JP2007325781A - Observation device and method for inside of scattering medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly precisely confirm the presence/absence of matters inside an observation object including scattering media such as visceral fat. <P>SOLUTION: This observation device 1 for inside of a scattering medium is provided with a light source 2, an illumination optical system 3 guiding the light L1 from the light source 2 to an observation object A including the scattering media, and an observation optical system 6 acquiring an image of the observation object A illuminated by the illumination optical system 3. Also, the observation optical system 6 is disposed with a light shielding member 8 shielding the image of the light source 2 projected on the surface of the observation object A by the illumination optical system 3 in a position conjugated with the image of the light source 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a scattering medium observation device and a scattering medium observation method.

  When performing a surgical operation such as removing a diseased part, the operation is performed while grasping the position so as not to damage the circulatory organs and nerves such as blood vessels and lymph vessels. For this reason, it is necessary for the attending physician to know the position of blood vessels and the like anatomically. In particular, it is essential to identify the location of blood vessels.

However, since there are individual differences in the arrangement / distribution of blood vessels and the like, it is necessary to make an incision while carefully searching for the position of the blood vessels during the operation, which disadvantageously increases the operation time.
Prolonging the operation time increases the burden on the patient. Therefore, in order to reduce the burden on the patient, it is necessary to confirm the arrangement of blood vessels regardless of individual differences.

As a method for detecting the position information of a blood vessel, for example, there is one disclosed in Patent Document 1.
The method of this patent document 1 is a vein authentication technique, and is a technique for specifying an individual from the arrangement / distribution of blood vessels by utilizing the individual difference in the arrangement / distribution of blood vessels.
JP 2000-339445 A

  However, since this vein authentication technique is a technique for detecting a vein existing in the vicinity of the skin of the palm using the light absorption characteristics of hemoglobin in the blood vessel, it cannot detect a blood vessel at a deep position from the skin surface. In addition, this vein authentication technique targets a subcutaneous blood vessel. This is because the skin has the characteristic of transmitting light without being scattered relatively in the living tissue.

On the other hand, blood vessels and the like whose arrangement and distribution are to be confirmed in a surgical operation or the like are present inside visceral fat on the surface of an organ, deep subcutaneous tissue, or the like. Visceral cells and subcutaneous deep tissues have stronger light scattering characteristics than skin and are strongly reflected near the surface, making it difficult to detect information on objects such as internal blood vessels.
Therefore, the vein authentication technique disclosed in Patent Document 1 has a disadvantage in that it cannot be confirmed whether or not an object inside the observation target including a scattering medium such as visceral fat is present.

  The present invention has been made in view of the above-described circumstances, and is an in-scattering medium observation device and a scattering medium capable of accurately confirming the presence or absence of an object inside an observation target including a scattering medium such as visceral fat. The purpose is to provide an internal observation method.

In order to achieve the above object, the present invention provides the following means.
The present invention includes a light source, an illumination optical system that guides light from the light source to an observation target including a scattering medium, and an observation optical system that acquires an image of the observation target illuminated by the illumination optical system, A scattering medium observation device in which a light-shielding member that shields an image of the light source projected on the surface of the observation target by the illumination optical system is disposed at a position substantially conjugate with the image of the light source. provide.

  According to the present invention, when the light emitted from the light source is irradiated onto the observation target by the illumination optical system, a part of the observation target including the scattering medium is reflected on the surface and a part of the light travels in the observation target. To do. Although the light source image is formed by the light reflected on the surface of the observation target, the observation optical system is provided with a light shielding member, so that the image of the light source is prevented from being included in the acquired image. Then, after traveling from the surface of the observation target to the inside, the light emitted back to the surface of the observation target is imaged. Since the light that has traveled into the observation target is scattered by the scattering medium inside the observation target to form a virtual light source, the shadow of the object placed on the surface side of the formed virtual light source is photographed. It becomes possible to do. As a result, the presence or absence of an object inside the observation target including a scattering medium such as visceral fat can be accurately confirmed.

