CN111543959B - Coherence tomography system and reference wavefront correction method, device and equipment - Google Patents

Abstract

The invention discloses an optical coherence tomography imaging system, which includes a light source, an interferometer, a photodetector, and a temperature control device. A reference arm in the interferometer includes a spherical reflector; wherein, the back of the spherical reflector is attached with glue The surface of the rubber pad facing away from the spherical reflector is evenly provided with a plurality of heating pieces; each heating piece is connected with a temperature control device; the temperature control device is used to control the heating of each heating piece according to the contrast of the interference fringes collected by the photodetector The mirror is heated and deformed so that the contrast of the interference fringes detected by the photodetector reaches a predetermined contrast. In this application, the reference arm adopts a spherical reflector, which can directly reflect the incident spherical wave, and the heating plate on the back can change the shape of the spherical reflector, compensate and correct the incident light wave, and improve the contrast of interference fringes. The present application also provides a reference wavefront correction method, device, and device for an optical coherence tomography system, which have the above beneficial effects.

Description

Coherence tomography system and reference wavefront correction method, device and equipment

technical field

The present application relates to the technical field of optical coherence tomography, and in particular, to an optical coherence tomography system and a reference wavefront correction method, device, and device thereof.

Background technique

Optical coherence tomography (OCT) is a new three-dimensional tomography technology developed in the 1990s. OCT obtains the tomographic capability in the depth direction based on the principle of low coherence interference. Through scanning, two-dimensional or three-dimensional images of the internal structure of biological tissues or materials can be reconstructed. The signal contrast is derived from the optical reflection (scattering) characteristics of biological tissues or materials. space changes. The tissue characteristics of optical tomographic images obtained by coherence tomography systems are used to determine the targets to be identified for diagnosis. Compared with conventional imaging methods, optical coherence tomography has unique advantages. Its imaging effect is close to pathology, and it has the advantages of non-invasive and non-radiation, real-time observation of living body, high resolution (16 microns), deep imaging in tissue, and 3D image data.

As shown in FIG. 1, FIG. 1 is a schematic diagram of the frame structure of a conventional optical coherence tomography system in the prior art. In FIG. 1, the light beam emitted by the low coherence light source 1 is transmitted to the fiber coupler 2 through the light, and is divided into two paths of light. , one light is transmitted to the reference arm 3 and then reflected and then transmitted to the fiber coupler 2, while the other light is incident on the human tissue 5, and after being reflected by different tissue layers of the human tissue, it returns to the fiber coupler 2 along the original path; The optical path of the beam reflected back to the fiber coupler 2 by the reference arm 3 is different from that of the beam reflected back to the fiber coupler 2 through the human tissue 5. The two beams can interfere, and the interference image is detected by the spectrometer 4. Based on the interference image, that is, Human tissue images are available.

Based on Fig. 1 , the reference arm 3 is mainly composed of a collimating lens group 31 and a reflecting plane mirror 32. Because the light beam transmitted by the optical fiber to the reference arm 3 is a divergent beam, it needs to be converted into a parallel beam by the collimating lens group 31, and then passes through the reflecting plane mirror. 32 reflections can ensure that the beam returns along the original optical path and is transmitted to the fiber coupler 2. Obviously, the end of the optical fiber in the optical path needs to be located at the focal point of the collimating lens group 31, and the optical axis of the collimating lens group 31 needs to be perpendicular to the reflection plane mirror 32. However, in the actual application process, the end of the optical fiber, the collimating lens The alignment accuracy of the relative positions between the group 31 and the reflecting plane mirror 32 is not necessarily perfect, and during the handling of the optical coherence tomography system, the alignment accuracy between the various components will be reduced, thereby affecting the transmission of the light beam , which reduces the contrast of the interference fringes and affects the performance of the optical coherence tomography system.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an optical coherence tomography imaging system and its reference wavefront correction method, device and equipment, which improve the contrast of interference fringes of the optical coherence tomography imaging system, thereby improving the accuracy of human tissue detection.

In order to solve the above technical problems, the present invention provides an optical coherence tomography system, including a light source, an interferometer, a photodetector, and a temperature control device, and the reference arm in the interferometer includes a spherical mirror;

Wherein, a rubber pad is attached to the back of the spherical reflector; a plurality of heating sheets are evenly arranged on the surface of the rubber pad away from the spherical reflector; each of the heating sheets is connected to a temperature control device;

The temperature control device is used to control the heating of each of the heating plates according to the contrast of the interference fringes collected by the photodetector, and the spherical mirror is heated and deformed, so that the contrast of the interference fringes detected by the photodetector reaches a predetermined level. contrast.

