JP2004337605A - Optical probe, measuring system using the same, and reflected light detecting method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical sensor of which the miniaturization is easy, and also, which is less prone to be affected by heat generation by a light emitting section. <P>SOLUTION: The light emitting section 11 emits a light toward a reflecting section 131 which is a diffuse-reflective surface. The emitted light passes through an optical passage 14, and reaches the reflecting section 131. Then, the reflecting section 131 diffuse-reflects the light from the light emitting section 11, and returns it to the optical passage 14. The inside of the optical passage 14 becomes an integrating sphere by the diffuse-reflection at the reflecting section 131. The optical passage 14 transmits the light which is diffuse-reflected by the reflecting section 131 from the end part 141 toward a nail 511. A part of the transmitted light is scattered within a finger 51, and also, reflected and received by a light receiving section 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical probe, a measurement system using the same, and a reflected light detection method using the same. In particular, the present invention relates to a reflective optical probe.

  As a conventional reflection-type optical sensor, for example, there is one described in Patent Document 1 below. This optical sensor detects light (reflected light) that is irradiated on the surface of a human body, scattered inside the human body, and returned to the irradiated surface. By detecting the reflected light, the oxygen saturation of blood can be measured. An apparatus for measuring the oxygen saturation in blood is called a pulse oximeter.

  Such a reflection type optical sensor can be used simply by sticking it on the surface of a human body (for example, a finger). On the other hand, in the transmission type optical sensor, a part of the subject's body is sandwiched between the light emitting body and the light receiving body, which may cause injury or discomfort such as compression. Therefore, the reflective optical sensor has an advantage that the burden on the subject is less than that of the transmissive optical sensor.

  By the way, if the reflection type optical sensor can be made smaller than the conventional one, the restriction on the use site decreases. If it is sufficiently small, it can be used, for example, for a little fingernail or a child's nail.

Further, the light sensor described in Patent Document 1 has a problem that the subject is easily affected by heat generation because the LED for light emission is adhered to the surface of the nail. Therefore, in the conventional device, it is necessary to take measures such as limiting the light emission time and power consumption (that is, the light emission amount) to suppress the heat generation amount.
JP 2001-501847 A

  The present invention has been made in view of the above circumstances. One of the main objects of the present invention is to provide an optical probe that can be easily miniaturized and a measurement system using the same. Another object of the present invention is to provide an optical sensor that is hardly affected by a measurement target (person, animal, plant or object) by the influence of heat generated by the light emitting unit.

  An optical probe according to the present invention includes a light emitting unit, a light receiving unit, a reflecting unit, and an optical path. The light receiving unit receives light emitted from the light emitting unit and passing through the light path and the outside. The reflection unit reflects light that has entered the light path from the light emitting unit and returns the light to the inside of the light path. The light path is for transmitting light emitted from the light emitting unit to the light receiving unit via the reflecting unit or the outside.

  The light emitting unit may emit light toward the reflection unit or the light path.

  The light emitting section may emit light toward the outside.

  The light emitting section may emit light of at least two wavelengths.

  The light emitting unit may be configured to include a light emitting LED or a laser diode.

  The light emitting unit may include a first light emitting unit and a second light emitting unit. The first light emitting unit may include an LED or a laser diode that emits light of a first wavelength. The second light emitting unit may include an LED or a laser diode that emits light of a second wavelength.

  The light receiving unit may include a photodiode that detects the received light.

  The reflection section may be a diffuse reflection surface.

  The reflector may be formed in a spherical shape.

  The optical probe may further include a main body. Further, the reflection portion may be formed on an inner surface of the main body, and the main body may be deformable.

  The light path may include an end arranged around the light emitting unit or the light receiving unit.

  The light path may be filled with a transparent material. All or part of this transparent material can be an epoxy resin. Further, all or a part of the transparent material can be made of a silicone resin.

  The light receiving section or the light emitting section may be arranged on a substrate. Further, the substrate may be deformable.

  The light emitting unit may be arranged on a substrate, and the substrate may have a heat conductivity for guiding heat generated in the light emitting unit to the outside.

  The light emitting section may include a light guide such as an optical fiber.

  The light receiving section may include a light guide such as an optical fiber.

