CN205458608U - Blood capillary radiography system based on it is compound that angle is cut apart to total space modulation register for easy reference - Google Patents

Abstract

The utility model discloses a blood capillary radiography system based on it is compound that angle is cut apart to total space modulation register for easy reference, this system is including low relevant broadband light source, optical circulator, fiber coupler, reference arm, sample arm, spectrum appearance and signal processing module, wherein reference arm includes reference arm polarization controller spare, reference arm collimating lens, reference arm focusing lens and planar mirror, the sample arm includes sample arm polarization controller, sample arm collimating lens, orthogonal scanning mirror and the sample arm focus objective that shake, the spectrum appearance includes spectrum appearance collimating lens, blazed grating, fourier's lens and linear array CMOS camera, utilize the utility model discloses the compound blood capillary radiography picture of a plurality of spaces angle that obtains has the contrast and the vascular connectivity of reinforcing, the utility model discloses the horizontal modulation register for easy reference segmentation technology of the total space referred to can provide the horizontal modulation register for easy reference in the spatial frequency territory of maximize, eliminates because the lateral resolution who leads to is cut apart to the modulation register for easy reference descends.

Description

Based on the microangiography system that total space modulation spectrum segmentation angle is compound

Technical field

This utility model relates to Optical Coherence Tomography Imaging Technology (Optical Coherence Tomography, OCT) and unmarked three-dimensional optical microangiography technology on this basis (OCT Angiography, Angio-OCT), particularly relates to split angle based on total space modulation spectrum Compound microangiography method and system.

Technical background

OCT technology be progressively grow up after the nineties in last century at biomedical sector There is the novel imaging technique of one that major application is worth.By feat of marker free, Noninvasive, non- The advantages such as contact, high imaging resolution and high detection sensitivity, it attracts the most domestic It is more in depth studied by outer researcher, obtain at present extensively should in clinical medicine With.The optical heterogeneity due to biological sample that OCT technology Main Basis is detected is caused Sample back-scattering light light intensity changes, and obtains the reflectivity information of sample interior, and then reconstructs sample Fault structure image.But generally at the commitment of disease, due to normal and the biology of pathological changes Between tissue, the diversity of light scattering characteristic is less, uses that traditional structural type OCT is more difficult to be detected And distinguish, so there is many limitation in it in clinical practice.In order to obtain except biological sample More physiologic information outside product histology and morphology structure, it is the widest that functional type OCT technology has obtained exploitation General application.

Many diseases (such as disease of brain such as the fundus oculi disease such as glaucoma, age related macular degeneration, apoplexy) There is close dependency in the morbid state change with blood perfusion.If patient's blood vessel can be monitored in real time Change, and the 3-dimensional image of blood vessel is provided, early diagnosis and control to such disease have important Meaning.Angio-OCT technology is a work that can help to the diagnosis of vascular diseases with huge prospect Tool, its tissue that can preferably distinguish static state and dynamic blood flow signal, it is achieved that OCT is obtaining Take the functional expansion in terms of Ink vessel transfusing blood flow information.Compared to traditional shadowgraph technique, its advantage body Now without injecting developing agent and utilizing X-ray, and combine the feature of OCT technology noted earlier, It is capable of the imaging of the high-contrast that blood capillary three dimensional depth is differentiated.Generally, the mould of blood flow contrast The time statistical property of the means analysis light scattering signal being utilization mathematics set up by type, and uses Threshold segmentation Dynamic blood flow signal and static background tissue signal realize.Yet with dynamic and static letter There is overlap between number statistic curve, cause dynamically and stationary singnal segmentation errors, blood flow contrast is subject to To suppression.Therefore, take effective method to improve the blood flow contrast of radiography figure, contribute to becoming apparent from Ground illustrates the feature of image.

Time statistical property research based on Angio-OCT signal draws: multiple independent angiographys The contrast that averagely can improve radiography of subgraph.The method eliminating speckle with reference to some, can pass through The methods such as wavelength multiformity, angular diversity and polarization diversity obtain independent radiography subgraph.Jia Et al. propose one be similar to wavelength multifarious spectrum segmentation Angio-OCT method.The method will The full spectrum of wavelengths of OCT interference signal is divided into different sub-spectrum, every sub-spectrum can produce independence Radiography subgraph, by being compounded to form new angiogram.But relative to original full spectrum, Every sub-spectral bandwidth narrows, and causes the axial resolution of image to decline.

Summary of the invention

This utility model is for the deficiencies in the prior art, it is proposed that split angle based on total space modulation spectrum Compound microangiography system.