Optionally, the spherical reflector is a K9 glass aluminized film reflector.

Optionally, the rubber pad is an RTV rubber pad.

，其中，t为所述RTV胶垫的厚度，

为所述球面反射镜的半径，

为所述加热片热膨胀系数，

为所述球面反射镜的热膨胀系数，

为受载情况下所述RTV胶垫的热膨胀系数Optionally, the thickness of the rubber pad satisfies:

, where t is the thickness of the RTV pad,

is the radius of the spherical mirror,

is the thermal expansion coefficient of the heating sheet,

is the thermal expansion coefficient of the spherical mirror,

is the thermal expansion coefficient of the RTV pad under load

Optionally, the heating sheet is a copper sheet or an aluminum sheet.

The present application also provides a reference wavefront correction method for an optical coherence tomography system, which is applied to the optical coherence tomography system as described in any of the above, including:

According to the interference fringes detected by the photodetector, the interference fringe contrast is obtained;

Determine the heating power of each heating plate according to the contrast of the interference fringes;

The heating plates are heated according to the heating power, and the steps of obtaining the contrast of the interference fringes according to the interference fringes detected by the photodetector are repeated until the contrast of the interference fringes reaches a preset contrast.

Optionally, determining the heating power of each heating plate according to the interference fringe contrast, including:

Pre-collecting interference fringe contrast data of the spherical mirror corresponding to different heating powers of each of the heating plates;

According to the different heating power of each of the heating plates and the interference fringe contrast data corresponding to the heating power, based on neural network learning, determine the correspondence between the different heating powers and the interference fringe contrast;

The heating power of each of the heating plates is determined according to the corresponding relationship and the current contrast of the interference fringes.

Optionally, determining the heating power of each heating plate according to the interference fringe contrast, including:

Based on the parallel gradient descent algorithm in advance, the formula for determining the heating power is:

，其中，

为第n+1次第i个加热片加热的加热功率，

为第n次第i个加热片加热的加热功率，

为第n次加热后对比度的变化值，

为第n次第i个加热片加热的加热功率变化值；

,in,

is the heating power for the n+1th heating of the i-th heating element,

Heating power for heating the nth i-th heating piece,

is the change value of the contrast after the nth heating,

It is the heating power change value for the nth heating of the i-th heating piece;

The heating power of each of the heating sheets is determined according to the heating power.

The present application also provides a reference wavefront correction device for an optical coherence tomography imaging system, which is applied to the optical coherence tomography imaging system as described in any of the above, including:

The contrast acquisition module is used to obtain the contrast of the interference fringes according to the interference fringes detected by the photodetector;

determining a power module for determining the heating power of each heating plate according to the contrast of the interference fringes;

Controlling a heating module for heating each of the heating sheets according to the heating power, and repeating the step of collecting the interference fringe contrast detected by the photodetector until the interference fringe contrast detected by the photodetector is to achieve the preset contrast.

The present application also provides a reference wavefront correction device for an optical coherence tomography system, which is applied to the optical coherence tomography system as described in any of the above, including:

memory for storing computer programs;

The processor is configured to execute the computer program to implement the operation steps of the reference wavefront correction method of the optical coherence tomography system according to any one of the above.

The optical coherence tomography system provided by the present invention includes a light source, an interferometer and a photodetector, as well as a temperature control device, and the reference arm in the interferometer includes a spherical reflector; wherein, the back of the spherical reflector is fitted with a rubber pad ; The surface of the rubber pad facing away from the spherical reflector is evenly arranged with a plurality of heating plates; each heating plate is connected with a temperature control device; the temperature control device is used to control the heating of each heating plate according to the contrast of interference fringes collected by the photodetector, and the spherical reflection The mirror is heated and deformed so that the contrast of the interference fringes detected by the photodetector reaches a predetermined contrast.

