Abstract:
Provided is a phototherapy apparatus capable of applying appropriate treatment. Specifically, the purpose of the present invention is to provide a phototherapy apparatus capable of easily supplying adequate treatment light even when a region to be treated is a bent region like finger joints of a patient having severe rheumatoid arthritis, thus making it possible to apply appropriate treatment. This phototherapy apparatus is configured to include: a light guide including a first surface on which an affected part is placed and a second surface on a back surface side of the first surface; a light source that outputs therapeutic light to enter an inside of the light guide body; and a light guide member that has softness and surface tackiness and is disposed on a part of the first surface.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a phototherapy apparatus. 
       BACKGROUND ART 
       [0002]    Phototherapy apparatuses, using, for example, infrared light (about 700 to 2500 nm) as therapeutic light, are used to alleviate pain due to chronic non-infectious inflammation in muscles and joints or to treat rheumatoid arthritis. These conventional phototherapy apparatuses are so configured as to apply therapeutic light from a light source onto a part to be treated (treatment part) in a non-contact manner either directly or via a light guide path (see, e.g., PTL 1). However, the intensity of the light used for such therapy is strong, and hence the direct entry of intense light to the eye of a patient is not desirable. 
         [0003]    To cope with this problem, there has been proposed a configuration in which, in the state where therapeutic light from a light source is introduced into a light guide body, such as acrylic and glass, a treatment part is brought into contact with the surface of the light guide body (see, e.g., PTL 2). The therapeutic light introduced into the light guide body is applied to the treatment part which is in contact with the light guide body. That is, in the phototherapy apparatus proposed by PTL 2, in the state where the treatment part is not in contact with the surface of the light guide body, the therapeutic light introduced into the light guide body from the light source is prevented from being emitted to the outside of the light guide body, while, in the state where the treatment part is in contact with the surface of the light guide body, the therapeutic light introduced into the light guide body is applied to the treatment part which is in contact with the surface of the light guide body. 
         [0004]    Thereby, unnecessary emission of therapeutic light from the light guide body is prevented, and entry of therapeutic light into the eye of a patient is prevented. 
       CITATION LIST 
     Patent Literature 
     PTL 1 
       [0000]    
       
         Japanese Patent Application Laid-Open. No. SHO 63-21069 
       
     
       PTL 2 
       [0000]    
       
         Japanese Patent Application Laid-Open No. 2009-95549 
       
     
       SUMMARY OF INVENTION 
     Technical Problem 
       [0007]    When phototherapy is performed by using the phototherapy apparatus described in PTL 2, and when a treatment part is a bent part, such as a joint, the therapeutic light cannot be supplied to the treatment part unless the bent part is brought into contact with the surface of the light guide body. However, the phototherapy apparatus has a problem that, since it is difficult to bring such a bent part into contact with the surface of the light guide body, it is difficult to suitably supply the therapeutic light to the treatment part, and hence suitable therapeutic treatment cannot be performed. 
         [0008]    For example, in the case of a patient with rheumatoid arthritis, especially in the case of a patient with severe rheumatoid arthritis, swelling of the joint continues for a long time, and thereby the joint capsule and the tissue around the joint are distorted or deformed. When the symptoms progress further, so-called joint deformation is caused. Joint deformation is a symptom in which the joint is bent because the articular surface is shifted and pulled by muscles around the joint with the progress of destruction of articular cartilage and joint subchondral bone due to synovitis. The symptom of joint deformation notably appears in finger joints. 
         [0009]    Therefore, in the case of a patient with rheumatoid arthritis, therapeutic treatment needs to be applied to finger joints as treatment parts by bringing the finger joints into contact with the surface of the light guide body. For example, when the patient places a palm of a hand on the surface of the light guide body so as to receive therapeutic treatment of the hand and fingers, the patient must be required to perform an unnatural action to bring the finger joints into contact with the surface of the light guide body. Especially for a patient with severe rheumatoid arthritis, who has developed symptoms of joint deformation, such unnatural action causes pain. Further, in some patients with such symptoms, the finger joints are so deformed that it is difficult to bring the finger joints into contact with the surface of the light guide body. Such patients are difficult to bring the finger joints into contact with the surface of the light guide body. As a result, sufficient light cannot be supplied to the affected part, and thereby suitable therapeutic treatment becomes difficult to be performed. 
         [0010]    On the other hand, it is also conceivable that the shape of the light guide body is made to match the shape of the affected part of the patient with rheumatoid arthritis so that the light guide body is brought into close contact with the bent part, such as finger joints, to enable sufficient therapeutic light to be supplied to the affected part. However, the states of deformation of finger joints of patients who have developed symptoms of joint deformation are different for each of the patients. For this reason, it is not realistic to prepare the light guide body for each shape of the affected parts. As a result, it becomes difficult to perform suitable therapeutic treatment. 
         [0011]    Therefore, an object of the present invention is to provide a phototherapy apparatus which, even when a treatment part is a bent part, such as a finger joint of a patient with severe rheumatoid arthritis, can simply supply sufficient therapeutic light to the treatment part, and as a result, can provide suitable therapeutic treatment. 
       Solution to Problem 
       [0012]    To this end, a phototherapy apparatus according to the present invention is configured, by including: a light guide body that includes a first surface on which an affected part is placed, and a second surface on a back surface side of the first surface; a light source that outputs therapeutic light to enable the therapeutic light to enter an inside of the light guide body; and a light guide member that has softness and surface tackiness and is disposed on a part of the first surface. The present invention is featured in that the intended purpose is achieved by the above-described configuration. 
       Advantageous Effects of Invention 
       [0013]    In the phototherapy apparatus according to the present invention, the light guide member has softness, and hence is deformed according to the shape of a treatment part when the treatment part is merely disposed so as to be brought into contact with the light guide member disposed on the surface of the light guide body. Thereby, a bent part, such as a finger joint, can be brought into contact with the light guide member without requiring a patient to perform an unnatural action. Further, light having entered the inside of the light guide body can be supplied to the treatment part via the light guide member. As a result, sufficient therapeutic light can be supplied to a bent part, such as a finger joint, and thereby suitable therapeutic treatment can be performed. 
         [0014]    Further, in a conventional phototherapy apparatus, when a hand is placed on a light guide body to supply light to a finger joint as a treatment part of therapeutic treatment of rheumatism, parts of the hand other than the finger joint are in contact with the light guide body, and hence are also supplied with light. On the other hand, in the phototherapy apparatus according to the present invention, the light guide member is disposed on the surface of the light guide body, and hence light can be intensively supplied to the treatment part. As a result, the energy efficiency of the phototherapy apparatus can also be improved. Further, even when therapeutic treatment needs to be intensively applied to the finger joint portion, therapeutic light can be highly efficiently supplied to the finger joint portion, and hence an improvement in therapeutic efficacy can also be expected. 
