CN107374610B - Magnetocardiogram generation method and system - Google Patents
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Abstract
The invention provides a magnetocardiogram generation method and system applied to a magnetocardiogram instrument, comprising the following steps: 1) firstly, intercepting data of each channel in one period, selecting a certain moment from the intercepted data, taking out the data of each channel at the moment, and then calculating corresponding position coordinates of each channel above the chest; 2) enabling data of each channel at a certain moment to correspond to the coordinates; 3) performing two-dimensional interpolation on the two-dimensional magnetocardiogram data arranged according to the position; 4) inquiring a color table for the interpolated two-dimensional data; 5) and drawing a heart magnetic picture. The magnetocardiogram generated by the invention has clear image and uniform color distribution, and + -two dipoles can be clearly seen in the T wave band. In addition, if the magnetocardiogram at different time points is drawn from the S section to the T section of the QRS wave according to the set step length, the time-space evolution process of the heart activity current can be seen, and a doctor can diagnose whether the patient suffers from heart diseases or not according to the dipole number of the magnetocardiogram and the evolution direction of the heart activity current.
Description
Technical Field
The invention belongs to the field of biomedical signal analysis, and particularly relates to a magnetocardiogram generation method and system applied to a magnetocardiogram instrument.
Background
The periodic polarization and depolarization process of cardiac muscle cells form an Electrocardiogram (ECG), but because the ECG signal is transmitted through human tissues with large signal loss, and the transmission of the magnetic signal is not affected by tissues such as muscle, the Magnetocardiogram (MCG) becomes a hot spot in recent research.
The magnetocardiogram is obtained by measuring the magnetic field intensity of different regions above the heart of a human body by using a multi-channel magnetocardiogram instrument, and displaying the measured magnetic field values in different colors according to the position arrangement. Research shows that the magnetocardiogram is in coronary heart disease, arrhythmia and other heart diseasesThe diagnosis of diseases, risk classification and the like have obvious advantages. Brisinda et al found that magnetocardiograms could be used to identify left bundle branch block patients (the direction of magnetic field evolution at the R peak of their magnetocardiograms was opposite to that of normal persons)[1]. The study by Park et al shows that MCG is superior to ECG, echocardiogram and troponin tests for patients with coronary heart disease who are predicted to have acute chest pain and no ST elevation; in addition, MCG can accurately detect bundle branch block patients with acute chest pain, and ECG cannot diagnose[2]. Fainziberg et al studied 123 coronary heart disease patients and 124 normal persons using a 4-channel magnetocardiograph, and classified the magnetocardiographs of the subjects (0 normal to 4 complete abnormalities), and found that the sensitivity and consistency of MCG classification reached 76% and 81%, respectively, with the classification value of 1.75 as the threshold[3]。
The above studies show that the magnetocardiogram has potential advantages in the diagnosis, prediction, risk assessment and the like of heart diseases, and therefore, how to generate a high-quality magnetocardiogram by using a magnetocardiogram algorithm becomes a hot spot of clinical research. Chinese patent document No. CN1552285A published (published) No. 2004.12.08 discloses a magnetocardiogram diagram and an analysis method thereof, but the method only draws magnetocardiogram signals measured at different positions and at the same time on the same coordinate axis, and cannot reflect the magnetic field distribution at different positions above the heart. Chinese patent document No. CN102682425B granted (bulletin) day 2014.10.15 discloses a magnetocardiogram system and a method of creating magnetocardiogram images, which uses an algorithm based on model learning, i.e., a large number of high-resolution MCG images randomly generated based on biot-savart law to construct a model, and creates high-resolution MCG images by equipping the model with sparse measurements. However, the method can generate the magnetocardiogram image only by creating the model and providing sparse measurement for the model, and the algorithm is too complex and long in processing time, so that the requirement of clinical real-time analysis of the magnetocardiogram image cannot be met. Therefore, how to generate a high-resolution and real-time magnetocardiogram with the magnetic field intensity values of the finite point positions is a difficult problem to be solved.
Reference documents:
[1]D.Brisinda and R.Fenici,"Magnetocardiographic study of patientswith right and left bundle branch blocks,"in International Congress Series,2007,pp.451-454.
[2]J.W.Park,P.M.Hill,N.Chung,P.G.Hugenholtz,and F.Jung,"Magnetocardiography predicts coronary artery disease in patients with acutechest pain,"Annals of noninvasive electrocardiology,vol.10,pp.312-323,2005.
