Abstract:
A probe device for optically measuring a condition of an object includes a light emitter for emitting a light to proceed into the object through a surface of the object, a light sensor for measuring an optical condition of the light proceeding from the surface through the object and subsequently emitted from the surface to reach the light sensor, and a body holding thereon at least one of the light emitter and the light sensor. The body includes at least one main protrusion protruding so as to face to the surface, and at least two sub-protrusions arranged around the at least one main protrusion and protruding so as to face to the surface.

Description:
INCORPORATION BY REFERENCE 
       [0001]    The present application claims priority from Japanese application JP2006-350850 filed on Dec. 27, 2006, the content of which is hereby incorporated by reference into this application. 
       BACKGROUND OF THE INVENTION  
       [0002]    The present invention relates to a probe device for a biological optical measurement device, and more particularly, to a probe device for a biological optical measurement device suitably applicable to measurement of local hemodynamic variations in a living body. 
         [0003]    A measurement device called an “optical topographic device” is known as a biological optical measurement device. This device is designed to perform measurement by attaching a probe device with many probe units having a light irradiation/detection section arranged in such a way that the respective probe units sticks fast to a measurement region, for example, the head, and irradiating the region with near infrared rays from the respective probe units. 
         [0004]    A probe device according to a conventional technology as disclosed by JP-A-2001-286449 is configured with a plurality of probe units arranged in a grid-like pattern in a shell section made of a sheet material formed into a bowl-like shape conforming to the shape of the head of an examinee. The probe units are individually detachable from the shell section and when it is confirmed from a monitor screen that the contact between a certain probe unit and the scalp is incomplete due to hair or the like, only the probe unit in question can be reattached. When attached to the head of the examinee, the probe device configured as shown above does not always fit with the head due to individual differences in the shape of the head of the examinee and differences in the region of attachment, and therefore the probe device is used with a fixing belt attached to the jaw and with the shell section firmly pressed and fixed to the head. When carrying out measurement, the prove device has such a structure that near infrared rays transmitted through each optical fiber are irradiated onto the subcutaneous region of the head through a light-emitting probe unit and reflected light is received with a light-receiving probe unit and sent back to the main unit of a measurement device through the optical fiber. 
         [0005]    The conventional technology has a structure that projections are formed at the tips of the light-emitting probe unit and the light-receiving probe unit and the end of the optical fiber protrudes from the center of the projection. Furthermore, as another conventional example, the tip of an optical fiber is attached to a fiber holding member, an adjustment knob is provided for this fiber holding member to allow height adjustment and fine adjustment. The probe configured in this way cannot be removed from the shell section, but the tip of the optical fiber can be moved inside the shell section through the adjustment knob and when the contact between the tip of the optical fiber and scalp is not sufficient or the like, it is possible to sweep aside the hair and make an adjustment. 
       BRIEF SUMMARY OF THE INVENTION  
       [0006]    According to the above described conventional technology, contact between the probe unit and the subcutaneous region of the head is realized at the tip of the light-emitting or light-receiving optical fiber arranged so as to protrude from this probe unit. In other words, contact between the probe unit and the subcutaneous region of the head constitutes “point contact.” For this reason, there is a problem that it is difficult to keep the tip of the optical fiber provided so as to protrude at the tip of the probe unit arranged in the shell portion in a vertical posture with respect to the subcutaneous region of the head. 
         [0007]    In the above described conventional example, a fine adjustment knob is provided to make the posture of the tip of the optical fiber changeable, but there is a problem that it takes time to adjust the vertical postures of many probes or the like. 
         [0008]    Furthermore, in the above described conventional technology, since the contact between the probe and the subcutaneous region of the head is “point contact”, an adjustment is made by sweeping aside the hair using the tip of this optical fiber and there is a problem that it takes time to adjust the vertical postures of many probes while sweeping aside the hair. 
         [0009]    Therefore, it is an object of the present invention to provide a probe device provided with probe units easy to keep the vertical posture of each probe unit when attached to an examinee and easy to sweep aside the hair while keeping this vertical posture. 
         [0010]    In order to attain the above described object, the probe device according to the present invention is used for a biological optical measurement device provided with light irradiation means for irradiating light onto the surface of a living body and light detection means for detecting intensity of light passing through the interior of the living body and emerging from the surface of the living body and includes a plurality of light irradiation probe units provided with light irradiation means at the tip, a plurality of light detection probe units provided with the light detection means at the tip, a probe support body that holds the light irradiation probe units and the light detection probe units in a mutually adjacent grid-like array and a main unit support section that supports the light detection probe units and the light irradiation probe units at predetermined positions of the probe support body, wherein the light detection probe unit is provided with a main projection formed protruding toward the surface of the living body and a plurality of sub projections arranged around the main projection, the main projection is provided with light communication means that communicates the light detection means with the outside on the axial core thereof, and the main unit support section causes the probe support body to support the sub projections in a manner pivotable around the axial core of the light communication means. 
         [0011]    According to the present invention, it is possible to easily keep the vertical posture of each probe unit when attached to the examinee and easily sweep aside the hair while keeping this vertical posture. 
         [0012]    Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS  
         [0013]      FIG. 1  is a schematic configuration diagram of a biological optical measurement device according to a first embodiment; 
           [0014]      FIG. 2  is a central longitudinal cross-sectional view of a detection probe according to the first embodiment; 
           [0015]      FIG. 3  is a perspective view of the detection probe seen from the top surface according to the first embodiment; 
           [0016]      FIG. 4  is a traverse cross-sectional view of the detection probe according to the first embodiment; 
           [0017]      FIG. 5A  is an oblique projection view showing the projections according to the first embodiment, and  FIG. 5B  is a front view showing an arrangement of the projections; 
           [0018]      FIGS. 6A and 6B  are side views showing a vertical control operation of the detection probe according to the first embodiment; 
           [0019]      FIG. 7  is a schematic view showing a hair sweeping operation of the detection probe according to the first embodiment; 
           [0020]      FIG. 8  is a central longitudinal cross-sectional view of a detection probe according to a second embodiment; 
           [0021]      FIG. 9  is an oblique projection view of the detection probe seen from the top surface according to the second embodiment; 
           [0022]      FIG. 10  is a traverse cross-sectional view of the detection probe according to the second embodiment; 
           [0023]      FIG. 11  is a central longitudinal cross-sectional view of a detection probe according to a third embodiment; 
           [0024]      FIG. 12  is an oblique projection view of the detection probe seen from the top surface according to the third embodiment; 
           [0025]      FIG. 13  is a central longitudinal cross-sectional view of a detection probe according to a fourth embodiment; 
           [0026]      FIG. 14  is an oblique projection view of the detection probe seen from the top surface according to the fourth embodiment; 
           [0027]      FIG. 15  is a central longitudinal cross-sectional view of a detection probe according to a fifth embodiment; 
           [0028]      FIG. 16  is a perspective view showing how the detection probe unit according to the fifth embodiment is mounted in the detection probe mounting section; 
           [0029]      FIGS. 17A-17D  show another arrangement of a main projection and sub projections of the detection probe unit according to the fifth embodiment; 
           [0030]      FIGS. 18A and 18B  are bottom views showing the other arrangement of the sub projections according to the fifth embodiment; 
           [0031]      FIG. 19  is a central longitudinal cross-sectional view of a detection probe according to a sixth embodiment; and 
           [0032]      FIG. 20  is an oblique projection view of the detection probe seen from the top surface according to the sixth embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0033]    Hereinafter, a biological optical measurement device according to the present invention will be explained more specifically with reference to  FIG. 1  to  FIG. 20 .  FIG. 1  to  FIG. 7  show a biological optical measurement device according to a first embodiment,  FIG. 8  to  FIG. 10  show a biological optical measurement device according to a second embodiment,  FIG. 11  and  FIG. 12  show a biological optical measurement device according to a third embodiment,  FIG. 13  and  FIG. 14  show a biological optical measurement device according to a fourth embodiment,  FIG. 15  to  FIGS. 18A and 18B  show a biological optical measurement device according to a fifth embodiment, and  FIG. 19  and  FIG. 20  show a biological optical measurement device according to a sixth embodiment respectively. Identical parts and directions or the like are shown using identical reference numerals and overlapping explanations will be omitted. 