  The optical probe of the present invention may have the following configuration. That is, this optical probe includes a light emitting unit, a light receiving unit, a reflecting unit, and an optical path. The light emitting section emits light toward the reflecting section. The reflection unit faces the light emitting unit, and returns the light emitted from the light emitting unit to the light path. The light path is disposed between the light emitting unit and the reflecting unit. Further, the light path sends out the light emitted from the light emitting unit and reflected by the reflecting unit to the outside. The light receiving unit receives light emitted from the light emitting unit and passing through the light path and the outside.

  The optical probe of the present invention may have the following configuration. That is, this optical probe includes a light emitting unit, a light receiving unit, a reflecting unit, and an optical path. The light emitting section emits light toward the outside. The light path is for taking in light emitted from the light emitting unit and passing through the outside, and guiding the light to the reflecting unit. The reflecting section reflects the light taken in the light path and sends the light to the light receiving section via the light path. The light receiving unit receives the light transmitted through the light path.

  The light emitting unit may be disposed on one surface of the substrate, and the light receiving unit may be disposed on another surface of the substrate.

  A measurement system according to the present invention includes any one of the above-described optical probes and an analysis unit that analyzes characteristics of light received by the optical probe.

The reflected light detection method according to the present invention includes the following steps:
(1) emitting the light emitted from the light emitting unit to the outside from around the light receiving unit;
(2) receiving a part of the light emitted to the outside and passing through the outside by the light receiving section;

  In the step (1), the emission may be performed after the light emitted from the light emitting unit is diffusely reflected.

The reflected light detection method according to the present invention may have the following configuration. That is, the method has the following steps:
(1) emitting light from the light emitting unit to the outside;
(2) capturing a part of the light emitted toward the outside and passing through the outside into the light path from around the light emitting unit;
(3) receiving the light taken in the light path by the light receiving section;

  In the step (3), the light captured in the light path may be diffusely reflected and then received by the light receiving unit.

  In the optical probe of the present invention, the substrate may include a first substrate, a second substrate, and an intermediate layer. The first substrate is disposed on one surface of the substrate. The second substrate is disposed on the other surface of the substrate. The intermediate layer is disposed between the first substrate and the second substrate. Further, the intermediate layer has conductivity.

  The intermediate layer may have a light shielding property.

  The optical probe of the present invention may further include a main body, wherein the reflection section is formed on an inner surface of the main body, and a conductive material is provided on an outer surface of the main body.

  The optical probe of the present invention may include a protection unit that at least partially covers the periphery of the light receiving unit disposed on the substrate, and the protection unit may include a conductive material.

  The optical probe of the present invention may have a configuration in which a nail attachment is attached around an end of the optical path, and an outer surface of the nail attachment is formed in a substantially cylindrical shape.

  The nail attachment may have a light shielding property outside a position facing an end of the light path.

  The optical probe according to the present invention may include a protection unit that at least partially covers a periphery of the light receiving unit disposed on the substrate, and the protection unit may have a light shielding property.

  The optical probe of the present invention may have a configuration in which a light scattering medium is disposed inside the transparent material.

  The optical probe of the present invention may further include a heat conductor. The light emitting unit may be arranged at a position facing the reflecting unit. The heat conductor extends from the vicinity of the light emitting portion to the reflecting portion or outside thereof.

According to the present invention, an optical sensor that can be easily miniaturized can be provided.
Further, according to the present invention, the light emitting unit can be separated from the target person (or the target object), and in this case, it is possible to provide an optical sensor which is hardly affected by heat generated by the light emitting unit. .

(Configuration of First Embodiment)
A measurement system according to a first embodiment of the present invention will be described below with reference to FIGS. The measurement system of this embodiment is used as a pulse oximeter. This measurement system mainly includes an optical probe 1, an analysis unit 2, a wiring 3, and a fixture 4 (see FIG. 1). In this embodiment, the measurement system is attached to the hand 5 of the person to be measured.

  The optical probe 1 mainly includes a light emitting unit 11, a light receiving unit 12, a main body 13, an optical path 14, a substrate 15, and a protection unit 16 (see FIGS. 2 to 11).

