CN103637794A - Three-dimensional color coding display method for myocardial blood volume distribution - Google Patents

Abstract

The invention relates to a three-dimensional color coding display method for myocardial blood volume distribution, through which the blood volume distribution information of electrocardiosignals is converted and displayed on a visual three-dimensional color model. The method is characterized in that a 12-lead electrocardiogram (ECG) of a human body is collected, and the myocardial blood volume distribution information of the ECG, i.e. ST-segment deviation, is extracted; in a cardiac electric axis system, the total electrocardial damage vector is obtained through the adverse projection of the ST-segment damage vector of each lead; a standard three-dimensional heart model is established, the central position of an area where the blood volume is scarcely distributed is the joint of the total damage vector and the surface of the heart model, the distribution range is proportional to the total damage vector, and RGB (red, green and blue) coding is carried out according to the different distances between all the positions and the center of the area where the blood volume is scarcely distributed, so as to display the myocardial blood volume distribution on the surface of the heart model.

Description

A kind of myocardium blood volume distribution three-dimensional colour coding display packing

Technical field

The present invention relates to show by three-dimensional colour heart model directly perceived the method that myocardium blood volume distributes, particularly a kind of display packing that is converted to three-dimensional colour coding by one dimension electrocardiosignal.

Background technology

Electrocardiogram: heart is in each cardiac cycle, in succession excited by pacemaker, atrium, ventricle, is accompanied by bioelectric variation, draws the figure (being called for short ECG) of the potential change of various ways from body surface by electrocardiograph.Electrocardiogram is the objective indicator of generation, propagation and the recovery process of heart excitement.Electrocardiogram has comprised the information that Heart center flesh blood volume distributes, but not two-dimentional or three-dimensional blood volume distribution situation, the situation that simple one dimension ECG signal can only distribute to myocardium blood volume by empirical equation be analyzed.

Summary of the invention

Technical problem to be solved by this invention is: a kind of myocardium blood volume distribution three-dimensional colour coding display packing is provided, use portable gauge to gather out human body 12 and lead electrocardiogram, one dimension electrocardiosignal is converted into three-dimensional image information, according to the feature extraction of primary signal, go out useful information, two-dimentional cardiac electric axis system is improved to three-dimensional cardiac electric axis system, by the contrary projection of electrocardial vector, use the synthetic ST of method of least square always to damage vector, and demonstrate by its direction and size scope and the degree that heart blood volume distributes.

The technical solution adopted in the present invention is:

A myocardium blood volume distribution three-dimensional colour coding display packing, the method comprises that the obtaining of electrocardiosignal, the calculating of ST field offset amount, the contrary projection of electrocardial vector, myocardium blood volume distribution are definite, the realization of coloud coding, wherein:

Electrode connection is identical with the connection of conventional twelve-lead electrocardiogram.V1 leads at right border of sternum the 4th intercostal, and V2 leads at left border of sternum the 4th intercostal, and V3 leads at the mid point of V2 and V4 line, and V4 leads at left mid-clavicular line and the 5th intercostal place, V ₅lead and V ₆lead and V ₄lead in same level, lay respectively at left anterior axillary line and left midaxillary line.Right upper extremity is red conducting wire, and left upper extremity is yellow conducting wire, and left lower extremity is green, and right lower extremity is black.

It is carried out to pretreatment after signal-obtaining, a time period of setting (tentative 10s), R ripple is the wave band of electrocardiosignal amplitude maximum in each heart beating, and the R wave crest point place backward potential value of 108ms is used for characterizing the current potential V of ST section ₁, the R wave crest point place forward potential value of 80ms is used for characterizing reference potential V ₀, the side-play amount V of ST section _sT=V ₁-V ₀; Every the ST field offset value of leading is obtained successively.

