CN1799505A - Measuring method and apparatus of near infrared polarized photon pair spectrograph - Google Patents

Abstract

The invention relates to a measuring method of the near-infrared polarized photo pair optical spectrometer and the device, the measuring method comprising: incidenting the bi-frequent sphere or linear polarization photon pair laser beam into a scattering medium of high concentration to generate a diffusing polarized photon pair density wave, then scanning the scattering medium with space scanistor to detect the amplitude and phase of the scattering polarized photon pair density wave and thus getting the propagation scattering coefficient and propagation coefficient of the scattering medium for the object image reduction in the scattering medium, furthermore, employing two kinds or several kinds of bi-frequent polarized near-infrared laser beam with different wavelength to detect the blood oxygen saturation concentration and the changing amount in real time, and then employing the spaces scanning to get the image of the blood oxygen saturation concentration.

Description

The near-infrared polarized photon is to spectrometer measurement method and device

Technical field

The invention relates to that a kind of near-infrared polarized photon is to the spectrometer measurement method and apparatus, be meant especially and use the bifrequency polarized photon in scattering medium, propagating to form the diffusion polarization photon to density wave (Diffused Photon Pair Density Wave, DPPDW), and measure phase place and the amplitude of diffusion polarization photon to density wave (DPPDW), with the method and apparatus of reduction object image.

Background technology

The tissue of human body belongs to high concentration scattering medium (multiple scatteringmedium) and has the characteristic of scattering coefficient much larger than absorptance, the general method that obtains image in scattering medium is all just measured its absorptance and is obtained the correlated image of light and shade, in the high concentration scattering medium, obtain object image if desire, because light wave is subjected to the height scattering, cause image fog, and then cause image resolution to decline to a great extent, therefore, if can reduce the scattering effect of light in the high concentration scattering medium, or filter out the photon (snake photon) of slight scattering and directly advance photon (ballistic photon), raising then can effectively be lifted at the image resolution in the high concentration scattering medium to the sensitivity of absorptance.

Yet the mode of screening slight scattered photon and directly advancing photon only is adapted at imaging in the low scattering medium, imaging method is mainly divided the imaging technique of time domain (time domain) and frequency domain (frequency domain) in the high concentration scattering medium at present, diffusion photon density wave (diffused photon density wave has been proposed in the frequency domain technology, DPDW) notion, diffusion photon density wave (DPDW) satisfies diffusion equation (diffusion equation), and the absorptance (absorption coefficient) that can quantitatively obtain tested thing with propagate scattering coefficient (reduced scatteringcoefficient), and then the image of object in the reduction scattering medium.The frequency domain technology is that imaging is than effective method in the high concentration scattering medium at present, and its shortcoming is that spatial resolution is not high.

Summary of the invention

In order to improve above-mentioned shortcoming, the present invention provides a kind of near-infrared polarized photon to spectrometer measurement method and device, described near-infrared polarized photon comprises the spectrometer measurement method: earlier with the orthogonal polarization photon of a bifrequency to laser beam incident to high concentration scattering medium after, produce a diffusion polarization photon to density wave (DPPDW), utilize a spacescan device to this high concentration scattering medium scanning again, permeametry diffusion polarization photon is to the amplitude and the phase place of density wave (DPPDW), and tries to achieve the propagation scattering coefficient μ of scattering medium _s' and absorptance μ _aAnd then reduce image in this high concentration scattering medium.

More utilize the orthogonal laser beam measuring blood of the bifrequency near-infrared oxygen saturation density and the variable quantity thereof of two or more different centre wavelengths in addition, relend the image that to try to achieve blood oxygen saturation by spacescan.

Near-infrared polarized photon of the present invention comprises the spectrometer measurement device: a bifrequency polarization LASER Light Source, interrelated in order to produce, a mutually perpendicular bifrequency polarization photon is to laser beam, and this bifrequency polarization photon can produce a diffusion polarization photon to density wave after laser beam is entered this scattering medium; One reference light difference interference signal, the beat frequency of this reference light difference interference signal is identical to the beat frequency of density wave difference interference signal with this diffusion polarization photon; One spacescan device is that this scattering medium is made spacescan; One smooth detection device is that this diffusion polarization photon of detecting is to density wave; And a signal processing apparatus, in order to calculating, and try to achieve absorptance and the spatial distribution of propagating scattering coefficient in the scattering medium by phase place and the amplitude signal and the spatial distribution of this diffusion polarization photon behind this light detection device to density wave.This bifrequency polarization LASER Light Source produces the mutually perpendicular polarization photon of bifrequency to laser beam, and light detection device wherein be provided with respect to the position of this bifrequency polarization LASER Light Source, and signal processing apparatus is connected with this light detection device.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, this bifrequency polarization LASER Light Source is to be bifrequency circle polarization LASER Light Source, this bifrequency polarization laser beam is to be bifrequency circle polarization laser beam, and this diffusion polarization photon is by this bifrequency circle polarization photon laser beam to be produced in scattering medium to density wave.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, and this measuring device more comprises a polaroid, after this circle polarization diffusion polarization photon passes through this polaroid and this light detection device to density wave, produces a difference interference signal.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, this measuring device more comprises a polarization spectroscope and a differential amplifying device, this diffusion polarization photon passes through this polarization spectroscope to density wave, and on this light detection device, produce the difference interference signal simultaneously respectively, and be input to this differential amplifying device to form bifrequency differential type near-infrared polarized photon to spectrogrph.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, this bifrequency polarization LASER Light Source is to be bifrequency line polarization LASER Light Source, this bifrequency polarization laser beam is to be bifrequency line polarization laser beam, and this diffusion polarization photon is by this bifrequency line polarization photon laser beam to be produced in scattering medium to density wave.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, and this measuring device more comprises a polaroid, this line polarization photon to laser beam by producing a line polarization photon parallel to each other behind this polaroid to laser beam.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, this measuring device more comprises a λ/2 wave plates and a polarization spectroscope, after this line polarization photon passes through this λ/2 wave plates to laser beam, cause line polarization photon that the laser beam polarised direction is rotated an angle, again by this polarization spectroscope, and the difference interference signal that produces on this light detection device is input in the differential amplifying device, form line polarization differential type near-infrared polarized photon to spectrogrph.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, this measuring device more includes a differential amplifying device, this differential amplifying device and this signal processing apparatus electrically connect, and make this diffusion polarization photon have preferable noise stability when to density wave.