In the optical coherence tomography system provided by the present application, the reference arm composed of the collimating lens group and the plane reflector in the conventional technology is replaced by a spherical reflector, so that the spherical reflector can directly realize the detection of incident spherical waves. For reflection, there is no need to collimate the light wave through the collimating lens group, which simplifies the light rate structure to a large extent, avoids the deviation of the beam in the optical path propagation process, and affects the contrast of subsequent interference fringes; A heating plate is arranged on the back of the device, and the surface shape of the spherical mirror can be fine-tuned by heating through the heating plate, so that the spherical mirror can compensate the phase of the incident spherical light wave and improve the contrast of subsequent interference fringes.

The present application also provides an optical coherence tomography imaging method, device and device, which have the above beneficial effects.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following will briefly introduce the accompanying drawings used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic diagram of a frame structure of a conventional optical coherence tomography system in the prior art;

2 is a schematic structural diagram of an optical coherence tomography system provided by an embodiment of the present application;

3 is a schematic structural diagram of the back surface of the spherical mirror provided by the embodiment of the present application;

Figure 4 is a graph showing the relationship between the shape factor and the correction coefficient of the RTV pad material;

5 is a schematic flowchart of a reference wavefront correction method of an optical coherence tomography system provided by an embodiment of the present application;

FIG. 6 is a structural block diagram of a reference wavefront correction device of an optical coherence tomography system according to an embodiment of the present invention.

Detailed ways

The core of the present invention is to provide a technical solution for optical coherence tomography, which can greatly improve the contrast of the generated interference fringes, thereby improving the clarity of the detection of human tissue images during the actual application of the optical coherence tomography technology. Spend.

In order to make those skilled in the art better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in FIG. 2 and FIG. 3 , FIG. 2 is a schematic structural diagram of an optical coherence tomography system provided by an embodiment of the present application, and FIG. 3 is a schematic structural schematic diagram of a back surface of a spherical mirror provided by an embodiment of the present application. The system can include:

a light source, specifically a low-coherence laser light source 1;

The interferometer may specifically include components such as a reference arm 3, a fiber coupler 2, and the like;

The photodetector may specifically be the spectrometer 4, and the connection relationship between the photodetector and the light source, reference FIG. 3 and the fiber coupler 2 and other components is the same as the connection method in the prior art in FIG. 1, and will not be repeated here.

Also includes a temperature control device 6, and the reference arm 3 in the interferometer includes a spherical mirror 33;

Wherein, a rubber pad 34 is attached to the back of the spherical mirror 33; a plurality of heating sheets 35 are evenly arranged on the surface of the rubber pad 34 away from the spherical mirror 33; each heating sheet 35 is connected to the temperature control device 6;

The temperature control device 6 is used to control the heating of each heating plate according to the contrast of the interference fringes collected by the photodetector, and the spherical mirror 33 can be deformed when heated, so that the contrast of the interference fringes detected by the photodetector reaches a predetermined contrast.

Specifically, the heating sheet 35 in this embodiment may be an electric heating sheet such as a copper sheet or an aluminum sheet, which can generate heat after being energized.

It should be noted that in the actual application of the optical coherence tomography system, the light beam generated by the light source can be transmitted through the optical fiber to the optical fiber coupler 2, which is split into two light waves by the optical fiber coupler 2, and a part is transmitted to the human tissue 5 through the optical fiber, Another part of the light wave is transmitted to the reference arm 3 through the optical fiber; under normal circumstances, the light wave incident on the reference arm 3 is a spherical light wave, so in this embodiment, the surface shape of the spherical mirror 33 in the reference arm 3 and the wavefront shape of the beam It is the closest, so that the light wave incident into the reference arm 3 can return along the original path to the greatest extent.

Compared with the prior art in which the quasi-lens group 31 is used to first convert the spherical light wave into a parallel beam, and the beam is reflected by the plane mirror 32 to return along the original optical path, the structure of the reference arm 3 in this embodiment is simpler, then In the actual application process, it is largely avoided that the relative positions of the collimating lens group and the plane mirror and other devices are shifted due to the long-term use of the optical coherence tomography system, and the accurate calibration cannot be performed. , resulting in a change in the wavefront of the light beam reflected by the reference arm 3 , which eventually leads to the problem of low contrast of the interference fringes.

In this embodiment, it is also considered that the optical fiber coupler 2 is prone to chromatic dispersion during the stretching and forming process because the light beam needs to pass through multiple optical elements during the transmission process, and in the actual optical path, it also has uneven pupil illumination. and other problems, which eventually also leads to a decrease in the contrast of the formed interference fringes, which affects the detection effect of human tissue.

