Patent Publication Number: US-2019175301-A1

Title: Near-nfrared imaging apparatus and marker member for near-infrared imaging apparatus

Description:
TECHNICAL FIELD 
     This invention relates to a near infrared imaging apparatus, and particularly relates to a near infrared imaging apparatus including a near infrared detector that detects near infrared light generated from a fluorescent agent in a test object, and a marker member for the near infrared imaging apparatus. 
     BACKGROUND ART 
     Conventionally, a near infrared imaging apparatus including a near infrared detector that detects near infrared light generated from a fluorescent agent in a test object has been known. For example, such a near infrared imaging apparatus is disclosed in JP-A-2015-188559. 
     A medical imaging apparatus disclosed in the above-mentioned JP-A-2015-188559 includes an illumination unit, an imaging unit, and a surgeon observation monitor. Further, the medical imaging apparatus (near infrared imaging apparatus) is configured as apart of an intraoperative support apparatus. Further, this medical imaging apparatus is configured such that a contrast medium injected into a blood vessel of a patient is irradiated with excitation light of a near infrared ray from the illumination unit during surgery. Further, the imaging unit is configured to capture an image of fluorescence in an infrared region generated by irradiating the contrast medium with excitation light. Further, the surgeon observation monitor is configured such that the image captured by the imaging unit is displayed. 
     In addition, when the conventional medical imaging apparatus disclosed in the above-mentioned JP-A-2015-188559 is used, a surgeon places a mark at (marks) a position on a skin of the patient corresponding to a path of a lymph duct using a pen-shaped marker member while checking an image of a blood vessel or the lymph duct displayed on the surgeon observation monitor after injecting a contrast medium into the blood vessel or the lymph duct of the patient and before determining an incision site of the patient, in some cases. 
     CITATION LIST 
     Patent Document 
     Patent Document 1: JP-A-2015-188559 
     SUMMARY OF THE INVENTION 
     Technical Problem 
     However, in the conventional medical imaging apparatus (near infrared imaging apparatus) disclosed in the above-mentioned JP-A-2015-188559, when the surgeon places a mark on the patient, the surgeon needs to place the mark on an actual skin of the patient by relying on the image of the blood vessel or the lymph duct while visually recognizing the image of the blood vessel or the lymph duct displayed on the surgeon observation monitor. However, the conventional marker member has a problem that the marker member is not displayed on the surgeon observation monitor and a position at which the mark is actually placed may be shifted from a position at which the mark needs to be placed. 
     The invention has been made to solve the above-mentioned problem, and an object of the invention is to provide a near infrared imaging apparatus capable of inhibiting a position at which a mark is actually placed from being shifted from a position at which the mark needs to be placed when the mark is placed on a test object using a marker member, and a marker member for the near infrared imaging apparatus. 
     Solution to Problem 
     To achieve the object, a near infrared imaging apparatus according to a first aspect of the invention includes a first light source unit that irradiates a test object-side fluorescent agent inside a test object with near infrared excitation light, a marker member that includes a near infrared ray generator for generating first near infrared light and is used to place a mark on the test object, a near infrared detector that detects the first near infrared light and detects second near infrared light generated from the test object-side fluorescent agent by the irradiated near infrared excitation light, and an imaging unit that images the first near infrared light and the second near infrared light detected by the near infrared detector. In the specification, a “near infrared ray” means light having a longer wavelength than that of a visible ray, and is described to mean, for example, light having a wavelength within a range of 700 nm or more and 900 nm or less. 
     In the near infrared imaging apparatus according to the first aspect of the invention, as described above, the near infrared ray generator that generates the first near infrared light is included, and the marker member for placing the mark on the test object is provided. Further, the near infrared detector is configured to detect the first near infrared light and detect the second near infrared light generated from the test object-side fluorescent agent by the irradiated near infrared excitation light. In addition, the imaging unit is configured to image the first near infrared light and the second near infrared light detected by the near infrared detector. In this way, it is possible to allow a user to visually recognize an image in a state in which an image corresponding to a position of the marker member held by the user (surgeon) is superimposed on an image of the test object-side fluorescent agent (blood vessel or lymph duct of the patient). As a result, it is possible to allow the user to visually recognize an image of the test object-side fluorescent agent related to a position at which the mark needs to be placed and an image indicating a position of the marker member used to actually place the mark together. Therefore, when the mark is placed on the test object by the marker member, it is possible to inhibit the position at which the mark is actually placed from being shifted from the position at which the mark needs to be placed. 
     In the near infrared imaging apparatus according to the first aspect, preferably, the marker member includes a holding portion corresponding to a portion held by a user and a pen tip disposed on the test object, and the near infrared ray generator is provided around the pen tip of the marker member. According to this configuration, it is possible to image an image indicating a position around the pen tip of the marker member disposed on the test object. Thus, it is possible to effectively inhibit the position at which the mark is actually placed by the pen tip of the marker member from being shifted from the position on the test object at which the mark needs to be placed. 
     In the near infrared imaging apparatus according to the first aspect, preferably, the near infrared ray generator is formed to have at least one of an arrow shape, a rectangular shape, or a circular shape. According to this configuration, the first near infrared light is imaged in a state of having an arrow shape, a rectangular shape, or a circular shape, and thus it is possible to improve discrimination as an image indicating the position of the marker member. 
