阅读说明：本技术 计算血流速度的方法、装置、介质及血流成像方法和系统 (Calculate method, apparatus, medium and the blood flow imaging method and system of blood flow velocity ) 是由 李鹏程 洪嘉驰 陆锦玲 于 2019-07-31 设计创作，主要内容包括：本发明公开了一种计算血流速度的方法、装置、存储介质以及血流成像方法和系统,其中,计算血流速度方法包括：获取步骤,获取N帧被测对象的原始散斑图像；组成像素集步骤,获取N帧所述原始散斑图像中相同像素区域的像素以组成像素集；计算统计量步骤,计算所述像素集的信号强度以及信号强度倒数的协方差,获得所述像素区域中对应的时间序列上所有像素的统计量；计算血流速度步骤,根据所述统计量计算所述像素区域的血流速度。本发明的计算血流速度方法可以减小原始散斑图像帧数对血流速度估计的影响,提高信噪比和准确性。(The invention discloses a kind of method, apparatus, storage medium and blood flow imaging method and systems for calculating blood flow velocity, wherein calculating blood flow velocity method includes: obtaining step, obtains the original speckle image of N frame measurand；Set of pixels step is formed, obtains the pixel in same pixel region in original speckle image described in N frame to form set of pixels；Counting statistics amount step calculates the signal strength of the set of pixels and the covariance of signal strength inverse, obtains the statistic of all pixels in corresponding time series in the pixel region；Blood flow velocity step is calculated, according to the blood flow velocity of pixel region described in the normalized set.Calculating blood flow velocity method of the invention can reduce the influence that original speckle image frame number estimates blood flow velocity, improve signal-to-noise ratio and accuracy.)

1. a kind of method for calculating blood flow velocity, which is characterized in that the described method includes:

Obtaining step obtains the original speckle image of N frame measurand；

Set of pixels step is formed, obtains the pixel in same pixel region in original speckle image described in N frame to form set of pixels；

Counting statistics amount step, calculates the signal strength of the set of pixels and the covariance of signal strength inverse, described in acquisition In pixel region in corresponding time series all pixels statistic；

Blood flow velocity step is calculated, according to the blood flow velocity of pixel region described in the normalized set.

2. the method according to claim 1 for calculating blood flow velocity, which is characterized in that the method also includes:

The composition set of pixels step, the Counting statistics amount step and the calculating blood flow velocity step are repeated, described in traversal Original speckle image obtains the blood flow velocity of each of the original speckle image pixel region.

3. the method according to claim 1 for calculating blood flow velocity, which is characterized in that obtain the system by following formula Metering:

Wherein,

MAC is the statistic, and N is the frame number of the original speckle image, I_jIt is original described in jth frame at the pixel region The signal strength of speckle image.

4. the method according to claim 3 for calculating blood flow velocity, which is characterized in that be calculated by the following formula the blood Flow velocity degree:

Wherein, v is the blood flow velocity, and k is calibration coefficient.

5. the method according to claim 1 for calculating blood flow velocity, which is characterized in that the acquisition N frame measurand Original speckle image includes:

Pass through laser speckle imaging, ultrasound speckle imaging, single-point detection, Mapping, linear array scanning imaging and planar array scanning Any mode in imaging obtains the original speckle image of the measurand, and obtains original speckle image described in N frame.

6. a kind of speckle blood flow imaging method, which is characterized in that

Blood flow velocity is obtained using the method as described in any one in claim 1-5 for calculating blood flow velocity；

Blood distribution figure is generated according to the blood flow velocity.

7. a kind of computer readable storage medium, which is characterized in that be stored with computer executable instructions, the computer can be held Row instruction is arranged to carry out the method as described in any one in claim 1-5 for calculating blood flow velocity, or executes such as claim 6 The speckle blood flow imaging method.