         [0015]    Further, in the phototherapy apparatus according to the present invention, when an inexpensive and general-purpose material, such as silicone, resin, is used as the material of the light guide member, the light guide member can be used as a disposable member, and hence therapeutic treatment in consideration of sanitation can be performed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]      FIG. 1  is a perspective view illustrating a phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0017]      FIG. 2  is a perspective view illustrating a use state of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0018]      FIG. 3  is a front perspective view of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0019]      FIG. 4  is a lateral perspective view of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0020]      FIG. 5  is a cross-sectional view of a light guide body of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0021]      FIG. 6  is a bottom view of the light guide body of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0022]      FIG. 7  is a perspective view of an auxiliary light guide body of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0023]      FIG. 8  is a top view of the auxiliary light guide body of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0024]      FIG. 9  is a side view of the light guide body provided with the auxiliary light guide body of the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0025]      FIG. 10  is a perspective view illustrating an example of phototherapeutic treatment using the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0026]      FIG. 11  is a bottom view illustrating the example of phototherapeutic treatment using the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0027]      FIG. 12  is a view illustrating a state where therapeutic light is applied to an affected part by a conventional phototherapy apparatus; 
           [0028]      FIG. 13  is a view illustrating a state where therapeutic light is applied to an affected part by the phototherapy apparatus according to Embodiment 1 of the present invention; 
           [0029]      FIG. 14  is a front perspective view of a phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0030]      FIG. 15  is a lateral perspective view of the phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0031]      FIG. 16  is a perspective view of an auxiliary light guide body of the phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0032]      FIG. 17  is a cross-sectional view of the auxiliary light guide body of the phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0033]      FIG. 18  is a perspective view illustrating a state where the auxiliary light guide body is disposed on the surface of the light guide body of the phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0034]      FIG. 19  is a lateral cross-sectional view illustrating a state where the auxiliary light guide body is disposed on the surface of the light guide body of the phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0035]      FIG. 20  is a view illustrating phototherapeutic treatment of a hand using the phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0036]      FIGS. 21A and 21B  are a view illustrating a change in the shape of a projecting section when a treatment part is placed on the auxiliary light guide body according to Embodiment 3 of the present invention; 
           [0037]      FIG. 22  is a bottom view illustrating a state where a hand is placed on the auxiliary light guide body according to Embodiment 3 of the present invention; 
           [0038]      FIG. 23  is a view illustrating supply of light to an affected part by using the phototherapy apparatus according to Embodiment 3 of the present invention; 
           [0039]      FIG. 24  is a top view of a light guide body disposed on a base of a phototherapy apparatus according to Embodiment 4 of the present invention; 
           [0040]      FIG. 25  is a top view illustrating a state where an auxiliary light guide body is disposed on the light guide body of the phototherapy apparatus according to Embodiment 4 of the present invention; and 
           [0041]      FIG. 26  is a top view of the auxiliary light guide body according to Embodiment 4 of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0042]    Embodiments of a phototherapy apparatus according to the present invention will be described in detail with reference to accompanying drawings. Note that the phototherapy apparatus described below in each of Embodiments 1 to 4 is assumed to have, as an example, a configuration used for therapeutic treatment of finger joints of a patient with rheumatoid arthritis. Of course, the phototherapy apparatus according to the present invention is not limited to these. 
       Embodiment 1 
       [0043]      FIG. 1  is a perspective view illustrating a phototherapy apparatus according to Embodiment 1 of the present invention. Phototherapy apparatus  1  is mounted on desk  2 . As shown in  FIG. 2 , patient  3  can sit on chair  4  and receive phototherapy using phototherapy apparatus  1  in his/her house or in a hospital. 
         [0044]    As shown in  FIGS. 3 and 4 , phototherapy apparatus  1  includes disc-like base  5  and lid  6 . Lid  6  has a capped cylindrical shape whose lower surface is open. Lid  6  is connected to base  5  by hinge  7 , and can cover the surface of base  5  in an openable and closable manner. When the surface of base  5  is covered by lid  6 , intense light for use in phototherapeutic treatment can be prevented from directly entering the eye of the patient  3 . 
         [0045]    Left and right two affected part insertion ports  8  are provided on the front surface side of the outer peripheral surface of lid  6 , that is, on the side opposite to hinge  7 . Further, hook  10  is provided on the front side of the outer peripheral surface of lid  6  and between two affected part insertion ports  8 . When hook  10  engages with engagement hole  9  of base  5 , lid  6  is locked. Hook button  11  for releasing the lock is provided above hook  10 . 
         [0046]    On the surface of base  5 , left and right two light guide bodies  12  are provided at a predetermined spacing. One or more detachable auxiliary light guide bodies  13  are disposed on a part of the outer surface (placement surface  14 ) of light guide body  12 . The number and size of auxiliary light guide bodies  13  are freely determined according to the contents of therapeutic treatment, but in  FIGS. 3 and 4 , one auxiliary light guide body  13  is disposed on one light guide body  12 . 
         [0047]      FIG. 5  is a cross-sectional view of light guide body  12 .  FIG. 6  is a bottom view of light guide body  12 . As can be seen from  FIGS. 5 and 6 , light guide body  12  is formed in a hollow semi-spherical shape. Therefore, each of the outer and inner surfaces of light guide body  12  is also formed in a substantially semi-spherical shape. The outer surface of light guide body  12  is placement surface  14  on which an affected part (e.g., a hand and fingers) is placed, and the inner surface on the hack side of placement surface  14  is back-facing surface  15 . 
         [0048]    The space between placement surface  14  and back-facing surface  15  of light guide body  12  serves as a light guide path. The thickness of the light guide path (distance between placement surface  14  and back-facing surface  15 ) is substantially uniform. Placement surface  14  of light guide body  12  has a size sufficient for placing a hand and fingers thereon. Placement surface  14  of light guide body  12  is formed in a substantially semi-spherical shape, but as can be seen from  FIG. 6 , placement surface  14  needs not be formed in an exactly semi-spherical shape. Light guide body  12  illustrated in  FIG. 6  is formed such that one diameter (lateral diameter in  FIG. 6 ) is slightly larger than the other diameter (vertical diameter in  FIG. 6 ) perpendicular to the one diameter. In this way, placement surface  14  of light guide body  12  is formed in a substantially semi-spherical shape in which the diameter in the direction perpendicular to the insertion direction from insertion port  8  is set slightly larger than the diameter in the insertion direction from insertion port  8 . Thereby, a hand can be easily put on placement surface  14 . 
