WO2013061590A1

WO2013061590A1 - Optical probe and method for manufacturing same

Info

Publication number: WO2013061590A1
Application number: PCT/JP2012/006835
Authority: WO
Inventors: 夏野　靖幸; 祥一田尾
Original assignee: コニカミノルタアドバンストレイヤー株式会社
Priority date: 2011-10-25
Filing date: 2012-10-25
Publication date: 2013-05-02
Also published as: JPWO2013061590A1

Abstract

This optical probe is provided with: a first optical fiber which has a first fiber front end part that emits irradiation light; a second optical fiber which has a second fiber front end part that receives fluorescent light or Raman scattering light; a first optical filter which is arranged on the first fiber front end part; and a second optical filter which is arranged on the second fiber front end part. At least one of the first optical fiber, the second optical fiber, the first optical filter and the second optical filter is subjected to a process of forming a metal film.

Description

Optical probe and manufacturing method thereof

The present invention relates to an optical probe, more specifically, a medical optical probe used for measuring optical characteristics inside a body cavity, and a method for manufacturing the same.

A long optical probe having flexibility (hereinafter simply referred to as “probe”) is inserted into a body cavity (in the case of digestive system, stomach, esophagus, etc.) by inserting it into a channel of an endoscope, for example. It is conventionally known to measure the optical characteristics of a living tissue inside a body cavity by using a probe using a probe (see, for example,

Patent Documents

1, 2, and 3).

As a spectroscopic method for measurement using a probe, a near infrared spectroscopic method, a fluorescence method, a Raman spectroscopic method, and the like are known. In the measurement of the inside of a body cavity by near infrared spectroscopy, near-infrared light is irradiated to a site to be observed in the body cavity, for example, a lesion, and the spectrum of reflected light from the lesion is analyzed, so that the living body of the lesion is analyzed. Analyze tissue components. A common point between fluorescence and Raman spectroscopy is that a biological tissue is irradiated with a relatively narrow-band excitation light, and as a result, fluorescence or Raman scattered light (measurement light) that appears in a wavelength region different from the excitation light is included. The reflected light is generated from the living tissue, and the reflected light is received and detected by the spectroscope, thereby analyzing the state of the living tissue of the lesioned part.

By the way, in a probe used for measurement of the inside of a body cavity by Raman spectroscopy, for example, as described in Patent Document 1, an optical filter that passes only the wavelength of irradiation light is attached to the tip on the irradiation side, and the tip on the light receiving side. Is equipped with an optical filter for cutting the wavelength of the irradiation light.

Usually, since the intensity of the measurement light is significantly lower than the intensity of the excitation light, it is required to detect only the measurement light by separating the high-intensity excitation light and the low-intensity measurement light. For this purpose, it is known to install an optical filter in a probe that uses both an optical fiber for irradiating excitation light (irradiation optical fiber) and an optical fiber for receiving measurement light (light receiving optical fiber). For example, an optical filter that passes only the wavelength of the excitation light is installed near the exit end face of the irradiation optical fiber, and an optical filter that cuts the wavelength of the excitation light is installed near the incident end face of the light receiving optical fiber (for example, patent Reference 3).

Even when the optical filter is installed as described above in the probe using both the irradiation optical fiber and the light receiving optical fiber, crosstalk between these fibers may be a problem. That is, extremely weak light leaking from the irradiation optical fiber may enter the light receiving optical fiber, and a part of the light may be conducted in the light receiving optical fiber. This light is very small of the light conducted through the irradiation optical fiber, but usually the optical signal itself to be measured is very small, and may have the same intensity as this optical signal.

In order to prevent such crosstalk, the probe described in Patent Document 2 uses a quartz fiber having an outer layer with a metal jacket having a thickness of about 10 to 20 μm as an irradiation optical fiber, and leaks light from the outer peripheral surface thereof. It is preventing.

Similarly, in order to improve the accuracy of measurement inside the body cavity by Raman spectroscopy, it is required to avoid the influence of Raman scattered light or fluorescence caused by body fluid in the body cavity by ensuring the airtightness of the optical path. It is done. Therefore, it is necessary to mount the optical filters on the irradiation side and the light receiving side so that the airtightness of the optical path is ensured.

In addition, it is also required to ensure the light shielding property of the outer peripheral portion of each optical filter so that light does not leak from the outer peripheral portion of the irradiation side optical filter to the outer peripheral portion of the light receiving side optical filter. This is because the above crosstalk can occur between filters or between a filter and an optical fiber.

JP 2005-305182 A Japanese Patent No. 4588324 JP 2006-317319 A

However, the optical fiber with the metal jacket as described above is a probe due to the fact that there are few suppliers, it is expensive, and the core diameter / cladding diameter / jacket diameter is limited in what is usually available. There is a problem that the optical design is limited.

Also, as a general mounting method for ensuring the airtightness of the optical path, there is an adhesive bonding. However, since the adhesive is usually a plastic that generates fluorescence and Raman scattered light with respect to the irradiation light, there is a problem that it is not suitable for use in an optical path.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical probe capable of ensuring light-shielding performance without using a special optical fiber such as an optical fiber with a metal jacket in a probe including an optical fiber and a filter, and a method for manufacturing the same. That is. The light shielding property here means, for example, the light shielding property between the irradiation optical fiber and the light receiving optical fiber, between the filters, and between the fiber and the filter.

Another object of the present invention is to provide an optical probe capable of improving the accuracy of internal measurement of a body cavity by Raman spectroscopy and a method for manufacturing the same, in which the tightness of the optical path is ensured.

The optical probe according to the present invention is:
A first optical fiber having a first fiber tip that emits irradiation light to the site to be observed in the body cavity;
A second optical fiber having a second fiber tip that receives fluorescence or Raman scattered light from the site to be observed;
A first optical filter disposed at the tip of the first fiber;
A second optical filter disposed at the tip of the second fiber,
At least one of the first optical fiber, the second optical fiber, the first optical filter, and the second optical filter is subjected to a process for forming a metal film.

