Line scanning spectrum optical coherence tomography system and device

Abstract

The invention provides a line scanning spectrum optical coherence tomography system and equipment. The imaging system comprises a light source generation device, a light splitting device, a reference arm, a sample arm, a signal detection device and a signal generator, the sample arm is provided with an MEMS galvanometer and a one-dimensional scanning galvanometer, the conduction or cut-off of a light path of the sample arm is realized by controlling the angle deflection of the MEMS galvanometer, and the light path is conducted only during the exposure period of the area-array camera, so that the total light energy received by the sample tissue in the shooting period of the area-array camera is equal to the light energy which is effectively utilized, the illumination utilization rate is remarkably improved, the light power time sequence is synchronously regulated and controlled, and the detection accuracy is improved. The signal-to-noise ratio is enhanced on the premise of maintaining the safe light dose of the sample tissue, and high-quality imaging is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical imaging, and in particular relates to a line scanning spectral optical coherence tomography system. Background Art

[0002] The Line Scanning Spectral Domain Optical Coherence Tomography (LSSDOCT) system uses a line light source to scan sample tissue, combines the backscattered light from the sample tissue with the interference of reference light, and uses a two-dimensional array camera to collect the signal. Finally, the axial information of the sample tissue is extracted by Fourier transform. This is a non-invasive, low-cost, non-traumatic high-resolution imaging method.

[0003] Compared with the traditional point scanning optical coherence tomography (PSOCT) system, the LSSDOCT system has a faster imaging speed. However, the light utilization rate of LSSDOCT is far lower than that of PSOCT. Generally, the PSOCT system uses a one-dimensional linear array camera for signal acquisition. The exposure time of this detector can account for up to 90% of the sampling time, and its light utilization rate reaches a very high ideal value; while the traditional LSSDOCT system has a very low light utilization rate. For example, for a two-dimensional array camera with a frame rate of 200fps, its shooting cycle is 5ms and the exposure time is 500μs, which accounts for 10% of the shooting cycle. During the time when the light beam is irradiated on the surface of the sample tissue, only the light during the exposure time is effectively utilized, and the light on the sample tissue during the rest of the time is ineffectively utilized. At this time, if the light power irradiated on the surface of the sample tissue is 10mw, the total light energy received by the sample tissue during the shooting cycle is 5×10 -5 J, the effective light energy is 5×10 -6 J, the rest is invalid light energy, and the light utilization rate is only 10%, which is nearly 10 times lower than that of PSOCT.

[0004] Therefore, how to improve the utilization rate of ineffective light without damaging the sample tissue due to the light thermal effect is an urgent problem to be solved. Summary of the Invention

[0005] The present invention provides a line scanning spectral optical coherence tomography system and equipment to solve the problem of how to improve the utilization rate of invalid light without damaging the sample tissue due to the light thermal effect.

[0006] In a first aspect, the present invention provides a line scanning spectral optical coherence tomography system, comprising:

[0007] a light source generating device for emitting a light beam;

[0008] A light splitting device, located at an extended position in the direction of emission of the light beam of the light source generating device, for splitting the light beam emitted by the light source generating device into a first light beam and a second light beam;

[0009] a reference arm, located in the optical path of the first light beam, for receiving the first light beam emitted by the light splitting device and reflecting the first light beam back to the light splitting device;

[0010] a sample arm, located in the optical path of the second light beam, for receiving the second light beam emitted by the spectrometer, and irradiating the second light beam onto the sample tissue, and returning the backscattered light carrying the sample tissue information to the spectrometer along the original path;

[0011] The sample arm includes a MEMS galvanometer and a one-dimensional scanning galvanometer; the MEMS galvanometer is located in the optical path of the second light beam; the MEMS galvanometer can be angularly deflected. When the MEMS galvanometer is not angularly deflected, the second light beam is reflected by the MEMS galvanometer and incident on the one-dimensional scanning galvanometer, the optical path is open, and the sample tissue receives light; when the MEMS galvanometer is angularly deflected, the second light beam is reflected by the MEMS galvanometer and deflected from the one-dimensional scanning galvanometer, the optical path is closed, and the sample tissue does not receive light;