         [0049]    As illustrated in  FIG. 5 , light incident port  16  is provided on the lower end surface of light guide body  12 . Light source  17  is disposed at incident port  16 . Further, as shown in  FIG. 6 , light guide body  12  is provided with a plurality of incident ports  16 , and light sources  17  corresponding to respective incident ports  16 . Light guide body  12  is configured to enable the light from light source  17  to enter the light guide path via incident port  16 . The light irradiated from light source  17  has a main wavelength range of near-infrared light (about 750 nm to about 2 μm) which is preferred as light for therapeutic treatment of articular rheumatism. 
         [0050]    Light guide body  12  may be made of a material having a light-guiding property with respect to the therapeutic light from light source  17 . In Embodiment 1, a case is described in which light guide body  12  is made of a material having a refractive index higher than a refractive index of a biological tissue. The refractive index of a biological tissue is different depending on the part and state of the biological tissue, but is generally in the range of 1.4 to 1.5. In Embodiment 1, the refractive index of a biological tissue is assumed to be 1.4, and the refractive index of the material of light guide body  12  is set higher than 1.4. 
         [0051]    Examples of the material of light guide body  12  include transparent acrylic resin (refractive index: 1.49), transparent polyethylene terephthalate (PET) resin (refractive index: 1.66), transparent glass (refractive index: 1.51), transparent silicone resin having a refractive index adjusted to be higher than 1.4, and the like. 
         [0052]    In phototherapy apparatus  1  configured as described above, light emitted from light source  17  is made to enter the inside of light guide body  12 . The light having entered the inside first reaches the inner surface of placement surface  14  or the inner surface of back-facing surface  15 . The light having reached the inner surface of placement surface  14  or of back-facing surface  15  is emitted to the outside or reflected on the inner surface according to the incident angle of the light with respect to the inner surface. That is, when the incident angle of the light with respect to the inner surface is smaller than the critical angle derived from the material of light guide body  12  and the outside environment (assumed to be air at this time) at the part of the inner surface reached by the light, the light is emitted to the outside of light guide body  12 . On the other hand, when the incident angle of the light with respect to the inner surface is larger than the critical angle, the light is reflected on the inner surface. 
         [0053]    Since the thickness of the light guide path is substantially uniform, the light reflected on the inner surface propagates in the light guide path while repeating reflection at substantially the same incident angle with respect to the inner surface. The light propagating in the light guide path while repeating reflection is principally trapped inside light guide body  12  when nothing is brought into contact with light guide body  12  (that is, when air is in contact with light guide body  12 ). 
         [0054]    On the other hand, when a substance (e.g., a biological tissue, such as a hand) having a refractive index higher than the refractive index (1.0) of air is brought into contact with placement surface  14 , the light, which is not emitted to the outside at the time when air is in contact with placement surface  14 , is emitted to the outside. That is, when a substance having a refractive index higher than the refractive index (1.0) of air is brought into contact with placement surface  14 , the critical angle on the boundary surface of the contact portion is increased. The portion of the light corresponding to an increase in the critical angle is emitted to the outside of light guide body  12  from the contact portion. 
         [0055]    Next, auxiliary light guide body  13  is described with reference to  FIGS. 7 and 8 .  FIG. 7  is a perspective view of auxiliary light guide body  13 .  FIG. 8  is a top view of auxiliary light guide body  13 . Auxiliary light guide body  13  is configured by hollow holding member  19  and light guide member  18 . Auxiliary light guide body  13  is configured by inserting and holding light guide member  18  in the hollow part of holding member  19 . 
         [0056]    As shown in  FIG. 9 , auxiliary light guide body  13  is disposed at a part of placement surface  14  of light guide body  12  so as to be in contact with light guide member  18 . Light guide member  18  can be disposed at any place of placement surface  14  of light guide body  12 , and is also configured to be detachable. 
         [0057]    As shown in  FIG. 10 , therapeutic treatment is performed in such a manner that affected part, such as a hand and fingers, is placed on placement surface  14 , and that a treatment part, such as finger joints, is placed in contact with light guide member  18  of auxiliary light guide body  13 . That is auxiliary light guide body  13  is used in the state of being inserted between the treatment part and light guide body  12 . 
         [0058]    Embodiment 1 is described by taking, as an example, phototherapeutic treatment of a hand or fingers of a patient with rheumatism. The affected parts of a hand or fingers of a patient with rheumatism in which the severest symptoms appear are metacarpophalangeal joint  21  and proximal interphalangeal joint  22 . Auxiliary light guide body  13  inserted between light guide body  12  and each of metacarpophalangeal joint  21  and proximal interphalangeal joint  22  as treatment parts is placed as shown in  FIG. 11 . Light guide member  18  of auxiliary light guide body  13  is mainly brought into contact with light guide body  12 . 
         [0059]    Next, light guide member  18  of auxiliary light guide body  13  is described. Light guide member  18  is made of a material having the following three features. 
         [0060]    The first feature is that the material has a light-guiding property. This is because, as will be described below, in the phototherapy apparatus according to the present invention, therapeutic light in light guide body  12  is applied to a treatment part via light guide member  18 . The material of light guide member  18  is not limited in particular as long as it has a light-guiding property. In Embodiment 1, a material having a relationship of refractive indexes expressed by Equation 1 is used as an example of the material of the light-guiding property. 
         [0000]      [1] 
         [0000]      Refractive index of air&lt;Refractive index of biological tissue&lt;Refractive index of light guide body&lt;Refractive index of light guide member  (Equation 1)
 
         [0061]    The second feature is that the material has at least softness, such as flexibility and resilience. As described above, auxiliary light guide body  13  is used in the state of being inserted between the affected part and placement surface  14 . When light guide member  18  does not have softness, light guide member  18  is difficult to be brought into close contact with the treatment part which is a bent part, such as a finger joint. When light guide member  18  and the treatment part are not in close contact with each other, sufficient light cannot be applied to the treatment part. When light guide member  18  has such softness that the shape thereof is changed according to the bent part of the treatment part, light guide member  18  and the affected part can be brought into close contact with each other. Further, when light guide member  18  has softness, light guide member  18  can be disposed in close contact with placement surface  14  of each of light guide bodies  12  having various shapes (placement surface  14  in Embodiment 1 is a substantially semi-spherical surface). 
         [0062]    The third feature is that the material has surface tackiness (adhesiveness). That is, light guide member  18  is disposed on placement surface  14  of light guide body  12 , and is brought into close contact with placement surface  14  by applying slight pressing force, or the like, to light guide member  18 . Thereby, light guide member  18  and placement surface  14  can substantially have no gap therebetween. For this reason, it is preferred that the material of light guide member  18  has a close contact property with a material constituting light guide body  12  (e.g., transparent acrylic resin, transparent polyethylene terephthalate (PET) resin, transparent glass, and transparent silicone resin having a refractive index adjusted to be higher than 1.4). 