8. a kind of information processing unit characterized by comprising

At least one processor；And

The memory being connect at least one described processor communication；Wherein,

The memory is stored with the instruction that can be executed by least one described processor, and described instruction is by described at least one When managing device execution, at least one described processor perform claim is made to require the described in any item methods for calculating blood flow velocity of 1-5, Alternatively, making speckle blood flow imaging method described at least one processor perform claim requirement 6.

9. a kind of speckle flow imaging system characterized by comprising

Emitter, for emitting laser or ultrasonic signal to measurand；

Acquisition device obtains the original speckle image of N frame for acquiring the light wave or ultrasonic signal of the measurand reflection；

Information processing unit as claimed in claim 8, the information processing unit are connect with the acquisition device.

10. speckle flow imaging system according to claim 9, which is characterized in that the acquisition device includes that laser dissipates Spot imaging device, ultrasound speckle imaging device, single point detection device, Mapping device, linear array scanning imaging device and face One of battle array scanned imagery device.

Technical field

The present invention relates to technical field of imaging, more particularly, to a kind of method for calculating blood flow velocity, calculate blood flow velocity Device, computer readable storage medium and speckle blood flow imaging method and speckle flow imaging system.

Background technique

Laser speckle contrast imaging technology is widely used in studying biological tissue blood flow's velocity variations, have it is contactless, The characteristics of wide field and high-resolution, has broad application prospects in clinical diagnosis and treatment.

But in the related technology, the laser speckle of use contrasts analysis method estimation blood flow velocity, fast-changing monitoring When blood flow, the original speckle image frame number of actual acquisition is limited, is influenced by the speckle image frame number acquired, different frame numbers are estimated The blood flow velocity difference arrived is larger, especially when frame number is less than 10 frame；And in the slow thin vessels region of blood flow velocity Statistical noise is larger, and noise is relatively low, the blood flow velocity inaccuracy of estimation.

Summary of the invention

The present invention is directed at least solve one of the technical problems existing in the prior art.For this purpose, one object of the present invention It is to propose that a kind of method for calculating blood flow velocity, the method for the calculating blood flow velocity can reduce original speckle image frame number Influence to blood flow velocity estimation improves signal-to-noise ratio and estimation result accuracy.

The second object of the present invention is to propose a kind of speckle blood flow imaging method.

The third object of the present invention is to propose a kind of computer readable storage medium.

The fourth object of the present invention is to propose a kind of information processing unit.

The fifth object of the present invention is to propose a kind of speckle flow imaging system.

To solve the above-mentioned problems, the method for the calculating blood flow velocity of first aspect present invention embodiment, comprising: obtain step Suddenly, the original speckle image of N frame measurand is obtained；Set of pixels step is formed, is obtained identical in original speckle image described in N frame The pixel of pixel region is to form set of pixels；Counting statistics amount step, signal strength and the signal for calculating the set of pixels are strong Covariance reciprocal is spent, the statistic of all pixels in corresponding time series in the pixel region is obtained；Calculate Hemodynamic environment Step is spent, according to the blood flow velocity of pixel region described in the normalized set.

The method according to an embodiment of the present invention for calculating blood flow velocity, by the signal strength and signal that calculate set of pixels The covariance of intensity inverse obtains statistic, and according to the blood flow velocity of the normalized set pixel region, dissipates compared to laser Spot contrasts method, can reduce influence of the sampling frame number of original speckle image to blood flow velocity estimated result, improves signal-to-noise ratio With the accuracy of estimation result, particularly with the small angiosomes of blood flow velocity.

In some embodiments, the method also includes: repeat the composition set of pixels step, the Counting statistics amount walks The rapid and calculating blood flow velocity step traverses the original speckle image, and it is described to obtain each of described original speckle image The blood flow velocity of pixel region.The signal-to-noise ratio of blood flow velocity estimation is also improved simultaneously, it is slow especially for blood flow velocity Thin vessels region.

In some embodiments, the statistic is obtained by following formula:

Wherein,

MAC is the statistic, and N is the frame number of the original speckle image, I_jFor described in jth frame at the pixel region The signal strength of original speckle image.

In some embodiments, it is calculated by the following formula the blood flow velocity:

Wherein, v is the blood flow velocity, and K is calibration coefficient.

