Visualization imaging device for early demineralization and caries of dental hard tissue based on PS-OCT

Abstract

The present invention discloses a visual imaging device for early demineralization and caries of hard tooth tissue based on PS-OCT. The laser emitted by the laser light source is divided into two paths, a reference light path and a detection light path, by a coupler; the laser reflected from the reference light path and the detection light path back to the coupler is coupled and input to the CCD detector through a transmission grating and a convex lens. The CCD detector converts the optical signal into an electrical signal, which is transmitted to a computer control system and collected by a built-in acquisition card; the computer completes the three-dimensional reconstruction and cross-sectional analysis of the image; the computer control system is connected to a scanning galvanometer to control the vibration of the scanning galvanometer. The present invention is designed to perform PS-OCT imaging examinations on the surface of hard tooth tissue in the patient's oral cavity, and the image is automatically subjected to cross-sectional imaging and three-dimensional reconstruction imaging by the computer control system, and a three-dimensional quantitative evaluation is completed. A new high-resolution detection method is provided for early clinical detection of hard tooth tissue demineralization.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a PS-OCT-based visualization imaging device for early demineralization and caries of dental hard tissues and a method for using the same. Background Art

[0002] Optical coherence tomography (OCT) is an optical imaging technology that has developed rapidly in the past decade. This technology uses the basic principle of weak coherent light interferometer to detect the back reflection or several scattered signals of the incident weak coherent light at different depths of biological tissues. By scanning, a two-dimensional or three-dimensional image of the biological tissue can be obtained. This technology has developed rapidly in recent years and is another new type of biological tissue imaging technology after ultrasound technology, X-ray computed tomography (XCT), nuclear magnetic resonance imaging (MRI) and other technologies. This technology combines confocal microscopy technology with ultra-sensitive detection technology, combined with automated control and computer graphics imaging processing technology, can achieve non-destructive and radiation-free detection of human biological tissues, and ultimately obtain high-resolution tomographic images of the internal microstructure of in vivo biological tissues.

[0003] Polarization Sensitive Optical Coherence Tomography (PS-OCT) is a modified OCT system that uses polarized incident light. The incident light in the orthogonal polarization state can reduce the strong reflection of the enamel surface and depolarize the scattering, thereby increasing the reflectivity of the demineralized enamel under the surface. Regardless of the surface morphology of the tooth, the degree of demineralization can be directly quantified using the orthogonal polarization reflectivity, so PS-OCT is particularly suitable for the detection of enamel demineralization.

[0004] Dental caries is a common and frequently occurring oral disease. It is a chronic infectious disease of the hard tooth tissue caused by bacteria. If dental caries is not effectively treated, it can cause damage to the hard tooth tissue, further develop into pulp disease and periapical disease, and even cause inflammation of the alveolar bone and jawbone, which may eventually lead to tooth loss. Dental caries is characterized by a high incidence rate and a wide distribution of people. It is one of the most common diseases in humans. The World Health Organization (WHO) has listed dental caries, tumors, and cardiovascular diseases as the three major preventable diseases in humans.

[0005] The early stage of caries often manifests as demineralization of the hard tissues of the teeth. This demineralization that occurs on the smooth enamel surface (such as the lip and cheek surface) often appears as white spots or plaques without substantial tooth defects. However, early carious demineralization that occurs in the pits and fissures of the heel surface of the teeth or the adjacent surfaces of the teeth is difficult to detect with the naked eye, and the latent development characteristics of caries in these areas often result in clinical findings that when the enamel surface is damaged, its deep tissue has already been damaged to a large extent, forming a defect in the hard tissues of the teeth. How to effectively detect and dynamically monitor the early demineralization of the hard tissues of the teeth is an important part of caries prevention. For early demineralization of the hard tissues of the teeth that is discovered early, mineralizing fluids containing calcium, phosphorus and fluoride can be used for treatment to remineralize the early demineralized hard tissues of the teeth (such as enamel and cementum), restore the hardness of the hard tissues of the teeth, and stop or eliminate the early caries. This is a reversible treatment. Once caries causes substantial hard tissue defects in the teeth, restorative materials are needed to restore the morphology.