[0012] The spectroscopic device is also used to receive the reflected light from the reference arm and the backscattered light from the sample arm containing sample tissue information, and the two beams of light interfere with each other in the spectroscopic device to form interference light;

[0013] a signal detection device, arranged in a direction opposite to the initial emission direction of the first light beam, for decomposing the interference light into interference spectrum signals, and converting the interference spectrum signals into electrical signals and transmitting them to a computer, where a Fourier transform algorithm is used to process and reconstruct a sample tissue image;

[0014] The signal detection device includes an area array camera, which is used to convert the interference spectrum signal into an electrical signal and transmit it to the computer;

[0015] The signal generator is electrically connected to the MEMS galvanometer, the one-dimensional scanning galvanometer and the area array camera, and is used to generate the deflection timing of the MEMS galvanometer, the scanning voltage step timing of the one-dimensional scanning galvanometer and the shooting timing of the area array camera.

[0016] Optionally, the light source generating device includes:

[0017] A broadband light source for generating a first low-coherence light;

[0018] a spectral filter, located in the optical path of the first low-coherence light, for filtering the first low-coherence light in a target spectral range to obtain a second low-coherence light;

[0019] a light expanding lens assembly, located on the optical path of the second low coherence light, and used for expanding the second low coherence light to obtain a third low coherence light;

[0020] The cylindrical mirror is located on the optical path of the third low-coherence light and is used to convert the third low-coherence light into a light beam with a linear light spot.

[0021] Optionally, the light expanding lens group includes a first double-cemented convex lens and a second double-cemented convex lens arranged coaxially.

[0022] Optionally, the reference arm comprises:

[0023] a neutral density filter, located on the optical path of the first light beam emitted by the light splitting device, and used to reduce the optical power of the first light beam;

[0024] a first microscope objective lens, located on a side of the neutral density filter away from the light splitting device, for receiving light emitted by the neutral density filter and irradiating the received light onto a first plane reflector;

[0025] a first plane reflector, located in the light-emitting direction of the first microscope objective lens, and configured to reflect the received first light beam to the neutral density filter;

[0026] The neutral density filter is also used to transmit the received reflected light to the spectroscopic device.

[0027] Optionally, the sample arm further comprises:

[0028] a second microscope objective lens, located in the light-emitting direction of the one-dimensional scanning galvanometer, for receiving the light emitted by the one-dimensional scanning galvanometer and irradiating the received light onto the sample tissue;

[0029] The second microscope objective lens is also used to receive the backscattered light carrying the sample tissue information;

[0030] The one-dimensional scanning galvanometer is further used to receive backscattered light carrying sample tissue information transmitted through the second microscope objective lens, and transmit the backscattered light carrying sample tissue information back to the spectroscopic device through the MEMS galvanometer.

[0031] Optionally, the signal detection device further includes:

[0032] a light-contracting lens assembly, located on the optical path of the interference light emitted by the light-splitting device, and used for constricting the interference light;

[0033] The grating is located on the optical path of the interference light after the beam is reduced, and is used to split the interference light after the beam is reduced to obtain interference light of different wavelengths;

[0034] The third double-cemented convex lens is located on the optical path of the interference light of different wavelengths, and is used to focus the interference light of different wavelengths onto a column of pixels of the area array camera respectively.

[0035] Optionally, the signal detection device further includes a second plane reflector located on the optical path of the interference light emitted by the light splitting device, and configured to change the optical path of the interference light.

[0036] Optionally, the light focusing lens group includes a fourth double-cemented convex lens and a fifth double-cemented convex lens arranged coaxially; a slit aperture is arranged between the fourth double-cemented convex lens and the fifth double-cemented convex lens; the focus of the fourth double-cemented convex lens is located within the slit of the slit aperture.

[0037] Optionally, the broadband light source includes a light emitting diode broadband light source or a superluminescent diode broadband light source.

[0038] In a second aspect, the present invention provides a line scanning spectral optical coherence tomography imaging device, comprising the line scanning spectral optical coherence tomography imaging system as described in the first aspect.