[3]L.Fainzilberg,I.Chaikovsky,S.Auth-Eisernitz,B.Awolin,D.Ivaschenko,and B.Hailer,"Sensitivity and specificity of magnetocardiography,usingcomputerized classification of current density vectors maps,in ischemicpatients with normal ECG and echocardiogram,"in International CongressSeries,2007,pp.468-471.
disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, it is an object of the present invention to provide a method and a system for generating a magnetocardiogram applied to a magnetocardiograph, which are used to solve the above-mentioned problems in the prior art, thereby providing a reference value for clinical diagnosis of heart diseases.
To achieve the above and other related objects, the present invention provides a method for generating a magnetocardiogram, comprising: respectively intercepting magnetocardiogram data of one period from each channel of the magnetocardiogram instrument, selecting a certain moment from the intercepted magnetocardiogram data, and taking out the magnetocardiogram data of each channel at the moment; calculating the corresponding position coordinates of each channel on the surface of the thoracic cavity; enabling the magnetocardiogram data of each channel at the moment to correspond to the calculated position coordinates, and arranging the corresponding coordinates according to positions to form a two-dimensional matrix; performing two-dimensional interpolation processing on the magnetocardiogram data of the two-dimensional matrix; the color corresponding to each interpolated magnetocardiogram data value is looked up in the color table and displayed at the corresponding position of the magnetocardiogram to draw a colored magnetocardiogram.
In an embodiment of the present invention, the intercepting of the magnetocardiogram data of each channel in one cycle includes: calculating the average period of all channel magnetocardiogram data
Wherein RtiAt the moment of the ith R peak, N is the number of R waves in the magnetocardiogram data, and K is the number of channels; and taking the time of the R peak in the magnetocardiogram data of each channel as a reference point, respectively taking the data of the fractional number of average periods forward and the data of 1-fractional number of average periods backward to form the magnetocardiogram data of one period.
In an embodiment of the present invention, the calculating the position coordinates of each channel on the surface of the thoracic cavity includes: order: all the channels are on an XY plane, the coordinate of the first channel is (0,0), and the distances among the channels are equal and are S; then: starting from the origin (0,0), the coordinates of the first column channel are (0,0+ iS), the coordinates of the second column channel are (S,0+ iS), the coordinates of the third column channel are (2S,0+ iS), …, and the coordinates of the nth column channel are ((n-1) S,0+ iS); where i is the number of steps moved along the Y axis.
In an embodiment of the present invention, the arranging the corresponding coordinates according to positions to form a two-dimensional matrix includes: arranging the corresponding magnetocardiogram data along the negative Y-axis and the positive X-axis, and expressing the coordinate distribution as C { (X)1,y1)、(x2,y2)、(x3,y3)...(xK,yK) }; searching for coordinates (X) in a coordinate distribution Ci，Yi) Channels corresponding to equal coordinates, wherein (X)i，Yi) Is the arrangement coordinate of the channel i on the XY plane; jumping out of the search cycle when finding the corresponding coordinates, and obtaining the magnetocardiogram data MCG of the channel iiPutting the data into the kth position of the one-dimensional array, wherein k is the execution times of the search cycle; repeating the execution until all the magnetocardiogram data are placed at the corresponding positions of the one-dimensional array; and taking the first n data from the obtained one-dimensional array and placing the data in the first row, taking the data from the (n + 1) th to the (2 n) th rows and placing the data in the second row, and so on until the one-dimensional array is arranged into a two-dimensional matrix according to the negative direction of the Y axis and the positive direction of the X axis.
In an embodiment of the invention, the two-dimensional interpolation is performed on the magnetocardiogram data of the two-dimensional matrixThe method comprises the following steps: order: a series of coordinate points (x) on the XY planei，yj) (i ═ 0,1,2,. times, n; a magnetocardiogram data value of 0,1, 2.. multidot.m): aij＝f(xi,yj) (ii) a Constructing a binary function z ═ z (x, y) such that z (x)i,yj) Approximation of the value of aijAt this time, z (x)i,yj) I.e. the coordinate point (x) soughti，yj) The interpolation of (c).