Near-infrared polarized photon of the present invention is to the spectrometer measurement device, this bifrequency polarization LASER Light Source is the bifrequency polarization LASER Light Source that has different centre wavelengths for many groups, and this diffusion polarization photon of measuring different centre wavelengths simultaneously is to density wave amplitude and phase signal, calculating blood oxygen saturation, and obtain the blood oxygen saturation image via spacescan.

The present invention provides a kind of near-infrared polarized photon to spectrometer measurement method and device, mainly be to utilize bifrequency, circle polarization or line polarization laser beam are propagated in the high concentration scattering medium and are formed the diffusion polarization photon to density wave (diffused photonpair density wave, DPPDW), based on optical heterodyne interference technique and right same tone (coherence) and the co-route (common-path) of polarized photon, and from the difference interference signal, measure the diffusion polarization photon to the phase place of density wave (DPPDW) and the size of amplitude, relend the absorptance μ that calculates scattering medium by Phase delay and amplitude fading parameter with the change of distance between signal optical fiber and detecting optical fiber _aWith propagation scattering coefficient μ _s', simultaneously also can be by the signal optical fibre and detecting optical fiber and a plurality of different spacing distances of fixing a plurality of diverse locations, calculate the absorptance and the spatial distribution of propagating scattering coefficient of scattering medium simultaneously, to reach the image that in the high concentration scattering medium, obtains object.

The present invention more provides a kind of can record blood oxygen saturation in the blood (Hemoglobin saturation, SaO in real time ₂) and the near-infrared polarized photon of blood oxygen saturation distribution image to spectrometer measurement method and device.The bifrequency near-infrared polarization laser beam that utilizes two or more different centre wavelengths is by Oxygenated blood red pigment (Oxyhemoglobin, HbO ₂) and the oxygen-free haemachrome (Deoxyhemoglobin Hb) has absorptance inequality to same near-infrared wavelength, to obtain blood oxygen saturation (Hemoglobin saturation, SaO in the blood ₂) real-time measurement, and more can be further obtain the spatial distribution image of blood oxygen saturation by while sweep signal optical fiber and detecting optical fiber or a plurality of signal optical fibre that is fixed on diverse location and different interval distance and detecting optical fiber.

Description of drawings

Fig. 1 be for the near-infrared polarized photon to the spectrometer measurement method flow diagram;

Fig. 2 be for the near-infrared polarized photon to spectrometer measurement blood oxygen saturation method flow diagram;

Fig. 3 is the sketch map of near-infrared polarized photon to first embodiment of spectrometer measurement device;

Fig. 4 is the second embodiment sketch map of near-infrared polarized photon to the spectrometer measurement device;

Fig. 5 is the three embodiment sketch map of near-infrared polarized photon to the spectrometer measurement device;

Fig. 6 is the four embodiment sketch map of near-infrared polarized photon to the spectrometer measurement device;

Fig. 7 is reference light difference interference reference signal among the 4th embodiment;

Fig. 8 is the five embodiment sketch map of near-infrared polarized photon to the spectrometer measurement device;

Fig. 9 be for bifrequency line polarization photon among the 5th embodiment to laser beam (P ripple+S ripple) anglec of rotation sketch map;

Figure 10 is the six embodiment sketch map of near-infrared polarized photon to the spectrometer measurement device;

Figure 11 a, 11b are in one even 10% Intralipid-10% solution, and the diffusion polarization photon is to (shown in Figure 11 a) amplitude spheric wave front (unit is dBm) and (shown in Figure 11 b) phase place spheric wave front (unit is degree) of density wave;

Figure 12 a, 12b are in the Intralipid of three kinds of different volumes concentration (refined lecithin) solution, and the diffusion polarization photon is to the amplitude fading (shown in Figure 12 a) and the linear relationship chart apart from r of Phase delay (shown in Figure 12 b) to signal optical fibre and detecting optical fiber of density wave;

Figure 13 a, 13b in the Intralipid-10% of 15% volumetric concentration solution, add assimilate india ink (india ink) preceding with add assimilate india ink after the diffusion polarization photon to the reaction of amplitude fading (shown in Figure 13 a) Yu Phase delay (shown in Figure 13 b) r that adjusts the distance of density wave;

Figure 14 a, 14b in the Intralipid-10% of 15% volumetric concentration solution, three kinds of bifrequency polarized photons to the LASER Light Source beat frequency under the diffusion polarization photon to the amplitude fading (shown in Figure 14 a) of density wave and the linear relationship chart of Phase delay (shown in Figure 14 b) r that adjusts the distance;

Figure 15 bifrequency polarized photon is 20MHz to the LASER Light Source beat frequency, and the volumetric concentration of Intralipid-10% solution is propagated the linear relationship chart of scattering coefficient to measured solution;

Figure 16 is in the Intralipid-10% of 15% volumetric concentration solution, and the bifrequency polarized photon is 20MHz to the LASER Light Source beat frequency, and assimilate Methylene-Blue (methylene blue) concentration that is added is to the linear relationship chart of measured solution absorption coefficient.

