Optical coherence tomography endoscope system for analyzing atherosclerotic plaque components by utilizing near-infrared light source and control method of optical coherence tomography endoscope system

Abstract

The present invention relates to an optical coherence tomography endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source, and a control method therefor, the system being capable of stably measuring and analyzing blood vessels and atherosclerotic plaques by using the characteristic that the light absorption intensity of a biological tissue (lipid) rapidly varies with the wavelength of a laser light source. Comprises: a light source unit which emits a laser light source and determines the distribution and fault structure of lipids in a biological tissue according to the change in the light absorption intensity of the biological tissue; an optical interferometer unit that irradiates the inside of a subject with the laser light source, detects each wavelength intensity of the return light, and generates an OCT interference signal using the return light; an endoscope unit that irradiates the inside of a subject with the laser light source; and an optical signal measurement unit for measuring and analyzing blood vessels and atherosclerotic plaques by means of a change in the light absorption intensity of the biological tissue caused by a change in the wavelength of the laser light source.

Description

Technical Field

[0001] The present invention relates to optical coherence tomography (OCT) technology, and particularly to an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and a control method thereof. By utilizing the fact that the light absorption intensity of biological tissues (lipids) changes rapidly with the wavelength of the laser light source, it is possible to stably measure and analyze blood vessels and atherosclerotic plaques. Background Art

[0002] In heart diseases, the incidence of ischemic heart diseases directly related to blood vessels, such as myocardial infarction and angina pectoris, is more than twice that of other heart diseases, and the mortality rate caused by such diseases is continuously increasing. Therefore, the importance of vascular imaging is becoming increasingly prominent.

[0003] Atherosclerosis is a disease in which lipid components such as calcium or cholesterol are deposited in blood vessels, causing the blood vessels to narrow or become blocked, thereby leading to blood flow disorders. Acute coronary syndrome is a type of myocardial infarction. In most cases, this disease is caused by the rupture of atherosclerotic plaques, as well as the exfoliation of the epidermis of the skin or mucous membrane, resulting in erosion of the dermis or mucous membrane tissue being exposed, thereby causing a sudden blockage of the coronary artery supplying blood to the heart muscle, leading to myocardial necrosis.

[0004] At this time, atherosclerotic plaques with a high risk of rupture are histologically characterized by a thin fibrous membrane and lipid components beneath it, and this thin fibrous membrane can be detected by high-resolution optical coherence tomography (OCT) technology.

[0005] Optical coherence tomography (OCT) technology is a device that constructs high-resolution tomographic images by irradiating a subject with a broadband wavelength-tunable laser or a broadband light source and using an optical interferometer to detect the light reflected from the internal boundaries of biological tissues.

[0006] In the field of cardiovascular OCT imaging of traditional technologies, the light source in the 1300nm wavelength range has the following problems.

[0007] In the 1300nm wavelength range, the difference in absorption spectra between the blood vessel wall and lipids is small, and due to the limited penetration depth of light, it is difficult to perform component analysis on the relatively shallow lipid layer. In addition, this technology mainly relies on the brightness and darkness of images to analyze tissues, resulting in low reliability of diagnostic results, so it cannot be used for clinical applications.

[0008] To supplement this, there are also examples of additionally installing other optical imaging systems capable of near-infrared spectroscopy analysis, but these technologies increase the price and complexity of the vascular imaging system.

[0009] Therefore, there is an urgent need to develop a new technology that can apply OCT technology to the field of cardiovascular endoscopy without increasing costs and complexity, so as to achieve imaging of deeper atherosclerotic plaque structures. Summary of the Invention

[0010] The present invention is to solve the problems existing in the optical coherence tomography (OCT) technology in the prior art, and provides an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and its control method. By utilizing the fact that the light absorption intensity of biological tissues (lipids) changes rapidly with the wavelength of the laser light source, it can stably measure and analyze blood vessels and atherosclerotic plaques.

[0011] The purpose of the present invention is to provide an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and its control method. By analyzing the wavelength range of the OCT light source, the measured biological substance has a specific attenuation rate within the imaging depth range of the OCT imaging technology, thereby facilitating signal analysis and improving the efficiency of measurement and analysis.

