A method and system for indocyanine green-loaded carbon nanotube-mediated optical coherence tomography

Abstract

The present invention discloses a method and system for indocyanine green-loaded carbon nanotube-mediated optical coherence tomography, comprising: injecting and infiltrating a sample of indocyanine green-loaded carbon nanotube solution, a light source system, a reference arm optical path system, a sample arm optical path system, a spectrometer system, and a linear array CCD camera for collecting optical signals; through the above components, the present invention realizes tomographic imaging, successfully suppresses the signals in the area injected with the indocyanine green-loaded carbon nanotube material solution, effectively improves the contrast of the collected images, is simple and safe to operate, easy to implement, and effectively improves the OCT imaging contrast; the present invention can be used for optical coherence tomography.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging, and in particular, to a carbon nanotube-mediated optical coherence tomography method and system. Background Art

[0002] Optical coherence tomography (OCT) is an optical imaging method developed in the past 20 years. Initially, it was used to study the monitoring imaging of the cross-section of optical fibers. OCT obtains tomographic capabilities in the depth direction based on the principle of low-coherence interference. By scanning, two-dimensional or three-dimensional images of the internal structure of biological tissues or materials are reconstructed. Its signal contrast originates from the spatial variation of the optical reflection (scattering) characteristics inside biological tissues or materials. The light absorption of biological tissues in the near-infrared region is very weak. Therefore, in order to present deeper biological tissue structures, OCT systems generally use near-infrared light with strong penetrability as the light source.

[0003] OCT can achieve real-time, non-destructive, and high-resolution three-dimensional tomography of biological tissues and has been applied in multiple medical fields. However, there are some deficiencies in its imaging process. Taking tumor diagnosis as an example, since the components of tumor tissues and surrounding normal tissues are basically similar, it is difficult to distinguish between normal tissues and abnormal tissues in OCT imaging diagrams.

[0004] At present, the existing imaging methods for improving the OCT imaging contrast can be divided into two categories: algorithm processing and physical processing. The former performs a series of algorithm processing on the collected data to improve the imaging contrast, and the latter directly improves the imaging contrast using physical methods. Algorithm processing does not require additional experimental operations and is relatively simple. However, it is very likely to have errors during signal separation, misclassifying the signals of some actual non-target regions as target regions, thereby enhancing some noises. This is because algorithm processing has low resolution for signals with little difference between the actual target regions and non-target region edges in the original collected data, making it difficult to accurately extract the target region signals and non-target region signals. As a result, the processed image has deviations due to boundary problems, and the imaging effect is reduced. Therefore, algorithm processing is more suitable for improving regions with larger differences between the two pieces of information collected by OCT, and has great limitations. The implementation of physical processing is always accompanied by disadvantages such as time-consuming and cumbersome, increasing the labor cost. The contrast improvement of the final image obtained by simple physical methods is not obvious and has little significance. Moreover, the image obtained through physical processing cannot completely increase the signal value of the target region or suppress the signal value of the non-target region.

[0005] In the imaging scan of OCT, if the non-target area has a strong reflection on the scanning laser, the signal value of the non-target area will be higher than that of the target area, resulting in a low signal-to-noise ratio, poor imaging effect, and difficulty in obtaining a good image of the target area. Summary of the Invention

[0006] The object of the present invention is to provide a carbon nanotube-mediated optical coherence tomography method and system to solve one or more technical problems existing in the prior art and at least provide a beneficial alternative or creative condition.