To this end, in this embodiment, a rubber pad 34 is further attached to the back of the spherical reflector 33, and a heating sheet 35 is arranged on the rubber pad 34. The heating sheet 35 is connected to the temperature control device 6, and the temperature control device 6 The heating plate 35 can be heated, so that the heat generated by the heating of the heating plate 35 is conducted to the spherical mirror 33 through the rubber pad 34, and the spherical mirror 33 is heated to produce a small amount of deformation, thereby changing the surface shape of the spherical mirror 33, so that The changed surface shape of the spherical reflector 33 can perform wavefront correction and compensation for the incident light wave, so as to realize the large-scale dispersion-free focusing and wavefront astigmatism correction of the reference arm 3 to a certain extent, and realize the illumination of the pupil in the optical path. The non-uniform compensation improves the contrast of interference fringes, greatly improves the clarity of the human body images detected and collected by the optical coherence tomography system, and improves the accuracy of the detection results.

Optionally, the spherical reflector 33 in the above embodiment may be a K9 glass aluminized film reflector.

For the rubber pad 34 in the above-mentioned embodiment, an elastic RTV rubber pad can be used to adapt to the deformation of the spherical mirror 33 .

As an elastomer support structure, the size and thickness of the RTV pad play a crucial role in controlling the deformation and displacement of the spherical mirror. The shape factor S of the elastomer in the design factor greatly affects the mechanical properties of the elastomer. performance, the form factor S can be defined as:

；

;

为受载面积的半径，t为RTV胶垫的厚度。实验证明，受约束RTV胶垫的热膨胀系数与材料本身的热膨胀系数有显著差异，因此引入热膨胀校正系数

，热膨胀系数的关系可以表示为：

；其中，

为RTV胶垫材料本身的热膨胀系数，

为受载情况下RTV胶垫的热膨胀系数。Among them, set the load area (loadarea) of the RTV pad as a circle,

is the radius of the loaded area, and t is the thickness of the RTV pad. Experiments have shown that the thermal expansion coefficient of the constrained RTV pad is significantly different from the thermal expansion coefficient of the material itself, so the thermal expansion correction coefficient is introduced.

, the relationship of thermal expansion coefficient can be expressed as:

;in,

is the thermal expansion coefficient of the RTV pad material itself,

is the thermal expansion coefficient of the RTV pad under load.

，可以表示为：

；其中

为在热载荷下RTV胶垫厚度改变量，

为工作温度改变量。Thermal expansion correction factor determined by shape factor S

,It can be expressed as:

;in

is the change in thickness of the RTV pad under thermal load,

is the change in operating temperature.

可知，该形状因子受RTV胶垫的影响。As shown in Figure 4, Figure 4 is a graph showing the relationship between the shape factor and the correction coefficient of the RTV rubber pad material, and different S values correspond to different thermal expansion coefficient correction factors. It can be seen that the corrected thermal expansion coefficient of the RTV pad has a strong correlation with the shape factor S, and according to the shape factor formula:

It can be seen that the shape factor is affected by the RTV pad.

；The thickness of the RTV pad in this embodiment can be expressed by Bayar's equation, Deluzio's equation and Muench's equation. The thickness of the RTV pad can finally be determined

;

为透镜的半径，

为铝片热膨胀系数，

为反射镜的热膨胀系数，

为受载情况下RTV垫片的热膨胀系数。in

is the radius of the lens,

is the thermal expansion coefficient of the aluminum sheet,

is the thermal expansion coefficient of the mirror,

is the thermal expansion coefficient of the RTV gasket under load.

The present application also provides an embodiment of a reference wavefront correction method for an optical coherence tomography system, which is applied to the optical coherence tomography system described in any of the above embodiments, as shown in FIG. 5 , which is the present application The embodiment provides a schematic flowchart of a reference wavefront correction method for an optical coherence tomography system, where the correction method may include:

S1: Obtain the interference fringe contrast according to the interference fringes detected by the photodetector.

