JP7142865B2 - Device for identifying suspected cancerous sites - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for identifying suspected cancerous sites.

Conventionally, various efforts have been made to discover and identify suspected carcinogenesis sites of breast cancer.
As an apparatus for identifying suspected cancerous sites of breast cancer, for example, a breast X-ray examination apparatus (X-ray mammography) is widely used. In X-ray mammography, X-rays are used to photograph the inside of the breast of a subject, and by analyzing the image obtained by the photographing, suspected cancerous sites are detected, and locations where suspected cancerous sites exist. (Hereinafter, finding a suspected cancerous site and specifying the location where the suspected cancerous site exists may be simply referred to as "examination".).
However, in X-ray mammography, the mammary glands appear white, so if there are cancer cells behind the densely distributed areas of the mammary glands, the cancer cells may be visible in the image of the mammary glands. They may hide in the background and overlook cancer cells. In addition, examination by X-ray mammography is accompanied by exposure to X-rays, and since X-ray imaging is performed while the breast is strongly sandwiched between compression plates, there is a problem that more or less damage is given to the person being examined. Yes (invasive test). These problems are also factors that make people hesitate to undergo breast cancer examinations.

As a device for performing cancer examination while solving the above problems, a device for displaying a suspected site of cancer occurrence using near-infrared light has also been proposed (conventional device for displaying a suspected site of cancer occurrence).
When a tissue of a living body (biological tissue) is irradiated with light, the light is absorbed by substances inside the tissue, and the intensity of the light is attenuated as the light travels. It is said that the main substances that absorb light inside living tissue are mainly water and hemoglobin (blood). The optical absorption spectra of water and hemoglobin are strongly wavelength dependent. Light in the near-infrared region is relatively weakly absorbed by water and hemoglobin. wavelengths are called the "optical window of the body").
A conventional cancer suspected site display device irradiates the body surface of the subject with near-infrared light including a wavelength range called the "optical window of the living body", and repeats absorption and scattering in the living tissue. By capturing and analyzing the light that has returned to the body surface, the state inside the body is displayed. For example, in the case of a device using a technique called DOS imaging described in Non-Patent Document 1, light absorption by oxygenated hemoglobin and light absorption by reduced hemoglobin present in tissue are captured, and these signals are quantified, Based on these, DOS imaging is displayed to display and specify a site suspected of developing cancer (see page 382 and FIG. 2 of Non-Patent Document 1).

By using such a conventional cancer-suspicious site display device, it is possible to configure a device for specifying a cancer-suspicious site (conventional cancer-suspicious site specifying device).
According to the conventional apparatus for identifying a suspected cancerous site, since near-infrared light is used, the examination can be performed with almost no invasive damage to the examinee.

Shigeto Ueda, "Optical Mammography: Clinical Application of Breast Cancer Imaging Using Diffuse Light Spectroscopy", Medical Oncology/Medical Oncology Editorial Committee, Science Hyoronsha, Vol. 7, No. 4 (No. 40), p.382 -387 Yukio Yamada, ``Noninvasive biodiagnosis using 3 lights'', [online], September 5, 2007, Ministry of Education, Culture, Sports, Science and Technology Science and Technology Council Resource Survey Subcommittee Report, [June 11, 2018 Date search], Internet (URL: http://www.mext.go.jp/b_menu/shingi/gijyutu/gijyutu3/toushin/attach/1333543.htm)

However, looking at the light absorption characteristic curves of oxygenated hemoglobin and reduced hemoglobin, the intensity of light absorption by hemoglobin is 1/10 or less of the intensity of light scattering in the wavelength range called the optical window of the living body. , the signal intensity (light absorption intensity of hemoglobin) is extremely weak relative to the noise intensity (light scattering intensity) (see FIG. 12).
For this reason, the conventional apparatus for identifying suspected cancerous sites must extract weak signal components of light absorption of oxygenated hemoglobin and light absorption of reduced hemoglobin from light information distorted by scattering. In other words, the signal tends to be buried in noise, and the signal-to-noise ratio (S/N ratio) is by no means high. This is one of the obstacles to improving the accuracy of detection of a suspected cancerous site in a conventional apparatus for identifying a suspected cancerous site.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and aims to provide an apparatus for identifying a suspected cancerous site, which has a higher S/N ratio than the conventional one and is capable of detecting a suspected cancerous site with higher accuracy than the conventional one. aim.

FIG. 12 is a diagram showing wavelength characteristics of light absorption (light absorption) and light scattering by living tissue. In FIG. 12, graphs annotated with "hemoglobin" and "water" represent graphs showing the intensity of light absorption (extinction coefficient) by each substance, and graphs annotated with "scattering" indicate 3 depicts a graph showing the intensity of light scattering at .

[1] The apparatus for identifying a suspected cancerous site of the present invention specifies a suspected cancerous site by irradiating a test site of a living body with irradiation light and analyzing the emitted light emitted from the test site to the outside. a light source that outputs irradiation light having an output intensity at a specific wavelength within a range of at least 700 nm to 1200 nm; An irradiator that irradiates a site, a plurality of light receivers that are arranged at a plurality of light receiving sites along the body surface of a living body and receive the emitted light emitted from the site to be inspected to the outside, and the emitted light received by the light receiver and a photodetector for detecting and converting into an optical measurement signal and outputting the optical measurement signal.
In addition, in each of a pressure application mode in which a predetermined pressure is applied to the site to be inspected and a pressure release mode in which the pressure on the site to be inspected is released, the apparatus for identifying suspected cancerous sites has the following functions: (a) optical measurement; Absorbance at a specific wavelength is calculated for each of a plurality of specific wavelengths different from each other, based on the output light intensity at the specific wavelength of the output light extracted from the signal and the irradiation light intensity at the specific wavelength of the irradiation light. (b) calculating the reduced hemoglobin ratio DHR based on the absorbance calculated for each specific wavelength different from each other, the characteristic absorption curve information of oxygenated hemoglobin, and the characteristic absorption curve information of reduced hemoglobin for each light receiving point; Then, the DHR change amount, which is the difference between the reduced hemoglobin ratio DHRp calculated in the pressure application mode and the reduced hemoglobin ratio DHRr calculated in the pressure release mode, is calculated for each light receiving point, and the calculated DHR change for each light receiving point is calculated. It is characterized by generating DHR variation map information representing a two-dimensional or three-dimensional distribution of the amount, and specifying locations of suspected cancerous sites based on the DHR variation map information.

The apparatus for identifying suspected cancerous sites of the present invention calculates the absorbance for each of a plurality of specific wavelengths different from each other, and the absorbance calculated for each specific wavelength, the characteristic absorption curve information of oxygenated hemoglobin, and the reduced Since the reduced hemoglobin ratio DHR is calculated based on hemoglobin characteristic absorption curve information, the reduced hemoglobin ratio DHR can be calculated with high accuracy without being affected by the absolute value (brightness/darkness) of the emitted light intensity on the receiver side. Therefore, the apparatus for identifying a suspected cancerous site has a higher S/N ratio than the conventional one and has a higher detection accuracy of the suspected cancerous site than the conventional one.
In addition, the apparatus for identifying suspected cancerous sites of the present invention has a reduced hemoglobin ratio of The DHR is calculated for each light receiving point, and the DHR change amount, which is the difference between the reduced hemoglobin ratio DHRp calculated in the pressure application mode and the reduced hemoglobin ratio DHRr calculated in the pressure release mode, is calculated for each light receiving point. Then, based on the DHR change amount map information representing the two-dimensional or three-dimensional distribution of the DHR change amount for each light receiving point, the location of the suspected cancerous site is specified.
By applying a predetermined pressure to the site to be inspected in this way, the reduced hemoglobin ratio DHR can be increased only for the red blood cells stagnant in the new blood vessels. When measuring , it is possible to highlight only the new blood vessels from the normal tissue. Therefore, the apparatus for identifying a suspected cancerous site of the present invention has a higher S/N ratio than the conventional one, and is capable of detecting a suspected cancerous site with higher accuracy than the conventional one.
In the present specification, the term "reduced hemoglobin ratio DHR" refers to the ratio of the number of reduced hemoglobins to the total number of hemoglobins (total number of oxygenated hemoglobin and reduced hemoglobin) when viewed per unit volume. Deoxy-Hemoglobin Raio) variable notation shall be used.

[2] The apparatus for identifying a suspected cancerous site of the present invention places the site to be inspected in a pressure application mode to acquire the reduced hemoglobin ratio HDRp, and then places the site to be inspected in a pressure release mode to obtain reduced hemoglobin. It is preferable that the DHR change amount for each light receiving point is calculated by obtaining the ratio HDRr.

By obtaining the reduced hemoglobin ratio DHR in such order, the S/N ratio can be further increased. In addition, it is also possible to first find a site with a relatively high reduced hemoglobin ratio HDRp in the pressure application mode, and then obtain the reduced hemoglobin ratio HDRr particularly precisely for that site in the pressure release mode, thereby improving the detection accuracy. can be done.

[3] In the pressure application mode, the apparatus for identifying suspected cancerous sites of the present invention preferably applies a pressure within a range of 15 mmHg to 25 mmHg to the site to be inspected.

With such a configuration, it is possible to increase the reduced hemoglobin ratio DHR in a limited manner only for red blood cells existing inside the newly formed blood vessels.

