An integrated system for endoscopic imaging and temperature sensing

Abstract

The present invention relates to the technical field of measurement and detection, and discloses an integrated system for endoscopic imaging and temperature sensing, an optical imaging and temperature measurement device, a signal detection device, and a control terminal. The optical imaging and temperature measurement device includes an excitation optical path module, a grating optical fiber module, and a sample control module. The signal detection device includes a fluorescence detection module and a spectral measurement module. The control terminal is used to calculate a hologram according to the optical field information, and send the hologram to an optical modulator so that the optical modulator performs wavefront shaping on the first laser based on the hologram, and generate a fluorescence imaging map according to the fluorescence signal, and determine the temperature of the sample to be measured according to the spectral information. The present invention can reduce the influence of engraving a Bragg grating inside a multimode optical fiber on the spot output by the multimode optical fiber by using the wavefront shaping technology, improve the endoscopic imaging quality, and can obtain high-quality images while measuring temperature based on a single multimode optical fiber.

Description

Technical Field

[0001] The present invention relates to the technical field of measurement and detection, and particularly to an integrated system for endoscopic imaging and temperature sensing. Background Art

[0002] The emergence and development of multimode fiber optic endoscopic imaging technology is an important achievement of the combination of modern medicine and optical technology. Multimode fiber optic endoscopic imaging technology has the advantages of minimally invasive, high resolution, real-time, flexibility, etc., and can perform deep imaging through a small incision. Existing multimode fiber optic endoscopic imaging systems focus on the speckles output by the optical fiber and use point scanning imaging.

[0003] Photothermal therapy is a treatment technology that converts light energy into heat energy to kill diseased tissues. During the process of photothermal therapy using multimode optical fibers, it is very important to achieve real-time imaging and temperature measurement of the diseased site. To achieve synchronous imaging and temperature measurement, it is necessary to engrave gratings inside the multimode optical fiber, which will affect the speckles of the output optical fiber and thus affect the imaging quality. Therefore, there is currently no system that integrates fiber optic endoscopic imaging and temperature sensing measurement. Summary of the Invention

[0004] In view of this, the present invention provides an integrated system for endoscopic imaging and temperature sensing to solve or partially solve the technical problem in the related art that endoscopic imaging and temperature measurement cannot be achieved simultaneously.

[0005] The technical solution proposed by the present invention is as follows:

[0006] The present invention provides an integrated system for endoscopic imaging and temperature sensing, comprising: an optical imaging and temperature measurement device, a signal detection device, and a control terminal; the optical imaging and temperature measurement device includes an excitation optical path module, a grating optical fiber module, and a sample control module, the grating optical fiber module includes a multimode optical fiber engraved with a Bragg grating, the sample control module includes a sample stage, the sample stage is connected to the output end of the multimode optical fiber, the sample stage is used to place the sample to be measured, the excitation optical path module includes a fluorescence excitation optical path, a temperature measurement excitation optical path, and an interference beam receiving module, the fluorescence excitation optical path includes a first laser and an optical modulator, the first laser output by the first laser is wavefront-shaped through the optical modulator, and the first laser after shaping enters the multimode optical fiber and is focused at different positions of the sample to be measured and excited by the sample to be measured to generate fluorescence, the temperature measurement excitation optical path includes a second laser, the second laser is used to output a second laser to the multimode optical fiber, after the second laser passes through the Bragg grating, reflected light of different wavelengths is reflected at different temperatures, the interference beam receiving module is used to receive the optical field information of the beam output after the first laser interferes in the multimode optical fiber, and send the optical field information to the control terminal; the signal detection device includes a fluorescence detection module and a spectral measurement module, the fluorescence detection module is used to receive the fluorescence reflected by the sample to be measured and convert the fluorescence into a fluorescence signal, and send the fluorescence signal to the control terminal, the spectral measurement module is used to receive the reflected light reflected by the Bragg grating, obtain the spectral information of the reflected light and send the spectral information to the control terminal; the control terminal is used to calculate a hologram according to the optical field information, and send the hologram to the optical modulator so that the optical modulator performs wavefront shaping on the first laser based on the hologram, and generate a fluorescence imaging map according to the fluorescence signal, and determine the temperature of the sample to be measured according to the spectral information.

