Temperature detection system and method based on phase-sensitive coherence tomography

Abstract

The invention provides a temperature detection system and method based on phase-sensitive coherence tomography. Relates to the technical field of temperature detection, and solves the problem of existing infrared thermal imaging temperature detection, and the method comprises the following steps: a light beam output by a laser light source is divided into a first light beam and a second light beam; the first light beam is emitted to a temperature monitoring position of a target skeleton through the detection light beam device group to serve as detection light; the second light beam passes through the reference light beam device group and is reflected to generate reference light with a preset phase; the probe light and the reference light are subjected to interference to generate interference signals; collecting the interference signal by using a detector and determining the phase change of the reference light and the detection light; and determining the temperature of the temperature monitoring position of the target skeleton by utilizing computing equipment according to the phase change of the reference light and the probe light. According to the invention, the precision of temperature detection can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature detection, and in particular, to a temperature detection system and method based on phase-sensitive optical coherence tomography. Background Art

[0002] Osteotomy (orthopedic surgery) is a surgical operation that involves processes such as drilling, sawing, and grinding bones. Flushing is required during laser osteotomy to replenish moisture and prevent thermal damage to surrounding critical tissues. However, due to the high absorption rate of lasers in water, excessive water will act as a protective layer by absorbing the energy of laser pulses, reducing the ablation efficiency. Therefore, to overcome this problem, a method for real-time detection of temperature changes is needed.

[0003] Currently, the method for measuring temperature changes during laser osteotomy without involving ablation (tissue removal) is mainly infrared thermal imaging technology. However, the image contrast of infrared thermal imaging technology is low, and the ability to resolve details is poor. Since an infrared thermal imager forms images based on temperature differences, and generally the temperature differences of targets are not large, the contrast of infrared thermal images is low, making the ability to resolve details poor. In addition, infrared thermal imaging technology cannot obtain the temperature changes of a target through a transparent obstacle, such as a window glass. Since an infrared thermal imager forms images based on temperature differences, for a transparent obstacle like a window glass, the infrared thermal imager cannot detect the temperature difference of the object behind it, and thus cannot obtain the temperature changes of the target through the transparent obstacle. In addition to the above technical drawbacks, infrared thermal imagers are costly and expensive, and currently the cost is still a factor limiting the widespread use of infrared thermal imagers. Summary of the Invention

[0004] A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify the key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is only to present certain concepts in a simplified form as a prelude to the more detailed description to be discussed later.

[0005] In view of this, in order to solve the above problems, the present invention provides a temperature detection system and method based on phase-sensitive optical coherence tomography.

[0006] In a first aspect, the present invention provides a temperature detection system based on phase-sensitive optical coherence tomography, including:

[0007] A laser light source, an optical circulator, an optical fiber coupler, a focusing and collimating device group, a reference beam device group, a detection beam device group, a detector, and a computing device;

[0008] The beam output by the laser light source is transmitted to the optical fiber coupler through the first branch of the optical circulator;

[0009] The light beam is divided into a first light beam and a second light beam by the optical fiber coupler;

[0010] The first light beam passes through the detection light beam device group and is emitted to the temperature monitoring position of the target bone; the light beam reflected by the temperature monitoring position of the target bone serves as the detection light and returns to the optical fiber coupler through the detection light beam device group;

[0011] The second light beam passes through the reference light beam device group and is reflected to generate a reference light with a preset phase, and the reference light returns to the optical fiber coupler;

[0012] The detection light and the reference light are respectively transmitted to the focusing and collimating device group through the second branch of the optical circulator, and the reference light and the detection light passing through the focusing and collimating device group generate an interference phenomenon to generate an interference signal;

[0013] The detector collects the interference signal and determines the phase changes of the reference light and the detection light;

[0014] The computing device determines the temperature of the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light.

[0015] In a possible implementation, the laser light source is a superluminescent light-emitting diode or an erbium-doped fiber laser.

[0016] In a possible implementation, the focusing and collimating device group includes: a first collimating lens, a diffraction grating, and a focusing lens. The first collimating lens and the focusing lens are coaxially arranged to form a 4f imaging system. The diffraction grating is disposed on the optical path between the first collimating lens and the focusing lens. The exit point of the second branch of the optical circulator is disposed at the focal point on one side of the first collimating lens, and the detector is disposed at the focal point on one side of the focusing lens.