Cardiac electric axis system is in three-dimensional system of coordinate XYZ, and XZ plane represents human body cross section, and XY plane represents human body face amount, Z axis be oriented human body the place ahead to, X-axis is on human body face amount and the cross section intersection of human body, Y-axis, on face amount, is oriented.Vectorial axle corresponding to the I, II, III, aVR, aVL, aVF of leading, on face amount, is 0 °, 60 °, 120 ° ,-150 ° ,-30 °, 90 ° (from X-axis, being rotated counterclockwise) respectively at X-axis; V leads ₁, V ₂, V ₃, V ₄, V ₅, V ₆corresponding vectorial axle, on horizontal plane, is 115 °, 90 °, 65 °, 40 °, 15 ° ,-10 ° (from X-axis, being rotated counterclockwise) respectively at X-axis.The ST compass of Denmark Aalborg university research thinks that the ST damage vector of frontal plane lead I, II, III, aVR, aVL, aVF is the projection that the total ST damage of face amount vector leads in cardiac electric axis at these, horizontal plane lead V ₁, V ₂, V ₃, V ₄, V ₅, V ₆sT damage vector be the vectorial projection of leading in cardiac electric axis at these of the total ST damage of horizontal plane.The present invention is combined into space cardiac electric axis system, and total ST damage vector is at the 12 ST damage vectors that being projected as in cardiac electric axis respectively lead that lead.Therefore respectively lead, there is contradiction solution in the vectorial direction vector group that mould=total damage vector respectively leads of damage when equation solution always damages vector thus, the right side, equation both sides takes advantage of the transposition of the direction vector group of respectively leading to draw the least square solution that total damage is vectorial.

Take that always to damage vectorial starting point (zero) be conical tip, total damage vector is as the high direction of circular cone, and crossing region myocardium blood volume distributes less, and central area is the joining that ST always damages vectorial extended line and heart model surface; Be the point of heart surface when always damaging vectorial angle and be less than angle value θ with respect to the vector sum of zero cardiac muscle blood volume distribute more rarely, the tangent value of θ and the vectorial size of total damage are directly proportional.

Compared with prior art, the present invention effectively changes one dimension electrocardiosignal into intuitive and reliable three-dimensional colour model; Adopt space cardiac electric axis system, more effective than the cardiac electric axis system of two dimensional surface; Not only consider 12 electrocardial vectors role separately, but consider the relation between each electrocardial vector and sum vector.

Accompanying drawing explanation

Fig. 1 is the hardware block diagram that detects electrocardiosignal;

Fig. 2 is electrocardiographic wave;

Fig. 3 is face amount and cross section cardiac electric axis system;

Fig. 4 is space cardiac electric axis system;

Fig. 5 is three-dimensional cardiac model;

Fig. 6 is myocardium blood volume distribution displaying principle;

Fig. 7 is that myocardium blood volume is distributed in the case showing on heart model.

The specific embodiment

Fig. 1 has described the hardware block diagram of ecg signal acquiring, uses ADS1298 that the electrocardiosignal of electrode collection is converted into digital signal, and digital signal is processed and transmitted back computer through FPGA, and sample rate is 500SPS.Computer is controlled the working method of ADS1298 by host computer procedure.

The connection of electrode is as follows: V1 leads at right border of sternum the 4th intercostal, and V2 leads at left border of sternum the 4th intercostal, and V3 leads at the mid point of V2 and V4 line, and V4 leads at left mid-clavicular line and the 5th intercostal place, V ₅lead and V ₆lead and V ₄lead in same level, lay respectively at left anterior axillary line and left midaxillary line.Right upper extremity is red conducting wire, and left upper extremity is yellow conducting wire, and left lower extremity is green, and right lower extremity is black.

Fig. 2 has described the electrocardiogram of standard, and after electrocardiosignal reads, in a time window, (tentative 10s) carries out pretreatment to it.The average voltage of each 10 points before and after the magnitude of voltage of each point of sampling is deducted, be that class high-pass filtering is processed, filter out the situation that T ripple potential value in some electrocardiogram is likely greater than R ripple potential value, processing the peak value position of signal is later exactly R wave crest point (as shown in Figure 2).Determine after R wave crest point, get the potential value of its front 80ms and the potential value of rear 108ms is used for respectively characterizing reference potential value V ₀and the potential value V of ST section ₁, the side-play amount V of ST section _sT=V ₁-V ₀; Article 12, the ST field offset value of leading thus method is obtained successively.

Fig. 3 has described face amount cardiac electric axis system and horizontal plane cardiac electric axis system, and the X-axis in figure is the intersection of face amount and horizontal plane, towards the right side of human body.V leads ₁, V ₂, V ₃, V ₄, V ₅, V ₆corresponding vectorial axle all on horizontal plane, is-115 ° ,-90 ° ,-65 ° ,-40 ° ,-15 °, 10 ° (from X-axis, being rotated counterclockwise) respectively at X-axis; Vectorial axle corresponding to the I, II, III, aVR, aVL, aVF of leading, on face amount, is 0 ° ,-60 ° ,-120 °, 150 °, 30 °, 90 ° (from X-axis, being rotated counterclockwise) respectively at X-axis.