The specific embodiment

For above and other objects of the present invention, feature and advantage can be become apparent, hereinafter enumerate preferred embodiment especially, and cooperate institute's accompanying drawing, be described in detail below.

See also Fig. 1,3, near-infrared polarized photon of the present invention is as follows to the spectrometer measurement method step: a. produces a diffusion polarization photon to density wave (DPPDW) 430 or 440 after the mutually perpendicular circle of one bifrequency or line polarization photon are incident to a high concentration scattering medium 260 to laser beam 410 or 420; B. utilize 260 scannings of 24 pairs of these high concentration scattering mediums of a spacescan device; C. borrow polaroid 280, light detection device 290, band pass filter means 310 and signal processing apparatus 320 to measure the phase place and the amplitude of this diffusion polarization photon, and spacescan device 24 comprise signal optical fibre 240 and detecting optical fiber 270 to density wave (DPPDW); D. utilize measured the diffusion polarization photon phase place of density wave (DPPDW) is changed and the spatial distribution of amplitude fading signal, can try to achieve absorptance μ _aWith propagation scattering coefficient μ _s' spatial distribution, and then the object image of reduction in the scattering medium 260.

See also Fig. 2,4, the present invention more can see through the following step and try to achieve blood oxygen saturation in the blood, at first, a. after the mutually perpendicular circle of bifrequency of two kinds or multiple different centre wavelengths or line polarization photon being incident to a high concentration scattering medium 260 to laser beam 410 or 420, produce a diffusion polarization photon to density wave (DPPDW) 430 or 440; B. utilize 260 scannings of 24 pairs of these high concentration scattering mediums of a spacescan device; C. optical filter 350 or 351, borrow polaroid 280 or 281, light detection device 290 or 291, signal amplifying apparatus 300 or 301, band pass filter means 310 or 311 and signal processing apparatus 320 measure phase place and the amplitude of these diffusion polarization photons to density wave (DPPDW), and spacescan device 24 comprises signal optical fibre 240 and detecting optical fiber 270; D. utilize the bifrequency polarization LASER Light Source 100,101 of two groups of different centre wavelengths in scattering medium, to produce the diffusion polarization photon, and can try to achieve the distribution image of blood oxygen saturation by scanning means 24 and light detection device 290,291 density wave (DPPDW).

First embodiment:

See also Fig. 3, the round polarization photon of bifrequency circle polarization LASER Light Source 100 exportable one interrelated (correlated), mutually vertical (orthogonal) is to laser beam 410, this circle polarization photon has round polarization R ripple and L ripple to laser beam 410, and its corresponding frequency is respectively ω _RWith ω _LAfter bifrequency circle polarization photon is to laser beam 410 process spectroscopes 200, by spectroscope 200 bifrequency circle polarization photon is divided into signal beams 450 and reference beam 460 to laser beam 410, after signal beams focuses on via microcobjective 210, be input to signal optical fibre 240 and enter in the scattering medium 260, bifrequency circle polarization this moment photon can form the diffusion polarization photon to density wave (DPPDW) 430 to laser beam 410, reference beam 460 is sent into light detection device 250 via reflecting surface mirror 220 and polaroid 230 simultaneously, to produce reference light difference interference signal, and signal beams 450 enter the detecting optical fiber 270 after, through a polaroid (analyzer) 280, light detection device 290, signal amplifying apparatus 300 and band pass filter means 310 are at last in reference beam 460 input signal blood processor 320.

Second embodiment:

See also Fig. 3, the round polarization photon of bifrequency circle polarization LASER Light Source 100 exportable one interrelated (correlated), mutually vertical (orthogonal) is to laser beam 410, this circle polarization photon has round polarization R ripple and L ripple to laser beam 410, and its corresponding frequency is respectively ω _RWith ω _L, or utilize bifrequency line polarization LASER Light Source 500 outputs one interrelated, orthogonal line polarization photon to laser beam 420, and this line polarization photon has line polarization P ripple and S ripple to laser beam 420, and its corresponding frequency is respectively ω _PWith ω _SIn addition, bifrequency polarization LASER Light Source 100 also can be a single-frequency frequency stabilization line polarization laser in conjunction with an electrooptic modulator (or acousto-optic modulator), polaroid and ^λ/ ₄Wave plate forms bifrequency circle polarization photon to laser beam 410, and also to can be a single-frequency frequency stabilization line polarization laser be in order to produce bifrequency line polarization photon to laser beam 420 in conjunction with an electrooptic modulator or acousto-optic modulator and polaroid to bifrequency polarization LASER Light Source 100 simultaneously.In addition, when bifrequency polarization LASER Light Source 100 comprises a single-frequency frequency stabilization line polarization semiconductor laser in conjunction with current-modulation, polaroid and wave plate, also can form bifrequency circle (or line) polarization photon to laser beam 410 or 420.

As Fig. 3, bifrequency circle polarization photon is to laser beam 410, through behind the spectroscope 200, bifrequency circle polarization photon is divided into signal beams 450 and reference beam 460 to laser beam 410, signal beams is input in the signal optical fibre 240 after focusing on via microcobjective 210, and reference beam 460 is sent into light detection device 250 via reflecting surface mirror 220 and polaroid 230 simultaneously, to produce reference light difference interference signal, reference light difference interference signal can be write as:

I _r(Δωt)＝DC+Гcos(Δωt)--------------------------------------------(1)