         [0063]    In the case where light guide member  18  has surface tackiness, the placement position of auxiliary light guide body  13  can be fixed when auxiliary light guide body  13  is merely disposed on placement surface  14  of light guide body  12 , or when auxiliary light guide body  13  is only slightly pressed after being disposed on placement surface  14 . Further, auxiliary light guide body  13  needs not be fixed by a tape, or the like, and auxiliary light guide body  13  can also be easily removed. 
         [0064]    In this way, even when phototherapeutic treatment (photo-irradiation) is performed by inserting auxiliary light guide body  13  between a treatment part and placement surface  14 , the position of auxiliary light guide body  13  initially disposed on placement surface  14  is hardly shifted because of the surface tackiness of auxiliary light guide body  13 . 
         [0065]    An elastomer having a light-guiding property is an example of the materials having the above-described three features and having the relationship between the refractive indexes expressed by Equation 1. Specifically, when the material of light guide body  12  is assumed to be transparent acrylic resin, transparent polyethylene terephthalate (PET) resin, or transparent glass, examples of elastomers having the three features include transparent silicone resin having a refractive index adjusted to be higher than the refractive index of the material of light guide body  12 , isoprene rubber (refractive index: 1.52), ethylene propylene rubber (refractive index: 1.48), chloroprene rubber (refractive index: 1.558), butyl rubber refractive index: 1.508), urethane rubber (refractive index: 1.50 to 1.55), epichlorohydrin rubber (refractive index: 1.51), butadiene rubber (refractive index: 1.516), styrene butadiene rubber (refractive index: 1.535), nitrile rubber (refractive index: 1.52), and the like. 
         [0066]    When transparent silicone resin is used as the material of each of light guide body  12  and light guide member  18 , it is necessary that the refractive index of the transparent silicone resin of light guide member  18  is adjusted to be higher than the refractive index of transparent silicone resin of light guide body  12 . Further, when transparent silicone resin is used as the material of light guide body  12 , and when isopropylene rubber is used as the material of light guide member  18 , it is necessary that the refractive index of transparent silicone resin is adjusted to be lower than the refractive index (1.52) of isopropylene rubber. 
         [0067]    As described above, holding member  19  has a shape having a hollow part therein. Light guide member  18  is configured to be inserted and held in the hollow part of holding member  19 . In Embodiment 1, holding member  19  is cylindrical in shape. 
         [0068]    It is preferred that holding member  19  be made of a rigid material, such as plastic, which is not optically transparent. Auxiliary light guide body  13  may not have holding member  19 . However, when light is applied to a treatment part via auxiliary light guide body  13 , holding member  19  prevents the light from leaking from a portion not in contact with the treatment part. 
         [0069]    Reflection film  20  may be provided on the inner surface of the hollow part of holding member  19 . When light is applied to an affected part from light guide body  12  via light guide member  18 , reflection film  20  enables the light to be efficiently applied to the affected part while preventing the light from leaking from a portion of light guide member  18 , which portion is not in contact with the treatment part. 
         [0070]    In auxiliary light guide body  13  in Embodiment 1, light guide member  18  held in the hollow part of holding member  19  is raised from the peripheral edge of the hollow part of holding member  19  as shown in  FIG. 7 . For example, the upper side of auxiliary light guide body  13  of  FIG. 7  is assumed to be treatment part contact surface  23  to be brought into contact with a treatment part. When the portion of treatment part contact surface  23  of light guide member  18  is raised and held, light guide member  18  can be brought into close contact with a finger joint which is a bent part. This is because the shape of light guide member  18  can be changed so as to fit the bent portion of the joint. On the other hand, when light guide member  18  is held in a state of not being raised from the peripheral edge of the hollow part of holding member  19  (a state where light guide member  18  is held inside the peripheral edge of the hollow part of holding member  19 ), the finger joint is hardly brought into close contact with light guide member  18 . This is because holding member  19  is made of a rigid material and the finger joint is a bent part. 
         [0071]    On the other hand, the underside of auxiliary light guide body  13  of  FIG. 7  is used as holding surface  24  which is brought into contact with placement surface  14 . When light guide member  18  is also raised on holding surface  24 , the positions of light guide body  12  and auxiliary light guide body  13  can be fixed to some extent so as not to be displaced from each other. Thereby, the positional displacement of auxiliary light guide body  13  is prevented at the time when the affected part is placed on auxiliary light guide body  13  for receiving therapeutic treatment using auxiliary light guide body  13 . 
         [0072]    When light guide member  18  is also raised on holding surface  24 , the light from light guide body  12  can also be made to suitably enter light guide member  18 . That is, when a gap exists between light guide body  12  and light guide member  18 , the boundary surface between the gap portion and light guide body  12  substantially becomes a boundary surface between light guide body  12  and air, and hence the light is difficult to be emitted from light guide body  12 . When a raised portion of light guide member  18  is provided on holding surface  24  of auxiliary light guide body  13  of  FIG. 7 , auxiliary light guide body  13  can be disposed in the state where the close contact state between light guide member  18  and placement surface  14  is improved. 
         [0073]    The state where light is irradiated during the phototherapeutic treatment using auxiliary light guide body  13  configured as described above is described with reference to  FIGS. 12 and 13 . In  FIG. 12 , a case is described in which acrylic resin (refractive index: 1.49) is used as the material of light guide body  12 , and light guide member  18  is not disposed. In  FIG. 13 , a case is described in which an auxiliary light guide body including light guide member  18  made of isoprene rubber (refractive index: 1.52) is disposed. 
         [0074]      FIG. 12  is a view illustrating a light irradiation state in the case where light guide member  18  is not disposed. That is,  FIG. 12  is a view illustrating a case where conventional phototherapeutic treatment is performed. In  FIG. 12 , when a treatment part is not brought into contact with light guide body  12 , placement surface  14  of light guide body  12  is in contact with air. When light is emitted from acrylic resin (refractive index: 1.49) as the material of light guide body  12  into air (refractive index: 1.00), the critical angle of the light at the boundary surface is 42.155 degrees. For this reason, as shown in  FIG. 12 , light having reached the inner wall surface of light guide body  12  at an incident angle of 42.155 degrees or more in light guide body  12  is totally reflected on the inner wall surface. The reflected light repeats reflection on the inner wall surface of light guide body  12 . On the other hand, light having reached the inner wall surface of light guide body  12  at an incident angle smaller than 42.155 degrees in light guide body  12  is emitted to the outside from light guide body  12 . 
         [0075]    That is,  FIG. 12 , light having reached the inner wall surface of placement surface  14  at an angle of 40.3 degrees (incident angle a: 25) has an incident angle smaller than the critical angle (42.155 degrees), and hence is emitted to the outside from placement surface  14 . On the other band, light having reached the inner wall surface of placement surface  14  at an angle of 62.1 degrees (incident angle b: 26) has an incident angle larger than the critical angle (42.155 degrees), and hence is totally reflected. 