[0012] The purpose of the present invention is to provide an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and its control method. The system uses OCT technology in the 1700 nm wavelength range to stably measure blood vessels and atherosclerotic plaques, and accurately observes the state of the lipid core through an optical attenuation coefficient analysis algorithm in different wavelength ranges.

[0013] The purpose of the present invention is to provide an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and its control method. The system adopts a single OCT structure and can analyze the structure and components of vascular tissue without applying other measurement technologies or systems.

[0014] The present invention provides an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and a control method thereof. By considering that the light scattering of the normal vascular inner wall decreases in the long-wavelength range, thereby reducing the attenuation rate of the OCT signal, while the atherosclerotic plaque tissue has the characteristic that its attenuation rate increases in the long-wavelength range due to the light absorption effect of secondary substances. Based on this characteristic, the system can separate and analyze the influence of secondary substances, and use wavelengths with selective specificity to achieve more accurate measurement and analysis, so as to analyze the components of atherosclerotic plaques.

[0015] The object of the present invention is to provide an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and a control method thereof. The system utilizes the characteristic that the change in the wavelength of the laser light source in the near-infrared wavelength range will cause a rapid change in the light absorption intensity of biological tissue (lipid). By irradiating the laser light source into the subject's body and analyzing the change in the intensity of different wavelengths of the returned light, the distribution of lipids inside the atherosclerotic plaque is detected. In addition, the system also generates an optical interference signal using the returned light to simultaneously obtain the tomographic structure of the tissue.

[0016] Other objects of the present invention are not limited to the above objects, and those skilled in the art can clearly understand other unmentioned objects from the following description.

[0017] To achieve the above object, the optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source of the present invention includes: a light source unit that emits a laser light source and determines the distribution and tomographic structure of lipids in biological tissue through the change in the light absorption intensity of the biological tissue; an optical interferometer unit that irradiates the laser light source into the subject's body, detects the intensity of each wavelength of the returned light, and generates an OCT interference signal using the returned light; an endoscope unit that irradiates the laser light source into the subject's body; and a light signal measurement unit that measures and analyzes blood vessels and atherosclerotic plaques through the change in the light absorption intensity of biological tissue caused by the change in the wavelength of the laser light source.

[0018] Here, the wavelength range emitted from the light source unit is characterized by using a 1700 nm wavelength range, which not only satisfies the characteristic that as the wavelength of the OCT light source becomes longer, the attenuation rate of the OCT optical signal caused by the light scattering effect in the living body decreases, but on the contrary, also satisfies the characteristic that the attenuation rate of the optical signal increases due to the light absorption effect of lipids in the living body containing lipid components.

[0019] Moreover, the wavelength range emitted by the light source unit is characterized by broadband light that includes a 1700 nm wavelength range with a relatively large change in light absorption caused by lipid components and a 1650 nm wavelength range with relatively weak light absorption. The OCT interference signal is divided into a wavelength range less affected by lipid component light absorption and a wavelength range more affected by lipid component light absorption, and comparative analysis is performed to distinguish the lipid components accumulated inside the vascular tissue.

[0020] The light signal measurement unit is characterized by obtaining spectral information of the tissue by comparing the light attenuation coefficients of each wavelength range of the entire spectrum before and after the OCT interference signal passes through the lipid layer, thereby separating the lipid layer of the vascular inner wall and the atherosclerotic plaque and imaging the position of the separated lipid layer.

[0021] Moreover, the light signal measurement unit is characterized by including a configuration for measuring the interference signals of each polarization component operating in the 1700 nm wavelength range to minimize the influence of polarization changes caused by the rotation and movement of the endoscopic sample end on the intensity of the light interference signal.

[0022] Moreover, the light signal measurement unit is characterized by including a signal processing device for analyzing the OCT interference signals of each polarization component measured in the 1700 nm wavelength range to stably extract the light signal attenuation value in the case of rotation and movement of the endoscopic sample end.

[0023] Moreover, the light signal measurement part is characterized in that, in order to prevent the loss of the OCT signal-to-noise ratio for measuring each polarization component in the 1700 nm wavelength range, an optical fiber circulator, a fiber beam splitter, and an optical amplifier module in this wavelength range are adopted.

[0024] Moreover, the optical coherence tomography endoscope system is characterized by a configuration that adopts a combination structure of a tunable laser and a photodetector in the 1700 nm wavelength range, or a structure of a broadband light source (SLED) and a spectrometer in the 1700 nm wavelength range.