The present invention also includes a light source, an illumination optical system that guides light from the light source to an observation target including a scattering medium, and an observation optical system that acquires an image of the observation target illuminated by the illumination optical system. The observation optical system provides an in-scattering medium observation device that photographs light emitted from a region other than the image of the light source projected onto the surface of the observation target by the illumination optical system.
According to the present invention, since the observation optical system captures light from a region other than the image of the light source projected on the surface of the observation target, it is not necessary to consider the image of the light source with high luminance. This makes it possible to confirm the presence or absence of an object inside the observation target without increasing the dynamic range of a camera such as a CCD. For example, by arranging the light source image outside the field of view of the camera, the image of the light source can be easily excluded from the acquired image.

In the above invention, the light-shielding member that shields the image of the light source projected on the surface of the observation target by the illumination optical system is disposed in the observation optical system at a position substantially conjugate with the image of the light source. It is good as well.
By doing in this way, the image of a light source can be easily excluded from the acquired image by the light shielding member.

Moreover, in the said invention, it is good also as the image of the said light source, and the said light-shielding member having a similar shape.
Moreover, in the said invention, it is good also as the said light source and the said light-shielding member being arrange | positioned in the conjugate position.

  In the above invention, the illumination optical system includes light source image scanning means for scanning a light source image projected onto the surface of the observation target in a direction intersecting an optical axis, and the observation optical system includes the light shielding member. It is also possible to provide a light shielding member scanning means for scanning the light source in a direction crossing the optical axis, and a control means for controlling the light source image scanning means and the light shielding member scanning means in synchronization.

  By the operation of the control means, the light shielding member is scanned by the light shielding member scanning means in synchronism with the scanning of the light source image by the light source image scanning means. By removing the image of the light source from the image, it is possible to form an image only with light emitted from a region other than the image of the light source. Accordingly, it is possible to prevent the generation of a blind spot occurring in the observation range when the light shielding member is fixed, and to perform observation in the scattering medium in the entire observation range.

Moreover, in the said invention, it is good also as providing the switching means which comprises two or more light shielding members, and switches a light shielding member according to the intensity | strength of the light from a light source.
In this way, increasing the intensity of light from the light source to detect an object at a deep position from the surface increases the size of the image of the light source on the surface. By switching the light shielding member, it is possible to select the light shielding member in accordance with the size of the image of the light source and exclude the image of the light source from the acquired image.

In the present invention, the light from the light source is projected onto the surface of the observation target including the scattering medium, and the light emitted from the region other than the image of the light source projected on the surface of the observation target is captured and acquired. Provided is an in-scattering medium observation method for observing the presence or absence of an object inside an observation target based on an image.
In the said invention, it is good also as shielding the image of the light source projected on the surface of the observation object.

  According to the present invention, there is an effect that the presence or absence of an object inside an observation target including a scattering medium such as visceral fat can be confirmed with high accuracy.

A scattering medium observation device (hereinafter simply referred to as an observation device) 1 according to a first embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the observation apparatus 1 according to the present embodiment has a light source 2, an illumination optical system 3 that collects the illumination light L ₁ from the light source 2, and the illumination optical system 3. a half mirror 4 that reflects part of the illumination light L _1, whereas for irradiating the observation target a condenses the illumination light L ₁ reflected by the half mirror 4, the return light L ₂ from the observation target a an objective lens 5 for focusing, is focused by the objective lens 5, and a viewing optical system 6 to obtain an image by capturing return light L ₂ having passed through the half mirror 4.

The observation optical system 6 condenses the return light L ₂ that has passed through the half mirror 4 to form an intermediate image, and a light shield disposed near the intermediate image position B by the imaging lens 7. A member 8, a relay optical system 9 that condenses the return light L ₂ that is transmitted without being shielded by the light shielding member 8, and relays an image by the imaging lens 7; and an imaging position by the relay optical system 9. It is disposed, and an imaging device 10 such as a CCD for capturing the return light L _2.

  The intermediate image position B by the imaging lens 7 on which the light shielding member 8 is arranged and the imaging position of the image of the light source 2 by the objective lens 5 are arranged in an optically conjugate positional relationship. Further, the image forming position of the image of the light source 2 by the objective lens 5 and the light source 2 are arranged in a substantially conjugate positional relationship.