[0006] At present, the inspection method and diagnosis basis of oral caries are mainly clinical examination combined with X-ray imaging. However, the demineralization of the hard tissue of the tooth formed in the early stage of the disease often has no obvious signs on the tooth surface, and clinical inspections such as visual examination and probing cannot be judged; and X-ray imaging technology can not only cause radioactive contamination, but also early demineralization of tooth enamel is difficult to show clearly on X-ray films, which seriously limits the accurate diagnosis of early caries. Summary of the invention

[0007] To solve the above problems, the purpose of the present invention is to design a PS-OCT-based visualization imaging quantitative evaluation system for early oral caries and non-carious hard tooth tissue demineralization, which aims to effectively monitor early demineralized hard tooth tissue in the oral cavity, accurately quantify the lesion range and depth of oral caries, and provide a reliable basis for clinicians' diagnosis and treatment.

[0008] The technical solution adopted by the present invention is:

[0009] A PS-OCT-based visualization imaging device for early demineralization and caries of dental hard tissues, comprising a laser light source, wherein the laser light emitted by the laser light source is divided into a reference light path and a detection light path through a coupler;

[0010] The reference optical path passes through the polarizer, grating, and optical path adjuster in sequence to reach the reflector, and the laser reflected by the reflector returns to the coupler along the original optical path;

[0011] The laser in the detection optical path enters the scanning galvanometer, which includes two galvanometers in the X-axis direction and the Y-axis direction; the laser emitted from the scanning galvanometer passes through a convex lens and irradiates the tooth to be detected, and the laser reflected by the tooth returns to the coupler along the original optical path;

[0012] The laser reflected from the reference optical path and the detection optical path back to the coupler is coupled and input into the CCD detector through the transmission grating and convex lens. The CCD detector converts the optical signal into an electrical signal, which is transmitted to the computer control system and collected by the built-in acquisition card. The computer completes the three-dimensional reconstruction and cross-sectional analysis of the image.

[0013] The computer control system is connected to the scanning galvanometer to control the vibration of the scanning galvanometer.

[0014] Furthermore, an inspection handle is provided on the detection optical path, the scanning galvanometer and the convex lens are installed in the inspection handle, a probe is provided on the inspection handle, a detection window is provided on the top of the probe, and a reflector for reflecting laser is provided on one side of the detection window

[0015] Furthermore, the computer control system is also connected with: a parameter adjustment display, a parameter adjustment panel and a control pedal.

[0016] The method for using the PS-OCT-based visualization imaging device for early demineralization and caries of dental hard tissues comprises the following steps:

[0017] Step 1) Place the head of the inspection handle on the surface of the tooth to be inspected in the patient's mouth, and the physician steps on the foot pedal to start the inspection;

[0018] Step 2) A diode laser generator emits polarized diode laser, which enters a reference optical path and a detection optical path respectively after being coupled by an optical fiber coupler;

[0019] Step 3) the light beam entering the reference optical path is polarized by the polarizer, and the polarized light beam enters the optical path adjuster after being adjusted by the fiber coupler and the grating and is reflected back by the reflector to form the reference arm light beam;

[0020] Step 4) The light beam entering the detection optical path passes through the optical fiber coupler to reach the scanning galvanometer. After passing through the scanning galvanometer, the optical signal is projected onto the patient's tooth surface to be tested through the achromatic lens, and the reflected light formed returns through the detection optical path;

[0021] Step 5) The two beams of light returned from the reference optical path and the detection optical path are coupled by the optical fiber coupler and enter the spectrometer: the coupled light enters the transmission grating, the scattered light formed is converged into parallel light by the lens, and enters the linear CCD detector to convert the optical signal into an electrical signal;

[0022] Step 6) The electrical signal is transmitted to the computer control system, and the built-in acquisition card collects information, performs graphic processing, and displays the 3D reconstruction and cross-sectional images on the screen for the doctor to review.

