CN103356207A - Medical test equipment and method based on grating shearing imaging - Google Patents

Abstract

The invention provides medical test equipment and a method based on grating shearing imaging. The system comprises a light source device for generating a one-dimensional multislit X-ray light source, a beam splitting grating for splitting an X-ray beam in a one-dimensional periodic beam array, a sample stage for bearing a human body site to be tested, an analysis grating for generating different light intensity backgrounds to enhance or inhibit a refraction signal or a scattered signal of the human body site, and a detector for detecting changes in the light intensity backgrounds and space positions, and acquiring projected images of the human body site under the different light intensity backgrounds, wherein the sample stage is arranged between the beam splitting grating and the analysis grating and is close to the beam splitting grating, or the sample stage is arranged between a light source grating and the beam splitting grating and is close to the beam splitting grating. The equipment is simple in structure and simple and quick in imaging, and can meet application requirements of medical testing and the like.

Description

Medical Equipment and method based on the grating shearing imaging

Technical field

The present invention relates to technical field of imaging, particularly relate to a kind of Medical Equipment based on the grating shearing imaging and method.

Background technology

The roentgen has found X ray in 1895, and wins first Nobel Prize in physics on the 10th in December in 1901.The X-ray photographs of wide-spread roentgen madam's hands has disclosed X ray and has had powerful penetration power, shows that the X ray direct imaging just can see the internal structure of human body.This based on material to the image-forming mechanism of X ray absorption difference last century the fifties be widely used in the human medical imaging, and in last century the eighties begin for the human body three-dimensional imaging.Although this imaging technique based on the X ray mechanism of absorption when observing heavy element formation article, can obtain the sufficiently high image of contrast (being contrast), when observing light element formation article, the image that only can obtain to blur.Its main cause is that the contained electron number of light element atom is few, and it is not little that light element consists of the article density contrast, and mobility scale is between 1%-5%, and a little less than not only X ray being absorbed, and it is little that X ray is absorbed difference, can not form sufficiently high contrast.Thereby based on the image-forming mechanism of traditional attenuation by absorption when checking skeleton, can obtain the sufficiently high image of contrast, yet when checking the tumor that is consisted of by light element, can not obtain the sufficiently high image of contrast.

X-ray phase contrast imaging research starts from the nineties in last century, and more than two decades has been arranged up till now.X-ray phase contrast imaging is aspect detection light element constitute, and it is much higher that its detectivity absorbs imaging than X ray, has vast potential for future development aspect medical imaging.Four kinds of X-ray phase contrast imaging methods have been developed, basically reach common understanding in this research field at present, the grating shearing formation method that utilizes grating to extract the human body phase information has the probability of practical application most, its maximum advantage be can with the combination of conventional X ray light source.In X ray grating shearing imaging research, research worker has also been found the scattering image-forming mechanism, it is to be formed by the multiple refraction of a lot of molecules in the human body to X ray, and this image-forming mechanism is relatively more responsive to the structures such as micropore, microvesicle, microgranule, crystallite and powder in the human body.

Utilizing at present raster scanning extraction phase information and scattered information is the main flow that develops in the world, yet the method for raster scanning does not meet the simple and rapid requirement of medical imaging.

Summary of the invention

Provide hereinafter about brief overview of the present invention, in order to basic comprehension about some aspect of the present invention is provided.Should be appreciated that this general introduction is not about exhaustive general introduction of the present invention.It is not that intention is determined key of the present invention or pith, neither be intended to limit scope of the present invention.Its purpose only is that the form of simplifying provides some concept, with this as the in greater detail preorder of discussing after a while.

The invention provides a kind of Medical Equipment based on the grating shearing imaging and method, to realize easy fast imaging, satisfy the application demand of the aspects such as medical science detection.

On the one hand, the invention provides a kind of Medical Equipment based on the grating shearing imaging, comprising:

Light supply apparatus stitches the X ray light source for generation of one dimension more, and every seam light source all produces the X ray light beam of illumination beam splitter grating;

Beam-splitting optical grating, being used for the beam splitting of described X ray light beam is the One Dimension Periodic beam array;

Sample stage is used for carrying human body to be measured;

Analyze grating, for generation of different light intensity backgrounds, refraction signal or the scattered signal of enhancer or inhibitor human body;

Detector is used for surveying the variation of light intensity background and locus, gathers the projection image of described human body under the different light intensity background;

Described sample stage is arranged at beam-splitting optical grating and analyzes between the grating and the setting of next-door neighbour's beam-splitting optical grating, or described sample stage is arranged between light source grating and the beam-splitting optical grating, and the setting of next-door neighbour's beam-splitting optical grating.

On the other hand, the present invention also provides a kind of medical detecting method based on the grating shearing imaging, comprising:

Adjust molybdenum target X ray light source, make the X ray light beam irradiates light source grating of its generation;

Adjust light source grating, make described light source grating that described molybdenum target X ray light source is divided into one dimension and stitch light source more, or described molybdenum grizzly bar target directly produces one dimension and stitches light source more;

Adjust beam-splitting optical grating, make the beam-splitting optical grating plane perpendicular to the described X ray beam center direction of propagation, and be the One Dimension Periodic beam array with the beam splitting of described X ray light beam;

Adjust and analyze grating, the One Dimension Periodic beam array that the described beam-splitting optical grating of described analysis grating alignment is produced;

Measure displacement curve: without human body to be measured the time, survey the variation of background light intensity by detector, in perpendicular to the plane of described beam center light transmition direction, move described light source grating or grizzly bar target or beam-splitting optical grating or analyze grating along the direction perpendicular to grizzly bar, adjust the shear displacemant between the one dimension beam array of analyzing grating and beam-splitting optical grating generation, detector records the displacement curve that background light intensity shear displacemant changes;

Detector gathers the projection image of human body: the shear displacemant between the one dimension beam array of analyzing the generation of grating and described beam-splitting optical grating is adjusted at the collection position that the background light intensity satisfies imaging requirements, put into human body to be measured, gather the projection image of described human body under described light intensity background by described detector.

In the technical scheme provided by the invention, Medical Equipment is simple in structure, and imaging is easy fast, can gather the projection image of human body based on the shearing image-forming principle, Real-Time Monitoring to human body can be realized based on projection image, the application demand of the aspects such as medical science detection can be satisfied.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art, obviously, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

A kind of optional structural representation based on the Medical Equipment of grating shearing imaging that Fig. 1 (a), Fig. 1 (b) are respectively that the embodiment of the invention provides; Wherein, Fig. 1 (a) is the structural representation of sample stage behind beam-splitting optical grating, and Fig. 1 (b) is the structural representation of sample stage before beam-splitting optical grating;

Fig. 2 is that inventor's body region is to the sketch map of X ray beam absorption attenuation, wherein I ₀Be incident intensity, I is output intensity;

Fig. 3 is inventor's body region produces refraction action to the X ray light beam sketch map;

Fig. 4 is inventor's body region produces scattering process to the X ray light beam sketch map;

Fig. 5 is that light intensity is analyzed the one dimension beam array (striped filling) of the relative beam-splitting optical grating generation of grating (four black) along the displacement curve of X-axis shear displacemant variation; Among the figure (from left to right) analyze that shear displacemant is separately fixed at details in a play not acted out on stage, but told through dialogues position, left half bright field position, bright field position, right half bright field position, details in a play not acted out on stage, but told through dialogues position between grating (four black) and the beam-splitting optical grating one dimension beam array (striped filling).

The specific embodiment

For the purpose, technical scheme and the advantage that make the embodiment of the invention clearer, below in conjunction with the accompanying drawing in the embodiment of the invention, technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.The element of describing in an accompanying drawing of the present invention or a kind of embodiment and feature can combine with element and the feature shown in one or more other accompanying drawing or the embodiment.Should be noted that for purpose clearly, omitted expression and the description of parts that have nothing to do with the present invention, known to persons of ordinary skill in the art and processing in accompanying drawing and the explanation.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not paying the every other embodiment that obtains under the creative work prerequisite.

A kind of optional structural representation based on the Medical Equipment of grating shearing imaging that Fig. 1 (a), Fig. 1 (b) are respectively that the embodiment of the invention provides; Wherein, Fig. 1 (a) is the structural representation of sample stage behind beam-splitting optical grating, and Fig. 1 (b) is the structural representation of sample stage before beam-splitting optical grating.As shown in the figure, the grating shearing imaging system that provides of the embodiment of the invention comprises: light supply apparatus, beam-splitting optical grating 3, sample stage 4, analyze grating 5 and detector 6.

Light supply apparatus stitches the X ray light source for generation of one dimension more, and every seam light source all produces the X ray light beam of illumination beam splitter grating.Optionally, described light supply apparatus comprises light source 1(such as molybdenum target X ray light source) and light source grating 2, or described light supply apparatus is the molybdenum grizzly bar target with light source grating complementary structure; Described light source grating is used for that described molybdenum target light source is divided into one dimension and stitches light source more, or described molybdenum grizzly bar target directly produces one dimension and stitches light source more.