[0007] The technical solution adopted to solve the above technical problems: A carbon nanotube-mediated optical coherence tomography method includes:

[0008] S100. Inject and infiltrate a carbon nanotube solution loaded with indocyanine green into the area to be scanned of the sample, and place it within the range of the system laser scan;

[0009] S200. Check the working state of the OCT system, start the system to perform real-time scanning and display of the sample, and finely adjust the position of the sample according to the real-time displayed scanning results to make the scanning laser of the OCT system accurately irradiate on the area to be scanned;

[0010] S300. The main process for the OCT system to achieve tomographic imaging of the sample is as follows:

[0011] S301. In the light source system, a low-coherence broadband light source generates near-infrared laser light that enters from the first port of the optical circulator and exits from the second port; the laser light exiting from the second port irradiates onto the first fiber coupler, and the first fiber coupler divides a beam of laser light into two beams;

[0012] S302. On the reference arm optical path, a beam of laser light split by the first fiber coupler vertically enters the first convex lens and is focused onto the single-sided mirror, forming a reversible laser beam that returns to the first fiber coupler along the original optical path;

[0013] S303. On the sample arm optical path, the other beam of laser light split by the first fiber coupler enters the second fiber coupler, and the second fiber coupler divides the other beam of laser light into two sub-laser beams. One of the sub-laser beams irradiates on the optical power meter to monitor and calculate the light intensity of the scanning laser in real time; the other sub-laser beam passes through the polarization controller, is deflected by the two-dimensional galvanometer, and is focused by the second convex lens to irradiate on the sample and scan the sample placed on the platform; the sub-laser beam forms another reversible laser beam after being reflected by the sample and returns to the first fiber coupler along the original optical path;

[0014] S304. In the spectrometer system, the first fiber coupler realizes the interference of the two reversible laser beams reflected back, and the generated interference light is collimated by the third collimating mirror and then enters the diffraction grating; the diffraction grating disperses the collimated light.

[0015] S305. In the system for collecting optical signals by a linear array CCD camera, the photosensitive element of the linear array CCD camera receives the laser light that has been split by a diffraction grating and focused by a focusing lens.

[0016] The parameters of the two reversible laser beams reflected by the reference arm optical path and the sample arm optical path satisfy the following after interference occurs on the first fiber optic coupler:

[0017]

[0018]

[0019] Wherein, I is the laser light intensity after interference; r1 and r2 are the reflection coefficients of the reference arm optical path and the sample arm optical path respectively; A is the laser amplitude; k is the wave vector; Δz is the optical path difference; n is the total number from one to different optical path differences, that is, the total number from one to the total number of camera CCDs; y is the number of different wavelengths of the interfering light; x is from 1 to y; i is the imaginary unit;

[0020] S400. Calculate and save the scanning results.

[0021] As a further improvement of the above technical solution, S100 specifically is: Inject 30 μL of a 25 μg / ml carbon nanotube solution loaded with indocyanine green into the target area to be scanned of the sample, place it for one hour, and then place the area to be scanned of the sample within the laser scanning range.

[0022] As a further improvement of the above technical solution, S400 specifically is: Create a document, collect the trigger signal data of the linear array CCD camera, and add the trigger signal data of the linear array CCD camera to the document; at the same time, process the trigger signal data of the linear array CCD camera, subtract the background light; and add the data without background light to the queue, and reprocess the data with background light; dequeue the data added to the queue and store it in the document; when the document has collected enough frames of data, end the collection, calculate the contrast of the collected data, save the data, and close the scanning system.

[0023] As a further improvement of the above technical solution, S302 further includes: A beam of laser light split by the first fiber optic coupler is vertically incident on the first collimating mirror through the first flange, and after being collimated by the first collimating mirror, it is incident on the first convex lens.

[0024] As a further improvement of the above technical solution, S303 is specifically as follows: On the optical path of the sample arm, another beam of laser split by the first fiber coupler is incident on the second fiber coupler. The second fiber coupler divides the other beam of laser into two sub-lasers in a ratio of 90:10. One of the sub-lasers with lower energy is incident on the optical power meter to monitor and calculate the laser intensity of the scanning laser in real time; the other sub-laser passes through the polarization controller, passes through the second flange, is collimated by the second collimator, deflected by the two-dimensional galvanometer, and focused by the second convex lens and then is incident on the sample to scan the sample placed on the platform; the sub-laser forms another beam of reversible laser after being reflected by the sample and returns to the first fiber coupler along the original optical path.