In some embodiments, it is described obtain N frame measurand original speckle image include: by laser speckle at Any mode in picture, ultrasound speckle imaging, single-point detection, Mapping, linear array scanning imaging and planar array scanning imaging The original speckle image of the measurand is obtained, and obtains original speckle image described in N frame.

The speckle blood flow imaging method of second aspect of the present invention embodiment, comprising: using the calculating blood flow velocity Method obtains blood flow velocity；Blood distribution figure is generated according to the blood flow velocity.

Speckle blood flow imaging method according to an embodiment of the present invention, by using the calculating blood flow velocity of above example Method obtains blood flow velocity using the analysis of covariance, image quality can be improved, and improves signal-to-noise ratio and accuracy.

The computer readable storage medium of third aspect present invention embodiment, comprising: computer executable instructions are stored with, The method that the computer executable instructions are arranged to carry out the calculatings blood flow velocity, or speckle blood flow described in executing at Image space method.

The device of the information processing of fourth aspect present invention embodiment, comprising: at least one processor；And with it is described extremely The memory of few processor communication connection；Wherein, the memory, which is stored with, to be executed by least one described processor Instruction, when described instruction is executed by least one described processor, at least one described processor is made to execute the calculating The method of blood flow velocity, alternatively, at least one described processor is made to execute the speckle blood flow imaging method.

The speckle flow imaging system of fifth aspect present invention embodiment, comprising: emitter, for emitting laser or surpassing Acoustic signals are to measurand；Acquisition device obtains N for acquiring the light wave or ultrasonic signal of the measurand reflection The original speckle image of frame；Information processing unit, the information processing unit are connect with the acquisition device.

Speckle flow imaging system according to an embodiment of the present invention, by using the information processing unit of above example, Contrast method compared to laser speckle, can reduce the shadow for acquiring the frame number of original speckle image to blood flow velocity estimated result It rings, improves the signal-to-noise ratio of thin vessels region blood flow velocity estimation slow for blood flow velocity, improve to biological tissue's Hemodynamic environment Two dimensional Distribution image quality is spent, and there is lower calculating time complexity, improves the real-time of blood flow measurement.

In some embodiments, the acquisition device includes laser speckle imaging device, ultrasound speckle imaging device, single-point One of detection device, Mapping device, linear array scanning device and planar array scanning imaging device.

Additional aspect and advantage of the invention will be set forth in part in the description, and will partially become from the following description Obviously, or practice through the invention is recognized.

Detailed description of the invention

Above-mentioned and/or additional aspect of the invention and advantage will become from the description of the embodiment in conjunction with the following figures Obviously and it is readily appreciated that, in which:

Fig. 1 is the flow chart according to an embodiment of the invention for calculating blood flow velocity method；

Fig. 2 is the flow chart of calculating blood flow velocity method according to another embodiment of the invention；

Fig. 3 is the flow chart of speckle blood flow imaging method according to an embodiment of the invention；

Fig. 4 is the structural block diagram of information processing unit according to an embodiment of the invention；

Fig. 5 is the block diagram of speckle flow imaging system according to an embodiment of the invention；

(a)-(c) in Fig. 6 is to be tried using the method and laser speckle contrast imaging method of the embodiment of the present invention in model Test the schematic diagram of comparison result；

(a)-(m) in Fig. 7 is method and laser speckle contrast imaging method using the embodiment of the present invention in animal reality Test the schematic diagram of comparison result；

(a)-(d) in Fig. 8 is made an uproar using the statistics of the method and laser speckle contrast imaging method of the embodiment of the present invention The schematic diagram of sound comparison result in zoopery；

(a)-(b) in Fig. 9 is method and laser speckle contrast imaging method using the embodiment of the present invention when calculating Between the schematic diagram of result is analyzed in complexity；

Specific embodiment

The embodiment of the present invention is described below in detail, the embodiment being described with reference to the drawings is exemplary, and is retouched in detail below State the embodiment of the present invention.