[0039] The present invention provides a line-scanning spectral optical coherence tomography system and apparatus. A MEMS galvanometer is positioned in the sample arm, preceding a one-dimensional scanning galvanometer. To improve the imaging system's light utilization, the MEMS galvanometer deflects the light beam to control the conduction or cutoff of the reference arm's optical path. This ensures that the total light energy received by the sample tissue during the area array camera's capture cycle equals the effectively utilized light energy. This significantly improves the imaging system's light utilization while maintaining the original imaging quality.

[0040] After improving the light utilization rate, the light power irradiating the sample tissue surface is further increased. After the imaging system's light utilization rate is adjusted to a high efficiency by the MEMS galvanometer, the irradiation power can be further enhanced. Within the period of one frame captured by the area array camera, through temporal regulation, the light power is significantly increased during the exposure time, while no light power is lost outside of the exposure time. This maintains the light power received by the sample tissue unchanged compared to traditional LSSDOCT systems. Therefore, without causing phototoxicity, the signal-to-noise ratio of the entire imaging system can be improved, enhancing the imaging quality of the sample tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A schematic structural diagram of a line scanning spectral optical coherence tomography system provided by an embodiment of the present invention;

[0043] Figure 2 Another structural schematic diagram of a line scanning spectral optical coherence tomography system provided by an embodiment of the present invention;

[0044] Figure 3 A schematic diagram of the optical path cutoff of the sample arm when the MEMS galvanometer provided in an embodiment of the present invention is deflected;

[0045] Figure 4 Schematic diagram of the optical path for imaging the sample tissue in the yz plane and the xz plane respectively provided by the embodiment of the present invention;

[0046] Figure 5 This is a timing diagram of the one-dimensional scanning galvanometer drive signal, MEMS galvanometer drive signal, and area array camera exposure signal provided in an embodiment of the present invention.

[0047] Among them, 1. light source generating device, 11. broadband light source, 12. spectral filter, 13. light beam expanding lens group, 131. first double-cemented convex lens, 132. second double-cemented convex lens, 14. cylindrical mirror; 2. spectrometer; 3. reference arm, 31. neutral density filter, 32. first microscope objective, 33. first plane mirror; 4. sample arm, 41. MEMS galvanometer, 42. one-dimensional scanning galvanometer, 43. second microscope objective; 5. signal detection device, 51. area array camera, 52. light beam reducing lens group, 521. fourth double-cemented convex lens, 522. fifth double-cemented convex lens, 523. slit aperture, 53. grating, 54. third double-cemented convex lens, 55. second plane mirror; 6. signal generator. DETAILED DESCRIPTION

[0048] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] Example 1

[0050] The embodiment of the present invention provides a line scanning spectral optical coherence tomography system, which has a higher light utilization rate than the traditional LSSDOCT system and can achieve high-resolution imaging of low-scattering or high-absorbing sample tissues (such as blood vessels under the skin, bone tissue, internal structure of teeth, etc.). Figure 1 and Figure 2 As shown, the line scanning spectral optical coherence tomography system comprises:

[0051] The light source generating device 1 is used to emit a light beam, comprising:

[0052] The broadband light source 11 includes a light emitting diode broadband light source or a superluminescent diode broadband light source, and is used to generate a first low-coherence light.

[0053] Spectral filter 12 is located in the optical path of the first low-coherence light and is used to filter the first low-coherence light within the target spectral range to obtain second low-coherence light. In this embodiment, spectral filter 12 is used to extract the spectrum. The spectral range of the broadband light source is 400-1700 nm, while the spectral range required by the imaging system provided in this embodiment is 850±50 nm.

[0054] The light expanding lens assembly 13 is located in the optical path of the second low-coherence light and is used to expand the second low-coherence light to produce third low-coherence light. The light expanding lens assembly 13 includes a first double-cemented convex lens 131 and a second double-cemented convex lens 132 arranged coaxially. The first double-cemented convex lens 131 and the second double-cemented convex lens 132 form a 4F system, which expands the spot diameter of the second low-coherence light and increases the line length and field of view of the imaging illumination line spot.

[0055] The cylindrical mirror 14 is located on the optical path of the third low-coherence light and is used to convert the third low-coherence light into a light beam of a linear light spot to achieve linear spot illumination.