[0007] Optionally, the temperature measurement excitation optical path further includes a beam splitting prism, a second dichroic mirror, a first dichroic mirror, and a third optical path adjustment unit arranged in sequence along the output direction of the second laser, the second dichroic mirror and the first dichroic mirror are both arranged obliquely to the output direction of the second laser, wherein the wavelength of the first laser is less than the cut-off wavelength of the first dichroic mirror, the cut-off wavelength of the first dichroic mirror is less than the wavelength of the fluorescence, the wavelength of the fluorescence is less than the cut-off wavelength of the second dichroic mirror, the cut-off wavelength of the second dichroic mirror is less than the wavelength of the second laser, the second laser passes through the beam splitting prism, the second dichroic mirror and the first dichroic mirror in sequence and then enters the multimode optical fiber through the third optical path adjustment unit, and the first laser modulated by the fluorescence excitation optical path enters the third optical path adjustment unit after being reflected by the first dichroic mirror and enters the multimode optical fiber through the third optical path adjustment unit.

[0008] Optionally, the fluorescence excitation optical path further includes a first adjustment optical path and a second adjustment optical path. The first adjustment optical path is used to initially adjust the first laser output by the first laser and transmit the initially adjusted first laser to the optical modulator. The second adjustment optical path is used to further adjust the first laser output by the optical modulator and transmit the further adjusted first laser to the first dichroic mirror.

[0009] Optionally, the first adjustment optical path includes a second reflector and a first 4f system, a half-wave plate, a polarization beam splitter prism, a second 4f system, and a first reflector sequentially arranged along the emission direction of the first laser output by the first laser. The first reflector reflects the first laser to the second reflector, and the second reflector reflects the first laser to the optical modulator.

[0010] Optionally, the second adjustment optical path includes a fourth reflector and a third 4f system and a third reflector sequentially arranged along the emission direction of the first laser output by the optical modulator. The third reflector reflects the first laser to the fourth reflector, and the fourth reflector reflects the first laser to the first dichroic mirror.

[0011] Optionally, the third optical path adjustment unit further includes a fifth reflector and a first objective lens. The fifth reflector is used to reflect the first laser and the second laser to the first objective lens, and the first objective lens is used to couple the first laser and the second laser into the multimode optical fiber.

[0012] Optionally, the fluorescence detection module includes a second lens and a photomultiplier tube. The fluorescence reflected by the sample to be measured passes through the first dichroic mirror and is transmitted to the second dichroic mirror. The second dichroic mirror reflects the fluorescence to the second lens. The second lens is used to converge the fluorescence and input it into the photomultiplier tube. The photomultiplier tube is used to convert the fluorescence into a fluorescence signal and send the fluorescence signal to the control terminal.

[0013] Optionally, the spectral measurement module includes a third lens, a single-mode optical fiber module, and a spectrometer. The reflected light reflected by the Bragg grating passes through the first dichroic mirror and the second dichroic mirror in sequence and is transmitted to the beam splitter prism. The beam splitter prism reflects the reflected light to the third lens. The third lens is used to converge the reflected light and input it into the single-mode optical fiber module. The reflected light passes through the single-mode optical fiber module and is input to the spectrometer. The spectrometer acquires the spectral information of the reflected light and sends the spectral information to the control terminal.

[0014] Optionally, the interference beam receiving module includes a second objective lens, a first filter, a first lens, and a camera sequentially arranged along the output direction of the multimode optical fiber. The second objective lens is used to collimate the beam output by the multimode optical fiber. The first filter is used to filter out the second laser. The first lens is used to focus the beam after filtering out the second laser. The camera is used to generate the light field information based on the focused beam and send the light field information to the control terminal.

[0015] Optionally, the Bragg grating is inscribed on one side of the multimode fiber close to the sample stage.

[0016] The present invention has the following beneficial effects:

[0017] The integrated endoscope imaging and temperature sensing system of the present invention inscribes a Bragg grating on a multimode fiber, uses an optical modulator to perform wavefront shaping on the light beam output from the first laser through the multimode fiber, and after the shaped first laser enters the multimode fiber, it is focused at different positions of the sample to be measured and fluorescence is generated through excitation by the sample to be measured. Then, the fluorescence signal is detected by the fluorescence detection module, and the control terminal generates a fluorescence imaging map according to the fluorescence signal, thereby realizing scanning at random different points and further realizing endoscope imaging. At the same time, by using the change of the reflection light spectrum of the Bragg grating at different temperatures, the temperature is corresponding to the spectral change. The spectral information of the reflected light after the second laser passes through the Bragg grating on the multimode fiber is detected by the spectral measurement module, and the control terminal obtains temperature data according to the spectral information. The present invention can reduce the influence of inscribing the Bragg grating inside the multimode fiber on the light spot output from the multimode fiber by using the wavefront shaping technology, improve the endoscope imaging quality, and can obtain high-quality images while measuring the temperature based on a single multimode fiber. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0019] Figure 1 It is a block diagram of the integrated endoscope imaging and temperature sensing system in the embodiment of the present invention;