     In the near infrared imaging apparatus according to the first aspect, preferably, the near infrared ray generator includes a second light source unit that irradiates the near infrared detector with the first near infrared light. According to this configuration, it is possible to easily generate the first near infrared light by providing the second light source unit in the marker member. 
     In this case, preferably, a switching unit that switches between a state in which power is supplied to the second light source unit and a state in which the power is not supplied to the second light source unit is further included. According to this configuration, it is possible to switch between a state in which the second light source unit is turned ON and a state in which the second light source unit is turned OFF according to a need of the user, and thus it is possible to improve convenience during use of the marker member. 
     In the near infrared imaging apparatus according to the first aspect, preferably, the near infrared ray generator includes a marker-side fluorescent agent that generates the first near infrared light by being irradiated with the near infrared excitation light from the first light source unit. According to this configuration, unlike the case of providing the second light source unit, a structure for supplying power to the near infrared ray generator is unnecessary, and thus it is possible to inhibit a structure of the near infrared ray generator from being complicated. 
     In the near infrared imaging apparatus according to the first aspect, preferably, the near infrared ray generator includes a detachable portion for attachment and detachment to and from the marker member. According to this configuration, using the detachable portion, the near infrared ray generator may be removed from the used marker member, and the near infrared ray generator may be attached to a new marker member. That is, when the consumable marker member is replaced, the near infrared ray generator can be reused. 
     In the near infrared imaging apparatus according to the first aspect, preferably, a wavelength of the first near infrared light is a wavelength in a vicinity of a wavelength of the second near infrared light. According to this configuration, the near infrared detector capable of detecting the second near infrared light may detect the first near infrared light from the near infrared ray generator. In this way, even in the case of using a conventional near infrared detector capable of detecting the second near infrared light from the test object-side fluorescent agent, it is possible to detect the first near infrared light from the marker member of the invention. 
     In the near infrared imaging apparatus according to the first aspect, preferably, the near infrared imaging apparatus is used as a medical imaging apparatus. In addition, preferably, the near infrared imaging apparatus is used as an intraoperative support apparatus. According to this configuration, when the surgeon places a mark on the patient using the marker member during surgery, it is possible to inhibit a position at which the mark is actually placed from being shifted from a position at which the mark needs to be placed. Thus, applying the near infrared imaging apparatus of the invention to the medical imaging apparatus or the intraoperative support apparatus is particularly effective. 
     In the near infrared imaging apparatus according to the first aspect, preferably, the near infrared imaging apparatus further includes a third light source unit that irradiates the test object with visible light, and a visible light detector that detects the visible light irradiated by the third light source unit and reflected by the test object, and the imaging unit includes an image composition unit that composes a near infrared light image obtained by imaging the first near infrared light and the second near infrared light detected by the near infrared detector and a visible light image obtained by imaging the visible light detected by the visible light detector. According to this configuration, it is possible to allow the user to visually recognize the position at which the mark is placed (marked position) using the visible light image. As a result, it is possible to allow the user to visually recognize the visible light image indicating the position at which the mark is placed while allowing the user to visually recognize the near infrared light image indicating the position of the marker member corresponding to the position at which the mark is actually placed. 
     A marker member for a near infrared imaging apparatus according to a second aspect of the invention is a marker member used for the near infrared imaging apparatus including a first light source unit that irradiates a test object-side fluorescent agent inside a test object with near infrared excitation light, a near infrared detector that detects second near infrared light generated from the test object-side fluorescent agent by the irradiated near infrared excitation light, and an imaging unit that images the second near infrared light detected by the near infrared detector, wherein the marker member includes a near infrared ray generator that generates first near infrared light detectable by the near infrared detector. 
     In the marker member for the near infrared imaging apparatus according to the second aspect of the invention, as described above, the near infrared ray generator that generates the first near infrared light detectable by the near infrared detector is included. In this way, it is possible to provide the marker member for the near infrared imaging apparatus capable of inhibiting the position at which the mark is actually placed from being shifted from the position at which the mark needs to be placed. 
     Advantageous Effects of the Invention 
     According to the invention, as described above, when a mark is placed on a test object using a marker member, it is possible to inhibit a position at which the mark is actually placed from being shifted from a position at which the mark needs to be placed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a near infrared imaging apparatus according to a first embodiment of the invention. 
         FIG. 2  is a diagram for description of an image displayed on a display unit of the near infrared imaging apparatus according to the first embodiment of the invention. 
         FIG. 3  is a schematic diagram of an entire configuration of the near infrared imaging apparatus according to the first embodiment of the invention. 
         FIG. 4  is a side view of a marker member of the near infrared imaging apparatus according to the first embodiment of the invention. 
         FIG. 5  is a diagram (cross-sectional view) illustrating a state in which the marker member of the near infrared imaging apparatus according to the first embodiment of the invention generates near infrared light. 
         FIG. 6  is a diagram specifically illustrating the image displayed on the display unit of the near infrared imaging apparatus according to the first embodiment of the invention. 
         FIG. 7  is a diagram (cross-sectional view) illustrating a state in which a marker member of a near infrared imaging apparatus according to a second embodiment of the invention generates near infrared fluorescence. 
         FIG. 8  is a partial side view illustrating a marker member of a near infrared imaging apparatus according to a third embodiment of the invention. 