[0056] The light splitting device 2 is located in an extended position in the direction of the light beam emitted by the light source generating device 1 and is used to split the light beam emitted by the light source generating device 1 into a first light beam and a second light beam. In this embodiment, the light splitting device 2 is a beam splitting prism. The split first and second light beams enter the reference arm 3 and the sample arm 4, respectively.

[0057] The reference arm 3 is located in the optical path of the first light beam and is used to receive the first light beam emitted by the light splitting device 2 and reflect the first light beam back to the light splitting device 2. The reference arm 3 includes:

[0058] The neutral density filter 31 is located on the optical path of the first light beam emitted by the spectrometer 2 and is used to reduce the optical power of the first light beam.

[0059] The first microscope objective lens 32 is located on the side of the neutral density filter 31 away from the spectrometer 2. It receives light emitted by the neutral density filter 31 and directs the received light onto the first plane reflector 33. Because the light power reflected by the first plane reflector 33 is too high, the neutral density filter 31 is provided to attenuate the light power. The first microscope objective lens 32 is used for microscopic imaging, achieving micron-level resolution.

[0060] The first plane reflective mirror 33 is located in the light-emitting direction of the first microscope objective lens 32 and is used to reflect the received first light beam to the neutral density filter 31 .

[0061] The neutral density filter 31 is also used to transmit the received reflected light to the spectroscopic device 2 .

[0062] The sample arm 4 is located in the optical path of the second light beam, and is used to receive the second light beam emitted by the spectrometer 2 and irradiate the second light beam onto the sample tissue. The backscattered light carrying the sample tissue information returns to the spectrometer 2 along the original path.

[0063] The sample arm 4 includes a MEMS galvanometer 41 and a one-dimensional scanning galvanometer 42; the MEMS galvanometer 41 is located in the optical path of the second light beam. The MEMS galvanometer 41 can be angularly deflected to deflect the direction of the second light beam, acting as an optical switch: when the MEMS galvanometer 41 is not angularly deflected, the second light beam is reflected by the MEMS galvanometer 41 and incident on the one-dimensional scanning galvanometer 42, the optical path is open, and the sample tissue receives light; Figure 3 As shown, when the MEMS galvanometer 41 is deflected, the second light beam is reflected by the MEMS galvanometer 41 and deflected out of the one-dimensional scanning galvanometer 42, cutting off the light path and preventing the sample tissue from receiving light. The one-dimensional scanning galvanometer 42 scans the sample tissue along the y-axis to obtain a 3D image of the sample tissue.

[0064] The sample arm 4 also includes a second microscope objective lens 43, located in the light-emitting direction of the one-dimensional scanning galvanometer 42. It is used to receive light emitted by the one-dimensional scanning galvanometer 42 and illuminate the received light onto the sample tissue. The second microscope objective lens 43 is also used to receive backscattered light containing sample tissue information. The second microscope objective lens 43 is used for microscopic imaging, achieving micron-level resolution.

[0065] The one-dimensional scanning galvanometer 42 is further configured to receive backscattered light carrying sample tissue information transmitted through the second microscope objective 43 , and transmit the backscattered light carrying sample tissue information back to the spectroscopic device 2 through the MEMS galvanometer 41 .

[0066] The spectrometer 2 is also used to receive the reflected light from the reference arm 3 and the backscattered light from the sample arm 4 that carries the sample tissue information. The two beams of light interfere with each other in the spectrometer 2 to form interference light.

[0067] Signal detection device 5 is positioned opposite the initial emission direction of the first light beam (i.e., the direction in which the first light beam is emitted by spectrometer 2). It is used to decompose the interference light into interference spectrum signals, convert the interference spectrum signals into electrical signals, and transmit them to a computer. The computer uses a Fourier transform algorithm to process and reconstruct the sample tissue image. Signal detection device 5 includes an area array camera 51, which is used to convert the interference spectrum signals into electrical signals and transmit them to the computer. Signal detection device 5 also includes:

[0068] The light-reducing lens assembly 52, located in the optical path of the interference light emitted by the spectrometer 2, is used to reduce the interference light. The light-reducing lens assembly 52 comprises a fourth double-cemented convex lens 521 and a fifth double-cemented convex lens 522, arranged coaxially, forming a 4F system. This system reduces the interference light spot and extends the transmission distance of the interference light. A slit aperture 523 is positioned between the fourth double-cemented convex lens 521 and the fifth double-cemented convex lens 522; the focal point of the fourth double-cemented convex lens 521 is located within the slit of the slit aperture 523.