[4] In the apparatus for identifying suspected cancerous sites of the present invention, in the characteristic absorption curve of oxygenated hemoglobin and the characteristic absorption curve of reduced hemoglobin, if the wavelength at which the absorption coefficient of oxygenated hemoglobin and the absorption coefficient of reduced hemoglobin are equal is λE, at least , Select one wavelength as a specific wavelength from wavelengths equal to or less than λE, and select one wavelength from wavelengths exceeding λE (wavelengths longer than λE) as a specific wavelength, and at each selected wavelength It is preferable that each absorbance is calculated.

With such a configuration, at least two wavelengths at the point where the magnitude relationship between the absorption coefficient of reduced hemoglobin and the absorption coefficient of oxidized hemoglobin is reversed is selected as the specific wavelength, and the error is suppressed and high. It is possible to accurately calculate the reduced hemoglobin ratio DHR.

[5] The apparatus for identifying suspected cancerous sites of the present invention preferably selects three or more different wavelengths as specific wavelengths and calculates the absorbance at each of the selected wavelengths.

By selecting three or more wavelengths as specific wavelengths in this way, the reduced hemoglobin ratio DHR is calculated based on three or more conditional expressions, so that the reduced hemoglobin ratio DHR can be calculated with even higher accuracy. It becomes possible.

[6] The apparatus for identifying a suspected cancerous site of the present invention includes, as light sources, a plurality of laser light sources that output irradiation light having peaks of output intensity at wavelengths within the range of 700 nm to 1200 nm, which are different from each other. and selects a specific wavelength for which absorbance is to be calculated by selecting any one of a plurality of laser light sources and irradiating a site to be inspected with irradiation light based on the selected laser light source. is preferably.

With such a configuration, by selecting a laser light source having an output intensity peak at an intended wavelength from among a plurality of laser light sources, it is possible to relatively easily select and set the wavelength at which the absorbance should be measured. becomes possible.

[7] The apparatus for identifying a suspected cancerous site of the present invention further comprises a plurality of bandpass filters that pass light in mutually different wavelength ranges, one of the plurality of bandpass filters is selected, and the selection is performed. It is preferable that the band-pass filter is arranged in front of the photodetector.

With such a configuration, by selecting a band-pass filter that passes light in the intended wavelength range from among a plurality of band-pass filters, the wavelength at which the absorbance should be measured can be relatively easily selected and set. In addition, it is possible to configure the apparatus for identifying a suspected cancerous site with only one type of light source without the need to prepare a plurality of light sources on the light projection side (light source and irradiator).

[8] In the apparatus for identifying a suspected cancerous site described in [6] above, the laser light source is preferably a pulse laser light source that outputs pulse laser light as irradiation light.
In addition, the apparatus for identifying a suspected cancerous site (a) inputs an optical measurement signal output by a photodetector based on the irradiation timing of a given pulsed laser beam, and measures the absorbance for each specific wavelength based on the optical measurement signal. are calculated for each of a plurality of specific wavelengths different from each other, and (b) the profile of the reduced hemoglobin ratio DHR for each light receiving point is calculated based on the absorbance profile for each specific wavelength. Calculation by diffuse optical tomography is performed based on the profile of the reduced hemoglobin ratio DHR for each light-receiving point, and the distribution of the DHR change amount in the inspection site is reproduced as DHR change amount map information (here, three-dimensional imaging). and identifying locations of suspected cancerous sites based on the DHR variation map information.

With such a configuration, DHR variation map information obtained by reconstructing the three-dimensional distribution of DHR variation by diffuse optical tomography can be obtained. It is possible to perform a bird's-eye view and relative evaluation (for example, also in the depth direction between the irradiator and the photodetector), and it is possible to specify the position of the suspected cancerous site with higher accuracy.

[9] It is preferable that the apparatus for identifying a suspected cancerous site of the present invention identifies a suspected cancerous site of breast cancer by applying part or all of a breast as a site to be inspected.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure shown in order to demonstrate the usage example of the cancer-occurrence-suspicious part identification apparatus 1 which concerns on Embodiment 1. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure shown in order to demonstrate the cancer occurrence suspected part identification apparatus 1 which concerns on Embodiment 1. FIG. 4 is a flow diagram for explaining control and calculation performed by a control calculation unit 50 and a cancer-occurrence suspicion determination unit 60 of Embodiment 1. FIG. FIG. 2 is a diagram showing a characteristic absorption curve C1 of oxygenated hemoglobin and a characteristic absorption curve C2 of reduced hemoglobin; FIG. 2 is a diagram for explaining the timing of measuring absorbance by the device 1 for identifying a suspected cancerous site according to Embodiment 1, calculations related to the reduced hemoglobin ratio DHR, and a DHR variation map. FIG. 11 is a block diagram shown for explaining a cancer-occurrence-suspicious site identification device 2 according to Embodiment 2. FIG. FIG. 11 is a block diagram shown for explaining a cancerous-suspicious-site-identifying device 3 according to Embodiment 3. FIG. FIG. 4 is a diagram for explaining a data measurement unit and an image reconstruction algorithm for diffuse optical tomography; FIG. 10 is a block diagram of a main part shown for explaining a cancerous-suspicious-site-identifying device 1' according to Modification 1. FIG. FIG. 11 is a diagram shown for explaining timing of measuring absorbance as Modified Example 2. FIG. FIG. 11 is a block diagram of a main part shown for explaining a cancer-occurrence-suspicious site identifying device 4 according to Modification 3; FIG. 4 is a diagram showing wavelength characteristics of light absorption (light absorption) and light scattering by living tissue;

An apparatus for identifying suspected cancerous sites of the present invention will be described below based on the embodiments shown in the drawings. Each drawing is a schematic diagram and does not necessarily strictly reflect actual dimensions. Subscripts i, j, and k described in the following description and drawings are all natural numbers.

[Embodiment 1]
1. Example of use of the apparatus 1 for identifying a suspected cancerous site according to the first embodiment In order to facilitate understanding of the apparatus 1 for identifying a suspected cancerous site according to the first embodiment, before explaining the configuration of the apparatus 1 for identifying a suspected cancerous site, An example of how the apparatus 1 for identifying a suspected cancerous site is applied and used will be described.

FIG. 1 is a diagram for explaining an example of use of the device 1 for identifying a suspected cancerous site according to the first embodiment. 1 and 2 will be explained in the explanation of FIG.
The apparatus 1 for identifying a suspected cancerous site according to the first embodiment irradiates an inspected site INP of a living body Bi with irradiation light IL, and analyzes the emitted light OL emitted from the inspected site INP to the outside, thereby suspecting the occurrence of cancer. (see FIG. 1).
When configuring the apparatus 1 for identifying a suspected cancerous site for examination of breast cancer, an examination space 660 in which the irradiator 15 and the light receiver 25 are arranged to face each other may be provided on the inner wall (see FIG. 1). In this case, first, the breast Br of the person to be examined (human Hu) is "inserted" into the examination space 660, and then the apparatus 1 for identifying suspected cancerous sites is operated to use the apparatus 1 for identifying suspected cancerous sites. do.
In addition, for example, the device 1 for identifying a suspected cancerous site can be easily carried, such as a simple sphygmomanometer having a belt-shaped or clip-shaped sensor head <<a set consisting of an irradiator 15, a light receiver 25, and a pressure applying means 40 (described later)>>. (not shown). In this case, first, the apparatus 1 for identifying suspected cancerous sites is "attached" to the site to be inspected INP, and then the apparatus 1 for identifying suspected cancerous sites is operated to use the apparatus 1 for identifying suspected cancerous sites.

Here, “analysis” refers to analysis including a series of detections, calculations, and the like from detection of emitted light OL, which will be described later, to identification of locations of suspected cancerous sites based on DHR variation map information.
The “inspection site INP” refers to a site of the living body Bi that is to be measured by the apparatus 1 for identifying a suspected cancerous site. In the present specification, it is assumed that the site to be inspected INP includes a site S suspected of developing cancer.

2. 2. Configuration of Cancer Site Suspected Identification Device 1 According to Embodiment 1 FIG. FIG. 2(a) is a block diagram of the apparatus 1 for identifying suspected cancerous sites. The arrow drawn in the region of the inspection site INP schematically represents how the light travels downward in the drawing while being absorbed and scattered after the irradiation light is incident. , the thick arrow drawn in the pressure applying means 40 schematically represents a part of the force generated by the pressure applying means 40, and the direction of the arrow indicates the direction in which the force is applied (see below). The same applies to drawings). In addition, the code|symbol N shows a new blood vessel, and the code|symbol C shall show a cancer cell (the same applies to other drawings).

(1) Configuration of optical system As shown in FIGS. a detector 20; The apparatus 1 for identifying suspected cancerous sites also includes a wavelength selector 30 arranged between the light source 10 and the irradiator 15 .

The light source 10 outputs illumination light IL having an output intensity at least at a specific wavelength within the range of 700 nm to 1200 nm. More preferably, the illumination light IL may have an output intensity at a specific wavelength within the range of 700 nm to 900 nm.
Here, the light source 10 is composed of a plurality of laser light sources 10a, 10b, 10c, . The plurality of laser light sources 10a, 10b, 10c, . , each of which can be output.

The irradiator 15 is optically connected to the light source 10 via a light guide 17 or the like, and irradiates the inspection site INP with the irradiation light IL output from the light source 10 . The illuminator 15 corresponds to, for example, the end portion of the light guide 17 (the end portion including the light emitting end surface). However, the specific configuration of the irradiator 15 is not limited to this.
The irradiator 15 is activated when the device 1 for identifying a suspected cancerous site and the site to be inspected INP are arranged in a predetermined relationship (when the site to be inspected INP is "inserted" into the device 1 for identifying a suspected cancerous site, or When the device 1 for identifying a suspected cancerous site is "attached" to the site to be inspected INP, it is arranged so as to face the site to be inspected INP.