The method for producing an optical probe according to the present invention includes:
A first optical fiber having a first fiber tip that emits irradiation light to the site to be observed in the body cavity;
A second optical fiber having a second fiber tip that receives fluorescence or Raman scattered light from the site to be observed;
A first optical filter disposed at the tip of the first fiber;
A second optical filter disposed at the tip of the second fiber, and a method of manufacturing an optical probe comprising:
At least one of the first optical fiber, the second optical fiber, the first optical filter, and the second optical filter is subjected to a process of forming a metal film.

According to the present invention, in a probe having an optical fiber and a filter, light shielding properties can be ensured without using a special optical fiber such as an optical fiber having a metal jacket.

Moreover, according to the present invention, the accuracy of measurement inside the body cavity by Raman spectroscopy can be improved.

Diagram showing a configuration example of a diagnostic system The perspective view of the front-end | tip part of the endoscope used for the diagnostic system of FIG. The figure which shows schematically the internal structure of the probe which concerns on Embodiment 1 of this invention. Sectional drawing which shows the structure of the optical fiber for irradiation in the probe which concerns on Embodiment 1, and the optical fiber for light reception except a front-end | tip part Sectional drawing which shows the principal part structure of the probe which concerns on Embodiment 1. FIG. Sectional drawing which shows the 1st modification about the principal part structure of the probe which concerns on Embodiment 1. FIG. Sectional drawing which shows the 2nd modification about the principal part structure of the probe which concerns on Embodiment 1. FIG. Sectional drawing which shows the 3rd modification about the principal part structure of the probe which concerns on Embodiment 1. FIG. Sectional drawing which shows the principal part structure of the probe which concerns on Embodiment 2 of this invention The figure which shows the 1st example of the arrangement | positioning position of the metal material for joining determined by the relationship with metallized film thickness in the probe which concerns on Embodiment 2. FIG. The figure which shows the 2nd example of the arrangement position of the metal material for joining determined by the relationship with metallized film thickness in the probe which concerns on Embodiment 2. FIG. The figure which shows the 3rd example of the arrangement position of the metal material for joining determined by the relationship with metallized film thickness in the probe which concerns on Embodiment 2. FIG. Sectional drawing which shows the principal part structure of the probe which concerns on Embodiment 3 of this invention Sectional drawing which shows the principal part structure of the probe which concerns on Embodiment 4 of this invention Sectional drawing which shows the principal part structure of the probe which concerns on Embodiment 5 of this invention

According to the configuration of the present invention (hereinafter, corresponding to Embodiments 1 to 5), the effect of eliminating or reducing the crosstalk of optical components (optical fibers and optical filters) at the probe tip can be obtained. Can be detected with high efficiency.

In addition, by applying a surface treatment that forms a metal film on the surface of the tip region of the optical fiber (hereinafter referred to as

Embodiments

1, 2, and 5), unnecessary light is incident on the optical fiber that has been subjected to the surface treatment.・ Ejecting can be suppressed. In particular, by forming a metal film on both the outgoing (irradiation) and received optical fibers (hereinafter, corresponding to the first, second, and fifth embodiments), unnecessary light can be reliably blocked, and the outgoing (irradiation), Crosstalk in the direction perpendicular to the optical axis between the received optical fibers can be eliminated.

Also, forming a metal film on the outer periphery of the optical filter (hereinafter, corresponding to Embodiments 2 to 5) is very effective in eliminating crosstalk. Since the optical filter has a thickness in the optical axis direction, light may leak from the thickness portion. In the optical probe of the present invention, since the optical filter is provided for both emission (irradiation) and light reception, it is considered that the light leaked from the thickness portion may cause crosstalk. Such a problem can be solved by forming a metal film and shielding light.

Further, it is most preferable in terms of light shielding to form a metal film on both the emission (irradiation) and light reception optical filters (hereinafter, corresponding to Embodiments 2 to 5). Joining two optical filters by brazing or soldering (hereinafter, corresponding to Embodiments 2 to 5) contributes to miniaturization in configuring the optical probe, which is very preferable.

Of course, a metal film may be formed on both the tip region of the optical fiber and the outer periphery of the optical filter (hereinafter, corresponding to Embodiments 2 to 5). Furthermore, a form in which these are joined (hereinafter, corresponding to Embodiments 3 and 4) is also preferable and can be employed. In this case, light shielding is particularly reliably performed.

In the internal structure of the optical probe, it is preferable that the position and state of the optical fiber be fixed by a holding portion (hereinafter, corresponding to Embodiments 1 to 5). This holding portion can be, for example, an exterior tube that holds a fiber bundle (hereinafter, corresponds to Embodiment 1).

On the other hand, the holding unit may be a so-called ferrule (hereinafter, corresponding to Embodiments 1 to 5). In this case, there is an advantage that it can be easily held and fixed by an exterior member or a frame member that holds the ferrule, and if the tip surface of the ferrule and the tip surface of the optical fiber are the same surface (hereinafter referred to as an embodiment) This also has the advantage of easy tip polishing. And especially in this case, the crosstalk between optical fibers can be eliminated.

Further, when the tip surface of the ferrule and the tip surface of the optical fiber are not the same surface (hereinafter referred to as Embodiments 2 to 5), a metal film is formed on the surface of the tip region of the optical fiber, thereby crosstalk. Can be reduced.

Further, the optical fiber is preferably a plastic fiber in order to achieve flexibility in the optical axis direction of the entire optical probe (hereinafter, corresponding to Embodiments 1 to 5). For the tip region of the optical fiber, it is preferable to remove the plastic jacket in order to form a metal film (hereinafter, corresponding to

Embodiments

1, 2, and 5).