[0069] The slit aperture 523 can effectively filter out some stray light outside the focal plane, further improving the imaging resolution. However, the slit aperture 523 reduces the signal-to-noise ratio of the imaging system. Traditional LSSDOCT systems cannot use the slit aperture 523 due to their low signal-to-noise ratio. However, the high-signal-to-noise ratio line scanning spectral optical coherence tomography imaging system proposed in this embodiment balances the conflicting relationship between the signal-to-noise ratio and resolution caused by the slit aperture 523. Therefore, a slit aperture 523 can be placed in the signal detection optical path of the imaging system to improve the imaging quality of the imaging system.

[0070] The grating 53 is located on the optical path of the interference light after the focus is reduced, and is used to split the interference light after the focus is reduced to obtain interference lights of different wavelengths.

[0071] The third double-cemented convex lens 54 is located on the optical path of the interference light of different wavelengths, and is used to focus the interference light of different wavelengths onto a column of pixels of the area array camera.

[0072] The second plane reflector 55 is located on the optical path of the interference light emitted by the spectrometer 2 and is used to change the optical path of the interference light. Compared with the volume of the imaging system without changing the optical path of the interference light, changing the optical path of the interference light can reduce the volume of the imaging system.

[0073] The signal generator 6 is electrically connected to the MEMS galvanometer 41 , the one-dimensional scanning galvanometer 42 and the area array camera 51 , and is used to generate the deflection timing of the MEMS galvanometer 41 , the scanning voltage step timing of the one-dimensional scanning galvanometer 42 and the shooting timing of the area array camera 51 .

[0074] The MEMS galvanometer mirror 41 is used to cut off the optical path, thereby improving the imaging system's light utilization efficiency. After adding the MEMS galvanometer mirror 41 to the sample arm 4, a periodic electrical signal controls the rapid scanning axis of the MEMS galvanometer mirror 41, causing light within the exposure time of the area array camera 51 to be reflected into the optical path of the sample arm 4. Light outside the exposure time of the area array camera 51 is reflected out of the optical path of the sample arm 4 by changing the angle of the MEMS galvanometer mirror 41. This ensures that the sample tissue receives light only during the exposure time of the area array camera 51. The rapid scanning axis frequency of the MEMS galvanometer mirror 41 can reach up to approximately 30kHz, which is on the same order of magnitude as the exposure time of the area array camera 51 (generally ranging from 10 to 600μs). To maximize light utilization, the drive signal of the MEMS galvanometer mirror 41 must be highly synchronized with the exposure signal period of the area array camera 51. In this case, the total light energy received by the sample tissue during the imaging cycle is effectively utilized light energy. This not only significantly improves the imaging system's light utilization efficiency, theoretically approaching 100%, but also maintains the original imaging quality of the imaging system. Compared with the traditional LSOCT system, the energy actually collected is about 10%. The light utilization rate of the line scanning spectral optical coherence tomography system proposed in this embodiment is increased by nearly 10 times.

[0075] In order to achieve high performance, after the light utilization rate of the imaging system is adjusted to a higher efficiency by the MEMS galvanometer 41, the irradiation power can be further enhanced. During the period of shooting one frame by the area array camera 51, the light power is greatly increased during the exposure time by regulating in the time domain, and there is no light power outside the exposure time, thereby keeping the light power received by the sample tissue unchanged compared with the traditional LSSDOCT system. Therefore, without generating phototoxicity, the signal-to-noise ratio of the entire imaging system can be improved, and the imaging quality of the sample tissue can be improved. For example, the light power on the surface of the sample tissue is increased from the original 10mw to 100mw. Under the traditional LSSDOCT, 100mw of light is irradiated on the surface of the sample tissue. At this time, the total light energy received by the sample tissue during one frame of shooting cycle is 5×10 -4 J; Under the LSSDOCT provided in this embodiment, the total light energy received by the sample tissue during one frame of shooting is 5×10 -5 Although the optical power is amplified 10-fold, this energy is equivalent to the light energy consumed by a traditional LSSDOCT to capture a single frame of a sample at 10 mW. Therefore, increasing the illumination power of the sample tissue does not cause phototoxicity, but can improve the signal-to-noise ratio of the entire imaging system and enhance the imaging quality of the sample tissue.