       First Embodiment  
       [0034]    The biological optical measurement device according to a first embodiment will be explained in detail with reference to  FIG. 1  to  FIG. 7 . The biological optical measurement device according to this embodiment is a device which measures local hemodynamic variations in a living body taking advantage of the fact that when a certain region of the brain starts to act, the amount of blood for sending oxygen to the region increases accordingly. More specifically, it is possible to simply observe the function of the brain by irradiating near infrared light from above the scalp, measuring scattering of this near infrared light by hemoglobin in the blood, thereby measuring variations in the amount of blood near the surface of the cerebrum and expressing these variations on a two-dimensional map or the like. The near infrared light here is an electromagnetic wave having an area of wavelength longer than that of visible light. 
         [0035]    First, a schematic structure of the biological optical measurement device according to this first embodiment will be explained with reference to  FIG. 1 .  FIG. 1  shows a schematic configuration of the biological optical measurement device. The biological optical measurement device generally denoted by reference numeral  1  in  FIG. 1  is constructed by including a probe device  100  attached to the head of an examinee  50  and a biological optical measurement device main unit  10  which processes an image of an electric signal outputted from this probe device  100  and displays a map or the like. 
         [0036]    The probe device  100  is composed of a probe holder  200  to be attached to the head of the examinee  50 , a plurality of light-emitting probes  300  and a plurality of detection probes  400  attached to this probe holder  200  at predetermined intervals. Furthermore, the plurality of light-emitting probes  300  and detection probes  400  are arranged alternately in a matrix shape so that the detection probes  400  are arranged on both sides of the light-emitting probes  300  shown with diagonally shaded areas in a layout seen from the top surface of the probe holder  200  shown at the top right of  FIG. 1 . 
         [0037]    Furthermore, the light-emitting probe  300  is constructed of a light-emitting probe unit  310  provided with a light-emitting section  311  and a light-emitting probe mounting section  350  which mounts this light-emitting probe unit  310  at the predetermined position of the probe holder  200 . As the light-emitting section  311 , a semiconductor laser, a titanium sapphire laser, a light-emitting diode or the like can be used, but this embodiment will explain a case with the light-emitting probe unit  310  adopting the light-emitting section  311  provided with a light-emitting diode. 
         [0038]    Furthermore, the detection probe  400  is constructed of a detection probe unit  410  provided with a detection section  411  and a detection probe mounting section  450  which mounts this detection probe unit  410  at a predetermined position of the probe holder  200 . As the detection section  411 , a photoelectric conversion element such as a photodiode and photo multiplier can be used and this embodiment will explain a case with the detection probe unit  410  adopting the detection section  411  provided with a photodiode. 
         [0039]    On the other hand, the biological optical measurement device main unit  10  is configured by including an oscillator  11  for removing noise introduced from outside, a lock amplifier  12 , a logarithmic amplifier  13 , a differential amplifier  14 , an A/D converter  15 , a calculator  16 , a display section  17  and a power supply section (not shown). 
         [0040]    According to this biological optical measurement device  1 , power is supplied from the power supply section (not shown), weak near infrared light (light) of approximately 1.5 mW which is emitted from the light-emitting section  311  is condensed in a light-emitting section  311  using a lens system (not shown) and irradiated onto the head of the examinee  50  through a fiber for irradiation  313  of the main projection  312  provided in the lower part of this light-emitting section  311 . The light emitted from the light-emitting section  311  is modulated in intensity by the oscillator  11  at an arbitrary frequency f of approximately 100 Hz to 10 MHz for removing noise introduced from outside. 
         [0041]    The wavelength of the light used depends on the spectral characteristic of a target matter in the living body, but when a degree of oxygen saturation and the amount of blood are measured from the concentration of Hb and HbO 2  in the blood, one or a plurality of wavelengths are selected from light having a wavelength range of 600 nm to 1400 nm. The light irradiated onto the head of the examinee  50  is passed through areas of fields of view  50   a ,  50   b  of a fiber for irradiation  313 , passed through an area  51  where hemodynamics locally varies such as blood vessels in this area and detected by the detection section  411  through a fiber for detection  413  of a main projection  412  formed in the lower part of the detection section  411 . 
         [0042]    As described above, since the plurality of light-emitting probes  300  and detection probes  400  are arranged alternately in a matrix form as a layout seen from the top surface of the probe holder  200  shown at the top right of  FIG. 1 , light irradiated from one light-emitting probe  300   a  can be detected by the detection section  411  of four detection probes  400   a ,  400   b ,  400   c  and  400   d  arranged on both sides in the X direction and the Y direction. In other words, one detection probe  400  can detect light irradiated from the four light-emitting probes  300  arranged on both sides in the X direction and the Y direction. That is, according to this embodiment, hemodynamic variations of the entire area to which the probe device  100  is attached can be measured. 
         [0043]    The light detected at the detection section  411  through the fiber for detection  413  is photoelectrically converted at this detection section  411  and the intensity of the transmitting light is outputted as the intensity of an electric signal. As for the electric signal indicating the intensity of the transmitting light outputted from the plurality of detection sections  411 , only the light intensity modulation frequency component of the light source is extracted by each lock-in amplifier  12 , logarithmically converted by each logarithmic amplifier  13  and then inputted to the differential amplifier  14 . This differential amplifier  14  inputs, for example, the output from the detection probe  400   a  to a negative electrode and inputs the output from the detection probe  400   b  to a positive electrode, and as a result, it outputs a differential signal of the intensity of the transmitting light at two different locations as an output signal. The output signal from this differential amplifier  14  is converted to a digital signal at the A/D converter  15 , inputted to and processed by the calculator  16  and then displayed as time sequence data on the display device  17 . 
         [0044]    One of major features of the biological optical measurement device  1  according to this embodiment lies in that substantially the same structure is used for the light-emitting probe  300  and the detection probe  400 . More specifically, though the light-emitting probe  300  and detection probe  400  differ from each other in whether the probe unit ( 310 ,  410 ) arranges the light-emitting section  311  or arranges the detection section  411 , or whether the connection between this probe unit ( 310 ,  410 ) and probe mounting section ( 350 ,  450 ) is accompanied by supplies of power or light or acquisition of an electric signal due to this difference, other basic structures are substantially the same. Hereinafter, the detection probe  400  will be mainly explained, but if the explanation is equivalent to that of the light-emitting probe  300 , the explanation of the light-emitting probe  300  will be omitted and if there is some difference, only the explanation thereof will be described. 