[0023] The beneficial effects of the present invention are as follows: the PS-OCT-based visualization imaging system for early demineralization and caries of dental hard tissues in the oral cavity designed by the present invention can perform PS-OCT imaging examinations on the surface of dental hard tissues in the oral cavity of patients, and the computer control system can automatically perform cross-sectional imaging and three-dimensional reconstruction imaging on the images, and complete three-dimensional quantitative evaluation, providing a new high-resolution detection method for early clinical detection of dental hard tissue demineralization. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the optical path design diagram of the PS-OCT imaging device;

[0025] Figure 2 Design drawings for the oral examination handle;

[0026] Figure 3 This is the overall design drawing of the equipment. DETAILED DESCRIPTION

[0027] like Figure 1 As shown, the PS-OCT imaging device includes a light source, a reference arm, a sample arm and a spectrometer. The polarized diode laser from the diode laser generator 06 is coupled by the fiber coupler 08 and transmitted to the reference arm and the sample arm respectively. The light beam entering the reference arm is first polarized by the polarizer 05. The polarized light beam is adjusted by the fiber coupler 04 and the grating 03 and enters the optical path regulator 01 and is reflected back by the reflector 01 to form the reference arm light beam. The light beam entering the sample arm first passes through the fiber coupler 14 to reach the scanning galvanometer 15. The scanning galvanometer 15 includes two galvanometers in the X-axis direction and the Y-axis direction. The vibration of the scanning galvanometer 15 is connected to the computer control system 13. After passing through the scanning galvanometer 15, the optical signal is projected onto the tooth 17 to be tested through the achromatic lens 16, and the reflected light formed returns through the sample arm. The two beams of light returned by the reference arm and the sample arm are coupled again through the fiber coupler 08 and enter the spectrometer. The coupled light enters the transmission grating 10, and the scattered light formed is converged into parallel light through the lens 11 and enters the linear CCD detector 12, where the light signal is converted into an electrical signal. The electrical signal is transmitted to the computer control system 13 and collected by the built-in acquisition card. The computer control system 13 is also connected to the scanning galvanometer 15 to control the vibration of the galvanometer. The computer control system 13 has a high-performance graphics card integrated inside, which can complete the three-dimensional reconstruction and cross-sectional analysis of the image.

[0028] like Figure 2As shown, the design of the oral examination handle and probe 21 mainly includes a built-in fiber coupler 19, an adjustable scanning galvanometer 18, a lens 20 and a reflector 22. The polarized light generated by the polarized light generator enters the handle along with the optical fiber transmission, and enters the galvanometer after passing through the fiber coupler. The X-axis galvanometer and the Y-axis galvanometer are controlled by the computer control system to vibrate. After the light passes through the scanning galvanometer, it passes through the lens and reaches the reflective mirror surface, which projects the light beam through the detection window 23 onto the tooth 24 to be inspected, and then collects its reflected light and transmits it back to the spectrometer.

[0029] like Figure 3 As shown, the overall design includes a computer control system 25, a PS-OCT imaging device, a parameter adjustment display 26, a parameter adjustment panel 27, a fiber optic transmission system and a foot pedal 30, an oral examination handle and a probe 28. The computer control system has a built-in acquisition card and its own software that can adjust the detection parameters, perform three-dimensional reconstruction of the detection image, and directly measure and evaluate the demineralization depth and range. The PS-OCT imaging device integrates a diode laser light source, a reference arm of the PS-OCT detection system, and a spectrometer. The fiber optic transmission system connects the PS-OCT imaging device to the oral examination handle and probe to transmit optical signals. The oral examination handle is used to be placed in the patient's mouth for inspection, collect optical signals and transmit the signals back to the spectrometer through optical fiber. The clinician controls the start and stop of the detection by controlling the foot switch 30.

[0030] The method of using the PS-OCT imaging device in the present invention is:

[0031] 1. The patient lies flat on the dental comprehensive treatment table, adjust the patient's position and check the lighting;

[0032] 2. Turn on the switch, place the head of the intraoral inspection handle on the surface of the tooth to be tested in the patient's mouth, and the doctor steps on the foot pedal to start the test;

[0033] 3. Polarized diode laser is emitted by the diode laser generator and coupled by the fiber coupler into the reference arm and sample arm respectively;

[0034] 4. The light beam entering the reference arm is first polarized by the polarizer. After being adjusted by the fiber coupler and grating, the polarized light beam enters the optical path adjuster and is reflected back by the reflector to form the reference arm light beam.