For satisfying the detection demand of the human bodies such as mammary gland or tumor, above-mentioned light source is the aligning X ray light beam of the characteristic spectrum of 27-29keV for generation of the X ray energy, and is preferred, is the X ray light beam of the characteristic spectrum of 28keV for generation of the X ray energy.

Light source grating 2, beam-splitting optical grating 3, sample stage 4, analysis grating 5 and detector 6 set gradually along the direction of described X ray beam propagation, in this programme, sample stage 4 is arranged at beam-splitting optical grating 3 and analyzes between the grating 5 and 3 settings of next-door neighbour's beam-splitting optical grating, or sample stage 4 is arranged between light source grating 2 and the beam-splitting optical grating 3 and next-door neighbour's beam-splitting optical grating 3 arranges.

Light source grating 2 is used for that described molybdenum target X ray light source is divided into one dimension and stitches light source more, or molybdenum grizzly bar target directly produces one dimension and stitches light source more.

It is the One Dimension Periodic beam array that beam-splitting optical grating 3 is used for the beam splitting of described X ray light beam.

Sample stage 4 is used for carrying human body to be measured.Human body to be measured can include but not limited to mammary gland or tumor.

Analyze grating 5 for generation of different light intensity backgrounds, refraction signal or the scattered signal of enhancer or inhibitor human body.

Detector is used for surveying the variation of light intensity background and locus, gathers the projection image of described human body under the different light intensity background.

Above-mentioned Medical Equipment based on the grating shearing imaging is simple in structure, imaging is easy fast, based on the projection image that shears image-forming principle and can gather human body, can realize Real-Time Monitoring to human body based on projection image, can satisfy the application demand of the aspects such as medical science detection.

This scheme is convenient to see the internal structure such as human bodies such as mammary gland or tumors, can better satisfy the application demand of the medical imagings such as human body.Optionally, aim at the X ray light beam in order to form, light source can comprise luminescence component and two collimators that are used for the light that luminescence component sends is carried out filtration treatment.For example, if the light beam that luminescence component sends is collimated light beam, the light after then filtering by two large collimators of the grade that sets gradually along the light transmition direction is described aligning X ray light beam.Again for example, when if the light beam that luminescence component sends is fan-beam, light after filtering by the first collimator placed successively along the fan light beam direction of propagation and the second collimator, be described aligning X ray light beam, wherein the light hole of the second collimator is how much enlarging projections of the light hole of first collimator.

Light source grating, beam-splitting optical grating and analysis grating are the critical components that extracts human body refraction angle and angle of scattering information, and be optional, is absorption grating in light source grating, beam-splitting optical grating and the analysis grating.The thickness of absorption grating can require design according to actual extinction degree.A kind of optional embodiment for example, when light source grating, described beam-splitting optical grating or described analysis grating were absorption grating, its grizzly bar thickness was for making at least through light intensity attenuation to 10% of incident intensity required thickness.Absorption grating can adopt such as light absorbents such as gold or other heavy metals and make, to improve its photo absorption performance.Optionally, light source grating and analysis grating are absorption grating, and only beam-splitting optical grating is phase grating, and the grizzly bar thickness of phase grating can make the phase shift that obtains π or pi/2 through light beam, and phase grating can adopt silicon or other light element materials to make.In order to improve the angle detectivity of detector, as for the angle detectivity that makes detector reaches the microradian magnitude, described beam-splitting optical grating and the distance of analyzing between the grating are 0.1～5 meter.The pin-hole imaging relation between the many seams of one dimension on the many seams of one dimension on light source grating or the molybdenum grizzly bar target and the analysis grating, pin hole is any seam on the beam-splitting optical grating, cycle on light source grating or the molybdenum grizzly bar target determines that by the pin-hole image of analyzing grating the cycle of described light source grating or molybdenum grizzly bar target equals the cycle of described analysis grating pin-hole image; The bar of described analysis grating is wide and seam is wide equates; The grizzly bar of described light source grating be wider than or equal to stitch wide, or the grizzly bar of described molybdenum grizzly bar target wide be less than or equal to the seam wide.The cycle of described analysis grating equals described light source center light to 1/2nd of how much enlarging projections in described beam-splitting optical grating cycle or how much enlarging projections.The cycle of described beam-splitting optical grating is 1～100 micron.Optionally, described light source grating is pressed close to described light source and is placed.Optionally, described detector is pressed close to described analysis grating placement, and described detector comprises one dimensional linear array or the two-dimensional array that a plurality of probe units consist of.

The following describes the formation method flow process of the grating shearing imaging system that the embodiment of the invention provides.Medical detecting method based on the grating shearing imaging comprises:

Step 21: adjust molybdenum target X ray light source, make the X ray light beam irradiates light source grating of its generation.

Step 22: adjust light source grating, make described light source grating that described molybdenum target X ray light source is divided into one dimension and stitch light source more, or described molybdenum grizzly bar target directly produces one dimension and stitches light source more;

Step 23: adjust beam-splitting optical grating, make the beam-splitting optical grating plane perpendicular to described X ray beam center light transmition direction, and be the One Dimension Periodic beam array with the beam splitting of described X ray light beam.

Step 24: adjust and analyze grating, the One Dimension Periodic beam array that the described beam-splitting optical grating of described analysis grating alignment is produced.

Step 25: measure displacement curve: without human body to be measured the time, survey the variation of background light intensity by detector, in perpendicular to the plane of beam center light transmition direction, move described light source grating or grizzly bar target or beam-splitting optical grating or analyze grating along the direction perpendicular to grizzly bar, adjust the shear displacemant between the one dimension beam array of analyzing grating and beam-splitting optical grating generation, detector records the displacement curve that background light intensity shear displacemant changes.

Step 26: detector gathers the projection image of human body: the shear displacemant between the one dimension beam array of analyzing the generation of grating and described beam-splitting optical grating is adjusted at the collection position that the background light intensity satisfies imaging requirements, put into human body to be measured, gather the projection image of described human body under described light intensity background by described detector.

Above-mentioned medical detecting method based on the grating shearing imaging only need be taken a width of cloth picture, just can realize the two-dimentional sxemiquantitative imaging of human body to be measured; Only need to take the different picture of three width of cloth light intensity backgrounds, just can realize the two-dimensional quantitative imaging of human body to be measured; Compare with the method that prevails at present both at home and abroad, not only density resolution is high, and Density inhomogeneity resolution is high, and method is easy, and the width of cloth number of required shooting picture is few, and the required radiation dose of human part is low, can the Quick Acquisition image, satisfy the application demand of the aspects such as medical science detection.The sxemiquantitative imaging only need be taken a width of cloth picture, quantitative imaging only need be taken the different picture of three width of cloth light intensity backgrounds, therefore, the medical detecting method based on the grating shearing imaging that the present invention proposes is for the phase contrast dynamic imaging in future, the parallel fast imaging of multiple image-forming mechanism lay the foundation.

Further, described shearing formation method also can comprise step 27: also comprise after detector gathers described projection image: extract described human body sxemiquantitative to be measured or the step of quantitative description information from the described projection image that gathers.

For example, the grating shearing formation method also can comprise minute sxemiquantitative formation method and/or quantitative imaging method.In the sxemiquantitative formation method that the present invention proposes, take a width of cloth projection image, just can obtain the image that attenuation by absorption or refraction angle or angle of scattering variance or delustring decay obviously is correlated with; In the quantitative imaging method, take at the most three width of cloth images, just can therefrom extract attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of human body.

For the ease of carrying out sxemiquantitative imaging and/or quantitative imaging, sxemiquantitative and/or the quantitative description information extracted in the described projection image according to the displacement curve of match in the described step 27 comprise:

Step (hf1): set up the grating shearing imaging equation: with the displacement curve that the cosine function curve fitting records, set up thing function mathematical model, according to the convolution algorithm of thing function and match displacement curve, set up the grating shearing imaging equation.

Step (hf2): the mathematic(al) representation of trying to achieve the projection image of detector collection: the mathematic(al) representation of trying to achieve respectively described light field image, dark field image and half light field image according to described grating shearing imaging equation.

Step (hf3): respectively the mathematic(al) representation of described light field image, dark field image and half light field image is out of shape, tries to achieve the semi-quantitative expressed formula of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human body; Perhaps, step (hf4): according to the quantitative relationship between the mathematic(al) representation of described light field image, dark field image and half light field image, obtain the quantitative expression of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human body.

In the embodiment of the invention, X ray beam center light transmition direction is the Z direction, in the plane of vertical X ray beam center light transmition direction, is directions X perpendicular to the direction of grating grizzly bar, and the direction that is parallel to the grating grizzly bar is Y-direction.