         FIG. 9  is a diagram for description of attachment and detachment of a detachable portion to and from the marker member of the near infrared imaging apparatus according to the third embodiment of the invention. 
         FIG. 10  is a block diagram of a near infrared imaging apparatus according to a first modified example of the first to third embodiments of the invention. 
         FIG. 11  is a diagram (cross-sectional view) illustrating a configuration of a marker member of a near infrared imaging apparatus according to a second modified example of the first embodiment and the third embodiment of the invention. 
         FIG. 12  is a schematic diagram illustrating a configuration of a near infrared imaging apparatus according to a third modified example of the first to third embodiments of the invention. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments embodying the invention will be described based on drawings. 
     First Embodiment 
     A near infrared imaging apparatus  100  according to a first embodiment of the invention will be described with reference to  FIG. 1  to  FIG. 6 . In addition, in the first embodiment, for example, the near infrared imaging apparatus  100  is used (configured) as a medical imaging apparatus used for angiography and lymphangiography during surgical operation. In addition, the near infrared imaging apparatus  100  is used (configured) as apart of an intraoperative support apparatus (intraoperative support system) used during surgery. In the specification of the present application, a “near infrared ray” means light having a longer wavelength than that of a visible ray, and is described to mean, for example, light having a wavelength within a range of 700 nm or more and 900 nm or less. 
     Specifically, the near infrared imaging apparatus  100  is used to allow a user such as a surgeon Q to check positions or paths of a blood vessel or a lymph duct and a lymph node of a contrasted patient P (test object) in a surgery of a breast cancer sentinel lymph node. 
     As illustrated in  FIG. 1 , the near infrared imaging apparatus  100  includes a light source unit  1 . The light source unit  1  includes, for example, a light emitting diode (LED). The light source unit  1  includes a white light source unit  1   a  that irradiates the patient P with white light including visible light and an excitation light source unit  1   b  that irradiates a fluorescent agent Pa (see  FIG. 5 ) (contrast medium) inside a body of the patient P with near infrared excitation light (hereinafter “excitation light IRe”). The white light source unit  1   a  is an example of a “third light source unit” in claims. In addition, the excitation light source unit  1   b  is an example of a “first light source unit” in the claims. In addition, the fluorescent agent Pa is an example of a “test object-side fluorescent agent” in the claims. 
     Specifically, for example, the fluorescent agent Pa is made of indocyanine green (ICG) which is a fluorescent pigment. Further, the excitation light IRe is near infrared light having a wavelength of 750 nm or more and 820 nm or less. For example, the excitation light IRe is near infrared light having a wavelength of about 810 nm. When indocyanine green is irradiated with the excitation light IRe, near infrared fluorescence IR 2  having a wavelength of about 845 nm is generated from indocyanine green. In addition, white light irradiated from the white light source unit  1   a  is reflected from a skin surface of the patient P as reflected light (visible light). The near infrared fluorescence IR 2  is an example of “second near infrared light” in the claims. 
     In addition, the near infrared imaging apparatus  100  includes an irradiation controller  2 . The irradiation controller  2  is configured as a control circuit and configured to control irradiation of light (white light, excitation light IRe) from the light source unit  1 , stop of irradiation, etc. based on an input operation by an operation unit  20  described below. 
     In addition, a zoom lens  3  is provided around the light source unit  1 . Reflected light (visible light) from the skin surface of the patient P, near infrared fluorescence IR 2  generated from the fluorescent agent Pa, and near infrared light IR 1  from a marker light source unit  41  described below enter the zoom lens  3 . The near infrared light IR 1  is an example of “first near infrared light” in the claims. 
     In addition, a prism  4  is provided around the zoom lens  3 . Light from the zoom lens  3  enters the prism  4 . Further, the prism  4  has a function of separating reflected light (visible light) from the skin surface of the patient P, the near infrared light IR 1 , and the near infrared fluorescence IR 2 . 
     In addition, the near infrared imaging apparatus  100  includes a visible light sensor  5  that detects visible light separated by the prism  4 . For example, the visible light sensor  5  includes a charge coupled device (CCD). Further, the visible light sensor  5  is an example of a “visible light detector” in the claims. 
     In addition, the near infrared imaging apparatus  100  includes a near infrared sensor  6  that detects the near infrared fluorescence IR 2  generated by the excitation light IRe irradiated from the excitation light source unit  1   b  and the near infrared light IR 1  from the marker light source unit  41 . For example, the near infrared sensor  6  is configured to be able to detect a near infrared ray having a wavelength within a range of 780 nm or more and 860 nm or less. For example, the near infrared sensor  6  includes a CCD or a photomultiplier tube. The near infrared sensor  6  is an example of a “near infrared detector” in the claims. 
     In addition, the near infrared imaging apparatus  100  includes an image formation unit  7 . The visible light detected by the visible light sensor  5  and the near infrared light IR 1  and the near infrared fluorescence IR 2  detected by the near infrared sensor  6  are input to the image formation unit  7 . Then, the image formation unit  7  forms the visible light detected by the visible light sensor  5  as a 24-bit (=3×8) image including three colors of RGB (red, green, and blue). In addition, the image formation unit  7  forms the near infrared light IR 1  and the near infrared fluorescence IR 2  detected by the near infrared sensor  6  as an 8-bit image. The image formation unit  7  is an example of an “imaging unit” in the claims. 
