KR20240039440A - Spectroscopic Endoscope OCT System for Analyzing Components of Atherosclerotic Plaque using NIR Source and Method for Controlling the Same - Google Patents

Abstract

The present invention is capable of analyzing the components of atherosclerotic plaques using a near-infrared light source, which allows stable measurement and analysis of blood vessels and atherosclerotic plaques by using rapid changes in the light absorption intensity of biological tissues (lipids) depending on the wavelength of the laser light source. Pertaining to an optical tomography endoscope system and its control method, which includes a light source unit that irradiates a laser light source to confirm the distribution and monolayer structure of lipids inside the biological tissue using changes in the light absorption intensity of the biological tissue; a laser light source is placed inside the subject; An optical interferometer unit that detects the intensity of each wavelength of the irradiated and returned light and generates an OCT interference signal with the returned light; An endoscope unit that irradiates a laser light source inside the subject; Light of biological tissue according to the wavelength of the laser light source It includes an optical signal measurement unit that measures and analyzes blood vessels and atherosclerotic plaques using changes in absorption intensity.

Description

Optical tomographic endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source and its control method {Spectroscopic Endoscope OCT System for Analyzing Components of Atherosclerotic Plaque using NIR Source and Method for Controlling the Same}

The present invention relates to optical coherence tomography (OCT) technology, and specifically, to stably treat blood vessels and arteriosclerotic plaques by using rapid changes in the light absorption intensity of biological tissues (lipids) depending on the wavelength of the laser light source. It relates to an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source for measurement and analysis and a control method thereof.

Among heart diseases, ischemic heart diseases such as myocardial infarction or angina, which are directly related to blood vessels, account for more than twice as many as other heart diseases, and the mortality rate due to them is steadily increasing, so the importance of vascular imaging is increasing. .

Typically, arteriosclerosis is a disease that causes blood flow disorders by narrowing or blocking blood vessels due to deposition of lipid components such as calcium or cholesterol in blood vessels, and acute coronary syndrome is a type of myocardial infarction, which mostly involves rupture of arteriosclerotic plaques and skin or mucous membranes. It is a disease in which the coronary artery that supplies blood to the heart muscle is suddenly blocked, resulting in necrosis of the muscle, caused by erosion in which the epidermis is peeled off and the dermis or mucosal tissue is exposed.

At this time, arteriosclerotic plaques with a high risk of rupture are histologically characterized by having a thin fibrous membrane and lipid components underneath, and the thin fibrous membrane is detected using optical coherence tomography (OCT) technology with excellent resolution. This is possible.

Optical coherence tomography (OCT) technology radiates a broadband tunable laser or a broadband light source to the subject and detects the light reflected from the boundaries of tissues inside the living body through an optical interferometer to create a high-resolution tomography image. It is a device that

The 1300 nm wavelength band light source used in the prior art cardiovascular OCT imaging field has the following problems.

In the 1300 nm wavelength band, the difference in absorption spectrum between the blood vessel wall and lipids is small, it is difficult to analyze the components of shallow lipid layers due to the limit of light penetration depth, and the reliability of diagnostic results is low by analyzing tissue based on the brightness and darkness of the image, making it difficult to use clinically. impossible.

To compensate for this, there is an example of additionally installing another optical imaging system capable of near-infrared spectral analysis, but this technology increases the price and complexity of the vascular imaging system.

Therefore, there is a need for the development of a new technology that can image deeper atherosclerotic plaque structures by applying OCT technology to the field of cardiovascular endoscopy without increasing cost and complexity.

Republic of Korea Patent Publication No. 10-2021-0016861 Republic of Korea Patent Publication No. 10-2016-0129599 Republic of Korea Patent Publication No. 10-2012-0039410

The present invention is intended to solve the problems of the optical coherence tomography (OCT) technology of the prior art, by using the rapid change in the light absorption intensity of biological tissue (lipid) according to the wavelength of the laser light source to detect blood vessels and arteries. The purpose is to provide an optical tomographic endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source that enables stable measurement and analysis of sclerotic plaques and a control method thereof.