In these two-dimentional cardiac electric axis systems, the ST of frontal plane lead I, II, III, aVR, aVL, aVF damage vector is the vectorial projection of leading in cardiac electric axis at these of the total ST damage of face amount, the cross section V that leads ₁, V ₂, V ₃, V ₄, V ₅, V ₆sT damage vector be the vectorial projection of leading in cardiac electric axis at these of the total ST damage of horizontal plane.

Fig. 4 has described space cardiac electric axis system, and this system combines the two-dimentional cardiac electric axis of face amount and horizontal plane.In these three systems, exist 12 cardiac electric axis Correspondence lead V respectively ₁, V ₂, V ₃, V ₄, V ₅, V ₆, I, II, III, aVR, aVL, aVF.Each ST field offset value of leading has represented respectively the mould of vector in corresponding cardiac electric axis.

The ST damage vector of 12 lead is that the projection that vector leads in cardiac electric axis at these is always damaged in space.Measure after the ST field offset value of 12 lead, and the direction of known every the cardiac electric axis of leading, by Converse solved matrix equation group, just can solve total ST damage vector.The cardiac electric axis direction vector that 12 lead is corresponding and the ST field offset value of respectively leading are as follows:

if vector is always damaged in space $\left\{\begin{array}{c}X\\ Y\\ Z\end{array}\right\},$ From projection equation:

$\left[\begin{array}{ccc}{x}_1& y_1& z_1\\ x_2& y_2& z_2\\ x_3& y_3& z_3\\ x_4& y_4& z_4\\ x_5& y_5& z_5\\ x_6& y_6& z_6\\ x_7& y_7& z_7\\ x_8& y_8& z_8\\ x_9& y_9& z_9\\ x_{10}& y_{10}& z_{10}\\ x_{11}& y_{11}& z_{11}\\ x_{12}& y_{12}& z_{12}\end{array}\right]\left\{\begin{array}{c}X\\ Y\\ Z\end{array}\right\}\left[\begin{array}{c}{U}_{V1}\\ U_{V2}\\ U_{V3}\\ U_{V4}\\ U_{V5}\\ U_{V6}\\ U_I\\ U_{\mathrm{II}}\\ U_{\mathrm{III}}\\ U_{\mathrm{aVR}}\\ U_{\mathrm{aVL}}\\ U_{\mathrm{aVF}}\end{array}\right]$

Equation solution thus $\left\{\begin{array}{c}X\\ Y\\ Z\end{array}\right\}$ Will cause contradiction solution, equal sign both sides premultiplication:

$\left[\begin{array}{cccccccccccc}{x}_1& x_2& x_3& x_4& x_5& x_6& x_7& x_8& x_9& x_{10}& x_{11}& x_{12}\\ y_1& y_2& y_3& y_4& y_5& y_6& y_7& y_8& y_9& y_{10}& y_{11}& y_{12}\\ z_1& z_2& z_3& z_4& z_5& z_6& z_7& z_8& z_9& z_{10}& z_{11}& z_{12}\end{array}\right]$

Obtain the least square solution of this inconsistent equation group, use total damage vector between least square solution clearancen.

From Fig. 3 and Fig. 4,

Fig. 5 has described heart threedimensional model, by the Surface disintegration of this model, is a plurality of small trianglees, preserves the RGB encoded radio of each vertex of a triangle coordinate and Fill Color.The triangle number that model surface decomposes is more, expression cardiac muscle blood volume distribution situation that more can be accurate and visual, but also can cause calculating slowly, therefore triangle number is decided to be to 6000.

Fig. 6 has described the determination methods that myocardium blood volume distributes, and the myocardium blood volume rare center that distributes is positioned at the joining that ST always damages vectorial extended line and heart surface.

On heart surface, each point always damages between vector and has an angle with respect to the formed vector sum ST of zero, and when angle is less than θ, the Fill Color that this point is sitting in position changes purple (in Fig. 6, violet region dots) into.Wherein the tangent value of θ and ST always damage vectorial size and are directly proportional.