         [0045]    Furthermore, another major feature of the biological optical measurement device  1  according to this embodiment is that a plurality of projections ( 312 ,  314 ,  412 ,  414 ) are provided for contact parts  60  of the light-emitting probe  300  and detection probe  400  with the examinee  50  and irradiation of light and acquisition of reflected light of this light are made possible through these projections. 
         [0046]    That is, this embodiment adopts a structure in which the main projection  412  provided with the fiber for detection  413  is provided on the contact surface  60  of the detection probe unit  410  with the examinee  50  and the plurality of sub projections  414  are arranged around this main projection  412 . Furthermore, this embodiment adopts a “planar structure consisting of a plurality of points” in which the light-emitting probe  300  is likewise provided with the main projection  312  provided with the fiber for irradiation  313  on the contact surface  60  with the examinee  50  and the plurality of sub projections  314  are arranged around this main projection  312 . 
         [0047]    The light-emitting probe and the detection probe of the conventional technology adopt a “one-point contact” scheme having a structure in which a fiber for irradiation or detection is directly attached to the contact surface  60  with the examinee  50  or attached reinforced with a projection. Therefore, there is a problem that it is difficult to keep the tip of the optical fiber provided so as to protrude at the tip of each of a plurality of probe units in the probe holder in a vertical posture with respect to the subcutaneous region of the head. There is a conventional technology provided with a fine adjustment knob to allow the posture of the tip of the optical fiber to be changed, yet has a problem that it takes time to adjust the vertical postures of many probes or the like. 
         [0048]    This embodiment adopts the structure in which contact with the surface of the living body (contact surface  60 ) of the examinee  50  is realized by the main projections  312 ,  412  provided with light communication means (fiber for irradiation  313  or for detection  413 ) for communicating light irradiation means (light-emitting section  311 ) or light detection means (detection section  411 ) with the outside on the axial core thereof and a plurality of sub projections ( 314 ,  414 ) having substantially the same length and protruding around these main projections  312 ,  412 , and can thereby easily support the light communication means in a posture perpendicular to the surface of the living body. 
         [0049]    As illustrated in the balloon at the bottom of  FIG. 1 , this embodiment provides four sub projections  414  on a concentric circle P 1  of the main projection  412  equidistantly, and can thereby suppress inclinations in four directions and alleviate the above described problem of the conventional technology. If there are three or more sub projections  414  around the main projection  412 , the detection probe unit  410  provided with the sub projections  414  stands on its own in a vertical posture, and therefore effects similar to those described above can be expected. 
         [0050]    This embodiment forms the sub projection  414  of a flexible resin material or a relatively soft material such as rubber or elastomer, and can thereby provide a probe device friendly to the examinee  50  and allow the detection probe unit  410  to easily keep the vertical posture. As described above, the light-emitting probe  300  can also obtain similar operations and effects by adopting the similar structure. 
         [0051]    Furthermore, one of other major features of this embodiment is that the plurality of sub projections  414  are supported in a manner pivotable around the main projection  412 . 
         [0052]    This type of the biological optical measurement device has a problem that the hair on the surface of the living body interferes making it difficult to cause the tip of the optical fiber to stick fast to the surface of the living body of the examinee  50 . However, according to the conventional technology, the contact between the probe and the subcutaneous region of the head is a “one-point contact” and the tip of this optical fiber makes an adjustment by sweeping aside the hair, and therefore there is a problem that it takes time to adjust the vertical postures of many probes while sweeping aside the hair. 
         [0053]    In this embodiment, the sub projections  414  are supported in a manner pivotable around the main projection  412 , and therefore by rotating these sub projections  414 , the tips of the sub projections  414  sweep aside the hair allowing the tip of the fiber for detection  413  to easily stick fast to the surface of the living body. Moreover, when the sub projections  414  rotate around the main projection  412 , it is possible to cause the detection probe unit  410  to easily take the vertical posture. Moreover, by forming the sub projections  414  of a flexible material and providing the fiber for detection  413  on the axial core and making the flexible sub projections  414  rotate around the main projection  412  having a higher degree of strength than the sub projections  414 , it is possible to easily perform hair sweeping and posture control. 
         [0054]    As described above, by adopting a similar structure, the light-emitting probe  300  can have similar operations and effects. 
         [0055]    Furthermore, one of other major features of this embodiment is that the support body  415  of the sub projections  414  is exposed from the outside surface of the probe holder  200  and this support body  415  is pivotably attached to the detection probe mounting section  450 . In this way, even after the probe device  100  is attached to the examinee, it is possible to pick up and turn the support body  415  exposed from the outside surface of the probe holder  200  by fingers or the like and thereby simply rotate the sub projections  414 . 
         [0056]    As described above, since the light-emitting probe  300  also has a similar structure, providing a support body  315  allows similar operations and effects to be obtained. 
         [0057]    Furthermore, one of other major features of this embodiment lies in that the detection probe unit  410  is configured by including a first housing  416  provided with the detection section  411  and the main projection  412  and a second housing  417  provided with the sub projections  414  and the support body  415 , the first housing  416  is fixed to and supported by the detection probe mounting section  450  and the second housing  417  is pivotably attached to the detection probe mounting section  450  or the first housing  416 . 
         [0058]    According to the embodiment having this feature, since only the sub projections  414  can be turned while leaving the main projection  412  in contact with the surface of the living body as is, it is possible to make easier the connection between the first housing  416  provided with the detection section  411  and an external device or the electrical connection through the detection probe mounting section  450 . Especially, in this embodiment, since the detection probe  400  and the first housing  416  are connected through a connection section  418 , it is possible to connect an electric signal outputted at the detection section  411  to a signal wiring in the probe holder  200  through the connection section  418 , and on the other hand, by rotating the second housing  417  and thereby rotating the sub projections  414  without influencing electrical connections, it is possible to move the hair and further keep the first housing  416  in a vertical posture. 
         [0059]    The light-emitting probe  300  is also provided with a first housing and a second housing having similar structures, making easier the connection between the first housing provided with the light-emitting section  311  and an external device or power supply to the light-emitting section  311  through the light-emitting probe mounting section. 
         [0060]    Furthermore, one of other major features of this embodiment is that a cushion material section  419  is provided around the detection probe unit  410  and the detection probe unit  410  is attached to the detection probe mounting section  450  through this cushion material section  419 . According to this structure, it is possible to improve the degree of contact of planar contact made up of a plurality of point contacts in accordance with the unevenness of the surface of the living body of the examinee  50 . 
         [0061]    Furthermore, one of other major features of this embodiment is that the detection probe unit  410  is attached to the detection probe mounting section in a detachable manner. This makes it possible to replace the detection probe unit  410 . 
         [0062]    Furthermore, one of other major features of this embodiment is that the second housing  417  provided with the sub projections  414  is provided in a detachable manner. This makes it possible to replace parts of the sub projections  414  which contact the examinee  50 . 
         [0063]    Hereinafter, the probe device  100  which constitutes a major feature of the biological optical measurement device  1  according to this embodiment will be explained more specifically with reference to  FIG. 2  to  FIG. 7 . As described above, the detection probe  400  will be explained more specifically in the following explanations, but since the light-emitting probe  300  also has a similar structure and similar operations and effects, specific explanations thereof will be omitted. Here,  FIG. 2  is a central longitudinal cross-sectional view of the detection probe.  FIG. 3  is a perspective view of the detection probe seen from the top surface.  FIG. 4  is a traverse cross-sectional view of the detection probe.  FIGS. 5A and 5B  show the projections,  FIG. 5A  is a partial perspective view of the detection probe unit and  FIG. 5B  is a bottom view of the detection probe unit.  FIGS. 6A and 6B  show a vertical control operation of the detection probe,  FIG. 6A  is a side view of the detection probe in a vertical posture and  FIG. 6B  is a diagram illustrating the posture control operation.  FIG. 7  is a diagram illustrating a hair sweeping operation. 