In one embodiment of the present invention, the constructed binary function z is:
wherein,
is an X-axis coordinate interval { X0＜x1＜x2＜...＜xnNon-zero cubic spline function on phij(Y) is the Y-axis coordinate interval { Y0＜y1＜y2＜...＜ymNon-zero cubic spline function on uijThe undetermined coefficient is obtained by derivation of z (x, y).
In an embodiment of the present invention, the drawing a color magnetocardiogram further includes: find the maximum and minimum in the image, draw + at the maximum and-at the minimum, respectively, and connect the maximum and minimum with a straight line with an arrow pointing to the minimum.
To achieve the above and other related objects, the present invention provides a system for generating a magnetocardiogram, including: the data acquisition module is used for respectively intercepting the magnetocardiogram data of one period from each channel of the magnetocardiogram instrument, selecting a certain moment from the intercepted magnetocardiogram data, and taking out the magnetocardiogram data of each channel at the moment; the coordinate calculation module is used for calculating the position coordinates of each channel corresponding to the surface of the thoracic cavity; the corresponding processing module is used for enabling the magnetocardiogram data of each channel at the moment to correspond to the calculated position coordinates, and arranging the corresponding coordinates according to positions to form a two-dimensional matrix; the interpolation processing module is used for carrying out two-dimensional interpolation processing on the magnetocardiogram data of the two-dimensional matrix; and the image generation module is used for searching the color corresponding to each interpolated magnetocardiogram data value in the color table and displaying the color at the corresponding position of the magnetocardiogram so as to draw a colorful magnetocardiogram.
In an embodiment of the present invention, the intercepting of the magnetocardiogram data of each channel in one cycle includes: calculating the average period of all channel magnetocardiogram data
Wherein RtiAt the moment of the ith R peak, N is the number of R waves in the magnetocardiogram data, and K is the number of channels; and taking the time of the R peak in the magnetocardiogram data of each channel as a reference point, respectively taking the data of the fractional number of average periods forward and the data of 1-fractional number of average periods backward to form the magnetocardiogram data of one period.
In an embodiment of the present invention, the calculating the position coordinates of each channel on the surface of the thoracic cavity includes: order: all the channels are on an XY plane, the coordinate of the first channel is (0,0), and the distances among the channels are equal and are S; then: starting from the origin (0,0), the coordinates of the first column channel are (0,0+ iS), the coordinates of the second column channel are (S,0+ iS), the coordinates of the third column channel are (2S,0+ iS), …, and the coordinates of the nth column channel are ((n-1) S,0+ iS); where i is the number of steps moved along the Y axis.
In an embodiment of the present invention, the arranging the corresponding coordinates according to positions to form a two-dimensional matrix includes: arranging the corresponding magnetocardiogram data along the negative Y-axis and the positive X-axis, and expressing the coordinate distribution as C { (X)1,y1)、(x2,y2)、(x3,y3)...(xK,yK) }; searching for coordinates (X) in a coordinate distribution Ci，Yi) Channels corresponding to equal coordinates, wherein (X)i，Yi) Is the arrangement coordinate of the channel i on the XY plane; jumping out of the search cycle when finding the corresponding coordinates, and obtaining the magnetocardiogram data MCG of the channel iiPutting the data into the kth position of the one-dimensional array, wherein k is the execution times of the search cycle; repeating the execution until all the magnetocardiogram data are placed at the corresponding positions of the one-dimensional array; and taking the first n data from the obtained one-dimensional array and placing the data in the first row, taking the data from the (n + 1) th to the (2 n) th rows and placing the data in the second row, and so on until the one-dimensional array is arranged into a two-dimensional matrix according to the negative direction of the Y axis and the positive direction of the X axis.
In an embodiment of the present invention, the performing two-dimensional interpolation processing on the magnetocardiogram data of the two-dimensional matrix includes: order: a series of coordinate points (x) on the XY planei，yj) (i ═ 0,1,2,. times, n; a magnetocardiogram data value of 0,1, 2.. multidot.m): aij＝f(xi,yj) (ii) a Constructing a binary function z ═ z (x, y) such that z (x)i,yj) Approximation of the value of aijAt this time, z (x)i,yj) I.e. the coordinate point (x) soughti，yj) The interpolation of (c).
In one embodiment of the present invention, the constructed binary function z (x, y) is:
wherein,
is an X-axis coordinate interval { X0＜x1＜x2＜...＜xnNon-zero cubic spline function on phij(Y) is the Y-axis coordinate interval { Y0＜y1＜y2＜...＜ymNon-zero cubic spline function on uijThe undetermined coefficient is obtained by derivation of z (x, y).