The wavelength selector 30 selects one of the plurality of laser light sources 10a, 10b, 10c, . . . , select a specific wavelength for which the absorbance a is to be calculated (described later).
The wavelength selector 30 is composed of an optical path selector having a plurality of notches (unsigned) connected to the respective laser light sources 10a, 10b, 10c, . (See FIGS. 1 and 2).

Next, before describing the light receiver 25, the light receiving point Rjk will be described.
FIG. 2B is a perspective view for explaining the positional relationship among the irradiator 15, the inspected site INP, the plurality of light receiving locations Rjk, and the plurality of light receivers 25. FIG. The ranges of the inspected portion INP, the light receiving portion Rjk, etc. are virtually indicated by dashed-dotted lines and dotted lines. Also, the light receiver 25 is only indicated by a symbol and its outline is not drawn. FIG. 2(c) illustrates the arrangement of a plurality of light-receiving points Rjk when the area A in FIG. 2(b) is viewed from the illuminator 15 side. The light receiving point Rjk is actually set on the curved surface (xy plane) of the body surface Bs of the living body Bi, but is shown on a plane for explanation.

The light receiving location Rjk is a location on the body surface Bs that receives the emitted light OL. In this specification, the light-receiving point Rjk is described as a "position" that receives light, but may be described as a "small area" having a certain area including such a position. A set of light-receiving locations Rjk as a "small area" forms a map area, which is a range for mapping a DHR change amount, which will be described later. In the example of FIG. 2, 20 light-receiving points Rjk indicated by R11 to R45 are set in an arrangement of 4 rows and 5 columns, and a set of them is the map area.

The device 1 for identifying a suspected cancerous site includes a plurality of light receivers 25 .
The light receivers 25 are arranged at a plurality of light receiving points Rjk along the body surface Bs of the living body Bi when the apparatus 1 for identifying a suspected cancerous site and the site to be inspected INP are arranged in a predetermined relationship. It receives the emitted light OL emitted from the inspection site INP to the outside.

In the example of FIG. 2, the light receivers 25 are arranged at 20 light receiving locations Rjk indicated by R11 to R45. In addition, in the examples of FIGS. 1 and 2, a so-called transmission-type suspected cancer site identification device is described as an example. They are arranged so as to face each other.

Individual (discrete) light receiving elements may be configured as the respective "light receivers 25". Alternatively, a pixel unit element of a CCD (Charge Coupled Device) image sensor having a certain area may be configured as each "light receiver 25".

The photodetector 20 detects the emitted light OL received by the light receiver 25, converts it into an optical measurement signal (not shown), and outputs the optical measurement signal.
Specifically, the photodetector 20 may be configured to detect the intensity of light according to the wavelength (in other words, frequency) and output it as an optical measurement signal (a signal including a spectrum of received light intensity). For example, a spectrometer can be employed as photodetector 20 .
As for the photodetector 20, one common photodetector is connected to a plurality of light receivers 25 (see FIGS. 1 and 2). However, the specific configuration of the photodetector 20 is not limited to this, and individual photodetectors may be arranged so as to correspond to the plurality of light receivers 25, respectively.

(2) Pressure applying means 40
The apparatus 1 for identifying a suspected cancerous site includes pressure applying means 40 (see FIGS. 1 and 2).
The pressure application means 40 applies a given pressure to the inspection site INP. The pressure applying means 40 is configured by a mechanism that presses the living body Bi with the inner wall of the examination space 660 so that the pressure is applied to the living body Bi including the site to be examined INP accommodated in the examination space 660 approximately uniformly. You may
The "pressure" here is a so-called static pressure, for example, the pressure in a state where there is no influence of flow and fluctuation of moisture inside the breast Br.

The pressure application means 40 is connected to a pressure application control section (not shown) in the control calculation section 50, which will be described later, and operates according to instructions from the pressure application control section. A pressure application control unit (not shown) in the control calculation unit 50 issues instructions such as appropriately changing the timing of applying pressure, the magnitude of pressure, and a profile representing changes in the magnitude of pressure with respect to the application time. It is output to the application means 40 to control pressure application.

In this specification, the operating state in which a given pressure is applied to the inspection site INP is referred to as a "pressure application mode". Further, the state in which the pressure application by the pressure applying means 40 is released and the site to be inspected INP is released from the compulsory pressure will be referred to as a "pressure release mode".

In the pressure application mode, the cancerous suspected site identification device 1 applies a predetermined pressure to the site to be inspected INP. The degree of the "predetermined pressure" is preferably such that the flow of erythrocytes that are about to pass through new blood vessels is stagnated, but the flow of erythrocytes that are about to pass through capillaries of normal tissues is not blocked. . Furthermore, it is more preferable to apply a pressure within the range of 15 mmHg to 25 mmHg.

(3) Control calculation unit 50
FIG. 3 is a flowchart for explaining the control and calculation performed by the control calculation unit 50 and the cancer-occurrence-suspicious determination unit 60 of the first embodiment. FIG. 3(a) is a general flow diagram. FIG. 3(b) is a flowchart showing in detail only step S10 and/or step S20 for calculating the reduced hemoglobin ratio DHR.
The control calculation performed by the control calculation unit 50 will be described below mainly with reference to FIG.

(3-1) Overview of Control Calculation Unit 50 The device 1 for identifying a suspected cancerous site includes a control calculation unit 50 .
The control calculation unit 50 is connected to the photodetector 20 and receives an optical measurement signal (described later) from the photodetector 20 . Also, the control calculation unit 50 is connected to the pressure applying means 40 , the wavelength selector 30 and the light source 10 . Further, the control calculation unit 50 may be connected to display means 500 for displaying DHR variation map information (described later) generated by the control calculation unit 50 .
A signal relating to the irradiation light intensity Iinλi is supplied to the control calculation unit 50 from the outside. The signal related to the irradiation light intensity Iinλi is used when the control calculation unit 50 calculates the absorbance a corresponding to the specific wavelength (described later). This irradiation light intensity Iinλi may be given by drawing the irradiation light IL output from the light source 10 directly to the control calculation unit 50 side as a reference light. It may be given to the calculation unit 50 (see also FIGS. 1 and 2).

The control calculation unit 50 may be embodied by any device as long as it provides the control/calculation functions described below. For example, in addition to necessary conversion circuits (A/D conversion circuits, etc.), DSP (Digital Signal Processor), processors such as microcomputers, etc. are prepared, and programs describing algorithms related to control and calculation described below and related data are stored. The control calculation unit 50 may be implemented by being implemented in a processor and executing the program.

The control calculation unit 50 performs the above-described control related to pressure application, control related to wavelength selection, and control related to light irradiation (adjustment of magnitude of irradiation output, control of irradiation timing, etc.). The control calculation unit 50 also calculates the reduced hemoglobin ratio DHR for each light receiving point Rjk (S10, S20), and generates a DHR change amount map used for determining whether cancer is suspected (S30, S40).

(3-2) Calculation of reduced hemoglobin ratio DHR performed by control calculation unit 50 (S10, S20)
The control operation unit 50 calculates the ratio of reduced hemoglobin for each light receiving site Rjk in each of a pressure application mode for applying a predetermined pressure to the site under inspection INP and a pressure release mode for releasing the pressure on the site under inspection INP. Calculate the DHR.

The apparatus 1 for identifying suspected cancerous sites according to the first embodiment places the site under inspection INP in the pressure application mode to acquire the reduced hemoglobin ratio HDRp, and then places the site under inspection INP in the pressure release mode. By acquiring the reduced hemoglobin ratio HDRr, the DHR change amount for each light receiving point Rjk is calculated.
Specifically, first, as a “first measurement”, the emitted light OL is measured in the pressure application mode to calculate the reduced hemoglobin ratio DHR (S10), and the reduced hemoglobin ratio DHRp in the pressure application mode is calculated for each light receiving point Rjk. (D1). Next, as a “second measurement”, the emitted light OL is measured in the pressure release mode to calculate the reduced hemoglobin ratio DHR (S20), and the reduced hemoglobin ratio DHRr in the pressure release mode is acquired for each light receiving point Rjk (D2 ) (see also FIG. 5).

(3-3) Control/calculation until obtaining absorbance a Detailed control/calculation until obtaining the reduced hemoglobin ratio DHR for each light receiving point by the control calculation unit 50 is performed as follows (see FIG. 3(b) below). >>.

(a) Measurement of emitted light intensity Ioutλi at a specific wavelength (S2)
First, a wavelength λi (where i is a natural number) is selected as a specific wavelength (S201). Specifically, the notch of the optical path selector of the wavelength selector 30 is switched to the laser light source 10a. Next, irradiation of the irradiation light IL from the irradiator 15 toward the site to be inspected INP is started (S202). Accordingly, the light receiver 25 receives the emitted light OL, and the photodetector 20 outputs an optical measurement signal based on the emitted light OL received by the light receiver 25 (S203). Next, the emitted light intensity Ioutλi at the specific wavelength λi is extracted based on the optical measurement signal (S204). At this stage, the irradiation of the irradiation light IL may be finished. Among these steps, steps S203 and S204 are performed for each light receiving point Rjk.

(b) Calculation of absorbance ai at specific wavelength (S4)
Next, the absorbance ai at the specific wavelength λi is calculated based on the output light intensity Ioutλi at the specific wavelength of the output light OL and the irradiation light intensity Iinλi at the specific wavelength of the irradiation light IL extracted from the optical measurement signal (S4).
The output light intensity Ioutλi uses the value obtained in step S2, and the irradiation light intensity Iinλi uses an externally given value. Further, in calculating the absorbance ai, the formula of the Lambert-Beer law {here, the formula shown at the left end in the frame of S4 in FIG. 3(b)} is used. The calculation of the absorbance ai is performed for each light receiving point Rjk.