In the technique scheme, the light intensity background of described acquired projections picture can be: bright field background, details in a play not acted out on stage, but told through dialogues background and/or half bright field background; Described half bright field background can be: left half bright field background and/or right half bright field background; Described acquired projections looks like can be: half light field image that described human part is taken under described half bright field background at the dark field image of taking under the described details in a play not acted out on stage, but told through dialogues background, described human part at the light field image of taking under the described bright field background, described human part; Described half light field image comprises: right half light field image and/or left half light field image.

Described acquired projections looks like to be detector and directly gathers, and therefrom can extract sxemiquantitative or quantitative projection image, and dynamic imaging or the fast quantification that can be used for detected article detect in real time.

For example, the grating shearing formation method also can comprise minute sxemiquantitative formation method and/or quantitative imaging method.In the sxemiquantitative formation method that the present invention proposes, gather a width of cloth projection image, just can obtain or with attenuation by absorption with the refraction angle or with the angle of scattering variance or with the obvious relevant sxemiquantitative image of delustring decay; In the quantitative imaging method, gather at the most three width of cloth images, just can therefrom extract the attenuation by absorption picture, refraction angle picture, angle of scattering variance picture of human part or delustring decay and the quantitative image such as look like.

In the step (hf1), the process of setting up the grating shearing imaging equation is:

The first step, the impulse response function that is described as the picture system performance is obtained in the filter action of the one dimension beam array that the described beam-splitting optical grating of the described analysis grating pair of mathematical description produces; Second step is set up human part to the mathematical model of X ray effect, writes out the mathematical expression of thing function; In the 3rd step, the convolution of calculating thing function and impulse response function is set up the grating shearing imaging equation.

The first step: the filter action of the one dimension beam array that the described beam-splitting optical grating of the described analysis grating pair of mathematical description produces.Because the one dimension beam array that beam-splitting optical grating produces and analysis grating all are the One Dimension Periodic functions, has the identical cycle, the shear displacemant of the one dimension beam array that the relative beam-splitting optical grating of analysis grating produces can be adjusted dependency between the two, is computing cross-correlation so analyze the filter action of the one dimension beam array of grating pair beam-splitting optical grating generation at mathematics.

Such as Fig. 1, each grating grizzly bar is parallel with Y, when along directions X mobile light source grating or grizzly bar target or beam-splitting optical grating or analysis grating, will cause the one dimension beam array that beam-splitting optical grating produces and analyze between the grating shear displacemant occurs, each pixel of detector (or being called probe unit) can measure background light intensity shear displacemant and the displacement curve that changes, because the displacement curve that each pixel records is identical, satisfy translation invariance at imaging surface, so displacement curve is exactly the impulse response function of imaging system.Fig. 5 is the one dimension beam array that produces of beam-splitting optical grating and analyzes between the grating displacement curve when carrying out shear displacemant along X-direction; Because the similar cosine curve of displacement curve shape, in order to utilize the symmetric property of cosine curve, simplify the mathematical expression that extracts refraction and scattered information, so with cosine curve match displacement curve S (θ _g), its expression formula is:

$S\left({\mathrm{\θ}}_g\right)\≈\stackrel{\‾}{S}[1+V_0\cos \left(\frac{2\mathrm{\πD}}{p}{\mathrm{\θ}}_g\right)],---\left(1\right)$

Wherein For the one dimension beam array of analyzing the relative beam-splitting optical grating generation of grating is analyzed grating relatively at the angle of shear displacement of directions X, x _gFor the one dimension beam array of analyzing the relative beam-splitting optical grating generation of grating is analyzed grating relatively at the shear displacemant of X-direction, D is the distance on direction of beam propagation between beam-splitting optical grating and the analysis grating, and p also is the cycle of displacement curve for analyzing the cycle of grating,

Displacement curve meansigma methods for without human part the time, S _MaxAnd S _MinBe respectively maximum and the minima of displacement curve,

The visibility of displacement curve for without human part the time.The corresponding bright field of a point on the displacement curve among Fig. 5, the corresponding details in a play not acted out on stage, but told through dialogues of d point, corresponding left half bright field of b point, corresponding right half bright field of c point.Bright field represents the one dimension beam array of beam-splitting optical grating generation almost all by analyzing grating; Details in a play not acted out on stage, but told through dialogues represent one dimension beam array that beam-splitting optical grating produces almost complete analyzed grating stop; Left half bright field represents in the one dimension beam array, and the analyzed grating of each microbeam right half part stops, and left-half is by analyzing grating; Right half bright field represents in the one dimension beam array of beam-splitting optical grating generation, and the analyzed grating of each microbeam left-half stops that right half part is by analyzing grating, referring to Fig. 5.

Second step: set up thing function mathematical model.Before setting up thing function mathematical model, first to a bit defining in the human part.In two-dimensional imaging, a bit (x, y) is not a two-dimensional geometry point on the object plane of human part place, but the thing cell area Δ x Δ y centered by (x, y), the size of Δ x and Δ y is determined by dimension of light source and detector resolution.

Human part produces absorption, refraction and three kinds of effects of scattering to incident X-rays.Absorbing (comprising inelastic scattering) is an X ray energy is converted into heat energy in human part dissipation process, as shown in Figure 2, has described human part to incident X-rays attenuation by absorption action diagram picture.

According to Fig. 2, a bit (x, y) can be expressed as the absorption by this light in the human part:

The following formula left side represents incident beam, and irradiating light beam is expressed on the right, wherein

Expression beam angle vector,

$M(x,y)=\underset{-\∞}{\overset{\∞}{\∫}}\mathrm{\μ}(x,y,z)\mathrm{dz},---\left(3\right)$

Wherein μ (x, y, z) is the linear absorption coefficient of human part.(2) physical significance of formula is, absorbs to cause the light intensity decay, but does not change radiation direction.(2) formula can also be expressed as weight expression:

Refraction is the process of a preservation of energy, as shown in Figure 3, has described the image of human part to the incident X-rays refraction action.According to Fig. 3, a bit (x, y) can be expressed as the refraction by this light in the human part:

The following formula left side represents incident beam, and irradiating light beam is expressed on the right, wherein

Expression beam angle vector,

Be the refraction angle vector, its mathematical expression is:

$\stackrel{\→}{\mathrm{\θ}}(x,y)=-\underset{-\∞}{\overset{\∞}{\∫}}\▿\mathrm{\δ}(x,y,z)\mathrm{dz}$

$=-\underset{-\∞}{\overset{\∞}{\∫}}(\frac{\∂\mathrm{\δ}(x,y,z)}{\∂x}{\stackrel{\→}{e}}_x+\frac{\∂\mathrm{\δ}(x,y,z)}{\∂y}{\stackrel{\→}{e}}_y)\mathrm{dz},---\left(6\right)$

$={\stackrel{\→}{e}}_x{\mathrm{\θ}}_x(x,y)+{\stackrel{\→}{e}}_y{\mathrm{\θ}}_y(x,y)$

Wherein δ (x, y, z) is human part refractive index real part attenuation rate.(5) physical significance of formula is, refraction changes radiation direction, but does not change light intensity.(5) formula can also be written as weight expression:

Scattering is caused by the inner a lot of short grained multiple refractions of cell area, also is the process of a preservation of energy, as shown in Figure 4, has described the image of human part to the incident X-rays scattering process.The difference of scattering and refraction is, refraction is done as a whole research to cell area on the human part object plane, namely cell area on the human part object plane as a micro prisms, the inhomogeneous character of this cell area inside is then studied in scattering, and bubble, granule, micropore, crystallite and the impurity etc. that namely are equivalent to study micro prisms inside are inhomogeneous.Therefore, for each cell area, only have a refracted ray and a refraction angle, many scattered beams and a plurality of angle of scattering are but arranged.In other words, scattering is the process that a light beam disperses.Because human part has certain thickness, in cell area inside along direction of beam propagation, each granule distribution is at random, the refraction that former and later two granules produce is separate, the angle that the each refraction of granule makes incident ray depart from incident direction is at random, so according to central limit theorem, angle of scattering is to obey two-dimentional normal state statistical distribution centered by angle of incidence (perhaps refraction angle), can describe the scattering angular distribution scope with variance.According to Fig. 4, when a light was injected human part, because scattering causes dispersion, emergent ray was divided into two parts, scattered beam and scattered beam not, and scattered beam is still propagated along incident direction, and scattered beam departs from the incident direction propagation.Along with light is walked in human part, the continuous generation of scattering events, scattered beam constantly produces, and scattared energy strengthens gradually, and scattered beam does not slacken gradually, scattared energy does not weaken gradually, is called the delustring decay.Of particular note, every light all may run into the inner a plurality of short grained refractions of cell area, need to continue scattered beam and this scattered beam of being departed from for the first time by granule refraction generation for the first time to be considered respectively by the scattered beam that follow-up granule refraction generation further departs from, this is because scattared energy is once to depart from decision by what unirefringence produced, and repeatedly departing from that later repeatedly refraction produces only makes the scattared energy distribution larger, increase the angle of scattering variance, and work hardly to increasing or reduce scattared energy.In brief, granule unirefringence determines scattared energy and the ratio of scattared energy not, and granule repeatedly reflects decision angle of scattering variance.Therefore, Beer law is equally followed in the decay of delustring attenuation and absorption.If the incident ray energy is 1, scattered beam does not continue to propagate along incident direction, its entrained energy, i.e. and delustring decays to exp (Γ (x, y)), and the scattered beam energy is 1-exp (Γ (x, y)).Under the condition of scattering center symmetry, human part a bit (x, y) can be expressed as the scattering by this light:

The following formula left side represents incident beam, and irradiating light beam is expressed on the right, wherein

Expression beam angle vector.(8) formula can also be written as weight expression:

In first on (8) formula or (9) formula the right

$\mathrm{\Γ}(x,y)=\underset{-\∞}{\overset{\∞}{\∫}}\mathrm{\γ}(x,y,z)\mathrm{dz},---\left(10\right)$

Wherein γ (x, y, z) is the linear extinction coefficient of human part, σ in second ²(x, y) is the angle of scattering variance that (x, y) some place human part integral thickness produces.Because the angle of scattering variances sigma of human part integral thickness ²(x, y) is that a series of thickness are Δ z on the light transmition path _iThe scattering angular variance Δ σ of thin slice ²(x, y, z) sum, so the angle of scattering variance of human part integral thickness can be expressed as:

${\mathrm{\σ}}^2(x,y)=\underset{\mathrm{\Δ}{z}_i\→0}{\lim }\underset{i}{\mathrm{\Σ}}\mathrm{\Δ}{\mathrm{\σ}}^2(x,y,z)$

$=\underset{\mathrm{\Δ}{z}_i\→0}{\lim }\underset{i}{\mathrm{\Σ}}\mathrm{\ω}(x,y,z)\mathrm{\Δ}{z}_i=\underset{-\∞}{\overset{+\∞}{\∫}}\mathrm{\ω}(x,y,z)\mathrm{dz},---\left(11\right)$

Wherein ω (x, y, z) is the linear scattering coefficient.In order to set up the relation between linear scattering coefficient and the linear extinction coefficient, (11) formula and (10) formula are compared, can get:

ω (x, y, z)=ε (x, y, z) γ (x, y, z), (12) wherein ε (x, y, z) are invasin.If human part is when being made of the identical material of scattering nature, invasin ε (x, y, z) is exactly constant, and then following formula is set up:

σ(x,y)=ε·Γ(x,y)。(13)

This moment just can be from the another kind of signal of a kind of signal acquisition.In other words, if human part is when being made of the identical material of scattering nature, then two different scattered signals of geometric meaning can be summed up as a signal.

Consider above-mentioned three kinds of effects, under the condition of human part scattering center symmetry, a bit (x, y) can use the thing function to the effect by this light in the human part Express,

Its weight expression is:

According to (15) formula, the thing function that only works at directions X as can be known is:

The thing function that only works in Y-direction is:

According to (14) formula or (15) formula, the outgoing X ray has carried following four kinds of human part signals as can be known:

(1) attenuation by absorption exp (Μ (x, y)), wherein Μ (x, y) is the projection path integration of linear absorption coefficient μ (x, y, z)

(2) refraction angle $\stackrel{\→}{\mathrm{\θ}}(x,y)={\stackrel{\→}{e}}_x{\mathrm{\θ}}_x(x,y)+{\stackrel{\→}{e}}_y{\mathrm{\θ}}_y(x,y),$ Wherein

Be the unit vector of directions X,

Be the unit vector of Y-direction, θ _x(x, y) is the projection path integration of the partial derivative of human part refractive index real part attenuation rate δ (x, y, z) directions X

θ _y(x, y) is the projection path integration of the partial derivative of human part refractive index real part attenuation rate δ (x, y, z) Y-direction $-\underset{-\∞}{\overset{\∞}{\∫}}\frac{\∂\mathrm{\δ}(x,y,z)}{\∂y}\mathrm{dz};$

(3) delustring decay exp (Γ (x, y)), wherein Γ (x, y) is the projection path integration of linear extinction coefficient γ (x, y, z) $\mathrm{\Γ}(x,y)=\underset{-\∞}{\overset{\∞}{\∫}}\mathrm{\γ}(x,y,z)\mathrm{dz};$

(4) angle of scattering variances sigma ²(x, y) is the projection path integration of linear scattering coefficient:

${\mathrm{\σ}}^2(x,y)=\underset{-\∞}{\overset{+\∞}{\∫}}\mathrm{\ω}(x,y,z)\mathrm{dz},$

Pass between linear scattering coefficient and the linear extinction coefficient is:

ω(x,y,z)=ε(x,y,z)γ(x,y,z)，

Wherein ε (x, y, z) is invasin.If human part is to be made of the identical material of scattering nature, invasin ε is constant just, and then the pass between linear scattering coefficient and the linear extinction coefficient is:

ω(x,y,z)=ε·γ(x,y,z)，

Pass between delustring decay and the angle of scattering variance is:

σ ²(x,y)=ε·Γ(x,y)。

The 3rd step: set up the grating shearing imaging equation.

In the time of before human part is put into close beam-splitting optical grating or behind the back side, human part produces absorption, refraction and scattering process to the one dimension beam array that described beam-splitting optical grating produces, and the one dimension beam array that the analysis grating pair has loaded human part information carries out filtering.Because beam-splitting optical grating and acting on the imaging surface of analysis grating pair incident beam are translation invariant, during namely without human part, the displacement curve that each resolution cell records is identical, so and detector is the convolution of thing function and displacement curve in the light distribution that the analysis grating records later.The grating shearing imaging equation can be from the thing function O of X-direction effect _x(x, y, θ _g) and displacement curve S (θ _g) convolution derive and go out:

I(x,y,θ _g)=I ₀O _x(x,y,θ _g)*S(θ _g)

=I ₀exp(-Μ(x,y))·

$\left\{\exp (-\mathrm{\Γ}(x,y))\mathrm{\δ}({\mathrm{\θ}}_g-{\mathrm{\θ}}_x(x,y)\right)+[1-\exp (-\mathrm{\Γ}(x,y))]\frac{\exp [-\frac{({\mathrm{\θ}}_g-{\mathrm{\θ}}_x(x,y){)}^2}{{2\mathrm{\σ}}^2(x,y)}]}{\sqrt{2\mathrm{\π}}\mathrm{\σ}(x,y)}\},---\left(18\right)$

$*\stackrel{\‾}{S}[1+V_0\cos \left(\frac{2\mathrm{\πD}}{p}{\mathrm{\θ}}_g\right)]$

$=I_0\stackrel{\‾}{S}\exp (-M(x,y))[1+V(x,y)\cos \left(\frac{2\mathrm{\πD}}{p}({\mathrm{\θ}}_g-{\mathrm{\θ}}_x(x,y))\right)]$

Wherein, I ₀Be the incident illumination light intensity without human part time-division bundle grating, exp (Μ (x, y)) is the attenuation by absorption picture, θ _x(x, y) is refraction angle picture, wherein θ _gBe to analyze the relative beam-splitting optical grating of grating along the angle of shear displacement of X-direction, V (x, y) is called again the visibility picture of human part for putting into the visibility of displacement curve behind the human part, and its expression formula is:

$V(x,y)=V_0\·$

$\{\exp (-\mathrm{\Γ}(x,y))+\exp [-\frac{1}{2}{\left(\frac{2\mathrm{\πD}}{p}\mathrm{\σ}(x,y)\right)}^2]-\exp [-\mathrm{\Γ}(x,y)-\frac{1}{2}{\left(\frac{2\mathrm{\πD}}{p}\mathrm{\σ}(x,y)\right)}^2\left]\right\}.---\left(19\right)$

The visibility of displacement curve for without human part the time, exp (Γ (x, y)) is the delustring decay picture of human part, σ ²(x, y) is the angle of scattering variance picture of human part.