[0017] In a possible implementation, the reference light beam device group includes a second collimating lens and a mirror. The reference light exit point of the optical fiber coupler is disposed at the focal point of the second collimating lens, and the mirror is disposed at a position having the same optical path as the temperature monitoring position of the target bone.

[0018] In a possible implementation, the detection light beam device group includes a third collimating lens and an objective lens. The third collimating lens and the objective lens are coaxially arranged to form a 4f imaging system. The detection light exit point of the optical fiber coupler is disposed at the focal point of the third collimating lens, and the light beam emitted from the objective lens converges to the temperature monitoring position of the target bone.

[0019] In a possible implementation, the laser light source, the optical circulator, and the fiber optic coupler are connected by optical fibers.

[0020] In a second aspect, the present invention further provides a temperature detection method based on phase-sensitive optical coherence tomography, which is characterized in that it is implemented based on the above system and includes:

[0021] The light beam output by the laser light source is transmitted to the fiber optic coupler through the first branch of the optical circulator;

[0022] The light beam is divided into a first light beam and a second light beam by the fiber optic coupler;

[0023] The first light beam is emitted to the temperature monitoring position of the target bone through the detection light beam device group; the light beam reflected by the temperature monitoring position of the target bone is used as the detection light and returns to the fiber optic coupler through the detection light beam device group;

[0024] The second light beam passes through the reference light beam device group and reflects to generate reference light with a preset phase, and the reference light returns to the fiber optic coupler;

[0025] The detection light and the reference light are respectively transmitted to the focusing and collimating device group through the second branch of the optical circulator, and the reference light and the detection light passing through the focusing and collimating device group generate an interference phenomenon to generate an interference signal;

[0026] Using a detector to collect the interference signal and determine the phase changes of the reference light and the detection light;

[0027] Using a computing device to determine the temperature of the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light.

[0028] In a possible implementation, using a detector to collect the interference signal and determine the phase changes of the reference light and the detection light includes:

[0029] Using a detector to periodically collect the bidirectional prediction frames corresponding to each interference signal, and the bidirectional prediction frames record the phase differences between the current frame, the previous frame, and the next frame;

[0030] Performing a Fourier transform on the optical coherence tomography (OCT) image of each bidirectional prediction frame along a preset direction to convert it into a frequency-domain OCT signal, and the frequency-domain OCT signal carries the phase information carried by the interference signal;

[0031] Calculating the phase difference between the frequency-domain OCT signals corresponding to every two consecutive bidirectional prediction frames collected.

[0032] In a possible implementation, using a computing device to determine the temperature of the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light includes:

[0033] Calibrate the temperature detection system based on phase-sensitive optical coherence tomography in advance to obtain the correlation between the temperature increase caused by the ablation laser of the target bone and its photo-thermal expansion parameters;

[0034] According to the phase difference and the correlation, use the following formula to determine the temperature of the temperature monitoring position of the target bone:

[0035] δ(T) = C a0 +C a1 ΔT + C a2 ΔT 2 +C a3 ΔT 3

[0036] where δ(T) is the phase difference between the frequency-domain OCT signals corresponding to two consecutive bidirectional prediction frames, ΔT represents the difference from a preset standard temperature, and C a0 、C a1 、C a2 、C a3 are photo-thermal expansion parameters determined according to the relationship between the temperature increase caused by the ablation laser of the target bone and the phase difference during calibration; the preset standard temperature is the temperature set during calibration.

[0037] In a possible implementation, calibrating the temperature detection system based on phase-sensitive optical coherence tomography in advance includes:

[0038] Record the phase change and temperature change caused by the ablation laser of the target bone, perform curve fitting according to the phase change and the temperature change, and determine the photo-thermal expansion parameters associated with the temperature increase and its axial displacement.

[0039] The temperature detection system and method based on phase-sensitive optical coherence tomography of the present invention can measure the temperature change of the target bone according to its photo-thermal expansion. And since phase-sensitive optical coherence tomography is a non-invasive, high-resolution, non-contact and high-speed interference imaging technology, therefore, the system and method of the present invention can detect the tissue-induced thermal expansion caused by the absorption of laser pulse energy during laser surgery, can detect the axial deformation exceeding the normal axial resolution of the bone, and has high sensitivity and time resolution. And phase-sensitive optical coherence tomography can work in a low-temperature environment (below the coagulation threshold), so it can measure the low-temperature change of the target bone. The method of the present invention can resolve the thermal expansion movement speed of the target bone as low as 2.6 nm / s by calculating the phase difference between consecutive B frames and applying the phase-resolved Doppler algorithm along the slow-scan axis.

