WO2018193526A1

WO2018193526A1 - Blood vessel identification apparatus and observation system

Info

Publication number: WO2018193526A1
Application number: PCT/JP2017/015616
Authority: WO
Inventors: 武史渡邉
Original assignee: オリンパス株式会社
Priority date: 2017-04-18
Filing date: 2017-04-18
Publication date: 2018-10-25

Abstract

A blood vessel identification apparatus (100) is provided with: a laser beam irradiation unit (6) that irradiates a deep part (C) of a tissue with a laser beam; a spectrum acquisition unit (7, 3, 10) that acquires real-time Doppler spectra based on scattered light from the tissue; a storage unit (10) that stores the Doppler spectrum of a thin blood vessel (D1) that is in the surface layer (B) of the tissue; an analysis unit (11) that separates the Doppler spectrum of the blood vessel (D1) included in the real-time Doppler spectra by using the Doppler spectrum of the blood vessel (D1) stored in the storage unit (10); and a blood vessel determination unit (12) that determines whether there is a thick blood vessel (D2) in the deep part (C) on the basis of the real-time Doppler spectra from which the Doppler spectrum of the blood vessel (D1) has been separated.

Description

Blood vessel recognition device and observation system

The present invention relates to a blood vessel recognition device and an observation system.

In the surgical treatment of tissue, it is important that the surgeon accurately recognizes the presence of blood vessels hidden inside the tissue and performs treatment so as to avoid the blood vessels. Therefore, an apparatus having a function of optically detecting a blood vessel existing in a tissue by a laser Doppler method is known (for example, see Patent Document 1). The light scattered by the blood in the blood vessel undergoes a frequency shift according to the blood flow speed, and the average frequency of the Doppler spectrum of the scattered light has a correlation with the blood flow speed. The speed of blood flow is approximately proportional to the thickness of the blood vessel. In Patent Document 1, the thickness of a blood vessel is estimated based on the average frequency of the Doppler spectrum of scattered light.

International Publication No. 2016/170636

When a thin blood vessel and a thick blood vessel are present at the same depth, there is a clear difference in the average frequency of the Doppler spectrum between the thin blood vessel and the thick blood vessel, so that the thin blood vessel and the thick blood vessel can be distinguished and recognized. . However, many thin blood vessels are present in the surface layer including the surface of the tissue, and many thick blood vessels are present in deeper portions than the surface layer. It is difficult to distinguish such a thin blood vessel from the surface layer and a deep blood vessel based on the average frequency of the Doppler spectrum.

That is, laser light and scattered light are attenuated by scattering or the like while propagating between the surface of the tissue and a deep blood vessel, so that the intensity of the entire Doppler spectrum is lowered. As a result, the average frequency of the Doppler spectrum of the deep thick blood vessel shifts to the lower frequency side and becomes close to the average frequency of the Doppler spectrum of the thin blood vessel on the surface layer, and the average between the deep blood vessel and the thin blood vessel on the surface layer The frequency difference is reduced.

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a blood vessel recognition device and an observation system that can recognize a thick blood vessel in a deep part from a blood vessel having a thin surface layer.

In order to achieve the above object, the present invention provides the following means.
A first aspect of the present invention is a blood vessel recognition device for recognizing a thick blood vessel existing in a deep part of a tissue in a living body, and a laser light irradiation unit that irradiates the tissue with laser light that can reach the deep part; Compared to the thick blood vessel, a spectrum acquisition unit that acquires a time waveform of the intensity of scattered light generated in the tissue by irradiation with the laser light, and obtains a real-time Doppler spectrum by Fourier transforming the acquired time waveform The storage unit that stores the Doppler spectrum of the thin blood vessel on the surface layer of the tissue having a small diameter, and the real spectrum acquired by the spectrum acquisition unit using the Doppler spectrum of the thin blood vessel on the surface layer stored in the storage unit. An analysis unit that separates the Doppler spectrum of the thin blood vessel in the surface layer included in the temporal Doppler spectrum, and the analysis unit Tsu based on puller spectrum separated the real time Doppler spectrum is a vascular recognition device and a determining vascular determining unit whether said thick blood vessel in the deep is present.

According to the first aspect of the present invention, when the laser light is irradiated from the laser light irradiation unit to the deep part of the tissue in the living body, the real-time Doppler spectrum based on the scattered light generated by the laser light irradiation is converted into the spectrum acquisition unit. Obtained by. Real-time Doppler spectra can include superficial thin blood vessel Doppler spectra and deep thick blood vessel Doppler spectra. The Doppler spectrum of the thin blood vessel on the surface layer is separated from the real-time Doppler spectrum by the analysis unit using the Doppler spectrum of the thin blood vessel on the surface layer stored in the storage unit.

Thus, when the real-time Doppler spectrum includes a deep-blood vessel Doppler spectrum, the deep-blood vessel Doppler spectrum is extracted. Accordingly, the blood vessel determination unit can determine the presence or absence of a deep thick blood vessel based on the real-time Doppler spectrum after the surface thin blood vessel Doppler spectrum has been separated. And can be recognized separately.

In the first aspect, the storage unit stores a first base spectrum, which is a Doppler spectrum of a thin blood vessel in the surface layer, and a second base spectrum, which is a Doppler spectrum of a deep blood vessel, and performs the analysis. Calculating a coefficient of the second base spectrum in the linear sum when the difference between the real-time Doppler spectrum and the linear sum of the first base spectrum and the second base spectrum is minimized, The blood vessel determination unit may determine whether or not the thick blood vessel exists in the deep portion based on the coefficient of the second base spectrum calculated by the analysis unit.

The real-time Doppler spectrum acquired by the spectrum acquisition unit is expressed as a linear sum of the first base spectrum and the second base spectrum. Then, using the combination of the coefficient values of the first and second basis spectra when the difference between the real-time Doppler spectrum and the linear sum is minimized, the Doppler spectrum of the thin blood vessels in the surface layer included in the real-time Doppler spectrum and Deep Doppler spectra of thick blood vessels can be separated from each other. Here, since the coefficient of the second basis spectrum represents the magnitude of the contribution of the deep thick blood vessel in the real-time Doppler spectrum, the presence or absence of the deep thick blood vessel is determined based on the value of the coefficient of the second base spectrum. Can be determined.

