KR102204680B1 - System and method for providing endoscope image, and a recording medium having computer readable program for executing the method - Google Patents

Abstract

Disclosed are an endoscope system, a method for providing an endoscope image, and a recording medium in which a computer-readable program for executing the method is recorded. The endoscope system includes a first optical measuring unit, a second optical measuring unit, a correction factor calculating unit, and a correction value calculating unit. The first optical measurement unit measures the induction fluorescence generated by the fluorescent labeling material previously injected into the observation area to which the excitation light is irradiated, and the second optical measurement unit measures light in a wavelength band different from the induction fluorescence generated at the observation area. , The correction factor calculation unit calculates a preset correction factor using the measured value of the light measured by the second optical measurement unit, and the correction value calculation unit applies the calculated correction factor to the measured value of the induction fluorescence to calculate the correction value of the induced fluorescence. Calculate.

Description

Endoscopic imaging system, method, and recording medium recording a program for performing the method TECHNICAL FIELD [SYSTEM AND METHOD FOR PROVIDING ENDOSCOPE IMAGE, AND A RECORDING MEDIUM HAVING COMPUTER READABLE PROGRAM FOR EXECUTING THE METHOD}

The present invention relates to a medical endoscope, and more particularly, to a system and method for providing an endoscopic image for photodynamic diagnosis or photodynamic therapy.

Since conventional anticancer chemicals are non-specific without distinction between normal cells and cancer cells, there is a problem of side effects due to toxicity to normal cells. Accordingly, in recent years, many studies have been conducted on targeted therapy to overcome the side effects of existing anticancer drugs, and photosensitizers are widely used as bioimaging probes for cell observation through induced fluorescence.

This is because cancer can be visualized or diagnosed through the induced fluorescence of the photosensitizer expressed in the tumor tissue, in contrast to the surrounding normal tissues after administration of the photosensitizer. More specifically, the photosensitizer is selectively accumulated in the tumor tissue, and significantly high fluorescence is expressed in the area where the photosensitizer is accumulated, and the photosensitizer is accumulated in the target material and the location in the body through observation of fluorescence images. This is because cancer cells can be accurately diagnosed in local areas by grasping the concentration. In addition, photosensitizers can be used in photodynamic therapy to kill cancer cells by generating active oxygen.

However, in the case of a photosensitizer having a characteristic in which the absorption spectrum and the fluorescence spectrum overlap, the expressed fluorescence is reabsorbed, which makes it difficult to accurately measure the fluorescence intensity.

1 is a diagram showing an example of a change in fluorescence intensity of a photosensitizer. The photosensitizer of FIG. 1 is Photolon, which is a photosensitizer made water-soluble by polymerizing with polyvinylpyrrolidone (PVP) in Chlorin e6 (Ce6), a chlorin derivative. Compared with the first-generation photosensitizers, the treatment time and discharge This is much faster and more than four times the depth of the curable tumor, making it effective for photodynamic diagnosis and photodynamic therapy.

As shown in Figure 1, the photoron has a strong absorption spectrum at 400 nm and 660 nm, and maximum fluorescence is observed at 670 nm. Therefore, the absorption spectrum and fluorescence spectrum of the photoron overlap around the 660nm peak. This causes reabsorption of fluorescence, which is not proportional to the concentration of the photosensitizer, and decreases the fluorescence intensity, thereby reducing the accuracy of cancer visualization and diagnosis by fluorescence.

In addition, the correlation between the pathological substrate of the tumor and the pH dependence of the photosensitizer is also a factor that degrades the accuracy of cancer diagnosis by fluorescence intensity. In cancer cells, glucose metabolism is promoted, resulting in increased production of lactic acid and hydrogen ions (H+), which are then discharged out of the cell. Moreover, because the microenvironment of cancer tissues has poor circulation of blood and lymph fluid, hydrogen ions are increased in tissues around the cancer. As a result, the pH around the cancer cells goes down and the cancer tissue becomes acidic.

For example, the molecule of Chlorin e ₆ contains three carboxyl groups that dissolve in an aqueous medium.