[0035] 5. The light beam entering the sample arm first passes through the fiber coupler to the scanning galvanometer. The vibration of the scanning galvanometer is connected to the computer control system. After passing through the scanning galvanometer, the optical signal is projected onto the patient's tooth surface to be tested through the achromatic lens, and the reflected light is returned through the sample arm;

[0036] 6. The two beams of light returned from the reference arm and the sample arm are coupled through the fiber coupler and enter the spectrometer. The coupled light enters the transmission grating, and the scattered light formed is converged into parallel light through the lens and enters the linear CCD detector to convert the optical signal into an electrical signal;

[0037] 7. The electrical signal is transmitted into the computer control system, the built-in acquisition card collects information, the high-performance graphics card completes the graphics processing, and the three-dimensional reconstruction image and cross-sectional image are displayed on the screen for the doctor to review.

[0038] The above description is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein and should not be regarded as excluding other embodiments. Changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention and shall be within the scope of protection of the appended claims of the present invention.

Claims

1. A method for detecting early demineralization and caries of dental hard tissue using a visual imaging device based on PS-OCT, characterized in that: The PS-OCT-based visualization imaging device for early demineralization and caries of dental hard tissues comprises a laser light source, wherein the laser light emitted by the laser light source is divided into a reference light path and a detection light path through a coupler; the reference light path passes through a polarizer, a grating, and an optical path adjuster in sequence to reach a reflector, and the laser reflected by the reflector returns to the coupler along the original light path; the laser light in the detection light path enters a scanning galvanometer, and the scanning galvanometer comprises two galvanometers in the X-axis direction and the Y-axis direction; the laser light emitted from the scanning galvanometer passes through a convex lens and irradiates the tooth to be detected, and the laser light reflected by the tooth returns to the coupler along the original light path; the laser light reflected from the reference light path and the detection light path back to the coupler is coupled and input into a CCD detector through a transmission grating and a convex lens, and the CCD detector converts the optical signal into an electrical signal, which is transmitted to a computer control system and collected by a built-in acquisition card; the computer completes three-dimensional reconstruction and cross-sectional analysis of the image; the computer control system is connected to the scanning galvanometer to control the vibration of the scanning galvanometer; An inspection handle is provided on the detection optical path, the scanning galvanometer and the convex lens are both installed in the inspection handle, a probe is provided on the inspection handle, a detection window is provided on the top of the probe, and a reflector for reflecting laser light is provided on one side of the detection window; The computer control system is also connected with: a parameter adjustment display, a parameter adjustment panel and a control foot pedal; The detection method comprises the following steps: Step 1) Place the head of the inspection handle on the surface of the tooth to be inspected in the patient's mouth, and the physician steps on the foot pedal to start the inspection; Step 2) A diode laser generator emits polarized diode laser, which enters a reference optical path and a detection optical path respectively after being coupled by an optical fiber coupler; Step 3) the light beam entering the reference optical path is polarized by the polarizer, the polarized light beam is adjusted by the fiber coupler and the grating, enters the optical path adjuster and is reflected back by the reflector to form the reference arm light beam; Step 4) The light beam entering the detection optical path passes through the optical fiber coupler to reach the scanning galvanometer. After passing through the scanning galvanometer, the optical signal is projected onto the patient's tooth surface to be tested through the achromatic lens, and the reflected light formed returns through the detection optical path; Step 5) The two beams of light returned from the reference optical path and the detection optical path are coupled by the optical fiber coupler and enter the spectrometer: the coupled light enters the transmission grating, the scattered light formed is converged into parallel light by the lens, and enters the linear CCD detector to convert the optical signal into an electrical signal; Step 6) The electrical signal is transmitted to the computer control system, and the built-in acquisition card collects information. After graphic processing, the three-dimensional reconstruction image and cross-sectional image are displayed on the screen for the doctor to review.

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