[0025] For other purposes, a control method for an optical coherence tomography endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention includes: a light source irradiation step of irradiating a laser light source to a measurement object by using the change in the light absorption intensity of biological tissue to confirm the distribution and tomographic structure of lipids inside the biological tissue; a step of recovering a spectrum from the OCT interference signal; a step of obtaining spectral information of the tissue by comparing the light attenuation coefficients of each spectral band of the entire spectrum before and after the OCT interference signal passes through the lipid layer; a step of dividing the measured OCT interference signal into multiple wavelength ranges, and distinguishing the vascular inner wall tissue with low lipid content and atherosclerotic plaques rich in lipids by relatively comparing the light signal attenuation rates in the wavelength range with low lipid absorption and the wavelength range with high lipid absorption; and a step of separating the lipid layer of the vascular inner wall and atherosclerotic plaques, and imaging the position of the lipid layer to output an analysis result.

[0026] Here, the wavelength range irradiated in the light source emission step is characterized by using a wavelength range of 1700 nm, which not only satisfies the characteristic that as the wavelength of the OCT light source becomes longer, the attenuation rate of the OCT optical signal due to the light scattering effect in the living body decreases, but on the contrary, also satisfies the characteristic that in the living body containing lipid components, the attenuation rate of the optical signal due to the light absorption effect of lipids increases.

[0027] And in the light source emission step, the irradiated wavelength range includes broadband light with a wavelength range of 1700 nm where the light absorption change caused by lipid components is large and a wavelength range of 1650 nm where the light absorption is relatively weak. By dividing the OCT interference signal into a wavelength range less affected by the light absorption of lipid components and a wavelength range more affected by the light absorption of lipid components, and performing comparative analysis, the lipid components accumulated inside the vascular tissue are distinguished.

[0028] And, in order to recover the spectrum from the OCT interference signal, it is characterized by measuring the optical interference signals of each polarization component operating in the 1700 nm wavelength range to minimize the influence of polarization changes caused by the rotation and movement of the endoscope sample end on the intensity of the optical interference signal.

[0029] And in the step of obtaining spectral information, the OCT interference signals of each polarization component measured in the 1700 nm wavelength range are analyzed and signal processing is performed to stably extract the light signal attenuation value regardless of the rotation and movement of the endoscope sample end.

[0030] The optical coherence tomography endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention and its control method as described above have the following effects.

[0031] First, by taking advantage of the fact that the light absorption intensity of biological tissue (lipids) changes rapidly according to the wavelength of the laser light source, blood vessels and atherosclerotic plaques can be stably measured and analyzed.

[0032] Second, by using the wavelength range of the OCT light source, within the depth range possible for OCT imaging technology, there is a sufficiently specific attenuation rate, which is convenient for signal analysis, thus improving the efficiency of measurement and analysis.

[0033] Third, by using the OCT technology in the 1700nm wavelength range, blood vessels and atherosclerotic plaques can be stably measured, and through the light attenuation coefficient analysis algorithm in different wavelength ranges, the state of the lipid core can be accurately observed.

[0034] Fourth, by adopting a single OCT structure, without the need to apply other measurement techniques or systems, the structure and composition of blood vessel tissue can be analyzed.

[0035] Fifth, as the light wavelength increases, the light scattering of the inner wall of normal blood vessels decreases, thereby reducing the attenuation ratio of the OCT signal. However, in atherosclerotic plaque tissue, due to the light absorption effect of added secondary substances, the opposite trend is presented, and the attenuation rate in the long wavelength range increases instead. In this way, it is easy to separate and analyze the influence of secondary substances, and through the use of wavelengths with selective specificity, accurate measurement and analysis can be carried out.

[0036] Sixth, by taking advantage of the characteristic that the light absorption intensity of biological tissue (lipids) changes rapidly according to the wavelength of the laser light source in the near-infrared wavelength range, the laser light source is irradiated into the subject's body, and by analyzing the intensity change of the returned light according to the wavelength, the distribution of lipids inside atherosclerotic plaques can be determined, and by using the returned light to generate an optical interference signal, the tomographic structure of the tissue can be obtained simultaneously. Description of the Drawings

[0037] Figures 1a to 1c Schematic diagram of the change characteristic of the light absorption rate of the 1700nm wavelength range light used in the present invention.

