JP2007159862A - Light irradiating chip and optical waveguide fiber body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light irradiating chip and an optical waveguide fiber body which can output light laterally with optical intensity nearly equal in the extending direction and reduce a load on a living body. <P>SOLUTION: The light irradiating chip 5 is attached to an emitting end 3b of an optical fiber body 3 and scatters light emitted from the emitting end 3b, and is extended in one direction from one end 5a connected to the emitting end 3b to the other end 5b. A light scattering coefficient is varied from the one end 5a toward the other end 5b. In this case, the light emitted from the emitting end 3b is scattered in order from the one end 5a in the light irradiating chip 5, so that intensity of the light tends to vary toward the other end 5b, however, the light scattering coefficient is varied from the one end 5a toward the other end 5b, so that the light can be uniformly output in the extending direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light irradiation chip and an optical waveguide fiber body used for medical purposes.

  In recent years, photodynamic therapy (PDT) has attracted attention in the medical field such as cancer therapy. This PDT will be described taking cancer treatment as an example. In PDT, first, a cancer affinity sensitive drug (PS: photosensitizer) is administered to a human body (living body). Since PS has affinity for cancer cells, it is selectively taken up by cancer tissues. Next, the cancer tissue is irradiated with light having a wavelength capable of exciting PS. As a result, PS taken into the cancer tissue is photoexcited, and active species such as active oxygen or active radical species are generated when the excited PS relaxes. This active species attacks the cancer tissue and necroses the cancer tissue. Since PS is almost released outside the body except for that taken into the cancer tissue, side effects due to drug administration do not occur.

  In PDT, for example, an optical fiber described in Patent Document 1 and a phototherapy device described in Patent Document 2 are used to irradiate light on the entire lesion such as cancer tissue.

  In the optical fiber described in Patent Document 1, the core portion is tapered at the tip portion and is tapered. And the scatterer is disperse | distributed to the clad part around the taper-shaped core part. In this optical fiber, light leaked from the core portion processed into a tapered shape to the clad portion is scattered by the scatterer, whereby light is output from the outer peripheral surface of the clad portion. Therefore, after placing the tip of the optical fiber in the vicinity of the lesion, it is possible to irradiate the lesion by irradiating light into the optical fiber.

  In the phototherapy device described in Patent Document 2, a tip (light irradiation tip) having a scatterer (alumina, silica, titanium compound) inside is attached to the tip of the optical fiber. In the phototherapy device, a reflector is provided at the end of the tip opposite to the optical fiber side so that light is reliably output from the outer peripheral surface of the tip along the longitudinal direction of the optical fiber.

In this configuration, light incident on the chip from the optical fiber is scattered by the scatterer while propagating in the longitudinal direction and output from the outer peripheral surface of the chip. The light that has not been scattered by the scatterer is reflected by the reflector, then scattered by the scatterer while going toward the optical fiber, and output from the outer peripheral surface of the chip.
JP-A-8-164215 Japanese National Patent Publication No. 10-504989

  By the way, in PDT, it is desired to irradiate light uniformly and surely to the whole lesion. In the optical fiber described in Patent Document 1, the amount of light leaking to the clad portion is increased by making the core portion tapered, but the amount of light propagating in the core portion is still large and the shape of the taper is controlled. Since it is difficult to make the scattered light intensity uniform, it is difficult to irradiate the entire lesion evenly and reliably because much light is irradiated from the tip.

  On the other hand, in the phototherapy device described in Patent Document 2, since the reflecting plate is provided at the tip of the chip, light is scattered by the scatterer in the round-trip path toward the reflecting plate. Therefore, there is a tendency that light of uniform intensity is more reliably output from the chip.

  However, usually, most of the light incident on the reflecting plate is reflected, but a part of the incident light is absorbed by the reflecting plate. Therefore, when the intensity of light incident on the chip from the optical fiber is increased, the chip portion may be heated in the device described in Patent Document 2. As a result, the chip portion may burn out or break at the connection portion between the chip and the optical fiber, and the chip may be removed from the optical fiber. In this case, a part of the chip or the optical fiber remains in the body, and a load is applied to the living body.

  Accordingly, an object of the present invention is to provide a light irradiation chip and an optical waveguide fiber body that are capable of outputting light laterally with a substantially uniform light intensity in the extending direction and have a reduced load on the living body. To do.

  A light irradiation chip according to the present invention is a light irradiation chip that is attached to an output end of an optical fiber and scatters light emitted from the output end, and is directed in one direction from one end connected to the output end to the other end. The light scattering coefficient extends from the one end to the other end.

  In this light irradiation chip, light emitted from the emission end of the optical fiber is scattered in order from one end. Therefore, although the intensity of light passing through the light irradiation chip changes toward the other end, as described above, the light scattering coefficient changes from one end to the other end, so that more light is applied on the other end side. Light is scattered. As a result, the extending direction of the intensity of the light output to the side can be made uniform.