         [0076]    A portion of light guide body  12  having a uniform thickness in which light is emitted to the outside is substantially limited only to the vicinity of incident port  16  of light source  17 . This is because the portion where light having a large incident angle reaches placement surface  14  is limited only to the vicinity of incident port  16  of light source  17 . As a result, in the state where air is in contact with placement surface  14  of light guide body  12 , the amount of light emitted to the outside from placement surface  14  is very small. 
         [0077]    When a hand and fingers are placed on placement surface  14  of light guide body  12 , a part of placement surface  14  and biological tissue as the hand and fingers are brought into close contact with each other. When light is emitted to the biological tissue (refractive index: 1.40) from acrylic resin (refractive index: 1.49) used as the material of light guide body  12 , the light has a critical angle of 69.984 degrees at the boundary surface. For this reason, light having reached the inner surface of placement surface  14  at an angle smaller than 69.984 degrees is emitted from placement surface  14 . 
         [0078]    Among affected parts of a hand and fingers of a patient with rheumatoid arthritis, the affected part which most needs to be treated is finger joint  27 . However, finger joint  27  is a bent part, and hence gap  28  is easily generated between the bent part and placement surface  14  of light guide body  12 . A healthy person and a patient with slight symptoms of rheumatism can prevent the generation of gap  28  by bringing the bent part into close contact with light guide body  12  according to the shape of light guide body  12 . However, it is difficult for a patient with severe rheumatism accompanied by joint deformation to prevent the generation of gap  28  by bringing the bent part into close contact with light guide body  12 . As a result, sufficient light is not applied to finger joint  27  which most needs to receive the therapeutic treatment. 
         [0079]    On the other hand,  FIG. 13  is a vie illustrating a light irradiation state in the case where auxiliary light guide body  13  is disposed on light guide body  12 . That is,  FIG. 13  is a view illustrating a case where phototherapeutic treatment is performed by using the phototherapy apparatus according to the present invention. As shown in  FIG. 13 , when auxiliary light guide body  13  is disposed on placement surface  14  of light guide body  12 , light guide member  18  is brought into close contact with placement surface  14 . This is because light guide member  18  has a close contact property and softness, and also light guide member  18  is held and raised from the peripheral edge of the hollow part of holding member  19 . That is, almost no gap is generated between light guide body  12  and light guide member  18 . Therefore, placement surface  14  of light guide body  12  and the isoprene rubber serving as light guide member  18  are brought into close contact with each other. 
         [0080]    The refractive index (1.52) of isoprene rubber is higher than the refractive index (1.49) of acrylic resin, and hence all the light having reached placement surface  14  of light guide body  12  enters light guide member  18  from light guide body  12  as shown in  FIG. 13 . That is, as can be seen from  FIG. 13 , even the light having the incident angle of 62.1 degrees (incident angle c: 29) is emitted from placement surface  14 . As is apparent from the comparison of  FIG. 13  with  FIG. 12 , the amount of light emitted from placement surface  14  of light guide body  12  in the vicinity of finger joint  27  is increased. 
         [0081]    The light having entered light guide member  18  propagates toward finger joint  27 . When the light enters light guide member  18 , the light propagating in the direction different from the direction to finger joint  27  is reflected by reflection film  20  provided, on the inner surface of holding member  19 , so as to be guided in the direction toward finger joint  27 . 
         [0082]    Since light guide member  18  has a light-guiding property, softness, and surface tackiness, and since light guide member  18  is held so as to be raised from the peripheral edge of the hollow part of holding member  19 , light guide member  18  is brought into close contact with finger joint  27  without a gap. That is, substantially no gap exists between light guide member  18  and finger joint  27 . The refractive index (1.52) of the isoprene rubber as the material of light guide member  18  is higher than the refractive index (1.40) of the biological tissue. Since the critical angle at the boundary surface between light guide member  18  and finger joint  27  is 67.08 degrees, the light having entered the boundary surface at an angle of 67.08 degrees or more is totally reflected, and a part of the light enters the biological tissue after being repeatedly reflected by reflection film  20 , and the like, of the inner wall of holding member  19 . 
         [0083]    With the above-described configuration, even in therapeutic treatment of a patient with serious rheumatism accompanied by joint deformation, sufficient therapeutic light can be supplied to a deep part of tissue of an affected part without requiring an unnatural action of the patient and without giving pin and suffering to the patient. As a result, suitable therapeutic treatment can be performed. 
         [0084]    Further, when auxiliary light guide body  13  is disposed on a part of placement surface  14  of light guide body  12 , more intense light can be applied to the affected part. Specifically, when a hand and fingers as affected parts are directly placed on the placement surface of light guide body  12  without disposing auxiliary light guide body  13  on placement surface  14  of light guide body  12 , the whole of the hand and fingers are brought into contact with placement surface  14  of light guide body  12 . Therefore, the contact area of placement surface  14  with the hand and fingers is increased. Therefore, light is applied to a part to which the light needs not be applied. However, the amount of therapeutic light from light source  17  is limited. Therefore, when the contact area of placement surface  14  with the hand and fingers is too large, the amount of the therapeutic light supplied to the treatment part is relatively reduced, and hence sufficient therapeutic light cannot be applied to the treatment part. 
         [0085]    In the present invention, the main portion in contact with placement surface  14  can be limited to light guide member  18  by using auxiliary light guide body  13 , and thereby the therapeutic light from light guide body  12  can be collected to auxiliary light guide body  13  disposed on placement surface  14 . As a result, the therapeutic light applied to the treatment part can be increased. 
       Embodiment 2 
       [0086]    Embodiment 2 as a modification of Embodiment 1 describes a configuration in which the relationship in the refractive index between light guide body  12  and light guide member  18  of auxiliary light guide body  13  is set as expressed by Equation 2. The other parts of the configuration are the same as those in Embodiment 1, and hence explanation thereof is omitted. 
         [0000]      [2] 
         [0000]      Refractive index of air&lt;Refractive index of light guide body&lt;Refractive index of light guide member≦Refractive index of biological tissue  (Equation 2)
 
         [0087]    The material of light guide body  12  is a material which is transparent to the light from light source  17 , and which has a refractive index higher than the refractive index (1.0) of air and lower than the refractive index of the biological tissue. Examples of such material include perfluoro resin, silicone resin having a refractive index adjusted to 1.4 or less, FEP (tetrafluoroethylene-hexafluoropropylene copolymer) resin, polytetrafluoroethylene, and the like. 