Chlorin is anionic in an alkaline medium, but when the pH of the medium decreases, the carboxyl groups are protonated, resulting in hydrophobicity, resulting in poor solubility and aggregation. That is, due to this pH dependence, the photoron exhibits a property that a major decrease in fluorescence intensity occurs and the fluorescence band is shifted when the pH is low. Therefore, cancer tissue in an acidified environment becomes a factor that decreases the fluorescence intensity of the photoron.

In this way, when the absorption spectrum of the photosensitizer and the fluorescence emission spectrum of the photosensitizer are overlapped and the emitted fluorescence is reabsorbed, or if the fluorescence intensity of the photosensitizer is dependent on the change in the tumor microenvironment, a change in the fluorescence intensity occurs, more accurate cancer diagnosis is provided For this, we need a way to correct it.

KR 100896864 B1

The present invention has been devised to solve the above-described conventional problem, and the absorption spectrum and the fluorescence emission spectrum of the photosensitizer are overlapped to cause reabsorption of the emitted fluorescence, or the fluorescence intensity of the photosensitizer is increased due to changes in the tumor microenvironment. An object of the present invention is to provide an endoscopic imaging system and method capable of providing a more accurate diagnostic image even with an unintended change in fluorescence intensity that may occur in a dependent case.

In order to achieve the above object, the endoscope imaging system according to the present invention includes a first optical measurement unit, a second optical measurement unit, a correction factor calculation unit, and a correction value calculation unit. The first optical measuring unit measures the induced fluorescence generated by a fluorescent label (photosensitizer) previously injected into the observation area to which the excitation light is irradiated, and the second optical measuring unit observes by excitation light that excites the fluorescent label. Intrinsic fluorescence generated at the site is measured and has a wavelength band different from the induced fluorescence of the fluorescent labeling material. The correction factor calculation unit calculates a correction factor using the measured value of the light measured by the second optical measurement unit, and the correction value calculation unit calculates a correction value of the induced fluorescence by applying the calculated correction factor to the measured value of the induced fluorescence.

According to this configuration, induction using intrinsic fluorescence including biometric information of the observation site having information independent of the fluorescent labeling material as well as the measured value of the induced fluorescence generated at the observation site of the endoscope by the fluorescent labeling material By correcting the measured value of the fluorescence intensity to derive a fluorescence image, it is possible to provide a more accurate diagnostic image in response to a distorted and unintended change in the induced fluorescence intensity.

At this time, the second optical measurement unit measures the intrinsic fluorescence generated by the endogenous fluorescent material at the observation site having physiological characteristics independent from the measurement object of the first optical measurement unit, and the correction factor calculation unit measures the lesion tissue and the normal tissue of the observation area. A correction factor representing the degree of abnormality in the lesion tissue can be calculated by using the measurement values of each of the intrinsic fluorescence measured at. According to this configuration, the absorption spectrum of the fluorescent labeling material and the fluorescence emission spectrum of the fluorescent labeling material are overlapped to cause reabsorption of the emitted fluorescence, or the intended value generated because the fluorescence intensity of the fluorescent labeling material is dependent on changes in the microenvironment in the lesion tissue. It is possible to provide a more accurate diagnostic image even when the inductive fluorescence intensity changes.

At this time, the fluorescent labeling material may be a photosensitizer, and in particular, may be a photoron.

In this case, intrinsic fluorescence may be fluorescence in a green wavelength region, and inductive fluorescence may be fluorescence in a red wavelength region.

수학식에 의해 산출되어, 유도형광의 보정값

산출에 이용된다. G_tumor는 병변조직에서의 녹색 파장 영역에서의 고유형광 세기이고, G_normal은 정상조직에서의 녹색 파장 영역에서의 고유형광의 세기이며, R은 유도형광의 측정값일 수 있다.In addition, the correction factor is as follows through intrinsic fluorescence information having physiological characteristics independent of induced fluorescence.