In the first aspect, the laser beam irradiation unit sequentially irradiates the tissue with the first laser beam that reaches only the surface layer and the second laser beam that reaches the deep portion, and acquires the spectrum. Sequentially obtains a first real-time Doppler spectrum based on the scattered light caused by the irradiation with the first laser light and a second real-time Doppler spectrum based on the scattered light caused by the irradiation with the second laser light. The storage unit stores the first real-time Doppler spectrum as the Doppler spectrum of the thin blood vessel on the surface layer, and the analysis unit converts the first real-time Doppler spectrum into the second real-time Doppler spectrum. Estimating the Doppler spectrum of the thin blood vessels contained in the surface layer, and calculating the estimated Doppler spectrum of the thin blood vessels in the surface layer. Calculating a difference spectrum by subtracting the real-time Doppler spectrum, the blood vessel determining unit, based on the calculated difference spectrum, it may be determined whether the thick blood vessel in the deep is present.

The second real-time Doppler spectrum acquired by irradiating the tissue with the second laser light reaching the deep part may include a Doppler spectrum of a thin blood vessel in the surface layer and a thick blood vessel in the deep part. The Doppler spectrum of a thin blood vessel in the second real-time Doppler spectrum can be estimated using the first real-time Doppler spectrum obtained by irradiating the tissue with the first laser light that reaches only the surface layer. Therefore, by subtracting the estimated thin blood vessel Doppler spectrum from the second real-time Doppler spectrum, the deep blood vessel Doppler spectrum can be extracted, and the presence or absence of the deep thick blood vessel can be determined.

In the first aspect, the laser beam irradiation unit may irradiate the first laser beam having low intensity and the second laser beam having higher intensity than the first laser beam. . Alternatively, the laser beam irradiation unit may irradiate the first laser beam having a short wavelength and the second laser beam having a longer wavelength than the first laser beam.
In this way, the depth of arrival of the laser light in the tissue can be varied only by varying the intensity or wavelength of the first laser light and the second laser light.

In the first aspect, a visible light irradiating unit that irradiates visible light to an irradiation position of the laser light on the tissue is provided, and the visible light irradiating unit includes the thick blood vessel in the deep portion by the blood vessel determining unit. The tissue may be irradiated with the visible light only when it is determined to exist.
In this way, only when a thick blood vessel exists in the laser light irradiation region, the irradiation region is also irradiated with visible light. Therefore, the user can recognize the irradiation region of visible light as a region where a thick blood vessel exists.

According to a second aspect of the present invention, there is provided the blood vessel recognition device according to any one of the above, an observation device for observing the tissue in the living body, and a display device for displaying an image of the tissue acquired by the observation device. Is an observation system.

In the second aspect, the first laser spot position is calculated in the first frame obtained by the observation device when the deep blood vessel is recognized by the blood vessel recognition device, and the first laser spot position is calculated. Calculation for adding a marker corresponding to the first laser spot position to a position on the second frame corresponding to the first frame with respect to the second frame acquired at a time different from the frame The display device may display a plurality of the markers that are recognized by a blood vessel at a plurality of different times and added by the calculation unit with respect to the image acquired by the observation device.
By doing in this way, an image in which a marker is added to the position where the deep blood vessel is recognized by the blood vessel recognition device is displayed on the display device, so the surgeon uses the position of the thick blood vessel as the marker in the image. Can be easily recognized.

According to the present invention, there is an effect that a thick blood vessel in a deep part can be recognized separately from a blood vessel having a thin surface layer.

1 is an overall configuration diagram of a blood vessel recognition device according to a first embodiment of the present invention. It is a schematic diagram explaining the structure of a structure | tissue. It is a figure explaining the relationship between the distribution of a thin blood vessel and a thick blood vessel, and the irradiation position of a laser beam. It is an example of the Doppler spectrum of a thin blood vessel with slow blood flow. It is an example of a Doppler spectrum of a thick blood vessel with a fast blood flow. FIG. 2 is a diagram for explaining a correspondence relationship between an analysis result by an analysis unit and a determination by a blood vessel determination unit in the blood vessel recognition device of FIG. 1. It is a flowchart explaining operation | movement of the blood-vessel recognition apparatus of FIG. It is a whole block diagram of the blood-vessel recognition apparatus which concerns on the 2nd Embodiment of this invention. 8 is a diagram for explaining a correspondence relationship between an analysis result by an analysis unit and a determination by a blood vessel determination unit in the blood vessel recognition device in FIG. It is a flowchart explaining operation | movement of the blood-vessel recognition apparatus of FIG. It is a whole block diagram of the blood-vessel recognition apparatus which concerns on the 3rd Embodiment of this invention. It is a flowchart explaining operation | movement of the blood-vessel recognition apparatus of FIG. It is a whole block diagram of the observation system which concerns on the 4th Embodiment of this invention. It is a figure which shows an example of the display in the display apparatus of the observation system of FIG. It is a figure which shows the other example of the display in the display apparatus of the observation system of FIG.

(First embodiment)
A blood vessel recognition device according to a first embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the blood vessel recognition device 100 according to the present embodiment can be inserted into a living body, emits laser light L toward the tissue A in the living body, and receives scattered light S from the tissue A. , A light source unit 2 that supplies laser light L and visible light V to the probe 1, a light detection unit (spectrum acquisition unit) 3 that detects scattered light S received by the probe 1, and a light detection unit 3 And a control device 4 for controlling the light source unit 2 while analyzing the data of the scattered light S detected by.