  The size of the light shielding member 8 is determined according to the size of the image of the light source 2 formed on the surface of the observation object A. When the intensity of the light source 2 is high and the scattering characteristics of the scattering medium in the observation target A are strong, a large light source image (including a relatively shallow virtual light source image described later) C is formed on the surface of the observation target A. Accordingly, in accordance with this, the light shielding member 8 has a size and a shape necessary for preventing the return light from the light source image C from passing toward the image sensor 10.

  That is, the image of the light source 2 projected on the surface of the observation target A is determined by the size of the light source 2, but the image of the virtual light source formed as a result of scattering by the scattering medium inside the observation target A is the intensity of the light source 2. Therefore, the size of the light shielding member 8 is large enough to shield the image of the light source 2 projected on the surface of the observation target A and the image of the virtual light source formed at a shallow position in the observation target A. Is set to

An observation method using the observation apparatus 1 according to the present embodiment configured as described above will be described below.
In order to observe the observation object A including a scattering medium such as visceral fat using the observation apparatus 1 according to the present embodiment, the half mirror 4 is generated from a light source 2 such as a lamp, condensed by an illumination optical system 3, and the half mirror 4. The illumination light L ₁ propagated through the objective lens 5 is irradiated onto the observation object A, and an image C of the light source 2 is formed on the surface of the observation object A.

Some of the irradiated on the observation target A illumination light L ₁ is reflected by the surface, other portions are scattered by the scattering medium in the observation object A, as shown in FIGS. 2 and 3, from the surface A large number of virtual light sources (hereinafter referred to as virtual light sources) 2A to 2C are successively formed. Here, the virtual light sources 2 </ b> A to 2 </ b> C are formed innumerably continuously in the observation target A, but here, for the sake of simplicity of explanation, it is assumed that a plurality of finite virtual light sources 2 </ b> A to 2 </ b> C are formed. .

  The virtual light sources 2A to 2C formed in the observation object A and the image C of the light source 2 formed on the surface of the observation object A are relayed to the intermediate image position B via the objective lens 5 and the imaging lens 7. Further, the relay optical system 9 relays the image pickup surface 10a to the image pickup surface 10a. Then, the image of the surface of the observation target A is acquired by the operation of the image sensor 10.

  In this case, in the observation apparatus 1 according to the present embodiment, since the light shielding member 8 is disposed at the intermediate image position B by the imaging lens 7, the light shielding member 8 is formed on the surface of the observation target A. The image C of the light source 2 and the image of the virtual light source 2 </ b> A formed at a shallow position of the observation target A are shielded by the light shielding member 8. Thereby, the image C of the light source 2 and the image of the virtual light source 2A having high intensity are prevented from being taken by the image sensor 10.

  That is, according to the observation device 1 according to the present embodiment, only the weak light from the virtual light sources 2B and 2C formed at a relatively deep position below the surface of the observation target A is imaged by the imaging element 10. Therefore, when a detection target X such as a blood vessel exists between the virtual light sources 2B and 2C at a relatively deep position imaged by the image sensor 10 and the surface of the observation target A, in the image acquired by the image sensor 10 In this case, the detection target X appears as a shadow. This makes it possible to easily determine whether the detection target X exists.

  In this case, since the light shielding member 8 prevents the image C of the light source 2 and the image of the virtual light source 2A from being captured by the image sensor 10, the amount of light incident on the image sensor 10 is reduced as a whole. Therefore, the generation of noise due to strong light from the image C of the light source 2 can be reduced, and the presence or absence of the detection target X can be easily determined by increasing the sensitivity of the image sensor 10.

2 and 3 show the relationship between the light shielding region by the light shielding member 8 and the depth of the detection target X that can be observed.
As shown in FIG. 2, when the detection target X is at a relatively shallow position in the observation target A, the surface side virtual light source 2A formed between the detection target X and the surface of the observation target A is also the observation target. It is formed near the surface of A. For this reason, the influence of scattering in the observation target A is small, and the size of the image of the virtual light source 2A on the surface side is not so large as compared with the image C of the light source 2 projected on the surface of the observation target A. Therefore, as the light shielding member 8 for shielding the virtual light source 2A on the surface side from the detection target X, a slightly larger one than the image C of the light source 2 projected on the surface may be employed.