     In addition, the near infrared imaging apparatus  100  includes an image composition unit  8 . Here, in the first embodiment, as illustrated in  FIG. 2 , the image composition unit  8  is configured to form a composite image  93  by composing a visible light image  91  obtained by imaging the visible light and a near infrared light image  92  obtained by imaging the near infrared light IR 1  and the near infrared fluorescence IR 2 . For example, each of the image formation unit  7  and the image composition unit  8  is configured as an image processing circuit. In addition, the image composition unit  8  is an example of the “imaging unit” in the claims. 
     In addition, the near infrared imaging apparatus  100  includes a display unit  9 . As illustrated in  FIG. 2 , the visible light image  91 , the near infrared light image  92 , and the composite image  93  are displayed on the display unit  9 . 
     In addition, as illustrated in  FIG. 1 , the near infrared imaging apparatus  100  includes a storage unit  10 . The storage unit  10  includes a storage element, etc. and is configured to save the visible light (signal) detected by the visible light sensor  5  and the near infrared light IR 1  and the near infrared fluorescence IR 2  (signal) detected by the near infrared sensor  6 . 
     In addition, a recording unit  11  is provided in the near infrared imaging apparatus  100 . The recording unit  11  includes a storage element, etc. and is configured to record an image displayed on the display unit  9 . 
     In addition, the near infrared imaging apparatus  100  includes an operation unit  20 . The operation unit  20  is configured to receive an input operation to the near infrared imaging apparatus  100  by the user (surgeon Q, etc.). In addition, the operation unit  20  includes a control circuit. Further, the operation unit  20  is configured to operate (control) irradiation of light from the light source unit  1 , stop of irradiation, adjustment of brightness and sensitivity, a method of displaying an image displayed on the display unit  9 , etc. based on the input operation. 
     In addition, as illustrated in  FIG. 3 , the near infrared imaging apparatus  100  includes a main apparatus body  30  provided with the white light source unit  1   a,  the excitation light source unit  1   b,  the visible light sensor  5 , the near infrared sensor  6 , etc. The white light source unit  1   a,  the excitation light source unit  1   b,  the visible light sensor  5 , the near infrared sensor  6 , etc. are disposed inside an illumination/photographing unit  31 . In addition, an arm  32  is provided on the main apparatus body  30 . The illumination/photographing unit  31  is attached to the arm  32 , and the illumination/photographing unit  31  is configured to be movable. 
     In addition, the display unit  9  is provided separately from the main apparatus body  30 . For example, the display unit  9  is disposed in a facing direction of the surgeon Q (user) (on an arrow A 1  direction side), and is disposed at a height position at which an image displayed on the display unit  9  is visually recognizable when the surgeon Q performs treatment on the patient P (test object). 
     Here, in the first embodiment, the near infrared imaging apparatus  100  is provided separately from the main apparatus body  30  and used around the patient P, and includes a marker member  40  for placing a mark on the skin of the patient P (test object). Further, the marker member  40  includes the marker light source unit  41  that irradiates the near infrared sensor  6  with the near infrared light IR 1 . The marker light source unit  41  is an example of a “near infrared ray generator” and a “second light source unit” in the claims. 
     Specifically, as illustrated in  FIG. 3 , the marker member  40  is configured as a surgical marker (skin marker). Further, the marker member  40  includes a main marker body  42  corresponding to a portion held by the surgeon Q and a pen tip  43  disposed on the skin of the patient P (disposed on the patient P side in relation to the main marker body  42 ) during use. The main marker body  42  is an example of a “holding portion” in the claims. 
     As illustrated in  FIG. 4 , for example, the main marker body  42  is formed to have a cylindrical shape. In addition, as illustrated in  FIG. 5 , an ink tank  42   a  is provided inside the main marker body  42 . The ink tank  42   a  is configured to supply marker ink to the pen tip  43 . 
     The pen tip  43  is configured such that the marker ink is applied to the skin of the patient P by being brought into contact with the skin of the patient P. Further, when the marker ink is applied to the skin of the patient Q using the marker member  40 , a treatment of placing a mark (marking) is performed. 
     Here, in the first embodiment, as illustrated in  FIG. 4 , the marker light source unit  41  is provided around the pen tip  43  of the marker member  40 . Further, the marker light source unit  41  is formed to have an arrow shape. For example, the marker light source unit  41  is configured to have an arrow shape in which an arrow tip end is directed to the pen tip  43  side in a side view (see  FIG. 4 ) and such that an entire arrow-shaped portion emits light. 
     Further, for example, the marker light source unit  41  includes an LED. In this way, the marker light source unit  41  is configured to be able to emit the near infrared light IR 1  by being supplied with power. Further, the marker light source unit  41  is configured to generate the near infrared light IR 1  detectable by the near infrared sensor  6 . For example, the marker light source unit  41  is configured to generate near infrared light IR 1  having a wavelength of about 845 nm. That is, the wavelength of the near infrared light IR 1  emitted by the marker light source unit  41  is a wavelength in the vicinity of (substantially the same as) the wavelength of the near infrared fluorescence IR 2  emitted by the fluorescent agent Pa. 