The configuration of the optical probe is preferably a configuration in which a metal frame is provided and the outer peripheral portion of the optical filter is joined to the metal frame (hereinafter, corresponding to Embodiments 2 to 5). With such a configuration, airtightness is maintained before and after the optical filter, and foreign matter can be prevented from entering the optical path. In particular, it is most reliable and preferable in terms of strength if it is bonded over the entire thickness direction of the optical filter (hereinafter, corresponding to

Embodiments

2, 3, and 5).

Here, as a method of forming a metal film on the surface of the tip region of the optical fiber and the outer peripheral portion of the optical filter, metal plating and metallization treatment may be mentioned. Any method means a process of forming (metalizing) a metal film on the surface of an optical fiber or optical filter which is a non-metallic material.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram illustrating a configuration example of a diagnostic system. A diagnostic system 1 in FIG. 1 includes an endoscope 2, an endoscope processor 3, a base unit 4, an input device 5, monitors 6, 7, and a probe 10 according to Embodiment 1 of the present invention.

The endoscope 2 is provided at a long flexible endoscope body 21 formed so as to be capable of being introduced into a body cavity, and a proximal end portion (endoscope proximal end portion) 21a of the endoscope body 21. And the cable 23 that connects the endoscope main body 21 and the endoscope processor 3 via the operation unit 22 so as to communicate with each other.

The endoscope main body 21 has a flexibility that can be easily bent following the curvature of the body cavity when entering the inside of the body cavity over substantially the entire length thereof. Further, the endoscope body 21 has a mechanism (not shown) capable of bending a predetermined range (operable portion 21c) on the endoscope distal end portion 21b side at an arbitrary angle in accordance with the operation of the knob 22a of the operation portion 22. Have

The endoscope main body 21 has a camera CA, a light guide LG, and a channel CH as shown in a perspective view (FIG. 2) of the endoscope distal end portion 21b. The light guide LG guides light (visible light) emitted from the illumination light source 31 of the endoscope processor 3 to the endoscope distal end portion 21b, and emits the light from the end face of the endoscope distal end portion 21b. The camera CA is an electronic camera equipped with a solid-state imaging device, images an area illuminated by light emitted from the light guide LG, and sends the signal (imaging signal) to the image processing unit 32 of the endoscope processor 3. To transmit. An image (endoscopic image) based on the transmitted imaging signal is displayed on the monitor 6. The channel CH is a lumen having a diameter of, for example, 2.6 mm formed in the endoscope main body 21 so as to communicate with the introduction port 22 b formed in the operation unit 22.

The probe main body 11 has an outer diameter (for example, 2.4 mm) that can be inserted into the channel CH of the endoscope 2, and is a long flexible wire that extends from the probe proximal end portion 11a to the probe distal end portion 11b. It is a shaped member and is introduced into the body cavity by insertion through the channel CH. The probe body 11 is connected to the base unit 4 via

connectors

11c and 11d provided at the probe base end portion 11a. The probe body 11 guides the excitation light emitted from the laser 41 of the base unit 4 by the irradiation optical fiber 110 (see FIG. 3), and emits the light as irradiation light to the observation target site in the body cavity. The laser 41 is a semiconductor laser, a solid laser, or the like, but it is preferable to use a semiconductor laser from the viewpoint of downsizing the apparatus. The wavelength of the laser light is preferably 400 to 410 nm, 487 nm, 630 to 660 nm, 780 to 790 nm, 830 to 860 nm, 1290 to 1330 nm, or 1520 to 1580 nm. The light source of the excitation light may not be the laser 41 but may be an LED (Light Emitting Diode) or the like.

Also, the probe body 11 receives the reflected light from the site to be observed by the light receiving optical fiber 120 (see FIG. 3), and guides the light to the spectroscope 42 of the base unit 4. The fluorescence or Raman scattered light contained in the light guided to the spectroscope 42 is subjected to spectrum analysis by the spectroscope 42. The spectrum analysis result is subjected to image processing and the like by a CPU (Central Processing Unit) 43a of the computer 43 and displayed on the monitor 7 in the form of a graph or the like. The CPU 43a may determine a medical condition and the like, and the determination result may be stored in the memory 43b and displayed on the monitor 7. The execution and setting of various analyzes and determinations in the computer 43 can be performed by operating the input device 5 (for example, a keyboard or a mouse).

FIG. 3 is a diagram schematically showing the internal configuration of the probe 10 shown in FIG.

The irradiation optical fiber 110 (first optical fiber) and the light receiving optical fiber 120 (second optical fiber) are both long linear members having a total length of several meters and an outer diameter of about 100 to 300 μm, and are housed in the probe body 11. ing. The irradiation optical fiber 110 is optically connected to the laser 41 of the base unit 4 by the connector 11c of the probe base end portion 11a. The light receiving optical fiber 120 is optically connected to the spectroscope 42 of the base unit 4 by a connector 11d of the probe base end portion 11a.

The tip region (fiber tip region) 111 of the irradiation optical fiber 110 and the tip region (fiber tip region) 121 of the light receiving optical fiber 120 are held by the holding unit 130. Accordingly, the irradiation optical fiber 110 and the light receiving optical fiber 120 form a bundle, and the emission end face (that is, the emission surface of the irradiation light to the observation target part) and the incident end face (that is, the light reception surface of the reflected light from the observation target part). It is positioned. The lengths of the

fiber tip regions

111 and 121 held by the holding unit 130 are about 5 to 10 mm. The main configuration of the probe 10 including the holding unit 130 that holds the

fiber tip regions

111 and 121 will be described later.