Computed by the equation, the correction value of the induced fluorescence

It is used for calculation. G _tumor is the intrinsic fluorescence intensity in the green wavelength region in the lesion tissue, G _normal is the intrinsic fluorescence intensity in the green wavelength region in the normal tissue, and R may be a measured value of induced fluorescence.

In addition, the fluorescent labeling material may be indocyanine green having near-infrared fluorescence. At this time, the second optical measuring unit observes the wavelength range of visible light generated from the observation area and measures the dye color of indocyanine green, and the correction factor calculator calculates the concentration of indocyanine green dye corresponding to the dye color from the measured value of visible light. Indocyanine green fluorescence intensity correction factor as a function of dye concentration can be calculated using.

의 수학식에 의해 산출되고, I_ICG는 측정된 유도형광의 세기이고, K_color는 염료 농도 함수로서의 인도시아닌 그린 형광 세기 보정인자일 수 있다.In addition, the correction value of the induced fluorescence is

It is calculated by the equation of, I _ICG is the measured intensity of induced fluorescence, and K _color may be an indocyanine green fluorescence intensity correction factor as a function of dye concentration.

In addition, an invention in which the system is implemented in the form of a method and a recording medium recording a program for performing the method are disclosed together.

According to the present invention, when the measured value of the induced fluorescence generated at the observation site of the endoscope is unintentionally distorted by the fluorescent labeling material, information from the light measured at a different wavelength having a physiological characteristic independent from the measurement object is By correcting the distorted measurement value by using, it is possible to provide a more accurate diagnostic image.

In particular, the absorption spectrum of the fluorescent labeling material and the fluorescence emission spectrum of the fluorescent labeling material are overlapped, so that the emitted fluorescence is reabsorbed, or the induced fluorescence intensity change of the fluorescent labeling material that may occur because the fluorescence intensity of the fluorescent labeling material is dependent on the microenvironment change in the lesion tissue. It is possible to provide a more accurate diagnostic image.

1 is a view showing an absorption spectrum and a fluorescence spectrum of a photo-sensitizer photoron.
2 is a schematic block diagram of an endoscopic imaging system according to an embodiment of the present invention.
3 is a diagram illustrating an example of a state of use of the endoscope imaging system of FIG. 1;
FIG. 4 is a view showing wavelengths of light generated from a UV LED and a white LED selected by the dichroic mirror of FIG. 3.
5 is a view showing a wavelength of light for a camera response selected by the shielding filter of FIG. 3;
6 is a diagram schematically showing the shapes of induced fluorescence and intrinsic fluorescence generated in normal tissues and tumor tissues, respectively, by an excitation light source.
7 is a diagram showing the absorption and fluorescence spectrum of indocyanine green.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a schematic block diagram of an endoscopic imaging system according to an embodiment of the present invention. In FIG. 2, the endoscope imaging system 100 includes a first optical measurement unit 110, a second optical measurement unit 120, a correction factor calculation unit 130, and a correction value calculation unit 140.

In the fluorescence mode, the first light measuring unit 110 measures the induced fluorescence generated by the photosensitizer at the observation area irradiated with the excitation light, and the second light measuring unit 120 measures intrinsic fluorescence to which the excitation light is irradiated. Measure

The correction factor calculation unit 130 calculates a correction factor representing the degree of abnormality of the tumor tissue by using the measurement values of the intrinsic fluorescence measured in the tumor tissue and the normal tissue measured by the second optical measurement unit, and the correction value calculation unit Step 140 calculates a correction value of the induced fluorescence by applying the calculated correction factor to the measured value of the induced fluorescence.

The intrinsic fluorescence measured in the second optical measuring unit and used to calculate the correction factor is excited by the excitation light that excites the optical sensitizer, which corresponds to the wavelength range of the induced fluorescence of the optical sensitizer measured by the first optical measuring unit. Is characterized in that it is generated from an endogenous fluorescent material having a distinct fluorescence wavelength band. In addition, this endogenous fluorescent substance is characterized by exhibiting intrinsic fluorescence changes distinguished from normal tissues in tumor tissues due to changes in the metabolic state of tissues, microenvironments, etc., and having fluorescence information independent of photosensitizers.