         [0064]    First, in  FIG. 2 , a wiring to be led to the biological optical measurement device main unit  10  is provided inside the probe holder  200  for attaching the detection probe  400  at a predetermined position and a signal line  201  is wired. This wire is bundled at an end of the probe holder  200  and connected to the biological optical measurement device main unit  10 . In the same way, a power cable (not shown) is also provided in this probe holder  200  to supply power to the light-emitting probe  300  and this power cable is also bundled at a predetermined position and connected to the biological optical measurement device main unit  10  as in the case of the signal line  201 . 
         [0065]    Furthermore, as explained in  FIG. 1 , an opening  202  is formed in the probe holder  200  to attach the light-emitting probes  300  and detection probes  400  at matrix-shaped intersections and the light-emitting probe mounting section  350  or detection probe mounting section  450  is alternately attached to this opening  202  and the signal line  201  or power cable is connected to each section.  FIG. 2  shows a cross-sectional view of the detection probe  400  attached to the opening  202 . 
         [0066]    In this embodiment, the diameter of the light-emitting probe mounting section  350  or the detection probe mounting section  450  is assumed to be approximately 20 mm and the interval of the matrix-shaped intersections is set to 30 mm. A distance between the fiber for irradiation  313  and the fiber for detection  413  adjacent to each other is set to 30 mm. Furthermore, the thickness of probe holder  200  is set to 15 mm. Incidentally, in the probe device  100  for children, the distance between the fiber for irradiation  313  and the fiber for detection  413  adjacent to each other may be set to 20-30 mm. 
         [0067]    The detection probe mounting section  450  is configured by including a ring-shaped base  452  having an “I-shaped” cross-section provided with an overhang  451  which protrudes to the inner and outer perimeters in an edged shape at the top and bottom ends, a connection receiving section  454  attached inside this ring-shaped base  452  and a cushion material section  419 . A recessed part  453   a  is formed between the upper and lower overhangs  451  on the perimeter of the ring-shaped base  452  and the end of the opening  202  engages with this recessed part  453   a.    
         [0068]    Here, the thickness of the recessed part  453   a  is smaller than the thickness of the probe holder  200  and when the opening  202  is fitted into this recessed part  453   a , the surface and the back of the opening  202  are caved in and set to a size that the overhangs  451  can be fitted into this cave-in part. In this way, the upper and lower surfaces of the detection probe mounting section  450  are made flush with the surface of the probe holder  200  and it is thereby possible to adopt a structure in which the detection probe  400  conforms to the probe holder  200 . 
         [0069]    Also, the connection receiving section  454  coupled with the connection section  418  is provided at a predetermined position of the internal circumference of a recessed part  453   b  inside the ring-shaped base  452 . This connection receiving section  454  couples with the connection section  418  and thereby supports the detection probe unit  410  like a cantilever and is also electrically connected therewith. In this embodiment, the connection receiving section  454  is provided with a protruding lug  455  and the connection section  418  is provided with a groove  420  which engages with this lug  455 . The engagement between the lug  455  and the groove  420  is realized by inserting the detection probe unit  410  from below the detection probe mounting section  450 , sliding the lug  455  and inserting into the groove  420  from below. The strength of this engagement is set to a level enough to keep and connect the detection probe unit  410  dynamically as well as electrically. 
         [0070]    The cushion material section  419  has a ring shape arranged along the overhang  451  in the upper part of the recessed part  453   b  inside. This cushion material section  419  is provided with the function to prevent the connection section  418  from moving upward. That is, the cushion material section  419  becomes an appropriate buffering material between the detection probe mounting section  450  and the detection probe unit  410  and absorbs stress which the detection probe unit  410  receives from the examinee side, and can thereby cause the tip of the main projection  412  provided at the tip of the detection probe unit  410  to stick fast to the surface of the living body of the examinee  50  conforming to the unevenness thereof. Furthermore, the inclination of the detection probe unit  410  caused by the unevenness of the surface of the living body of the examinee  50  can also be absorbed by providing this cushion material section  419 . 
         [0071]    Furthermore, in this embodiment, since the detection probe unit  410  can be freely attached/detached to/from the probe holder  200 , it is possible to replace the detection probe unit  410  and improve cleanability. 
         [0072]    The detection probe unit  410  is constructed of the first housing  416  provided with the detection section  411 , main projection  412  and fiber for detection  413  and second housing  417  that covers the perimeter of the first housing  416 . The first housing  416  basically has a columnar shape and has an appearance provided with the main projection  412  which protrudes like a circular truncated cone in the center of this column-shaped bottom surface. The detection section  411  is provided inside this column, a linear fiber for detection  413  to transmit light to the detection section  411  is provided on the central axis Q 1  of the main projection  412  and the connection section  418  is provided at a predetermined position of the circumferential surface of the column. 
         [0073]    In this embodiment, the first housing of the light-emitting probe unit  310  also has a structure substantially equivalent to that of the first housing  416  of this detection probe unit  410  and differs in the light-emitting section  311  instead of the detection section  411  and in that power is supplied from the connection section  418 . This embodiment has explained that the detection section  411  is a photo diode, but it is also possible to reduce the sizes of the lock amplifier  12  and logarithmic amplifier  13  or the like and fit them into the area of this detection section  411  compactly. It has been likewise explained that the light-emitting section  311  is a light-emitting diode, but it is also possible to reduce the size of the oscillator  11  or the like and provide it in the area of this light-emitting section  311 . 
         [0074]    The second housing  417  has an outside shape that covers part of the top surface, bottom surface and circumferential surface of the first housing  416 . That is, the bottom surface of the second housing  417  has the size that covers the whole bottom surface of the first housing  416 , provides an opening hole  421  which exposes the main projection  412  provided in the first housing  416  in the center and the sub projections  414  are provided around this opening hole  421 . On the other hand, the perimeter and top surface of the second housing  417  are formed into a cylindrical shape, part of which is cut out so as to expose the circumferential surface to which the connection section  418  is attached. The top surface of the second housing  417 , part of which is cut out constitutes the support body  415  formed so as to protrude upward from the top surface of the detection probe mounting section  450 . 
         [0075]      FIG. 3  shows an appearance perspective view of the detection probe  400  when the support body  415  which protrudes outward is seen from above. According to the structure of this detection probe  400 , by rotating the support body  415  which protrudes in a semicircular shape in the center of the detection probe  400  and thereby rotating the plurality of sub projections  414  provided in the lower part of this support body  415 , it is possible to move the hair from right below the main projection  412 . Furthermore, adopting a semicircular shape for the support body  415  makes it easier to pick it up by fingers or the like and allows the rotation condition to be visually checked. 
         [0076]    Furthermore,  FIG. 4  shows a traverse cross-sectional view of the detection probe  400  to explain the rotation range of the second housing  417  provided with the support body  415 . As is clear from  FIG. 4 , the second housing  417  covers the circumferential surface of the first housing  416  so as to partially expose the circumferential surface of the first housing  416  to which the connection section  418  is attached. For this reason, a space  457  where the second housing  417  having a half-ring shaped cross-section can rotate is formed on both sides of the joint between the connection section  418  and connection receiving section  454 . This allows the second housing  417  to rotate around the center axis Q 1  in the space between the detection probe mounting section  450  including this space  457  and the first housing  416  as a moving path  456 . 