The microangiography system that this utility model is combined based on total space modulation spectrum segmentation angle, including Low coherence wideband light source, optical circulator, fiber coupler, reference arm, sample arm, spectrogrph and letter Number processing module；Wherein reference arm includes reference arm Polarization Control device, reference arm collimating lens, ginseng Examine arm condenser lens and plane mirror；Sample arm includes that sample arm Polarization Controller, sample arm collimate Lens, orthogonal scanning galvanometer and sample arm focusing objective len；Spectrogrph includes spectrogrph collimating lens, sudden strain of a muscle Credit grating, fourier lense and linear array CMOS camera；

Low coherence wideband light source is connected through the input of optical circulator with fiber coupler side；Light One of them output port of fine bonder opposite side is accurate with reference arm through reference arm Polarization Control device Straight lens are connected；The optical axis of reference arm condenser lens and the optical axis coincidence of reference arm collimating lens, put down Face reflecting mirror is placed at the focal plane of reference arm condenser lens；The another one of fiber coupler opposite side Output port, is connected with sample arm collimating lens through sample arm Polarization Controller；Orthogonal scanning is shaken First scanning mirror spindle central of mirror is positioned on the optical axis of sample arm collimating lens, the second scanning mirror rotating shaft Being centrally located on the optical axis of sample arm focusing objective len, testing sample is placed in Jiao of sample arm focusing objective len and puts down At face；Another output port of optical circulator is connected with spectrogrph collimating lens, balzed grating, root Being placed on the emitting light path of spectrogrph collimating lens according to light-dividing principle, fourier lense is placed in and glares On the emitting light path of grid, the lighting surface of linear array CMOS camera overlaps with the back focal plane of fourier lense； Signal processing module is connect after linear array CMOS camera；

The light that Low coherence wideband light source sends incides fiber coupler, emergent light after optical circulator It is divided into two parts, is partly into reference arm, after collimated focusing, is irradiated to plane mirror；Another It is partially into sample arm, is irradiated on testing sample after collimation focusing；The orthogonal scanning of sample arm Galvanometer realizes sample arm light beam and treats the 3-D scanning of test sample product；The light that reference arm reflecting mirror is reflected back with The light that testing sample backscattering returns interferes at fiber coupler, and the interference light of outgoing is through light By signal processing module acquisition process after spectrometer.

Compared with background technology, this utility model has the beneficial effect that

1) the microangiography figure that the multiple space angles utilizing this utility model to obtain are combined, has The contrast strengthened and blood vessel are connective；

2) the transverse modulation spectrum cutting techniques of the total space that this utility model is referred to, it is provided that maximum The transverse modulation spectrum of the spatial frequency domain changed, eliminates owing to modulation spectrum is split under the lateral resolution caused Fall.

3) utilize that this utility model refers to is based on the segmentation of total space modulation spectrum multiple angle-resolved Detection Techniques, can realize the measurement of blood flow absolute flow velocity in the case of single beam single measurement.

Accompanying drawing explanation

Fig. 1 is sample arm scanning light beam schematic diagram；

Fig. 2 is modulating frequency f that offset delta introduces_mFigure；

Fig. 3 is transversal scanning modulation spectrum positive and negative frequency alias figure；

Fig. 4 is method flowchart of the present utility model；

Fig. 5 is imaging system schematic diagram of the present utility model.

In Fig. 1: 1., detect light beam；2., scanning galvanometer；3., galvanometer spindle central；4., poly- Focus objective lens.

In Fig. 2: modulating frequency f that offset delta introduces_m。

In Fig. 3: the transversal scanning modulation spectrum of positive and negative frequency alias.

In Fig. 4: A represents OCT interference spectrum real number signal；B represents the space in the degree of depth (z) territory Structural information；C represents the spatial structural form after removing conjugation item；D represents the interference light of complex values Spectrum；The total space transversal scanning modulation spectrum of E representation space frequency domain；F1 to Fn represents segmentation respectively The sub-spectrum of modulation obtained；G1 to Gn represents z domain space architecture signals respectively；H1 to Hn is respectively Represent optics radiography subgraph；I represents optics radiography figure；

In Fig. 5: 1, Low coherence wideband light source；2, optical circulator；3, fiber coupler；4, ginseng Examine arm Polarization Control device；5, reference arm collimating lens；6, reference arm condenser lens；7, plane Reflecting mirror；8, sample arm Polarization Control device；9, sample arm collimating lens；10, orthogonal scanning is shaken Mirror；11, sample arm focusing objective len；12, testing sample；13, collimating lens；14, balzed grating,； 15, fourier lense；16, linear array CMOS camera；17, signal processing module.