The present invention uses the wavelength band of the OCT light source for analysis, where the size of the intrinsic light absorption of the biological material being measured has a specific attenuation ratio to facilitate signal analysis within the possible depth image range of OCT imaging technology. The purpose is to provide an optical tomography endoscope system and a control method capable of analyzing atherosclerotic plaque components using a near-infrared light source that increases the efficiency of measurement and analysis.

The present invention stably measures blood vessels and atherosclerotic plaques using OCT technology in the 1700 nm band and detects atherosclerotic plaques using a near-infrared light source that allows precise observation of the state of the lipid core through an optical attenuation coefficient analysis algorithm for each wavelength band. The purpose is to provide an optical tomography endoscope system capable of component analysis and a control method thereof.

The present invention provides an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source, which allows analysis of the structure and components of vascular tissue using a single OCT structure without applying other measurement techniques or systems, and a control method thereof. The purpose is to provide.

The present invention provides a light absorption effect by a secondary material in arteriosclerotic plaque tissue, which is contrary to the light attenuation characteristics of the normal blood vessel inner wall, which has the characteristic that the scattering of light decreases as the light goes to a long wavelength band and the attenuation ratio of the OCT signal decreases. is added, taking into account the opposite tendency and the characteristic that the attenuation ratio increases as the wavelength increases, it becomes easier to separate and analyze the effects of secondary materials, and precise measurement and analysis is possible using wavelengths with selection specificity. The purpose is to provide an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source and a control method thereof.

The present invention utilizes the fact that the light absorption intensity of biological tissue (lipid) changes rapidly depending on the wavelength of the laser light source in the near-infrared band to irradiate the inside of the subject with a laser light source and analyze the change in intensity by wavelength of the returned light to form arteriosclerotic plaques. We provide an optical tomography endoscope system capable of analyzing the composition of atherosclerotic plaques using a near-infrared light source that determines the distribution of internal lipids and generates an optical interference signal with returned light to determine the monolayer structure of the tissue, and a control method thereof. It has a purpose.

Other objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the description below.

In order to achieve the above object, the optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention uses the change in light absorption intensity of biological tissue to identify the distribution of lipids and monolayer structure within the biological tissue. A light source unit that irradiates a laser light source to detect the intensity of each wavelength of the returned light by irradiating the laser light source inside the subject, and an optical interferometer unit that generates an OCT interference signal with the returned light; A laser light source inside the subject It is characterized by comprising an endoscope unit that irradiates; an optical signal measurement unit that measures and analyzes blood vessels and atherosclerotic plaques using changes in the light absorption intensity of biological tissue according to the wavelength of the laser light source.

Here, the wavelength band irradiated from the light source unit has the characteristic that as the wavelength of the OCT light source changes to a long wavelength, the attenuation rate of the OCT optical signal due to the light scattering effect in the living body decreases and, on the contrary, the light absorption effect of lipids in the living body containing lipid components. It is characterized by using the 1700nm wavelength band, which satisfies all the characteristics of increasing the optical signal attenuation ratio.

In addition, the wavelength band irradiated from the light source unit irradiates a broadband light including the 1700 nm wavelength band in which there is a large change in light absorption due to lipid components and the 1650 nm wavelength band in which light absorption occurs relatively weakly, and the OCT interference signal is transmitted to the lipid component. It is characterized by distinguishing the lipid components accumulated inside the vascular tissue by dividing and analyzing them into a wavelength band in which the light absorption change is weak and a wavelength band in which the light absorption change is large due to the lipid component.

And the optical signal measurement unit compares the optical attenuation coefficient for each band of the entire spectrum of the OCT interference signal before and after passing through the lipid layer to obtain spectroscopic information of the tissue, separates the lipid layer of the blood vessel inner wall and the atherosclerotic plaque, and separates the location of the lipid layer. It is characterized by imaging,

In addition, the optical signal measurement unit is configured to measure the optical interference signal for each polarization component operating in the 1700 nm band to minimize the impact of polarization changes that occur due to the rotation and movement of the endoscope sample stage on the intensity of the optical interference signal. It is characterized by including.