  Further, since the light intensity to be output is made uniform by changing the light scattering coefficient in this way, for example, a reflecting means such as a mirror is not required. As a result, it is possible to prevent the light irradiation chip from being burned out due to heat and being removed from the optical fiber. Therefore, even when it is used for medical purposes, the light irradiation chip hardly remains in the living body, and the load on the living body is small. Therefore, it can be suitably used for medical purposes.

  In the light irradiation chip according to the present invention, it is preferable that the light scattering coefficient increases from one end of the optical fiber chip to the other end.

  As described above, since the light scattering coefficient increases from one end to the other end, more light is scattered on the other end side. As a result, even if the intensity of light passing through the light irradiation chip changes toward the other end, the intensity of light output to the side can be made uniform in the extending direction.

  Moreover, in the light irradiation chip | tip which concerns on this invention, it is preferable that the several scatterer which consists of a component different from a main component is disperse | distributed from one end to the other end so that a light-scattering coefficient may increase.

  In the light irradiation chip, scatterers having components different from the main component of the light irradiation chip are dispersed, so that light incident on the light irradiation chip is reliably scattered. Then, as the scatterers are dispersed from one end to the other end as described above, the light scattering coefficient increases from one end to the other end. Therefore, the light intensity in the longitudinal direction of the light irradiation chip can be made uniform.

  Furthermore, the main component of the light irradiation chip according to the present invention is preferably an aliphatic polyester. In this configuration, when the light irradiation chip is used for medical purposes, even if the light irradiation chip remains in the living body, since the main component is aliphatic polyester, most of the light irradiation chip is decomposed into the living body. Absorbed. Therefore, the load on the living body is reduced.

  Furthermore, when the main component is an aliphatic polyester, in the light irradiation chip according to the present invention, the aliphatic polyester as the main component is amorphous, and the scatterer is preferably a crystallized aliphatic polyester. . In this case, since the scatterer is also an aliphatic polyester, the load on the living body is further reduced.

  An optical waveguide fiber according to the present invention includes an optical fiber that propagates light incident from an incident end and exits from an output end, and the light irradiation chip according to the present invention, and one end of the light irradiation chip is It is connected to the output end of the optical fiber.

  In this optical waveguide fiber body, the light emitted from the emission end of the optical fiber enters the light irradiation chip from one end, and is sequentially scattered while propagating through the light irradiation chip toward the other end. Therefore, the intensity of light passing through the light irradiation chip tends to change toward the other end. However, as described above, in the light irradiation chip according to the present invention, the light scattering coefficient changes from one end to the other end. Therefore, it is possible to output light uniformly in the extending direction.

  Since the light intensity output is made uniform by changing the light scattering coefficient in this way, for example, no reflecting means such as a mirror is required. As a result, it is possible to prevent the light irradiation chip from being burned out due to heat and being removed from the optical fiber. Therefore, even when it is used for medical purposes, the light irradiation chip hardly remains in the living body, and the load on the living body is small. Therefore, it can be suitably used for medical purposes.

  The light irradiation chip and the optical waveguide fiber body according to the present invention can output light laterally with a substantially uniform light intensity in the extending direction, and the load on the living body is reduced. Is possible.

  Hereinafter, an embodiment of an optical waveguide fiber according to the present invention will be described with reference to the drawings. For convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a cross-sectional view of an embodiment of an optical waveguide fiber body according to the present invention. The optical waveguide fiber body 1 is used for irradiating light to a lesion such as cancer tissue in photodynamic therapy (PDT). The total length of the optical waveguide fiber body 1 used for medical use is, for example, 2 to 3 m. The optical waveguide fiber body 1 has an optical fiber 3. The optical fiber 3 is a plastic optical fiber (POF) and propagates light incident from the incident end 3a to the output end 3b. The wavelength of light propagating through the optical fiber 3 may be any wavelength that is suitably used for PDT, and is, for example, a wavelength of 300 to 800 nm. Although the optical fiber 3 is POF, it may be composed mainly of quartz glass.

  A light irradiation chip 5 is provided at the emission end 3 b of the optical fiber 3. The light irradiation chip 5 is attached to the optical fiber 3 by the attachment means 7 so that the first end 5a which is one end thereof is optically connected to the emission end 3b. The light irradiation chip 5 scatters the light incident from the first end 5a while propagating to the second end 5b, which is the other end, and scatters the side of the optical waveguide fiber body 1 (for example, the direction orthogonal to the extending direction). ) To output light.