Below with reference to the accompanying drawings the method for the calculating blood flow velocity of embodiment according to a first aspect of the present invention is described.According to the party Method can reduce influence of the original speckle image frame number to blood flow velocity estimated result, be conducive to change according to situation in practical applications Measurement result is not influenced when becoming the frame number of original speckle image, and signal-to-noise ratio can be improved, it is small particularly with blood flow velocity Angiosomes.

Fig. 1 shows the flow chart of the calculating blood flow velocity method of one embodiment of the present of invention offer.As shown in Figure 1, The method of the calculating blood flow velocity of the embodiment of the present invention includes step S1-S4.

Step S1, obtaining step obtain the original speckle image of N frame measurand.

In embodiment, for obtaining the mode of original speckle image with no restrictions, for example, can by laser speckle at Any mode in picture, ultrasound speckle imaging, single-point detection, Mapping, linear array scanning imaging and planar array scanning imaging The original speckle image of measurand is obtained, and acquires n times, to obtain the original speckle image of N frame.

Step S2 forms set of pixels step, obtains the pixel in same pixel region in the original speckle image of N frame with a group imaging Element collection.

Specifically, the original speckle image of N frame that will acquire is divided into multiple pixel regions, for example, by a pixel and its 8 adjacent interior pixels are classified as a pixel region.By the pixel in same pixel region in the original speckle image of N frame with a group imaging Element collection is for example denoted as { I₁,I₂,...,I_N, wherein I_jFor the original speckle image of jth frame at pixel region signal strength for example The intensity of light wave or sound wave, same pixel region can be understood as the picture of same position and size in original speckle image Plain region.

Step S3, Counting statistics amount step calculate the signal strength of set of pixels and the covariance of signal strength inverse, obtain Obtain the statistic of all pixels in corresponding time series in pixel region.

In some embodiments, blood flow velocity can be calculated using the method for auto-reciprocal covariance.Specifically, picture can be based on The signal strength of element collection and the covariance of signal strength inverse obtain corresponding time series in pixel region by following formula The statistic of upper all pixels:

Wherein,

MAC is statistic, and N is the frame number of original speckle image, I_jFor the letter of the original speckle image of jth frame at pixel region Number intensity.

Step S4 calculates blood flow velocity step, according to the blood flow velocity of normalized set pixel region.

Specifically, in some embodiments, with the increase of statistic, blood flow velocity can reduce.For example, can be according to step The resulting statistic MAC of rapid S3, is calculated by the following formula blood flow velocity:

Wherein, v is blood flow velocity, and K is calibration coefficient.

It further, is the blood flow velocity of each pixel region of the original speckle image of acquisition, in some embodiments, this The method of the calculating blood flow velocity of inventive embodiments further includes step S5, as shown in Figure 2:

Step S5, repeating groups pixel collection step, Counting statistics amount step and calculating blood flow velocity step, traverses original dissipate Spot image obtains the blood flow velocity of each pixel region of original speckle image.

Specifically, the different physiology of organism, pathological state often correspond to different blood flow and microcirculating state, to life The detection of object blood vessels in tissue and blood flow is to study the important tool of biological function of organization's activity and pathogenic mechanism.The present invention is implemented Example, blood flow velocity is estimated by the method for covariance, and then can be based on the blood of each pixel region of original speckle image Flow velocity degree generates blood distribution image, supports to provide data for biological function of organization's activity and the research of pathogenic mechanism.

The method of the calculating blood flow velocity of the embodiment of the present invention can be used for estimating the variation of cortex blood flow, SkBF Variation, blood flow velocity of biological tissue etc., for example, caused by the nervous activity of experimental animals such as research rat, mouse, rabbit, monkey The blood flow variation of human body superficial skin caused by the variation of cortex blood flow and diagnosis skin disease.

The method of calculating blood flow velocity based on above example 3 describes second party according to the present invention with reference to the accompanying drawings The speckle blood flow imaging method of face embodiment.

