Endoscopic imaging and temperature sensing integrated system

Abstract

The invention relates to the technical field of measurement and detection, and discloses an endoscopic imaging and temperature sensing integrated system, which comprises an optical imaging and temperature measuring device, a signal detection device and a control terminal, and is characterized in that the optical imaging and temperature measuring device comprises an excitation light path module, a grating fiber module and a sample control module; the signal detection device comprises a fluorescence detection module and a spectral measurement module, and the control terminal is used for calculating a hologram according to the light field information, sending the hologram to the light modulator to enable the light modulator to carry out wavefront shaping on the first laser based on the hologram, generating a fluorescence imaging graph according to a fluorescence signal, and sending the fluorescence imaging graph to the spectral measurement module. And determining the temperature of the to-be-measured sample according to the spectral information. By utilizing the wavefront shaping technology, the influence of the Bragg grating engraved in the multimode fiber on the light spot output by the multimode fiber can be reduced, the endoscopic imaging quality is improved, and high-quality images can be obtained while the temperature is measured based on the single multimode fiber.

Description

Technical Field

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

[0002] The emergence and development of multimode fiber endoscopic imaging technology is an important achievement of the combination of modern medicine and optical technology. Multimode fiber endoscopic imaging technology has the advantages of minimally invasive, high resolution, real-time, flexibility, etc., and can perform deep imaging through tiny incisions. The existing multimode fiber endoscopic imaging system uses the focus of the speckle output by the optical fiber and uses point scanning imaging.

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

[0004] In view of this, the present invention provides an integrated endoscopic imaging and temperature sensing system 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: The present invention provides an integrated system of endoscopic imaging and temperature sensing, comprising: an optical imaging and temperature measuring device, a signal detection device and a control terminal; the optical imaging and temperature measuring device comprises an excitation optical path module, a grating optical fiber module and a sample control module, the grating optical fiber module comprises a multimode optical fiber engraved with a Bragg grating, the sample control module comprises a sample stage, the sample stage is connected to the output end of the multimode optical fiber, the sample stage is used to place a sample to be measured, the excitation optical path module comprises a fluorescence excitation optical path, a temperature measurement excitation optical path and an interference beam receiving module, the fluorescence excitation optical path comprises a first laser and an optical modulator, a first laser output by the first laser is wavefront shaped by the optical modulator, the shaped first laser 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 comprises a second laser, and the second laser is used to output a second laser to the multimode optical fiber, the second laser reflects reflected light of different wavelengths at different temperatures after passing through the Bragg grating, the interference beam receiving module is used to receive the light field information of the light beam output by the first laser after interference in the multimode optical fiber, and send the light field information to the control terminal; the signal detection device includes a fluorescence detection module and a spectrum 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, the spectrum measurement module is used to receive the reflected light reflected by the Bragg grating, obtain the spectrum information of the reflected light and send the spectrum information to the control terminal; the control terminal is used to calculate a hologram according to the light 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 diagram according to the fluorescence signal, and determine the temperature of the sample to be tested according to the spectrum information.

[0006] Optionally, the temperature measurement excitation optical path also includes a beam splitter prism, a second dichroic mirror, a first dichroic mirror and a third optical path adjustment unit which are sequentially arranged along the emission direction of the second laser, the second dichroic mirror and the first dichroic mirror are both arranged obliquely to the emission direction of the second laser, wherein the wavelength of the first laser is smaller than the cut-off wavelength of the first dichroic mirror, the cut-off wavelength of the first dichroic mirror is smaller than the wavelength of the fluorescence, the wavelength of the fluorescence is smaller than the cut-off wavelength of the second dichroic mirror, the cut-off wavelength of the second dichroic mirror is smaller than the wavelength of the second laser, the second laser is sequentially transmitted through the beam splitter prism, the second dichroic mirror and the first dichroic mirror, and then enters the multimode optical fiber through the third optical path adjustment unit, the first laser modulated by the fluorescence excitation optical path is reflected by the first dichroic mirror and enters the third optical path adjustment unit, and then enters the multimode optical fiber through the third optical path adjustment unit.

[0007] Optionally, the fluorescence excitation optical path also 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, and the second adjustment optical path is used to re-adjust the first laser output by the optical modulator and transmit the re-adjusted first laser to the first dichroic mirror.

[0008] 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 arranged in sequence 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.

[0009] 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.

[0010] 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.