[0040] These and other advantages of the present invention will become more apparent from the following detailed description of the best mode of the invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention can be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which like or similar reference numerals are used throughout the drawings to designate like or similar parts. The accompanying drawings, together with the following detailed description, are included in this specification and form a part of this specification, and are further used to illustrate the preferred embodiments of the present invention and to explain the principles and advantages of the present invention. In the drawings:

[0042] Figure 1 is a schematic structural diagram showing the temperature detection system based on phase-sensitive optical coherence tomography of the present invention;

[0043] Figure 2 is a schematic diagram showing the working process of the optical circulator of the present invention;

[0044] Figure 3 is a flowchart showing the temperature detection method based on phase-sensitive optical coherence tomography of the present invention;

[0045] Figure 4 is a schematic diagram showing the temperature change and the axial displacement amount of the present invention.

[0046] Those skilled in the art should understand that the elements in the drawings are shown only for simplicity and clarity, and are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be enlarged relative to other elements to help improve the understanding of the embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] In the following, exemplary embodiments of the present invention will be described in conjunction with the accompanying drawings. For clarity and conciseness, not all features of the actual embodiments are described in the specification. However, it should be understood that many specific implementation decisions must be made in the development of any such actual embodiment to achieve the specific goals of the developer, for example, to comply with those limitations related to the system and business, and these limitations may vary with different embodiments. In addition, it should be understood that although the development work may be very complex and time-consuming, for those skilled in the art who benefit from the present disclosure, such development work is only a routine task.

[0048] Here, it should also be noted that in order to avoid obscuring the present invention with unnecessary details, only the device structures and / or processing steps closely related to the solution of the present invention are shown in the drawings, while other details less related to the present invention are omitted.

[0049] As shown Figure 1 in the figure, an embodiment of the present invention provides a temperature detection system based on phase-sensitive optical coherence tomography, including:

[0050] a laser light source, an optical circulator, an optical fiber coupler, a focusing and collimating device group, a reference beam device group, a detection beam device group, a detector, and a computing device;

[0051] The light beam output by the laser light source is transmitted to the optical fiber coupler through the first branch of the optical circulator;

[0052] The light beam is divided into a first light beam and a second light beam by the optical fiber coupler;

[0053] The first light beam is emitted to the temperature monitoring position of the target bone through the detection beam device group; the light beam reflected by the temperature monitoring position of the target bone is used as the detection light and returns to the optical fiber coupler through the detection beam device group;

[0054] The second light beam passes through the reference beam device group and reflects to generate a reference light with a preset phase, and the reference light returns to the optical fiber coupler;

[0055] The detection light and the reference light are respectively transmitted to the focusing and collimating device group through the second branch of the optical circulator, and the reference light and the detection light passing through the focusing and collimating device group generate an interference phenomenon to generate an interference signal;

[0056] The detector collects the interference signal and determines the phase changes of the reference light and the detection light;

[0057] The computing device determines the temperature of the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light.

[0058] In the embodiment of the present invention, the optical coherence tomography (OCT) method is used to measure the temperature change during laser treatment, and the corresponding temperature change is measured according to the photothermal expansion of the temperature monitoring position of the target bone. Among them, OCT temperature detection is a non-invasive, high-resolution, non-contact and high-speed interference imaging technology, which can generate three-dimensional images of biological tissues according to the specific optical scattering characteristics of various tissues. Phase-sensitive OCT (PhS-OCT) can detect the tissue-induced thermal expansion caused by the absorption of laser pulse energy during laser surgery. In the embodiment of the present invention, the dependence of the optical path difference (OPD) on temperature can be used for photothermal tissue imaging during hyperthermia. Moreover, PhS-OCT can predict the low-temperature change (below the coagulation threshold) of a given sample. PhS-OCT has been proven to be able to quantify tissue movement at the nanoscale.

[0059] In an embodiment of the present invention, the laser light source is a superluminescent light-emitting diode or an erbium-doped fiber laser.

[0060] In an embodiment of the present invention, the focusing and collimating device group includes: a first collimating lens, a diffraction grating, and a focusing lens. The first collimating lens and the focusing lens are coaxially arranged to form a 4f imaging system. The diffraction grating is disposed on the optical path between the first collimating lens and the focusing lens. The output point of the second branch of the optical circulator is disposed at the focal point on one side of the first collimating lens, and the detector is disposed at the focal point on one side of the focusing lens.