[0038] Figure 2 Structural diagram of an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to an embodiment of the present invention.

[0039] Figure 3 Flowchart of a control method of an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to an embodiment of the present invention.

[0040] Figure 4 Curve graph of the light absorption characteristic of lipid components changing with the wavelength of light.

[0041] Figure 5a , 5b are respectively a diagram showing the range of the OCT interference signal measured by a light source in the 1700 nm wavelength range and the division process.

[0042] Figure 6 is a graph showing the optical attenuation coefficient characteristics obtained by recovering the spectrum of the OCT signal passing through the lipid component part and showing the changes in each frequency band of the spectrum.

[0043] Figure 7 is a structural diagram of an optical interference signal measurement unit for each polarization component for canceling polarization changes occurring due to the rotation of the sample end of the endoscope according to an embodiment of the present invention.

[0044] Figure 8 is a structural diagram of an optical amplifier for improving the signal-to-noise ratio and obtaining a stable signal according to another embodiment of the present invention.

[0045] Figure 9 is a structural diagram of an optical coherence tomography endoscope system using a 1700 nm wavelength range broadband light source (SLED) and a spectrometer according to another embodiment of the present invention. Detailed implementation manners

[0046] Hereinafter, preferred embodiments of an optical coherence tomography endoscope system and a control method thereof for analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention will be described in detail.

[0047] The features and advantages of the optical coherence tomography endoscope system and the control method thereof for analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention will become apparent through the detailed description of the following embodiments.

[0048] Figures 1a to 1c is a schematic diagram showing the change characteristics of the absorption rate of light in the 1700 nm wavelength range used in the present invention.

[0049] The terms used in the present disclosure are selected as currently widely used general terms in consideration of the functions of the present disclosure, but these terms may change according to the intentions of those skilled in the art, precedents, or the emergence of new technologies. In addition, in specific cases, the applicant may choose to use custom terms, and in such cases, the meanings thereof will be described in detail in the description part of the relevant invention. Therefore, the terms used in the present disclosure are not merely the names of the terms, but should be defined based on the meanings of the terms and the overall content of the present disclosure.

[0050] Throughout the specification, when a certain part mentions that a certain component "includes" certain elements, unless otherwise specified to the contrary, it does not mean excluding other components, but may include other components. In addition, terms such as "part" and "module" mentioned in the specification refer to units that process at least one function or operation, which can be implemented by hardware or software, or by a combination of hardware and software.

[0051] An optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and its control method of the present invention utilize the characteristic that the light absorption intensity of biological tissue (lipid) rapidly changes with the wavelength of a laser light source in the near-infrared wavelength range with a central wavelength of 1700 nm. The laser light source is irradiated into the subject's body, and the intensity change with the wavelength of the returned light is analyzed to find out the distribution of lipids inside the biological tissue, and at the same time, an optical interference signal is generated with the returned light, and the tomographic structure of the tissue is obtained.

[0052] As Figures 1a to 1c shown, the fat component of lipids, which is the component of atherosclerotic plaques that appear in the blood vessels inside the human body, has a light absorption rate that rapidly changes with the wavelength in the 1700 nm wavelength range compared with the surrounding blood vessel inner wall.

[0053] When a lipid-rich tissue is irradiated with light in the 1700 nm wavelength range, the wavelength with strong light absorption will cause the intensity of the light signal to weaken. And the wavelength outside the absorption band range has relatively little attenuation of the light signal intensity because there is no loss of light absorption.

[0054] Therefore, laser light sources in different wavelength ranges will show different degrees of light signal attenuation, which can be used to distinguish between the blood vessel inner wall tissue without light absorption and the lipid-rich area.

[0055] In addition, OCT technology can be manufactured in the form of a super-small endoscope, so it can be inserted into narrow spaces inside organs such as blood vessels or bronchi to obtain high-resolution images. In visceral organs, high concentrations of lipids will accumulate in blood vessels such as coronary arteries and carotid arteries. An accidental rupture of a lipid mass (atherosclerotic plaque) will block the blood flow to the myocardium or brain tissue, causing myocardial infarction or cerebral infarction.