According to this configuration, even if the induced fluorescence generated at the observation site of the endoscope by the fluorescent labeling material causes unintended distortion of the fluorescence intensity due to the characteristics of the fluorescent labeling material, it contains information on the degree of abnormality of the tumor tissue. By using information from intrinsic fluorescence measured at a wavelength different from fluorescence by the type and labeling material, the degree of distortion is compensated and corrected, thereby providing a more accurate diagnostic image.

3 is a diagram illustrating a state of use of the endoscope imaging system of FIG. 2. 3, the endoscope imaging system 100 is located between the detection unit 200 of the endoscope and the image processing unit 300 to transmit image data, and is implemented so that the white light mode and the fluorescence mode are switched by the mode control driver 400. An example is shown.

The light source unit 500 includes a white LED 510 and a UV LED 520, and selectively transmits and reflects the UV LED 520 and the white LED 510 by the dichroic mirror 530. In the fluorescence mode, the UV LED 520 and the white LED in the white light mode (a typical white LED has a wavelength range of 420 nm to 720 nm; 510) are respectively used.

FIG. 4 is a diagram showing the wavelengths of light generated from the UV LED and the white LED selected by the dichroic mirror of FIG. 3, and FIG. 5 shows the wavelength of light for the camera response selected by the shielding filter of FIG. 3 It is a drawing.

The detection unit 200 includes a camera 210 composed of one or more CCD/CMOS image sensors, and includes a single camera including a Bayer filter divided into R, G, and B wavelength ranges, or a camera composed of a plurality of image sensors. It can be implemented to detect R, G, and B, respectively.

The shielding filter 220 shields the excitation light (λex=400nm) by the UV LED, but is configured to transmit the wavelength range of 420nm to 720nm of a general white LED. Accordingly, the same shielding filter 220 can be used without adjusting the shielding filter 220 in a white light mode or a fluorescence mode. The shielding filter 220 may be composed of a bandpass filter or a longpass filter.

In the camera 210, in the white light mode, all the wavelengths of the white LED are detected, and in the fluorescence mode, the intrinsic fluorescence by the endogenous fluorescent material in which the fluorescence wavelength region is divided and the induced fluorescence by the photoron are simultaneously separated and detected. In an example configured with a single camera, channels B and G may be defined as the second light measuring unit 120 and channel R may be defined as the first light measuring unit 110. In this case, the fluorescent labeling material measured by the first light measuring unit 110 may be a photosensitizer, and in particular, may be a photoron.

Endogenous fluorophores that emit autofluorescence of tissues originating from internal materials include connective tissues (collagen, elastin), coenzyme-related cell metabolites (NADH, FAD, FMN), amino acids (tryptophan, tyrosine, etc.). phenylalanine), heme synthetic products (porphyrins), and fatty pigments (lipofuscin, ceroids).

At this time, an example of the main endogenous fluorophores measured by the second optical measuring unit 120 is excited by the excitation wavelength (λex=400nm) of the photosensitizer photoron, and is associated with a coenzyme having a maximum fluorescence peak at 525nm. There is Flavin, a cell metabolite.

In this case, the correction factor calculation unit 130 may calculate a correction factor by using the measurement values of intrinsic fluorescence measured in the lesion tissue and the normal tissue, respectively, among the observation sites.

Tissues are composed of several fluorophores of different concentrations depending on the depth such as mucous membrane, submucosa, and muscle layer, and the intensity of intrinsic fluorescence differs between normal and tumor tissues.

This is because intrinsic fluorescence is strongly produced by the submucosal stroma, but the epithelium, mucosa, and cancerous tissue hardly emit fluorescence.

In addition, in the case of tumor tissues, internal fluorescence changes occur due to changes in the metabolic state of the tissue, microenvironment, etc., but internal fluorescence changes occur due to changes in mucosal thickness or changes in blood concentration.