The probe 1 includes an elongated probe body 5, an irradiation optical fiber (laser light irradiation unit, visible light irradiation unit) 6 and a light receiving optical fiber (spectrum acquisition unit) 7 provided in the probe body 5 along the longitudinal direction. It has.
The probe 1 may be a treatment device that treats the tissue A, such as a high-frequency knife. In this case, an action portion (not shown) for treating the tissue A is provided at the tip of the probe body 5.

The distal end of the irradiation optical fiber 6 is disposed near the distal end of the probe body 5, and the proximal end of the irradiation optical fiber 6 is connected to the light source unit 2. Laser light L and visible light V supplied from the light source unit 2 to the proximal end of the irradiation optical fiber 6 are emitted from the distal end of the irradiation optical fiber 6 to the front in the longitudinal direction of the probe body 5. .
The distal end of the light receiving optical fiber 7 is disposed in the vicinity of the distal end of the probe body 5, and the proximal end of the light receiving optical fiber 7 is connected to the light detection unit 3. The scattered light S of the laser light L scattered by the tissue A is received by the light receiving optical fiber 7 and guided to the light detection unit 3.

The light source unit 2 includes a laser light source 8 that outputs laser light L, a visible light source 9 that outputs visible light V having a visible wavelength, and an irradiation optical fiber 6 that combines the laser light L and the visible light V. And an optical multiplexer (not shown) to be incident.

The laser light source 8 outputs laser light L in a wavelength region (for example, near infrared region) that is less absorbed by blood. Further, as shown in FIG. 2, the laser light source 8 outputs high-intensity laser light L that propagates from the surface of the tissue A through the surface layer B and reaches the deep part C. The surface layer B is a region from the surface of the tissue A to a depth of about several tens of μm to several hundreds of μm, and the deep portion C is a region deeper than several hundred μm from the surface of the tissue A. There are many thin blood vessels D1 in the surface layer B, and there are many thick blood vessels D2 (for example, a diameter of 2 mm or more) deeper than the surface layer B (for example, a depth of 3 mm or more from the surface of the tissue A). To do. Accordingly, the scattered light S received by the light receiving optical fiber 7 can include scattered light S from the thin blood vessel D1 in the surface layer B and scattered light S from the thick blood vessel D2 in the deep part C.

The wavelength of the laser beam L can be selected from various wavelengths according to the scene to be used, the performance of the measuring device, and the like. For example, in consideration of the depths of the surface layer B and the deep part C described above, when mainly observing the surface layer B, the laser light L having a wavelength shorter than 680 nm can be suitably used. When observing, laser light L having a wavelength longer than 600 nm (including near-infrared and infrared wavelength regions) can be suitably used. Moreover, both the surface layer B and the deep part C can be observed in the wavelength range where the wavelength ranges are common (overlapping). Further, the wavelength of the laser light L is not limited to the above. For example, a long wavelength of 680 nm or more can be used for observation of the surface layer B. In this case, the contrast of the observation image of the surface layer B tends to be lower than that of the deep part C.
The visible light source 9 is preferably a laser light source 8. The color of the visible light V is preferably a color that allows the operator to easily visually recognize the visible light V irradiated to the tissue A, for example, green or blue.

The light detection unit 3 includes a photodetector such as a photodiode or a photomultiplier tube. The light detection unit 3 receives the scattered light S guided by the light receiving optical fiber 7 and converts the intensity of the received scattered light S into a digital value. The obtained digital value is transmitted to the storage unit 10 (described later) in the control device 4.

The control device 4 includes a storage unit (spectrum acquisition unit) 10 that accumulates data on the intensity of the scattered light S detected by the light detection unit 3, an analysis unit 11 that analyzes data accumulated in the storage unit 10, and an analysis A blood vessel determination unit 12 that determines the presence or absence of a blood vessel based on an analysis result by the unit 11 and a control unit 13 that controls the laser light source 8 and the visible light source 9 are provided.

The control device 4 is, for example, a computer, and includes a central processing unit (CPU), a main storage device such as a RAM, and an auxiliary storage device. The auxiliary storage device is a non-temporary storage medium such as a hard disk drive, and stores a program for causing the CPU to execute processing to be described later of the analysis unit 11, the blood vessel determination unit 12, and the control unit 13. The program is loaded from the auxiliary storage device to the main storage device, and the CPU executes the processing according to the program, whereby the processing of each

unit

11, 12, 13 is realized. Alternatively, the processing of the

units

11, 12, and 13 may be an FPGA (programmable logic device) or may be realized by dedicated hardware such as an ASIC (application-specific integrated circuit).

The storage unit 10 includes, for example, a main storage device or other storage. The storage unit 10 generates time waveform data of the intensity of the scattered light S by storing the digital values received from the light detection unit 3 in time series.

The analysis unit 11 reads the time waveform data from the storage unit 10 and performs fast Fourier transform on the time waveform data to obtain a real time Doppler spectrum Freal (ω).
Here, the relationship between the real-time Doppler spectrum Freal (ω) and the thickness and depth of the blood vessel will be described.

When a blood vessel is included in the irradiation region of the laser light L, the scattered light S scattered by a static component that is stationary like fat or bleeding and the scattered light scattered by blood flowing in the blood vessel S is simultaneously received by the light receiving optical fiber 7. The scattered light S due to the static component has a frequency f equal to the frequency of the laser light L, but the scattered light S due to blood is shifted from the frequency f of the laser light L according to the blood flow speed by Doppler shift. It has a frequency f + Δf shifted by an amount Δf. Therefore, a beat having a period corresponding to the shift amount Δf appears in the time waveform data generated in the storage unit 10. Hereinafter, | Δf | is expressed as ω. When such a time waveform is subjected to fast Fourier transform, a real-time Doppler spectrum Freal (ω) having an intensity at a frequency ω corresponding to the speed of blood flow is obtained.