[0025] As a further improvement of the above technical solution, S305 further includes: The interference light is incident on the third collimator after passing through the third turning plate.

[0026] A carbon nanotube-mediated optical coherence tomography system, comprising:

[0027] A sample injected with a carbon nanotube solution loaded with indocyanine green.

[0028] A light source system, comprising a low-coherence broadband light source, an optical circulator, and a first fiber coupler. The low-coherence broadband light source is used to generate a near-infrared laser beam and sequentially inject it into the optical circulator and the first fiber coupler; the first fiber coupler is used to divide the near-infrared laser beam into two beams of laser.

[0029] A reference arm optical path system, comprising a first convex lens and a single-sided mirror. A beam of laser split by the first fiber coupler is sequentially and perpendicularly incident on the first convex lens and the single-sided mirror; the single-sided mirror reflects the laser to form a beam of reversible laser and returns to the first fiber coupler along the original optical path.

[0030] A sample arm optical path system, comprising a second fiber coupler, an optical power meter, a polarization controller, a two-dimensional galvanometer, a second convex lens, a sample, and a sample loading platform. The sample is placed on the sample loading platform; another beam of laser split by the first fiber coupler is incident on the second fiber coupler and divided into two sub-lasers; the optical power meter is used to monitor and calculate the laser intensity of a beam of sub-laser split by the second fiber coupler in real time; another sub-laser split by the second fiber coupler is sequentially incident on the polarization controller, the second convex lens, and the sample; the sample reflects the other sub-laser to form another beam of reversible laser and returns to the first fiber coupler along the original optical path.

[0031] The first fiber coupler is further used to form interference light from the two beams of reversible laser.

[0032] A spectrometer system, comprising a third collimator and a diffraction grating.

[0033] The optical signal acquisition system of the linear array CCD camera includes a focusing lens and a linear array CCD camera; the interference light of the first fiber coupler is sequentially incident into the third collimator, the diffraction grating, the focusing lens, and the linear array CCD camera.

[0034] As a further improvement of the above technical solution, the reference arm optical path system further includes a first flange and a first collimator; a beam of laser light split by the first fiber coupler is sequentially vertically incident into the first flange, the first collimator, the first convex lens, and the single-sided mirror.

[0035] As a further improvement of the above technical solution, the sample arm optical path system further includes a second flange and a second collimator; another beam of sub-laser light split by the second fiber coupler is sequentially incident into the second flange, the second collimator, the polarization controller, the second convex lens, and the sample.

[0036] As a further improvement of the above technical solution, the spectrometer system further includes a third flange, and the interference light of the first fiber coupler is sequentially incident into the third flange, the third collimator, the diffraction grating, the focusing lens, and the linear array CCD camera.

[0037] The beneficial effects of the present invention: The present invention realizes tomographic imaging through the sample of injecting and permeating the carbon nanotube solution loaded with indocyanine green, the light source system, the reference arm optical path system, the sample arm optical path system, the spectrometer system, and the optical signal acquisition system of the linear array CCD camera, successfully suppresses the signal in the area injected with the carbon nanotube material solution loaded with indocyanine green, effectively improves the contrast of the acquired image, is simple and safe to operate, is easy to implement, and effectively improves the OCT imaging contrast.