In addition, the optical signal measurement unit analyzes the OCT interference signal measured for each polarization component in the 1700 nm wavelength band and includes signal processing means to consistently extract the optical signal attenuation value regardless of the rotation and movement of the endoscope sample stage. do.

In order to prevent loss of the signal-to-noise ratio of OCT, which can measure each polarization component in the 1700 nm wavelength band, the optical signal measurement unit is equipped with an optical fiber circulator and a polarization maintaining beam splitter in the corresponding wavelength band. It is characterized by applying an optical amplifier module.

The optical tomography endoscope system is characterized by a structure that combines a tunable laser in the 1700 nm band and a photodetector, or a structure using a broadband light source (SLED) in the 1700 nm band and a spectrometer.

In order to achieve another purpose, the control method of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention uses changes in the light absorption intensity of biological tissue to determine the distribution and monolayer structure of lipids inside the biological tissue. A light source irradiation step of irradiating a laser light source to the measurement object to confirm; A step of restoring the spectrum from the OCT interference signal; Comparing the optical attenuation coefficient for each spectral band of the entire spectrum of the OCT interference signal before and after passing through the lipid layer to determine the spectroscopic effect of the tissue Step of acquiring information; Dividing the measured OCT interference signal into bands and comparing the optical signal attenuation ratio in the band with low lipid absorption and the optical signal attenuation ratio in the band with high lipid absorption, It is characterized in that it includes the step of distinguishing a portion of an atherosclerotic plaque with many lipid components; separating the lipid layer of the blood vessel inner wall and the atherosclerotic plaque, imaging the location of the lipid layer, and outputting an analysis result.

Here, the wavelength band irradiated in the light source irradiation step is characterized by a decrease in the attenuation rate of the OCT optical signal due to the light scattering effect in the living body as the wavelength of the OCT light source changes to a long wavelength, and, on the contrary, the light absorption of lipids in living organisms containing lipid components. It is characterized by using the 1700nm wavelength band, which satisfies all the characteristics of increasing the optical signal attenuation ratio due to the effect.

In addition, the wavelength band irradiated in the light source irradiation step is irradiated with broadband light including the 1700 nm wavelength band where light absorption changes due to lipid components are large and the 1650 nm wavelength band where light absorption is relatively weak, and OCT interference signals are generated. It is characterized by distinguishing the lipid components accumulated inside the vascular tissue by dividing and analyzing them into a wavelength band in which the light absorption change is weak due to the lipid component and a wavelength band in which the light absorption change is large due to the lipid component.

In order to restore the spectrum from the OCT interference signal, an optical interference signal for each polarization component operates in the 1700 nm band to minimize the effect of polarization changes that occur due to the rotation and movement of the endoscope sample stage on the intensity of the optical interference signal. It is characterized by measuring.

In the step of acquiring spectroscopic information, the OCT interference signal measured for each polarization component in the 1700 nm wavelength band is analyzed and signal processing is performed to consistently extract the optical signal attenuation value regardless of the rotation and movement of the endoscope sample stage. It is characterized by

As described above, the optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention and its control method have the following effects.

First, it enables stable measurement and analysis of blood vessels and atherosclerotic plaques by using the rapid change in light absorption intensity of biological tissue (lipid) depending on the wavelength of the laser light source.

Second, the size of the intrinsic light absorption of the biological material being measured is measured by using the wavelength band of the OCT light source that shows a specific attenuation ratio to facilitate signal analysis within the possible depth image range of OCT imaging technology. and increase the efficiency of analysis.

Third, using OCT technology in the 1700 nm band, blood vessels and atherosclerotic plaques can be reliably measured, and the state of the lipid core can be precisely observed through an optical attenuation coefficient analysis algorithm for each wavelength band.

Fourth, it allows the structure and components of vascular tissue to be analyzed using a single OCT structure without applying other measurement techniques or systems.

Fifth, as light goes to a longer wavelength band, the scattering of light decreases and the attenuation rate of the OCT signal decreases. Contrary to the light attenuation characteristics of the normal blood vessel inner wall, the light absorption effect by secondary substances occurs in arteriosclerotic plaque tissue. In addition, considering the opposite tendency and the characteristic that the attenuation ratio increases as the wavelength increases, it becomes easier to separate and analyze the effects of secondary materials, and precise measurement and analysis is possible using wavelengths with selectivity. Let's do it.