It is known that the speed of blood flow in a blood vessel is approximately proportional to the thickness of the blood vessel. Therefore, at a position where only the thin blood vessel D1 exists (see position P1 in FIG. 3), as shown in FIG. 4A, a Doppler spectrum Freal (ω) having intensity only in the low frequency region is obtained. At the position where only the thick blood vessel D2 exists (see the position P2 in FIG. 3), as indicated by the solid line in FIG. 4B, the Doppler spectrum Freal (ω ), A Doppler spectrum Freal (ω) having a higher average frequency is obtained. At a position where both the thin blood vessel D1 and the thick blood vessel D2 exist (see position P3 in FIG. 3), a Doppler spectrum in which the Doppler spectrum of the thin blood vessel D1 and the Doppler spectrum of the thick blood vessel D2 are superimposed is obtained. At the position where the blood vessel does not exist (see position P4 in FIG. 3), the above-mentioned beat does not occur, so the Doppler spectrum has a flat shape having no intensity over the entire frequency region.

However, although there is a clear difference in the average frequency of the Doppler spectrum between the thin blood vessel D1 and the thick blood vessel D2 existing at the same depth as described above, the thin blood vessel D1 in the surface layer B and the thick blood vessel D2 in the deep portion C are produced. And the average frequencies of the Doppler spectra approximate each other. That is, the laser light L and the scattered light S are attenuated by scattering by the tissue A while propagating between the surface of the tissue A and the blood vessel of the deep part C, and the intensity of the scattered light S detected by the light detection unit 3. Decreases. As a result, as shown by a broken line in FIG. 4B, the average frequency of the Doppler spectrum of the thick blood vessel D2 shifts to the low frequency side, and the difference from the average frequency of the Doppler spectrum of the thin blood vessel D1 becomes small. Therefore, it is difficult to distinguish the thin blood vessel D1 in the surface layer B and the thick blood vessel D2 in the deep part C based on the difference in average frequency.

The storage unit 10 is a first base spectrum Fs (ω), which is a Doppler spectrum of the thin blood vessel D1 in the surface layer B, and a Doppler spectrum of the thick blood vessel D2 in the deep part C for analysis of the real-time Doppler spectrum Freal (ω). The second basis spectrum Fd (ω) is stored in advance. The first base spectrum Fs (ω) selectively irradiates the thin blood vessel D1 with the low-intensity laser light L reaching only the surface layer B to the thin blood vessel D1 and selectively uses the scattered light S from the thin blood vessel D1. It is obtained by receiving and detecting light. The second base spectrum Fd (ω) selectively irradiates the thick blood vessel D2 of the deep portion C with the high-intensity laser light L reaching the deep portion C, and selectively receives and detects the scattered light S from the thick blood vessel D2. To get it.

The analysis unit 11 reads the first base spectrum Fs (ω) and the second base spectrum Fd (ω) from the storage unit 10, and the first base spectrum Fs (ω) and the second base spectrum Fd ( A combination of coefficients α and β (0 ≦ α, 0 ≦ β) that minimizes the difference δ obtained by subtracting the linear sum of ω) from the real-time Doppler spectrum F (ω) is calculated. The linear sum is the sum of the product of the first base spectrum Fs (ω) and the coefficient α and the product of the second base spectrum Fd (ω) and the coefficient β.
δ = Freal (ω) − (α × Fs (ω) + β × Fd (ω))

The calculated values of the coefficients α and β represent the magnitudes of contribution of the Doppler spectrum of the thin blood vessel D1 in the surface layer B and the Doppler spectrum of the thick blood vessel D2 in the deep part C in the real-time Doppler spectrum Freal (ω), respectively. . That is, ideally, α> 0 and β = 0 at the position P1 where only the thin blood vessel D1 exists, and α = 0 and β> 0 at the position P2 where only the thick blood vessel D2 exists, and the thin blood vessel D1 and In the position P3 where the thick blood vessel D2 exists, α> 0 and β> 0, and in the position P4 where the thin blood vessel D1 and the thick blood vessel D2 do not exist, α = β = 0. The analysis unit 11 transmits the calculated combination of the coefficients α and β to the blood vessel determination unit 12.

FIG. 5 shows a correspondence relationship between the combinations of the values of the coefficients α and β and the determination result by the blood vessel determination unit 12. The blood vessel determination unit 12 compares the values of the coefficients α and β with a predetermined threshold Th. The predetermined threshold Th is a value larger than 0 and in the vicinity of 0. When only coefficient β is greater than or equal to threshold Th among coefficients α and β, blood vessel determination unit 12 determines that only deep blood vessel D2 exists within the irradiation range of laser light L, and the TRUE signal is transmitted to control unit 13. Output to. In other cases, that is, when the value of the coefficient β is less than the threshold Th or when both the values of the coefficients α and β are equal to or greater than the threshold Th, the blood vessel determination unit 12 sends the FALSE signal to the control unit 13. Output.

The control unit 13 outputs the visible light V from the visible light source 9 when receiving the TRUE signal from the blood vessel determining unit 12, and outputs the visible light V from the visible light source 9 when receiving the FALSE signal from the blood vessel determining unit 12. Stop. Thereby, visible light is irradiated only to the position where only the thick blood vessel D2 in the deep part C is detected.

Next, the operation of the blood vessel recognition device 100 configured as described above will be described.
The blood vessel recognition device 100 according to the present embodiment is used together with an endoscope that observes the inside of a living body. First, the endoscope and the probe 1 of the blood vessel recognition device 100 are inserted into the body.
Next, as shown in FIG. 6, the output of the laser light L from the laser light source 8 is started (step SA1), and the light is emitted from the irradiation optical fiber 6 while observing the surface of the tissue A with an endoscope. The probe 1 is moved so that the laser beam L is scanned on the surface of the tissue A. FIG. 1 shows a state in which the tip of the probe 1 is arranged at a position separated from the tissue A and the blood vessels D1 and D2 are detected without contact with the tissue A. As long as the laser light L is used in a state where it reaches the deep part C, the separation distance of the tip of the probe 1 from the surface of the tissue A can be arbitrarily changed. That is, the probe 1 may be used in a state where the tip is in contact with the surface of the tissue A.