         [0088]    Examples of the material of light guide member  18 , which satisfies Equation 2, include elastomers having a light-guiding property. Examples of such elastomers include fluororubber (refractive index: 1.38), and silicone resin having a refractive index adjusted to 1.4 or less. When the refractive index of the biological tissue is 1.5, the elastomer may be ethylene propylene rubber (refractive index: 1.48), acrylic rubber (refractive index: 1.465), and the like. 
         [0089]    When silicone resin having a refractive index adjusted to 1.4 or less is used as the material of light guide body  12 , the refractive index of the silicone resin must be adjusted to a value equal to or lower than the refractive index of light guide member  18 . Further, when silicone resin having a refractive index adjusted to 1.4 or less is used as the material of light guide body  12  and light guide member  18 , the refractive index of each of light guide body  12  and light guide member  18  needs to be adjusted to satisfy Equation 2. 
         [0090]    A state of light irradiation in the phototherapeutic treatment using auxiliary light guide body  13  configured as described above is described with reference to  FIG. 13 , in an example in which perfluoro resin (refractive index: 1.34) is used as the material of light guide body  12  and in which silicone resin having a refractive index adjusted to 1.4 is used as the material of light guide member  18 . As shown in  FIG. 13 , when auxiliary light guide body  13  is used, the boundary surface between light guide member  18  and placement surface  14  is formed by perfluoro resin and silicone resin. 
         [0091]    Light having entered the light guide path of light guide body  12  from light source  17  first reaches the inner surface of placement surface  14  or the inner surface of back-facing surface  15 . When the light having reached the inner surface of placement surface  14  or of back-facing surface  15 , and when the incident angle of the light with respect to the inner surface is smaller than the critical angle derived from the material of light guide body  12  and air (refractive index: 1.0), the light is emitted to the outside from light guide body  12 . 
         [0092]    On the other hand, when the incident angle of the light having readied the inner surface is larger than the critical angle, the light is reflected on the inner surface. Then, the reflected light propagates while repeating the reflection. At this time, the light guide path has a substantially uniform thickness, and hence the incident angle of the light with respect to the inner surface is substantially fixed. 
         [0093]    When the light propagating while repeating the reflection reaches a part on which light guide member  18  is disposed within placement surface  14  of light guide body  12 , all the light enters light guide member  18  in principle without causing total reflection. This is because the refractive index (1.4) of silicone resin used as the material of light guide member  18  is higher than the refractive index (1.34) of perfluoro resin. 
         [0094]    The light having entered light guide member  18  reaches the boundary surface between light guide member  18  and finger joint  27  after reflection on reflection film  20  and the like. The refractive index of light guide member  18  is equal to or lower than the refractive index of the biological tissue, and hence all the light also enters finger joint  27  in principle without being totally reflected by the boundary surface. 
         [0095]    With the above-described configuration, all the light having reached the boundary surface between light guide member  18  and the affected part from light guide body  12  through light guide member  18  can be made, in principle, to enter the affected part from light guide member  18 . Thereby, light can be supplied to a bent part, such as finger joint  27  without requiring an unnatural action of a patient with rheumatoid arthritis and without giving pain and suffering to the patient. Further, even when the portion of finger joint  27  in particular needs to be intensively treated, light can be highly efficiently supplied to the finger joint portion, and hence the improvement of the therapeutic efficacy can be expected. 
       Embodiment 3 
       [0096]    As shown in  FIGS. 14 and 15 , Embodiment 3 is different in the configuration of auxiliary light guide body  13  from Embodiment 1 and Embodiment 2. The other parts of the configuration are the same as those in Embodiment 1 and Embodiment 2, and hence explanation thereof is omitted. Further, the materials of light guide body  12  and light guide member  18  are not particularly limited as long as the materials have light-guiding properties. However, in Embodiment 3, a case is described in which the refractive indexes of the materials have the same relationship (see Equation 2) as that in Embodiment 2. 
         [0097]    Auxiliary light guide body  13  in Embodiment 3 is illustrated in  FIGS. 16 and 17 .  FIG. 16  is a perspective view of auxiliary light guide body  13 .  FIG. 17  is a longitudinal cross-sectional view of auxiliary light guide body  13 . 
         [0098]    Auxiliary light guide body  13  is configured by light guide member  18  and reflection film  20 . Light guide member  18  is substantially sheet-shaped. The surface of light guide member  18  is the surface on which an affected part is placed. The back surface of light guide member  18  is holding surface  24  which is disposed on placement surface  14  of light guide body  12 . 
         [0099]    A part of the surface of light guide member  18  is treatment part contact surface  23  which is brought into contact with a treatment part. In treatment part contact surface  23 , the thickness of light guide member  18  is set larger than the other parts thereof. That is, treatment part contact surface  23  is formed as projecting section  30 . As shown in  FIG. 16 , projecting section  30  has the lateral width larger than the longitudinal width. Treatment part contact surface  23  needs only to have a size sufficient for placing an affected part thereon. Further, as will be described below, auxiliary light guide body  13  is used by being disposed on placement surface  14  of light guide body  12 , and hence has a size smaller than the size of placement surface  14 . 
         [0100]    Reflection film  20  is provided on the surface of light guide member  18  except projecting section  30 . It is only necessary that reflection film  20  is configured to reflect the light in light guide member  18  from the surface side in the direction toward holding surface  24 . For example, the surface of light guide member  18  is coated with silver color, gold color, or the like except projecting section  30 . 
         [0101]    Similarly to Embodiment 1 and Embodiment 2, the material of light guide member  18  has surface tackiness, softness, and a light-guiding property, and may be an elastomer or the like. 
         [0102]    In the following, a propagation state is described in which light is supplied to a treatment part from light source  17  via light guide body  12  and light guide member  18 . The refractive indexes of the respective sections are not limited in particular, and the respective sections may be configured such that the light from light source  17  is supplied to the treatment part via light guide body  12  and light guide member  18 . However, in Embodiment 3, the relationship between, the refractive index of light guide body  12  and the refractive index of light guide member  18  is set as expressed by Equation 3. 
         [0000]      [3] 
         [0000]      Refractive index of air&lt;Refractive index of light guide body&lt;Refractive index of light guide member≦Refractive index of biological tissue  (Equation 3)
 
         [0103]    Refractive index of a biological tissue is different depending on the part and state of the biological tissue, but is roughly in the range of 1.4 to 1.5. In Embodiment 3, the refractive index of the biological tissue is set to 1.4. Specific examples of the material of light guide body  12 , which material satisfies Equation 3, includes perfluoro resin (refractive index: 1.34), FEP resin (refractive index: 1.34), polytetrafluoroethylene (refractive index: 1.35), and silicone resin having a refractive index adjusted to a value in the range expressed by Equation 3. Further, specific examples of the material of light guide member  18  includes fluororubber (refractive index: 1.38), and silicone resin having a refractive index adjusted to a value in the range expressed by Equation 3. The materials of light guide body  12  and light guide member  18  are not limited to these. 