[0076] The signal generator 6 generates three digital electrical signals: the first is the deflection timing of the MEMS galvanometer mirror 41, which is used to control the deflection time of the MEMS galvanometer mirror 41; the second is the capture timing of the area array camera 51 (i.e., the externally triggered acquisition timing), where the exposure time of the area array camera 51 is adjustable; and the third is the scanning voltage step timing of the one-dimensional scanning galvanometer mirror 42, which is used to complete the sample tissue scanning. After the exposure time and frame rate of the area array camera 51 are set, the capture timing of the area array camera 51 is roughly determined. The deflection timing of the MEMS galvanometer mirror 41 and the scanning timing of the one-dimensional scanning galvanometer mirror 42 are synchronized with the capture timing of the area array camera 51. During the exposure time of the area array camera 51, the MEMS galvanometer mirror 41 timing remains low and does not deflect. The optical path of the sample arm 4 is open, and the sample tissue receives the light signal. After the exposure of the area array camera 51 ends, the MEMS galvanometer mirror 41 timing becomes high, driving the MEMS galvanometer mirror 41 to deflect at a small angle. The light is reflected out of the sample arm 4, and the optical path of the sample arm 4 is cut off. The scanning timing of the one-dimensional scanning galvanometer 42 gradually increases in voltage stepping after the shooting sequence begins. After each frame is captured, the voltage is stepped by a certain value, and the one-dimensional scanning galvanometer 42 deflects once per unit angle until the maximum voltage value is reached after all the shooting signals are completed. At this point, the deflection angle of the one-dimensional scanning galvanometer 42 reaches its maximum. After traversing the entire scanning range, the scanning timing of the one-dimensional scanning galvanometer 42 returns to the initial voltage value, and the lens of the one-dimensional scanning galvanometer 42 returns to its initial position.

[0077] like Figure 5 Figure 2 shows the timing diagram for the drive signals of the one-dimensional scanning mirror 42, the MEMS mirror 41, and the exposure signals of the area array camera 51. The timing diagram for the area array camera 51 is represented by each row of pixels on the area array camera 51 sensor. When the sensor is illuminated, the pixels in that row begin to reset before exposure begins. The area array camera 51 is a global camera, exposing different rows of pixels simultaneously at the same time. After exposure, the data is read from the sensor register. After a frame is read, the sensor undergoes vertical blanking before the next frame is read, which consumes some time. The signal from the one-dimensional scanning mirror 42 must also be synchronized with the capture signal from the area array camera 51. After each frame is captured, the voltage is stepped by a certain value, and the one-dimensional scanning mirror 42 deflects once per unit angle until the maximum voltage value is reached after all capture signals have been captured, at which point the deflection angle reaches its maximum. After traversing the entire scanning range, the one-dimensional scanning mirror 42 returns to its initial voltage value, and its lens returns to its initial position. The drive signal for MEMS galvanometer 41 is a square wave with a period of T, where the high-level duration is t1 and the low-level duration is t2. The period and duty cycle can be set by signal generator 6 to ensure that the voltage-time control of the light-transmitting position of MEMS galvanometer 41 is synchronized with the exposure signal from area array camera 51.