[0056] OCT is an endoscope technology that can enter the inside of blood vessels. Using OCT in a special wavelength range with good lipid absorption, the internal structure of blood vessels and the distribution of lipid masses accumulated on the blood vessel wall can be observed.

[0057] The central wavelength of 1700 nm is the wavelength range where lipid absorption changes rapidly, so three-dimensional lipid distribution information can be obtained without additional optical analysis technology (NI RS).

[0058] Figure 2 Configuration diagram of an optical coherence tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention.

[0059] The optical coherence tomography endoscope system and its control method for analyzing atherosclerotic plaque components using a near-infrared light source of the present invention can stably measure and analyze blood vessels and atherosclerotic plaques by utilizing the phenomenon that the light absorption intensity of biological tissue (lipid) changes rapidly with the wavelength of the laser light source.

[0060] For this purpose, the present invention takes into account the characteristic that the attenuation rate of light gradually decreases in a longer wavelength range, and the effect caused by secondary substances has an opposite trend, that is, the attenuation ratio increases with the increase of wavelength, so that the analysis of the secondary substance effect becomes more convenient, and a wavelength with selective specificity is adopted to achieve accurate measurement and analysis.

[0061] The optical coherence tomography endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source of the present invention is as Figure 2 shown, and includes: a light source unit 10 that irradiates a laser light source and uses the change in the light absorption intensity of biological tissue (lipid) to confirm the distribution and tomographic structure of lipids inside the biological tissue; an optical interferometer unit 20 that irradiates the laser light source in the subject to be examined, detects the intensity of the returned light according to the wavelength, and generates an optical interference signal with the returned light; an endoscope unit 30 that irradiates the laser light source in the subject to be examined; and an optical signal measurement unit 40 that measures and analyzes blood vessels and atherosclerotic plaques by using the change in the light absorption intensity of biological tissue according to the wavelength of the laser light source.

[0062] Here, in order to send the laser deeper into the body, it is preferable to use a wavelength range of 1700 nm with the least light loss considering both light absorption and light scattering in the body as the wavelength range irradiated by the light source unit 10.

[0063] Moreover, the light source unit 10 irradiates broadband light including a wavelength range of 1700 nm with a large change in light absorption caused by lipid components and a wavelength range of 1650 nm with relatively weak light absorption, and compares and analyzes the OCT signals to distinguish the components (lipids) accumulated inside the vascular tissue.

[0064] In addition, the optical signal measurement unit 40 obtains the spectral information of the tissue by comparing the light attenuation coefficients of each wavelength range of the entire spectrum of the OCT interference signal before and after passing through the lipid layer, and separates the lipid layer of the blood vessel inner wall and the atherosclerotic plaque through an algorithm and determines the position of the lipid layer, thereby realizing imaging.

[0065] In addition, preferably, the optical signal measurement unit 40 includes a configuration for measuring the optical interference signals of each polarization component operating in the 1700 nm wavelength range, so as to minimize the influence of polarization changes caused by the rotation and movement of the endoscopic sample end on the intensity of the optical interference signals.

[0066] Moreover, the optical signal measurement unit 40 includes a signal processing device that analyzes the OCT interference signals of each polarization component measured within the 1700 nm wavelength range to stably extract the optical signal attenuation value in the case of the rotation and movement of the endoscopic sample end.

[0067] Furthermore, it is best to apply an optical fiber circulator, an optical fiber splitter, and an optical amplifier module in the corresponding wavelength range to prevent the loss of the signal-to-noise ratio of the OCT for measuring the polarization components in the 1700 nm wavelength range.

[0068] The optical coherence tomography endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention can be implemented by adopting a structure combining a tunable laser in the 1700 nm wavelength range and a photodetector, or as another embodiment, by adopting a structure of a broadband light source (SLED) in the 1700 nm wavelength range and a spectrometer.

[0069] The optical coherence endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention applies the OCT technology using a laser light source with a wavelength range of 1700 nm to the field of cardiovascular endoscopes, so that (1) it can image the deeper atherosclerotic plaque structure, (2) it can confirm the substance analysis (lipid core) and its distribution degree in the blood vessel, and (3) it can simplify the structure of the endoscope, minimize its size and volume, and reduce the complexity and price of the system.