  The attachment means 7 has two heat shrinkable tubes 9 and 11 having different thicknesses. The material of the heat-shrinkable tubes 9 and 11 is not particularly limited as long as it is transparent to the light propagated through the optical fiber 3, and uses Teflon (registered trademark) resin, polyolefin (PE, PP, etc.), etc. The heat shrinkable tubes 9 and 11 are exemplified by FEP heat shrinkable tubes. The tube length / tip length is, for example, 2 to 30.

  The heat shrinkable tube 9 accommodates the portion of the optical fiber 3 on the emission end 3 b side and the light irradiation chip 5, and holds them with the light irradiation chip 5 attached to the optical fiber 3. The heat shrinkable tube 9 also has a function of protecting the optical fiber 3 and the light irradiation chip 5. The first end 9a (end on the optical fiber 3 side) side of the heat shrinkable tube 9 is heat-shrinked and fixed to the optical fiber 3, and the second end 9b side is melted and closed. Thereby, the light irradiation chip 5 and the optical fiber 3 are securely fixed, and the light irradiation chip 5 is prevented from being removed.

  Further, in the heat shrinkable tube 9, the refractive index matching for matching the refractive index between the optical fiber 3 and the light irradiation tip 5 and the heat shrinkable tube 9 or between the optical fiber 3 and the light irradiation tip 5. Agent 13 is filled. The refractive index matching agent 13 is, for example, silicon oil.

  A heat shrinkable tube 11 having an outer diameter larger than the outer diameter of the heat shrinkable tube 9 is covered on the first end 9 a side of the heat shrinkable tube 9. The first end 11 a side of the heat-shrinkable tube 11 is bonded to the heat-shrinkable tube 9 with, for example, an ultraviolet curable adhesive 15, and the second end 11 b side is heat-shrinked and fixed to the heat-shrinkable tube 9.

  In the optical waveguide fiber body 1, the optical fiber 3 and the light irradiation chip 5 are connected and accommodated in the heat shrinkable tube 9 filled with the refractive index matching agent 13, and the heat shrinkable tube 9 is accommodated in the optical fiber 3 and the light irradiation chip 5. The optical fiber 3 and the light irradiation chip 5 are connected to each other. Therefore, the light emitted from the optical fiber 3 is reliably incident on the light irradiation chip 5. Moreover, since the heat-shrinkable tube 9 is fixed by the heat-shrinkable tube 11, the light irradiation chip 5 is further prevented from being removed.

  Here, the heat-shrinkable tube 9 and the heat-shrinkable tube 11 are used to form a two-layer structure. However, the structure is not limited to a two-layer structure. For example, a single-layer structure may be used as long as the refractive index matching agent 13 does not leak. In addition, the ultraviolet curable adhesive 15 is filled between the heat shrinkable tube 11 and the heat shrinkable tube 9 and bonded to each other. For example, the heat shrinkable tube 11 may have an adhesive on the inside. When used, an adhesive such as the ultraviolet curable adhesive 15 may not be used.

  The light irradiation chip 5 will be described in more detail with reference to FIG. FIG. 2 is a cross-sectional view of the light irradiation chip 5.

  The light irradiation chip 5 is composed mainly of polylactic acid, which is an aliphatic polyester. Polylactic acid as a main component is amorphous. The light irradiation chip 5 has a cylindrical shape and has substantially the same diameter (for example, 0.5 mm) as the optical fiber 3. The light irradiation chip 5 extends in one direction, and its total length is, for example, 30 mm. The main component of the light irradiation chip 5 may be any material that hardly absorbs light propagating in the optical waveguide fiber body 1, but an aliphatic polyester that is decomposed and absorbed by the living body is preferable from the viewpoint of reducing the load on the living body. . Examples of the aliphatic polyester include polyglycolic acid in addition to polylactic acid, and combinations of polylactic acid and polyglycolic acid are also effective.

  A plurality of scatterers 17 are dispersed in the light irradiation chip 5 in order to scatter light. Examples of the size of the scatterer 17 include sub-μm to several tens of μm. Each scatterer 17 is obtained by crystallizing polylactic acid which is a main component of the light irradiation chip 5. Since the light that is incident on and propagates to the light irradiation chip 5 is scattered at the interface between the crystallized portion and the surrounding amorphous portion, the crystallized portion functions as the scatterer 17.

  In the configuration of the light irradiation chip 5, the light incident on the first end 5 a of the light irradiation chip 5 is scattered by the scatterer 17 while propagating through the light irradiation chip 5 toward the second end 5 b. Most of the scattered light is output from the outer peripheral surface 5 c of the light irradiation chip 5, passes through the heat shrinkable tube 9, and is output to the side (side) of the optical waveguide fiber body 1. The light that has not been scattered by the scatterer 17 is output from the second end 5b.

  In the light irradiation chip 5, by increasing the light scattering coefficient from the first end 5a toward the second end 5b, the longitudinal direction of the intensity of light output to the side of the light irradiation chip 5 (of the light irradiation chip 5). Uniformity in the extending direction) is achieved.