I _rBe the intensity of reference light difference interference signal, Δ ω=ω _R-ω _LBe the beat frequency of difference interference signal, DC is the direct current signal size, and Г is the amplitude size of reference light difference interference signal, and t is a time coordinate.The bifrequency polarization photon of signal optical fibre 240 outputs diffuses to form the diffusion polarization photon to density wave (DPPDW) 430 to laser beam in scattering medium 260, beyond parallel distance r, settle another identical detecting optical fiber 270 to be used for detecting the diffusion polarization photon to density wave (DPPDW) 430, the diffusion polarization photon passes through polaroid 280 to density wave (DPPDW) 430, produce the difference interference signal at light detection device 290, by signal amplifying apparatus 300 and band pass filter means 310 the difference interference signal is outputed to signal processing apparatus 320 (for example phase-locked amplifying device) and measure amplitude and phase place, wherein signal optical fibre 240 can be replaced by point source, and detecting optical fiber 270 can be replaced by small size light detection device.Signal beams 450 can further be write as (2) by the scattering medium 260 difference interference signal that produces:

I is a signal intensity, and Δ ω is the beat frequency of difference interference signal, and t is a time coordinate, ₀ ²Be the flux of energy rate (rate of energyfluence) of diffusion polarization photon to density wave (DPPDW), k ₂Be the wave number (wavenumber) of diffusion polarization photon to density wave (DPPDW), k ₂=k _2r+ ik _2iK wherein _2r, k _2iBe respectively the wave number k of diffusion polarization photon to density wave (DPPDW) ₂Real part and imaginary part, k _2r, k _2iCorresponding to the absorption characteristic and the scattering properties of scattering medium 260, r is the spacing distance of signal optical fibre 240 and detecting optical fiber 270, and ΔΦ is a phase contrast.

k _2r＝[3μ _a(μ _s′+μ _a] ^1/2-----------------------------------------------(3)

μ _s', μ _aBe respectively the propagation scattering coefficient and the absorptance of scattering medium 260, by equation (2) can try to achieve in Fig. 3 signal optical fibre 240 and detecting optical fiber 270 respectively in different interval apart from r ₀And r, the amplitude fading of difference interference signal in scattering medium 260:

$\mathrm{In}\left(\frac{I}{I_0}\right)=[\mathrm{In}\left(\frac{r_0}{r}\right)-k_{2r}\mathrm{\Δr}]---\left(4\right)$

I ₀With I be respectively at r ₀With the difference interference signal light intensity size of r, wherein Δ r=r-r ₀In like manner ΔΦ is a phase contrast, can be expressed as:

$\mathrm{\Δ\Φ}=\frac{\mathrm{n\Δ\ω}}{c}{\left(\frac{3{\mathrm{\μ}}_s^{\′}}{4{\mathrm{\μ}}_a}\right)}^{1/2}\·r=k_{2i}---\left(5\right)$

$k_{2i}=\frac{\mathrm{n\Δ\ω}}{c}{\left(\frac{3{\mathrm{\μ}}_s^{\′}}{4{\mathrm{\μ}}_a}\right)}^{1/2}---\left(6\right)$

N is the refractive index of scattering medium, and Δ ω is the beat frequency of difference interference signal, and c is the very aerial light velocity, μ _s', μ _aBe respectively the diffusion polarization photon to propagation scattering coefficient and the absorptance of density wave (DPPDW) in scattering medium 260, k _2iBe the wave number k of diffusion polarization photon to density wave (DPPDW) ₂Imaginary part, the scattering properties of its corresponding scattering medium 260.Try to achieve by equation (3) and (6):

${\mathrm{\μ}}_s^{\′}=\frac{2c{k}_{2r}{k}_{2i}}{3n\left(\mathrm{\Δ\ω}\right)}---\left(7\right)$

${\mathrm{\μ}}_a=\frac{\mathrm{n\Δ\ω}}{2c}\left(\frac{k_{2r}}{k_{2c}}\right)---\left(8\right)$

So characteristic μ of scattering medium 260 _s', μ _aCan try to achieve by the amplitude fading and the Phase delay of difference interference signal measured in Fig. 3 device.

As shown in Figure 4, apparatus of the present invention can use the bifrequency circle polarization LASER Light Source 101 of another different centre wavelengths through reflecting surface mirror 102, spectroscope 103 and 200 simultaneously, via aforementioned identical optical system bifrequency circle polarization photon are formed the diffusion polarization photon to density wave (DPPDW) 440 to laser beam 510 in scattering medium 260.Bifrequency circle polarization photon is to the difference interference signal of laser beam 510 via formation reference light in light splitting piece 201, optical filter 351 and polaroid 231 and the light detection device 251, synchronous signal light beam 450 is via light splitting piece 340, optical filter 351, polaroid 281, produce the difference interference signal at light detection device 291, by signal amplifying apparatus 301 and band pass filter means 311 the difference interference signal is outputed to signal processing apparatus 320 (for example phase-locked amplifying device) and measure amplitude and phase place, form the measurement function of dual wavelength near-infrared polarized photon spectrogrph to reach.The present invention utilizes light splitting piece 340, optical filter 350 and 351 can be with different central wavelength lambda ₁, λ ₂The diffusion polarization photon to density wave (DPPDW) separately and measure its amplitude and phase signal size simultaneously.