[0020] Figure 2 It is a schematic structural diagram of the multimode grating in the embodiment of the present invention;

[0021] Figure 3 It is a schematic structural diagram of the integrated endoscope imaging and temperature sensing system in the embodiment of the present invention;

[0022] Figure 4a 、 Figure 4b and Figure 4c They are respectively schematic diagrams of the focal points when holograms are input at different positions in the embodiment of the present invention;

[0023] Figure 5 It is a spectral peak translation diagram of the temperature measurement principle in the embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of the result of temperature measurement in the embodiment of the present invention;

[0025] Reference numerals: 1 - first laser; 2 - first 4f system; 3 - half-wave plate; 4 - polarization beam splitter prism; 5 - second 4f system; 6 - first mirror; 7 - second mirror; 8 - optical modulator; 9 - third 4f system; 10 - third mirror; 11 - fourth mirror; 12 - first dichroic mirror; 13 - fifth mirror; 14 - first objective lens; 15 - multimode fiber module; 16 - second objective lens; 17 - first filter; 18 - first lens; 19 - camera; 20 - second dichroic mirror; 21 - second lens; 22 - photomultiplier tube; 23 - beam splitter prism; 24 - third lens; 25 - single-mode fiber module; 26 - spectrometer; 27 - second laser; 28 - control terminal; 0201 - fourth lens; 0202 - filtering aperture; 0203 - fifth lens; 0501 - sixth lens; 0502 - seventh lens; 0901 - eighth lens; 0902 - aperture; 0903 - ninth lens; 1501 - first fiber collimator; 1502 - multimode fiber; 1503 - sample stage; 2501 - second fiber collimator; 2502 - single-mode fiber. Detailed implementation manners

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying 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 therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Since engraving a grating inside the multimode optical fiber 1502 will affect the speckle output by the optical fiber, thereby affecting the imaging quality, and at the same time the fluorescence reflected by the sample will also affect the spectrum of the grating reflected light used in the temperature measurement process, thereby affecting the accuracy of temperature measurement. In view of this, the embodiment of the present invention provides an integrated system for endoscopic imaging and temperature sensing. A Bragg grating is engraved at the end of a multimode optical fiber 1502 close to the sample. The optical modulator 8 is used to perform wavefront shaping based on the Hadamard basis calculation transmission matrix to focus the speckle of the output optical fiber, realizing random different point scanning and thus realizing endoscopic imaging. At the same time, by using the change in the reflection light spectrum of the Bragg grating at different temperatures, which is actually manifested as a translation in the wavelength direction on the spectrometer 26, the temperature is corresponded to the spectral change to measure the temperature, realizing the simultaneous use of a single multimode optical fiber 1502 to perform endoscopic imaging and temperature sensing measurement on the sample.

[0031] As Figure 1 、 Figure 2 and Figure 3 shown, the embodiment of the present invention provides an integrated system for endoscopic imaging and temperature sensing, including an optical imaging and temperature measurement device, a signal detection device, and a control terminal 28.

[0032] The optical imaging and temperature measurement device includes an excitation light path module, a grating optical fiber module, and a sample control module. The grating optical fiber module includes a multimode optical fiber 1502 engraved with a Bragg grating. The sample control module includes a sample stage 1503. The sample stage 1503 is connected to the output end of the multimode optical fiber 1502. The sample stage 1503 is used to place the sample to be measured. The excitation light path module includes a fluorescence excitation light path, a temperature measurement excitation light path, and an interference beam receiving module. The fluorescence excitation light path includes a first laser 1 and an optical modulator 8. The optical modulator 8 performs wavefront shaping on the first laser output by the first laser 1. After the shaped first laser enters the multimode optical fiber 1502, it is focused at different positions of the sample to be measured and excites fluorescence through the sample to be measured. The temperature measurement excitation light path includes a second laser 27. The second laser 27 is used to output a second laser to the multimode optical fiber 1502. After the second laser passes through the Bragg grating, it reflects reflected light with different wavelengths at different temperatures. The interference beam receiving module is used to receive the optical field information of the beam output after the first laser interferes in the multimode optical fiber 1502 and send the optical field information to the control terminal 28.

[0033] The signal detection device includes a fluorescence detection module and a spectral measurement module. The fluorescence detection module is used to receive the fluorescence reflected by the sample to be tested and convert the fluorescence into a fluorescence signal, and send the fluorescence signal to the control terminal 28. The spectral measurement module is used to receive the reflected light reflected by the Bragg grating, obtain the spectral information of the reflected light and send the spectral information to the control terminal 28.