[0038] The additional aspects and advantages of the present invention will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present invention. Description of the Drawings

[0039] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0040] Figure 1 is the structural diagram of the optical coherence tomography system of a carbon nanotube-mediated optical coherence tomography method and system provided by the present invention;

[0041] Figure 2 is the signal data diagram of the cross-section of the sample target area of a carbon nanotube-mediated optical coherence tomography method and system provided by the present invention;

[0042] Figure 3It is the signal diagram of the same interference depth of the sample of a carbon nanotube-mediated optical coherence tomography method and system provided by the present invention;

[0043] Figure 4 It is the full-depth information diagram of two different positions of the sample of a carbon nanotube-mediated optical coherence tomography method and system provided by the present invention. Specific embodiments

[0044] The embodiments of the present invention are described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0045] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0046] In the description of the present invention, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If the first and second are described only for the purpose of distinguishing technical features, they should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0047] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0048] A carbon nanotube-mediated optical coherence tomography method includes:

[0049] S100. Inject and infiltrate a carbon nanotube solution loaded with indocyanine green into the area to be scanned of the sample, and place it within the laser scanning range of the system;

[0050] Specifically, inject 30 μL of a 25 μg / ml graphene solution loaded with indocyanine green into the target area to be scanned of the sample, place it for one hour, and then place the area to be scanned of the sample within the laser scanning range.

[0051] Preferably, prepare a carbon nanotube material solution loaded with indocyanine green: modify indocyanine green onto the surface of carbon nanotubes through the interaction of π-π bonds between indocyanine green and carbon nanotubes. First, take 50 mL of 0.1 mg / mL carbon nanotubes and place them in a 100 mL round-bottom flask, then add an appropriate amount of indocyanine green, and stir overnight in the dark. The product is ultrafiltered with a 100 kDa ultrafiltration tube under dark conditions to wash away the indocyanine green that has not been effectively loaded.

[0052] Utilize the characteristic that the carbon nanotubes loaded with indocyanine green have an extremely low infrared spectral reflectivity, and inject a mixed solution of carbon nanotubes loaded with indocyanine green into the non-target area of the biological sample. The area treated with the mixed solution of carbon nanotubes loaded with indocyanine green will absorb a large amount of laser energy due to the characteristics of the carbon nanotubes loaded with indocyanine green, reducing the intensity of the reflected light in this area, thereby causing a significant decrease in the signal intensity of the non-target area, while the signal intensity of the target area remains unchanged, increasing the difference between the two and improving the contrast.

[0053] S200. Check the working status of the OCT system, start the system to perform real-time scanning and display of the sample, and finely adjust the position of the sample according to the real-time displayed scanning results, so that the scanning laser of the OCT system accurately irradiates the area to be scanned.

[0054] S300. The main process for the OCT system to achieve sample tomography imaging is as follows:

[0055] S301. In the light source system, a low-coherence broadband light source generates near-infrared laser light that enters from the first port of the optical circulator and exits from the second port; the laser light exiting from the second port irradiates onto the first fiber optic coupler, and the first fiber optic coupler divides a beam of laser light into two beams.

[0056] S302. On the reference arm optical path, a beam of laser light split by the first fiber optic coupler vertically enters the first collimator through the first flange, and after being collimated by the first collimator, it enters the first convex lens and is focused onto the single-sided mirror, forming a reversible beam of laser light that returns to the first fiber optic coupler along the original optical path.

[0057] Return the beam with the optical path reference information to the first fiber optic coupler to provide an optical path reference value for the detection optical path system.

[0058] S303. On the optical path of the sample arm, another beam of laser split by the first fiber coupler enters the second fiber coupler. The second fiber coupler divides the other beam of laser into two sub-lasers at a ratio of 90:10. One of the sub-lasers with lower energy is incident on the optical power meter to monitor and calculate the intensity of the scanning laser in real time. The other sub-laser passes through the polarization controller, passes through the second flange, is collimated by the second collimator, deflected by the two-dimensional galvanometer, and focused by the second convex lens and then is incident on the sample to scan the sample placed on the platform. The sub-laser forms another reversible laser after being reflected by the sample and returns to the first fiber coupler along the original optical path.

[0059] The sub-laser forms another reversible laser after being reflected by the sample and returns along the original optical path, providing the optical path sample value for the detection optical path system.