  The light emitting unit 11 includes a first light emitting unit 111 and a second light emitting unit 112 (see FIGS. 5, 10, and 11). The first light emitting unit 111 is, specifically, an LED as a light emitting body that emits light of the first wavelength. The light of the first wavelength is, for example, red light having a wavelength near 660 [nm]. The second light emitting unit 112 is, specifically, an LED as a light emitter that emits light of the second wavelength. The light of the second wavelength is, for example, near-infrared light having a wavelength near 880 [nm]. However, the light emitting unit 11 may be configured to use only one light emitting body. Further, the light emitter is not limited to the LED, and another light emitter such as a laser diode or a lamp may be used. Further, the number of light emitters such as LEDs may be singular or plural. The first and second light emitting units 111 and 112 are attached to one surface of the substrate 15 (the surface facing the main body 13). Thus, the light emitting section 11 emits light toward the reflecting section 131 (described later) or the optical path 14.

  In this embodiment, the light receiving unit 12 uses a photodiode as a light receiving body. The light receiving unit 12 is attached to the other surface (a surface facing the outside) of the substrate 15 (see FIGS. 5, 9 and 10). Thereby, the light receiving unit 12 receives light emitted from the light emitting unit 11 and passing through the light path 14 and the outside (for example, inside the object).

  A reflecting portion 131 having a spherical shape is formed on one surface (inner surface) of the main body 13 (see FIGS. 2, 3 and 5). The main body 13 is made of a hard resin as a whole. However, the main body 13 may be made of a flexible resin or may be made of a material other than a resin.

  The reflector 131 is made of a material (for example, a white material) that reflects light (especially, infrared light or red light) with high reflectance. In addition, fine irregularities (that is, “rough surface”) (not shown) are formed on the reflecting portion 131. Thereby, the reflection section 131 is a diffuse reflection surface. Such fine unevenness (rough surface) can be obtained, for example, by applying a white fine powder. The reflection section 131 reflects light that has entered the light path 14 from the light emitting section 11 and returns the light to the inside of the light path 14.

  The light path 14 is a space formed between the reflecting section 131 (that is, the inner surface of the main body 13) and the light emitting section 11 (see FIG. 5). The light path 14 has an end 141 (ie, a part where light enters and exits) 141 arranged around the light emitting unit 11. The inside of the light path 14 is filled with a transparent material 142. The transparent material 142 is preferably capable of dissipating heat generated by the light emitting body, and is, for example, an epoxy resin. However, another material such as a silicone resin can be used as the transparent material 142. Also, for example, only the portion that contacts the human body may be made of a flexible silicone resin, and the other portions may be made of an epoxy resin. The light path 14 is configured to transmit the light emitted from the light emitting unit 11 to the light receiving unit 12 via (ie, via) the reflecting unit 131 and the outside (for example, inside the object). The end 141 of the light path 14 is formed around the light receiving unit 12. Here, the periphery does not necessarily mean the entire circumference, but includes a part of the entire circumference. The end 141 of the light path 14 faces outside around the light receiving unit 12 except for the part corresponding to the substrate 15.

  The substrate 15 is attached to one surface of the main body 13. One end of the substrate 15 is extended to substantially the center of the light path 14 formed on the inner surface side of the reflection section 131. The other end of the substrate 15 extends to the outside of the main body 13. The light emitting unit 11 and the light receiving unit 12 are mounted near one end of the substrate 15. Thus, the light emitting unit 11 attached to the substrate 15 is disposed at a position facing substantially the center of the reflecting unit 131. The light receiving unit 12 is directed to the outside of the main body 13 in the state where the light receiving unit 12 is attached to the substrate 15 as described above. The substrate 15 is a flexible substrate, and has flexibility. That is, the substrate 15 is deformable. The surface of the substrate 15 that is in contact with the light path 14 is preferably a diffuse reflection surface except for the light emitting unit 11 and the light receiving unit 12.

  The protection section 16 is attached to the surface of the substrate 15 as shown in FIGS. 2, 3, and 5. The protection portion 16 has a hole 161 formed therethrough in the thickness direction (see FIG. 5). The light receiving unit 12 is housed inside the hole 161. The inside of the hole 161 is filled with a transparent material 162 similar to the transparent material 142 filled in the optical path 14. Of course, the transparent material 162 may be a material different from the transparent material 142.

  The analysis unit 2 includes a signal amplifier 21, an A / D converter 22, a CPU 23, an interface unit 24, a memory unit 25, a display unit 26, an operation unit 27, and a power supply unit 28 ( See FIG. 12).

  The signal amplifier 21 is a part that amplifies a signal from the light receiving unit 12 of the optical probe 1. The A / D converter 22 converts an analog signal from the optical probe 1 into a digital signal and sends the digital signal to the CPU 23. The CPU 23 processes a signal sent from the A / D converter 22 in accordance with a program stored in the memory unit 25.