  The fact that the intensity of the light output from the light irradiation chip 5 to the side can be made uniform as described above by changing the light scattering coefficient of light as described above will be described using simulation results.

FIG. 3 is a schematic diagram of an optical waveguide fiber modeled for simulation. In the simulation, the longitudinal direction of the optical waveguide fiber body 1 is taken as the X axis. Further, the position of the first end 5a (the area indicated by hatching in FIG. 3) of the light irradiation chip 5 is the origin, and the length of the light irradiation chip 5 is L. Further, the light intensity and P (x) at position x, the light intensity at the origin (x = 0) and _{P (0)} = P 0.

式（１）における比例係数ｑ（ｘ）が光散乱係数である。 In the simulation, the following three points are assumed. That is, (i) it is assumed that there is no light intensity distribution in the radial direction of the light irradiation chip 5. (ii) It is assumed that scattered light is emitted concentrically only in a direction (radial direction) orthogonal to the longitudinal direction. (iii) The scattered light intensity dP (x) at the position x is proportional to the light intensity P (x) as shown in the following equation.

The proportionality coefficient q (x) in equation (1) is the light scattering coefficient.

が成り立つ。Ｌは光照射チップ５の長さで、Ｐ（Ｌ）はｘ＝Ｌでの光強度、すなわち、光照射チップ５に入射された光のうち散乱されずに光照射チップ５を抜けてしまう光強度を示している。 When the scattered light intensity dP (x) is constant, P (x) · q (x) is constant.

Holds. L is the length of the light irradiation chip 5, and P (L) is the light intensity at x = L, that is, light that passes through the light irradiation chip 5 without being scattered among the light incident on the light irradiation chip 5. Indicates strength.

FIG. 4 is a graph showing the position dependence of the light scattering coefficient q (x) obtained from Equation (2). FIG. 4 shows a case where P (L) / P ₀ is changed in Expression (2). The total length L of the light irradiation tip 5 was 30 mm. The horizontal axis indicates the distance from the origin, and the vertical axis indicates the light scattering coefficient q (x) [mm ⁻¹ ]. FIG. 4 shows that under the condition that the intensity of light output from the side of the optical waveguide fiber body 1 is constant in the longitudinal direction, the light scattering coefficient q (x) is at the other end of the light irradiation chip 5. It shows increasing toward a certain second end 5b. That is, by forming a gradient of the light scattering coefficient q (x) as shown in FIG. 3, it is possible to make the intensity of light output from the side uniform in the longitudinal direction.

  Here, an example of a method for manufacturing the light irradiation chip 5 will be described.

  Polylactic acid, which is an aliphatic polyester, is amorphous below the glass transition temperature (in other words, has an amorphous property), but when heated above the glass transition temperature, crystallization occurs and polycrystalline fine particles are generated and become cloudy. The light irradiation chip 5 is manufactured using this property.

  First, a tip rod 19 made of polylactic acid is manufactured using an extrusion method or the like. At this time, the rod 19 is amorphous. Next, as shown in FIG. 5, the rod 19 is fixed to a metal frame 23 included in the rod heating device 21, and is immersed in an oil bath 25 of about 100 ° C., for example, to heat the rod 19.

  At this time, a part of the rod 19 is crystallized while the heating time of the rod 19 is changed in the longitudinal direction by pulling up the metal frame 23 at a predetermined speed using, for example, a winder 27. This crystallized portion becomes the scatterer 17 and the light irradiation chip 5 is obtained. In this case, the crystallization state is changed in the longitudinal direction of the rod 19 by pulling up while changing the heating time in the longitudinal direction. The predetermined speed is a speed at which the intensity of light output from the outer peripheral surface 5c of the light irradiation chip 5 becomes substantially uniform in the longitudinal direction.

  Here, a method for determining a predetermined speed when the rod 19 is pulled up will be described.

が成り立つ。 When the crystallization time for heating and crystallization of the rod 19 (hereinafter also referred to as heating time) is constant, the light scattering coefficient q (x) becomes a constant q _s .

Holds.

Therefore, by measuring the intensity (light scattering intensity) of light that is output from the light irradiation chip 5 that is manufactured under the condition that the heating temperature and the heating time are constant, the light at the heating time is measured. The scattering coefficient q _s can be calculated. Then, by calculating the light scattering coefficient q _s while changing the heating time, the heating time dependence of the light scattering coefficient q _s can be obtained. Therefore, the heating time dependency is calculated in advance for the polylactic acid for producing the light irradiation chip 5, and the light scattering coefficient q (x) as shown in FIG. 4 is calculated from the calculated heating time dependency. The pulling speed is determined so that a gradient is formed.