[0011] Optionally, the fluorescence detection module includes a second lens and a photomultiplier tube. The fluorescence reflected by the sample to be tested is transmitted to the second dichroic mirror through the first 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.

[0012] 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 is transmitted to the beam splitter prism through the first dichroic mirror and the second dichroic mirror in sequence. 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 is input into the spectrometer through the single-mode optical fiber module. The spectrometer obtains the spectral information of the reflected light and sends the spectral information to the control terminal.

[0013] Optionally, the interference beam receiving module includes a second objective lens, a first filter, a first lens and a camera which are arranged in sequence along the output direction of the multimode optical fiber, the second objective lens is used to collimate the light 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 light beam after filtering out the second laser, and the camera is used to generate light field information based on the focused light beam and send the light field information to the control terminal.

[0014] Optionally, a Bragg grating is inscribed on a side of the multimode optical fiber close to the sample stage.

[0015] The present invention has the following beneficial effects: The integrated system of endoscopic imaging and temperature sensing of the present invention is characterized in that a Bragg grating is engraved on a multimode optical fiber, and a light modulator is used to perform wavefront shaping on the light beam output by the first laser through the multimode optical fiber. After the shaped first laser enters the multimode optical fiber, it is focused at different positions of the sample to be tested and excited by the sample to be tested to generate fluorescence, and then the fluorescence signal is detected by the fluorescence detection module, and the control terminal generates a fluorescence imaging diagram according to the fluorescence signal, thereby realizing the scanning of random different points and thus realizing endoscopic imaging. At the same time, the change of the reflected light spectrum of the Bragg grating at different temperatures is used to correspond the temperature to the spectrum change, and the spectrum information of the reflected light of the second laser after passing through the Bragg grating on the multimode optical fiber is detected by the spectrum measurement module, and the control terminal obtains temperature data according to the spectrum information. The present invention uses the wavefront shaping technology to reduce the influence of the Bragg grating engraved inside the multimode optical fiber on the light spot output by the multimode optical fiber, improve the quality of endoscopic imaging, and can achieve high-quality images while measuring temperature based on a single multimode optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly express the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a module block diagram of the integrated system of endoscopic imaging and temperature sensing in an embodiment of the present invention; Figure 2 Schematic diagram of the structure of a multi-mode grating in an embodiment of the present invention; Figure 3 It is a structural schematic diagram of an integrated system for endoscopic imaging and temperature sensing in an embodiment of the present invention; Figure 4a , Figure 4b and Figure 4c They are respectively schematic diagrams of focusing points when holograms are input at different positions in the embodiments of the present invention; Figure 5 It is a spectrum peak shift diagram of the temperature measurement principle in the embodiment of the present invention; Figure 6 This is a schematic diagram of the temperature measurement results in an embodiment of the present invention; Figure numerals: 1-first laser; 2-first 4f system; 3-half-wave plate; 4-polarization beam splitter; 5-second 4f system; 6-first reflector; 7-second reflector; 8-light modulator; 9-third 4f system; 10-third reflector; 11-fourth reflector; 12-first dichroic mirror; 13-fifth reflector; 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-photoelectric Multiplier tube; 23-beam splitter prism; 24-third lens; 25-single-mode optical fiber module; 26-spectrometer; 27-second laser; 28-control terminal; 0201-fourth lens; 0202-filter aperture; 0203-fifth lens; 0501-sixth lens; 0502-seventh lens; 0901-eighth lens; 0902-aperture; 0903-ninth lens; 1501-first optical fiber collimator; 1502-multimode optical fiber; 1503-sample stage; 2501-second optical fiber collimator; 2502-single-mode optical fiber. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "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 a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] 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 the temperature measurement. In view of this, an embodiment of the present invention provides an integrated system for endoscopic imaging and temperature sensing, in which a Bragg grating is engraved on a multimode optical fiber 1502 near the sample end, and a light 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, realize scanning of random different points, and thus realize endoscopic imaging, and at the same time, the change of the reflected light spectrum of the Bragg grating at different temperatures is used, which is actually manifested as a translation in the wavelength direction on the spectrometer 26, and the temperature is measured by corresponding the change in the spectrum to the change in the spectrum, so as to realize endoscopic imaging and temperature sensing measurement of the sample simultaneously using a single multimode optical fiber 1502.

[0023] like Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of the present invention provides an integrated endoscopic imaging and temperature sensing system, including an optical imaging and temperature measuring device, a signal detection device and a control terminal 28.