  The interface section 24 is a section that transfers signals and power between the CPU 23 and the memory section 25 to the power supply section 28.

  The memory unit 25 stores programs and data necessary for signal processing. The display unit 26 displays a processing result in the CPU 23, and is, for example, a liquid crystal display. The display unit 26 is arranged at a position visible from the outside (see FIG. 1).

  The operation unit 27 is a part for inputting an external instruction (for example, operation start) to the analysis unit 2.

  The power supply 28 is, for example, a battery. The power supply 28 supplies power necessary for the operation of the analysis unit 2. Further, the power supply 28 supplies power to the light emitting unit 11 via the interface unit 24 and the wiring 3. The amount of power supplied from the power supply 28 to the light-emitting unit 11 (that is, the amount of light emission) or the supply timing (that is, the light emission timing) is controlled by the CPU 23. Such an analysis unit 2 can be easily configured by using appropriate components such as a microcomputer chip.

  The wiring 3 connects the substrate 15 of the optical probe 1 and the signal amplifier 21 of the analyzer 2, and performs signal transmission and power supply between the two. The wiring 3 and the substrate 15 are detachable.

  The fixture 4 is formed in a belt shape, and both ends are attached to the analysis unit 2. The fixing tool 4 is, for example, a stretchable belt. In short, the fixture 4 may be any as long as it can fix the analysis unit 2 to the body.

(Operation of First Embodiment)
Next, an example of a reflected light detection method using the apparatus of the present embodiment configured as described above will be described. Before the measurement, a transparent adhesive (not shown) is applied to the surface of the nail 511 (see FIG. 1) of the thumb 51 of the subject's hand 5. Next, the optical probe 1 is attached to the nail 511. At this time, the light receiving section 12 of the optical probe 1 is turned to the surface of the nail 511 (see FIG. 13). Of course, as a method of bonding the optical probe 1, for example, a method in which an adhesive layer is provided on the bottom surface of the main body 13 (the surface that comes into contact with the claws 511) may be used. Further, the analysis unit 2 is attached to the wrist 52 using the fixing tool 4.

  Next, power is supplied from the power supply unit 28 of the analysis unit 2 to the first light emitting unit 111 of the light emitting unit 11 via the CPU 23. Thus, the first light emitting unit 111 emits light. The red light emitted from the first light emitting unit 111 passes through the light path 14 and is diffusely reflected by the reflecting unit 131. Since the reflection section 131 is a diffuse reflection surface, the inside of the light path 14 is an integrating sphere. Therefore, in this embodiment, the light emitted from the light emitting unit 11 is emitted to the outside from the end 141 of the light path 14 (that is, the exit of the light path 14) regardless of the directivity. Moreover, in this embodiment, since the reflecting portion 131 is a diffuse reflecting surface, the directivity of light emitted from the end 141 can be reduced.

  In this embodiment, since the end 141 of the light path 14 is disposed around the light receiving unit 12, light is emitted from the periphery of the light receiving unit 12 to the outside. However, since light corresponding to the substrate 15 is blocked by the substrate 15, no light is emitted. As described above, “surrounding” does not necessarily mean the entire circumference.

  Light emitted from the end 141 of the light path 14 to the outside is applied to a nail 511 as an object located outside. The irradiated light is reflected after passing through human body tissues, that is, nails 511, tissues 512 under the nails, muscles 513, and bones 514, as shown in FIG. A part of the light is reflected on the surface of the nail 511 and returns to the light path 14.

  Part of the light that has passed through the human body tissue is received by the light receiving unit 12. The received light is photoelectrically converted by the light receiving unit 12, and the intensity signal of the light is sent to the analyzing unit 2 as an electric signal.

  Next, power is supplied from the power supply unit 28 to the second light emitting unit 112 of the light emitting unit 11. Thereby, the second light emitting unit 112 emits light. The infrared light emitted from the second light emitting unit 112 is received by the light receiving unit 12 in the same manner as in the case of the first light emitting unit 111, and a light intensity signal is sent to the analysis unit 2.