Further specify, as shown in Figure 4, also can export the orthogonal line polarization of different centre wavelengths photon to laser beam 420,520 by two groups of bifrequency line polarization LASER Light Sources, P ripple (being parallel to the X coordinate axes) and S ripple (being parallel to the Y coordinate axes), its time frequency is respectively ω _PWith ω _S, and the Z axle is the laser light direction of propagation.When the mutual vertical different central wavelength lambda in polarization direction ₁, λ ₂Bifrequency circle polarization photon when entering in the high concentration scattering medium 260 to laser beam 410,510 since bifrequency circle polarization photon to laser beam 410,510 through a series of collision accidents (events), and form different central wavelength lambda ₁, λ ₂The diffusion polarization photon to density wave (DPPDW) 430,440, right space same tone degree (degree of spatial coherence) and degree of polarization (the Degree of polarization of while polarized photon, DOP) thereby descend, therefore the round polarization photon of still keeping interrelated (correlation) is only arranged to (circular polarizedphoton pair, CPPP), could produce the difference interference signal also can pass through in the light detection device with Δ ω=ω _R-ω _LBand pass filter means (Band pass filter for mid frequency, BPF) 310,311, justify the polarization photon to laser beam 410 owing to produce the polarized photon of difference interference signal in high concentration scattering medium 260, belonging to the bifrequency of passing through less collision accident, and can keep more polarization characteristic and space same tone.Therefore the present invention can screen (polarization gating) and space people having the same aspiration and interest screening (spatial coherence gating) via polarized light, and then the lower bifrequency circle polarization photon of screening scattering degree is to (CPPP) and form the diffusion polarization photon to density wave (DPPDW), and their also satisfy diffusion equation simultaneously.In like manner, the inventive method and the also available different wave length λ of device ₁, λ ₂Bifrequency line polarization photon is finished the near-infrared polarized photon to spectrogrph to laser beam 420,520 by Fig. 4.

Among Fig. 4, LASER Light Source is except justifying polarization LASER Light Source 100 with the bifrequency line, 101 as outside implementing, also can bifrequency line polarization LASER Light Source 500,501 as implementing, former bifrequency circle (or line) diffusion polarization photon that enters detecting optical fiber 270 can effectively be justified (or line) polarization photon to laser beam 410 and 510 with mutually perpendicular bifrequency to density wave 410 or 420 through a polaroid (analyzer) 280 or 281, or 420 and 520 convert the bifrequency line polarization photon that is parallel to each other to laser beam 420 ', received by light detection device 300 at last, the difference interference signal that it produced, its intensity can be expressed as:

I(Δωt)＝DC+γcos(Δωt+ΔΦ)----------------------------------------(9)

I is a signal intensity, Δ ω is the beat frequency of difference interference signal, t is a time coordinate, DC is the direct current signal size, γ is the amplitude of diffusion polarization photon to density wave (DPPDW), Δ Ф is its Phase delay, the μ that can obtain scattering medium to the Phase delay and the amplitude fading signal of density wave (DPPDW) by the diffusion polarization photon _s' and μ _aRelend spacescan and obtain μ by diffusion equation _s' and μ _aSpatial distribution with reach in high concentration scattering medium 260, utilize the diffusion polarization photon to density wave (DPPDW) 430 or 440 the reduction images purpose.

The 3rd embodiment:

Present embodiment is the embodiment that applies the present invention to dual space, utilizes the device of bifrequency circle (or line) polarization LASER Light Source 100 or 101 to reduce the image of thing 610 to be detected in high concentration scattering medium 260.See also Fig. 5, the present invention sees through bifrequency circle (or line) polarization LASER Light Source 100 or 101, for example strange graceful helium-neon laser (Zeeman He-Ne laser), the round polarization photon that produces bifrequency interrelated (correlated) and mutually vertical (orthogonal) is to (circular polarized photonpair, CPPP) or line polarization photon to (linear polarized photon pairLPPP) laser beam 410 or 420, circle (or line) polarization photon can incide in high concentration scattering medium 260 and the thing to be detected 610 laser beam 410 or 420, and produces diffusion circle (or line) polarized photon to density wave (DPPDW) 430 or 440.Then, the diffusion polarization photon passes through light detection device 290 or 291 to density wave (DPPDW) 430 or 440, directly measure amplitude (amplitude) and the phase place (phase) of diffusion polarization photon, measure the absorptance μ of scattering medium in real time density wave (DPPDW) _aWith propagation scattering coefficient μ _s', and μ _s'=μ _s(1-g).μ _sBe scattering coefficient, g is non-equal tropism's parameter (scattering anisotropic parameter) of scattering medium, and this bifrequency circle (or line) polarization LASER Light Source 100 or 101 and light detection device 290 or 291 can displacement scanning in dual space, relend by separating of diffusion equation and try to achieve μ _s' and μ _aSpatial distribution map, to obtain the optical characteristics (μ in the scattering medium _s', μ _a) spatial distribution that changes, with the reduction object image.In addition, further by Oxygenated blood red pigment (Oxyhemoglobin, HbO ₂) and the oxygen-free haemachrome (Deoxyhemoglobin Hb) has absorptance inequality to same wavelength, utilizes two kinds of different central wavelength lambda simultaneously ₁, λ ₂Bifrequency circle polarization LASER Light Source or two kinds of different central wavelength lambda ₁, λ ₂Bifrequency line polarization LASER Light Source, measure blood oxygen saturation in the blood (Hemoglobinsaturation, SaO in real time ₂), relend by dual space scanning, more can further obtain the distribution image of blood oxygen saturation.

With bifrequency circle (or line) polarization LASER Light Source 100 or 101 and light detection device 290 or 291 pairs of scattering medium 260 common displacements and do two dimension (2-D) and three-dimensional (3-D) scans, can try to achieve μ to the amplitude of density wave (DPPDW) 430 or 440 and the data of phase place from acquisition diffusion polarization photon _s' and μ _aSpatial distribution, utilize diffusion equation that object is reduced into picture again in scattering medium 260.Bifrequency polarization LASER Light Source 100 or 101 and the number of light detection device 290 or 291 can suitably adjust imaging effect in the hope of the best.