[0024] 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 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 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 1 outputs a second light. A laser performs wavefront shaping. After the shaping, the first laser enters the multimode optical fiber 1502 and is focused at different positions of the sample to be measured and excited by the sample to be measured to produce fluorescence. 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, it reflects light of different wavelengths at different temperatures. The interference beam receiving module is used to receive the light field information of the light beam output by the first laser after interference in the multimode optical fiber 1502, and send the light field information to the control terminal 28.

[0025] 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.

[0026] 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.

[0027] Specifically, the first laser 1 is a continuous laser that outputs a first laser with a wavelength of 532 nm.

[0028] 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.

[0029] The light modulator 8 uses a digital micromirror device (DMD) or a liquid crystal spatial light modulator 8 (Spatial Light Modulator, SLM).

[0030] The control terminal 28 is a smart device such as a computer, a tablet, or a smart phone.

[0031] 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 achieving focusing at different positions of the output end of the multimode optical fiber 1502. Figure 4a , Figure 4b and Figure 4cAs shown, different holograms can make the multimode optical fiber 1502 output a focused light beam at a corresponding position. In this method, by using a digital micromirror device DMD to perform wavefront shaping based on the Hadamard base calculation transmission matrix, the speckle of the output optical fiber is focused, and random scanning of different points is achieved to achieve endoscopic imaging. Experiments have shown that the Bragg grating has almost no effect on the imaging output spot, which improves the endoscopic imaging quality, thereby ensuring that high-quality images can be obtained while measuring temperature.

[0032] After the first laser is adjusted through the fluorescence excitation optical path, it enters the multimode optical fiber 1502, is focused at different positions of the sample to be tested, and is excited by the sample to be tested to generate fluorescence, which is then reflected and received by the fluorescence detection module to obtain the reflected fluorescence intensity, i.e., the fluorescence signal. The control terminal 28 arranges the fluorescence signals received at different scanning points in sequence to obtain the fluorescence imaging diagram within the field of view of the sample to be tested.

[0033] 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 light of different wavelengths at different temperatures, and then is received by the spectrum measurement module to obtain spectrum information. Figure 5 As shown, the spectrum shifts to different degrees at different temperatures. The control terminal 28 calculates the horizontal shift distance of the spectrum at different temperatures, and obtains a temperature measurement data correspondence table by corresponding the distance to the temperature. Then, when measuring the temperature, the corresponding temperature is determined according to the received spectrum information. The temperature measurement result is shown in FIG. Figure 6 shown.

[0034] 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 spectrum measurement module, so as to achieve real-time imaging and temperature measurement.

[0035] The integrated endoscopic imaging and temperature sensing system of the embodiment of the present invention is characterized in that a Bragg grating is engraved on the multimode optical fiber 1502, and the light modulator 8 is used to perform wavefront shaping on the light beam output by the first laser through the multimode optical fiber 1502. After the first laser after shaping enters the multimode optical fiber 1502, it is focused at different positions of the sample to be tested and excited by the sample to be tested to generate fluorescence. Then, the fluorescence signal is detected by the fluorescence detection module, and the control terminal 28 generates a fluorescence imaging diagram according to the fluorescence signal, thereby realizing scanning of different random points and thus realizing endoscopic imaging. At the same time, the change in the reflected light spectrum of the Bragg grating at different temperatures is used to correspond the temperature to the spectral change. The spectral information of the reflected light of the second laser after passing through the Bragg grating on the multimode optical fiber 1502 is detected by the spectral measurement module, and the control terminal 28 obtains temperature data according to the spectral information. The present invention utilizes wavefront shaping technology to reduce the influence of the Bragg grating inside the multimode optical fiber 1502 on the light spot output by the multimode optical fiber 1502. Experiments have shown that the Bragg grating has almost no influence on the imaging output light spot, thereby improving the quality of endoscopic imaging and being able to obtain high-quality images while measuring temperature based on a single multimode optical fiber.

[0036] In some embodiments, the temperature measurement excitation optical path also includes a beam splitter 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. The wavelength of the first laser is smaller than the cutoff wavelength of the first dichroic mirror 12, the cutoff wavelength of the first dichroic mirror 12 is smaller than the wavelength of the fluorescence, the wavelength of the fluorescence is smaller than the cutoff wavelength of the second dichroic mirror 20, the cutoff wavelength of the second dichroic mirror 20 is smaller than the wavelength of the second laser. After the second laser is sequentially transmitted through the beam splitter prism 23, the second dichroic mirror 20 and the first dichroic mirror 12, it passes through the third optical path adjustment unit and enters the multimode optical fiber 1502. The first laser modulated by the fluorescence excitation optical path is reflected by the first dichroic mirror 12 and enters the third optical path adjustment unit, and then enters the multimode optical fiber 1502 through the third optical path adjustment unit.