[0060] S304. In the spectrometer system, the first fiber coupler causes the two reflected reversible lasers to interfere. The generated interference light passes through the third turntable and then is collimated by the third collimator and enters the diffraction grating. The diffraction grating disperses the collimated light.

[0061] The two reflected reversible lasers meet and interfere in the first fiber coupler. The interference light enters the diffraction grating from another path and undergoes multi-slit diffraction to disperse the interference light. The first-order diffraction fringes after dispersion are taken, and the third convex lens collimates the laser after dispersion into parallel light to ensure that all the energy can be absorbed by the acquisition element.

[0062] S305. In the system where the linear array CCD camera collects optical signals, the photosensitive element of the linear array CCD camera receives the laser that has been dispersed by the diffraction grating and focused by the focusing lens.

[0063] The parameters of the two reversible lasers reflected by the reference arm optical path and the sample arm optical path satisfy the following after interfering on the first fiber coupler:

[0064]

[0065]

[0066] where I is the intensity of the laser after interference; r1 and r2 are the reflection coefficients of the reference arm optical path and the sample arm optical path respectively; A is the amplitude of the laser; k is the wave vector; Δz is the optical path difference; n is the total number from one to different optical path differences, that is, the total number from one to the camera CCD; y is the number of different wavelengths of the interference light; x is from 1 to y; and i is the imaginary unit.

[0067] S400. Calculate and save the scanning results.

[0068] Specifically: Create a document, collect the trigger signal data of the linear array CCD camera, and add the trigger signal data of the linear array CCD camera to the document; at the same time, process the trigger signal data of the linear array CCD camera, subtract the background light; and add the data without background light to the queue, and reprocess the data with background light; dequeue the data added to the queue and store it in the document; when the document has collected enough frames of data, end the collection, calculate the contrast of the collected data, save the data, and turn off the scanning system.

[0069] Please refer to Figure 1 , a carbon nanotube-mediated optical coherence tomography system, comprising: a sample for injecting and permeating a carbon nanotube solution loaded with indocyanine green, a light source system, a reference arm optical path system, a sample arm optical path system, a spectrometer system, and a linear array CCD camera for collecting optical signals.

[0070] Prepare a carbon nanotube material solution loaded with indocyanine green: Modify indocyanine green onto the surface of carbon nanotubes through the π-π bond interaction between indocyanine green and carbon nanotubes. First, take 50 mL of 0.1 mg / mL carbon nanotubes and place them in a 100 mL round-bottom flask, then add an appropriate amount of indocyanine green, and stir overnight in the dark. The product is ultrafiltered with a 100 kDa ultrafiltration tube under dark conditions to wash away the indocyanine green that has not been effectively loaded.

[0071] Utilize the characteristic that the carbon nanotubes loaded with indocyanine green have extremely low infrared spectral reflectivity, and inject a mixed solution of carbon nanotubes loaded with indocyanine green into the non-target area of the biological sample. The area treated with the mixed solution of carbon nanotubes loaded with indocyanine green will absorb a large amount of laser energy due to the characteristics of the carbon nanotubes loaded with indocyanine green, reducing the reflected light intensity in this area, thereby causing a significant decrease in the signal intensity of the non-target area, while the signal intensity of the target area remains unchanged, increasing the difference between the two and improving the contrast.

[0072] The light source system includes a low-coherence broadband light source, an optical circulator, and a first fiber optic coupler; the reference arm optical path system includes a first convex lens and a single-sided mirror; the sample arm optical path system includes a second fiber optic coupler, an optical power meter, a polarization controller, a two-dimensional galvanometer, a second convex lens, and a sample loading stage; the spectrometer system includes a third collimating mirror and a diffraction grating; the linear array CCD camera for collecting optical signals includes a focusing lens and a linear array CCD camera.

[0073] The low-coherence broadband light source is used to generate a near-infrared laser beam. In order to present deeper biological tissue structures, the OCT system generally uses near-infrared light with strong penetrability as the light source.