Sixth, by using the fact that the light absorption intensity of biological tissue (lipid) changes rapidly depending on the wavelength of the laser light source in the near-infrared band, the laser light source is irradiated inside the subject and the intensity change by wavelength of the returned light is analyzed to determine the inside of the atherosclerotic plaque. It determines the distribution of lipids and generates an optical interference signal with the returned light, allowing the single layer structure of the tissue to be determined.

Figure 1 is a configuration diagram showing the change characteristics of light absorption rate in the 1700 nm wavelength band for use in the present invention.
Figure 2 is a block diagram of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention.
Figure 3 is a flow chart showing a control method of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention.
Figure 4 is a graph of the light absorption characteristics of lipid components that change according to the wavelength of light.
Figure 5 is a configuration diagram showing the range and process of dividing the OCT interference signal measured with a light source in the 1700 nm band into bands.
Figure 6 is a graph of the characteristics of the optical attenuation coefficient that restores the spectrum from the OCT signal that passed through the lipid component portion and changes for each band of the spectrum.
Figure 7 is a configuration diagram of an optical interference signal measurement unit for each polarization component that cancels out the polarization change occurring when the endoscope sample stage is rotated according to an embodiment of the present invention.
Figure 8 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.
Figure 9 is a configuration diagram of an optical tomography endoscope system using a broadband light source (SLED) in the 1700 nm band and a spectroscope according to another embodiment of the present invention.

Hereinafter, a preferred embodiment of the optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source and its control method according to the present invention will be described in detail as follows.

The characteristics and advantages of the optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source and its control method according to the present invention will become clear through the detailed description of each embodiment below.

Figure 1 is a configuration diagram showing the change characteristics of light absorption rate in the 1700 nm wavelength band for use in the present invention.

The terms used in the present disclosure have selected general terms that are currently widely used as much as possible while considering the functions in the present disclosure, but this may vary depending on the intention or precedents of those skilled in the art, the emergence of new technologies, etc. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the relevant invention. Therefore, the terms used in this disclosure should be defined based on the meaning of the term and the overall content of this disclosure, rather than simply the name of the term.

When it is said that a part "includes" a certain element throughout the specification, this means that, unless specifically stated to the contrary, it does not exclude other elements but may further include other elements. In addition, terms such as "... unit" and "module" used in the specification refer to a unit that processes at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software. .

In the optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention and its control method, the light absorption intensity of biological tissue (lipid) changes rapidly depending on the wavelength of the laser light source in the near-infrared band with a center wavelength of 1700 nm. By irradiating a laser light source inside the subject and analyzing the intensity change for each wavelength of the returned light, the distribution of lipids inside the biological tissue is determined, and an optical interference signal is generated with the returned light to determine the single layer structure of the tissue. will be.

As shown in Figure 1, the absorption rate of light in the 1700 nm wavelength band of the lipid component of atherosclerotic plaques that develop in blood vessels inside the human body changes rapidly depending on the wavelength compared to the inner wall of surrounding blood vessels.

When light in the 1700 nm band passes through tissues containing a lot of lipids, the intensity of the optical signal at wavelengths with high optical absorption is weakened, and light at wavelengths outside the absorption band does not suffer loss due to optical absorption, so the optical signal intensity is relatively high. becomes less weak.

Therefore, since the degree of optical signal attenuation will vary depending on the wavelength band of the laser light source, it is possible to distinguish between the vascular inner wall tissue, which does not absorb light, and the part containing a lot of lipid components.

In addition, OCT technology can be manufactured in the form of an ultra-small endoscope, so high-resolution images can be obtained by inserting it into narrow areas of organs such as blood vessels or bronchial tubes. Among internal organs, high concentrations of lipids may accumulate inside blood vessels such as the coronary and carotid arteries. Unexpected rupture of lipid lumps (atherosclerotic plaques) can block blood flow to the heart muscle or brain tissue, causing myocardial infarction or cerebral infarction. You can.