As shown in figure 3, the speckle blood flow imaging method of the embodiment of the present invention includes step S11 and step S12.

Step S11 obtains blood flow velocity.

It specifically, can be according to the method for the calculating blood flow velocity of above example, to obtain the every of original speckle image The blood flow velocity of a pixel region.

Step S12 generates blood distribution figure according to blood flow velocity.

Speckle blood flow imaging method according to an embodiment of the present invention, by using the calculating blood flow velocity of above example Method obtains blood flow velocity using the analysis of covariance, image quality can be improved, and improves signal-to-noise ratio and accuracy.

Third aspect present invention embodiment provides a kind of computer readable storage medium, the computer readable storage medium Computer executable instructions are stored with, wherein computer executable instructions are arranged to carry out the calculating blood flow velocity of above example Method, or execute speckle blood flow imaging method, thus for calculating blood flow velocity realization basis is provided.

The 4 description information processing unit that embodiment provides according to a fourth aspect of the present invention with reference to the accompanying drawings.

As shown in figure 4, the calculating blood flow velocity device 10 of the embodiment of the present invention include at least one processor 100 and with The memory 200 of at least one processor communication connection.

Further, memory 200 is stored with the instruction that can be executed by least one processor 100, instructs by least one When a processor 100 executes, at least one processor 100 is set to execute the method for calculating blood flow velocity, alternatively, making at least one It manages device 100 and executes speckle blood flow imaging method, supported to provide data for blood flow imaging.

The method of calculating blood flow velocity based on foregoing embodiments describes fifth aspect present invention implementation with reference to the accompanying drawings The speckle flow imaging system that example provides.

As shown in figure 5, the speckle flow imaging system 1 of fifth aspect present invention embodiment includes information processing unit 10, Acquisition device 20 and emitter 30.Emitter 30, for emitting laser or ultrasonic signal to measurand.Acquisition device 20, for acquiring the light wave or ultrasonic signal of measurand reflection, obtain the original speckle image of N frame.

Specifically, emitter 30 exposes to wave signal such as laser beam or acoustic signals in measurand, then The wave signal that the reflection of N frame measurand is acquired by acquisition device 20, obtains the original speckle image of N frame.Wherein, in some embodiments In, acquisition device 20 includes laser speckle imaging device, ultrasound speckle imaging device, single point detection device, Mapping dress It sets, one of linear array scanning imaging device and planar array scanning imaging device, for example, by laser speckle imaging device to acquisition Optical signal be imaged to obtain original speckle image, alternatively, pass through ultrasound speckle imaging or single-point detection or spot scan face The mode of battle array scanning obtains original speckle image, is not specifically limited to this.

Information processing unit 10, for calculating blood flow velocity and generating blood distribution figure.Specifically, information processing unit 10 Method by executing the calculating blood flow velocity of above example, or the speckle blood flow imaging method of above example is executed, The blood flow velocity of each pixel region of original speckle image is obtained, and blood distribution figure is generated according to gained blood flow velocity.

Speckle flow imaging system 1 according to an embodiment of the present invention, by using the information processing unit of above example 10, it can reduce influence of the original speckle image frame number to blood flow velocity estimated result, be conducive in practical applications according to situation Without influencing measurement result when changing original speckle image frame number；The signal-to-noise ratio for improving blood flow velocity estimation, especially for Image quality is improved in the slow thin vessels region of blood flow velocity；The system also has lower calculating time complexity simultaneously, mentions The high real-time of blood flow measurement.

Blood flow imaging is carried out using the method for the calculating blood flow velocity of the embodiment of the present invention below by two description of test Possessed advantage.In embodiment, it can be obtained respectively by model test and zoopery using the embodiment of the present invention The result being imaged by Covariance Analysis Technique and the result using laser speckle contrast imaging.

1, model experiment:

The flowing speed for 1% fat emulsion solution in glass capillary for being 500 microns by step motor control internal diameter The laser beam that the semiconductor laser that wavelength is 785nm generates is radiated above glass capillary by degree, while with CCD phase Machine acquires the reflected optical signal of glass capillary right above glass capillary, to obtain original speckle image.Setting Time for exposure is 10ms.