More specifically, in the case of tumors, the mucous membrane covering the submucosal connective tissue is thickened, resulting in a masking effect that reduces the fluorescence of the tumor tissue, or abnormal epithelial cells are thicker than normal epithelial cells, resulting in significant amounts of fluorescent substances. A change in the light scattering process, that is, a change in the concentration or distribution of a fluorescent substance, occurs due to absorption or blocking of light that stimulates the light, or an increase in nuclear size, cellular density, or cancer cell distribution.

Most endogenous fluorescent substances are associated with tissue matrices such as collagen and elastin or involved in cellular metabolic processes, and since the content of extracellular matrix in precancerous or tumor tissues decreases, intrinsic fluorescence intensity decreases.

In addition, a difference in fluorescence may be shown according to the amount of blood flow in the lesion tissue. Since it contains chromophore internal substances such as hemoglobin that absorb light without re-emission of fluorescence, the fluorescence intensity decreases.

Accordingly, when excitation light (λex=400nm) is irradiated to the observation site, intrinsic fluorescence in the Green wavelength region of the endogenous fluorescent material having a greater intensity than the tumor tissue is observed in the normal tissue. In addition, in tumor tissues, intrinsic fluorescence in the Green wavelength region due to the reduced endogenous fluorescent material than in the normal tissue and induction fluorescence in the red wavelength due to the photosensitizer photoron having a greater intensity than the normal tissue are observed. 6 is a diagram schematically showing the shapes of induced fluorescence and intrinsic fluorescence generated in normal tissues and tumor tissues, respectively, by an excitation light source.

Therefore, since photoron-induced fluorescence weakens the fluorescence intensity according to the environmental conditions of the photoron itself or the living tissue, in order to compensate for this, endogenous fluorescence that is independent of the photoron and can provide independent biometric information even with changes in the environmental conditions of the living tissue. The intensity of photoron-induced fluorescence can be corrected by using the material as a correction factor.

More specifically, the region in which the signal is detected in the R channel is classified as a tumor tissue in which induced fluorescence is generated as photorons are selectively accumulated, and the other regions are classified as normal tissues.

The G-channel signal by intrinsic fluorescence of the endogenous fluorescent material detected in the area divided into tumor tissue is called G _tumor , and the G-channel signal by intrinsic fluorescence of the endogenous fluorescent material detected in the area divided into the normal tissue is G _normal . When doing so, the normal to tumor ratio or coefficient in the G channel can be calculated as follows.

The higher the concentration of photoron accumulated in the tumor, the more reabsorption of the induced fluorescence occurs, and the more severe the acidification of the cancer, the dependently decreases the intensity of the photon-induced fluorescence. Using K _G, which is the ratio of normal tissue to tumor tissue in the G channel, which is a discriminant factor, it is applied to the correction of the induced fluorescence intensity as follows.

In addition, the second optical measuring unit 120 measures visible light generated in the observation area, and the correction factor calculating unit 130 measures the color density in a preset wavelength band from the measured value of visible light, which is a dye color corresponding to the dye concentration. The correction factor can also be calculated using. In this case, the near-infrared fluorescent labeling material may be indocyanine green.

More specifically, Indocyanine Green, a near-infrared fluorescent labeling substance that is actively used clinically for inflammatory response, detection of tumor and angiogenesis (angiogenesis), blood flow analysis, etc., has an absorption spectrum that reaches 805 nm maximum. It has fluorescence characteristics in the near-infrared region of 800 to 870 nm, which is a long wavelength. 7 is a diagram showing the absorption and fluorescence spectrum of indocyanine green.

The near-infrared wavelength is very useful for fluorescence imaging of a target site because it has excellent tissue permeability and has an excellent signal to noise ratio since it hardly affects biological samples. However, some fluorescence spectral regions overlap with the absorption spectral region, and if the concentration of the dye is too high, the fluorescence is absorbed again and the fluorescence intensity decreases, thereby reducing the accuracy of fluorescence image observation. However, since indocyanine green has a darker green color at higher concentrations, it is possible to approximate the fluorescence response of indocyanine green due to the overlap between the absorption and fluorescence spectra of indocyanine green as a function of dye concentration. , By measuring the color of the observed indocyanine green as well as the induced fluorescence of indocyanine green, the effect of the dye concentration-dependent fluorescence intensity reduction can be corrected as follows.