         [0077]    Next, the structure, operations and effects of the main projection  412  and sub projections  414  will be further explained with reference to  FIGS. 5A and 5B  to  FIG. 7 . In  FIGS. 5A and 5B , this embodiment provides the main projection  412  and sub projections  414  having substantially the same heights L 1 , L 2  on the bottom surface (the surface on the examinee  50  side) of the detection probe unit  410 . Furthermore, providing the main projection  412  and sub projections  414  in a circular truncated cone shape which is thick at the root and becomes thinner toward the tip improves the flexibility when contacting the scalp of the examinee  50  and processability during molding. This embodiment improves the closeness of contact with the scalp of the examinee  50  by forming the second housing  417  provided with sub projections  414  of a flexible resin material or a relatively soft material such as rubber and elastomer. 
         [0078]    In this embodiment, the heights of the main projection  412  and sub projections  414  are set to within a range of 3 mm to 5 mm and the diameter of the bottom surface of the second housing  417  to which the main projection  412  and sub projection  414  are attached is set to 17 mm. 
         [0079]    Furthermore, this embodiment also forms the first housing  416  of a flexible resin material or a relatively soft material such as rubber and elastomer. Therefore, the main projection  412  provided for this first housing  416  is also formed of a relatively soft material. As explained in  FIG. 4 , in this embodiment, part of the circumferential surface of the second housing  417  is cut out so as to allow the second housing  417  to rotate around the first housing  416  while seguring the coupling between the connection receiving section  454  and connection section  418 . 
         [0080]    Using this partially cut-out shape, this embodiment allows the first housing  416  to be separated from the second housing  417 . In other words, the detection probe  400  can be removed from the detection probe mounting section  450  and further the second housing  417  can be separated. This allows the second housing  417  provided with the sub projections  414  which move on the scalp of the examinee  50  to be replaced, which is therefore hygienic. Especially, this embodiment can replace only the sub projections  414  which move except the main projection  412  which is provided with the fiber for detection  413  inside and hard to be replaced and can thereby reduce the cost. 
         [0081]    Furthermore, as shown in  FIG. 5B , the four sub projections  414  are provided equidistantly on the concentric circle P 1  of the main projection  412  and in this way as shown in  FIG. 6A , the detection probe unit  410  can stand on its own on the scalp of the examinee  50  in a vertical posture. This makes it possible to keep the fiber for detection  413  provided on the central axis Q 1  of the main projection  412  in a vertical posture and thereby improve the accuracy. 
         [0082]    Furthermore, when the probe device  100  is attached to the examinee  50  as shown in  FIG. 6B , if the central axis Q 1  of the detection probe unit  410  is in an inclined posture, it is possible to pick up the support body  415  to rotate the second housing  417 , thereby bring the central axis Q 1  of the detection probe unit  410  closer to the vertical position and put it in a vertical posture as shown in  FIG. 6A . In this case, using the cushion material section  419  together makes the above described posture control operation easier. Furthermore, as shown in  FIG. 6B , forming the sub projection  414  of a flexible material can improve the posture control operation using this elasticity. Especially, the main projection  412  is provided with the fiber for detection  413  on the axial core and it is harder compared with the flexible sub projections  414 , and it is thereby possible to improve the posture control operation accompanying the rotation. 
         [0083]    Furthermore, as shown in  FIG. 7 , this embodiment has operations and effects of sweeping aside the hair of the scalp of the examinee  50  accompanying the rotation of the sub projections  414 .  FIG. 7  shows a situation in which when the probe device  100  is attached, the hair is located right below the main projection  412  interfering detection from the fiber for detection  413 . In such a situation, since this embodiment can rotate the sub projections  414  around the fiber for detection  413 , the rotation and movement of the tips of the sub projections  414  can move this interfering hair. For example, in  FIG. 7 , since the interfering hair  52  is blocking the fiber for detection  413  with a certain length, this hair  52  is located in a posture across a plurality of sub projections  414 . When the sub projections  414  rotate in the Q 2  direction in this condition, the sub projection  414   a  moves the crossing hair  52 , and can thereby move the hair  52  which is blocking the fiber for detection  413 . As for the rotation operation of the sub projections  414 , rotating them in the Q 2  direction and Q 3  direction which is opposite thereto alternately can even move the flexible hair  52 . This embodiment sets the range in which the sub projections  414  rotate to between 30 to 90 degrees. 
       Second Embodiment  
       [0084]    Next, a detection probe  400   b  according to a second embodiment will be explained in detail with reference to  FIG. 8  to  FIG. 10 . Parts common to those in the first embodiment are assigned the same reference numerals and overlapping explanations will be omitted. Furthermore, since the light-emitting probe also has a structure similar to that of this detection probe  400   b , explanations thereof will be omitted. Here,  FIG. 8  is a central longitudinal cross-sectional view of the detection probe.  FIG. 9  is a perspective view of the detection probe seen from the top surface.  FIG. 10  is a traverse cross-sectional view of the detection probe. 
         [0085]    In  FIG. 8 , one feature of the detection probe  400   b  according to this second embodiment lies in that a first housing  416   b  is supported on both sides with respect to a detection probe mounting section  450 . The first embodiment adopts the cantilever supporting structure whereby the connection section  418  is provided on one circumferential surface of the first housing  416  having a cylindrical appearance and this connection section  418  is supported by the connection receiving section  454 , whereas this second embodiment adopts a both-side supporting structure in which connection sections  418   b  are provided on circumferential surfaces on both sides of the first housing  416   b  having a cylindrical appearance and these connection sections  418   b  are supported by connection receiving sections  454   b  on both sides. According to this embodiment, since the first housing  416   b  can be supported on both sides, the first housing  416   b  can be supported more reliably. 
         [0086]    Furthermore, since the connection between the connection section  418   b  and the connection receiving section  454   b  can be distributed on both sides, the sizes of the individual connection sections  418   b  and connection receiving sections  454   b  can be reduced. Furthermore, since electric connections can also be distributed between the connection sections  418   b  and connection receiving sections  454   b  on both sides, downsizing can be realized in this aspect, too. Electric connections can be concentrated on one coupling section to thereby simplify the wiring of a probe holder  200 . Furthermore, since the coupling structure between the connection sections  418   b  and connection receiving sections  454   b  is similar to that of the first embodiment, detailed explanations thereof will be omitted. 
         [0087]    Furthermore, another feature of the detection probe  400   b  according to this second embodiment lies in that the appearance structure of the second housing  417   b  has been changed by adopting a both-side supporting structure. That is, the second housing  417  of the first embodiment has adopted the structure in which one side of the cylindrical shape is cut out to avoid the coupling of a set of the connection section  418  and connection receiving section  454 , whereas this second housing  417   b  adopts a structure in which both sides of the cylindrical shape are cut out to avoid the coupling of two sets of the connection section  418   b  and connection receiving section  454   b.    
         [0088]    That is, as for this second housing  417   b  according to this embodiment, strip-shaped support bodies  415   b  are formed which extend upward from both sides of the bottom surface of the circle provided with sub projections  414  and coupled together at the top of the first housing  416   b.    FIG. 9  shows an appearance perspective view of the detection probe  400   b  when this strip-shaped support body  415   b  is seen from above. 