[0074] The near-infrared laser beam generated by the low-coherence broadband light source first passes through the optical circulator and then enters the first fiber optic coupler. The optical circulator prevents the laser from flowing back and damaging the light source.

[0075] The first fiber optic coupler is used to split the near-infrared laser beam generated by the low-coherence broadband light source into two laser beams, form interference light from the reversible lasers of the two laser beams, and the splitting ratio is 50:50.

[0076] A fiber optic coupler, also known as a splitter, connector, adapter, or fiber optic flange, is a component used to achieve optical signal splitting / combining or to extend an optical fiber link, belonging to the field of optical passive components. It is an optical device that realizes the distribution or combination of optical signal power between different optical fibers and is composed of the mutual exchange of guided wave energy in the adjacent fiber core regions of different fiber surfaces.

[0077] The first convex lens is used to vertically receive one of the laser beams split by the first fiber optic coupler and focus it onto the single-sided mirror to match the system dispersion parameters.

[0078] The single-sided mirror is used to reflect the laser to form a reversible laser.

[0079] The second fiber optic coupler is used to divide the other laser beam split by the first fiber optic coupler into two sub-laser beams.

[0080] The optical power meter is used to monitor and calculate the laser intensity of one of the sub-laser beams scanned through the second fiber optic coupler in real time.

[0081] The polarization controller is used to deflect the other sub-laser beam split by the second fiber optic coupler.

[0082] The second convex lens is used to focus the sub-laser beam deflected by the polarization controller.

[0083] The sample is placed on the sample loading stage, and the sample receives the focused sub-laser beam and reflects to form a reversible laser.

[0084] The first fiber optic coupler is also used to form interference light from the two reversible lasers.

[0085] The third convex lens is used to receive the interference light passing through the first fiber optic coupler and collimate it into parallel light;

[0086] The diffraction grating is used to split the collimated parallel light; the diffraction grating is a type of grating. It makes the amplitude or phase (or both) of the incident light be periodically spatially modulated through a regular structure.

[0087] The focusing lens is used to focus the light split by the diffraction grating.

[0088] The linear array CCD camera is used to receive the laser focused by the focusing lens.

[0089] In some embodiments, the reference arm optical path system further includes a first flange and a first collimator. The first flange is used to pass a beam of laser light split by the first fiber coupler, and the first collimator is used to collimate the laser light passing through the first flange into parallel light and inject it into the first convex lens.

[0090] In some embodiments, the sample arm optical path system further includes a second flange and a second collimator. The second flange is used to pass the sub-laser light deflected by the polarization controller, and the second collimator is used to collimate the sub-laser light passing through the second flange into parallel light and inject it into the two-dimensional galvanometer.

[0091] In some embodiments, the spectrometer system further includes a third flange for passing the interference light interfered by the first fiber coupler.

[0092] The signal data diagram of the sample target area is as Figures 2 to 4 shown. Figure 2 It is the signal data diagram of the cross-section of the sample target area. Because the carbon nanotube material loaded with indocyanine green has the characteristics of high infrared spectrum absorption rate and low reflectivity, a large amount of laser light is absorbed in the sample area injected with the carbon nanotube material solution loaded with indocyanine green and fails to enter the interior of the sample tissue. Therefore, the signal intensity of the area where the carbon nanotube material solution loaded with indocyanine green penetrates in the collected image is lower than that of the non-penetrated area, which better suppresses the signal intensity of the penetrated area and greatly improves the contrast of the collected image.

[0093] Figure 3 It is the signal diagram of the same interference depth. It can be seen from the figure that a fault occurs in the signal at the junction of the penetrated area and the non-penetrated area, that is, the signal contrast between the penetrated area and the non-penetrated area is large.