[0070] The following specifically describes a control method of an optical coherence tomography endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention.

[0071] Figure 3 It is a flowchart showing a control method of an optical coherence tomography endoscope system for analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention.

[0072] First, use an optical coherence tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source to irradiate a measurement target with a light source in the 1700 nm wavelength range and perform OCT measurement. S301

[0073] Next, recover the spectrum from the OCT interference signal. S302

[0074] And by comparing the light attenuation coefficients of each wavelength range of the entire spectrum before and after the OCT interference signal passes through the lipid layer, spectral information of the tissue is obtained. S303

[0075] Next, the measured OCT interference signal is divided into multiple wavelength ranges, and by comparing the light signal attenuation rate in the wavelength range with low lipid absorption and the light signal attenuation rate in the wavelength range with high lipid absorption, the vascular inner wall tissue with low lipid content and the atherosclerotic plaque area rich in lipids are distinguished. S304

[0076] Separate the lipid layer of the vascular inner wall and atherosclerotic plaque, and image the position of the lipid layer. S305

[0077] Next, combine the OCT-specific structural information with the spectral analysis results, and output the analysis results of the presence and position of the atherosclerotic plaque lipid layer. S306

[0078] The OCT imaging system adopted in the present invention uses a wavelength range of 1700 nm, while considering light absorption and light scattering in the living body, minimizing light loss to send the laser deeper into the living body.

[0079] In addition, by comparing the OCT signals in the 1700 nm wavelength range with relatively large light absorption changes caused by the component lipid components and the 1650 nm wavelength range with relatively weak light absorption, the components (lipids) accumulated inside the vascular tissue can be distinguished.

[0080] Divide the measured OCT light interference signal into multiple wavelength ranges, and relatively compare the light signal attenuation rate in the wavelength range with low lipid absorption and the light signal attenuation rate in the wavelength range with high lipid absorption to distinguish the vascular inner wall tissue with low lipid content and the atherosclerotic plaque rich in lipids.

[0081] And use an algorithm to recover the spectrum from the OCT signal and analyze the light attenuation coefficients of each wavelength range of the spectrum. When the broadband laser light source passes through the lipid layer, the envelope of the light signal changes asymmetrically with the wavelength range. By comparing the light attenuation coefficients of each wavelength range of the entire spectrum before and after the OCT interference signal passes through the lipid layer, the spectral information of the tissue can be obtained.

[0082] Separate the vascular wall lipid layer and atherosclerotic plaque through an algorithm, and image the position of the lipid layer. By combining the OCT-specific structural information and spectral analysis results, the presence and position of the atherosclerotic plaque lipid layer can be accurately identified.

[0083] Figure 4 It is a graph showing the change of the light absorption characteristics of lipid components with the wavelength of light.

[0084] Such as Figure 4As shown, the change in the wavelength of light conforms to the light absorption characteristics of lipid components. Under the influence of the lipid components on the inner wall of blood vessels, for the fat components in atherosclerotic plaques, when the wavelength of light is greater than 1700 nm, the light absorption rate increases sharply (more than 10 times) with the increase in wavelength compared to the surrounding blood vessel inner wall.

[0085] When tissues rich in lipids are irradiated with light in the wavelength range of 1700 nm, wavelengths with strong light absorption will cause a decrease in the intensity of the light signal. For wavelengths outside the absorption band range, since there is no loss due to light absorption, relatively speaking, the attenuation of the light signal intensity is smaller.

[0086] Figure 5a 、 5b It is a schematic diagram of the range division and process of the OCT interference signal measured by a light source in the wavelength range of 1700 nm.

[0087] As Figure 5a and Figure 5b shown, the OCT interference signal measured by a light source in the wavelength range of 1700 nm is divided into multiple wavelength ranges, and the light signal attenuation rates in the wavelength range with low lipid absorption and the wavelength range with high lipid absorption are relatively compared.

[0088] Figure 6 It is a characteristic diagram of the spectrum of the OCT signal partially restored by lipid components and the light attenuation coefficient varying with the spectral band.

[0089] An algorithm for recovering the spectrum from the OCT signal and analyzing the light attenuation coefficient of each wavelength range of the spectrum is used. As Figure 6 shown, when a broadband laser light source passes through a lipid layer, by comparing the light attenuation coefficients of each wavelength range of the entire spectrum before and after the OCT interference signal passes through the lipid layer, the spectral information of the tissue is obtained.