[0034] The control terminal 28 is used to calculate the hologram according to the light field information, and send the hologram to the optical modulator 8 so that the optical modulator 8 performs wavefront shaping on the first laser based on the hologram, and generates a fluorescence imaging image according to the fluorescence signal, and determines the temperature of the sample to be measured according to the spectral information.

[0035] Specifically, the first laser 1 is a continuous laser that outputs a first laser with a wavelength of 532 nm.

[0036] The second laser 27 is an amplified spontaneous emission (ASE) laser, and outputs a second laser with a wavelength in the range of 1520 nm to 1620 nm.

[0037] The light modulator 8 uses a digital micromirror device (DMD) or a liquid crystal spatial light modulator 8 (Spatial Light Modulator, SLM).

[0038] The control terminal 28 is a smart device such as a computer, a tablet, or a smart phone.

[0039] In one example, the optical modulator 8 is a digital micromirror device (DMD). The control terminal 28 inputs 64×64 groups of 4 Hadamard matrices with a phase interval of pi / 2 to the DMD. The light field information received by the interference beam receiving module, i.e., the output light field, is calculated using the four-step phase shift principle to obtain the phase of the corresponding light field. The transmission matrix of the fluorescence excitation light path is calculated when the input Hadamard matrix and the output light field are known. The hologram input to the DMD is changed according to the transmission matrix, so that the DMD outputs focusing points at different positions to achieve the goal of random point scanning, thereby realizing the focusing of different positions at the output end of the multimode optical fiber 1502. Figure 4a , Figure 4b and Figure 4cAs shown, different holograms can enable the multimode optical fiber 1502 to output focused light beams at corresponding positions. In this way, by using a digital micromirror device (DMD) to perform wavefront shaping based on Hadamard matrix calculation of the transmission matrix, the speckles of the output optical fiber are focused, random different points are scanned, and endoscopic imaging is realized. Through experiments, it has been realized that the Bragg grating pair has almost no influence on the imaging output spot, improving the quality of endoscopic imaging, and thus ensuring that high-quality images can be obtained while measuring the temperature.

[0040] The first laser enters the multimode optical fiber 1502 after being adjusted by the fluorescence excitation optical path, is focused at different positions of the sample to be measured, and fluoresces after being excited by the sample to be measured. The generated fluorescence is reflected and received by the fluorescence detection module to obtain the reflected fluorescence intensity, that is, the fluorescence signal. The control terminal 28 arranges the fluorescence signals received at different scanning points in sequence, and then obtains the fluorescence imaging diagram within the field of view of the sample to be measured.

[0041] The second laser enters the multimode optical fiber 1502 through the temperature measurement excitation optical path. After passing through the Bragg grating, the second laser reflects reflected light of different wavelengths at different temperatures, and then is received by the spectral measurement module to obtain spectral information. As Figure 5 shown, the spectra are translated to different degrees at different temperatures. The control terminal 28 calculates the distance of the horizontal translation of the spectra at different temperatures and obtains the temperature measurement data correspondence table corresponding to this distance and the temperature. Then, during temperature measurement, the corresponding temperature is determined according to the received spectral information. The temperature measurement results are as Figure 6 shown.

[0042] It should be understood that when the control terminal 28 performs corresponding calculations and analyses, it is necessary to synchronize the signals of the fluorescence detection module and the spectral measurement module to achieve real-time imaging and temperature measurement.

[0043] The integrated endoscope imaging and temperature sensing system according to the embodiments of the present invention has a Bragg grating engraved on a multimode optical fiber 1502. The optical modulator 8 is used to perform wavefront shaping on the light beam output from the first laser through the multimode optical fiber 1502. After the wavefront shaping, the first laser enters the multimode optical fiber 1502 and is focused at different positions of the sample to be measured, and fluorescence is generated by exciting the sample to be measured. Then, the fluorescence signal is detected by the fluorescence detection module, and the control terminal 28 generates a fluorescence imaging map according to the fluorescence signal, so as to realize scanning at random different points and then realize endoscope imaging. At the same time, by using the change of the reflection light spectrum of the Bragg grating at different temperatures, the temperature is corresponding to the spectrum change. The spectrum measurement module detects the spectrum information of the reflection light after the second laser passes through the Bragg grating on the multimode optical fiber 1502, and the control terminal 28 obtains temperature data according to the spectrum information. The present invention uses the wavefront shaping technology to reduce the influence of engraving the Bragg grating inside the multimode optical fiber 1502 on the light spot output from the multimode optical fiber 1502. Through experiments, it has been realized that engraving the Bragg grating has almost no influence on the imaging output light spot, improves the endoscope imaging quality, and can obtain high-quality images while measuring temperature based on a single multimode optical fiber.