Interference fringe contrast is a measure of the sharpness of fringes near a point in the interference field. According to the optical principle, the intensity of the interference fringes can be expressed as:

；

;

是相干光波长，

和

是干涉仪中两干涉臂入射光强，

为复相干度，模为

；相位为

，

为目标源相位，

为两干涉臂光程

与

之差引入相位。干涉条纹对比度（contrast）或可见度（visibility）可表达为条纹振幅与总背景照度之比（illumination），具体可以表示为：

；in,

is the wavelength of coherent light,

and

is the incident light intensity of the two interference arms in the interferometer,

is the complex coherence degree, and the modulus is

; the phase is

,

is the target source phase,

is the optical path of the two interference arms

and

The difference introduces the phase. The interference fringe contrast (contrast) or visibility (visibility) can be expressed as the ratio of the fringe amplitude to the total background illumination (illumination), which can be expressed as:

;

It can be seen from the above formula that the contrast of interference fringes depends on the following three factors: the size of the light source, the non-monochromaticity of the light source, and the amplitude ratio of the two coherent light waves.

，其中，

为干涉条纹光强的极大值、

为干涉条纹光强的极小值。The above formula is the determining formula of the contrast of the interference fringes, and it can also be considered as the formula that the contrast of the interference fringes should satisfy in the theoretical state, but in the actual application process, the interference fringes may , etc. are deviated from the theoretical state, resulting in a shift in the intensity, position and theoretical situation of the interference fringes. Therefore, in the actual application process, in this embodiment, the contrast of the interference fringes is determined based on the actually obtained interference fringes. That is:

,in,

is the maximum value of the light intensity of the interference fringes,

is the minimum value of the light intensity of the interference fringes.

S2: Determine the heating power of each heating plate according to the contrast of the interference fringes.

S3: Each heating piece is heated according to the heating power.

Specifically, heating each heating plate can cause slight deformation of the spherical reflector, thereby changing the surface shape of the spherical reflector, so that the spherical reflector can adjust the wavefront phase and optical path difference of the incident light wave. Correction and compensation are used to eliminate the deviation of the light wave during the transmission process, so that when the light wave reflected by the reference arm interferes with the light wave reflected by the incident human tissue, the contrast of the interference fringes is higher.

S4: Obtain the interference fringe contrast according to the interference fringes detected by the photodetector;

S5: Determine whether the contrast of the interference fringes reaches the preset contrast, and if so, the correction ends, and if not, enter S2.

In this embodiment, the heating adjustment of the heating plate is a trial-and-error adjustment method. First, obtain the contrast of the interference fringes when each heating plate is heated. If the contrast of the interference fringes does not reach the preset contrast, then set the heating power of each heating plate based on the current contrast of the interference fringes and heat each heating plate, and collect the contrast again. The interference fringe contrast under the heating power, if the interference fringe contrast reaches the preset contrast, the calibration is completed; if the interference fringe contrast does not reach the preset contrast, continue to increase the heating power of the heating plate, repeat the above process, and finally make the interference fringe contrast. The fringe contrast meets the requirements, and accordingly, the human tissue image obtained based on the interference fringe contrast is also clearer.

In an optional embodiment of the present application, determining the heating power of each heating sheet for each heating according to the contrast of the interference fringes may include:

Pre-collecting interference fringe contrast data of the spherical mirror corresponding to different heating powers of each of the heating plates;

According to the different heating power of each of the heating plates and the interference fringe contrast data corresponding to the heating power, based on neural network learning, determine the correspondence between the different heating powers and the interference fringe contrast;

The heating power of each of the heating plates is determined according to the corresponding relationship and the current contrast of the interference fringes.

Specifically, each heating element can be individually heated in advance to obtain the different heating power and corresponding interference fringe contrast of each heating element, and the neural network training can be performed by taking the heating power of each heating element and the corresponding interference fringe contrast as sample data. , and finally determine the correspondence between heating power and interference fringe contrast. Then, in practical applications, according to the corresponding relationship, the magnitude of the heating power of the current heating plate can be determined based on the current interference fringe contrast and the corresponding relationship.

In this embodiment, a wavelet neural network can be used for training. The wavelet neural network combines the characteristics of multi-scale representation of wavelet transform, and at the same time retains the characteristics of good generalization ability and strong nonlinear mapping ability of the neural network. Based on deep learning algorithm "end-to-end" construction of system error (gravity, temperature, airflow, vibration, actuator error, optical element surface error, polarization error, light intensity flicker) model, to achieve system calibration, reduce hardware implementation pressure.