Detailed description of the invention

With examples of implementation, this utility model is further described below in conjunction with the accompanying drawings.

Fig. 1, Fig. 2 and Fig. 3 show transverse modulation principle schematic of the present utility model.The most right Schematic diagram in Fig. 1, Fig. 2 and Fig. 3 elaborates.

1) generally in the sample arm of OCT system, for obtaining higher horizontal imaging resolution, Ask the beam diameter size being irradiated on object lens the biggest.Therefore, in FIG, when one fixed width When collimated beam is irradiated to the spindle central of sample arm scanning galvanometer, beam distance spindle central exists one Fixed offset delta.And offset delta can introduce the modulation of sample arm light path, cause in spatial frequency domain Transversal scanning modulation (such as Fig. 2), its modulating frequency f_mWith offset delta linear function:

$f_m=\frac{2k\mathrm{\δ}}{\mathrm{\π}\mathrm{\ω}},$

Wherein, k represents the center wave number of light source, and ω represents the angular velocity of scanning galvanometer.Therefore, complete empty Between transversal scanning modulation spectrum in, different modulating frequencies correspond to the detection light of different incidence angles degree.

2) in OCT image, the interference spectrum obtained corresponding to a transversal scanning is real number value letter Number.Owing to directly spectrum real number signal transversely fast-scan direction being made Fourier transformation, obtained sky Between frequency distribution can produce the aliasing (such as Fig. 3) of positive negative frequency, it is therefore desirable to reconstruct complex values OCT interference spectrum.

What Fig. 4 showed method of the present utility model implements flow chart.Below to the mistake in Fig. 4 Journey is described in detail:

1) in OCT image, obtain corresponding to a transversal scanning is interference spectrum real number signal (i.e. square frame A).In order to reconstruct the spectral signal of complex values, real number is composed along wave number k direction Carry out Fourier transformation, obtain the spatial structural form (i.e. square frame B) in degree of depth z territory.Generally in spectrum In the OCT of territory, the areas imaging of the corresponding about 3mm in the z space of half, it is possible to meet most of Application requirement, is then completely disposed at zero optical path difference by testing sample, to differentiate complex conjugate mirror image. By removing the conjugation item in z territory, obtain new z domain space structural information (i.e. square frame C).And After carry out inverse Fourier transform along k direction, finally give the spectral signal of complex values(i.e. Square frame D).This complex number spectrum is carried out in the x-direction Fourier transform, obtains in spatial frequency domain complete empty Between transversal scanning modulation spectrum (i.e. square frame E).

2) the transverse modulation spectrum obtained is split, the separate of incident angle resolution can be obtained OCT interfere sub-spectrum (i.e. square frame F1 to Fn).Split sub-spectrum number n and sub-light obtained Overlap between spectrum is depending on final image effect: the number of segmentation is the most can cause lateral resolution to subtract Little must be the most, additionally add the complexity of Processing Algorithm；Part overlapped between sub-spectrum is more Greatly, sub-spectrum independence each other can be caused to decline, the detection of impact coding different incidence angles degree Light.

3) the separate sub-spectrum (i.e. square frame F1 to Fn) that the incident angle obtained is differentiated, Carry out inverse Fourier transform respectively along x direction, carry out Fourier transformation further along k direction, obtain The spatial structural form (i.e. square frame G1 to Gn) in z territory.Utilize current optics microangiography skill Art, such as difference in magnitude point-score, cross-correlation method etc., produces corresponding independent radiography subgraph (i.e. respectively Square frame H1 and Hn).The radiography subgraph differentiating these space angles carries out compound average, obtains new Microangiography figure (i.e. square frame I), its blood flow contrast is improved.

Traditional Doppler frequency shift velocity measurement method can only be measured the speed parallel with detecting beam direction and divide Amount.The absolute velocity of blood flow to be measured, also needs to record the angle of detection beam direction and blood flow direction (i.e. Doppler angle).Split based on total space modulation spectrum, it is possible to differentiate the detection light beam of different incidence angles degree. The sub-spectrum of modulation (i.e. square frame F1 to Fn) obtaining segmentation, utilizes doppler blood flow/velocity meter to calculate Method, it is possible to obtain the velocity component of different incidence angles degree detection direction, can determine that according to geometrical relationship Absolute Hemodynamic environment angle value.

Fig. 5 show imaging system schematic diagram of the present utility model.Below Fig. 5 is described in detail.