  Next, an example of a method for manufacturing the optical waveguide fiber body 1 using the light irradiation chip 5 manufactured as described above will be described with reference to FIGS.

  Here, the outer diameter of the light irradiation chip 5 and the optical fiber 3 is 0.5 mm, and the total length of the light irradiation chip 5 is about 30 mm. The heat shrinkable tube 9 has an outer diameter of about 0.9 mm and an inner diameter of about 0.6 mm (about 0.45 mm after heat shrinkage). The heat shrinkable tube 11 has an outer diameter of about 1.4 mm and an inner diameter of about 1 mm. .1 mm (about 0.9 mm after shrinking). In addition, the magnitude | size of the light irradiation chip | tip 5, the optical fiber 3, and the heat contraction tubes 9 and 11 is not limited to these.

  First, as shown in FIG. 6A, after the refractive index matching agent 13 is filled in the heat shrinkable tube 9 using the syringe 29, as shown in FIG. 6B, on the second end 9b side. The optical fiber 3 is inserted from the first end 9 a of the heat-shrinkable tube 9, leaving an extra length for the length of the light irradiation tip 5. Here, the refractive index matching agent 13 is filled again from the second end 9b of the heat shrinkable tube 9 to remove the internal bubbles. Next, as shown in FIG. 6C, the light irradiation chip 5 is inserted into the heat shrinkable tube 9 from the second end 9b. At this time, a part of the light irradiation chip 5 protrudes from the second end 9b to the outside by about 1 mm, for example, and the refractive index matching agent 13 is applied to the protruding part.

  Since the optical fiber 3 and the light irradiation chip 5 are inserted from both sides into the heat shrinkable tube 9 filled with the refractive index matching agent 13 in this way, the emission end 3b of the optical fiber 3 and the first of the light irradiation chip 5 are inserted. The end 5a can be adjusted in refractive index matching by the refractive index matching agent 13. Further, the refractive index matching between the outer peripheral surface 5c of the light irradiation chip 5 and the heat shrinkable tube 9 can be obtained.

  Subsequently, as shown in FIG. 7A, the soldering iron 31 heated to, for example, about 450 ° C. is pressed against the second end 9b side of the heat-shrinkable tube 9, and a part of the light irradiation chip 5, the heat-shrinkable tube 9, To integrate. Further, as shown in FIG. 7B, the soldering iron 31 heated to, for example, about 120 ° C. is applied to the first end 9 a side of the heat shrinkable tube 9, and the heat shrinkable tube 9 is not melted without melting the optical fiber 3. The heat shrinkable tube 9 is fixed to the optical fiber 3 by heat shrinking. The length of the portion to be heat shrunk is about 30 mm, for example.

  Then, as shown in FIG. 8, after covering the heat shrinkable tube 11 on the first end 9a side of the heat shrinkable tube 9, as shown in FIG. 9A, on the second end 11b side of the heat shrinkable tube 11 For example, the soldering iron 31 is pressed into an area of about 10 mm to cause heat shrinkage, and the heat shrinkable tube 11 is fixed to the heat shrinkable tube 9. Next, as shown in FIG. 9B, the ultraviolet curable adhesive 15 is filled between the heat shrinkable tube 9 and the heat shrinkable tube 11 and cured on the first end 11 a side of the heat shrinkable tube 11. Thereby, the heat-shrinkable tube 11 is reliably fixed to the heat-shrinkable tube 9, and the optical waveguide fiber body 1 is obtained.

  Next, functions and effects of the optical waveguide fiber body 1 will be described with reference to FIG. FIG. 10 is a schematic diagram of an embodiment of PDT in cancer treatment using the optical waveguide fiber body 1.

  First, a cancer affinity photosensitizer (PS: photo synthesizer) having affinity for cancer cells is administered to the human body (living body) 33. Here, letaphyrin that reacts with light having a wavelength of 664 nm is PS. Most of PS is selectively taken up by cancer tissue 35 which is a lesion, while those other than the taken up are almost released outside the body.

  Next, as shown in FIG. 10, a guide tube 37 made of Teflon (registered trademark) or the like is inserted into the human body 33, and then passed through the optical waveguide fiber body 1 into the guide tube 37, so that the light irradiation chip of the optical waveguide fiber body 1 is used. 5 is disposed on or near the cancer tissue 35. Subsequently, light having a wavelength of 664 nm capable of exciting PS is made incident from the incident end 3 a of the optical waveguide fiber body 1.