With OCT endoscopic technology that allows access to the internal vascular system, the structure inside blood vessels and the distribution of lipid masses accumulated on the inner walls of blood vessels can be imaged using OCT in a special wavelength band that lipids absorb well.

Since the 1700 nm center wavelength is a wavelength band where lipid absorption changes rapidly, lipid distribution information can be obtained in three dimensions without additional optical analysis technology (NIRS).

Figure 2 is a diagram showing the configuration of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention.

The optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention and its control method utilizes a rapid change in the light absorption intensity of biological tissue (lipid) according to the wavelength of the laser light source to identify blood vessels and atherosclerotic plaques. This allows for stable measurement and analysis.

For this purpose, the present invention takes into account the characteristic that the attenuation ratio of light decreases as the wavelength increases, and the effect of secondary materials has the opposite tendency and the attenuation ratio increases as the wavelength increases. It makes it easier to analyze the effects of substances by dividing them and may include a configuration that allows precise measurement and analysis using wavelengths with selectivity.

As shown in FIG. 2, the optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention uses the change in light absorption intensity of biological tissue (lipid) to determine the distribution and monolayer structure of lipids inside the biological tissue. A light source unit (10) that irradiates a laser light source for confirmation, an optical interferometer unit (20) that detects the intensity of each wavelength of the returned light by irradiating the laser light source inside the subject, and generates an optical interference signal with the returned light. ), an endoscope unit 30 that irradiates a laser light source inside the subject, and an optical signal measurement unit that measures and analyzes blood vessels and arteriosclerotic plaques using the change in light absorption intensity of biological tissue according to the wavelength of the laser light source. Includes (40).

Here, it is preferable to use the 1700 nm wavelength band irradiated from the light source unit 10, which minimizes light loss when considering both light absorption and light scattering in the living body in order to send the laser light deeper into the living body.

And the light source unit 10 irradiates light in a wavelength band (1700 nm band) in which light absorption changes rapidly to the component (lipid) and light in a wavelength band (1650 nm band) in which light absorption occurs relatively weakly, and compares the OCT signal. Through analysis, it is possible to distinguish components (lipids) accumulated inside vascular tissue.

And the optical signal measurement unit 40 compares the optical attenuation coefficient for each band of the entire spectrum of the OCT interference signal before and after passing through the lipid layer to obtain spectroscopic information of the tissue, and separates the lipid layer of the blood vessel inner wall and the atherosclerotic plaque through an algorithm. The location of the lipid layer is separated and imaged.

In addition, the optical signal measurement unit 40 measures the optical interference signal for each polarization component operating in the 1700 nm band in order to minimize the influence of polarization changes that occur due to the rotation and movement of the endoscope sample stage on the intensity of the optical interference signal. It is desirable to include a configuration.

In addition, the optical signal measurement unit 40 includes signal processing means that analyzes the OCT interference signal measured for each polarization component in the 1700 nm wavelength band and extracts the optical signal attenuation value consistently regardless of the rotation and movement of the endoscope sample stage. .

In order to prevent loss of signal-to-noise ratio of OCT, which can measure each polarization component in the 1700 nm wavelength band, an optical fiber circulator, polarization maintaining beam splitter, and optical amplification module ( It is desirable to apply an optical amplifier module.

In addition, the optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention uses a structure that combines a tunable laser in the 1700 nm band and a photodetector, or, in another embodiment, a broadband light source (SLED) in the 1700 nm band and It can be implemented in a structure using a spectroscope.

The optical tomography endoscopy system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention applies OCT technology using a laser light source in the 1700 nm wavelength band to the field of cardiovascular endoscopy to (1) detect deeper atherosclerotic plaques; The structure can be imaged, (2) material analysis (lipid core) and distribution within blood vessels can be confirmed, and (3) the structure of the endovascular endoscope has been simplified to minimize the size and volume and reduce the complexity and price of the system. You can.

The control method of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention will be described in detail as follows.

Figure 3 is a flow chart showing a control method of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source according to an embodiment of the present invention.

First, OCT measurement is performed by irradiating a light source in the 1700 nm band to the measurement object using an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source (S301).