The optical filter 141 (first optical filter) is located in the irradiation optical system including the irradiation optical fiber 110, and one end surface thereof is close to the emission end surface of the fiber tip region 111. The optical filter 141 has a configuration in which a light absorbing material (or a light reflecting material) is dispersed in a transparent base material such as quartz glass, or a configuration in which a dielectric multilayer film is formed on a transparent substrate. Only the wavelength can be transmitted.

The optical filter 142 (second optical filter) is located in the light receiving optical system including the light receiving optical fiber 120, and one end surface thereof is close to the incident end surface of the fiber tip region 121. The optical filter 142 has a configuration in which a light absorbing material (or light reflecting material) is dispersed in a transparent base material such as quartz glass, or a configuration in which a dielectric multilayer film is formed on a transparent substrate. Only the wavelength cannot be transmitted.

A lens 150 made of, for example, quartz glass or sapphire is disposed at the probe tip 11b in front of the

optical filters

141 and 142. The lens 150 is equipped for the purpose of improving the air tightness of the optical path, the external light reception, the external light reception, and the optical path. The lens 150 may be a plurality of lens groups.

The

fiber tip regions

111 and 121, the holding unit 130, the

optical filters

141 and 142, and the lens 150 are housed in a cylindrical metal frame (not shown) having a length of about 10 to 15 mm.

The configuration of the irradiation optical fiber 110 and the light receiving optical fiber 120 excluding the

fiber tip regions

111 and 121 has a three-layer structure including a core, a clad, and a plastic jacket, as shown in the sectional view of FIG.

The core and the clad are made of a transparent material such as quartz glass, and the core has a higher refractive index than that of the clad, so that light is confined in the core and propagates. In order to improve the handleability of the irradiation optical fiber 110 and the light receiving optical fiber 120, the core and clad of the irradiation optical fiber 110 and the light receiving optical fiber 120 are made of a plastic that is resistant to bending (that is, the irradiation optical fiber 110 and the light receiving optical fiber). 120 is preferably configured as a plastic fiber). The plastic jacket covers the outer periphery of the clad for reinforcement of the irradiation optical fiber 110 and the light receiving optical fiber 120, improvement of mechanical characteristics, and the like.

FIG. 5 is a cross-sectional view showing the main configuration of the probe 10 including the holding portion 130 that holds the

fiber tip regions

111 and 121.

The holding unit 130 includes a ferrule 132 and an outer skin 134. The ferrule 132 is a member made of, for example, metal, quartz glass, zirconia, or the like. The ferrule 132 is formed with a hole into which the irradiation optical fiber 110 and each light receiving optical fiber 120 can be inserted. The irradiation optical fiber 110 and the light receiving optical fiber 120 are held by the ferrule 132 by being inserted into this hole. The outer skin 134 is a thin tube made of vinyl, for example, and covers the outer periphery of the ferrule 132.

The irradiation optical fiber 110 and the light receiving optical fiber 120 held by the holding unit 130 are arranged so as to form a bundle in contact with each other or close to each other for the purpose of improving the light receiving efficiency and reducing the probe diameter.

The light receiving optical fiber 120 disposed so as to surround the irradiation optical fiber 110 has the three-layer structure shown in FIG. 4 in the fiber tip region 121 as well as the region other than the fiber tip region 121.

On the other hand, in the optical fiber for irradiation 110, unlike the region other than the fiber tip region 111, the plastic jacket corresponding to the outer layer of the three-layer structure is removed in the fiber tip region 111, and the portion (jacket removing portion) is made of metal. Plating is applied. The thickness of the metal plating layer 112 is about several μm to 100 μm, and can be adjusted by the length of the metal plating process, the number of times the metal plating process is repeated, or the method of the metal plating process. Therefore, the fiber outer diameter can be set to an arbitrary diameter. In addition, examples of the metal material used in the plating process and constituting the metal plating layer 112 include Ni, Ti, Au, and the like.

Thus, in this embodiment, optical fibers having a plastic jacket are used as the irradiation optical fiber 110 and the light receiving optical fiber 120. A plastic jacket type optical fiber is advantageous in comparison with a metal jacket type optical fiber in that it is not only inexpensive but also has a low possibility of deterioration or peeling when repeatedly bent. Moreover, the use of a plastic jacket type optical fiber can ensure the flexibility of the probe 10 and facilitate the handling of the probe 10 during production, packaging, and treatment.

In addition, when a generally distributed connector is used as the

connectors

11c and 11d used for connection to the base unit 4, the usable fiber outer diameter is limited by the connector. However, since plastic jacket type optical fibers have a wide variety of fiber outer diameters, it is easy to obtain optical fibers suitable for the connectors used.

The plastic jacket type optical fiber to be used is plated with metal. Metal plating can be applied to a desired location. Therefore, as in the present embodiment, the metal plating layer 112 can be formed only in the fiber tip region 111 of the irradiation optical fiber 110. Therefore, the metal plating layer 112 does not become an obstacle to the above effect due to the use of a plastic jacket type optical fiber. Further, since the metal plating layer 112 is formed in the fiber tip region 111, it is possible to prevent light from leaking out of the fiber tip region 111 by the metal plating layer 112. That is, the light shielding property capable of preventing crosstalk between the irradiation optical fiber 110 and the light receiving optical fiber 120 is formed so that the irradiation optical fiber 110 and the light receiving optical fiber 120 form a bundle (that is, in contact with or close to each other). This can be ensured in the fiber tip region 111, which is a held region. In addition, since the fiber outer diameter does not become a problem in the process of metal plating, it is possible to use optical fibers of various sizes. Further, when the outer diameter and inner diameter of the tube (outer skin 134) and the outer diameters of the irradiation optical fiber 110 and the light receiving optical fiber 120 are determined from the specifications, the bundle of the irradiation optical fiber 110 and the light receiving optical fiber 120 is not necessarily within the tube. It may not be kept in close contact. In such a case, the filling rate of the irradiation optical fiber 110 and the light receiving optical fiber 120 within the inner diameter of the tube is increased by thickening the diameter of the irradiation optical fiber 110 by performing metal plating on the fiber tip region 111 of the irradiation optical fiber 110. As a result, the stability of the bundle of the irradiation optical fiber 110 and the light receiving optical fiber 120 in the tube can be improved.