         [0104]    Auxiliary light guide body  13  configured as described above is disposed on placement surface  14  of light guide body  12  as illustrated in  FIGS. 18 and 19 . Then, as illustrated in  FIG. 20 , phototherapeutic treatment is performed by placing an affected part so that a treatment part is brought into contact with projecting section  30 . In Embodiment 3, an example is described in which a finger joint of a hand of a patient with rheumatoid arthritis is treated. In the hand of a patient rheumatoid arthritis, the parts in which symptoms most notably appear are metacarpophalangeal joint  21  and proximal interphalangeal joint  22 . Therefore, the treatment parts in Embodiment 3 mainly mean metacarpophalangeal joint  21  and proximal interphalangeal joint  22 . 
         [0105]    Since light guide member  18  of auxiliary light guide body  13  has softness, auxiliary light guide body  13  can be disposed on placement surface  14  of light guide body  12  so that holding surface  24  of auxiliary light guide body  13  matches the substantially semi-spherical shape of placement surface  14  of light guide body  12 . Further, when bent parts, such as metacarpophalangeal joint  21  and proximal interphalangeal joint  22 , which are treatment parts, are placed on projecting section  30 , the shape of projecting section  30  is changed due to the softness of light guide member  18 . Thereby, projecting section  30  can be brought into close contact with the bent parts. 
         [0106]    The degree of softness of light guide member  18  is suitably set according to use, and needs only to be set to such an extent that, when the treatment part is placed on projecting section  30  of light guide member  18 , the shape of projecting section  30  is changed according to the shape of the treatment part so as to enable projecting section  30  and the treatment part to be brought into close contact with each other. That is, light guide member  18  may have a level of softness such that, when a hand is placed on the affected part placement surface of light guide member  18 , the shape of projecting section  30  is changed by the weight of the hand, or pressure such as slight pressing pressure. For example, the level of softness corresponds to about 3° to 30° in terms of rubber hardness. Note that it is preferred that light guide member  18  used in Embodiment 1 and Embodiment 2 also has the same level of hardness. 
         [0107]    Since light guide member  18  has surface tackiness (adhesiveness), the placement position of auxiliary light guide body  13  can be fixed only by disposing auxiliary light guide body  13  on placement surface  14  of light guide body  12 , or only by slightly pressing auxiliary light guide body  13  after auxiliary light guide body  13  is disposed thereon. Since it is also not necessary to fix light guide member  18  by a tape, or the like, auxiliary light guide body  13  can be detached only by peeling off auxiliary light guide body  13 , in this way, auxiliary light guide body  13  can be easily attached and detached. Further, even when an affected part is placed on the surface of light guide member  18  in order to receive phototherapeutic treatment, the placement position of auxiliary light guide body  13  on placement surface  14  of light guide body  12  is not shifted. 
         [0108]    Auxiliary light guide body  13  is held on placement surface  14  of light guide body  12  by holding surface  24  of auxiliary light guide body  13 . An affected part is placed on the surface of projecting section  30  of auxiliary light guide body  13 . For this reason, several mm of thickness d 1  (distance between holding surface  24  and the surface (see  FIG. 17 )) of light guide member  18  of auxiliary light guide body  13  is sufficient, and it is not necessary to increase thickness d 1  more. 
         [0109]    Further, the shape and thickness (height from the surface of light guide member  18  to the top of projecting section  30 ) of projecting section  30  can be suitably set according to the affected part to be treated. For example, when a finger joint is to be treated, projecting section  30  needs to have a thickness of at least about 1 cm in order to be brought into close contact with the finger joint. 
         [0110]    Next, the reason why projecting section  30  is brought into close contact with a treatment part which is a bent part such as a finger joint, when the treatment part is placed on projecting section  30 , is described with reference to  FIG. 21 .  FIG. 21A  is a view illustrating a state where finger joint  27  is not placed on projecting section  30 .  FIG. 21B  is a view illustrating a state where finger joint  27  is placed on projecting section  30 . In  FIG. 21A  and  FIG. 21B , the configuration of reflection film  20  is omitted in order to facilitate explanation. 
         [0111]    As shown in  FIG. 21A , when finger joint  27  is not placed on projecting section  30 , substantially semi-spherical projecting section  30  is formed within distance d 3 . Distance d 3  is the width of projecting section  30  projecting from light guide member  18 , and the distance between boundary  31  and boundary  32 . 
         [0112]    Light guide member  18  has softness, and hence when finger joint  27  is placed on projecting section  30 , projecting section  30  is deformed, as shown in  FIG. 21B , in the lateral and longitudinal directions by application of pressure from the placed hand. Specifically, the size of the most deformed portion becomes larger than distance d 3 . Finger joint  27  and the vicinity thereof are brought into contact with deformed projecting section  30 . 
         [0113]    Therefore, even when the placement position of the top of projecting section  30  is slightly deviated from the position of finger joint  27 , finger joint  27  and the vicinity thereof can be brought into contact with projecting section  30  by shape change of projecting section  30 . For this reason, when a hand is placed on the surface of light guide member  18 , it is not necessary that finger joint  27  of the band and projecting section  30  of light guide member  18  are strictly aligned with each other. That is, efficient phototherapeutic treatment can be performed only by simply placing a hand on the surface of light guide member  18 . 
         [0114]    In  FIG. 21A  and  FIG. 21B , a configuration, in which one projecting section  30  is disposed in correspondence with one finger joint, is illustrated, but the configuration is not limited to this. As shown in  FIG. 22 , integrated projecting section  30  configured to be able to be brought into close contact with both metacarpophalangeal joint  21  and proximal interphalangeal joint  22  (see  FIG. 20 ) may also be used. The broken line of projecting section  30  in  FIG. 22  indicates the position of projecting section  30  before the affected part is placed thereon. The solid line of projecting section  30  in  FIG. 22  indicates the position of projecting section  30  whose shape is changed by placing the affected part thereon. Deformed projecting section  30  is brought into contact with the whole of metacarpophalangeal joint  21  and the whole of proximal interphalangeal joint  22 . 
         [0115]      FIG. 23  illustrates an example in the state where light is applied to an affected part by using phototherapy apparatus  1  of Embodiment 3. Light, having entered the inside of light guide body  12  having a substantially uniform thickness from the light source, propagates between the inner surface of placement surface  14  and the inner surface of back-facing surface  15  of light guide body  12  while repeating reflection and maintaining a substantially fixed reflection angle. When the light, propagating in light guide body  12  reaches the inner surface (a in  FIG. 23 ) of placement surface  14 , on which auxiliary light guide body  13  is disposed, all the light enters light guide member  18  in principle without being totally reflected. This is because the boundary surface of the part reached by light (“a” in  FIG. 23 ) is formed by light guide body  12  and light guide member  18 , and the refractive index of light guide member  18  is higher than the refractive index of light guide body  12 . 