In the step (hf2), the process of described " try to achieve the mathematic(al) representation of the projection image that detector gathers: the mathematic(al) representation of trying to achieve respectively described light field image, dark field image and half light field image according to described grating shearing imaging equation " is:

If the one dimension beam array that the relatively described beam-splitting optical grating of described analysis grating produces and the shear displacemant x between the described analysis grating _gFor:

x _g=0，

The shearing angular displacement of the relatively described beam-splitting optical grating of described analysis grating then _gFor:

${\mathrm{\θ}}_g=\frac{x_g}{D}=0,$

The one dimension beam array that namely in experiment described beam-splitting optical grating is produced and the shear displacemant between the described analysis grating are fixed on the bright field position, and background is bright field, puts into the light field image I that the human part detector can collect human part _Bright(x, y), according to (18) formula, its expression formula is:

$I_{\mathrm{Bright}}(x,y)=I_0\stackrel{\‾}{S}\exp (-M(x,y))[1+V(x,y)\cos \left(\frac{2\mathrm{\πD}}{p}{\mathrm{\θ}}_x(x,y)\right);---\left(20\right)$

If the shear displacemant x of the one dimension beam array that the relatively described beam-splitting optical grating of described analysis grating produces _gFor:

$x_g=\&PlusMinus;\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2},$

The shearing angular displacement of the relatively described beam-splitting optical grating of described analysis grating then _gFor:

${\mathrm{\&theta;}}_g=\frac{x_g}{D}=\&PlusMinus;\frac{p}{2D},$

The one dimension beam array that namely in experiment beam-splitting optical grating is produced and the shear displacemant of analyzing between the grating are fixed on the details in a play not acted out on stage, but told through dialogues position, and background is details in a play not acted out on stage, but told through dialogues, puts into the human part detector and can collect dark field image I _Dark(x, y), according to (18) formula, its expression formula is:

$I_{\mathrm{Dark}}(x,y)=I_0\stackrel{\&OverBar;}{S}\exp (-M(x,y))[1-V(x,y)\cos \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_x(x,y)\right)];---\left(21\right)$

If the shear displacemant x of the one dimension beam array that the relatively described beam-splitting optical grating of described analysis grating produces _gFor:

$x_g=\frac{\mathrm{<figure-callout\; id="4"\; label="p"\; filenames="HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{4},$

The shearing angular displacement of the relatively described beam-splitting optical grating of described analysis grating then _gFor:

${\mathrm{\&theta;}}_g=\frac{x_g}{D}=\frac{p}{4D},$

The one dimension beam array and the shear displacemant between the described analysis grating that namely in experiment described beam-splitting optical grating are produced are fixed on right half bright field position, and background is right half bright field, puts into human part, the right side half light field image I that detector collects _Right(x, y), according to (18) formula, its expression formula is:

$I_{\mathrm{Right}}(x,y)=I_0\stackrel{\&OverBar;}{S}\exp (-M(x,y))[1+V(x,y)\sin \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_x(x,y)\right)];---\left(22\right)$

If the shear displacemant x of the one dimension beam array that the relatively described beam-splitting optical grating of described analysis grating produces _gFor:

$x_g=-\frac{\mathrm{<figure-callout\; id="4"\; label="p"\; filenames="HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{4},$

The shearing angular displacement of the relatively described beam-splitting optical grating of described analysis grating then _gFor:

${\mathrm{\&theta;}}_g=\frac{x_g}{D}=-\frac{p}{4D},$

The one dimension beam array and the shear displacemant between the described analysis grating that namely in experiment described beam-splitting optical grating are produced are fixed on left half bright field or second bright field position, background is left half bright field or second bright field, put into human part, a left side half light field image I that detector collects _Left(x, y), according to (18) formula, its expression formula is:

$I_{\mathrm{Left}}(x,y)=I_0\stackrel{\&OverBar;}{S}\exp (-M(x,y))[1+V(x,y)\sin \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_x(x,y)\right)].---\left(23\right)$

In the step (hf3), the process of described " respectively the mathematic(al) representation of described light field image, dark field image and half light field image is out of shape, obtains the semi-quantitative expressed formula of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human part " is:

Under the condition of ignoring human part refraction and scattering,

θ _x(x,y)≈0，V(x,y)≈V ₀，

According to (20) formula or (21) formula, the semi-quantitative expressed formula of attenuation by absorption picture is:

$\exp (-M(x,y))=\frac{I_{\mathrm{Bright}}(x,y)}{(1+V_0)I_0\stackrel{\&OverBar;}{S}},---\left(24\right)$

Or

$\exp (-M(x,y))=\frac{I_{\mathrm{Dark}}(x,y)}{I_0(1-V_0)\stackrel{\&OverBar;}{S}},---\left(25\right)$

Under the condition of ignoring human part absorption and scattering,

Μ(x,y)≈0，V(x,y)≈V ₀，

According to (22) formula or (23) formula, perpendicular to the semi-quantitative expressed formula of the refraction angle picture of human part rotating shaft be:

${\mathrm{\&theta;}}_x(x,y)=\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)\arcsin \left(\frac{I_{\mathrm{Right}}(x,y)-I_0\stackrel{\&OverBar;}{S}}{V_0{I}_0\stackrel{\&OverBar;}{S}}\right),---\left(26\right)$

Or

${\mathrm{\&theta;}}_x(x,y)=\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)\arcsin \left(\frac{I_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Left}}(x,y)}{V_0{I}_0\stackrel{\&OverBar;}{S}}\right),---\left(27\right)$

Under the condition of ignoring human part absorption and refraction,

Μ(x,y)≈0，θ _x(x,y)≈0，

According to (20) formula or (21) formula, the semi-quantitative expressed formula of described visibility picture is:

$V(x,y)=\frac{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}{I_0\stackrel{\&OverBar;}{S}},---\left(28\right)$

Or

$V(x,y)=\frac{I_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Dsrk}}(x,y)}{I_0\stackrel{\&OverBar;}{S}};---\left(29\right)$

Under the weak scattering condition,

$0\&le;\mathrm{\&sigma;}(x,y)<<\frac{p}{D}\&DoubleRightArrow;0\&le;\frac{D}{p}\mathrm{\&sigma;}(x,y)<<1,---\left(30\right)$

Have:

$\exp \left[{-\frac{1}{2}\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2\right]>>\{1-\exp [-\frac{1}{2}{\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2\left]\right\}$ $,---\left(31\right)$

$>\exp (-\mathrm{\&Gamma;}(x,y))\{1-\exp [-\frac{1}{2}{\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2\left]\right\}$

(31) formula substitution (19) formula,

$V(x,y)\&ap;V_0\exp [-\frac{1}{2}{\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2],---\left(32\right)$

(28) formula substitution (32) formula, the semi-quantitative expressed formula that gets angle of scattering variance picture is:

${\mathrm{\&sigma;}}^2(x,y)=2{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}=2{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \left(\frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}\right),---\left(33\right)$

Or (29) formula substitution (32) formula, the semi-quantitative expressed formula that gets angle of scattering variance picture is:

${\mathrm{\&sigma;}}^2(x,y)=2{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}=2{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \left(\frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Dark}}(x,y)}\right);---\left(34\right)$

At this moment, if human part is to be made of the identical material of scattering nature, then invasin ε is constant, and the semi-quantitative expressed formula of described linear delustring picture is:

$\exp (-\mathrm{\&Gamma;}(x,y))=\exp (-\frac{1}{\mathrm{\&epsiv;}}{\mathrm{\&sigma;}}^2(x,y))=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}]$ $;---\left(35\right)$

$=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \left(\frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}\right)]$

Or

$\exp =(-\mathrm{\&Gamma;}(x,y))=\exp (-\frac{1}{\mathrm{\&epsiv;}}{\mathrm{\&sigma;}}^2(x,y))=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}]$ $;---\left(36\right)$

$=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \left(\frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Dark}}(x,y)}\right)]$

Under the strong scattering condition,

$\mathrm{\&sigma;}(x,y)\&GreaterEqual;\frac{p}{D},---\left(37\right)$

Have:

$\exp [-\frac{1}{2}{\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2]\&le;\exp \left({-2\mathrm{\&pi;}}^2\right)\&ap;0,---\left(38\right)$

Have:

$\exp (-\mathrm{\&Gamma;}(x,y))>>[1-\exp (-\mathrm{\&Gamma;}(x,y))]$

$>\exp [-\frac{1}{2}{\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2][1-\exp (-\mathrm{\&Gamma;}(x,y))],---\left(39\right)$

(39) formula substitution (19) formula:

V(x,y)≈V ₀exp(-Γ(x,y))， (40)

(28) formula substitution (40) formula, the semi-quantitative expressed formula that gets delustring decay picture is:

$\exp (-\mathrm{\&Gamma;}(x,y))=\frac{V(x,y)}{V_0}=\frac{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}{V_0{I}_0\stackrel{\&OverBar;}{S}};---\left(41\right)$

Or (29) formula substitution (40) formula, the semi-quantitative expressed formula that gets delustring decay picture is:

$\exp (-\mathrm{\&Gamma;}(x,y))=\frac{V(x,y)}{V_0}=\frac{I_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Dark}}(x,y)}{V_0{I}_0\stackrel{\&OverBar;}{S}};---\left(42\right)$

At this moment, if human part is to be made of the identical material of scattering nature, then invasin ε is constant, and described angle of scattering variance picture fixed partly measured expression formula and be:

${\mathrm{\&sigma;}}^2(x,y)=\mathrm{\&epsiv;}\&CenterDot;\mathrm{\&Gamma;}(x,y)=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0}{V(x,y)}=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_{\mathrm{Bright}}(x,y)I{-}_0\stackrel{\&OverBar;}{S}}.---\left(43\right)$

Or

${\mathrm{\&sigma;}}^2(x,y)=\mathrm{\&epsiv;}\&CenterDot;\mathrm{\&Gamma;}(x,y)=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0}{V(x,y)}=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I{-}_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Dark}}(x,y)}.---\left(44\right)$