At this time, I _ICG is the measured intensity of induced fluorescence, and K _color is a fluorescence intensity correction factor at the dye concentration corresponding to the measured dye color of indocyanine green.

In summary, the present invention improves the accuracy of cancer diagnosis by using characteristics such as induced fluorescence of a photosensitizer and autofluorescence generated from endogenous fluorophore of tissue. It relates to a system and method for.

It is difficult to distinguish early cancer or precancerous lesions in normal white light endoscopy observation. On the other hand, conventionally, a method of constructing a background image for an observation site by optically or electronically controlling the reflected light of excitation light, and distinguishing a lesion by fluorescence has been attempted.

In the present invention, a change in fluorescence intensity occurs due to reabsorption of fluorescence due to overlapping of a photosensitizer absorption spectrum and a fluorescence spectrum, or when a change in the fluorescence intensity of a photosensitizer occurs due to a change in pathological properties of a tumor tissue Edo, by using the intrinsic fluorescence properties of precancerous or tumor tissues to correct unwanted changes in the intensity of photosensitizing agent-induced fluorescence to increase the accuracy of diagnosis.

To this end, after administration of the photosensitizer, when the photosensitizer is selectively accumulated in cancer tissues, excitation light (λex=400nm) is irradiated to the observation site (through a laparoscope). The excitation light (λex=400nm) excites the photosensitizer, but also excites the endogenous fluorescent substance in the living tissue, so intrinsic fluorescence by the endogenous fluorescent substance in the normal tissue can be used as a background image of the observation site.

In addition, by using an intrinsic fluorescence G channel by an endogenous fluorescent substance having a characteristic that decreases in cancer tissue, the induction of a decrease in the concentration of the photosensitizer due to pathological properties such as reabsorption and/or pH of the photosensitizer fluorescence. Correct the fluorescence intensity. The corrected R', G, B channel signal values are used as an image of the tumor area.

Although the present invention has been described by some preferred embodiments, the scope of the present invention should not be limited thereto, and modifications or improvements of the above embodiments supported by the claims should also be reached.

100: endoscopic imaging system
110: first optical measuring unit
120: second optical measuring unit
130: correction factor calculation unit
140: correction value calculation unit
200: detection unit
210: camera
220: shielding filter
300: image processing unit
400: mode control driver
500: light source
510: White LED
520: UV LED
530: dichroic mirror

Claims (19)

A first light measuring unit for measuring induced fluorescence generated by a fluorescent labeling material previously injected into the observation area to which the excitation light is irradiated;
A second optical measurement unit measuring light in a wavelength band different from that of the induction fluorescence at the observation area;
A correction factor calculation unit that calculates a correction factor using a measurement value of light measured by the second light measurement unit; And
An endoscopic imaging system comprising a correction value calculator configured to calculate a correction value of the induced fluorescence by applying the correction factor to the measured value of the induction fluorescence,
The correction factor calculation unit calculates the correction factor by using the measurement values of intrinsic fluorescence measured in the lesion tissue and the normal tissue, respectively, of the observation site.
delete The method according to claim 1,
The fluorescent labeling material is an endoscopic imaging system, characterized in that the photosensitizing agent.
The method of claim 3,
An endoscopic imaging system, characterized in that the photosensitizer is a photoron.
The method of claim 4,
The intrinsic fluorescence is fluorescence in a green wavelength region, the induction fluorescence is fluorescence in a red wavelength region, and the intrinsic fluorescence and induction fluorescence are excited by excitation light of the same wavelength.
The method of claim 5,
The correction factor is

Is calculated by the equation of, and the correction value of the induced fluorescence is