[0078] In summary, if Figure 2 Figure 3 and Figure 4 As shown, this embodiment provides a line scanning spectral optical coherence tomography system. The principle optical path for imaging low-scattering or high-absorbing sample tissues in the yz plane and xz plane, respectively, is as follows: a high-power broadband light source 11 emits light, which passes through a spectral filter 12 and then expands through a 4F system consisting of two doublet lenses (a first doublet convex lens 131 and a second doublet convex lens 132) with specific focal lengths, and then passes through a cylindrical mirror 14. In the reference arm 3, the light first passes through a neutral density filter 31 to reduce the optical power, and then is irradiated on the first plane mirror 33 and reflected. In the sample arm 4, the light is first reflected by the MEMS galvanometer 41, reflected to the one-dimensional scanning galvanometer 42, and then reflected by the plane mirror through the second microscope objective 43 to be focused on the surface of the sample tissue. The drive signal for MEMS galvanometer 41 is synchronized with the exposure signal from 2D area array camera 51. During the exposure time of area array camera 51, MEMS galvanometer 41 remains stationary, and the optical path to sample arm 4 is open. After exposure, MEMS galvanometer 41 undergoes a small deflection and maintains this position, blocking the optical path to sample arm 4. Light returning from reference arm 3 and sample arm 4 interferes and is narrowed in the optical path of signal detection device 5 by a 4F system consisting of two doublets (fourth doublet convex lens 521 and fifth doublet convex lens 522) of specific focal lengths. Stray light is filtered out by a slit aperture 523 before irradiating the surface of grating 53.

[0079] On the yz plane, the light beam is transmitted in parallel along the z direction and is focused on the sample tissue surface by the second microscope objective lens 43. The backscattered light of the sample tissue is transmitted in parallel again by the second microscope objective lens 43 ( Figure 4The sample tissue is located between the two second microscope objective lenses 43). After the beam is reduced by the 4F system composed of the fourth double-cemented convex lens 521 and the fifth double-cemented convex lens 522, the spot size is modulated. The slit aperture 523 also blocks the stray light. The (diffraction) grating 53 (the grating 53 disperses the light according to different wavelengths) and the third double-cemented convex lens 54 focus the dispersed spectrum of the light beam (forming a linear spot of multiple colors after focusing) to the (two-dimensional) area array camera 51 (the two-dimensional area array camera is a global camera). The area array camera 51 collects all Focused wavelength spot; on the xz plane, the light beam propagates along the z direction. The spot is focused by cylindrical mirror 14, then passes through spectrometer 2, fourth double-cemented convex lens 521, slit aperture 523, and fifth double-cemented convex lens 522. After dispersion by grating 53, the interference beam is broadened by third double-cemented convex lens 54. Area array camera 51 captures all x-direction light spots and, combined with the lateral spectral information, generates an xz cross-sectional image through fast Fourier transform. This improves the utilization of ineffective light without damaging the sample tissue due to the thermal effects of illumination. The y-axis is perpendicular to the paper and extends inward, while the z-axis is the direction of the light beam emitted by light source generator 1.

[0080] Example 2

[0081] This embodiment provides a line scanning spectral optical coherence tomography imaging device, including the line scanning spectral optical coherence tomography imaging system as described in Example 1.

[0082] For more specific working process of the above imaging system, please refer to the corresponding content disclosed in Example 1, which will not be repeated here.

[0083] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A line scanning spectral optical coherence tomography system, characterized in that: include: a light source generating device for emitting a light beam; A light splitting device, located at an extended position in the direction of emission of the light beam of the light source generating device, for splitting the light beam emitted by the light source generating device into a first light beam and a second light beam; a reference arm, located in the optical path of the first light beam, for receiving the first light beam emitted by the light splitting device and reflecting the first light beam back to the light splitting device; a sample arm, located in the optical path of the second light beam, for receiving the second light beam emitted by the spectrometer, and irradiating the second light beam onto the sample tissue, and returning the backscattered light carrying the sample tissue information to the spectrometer along the original path; The sample arm includes a MEMS galvanometer and a one-dimensional scanning galvanometer; the MEMS galvanometer is located in the optical path of the second light beam; the MEMS galvanometer can be angularly deflected. When the MEMS galvanometer is not angularly deflected, the second light beam is reflected by the MEMS galvanometer and incident on the one-dimensional scanning galvanometer, the optical path is open, and the sample tissue receives light; when the MEMS galvanometer is angularly deflected, the second light beam is reflected by the MEMS galvanometer and deflected from the one-dimensional scanning galvanometer, the optical path is closed, and the sample tissue does not receive light; The spectroscopic device is also used to receive the reflected light from the reference arm and the backscattered light from the sample arm containing sample tissue information, and the two beams of light interfere with each other in the spectroscopic device to form interference light; a signal detection device, arranged in a direction opposite to the initial emission direction of the first light beam, for decomposing the interference light into interference spectrum signals, and converting the interference spectrum signals into electrical signals and transmitting them to a computer, where a Fourier transform algorithm is used to process and reconstruct a sample tissue image; The signal detection device includes an area array camera, which is used to convert the interference spectrum signal into an electrical signal and transmit it to the computer; The signal generator is electrically connected to the MEMS galvanometer, the one-dimensional scanning galvanometer and the area array camera, and is used to generate the deflection timing of the MEMS galvanometer, the scanning voltage step timing of the one-dimensional scanning galvanometer and the shooting timing of the area array camera.