Experimental result is as shown in fig. 6, Fig. 6 is existing laser speckle contrast imaging method and the association using the embodiment of the present invention The imaging method of variance analysis resulting comparison result in model experiment.Wherein, K_N ²It is using laser speckle contrast imaging side The statistic of method, MAC_NIt is the statistic using the analysis of covariance imaging method of the embodiment of the present invention.(a)~(c) points in Fig. 6 The result that two methods measure under 0,0.1,0.2mm/s scattering liquid flow velocity is not corresponded to.Horizontal axis is sampling frame number, is indulged Axis is blood flow index.

In above-mentioned experiment, for each original speckle image, statistic K is obtained respectively by two methods_N ²And MAC_N, To estimate average value BFI (Blood flow index, blood flow index).(a)~(c) respectively corresponds two kinds as shown in Figure 6 The BFI that method measures under 0,0.1,0.2mm/s scattering liquid flow velocity respectively.As can be seen that according to K_N ²Estimation obtains BFI be obviously reduced with the increase of sampling frame number N, according to MAC_NEstimate the BFI kept stable value obtained, i.e., it is of the invention The method that blood flow velocity is calculated using the analysis of covariance of embodiment is influenced small by sampling frame number N.

2, zoopery:

Experimental subjects is C57BL mouse, fixes on the table, the semiconductor laser that wavelength is 785nm is generated Laser beam is radiated on the mouse cortex of removal cranium, is acquired and is reflected back right above glass capillary with CCD camera The optical signal come obtains original speckle image.Imaging system amplification factor is set as 4 times, time for exposure 10ms.

Experimental result is as shown in fig. 7, Fig. 7 is existing laser speckle contrast imaging method (Fig. 7 (a)) and uses of the invention Comparison result of the Covariance Analysis Technique (Fig. 7 (b)) of embodiment in zoopery.(c)~(f) is existing sharp in Fig. 7 Light speckle contrast imaging method under the different sampling frame numbers of acquisition Fig. 7 (a) boxed area as a result, (g)~(j) is in Fig. 7 The result of the Covariance Analysis Technique of embodiment of the present invention Fig. 7 (b) boxed area under the different sampling frame numbers of acquisition.Fig. 7 (k) Be existing laser speckle contrast imaging method under the different sampling frame numbers of acquisition at Fig. 7 (a) horizontal line as a result, Fig. 7 (l) is Result of the Covariance Analysis Technique of the embodiment of the present invention under the different sampling frame numbers of acquisition at Fig. 7 (b) horizontal line.Fig. 7 (m) is The value of delta of the result of N=2 and N=20.

In above-mentioned experiment, as shown in fig. 7, wherein (a) and (b) shows the BFI that two methods are obtained from mouse cortex Respectively K_N ²And MAC_N.(c)~(f) is shown in boxed area in (a) and is obtained respectively by existing laser speckle contrast imaging method Take sampling frame number N=2,5,10 and 20 when resulting result.(g)~(j) is shown in boxed area in (b) to be implemented through the invention The Covariance Analysis Technique of example obtains sampling frame number N=2 respectively, 5,10 and 20 when resulting result.Pass through (c)~(f) and (g) ~(j) comparison is as can be seen that K_N ²Depending on the size of sampling frame number N, and MAC_NImage between there is no notable difference.(k) it shows Show in (a) and sampling frame number N=2 to be obtained by existing laser speckle contrast imaging method respectively at horizontal line, 5,10 and 20 whens institute The result obtained.(l) it is shown in the Covariance Analysis Technique in (b) at horizontal line through the embodiment of the present invention and obtains sampling frame number respectively N=2,5,10 and 20 when resulting result.By being compared (k) and (l) as can be seen that K_N ²It is influenced by sampling frame number N, And MAC_NIt is influenced by sampling frame number smaller.In addition, showing two methods in sampling frame number N=2 and N=20 in (m) respectively The value of delta of BFI result.It can be seen that K_N ²Value of delta be 3, and MAC_NValue of delta be 0.Wherein, although BFI is average value, Due to limited sample size, this two curves can be fluctuated.