  The light incident on the optical waveguide fiber 1 propagates through the optical fiber 3 and then exits from the exit end 3b. Since the first end 5a and the emission end 3b of the light irradiation chip 5 are optically coupled, the light emitted from the emission end 3b enters the light irradiation chip 5 from the first end 5a. While the light incident on the light irradiation chip 5 is propagated in the longitudinal direction, a part of the light is scattered by the scatterer 17 and output from the outer peripheral surface 5 c, passes through the heat shrinkable tube 9, and is output from the optical waveguide fiber body 1. Is done. Thereby, most of the light incident on the light irradiation chip 5 is output from the outer peripheral surface of the optical waveguide fiber body 1 in all directions around the optical waveguide fiber body 1 when viewed from the second end 5b.

  At this time, a plurality of scatterers 17 are dispersed in the light irradiation chip 5 under the condition that the light scattering coefficient q (x) increases from the first end 5a toward the second end 5b, for example, as shown in FIG. Therefore, the light irradiation chip 5 outputs light with a substantially uniform intensity along the longitudinal direction.

  Since the light irradiation tip 5 is disposed in the vicinity of the cancer tissue 35, the light output from the light irradiation tip 5 in all directions is irradiated to the entire cancer tissue 35 with substantially uniform intensity. The PS taken into the cancer tissue 35 is photoexcited by the irradiated light. Active species such as active oxygen or active radical species generated during relaxation of the photoexcited PS attack the cancer tissue and cause the cancer tissue to die. In PDT, the administered drug selectively acts only on the cancer tissue 35, so that no side effects are caused by the drug administration. In the above description, the optical waveguide fiber body 1 is inserted into the guide tube 37. However, the optical waveguide fiber body 1 may be used in combination with, for example, an endoscope.

  In the optical waveguide fiber body 1, since the scatterer 17 is dispersed in the light irradiation chip 5, light can be output more reliably to the side. Furthermore, a scatterer 17 is provided in the light irradiation chip 5 so that the light scattering coefficient at the light irradiation chip 5 increases toward the second end 5b side, and light is scattered on the second end 5b side. The probability of being made is high. The increase in the scattering probability on the second end 5b side compensates for a decrease in the intensity of the light propagating through the light irradiation chip 5, and from the side of the light irradiation chip 5 almost the same intensity regardless of the position in the longitudinal direction. Is output. As a result, the entire lesion can be irradiated with substantially uniform light.

  Moreover, since the light irradiation chip 5 has almost no absorption with respect to the wavelength of light emitted from the optical fiber 3, there is no heat generation due to absorption. As a result, since the light irradiation chip 5 does not take heat, burnout due to heat generation does not occur. Furthermore, since heat generation does not occur in the portion inserted into the human body 33, it can be suitably used for medical purposes.

  Even if a part of the optical waveguide fiber body 1 is damaged and the light irradiation chip 5 remains in the living body, the light irradiation chip 5 is formed of a bioabsorbable polymer. The remaining part is decomposed and absorbed by the living body. Therefore, the optical waveguide fiber body 1 is improved in safety with respect to a living body, and can be suitably used for medical purposes such as PDT as described above.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, the light irradiation tip 5 is formed by heating a rod 19 made of non-crystallized aliphatic polyester using an oil bath 25, and the heating method of the rod 19 is to attach to the oil bath 25. It is not limited as long as it can be heated so that a crystallized portion is formed.

  Moreover, although the scatterer 17 shall have crystallized the main component (for example, polylactic acid) of the light irradiation chip | tip 5, if it can scatter the light which injected into the light irradiation chip | tip 5, it will not specifically limit. For example, bubbles are also effective. In this case, bubbles may be generated in the rod 19 and the generated amount may be changed in the longitudinal direction. In order to generate bubbles, a non-crystallized rod is placed in a high-pressure bubble gas environment and then returned to normal pressure at a stroke. Further, the distribution of bubbles in the longitudinal direction is changed by applying heat to the rod 19. It is possible.

  Examples of the scatterer 17 include food dyes, vitamins, and medical dyes, which are preferable from the viewpoint of reducing the load on the living body. Food dyes include gardenia yellow pigments, gardenia yellow pigments, safflower yellow pigments, turmeric pigments, benichou yellow pigments, palm oil carotene, benichouge pigments, gardenia red pigments, safflower red pigments, beet red, cochineal pigments, lac pigments, and akane pigments , Perilla pigment, red cabbage pigment, red radish pigment, purple potato pigment, purple corn pigment, grape skin pigment, elderberry pigment, grape juice pigment, blueberry pigment, red pepper pigment, anato pigment, chlorophyll, gardenia blue pigment, spirulina pigment, Natural dyes such as cacao pigment, tamarind pigment, oyster pigment, cucumber pigment, plant charcoal pigment, hemoglobin, Tartrazine, Sunset Yellow FCF, Amaranth, Erythrosine, Allura Red AC, NewCoccine, Phloxine, Rose Bengale, Acid Red, Brilliant Blue Artificial dyeing such as FCF, Indigo Carmine , And, further, beta-carotene, are also illustrated like annatto pigment.