In the present embodiment, the plastic jacket is removed from the fiber tip region 111, and the jacket removing portion is subjected to metal plating. In the fiber tip region 111, metal plating may be applied to the outer peripheral portion without removing the plastic jacket, but removing the plastic jacket is advantageous in terms of reducing the probe diameter.

Hereinafter, modifications of the main configuration of the probe 10 will be described with some examples.

In the first modification shown in FIG. 6, the ferrule 132 used in the example shown in FIG. 5 is not used. Accordingly, the light receiving optical fiber 120 surrounding the irradiation optical fiber 110 is bonded to the irradiation optical fiber 110 with an adhesive, for example, in contact with the metal plating layer 112 on the outer periphery of the irradiation optical fiber 110 and inserted into the outer skin 134. ing. In this configuration, a positioning member such as the ferrule 132 is not required, and the irradiation optical fiber 110 can be easily arranged at the center of the probe 10. In addition, since the ferrule 132 is not used, the probe diameter can be reduced, and the probe outer diameter can be adjusted by adjusting the thickness of the metal plating layer 112.

The second modification shown in FIG. 7 is similar to the example shown in FIG. 6, but the plastic jacket is removed from the fiber tip region 121 of the light receiving optical fiber 120, and a metal plating layer 122 is formed on the jacket removal portion by metal plating. This is different from the example shown in FIG. In this configuration, since the metal plating is applied to both the irradiation optical fiber 110 and the light receiving optical fiber 120, the light shielding property between the irradiation optical fiber 110 and the light receiving optical fiber 120 can be further improved.

The third modification shown in FIG. 8 is similar to the example shown in FIG. 7, but the plastic jacket is not removed in the fiber tip region 111 of the irradiation optical fiber 110, leaving the three-layer structure shown in FIG. This is different from the example shown in FIG. In this configuration, even if light leaks from the fiber tip region 111 of the irradiation optical fiber 110, the metal plating layer 122 can prevent this light from entering the fiber tip region 121 of the light receiving optical fiber 120.

In each of the above examples, the number of irradiation optical fibers 110 and light receiving optical fibers 120 can be changed as appropriate.

(Embodiment 2)
The second embodiment of the present invention will be described below. In the present embodiment, the same or corresponding components as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 9 is a cross-sectional view showing the main configuration of the probe 15 according to the present embodiment that can be used in the above-described diagnostic system 1. The probe 15 has a probe main body 11 that extends from the probe proximal end portion 11 a to the probe distal end portion 11 b, can be inserted into the channel CH of the endoscope 2, and can be connected to the base unit 4, similarly to the probe 10 described above.

The irradiation optical fiber 211 (first optical fiber) is a long and narrow optical fiber having the three-layer structure shown in FIG. In the tip region of the irradiation optical fiber 211, the plastic jacket corresponding to the outer layer of the three-layer structure is removed, and the metal plating layer 112 is formed in that portion. The irradiation optical fiber 211 emits the irradiation light to the site to be observed from the fiber tip portion 211a (first fiber tip portion).

The light receiving optical fiber 212 (second optical fiber) is a long and narrow optical fiber having the three-layer structure of FIG. The metal plating layer 112 is also formed in the tip region of the light receiving optical fiber 212 as in the case of the irradiation optical fiber 211. The optical fiber for light reception 212 receives reflected light from the observation target part including Raman scattered light generated with respect to the irradiation light by the living tissue of the observation target part at the fiber tip part 212a (second fiber tip part). .

The irradiation optical fiber 211 and the light receiving optical fiber 212 are held by a ferrule 213 (holding unit) made of, for example, metal, quartz glass, zirconia, or the like. The ferrule 213 is fitted into a cylindrical metal frame 214 (for example, made of stainless steel) having a length of about 5 to 10 mm. As a result, the irradiation optical fiber 211 including the fiber tip 211 a and the light receiving optical fiber 212 including the fiber tip 212 a are accommodated in the metal frame 214.

A lens 215 having a circular cross section (not shown) is disposed at the probe tip 11b and is held in the metal frame 214. The lens 215 is equipped for the purpose of improving the light irradiation to the outside, the reception of the light from the outside, and the air tightness of the optical path, and is made of, for example, quartz glass or sapphire. As a method for holding the lens 215, a conventionally known method can be employed. In the present embodiment, the lens 215 has a convex surface on the probe base end 11a side as shown in FIG. 9, but it may be a flat surface. Although the surface on the tip 11b side is formed in a flat shape, it may be convex. The lens 215 may be a plurality of lens groups.

Optical filters

221 and 222 are disposed between the

fiber tip portions

211 a and 212 a and the lens 215, and are housed in the metal frame 214. Each of the

optical filters

221 and 222 has a semicircular cross section (not shown) so as to form a circular cross section by combination.

The optical filter 221 (first optical filter) is located in the irradiation optical system including the irradiation optical fiber 211, and one end face thereof is close to the fiber tip 211 a of the irradiation optical fiber 211. The internal configuration and wavelength transmission characteristics of the optical filter 221 are the same as those of the optical filter 141 described above.

The optical filter 222 (second optical filter) is located in the light receiving optical system including the light receiving optical fiber 212, and one end face thereof is close to the fiber tip 212 a of the light receiving optical fiber 212. The internal configuration and wavelength transmission characteristics of the optical filter 222 are the same as those of the optical filter 142 described above.