On the other hand, as shown in FIG. 3, when the detection target X is at a relatively deep position in the observation target A, the scattering medium disposed on the surface side of the detection target X increases, so that the formed virtual light source 2A , 2B increases. Moreover, since the influence by scattering becomes large, the size of the virtual light sources 2A and 2B also becomes large. Furthermore, when the detection target X at a relatively deep position is to be detected, the illumination light L ₁ incident from the surface of the observation target A is difficult to reach the detection target X, so that the illumination light L ₁ emitted from the light source 2 It is also necessary to increase the strength. As a result, the sizes of the virtual light sources 2A and 2B are further increased.
For this reason, in order to detect the detection target X arranged at a relatively deep position, the light shielding region by the light shielding member 8 is made larger than when detecting the detection target X arranged at a relatively shallow position. There is a need.

Therefore, when the depth position of the detection target A cannot be specified, a plurality of light shielding members 8 having different sizes are prepared as the light shielding member 8 and switched by a switching means (not shown) such as a turret. It is good also to observe while doing. Thus, the presence or absence of the detection target X can be confirmed by shielding the image C or the like of the light source 2 by the light shielding member 8 having a size suitable for the depth of the detection target X.
Further, as described above, the switching of the light shielding member 8 by the switching unit may be performed in synchronization with the switching of the intensity of the illumination light L ₁ emitted from the light source 2.

  In the observation apparatus 1 according to the present embodiment, the image C or the like of the light source 2 is shielded from light by the light shielding member 8 fixed at the intermediate image position B by the imaging lens 7. The image of the light source 2 on the surface A may be moved in a direction intersecting the optical axis, and the light shielding member 8 may be moved in a direction intersecting the optical axis in synchronization with this.

  For example, the illumination optical system 3 has a slit (not shown) that forms an image C of the light source 2 projected on the surface of the observation target A in a rectangular shape as shown in FIG. 4, and the slit as an optical axis. A slit moving mechanism (not shown) for moving in an orthogonal direction is provided. Further, as the light shielding member 8, a rectangular shape having a size that shields the image C of the rectangular light source 2 and the like is adopted, and the light shielding member moving mechanism that moves the light shielding member 8 in a direction perpendicular to the optical axis. (Not shown) is provided. And it is good also as providing the control apparatus (illustration omitted) which moves a slit moving mechanism and a light-shielding member moving mechanism synchronously.

  In this way, as shown in FIGS. 4A and 4B, the image C of the rectangular light source 2 is moved on the surface of the observation target A, and different regions of the observation target A are sequentially displayed. Illumination can be performed, and at that time, the image C of the light source 2 projected onto the surface of the observation target A and the image of the virtual light source 2A formed therearound can be shielded by the light shielding member 8 each time. Therefore, in the same manner as described above, the light from the virtual light sources 2B and 2C formed at a position deeper than the detection target X such as a blood vessel, which is emitted from the surface other than the surface of the observation target A and its vicinity, is imaged Can do.

Then, an image of the surface of the observation target A is acquired and stored by the image sensor 10 at a predetermined time interval, and the plurality of obtained images are combined to obtain the observation target A as shown in FIG. An image of the entire observation range can be generated.
As a result, when the light shielding member 8 is fixed, the observation target A arranged at the blind spot of the light shielding member 8 may not be observed, but by scanning the light source 2 and the light shielding member 8, the blind spot of the light shielding member 8 is reduced. It is possible to determine whether the detection target X exists in the entire observation range from the obtained image.