In another optional embodiment of the present application, determining the heating power of each heating sheet for each heating according to the contrast of the interference fringes may include:

Based on the parallel gradient descent algorithm in advance, the formula for determining the heating power is:

，其中，

为第n+1次第i个加热片加热的加热功率，

为第n次第i个加热片加热的加热功率，

为第n次加热后对比度的变化值，

为第n次第i个加热片加热的加热功率变化值；

,in,

is the heating power for the n+1th heating of the i-th heating element,

Heating power for heating the nth i-th heating piece,

is the change value of the contrast after the nth heating,

It is the heating power change value for the nth heating of the i-th heating piece;

The heating power of each heating sheet is determined according to the heating power.

Specifically, the derivation principle of the heating power formula is as follows:

，增加电热片扰动电功率

之后得到的性能指标变化量为

，由于在实际的工程应用与科研实践中，不会出现能量激变的情况，故假设系统性能指标（对比度）

可导，通过泰勒展开可以得到：Let the fringe contrast be

, increase the disturbance electric power of the heater

The change in performance index obtained after that is

, because in the actual engineering application and scientific research practice, there will be no sudden energy change, so it is assumed that the system performance index (contrast)

Differentiable, it can be obtained by Taylor expansion:

；其中，

为展开式中的剩余项。

;in,

is the remainder of the expansion.

，取期望可得：

；Use to get the gradient of performance index drop, multiply both left and right sides by

, take the expectation to get:

;

中的各个元素独立同分布，可以得到Assumption

Each element in is independent and identically distributed, we can get

；

;

为

的方差，可以通过统计规律得到评价指标的下降梯度无偏估计

；in,

for

The variance of , the unbiased estimate of the descending gradient of the evaluation index can be obtained through statistical laws

;

；其中，

为第n+1次第i个加热片加热的加热功率，

为第n次第i个加热片加热的加热功率，

为第n次加热后对比度的变化值，

为第n次第i个加热片加热的加热功率变化值。Based on the above method, we can get:

;in,

is the heating power for the n+1th heating of the i-th heating element,

Heating power for heating the nth i-th heating piece,

is the change value of the contrast after the nth heating,

The heating power change value for the n-th heating of the i-th heating piece.

The parallel gradient descent algorithm is a method that relies on the estimation of mathematical statistics to approximate the gradient. According to the parallel gradient descent algorithm, the heating power formula is determined, and a reasonable disturbance electric power can be selected to obtain better convergence characteristics. And the parallel gradient descent algorithm is a method that relies on mathematical statistics to obtain estimates to approximate the gradient.

The following describes the reference wavefront correction device of the optical coherence tomography system provided by the embodiments of the present invention. The reference wavefront correction device of the optical coherence tomography system described below and the reference of the optical coherence tomography system described above The wavefront correction methods can refer to each other correspondingly.

6 is a structural block diagram of a reference wavefront correction device of an optical coherence tomography system provided by an embodiment of the present invention, which is applied to the optical coherence tomography system described in any of the above embodiments. Referring to the optical coherence tomography imaging system in FIG. 6 The reference wavefront correction device of the system may include:

The contrast acquisition module 100 is used for obtaining the contrast of the interference fringes according to the interference fringes detected by the photodetector;

determining a power module 200 for determining the heating power of each heating plate according to the interference fringe contrast;

The heating module 300 is controlled to heat each of the heating sheets according to the heating power, and repeat the step of collecting the contrast of the interference fringes detected by the photodetector until the interference fringes detected by the photodetector are The contrast reaches the preset contrast.

The reference wavefront correction device of the optical coherence tomography system in this embodiment is used to realize the aforementioned reference wavefront correction method of the optical coherence tomography system. Therefore, the specific reference wavefront correction device of the optical coherence tomography system The embodiment can be seen in the foregoing example of the reference wavefront correction method of the optical coherence tomography system, for example, the contrast acquisition module 100, the determination power module 200, and the control heating module 300 are used to realize the above-mentioned optical coherence tomography system. Steps S1, S2, S3, and S4 in the reference wavefront correction method of . Therefore, the specific implementation can refer to the descriptions of the corresponding partial embodiments, which will not be repeated here.

The present application also provides a reference wavefront correction device for an optical coherence tomography system, which is applied to the optical coherence tomography system described in any of the above embodiments, including:

memory for storing computer programs;

The processor is configured to execute the computer program to implement the operation steps of the reference wavefront correction method of the optical coherence tomography system according to any embodiment.