[0044] In some embodiments, the temperature measurement excitation optical path further includes a beam splitting prism 23, a second dichroic mirror 20, a first dichroic mirror 12, and a third optical path adjustment unit arranged in sequence along the emission direction of the second laser. Both the second dichroic mirror 20 and the first dichroic mirror 12 are arranged obliquely to the emission direction of the second laser. Among them, the wavelength of the first laser is less than the cut-off wavelength of the first dichroic mirror 12, the cut-off wavelength of the first dichroic mirror 12 is less than the wavelength of the fluorescence, the wavelength of the fluorescence is less than the cut-off wavelength of the second dichroic mirror 20, the cut-off wavelength of the second dichroic mirror 20 is less than the wavelength of the second laser. After the second laser passes through the beam splitting prism 23, the second dichroic mirror 20, and the first dichroic mirror 12 in sequence and is transmitted, it enters the multimode optical fiber 1502 through the third optical path adjustment unit. The first laser modulated by the fluorescence excitation optical path enters the third optical path adjustment unit after being reflected by the first dichroic mirror 12, and enters the multimode optical fiber 1502 through the third optical path adjustment unit.

[0045] Specifically, the dichroic mirror can have significantly different reflection or transmission characteristics for two light beams with different wavelengths. When the wavelength of the light beam is less than the cut-off wavelength of the dichroic mirror, the dichroic mirror reflects the light beam. When the wavelength of the light beam is greater than the cut-off wavelength of the dichroic mirror, the dichroic mirror transmits the light beam.

[0046] Since the wavelength of the first laser is less than the cut-off wavelength of the first dichroic mirror 12, the cut-off wavelength of the first dichroic mirror 12 is less than the wavelength of the fluorescence, the wavelength of the fluorescence is less than the cut-off wavelength of the second dichroic mirror 20, and the cut-off wavelength of the second dichroic mirror 20 is less than the wavelength of the second laser. Among them, the reflected light returned by the Bragg grating is similar in wavelength to the second laser. Therefore, the first dichroic mirror 12 and the second dichroic mirror 20 can filter the reflected fluorescence and the excess first laser, avoid the influence of the fluorescence on the reflected light, and improve the accuracy of temperature detection.

[0047] Further, the third optical path adjustment unit further includes a fifth mirror 13 and a first objective lens 14. The fifth mirror 13 is used to reflect the first laser and the second laser to the first objective lens 14, and the first objective lens 14 is used to couple the first laser and the second laser into the multimode optical fiber 1502.

[0048] In some embodiments, the fluorescence excitation optical path further includes a first adjustment optical path and a second adjustment optical path. The first adjustment optical path is used to initially adjust the first laser output by the first laser and transmit the initially adjusted first laser to the optical modulator 8. The second adjustment optical path is used to re-adjust the first laser output by the optical modulator 8 and transmit the re-adjusted first laser to the first dichroic mirror 12.

[0049] Further, the first adjustment optical path includes a second mirror 7 and a first 4f system 2, a half-wave plate 3, a polarization beam splitter prism 4, a second 4f system 5, and a first mirror 6 arranged in sequence along the output direction of the first laser from the first laser 1. The first mirror 6 reflects the first laser to the second mirror 7, and the second mirror 7 reflects the first laser to the optical modulator 8.

[0050] Specifically, the first 4f system 2 includes a fourth lens 0201, a filtering small hole 0202, and a fifth lens 0203, and the second 4f system 5 includes a sixth lens 0501 and a seventh lens 0502.

[0051] After the first laser exits from the first laser 1, it is expanded by the first 4f system 2. The filtering small hole 0202 in the first 4f system 2 filters the first laser to eliminate stray waves. The half-wave plate 3 and the polarization beam splitter prism 4 are used to adjust the power of the first laser. After passing through the polarization beam splitter prism 4, the first laser is further expanded by the second 4f system 5 and then hits the optical modulator 8.

[0052] Components such as the 4f system, the half-wave plate 3, and the polarization beam splitter prism 4 in the first adjustment optical path can perform wavefront shaping and polarization control on the first laser, improve the quality and stability of the light beam, and are beneficial to improving the resolution and contrast of imaging.

[0053] Further, the second adjustment optical path includes a fourth mirror 11, and a third 4f system 9 and a third mirror 10 arranged in sequence along the outgoing direction of the first laser output by the optical modulator 8. The third mirror 10 reflects the first laser to the fourth mirror 11, and the fourth mirror 11 reflects the first laser to the first dichroic mirror 12.