Next, an in-scattering medium observation apparatus (hereinafter referred to as an observation apparatus) 1 ′ according to a second embodiment of the present invention will be described with reference to FIG.
In the description of the present embodiment, portions having the same configuration as those in the scattering medium observation device 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

The observation apparatus 1 ′ according to the present embodiment is so-called epi-illumination in which the observation apparatus 1 according to the first embodiment irradiates the illumination light L _{1 in the} direction along the optical axis of the objective lens 5. The difference is that the illumination light L ₁ is irradiated obliquely from the outside of the objective lens 5.

An observation method using the observation apparatus 1 ′ configured as described above will be described below.
According to the observation apparatus 1 ′ according to the present embodiment, the illumination light L _{1 that} is collected from the light source 2 through the illumination optical system 3 and is irradiated on the surface of the observation target A from an oblique direction is A part of the light is reflected on the surface and the other part is incident on the observation object A from the surface. However, the illumination light L ₁ reflected on the surface is reflected in a direction not incident on the objective lens 5. Therefore, the return light L ₂ to be focused through the objective lens 5, is only the light from the formed therein observation target A virtual light source 2A-2C.

  Then, the light from the virtual light source 2A formed at a relatively shallow position is shielded by the light shielding member 8 arranged at the intermediate image position B of the imaging lens 7, and the virtual light source 2B formed at a relatively deep position. An image in which the detection target X such as a blood vessel appears as a shadow by the light from 2C can be acquired. Thereby, similarly to 1st Embodiment, the presence or absence of the detection target X in the observation target A can be determined easily.

Note that it is effective to switch the size of the light shielding member 8 according to the intensity of the illumination light L ₁ from the light source 2 or according to the depth of the detection target X, and the light source 2 and the light shielding member 8. As in the observation apparatus 1 in the first embodiment, the entire observation range can be observed without causing the blind spot of the light shielding member 8 by scanning in synchronization.

Next, a scattering medium observation device (hereinafter referred to as an observation device) 1 ″ according to a third embodiment of the present invention will be described below with reference to FIG.
In the description of the present embodiment, portions having the same configuration as those in the scattering medium observation device 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  The observation apparatus 1 ″ according to the present embodiment is different from the first embodiment in that a laser light source 2 ′ is used as a light source and a polarization beam splitter 4 ′ is used instead of the half mirror 4. is doing.

According to the observation apparatus 1 ″ according to the present embodiment, since the laser light L ₁ emitted from the laser light source 2 ′ is linearly polarized light, it is reflected by the polarization beam splitter 4 ′ and is observed through the objective lens 5. is irradiated. the part of the laser beam L ₁ irradiated on the observation target a, is reflected at the surface of the observation target a, the other part reflected at the surface of the. observation target a to be incident on the observation target a The laser beam L ₁ thus collected is collected by the objective lens 5 and incident on the polarization beam splitter 4 ′. In this case, since the polarization direction of the laser beam L ₁ does not change, the polarization beam splitter 4 ′ again Reflected and prevented from entering the relay optical system 9.

Laser light L ₁ incident on the observation object A without being reflected at the surface of the observation target A is scattered by the observation object A inside the scattering medium, it will form a virtual light source 2A-2C. The laser beam L ₁ is gradually disturbed polarization state according scattered by the scattering medium, will become a state of non-polarized light. As a result, the light from the virtual light sources 2A to 2C emitted from the surface of the observation target A and condensed by the objective lens 5 is transmitted through the polarization beam splitter 4 'to form images of the virtual light sources 2A to 2C. An intermediate image position B is formed by the lens 7.

In particular, the return light L ₂ laser beam L ₁ forming a virtual light source 2A to the relatively shallow position inside the observation object A is relatively deep position in the virtual light source 2B, the laser light L ₁ formed with 2C returned light L _Since there is less scattering than ₂ , the polarization state is less disturbed and contains a large amount of linearly polarized light components. Therefore, the return light L ₂ laser beam L ₁ forming a virtual light source 2A at a relatively shallow position, the linearly polarized light component is reflected by the polarization beam splitter 4 ', a relatively deep position in the virtual light source 2B, a 2C Almost the entire return light L ₂ of the formed laser light L ₁ is transmitted through the polarization beam splitter 4 ′.