[0061] In an embodiment of the present invention, the reference beam device group includes a second collimating lens and a mirror. The reference light output point of the fiber coupler is disposed at the focal point of the second collimating lens, and the mirror is disposed at a position having the same optical path as the temperature monitoring position of the target bone.

[0062] In an embodiment of the present invention, the detection beam device group includes a third collimating lens and an objective lens. The third collimating lens and the objective lens are coaxially arranged to form a 4f imaging system. The detection light output point of the fiber coupler is disposed at the focal point of the third collimating lens, and the beam emitted from the objective lens converges to the temperature monitoring position of the target bone.

[0063] In an embodiment of the present invention, the laser light source, the optical circulator, and the fiber coupler are connected by optical fibers.

[0064] As Figure 2 shown, the optical circulator in the embodiment of the present invention has two branches. The beam output from the first branch (shown in red) of the optical circulator is transmitted to the fiber coupler. The detection light and the reference light are transmitted to the optical circulator through the fiber coupler and then transmitted to the focusing and collimating device group through the second branch (shown in green) of the optical circulator.

[0065] As Figure 3 shown, the embodiment of the present invention further provides a temperature detection method based on phase-sensitive optical coherence tomography, which is implemented based on the above system and includes:

[0066] S101. The beam output by the laser light source is transmitted to the fiber coupler through the first branch of the optical circulator;

[0067] S102. The beam is divided into a first beam and a second beam by the fiber coupler;

[0068] S103. The first beam is emitted to the temperature monitoring position of the target bone through the detection beam device group; the beam reflected by the temperature monitoring position of the target bone is used as detection light and returns to the fiber coupler through the detection beam device group;

[0069] S104. The second light beam passes through the reference light beam device group and is reflected to generate a reference light with a preset phase, and the reference light returns to the fiber coupler;

[0070] S105. The detection light and the reference light are respectively transmitted to the focusing and collimating device group through the second branch of the optical circulator, and the reference light and the detection light passing through the focusing and collimating device group interfere to generate an interference signal;

[0071] S106. Use a detector to collect the interference signal and determine the phase changes of the reference light and the detection light;

[0072] S107. Use a computing device to determine the temperature of the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light.

[0073] In the embodiment of the present invention, using a detector to collect the interference signal and determine the phase changes of the reference light and the detection light includes:

[0074] Using a detector to periodically collect the bidirectional prediction frames corresponding to each interference signal, and the bidirectional prediction frames record the phase differences between the current frame and the previous frame and the next frame;

[0075] Fourier transform the optical coherence tomography (OCT) image of each bidirectional prediction frame along a preset direction to convert it into a frequency-domain OCT signal, and the frequency-domain OCT signal carries the phase information carried by the interference signal;

[0076] Calculate the phase difference between the frequency-domain OCT signals corresponding to every two consecutive bidirectional prediction frames collected.

[0077] In the embodiment of the present invention, the bidirectional prediction frames record the phase differences after conversion of the interference signals between the current frame and the previous frame and the next frame. The frequency-domain OCT signal carries the phase information carried by the interference signal.

[0078] In the embodiment of the present invention, using a computing device to determine the temperature of the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light includes:

[0079] Calibrate the temperature detection system based on phase-sensitive optical coherence tomography in advance to obtain the correlation between the temperature rise caused by the ablation laser of the target bone and its photo-thermal expansion parameters;

[0080] According to the phase difference and the correlation, use the following formula to determine the temperature of the temperature monitoring position of the target bone:

[0081] δ(T) = C a0 + C a1 ΔT + C a2 ΔT2 +C a3 ΔT 3

[0082] Wherein, δ(T) is the phase difference between the frequency-domain OCT signals corresponding to two consecutive bidirectional prediction frames, ΔT represents the difference from a preset standard temperature, and C a0 、C a1 、C a2 、C a3 are photothermal expansion parameters, which are determined according to the relationship between the temperature increase caused by the target bone ablation laser and the phase difference during calibration; the preset standard temperature is the temperature set during calibration.

[0083] In the embodiments of the present invention, the temperature detection system based on phase-sensitive optical coherence tomography is pre-calibrated, including:

[0084] Recording the phase change and temperature change caused by the target bone ablation laser, performing curve fitting according to the phase change and the temperature change, and determining the photothermal expansion parameter associated with the temperature increase and its axial displacement.