         [0089]    According to the structure of this detection probe  400   b , by rotating the support body  415   b  which protrudes in a strip shape in the center of the detection probe  400   b  and thereby rotating a plurality of sub projections  414  provided in the lower part of this support body  415 , it is possible to move the hair  52  from right below the main projection  412 . Furthermore, in this case, adopting the strip-shaped support body  415   b  makes it easy to pick it up by fingers or the like and makes it possible to visually check the rotation situation. 
         [0090]    Furthermore,  FIG. 10  shows a traverse cross-sectional view of the detection probe  400   b  to illustrate the rotation range of a second housing  417   b  provided with the support body  415   b . As is clear from  FIG. 10 , the second housing  417   b  is formed in spaces other than those of the connection section  418   b  and connection receiving section  454   b  provided on both sides of the first housing  416   b  so as to avoid these sections. For this reason, spaces  457   b  in which the second housing  417   b  can rotate are formed on both sides of the joint between the respective connection sections  418   b  and connection receiving sections  454   b . This allows the second housing  417   b  to rotate around the central axis Q 1  using the space between the detection probe mounting section  450  including this space  457   b  and the first housing  416   b  as a moving path  456 . 
       Third Embodiment  
       [0091]    Next, a detection probe  400   c  according to a third embodiment will be explained in detail with reference to  FIG. 11  and  FIG. 12 . Parts common to the first and second embodiments are assigned the same reference numerals and overlapping explanations will be omitted. The light-emitting probe also has a structure similar to that of this detection probe  400   c , and therefore explanations thereof will be omitted. Here,  FIG. 11  is a central longitudinal cross-sectional view of the detection probe.  FIG. 12  is a perspective view of the detection probe seen from the top surface. 
         [0092]    In  FIG. 11 , one of features of the detection probe  400   c  according to this third embodiment lies in that a probe holder  200   c  is formed of rubber or a flexible resin material, an opening  202   c  which is formed at a predetermined position of this probe holder  200   c  is formed with certain hardness and the detection probe  400   c  is fitted into this opening  202   c  in a detachable and pivotable manner. 
         [0093]    This embodiment adopts a structure in which the perimeter of the detection probe  400   c  is formed of rubber or a flexible resin material, this detection probe  400   c  formed of rubber or a flexible resin material is inserted into the opening  202   c  formed of a similar material and the detection probe  400   c  is held to the probe holder  200   c  in a detachable and pivotable manner through friction between both members accompanying this insertion. 
         [0094]    A cap  422  connected to the top of the detection probe  400   c  is attached to the opening  202   c  of the probe holder  200   c  via a coupling member  423 . This cap  422  is provided with a connection receiving section  454   c  and this connection receiving section  454   c  is connected to a signal line  201  of a probe holder  200  through the signal line  424  provided for a coupling member  423 . 
         [0095]    On the other hand, the detection probe  400   c  is constructed of a detection probe mounting section  450   c  inserted into the opening  202   c  and a detection probe unit  410   c  which is inserted into this detection probe mounting section  450   c.    
         [0096]    The detection probe mounting section  450   c  has a cylindrical shape whose upper part is open and a mounting flange  458  protruding therearound is formed in the upper part of the circumferential surface thereof, and an opening which exposes a main projection  412  and a plurality of sub projections  414  formed around this opening  421  are formed in the bottom surface. 
         [0097]    The mounting flange  458  has a petal-like shape which extends diagonally upward. By leaving a cylindrical circumferential part  415   c  in a size that can be picked up by fingers above the mounting flange  458 , it is possible to attach/detach and rotate this detection probe  400   c . Furthermore, by providing a notch  424  in the vicinity of the coupling member  423  as shown in  FIG. 12 , this mounting flange  458  can rotate the detection probe  400   c.    
         [0098]    Furthermore, the detection probe unit  410   c  has a columnar appearance that can be inserted into a main unit storage section  459  formed inside the detection probe mounting section  450   c , a main projection  412  is provided in the center of the bottom surface of this columnar shape and a connection section  418   c  to be connected to the connection receiving section  454   c  is provided on the top surface. Here, as for the engagement between main unit storage section  459  and the detection probe unit  410   c , the inner diameter and the outside shape are set so as to have strength enough to keep a positional relationship between both members by means of friction between the contact surfaces of both members or the like. 
         [0099]    According to this embodiment, the detection probe unit  410   c  is inserted up to a position at which the main projection  412  of this detection probe unit  410   c  protrudes from the opening  421  of the detection probe mounting section  450   c  through the opening formed in the upper part of the detection probe mounting section  450   c  first, and it is thereby possible to couple this detection probe unit  410   c  with the detection probe mounting section  450   c  to assemble the detection probe unit  400   c . This detection probe  400   c  is inserted into the opening  202   c  of the probe holder  200   c  and the connection receiving section  454   c  of the cap  422  is coupled with the connection section  418   c , and it is thereby possible to attach the detection probe  400   c  to the probe holder  200   c  electrically as well as structurally. 
         [0100]    In this way, according to the detection probe  400   c  mounted in the probe holder  200   c , when the probe device  100  is attached to the examinee  50 , the contact between the scalp of the examinee  50  and the tip of the main projection  412  can be adjusted with the engagement between the detection probe  400   c  and the opening  202   c . Especially, this embodiment adopts the mounting flange  458  having a petal-shape which is open to the outside in an inward curve and thereby provides a height difference adjusting space  460  in a gap with the opening  202   c , and therefore it is possible to adjust the depth of insertion of the detection probe  400   c  with respect to the opening  202   c  using this height difference adjusting space  460  and thereby satisfactorily keep contact between the scalp of the examinee  50  and the tip of the main projection  312 . 
         [0101]    Furthermore, when contacting the scalp of the examinee  50  with the tip of the main projection  412 , it is possible to adjust the height (insertion width) of the main projection  412  and adjust the height difference (insertion width) of the sub projections  414  separately and thereby improve the closeness of contact. 
         [0102]    Furthermore, the sub projections  414  can be rotated around the central axis Q 1  by picking up the circumferential part  415   c  provided above the mounting flange  458  by fingers. In this case, the rotation of the detection probe unit  410   c  is restrained because of the connection of the cap  422  and it is thereby possible to rotate only the sub projections  414  a great deal. 
       Fourth Embodiment  
       [0103]    Next, a detection probe  400   d  according to a fourth embodiment will be explained with reference to  FIG. 13  and  FIG. 14 . Parts common to those in the first to third embodiments are assigned the same reference numerals and overlapping explanations will be omitted. Furthermore, the light-emitting probe is also provided with a structure similar to that of this detection probe  400   d , and therefore explanations thereof will be omitted. Here,  FIG. 13  is a central longitudinal cross-sectional view of the detection probe.  FIG. 14  is a perspective view of the detection probe seen from the top surface. 
         [0104]    In  FIG. 13 , one feature of the detection probe  400   d  according to this fourth embodiment lies in that this detection probe  400   d  is constructed of a detection probe mounting section  450   d  attached to an opening  202  of a probe holder  200  and a detection probe unit  410   d  housed in a main unit storage section  459   d  of the detection probe mounting section  450   d  and this detection probe unit  410   d  is provided in a manner pivotable with respect to the main unit storage section  459   d  and in such a way that the amount of protrusion toward the examinee is adjustable. 