(c) Measurement of Emitted Light Intensity Ioutλ Using Multiple Wavelengths and Calculation of Absorbance a Next, a wavelength λi+1 different from the wavelength λi is reselected as a specific wavelength (S301). After that, irradiation of irradiation light IL with a new wavelength λi+1 is started (S302). The light receiver 25 receives the emitted light OL, and the photodetector 20 outputs an optical measurement signal based on the emitted light OL received by the light receiver 25 (S303). Next, the emitted light intensity Ioutλi+1 at the specific wavelength λi+1 is extracted based on the optical measurement signal (S304). Similarly, among these, steps S303 and S304 are performed for each light receiving point Rjk.
Then, the absorbance ai+1 at the specific wavelength λi+1 is calculated based on the output light intensity Ioutλi+1 at the specific wavelength of the output light OL extracted from the optical measurement signal and the irradiation light intensity Iinλi+1 at the specific wavelength of the irradiation light IL (here, , using the equation shown in the middle of the frame of S4 in FIG. 3(b)). The calculation of the absorbance ai+1 is performed for each light receiving point Rjk.
After that, the same control/calculation is repeated while changing the wavelength λ as the specific wavelength, that is, while increasing the value of i by 1 (see S2).

In this way, the control operation unit 50 outputs (a) the output at the specific wavelength while changing the wavelength of the specific wavelength for a plurality of specific wavelengths (which may be referred to as “multiple wavelengths” in this specification) that are different from each other. Measurement S2 of the incident light intensity Ioutλ and (b) calculation of the absorbance a at the specific wavelength are performed respectively.
As a result, absorbances (ai, ai+1, ai+2, . . . ) for multiple wavelengths (.lambda.i, .lambda.i+1, .lambda.i+2, .

In the characteristic absorption curve C1 of oxygenated hemoglobin and the characteristic absorption curve C2 of reduced hemoglobin, the cancer-causing-suspected-site identifying device 1 assumes that the wavelength at which the absorption coefficients of oxygenated hemoglobin and reduced hemoglobin are equal to λE is at least: Select one wavelength as a specific wavelength from wavelengths below λE, and select one wavelength from wavelengths exceeding λE (longer wavelengths than λE) as a specific wavelength, and absorbance at each selected wavelength It is preferable to calculate a respectively.
More preferably, the apparatus 1 for identifying suspected cancerous sites selects three or more different wavelengths as specific wavelengths, and calculates the absorbance a at each of the selected wavelengths.

(3-4) Details of reduced hemoglobin ratio DHR calculation (S8)
FIG. 4 is a diagram showing a characteristic absorption curve C1 of oxygenated hemoglobin and a characteristic absorption curve C2 of reduced hemoglobin. Here, the “characteristic absorption curve of oxygenated hemoglobin and the characteristic absorption curve of reduced hemoglobin” refer to the light absorption curve specific to oxygenated hemoglobin (see C1 in FIG. 4) and the light absorption curve specific to reduced hemoglobin (C2 in FIG. 4). shall mean.

Subsequently, the control calculation unit 50 calculates the absorbance (ai, ai+1, ai+2, . . . ) calculated for each specific wavelength (λi, λi+1, λi+2, . Based on the information and the reduced hemoglobin characteristic absorption curve information INF1, the reduced hemoglobin ratio DHR is calculated for each light receiving point Rjk (S8).

Specifically, the calculation of the reduced hemoglobin ratio DHR is performed as follows (see FIG. 4).
First, "characteristic absorption curve information of oxygenated hemoglobin and characteristic absorption curve information of reduced hemoglobin" corresponding to an intended specific wavelength is grasped from "characteristic absorption curve C1 of oxygenated hemoglobin and characteristic absorption curve C2 of reduced hemoglobin". When the wavelength at which the absorption coefficient of oxygenated hemoglobin and the absorption coefficient of reduced hemoglobin are equal is λE (around 800 nm in FIG. 4), for example, a wavelength around 700 nm is used as the specific wavelength λ1, and a wavelength around 880 nm as the specific wavelength λ2. , λE is selected as the specific wavelength λ3. The absorption coefficient of oxygenated hemoglobin (hereinafter referred to as "HbO2" for convenience) at λ1 is understood to be 0.3, and the absorption coefficient of reduced hemoglobin (hereinafter referred to as "Hb" for convenience) is understood to be 1.8. Similarly, the absorption coefficient of HbO2 at λ2 is 1.3 and the absorption coefficient of Hb is 0.8, and the absorption coefficient of HbO2 at λ3 is 0.85 and the absorption coefficient of Hb is 0.85. These are referred to as "characteristic absorption curve information of oxygenated hemoglobin and characteristic absorption curve information of reduced hemoglobin".
Let a1, a2, and a3 be the respective absorbances when the specific wavelengths are λ1, λ2, and λ3, respectively, and let the ratio of the number of reduced hemoglobin and the number of oxidized hemoglobin be x:y. It is possible to set up simultaneous equations such as Eq.
a1=1.8x+0.3y (1)
a2=0.8x+1.3y (2)
a3=0.85x+0.85y (3)
Subsequently, the absorbances a1, a2, and a3 measured and calculated for each specific wavelength are applied to the above simultaneous equations. The control calculation unit 50 can calculate the values of x and y corresponding to the light receiving point Rjk by solving the simultaneous equations.
Ultimately, using these calculated solutions of x and y, the reduced hemoglobin ratio DHR corresponding to the light receiving location Rjk can be calculated by the following equation (4).
Reduced hemoglobin ratio DHR=x/(x+y) (4)

The reduced hemoglobin ratio DHRp in the pressure application mode can be obtained by the control calculation unit 50 performing the above calculation in the pressure application mode (see D1 in FIG. 3A). Similarly, the reduced hemoglobin ratio DHRr in the pressure release mode can be obtained by the control calculation unit 50 performing the above calculation under the pressure release mode (D2).

(3-5) Generation of DHR variation map information performed by control calculation unit 50 (S30, S40)
(a) Calculation of DHR variation (S30)
The control calculation unit 50 calculates the "DHR change amount", which is the difference between the reduced hemoglobin ratio DHRp calculated in the pressure application mode and the reduced hemoglobin ratio DHRr calculated in the pressure release mode, for each light receiving point (FIG. 3). S30, D3 of (a)>>.

FIG. 5 is a diagram for explaining the measurement timing of absorbance, the calculation related to the reduced hemoglobin ratio DHR, and the DHR change amount map by the cancer-causing-suspected-site identifying device 1 according to the first embodiment.

By the control/calculation of (3-1) to (3-4) above, the value of the reduced hemoglobin ratio DHRp (hereinafter sometimes simply referred to as “DHRp”) in the pressure application mode and the pressure release mode for each light receiving point Rjk A value of the reduced hemoglobin ratio DHRr (hereinafter sometimes simply referred to as "DHRr") was obtained (see D1 and D2 in FIG. 3(a) and MAPp and MAPr in FIG. 5).
Based on these DHRp and DHRr, the control calculation unit 50 calculates the DHR change amount for each light receiving point Rjk by calculating the difference between DHRp and DHRr (S30 in FIG. 3A and See S30>>.

(b) Generation of DHR variation map information (S40)
The control calculation unit 50 creates a DHR change amount map MAPd representing a two-dimensional or three-dimensional distribution of the DHR change amount for each light receiving point Rjk based on the DHR change amount obtained corresponding to the light receiving point Rjk. to generate The control calculation unit 50 generates DHR variation map information representing the DHR variation map MAPd (see S40 and D4 in FIG. 3A and MAPd in FIG. 5).

The aspect of "DHR variation" may be a continuous numerical value, or may be represented by a level/stage/level/rank defined for each predetermined numerical range. good. In the DHR change amount map MAPd of FIG. 5, the DHR change amount is divided into four levels (Po1 to Po4) for convenience, from small to large. The type of shading is changed accordingly.

In FIG. 5, for the sake of convenience, a map MAPp of the reduced hemoglobin ratio DHRp in the pressure application mode is created, a map MAPr of the reduced hemoglobin ratio DHRr in the pressure release mode is created, and then a DHR variation map MAPd is created. An example is described. However, the specific configuration of the control calculation unit 50 is not limited to this. For example, instead of creating MAPp and MAPr, the DHR variation map MAPd may be created based on the DHR variation for each light receiving location Rjk, which is determined individually for each light receiving location Rjk.

(4) Cancer occurrence suspicion determination unit 60
The apparatus 1 for identifying a suspected cancerous site includes a suspected cancerous determination unit 60 (see FIGS. 1 and 2).
The cancer suspicion determination unit 60 identifies the location of the cancer suspicion site S based on the DHR variation map information.

Judgment of suspicion of cancer development is made by taking into consideration the condition of the subject, setting of inspection parameters by the device 1 for identifying a suspected cancerous site, a margin for avoiding overlooking of a suspected cancerous site, etc., and the absolute value of the DHR change amount. , the relative difference from the DHR variation of other sites, and the like. Ultimately, it largely depends on the doctor as to what point of view and what level of threshold is used to determine the presence or absence of a suspected cancerous site. However, since the apparatus 1 for identifying suspected cancerous sites has a higher S/N ratio than the conventional apparatus, as will be described later, it is possible to identify the suspected cancerous sites with a certain degree of accuracy. help.