In an embodiment of the present invention, the image generating module is further configured to: find the maximum and minimum in the image, draw + at the maximum and-at the minimum, respectively, and connect the maximum and minimum with a straight line with an arrow pointing to the minimum.
As described above, the magnetocardiogram generation method and system provided by the invention have the advantages that the generated magnetocardiogram image is clear, the color distribution is uniform, and the + -two dipoles can be clearly seen in the T wave band. If the magnetocardiogram at different time is drawn from the S section to the T section of the QRS wave according to the set step length, the space-time evolution of the cardiac activity current can be seen, and a doctor can diagnose whether the patient suffers from the heart disease or not according to the dipole number of the magnetocardiogram and the evolution direction of the cardiac activity current.
Drawings
Fig. 1 is a flowchart of a method for generating a magnetocardiogram according to an embodiment of the present invention.
Fig. 2 shows the coordinate distribution of K channels in the XY plane when the step length i is 5 in an embodiment of the present invention.
FIG. 3 is a schematic diagram illustrating an interpolation algorithm for magnetocardiogram data according to an embodiment of the present invention.
FIG. 4 shows a normal person's magnetocardiogram generated using the magnetocardiogram algorithm of the present invention.
FIG. 5 shows a magnetocardiogram of a patient with a heart disease generated using the magnetocardiogram algorithm of the present invention.
FIG. 6 is a block diagram of a system for generating a magnetocardiogram according to an embodiment of the present invention.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
As shown in fig. 1, the magnetocardiogram generation method of the present invention specifically includes 5 steps:
step S1: and intercepting the magnetocardiogram data of each channel at a certain moment. The specific implementation method comprises the following steps: firstly, intercepting magnetocardiogram data MCG 1-MCGM of each channel in one period (namely, the number of magnetocardiogram data of one period extracted from each channel is M, the total number of channels is 36 for a 36-channel magnetocardiogram acquisition system, and the number of data of one period of each channel is about 800), and selecting a certain moment from the intercepted data and extracting the data of the moment of each channel; then, the position coordinates of the measurement points corresponding to the respective channels on the chest surface are calculated.
The intercepting of data of each channel in one cycle comprises the following steps: first, the average period of the magnetocardiogram data of all channels is calculated
Then, with the time of the R peak in the magnetocardiogram data of each channel as a reference point, 2/5 average periods of data are taken forward, and 3/5 average periods of data are taken backward, respectively, to form a period.
The average period is calculated by the formula as follows,
wherein RtiAnd N is the number of R waves in the magnetocardiogram data, and K is the total number of channels.
The position coordinates corresponding to the channels above the chest are calculated: assuming that all channels (K) are on an XY plane, the coordinate of the first channel iS (0,0), the distance between the channels iS equal and iS S, the coordinate of the first row of channels starting from the origin along the X-axis direction iS (0,0+ iS), i iS the step number moving upwards along the Y-axis direction, and the value of i iS an integer in the range of 1-K; the coordinates of the second row of channels are (S,0+ iS), and by analogy, the XY plane coordinates corresponding to all other channels can be calculated. Fig. 2 shows the coordinate distribution of K channels when the step length i is 5.
Step S2: the magnetocardiogram data of each channel at a certain time is corresponding to the coordinates, that is, each channel is corresponding to the coordinate at a certain timeAnd putting the carved magnetocardiogram data on the corresponding position coordinates to form a two-dimensional matrix. The specific implementation method comprises the following steps: assuming that the data after coordinate correspondence is completed are arranged along the positive direction of the Y axis and the positive direction of the X axis, the coordinate distribution is C { (X)1,y1)、(x2,y2)、(x3,y3)...(xK,yK) }; let the arrangement coordinate of the channel i on the XY two-dimensional plane be (X)i，Yi). First, find and coordinate (X) in coordinate distribution Ci，Yi) The equal channels jump out of the search cycle when finding the corresponding coordinates, and if the cycle number is k at the moment, the magnetocardiogram data MCGi of the channel i is placed at the kth position of the one-dimensional array; then, all the magnetocardiogram data are put at the corresponding positions of the one-dimensional array according to the method; for example: 36-channel magnetocardiogram system, each channel at the same time respectively takes out the data at the time, namely each channel takes out one data, total 36 data are taken out, and the coordinate (X) of each data is searched on Ci,Yi) The coordinates are completely the same, a loop is found, namely quitted, and the loop time is the corresponding position number 1.. 36 in 36 positions; and finally, arranging the one-dimensional arrays into a two-dimensional matrix according to the negative direction of the Y axis and the positive direction of the X axis, namely, assuming that the number of columns of the two-dimensional matrix is n, firstly taking out the first n data of the one-dimensional arrays and placing the first n data in a first row, then taking out the (n + 1) th to 2n data of the one-dimensional arrays and placing the data in a second row, and so on, and placing all the data at corresponding positions of the two-dimensional matrix.