[0037] Specifically, a dichroic mirror can have significantly different reflection or transmission characteristics for two light beams of different wavelengths. When the wavelength of the light beam is less than the cutoff wavelength of the dichroic mirror, the dichroic mirror reflects the light beam. When the wavelength of the light beam is greater than the cutoff wavelength of the dichroic mirror, the dichroic mirror transmits the light beam.

[0038] Since the wavelength of the first laser is smaller than the cutoff wavelength of the first dichroic mirror 12, the cutoff wavelength of the first dichroic mirror 12 is smaller than the wavelength of the fluorescence, the wavelength of the fluorescence is smaller than the cutoff wavelength of the second dichroic mirror 20, the cutoff wavelength of the second dichroic mirror 20 is smaller than the wavelength of the second laser, wherein the reflected light returned through the Bragg grating has a similar wavelength to the second laser, therefore, the first dichroic mirror 12 and the second dichroic mirror 20 can filter the reflected fluorescence and excess first laser, avoid the influence of fluorescence on the reflected light, and improve the accuracy of temperature detection.

[0039] Furthermore, the third optical path adjustment unit also includes a fifth reflector 13 and a first objective lens 14 . The fifth reflector 13 is used to reflect 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 multimode optical fiber 1502 .

[0040] In some embodiments, the fluorescence excitation optical path also 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.

[0041] Furthermore, the first adjustment optical path includes a second reflector 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 reflector 6 which are arranged in sequence along the emission direction of the first laser output by the first laser 1. The first reflector 6 reflects the first laser to the second reflector 7, and the second reflector 7 reflects the first laser to the optical modulator 8.

[0042] Specifically, the first 4f system 2 includes a fourth lens 0201 , a filter aperture 0202 , and a fifth lens 0203 , and the second 4f system 5 includes a sixth lens 0501 and a seventh lens 0502 .

[0043] After the first laser is emitted from the first laser 1, it is expanded by the first 4f system 2. The filter aperture 0202 in the first 4f system 2 filters the first laser to eliminate stray waves. The power of the first laser is adjusted by the half-wave plate 3 and the polarization beam splitter prism 4. 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 light modulator 8.

[0044] The 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, thereby improving the quality and stability of the light beam and facilitating improving the resolution and contrast of imaging.

[0045] Furthermore, the second adjustment optical path includes a fourth reflector 11 and a third 4f system 9 and a third reflector 10 which are sequentially arranged along the emission direction of the first laser output by the optical modulator 8. The third reflector 10 reflects the first laser to the fourth reflector 11, and the fourth reflector 11 reflects the first laser to the first dichroic mirror 12.

[0046] Specifically, the third 4f system 9 includes an eighth lens 0901, an aperture 0902 and a ninth lens 0903. The eighth lens 0901 is used to implement Fourier transform of the first laser. The aperture 0902 implements the selection of diffraction-order reflected light of the target light field on the Fourier plane. The ninth lens 0903 implements inverse Fourier transform of the first laser. The first laser is reflected to the first dichroic mirror 12 through the third reflector 10 and the fourth reflector 11 in sequence. After passing through the first dichroic plate, it is reflected because it is smaller than the cut-off wavelength. Then, the light beam is coupled into the multimode optical fiber 1502 engraved with a Bragg grating through the first objective lens 14.

[0047] The third 4f system 9 and the reflector in the second adjustment optical path can further adjust the transmission direction and quality of the light beam, while making the entire optical system more compact and integrated, and easy to use.

[0048] In some embodiments, the grating fiber module also includes a first fiber collimator 1501, which is disposed between the first objective lens 14 and the multimode optical fiber 1502. The fifth reflector 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 beams are collimated by the first fiber collimator 1501 and then input into the multimode optical fiber 1502.

[0049] 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 which are arranged in sequence along the output direction of the multi-mode optical fiber 1502. The second objective lens 16 is used to collimate the light beam output by the multi-mode 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.

[0050] Specifically, the camera 19 adopts a CMOS optical sensor.