         [0116]    The light having entered light guide member  18  reaches the surface of light guide member  18  (“b” in  FIG. 23 ), and is reflected by reflection film  20 . The reflected light again enters light guide body  12  (“c” in  FIG. 23 ). Then, the light having entered light guide body  12  is again reflected by back-facing surface  15  of light guide body  12  (“d” in  FIG. 23 ), and again enters light guide member  18  (“e” in  FIG. 23 ). 
         [0117]    The light again having entered light guide member  18  reaches the boundary surface with finger joint  27  placed on projecting section  30  (“f” in  FIG. 23 ), so that all the light is applied, in principle, to finger joint  27  without being totally reflected. This is because the refractive index of the biological tissue is equal to or higher than the refractive index of light guide member  18 . 
         [0118]    With the above-described configuration, even in the case of a patient with rheumatism accompanied by joint deformation, phototherapeutic treatment can be performed in the state where the bent part of the finger joint is brought into contact with light guide member  18  without requiring an unnatural action of the patient and without giving pain and suffering to the patient. Further, it is configured such that most of light having entered light guide body  12  is emitted from projecting section  30 . Thereby, light can be efficiently supplied to the affected part which is placed on projecting section  30  and which is to be treated, and unnecessary emission of light to the outside from light guide body  12  can be prevented. As a result, efficient therapeutic treatment can be provided. 
       Embodiment 4 
       [0119]    Embodiment 4 has basically the same configuration as the configuration of phototherapy apparatus  1  in Embodiment 3, but has a configuration which can be more easily used by a user. 
         [0120]    When phototherapeutic treatment is performed by using phototherapy apparatus  1  according to the present invention, a patient has to place his/her affected part on light guide body  12  and auxiliary light guide body  13  periodically for a certain period of time. Therefore, it is preferred that phototherapeutic treatment can be performed in a state comfortable for a patient with rheumatoid arthritis. 
         [0121]      FIG. 24  is a top view of light guide body  12  disposed on base  5 . As shown in  FIG. 24 , positioning indications  33  and positioning auxiliary lines  33 ′ for disposing auxiliary light guide body  13  are provided on base  5  around light guide body  12  of phototherapy apparatus  1  in Embodiment 4. Since light guide body  12  is transparent, positioning auxiliary lines  33 ′ can be visually checked from the upper surface of light guide body  12 . 
         [0122]    As shown in  FIG. 25 , auxiliary light guide body  13  is disposed on placement surface  14  of light guide body  12  so that positioning indications  33  and positioning auxiliary lines  33 ′ respectively coincide with the corner parts of auxiliary light guide body  13 . For example, in the case where therapeutic treatment can be applied to a patient in a state most comfortable for the patient at the time when auxiliary light guide body  13  is disposed at the positions of A 1 , A 3 , A 7 , and A 9 , the patient needs only to grasp positioning indications  33 . Then, each time the therapeutic treatment is applied to the patient, the therapeutic treatment may be performed by disposing auxiliary light guide body  13  so that the corner parts of auxiliary light guide body  13  coincide with the positions of A 1 , A 3 , A 7  and A 9  as shown in  FIG. 25 . 
         [0123]    In this way, when positioning indications  33  and positioning auxiliary lines  33 ′ for disposing auxiliary light guide body  13  are provided on base  5  around light guide body  12  so as to be used as marks for determining the placement position of auxiliary light guide body  13 , a patient can receive therapeutic treatment in a state comfortable for the patient. The patient can easily receive therapeutic treatment without the need of finely adjusting the placement of auxiliary light guide body  13  each time receiving the therapeutic treatment. 
         [0124]    Note that, for example, when characters and figures indicating the method for disposing auxiliary light guide body  13  on light guide body  12 , the method for using the phototherapy apparatus, precautions, and the like are printed (printed section  34 ) on reflection film  20  of auxiliary light guide body  13  as shown in  FIG. 26 , auxiliary light guide body  13  can be configured to be more easily used by a user. 
       INDUSTRIAL APPLICABILITY 
       [0125]    In the phototherapy apparatus according to the present invention, only by placing an affected part so that a treatment part is brought into contact with the light guide member disposed on the surface of the light guide body, the treatment part can be brought into contact with the light guide member. This is because the light guide member constituting the auxiliary light guide body has softness and hence is deformed according to the shape of the treatment part. Further, even when an affected part is a bent part, such as a finger joint, therapeutic treatment can be performed without requiring an unnatural action of a patient. 
         [0126]    Further, light having entered the inside of the light guide body from a light source can be supplied to a treatment part via the light guide member of the auxiliary light guide body. As a result, sufficient therapeutic light can also be supplied to a bent part, such as a finger joint, and hence suitable therapeutic treatment can be performed. 
         [0127]    Further, light can be intensively supplied to a treatment part by using the light guide member according to the present invention. For example, when a hand is assumed to be a target of treatment of rheumatism, the treatment part is a finger joint. In this case, use of the light guide member prevents light from being supplied to parts other than the finger joint. As a result, the energy efficiency of the phototherapy apparatus can also be improved. Further, even when therapeutic treatment needs to be intensively applied to the finger joint portion, therapeutic light can be highly efficiently supplied to the finger joint portion, and hence the improvement of the therapeutic efficacy can also be expected. 
         [0128]    Further, in the phototherapy apparatus according to the present invention, since an inexpensive and general-purpose material, such as silicone resin, can be used as the material of the light guide member, the light guide member is suitable to be used as a disposable member, and hence therapeutic treatment in consideration of sanitation can be performed. 
         [0129]    For this reason, the phototherapy apparatus according to the present invention is expected to be widely used as a phototherapy apparatus, for example, for treating a hand and finger joints of a patient with rheumatoid arthritis. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  Phototherapy apparatus 
           2  Desk 
           3  Patient 
           4  Chair 
           5  Base 
           6  Lid 
           7  Hinge 
           8  insertion port 
           9  Engagement hole 
           10  Hook 
           11  Hook button 
           12  Light guide body 
           13  Auxiliary light guide body 
           14  Placement surface 
           15  Back-facing surface 
           16  Incident port 
           17  Light source 
           18  Light guide member 
           19  Holding member 
           20  Reflection film 
           21  Metacarpophalangeal joint 
           22  Proximal interphalangeal joint 
           23  Treatment part contact surface 
           24  Holding surface 
           25  Incident angle a 
           26  Incident angle b 
           27  Finger joint 
           28  Gap 
           29  Incident angle c 
           30  Projecting section 
           31 ,  32  Boundary 
           33  Positioning indication 
           33 ′ Positioning auxiliary line 
           34  Printed section