a method for converting blasting-vibration acceleration into velocity, which comprises the following steps: firstly, carrying out empirical mode decomposition, low-frequency processing and high-frequency threshold noise reduction processing on an acceleration data sequence; then, obtaining a velocity data sequence through time-domain integration; and finally, respectively carrying out piecewise least-squares correction on components having the drift phenomenon so as to obtain a high-precision velocity data sequence. By using the method for converting blasting-vibration acceleration into velocity disclosed by the invention, the problem of drifting can be effectively solved, and the similarity between a velocity waveform obtained by using the method and an actually-measured velocity waveform is more ideal, therefore, the method can guide the blasting construction better, and is beneficial for popularization.

The invention relates to an acoustic emission simulation method and system based on a discrete element method. The simulation method comprises the steps of: arranging monitoring points on the surfaceof a calculation model; monitoring the speed waveform of the monitoring point; and analyzing the speed waveform to obtain an acoustic emission number, energy and a b value. According to the method, the problems that a traditional acoustic emission simulation method is inconsistent in principle, poor in authenticity and too high in computing resource occupation can be solved.

A movement analysis display apparatus includes a analyzing unit for analyzing waveform data of a time series which is acquired from a movement sensor, and a display unit for displaying an analysis result that is analyzed by the analyzing unit. The analyzing unit includes a movement waveform generating section for generating a movement waveform from the waveform data, an energy balance value calculating means for calculating a movement energy ratio in opposed movement directions in a velocity waveform, an envelope curve generating section for generating an envelope curve at a given time width in a distance waveform, and a time integration curve analyzing section for integrating a movement waveform with respect to time.

The invention provides a peripheral arterial blood vessel elasticity evaluation system based on a double triangle blood flow model, and relates to the technical field of medical and health electronics. The present invention first collects peripheral arterial pulse waves, and removes noises such as power frequency interference and baseline drift from the pulse waves. The feature points were extracted from the filtered signal, and the blood flow velocity waveform was fitted using the double triangle blood flow model according to the position of the feature points, and the pulse waveform was decomposed based on the double triangle blood flow velocity waveform to obtain the forward wave and the backward wave. Finally, according to the extracted characteristic points of the forward wave and backward wave, the backward wave enhancement index RM and reflection index RI reflecting the elasticity of peripheral arterial vessels are calculated. The present invention accurately decomposes the peripheral arterial pulse wave according to the fitted blood flow waveform, calculates relevant parameters based on the decomposed result, integrates the characteristics of the forward wave and the backward wave, and realizes the evaluation of the vascular sclerosis degree of the peripheral artery and the function of the cardiovascular system Evaluation makes it easier to detect cardiovascular function.

Techniques exist for measuring local blood velocity of flow rate waveforms in, for example, mammalian vascular segments. A method and system for deriving information on disease in vascular segments, for example mean pressure, drop in mean pressure and / or hydraulic resistance, from such measured waveforms is described. The waveforms can, for example, be measured non-invasively using Doppler ultrasound or magnetic resonance techniques. Form factors (Vff, Pff) for the velocity waveform and the central arterial pressure are determined. Stenosis may be detected by detecting changes e.g in Vff / Pff.

The invention relates to an acoustic emission simulation method and system based on a discrete element method. The simulation method includes: arranging monitoring points on the surface of a calculation model; monitoring the velocity waveform of the monitoring point; analyzing the velocity waveform to obtain the acoustic emission Emission number, energy, and b-value. The above-mentioned method in the present invention can solve the problems of inconsistent principles, poor authenticity, and high occupation of computing resources in the traditional acoustic emission simulation method.

A system and method is provided for acquiring flow encoded data from a subject using a magnetic resonance imaging (MRI) system. The method includes acquiring flow encoded (FE) data with alternating encoding polarities and along two of three orthogonal directions through the subject over at least two cycles of the flow within the subject; and separating the FE data into directional FE datasets using a temporal filter that separates the FE data based on temporal modulation of the FE directions caused by the alternating encoding polarities extending over the at least two cycles of the flow within the subject that shift the Fourier spectrum of velocity waveforms corresponding to the FE data. The method also includes using the directional FE datasets to generate an image of the subject showing flow within the subject caused by the at least two cycles of flow within the subject.

The invention relates to an automatic identification method of blood flow velocity waveform based on an ultrasonic image, which belongs to the field of image processing algorithms. The method is based on the collected or photographed clinical ultrasound images containing blood flow velocity waveforms, and performs grayscale and binarization preprocessing on the images; The area of ​​high gray value below the waveform; traverse upwards from the last line of the segmented area as a whole, and when the maximum gray gradient is experienced and there is no high-brightness gray in a certain length of area that continues upward, the boundary of the waveform can be identified. That is, the blood flow velocity waveform; finally, it traverses from the middle position of the waveform to both ends to remove the non-waveform numbers, borders and other interferences, and output the digital waveform. The invention realizes the automatic identification and digital output of the blood flow velocity waveform in the image, and lays a foundation for the analysis of the blood flow velocity waveform when the waveform source data of the ultrasonic equipment cannot be obtained.