In the described step (hf4), the process approach of described " according to the quantitative relationship between the mathematic(al) representation of described light field image, dark field image and half light field image, obtaining the quantitative expression of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human part " is as follows:

According to (20) formula and (21) formula, or (22) formula and ((23) formula, the quantitative expression that gets the attenuation by absorption picture is:

$\exp (-M(x,y))=\frac{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}{{2I}_0\stackrel{\&OverBar;}{S}},---\left(45\right)$

Or

$\exp (-M(x,y))=\frac{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}{{2I}_0\stackrel{\&OverBar;}{S}};---\left(46\right)$

Described light field image, dark field image, right half light field image and left half light field image are aimed at one by one according to respective pixel, and carried out additive operation according to described formula;

According to (20) formula, (21) formula, (22) formula and (23) formula, described refraction angle can obtain from following equation group as quantitative expression:

$\left\{\begin{array}{c}{\mathrm{\&theta;}}_x(x,y)=\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)\arctan \left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}\right)\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array};---\left(47\right)\right.$

Light field image, dark field image, right half light field image and left half light field image are aimed at one by one according to respective pixel, and carried out subtraction, division and arctangent cp cp operation according to described formula;

Under the weak scattering condition, according to (20) formula, (21) formula, (22) formula, (23) formula, the quantitative expression of described angle of scattering variance picture can obtain from following equation group:

$\left\{\begin{array}{c}{\mathrm{\&sigma;}}^2(x,y)=2{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}\\ =2{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2}};---\left(48\right)\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}\right.$

At this moment, if human part is to be made of the identical material of scattering nature, then invasin ε is constant, and the quantitative expression of described delustring decay picture can obtain from following equation group:

$\left\{\begin{array}{c}\exp (-\mathrm{\&Gamma;}(x,y))=\exp (-\frac{1}{\mathrm{\&epsiv;}}{\mathrm{\&sigma;}}^2(x,y))\\ =\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA00002998091400011.png,HDA00002998091400021.png"\; state="\{\{state\}\}">p</figure-callout>}}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2}}\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}];---\left(49\right)\right.$

Light field image, dark field image, right half light field image and left half light field image are aimed at one by one according to respective pixel, and carried out addition, subtraction, division, power, evolution and logarithm operation according to described formula;

Under the strong scattering condition, according to (20) formula, (21) formula, (22) formula, (23) formula, the quantitative expression of described delustring decay picture can obtain from following equation group:

$\left\{\begin{array}{c}\exp (-\mathrm{\&Gamma;}(x,y))=\frac{V(x,y)}{V_0}\\ =\frac{1}{V_0}\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2}\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array};---\left(50\right)\right.$

At this moment, if human part is to be made of the identical material of scattering nature, then invasin ε is constant, and the quantitative expression of described angle of scattering variance picture can obtain from following equation group:

$\left\{\begin{array}{c}{\mathrm{\&sigma;}}^2(x,y)=\mathrm{\&epsiv;}\&CenterDot;\mathrm{\&Gamma;}(x,y)=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0}{V(x,y)}\\ =\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0}{\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2}+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2};---\left(51\right)\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}\right.$

Light field image, dark field image, right half light field image and left half light field image are aimed at one by one according to respective pixel, and carried out addition, subtraction, division, power, evolution and logarithm operation according to described formula.

In the various embodiments described above of the present invention, the sequence number of embodiment only is convenient to describe, and does not represent the quality of embodiment.Description to each embodiment all emphasizes particularly on different fields, and does not have the part of detailed description among certain embodiment, can be referring to the associated description of other embodiment.

In the embodiment such as apparatus and method of the present invention, obviously, after can decomposing, make up and/or decompose, each parts or each step reconfigure.These decomposition and/or reconfigure and to be considered as equivalents of the present invention.Simultaneously, in the above in the description to the specific embodiment of the invention, can in one or more other embodiment, use in identical or similar mode for the feature that a kind of embodiment is described and/or illustrated, combined with the feature in other embodiment, or the feature in alternative other embodiment.

Should emphasize that term " comprises/comprise " existence that refers to feature, key element, step or assembly when this paper uses, but not get rid of the existence of one or more further feature, key element, step or assembly or additional.

It should be noted that at last: although above the present invention and the advantage thereof of having described in detail is to be understood that and can carries out various changes, alternative and conversion in the situation that does not exceed the spirit and scope of the present invention that limited by appended claim.And scope of the present invention is not limited only to the specific embodiment of the described process of description, equipment, means, method and step.The one of ordinary skilled in the art will readily appreciate that from disclosure of the present invention, can use according to the present invention carry out with the essentially identical function of corresponding embodiment described herein or obtain result essentially identical with it, existing and want exploited process, equipment, means, method or step future.Therefore, appended claim is intended to comprise such process, equipment, means, method or step in their scope.

Claims (14)

1. the Medical Equipment based on the grating shearing imaging is characterized in that, comprising:

Light supply apparatus stitches the X ray light source for generation of one dimension more, and every seam light source all produces the X ray light beam of illumination beam splitter grating;

Beam-splitting optical grating, being used for the beam splitting of described X ray light beam is the One Dimension Periodic beam array;

Sample stage is used for carrying human body to be measured;

Analyze grating, for generation of different light intensity backgrounds, refraction signal or the scattered signal of enhancer or inhibitor human body;

Detector is used for surveying the variation of light intensity background and locus, gathers the projection image of described human body under the different light intensity background;

Described sample stage is arranged at beam-splitting optical grating and analyzes between the grating and the setting of next-door neighbour's beam-splitting optical grating, or described sample stage is arranged between light source grating and the beam-splitting optical grating, and the setting of next-door neighbour's beam-splitting optical grating.

2. grating shearing two-dimensional imaging according to claim 1 system it is characterized in that described light supply apparatus comprises molybdenum target X ray light source and light source grating, or described light supply apparatus is the molybdenum grizzly bar target with light source grating complementary structure; Described light source grating is used for that described molybdenum target light source is divided into one dimension and stitches light source more, or described molybdenum grizzly bar target directly produces one dimension and stitches light source more.

3. the Medical Equipment based on the grating shearing imaging according to claim 1 is characterized in that,

Described human body to be measured comprises: mammary gland or tumor; And/or,

Described light source is the X ray light beam of the characteristic spectrum of 27-29keV for generation of the X ray energy; And/or,

Described light source grating, described beam-splitting optical grating and described analysis grating are absorption grating or described beam-splitting optical grating is phase grating, and described light source grating and described analysis grating are absorption grating;

Described light source grating is pressed close to described light source and is placed; And/or,

The grizzly bar of described light source grating be wider than or equal to stitch wide, or the grizzly bar of described grizzly bar target wide be less than or equal to the seam wide; And/or,

The period-producer pin-hole imaging relation of the cycle of described light source grating and described analysis grating, pin hole is any seam on the beam-splitting optical grating; And/or,

Described beam-splitting optical grating and the distance of analyzing between the grating are 0.1～5 meter; And/or,

The cycle of described beam-splitting optical grating is 1～100 micron; And/or,

The grizzly bar of described beam-splitting optical grating is wide and seam is wide equates; And/or,

The cycle of described analysis grating equals described light source center light to 1/2nd of the geometric projection in described beam-splitting optical grating cycle or geometric projection; And/or,

The grizzly bar of described analysis grating is wide and seam is wide equates; And/or,

Described detector is pressed close to described analysis grating and is placed; And/or,

Described detector comprises the two-dimensional array that a plurality of probe units consist of,

Described grizzly bar target is the structure of setting that target light source and light source grating are become one.

4. the Medical Equipment based on the grating shearing imaging according to claim 2, it is characterized in that, when described light source grating, described beam-splitting optical grating or described analysis grating were absorption grating, its grizzly bar thickness was for making at least through light intensity attenuation to 10% of incident intensity required thickness; When described beam-splitting optical grating was phase grating, its grizzly bar thickness can make the phase shift that obtains π or pi/2 through light beam.

5. the medical detecting method based on the grating shearing imaging is characterized in that, comprising:

Adjust molybdenum target X ray light source, make the X ray light beam irradiates light source grating of its generation;

Adjust light source grating, make described light source grating that described molybdenum target X ray light source is divided into one dimension and stitch light source more, or described molybdenum grizzly bar target directly produces one dimension and stitches light source more;

Adjust beam-splitting optical grating, make the beam-splitting optical grating plane perpendicular to the described X ray beam center direction of propagation, and be the One Dimension Periodic beam array with the beam splitting of described X ray light beam;

Adjust and analyze grating, the One Dimension Periodic beam array that the described beam-splitting optical grating of described analysis grating alignment is produced;

Measure displacement curve: without human body to be measured the time, survey the variation of background light intensity by detector, in perpendicular to the plane of described beam center light transmition direction, move described light source grating or grizzly bar target or beam-splitting optical grating or analyze grating along the direction perpendicular to grizzly bar, adjust the shear displacemant between the one dimension beam array of analyzing grating and beam-splitting optical grating generation, detector records the displacement curve that background light intensity shear displacemant changes;

Detector gathers the projection image of human body: the shear displacemant between the one dimension beam array of analyzing the generation of grating and described beam-splitting optical grating is adjusted at the collection position that the background light intensity satisfies imaging requirements, put into human body to be measured, gather the projection image of described human body under described light intensity background by described detector.