[0094] Figure 4 It is the full-depth information diagram of two different positions. The dotted line is the signal of the non-penetrated area, and the dashed line is the signal of the penetrated area. It can be seen from the figure that the signal of the non-penetrated area decays slowly with depth, and the signal of the penetrated area only has a high value on the sample surface, and then decays in a fault-like manner and is lower than the signal of the non-penetrated area at the same distance from the surface. This shows that the carbon nanotube solution loaded with indocyanine green greatly improves the OCT imaging contrast.

[0095] The present invention realizes tomographic imaging through the sample injected with the carbon nanotube solution loaded with indocyanine green, the light source system, the reference arm optical path system, the sample arm optical path system, the spectrometer system and the linear array CCD camera for collecting optical signals, successfully suppresses the signal in the area injected with the carbon nanotube material solution loaded with indocyanine green, effectively improves the contrast of the collected image, is simple and safe to operate, easy to implement, and effectively improves the OCT imaging contrast.

[0096] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A method for indocyanine green-loaded carbon nanotube-mediated optical coherence tomography, characterized in that: The method comprises the following steps: S100. Inject and infiltrate the indocyanine green-loaded carbon nanotube solution into the area to be scanned of the sample, and place it within the range of the system laser scan; S200. Check the working state of the OCT system, start the system to perform real-time scanning and display of the sample, and finely adjust the position of the sample according to the real-time displayed scanning result so that the scanning laser of the OCT system accurately irradiates the area to be scanned; S300. The main process for the OCT system to realize tomography imaging of the sample is as follows: S301. In the light source system, a low-coherence broadband light source generates near-infrared laser light that enters from the first port of the optical circulator and exits from the second port; the laser light exiting from the second port irradiates the first fiber coupler, and the first fiber coupler divides a beam of laser light into two beams; S302. On the reference arm optical path, a beam of laser light split by the first fiber coupler vertically enters the first convex lens and is focused on the single-sided mirror, forming a beam of reversible laser light that returns to the first fiber coupler along the original optical path; S303. On the sample arm optical path, the other beam of laser light split by the first fiber coupler enters the second fiber coupler, and the second fiber coupler divides the other beam of laser light into two sub-laser beams. One of the sub-laser beams irradiates the optical power meter to monitor and calculate the scanning laser light intensity in real time; the other sub-laser beam passes through the polarization controller, is deflected by the two-dimensional galvanometer, and is focused by the second convex lens and irradiates the sample to scan the sample placed on the platform; the sub-laser beam forms another beam of reversible laser light that returns to the first fiber coupler along the original optical path after being reflected by the sample; S304. In the spectrometer system, the first fiber coupler realizes the interference of the two reversible laser lights reflected back, and the generated interference light is collimated by the third collimating mirror and then enters the diffraction grating; the diffraction grating disperses the collimated light; S305. In the system where the linear array CCD camera collects optical signals, the photosensitive element of the linear array CCD camera receives the laser light that has been dispersed by the diffraction grating and focused by the focusing lens; The parameters of the two beams of reversible laser lights reflected by the reference arm optical path and the sample arm optical path satisfy the following after interference on the first fiber coupler: where I is the laser light intensity after interference; r1 and r2 are the reflection coefficients of the reference arm optical path and the sample arm optical path respectively; A is the laser amplitude; k is the wave vector; Δz is the optical path difference; n is the total number from one to different optical path differences, that is, the total number from one to the camera CCD; y is the number of different wavelengths of the interference light; x is from 1 to y; i is the imaginary unit; S400. Calculate and save the scanning result; Step S100 is specifically: Inject 30 μL of 25 μg / ml indocyanine green-loaded carbon nanotube solution into the area to be scanned of the sample, place it for one hour, and then place the area to be scanned of the sample within the range of the laser scan; Step S400 specifically includes: creating a document, collecting the trigger signal data of the line array CCD camera, and adding the trigger signal data of the line array CCD camera to the document; meanwhile, processing the trigger signal data of the line array CCD camera to subtract the background light; adding the data without background light to a queue, and reprocessing the data with background light; dequeuing the data added to the queue and storing it in the document; when the document has collected enough frames of data, end the collection, calculate the contrast of the collected data, save the data, and turn off the scanning system; Step S302 further includes: a beam of laser split by the first fiber optic coupler vertically enters the first collimator through the first flange, and after being collimated by the first collimator, enters the first convex lens; Step S303 specifically includes: on the sample arm optical path, another beam of laser split by the first fiber optic coupler enters the second fiber optic coupler, and the second fiber optic coupler divides the other beam of laser into two sub-lasers at a ratio of 90:

10. The sub-laser with lower energy is incident on the optical power meter to monitor and calculate the scanning laser intensity in real time; the other sub-laser passes through the polarization controller, through the second flange, after being collimated by the second collimator, is deflected by the two-dimensional galvanometer and focused by the second convex lens and is incident on the sample to scan the sample placed on the platform; the sub-laser forms another reversible laser after being reflected by the sample and returns to the first fiber optic coupler along the original optical path; Step S305 further includes: the interference light enters the third collimator after passing through the third turning plate.

2. A carbon nanotube-mediated optical coherence tomography imaging system loaded with indocyanine green, characterized in that, executing the imaging method according to claim 1, the imaging system includes: injecting and permeating a sample of a carbon nanotube solution loaded with indocyanine green; a light source system, including a low-coherence broadband light source, an optical circulator, and a first fiber optic coupler. The low-coherence broadband light source is used to generate a near-infrared laser beam and sequentially inject it into the optical circulator and the first fiber optic coupler; the first fiber optic coupler is used to divide the near-infrared laser beam into two beams of laser; a reference arm optical path system, including a first convex lens and a single-sided mirror. A beam of laser split by the first fiber optic coupler is sequentially vertically incident on the first convex lens and the single-sided mirror; the single-sided mirror reflects the laser to form a beam of reversible laser and returns to the first fiber optic coupler along the original optical path; a sample arm optical path system, including a second fiber optic coupler, an optical power meter, a polarization controller, a two-dimensional galvanometer, a second convex lens, a sample, and a sample loading stage. The sample is placed on the sample loading stage; another beam of laser split by the first fiber optic coupler enters the second fiber optic coupler and is divided into two sub-lasers; the optical power meter is used to monitor and calculate the laser intensity of a sub-laser scanned by the second fiber optic coupler in real time; another sub-laser split by the second fiber optic coupler is sequentially incident on the polarization controller, the second convex lens, and the sample; the sample reflects the other sub-laser to form another beam of reversible laser and returns to the first fiber optic coupler along the original optical path; The first fiber optic coupler is also used to form interference light from the two beams of reversible laser; a spectrometer system, including a third collimator and a diffraction grating; The optical signal acquisition system of the linear array CCD camera includes a focusing lens and a linear array CCD camera; the interference light of the first fiber coupler is sequentially incident on the third collimating mirror, the diffraction grating, the focusing lens and the linear array CCD camera.

3. The carbon nanotube-mediated optical coherence tomography system loaded with indocyanine green according to claim 2, characterized in that: the reference arm optical path system further includes a first flange and a first collimating mirror; a beam of laser light split by the first fiber coupler is sequentially vertically incident on the first flange, the first collimating mirror, the first convex lens and the single-sided reflecting mirror.

4. The carbon nanotube-mediated optical coherence tomography system loaded with indocyanine green according to claim 2, characterized in that: the sample arm optical path system further includes a second flange and a second collimating mirror; another beam of sub-laser light split by the second fiber coupler is sequentially incident on the second flange, the second collimating mirror, the polarization controller, the second convex lens and the sample.

5. The carbon nanotube-mediated optical coherence tomography system loaded with indocyanine green according to claim 2, characterized in that: the spectrometer system further includes a third flange, and the interference light of the first fiber coupler is sequentially incident on the third flange, the third collimating mirror, the diffraction grating, the focusing lens and the linear array CCD camera.

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