The invention belongs to the technical field of inertia identification, and discloses an inertia identification method, system and storage medium based on speed interpolation, and uses different improved MRAS inertia identification algorithms for inertia identification based on different input speed waveforms. Determine whether the input speed waveform is a triangle wave or square wave; when the input speed waveform is a triangle wave, select the improved MRAS inertia identification algorithm based on the triangle wave input for MRAS inertia identification; when the input speed waveform is a square wave, select the improved MRAS based on the square wave input. The inertia identification algorithm performs the MRAS inertia identification. The present invention uses triangular wave and square wave as the input speed signal to perform inertia identification, which has the problem of low precision. A targeted and improved MRAS inertia identification algorithm is proposed to improve the accuracy of inertia identification results. Compared with other improved solutions of MRAS, the present invention has the characteristics of less computational burden and more practicality.

The invention discloses a method for converting blasting-vibration acceleration into velocity, which comprises the following steps: firstly, carrying out empirical mode decomposition, low-frequency processing and high-frequency threshold noise reduction processing on an acceleration data sequence; then, obtaining a velocity data sequence through time-domain integration; and finally, respectively carrying out piecewise least-squares correction on components having the drift phenomenon so as to obtain a high-precision velocity data sequence. By using the method for converting blasting-vibration acceleration into velocity disclosed by the invention, the problem of drifting can be effectively solved, and the similarity between a velocity waveform obtained by using the method and an actually-measured velocity waveform is more ideal, therefore, the method can guide the blasting construction better, and is beneficial for popularization.

The present application relates to a method, device, computer equipment and storage medium for determining the running speed of an escalator, including: receiving signal data sent by a detection device; The area emits electromagnetic waves and generates signal data according to the returned electromagnetic waves; the signal data is extracted by fast Fourier transform to obtain the energy waveform characteristic spectrum and velocity waveform characteristic spectrum of the signal data; according to the energy waveform characteristic spectrum and velocity waveform characteristic spectrum , determine the passenger flow state in the preset area; determine the target running speed of the escalator according to the passenger flow state in the preset area. The method realizes timely adjustment of the running speed of the escalator according to different passenger flow conditions, enriches the running speed mode of the escalator, and improves the overall carrying efficiency of the escalator.

The invention discloses an improved diameter velocity loop method for measuring the pulse wave velocity of the ascending aorta. The diameter waveform of the ascending aorta was extracted from the M-mode ultrasound image of a good cardiac cycle; the blood flow velocity waveform of the ascending aorta was extracted from the D-mode ultrasound image of a good cardiac cycle; the diameter waveform and the blood flow velocity waveform were respectively obtained Ascent point, and use RANSAC to calculate PWV value. The invention reduces the excessive manual intervention of the original ln(D)U-loop method when calculating the diameter waveform through the image data of the ultrasonic M mode through the improved diameter waveform extraction method combined with the gradient calculation and the center of gravity method, and can effectively shorten the The processing time of the diameter waveform extraction and the reduction of errors; thus improving the error tolerance rate when calculating the diameter waveform.

The invention provides a method for estimating the pedaling torque by using the pedaling speed of the bicycle, and the pedaling torque refers to the pedaling torque of a crank of the bicycle. The method includes the following steps: within a predetermined time interval, a speed sensor is used to detect the pedaling speed of a crank of the bicycle for a predetermined number of times; the area of ​​the ideal waveform of the pedaling speed and the actual waveform of the pedaling speed is calculated as V 0 and V 1 , and find V 0 -V 1 The difference as ΔV i ; Obtain a correction amount c according to the relationship between pedaling speed and torque; calculate according to the following first formula: ΔM i / M 0 =ΔV i / V 0 +c; to obtain the relative change of pedaling torque ΔM i / M 0 ; among them, M 0 to generate V 0 Moment, M 0 obtained through actual experiments; M 0 -M 1 The difference is then ΔM i ; 1 to generate V 1 Moment, M 1 is the pedaling torque to be estimated.

The invention discloses a method for measuring ascending aorta pulse wave velocity by an improved diameter velocity loop way. The method comprises the following steps of: respectively segmenting a cardiac cycle of an M-mode ultrasonic image and a D-mode ultrasonic image of the ascending aorta by using an R-wave peak of an electrocardiogram; extracting the diameter waveform of the ascending aorta from the M-mode ultrasonic image with the segmented cardiac cycle; extracting a blood flow velocity waveform of the ascending aorta from the D-mode ultrasonic image of which the cardiac cycle is segmented; and respectively acquiring ascending points in the diameter waveform and the blood flow velocity waveform, and calculating the PWV value through RANSAC. According to the invention, through an improved diameter waveform extraction method combining gradient calculation and a gravity center method, excessive manual intervention of an original ln (D) U-loop method when the diameter waveform is calculated through image data in an ultrasonic M mode is reduced, the processing time of diameter waveform extraction can be effectively shortened, and errors are reduced; therefore, the error-tolerantrate during diameter waveform calculation is improved.

Provided is a controller for fuel injection, comprising a parameter obtaining part (33a) for obtaining the parameter (R4) of the injection velocity waveform indicating the changes of the injection velocity based on the detecting value of the fuel pressure sensor, a learning part (33b) used for learning the fuel injection order signal (Tq) of the fuel injector and the parameter (R4) corresponding to the fuel injection order signal as the learning value, a storage part (32) used for storing and indicating the model waveform (M3) of the parameter (R4) changes resulting from the changes of the fuel injection order signal (Tq), and an inner inserting part (33c) used for inserting the learning value and calculating the fuel injection order signal (Tq) and the parameters (R4) of the fuel injection order signal by utilizing the model waveform (M3).