  Such light emission of the first light emitting unit 111 and light emission of the second light emitting unit 112 are repeated in a short cycle. The light emission cycle is preferably sufficiently shorter than the pulse wave cycle. For example, the light emission cycle is set to a value of 1/10 or less of the expected pulse wave cycle. In this way, even when one light receiving unit 12 is used, a pulse wave intensity signal can be obtained at two wavelengths.

  The CPU 23 of the analysis unit 2 obtains a fluctuation width (width of the fluctuation amount excluding the DC component) in the intensity signal of each wavelength. Next, assuming that the fluctuation width of the red light is R and the near-infrared light is IR, a ratio R / IR of the fluctuation width is obtained. The higher the ratio, the lower the oxygen saturation in the blood, and the lower the ratio, the higher the oxygen saturation. Since such a data processing method is well known, further description will be omitted. Further, the CPU 23 searches the memory unit 25 for a numerical value of the oxygen saturation corresponding to the ratio of the fluctuation range, and outputs the numerical value to the display unit 26 for display.

  In this embodiment, since the light from the light emitting unit 11 is emitted to the outside from the periphery of the light receiving unit 12, the light passing through a wide area can be received by the light receiving unit 12. Therefore, it is possible to acquire information on the object in a wide range. For example, in a living tissue, a blood vessel is localized, so that a change in a pulse wave cannot always be captured with information in a narrow range. On the other hand, in this embodiment, there is an advantage that the fluctuation of the pulse wave is easily captured.

  Further, in this embodiment, by adjusting the area of the end portion (portion facing the outside) 141 in the light path 14, the irradiation amount of light to the object can be easily adjusted. The adjustment of the area can be performed, for example, by attaching a shield.

  Furthermore, in this embodiment, since the light emitting unit 11 is arranged on one surface side of the substrate 15 (side away from the object), there is an advantage that the object (for example, a human body) is hardly affected by heat generation. For this reason, for example, it is easy to increase the light emission amount and the light emission time, and it is possible to improve the SN ratio of the detection signal. Further, there is an advantage that the subject is less likely to be injured by the heat generation and less likely to feel discomfort. Further, even when the size of the optical probe 1 is reduced and thereby the area of the end portion 141 of the optical path 14 is reduced, it is easy to obtain a sufficient amount of received light by increasing the amount of light from the light emitting unit 11. .

  Further, in the optical probe of this embodiment, since the light from the light emitting unit 11 is emitted to the outside through the light path 14, the light emitting unit 11 and the light receiving unit 12 are separated along the direction away from the object. Can be arranged. In the conventional optical probe described in Patent Literature 1, the light emitting unit and the light receiving unit are arranged in a direction along the body surface. Moreover, in this conventional optical probe, sufficient information cannot be obtained unless the light emitting unit and the light receiving unit are separated from each other to some extent. Therefore, it is difficult to further reduce the size of the conventional optical probe. On the other hand, in the optical probe of the present embodiment, the light emitting unit 11 and the light receiving unit 12 can be arranged along the direction away from the object, so that the area required for installing the optical probe is reduced ( In other words, there is an advantage that it is easy to reduce the size. Moreover, in the present embodiment, even if the size is reduced, light can be applied to the object from a wide range around the light receiving unit 12 as described above, so that it is easy to secure a sufficient amount of received light. .

  Further, in the optical probe of the present embodiment, a part of the light reflected on the surface of the nail 511 enters the optical path 14 again through the end 141. The light that has entered the light path 14 is radiated again from the end 141 to the outside because the inside of the light path 14 is an integrating sphere (that is, the reflecting portion 131 is a diffuse reflection surface). . Thus, in this embodiment, part of the emitted light can be reused. Therefore, in this embodiment, the use efficiency of the emitted light can be improved, and therefore, there is an advantage that the size of the optical probe can be further reduced.

  In addition, according to the optical probe of the present embodiment, the size can be reduced as described above, so that the optical probe can be easily attached to a curved surface such as the surface of a living body or fruits and vegetables.

  Furthermore, in the optical probe of this embodiment, if the main body 13 is made of a deformable material, attachment to a curved surface becomes easier. In this optical probe, similar advantages can be obtained if the transparent material 142 and the substrate 15 are made deformable. Furthermore, by making the portion of the transparent material 142 that is in contact with the human body particularly a soft material, it is possible to obtain the advantage of improving the adhesion and the feeling of use.