     Further, as illustrated in  FIG. 5 , the near infrared sensor  6  provided inside the illumination/photographing unit  31  is configured to detect the near infrared light IR 1  from the marker light source unit  41  and the near infrared fluorescence IR 2  from the fluorescent agent Pa inside the patient P. 
     In addition, a battery  44 , a switch  45 , and wires  46   a  and  46   b  are provided in the marker member  40 . The battery  44  is provided inside the main marker body  42  and disposed on an opposite side from the pen tip  43  of the main marker body  42 . In addition, the wire  46   a  is connected to the battery  44 . The wire  46  is connected to the marker light source unit  41 . Further, the battery  44  is configured to supply power to the marker light source unit  41  through the wires  46   a  and  46   b.    
     Here, in the first embodiment, the switch  45  is configured to switch between a state in which power from the battery  44  is supplied to the marker light source unit  41  and a state in which power from the battery  44  is not supplied to the marker light source unit  41 . 
     For example, as illustrated in  FIG. 4 , an opening  42   b  is provided in the main marker body  42 , and the switch  45  is disposed to protrude to an outside of the main marker body  42  from the opening  42   b.  Further, the switch  45  is configured to be slidable in a direction in which the main marker body  42  extends (arrow B 1  direction and arrow B 2  direction). Further, as illustrated in  FIG. 5 , the switch  45  contains a conductor and is configured to connect the wire  46   a  and the wire  46   b  to each other in a state of being disposed on the arrow B 1  direction side. In addition, the switch  45  is configured to electrically disconnect the wire  46   a  and the wire  46   b  from each other in a state of being disposed on the arrow B 2  direction side. 
     That is, the marker member  40  is configured to be able to switch ON and OFF the marker light source unit  41  by a switching operation of the switch  45  by the surgeon Q. 
     Next, a specific use example of the marker member  40  according to the first embodiment will be described with reference to  FIG. 6 . A description will be given of an example in which a position of a blood vessel or a lymph duct of the patient P (test object) is marked by the surgeon Q using the marker member  40  in a surgery of abreast cancer sentinel lymph node. For example, an example is shown in which a position on the skin surface corresponding to the position and the path of the lymph duct into which the fluorescent agent Pa is injected is marked as a position at which a mark needs to be placed. 
       FIG. 6( a )  illustrates a state in which the visible light image  91  obtained by imaging reflected light reflected from the patient P is displayed on the display unit  9 . Further,  FIG. 6( b )  illustrates a state in which the composite image  93  of a state in which the fluorescent agent Pa is injected into the lymph duct (lymph node) of the patient P is displayed on the display unit  9 . That is, in  FIG. 6( b ) , the near infrared fluorescence IR 2  from the fluorescent agent and the near infrared light IR 1  from the marker light source unit  41  of the marker member  40  are imaged. 
     Further, the surgeon Q (not illustrated in  FIG. 6 ) performs a treatment of placing a mark on the skin of the patient P corresponding to the imaged lymph duct while visually recognizing an image (display of an arrow shape) of the near infrared light IR 1  and an image of the near infrared fluorescence IR 2  displayed on the display unit  9  in a state of holding the marker member  40 . In this way, as illustrated in  FIG. 6( c ) , the mark (thick line portion of reference symbol M of  FIG. 6 ) is placed on the skin of the patient P at a position corresponding to the lymph duct. Then, as illustrated in  FIG. 6( c ) , the position (reference symbol M) at which the mark is actually placed is inhibited from being shifted from a position at which the mark needs to be placed (position of the fluorescent agent Pa in the first embodiment). 
     Effects of First Embodiment 
     In the first embodiment, it is possible to obtain the following effects. 
     In the first embodiment, as described above, in the near infrared imaging apparatus  100 , the marker light source unit  41  for generating the near infrared light IR 1  is included, and the marker member  40  for placing a mark on the skin of the patient P is provided. Further, the near infrared sensor  5  is configured to detect the near infrared light IR 1  and detect the near infrared fluorescence IR 2  generated from the fluorescent agent Pa by the irradiated excitation light IRe. In addition, the image formation unit  7  is configured to image the near infrared light IR 1  and the near infrared fluorescence IR 2  detected by the near infrared sensor  6 . In this way, it is possible to allow the user (surgeon Q) to visually recognize an image in a state in which an image corresponding to a position of the marker member  40  held by the user is superimposed on an image of the fluorescent agent Pa (blood vessel or lymph duct of the patient P). As a result, it is possible to allow the user to visually recognize an image of the fluorescent agent Pa related to the position at which the mark needs to be placed and an image indicating the position of the marker member  40  used to actually place the mark together (see  FIG. 6 ). Therefore, when the mark is placed on the skin of the patient P using the marker member  40 , it is possible to inhibit the position at which the mark is actually placed from being shifted from the position at which the mark needs to be placed. 
     In addition, in the first embodiment, as described above, the main marker body  42  corresponding to a portion held by the user and the pen tip  43  disposed on the test object (on the skin of the patient P) are provided in the marker member  40 . In addition, the marker light source unit  41  is provided around the pen tip  43  of the marker member  40 . In this way, it is possible to image an image indicating a position around the pen tip  43  of the marker member  40  relatively close to the test object. Thus, it is possible to effectively inhibit the position at which the mark is actually placed by the pen tip  43  of the marker member  40  from being shifted from the position on the test object at which the mark needs to be placed. 