[0051] Since the multimode optical fiber 1502 has multiple modes, the light beam entering the multimode optical fiber 1502 undergoes internal interference, and 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 reflected light used to measure the temperature, and then the light beam is focused by the first lens 18 to enter the camera 19 and the control terminal 28 performs light field calculation and modulation.

[0052] 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 obtain the light field information of the output light beam of the multimode optical fiber 1502, providing high-quality data for the generation of the hologram.

[0053] In some embodiments, the fluorescence detection module includes a second lens 21 and a photomultiplier tube (PMT) 22. The fluorescence reflected by the sample to be tested 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.

[0054] Specifically, the multimode optical fiber 1502 is inserted into the sample placed on the sample stage 1503, and the light beam of the multimode optical fiber 1502 is scanned to form an image at a point in the field of view of the sample to be tested. After being focused, the first laser hits the sample to be tested and excites fluorescence, which is reflected back to the multimode optical fiber 1502 and returns to the first objective lens 14, the fifth reflector 13 and the first dichroic mirror 12 in sequence through the multimode optical fiber 1502. Since the wavelength of the reflected fluorescence is greater than the cutoff wavelength of the first dichroic film, the fluorescence passes through the first dichroic film, and after passing through the second dichroic film, it is immediately reflected because the fluorescence wavelength is less than the cutoff wavelength of the second dichroic film. After entering the second lens 21, the light beam is focused and enters the photomultiplier tube 22 to obtain a fluorescence signal.

[0055] 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 is transmitted to the dichroic mirror 12 and the second dichroic mirror 20 in sequence 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 is input to the spectrometer 26 through the single-mode optical fiber module 25. The spectrometer 26 obtains the spectral information of the reflected light and sends the spectral information to the control terminal 28.

[0056] Specifically, after the second laser enters the multimode optical fiber 1502, it reflects light of different wavelengths at different temperatures when passing through the Bragg grating engraved on the multimode optical fiber 1502. The reflected light of corresponding wavelengths returns to the first objective lens 14, the fifth reflector 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 wavelength of the two dichroic mirrors, the reflected light containing temperature information will be transmitted on the beam splitter prism 23. The separated light beams are focused by the third lens 24 and coupled into the single-mode optical fiber module 25. The single-mode optical fiber module 25 includes a second optical fiber collimator 2501 and a single-mode optical fiber 2502. The reflected light enters the single-mode optical fiber 2502 after being collimated by the second optical fiber collimator 2501, and then is transmitted to the spectrometer 26 to detect the spectral information of the reflected light.

[0057] In some embodiments, a Bragg grating is engraved on a side of the multimode optical fiber 1502 close to the sample stage 1503 .

[0058] In this method, the Bragg grating is engraved on the side of the multimode optical fiber 1502 close to the sample stage 1503, so that the Bragg grating can be closer to the sample to be measured, thereby improving the accuracy and sensitivity of temperature measurement.

[0059] An integrated endoscopic imaging and temperature sensing system of an embodiment of the present invention has a Bragg grating engraved on the end of a multimode optical fiber 1502 close to the sample to be tested, and uses the transmission matrix method to perform wavefront shaping. By inputting the calculated hologram into the optical modulator 8, the focusing and point scanning imaging of the output speckle of the multimode optical fiber 1502 at different positions are realized, and the resolution can reach 1μm. At the same time, infrared light in the 1520nm-1620nm band is used to pass through the multimode optical fiber 1502 engraved with the Bragg grating, and the spectral change of the reflected wave is detected by the spectrometer 26 to achieve temperature measurement with an accuracy of 0.1°C.

[0060] The embodiment of the present invention can be applied to photothermal therapy experiments, and can simultaneously realize endoscopic imaging of samples and measurement of the temperature of the imaging site.

[0061] Although example embodiments and their advantages have been described in detail, those skilled in the art may make various changes, substitutions and modifications to these embodiments without departing from the spirit and defined scope of the present invention, and such modifications and variations are all within the defined scope.