[0090] Figure 7 It is a diagram showing the configuration of a polarization component specific light interference signal measurement unit for canceling the polarization change that occurs due to the rotation of the endoscope sample end according to an embodiment of the present invention.

[0091] The endoscope rotates autonomously to obtain a cross-sectional image of a blood vessel. The polarization change that occurs due to the rotation and movement of the endoscope sample end affects the intensity of the light interference signal. In order to minimize the influence occurring at this time and improve the measurement accuracy of the light attenuation signal, a polarization component specific light interference signal measurement structure operating in the wavelength range of 1700 nm is adopted, as Figure 7 shown.

[0092] Figure 8 It is a configuration diagram of an optical amplifier for improving the signal-to-noise ratio and obtaining a stable signal according to another embodiment of the present invention.

[0093] Figure 8Shows the configuration of an OCT capable of measuring polarization components in the 1700 nm wavelength range. To obtain a stable signal, an optical fiber circulator, an optical fiber splitter, and an optical amplifier module optimized for the Figure 6 1700 nm wavelength range are adopted.

[0094] Figure 9 Is a structural diagram of an optical coherence tomography endoscope system using a broadband light source (SLED) and a spectrometer in the 1700 nm wavelength range according to another embodiment of the present invention.

[0095] The OCT technology of the embodiments of the present invention can be implemented in a modified form by adopting a structure combining a tunable laser in the 1700 nm wavelength range and a photodetector, or a structure of a broadband light source (SLED) in the 1700 nm wavelength range and a spectrometer by modifying the optical design.

[0096] The above optical coherence tomography endoscope system and its control method for analyzing the components of atherosclerotic plaques using a near-infrared light source utilize the characteristic that the light absorption intensity of biological tissues (lipids) changes rapidly with the wavelength of the laser light source in the near-infrared wavelength range with a central wavelength of 1700 nm. The laser light source is irradiated into the subject's body, and the intensity change of the returned light with the wavelength is analyzed to find out the distribution of lipids inside the biological tissue, and an optical interference signal is generated with the returned light, and the tomographic structure of the tissue is obtained and analyzed together.

[0097] It can be understood that the present invention can be implemented in a modified form within the range not deviating from its essential characteristics, as described in the above description.

[0098] Therefore, the embodiments should be considered from an illustrative rather than a restrictive perspective. The scope of the present invention should not be limited to the above description, but should be defined according to the content of the patent claims, and all differences within the equivalent range should be construed as being included in the present invention.

[0099]

Industrial Applicability

[0100] The present invention relates to optical coherence tomography (OCT, Optical Coherence Tomography) technology, and particularly relates to an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source and its control method. The system utilizes the rapid change of the light absorption intensity of biological tissues (lipids) with the wavelength of the laser light source to achieve stable measurement and analysis of blood vessels and atherosclerotic plaques.

Claims

1. An optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source, characterized in that, comprising: A light source unit that emits a laser light source and determines the distribution and tomographic structure of lipids in biological tissue by the change in the light absorption intensity of the biological tissue; An optical interferometer unit that irradiates the laser light source into the interior of the subject to be examined, detects the intensity of each wavelength of the returned light, and generates an OCT interference signal using the returned light; An endoscope unit that irradiates the laser light source into the interior of the subject to be examined; A light signal measurement unit that measures and analyzes blood vessels and atherosclerotic plaques through the change in the light absorption intensity of biological tissue caused by the change in the wavelength of the laser light source.

2. The optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 1, characterized in that, The wavelength range emitted by the light source unit is The 1700 nm wavelength range is adopted, which not only satisfies the characteristic that as the wavelength of the OCT light source becomes longer, the attenuation rate of the OCT light signal caused by the light scattering effect in the living body decreases, but on the contrary, also satisfies the characteristic that in the living body containing lipid components, the attenuation rate of the light signal caused by the light absorption effect of lipids increases.