Based on the DHR change amount map information MAPd, the cancer suspicion determination unit 60 determines a site where the DHR change amount is large (that is, a site where the reduced hemoglobin ratio DHR was low in the pressure release mode and the reduced hemoglobin ratio DHR in the pressure application mode). ) is assumed to be the presence of new blood vessels N, and is identified as the site S of suspected cancer development.

The cancer suspicion determination unit 60 may refer to the DHR variation map information MAPd and specify, as the cancer suspicion site S, a site having a DHR variation larger than a given "threshold".
For example, in the site to be inspected INP, there is a suspected cancerous site S at a position as shown in FIG. 2(b). is distributed.
Assume that the above "threshold" is set between the second level Po2 and the third level Po3. When extracting parts showing a DHR change amount larger than the "threshold" in the DHR change amount map MAPd, a part (third level Po3) corresponding to the light receiving points R23, R33, R34 and a part (fourth level Po3) corresponding to the light receiving point R24 are extracted. The level Po4) is extracted. In this case, the sites corresponding to the light-receiving sites R23, R33, R34, and R24 can be evaluated as sites with a high possibility of having the cancerous suspected site S. Furthermore, it can be evaluated that the site corresponding to the light receiving site R24 showing the fourth level Po4 with the largest DHR variation has a higher possibility of having a site S suspected of cancer development. The cancer suspicion determination unit 60 can specify the cancer suspicion site S based on these evaluation results.

For reference, the following is a supplementary explanation of the significance of specifying a suspected cancerous site based on the amount of DHR change in the light-receiving site Rjk.
As shown in FIG. 2(b), the irradiation light IL is emitted from the irradiator 15 to the inspection site INP. In this way, the light incident on the inspection site INP travels through the inspection site INP while being scattered in various directions. , does not necessarily directly reflect the projected image when the irradiator 15 and the light receiver 25 are linearly connected.
However, assuming that water, fat, etc., are uniformly distributed in the inspection site INP, a two-dimensional image (two-dimensional map) based on the emitted light received by the plurality of light receivers 25 , it is considered that the positional relationship of the cancerous suspected site S within the site to be inspected INP is generally reflected. For example, if the suspected cancerous site S exists in the vicinity of the center of the inspection site INP, the DHR variation map drawn based on the emitted light received by the photodetector 25 also shows a map area approximately in the center of the map area. It is thought that it will be displayed as a peculiar point in the vicinity.
Therefore, in the apparatus for identifying suspected cancerous sites 1 (examples in FIGS. 1 and 2), although the position/location of the suspected cancerous sites S in the depth direction is unknown, two-dimensional cancer occurrence in the DHR variation map is determined. The place/position of the suspected site S can be easily specified with the bundled resolution of the light receiving site Rjk.

3. Functions and effects of the device 1 for identifying a suspected cancerous site according to the first embodiment (1) Reduced hemoglobin ratio DHR calculated using multiple wavelengths
In the conventional apparatus for identifying suspected cancerous sites, it is also possible to calculate the reduced hemoglobin ratio DHR based only on the absorbance measured at one specific wavelength (hereinafter sometimes referred to as "single wavelength") under certain conditions. may be possible under
However, in this case, the calculated value of the reduced hemoglobin ratio DHR varies depending on the conditions. For example, assume that the absorbance a is measured at the wavelength λ1 shown in FIG. 4 to calculate the reduced hemoglobin ratio DHR. Considering the case where the emitted light is relatively dark, the absolute value of the emitted light intensity I is measured as a relatively small value, and the absorbance a calculated based thereon is calculated as a relatively high value. However, the reason why the absorbance a increased in this way is that the absorbance a as a whole increased because the living tissue is originally a tissue that is difficult to transmit light, or the reduced hemoglobin ratio DHR at the inspection site INP It cannot be determined whether the absorbance a is high because it is actually high. Even if the reduced hemoglobin ratio DHR is calculated, the value will contain a lot of errors.
Under these circumstances, when calculating the reduced hemoglobin ratio DHR using only the absorbance measured at a single wavelength, there is a limit to increasing the accuracy of the reduced hemoglobin ratio DHR.

On the other hand, in the apparatus for identifying a suspected cancerous site of the present invention, (a) at a specific wavelength based on the emitted light intensity at a specific wavelength of the emitted light extracted from the optical measurement signal and the irradiation light intensity at the specific wavelength of the irradiated light Absorbance is calculated for a plurality of specific wavelengths different from each other, and (b) Absorbance calculated for each specific wavelength different from each other, characteristic absorption curve information of oxygenated hemoglobin, and characteristics of reduced hemoglobin It is configured to calculate the reduced hemoglobin ratio DHR based on the absorption curve information.

As described above, the apparatus for identifying a suspected cancerous site 1 according to the first embodiment obtains the absorbance for a plurality of specific wavelengths different from each other, and calculates the reduced hemoglobin ratio DHR based on the plurality of absorbances. The reduced hemoglobin ratio DHR can be calculated with high accuracy without being affected by the absolute value (brightness/darkness) of the emitted light intensity Ioutλi on the light receiver side.
Therefore, according to the apparatus 1 for identifying a suspected cancerous site according to the first embodiment, it is possible to provide an apparatus for identifying a suspected cancerous site that has a higher S/N ratio than the conventional one and a higher detection accuracy of the suspected cancerous site than the conventional one. can be done.

(2) Measurement by pressure application mode and pressure release mode (2-1) Consideration of relationship between cancer cells, new blood vessels, reduced hemoglobin ratio DHR, and pressure application In general, cancer cells require a lot of nutrients and oxygen for their growth. It is known that new blood vessels are densely formed around cancer cells. Therefore, by discovering a site where new blood vessels are concentrated, the site near the discovered new blood vessel can be identified as a suspected cancerous site (relationship between cancer cells and new blood vessels).

As for the shape of the new blood vessel, the inside (lumen) of the new blood vessel has a very small inner diameter, and there are many narrow parts where a single erythrocyte can hardly pass through. In addition, the new blood vessels have an irregular tube shape with some parts that bend and twist in places, and are originally unsuitable for the flow of fluid (new blood vessels). shape knowledge).
Since the new blood vessel has such a shape, the inventors found that when the biological tissue including the new blood vessel is compressed (applied pressure), the inner side of the new blood vessel becomes narrower around the bent portion. , considers that the flow of red blood cells that try to pass through the new blood vessels is blocked. They also consider that new blood vessels are more likely to cause red blood cell stagnation due to pressure than normal capillaries.

When red blood cells become stagnant inside new blood vessels, the stagnant red blood cells are deprived of oxygen by nearby cancer cells (chronically oxygen-depleted), and oxygenated hemoglobin is converted to reduced hemoglobin at a high rate. It is considered that the reduced hemoglobin ratio DHR increases inside the new blood vessels.

Based on the above, the inventors presume that new blood vessels are present at sites where the reduced hemoglobin ratio DHR is particularly increased in response to compression (applied pressure) of the living tissue. It is considered that the vicinity of the estimated site can be specified as a suspected site of cancer development because there is a high possibility that cancer cells are present.

(2-2) Using the pressure application mode and pressure release mode to expose the site where new blood vessels exist (a) Problems when detecting new blood vessels based on the amount of total hemoglobin New blood vessels are formed around cancer cells. There is another theory that, due to the high density, the blood flow is higher and the total hemoglobin count is higher in the vicinity of the neoplastic tissue than in the normal tissue. According to this theory, it is possible to measure the blood flow, the total hemoglobin count, etc., without applying any particular pressure to the site to be inspected, and determine the site where these values are large as a suspected cancerous site. However, in this case, it may be difficult to determine whether the blood flow, total hemoglobin count, etc., are large because the site has capillaries of normal tissue, or whether the blood flow, total hemoglobin count, etc., are large due to the presence of new blood vessels. . In that case, there is a possibility of erroneously detecting new blood vessels even though the tissue is normal tissue (erroneous detection problem). So to speak, there is a possibility of picking up noise.

(b) Detection of New Blood Vessels by the Device 1 for Identifying a Suspected Cancer Site According to Embodiment 1 Consideration of the relationship between the ratio of reduced hemoglobin DHR and the application of pressure", it is configured as follows.
That is, the apparatus for identifying a suspected cancerous site 1 according to the first embodiment operates in a pressure application mode for applying a predetermined pressure to the site to be inspected and a pressure release mode for releasing the pressure on the site to be inspected INP. , the reduced hemoglobin ratio DHR is calculated for each light receiving point. Then, the DHR change amount, which is the difference between the reduced hemoglobin ratio DHRp calculated in the pressure application mode and the reduced hemoglobin ratio DHRr calculated in the pressure release mode, is calculated for each light receiving point.
As a result, the DHR change amount can be grasped with a resolution at least in units of light-receiving points Rjk.
Further, the apparatus 1 for identifying a suspected cancerous site is configured to generate DHR change amount map information representing a two-dimensional or three-dimensional distribution of the calculated DHR change amount for each light receiving site Rjk. As a result, the two-dimensional or three-dimensional distribution of the DHR change amount inside the inspected portion INP can be overviewed and relatively evaluated.
Furthermore, based on the DHR change map information MAPd, the apparatus for identifying a suspected cancerous site 1 detects a site where the DHR change amount is large (that is, a site where the reduced hemoglobin ratio DHR was low in the pressure release mode and the reduced hemoglobin ratio in the pressure application mode). The site where the hemoglobin ratio DHR is high) is assumed to be the presence of new blood vessels N, and is configured to be identified as the location of the suspected cancerous site S.