Based on the microangiography system that total space modulation spectrum segmentation angle is compound, including Low coherence broadband Light source 1, optical circulator 2, fiber coupler 3, reference arm, sample arm, spectrogrph and signal processing Module 17；Wherein reference arm includes reference arm Polarization Control device 4, reference arm collimating lens 5, ginseng Examine arm condenser lens 6 and plane mirror 7；Sample arm includes sample arm Polarization Controller 8, sample arm Collimating lens 9, orthogonal scanning galvanometer 10 and sample arm focusing objective len 11；Spectrogrph includes that spectrogrph is accurate Straight lens 13, balzed grating, 14, fourier lense 15 and linear array CMOS camera；

It is characterized in that: Low coherence wideband light source 1 is through optical circulator 2 and fiber coupler 3 side Input be connected；One of them output port of fiber coupler 3 opposite side is inclined through reference arm The control device 4 that shakes is connected with reference arm collimating lens 5；The optical axis of reference arm condenser lens 6 and ginseng Examining the optical axis coincidence of arm collimating lens 5, plane mirror 7 is placed in Jiao of reference arm condenser lens 6 and puts down At face；The another one output port of fiber coupler 3 opposite side, through sample arm Polarization Controller 8 are connected with sample arm collimating lens 9；First scanning mirror spindle central position of orthogonal scanning galvanometer 10 On the optical axis of sample arm collimating lens 9, the second scanning mirror spindle central is positioned at sample arm focusing objective len On the optical axis of 11, testing sample 12 is placed at the focal plane of sample arm focusing objective len 11；Optical circulator Another output port of 2 is connected with spectrogrph collimating lens 13, and balzed grating, 14 is according to light splitting Principle is placed on the emitting light path of spectrogrph collimating lens 13, and fourier lense 15 is placed in and glares On the emitting light path of grid 14, after the lighting surface of linear array CMOS camera 16 and fourier lense 15 Focal plane overlaps；Linear array CMOS camera 16 connects signal processing module 17 below；

The light that Low coherence wideband light source 1 sends incides fiber coupler 3 after optical circulator 2, Emergent light is divided into two parts, is partly into reference arm, is irradiated to plane mirror after collimated focusing 7；Another part enters sample arm, is irradiated on testing sample 12 after collimation focusing；Sample arm Orthogonal scanning galvanometer 10 realize sample arm light beam and treat the 3-D scanning of test sample product 12；Reference arm is anti- Penetrate the light that light that mirror 7 is reflected back and testing sample 12 backscattering return to occur at fiber coupler 3 Interfere, the interference light of outgoing after spectrogrph by signal processing module 17 acquisition process.

Claims (1)

1. based on the microangiography system that total space modulation spectrum segmentation angle is compound, including Low coherence width Band light source, optical circulator, fiber coupler, reference arm, sample arm, spectrogrph and signal processing mould Block；Wherein reference arm includes that reference arm Polarization Control device, reference arm collimating lens, reference arm focus on Lens and plane mirror；Sample arm includes sample arm Polarization Controller, sample arm collimating lens, just Hand over scanning galvanometer and sample arm focusing objective len；Spectrogrph include spectrogrph collimating lens, balzed grating, Fourier lense and linear array CMOS camera；

It is characterized in that: Low coherence wideband light source is through the input of optical circulator Yu fiber coupler side End is connected；One of them output port of fiber coupler opposite side is through reference arm Polarization Controller Part is connected with reference arm collimating lens；The optical axis of reference arm condenser lens and reference arm collimating lens Optical axis coincidence, plane mirror is placed at the focal plane of reference arm condenser lens；Fiber coupler another The another one output port of side, is connected with sample arm collimating lens through sample arm Polarization Controller； First scanning mirror spindle central of orthogonal scanning galvanometer is positioned on the optical axis of sample arm collimating lens, and second Scanning mirror spindle central is positioned on the optical axis of sample arm focusing objective len, and testing sample is placed in sample arm and focuses on At the focal plane of object lens；Another output port of optical circulator is connected with spectrogrph collimating lens, Balzed grating, is placed on the emitting light path of spectrogrph collimating lens according to light-dividing principle, fourier lense It is placed on the emitting light path of balzed grating, after the lighting surface of linear array CMOS camera and fourier lense Focal plane overlaps；Signal processing module is connect after linear array CMOS camera；

The light that Low coherence wideband light source sends incides fiber coupler, emergent light after optical circulator It is divided into two parts, is partly into reference arm, after collimated focusing, is irradiated to plane mirror；Another It is partially into sample arm, is irradiated on testing sample after collimation focusing；The orthogonal scanning of sample arm Galvanometer realizes sample arm light beam and treats the 3-D scanning of test sample product；The light that reference arm reflecting mirror is reflected back with The light that testing sample backscattering returns interferes at fiber coupler, and the interference light of outgoing is through light By signal processing module acquisition process after spectrometer.