  As vitamins, vitamin A, vitamin K1, vitamin K2, vitamin K3, vitamin D2, vitamin D3, vitamin E, vitamin F (linoleic acid, linolenic acid), vitamin B1, vitamin B2, vitamin M, pantothenic acid, lipo Examples include acid, vitamin B9, vitamin B12, vitamin H, vitamin C, vitamin P and the like.

  Furthermore, examples of medical dyes include nucleic acid labeling reagents that can be used as medical dyes, Nile Blue, Malachite Green, and the like.

  The light irradiation chip 5 may be a so-called optical fiber having a core / cladding structure. In this case, an optical fiber having quartz glass as a main component and germanium added as a scatterer in the core is manufactured. Then, the optical fiber is heated to diffuse germanium added in the core portion, thereby increasing the light scattering coefficient in the longitudinal direction to obtain a light irradiation chip. In addition, as a scatterer added to a core part, it is also possible to use food dyes, vitamins, and medical dyes as described above.

  Furthermore, even when the light irradiation chip 5 is an optical fiber having a core / cladding structure, it is preferable that the main component is made of aliphatic polyester from the viewpoint of not applying a load to the living body.

  Moreover, the attachment means 7 is not limited to a heat-shrinkable tube but may be an ordinary tube or pipe. Again, they are made of a material that is transparent to the light propagated through the optical fiber 3.

  Furthermore, in the optical waveguide fiber body 1, the second end 9 b side of the heat shrinkable tube 9 is melted and integrated with the light irradiation chip, but is not limited thereto. For example, the second end 9b may be filled with a metal rod (gold, silver, platinum, aluminum, or the like) that becomes an ultrasonic sensor, or a plastic rod such as Teflon (registered trademark) may be packed at the tip. is there. Furthermore, even when a normal tube or pipe is used in place of the heat shrinkable tube, the above-mentioned one can be filled with an adhesive or the like. However, since it is difficult to fix Teflon (registered trademark) with an adhesive, it is preferable to roughen the inner surface of the pipe or tube in advance.

  In the light irradiation chip 5, the light scattering coefficient increases from the first end (one end) 5 a toward the second end (other end) 5 b, but the intensity of light output from the outer peripheral surface 5 c is in the longitudinal direction. The light scattering coefficient only needs to change from the first end 5a to the second end 5b so as to be substantially uniform.

  Hereinafter, the light irradiation chip and the optical waveguide fiber body according to the present invention will be described using examples. The present invention is not limited to the following examples.

  In this example, in order to manufacture the light irradiation chip 5, the heating condition of the rod 19 for making the intensity of the light output from the side uniform along the longitudinal direction was determined. Subsequently, the optical waveguide fiber body 1 was manufactured using the light irradiation chip 5 manufactured based on the heating conditions. In the following description, for convenience of explanation, the same reference numerals as those in the embodiment are also given to the light irradiation chip in which the scatterers are uniformly distributed in the longitudinal direction and the optical waveguide fiber body using the light irradiation chip.

  In the examples, Lacia H400 transparent grade (Mitsui Chemicals, Inc.) was used as polylactic acid. As the optical fiber 3, a plastic optical fiber (manufactured by Toray Industries, Inc.) having an outer diameter of 0.5 mm was used. Further, the heat shrinkable tube 9 uses an FRP heat shrinkable tube having an outer diameter of 0.9 mm and an inner diameter of 0.6 mm (0.45 mm after heat shrinkage), and the heat shrinkable tube 11 has an outer diameter of about 1 mm. An FRP heat-shrinkable tube having a diameter of 4 mm and an inner diameter of 1.1 mm (the inner diameter after shrinkage is about 0.9 mm) was used. Further, as the refractive index matching agent 13, silicon oil having a refractive index of 1.4580 at a temperature of 25 ° C. was used.

  First, six rods 19 made of polylactic acid and having a diameter of 0.5 mm were produced using an extruder. It should be noted that the total length of each rod 19 when the optical waveguide fiber body 1 is manufactured is such that the total length of the light irradiation chip 5 is about 30 mm when incorporated in the optical waveguide fiber body 1. A surplus length for projecting from the two ends 9b is added.

  Next, the entire rod 19 was heated at a uniform temperature using the rod heating device 21 shown in FIG. The oil bath 25 was made of silicon oil, and the temperature was about 100 ° C. The manufacturing conditions of the six light irradiation chips 5 were the same except that the heating time of each rod 19 was changed to 1 minute, 2 minutes, 4 minutes, 8 minutes, 16 minutes, and 32 minutes.