As described above, according to the apparatus for identifying a suspected cancerous site 1 according to the first embodiment, by applying a predetermined pressure to the site to be inspected, the reduced hemoglobin ratio DHR is limited only to the red blood cells stagnating in the new blood vessels. can increase That is, by applying pressure, when measuring the site to be inspected with a measure of the reduced hemoglobin ratio DHR, for example, the intensity of light absorption/strength of light scattering is 1/10, which is an adverse condition (Fig. Problems to be attempted], etc.), the signal (light absorption) can be extracted with high accuracy, and it is possible to highlight only the new blood vessels from the normal tissue.
Therefore, the apparatus 1 for identifying a suspected cancerous site according to the first embodiment has a higher S/N ratio than the conventional one and a higher detection accuracy for the suspected cancerous site than the conventional apparatus for identifying a suspected cancerous site.

(3) How to Select a Specific Wavelength The apparatus 1 for identifying a suspected cancerous site according to the first embodiment has the absorption coefficient of oxygenated hemoglobin and the absorption of reduced hemoglobin in the characteristic absorption curve C1 of oxygenated hemoglobin and the characteristic absorption curve C2 of reduced hemoglobin. Let λE be the wavelength at which the coefficients are equal, at least one wavelength is selected as a specific wavelength from among the wavelengths below λE, and one wavelength is specified from among the wavelengths exceeding λE (wavelengths longer than λE). The wavelengths are selected and the absorbance at each selected wavelength is calculated respectively.
With such a configuration, at least two wavelengths at the point where the magnitude relationship between the absorption coefficient of reduced hemoglobin and the absorption coefficient of oxygenated hemoglobin is reversed is selected as the specific wavelength, thereby further suppressing errors. It is possible to calculate the reduced hemoglobin ratio DHR with high accuracy.

Further, the apparatus 1 for identifying suspected cancerous sites according to the first embodiment selects three or more different wavelengths as specific wavelengths, and calculates the absorbance at each of the selected wavelengths.
With such a configuration, the reduced hemoglobin ratio DHR is calculated based on three or more conditional expressions, and it becomes possible to calculate the reduced hemoglobin ratio DHR with higher accuracy.

(4) Wavelength Selection by Switching a Plurality of Laser Light Sources The apparatus 1 for identifying a suspected cancerous site according to the first embodiment uses the light source 10 as the wavelength within the range of 700 nm to 1200 nm, and outputs intensities to wavelengths different from each other. , one of the plurality of laser light sources is selected, and the irradiation light IL based on the selected laser light source is applied to the inspection site INP A specific wavelength for which the absorbance a is to be calculated is selected by irradiating with .
With such a configuration, by selecting a laser light source having an output intensity peak at an intended wavelength from a plurality of laser light sources, it is relatively easy to select and set the wavelength at which the absorbance should be measured. becomes possible.

(5) The apparatus 1 for identifying a suspected cancerous site according to the first embodiment places the site to be inspected in the pressure application mode to acquire the reduced hemoglobin ratio HDRp, and then places the site to be inspected in the pressure release mode. By obtaining the reduced hemoglobin ratio HDRr, the DHR change amount for each light receiving point is calculated.
By obtaining the reduced hemoglobin ratio DHR in such order, the S/N ratio can be further increased. In addition, it is also possible to first find a site with a relatively high reduced hemoglobin ratio HDRp in the pressure application mode, and then obtain the reduced hemoglobin ratio HDRr particularly precisely for that site in the pressure release mode, thereby improving the detection accuracy. can be done.

Note that the time t1 (FIG. 5) from the start of pressure application until the optical measurement is performed is the time until most of the red blood cells trying to pass through the new blood vessel N become stagnant in the new blood vessel N. is preferably the time of This time t1 can be appropriately set depending on which part of the living body Bi is inspected and the magnitude of the pressure applied. You can set it in
On the other hand, it is preferable that the time t2 (FIG. 5) from the time when the first measurement is completed to the time when the pressure application mode is shifted to the pressure release mode is as short as possible. This is because the inspection can be performed under the same conditions as much as possible before the condition of the person to be inspected or the condition of the external environment changes.
The time t3 from the time when the pressure application mode is shifted to the pressure release mode to the time when the second measurement is started is necessary for the behavior of the red blood cells in the new blood vessels to return to a normal state similar to the state in which no pressure is applied. It is preferable to set the minimum time.

(6) The apparatus 1 for identifying a suspected cancerous site according to the first embodiment applies a pressure within a range of 15 mmHg to 25 mmHg to the site to be inspected in the pressure application mode.

If the pressure applied to the inspection site INP in the pressure application mode is less than 15 mmHg, red blood cells in the new blood vessels cannot be sufficiently stagnated. In other words, deoxidation cannot be promoted sufficiently. On the other hand, if it exceeds 25 mmHg, there is a risk that even erythrocytes in the capillaries of normal tissue will stagnate and become deoxygenated.
Therefore, by applying a pressure within the range of 15 mmHg to 25 mmHg as the degree of pressure applied to the inspection site INP, it is possible to increase the reduced hemoglobin ratio DHR only for red blood cells present inside the new blood vessels. can be done.

(7) For Breast Cancer Examination The device 1 for specifying a suspected cancerous site according to the first embodiment is to specify a suspected cancerous site S of breast cancer by applying part or all of the breast Br as the site to be inspected INP. , is preferred.

Since the breast Br is mostly soft tissue composed of water and fat, light is likely to penetrate/scatter relatively deeply inside the breast Br. In addition, since the external shape of the breast is easily deformed, the breast can be easily arranged in the examination space 660 in which the irradiator 15, the light receiver 25, the pressure applying means 40 and the like are arranged. Alternatively, the irradiator 15, the light receiver 25, the pressure applying means 40, etc. can be easily attached to the breast. In addition, in the current situation where most of the breast cancer examinations in the medical field are conducted by X-ray mammography, the apparatus 1 for identifying a suspected cancerous site according to the first embodiment causes little damage to the examinee and prevents the occurrence of cancer. The point that the detection accuracy of the suspected part S is high is attractive. Therefore, the "breast" is suitable as an object to be inspected by the apparatus 1 for identifying a suspected cancerous site, and the apparatus 1 for identifying a suspected cancerous site can also accurately specify a "breast cancer" suspected cancerous site S. can.

[Embodiment 2]
FIG. 6 is a block diagram for explaining the apparatus 2 for identifying a suspected cancerous site according to the second embodiment. FIG. 6(a) is a block diagram of the device 2 for specifying a suspected cancerous site. FIG. 6B is a diagram for explaining the arrangement and irradiation sequence of the plurality of irradiators 15a to 15t. Constituent elements common to those of the first embodiment are denoted by common reference numerals, and descriptions thereof are omitted.

The apparatus 2 for identifying a suspected cancerous site according to the second embodiment basically has the same configuration as the apparatus 1 for identifying a suspected cancerous site according to the first embodiment, but the configuration on the side that irradiates the irradiation light IL is the same as that of the embodiment. 1 is different from the apparatus 1 for identifying a suspected cancerous site according to 1.
That is, as shown in FIG. 6(a), the apparatus 2 for identifying a suspected cancerous site according to the second embodiment includes a plurality of irradiators 15a to 15t and, in addition, a light projection scanning means .
A plurality of irradiators 15a to 15t are arranged at a plurality of candidate light projection locations Pjk along the body surface Bs of the living body Bi. The array of candidate light projection locations Pjk is set to correspond to the array of light receiving locations Rjk. In the example of FIG. 6B, 20 positions indicated by P11 to P45 are set.
The light projection scanning means 70 is composed of, for example, an optical path selector (no reference numeral). The optical path selector has a plurality of notches connected to the respective illuminators 15a to 15t and a common terminal connected to the wavelength selector 30 (see FIG. 6A).

By switching the notch of the light projection scanning means 70 (optical path selector), the irradiation position to which the irradiation light IL is applied can be sequentially selected from a plurality of candidate light projection positions P11 to P45. For example, as shown in FIG. 6B, after irradiation from the irradiator 15a of P11 and necessary measurement are performed, the irradiation point is switched to P12 by the light projection scanning means 70 (optical path selector), and then the irradiation of P12 is performed. Irradiation may be performed sequentially by switching irradiation locations one after another, such as irradiating from the device 15b and performing necessary measurements.

The apparatus 2 for identifying a suspected cancerous site according to the second embodiment further includes a plurality of irradiators 15a to 15t and a light projection scanning means 70, and is configured to perform the irradiation sequence as described above. A wider range of the inspected site INP can be inspected than when the inspection is performed by the irradiator 15 of .

Note that the apparatus 2 for identifying a suspected cancerous site according to the second embodiment has the same configuration as the apparatus 1 for identifying a suspected cancerous site according to the first embodiment except for the configuration on the side that irradiates the irradiation light IL. Therefore, among the effects of the device for identifying a suspected cancerous site 1 according to the first embodiment, the corresponding effects are similarly obtained.

[Embodiment 3]
FIG. 7 is a block diagram for explaining the cancer-occurring-suspicious site identification device 3 according to the third embodiment. FIG. 8 is a diagram for explaining the data measurement unit and image reconstruction algorithm of diffuse optical tomography. In FIG. 8, the upper half of the range labeled "time-resolved measurement" corresponds to the data measurement unit, and the lower half labeled "inverse problem calculation" corresponds to the image reconstruction algorithm. Yes. Components common to those of Embodiments 1 and 2 are denoted by common reference numerals, and descriptions thereof are omitted.