     In addition, in the first embodiment, as described above, the marker light source unit  41  is formed to have an arrow shape. In this way, the near infrared light IR 1  is imaged in a state having an arrow shape (see  FIG. 6 ), and thus it is possible to improve discrimination as an image indicating the position of the marker member  40 . 
     In addition, in the first embodiment, as described above, the marker light source unit  41  is configured to irradiate the near infrared sensor  6  with the near infrared light IR 1 . In this way, it is possible to easily generate the near infrared light IR 1  by providing the marker light source unit  41  in the marker member  40 . 
     In addition, in the first embodiment, as described above, the marker member  40  is provided with the switch  45  that switches between the state in which power is supplied to the marker light source unit  41  and the state in which power is not supplied to the marker light source unit  41 . In this way, it is possible to switch between a state in which the marker light source unit  41  is turned ON and a state in which the marker light source unit  41  is turned OFF according to a need of the user, and thus it is possible to improve convenience during use of the marker member  40 . 
     In addition, in the first embodiment, as described above, the wavelength of the near infrared light IR 1  is configured to be a wavelength in the vicinity of the wavelength of the near infrared fluorescence IR 2 . In this way, the near infrared light IR 1  from the marker light source unit  41  may be detected by the near infrared sensor  6  capable of detecting the near infrared fluorescence IR 2 . In this way, even in the case of using a conventional near infrared sensor capable of detecting the near infrared fluorescence IR 2  from the fluorescent agent Pa, it is possible to detect the near infrared light IR 1  from the marker member  40  of the first embodiment. 
     In addition, in the first embodiment, as described above, the near infrared imaging apparatus  100  is used as the medical imaging apparatus. In addition, the near infrared imaging apparatus  100  is used as the intraoperative support apparatus. In this way, when the surgeon Q places a mark on the patient P using the marker member  40  during surgery, it is possible to inhibit a position at which the mark is actually placed from being shifted from a position at which the mark needs to be placed. Thus, the first embodiment in which the near infrared imaging apparatus  100  is applied to the medical imaging apparatus or the intraoperative support apparatus is particularly effective. 
     In addition, in the first embodiment, as described above, the light source unit  1  is provided with the white light source unit  1   a  that irradiates the test object with white light having visible light. In addition, the near infrared imaging apparatus  100  is provided with the visible light sensor  5  that detects visible light irradiated by the white light source unit la and reflected by the test object. In addition, the near infrared imaging apparatus  100  is provided with the image composition unit  8  that generates the composite image  93  by composing the near infrared light image  92  obtained by imaging the near infrared light IR 1  and the near infrared fluorescence IR 2  detected by the near infrared sensor  6  and the visible light image  91  obtained by imaging visible light detected by the visible light sensor  5 . In this way, it is possible to allow the user to visually recognize the position at which the mark is placed (reference symbol M of  FIG. 6 ) using the visible light image  91 . As a result, it is possible to allow the user to visually recognize the visible light image  91  indicating the position at which the mark is placed while allowing the user to visually recognize the near infrared light image  92  indicating the position of the marker member  40  corresponding to the position at which the mark is actually placed. 
     Second Embodiment 
     Next, a description will be given of a configuration of a near infrared imaging apparatus  200  according to a second embodiment with reference to  FIG. 7 . In a marker member  240  of the near infrared imaging apparatus  200  according to the second embodiment, unlike the marker member  40  configured to be able to irradiate the near infrared light IR 1  using the marker light source unit  41 , near infrared fluorescence IR 3  may be generated by a marker-side fluorescent agent  241   a  of a marker-side fluorescent portion  241 . The same reference symbol will be assigned to the same component as that of the first embodiment, and a description thereof will be omitted. 
     As illustrated in  FIG. 7 , the near infrared imaging apparatus  200  according to the second embodiment includes the marker member  240 . Further, the marker member  240  includes the marker-side fluorescent portion  241 . Further, the marker-side fluorescent portion  241  includes the marker-side fluorescent agent  241   a  that generates the near infrared fluorescence IR 3  by being irradiated with excitation light IRe from an excitation light source unit  1   b  of a light source unit  1 . The marker-side fluorescent portion  241  is an example of the “near infrared ray generator” in the claims. In addition, the near infrared fluorescence IR 3  is an example of the “first near infrared light”. 
     Specifically, the marker-side fluorescent agent  241   a  is made of indocyanine green. That is, the marker-side fluorescent agent  241   a  is the same fluorescent agent as a fluorescent agent Pa injected into the patient P. In this way, the marker-side fluorescent portion  241  is configured to be able to generate the near infrared fluorescence IR 3  having a wavelength of about 845 nm which can be detected by a near infrared sensor  6  by the marker-side fluorescent agent  241   a  being irradiated with the excitation light IRe from the excitation light source unit  1   b.    
     Specifically, as illustrated in  FIG. 7 , the marker-side fluorescent portion  241  includes a member  241   b  containing (coated with) the marker-side fluorescent agent  241   a.  The marker-side fluorescent portion  241  is attached to a pen tip  43  side of a main marker body  242 . 
     Further, the near infrared imaging apparatus  200  is configured to image the near infrared fluorescence IR 3  indicating a position of the marker member  240  and image near infrared fluorescence IR 2  from the fluorescent agent Pa inside the patient P. 