         [0105]    That is, the detection probe mounting section  459   d  according to this embodiment is constructed of a cylindrical base  461  provided with the column-shaped main unit storage section  459   d  inside and a cap  422   d  to be attached to an upper opening  462  of this base  461 . The upper part of the base  461  is open through the upper opening  462  and a lower opening  463  having a smaller diameter than that of the upper opening  462  is formed of a ring projection  466  protruding inward at the bottom. 
         [0106]    The cap  422   d  is provided with a coupling member  423   d  connected to one top end of the base  461  on one side and also provided with a mounting coupling section  465  attached to a protruding mounting section  464  attached to the other top end of the base  461  on the other side. This coupling member  423   d  and the mounting coupling section  465  are made of rubber or a flexible resin material. Furthermore, a connection receiving section  454   d  is further provided inside the cap  422   d  and this connection receiving section  454   d  is connected to a signal line  201  of the probe holder  200  through a signal line  423  provided for the coupling member  423   d.    
         [0107]    On the other hand, a detection probe unit  410  is constructed of a first housing  416   d  provided with a detection section  411  and a second housing  417   d  that covers the perimeter of this first housing  416   d . The first housing  416   d  has a columnar appearance and is provided with a main projection  412  at the center of the bottom surface thereof and a connection section  418   d  on the top surface thereof. The second housing  417   d  has a “tub-like” appearance that covers the circumferential surface and bottom surface and is provided with an opening  421  that exposes the main projection  412  in the center of the bottom surface thereof and a plurality of sub projections  414  arranged around this opening  421 , and the circumferential surface thereof is provided with a ring-shaped positioning flange  425 . This positioning flange  425  is formed so as to have a diameter of L 7  which has an appropriate space from the inner surface of the main unit storage section  459   d  to thereby reduce backlash in the horizontal direction. 
         [0108]    According to this embodiment, the first housing  416   d  is inserted from the opening above the second housing  417   d  first and the detection probe unit  410   d  can thereby be assembled at a position at which the main projection  412  protrudes from the opening  421  of the detection probe mounting section  450   d . This assembled detection probe unit  410   d  is inserted from the upper opening  462  of the detection probe mounting section  450   d  into the main unit storage section  459   d.    
         [0109]    According to this embodiment, the diameter L 6  of the detection probe unit  410   d  is smaller than the inner diameter L 5  of the lower opening  463  and the diameter L 7  of the positioning flange  425  is larger than the inner diameter L 5  of the lower opening  463 , and therefore the positioning flange  425  is held by the ring projection  466  so as to expose the lower part of the detection probe unit  410   d  from the lower opening  463 . 
         [0110]    The connection receiving section  454   d  of the cap  422   d  and the connection section  418  provided for the upper part of the first housing  416   d  are coupled together and the mounting coupling section  465  provided at the other end of the cap  422   d  is attached to the mounting section  464  of the detection probe mounting section  450   d , and the detection probe unit  410   d  is thereby held by the cap  422   d  upper portion of which is attached to the detection probe mounting section  450 . 
         [0111]    According to this structure, the detection probe unit  410   d  is attached to the detection probe mounting section  450   d  through the flexible coupling member  423   d  coupled with the cap  422   d  and mounting coupling section  465 , and can thereby be moved in the examinee direction L 8 . With the elasticity of the coupling member  423   d  and mounting coupling section  465 , it is possible to change the posture of the detection probe  410   d  according to the unevenness of the head of the examinee  50 . 
         [0112]    Furthermore, according to this embodiment, the detection probe unit  410  is held with the cap  422   d  protruding above the detection probe mounting section  450   d  and the coupling member  423   d  and the mounting coupling section  465  have a flexible strip-shape, and it is thereby possible to rotate the detection probe unit  410   d  around the central axis Q 1  by picking up the cap  422   d  by fingers or the like. The width of this rotation is not so large, but allows rotation to an extent that it moves the sub projections  414  to sweep aside the hair  52 . Moreover, this rotation also allows the detection probe unit  410   d  to be adjusted to a posture perpendicular to the scalp of the examinee  50 . 
       Fifth Embodiment  
       [0113]    Next, a detection probe  400   e  according to a fifth embodiment will be explained in detail with reference to  FIG. 15  to  FIGS. 18A and 18B . Parts common to those in the first to fourth embodiments are assigned the same reference numerals and overlapping explanations will be omitted. Furthermore, the light-emitting probe is also provided with a structure similar to that of this detection probe  400   e , and therefore explanations thereof will be omitted. Here,  FIG. 15  is a central longitudinal cross-sectional view of the detection probe.  FIG. 16  is a perspective view showing how a detection probe unit is attached to a detection probe mounting section.  FIGS. 17A-17D  show another arrangement of a main projection and sub projections of the detection probe unit,  FIG. 17A  is a bottom view,  FIG. 17B  is a plan view,  FIG. 17C  is a central cross-sectional view and  FIG. 17D  is a side view.  FIGS. 18A and 18B  are bottom views showing another arrangement of sub projections. 
         [0114]    In  FIG. 15 , one feature of a detection probe  400   e  according to this fifth embodiment lies in that it is configured by including a detection probe mounting section  450   e  attached to an opening  202  of a probe holder  200  and a detection probe unit  410   e  which can be attached/detached to/from this detection probe mounting section  450   e  and which is attached in a manner pivotable around the central axis Q 1 . 
         [0115]    The detection probe mounting section  450   e  has a ring-shaped appearance provided with a flange  467  protruding outward at the top and bottom ends and mounting engagement holes  468  are provided on both sides of the ring-shaped inner circumferential surface thereof. According to this structure, the detection probe mounting section  450   e  can be attached to a probe holder  200  with an opening  202  interposed in a recessed part  453   a  between the upper and lower flanges  467 . 
         [0116]    The detection probe unit  410   e  is configured by including a column-shaped main housing  427  provided with a ring-shaped overhang  426  at the top, a contact member  428  attached to the bottom surface of this main housing  427  in a detachable manner and a cap  429  attached to the top surface of this main housing  427  in a detachable manner. 
         [0117]    The main housing  427  is provided with a detection section  411  inside and a fiber for detection  413  coupled with this detection section  411  is provided so as to protrude from the center of the bottom surface of the main housing  427 . Mounting engagement projections  430  which engage with the above described mounting engagement holes  468  are provided on both sides of the circumferential surface of this main housing  427 . Furthermore, the diameter of the ring-shaped overhang  426  is set to substantially the same size of the diameter of the flange  467 . Furthermore, a mounting section  431  of a contact member  428  having a stepped perimeter is formed in the lower part of the main housing  427 . Furthermore, a connection receiving section  454   e  connected to the connection section  418   e  provided for the cap  429  is provided on the top surface of the main housing  427 . 
         [0118]    On the other hand, the above described contact member  428  is formed of rubber or a flexible resin material and has an appearance with main projection  412  and a plurality of sub projections  414  protruding downward on the bottom surface which is a thin circular base. The plurality of sub projections  414  are arranged on a concentric circle of the main projection  412  in this embodiment, too. A through hole  433  is formed on the central axis of the main projection  412  and a fiber for detection  413  can be inserted into this through hole  433 . Furthermore, an engagement recessed part  432  which engages with the mounting section  431  of the main housing  427  is formed on the top surface side of the circular base. According to this contact member  428 , the engagement recessed part  432  can be attached to the mounting section  431  using elasticity of resin while passing the fiber for detection  413  through the through hole  433  of the main projection  412 . 