The apparatus for identifying a suspected cancerous site 3 according to the third embodiment basically has the same configuration as the apparatuses for identifying a suspected cancerous site 1 and 2 according to the first and second embodiments. It is different from the suspected cancerous site identification devices 1 and 2 according to the first and second embodiments in that DHR variation map information representing a three-dimensional distribution is generated by calculation. The apparatus 3 for identifying a suspected cancerous site according to Embodiment 3 will be described below with reference to FIGS. .

(1) Basic configuration of the suspected cancer site identification device 3 The laser light sources (10a′, 10b′, 10c′, . A light source.
The apparatus 3 for identifying suspected cancerous sites (a) receives an optical measurement signal output from the photodetector 20 based on the irradiation timing of a given pulsed laser beam, and measures the absorbance for each specific wavelength based on the optical measurement signal. The profile PRAλi is calculated for each of a plurality of specific wavelengths λi that are different from each other, and (b) the profile PRdhr of the ratio of reduced hemoglobin DHR for each light-receiving point is calculated based on the absorbance profile PRAλi for each specific wavelength. This is performed for each light receiving point Rjk.
Next, the cancerous suspected site identification device 3 performs calculation by diffuse optical tomography based on the profile PRdhr of the reduced hemoglobin ratio DHR for each light receiving site Rjk, and obtains the distribution of the DHR change amount at the inspection site INP as the DHR change amount map information. Reconstruct as D4'.
The device 3 for identifying the suspected cancerous site identifies the location of the suspected cancerous site S based on the DHR variation map information D4' (see FIG. 7).
It should be noted that the term "profile" as used herein refers to the change history of the physical quantity with consideration given to the time factor.

(2) Diffuse Optical Tomography Diffuse optical tomography is a technique for obtaining tomographic images of living tissue mainly using near-infrared light. In order to realize diffuse optical tomography, a data measurement unit and an image reconstruction algorithm are roughly classified (see Non-Patent Document 2).

(a) Data measurement unit Generally, in the data measurement unit in diffuse optical tomography, light is incident on a certain point on the target biological surface, propagates while being scattered and absorbed in the biological body, and appears again on the biological surface. Detect light at many points simultaneously. Similar measurements are performed while changing the incident point, and many data are collected (see FIG. 8).
In the apparatus 3 for identifying suspected cancerous sites according to the third embodiment, as shown in FIG. It consists of On the other hand, the function of detecting the light that has reappeared on the surface of the living body at many points is constituted by a plurality of light receivers 25, the photodetector 20, and part of the control/calculation unit 50 (if necessary).

(b) Acquisition of Profile PRdhr of Reduced Hemoglobin Ratio DHR The control calculation unit 50 partially includes a profile calculation unit 52 .
The profile calculator 52 calculates optical measurement signals from the plurality of light receivers 25 and the photodetectors 20 based on the irradiation timing of the irradiation light IL from the light source 10 (laser light sources 10a′, 10b′, 10c′, . . . ). A profile PRIi of input and output light intensity is recorded for each specific wavelength.
Next, an absorbance profile PRAλi for each specific wavelength is calculated based on the profile PRIi of the emitted light intensity for each specific wavelength and the profile PRIi of the irradiation light intensity Iinλi.
Next, based on the absorbance profile PRAλi for each specific wavelength, the reduced hemoglobin ratio DHR profile PRdhr is calculated.
The principle of calculating the reduced hemoglobin ratio DHR at each time is the same as that of Embodiment 1. Specifically, the absorbance value at each specific wavelength at a certain time (acquirable from the absorbance profile PRAλi for each specific wavelength) and , the reduced hemoglobin ratio DHR is calculated based on the absorbance of Hb and the absorbance of HbO2 at a specific wavelength. A profile PRdhr of the reduced hemoglobin ratio DHR can be obtained by performing such calculations at predetermined time intervals and plotting them along the time series.
The profile calculators 52 ₁ , 52 ₂ , 52 ₃ , . . . perform the above control/calculation for each light receiving point Rjk to obtain the profile PRdhr of the reduced hemoglobin ratio DHR for each light receiving point Rjk.

(c) In general, an image reconstruction algorithm in diffuse optical tomography numerically solves an intra-vivo light propagation model assuming an optical characteristic value distribution of the living body (forward problem). If the result is compared with the measurement data and they match, it is considered that the assumed optical characteristic value distribution is correct and that the image has been reconstructed. If they do not match, the optical characteristic value distribution is re-assumed, the forward problem is solved again, and this operation is repeated until they match (inverse problem) (see FIG. 8).
In the apparatus 3 for identifying a suspected cancerous site according to the third embodiment, this function is implemented by a tomography calculation unit 55, as shown in FIG. The tomography calculation unit 55 inputs the profile PRdhr of the reduced hemoglobin ratio DHR obtained for each light-receiving location in the above (b), repeats the inverse problem calculation based on these (see FIG. 8), and determines the inspection site INP Reconstruct the distribution of the reduced hemoglobin ratio DHR in .

(3) DHR change amount map The distribution of the reduced hemoglobin ratio DHRp in the pressure application mode is obtained by performing the control/calculation of (2) above by the profile calculation unit 52 and the tomography calculation unit 55 in the pressure application mode. In addition, the distribution of the reduced hemoglobin ratio DHRr in the pressure release mode is obtained by the profile calculation unit 52 and the tomography calculation unit 55 performing the control/calculation of (2) above in the pressure release mode.
Next, at each predetermined coordinate within the site to be inspected INP, a calculation is performed to obtain the difference between the reduced hemoglobin ratios in these two modes, thereby obtaining the DHR variation at each coordinate.
A DHR variation map within the inspection site INP is reconstructed based on the DHR variation at each of these coordinates. Information for expressing the DHR variation map is DHR variation map information D4' (three-dimensional imaging information in the third embodiment).
The cancer suspicion determination unit 60 specifies the location of the cancer suspicion site S based on the DHR variation map information D4'.

According to the apparatus 3 for identifying a suspected cancerous site according to the third embodiment, DHR variation map information obtained by reconstructing the three-dimensional distribution of DHR variation by diffuse optical tomography can be obtained. The distribution of the amount of change can be viewed three-dimensionally (for example, also in the depth direction between the irradiator and the light receiver) and relatively evaluated.
As an example, the display means 500 in FIG. 7 displays the distribution of the DHR change amount inside the inspection site INP as a three-dimensional imaging, so that the DHR change amount can be viewed three-dimensionally and relatively evaluated. can. In the drawing, cross sections parallel to the irradiation direction of the irradiation light IL are hierarchically shown as SC1, SC2, and SC3. Also, the cross sections perpendicular to the irradiation direction of the irradiation light IL are shown hierarchically as SC4, SC5, and SC6. In this manner, the DHR change amount within the inspected site INP can be evaluated from various perspectives.
Therefore, according to the apparatus 3 for identifying a suspected cancerous site according to the third embodiment, it is possible to identify the position of the suspected cancerous site with higher accuracy.

In addition, the cancerous-suspected-site-identifying device 3 according to the third embodiment has the same configuration as the cancerous-suspected-site-identifying devices 1 and 2 according to the first and second embodiments except for the features described above. Therefore, among the effects of the devices 1 and 2 for identifying a suspected cancerous site according to the first and second embodiments, the same effects are obtained.

[Modification]
Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments. It can be implemented in various aspects without departing from the spirit thereof, and for example, the following modifications are also possible.

(1) The number, material, shape, position, size, and the like of the constituent elements described in each embodiment are examples, and can be changed within a range that does not impair the effects of the present invention.

(2) In each embodiment, the wavelength selector 30 is configured as an optical path selector, selects one of a plurality of laser light sources, and emits the irradiation light IL based on the selected laser light source to the inspection site INP. By irradiating , the wavelength as a specific wavelength was switched. However, the invention is not limited to this. For example, the light source 10′ may be configured with a halogen lamp or the like that outputs continuous light having output intensity at least at a plurality of specific wavelengths, and a bandpass filter may be used on the light receiving side to extract only light in a specific range of wavelengths. .
Specifically, as shown in FIG. 9, the apparatus 1' for identifying a suspected cancerous site further includes a plurality of bandpass filters 35a and 35b that pass light in mutually different wavelength bands. Any one of 35b may be selected and the selected band-pass filter may be arranged in front of the light receiver 25 (Modification 1).
In addition, FIG. 9 is a block diagram of a main part shown for explaining the apparatus 1′ for identifying a suspected cancerous site according to Modification 1. As shown in FIG.

According to Modification 1, the wavelength at which the absorbance should be measured is selected and set by selecting and switching the band-pass filter in the preceding stage of the light receiver in this way, so one type of light source is prepared. Since it is sufficient to connect the light source to the illuminator, the light projection side (light source and illuminator) can be configured simply and economically.

(3) In each embodiment, the test site INP is placed in the pressure application mode as the first measurement to obtain the reduced hemoglobin ratio HDRp, and then the test site INP is placed in the pressure release mode as the second measurement. Although the reduced hemoglobin ratio HDRr was obtained by setting the ratio, the present invention is not limited to this.
That is, as shown in FIG. 10, the site under test INP is placed under the pressure release mode as the first measurement to obtain the reduced hemoglobin ratio HDRr, and then the site under test INP is placed under the pressure application mode as the second measurement. (Modification 2). In this case, the time t4 from the time when the first measurement is completed to the time when the pressure release mode is switched to the pressure application mode should be as short as possible. t5 is treated the same as t1 in FIG. That is, it is preferable that it is the time until most of the red blood cells that are about to pass through the new blood vessel N become stagnant in the new blood vessel N.
10A and 10B are diagrams shown for explaining the measurement timing of the absorbance as Modified Example 2. FIG.