Next, the spectrum is restored from the OCT signal (S302).

Then, the optical attenuation coefficient for each band of the entire spectrum of the OCT interference signal is compared before and after passing through the lipid layer to obtain spectroscopic information about the tissue (S303).

Next, the measured OCT optical interference signal was divided into bands and the optical signal attenuation ratio in the band with low lipid absorption was compared with the optical signal attenuation ratio in the band with high lipid absorption, and the vascular inner wall tissue with low lipid absorption and lipid components were compared. Distinguish between many arteriosclerotic plaques (S304)

Then, the lipid layer of the blood vessel inner wall and the atherosclerotic plaque are separated and the location of the lipid layer is imaged (S305).

Next, OCT's unique structural information and spectroscopic analysis results are collected and the presence and location analysis results of the lipid layer of the atherosclerotic plaque are output (S306).

The present invention uses an OCT imaging system using the 1700nm wavelength band, which minimizes light loss when considering both light absorption and light scattering in the living body, in order to send laser light deeper into the living body.

In addition, by comparative analysis of OCT signals in the wavelength band (1700 nm band) where light absorption changes rapidly in components (lipids) and the wavelength band (1650 nm band) where light absorption is relatively weak, the components accumulated inside the vascular tissue ( lipids).

By dividing the measured OCT optical interference signal into bands and comparing the optical signal attenuation ratio in the band with low lipid absorption and the optical signal attenuation ratio in the band with high lipid absorption, the blood vessel inner wall tissue with low lipid content and lipid components are compared. Many atherosclerotic plaque areas can be distinguished.

Then, an algorithm is used to restore the spectrum from the OCT signal and analyze the optical attenuation coefficient for each band of the spectrum. As the broadband laser light source passes through the lipid layer, the envelope of the optical signal changes asymmetrically in each wavelength band. Spectroscopic information on the tissue is obtained by comparing the optical attenuation coefficient for each band of the entire spectrum of the OCT interference signal before and after passing through the lipid layer. Pay it out

Through an algorithm, the lipid layer of the blood vessel inner wall and the atherosclerotic plaque are separated and the location of the lipid layer is imaged. By combining OCT's unique structural information and spectroscopic analysis results, the presence and location of the lipid layer of the atherosclerotic plaque can be precisely identified.

Figure 4 is a graph of the light absorption characteristics of lipid components that change depending on the wavelength of light.

As shown in the light absorption characteristics of lipid components that change depending on the wavelength of light in Figure 4, the lipid component of lipids, which is a component of atherosclerotic plaques, has a light absorption rate at a wavelength longer than 1700 nm depending on the component (lipid) of the inner wall of blood vessels. It uses the characteristic of rapidly increasing (more than 10 times) depending on the wavelength compared to the inner wall of surrounding blood vessels.

When light in the 1700 nm band passes through tissues containing a lot of lipids, the intensity of the optical signal at wavelengths with high optical absorption is weakened, and light at wavelengths outside the absorption band does not suffer loss due to optical absorption, so the optical signal intensity is relatively high. becomes less weak.

Figure 5 is a configuration diagram showing the range and process of dividing the OCT interference signal measured with a light source in the 1700 nm band into bands.

As shown in Figure 5, the OCT interference signal measured with a light source in the 1700 nm band is divided into bands to compare the optical signal attenuation ratio in the band with low lipid absorption and the optical signal attenuation ratio in the band with high lipid absorption.

Figure 6 is a graph of the characteristics of the optical attenuation coefficient that restores the spectrum from the OCT signal that has passed through the lipid component portion and changes for each band of the spectrum.

An algorithm is used to restore the spectrum from the OCT signal and analyze the optical attenuation coefficient for each band of the spectrum. As shown in Figure 6, as the broadband laser light source passes through the lipid layer, the optical attenuation coefficient for each band of the entire spectrum of the OCT interference signal is calculated into the lipid layer. Spectroscopic information of the tissue is obtained by comparing before and after passage.

Figure 7 is a configuration diagram of an optical interference signal measurement unit for each polarization component that cancels out polarization changes occurring when the endoscope sample stage is rotated according to an embodiment of the present invention.