         [0119]    Furthermore, the cap  429  has a thin disk-shaped outside shape having the same diameter as that of the overhang  426  and is provided with a connection section  418   e  on one side thereof. A wire (not shown) to be connected to this connection section  418   e  is drawn out from the other side of the cap  429 . This drawn wire is put together with other wires of the detection probe  400   e  and a light-emitting probe and connected to a biological optical measurement device main unit  10 . 
         [0120]    In this embodiment, the detection probe mounting section  450   e  is made of a flexible material and the diameter of the main housing  427  is set such that the detection probe unit  410   e  (main housing  427 ) can be inserted with a certain margin with respect to the inner diameter of the detection probe mounting section  450   e . Therefore, as shown in  FIG. 16 , when the main housing  427  provided with the mounting engagement projections  430  on both sides is inserted into the detection probe mounting section  450   e , this detection probe mounting section  450   e  is distorted using elasticity of the resin, making it possible to attach the detection probe mounting section  450   e.    
         [0121]    When the main housing  427  is attached to the detection probe mounting section  450   e , the mounting engagement projections  430  engage with the mounting engagement holes  468  and it is thereby possible to maintain this engagement condition. Furthermore, since the horizontal width L 10  of the mounting engagement projection  430  is set to be narrower than the horizontal width L 11  of the mounting engagement hole  468 , it is possible to rotate the main housing  427  around the central axis Q 1  using this wide mounting engagement hole  468 . 
         [0122]    According to this embodiment, since the contact member  428  provided with the main projection  412  and sub projections  414  can be easily replaced, the contact member  428  can be replaced according to the examinee. 
         [0123]    Next, other embodiments of the contact member  428  will be explained with reference to  FIGS. 17A-17D  and  FIGS. 18A and 18B . The structure explained with this contact member  428  is not limited to this embodiment and a similar structure may also be adopted for the first to fourth embodiments explained above. 
         [0124]    First,  FIGS. 17A-17D  show an embodiment of the main projection  412  and sub projections  414  having other shapes. A contact member  428   b  according to the embodiment in these  FIGS. 17A-17D  is obtained by forming protuberance  434  at the root of the main projection  412  and sub projections  414  and providing the main projection  412  and sub projections  414  on this protuberance  434 . Providing this protuberance  434  makes it possible to adjust the flexibility and strength of the main projection  412  and sub projections  414 . 
         [0125]    The protuberance  434  can take various forms. For example, in  FIG. 17A , the solid line shows a protuberance  434   a  connecting the roots of the four sub projections  414  seen from the bottom surface with a continuous inward curve. The dotted line shows a protuberance  434   b  connecting the roots of the four sub projections  414  with a continuous cross-shaped line. Furthermore, the two-dot dashed line shows a protuberance  434   c  connecting the roots of the four sub projections  414  with a continuous straight line. 
         [0126]    Furthermore, the aforementioned embodiments have explained the examples where the four sub projections  414  are provided equidistantly on the concentric circle P 1  of the main projection  412 , but the present invention is not limited to these in  FIGS. 18A and 18B . For example, as shown in  FIG. 18A , three sub projections  414  may be provided equidistantly on the concentric circle P 1  of the main projection  412 . Furthermore, as shown in  FIG. 18B , even when four sub projections  414  are provided equidistantly, it is possible to provide sub projections  414   a  on both sides (in the drawing) on the concentric circle P 1  and provide upper and lower (in the drawing) sub projections  414   b  on a concentric circle P 2  having a different diameter. By providing the sub projections  414  on this different concentric circle, it is possible to uniformly sweep aside hair within the projected area of the contact member  428 . 
       Sixth Embodiment  
       [0127]    Next, a detection probe  400   f  according to a sixth embodiment will be explained in detail with reference to  FIG. 19  and  FIG. 20 . Parts common to those in the first to fifth embodiments are assigned the same reference numerals and overlapping explanations will be omitted. Furthermore, the light-emitting probe is also provided with a structure similar to that of this detection probe  400   f , and therefore explanations thereof will be omitted. Here,  FIG. 19  is a central longitudinal cross-sectional view of the detection probe.  FIG. 20  is a perspective view of the detection probe seen from the top surface. 
         [0128]    The above described embodiments have explained the cases of embodiments where the probe device  100  and biological optical measurement device main unit  10  are electrically connected, but the present invention is not limited to this embodiment. For example, the present invention is also applicable to a probe device  100  having a structure in which, for example, a light source is provided for the biological optical measurement device main unit  10 , light from this light source is supplied to each light-emitting probe  300  through an optical fiber  18 , light detected by each detection probe  400  is collected by the biological optical measurement device main unit  10  through the optical fiber  18 .  FIG. 19  and  FIG. 20  show an embodiment adopting the structure of the optical fiber for the fourth embodiment. This structure will be explained hereinafter but this can be applied to the other embodiments explained above. 
         [0129]    In  FIG. 19 , one end of a fiber for detection  413   a  is exposed from the tip of a main projection  412  and the other end is connected to an optical connector connection section  435  provided in the upper part of a second housing  417   d . On the other hand, a cap  422   d  is provided with an optical connector connection receiving section  469  connectable to the optical connector connection section  435 . The optical fiber  18  to be connected to the biological optical measurement device main unit  10  is connected to the optical connector connection receiving section  469 . It will be effective if the coupling between this optical fiber  18  and the optical connector connection receiving section  469  is made detachable. As for this structure, the same structure may also be adopted for the light-emitting probe. 
         [0130]    According to this embodiment, even when the optical fiber  18  is attached, the detection probe unit  410   f  can be made rotatable, and therefore operations and effects similar to those in the third embodiment can be obtained. 
         [0131]    As described above, the probe device according to this embodiment is used for a biological optical measurement device provided with light irradiation means for irradiating light onto a surface of a living body and light detection means for detecting intensity of light passing through the inside of the living body and emerging from the surface of the living body, including a plurality of light irradiation probe units provided with light irradiation means at a tip thereof, a plurality of light detection probe units provided with light detection means at a tip thereof, a probe support unit which holds a grid-shaped array of the mutually neighboring light irradiation probe units and light detection probe units and a main unit support section which supports the light detection probe unit and the light irradiation probe unit at predetermined positions of the probe support body, wherein the light detection probe unit and the light irradiation probe unit are provided with a main projection formed so as to protrude on the surface side of the living body and a plurality of sub projections arranged around the main projection, the main projection is provided with light communication means for communicating the light irradiation means or the light detection means on an axial core thereof and the main unit support section supports the sub projections to the probe support body in a manner rotatable around the axial core of the light communication means. 
         [0132]    In this case, three or more sub projections may be arranged equidistantly on a concentric circle of the main projection. Furthermore, the light detection probe unit and the light irradiation probe unit may be provided with a first housing provided with the main projection and a second housing provided with the sub projections and the second housing may be supported in a manner rotatable with respect to the first housing. Furthermore, the first housing may be provided with connection means for electrically connecting the light irradiation means or the light detection means with the main unit support body section or optically or electrically connecting with an outside device. Moreover, the light detection probe unit and the light irradiation probe unit may also be attached to the main unit support section in a manner detachable therefrom. Furthermore, the sub projection may be mutually coupled via a base plate and the sub projections coupled through the base plate may be attached to the light detection probe unit or the light irradiation probe unit in a manner detachable therefrom. In addition, the second housing may also be attached to the first housing in a manner detachable therefrom. 
         [0133]    It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.