(4) In the drawings for explaining each embodiment and Modifications 1 and 2, the pressure applied to the inspection site INP in the pressure application mode is constant. However, the present invention is not limited to this. For example, the pressure may be changed over time instead of being constant. A pressure application profile capable of efficiently stagnating only erythrocytes in new blood vessels can be appropriately selected.

(5) In the second embodiment, the light projecting scanning means 70 is configured by optical path selectors connected to a plurality of illuminators 15 (sequential lighting type scanning). However, the invention is not limited to this. For example, although not shown, the light projection scanning means may be configured with a mechanism for physically moving the irradiator 15 along the candidate light projection locations Pi (moving scanning). By sequentially irradiating the irradiation light IL while moving the irradiator 15, the irradiated portion can be scanned.
Further, for example, although illustration is omitted, the light projecting scanning means may be configured with a mechanism for changing the attitude of the illuminator 15 while the position of the illuminator 15 is fixed (swing type scanning). By sequentially irradiating the irradiation light IL while changing the attitude of the irradiator 15, the irradiated part can be scanned.
Further, the light projecting scanning means 70 may be configured by combining the sequential lighting type scanning, the moving type scanning, and the swinging type scanning.

(6) The cancer suspicion judging unit 60 of each embodiment judged a site where the DHR change amount is higher than a given "threshold" as a cancer suspicion site S, and specified the location. That is, the determination was made based on the absolute value of the DHR change amount. However, the invention is not limited to this.
For example, it may be determined by making a relative comparison of DHR change amounts. That is, based on the amount of DHR change at the portion where the amount of DHR change is the smallest (minimum amount of DHR change), a site where the amount of DHR change is a predetermined multiple or more of the minimum amount of DHR change is determined to be a suspected cancerous site S. You may
In addition, the amount of change in DHR of normal tissue is sample-measured in advance, and a site where the amount of change in DHR is a predetermined multiple or more of the amount of change in DHR in normal tissue in the main measurement, which is a regular examination, is designated as a suspected cancerous site S. You can judge.

(7) The cancer suspicion determining unit 60 of each embodiment determined the cancer suspicion site S based on the narrowly defined DHR change amount and specified the location. However, the invention is not limited to this.
For example, the DHR is continuously recorded for each light receiving point Rjk for a predetermined time (for example, 20 to 30 seconds) after the pressure application is started in the pressure application mode, and then the change in the DHR over time The method/change pattern (DHR change profile) can be grasped, the site where the DHR change profile is characteristic is specified, and the site is determined as the suspected cancerous site S. Such a DHR change profile is also included in the concept of "DHR change amount" in the present invention, and a device having such a configuration is equivalent to the suspected cancerous site identification device according to the present invention.

(8) The apparatus 1, 2, and 3 for identifying a suspected cancerous site of each embodiment are described using a so-called transmissive optical system as an example, and the light receiver 25 faces the irradiator 15 across the inspection site INP. are arranged so that However, the invention is not limited to this.
For example, as shown in FIG. 11, the apparatus 4 for identifying suspected cancerous sites has a so-called reflective optical system in which a photodetector 25 is paired with an irradiator 15 and placed near the irradiator 15. (Modification 3).
FIG. 11 is a block diagram of main parts for explaining the apparatus 4 for identifying a suspected cancerous site according to Modification 3. As shown in FIG. In the figure, only the illuminators 15A, 15B, 15c, the light receivers 25A, 25B, 25C, and the pressure application means 40 are shown, and the other components are omitted.

(9) The apparatuses 1, 2, and 3 for identifying a suspected cancerous site according to the first, second, and third embodiments can also be developed as a method for identifying a suspected cancerous site having the same characteristics in each processing step.

(10) In each embodiment, human breast cancer is taken up as the suspected cancerous site S, and the case of discovering and specifying breast cancer has been exemplified and explained. However, the invention is not limited to this. The apparatus for identifying suspected cancerous sites of the present invention can also be configured as an apparatus for discovering and identifying cancers other than breast cancer. In addition, it is possible to construct an apparatus that is applied to cancers of animals (living bodies) other than humans.

1, 1', 2, 3, 4... cancerous suspected site identification device, 10, 10'... light source, 10a, 10a', 10b, 10b', 10c, 10c'... laser light source, 15, 15a to 15t... irradiation Device 17 Light guide 20 Photodetector 25 Photodetector 30 Wavelength selector 35a, 35b Bandpass filter 40 Pressure application means 50 Control calculation unit 52 Profile calculation unit 55 Tomography calculation unit 60 Cancer occurrence suspicion determination unit 70 Light projection scanning means 500 Display means 660 Examination space

Claims (9)

A suspected cancerous site identification device for identifying a suspected cancerous site by irradiating a test site of a living body with irradiation light and analyzing the emitted light emitted from the test site to the outside,
a light source that outputs said irradiating light having an output intensity at least at a specific wavelength within the range of 700 nm to 1200 nm;
an irradiator that is optically connected to the light source and irradiates the irradiation light toward the inspection site;
a plurality of light receivers respectively arranged at a plurality of light receiving locations along the body surface of the living body and receiving the emitted light emitted from the inspection site to the outside;
a photodetector that detects the emitted light received by the photoreceiver, converts it into an optical measurement signal, and outputs the optical measurement signal;
The device for identifying a suspected cancerous site,
In each of a pressure application mode in which a predetermined pressure is applied to the inspection site and a pressure release mode in which pressure on the inspection site is released, (a) the emitted light extracted from the optical measurement signal Calculating the absorbance at the specific wavelength based on the emitted light intensity at the specific wavelength of and the irradiation light intensity at the specific wavelength of the irradiation light is performed for each of the plurality of specific wavelengths different from each other, ( b) calculating the reduced hemoglobin ratio DHR based on the absorbance calculated for each of the specific wavelengths different from each other, the characteristic absorption curve information of oxygenated hemoglobin, and the characteristic absorption curve information of reduced hemoglobin for each light receiving point; go to
calculating a DHR change amount, which is a difference between the reduced hemoglobin ratio DHRp calculated in the pressure application mode and the reduced hemoglobin ratio DHRr calculated in the pressure release mode, for each of the light receiving points;
generating DHR change amount map information representing a two-dimensional or three-dimensional distribution of the DHR change amount for each of the calculated light receiving points;
Identifying the location of a suspected cancerous site based on the DHR change map information;
An apparatus for specifying a suspected cancerous site, characterized by: The device for identifying a suspected cancerous site,
By placing the inspection site under the pressure application mode to obtain the reduced hemoglobin ratio HDRp and then placing the inspection site under the pressure release mode to obtain the reduced hemoglobin ratio HDRr, calculating the DHR change amount for each light receiving point,
The device for specifying a suspected cancerous site according to claim 1, characterized in that: The device for identifying a suspected cancerous site,
In the pressure application mode, a pressure within a range of 15 mmHg to 25 mmHg is applied to the inspection site,
3. The device for specifying a suspected cancerous site according to claim 1 or 2, characterized in that: The device for identifying a suspected cancerous site,
In the characteristic absorption curve of oxygenated hemoglobin and the characteristic absorption curve of reduced hemoglobin, if the wavelength at which the absorption coefficient of oxygenated hemoglobin and the absorption coefficient of reduced hemoglobin are equal is defined as λE,
At least one wavelength is selected as the specific wavelength from wavelengths equal to or less than λE, and one wavelength is selected from wavelengths exceeding λE as the specific wavelength, and the absorbance at each of the selected wavelengths is measured. is to calculate,
4. The device for specifying a suspected cancerous site according to any one of claims 1 to 3, characterized in that: The device for identifying a suspected cancerous site,
Three or more wavelengths different from each other are selected as the specific wavelengths, and the absorbance at each selected wavelength is calculated,
5. The apparatus for specifying a suspected cancerous site according to any one of claims 1 to 4, characterized in that: The device for identifying a suspected cancerous site,
As the light source, a plurality of laser light sources that output the irradiation light having output intensity peaks at wavelengths different from each other and having a wavelength within the range of 700 nm to 1200 nm,
By selecting one of the plurality of laser light sources and irradiating the inspection site with the irradiation light based on the selected laser light source, the specific wavelength for which the absorbance is to be calculated is determined. is the one to choose,
6. The device for specifying a suspected cancerous site according to any one of claims 1 to 5, characterized in that: The device for identifying a suspected cancerous site,
further comprising a plurality of bandpass filters that pass light in different wavelength ranges;
any one of the plurality of band-pass filters is selected, and the selected band-pass filter is arranged in front of the light receiver;
6. The device for specifying a suspected cancerous site according to any one of claims 1 to 5, characterized in that: The laser light source is a pulsed laser light source that outputs pulsed laser light as the irradiation light,
The device for identifying a suspected cancerous site,
(a) inputting the optical measurement signal output by the photodetector based on the irradiation timing of the given pulsed laser light, and calculating the absorbance profile for each specific wavelength based on the optical measurement signal; and (b) calculating a profile of the reduced hemoglobin ratio DHR for each of the light receiving locations based on the absorbance profile for each of the specific wavelengths. go point by point,
calculating by diffuse optical tomography based on the profile of the reduced hemoglobin ratio DHR for each of the light-receiving points, and reconstructing the distribution of the DHR change amount in the inspection site as the DHR change amount map information;
Identifying the location of a suspected cancerous site based on the DHR change map information;
The device for specifying a suspected cancerous site according to claim 6, characterized in that: The device for identifying a suspected cancerous site,
Part or all of the breast is applied as the site to be inspected to identify a suspected site of breast cancer.
The device for specifying a suspected cancerous site according to any one of claims 1 to 8, characterized in that:

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