[0085] As Figure 4 shown, the abscissa represents the temperature change amount, the ordinate represents the displacement amount, the discrete dots are the measured numerical points, and the red curve represents the fitted cubic curve. Through the data processing method of curve fitting in the embodiments of the present invention, the obtained fitted curve can be called the phase change curve of bone tissue at different temperatures.

[0086] In the embodiments of the present invention, the dependence of the optical path difference (OPD) on temperature can be used for photo-thermal tissue imaging during hyperthermia. Among them, PhS-OCT can predict the low-temperature changes (below the coagulation threshold) of a given sample. PhS-OCT can quantify tissue movement at the nanoscale. The PhS-OCT technology detects axial deformation beyond its axial resolution by calculating the phase shift between consecutive B frames, has high sensitivity and time resolution, and applies the phase-resolved Doppler algorithm along the slow-scanning axis, demonstrating the ability to resolve tissue movement speeds as low as 2.6 nm / s.

[0087] Embodiment

[0088] This embodiment illustrates the process of temperature detection based on PhS-OCT. This embodiment uses PhS-OCT to detect the thermal expansion generated by the target tissue due to the absorption of laser pulse energy. PhS-OCT can resolve tissue movement speeds as low as 2.6 nm / s and its acquisition rate can reach up to several MHz at most.

[0089] S100: Construct a temperature detection system based on Phs-OCT as Figure 1 shown;

[0090] S200: Use the Phs-OCT based temperature detection system to capture multiple consecutive B-frames by measuring a region at a spatial position in the region of interest through B-scanning;

[0091] S300: Fourier transform the OCT image of each B-frame along the z-direction into a frequency-domain OCT signal;

[0092] S400: Calculate the phase difference between the frequency-domain OCT signals between two consecutive B-frames among multiple consecutive B-frames;

[0093] S500: Calculate the temperature corresponding to the target bone through the phase difference.

[0094] In step S500, calibration of PhS-OCT is required. Specifically: Monitor the temperature rise of the target bone (for example, using an infrared thermal imager) and its photo-thermal expansion (using the PhS-OCT system) simultaneously, and define the correlation between them using the following formula:

[0095] δ(T)=C a0 +C a1 ΔT+C a2 ΔT 2 +C a3 ΔT 3

[0096] Before each measurement, adjust the PhS-OCT and the laser beam on the common axis (the axis in the vertical direction, which is the z-direction in this embodiment) by performing a volumetric PhS-OCT scan on the test target bone, so as to determine the center of the target bone. During laser osteotomy surgery, since the bone tissue will absorb the energy of the high-power laser and cause a temperature rise. Therefore, the bone tissue will expand due to the temperature rise, causing a change in the optical path difference (OPD) on the tissue surface. The change in the measured optical path difference can correspond to the tissue temperature.

[0097] In the embodiment of the present invention, a photodetector is used to detect the reflection and scattering signals of the target bone and convert them into electrical signals. The whole process is non-destructive and non-invasive, and has a lower price and a faster imaging speed compared with the above existing infrared imaging technology; the temperature detection system and method based on Phs-OCT can detect the internal temperature of the target bone and has a higher acquisition rate.

[0098] Although the present invention has been described in terms of a limited number of embodiments, those skilled in the art, having the benefit of the foregoing description, will appreciate that other embodiments can be conceived within the scope of the invention as thus described. In addition, it should be noted that the language used in this specification has been principally selected for readability and instructional purposes and not to limit or define the inventive subject matter. Accordingly, many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the appended claims. For the scope of the present invention, the disclosure of the present invention is illustrative, not restrictive, and the scope of the present invention is defined by the appended claims.

Claims

1. A temperature detection system based on phase-sensitive optical coherence tomography, characterized in that, Comprising: A laser light source, an optical circulator, an optical fiber coupler, a focusing and collimating device group, a reference beam device group, a detection beam device group, a detector, and a computing device; The beam output by the laser light source is transmitted to the optical fiber coupler through the first branch of the optical circulator; The beam is divided into a first beam and a second beam by the optical fiber coupler; The first beam exits through the detection beam device group to the temperature monitoring position of the target bone; the beam reflected by the temperature monitoring position of the target bone serves as the detection light and returns to the optical fiber coupler through the detection beam device group; The second beam passes through the reference beam device group and reflects to generate a reference light with a preset phase, and the reference light returns to the optical fiber coupler; The detection light and the reference light are respectively transmitted to the focusing and collimating device group through the second branch of the optical circulator, and the reference light and the detection light passing through the focusing and collimating device group interfere to generate an interference signal; The detector collects the interference signal and determines the phase changes of the reference light and the detection light; The computing device determines the temperature of the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light.