  As a result, the reflected light on the surface of the observation object A and the return light from the virtual light source 2A at a relatively shallow position of the observation object A are blocked by the polarization beam splitter 4 ', and the intensity of the virtual light sources 2B and 2C at a relatively deep position is reduced. It can be relatively strong. As a result, even if the light shielding member 8 is made small, it is possible to easily detect the detection target X existing at a relatively deep position, and there is an advantage that the blind spot due to the light shielding member 8 can be reduced.

Further, as shown in FIG. 8 (a), the laser beam L ₁ is irradiated from the illumination optical system 2 'is formed in an array, in response to this, as shown in FIG. 8 (b), shielding The members 8 may be formed in an array. By doing in this way, there exists an advantage that observation over a wide range can be performed with few blind spots.

It is a whole lineblock diagram showing the observation device for scattering media concerning a 1st embodiment of the present invention. FIG. 1A is a plan view showing a relationship between a light shielding region by a light shielding member and a virtual light source formed in an observation target when the detection target exists at a relatively shallow position in the scattering medium observation apparatus of FIG. FIG. FIG. 1A is a plan view showing a relationship between a light shielding region by a light shielding member and a virtual light source formed in an observation target when the detection target is present at a relatively deep position in the scattering medium observation apparatus of FIG. FIG. FIG. 4 is a modification of the observation apparatus for scattering medium in FIG. 1 and illustrates a case where a rectangular light source image and a light shielding member are scanned. FIG. It is. It is a figure which shows the example of an observation image of the whole observation range acquired by synthesize | combining the image of FIG. It is a whole block diagram which shows the observation apparatus for scattering media which concerns on the 2nd Embodiment of this invention. It is a whole block diagram which shows the observation apparatus for scattering media concerning the 3rd Embodiment of this invention. FIG. 8 is a modification of the scattering medium observation device of FIG. 7, (a) an example of a laser light source image in an array, and (b) an example of an array of light shielding members.

Explanation of symbols

A Observation object C Image 1 Observation device (scattering medium observation device)
2 Light source 2 'Laser light source (light source)
3 Illumination optical system 6 Observation optical system 8 Shading member

Claims (9)

A light source;
An illumination optical system for guiding light from the light source to an observation target including a scattering medium;
An observation optical system that acquires an image of the observation object illuminated by the illumination optical system,
In the observation optical system, a light shielding member that shields the image of the light source projected on the surface of the observation target by the illumination optical system is disposed at a position substantially conjugate with the image of the light source. . A light source;
An illumination optical system for guiding light from the light source to an observation target including a scattering medium;
An observation optical system that acquires an image of the observation object illuminated by the illumination optical system,
An observation apparatus in a scattering medium, wherein the observation optical system photographs light emitted from a region other than the image of the light source projected onto the surface of the observation target by the illumination optical system.   The light shielding member which shields the image of the said light source projected on the surface of the said observation object by the said illumination optical system in the said observation optical system is arrange | positioned in the substantially conjugate position with the image of this light source. In-scattering medium observation device.   The scattering medium observation device according to claim 1, wherein the image of the light source and the light shielding member have a similar shape.   The observation apparatus in a scattering medium according to claim 1, wherein the light source and the light shielding member are arranged at conjugate positions. The illumination optical system includes a light source image scanning unit that scans an image of a light source projected onto the surface of the observation target in a direction intersecting an optical axis,
The observation optical system includes a light shielding member scanning unit that scans the light shielding member in a direction intersecting the optical axis,
6. The scattering medium observation device according to claim 1, further comprising a control unit that controls the light source image scanning unit and the light shielding member scanning unit in synchronization. Comprising two or more shading members,
The observation apparatus in a scattering medium according to any one of claims 1 to 3, further comprising switching means for switching a light shielding member in accordance with the intensity of light from the light source. Project the light from the light source onto the surface of the observation object, including the scattering medium,
Photographing light emitted from a region other than the image of the light source projected on the surface of the observation target,
A scattering medium observation method for observing the presence / absence of an object inside an observation target based on an acquired image.   The observation method in a scattering medium according to claim 8, wherein an image of the light source projected on the surface of the observation target is shielded.

Images