[0054] Specifically, the third 4f system 9 includes an eighth lens 0901, a diaphragm 0902, and a ninth lens 0903. The Fourier transform of the first laser is realized through the eighth lens 0901, the selection of the diffracted order reflected light of the target light field on the Fourier plane is realized by the diaphragm 0902, and the inverse Fourier transform of the first laser is realized by the ninth lens 0903. The first laser is reflected to the first dichroic mirror 12 through the third mirror 10 and the fourth mirror 11 in sequence. After passing through the first dichroic sheet, it is reflected because it is less than the cut-off wavelength. Subsequently, the light beam is coupled into the multimode optical fiber 1502 engraved with a Bragg grating through the first objective lens 14.

[0055] The third 4f system 9 and the mirrors in the second adjustment optical path can further adjust the transmission direction and quality of the light beam, and at the same time make the entire optical system more compact and integrated, which is convenient for use.

[0056] In some embodiments, the grating optical fiber module further includes a first fiber collimator 1501. The first fiber collimator 1501 is arranged between the first objective lens 14 and the multimode optical fiber 1502. The fifth mirror 13 reflects the first laser and the second laser to the first objective lens 14. The first objective lens 14 is used to couple the first laser and the second laser into the first fiber collimator 1501, and the light beam is collimated by the first fiber collimator 1501 and then input into the multimode optical fiber 1502.

[0057] In some embodiments, the interference beam receiving module includes a second objective lens 16, a first filter 17, a first lens 18, and a camera 19 arranged in sequence along the output direction of the multimode optical fiber 1502. The second objective lens 16 is used to collimate the light beam output by the multimode optical fiber 1502. The first filter 17 is used to filter out the second laser. The first lens 18 is used to focus the light beam after filtering out the second laser. The camera 19 is used to generate light field information based on the focused light beam and send the light field information to the control terminal 28.

[0058] Specifically, the camera 19 uses a CMOS optical sensor.

[0059] Since the multimode optical fiber 1502 has multiple modes, the light beam entering the multimode optical fiber 1502 undergoes internal interference. The interfered light beam enters the second objective lens 16 for collimation. The collimated light beam passes through the first filter 17 to filter out the second laser and the reflected light for temperature measurement. Subsequently, the light beam is focused by the first lens 18 into the camera 19 and the control terminal 28 performs light field calculation and modulation.

[0060] The second objective lens 16, the first filter 17, the first lens 18, and the camera 19 in the interference beam receiving module can accurately acquire the optical field information of the output beam of the multimode optical fiber 1502, providing high-quality data for the generation of the hologram.

[0061] In some embodiments, the fluorescence detection module includes a second lens 21 and a photomultiplier tube 22 (PMT). The fluorescence reflected by the sample to be measured passes through the first dichroic mirror 12 and is transmitted to the second dichroic mirror 20. The second dichroic mirror 20 reflects the fluorescence to the second lens 21. The second lens 21 is used to converge the fluorescence and input it into the photomultiplier tube 22. The photomultiplier tube 22 is used to convert the fluorescence into a fluorescence signal and send the fluorescence signal to the control terminal 28.

[0062] Specifically, the multimode optical fiber 1502 is inserted into the sample placed on the sample stage 1503, and the beam passing through the multimode optical fiber 1502 is used to image the point scanning of the field of view range in the sample to be measured. The first laser is focused and hits the sample to be measured, exciting fluorescence. The fluorescence is reflected back to the multimode optical fiber 1502 and sequentially returns to the first objective lens 14, the fifth mirror 13, and the first dichroic mirror 12 through the multimode optical fiber 1502. Since the wavelength of the reflected fluorescence is greater than the cut-off wavelength of the first dichroic filter, the fluorescence is transmitted through the first dichroic filter. After passing through the second dichroic filter, since the fluorescence wavelength is less than the cut-off wavelength of the second dichroic filter, it is immediately reflected, enters the second lens 21, and then the beam is focused and enters the photomultiplier tube 22 to obtain a fluorescence signal.

[0063] In some embodiments, the spectral measurement module includes a third lens 24, a single-mode optical fiber module 25, and a spectrometer 26. The reflected light reflected by the Bragg grating passes through the first dichroic mirror 12 and the second dichroic mirror 20 in sequence and is transmitted to the beam splitter prism 23. The beam splitter prism 23 reflects the reflected light to the third lens 24. The third lens 24 is used to converge the reflected light and input it into the single-mode optical fiber module 25. The reflected light passes through the single-mode optical fiber module 25 and is input to the spectrometer 26. The spectrometer 26 acquires the spectral information of the reflected light and sends the spectral information to the control terminal 28.