The scattered light S generated in the irradiation region of the laser light L is received by the light receiving optical fiber 7 and detected by the light detection unit 3. And the time waveform data of the intensity | strength of the scattered light S is produced | generated in the memory | storage part 10, and real time Doppler spectrum Freal ((omega)) is acquired from the time waveform data in the analysis part 11 (step SA2).

Next, the first and second basis spectra Fs (ω) and Fd (ω) are read from the storage unit 10 to the analysis unit 11 (step SA3). In the analysis unit 11, the real-time Doppler spectrum F (ω) and The combination of the values of the coefficients α and β when the difference δ from the linear sum of the first and second basis spectra Fs (ω) and Fd (ω) is minimized is calculated (step SA4). The values of the coefficients α and β represent the presence or absence of a thin blood vessel D1 in the surface layer B and a thick blood vessel D2 in the deep part C, respectively.

Next, the blood vessel determination unit 12 determines whether or not only the thick blood vessel D2 having the deep portion C exists in the irradiation region of the laser light L based on the combination of the values of the coefficients α and β (step SA5). That is, when the value of the coefficient α is less than the threshold Th and the coefficient β is greater than or equal to the threshold Th, it is determined that only the thick blood vessel D2 in the deep part C exists (YES in Step SA5), and the control is performed from the blood vessel determination unit 12. A TRUE signal is transmitted to the unit 13. In other cases, it is determined that the thick blood vessel D2 in the deep portion C does not exist or that both the thin blood vessel D1 in the surface layer B and the thick blood vessel D2 in the deep portion C exist (NO in step SA5). A FALSE signal is transmitted to the control unit 13.

When the TRUE signal is received from the blood vessel determination unit 12, the control unit 13 causes the visible light V to be emitted from the irradiation optical fiber 6 together with the laser light L (step SA6). On the other hand, when receiving the FALSE signal from the blood vessel determination unit 12, the control unit 13 does not emit the visible light V. Therefore, the surgeon can recognize that the irradiation region of the visible light V is a region where only the thick blood vessel D2 having the deep part C exists.

Thus, according to the present embodiment, the thin blood vessel D1 included in the real-time Doppler spectrum Freal (ω) is calculated by calculating the coefficients α and β in the linear sum of the base spectra Fs (ω) and Fd (ω). And the Doppler spectrum of the thick blood vessel D2 can be separated, and the presence or absence of the thick blood vessel D2 in the deep part C can be accurately determined based on the coefficient β.
Further, only when a thick blood vessel D2 in the deep part C is detected, the position and travel of the thick blood vessel D2 that are particularly important for the surgeon during the treatment of the tissue A are irradiated with visible light at that position. Can be recognized based on visible light.

In the present embodiment, the blood vessel determination unit 12 determines only the presence or absence of the thick blood vessel D2 in the deep part C, but in addition to this, the presence or absence of the thin blood vessel D1 in the surface layer B may also be determined. As described above, since the value of the coefficient α represents the presence or absence of the thin blood vessel D1 in the surface layer B, the presence or absence of the thin blood vessel D1 in the surface layer B can be determined based on the value of the coefficient α.

(Second Embodiment)
Next, a blood vessel recognition device according to a second embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a configuration different from that of the first embodiment will be described, and a configuration common to the first embodiment will be denoted by the same reference numeral and description thereof will be omitted.
The blood vessel recognition apparatus 101 according to the present embodiment differs from the first embodiment in the processing in the analysis unit 111 and the blood vessel determination unit 121. As shown in FIG. 7, the blood vessel recognition device 101 according to the present embodiment analyzes the data of the scattered light S detected by the probe 1, the light source unit 2, the light detection unit 3, and the light detection unit 3. And a control device 41 for controlling the light source unit 2.

In addition to the storage unit 10, the analysis unit 111, the blood vessel determination unit 121, and the control unit 13, the control device 41 further includes a condition setting unit 14 that sets conditions for the laser light L output from the laser light source 8. .
The condition setting unit 14 sequentially sets the conditions of the laser light L to a surface layer condition where the laser light L reaches only the surface layer B and a deep condition where the laser light L propagates through the surface layer B and reaches the deep part C. Specifically, the condition setting unit 14 sets the intensity of the laser light L at a low intensity at which the laser light L reaches only the surface layer B in the surface layer condition, and the laser light is higher than the intensity in the surface layer condition in the deep condition. The intensity of the laser beam L is set to a high intensity at which L reaches the deep part C.

As a result, the laser light source 8 outputs a low-intensity laser beam (first laser beam) L and a high-intensity laser beam (second laser beam) L in order, and the low-intensity laser beam is output at the same position in the tissue A The laser beam L and the high-intensity laser beam L are irradiated in order. Then, a real-time Doppler spectrum (first real-time Doppler spectrum) Freal_s (ω) based on the scattered light S by the low-intensity laser light L and a real-time Doppler spectrum (first real-time Doppler spectrum based on the scattered light S by the high-intensity laser light L). Two real-time Doppler spectra) Freal_d (ω) are acquired in the analysis unit 111 in order. The real-time Doppler spectrum Freal_s (ω) in the surface layer condition may include only the Doppler spectrum of the thin blood vessel D1 in the surface layer B, but the real-time Doppler spectrum Freal_d (ω) in the deep condition is the thin blood vessel D1 and the deep portion C in the surface layer B. May also include a Doppler spectrum of a thick blood vessel D2. Two Doppler spectra Freal_s (ω) and Freal_d (ω) are stored in the storage unit 10.