Is calculated by the equation of, G _tumor is the intensity of intrinsic fluorescence in the green wavelength region in the lesion tissue, G _normal is the intrinsic fluorescence intensity in the green wavelength region in the normal tissue, and R is the induction An endoscopic imaging system, characterized in that it is a measurement value of fluorescence.
A first light measuring unit for measuring induced fluorescence generated by a fluorescent labeling material previously injected into the observation area to which the excitation light is irradiated;
A second optical measurement unit measuring light in a wavelength band different from that of the induction fluorescence at the observation area;
A correction factor calculation unit that calculates a correction factor using a measurement value of light measured by the second light measurement unit; And
An endoscopic imaging system comprising a correction value calculator configured to calculate a correction value of the induced fluorescence by applying the correction factor to the measured value of the induction fluorescence,
The second light measuring unit measures visible light generated from the observation area,
The correction factor calculation unit calculates the correction factor by using the color density of the fluorescent label material obtained from the measured value of the visible light.
The method of claim 7,
The fluorescent labeling material is an endoscopic imaging system, characterized in that the indocyanine green.
The method of claim 8,
The correction value of the induced fluorescence is

It is calculated by the equation of, I _ICG is the measured intensity of the induced fluorescence, and K _color is an endoscopic imaging system, characterized in that the fluorescence intensity correction factor of the indocyanine green set in advance.
As an image providing method performed by an endoscope system,
A first photometric step of measuring the induced fluorescence generated by the fluorescent labeling material previously injected into the observation area to which the excitation light is irradiated;
A second optical measurement step of measuring light having a wavelength band different from that of the induction fluorescence generated at the observation site;
A correction factor calculation step of calculating a correction factor using a measurement value of light measured by the second light measuring unit; And
Comprising a correction value calculation step of calculating a correction value of the induced fluorescence by applying the correction factor to the measured value of the induction fluorescence,
The second photometric step measures intrinsic fluorescence generated by the endogenous fluorescent material at the observation site,
In the step of calculating the correction factor, the correction factor is calculated using a measurement value of intrinsic fluorescence measured in lesion tissue and normal tissue, respectively, of the observation site.
delete The method of claim 10,
The method of providing an endoscopic image, wherein the fluorescent labeling material is a photosensitizer.
The method of claim 12,
The method of providing an endoscopic image, characterized in that the photosensitizer is a photoron.
The method of claim 13,
The intrinsic fluorescence is fluorescence in a green wavelength region, the inductive fluorescence is fluorescence in a red wavelength region, and the intrinsic fluorescence and induction fluorescence are excited by excitation light of the same wavelength.
The method of claim 14,
The correction factor is

Is calculated by the equation of, and the correction value of the induced fluorescence is

Is calculated by the equation of, G _tumor is the intensity of intrinsic fluorescence in the green wavelength region in the lesion tissue, G _normal is the intrinsic fluorescence intensity in the green wavelength region in the normal tissue, and R is the induction Method for providing an endoscopic image, characterized in that the measurement value of fluorescence.
As an image providing method performed by an endoscope system,
A first photometric step of measuring the induced fluorescence generated by the fluorescent labeling material previously injected into the observation area to which the excitation light is irradiated;
A second optical measurement step of measuring light having a wavelength band different from that of the induction fluorescence generated at the observation site;
A correction factor calculation step of calculating a correction factor using a measurement value of light measured by the second light measuring unit; And
Comprising a correction value calculation step of calculating a correction value of the induced fluorescence by applying the correction factor to the measured value of the induction fluorescence,
In the second light measuring step, visible light generated from the observation area is measured,
In the calculating of the correction factor, the correction factor is calculated by using the color density of the fluorescent label material obtained from the measured value of the visible light.
The method of claim 16,
The method for providing an endoscopic image, characterized in that the fluorescent labeling material is indocyanine green.
The method of claim 17,
The correction value of the induced fluorescence is

_Computed by the equation of, I _ICG is the measured intensity of the induced fluorescence, and K _color is an endoscopic image providing method, characterized in that the fluorescence intensity correction factor set in advance of the indocyanine green.
A recording medium storing a computer-readable program for executing the method of any one of claims 10 and 12 to 18.

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