2. The line scanning spectral optical coherence tomography system according to claim 1, characterized in that: The light source generating device includes: A broadband light source for generating a first low-coherence light; a spectral filter, located in the optical path of the first low-coherence light, for filtering the first low-coherence light in a target spectral range to obtain a second low-coherence light; a light expanding lens assembly, located on the optical path of the second low coherence light, and used for expanding the second low coherence light to obtain a third low coherence light; The cylindrical mirror is located on the optical path of the third low-coherence light and is used to convert the third low-coherence light into a light beam with a linear light spot.

3. The line scanning spectral optical coherence tomography system according to claim 2, characterized in that: The light expanding lens assembly includes a first double-cemented convex lens and a second double-cemented convex lens arranged coaxially.

4. The line scanning spectral optical coherence tomography system according to claim 1, characterized in that: The reference arm comprises: a neutral density filter, located on the optical path of the first light beam emitted by the light splitting device, and used to reduce the optical power of the first light beam; a first microscope objective lens, located on a side of the neutral density filter away from the light splitting device, for receiving light emitted by the neutral density filter and irradiating the received light onto a first plane reflector; a first plane reflector, located in the light-emitting direction of the first microscope objective lens, and configured to reflect the received first light beam to the neutral density filter; The neutral density filter is also used to transmit the received reflected light to the spectroscopic device.

5. The line scanning spectral optical coherence tomography system according to claim 1, characterized in that: The sample arm further comprises: a second microscope objective lens, located in the light-emitting direction of the one-dimensional scanning galvanometer, for receiving the light emitted by the one-dimensional scanning galvanometer and irradiating the received light onto the sample tissue; The second microscope objective lens is also used to receive the backscattered light carrying the sample tissue information; The one-dimensional scanning galvanometer is further used to receive backscattered light carrying sample tissue information transmitted through the second microscope objective lens, and transmit the backscattered light carrying sample tissue information back to the spectroscopic device through the MEMS galvanometer.

6. The line scanning spectral optical coherence tomography system according to claim 1, characterized in that: The signal detection device further includes: a light-contracting lens assembly, located on the optical path of the interference light emitted by the light-splitting device, and used for constricting the interference light; The grating is located on the optical path of the interference light after the beam is reduced, and is used to split the interference light after the beam is reduced to obtain interference light of different wavelengths; The third double-cemented convex lens is located on the optical path of the interference light of different wavelengths, and is used to focus the interference light of different wavelengths onto a column of pixels of the area array camera respectively.

7. The line scanning spectral optical coherence tomography system according to claim 6, characterized in that: The signal detection device further includes a second plane reflector located on the optical path of the interference light emitted by the light splitting device and used for changing the optical path of the interference light.

8. The line scanning spectral optical coherence tomography system according to claim 6, characterized in that: The light beam reduction lens group includes a fourth double-cemented convex lens and a fifth double-cemented convex lens arranged coaxially; a slit aperture is arranged between the fourth double-cemented convex lens and the fifth double-cemented convex lens; the focus of the fourth double-cemented convex lens is located in the slit of the slit aperture.

9. The line scanning spectral optical coherence tomography system according to claim 2, characterized in that: The broadband light source includes a light emitting diode broadband light source or a superluminescent diode broadband light source.

10. A line scanning spectral optical coherence tomography device, characterized in that: The method comprises the line scanning spectral optical coherence tomography system according to any one of claims 1 to 9.

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