The analysis unit 111 reads the Doppler spectra Freal_s (ω) and Freal_d (ω) from the storage unit 10 and executes the calculation shown in the following formula to calculate the difference spectrum δF (ω).
δF (ω) = Freal_d (ω) −γ × Freal_s (ω)

That is, the analysis unit 111 obtains an estimated Doppler spectrum (γ × Freal_s (ω)) by multiplying the intensity of the Doppler spectrum Freal_s (ω) of the surface layer condition by a predetermined coefficient γ. The estimated Doppler spectrum is a Doppler spectrum of the thin blood vessel D1 in the surface layer B that will be acquired when the tissue A is irradiated with the high-intensity laser light L under deep conditions. The coefficient γ is a value experimentally determined in advance based on, for example, the intensity ratio of the Doppler spectrum of the thin blood vessel D1 of the surface layer B acquired under the surface layer condition and the deep region condition, and is stored in the storage unit 10. Yes.

Next, the analysis unit 111 subtracts the estimated Doppler spectrum from the Doppler spectrum Freal_d (ω) acquired under the deep condition to obtain a difference spectrum δF (ω). At this time, when the real-time Doppler spectrum Freal_d (ω) includes the Doppler spectrum of the thick blood vessel D2 in the deep portion C, the Doppler spectrum of the deep blood vessel D2 in the deep portion C is obtained as the difference spectrum δF (ω). . On the other hand, when the real-time Doppler spectrum Freal_d (ω) does not include the Doppler spectrum of the thick blood vessel D2 in the deep part C (that is, only the Doppler spectrum of the thin blood vessel D1 of the surface layer B is included), A flat difference spectrum δF (ω) having no intensity over the frequency domain is obtained. The analysis unit 111 transmits the difference spectrum δF (ω) that is the analysis result to the blood vessel determination unit 121.

The blood vessel determination unit 121 determines whether or not a thick blood vessel D2 having a deep portion C exists based on the intensity of the difference spectrum δF (ω). Then, as shown in FIG. 8, when the blood vessel determination unit 121 determines that there is a thick blood vessel D2 in the deep portion C, it transmits a TRUE signal to the control unit 13 and determines that there is no deep blood vessel D2 in the deep portion C. When this occurs, a FALSE signal is transmitted to the control unit 13.

Next, the operation of the blood vessel recognition device 101 configured as described above will be described.
As shown in FIG. 9, the laser light source 8 sequentially outputs the low-intensity laser light L under the surface layer condition and the high-intensity laser light L under the deep condition according to the setting by the condition setting unit 14 (step SB1, SB3), the real-time Doppler spectrum Freal_s (ω) under the surface layer condition, and the real-time Doppler spectrum Freal_d (ω) under the deep condition are acquired in order (steps SB2 and SB4).

Next, in the analysis unit 111, the estimated Doppler spectrum is calculated by multiplying the real-time Doppler spectrum Freal_s (ω) obtained in step SB2 by the coefficient γ (step SB5). Next, the analysis unit 111 calculates a difference spectrum δF (ω) by subtracting the estimated Doppler spectrum from the real-time Doppler spectrum Freal_d (ω) obtained in step SB4 (step SB6).

Next, the blood vessel determination unit 121 determines whether or not the thick blood vessel D2 having the deep portion C exists in the irradiation region of the laser light L based on the intensity of the difference spectrum δF (ω) (step SB7). When it is determined that the thick blood vessel D2 in the deep part C exists (YES in step SB7), a TRUE signal is transmitted from the blood vessel determination unit 121 to the control unit 13, and the visible light V is irradiated along with the laser light L (step). SB8). On the other hand, when it is determined that the thick blood vessel D2 in the deep part C does not exist (NO in step SB7), the irradiation with the visible light V is not executed. Therefore, the surgeon can recognize that the irradiation region of the visible light V is a region where the thick blood vessel D2 having the deep part C exists.

Thus, according to the present embodiment, the Doppler spectrum of the thin blood vessel D1 in the surface layer B included in the real-time Doppler spectrum Freal_d (ω) in the deep condition is obtained using the real-time Doppler spectrum Freal_s (ω) in the surface layer condition. It can be estimated with high accuracy. Then, by removing the estimated Doppler spectrum from the Doppler spectrum Freal_d (ω), the Doppler spectrum of the thin blood vessel D1 in the surface layer B is separated from the Doppler spectrum Freal_d (ω), and the Doppler spectrum of the thick blood vessel D2 in the deep part C is extracted. be able to. Thereby, there exists an advantage that the presence or absence of the thick blood vessel D2 of the deep part C can be determined correctly.
Further, only when the thick blood vessel D2 in the deep part C is detected, the position is irradiated with visible light, so that the position and travel of the thick blood vessel D2 that are particularly important for the surgeon during the treatment of the tissue A are detected. There is an advantage that recognition can be performed based on visible light.

In the present embodiment, in calculating the estimated Doppler spectrum, the intensity is multiplied by a constant coefficient γ over the entire frequency region of the real-time Doppler spectrum Freal_s (ω) of the surface layer condition. However, the coefficient γ set for each frequency is used. (Ω) may be multiplied by the real-time Doppler spectrum Freal_s (ω). For example, the coefficient γ (ω) is calculated for each frequency ω by calculating the intensity ratio of the Doppler spectrum of the thin blood vessel D1 of the surface layer B acquired under the surface condition and the deep condition, and the calculated intensity ratio of each frequency ω. This is experimentally predetermined.
By doing in this way, the estimated Doppler spectrum which estimated more accurately the Doppler spectrum of the blood vessel D1 of the surface layer B in the deep part condition can be obtained, and the determination accuracy of the presence or absence of the blood vessel in the deep part C can be improved. .

In the present embodiment, the blood vessel determination unit 121 may determine the presence or absence of the thin blood vessel D1 of the surface layer B in addition to the presence or absence of the thick blood vessel D2 of the deep portion C. For example, the blood vessel determination unit 121 can determine the presence or absence of a thin blood vessel D1 in the surface layer B based on the average frequency of the Doppler spectrum Freal_s (ω) of the surface layer condition.

(Third embodiment)
Next, a blood vessel recognition device according to a third embodiment of the present invention will be described with reference to FIG. 8, FIG. 10, and FIG.
In the present embodiment, configurations different from those in the first and second embodiments will be described, and configurations common to the first and second embodiments will be denoted by the same reference numerals and description thereof will be omitted.