The endoscope is rotated independently to obtain a tomographic image of the blood vessel, and the polarization change that occurs due to the rotation and movement of the endoscope sample stage affects the intensity of the optical interference signal. In order to improve the measurement accuracy of the optical attenuation signal by minimizing the influence that occurs at this time, an optical interference signal measurement structure for each polarization component operating in the 1700 nm band is used, as shown in FIG. 7.

Figure 8 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.

Figure 8 shows the configuration of OCT capable of measuring each polarization component in the 1700 nm wavelength band. The optical fiber circulator and polarization maintaining fiber beam splitter that are most influential for stable signal acquisition, and the optical fiber beam splitter optimized for the 1700 nm wavelength band in Figure 6 are shown. Apply optical amplifier module.

Figure 9 is a configuration diagram of an optical tomography endoscope system using a 1700 nm band broadband light source (SLED) and a spectroscope according to another embodiment of the present invention.

The OCT technology according to an embodiment of the present invention can be used by using a structure that combines a tunable laser in the 1700nm band and a photodetector, or by modifying the optical design to use a structure using a broadband light source (SLED) in the 1700nm band and a spectrometer. do.

The optical tomography endoscope system and its control method capable of analyzing atherosclerotic plaque components using a near-infrared light source according to the present invention described above determines the light absorption intensity of biological tissue (lipid) according to the wavelength of the laser light source in the near-infrared band with a center wavelength of 1700 nm. By using the rapid change, a laser light source is irradiated inside the subject and the intensity change for each wavelength of the returned light is analyzed to determine the distribution of lipids inside the biological tissue, and an optical interference signal is generated with the returned light to determine the single layer structure of the tissue. This was done so that they could be acquired and analyzed together.

As described above, it will be understood that the present invention is implemented in a modified form without departing from the essential characteristics of the present invention.

Therefore, the specified embodiments should be considered from an illustrative rather than a limiting point of view, the scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the equivalent scope are intended to be included in the present invention. It will have to be interpreted.

10. Light source part
20. Optical interference counter
30. Endoscopy Department
40. Optical signal measurement unit

Claims (13)