The filter outer peripheral part 221a which is the outer peripheral part of the semicircular cross section of the optical filter 221 is subjected to metallization processing on the whole. Therefore, a metallized film 231 is formed on the filter outer peripheral part 221a. The metallized film thickness can be adjusted by the number of times the metallization process is repeated. The metal material used in the metallization process and constituting the metallization film 231 is preferably Ni, Ti or Au. The metal material is preferably a single material, but may be an alloy composed of a plurality of materials. However, when an alloy is used, the composition is preferably known. Various methods can be adopted as the metallization process. For example, techniques by vapor deposition such as physical vapor deposition and chemical vapor deposition can be used. Further, a method of bringing a molten metal into contact, a method of electroless plating, a method of combining these, a method of further combining electrolytic plating with the method of combining them, or the like may be used.

Of the metallized film 231 formed on the entire filter outer

peripheral portions

221a and 222a, portions facing each other are brazed or soldered. Therefore, the

optical filters

221 and 222 are joined to each other by the joining metal material 241 that is the brazing material or solder used for brazing or soldering.

As described above, in this embodiment, an airtight joint is formed between the optical filter 221 of the irradiation optical system and the optical filter 222 of the light receiving optical system by metallization processing and brazing or soldering. Therefore, airtightness between the optical filter 221 of the irradiation optical system and the optical filter 222 of the light receiving optical system can be ensured without using an adhesive. Adhesion with an adhesive is conventionally known as a general adhesion method for ensuring airtightness, but an adhesive is usually a plastic that generates fluorescence and Raman scattered light with respect to irradiation light. It is not necessarily suitable for use in the optical path. On the other hand, in this embodiment, an adhesive mainly made of plastic is not used at the joint between the

optical filters

221 and 222. Thereby, generation | occurrence | production of the Raman scattered light and fluorescence resulting from use of an adhesive agent can be prevented reliably. Furthermore, the filter outer peripheral part 221a of the irradiation optical system and the filter outer peripheral part 222a of the light receiving optical system are both subjected to metallization processing. Therefore, leakage of light from the filter outer peripheral portion 221a of the irradiation optical system to the filter outer peripheral portion 222a of the light receiving optical system is caused by the metallized film 231 interposed between the optical filter 221 of the irradiation optical system and the optical filter 222 of the light receiving optical system. Can be suppressed. Therefore, it is possible to suppress the mixing of noise light different from the Raman scattered light generated by the biological tissue of the observation target site into the light detected by the spectroscope 42. Therefore, it is possible to improve the accuracy of measurement inside the body cavity by Raman spectroscopy.

Further, among the metallized film 131 formed on the entire filter outer

peripheral portions

221a and 222a, a portion facing the metal frame 214 is also brazed or soldered. Therefore, the

optical filters

221 and 222 and the metal frame 214 are also joined by the joining metal material 241.

That is, an airtight joint is formed between the

optical filters

221 and 222 and the metal frame 214 by metallization and brazing or soldering. Therefore, airtightness can be ensured between the

optical filters

221 and 222 and the metal frame 214 without using an adhesive mainly made of plastic. Thereby, it can prevent reliably that a Raman scattered light and fluorescence generate | occur | produce from the junction part between each optical filter 221,222 and the metal frame 214. FIG.

The joining metal material 241 is preferably a single material such as Ag or Cu, but may be an alloy composed of a plurality of materials. However, when an alloy is used, the composition is preferably known.

In the probe 15 of the present embodiment, as described above, the metallized film thickness can be adjusted by the number of times the metallization process is repeated. That is, the metallized film thickness can be arbitrarily set.

When the metallized film thickness is set to, for example, about 100 μm or more, it is easy to ensure sufficient light shielding properties with the metallized film 231 alone. Therefore, for example, as shown in FIG. 10A, the bonding metal material 241 interposed between the

optical filters

221 and 222 and the metal frame 214 does not wrap around the entire thickness direction of the

optical filters

221 and 222. You may arrange | position so that the filter outer

peripheral parts

221a and 222a may be covered only in a part of the vertical direction. In this case, even if light sneaks into the gap between the metallized film 231 and the metal frame 214, the light is incident on the

optical filters

221 and 222 via the filter outer

peripheral portions

221a and 222a only by the metallized film 231. It can be surely prevented.

The joining metal material 241 shown in FIG. 10A can be formed by the following method, for example. First, before attaching the

optical filters

221 and 222 to the metal frame 214, a metal paste is disposed in the vicinity of the ferrule 213. After the

optical filters

221 and 222 are attached to the metal frame 214, the metal paste is melted by heating, and the metal paste is infiltrated into the gap between the metallized film 231 and the metal frame 214 using a capillary phenomenon. Then, after the metal paste penetrates into the gap, the metal paste is cooled.

Note that the bonding metal member 241 that covers the filter outer

peripheral portions

221a and 222a only in a part of the thickness direction of the

optical filters

221 and 222 is on the lens 215 side (in other words, the probe tip portion 11b) as shown in FIG. 10B. It may be.

Further, when the metallized film thickness is set to, for example, less than 100 μm, particularly about 10 μm, the metallization processing cost can be suppressed at a low cost. However, in this case, it is not easy to secure sufficient light shielding properties only with the metallized film 231. Therefore, for example, as shown in FIG. 10C, the bonding metal material 241 interposed between the

optical filters

221 and 222 and the metal frame 214 wraps around the entire area in the thickness direction of the

optical filters

221 and 222. It is preferable that the filter is disposed so as to cover the filter outer

peripheral portions

221a and 222a.

(Embodiment 3)
FIG. 11 is a cross-sectional view showing the main configuration of the probe according to Embodiment 3 of the present invention. The main configuration of the probe 20 of the present embodiment shown in FIG. 11 is similar to the main configuration of the probe 15 of the second embodiment shown in FIG. Therefore, in the present embodiment, the same or corresponding components as those described in the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted, and the difference from the second embodiment. The explanation will be focused on.