Fig. 7 has described the demonstration case that myocardium blood volume distributes, the full region of blood volume shown in red (Fig. 7 cardiac surface red area is represented by Lycoperdon polymorphum Vitt); If from heart model initial point, the vector sum ST forming separately to a model surface Atria summit always damages vectorial angle and is all less than decision content θ, myocardium blood volume is herein comparatively rare, change the rgb value of this triangle Fill Color: the average that the corresponding vector sum in summit is always damaged vectorial angulation is less, color more deeply more purple (Fig. 7 cardiac surface violet region is represented by black).

Claims (4)

1. a myocardium blood volume distribution three-dimensional colour coding display packing, is characterized in that: comprise the obtaining of electrocardiosignal, the calculating of ST field offset amount, the determining of the contrary projection of electrocardial vector, electrocardial vector center, myocardium blood volume distribution is definite, the realization of blood volume distribution coloud coding;

From human body, measure twelve-lead electrocardiogram: be respectively chest lead V ₁, V ₂, V ₃, V ₄, V ₅, V ₆and limb lead I, II, III, aVR, aVL, aVF, within the time period of setting, the signal respectively leading to be processed, in signal, peak is R wave crest point, it is reference voltage V that R wave crest is put the magnitude of voltage of 80ms forward ₀, it is ST segment value V that R wave crest is put the magnitude of voltage of 108ms backward ₁, the side-play amount V of ST section _sT=V ₁-V ₀; The V respectively leading _sTvalue is the mould of the damage vector of Correspondence lead in cardiac electric axis system, and the damage of respectively leading vector is the projection of total damage vector in the corresponding cardiac electric axis of respectively leading;

Cardiac electric axis system is put in three-dimensional system of coordinate XYZ, XZ plane represents human body cross section, XY plane represents human body face amount, parallel with cephalocaudal axis and with the perpendicular tangent plane of sagittal plane and cross section, Z axis be oriented human body the place ahead to, X-axis is on human body face amount and the cross section intersection of human body, and Y-axis, on face amount, is oriented; Vectorial axle corresponding to the I, II, III, aVR, aVL, aVF of leading, on face amount, is 0 ° ,-60 ° ,-120 °, 150 °, 30 ° ,-90 ° (from X-axis, being rotated counterclockwise) with X-axis respectively; V leads ₁, V ₂, V ₃, V ₄, V ₅, V ₆corresponding vectorial axle, on horizontal plane, is respectively-115 ° ,-90 ° ,-65 ° ,-40 ° ,-15 °, 10 ° (from X-axis, being rotated counterclockwise) with X-axis;

Heart model Surface disintegration is a plurality of small trianglees, preserves the RGB encoded radio of each vertex of a triangle information and Fill Color; Always damage vectorial starting point as summit, always damage vectorial direction as high direction, make circular cone and heart model and intersect, crossing regional myocardial blood volume distributes rare, and other region blood volumes fill.

2. according to a kind of myocardium blood volume distribution three-dimensional colour coding display packing shown in claim 1, it is characterized in that the direction vector group that the vectorial mould of damage=total damage vector respectively leads of respectively leading, when equation solution always damages vector thus, have contradiction solution, the right side, equation both sides takes advantage of the transposition of the direction vector group of respectively leading to draw the least square solution that total damage is vectorial.

3. according to a kind of myocardium blood volume distribution three-dimensional colour coding display packing shown in claim 1, the size and the vectorial size of total damage that it is characterized in that myocardium blood volume shortcoming region are directly proportional, take that always to damage vectorial starting point (zero) be conical tip, total damage vector is as the high direction of circular cone, and in crossing region, blood volume is comparatively rare; When to be heart surface somewhere always damage vectorial angle and be less than angle value θ with respect to the vector sum of zero, blood volume is comparatively rare, and the tangent value of θ and the vectorial size of total damage are directly proportional.

4. according to a kind of myocardium blood volume distribution three-dimensional colour coding display packing shown in claim 1, it is characterized in that the full region of blood volume shows red, the region of blood volume rareness is partially purple, total damage vectorial place direction and heart surface intersect, heart surface somewhere is less apart from the value of this intersection point, the more inclined to one side purple of Fill Color herein, thus characterize the difference that zones of different blood volume distributes.

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