[0064] Specifically, after the second laser enters the multimode optical fiber 1502 and passes through the Bragg grating engraved on the multimode optical fiber 1502, reflected light of different wavelengths is reflected at different temperatures. The reflected light corresponding to the wavelength returns to the first objective lens 14, the fifth mirror 13, and the first dichroic mirror 12 in sequence through the multimode optical fiber 1502. When passing through the first dichroic mirror 12 and the second dichroic mirror 20, since the wavelength of the reflected light is greater than the cut-off wavelengths of the two dichroic mirrors, the reflected light containing temperature information will be transmitted onto the beam splitter prism 23. The split beam is focused by the third lens 24 and then coupled into the single-mode optical fiber module 25. The single-mode optical fiber module 25 includes a second fiber collimator 2501 and a single-mode optical fiber 2502. The reflected light is collimated by the second fiber collimator 2501 and then enters the single-mode optical fiber 2502, and then is transmitted into the spectrometer 26 to detect the spectral information of the reflected light.

[0065] In some embodiments, the Bragg grating is engraved on one side of the multimode optical fiber 1502 close to the sample stage 1503.

[0066] In this way, engraving the Bragg grating on one side of the multimode optical fiber 1502 close to the sample stage 1503 enables the Bragg grating to be closer to the sample to be measured, improving the accuracy and sensitivity of temperature measurement.

[0067] An integrated endoscope imaging and temperature sensing system according to an embodiment of the present invention has a Bragg grating engraved at the end of a multimode optical fiber 1502 close to the sample to be measured. The wavefront shaping is performed by using the method of the transmission matrix. By inputting the calculated hologram into the optical modulator 8, focusing of the speckles output from the multimode optical fiber 1502 at different positions and point scanning imaging are realized, and the resolution can reach 1 μm. At the same time, infrared light in the 1520 nm - 1620 nm band is used to pass through the multimode optical fiber 1502 engraved with the Bragg grating, and the spectrometer 26 detects the spectral change of the reflected wave to realize temperature measurement with an accuracy of 0.1 °C.

[0068] The embodiment of the present invention can be applied to photothermal therapy experiments, and can simultaneously realize endoscope imaging of the sample and measurement of the temperature of the imaging part.

[0069] Although the exemplary embodiments and their advantages have been described in detail, those skilled in the art can make various changes, substitutions, and modifications to these embodiments without departing from the spirit of the present invention and the defined protection scope. Such modifications and variations all fall within the defined scope.

Claims

1. An integrated system for endoscopic imaging and temperature sensing, characterized in that, Comprising: An optical imaging and temperature measurement device, a signal detection device, and a control terminal (28); The optical imaging and temperature measurement device includes an excitation optical path module, a grating optical fiber module, and a sample control module. The grating optical fiber module includes a multimode optical fiber (1502) engraved with a Bragg grating. The multimode optical fiber (1502) is a multimode optical fiber with a single-core optical fiber, and the Bragg grating is engraved on the single core of the multimode optical fiber. The sample control module includes a sample stage (1503). The sample stage (1503) is connected to the output end of the multimode optical fiber (1502), and the sample stage (1503) is used to place the sample to be measured. The excitation optical path module includes a fluorescence excitation optical path, a temperature measurement excitation optical path, and an interference beam receiving module. The fluorescence excitation optical path includes a first laser (1) and an optical modulator (8). The first laser output by the first laser (1) is wavefront-shaped through the optical modulator (8). After the shaped first laser enters the multimode optical fiber (1502), it is focused at different positions of the sample to be measured and excites fluorescence through the sample to be measured. The temperature measurement excitation optical path includes a second laser (27). The second laser (27) is used to output a second laser to the multimode optical fiber (1502). After the second laser passes through the Bragg grating, reflected light with different wavelengths is reflected at different temperatures. The interference beam receiving module is used to receive the optical field information of the beam output after the first laser interferes in the multimode optical fiber (1502) and send the optical field information to the control terminal (28); The signal detection device includes a fluorescence detection module and a spectral measurement module. The fluorescence detection module is used to receive the fluorescence reflected by the sample to be measured, convert the fluorescence into a fluorescence signal, and send the fluorescence signal to the control terminal (28). The spectral measurement module is used to receive the reflected light reflected by the Bragg grating, obtain the spectral information of the reflected light, and send the spectral information to the control terminal (28); The control terminal (28) is used to calculate a hologram based on the optical field information, send the hologram to the optical modulator (8) so that the optical modulator (8) performs wavefront shaping on the first laser based on the hologram, generate a fluorescence imaging map according to the fluorescence signal, and determine the temperature of the sample to be measured according to the spectral information; The temperature measurement excitation optical path further includes a beam splitting prism (23), a second dichroic mirror (20), a first dichroic mirror (12), and a third optical path adjustment unit, which are sequentially arranged along the emission direction of the second laser. The second dichroic mirror (20) and the first dichroic mirror (12) are both arranged obliquely to the emission direction of the second laser. Among them, the wavelength of the first laser is less than the cut-off wavelength of the first dichroic mirror (12), the cut-off wavelength of the first dichroic mirror (12) is less than the wavelength of the fluorescence, the wavelength of the fluorescence is less than the cut-off wavelength of the second dichroic mirror (20), and the cut-off wavelength of the second dichroic mirror (20) is less than the wavelength of the second laser. After the second laser is transmitted through the beam splitting prism (23), the second dichroic mirror (20), and the first dichroic mirror (12) in sequence, it enters the multimode optical fiber (1502) through the third optical path adjustment unit. The first laser modulated by the fluorescence excitation optical path enters the third optical path adjustment unit after being reflected by the first dichroic mirror (12), and enters the multimode optical fiber (1502) through the third optical path adjustment unit.