The 4th embodiment:

See also Fig. 6, different central wavelength lambda ₁, λ ₂One interrelated, the vertical but different central wavelength lambda mutually of bifrequency line polarization LASER Light Source 500,501 output ₁, λ ₂Bifrequency line polarization photon to laser beam 710,720, bifrequency line polarization photon is to laser beam 710,720 after being the polaroid 280 of θ by the azimuth to X-axis, can produce be parallel to each other but the bifrequency line polarization photon of different centre wavelengths to laser beam 420 ' (as Fig. 7), by light splitting piece 200 bifrequency line polarization photon parallel to each other is divided into signal beams 450 and reference beam 460 to laser beam 420 ' again, after signal beams 450 focuses on via microcobjective 210, be input in the signal optical fibre 240, simultaneously reference beam 460 becomes two the tunnel, the one tunnel via spectroscope 201 beam split (centre wavelength is λ ₁) mating plate 351, light detection device 251 after filtration, and producing the difference interference reference optical signal, (centre wavelength is λ on another road ₂) send into light detection device 250 and produce the difference interference signal via reflecting surface mirror 220, optical filter 350, output to signal processing apparatus 320 more in the lump, and bifrequency line polarization photon is to the other end of laser beam 710,720 through signal optical fibre 240, beyond parallel distance r, settle another identical detecting optical fiber 270, (centre wavelength is λ by being divided into two the tunnel, the one tunnel behind the spectroscope 340 ₁) mating plate 351, light detection device 291, signal amplifying apparatus 301 and band pass filter means 311 after filtration, last entering signal blood processor 320, (centre wavelength is λ on another road ₂) after filtration in the mating plate 350 input light detection devices 290, be input in the signal processing apparatus 320 by signal amplifying apparatus 300 and band pass filter means 310, in like manner, Fig. 6 also can utilize the bifrequency circle polarization LASER Light Source 100 of one group of different centre wavelength, 101 also can export one interrelated, orthogonal bifrequency circle polarization photon is to laser beam 410 or 420, and process reflecting surface mirror 102 reflexes to spectroscope 103 with bifrequency circle polarization photon to laser beam 410 or 420, follow-up light path and signal processing thereof are through being same as bifrequency line polarization LASER Light Source 500,501, this section repeats no more, by spectroscope 340 and optical filter 351,350 respectively with central wavelength lambda ₁, λ ₂The diffusion polarization photon to density wave (DPPDW) separately and measure its amplitude and phase signal size simultaneously.

The 5th embodiment:

See also Fig. 8, bifrequency line polarization LASER Light Source 600 is by λ/2 wave plates 104, bifrequency line polarization photon is rotated an angle θ (as Fig. 9) to laser beam 610 (P ripple+S ripple), utilize light splitting piece 190 to be divided into signal beams 450 and reference beam 460 again, after signal beams 450 focuses on via microcobjective 210, be input in the signal optical fibre 240, the other end output signal beam of signal optical fibre 240 also diffuses to form the diffusion polarization photon to density wave (DPPDW) 440 in scattering medium 260, beyond parallel distance r, settle another identical detecting optical fiber 270 to be used for detecting the diffusion polarization photon to density wave (DPPDW) 440, the diffusion polarization photon to density wave (DPPDW) 440 through a polarized light spectroscope 130 with the diffusion polarization photon to density wave (DPPDW) 440 (P ripple+S ripple) at the component of the X-direction of polarized light spectroscope 130 and Y direction separately and be input to light detection device 140,150 and signal amplifying apparatus 160, produce the difference interference signal in 170, they can be expressed as:

I _x(Δωt)＝DC+γcos(Δωt+ΔΦ)-----------------------------------(10)

I _y(Δωt)＝DC-γcos(Δωt+ΔΦ)-----------------------------------(11)

I _xBe the axial signal intensity of x, I _yBe the axial signal intensity of y, DC is a direct current signal, γ is the amplitude of diffusion polarization photon to density wave (DPPDW), ΔΦ is the Phase delay of diffusion polarization photon to density wave (DPPDW), two groups of signal subtractions can be become balance detection circuit (balanced detector circuit), Δ I=I by differential amplifying device 180 _x-I _y=2 γ cos (Δ ω t+ Δ Ф)----------------------------------also send in the signal processing apparatus 320 by-----(12), measure amplitude fading and the phase contrast of diffusion polarization photon to density wave (DPPDW) 440, wherein reference optical signal 460 passes through polaroid 195 and light detection devices 250 and is input to signal processor 320.Finish differential type near-infrared polarized photon to spectrometer device,, and improve the sensitivity and the snr value (SNR) of detecting in the hope of the amplitude fading and the Phase delay of difference interference signal.

The 6th embodiment:

See also Figure 10, in like manner, present embodiment is with different central wavelength lambda ₁, λ ₂Bifrequency circle polarization photon can make bifrequency circle polarization photon that laser beam 410 is transformed into bifrequency line polarization photon to laser beam through λ/4 wave plates 105,106 to LASER Light Source 100,101, and constitute dual wavelength bifrequency circle polarization differential type near-infrared polarized photon to spectrogrph.

Because the absorptance μ of haemachrome (hemoglobin) in the blood _aAt anaerobic condition (Hb) and oxygenation state (Hb0 ₂) to different near-infrared wavelength λ ₁, λ ₂(λ for example ₁=780nm, λ ₂=850nm) tangible difference arranged, and can try to achieve blood oxygen saturation (SaO in real time by equation (13)～(16) ₂) variation.