A light source unit that irradiates a laser light source to confirm the distribution and monolayer structure of lipids inside the biological tissue using changes in the light absorption intensity of the biological tissue;
An optical interferometry unit that irradiates a laser light source inside the subject to detect the intensity of each wavelength of the returned light and generates an OCT interference signal with the returned light;
An endoscope unit that irradiates a laser light source inside the subject;
An optical signal measurement unit that measures and analyzes blood vessels and atherosclerotic plaques using changes in the light absorption intensity of biological tissue according to the wavelength of the laser light source; a component analysis of atherosclerotic plaques using a near-infrared light source is possible. Optical tomographic endoscopy system. The method of claim 1, wherein the wavelength band irradiated from the light source is:
As the wavelength of the OCT light source changes to a longer wavelength, the attenuation rate of the OCT optical signal decreases due to the light scattering effect in living organisms, and on the contrary, the attenuation rate of the optical signal increases due to the light absorption effect of lipids in living organisms containing lipid components. An optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source, which is characterized by using a satisfactory 1700nm wavelength band. The method of claim 1, wherein the wavelength band irradiated from the light source is:
Broadband light is irradiated, including the 1700 nm wavelength band where light absorption changes due to lipid components are large and the 1650 nm wavelength band where light absorption is relatively weak, and the OCT interference signal is transmitted to the wavelength band where light absorption changes due to lipid components are weak. An optical tomography endoscope system capable of analyzing the composition of atherosclerotic plaques using a near-infrared light source, characterized in that it distinguishes lipid components accumulated inside vascular tissue by dividing and analyzing them into wavelength bands with large changes in light absorption due to lipid components. The method of claim 1, wherein the optical signal measurement unit,
The optical attenuation coefficient for each band of the entire spectrum of the OCT interference signal is compared before and after passing through the lipid layer to obtain spectroscopic information of the tissue, and the lipid layer of the inner wall of the blood vessel and the atherosclerotic plaque are separated and the location of the lipid layer is separated and imaged. An optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source. The method of claim 4, wherein the optical signal measurement unit,
Characterized in that it includes a configuration for measuring the optical interference signal for each polarization component operating in the 1700 nm band in order to minimize the influence of polarization changes that occur due to the rotation and movement of the endoscope sample stage on the intensity of the optical interference signal. An optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source. The method of claim 5, wherein the optical signal measurement unit,
An artery using a near-infrared light source, characterized in that it includes a signal processing means that analyzes the OCT interference signal measured for each polarization component in the 1700 nm wavelength band and extracts the optical signal attenuation value consistently regardless of the rotation and movement of the endoscope sample stage. Optical tomography endoscope system capable of analyzing sclerotic plaque components. According to claim 5, the optical signal measurement unit is used to prevent loss of signal-to-noise ratio of OCT, which is capable of measuring polarization components in the 1700 nm wavelength band,
Light capable of analyzing atherosclerotic plaque components using a near-infrared light source, characterized by applying an optical fiber circulator, a polarization maintaining beam splitter, and an optical amplifier module in the corresponding wavelength band. Single-layer endoscopic system. The optical tomographic endoscope system of claim 1,
A structure that combines a tunable laser in the 1700nm band and a photodetector,
Alternatively, an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source, characterized by a structure using a broadband light source (SLED) in the 1700 nm band and a spectroscope. A light source irradiation step of irradiating a laser light source to a measurement object to confirm the distribution and monolayer structure of lipids inside the biological tissue using changes in the light absorption intensity of the biological tissue;
Recovering the spectrum from the OCT interference signal;
Obtaining spectroscopic information about the tissue by comparing the optical attenuation coefficient for each spectral band of the entire spectrum of the OCT interference signal before and after passing through the lipid layer;
By dividing the measured OCT interference signal into bands and comparing the optical signal attenuation ratio in the band with low lipid absorption and the optical signal attenuation ratio in the band with high lipid absorption, the vascular lining tissue with low lipid content and the arteriosclerosis with high lipid content were compared. Separating the halves;
A control method of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source, comprising the step of separating the lipid layer of the inner wall of the blood vessel and the atherosclerotic plaque, imaging the position of the lipid layer, and outputting the analysis results. The method of claim 9, wherein the wavelength band irradiated in the light source irradiation step is:
As the wavelength of the OCT light source changes to a longer wavelength, the attenuation rate of the OCT optical signal decreases due to the light scattering effect in living organisms, and on the contrary, the attenuation rate of the optical signal increases due to the light absorption effect of lipids in living organisms containing lipid components. A control method of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components using a near-infrared light source, characterized by using a satisfactory 1700nm wavelength band. The method of claim 9, wherein the wavelength band irradiated in the light source irradiation step is:
Broadband light is irradiated, including the 1700 nm wavelength band where light absorption changes due to lipid components are large and the 1650 nm wavelength band where light absorption is relatively weak, and the OCT interference signal is transmitted to the wavelength band where light absorption changes due to lipid components are weak. A control method of an optical tomography endoscope system capable of analyzing the composition of atherosclerotic plaques using a near-infrared light source, characterized in that the lipid components accumulated inside the vascular tissue are distinguished by comparing and analyzing the wavelength bands in which the light absorption change is large depending on the lipid component. . The method of claim 9, to restore the spectrum from the OCT interference signal,
In order to minimize the influence of polarization changes that occur due to the rotation and movement of the endoscope sample stage on the intensity of the optical interference signal, a near-infrared light source is used, which is characterized by measuring the optical interference signal for each polarization component operating in the 1700 nm band. Control method of an optical tomography endoscope system capable of analyzing atherosclerotic plaque components. The method of claim 9, wherein in the step of acquiring spectroscopic information,
Arteriosclerotic plaque using a near-infrared light source, which is characterized by analyzing the OCT interference signal measured for each polarization component in the 1700 nm wavelength band and performing signal processing to consistently extract the optical signal attenuation value regardless of the rotation and movement of the endoscope sample stage. Control method of an optical tomography endoscope system capable of component analysis.

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