6. the medical detecting method based on the grating shearing imaging according to claim 5 is characterized in that,

Described light intensity background comprises: bright field background, details in a play not acted out on stage, but told through dialogues background and/or half bright field background; Described half bright field background comprises right half bright field background and/or left half bright field background;

The described projection image that gathers comprises: gather described human body at the light field image under the described bright field background, at the dark field image under the described details in a play not acted out on stage, but told through dialogues background and/or half light field image under described half bright field background; Described half light field image comprises: right half light field image and/or left half light field image.

7. according to claim 5 or 6 described medical detecting methods based on the grating shearing imaging, it is characterized in that, after detector gathers described projection image, also comprise: from the described projection image that gathers, extract described human body sxemiquantitative to be measured or the step of quantitative description information.

8. the medical detecting method based on the grating shearing imaging according to claim 7 is characterized in that, extracts described human body sxemiquantitative to be measured or the step of quantitative description information from the described projection image that gathers, and comprising:

Set up the grating shearing imaging equation: with the displacement curve that the cosine function curve fitting records, set up thing function mathematical model, according to the convolution algorithm of thing function and match displacement curve, set up the grating shearing imaging equation;

Try to achieve the mathematic(al) representation of the projection image of detector collection: the mathematic(al) representation of trying to achieve respectively described light field image, dark field image and half light field image according to described grating shearing imaging equation;

Respectively the mathematic(al) representation of described light field image, dark field image and half light field image is out of shape, tries to achieve the semi-quantitative expressed formula of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human body;

Or

According to the quantitative relationship between the mathematic(al) representation of described light field image, dark field image and half light field image, obtain the quantitative expression of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human body.

9. the medical detecting method based on the grating shearing imaging according to claim 8 is characterized in that, describedly sets up the match displacement curve S (θ described in the grating shearing imaging equation step _g) Mathematical representation be:

$S\left({\mathrm{\&theta;}}_g\right)\&ap;\stackrel{\&OverBar;}{S}[1+V_0\cos \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_g\right)];$

S (θ wherein _g) light intensity surveyed for detector and without the ratio of incident intensity before the human body time-division bundle grating, D is beam-splitting optical grating and analyzes distance between the grating, p is for analyzing the cycle of grating and displacement curve, Displacement curve meansigma methods for without human body the time,

The visibility of displacement curve for without human body the time, S _MaxAnd S _MinBe respectively maximum and the minima of displacement curve, For analyzing the relative beam-splitting optical grating of grating edge perpendicular to the angle of shear displacement of the direction of grizzly bar, x _gFor analyzing one dimension beam array that the relative beam-splitting optical grating of grating produces along the shear displacemant perpendicular to the direction of grizzly bar.

10. the medical detecting method based on the grating shearing imaging according to claim 9 is characterized in that, described thing function

To the effect by this light, expression formula is to express in the human body a bit (x, y):

Or

Wherein only at the thing function of x directive effect be:

Only the thing function in the y directive effect is:

Wherein,

Expression beam angle vector,

With

Be respectively

Component along directions X and Y-direction;

In the thing function, the mathematical expression of attenuation by absorption picture is:

exp(-Μ(x,y))，

Wherein Μ (x, y) is the projection path integration of linear absorption coefficient μ (x, y, z):

$M(x,y)=\underset{-\&infin;}{\overset{\&infin;}{\&Integral;}}\mathrm{\&mu;}(x,y,z)\mathrm{dz};$

The mathematical expression of refraction angle picture is:

$\stackrel{\&RightArrow;}{\mathrm{\&theta;}}(x,y)={\stackrel{\&RightArrow;}{e}}_x{\mathrm{\&theta;}}_x(x,y)+{\stackrel{\&RightArrow;}{e}}_y{\mathrm{\&theta;}}_y(x,y),$

Wherein

Be the unit vector of directions X,

Be the unit vector of Y-direction, θ _x(x, y) be human body along the refraction angle of directions X, also be refractive index real part attenuation rate δ (x, y, z) along the projection path integration of directions X partial derivative:

${\mathrm{\&theta;}}_x(x,y)=-\underset{-\&infin;}{\overset{\&infin;}{\&Integral;}}\frac{\&PartialD;\mathrm{\&delta;}(x,y,z)}{\&PartialD;x}\mathrm{dz},$

θ _y(x, y) be human body along the refraction angle of Y-direction, also be human body refractive index real part attenuation rate δ (x, y, z) along the projection path integration of Y-direction partial derivative:

${\mathrm{\&theta;}}_y(x,y)=-\underset{-\&infin;}{\overset{\&infin;}{\&Integral;}}\frac{\&PartialD;\mathrm{\&delta;}(x,y,z)}{\&PartialD;y}\mathrm{dz};$

The mathematical expression of delustring decay picture is:

exp(-Γ(x,y))，

Wherein Γ (x, y) is the projection path integration of linear extinction coefficient γ (x, y, z):

$\mathrm{\&Gamma;}(x,y)=\underset{-\&infin;}{\overset{\&infin;}{\&Integral;}}\mathrm{\&gamma;}(x,y,z)\mathrm{dz};$

The mathematical expression of angle of scattering variance is:

σ ²(x,y)，

It is each differential thin layer dz angle of scattering variance d σ ²The projection path integration of (x, y, z):

${\mathrm{\&sigma;}}^2(x,y)=\underset{-\&infin;}{\overset{+\&infin;}{\&Integral;}}{\mathrm{d\&sigma;}}^2(x,y,z)=\underset{-\&infin;}{\overset{+\&infin;}{\&Integral;}}\mathrm{\&omega;}(x,y,z)\mathrm{dz},$

Wherein ω (x, y, z) is the linear scattering coefficient, and the pass between itself and the linear extinction coefficient is:

ω(x,y,z)=ε(x,y,z)γ(x,y,z)，

Wherein ε (x, y, z) is invasin, if human body is made of the identical material of scattering nature, ε (x, y, z) is constant, and then following formula is set up:

σ ²(x,y)=ε·Γ(x,y)。

11. the medical detecting method based on the grating shearing imaging according to claim 10 is characterized in that: described grating image equation is:

$I(x,y,{\mathrm{\&theta;}}_g)=I_0{\mathrm{\&theta;}}_{x,y}(x,y,{\mathrm{\&theta;}}_g)*S\left({\mathrm{\&theta;}}_g\right)$

$=I_0\stackrel{\&OverBar;}{S}\exp (-M(x,y))[1+V(x,y)\cos \left(\frac{2\mathrm{\&pi;D}}{p}({\mathrm{\&theta;}}_g-{\mathrm{\&theta;}}_{x,y}(x,y))\right)];$

Wherein D is the distance between beam-splitting optical grating and the analysis grating, and p is for analyzing the cycle of grating and displacement curve, I (x, y, θ _g) on the human body surveyed for detector a bit (x, y) be θ in angle of shear displacement _gThe time light intensity, I ₀For without incident intensity before the human body time-division bundle grating,

Displacement curve meansigma methods for without human body the time, S _MaxAnd S _MinBe respectively maximum and the minima of displacement curve, θ _x(x, y) be human body along the refraction angle of directions X, the visibility of V (x, y) displacement curve when human body is arranged claims again the visibility picture of human body, its expression formula is:

$V(x,y)$

$=V_0\{\exp (-\mathrm{\&Gamma;}(x,y))+\exp [-\frac{1}{2}{\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2]-\exp [-\mathrm{\&Gamma;}(x,y)-\frac{1}{2}{\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2\left]\right\},$

The visibility of displacement curve for without human body the time, exp (Γ (x, y)) is delustring decay picture, σ ²(x, y) is angle of scattering variance picture.