  And the optical waveguide fiber body 1 was each manufactured by the method shown in FIGS. 6-9 using each light irradiation chip | tip 5 manufactured as mentioned above. In the step shown in FIG. 6C, the length for projecting the light irradiation tip 5 from the heat shrinkable tube 9 was about 1 mm. In the step shown in FIG. 7A, the temperature of the soldering iron 31 is about 450 ° C., and in the step shown in FIG. 7B, the temperature of the soldering iron 31 is about 120 ° C. Further, in the step shown in FIG. 9A, the length for contracting the heat-shrinkable tube 11 is about 10 mm.

  Next, the intensity distribution in the longitudinal direction of the light output from the light irradiation chip 5 of each of the manufactured six optical waveguide fiber bodies 1 was measured by the method shown in FIG.

That is, light with a wavelength of 659 nm was incident on the optical fiber 3 at 10 mW. And the intensity | strength of the light output from the optical waveguide fiber body 1 was measured, moving the power meter 39 arrange | positioned to the side of the optical waveguide fiber body 1 from the 2nd end 5b side to the 1st end 5a side. The light receiving area of the power meter 39 was about 4 mm ² . Further, the power meter 39 was disposed about 3 mm away from the outer peripheral surface of the optical waveguide fiber body 1. Then, based on the obtained light intensity distribution and Equation (3), the light scattering coefficient q _s for each heating time was calculated.

Next, the relationship between the heating time and the scattering coefficient when P (L) / P ₀ was set as a target value was experimentally obtained. And after determining the heating conditions of the rod 19, the light irradiation chip | tip 5 was produced based on the heating conditions, and also the optical waveguide fiber body 1 which has the light irradiation chip | tip 5 was produced. And the optical intensity distribution in a longitudinal direction was measured by the measuring method shown in FIG. 11 using the produced optical waveguide fiber body 1.

  As a result, in the optical waveguide fiber body 1 having the light irradiation chip 5 formed so that the light scattering coefficient increases from the first end 5a toward the second end 5b, the region having a relative intensity of 0.8 or more is about About 21 mm was obtained, and it was confirmed that the light intensity in the longitudinal direction was made uniform.

It is sectional drawing of one Embodiment of the optical waveguide fiber body which concerns on this invention. It is sectional drawing of one Embodiment of the light irradiation chip | tip which concerns on this invention. It is the schematic diagram of the optical waveguide fiber body modeled for simulation. It is a graph which shows the position dependence of a light-scattering coefficient. It is a figure which shows one process in manufacture of a light irradiation chip | tip. It is a figure which shows one process in manufacture of an optical waveguide fiber body. It is a figure which shows the process following FIG. 6 in manufacture of an optical waveguide fiber body. It is a figure which shows the process following FIG. 7 in manufacture of an optical waveguide fiber body. It is a figure which shows the process following FIG. 8 in manufacture of an optical waveguide fiber body. It is a schematic diagram which shows one Embodiment of the photodynamic therapy to which an optical waveguide fiber body is applied. It is a figure which shows the measurement process of the light intensity distribution of the longitudinal direction of the light output from a light irradiation chip | tip.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical waveguide fiber body, 3 ... Optical fiber, 3a ... Incident end, 3b ... Outlet end, 5 ... Light irradiation chip, 5a ... 1st end (one end), 5b ... 2nd end (other end), 5c ... Outer periphery Surface, 7 ... Mounting means, 9, 11 ... Heat shrinkable tube, 9a ... First end, 9b ... Second end, 11a ... First end, 11b ... Second end, 13 ... Refractive index matching agent, 15 ... UV curing Adhesive, 17 ... scatterer, 19 ... polylactic acid rod, 21 ... rod heating device, 23 ... gold frame, 25 ... oil bath, 27 ... winder, 29 ... syringe, 31 ... soldering iron, 33 ... human body (living body) 35 ... Cancer tissue, 37 ... Guide tube.

Claims (6)

A light irradiation chip that is attached to an output end of an optical fiber and scatters light emitted from the output end,
A light irradiation chip, which extends in one direction from one end connected to the emission end to the other end, and whose light scattering coefficient changes from the one end to the other end.   The light irradiation chip according to claim 1, wherein the light scattering coefficient increases from the one end of the optical fiber chip toward the other end.   The light according to claim 1 or 2, wherein a plurality of scatterers composed of components different from the main component are dispersed from the one end toward the other end so that the light scattering coefficient increases. Irradiation tip.   The light irradiation chip according to claim 3, wherein the main component is an aliphatic polyester. The aliphatic polyester as the main component is amorphous,
5. The light irradiation chip according to claim 4, wherein the scatterer is formed by crystallization of the aliphatic polyester constituting the main component. An optical fiber that propagates light incident from the incident end and exits from the output end;
The light irradiation chip according to any one of claims 1 to 5,
With
The optical waveguide fiber body, wherein the one end of the light irradiation chip is connected to the emission end of the optical fiber.

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