Specifically, the memory may specifically be random access memory (RAM), internal memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or technology Any other form of storage medium known in the art.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that elements inherent to a process, method, article or apparatus of a list of elements are included. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element. In addition, parts of the above technical solutions provided in the embodiments of the present application that are consistent with the implementation principles of the corresponding technical solutions in the prior art are not described in detail, so as to avoid redundant descriptions.

The principles and implementations of the present invention are described herein by using specific examples, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (10)

1. an optical coherence tomography system, comprising light source, interferometer and photodetector, is characterized in that, also comprises temperature control device, and the reference arm in described interferometer comprises spherical reflector; Wherein, a rubber pad is attached to the back of the spherical reflector; a plurality of heating sheets are evenly arranged on the surface of the rubber pad away from the spherical reflector; each of the heating sheets is connected to the temperature control device; The temperature control device is used to control the heating of each of the heating plates according to the contrast of the interference fringes collected by the photodetector, and the spherical mirror is heated and deformed, so that the contrast of the interference fringes detected by the photodetector reaches a predetermined level. contrast. 2 . The optical coherence tomography system according to claim 1 , wherein the spherical mirror is a K9 glass aluminized film mirror. 3 . 3 . The optical coherence tomography system of claim 1 , wherein the rubber pad is an RTV rubber pad. 4 . 4. The optical coherence tomography system of claim 3, wherein the thickness of the rubber pad satisfies:

, where t is the thickness of the RTV pad,

is the radius of the spherical mirror,

is the thermal expansion coefficient of the heating sheet,

is the thermal expansion coefficient of the spherical mirror,

is the thermal expansion coefficient of the RTV pad under load. 5. The optical coherence tomography system of claim 1, wherein the heating plate is a copper plate or an aluminum plate. 6. A reference wavefront correction method for an optical coherence tomography system, characterized in that, applied to the optical coherence tomography system as claimed in any one of claims 1 to 5, comprising: According to the interference fringes detected by the photodetector, the interference fringe contrast is obtained; Determine the heating power of each heating plate according to the contrast of the interference fringes; The heating plates are heated according to the heating power, and the steps of obtaining the contrast of the interference fringes according to the interference fringes detected by the photodetector are repeated until the contrast of the interference fringes reaches a preset contrast. 7. The reference wavefront correction method for an optical coherence tomography system according to claim 6, wherein determining the heating power of each heating plate according to the interference fringe contrast, comprising: Pre-collecting interference fringe contrast data of the spherical mirror corresponding to different heating powers of each of the heating plates; According to the different heating power of each of the heating plates and the interference fringe contrast data corresponding to the heating power, based on neural network learning, determine the correspondence between the different heating powers and the interference fringe contrast; The heating power of each of the heating plates is determined according to the corresponding relationship and the current contrast of the interference fringes. 8. The reference wavefront correction method for an optical coherence tomography system according to claim 6, wherein determining the heating power of each heating plate according to the interference fringe contrast, comprising: Based on the parallel gradient descent algorithm in advance, the formula for determining the heating power is:

,in,

is the heating power for the n+1th heating of the i-th heating element,

Heating power for heating the nth i-th heating piece,

is the change value of the contrast after the nth heating,

It is the heating power change value for the nth heating of the i-th heating piece; The heating power of each of the heating sheets is determined according to the heating power. 9. A reference wavefront correction device for an optical coherence tomography imaging system, characterized in that, applied to the optical coherence tomography imaging system according to any one of claims 1 to 5, comprising: The contrast acquisition module is used to obtain the contrast of the interference fringes according to the interference fringes detected by the photodetector; determining a power module for determining the heating power of each heating plate according to the contrast of the interference fringes; The heating module is controlled to heat each of the heating sheets according to the heating power, and repeat the step of collecting the contrast of the interference fringes detected by the photodetector until the contrast of the interference fringes detected by the photodetector reaches a predetermined level. Set the contrast. 10. A reference wavefront correction device for an optical coherence tomography imaging system, characterized in that, applied to the optical coherence tomography imaging system according to any one of claims 1 to 5, comprising: memory for storing computer programs; The processor is configured to execute the computer program to implement the operation steps of the reference wavefront correction method of the optical coherence tomography system according to any one of claims 6 to 8.

Images