12. the medical detecting method based on the grating shearing imaging according to claim 11 is characterized in that, in described " trying to achieve the mathematic(al) representation of described acquired projections picture " step,

The angle of shear displacement of corresponding described bright field background

Described light field image I _BrightThe mathematic(al) representation of (x, y) is:

$I_{\mathrm{Bright}}(x,y)=I_0\stackrel{\&OverBar;}{S}\exp (-M(x.y))[1+V(x,y)\cos \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_x(x,y)\right)];$

The angle of shear displacement of corresponding described details in a play not acted out on stage, but told through dialogues background

Described dark field image I _DarkThe mathematic(al) representation of (x, y) is:

$I_{\mathrm{Dark}}(x,y)=I_0\stackrel{\&OverBar;}{S}\exp (-M(x,y))[1-V(x,y)\cos \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_x(x,y)\right)];$

The angle of shear displacement of the corresponding described right side half bright field background

The described right side half light field image I _RightThe mathematic(al) representation of (x, y) is:

$I_{\mathrm{Right}}(x,y)=I_0\stackrel{\&OverBar;}{S}\exp (-M(x,y))[1+V(x,y)\sin \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_x(x,y)\right)];$

The angle of shear displacement of a corresponding described left side half bright field background

A described left side half light field image I _LeftThe mathematic(al) representation of (x, y) is:

$I_{\mathrm{Left}}(x,y)=I_0\stackrel{\&OverBar;}{S}\exp (-M(x,y))[1-V(x,y)\sin \left(\frac{2\mathrm{\&pi;D}}{p}{\mathrm{\&theta;}}_x(x,y)\right)].$

13. the medical detecting method based on the grating shearing imaging according to claim 12, it is characterized in that, in described " respectively the mathematic(al) representation of described light field image, dark field image and half light field image being out of shape; obtain the semi-quantitative expressed formula of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human body " step

Under the condition of ignoring human body refraction and scattering,

θ _x(x,y)≈0，V(x,y)≈V ₀，

The semi-quantitative expressed formula of described attenuation by absorption picture is:

$\exp (-M(x,y))=\frac{I_{\mathrm{Bright}}(x,y)}{(1+V_0)I_0\stackrel{\&OverBar;}{S}},$ Or

$\exp (-M(x,y))=\frac{I_{\mathrm{Dark}}(x,y)}{I_0(1-V_0)\stackrel{\&OverBar;}{S}};$

Under the condition of ignoring human body absorption and scattering,

M(x，y)≈0，V(x，y)≈V ₀，

The semi-quantitative expressed formula of described refraction angle picture is:

${\mathrm{\&theta;}}_x(x,y)=\left(\frac{p}{2\mathrm{\&pi;D}}\right)\arcsin \left(\frac{I_{\mathrm{Right}}(x,y)-I_0\stackrel{\&OverBar;}{S}}{V_0{I}_0\stackrel{\&OverBar;}{S}}\right),$

Or

${\mathrm{\&theta;}}_x(x,y)=\left(\frac{p}{2\mathrm{\&pi;D}}\right)\arcsin \left(\frac{I_0\stackrel{\&OverBar;}{S}{-I}_{\mathrm{Left}}(x,y)}{V_0{I}_0\stackrel{\&OverBar;}{S}}\right);$

Under the condition of ignoring human body absorption and refraction,

M(x，y)≈0，θ _x(x，y)≈0，

The semi-quantitative expressed formula of described visibility picture is:

$V(x,y)=\frac{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}{I_0\stackrel{\&OverBar;}{S}},$ Or

$V(x,y)=\frac{I_0\stackrel{\&OverBar;}{S}{-I}_{\mathrm{Dark}}(x,y)}{I_0\stackrel{\&OverBar;}{S}};$

Under the weak scattering condition, the pass of angle of scattering variance picture and visibility picture is:

$V(x,y)=V_0\exp \left[{-\frac{1}{2}\left(\frac{2\mathrm{\&pi;D}}{p}\mathrm{\&sigma;}(x,y)\right)}^2\right],$

The semi-quantitative expressed formula that gets angle of scattering variance picture is:

${\mathrm{\&sigma;}}^2(x,y)=2{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}={\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \left(\frac{I_0{V}_0\stackrel{\&OverBar;}{S}}{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}\right),$ Or

${\mathrm{\&sigma;}}^2(x,y)=2{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}={\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Dark}}(x,y)};$

At this moment, if human body is to be made of the identical material of scattering nature, then invasin ε is constant, and the semi-quantitative expressed formula of described delustring decay picture is:

$\exp (-\mathrm{\&Gamma;}(x,y))=\exp (-\frac{1}{\mathrm{\&epsiv;}}{\mathrm{\&sigma;}}^2(x,y))=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}]$ , or

$=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \left(\frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}\right)]$

$\exp (-\mathrm{\&Gamma;}(x,y))=\exp (-\frac{1}{\mathrm{\&epsiv;}}{\mathrm{\&sigma;}}^2(x,y))=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}]$ ；

$=\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \left(\frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{{I_0\stackrel{\&OverBar;}{S}-I}_{\mathrm{Dark}}(x,y)}\right)]$

Under the strong scattering condition,, the pass of delustring decay picture and visibility picture is:

V(x，y)＝V ₀exp[-Γ(x，y)]，

The semi-quantitative expressed formula of delustring decay picture is:

$\exp (-\mathrm{\&Gamma;}(x,y))=\frac{V(x,y)}{V_0}=\frac{I_{\mathrm{Bright}}(x,y)-I_0\stackrel{\&OverBar;}{S}}{V_0{I}_0\stackrel{\&OverBar;}{S}};$ Or

$\exp (-\mathrm{\&Gamma;}(x,y))=\frac{V(x,y)}{V_0}=\frac{I_0\stackrel{\&OverBar;}{S}-I_{\mathrm{Dark}}(x,y)}{V_0{I}_0\stackrel{\&OverBar;}{S}};$

At this moment, if human body is to be made of the identical material of scattering nature, then invasin ε is constant, and described angle of scattering variance picture fixed partly measured expression formula and be:

${\mathrm{\&sigma;}}^2(x,y)=\mathrm{\&epsiv;}\&CenterDot;\mathrm{\&Gamma;}(x,y)=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0}{V(x,y)}=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{I_{\mathrm{Bright}}(x,y)I_0\stackrel{\&OverBar;}{S}},$ Or

${\mathrm{\&sigma;}}^2(x,y)=\mathrm{\&epsiv;}\&CenterDot;\mathrm{\&Gamma;}(x,y)=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0}{V(x,y)}=\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0{I}_0\stackrel{\&OverBar;}{S}}{{I_0\stackrel{\&OverBar;}{S}-I}_{\mathrm{Dark}}(x,y)}.$

14. the medical detecting method based on the grating shearing imaging according to claim 12, it is characterized in that, in described " according to the quantitative relationship between the mathematic(al) representation of described light field image, dark field image and half light field image; obtain the quantitative expression of attenuation by absorption picture, refraction angle picture, angle of scattering variance picture or the delustring decay picture of described human body " step

Quantitative expression according to described attenuation by absorption picture:

$\exp (-M(x,y))=\frac{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}{2I_0\stackrel{\&OverBar;}{S}},$ Or

$\exp (-M(x,y))=\frac{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}{2I_0\stackrel{\&OverBar;}{S}};$

The quantitative expression of described refraction angle picture can obtain from following equation group:

$\left\{\begin{array}{c}{\mathrm{\&theta;}}_y(x,y)=\left(\frac{p}{2\mathrm{\&pi;D}}\right)\arctan \left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}\right)\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}\right.;$

Under the weak scattering condition, the quantitative expression of described angle of scattering variance picture can obtain from following equation group:

$\left\{\begin{array}{c}{\mathrm{\&sigma;}}^2(x,y)=2{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{V(x,y)}\\ =2{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2}}\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}\right.;$

At this moment, if human body is to be made of the identical material of scattering nature, then invasin ε is constant, and the quantitative expression of described delustring decay picture can obtain from following equation group:

$\left\{\begin{array}{c}\exp (-\mathrm{\&Gamma;}(x,y))=\exp (-\frac{1}{\mathrm{\&epsiv;}}{\mathrm{\&sigma;}}^2(x,y))\\ =\exp [-\frac{2}{\mathrm{\&epsiv;}}{\left(\frac{p}{2\mathrm{\&pi;D}}\right)}^2\ln \frac{V_0}{\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2}}]\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}\right.;$

Under the strong scattering condition, the quantitative expression of described delustring decay picture can obtain from following equation group:

$\left\{\begin{array}{c}\exp (-\mathrm{\&Gamma;}(x,y))=\frac{V(x,y)}{V_0}\\ =\frac{1}{V_0}\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2}\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}\right.;$

At this moment, if human body is to be made of the identical material of scattering nature, then invasin ε is constant, and the quantitative expression of described angle of scattering variance picture can obtain from following equation group:

$\left\{\begin{array}{c}{\mathrm{\&sigma;}}^2(x,y)=\mathrm{\&epsiv;}\&CenterDot;\mathrm{\&Gamma;}(x,y)\\ =\mathrm{\&epsiv;}\&CenterDot;\ln \frac{V_0}{\sqrt{{\left(\frac{I_{\mathrm{Bright}}(x,y)-I_{\mathrm{Dark}}(x,y)}{I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)}\right)}^2+{\left(\frac{I_{\mathrm{Right}}(x,y)-I_{\mathrm{Left}}(x,y)}{I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)}\right)}^2}}\\ I_{\mathrm{Bright}}(x,y)+I_{\mathrm{Dark}}(x,y)=I_{\mathrm{Right}}(x,y)+I_{\mathrm{Left}}(x,y)\end{array}\right.;$

With unidirectional light field image, dark field image, right half light field image and left half light field image, aim at one by one according to respective pixel, and carry out addition, subtraction, division, power, evolution and logarithm operation according to described formula.

Images