The blood vessel recognition device 102 according to the present embodiment is a modification of the blood vessel recognition device 101 according to the second embodiment, and differs from the second embodiment in that the wavelength of the laser light is different between the surface layer condition and the deep condition. It is different.
As shown in FIG. 10, the blood vessel recognition device 102 according to the present embodiment includes a probe 1, a light source unit 21, a light detection unit 3, and a control device 42.

The light source unit 21 combines the two

laser light sources

81 and 82 that output the laser beams L1 and L2 having different wavelengths, the visible light source 9, the laser beams L1 and L2, and the visible light V, and the irradiation optical fiber 6. And an optical multiplexer (not shown) to be incident.
The laser light source 81 outputs short-wavelength laser light L1 that reaches only the surface layer B.
The laser light source 82 outputs a laser beam L2 having a longer wavelength than the wavelength of the laser beam L1 and propagating through the surface layer B and reaching the deep part C.

The control device 42 further includes a storage unit 10, an analysis unit 111, a blood vessel determination unit 121, a control unit 13, and a condition setting unit 141.
The condition setting unit 141 sequentially sets the laser light conditions to a surface layer condition where the laser light reaches only the surface layer B and a deep part condition where the laser light propagates through the surface layer B and reaches the deep part C. Specifically, the condition setting unit 141 causes the laser light source 81 to output the short wavelength laser light L1 in the surface layer condition, and causes the laser light source 82 to output the long wavelength laser light L2 in the deep part condition.

Accordingly, as shown in FIG. 11, the two

laser light sources

81 and 82 sequentially turn the short-wavelength laser light (first laser light) L1 and the long-wavelength laser light (second laser light) L2. (Steps SB1 ′ and SB3 ′), and the short wavelength laser beam L1 and the long wavelength laser beam L2 are sequentially irradiated to the same position of the tissue A. Then, a real-time Doppler spectrum (first real-time Doppler spectrum) Freal_s (ω) based on the scattered light S by the short-wavelength laser light L2 and a real-time Doppler spectrum (first time based on the scattered light S by the long-wavelength laser light L2). 2 real-time Doppler spectra) Freal_d (ω) are sequentially acquired by the analysis unit 111 (steps SB2 ′ and SB4 ′). The real-time Doppler spectrum Freal_s (ω) in the surface layer condition may include only the Doppler spectrum of the thin blood vessel D1 in the surface layer B, but the real-time Doppler spectrum Freal_d (ω) in the deep condition is the thin blood vessel D1 and the deep portion C in the surface layer B. May also include a Doppler spectrum of a thick blood vessel D2. Two Doppler spectra Freal_s (ω) and Freal_d (ω) are stored in the storage unit 10.

The processes performed by the analysis unit 111, the blood vessel determination unit 121, and the control unit 13 are the same as those in the second embodiment, as shown in FIGS.
Since the effect of this embodiment is the same as that of the second embodiment, the description thereof is omitted.

(Fourth embodiment)
Next, an observation system according to a fourth embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, configurations that are different from those in the first to third embodiments will be described, and configurations that are the same as those in the first to third embodiments will be denoted by the same reference numerals and description thereof will be omitted.
As shown in FIG. 12, an observation system 200 according to the present embodiment includes any one of the blood

vessel recognition devices

100, 101, and 102 according to the first to third embodiments, an endoscope device (observation device) 20, and The blood

vessel recognition devices

100, 101, 102, and the endoscope device 20 are provided with a calculation unit 30 and a display device 40 connected to the calculation unit 30. FIG. 12 shows a configuration including the blood vessel recognition device 100 according to the first embodiment as an example.

The endoscope device 20 acquires an in-vivo endoscopic image, and transmits the acquired endoscopic image to the calculation unit 30. Reference numeral 21 denotes an illuminating unit that emits illumination light toward the tissue A, and reference numeral 22 denotes an imaging unit that acquires an endoscopic image of the tissue A.
The arithmetic unit 30 is composed of, for example, a computer, like the control device 4 described above. The calculation unit 30 receives irradiation conditions of the laser light L, L1, and L2, on / off information of the visible light source 9, and blood vessels in the surface layer B and the deep part C by the blood

vessel determination units

12 and 121 from the

control device

4, 41, or 42 of the blood vessel recognition device. The determination result information on the presence / absence of D1 and D2 is received.

In addition, the calculation unit 30 is an endoscope acquired by the endoscope device 20 when the blood vessels D1 and D2 are recognized by the blood

vessel recognition devices

100, 101, and 102 (when it is determined that the blood vessels D1 and D2 exist). The spot positions of the laser beams L, L1, and L2 are calculated in the first frame of the image, and the calculated spot positions of the second frame acquired by the endoscope apparatus 20 at a time different from the first frame. A marker is added at a position corresponding to. As a result, blood vessels are recognized at a plurality of different times by the blood

vessel recognition devices

100, 101, and 102, and an endoscopic image to which a plurality of markers E1 and E2 are added is displayed by the arithmetic unit 30 as shown in FIG. It is displayed on the device 40. For specific processing by the arithmetic unit 30, International Publication No. 2016/171274 can be referred to.

Thus, according to the present embodiment, since the endoscope image with the markers E1 and E2 attached to the positions where the blood vessels D1 and D2 have been recognized so far is displayed on the display device 40, the operator can The distribution and running of the blood vessels D1, D2 can be easily recognized based on the markers E1, E2.

At this time, the calculation unit 30 may add the marker E2 only when the thick blood vessel D2 in the deep part C is recognized, so that only the thick blood vessel D2 in the deep part C is displayed on the display device 40. .
Alternatively, the calculation unit 30 may give the markers E1 and E2 to the thin blood vessel D1 having the surface layer B and the thick blood vessel D2 having the deep portion C, respectively, and cause the display device 40 to display them. In this case, the calculation unit 30 may make the aspects of the marker E1 of the blood vessel D1 of the surface layer B and the marker E2 of the blood vessel D1 of the deep portion C different from each other. For example, the hues of the markers E1 and E2 may be different or the brightness may be different. In particular, it is preferable to emphasize the marker E2 of the thick blood vessel D2 of the deep part C that should be noted by the surgeon with respect to the marker E1.