2. The system according to claim 1, wherein The laser light source is a superluminescent light-emitting diode or an erbium-doped fiber laser.

3. The system according to claim 1 or 2, characterized in that, The focusing and collimating device group includes: a first collimating lens, a diffraction grating, and a focusing lens. The first collimating lens and the focusing lens are coaxially arranged to form a 4f imaging system. The diffraction grating is arranged on the optical path between the first collimating lens and the focusing lens. The exit point of the second branch of the optical circulator is arranged at the focal point on one side of the first collimating lens, and the detector is arranged at the focal point on one side of the focusing lens.

4. The system according to claim 1 or 2, characterized in that, The reference beam device group includes a second collimating lens and a mirror. The reference light exit point of the optical fiber coupler is arranged at the focal point of the second collimating lens, and the mirror is arranged at a position with the same optical path as the temperature monitoring position of the target bone.

5. The system according to claim 1 or 2, characterized in that, The detection beam device group includes a third collimating lens and an objective lens. The third collimating lens and the objective lens are coaxially arranged to form a 4f imaging system. The detection light exit point of the optical fiber coupler is arranged at the focal point of the third collimating lens, and the beam exiting from the objective lens converges to the temperature monitoring position of the target bone.

6. The system according to claim 1 or 2, characterized in that, The laser light source, the optical circulator, and the optical fiber coupler are connected by optical fibers.

7. A temperature detection method based on phase-sensitive optical coherence tomography, characterized in that, Implemented based on the system according to any one of claims 1 to 6, comprising: The beam output by the laser light source is transmitted to the optical fiber coupler through the first branch of the optical circulator; The beam is divided into a first beam and a second beam by the optical fiber coupler; The first beam exits through the detection beam device group to the temperature monitoring position of the target bone; the beam reflected by the temperature monitoring position of the target bone serves as the detection light and returns to the optical fiber coupler through the detection beam device group; The second beam passes through the reference beam device group and reflects to generate a reference light with a preset phase, and the reference light returns to the optical fiber coupler; The detection light and the reference light are respectively transmitted to the focusing and collimating device group through the second branch of the optical circulator, and interference occurs between the reference light and the detection light passing through the focusing and collimating device group to generate an interference signal; A detector is used to collect the interference signal and determine the phase changes of the reference light and the detection light; A computing device is used to determine the temperature at the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light.

8. The method according to claim 7, wherein Using a detector to collect the interference signal and determine the phase changes of the reference light and the detection light includes: The detector periodically collects the bidirectional prediction frames corresponding to each interference signal, and the bidirectional prediction frames record the phase differences between the current frame and the previous frame and the next frame; The optical coherence tomography (OCT) images of each bidirectional prediction frame are Fourier-transformed along a preset direction into frequency-domain OCT signals, and the frequency-domain OCT signals carry the phase information carried by the interference signal; Calculate the phase difference between the frequency-domain OCT signals corresponding to every two consecutive bidirectional prediction frames collected.

9. The method according to claim 8, wherein Using a computing device to determine the temperature at the temperature monitoring position of the target bone according to the phase changes of the reference light and the detection light includes: Calibrate the phase-sensitive optical coherence tomography-based temperature detection system in advance to obtain the correlation between the temperature rise caused by the ablation laser of the target bone and its optothermal expansion parameters; According to the phase difference and the correlation, use the following formula to determine the temperature at the temperature monitoring position of the target bone: δ(T) = C a0 + C a1 ΔT + C a2 ΔT 2 + C a3 ΔT 3 Among them, δ(T) is the phase difference between the frequency-domain OCT signals corresponding to two consecutive bidirectional prediction frames, ΔT represents the difference from a preset standard temperature, C a0 、C a1 、C a2 、C a3 are photothermal expansion parameters, which are determined according to the relationship between the temperature increase caused by the target bone ablation laser and the phase difference during calibration; the preset standard temperature is the temperature set during calibration.

10. The method according to claim 9, wherein Pre-calibrating the phase-sensitive optical coherence tomography-based temperature detection system includes: Record the phase change and temperature change caused by the ablation laser of the target bone, perform curve fitting according to the phase change and the temperature change, and determine the optothermal expansion parameters associated with the temperature rise and its axial displacement.

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