Step S3: and performing two-dimensional interpolation on the two-dimensional magnetocardiogram data arranged according to the positions. Because of the limited number of signal channels of a magnetocardiograph, for example: the 36-channel magnetocardiogram instrument only has 36 magnetocardiogram data at a certain time, and the 36 magnetocardiogram data are used for magnetocardiogram imaging, so that the image resolution is too low, and therefore two-dimensional interpolation needs to be carried out on two-dimensional magnetocardiogram data arranged according to positions.
Referring to fig. 3, the two-dimensional magnetocardiogram data is interpolated by a bi-cubic spline interpolation algorithm, and the specific implementation method is as follows: assume a series of coordinate points (x) on the XY planei，yj) (i ═ 0,1,2,. times, n; j ═ 0,1,2,. ·, m; n and m are integers in the range of 1 to K) is added to the mixtureAccording to the value of aij＝f(xi,yj) Constructing a binary function z ═ z (x, y) such that z (x) isi,yj) Approximation of the value of aijI.e. z (x)i,yj) I.e. the coordinate point (x) soughti，yj) The interpolation of (c). FIG. 3 shows the acquired data z before interpolationi,j(xi，yj) And interpolation data zim,n(xim,n，yim,n) Distribution of (2).
Structure of the invention
Wherein,
is an X-axis coordinate interval { X0＜x1＜x2＜...＜xnNon-zero cubic spline function on phij(Y) is the Y-axis coordinate interval { Y0＜y1＜y2＜...＜ymNon-zero cubic spline function on uijThe undetermined coefficient can be calculated by differentiating z (x, y).
Step S4: and inquiring a color table for the interpolated two-dimensional data. And searching corresponding colors in a color table according to the interpolated magnetocardiogram data values, and displaying the colors at corresponding positions of the magnetocardiogram. In order to improve the image resolution of the magnetocardiogram, the color table adopts a for loop to generate a 256-color linear uniform color table, and the difference value of each color can be set by self to achieve better uniformity and continuity.
Step S5: and drawing a heart magnetic picture. The specific implementation method comprises the following steps: firstly, setting the size of an image; then, searching a color table according to the value of the magnetocardiogram data at the corresponding position of the image, and drawing the corresponding color value on the image; finally, find the maximum and minimum in the image, draw + number at the maximum, draw-at the minimum respectively, and connect the maximum and minimum with the straight line with arrow, the arrow points to the minimum.
Firstly, four times of magnetocardiogram data are collected by a 9-channel magnetocardiogram instrument at four fixed point positions set above a chest cavity to form 36-channel magnetocardiogram data, then ① is carried out on the magnetocardiogram data of the 36 channels in sequence according to the magnetocardiogram generation algorithm of the invention to intercept data of each channel for one period, a certain moment is selected from the intercepted data to take out the data of each channel at the moment, then corresponding position coordinates of each channel above the chest are calculated, ② the data of each channel at the certain moment corresponds to the coordinates, ③ carries out two-dimensional interpolation on the two-dimensional magnetocardiogram data arranged according to the positions, ④ inquires 5 steps such as a color table, ⑤ painting magnetocardiogram and the like, the generated normal magnetocardiogram is shown in figure 4, and the magnetocardiogram of a patient is shown in figure 5.
As shown in fig. 6, the present invention also provides a system for generating a magnetocardiogram, which is similar to the principle of the above method embodiment, and comprises: a data acquisition module 601, a coordinate calculation module 602, a correspondence processing module 603, an interpolation processing module 604, and an image generation module 605. Since the technical features in the foregoing method embodiments can be applied to this system embodiment, they are not repeated.