3. The optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 1, characterized in that, The wavelength range emitted by the light source unit is By irradiating broadband light in the 1700 nm wavelength range with a relatively large change in light absorption caused by the inclusion of lipid components and the 1650 nm wavelength range with relatively weak light absorption, the OCT interference signal is divided into a wavelength range with less influence from the change in light absorption of lipid components and a wavelength range with greater influence from the change in light absorption of lipid components, and a comparative analysis is performed to distinguish the lipid components accumulated inside the vascular tissue.

4. The optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 1, characterized in that, The light signal measurement unit Obtains the spectral information of the tissue by comparing the light attenuation coefficients of each wavelength range of the entire spectrum before and after the OCT interference signal passes through the lipid layer, thereby separating the lipid layer of the blood vessel inner wall and atherosclerotic plaque and imaging the position of the separated lipid layer.

5. The optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 4, characterized in that, The light signal measurement unit Includes a configuration for measuring the optical interference signals of each polarization component operating in the 1700 nm wavelength range to minimize the influence of polarization changes caused by the rotation and movement of the endoscope sample end on the intensity of the optical interference signal.

6. The optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 5, characterized in that, The light signal measurement unit Contains a signal processing device for analyzing the OCT interference signals of each polarization component measured in the 1700 nm wavelength range to stably extract the light signal attenuation value in the case of rotation and movement of the endoscope sample end.

7. The optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 5, characterized in that, in order to prevent the loss of the OCT signal-to-noise ratio for measuring each polarization component in the wavelength range of 1700 nm, the optical signal measurement unit adopts an optical fiber circulator, an optical fiber splitter and an optical amplifier module within this wavelength range.

8. The optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 1, characterized in that, the optical coherence tomography endoscope system adopts a structure combining a tunable laser and a photodetector in the wavelength range of 1700 nm, or adopts a structure of a broadband light source (SLED) and a spectrometer in the wavelength range of 1700 nm.

9. A control method for an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source, characterized in that, it includes: a light source irradiation step of irradiating a laser light source to a measurement object by using the change in the light absorption intensity of biological tissue to confirm the distribution and tomographic structure of lipids inside the biological tissue; a step of recovering the spectrum from the OCT interference signal; a step of obtaining the spectral information of the tissue by comparing the light attenuation coefficients of each wavelength range of the entire spectrum before and after the OCT interference signal passes through the lipid layer; a step of dividing the measured OCT interference signal into multiple wavelength ranges, and by comparing the light signal attenuation rate in the wavelength range with low lipid absorption and the light signal attenuation rate in the wavelength range with high lipid absorption, then distinguishing the vascular inner wall tissue with less lipid content from the atherosclerotic plaque part with more lipid components; a step of separating the lipid layer of the vascular inner wall and the atherosclerotic plaque, and imaging the position of the lipid layer to output an analysis result.

10. The control method for an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 9, characterized in that, the wavelength range irradiated in the light source irradiation step is adopting the wavelength range of 1700 nm, which not only satisfies the characteristic that as the wavelength of the OCT light source becomes longer, the attenuation rate of the OCT optical signal caused by the light scattering effect in the living body decreases, but on the contrary also satisfies the characteristic that in the living body containing lipid components, the attenuation rate of the light signal caused by the light absorption effect of lipids increases.

11. The control method for an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 9, characterized in that, the wavelength range irradiated in the light source irradiation step is by irradiating broadband light including the wavelength range of 1700 nm with a large change in light absorption caused by lipid components and the wavelength range of 1650 nm with relatively weak light absorption, and by dividing the OCT interference signal into a wavelength range with less influence from the change in light absorption by lipid components and a wavelength range with greater influence from the change in light absorption by lipid components, and performing comparative analysis, thereby distinguishing the lipid components accumulated inside the vascular tissue.

12. The control method for an optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 9, It is characterized in that In order to recover the spectrum from the OCT interference signal, The optical interference signals of each polarization component operating in the wavelength range of 1700 nm are measured to minimize the influence of polarization changes caused by the rotation and movement of the endoscope sample end on the intensity of the optical interference signal.

13. The control method of the optical coherence tomography endoscope system for analyzing the components of atherosclerotic plaques using a near-infrared light source according to claim 9, It is characterized in that In the step of obtaining spectral information, The OCT interference signals of each polarization component measured in the wavelength range of 1700 nm are analyzed and signal processing is performed to stably extract the optical signal attenuation value regardless of the rotation and movement of the endoscope sample end.

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