By two above test income analysis result it can be concluded that, as shown in Figure 6 and Figure 7, with existing laser speckle Contrast blood flow imaging method to compare, under different flow velocitys, blood flow velocity is calculated using the covariance method of the embodiment of the present invention Method there is the constant characteristic of mean value, i.e., blood flow velocity calculated is influenced smaller by the sampling frame number N obtained.

It is the system of existing laser speckle contrast imaging method and Covariance Analysis Technique of the embodiment of the present invention as shown in Figure 8 Count comparison result of the noise in zoopery.(a) pixel 1,2 and 3 respectively corresponds the region that blood flow velocity successively reduces in. (b) be theory deduction two methods statistical noise value of delta f.(c) be the two methods that practical zoopery obtains statistics Noise value of delta f.(d) be under 95.5% confidence level the embodiment of the present invention relative to existing laser speckle contrast imaging side The error rate δ E that method reduces.

In above-mentioned experiment, as shown in figure 8, figure (b) is shown under different sampling frame numbers, when the range of BFI is 10-50 When, the fluctuating change of the statistical noise value of delta f of two methods.It can be seen that MAC_NFluctuation to K_N ²Influence very little, especially When being BFI smaller.In addition with the reduction of sampling frame number N, K_N ²And MAC_NBetween fluctuation difference become larger.It is selected at random in (a) Selecting blood flow velocity successively reduces pixel 1,2 and 3 regions for comparing K_N ²And MAC_NFluctuation difference.(c) then show that difference is adopted The K of pixel 1,2 and 3 regions in (a) of sample frame number N_N ²And MAC_NFluctuation between difference.As can be seen that pixel 1,2,3 represents The blood vessel of different-diameter, wherein pixel 3 corresponds to the slow thin vessels region of blood flow velocity.With the reduction of blood flow velocity, statistics Noise value of delta f is gradually increased.In addition, the worst error estimated under 95.5% confidence level is defined asWherein f For K_N ²Or MAC_NFluctuation.(d) it is shown in the error rate δ E that two methods reduce under 95.5% confidence level, whereinAs can be seen that the K in pixel 1,2,3 at different sampling frame number N_N ²And MAC_NReduced mistake Rate δ E increases with the reduction of blood flow velocity, this shows MAC_NBlood flow in the slow thin vessels region of blood flow velocity can be improved The estimation of amount.Therefore there is higher signal-to-noise ratio by the method that Fig. 7 can obtain the analysis of covariance of the embodiment of the present invention, it is especially right In the slow thin vessels region of blood flow velocity.

It is existing laser speckle contrast imaging method and the embodiment of the present invention as shown in Figure 9 on calculating time complexity Analysis result.(a) K of different sampling frame number N and pixel quantity are shown respectively with (b)_N ²And MAC_NBetween calculate the time difference It is different.By comparison it can be seen that the analysis of covariance of the embodiment of the present invention method have faster speed, calculating treatmenting time compared with It is short.

The above is preferable implementation of the invention, but invention should not be limited to disclosed in the embodiment and attached drawing Content.So all do not depart from the lower equivalent or modification completed of spirit disclosed in this invention, the model all protected in the present invention It encloses.

In the description of this specification, reference term " one embodiment ", " some embodiments ", " illustrative examples ", The description of " example ", " specific example " or " some examples " etc. means specific features described in conjunction with this embodiment or example, knot Structure, material or feature are included at least one embodiment or example of the invention.In the present specification, to above-mentioned term Schematic representation may not refer to the same embodiment or example.

Although an embodiment of the present invention has been shown and described, it will be understood by those skilled in the art that: not A variety of change, modification, replacement and modification can be carried out to these embodiments in the case where being detached from the principle of the present invention and objective, this The range of invention is defined by the claims and their equivalents.