The markers E1 and E2 may be superimposed on the same endoscopic image, but may be superimposed on different endoscopic images and displayed in parallel on the display device 40 as shown in FIG. . Also, three endoscopic images in which the markers E1 and E2 are superimposed on both the surface layer B and the blood vessel in the deep portion C, only the blood vessel in the surface layer B, and only the blood vessel in the deep portion C may be displayed on the display device 40 in parallel. .

Furthermore, it may be configured such that the operator can select whether or not to attach the markers E1 and E2 to the blood vessel D1 of the surface layer B and the blood vessel D2 of the deep portion C using a user interface (not shown). .
Moreover, the calculating part 30 may display the information (for example, information of determination results, such as depth and thickness) regarding the blood vessels to which the markers E1 and E2 are attached in the endoscopic image at corresponding positions.

Further, the calculation unit 30 may superimpose and display the scanning trajectories F of the laser beams L, L1, and L2 on the surface of the tissue A on the endoscopic image. In this way, when the surgeon performs a surgical treatment on the tissue A, the surgeon can recognize whether or not blood vessel recognition has already been performed in the treatment target region. The surgeon may be configured to switch between display and non-display of the scanning trajectory F of the laser beams L, L1, and L2.

100, 101, 102 Blood vessel recognition device 1

Probe

2, 21 Light source unit 3

Light detection unit

4, 41, 42 Control device 5 Probe body 6 Irradiation optical fiber 7 Light reception

optical fiber

8, 81, 82 Laser light source 9 Visible light source 10

Storage unit

11, 111

Analysis unit

12, 121 Blood vessel determination unit 13

Control unit

14, 141 Condition setting unit 20 Endoscope device (observation device)
30 arithmetic unit 40 display device 200 observation system A tissue B surface layer C deep part D1, D2 blood vessel E1, E2 marker F scanning locus

Claims

A blood vessel recognition device for recognizing a thick blood vessel existing in a deep part of a tissue in a living body,
A laser beam irradiation unit that irradiates the tissue with a laser beam that can reach the deep part; and
A spectrum acquisition unit that acquires a time waveform of the intensity of scattered light generated in the tissue by irradiation of the laser light, and obtains a real-time Doppler spectrum by Fourier transforming the acquired time waveform;
A storage unit for storing a Doppler spectrum of a thin blood vessel in a surface layer of the tissue having a diameter smaller than that of the thick blood vessel;
An analysis unit that separates the Doppler spectrum of the thin blood vessel in the surface layer included in the real-time Doppler spectrum acquired by the spectrum acquisition unit using the Doppler spectrum of the thin blood vessel in the surface layer stored in the storage unit; ,
A blood vessel recognition apparatus comprising: a blood vessel determination unit that determines whether or not the thick blood vessel exists in the deep part based on the real-time Doppler spectrum obtained by separating the Doppler spectrum of the thin blood vessel by the analysis unit.
The storage unit stores a first base spectrum that is a Doppler spectrum of a thin blood vessel in the surface layer and a second base spectrum that is a Doppler spectrum of a deep blood vessel in the deep part,
The analysis unit calculates a coefficient of the second base spectrum in the linear sum when the difference between the real-time Doppler spectrum and the linear sum of the first base spectrum and the second base spectrum is minimized. ,
The blood vessel recognition device according to claim 1, wherein the blood vessel determination unit determines whether or not the thick blood vessel exists in the deep portion based on a coefficient of the second base spectrum calculated by the analysis unit.
The laser light irradiation unit sequentially irradiates the tissue with a first laser light that reaches only the surface layer and a second laser light that reaches the deep part,
The spectrum acquisition unit includes: a first real-time Doppler spectrum based on the scattered light by the first laser light irradiation; and a second real-time Doppler spectrum based on the scattered light by the second laser light irradiation. Get in order,
The storage unit stores the first real-time Doppler spectrum as the Doppler spectrum of the thin blood vessel in the surface layer;
The analysis unit estimates a Doppler spectrum of the thin blood vessel of the surface layer included in the second real time Doppler spectrum based on the first real time Doppler spectrum, and the estimated Doppler spectrum of the thin blood vessel of the surface layer is estimated. Subtract from the second real-time Doppler spectrum to calculate the difference spectrum;
The blood vessel recognition device according to claim 1, wherein the blood vessel determination unit determines whether or not the thick blood vessel exists in the deep portion based on the calculated difference spectrum.
The blood vessel recognition device according to claim 3, wherein the laser beam irradiation unit irradiates the first laser beam with low intensity and the second laser beam with higher intensity than the first laser beam.
The blood vessel recognition device according to claim 3, wherein the laser beam irradiation unit irradiates the first laser beam having a short wavelength and the second laser beam having a longer wavelength than the first laser beam.
A visible light irradiation unit that irradiates visible light to the irradiation position of the laser light to the tissue,
The visible light irradiation unit irradiates the tissue with the visible light only when the blood vessel determination unit determines that the thick blood vessel is present in the deep part. Blood vessel recognition device.
The blood vessel recognition device according to any one of claims 1 to 6,
An observation device for observing the tissue in the living body;
An observation system comprising: a display device that displays an image of the tissue acquired by the observation device.
The first laser spot position is calculated in the first frame acquired by the observation device when the deep blood vessel is recognized by the blood vessel recognition device, and is acquired at a time different from that of the first frame. A calculation unit for adding a marker corresponding to the first laser spot position to a position on the second frame corresponding to the first frame with respect to the second frame;
The observation system according to claim 7, wherein the display device displays a plurality of the markers that are recognized by a blood vessel at a plurality of different times and added by the calculation unit with respect to an image acquired by the observation device.