$\mathrm{\&Delta;}{\mathrm{\&mu;}}_a\left({\mathrm{\&lambda;}}_1\right)={\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_1}\mathrm{\&Delta;Hb}+{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_1}\mathrm{\&Delta;Hb}{O}_2---\left(13\right)$

$\mathrm{\&Delta;}{\mathrm{\&mu;}}_a\left({\mathrm{\&lambda;}}_2\right)={\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_2}\mathrm{\&Delta;Hb}+{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_2}\mathrm{\&Delta;Hb}{O}_2---\left(14\right)$

$\mathrm{\&Delta;Hb}=\frac{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_2}\mathrm{\&Delta;}{\mathrm{\&mu;}}_{2a}^{{\mathrm{\&lambda;}}_1}-{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_1}{\mathrm{\&Delta;}}_{2a}^{{\mathrm{\&lambda;}}_2}}{({\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_1}{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_2}-{\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_2}{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_1})}---\left(15\right)$

$\mathrm{\&Delta;<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2=\frac{{\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_2}\mathrm{\&Delta;}{\mathrm{\&mu;}}_{2a}^{{\mathrm{\&lambda;}}_1}-{\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_1}\mathrm{\&Delta;}{\mathrm{\&mu;}}_{2a}^{{\mathrm{\&lambda;}}_2}}{({\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_1}{\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_2}-{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="2"\; label="Hb\; O"\; filenames="A20051000004300351.png,A20051000004300372.png"\; state="\{\{state\}\}">Hb</figure-callout>}{O}_{}{}_2}^{{\mathrm{\&lambda;}}_2}{\mathrm{\&epsiv;}}_{\mathrm{Hb}}^{{\mathrm{\&lambda;}}_1})}---\left(16\right)$

Wherein Δ Hb, Δ HbO ₂, Δ μ _aBe respectively the variable quantity of Deoxygenated blood red pigment concentration, oxygenated blood red pigment concentration and haemachrome absorptance, ε _Hb ^{λ 1}, ε _HbO2 ^{λ 1}, ε _Hb ^{λ 2}, ε _HbO2 ^{λ 2}Be respectively haemachrome under anoxia and oxygenation state to different wave length λ ₁And λ ₂Not ear extinction coefficient (molarextinction coefficient), be known parameters.Can try to achieve the diffusion polarization photon to amplitude fading and the Phase delay of density wave (DPPDW) in blood by apparatus of the present invention, calculate the μ of haemachrome according to equation (3)～(8) again _s' and μ _aUtilize different wave length λ ₁And λ ₂Can accurately try to achieve haemachrome absorptance μ _a(λ ₁) and μ _a(λ ₂) value, and finish the real-time measurement that blood oxygen saturation changes, also can cooperate separating of diffusion equation to obtain the image of blood oxygen saturation simultaneously by spacescan.The present invention proposes a kind of differential type near-infrared polarized photon to spectrometer measurement method and device, and utilizes circle polarization photon can effectively obtain the optical characteristics (μ of scattering medium to laser beam to laser beam or line polarization photon _a, μ _s') measurement, via the tested object of scanning, cooperate the separating of diffusion equation can be again to object image-forming in scattering medium, also can accurately and in real time measure the μ of different wave length simultaneously by bifrequency circle (or line) polarization LASER Light Source of two kinds of different centre wavelengths _s' (λ) and μ _a(λ) value further records Deoxygenated blood red pigment concentration Hb, oxygenated blood red pigment concentration HbO ₂Variable quantity and blood oxygen saturation SaO ₂Variable quantity, and obtain the image of blood oxygen saturation via scanning.

Experimental result:

Figure 11 a to Figure 16 is the experimental result with the system architecture gained of Fig. 3, Figure 11 a wherein, the experiment situation of 11b is in one even 10% Intralipid-10% solution, the diffusion polarization photon to density wave (Figure 11 is the chart of amplitude spheric wave front (unit is dBm) and (Figure 11 b) phase place spheric wave front (unit is degree (degree)) experimental result a), and Figure 12 a, 12b is in the Intralipid of three kinds of different volumes concentration solution, the diffusion polarization photon to density wave (Figure 12 a) amplitude fading and (Figure 12 b) Phase delay to the linear relationship chart of the spacing distance r of signal optical fibre and detecting optical fiber, Figure 13 a, 13b is in the Intralipid-10% solution of 15% volumetric concentration (volume concentration), before adding assimilate india ink with add the amplitude fading of diffusion polarization photon behind the assimilate india ink to density wave (Figure 13 a) with the reaction of Phase delay (Figure 13 b) r that adjusts the distance, Figure 14 a, 14b is in the Intralipid-10% of 15% volumetric concentration solution, at three kinds of light source beat frequency (1.8MHZ, 2.6MHZ, 20MHZ) down the diffusion polarization photon to the amplitude fading of density wave (Figure 14 a) with the linear relationship chart of Phase delay (Figure 14 b) r that adjusts the distance, Figure 15 is that the light source beat frequency is 20MHz, the volumetric concentration of Intralipid-10% solution is propagated the linear relationship chart of scattering coefficient to measured solution, Figure 16 is in the Intralipid-10% of 15% volumetric concentration solution, the light source beat frequency is 20MHz, the assimilate that is added (absorber) Methylene-Blue concentration is to the linear relationship chart of measured solution absorption coefficient, by the feasibility of this system of above-mentioned experimental result susceptible of proof.

The above only is preferred embodiment of the present invention; so it is not in order to limit scope of the present invention; any personnel that are familiar with this technology; without departing from the spirit and scope of the present invention; can do further improvement and variation on this basis, so the scope that claims were defined that protection scope of the present invention is worked as with the application is as the criterion.