     In addition, other components of the near infrared imaging apparatus  200  according to the second embodiment are the same as those of the near infrared imaging apparatus  100  according to the first embodiment. 
     Effects of Second Embodiment 
     In the second embodiment, it is possible to obtain the following effects. 
     In addition, in the second embodiment, as described above, the marker-side fluorescent portion  241  includes the marker-side fluorescent agent  241   a  that generates the near infrared fluorescence IR 3  by being irradiated with the excitation light IRe from the first light source unit. In this way, unlike the case of providing the marker light source unit  41  as in the first embodiment, a structure (the battery  44 , etc.) for supplying power to the marker light source unit  41  is unnecessary, and thus it is possible to inhibit a structure of the marker member  40  from being complicated. 
     In addition, other effects of the near infrared imaging apparatus  200  according to the second embodiment are the same as those of the near infrared imaging apparatus  100  in the first embodiment. 
     Third Embodiment 
     Next, a description will be given of a configuration of a near infrared imaging apparatus  300  according to a third embodiment with reference to  FIG. 8  and  FIG. 9 . In the near infrared imaging apparatus  300  according to the third embodiment, a near infrared light emitting member  350  is provided with a detachable portion  351  for attachment and detachment to and from a marker member  340 . The same reference symbol will be assigned to the same component as that of the first embodiment and the second embodiment, and a description thereof will be omitted. 
     As illustrated in  FIG. 8 , the near infrared imaging apparatus  300  according to the third embodiment includes the marker member  340 . Further, the near infrared ray generating member  350  including a marker-side light source unit  352   a  having a circular shape (dot shape) capable of irradiating near infrared light IR 1  and a marker-side light source unit  352   b  having a rectangular shape (linear shape) is attached to the marker member  340 . 
     Here, in the third embodiment, as illustrated in  FIG. 9 , the near infrared ray generating member  350  includes the detachable portion  351  for attachment and detachment to and from the marker member  340 . The detachable portion  351  is configured to have a shape of a pair of hooks. As illustrated in  FIG. 9( a ) , the detachable portion  351  is formed to cover a part of an outer circumference of a main marker body  342  in a state of being attached to the marker member  340 . Further, the detachable portion  351  is fixed to the marker member  340  by pressing of a part thereof in the shape of the pair of hooks in a direction approaching each other. 
     In addition, as illustrated in  FIG. 9( b ) , the part of the detachable portion  351  in the shape of the pair of hooks is made of an elastically deformable material, and the near infrared ray generating member  350  can be detached from the marker member  340  as illustrated in  FIG. 9( c )  by the part in the shape of the pair of hooks being pulled apart to move away from each other. In addition, in the third embodiment, from a state in which the near infrared ray generating member  350  is detached from the marker member  340  as illustrated in  FIG. 9( c ) , the part of the detachable portion  351  in the shape of the pair of hooks is elastically deformed as illustrated in  FIG. 9( b ) , thereby allowing the near infrared ray generating member  350  to be attached to the marker member  340  again as illustrated in  FIG. 9( a ) . 
     In addition, other components of the near infrared imaging apparatus  300  according to the third embodiment are the same as those of the near infrared imaging apparatus  100  according to the first embodiment. 
     Effects of Third Embodiment 
     In the third embodiment, it is possible to obtain the following effects. 
     In addition, in the third embodiment, as described above, the detachable portion  351  for attachment and detachment to and from the marker member  340  is provided in the near infrared ray generating member  350 . In this way, using the detachable portion  351 , the near infrared ray generating member  350  may be removed from the used marker member  340 , and the near infrared ray generating member  350  may be attached to a new marker member  340 . That is, when the consumable marker member  340  is replaced, the near infrared ray generating member  350  can be reused. 
     In addition, other effects of the near infrared imaging apparatus  300  according to the third embodiment are the same as those of the near infrared imaging apparatus  100  in the first embodiment. 
     MODIFIED EXAMPLES 
     It should be considered that the embodiments disclosed this time are illustrative in all respects and are not restrictive. The scope of the invention is indicated not by the description of the embodiments but by the scope of claims, and includes meanings equivalent to the scope of claims and all changes (modified examples) within the scope. 
     For example, in the first to third embodiments, a description has been given of an example in which the near infrared imaging apparatus is configured as the medical imaging apparatus used for angiography and lymphangiography in a surgical operation. However, the invention is not limited thereto. For example, the near infrared imaging apparatus may be configured as an industrial imaging apparatus for product inspection or an imaging apparatus for academic research. 
     In addition, in the first to third embodiments, a description has been given of an example in which the near infrared imaging apparatus is configured to form the composite image of the near infrared light image and the visible light image. However, the invention is not limited thereto. For example, as in a first modified example illustrated in  FIG. 10 , a near infrared imaging apparatus  400  may be configured to be able to display only the near infrared light image  92 . 
     Here, as illustrated in  FIG. 10 , unlike the near infrared imaging apparatus  100  according to the first embodiment, the white light source unit, the visible light sensor, and the image composition unit are not provided in the near infrared imaging apparatus  400  of the first modified example of the first to third embodiments. In this way, only the near infrared light image  92  is displayed on the display unit  9 . In this case, when the marker member  40  capable of generating near infrared light is used, the image indicating the position of the marker member  40  is displayed as the near infrared light image  92  on the display unit  9 . Thus, even when a composite image of the near infrared light image  92  and the visible light image is not formed, it is possible to inhibit the position at which the mark is actually placed from being shifted from the position at which the mark needs to be placed. 