Claims

1. An integrated endoscopic imaging and temperature sensing system, characterized in that: include: Optical imaging and temperature measuring device, signal detection device and control terminal (28); The optical imaging and temperature measurement device comprises an excitation optical path module, a grating optical fiber module and a sample control module. The grating optical fiber module comprises a multimode optical fiber (1502) engraved with a Bragg grating. The sample control module comprises 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 a sample to be measured. The excitation optical path module comprises a fluorescence excitation optical path, a temperature measurement excitation optical path and an interference beam receiving module. The fluorescence excitation optical path comprises a first laser (1) and an optical modulator (8). The optical modulator (8) is used to excite the first laser (1) The output first laser undergoes wavefront shaping, and after the shaping, the first laser enters the multimode optical fiber (1502), is focused at different positions of the sample to be measured, and is excited by the sample to be measured to generate fluorescence, the temperature measurement excitation optical path comprises a second laser (27), the second laser (27) is used to output the second laser to the multimode optical fiber (1502), and after the second laser passes through the Bragg grating, it reflects light of different wavelengths at different temperatures, and the interference light beam receiving module is used to receive light field information of the light beam output by the first laser after interference in the multimode optical fiber (1502), and send the light field information to the control terminal (28); The signal detection device comprises a fluorescence detection module and a spectrum measurement module, wherein 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 spectrum measurement module is used to receive the reflected light reflected by the Bragg grating, obtain the spectrum information of the reflected light and send the spectrum information to the control terminal (28); The control terminal (28) is used to calculate a hologram based on the light field information, and send the hologram to the light modulator (8) so that the light modulator (8) performs wavefront shaping on the first laser based on the hologram, and to generate a fluorescence imaging image based on the fluorescence signal, and to determine the temperature of the sample to be measured based on the spectral information.

2. The integrated endoscopic imaging and temperature sensing system according to claim 1, characterized in that: The temperature measurement excitation optical path further comprises a beam splitter 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, wherein the second dichroic mirror (20) and the first dichroic mirror (12) are both arranged obliquely to the emission direction of the second laser, wherein the wavelength of the first laser is shorter than the cut-off wavelength of the first dichroic mirror (12), the cut-off wavelength of the first dichroic mirror (12) is shorter than the wavelength of the fluorescence, and the wavelength of the fluorescence is shorter than the wavelength of the second dichroic mirror (2 0), the cut-off wavelength of the second dichroic mirror (20) is smaller than the wavelength of the second laser, the second laser is transmitted through the beam splitter (23), the second dichroic mirror (20) and the first dichroic mirror (12) in sequence, and then passes through the third optical path adjustment unit to enter the multimode optical fiber (1502), the first laser modulated by the fluorescence excitation optical path is reflected by the first dichroic mirror (12) and then enters the third optical path adjustment unit, and then passes through the third optical path adjustment unit to enter the multimode optical fiber (1502).

3. The integrated endoscopic imaging and temperature sensing system according to claim 2, characterized in that: The fluorescence excitation optical path also includes a first adjustment optical path and a second adjustment optical path, wherein 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), and 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).

4. The integrated endoscopic imaging and temperature sensing system according to claim 3, characterized in that: The first adjustment optical path comprises a second reflector (7), and a first 4f system (2), a half-wave plate (3), a polarization beam splitter (4), a second 4f system (5), and a first reflector (6) which are arranged in sequence along the emission direction of the first laser light output by the first laser (1); the first reflector (6) reflects the first laser light to the second reflector (7), and the second reflector (7) reflects the first laser light to the optical modulator (8).

5. The integrated endoscopic imaging and temperature sensing system according to claim 3, characterized in that: The second adjustment optical path comprises a fourth reflector (11), and a third 4f system (9) and a third reflector (10) which are arranged in sequence along the emission direction of the first laser output by the optical modulator (8); the third reflector (10) reflects the first laser to the fourth reflector (11), and the fourth reflector (11) reflects the first laser to the first dichroic mirror (12).

6. The integrated endoscopic imaging and temperature sensing system according to claim 2, characterized in that: The third optical path adjustment unit further comprises a fifth reflector (13) and a first objective lens (14), wherein the fifth reflector (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).

7. The integrated endoscopic imaging and temperature sensing system according to claim 2, characterized in that: The fluorescence detection module comprises a second lens (21) and a photomultiplier tube (22); the fluorescence reflected by the sample to be tested 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).

8. The integrated endoscopic imaging and temperature sensing system according to claim 2, characterized in that: The spectrum measurement module comprises 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 then 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 into the spectrometer (26); the spectrometer (26) obtains spectrum information of the reflected light and sends the spectrum information to the control terminal (28).

9. The integrated endoscopic imaging and temperature sensing system according to claim 1, characterized in that: The interference light beam receiving module comprises a second objective lens (16), a first filter (17), a first lens (18) and a camera (19) which are 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; and 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).

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

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