Being simply described as follows of symbol in the accompanying drawing:

100,101～bifrequency circle polarization LASER Light Source

102,220～reflecting surface mirror

103,190,200,201,340～spectroscope

104～λ/2 wave plates

105～λ/4 wave plates

130,131～polarized light spectroscope

140,141,142,150,250,251,290,291,330,331～light detection device

160,161,162,170,300,301～signal amplifying apparatus

180～differential amplifying device

195,230,231,280,281～polaroid

210～microcobjective

24～spacescan device

240～signal optical fibre

260～scattering medium

270～detecting optical fiber

300,301～signal amplifying apparatus

310,311～band pass filter means

320～signal processing apparatus

350,351～optical filter

410,510～circle polarization photon is to laser beam

420,520,710,720～line polarization photon is to laser beam

420 '～bifrequency line polarization photon is to laser beam

430,440～diffusion polarization photon is to density wave (DPPDW)

450～signal beams

460～reference beam

500,501,600～bifrequency line polarization LASER Light Source

610～thing to be detected

Claims (11)

1, a kind of near-infrared polarized photon is characterized in that to the spectrometer measurement method described near-infrared polarized photon may further comprise the steps the spectrometer measurement method:

A. with bifrequency circle or line polarization photon to laser beam incident to high concentration scattering medium after, produce a diffusion polarization photon to density wave;

B. utilize a spacescan device that this high concentration scattering medium is made spacescan, to detect this diffusion polarization photon to density wave;

C. see through a smooth detection device again and receive this diffusion polarization photon that this spacescan device scans density wave;

D. seeing through a signal processing apparatus calculates by the phase place and the amplitude signal spatial distribution of this diffusion polarization photon behind this light detection device to density wave, and calculate the propagation scattering coefficient of this scattering medium and the spatial distribution of absorptance, with the image that reduces in this high concentration scattering medium.

2, a kind of near-infrared polarized photon is characterized in that to the spectrometer measurement method described near-infrared polarized photon may further comprise the steps the spectrometer measurement method:

A. with the bifrequency polarization photon of at least two kinds of different centre wavelengths to laser beam incident to high concentration scattering medium after, produce a diffusion polarization photon to density wave;

B. utilize a spacescan to be installed on this high concentration scattering medium and make spacescan, to detect this diffusion polarization photon to density wave;

C. see through a smooth detection device again and receive this diffusion polarization photon that this spacescan device scans density wave;

D. by Deoxygenated blood red pigment and oxygenated blood red pigment same wavelength there is absorptance reaction inequality, finishes dual wavelength or multi-wavelength near-infrared polarized photon the spectrometer measurement method.

3, a kind of near-infrared polarized photon is to the spectrometer measurement device, is applied in the scattering medium it is characterized in that in the hope of object image described near-infrared polarized photon comprises the spectrometer measurement device:

One bifrequency polarization LASER Light Source, interrelated in order to produce, a mutually perpendicular bifrequency polarization photon are to laser beam, and this bifrequency polarization photon can produce a diffusion polarization photon to density wave after laser beam is entered this scattering medium;

One reference light difference interference signal, the beat frequency of this reference light difference interference signal is identical to the beat frequency of density wave difference interference signal with this diffusion polarization photon;

One spacescan device is that this scattering medium is made spacescan;

One smooth detection device is that this diffusion polarization photon of detecting is to density wave; And

One signal processing apparatus in order to calculating by phase place and amplitude signal and the spatial distribution of this diffusion polarization photon behind this light detection device to density wave, and is tried to achieve absorptance and the spatial distribution of propagating scattering coefficient in the scattering medium.

4, near-infrared polarized photon according to claim 3 is to the spectrometer measurement device, it is characterized in that: this bifrequency polarization LASER Light Source is to be bifrequency circle polarization LASER Light Source, this bifrequency polarization laser beam is to be bifrequency circle polarization laser beam, and this diffusion polarization photon is by this bifrequency circle polarization photon laser beam to be produced in scattering medium to density wave.

5, near-infrared polarized photon according to claim 4 is to the spectrometer measurement device, it is characterized in that: this measuring device more comprises a polaroid, after this circle polarization diffusion polarization photon passes through this polaroid and this light detection device to density wave, produce a difference interference signal.

6, near-infrared polarized photon according to claim 4 is to the spectrometer measurement device, it is characterized in that: this measuring device more comprises a polarization spectroscope and a differential amplifying device, this diffusion polarization photon passes through this polarization spectroscope to density wave, and on this light detection device, produce the difference interference signal simultaneously respectively, and be input to this differential amplifying device to form bifrequency differential type near-infrared polarized photon to spectrogrph.

7, near-infrared polarized photon according to claim 3 is to the spectrometer measurement device, it is characterized in that: this bifrequency polarization LASER Light Source is to be bifrequency line polarization LASER Light Source, this bifrequency polarization laser beam is to be bifrequency line polarization laser beam, and this diffusion polarization photon is by this bifrequency line polarization photon laser beam to be produced in scattering medium to density wave.

8, near-infrared polarized photon according to claim 7 is to the spectrometer measurement device, it is characterized in that: this measuring device more comprises a polaroid, this line polarization photon to laser beam by producing a line polarization photon parallel to each other behind this polaroid to laser beam.

9, near-infrared polarized photon according to claim 7 is to the spectrometer measurement device, it is characterized in that: this measuring device more comprises a λ/2 wave plates and a polarization spectroscope, after this line polarization photon passes through this λ/2 wave plates to laser beam, cause line polarization photon that the laser beam polarised direction is rotated an angle, again by this polarization spectroscope, and the difference interference signal that produces on this light detection device is input in the differential amplifying device, form line polarization differential type near-infrared polarized photon to spectrogrph.

10, near-infrared polarized photon according to claim 3 is characterized in that the spectrometer measurement device: this measuring device more includes a differential amplifying device, and this differential amplifying device and this signal processing apparatus electrically connect.

11, near-infrared polarized photon according to claim 3 is to the spectrometer measurement device, it is characterized in that: this bifrequency polarization LASER Light Source is the bifrequency polarization LASER Light Source that has different centre wavelengths for many groups, and this diffusion polarization photon of measuring different centre wavelengths simultaneously is to density wave amplitude and phase signal, calculating blood oxygen saturation, and obtain the blood oxygen saturation image via spacescan.

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