The data obtaining module 604 captures the magnetocardiogram data of one cycle from each channel of the magnetocardiogram instrument, selects a certain time from the captured magnetocardiogram data, and extracts the magnetocardiogram data of each channel at the time. The coordinate calculation module 602 calculates the position coordinates of each channel on the surface of the thorax. The correspondence processing module 603 corresponds the magnetocardiogram data of each channel at the time point to the calculated position coordinates, and arranges the corresponding coordinates according to positions to form a two-dimensional matrix. The interpolation processing module 604 performs two-dimensional interpolation processing on the magnetocardiogram data of the two-dimensional matrix. The image generation module 605 looks up the color corresponding to each interpolated magnetocardiogram data value in the color table and displays the color at the corresponding position of the magnetocardiogram to draw a colored magnetocardiogram.
In summary, the magnetocardiogram generation method and system of the present invention effectively overcome the disadvantages of the prior art and have high industrial utility value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (10)
1. A method for generating a magnetocardiogram, comprising:
respectively intercepting magnetocardiogram data of one period from each channel of the magnetocardiogram instrument, selecting a certain moment from the intercepted magnetocardiogram data, and taking out the magnetocardiogram data of each channel at the moment;
calculating the corresponding position coordinates of each channel on the surface of the thoracic cavity, comprising: enabling all channels to be on an XY plane, enabling the coordinate of a first channel to be (0,0), and enabling the distances among the channels to be equal and to be S; then starting from the origin (0,0), the coordinates of the first column channel are (0,0+ iS), the coordinates of the second column channel are (S,0+ iS), the coordinates of the third column channel are (2S,0+ iS), …, and the coordinates of the nth column channel are ((n-1) S,0+ iS); wherein i is the number of steps of movement along the Y axis;
making the magnetocardiogram data of each channel at the moment correspond to the calculated position coordinates, and arranging the corresponding coordinates according to positions to form a two-dimensional matrix, comprising: arranging the corresponding magnetocardiogram data along the negative Y-axis and the positive X-axis, and expressing the coordinate distribution as C { (X)1,y1)、(x2,y2)、(x3,y3)...(xK,yK) }; searching for coordinates (X) in a coordinate distribution Ci，Yi) Channels corresponding to equal coordinates, wherein (X)i，Yi) Is the arrangement coordinate of the channel i on the XY plane; jumping out of the search cycle when finding the corresponding coordinates, and obtaining the magnetocardiogram data MCG of the channel iiPutting the data into the kth position of the one-dimensional array, wherein k is the execution times of the search cycle; repetition ofExecuting until all the magnetocardiogram data are placed at the corresponding positions of the one-dimensional array; taking out the first n data from the obtained one-dimensional array and placing the data in a first row, taking out the n +1 th to 2n data and placing the data in a second row, and so on until the one-dimensional array is arranged into a two-dimensional matrix according to the negative direction of the Y axis and the positive direction of the X axis;
performing two-dimensional interpolation processing on the magnetocardiogram data of the two-dimensional matrix;
the color corresponding to each interpolated magnetocardiogram data value is looked up in the color table and displayed at the corresponding position of the magnetocardiogram to draw a colored magnetocardiogram.
2. The method of claim 1, wherein intercepting the magnetocardiogram data for each channel for one cycle comprises:
calculating the average period of all channel magnetocardiogram data
Wherein RtiAt the moment of the ith R peak, N is the number of R waves in the magnetocardiogram data, and K is the number of channels;
and taking the time of the R peak in the magnetocardiogram data of each channel as a reference point, respectively taking the data of the fractional number of average periods forward and the data of 1-fractional number of average periods backward to form the magnetocardiogram data of one period.
3. The method of claim 1, wherein the two-dimensional interpolation processing of the magnetocardiac data of the two-dimensional matrix comprises:
order: a series of coordinate points (x) on the XY planei，yj) (i ═ 0,1,2,. times, n; a magnetocardiogram data value of 0,1, 2.. multidot.m): aij＝f(xi,yj)；
Constructing a binary function z ═ z (x, y) such that z (x)i,yj) Approximation of the value of aijAt this time, z (x)i,yj) I.e. the coordinate point (x) soughti，yj) The interpolation of (c).
4. The method of claim 3, wherein the constructed binary function z is:
wherein,
is an X-axis coordinate interval { X0＜x1＜x2＜...＜xnNon-zero cubic spline function on phij(Y) is the Y-axis coordinate interval { Y0＜y1＜y2＜...＜ymNon-zero cubic spline function on uijThe undetermined coefficient is obtained by derivation of z (x, y).