     In addition, the first to third embodiments show an example in which the marker light source unit or the marker-side fluorescent portion is disposed around the pen tip of the marker member. However, the invention is not limited thereto. For example, the marker light source unit or the marker-side fluorescent portion may be provided on an opposite side from the pen tip of the marker member. 
     In addition, the first to third embodiments show an example in which the wavelength of the near infrared light IR 1  and the wavelength of the near infrared fluorescence IR 3  are configured to be wavelengths in the vicinity of the wavelength of the near infrared fluorescence IR 2 . However, the invention is not limited thereto. That is, it is sufficient that the wavelength of the near infrared light IR 1  and the wavelength of the near infrared fluorescence IR 3  are wavelengths that can be detected by the near infrared sensor. The wavelength of the near infrared light IR 1  and the wavelength of the near infrared fluorescence IR 3  maybe different from the wavelength of the near infrared fluorescence IR 2 . 
     In addition, the first embodiment and the third embodiment show an example in which the marker light source unit irradiating the near infrared light IR 1  includes the light emitting diode. However, the invention is not limited thereto. That is, the marker light source unit may include a light emitting member other than the light emitting diode. For example, a light bulb may be provided or a laser diode may be provided in the marker light source unit. 
     In addition, the first embodiment and the third embodiment show an example of configuring the switch to be slidable along the direction in which the main marker body extends, thereby switching between the state in which power is supplied to the marker light source unit and the state in which power is not supplied to the marker light source unit. However, the invention is not limited thereto. For example, as in a marker member  540  of a second modified example illustrated in  FIG. 11 , a push button  545  may be provided on the marker member  540 . 
     Here, as illustrated in  FIG. 11 , in the second modified example of the first embodiment and the third embodiment, the marker member  540  is provided with the push button  545  and an urging member  545   a  movable in a direction of an arrow C. Further, the marker member  540  is configured such that power is supplied from the battery  44  to the marker light source unit  41  when the push button  545  is pushed to the main marker body  42  side by the user, and the urging member  545   a  pushes up the push button  545  to the outside of the main marker body  42  and power is not supplied from the battery  44  to the marker light source unit  41  when the push button  545  is not pushed. 
     In addition, the first embodiment and the third embodiment show an example in which the marker member is provided with the battery for supplying power to the marker light source unit. However, the invention is not limited thereto. For example, as in a near infrared imaging apparatus  600  according to a third modified example illustrated in  FIG. 12 , power may be supplied from a power supply unit  630   a  of a main apparatus body  630  to a marker light source unit  41  of a marker member  640  through a cable  630   a.    
     In addition, the second embodiment shows an example in which the marker-side fluorescent agent  241   a  and the fluorescent agent inside the test object are made of indocyanine green. However, the invention is not limited thereto. That is, the marker-side fluorescent agent  241   a  and the fluorescent agent inside the test object may be made of a fluorescent agent other than indocyanine green. For example, at least one of the marker-side fluorescent agent  241   a  and the fluorescent agent inside the test object may be made of 5-ALA. 
     In addition, the second embodiment shows an example in which the member  241   b  containing (coated with) the marker-side fluorescent agent  241   a  is provided in the marker fluorescent portion  240 . However, the invention is not limited thereto. For example, a storage container that stores the marker-side fluorescent agent  241   a  may be provided in the marker fluorescent portion  240 , and the storage container may be configured to transmit the near infrared fluorescence IR 3  from the inside of the container to the outside of the container. 
     In addition, the third embodiment shows an example in which the marker-side light source units  352   a  and  352   b  are provided in the near infrared light emitting member  350 . However, the invention is not limited thereto. For example, a marker-side fluorescent portion having a marker-side fluorescent agent may be provided in the near infrared light emitting member  350 . 
     In addition, the third embodiment shows an example in which the detachable portion  351  is configured to have the shape of the pair of hooks. However, the invention is not limited thereto. For example, an adhesive attachable to and detachable from the main marker body  342  may be provided in the near infrared light emitting member  350 . 
     REFERENCE SIGNS LIST 
       1   a  White light source unit (third light source unit) 
       1   b  Excitation light source unit (first light source unit) 
       5  Visible light sensor (visible light detector) 
       6  Near infrared sensor (near infrared detector) 
       7  Image formation unit (imaging unit) 
       8  Image composition unit (imaging unit) 
       30 ,  630  Main apparatus body 
       40 ,  240 ,  340 ,  540 ,  640  Marker member 
       41 ,  352   a,    352   b  Marker light source unit (second light source unit, near infrared ray generator) 
       42 ,  242 ,  342  Main marker body (holding portion) 
       43  Pen tip 
       45 ,  545  Switch (switching unit) 
       91  Visible light image 
       92  Near infrared light image 
       93  Composite image 
       100 ,  200 ,  300 ,  400 ,  600  Near infrared imaging apparatus (medical imaging apparatus, intraoperative support apparatus) 
       241  Marker-side fluorescent portion (near infrared ray generator) 
       241   a  Marker-side fluorescent agent 
       350  Near infrared ray generating member (near infrared ray generator) 
       351  Detachable portion