2. The integrated endoscope imaging and temperature sensing system according to claim 1, characterized in that The fluorescence excitation optical path further includes a first adjustment optical path and a second adjustment optical path. The first adjustment optical path is used to initially adjust the first laser output by the first laser and transmit the preliminarily adjusted first laser to the optical modulator (8). The second adjustment optical path is used to further adjust the first laser output by the optical modulator (8) and transmit the further adjusted first laser to the first dichroic mirror (12).

3. The integrated endoscope imaging and temperature sensing system according to claim 2, wherein The first adjustment optical path includes a second mirror (7), and a first 4f system (2), a half-wave plate (3), a polarization beam splitting prism (4), a second 4f system (5), and a first mirror (6) that are sequentially arranged along the emission direction of the first laser output by the first laser (1). The first mirror (6) reflects the first laser to the second mirror (7), and the second mirror (7) reflects the first laser to the optical modulator (8).

4. The integrated endoscope imaging and temperature sensing system according to claim 2, wherein The second adjustment optical path includes a fourth mirror (11), and a third 4f system (9) and a third mirror (10) that are sequentially arranged along the emission direction of the first laser output by the optical modulator (8). The third mirror (10) reflects the first laser to the fourth mirror (11), and the fourth mirror (11) reflects the first laser to the first dichroic mirror (12).

5. The integrated endoscope imaging and temperature sensing system according to claim 1, characterized in that The third optical path adjustment unit further includes a fifth mirror (13) and a first objective lens (14). The fifth mirror (13) is used to reflect the first laser and the second laser to the first objective lens (14), and the first objective lens (14) is used to couple the first laser and the second laser into the multimode optical fiber (1502).

6. The integrated endoscope imaging and temperature sensing system according to claim 1, characterized in that The fluorescence detection module includes a second lens (21) and a photomultiplier tube (22). The fluorescence reflected by the sample to be measured is transmitted to the second dichroic mirror (20) through the first dichroic mirror (12). The second dichroic mirror (20) reflects the fluorescence to the second lens (21). The second lens (21) is used to converge the fluorescence and input it into the photomultiplier tube (22). The photomultiplier tube (22) is used to convert the fluorescence into a fluorescence signal and send the fluorescence signal to the control terminal (28).

7. The integrated endoscope imaging and temperature sensing system according to claim 1, characterized in that The spectral measurement module includes a third lens (24), a single-mode fiber module (25), and a spectrometer (26). The reflected light reflected by the Bragg grating sequentially passes through the first dichroic mirror (12) and the second dichroic mirror (20) and is transmitted to the beam splitting prism (23). The beam splitting prism (23) reflects the reflected light to the third lens (24). The third lens (24) is used to converge the reflected light and input it into the single-mode fiber module (25). The reflected light passes through the single-mode fiber module (25) and is input into the spectrometer (26). The spectrometer (26) acquires the spectral information of the reflected light and sends the spectral information to the control terminal (28).

8. The integrated endoscope imaging and temperature sensing system according to claim 1, characterized in that The interference beam receiving module includes a second objective lens (16), a first filter (17), a first lens (18), and a camera (19) sequentially arranged along the output direction of the multimode fiber (1502). The second objective lens (16) is used to collimate the beam output by the multimode fiber (1502). The first filter (17) is used to filter out the second laser. The first lens (18) is used to focus the beam after filtering out the second laser. The camera (19) is used to generate light field information based on the focused beam and send the light field information to the control terminal (28).

9. The integrated endoscope imaging and temperature sensing system according to claim 1, characterized in that, The Bragg grating is engraved on one side of the multimode fiber (1502) close to the sample stage (1503).

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