As shown in FIG. 11, in the probe 20, the irradiation optical fiber 211 and the light receiving optical fiber 212 protrude from the ferrule 213 toward the probe tip 11b. Therefore,

protrusions

211 b and 212 b extending from the ferrule 213 to the

optical filters

221 and 222 are formed in the irradiation optical fiber 211 and the light receiving optical fiber 212.

In general, an epoxy-based adhesive can be used for bonding between the ferrule 213 and the irradiation optical fiber 211 and the light-receiving optical fiber 212, but there is a possibility that the adhesive protrudes to the protruding

portions

211b and 212b.

Therefore, the fiber outer

peripheral portions

211c and 212c, which are the outer peripheral portions of the protruding

portions

211b and 212b, are subjected to the same metallization processing as the

optical filters

221 and 222, respectively. Therefore, a metallized film 232 is formed on the fiber outer

peripheral portions

211c and 212c.

According to this configuration, even if the adhesive protrudes from the ferrule 213 to the protruding

portions

211b and 212b, the adhesive does not enter between the metallized film 232 and the fiber outer

peripheral parts

211c and 212c, and the metallized film 232 outside. It will come out in the gap. Therefore, the metallized film 232 can reliably prevent the optical path from being affected by the adhesive protruding from the ferrule 213.

(Embodiment 4)
FIG. 12 is a cross-sectional view showing the main configuration of the probe according to Embodiment 4 of the present invention. The main configuration of the probe 30 of the present embodiment shown in FIG. 12 is similar to the main configuration of the

probes

15 and 20 of the second and third embodiments shown in FIGS. Therefore, in this embodiment, the same or corresponding components as those described in

Embodiments

2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted, and Embodiments 2 and 3 are omitted. The difference will be mainly described.

As shown in FIG. 12, in the probe 30, the

optical filters

221 and 222 are equivalent to the irradiation optical fiber 211 and the light receiving optical fiber 212 so that the filter outer

peripheral parts

221a and 222a are flush with the fiber outer

peripheral parts

211c and 212c. Is processed into a size (cross section). The filter outer

peripheral portions

221a and 222a and the fiber outer

peripheral portions

211c and 212c having the metallized

films

231 and 232 are brazed or soldered, respectively. Therefore, the bonding between the optical filter 221 and the irradiation optical fiber 211 and the bonding between the optical filter 222 and the light receiving optical fiber 212 are formed by the

bonding metal materials

241 and 242.

According to this configuration, an airtight joint by metallization processing and brazing or soldering is formed between the

optical filters

221 and 222, the irradiation optical fiber 211, and the light receiving optical fiber 212. Therefore, the

optical filters

221 and 222 are directly connected to the irradiation optical fiber 211 and the light receiving optical fiber 212. Therefore, it is possible to prevent a gap in which noise light may circulate between the

optical filters

221 and 222, the irradiation optical fiber 211, and the light receiving optical fiber 212.

In the present embodiment, since the irradiation optical fiber 211 and the light receiving optical fiber 212 have the metallized film 232, it is not necessary to form a metal plating layer.

(Embodiment 5)
FIG. 13 is a cross-sectional view showing the main configuration of the probe according to Embodiment 5 of the present invention. The main configuration of the probe 40 of the present embodiment shown in FIG. 13 is similar to the main configuration of the

probes

15, 20, 30 of the second to fourth embodiments shown in FIGS. Therefore, in the present embodiment, the same or corresponding components as those described in Embodiments 2 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted, and Embodiments 2 to 4 are omitted. The difference will be mainly described.

As shown in FIG. 13, in the probe 40, the fiber tip portion 212a is disposed closer to the probe tip portion 11b than the fiber tip portion 211a, so that the length of the light receiving optical fiber 212 is the length of the irradiation optical fiber 211. It is longer than that.

According to this configuration, it is possible to efficiently collect Raman scattered light having a light amount that is much smaller than the irradiation light in the optical fiber 212 for light reception.

More specifically, vignetting can be prevented from occurring in the light emitted from the irradiation optical fiber 211 and the light incident on the light receiving optical fiber 212. In general, light emitted from an optical fiber or light incident on an optical fiber is divergent light or convergent light. For example, in the case of quartz fiber, NA (Numerical Aperture: numerical aperture) is about 0.2. In order to efficiently receive the reflection from the site to be observed, it is necessary to maximize the NA of the optical fiber (full NA). In the configuration examples shown in FIGS. 9 to 12, there is a possibility that vignetting may occur due to the optical filter 221 disposed in front of the irradiation optical fiber 211 and the metallized film 231 and the like around the optical filter 221 to hinder improvement in light receiving efficiency. In the configuration example shown in FIG. 13, the occurrence of vignetting can be prevented by separating the irradiation optical fiber 211 and the light receiving optical fiber 212 from each other.

Moreover, it is necessary to receive scattered light from a living body for observation with light. For this purpose, a layout in which the measurement target region is irradiated over a wide area with respect to irradiation and the light is focused on the fiber tip portion 212a is preferable. In the configuration example illustrated in FIG. 13, the irradiation optical fiber 211 can be relatively distant from the observation target part, and the light receiving optical fiber 212 can be relatively close. Therefore, the emitted light from the irradiating optical fiber 211 can be applied to the observation target area in a wide area, and the light can be condensed on the light receiving optical fiber 212.

Further, as shown in FIG. 13, a ferrule 213 may be interposed between the irradiation optical fiber 211 and the light receiving optical fiber 212 so that they are separated from each other. In this case, both the irradiation with the irradiation optical fiber 211 and the light reception with the light receiving optical fiber 212 can be performed with the full NA of the fiber, and the efficiency of both irradiation and light reception can be improved.