5. The method of claim 1, wherein said rendering a color magnetocardiogram further comprises: find the maximum and minimum in the image, draw + at the maximum and-at the minimum, respectively, and connect the maximum and minimum with a straight line with an arrow pointing to the minimum.
6. A system for generating a magnetocardiogram, comprising:
the data acquisition module is used for respectively intercepting the magnetocardiogram data of one period from each channel of the magnetocardiogram instrument, selecting a certain moment from the intercepted magnetocardiogram data, and taking out the magnetocardiogram data of each channel at the moment;
the coordinate calculation module is used for calculating the position coordinates of each channel corresponding to the surface of the thoracic cavity, and comprises: enabling all channels to be on an XY plane, enabling the coordinate of a first channel to be (0,0), and enabling the distances among the channels to be equal and to be S; then starting from the origin (0,0), the coordinates of the first column channel are (0,0+ iS), the coordinates of the second column channel are (S,0+ iS), the coordinates of the third column channel are (2S,0+ iS), …, and the coordinates of the nth column channel are ((n-1) S,0+ iS); wherein i is the number of steps of movement along the Y axis;
the corresponding processing module is used for making the magnetocardiogram data of each channel at the moment correspond to the calculated position coordinates, and arranging the corresponding coordinates according to positions to form a two-dimensional matrix, and comprises: arranging the corresponding magnetocardiogram data along the negative Y-axis and the positive X-axis, and expressing the coordinate distribution as C { (X)1,y1)、(x2,y2)、(x3,y3)...(xK,yK) }; searching for coordinates (X) in a coordinate distribution Ci，Yi) Channels corresponding to equal coordinates, wherein (X)i，Yi) Is the arrangement coordinate of the channel i on the XY plane; jumping out of the search cycle when finding the corresponding coordinates, and obtaining the magnetocardiogram data MCG of the channel iiPutting the data into the kth position of the one-dimensional array, wherein k is the execution times of the search cycle; repeating the execution until all the magnetocardiogram data are placed at the corresponding positions of the one-dimensional array; taking out the first n data from the obtained one-dimensional array and placing the data in a first row, taking out the n +1 th to 2n data and placing the data in a second row, and so on until the one-dimensional array is arranged into a two-dimensional matrix according to the negative direction of the Y axis and the positive direction of the X axis;
the interpolation processing module is used for carrying out two-dimensional interpolation processing on the magnetocardiogram data of the two-dimensional matrix;
and the image generation module is used for searching the color corresponding to each interpolated magnetocardiogram data value in the color table and displaying the color at the corresponding position of the magnetocardiogram so as to draw a colorful magnetocardiogram.
7. The system of claim 6, wherein the intercepting of one cycle of magnetocardiogram data for each channel comprises:
calculating the average period of all channel magnetocardiogram data
Wherein RtiAt the moment of the ith R peak, N is the number of R waves in the magnetocardiogram data, and K is the number of channels;
and taking the time of the R peak in the magnetocardiogram data of each channel as a reference point, respectively taking the data of the fractional number of average periods forward and the data of 1-fractional number of average periods backward to form the magnetocardiogram data of one period.
8. The system of claim 6, wherein the two-dimensional interpolation of the magnetocardiac data of the two-dimensional matrix comprises:
order: a series of coordinate points (x) on the XY planei，yj) (i ═ 0,1,2,. times, n; a magnetocardiogram data value of 0,1, 2.. multidot.m): aij＝f(xi,yj)；
Constructing a binary function z ═ z (x, y) such that z (x)i,yj) Approximation of the value of aijAt this time, z (x)i,yj) I.e. the coordinate point (x) soughti，yj) The interpolation of (c).
9. The system of claim 8, wherein the constructed binary function z (x, y) is:
wherein,
is an X-axis coordinate interval { X0＜x1＜x2＜...＜xnNon-zero cubic spline function on phij(Y) is the Y-axis coordinate interval { Y0＜y1＜y2＜...＜ymNon-zero cubic spline function on uijThe undetermined coefficient is obtained by derivation of z (x, y).
10. The system of claim 6, wherein the image generation module is further configured to: find the maximum and minimum in the image, draw + at the maximum and-at the minimum, respectively, and connect the maximum and minimum with a straight line with an arrow pointing to the minimum.
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