The embodiments of the present invention have been described above. The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The disclosures of the description, drawings and abstract contained in Japanese Patent Application No. 2011-257360 filed on November 25, 2011 and Japanese Patent Application No. 2011-233809 filed on October 25, 2011 are all incorporated herein. The

DESCRIPTION OF SYMBOLS 1 Diagnostic system 2 Endoscope 3 Endoscope processor 4 Base unit 5 Input device 6, 7

Monitor

10, 15, 20, 30, 40 Probe 11 Probe body 11a Probe base end part 11b

Probe tip part

11c,

11d Connector

110, 211 Optical fiber for

irradiation

111, 121

Fiber tip region

112, 122

Metal plating layer

120, 212 Optical fiber for receiving light 130

Holding part

132, 213 Ferrule 134

Outer skin

141, 142, 221, 222

Optical filter

150, 215

Lens

211a, 212a

Fiber tip part

211b, 212b

Protruding part

211c, 212c Fiber outer peripheral part 214

Metal frame

221a, 222a Filter outer peripheral part 231 232 Metallized film 241 242 Metal material for joining

Claims

A first optical fiber having a plastic jacket and having a first fiber tip that emits irradiation light to a site to be observed in a body cavity;
A second optical fiber having a plastic jacket and having a second fiber tip for receiving fluorescence or Raman scattered light from the observation site;
A first optical filter disposed at the tip of the first fiber;
A second optical filter disposed at the tip of the second fiber,
A process of forming a metal film is performed on at least one of the first optical fiber, the second optical fiber, the first optical filter, and the second optical filter.
Optical probe.
The first and second optical fibers are plastic fibers;
The optical probe according to claim 1.
A holding portion for holding the tip regions of the first and second optical fibers so that the first and second optical fibers form a bundle,
The optical probe according to claim 1.
The holding part is a tube,
With the second optical fiber in contact with the first optical fiber, the tip regions of the first and second optical fibers are inserted into the tube,
The optical probe according to claim 3.
The holding unit is a ferrule,
The tip regions of the first and second optical fibers are inserted into holes formed in the ferrule,
The optical probe according to claim 3.
The tip surfaces of the first and second fibers are formed in the same plane as the tip surface of the ferrule.
The optical probe according to claim 5.
At least one of the first and second fibers protrudes from the front end surface of the ferrule.
The optical probe according to claim 5.
The tip region held by the holding portion in at least one of the first and second optical fibers is subjected to metal plating,
In the tip region held by the holding part and subjected to the metal plating, the plastic jacket is removed,
The optical probe according to claim 3.
The first and second optical fibers protrude from the holding portion toward the probe tip,
The protruding portions of the first and second optical fibers have first and second fiber outer peripheral portions that are respectively subjected to metallization processing.
The optical probe according to claim 3.
The first optical fiber protrudes from the holding portion toward the probe tip,
The protruding part of the first optical fiber has a first fiber outer peripheral part subjected to metallization processing on the whole,
The optical probe according to claim 3.
The second optical fiber protrudes from the holding portion toward the probe tip,
The protruding portion of the second optical fiber has a second fiber outer peripheral portion subjected to metallization processing on the whole,
The optical probe according to claim 3.
The first optical filter has a first filter outer peripheral portion subjected to metallization processing on the whole,
The second optical filter has a second filter outer peripheral portion subjected to metallization processing on the whole,
The optical probe according to claim 1.
The first and second optical filters are joined to each other by brazing or soldering performed on the outer periphery of the first and second filters.
The optical probe according to claim 12.
The first and second optical fibers protrude from the holding portion toward the probe tip,
The protrusions of the first and second optical fibers respectively have first and second fiber outer peripheral portions that are subjected to metallization processing on the whole,
The first optical filter has a first filter outer peripheral portion subjected to metallization processing on the whole,
The second optical filter has a second filter outer peripheral portion subjected to metallization processing on the whole,
The optical probe according to claim 1.
The first and second optical filters are formed by brazing or soldering applied to the outer peripheral portions of the first and second filters and the outer peripheral portions of the first and second fibers. Bonded to optical fiber,
The optical probe according to claim 14.
A cylindrical metal frame that houses the first and second fiber tips and the first and second optical filters;
The first optical filter has a first filter outer peripheral portion subjected to metallization processing on the whole,
The second optical filter has a second filter outer peripheral portion subjected to a metallization process on the whole,
The first and second optical filters are joined to the metal frame by brazing or soldering performed on the outer periphery of the first and second filters,
The optical probe according to claim 7.
The brazing material or solder that joins the first and second optical filters and the metal frame is the outer periphery of the first and second filters in at least part of the thickness direction of the first and second optical filters. Covering the part,
The optical probe according to claim 16.
The second fiber tip is disposed closer to the probe tip than the first fiber tip.
The optical probe according to claim 7.
The second fiber tip is disposed closer to the probe tip than the first fiber tip.
The optical probe according to claim 16.
The second optical filter is disposed closer to the probe tip than the first optical filter.
The optical probe according to claim 7.
The second optical filter is disposed closer to the probe tip than the first optical filter.
The optical probe according to claim 16.
The second optical filter is disposed closer to the probe tip than the first optical filter.
The optical probe according to claim 18.
The second optical filter is disposed closer to the probe tip than the first optical filter.
The optical probe according to claim 19.
A first optical fiber having a plastic jacket and having a first fiber tip that emits irradiation light to a site to be observed in a body cavity;
A second optical fiber having a plastic jacket and having a second fiber tip for receiving fluorescence or Raman scattered light from the observation site;
A first optical filter disposed at the tip of the first fiber;
A second optical filter disposed at the tip of the second fiber, and a method of manufacturing an optical probe comprising:
A process of forming a metal film is performed on at least one of the first optical fiber, the second optical fiber, the first optical filter, and the second optical filter.
Manufacturing method of optical probe.