  In addition, in this embodiment, since the protection unit 16 is attached to the substrate 15, there is an advantage that the wiring connected to the light receiving unit 12 can be protected. Further, since the transparent material 162 is filled in the hole 161 of the protection section 16, the light receiving section 12 can be protected more reliably.

  Furthermore, in the optical probe of this embodiment, since the transparent material 142 is sealed inside the optical path 14, the strength of the main body 13 can be improved. Therefore, this optical probe also has an advantage that an internal structure such as a wiring of the light emitting unit 11 and the light receiving unit 12 can be protected.

(2nd Embodiment)
Next, a measurement system according to a second embodiment of the present invention will be described with reference to FIGS. The analysis unit 2 of this measurement system further includes a transmission unit 29. The transmitting section 29 transmits a radio signal to the receiving station 6. In this way, the information (for example, blood oxygen saturation) obtained by the analysis unit 2 can be sent to the facility 7 such as a hospital via the transmission unit 29. Other configurations and advantages of the second embodiment are the same as those of the first embodiment, and thus description thereof will be omitted.

(Third embodiment)
Next, an optical probe 1 according to a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the positional relationship between the light emitting unit 11 and the light receiving unit 12 is opposite to that in the first embodiment. That is, in the third embodiment, the light receiving section 12 is attached to the inner surface side (the side facing the light path 14 and the reflecting section 131) of the substrate 15. Further, the light emitting unit 11 is attached to the outer surface side of the substrate 15. In FIG. 16, the shapes of the substrate 15 and the protection portion 16 are simplified as appropriate (the same applies to FIGS. 17 and 18 described later).

  In the optical probe 1 according to the third embodiment, the light emitted from the light emitting unit 11 is immediately emitted to the outside. Next, a part of the light emitted to the outside enters the inside of the light path 14 from the end 141 of the light path 14 after passing through the outside (that is, inside the living body). The light that has entered the optical path 14 is reflected by the reflection unit 131 and is eventually received by the light receiving unit 12. Since the reflection section 131 is a diffuse reflection surface (that is, the inside of the light path 14 is an integrating sphere), the light entering the light path 14 is efficiently transmitted to the light reception section 12 regardless of the incident angle. Well received. Other configurations and advantages in the third embodiment are the same as those in the first embodiment, and thus detailed description is omitted. However, in the third embodiment, it is considered preferable to move the light emitting unit 11 away from the target object or to reduce the amount of light emission in order to avoid injury to living tissue due to heat generation.

(Fourth embodiment)
Next, an optical probe 1 according to a fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, unlike the third embodiment, the light receiving unit 12 is attached to the reflection unit 131. In this embodiment as well, similarly to the third embodiment, the light that has entered the optical path 14 after passing through the outside can be received by the light receiving section 12 regardless of the angle of incidence. As described above, when the inside of the light path 14 is an integrating sphere, the light receiving section 12 may be arranged anywhere as long as the light receiving section 12 faces the light path 14. Other configurations and advantages in the fourth embodiment are the same as those in the third embodiment, and thus detailed description will be omitted.

(Fifth embodiment)
Next, an optical probe according to a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the area of the end 141 of the light path 14 is reduced. In this way, it is considered that the light use efficiency is improved. The other configurations and advantages in the fifth embodiment are the same as those in the first embodiment, and thus detailed description will be omitted.

(Sixth embodiment)
Next, an optical probe 1 according to a sixth embodiment of the present invention will be described with reference to FIGS. In this embodiment, the substrate 15 includes a first substrate 151, a second substrate 152, and an intermediate layer 153.

  The first substrate body 151 is disposed on one surface side (upper side in the drawing) of the substrate 15. The light emitting unit 11 is arranged on the upper surface of the first substrate 151.

  The second substrate body 152 is disposed on the other surface side (the lower side in the drawing) of the substrate 15. The light receiving unit 12 is disposed on the lower surface of the second substrate 151.

  The intermediate layer 153 has substantially the same shape as the first substrate body 151 and the second substrate body 152, and is disposed therebetween. The intermediate layer 152 is made of a conductive material. Examples of such a material include copper, aluminum, gold, and a conductive resin. In addition to the single material, a composite material may be used. The intermediate layer 153 is electrically grounded.

  According to the optical probe 1 of the sixth embodiment, the intermediate layer 152 can reduce the amount of electric noise received from a living body. Thereby, it is possible to improve the SN ratio of the output in the light receiving unit 12.

  Further, the intermediate layer 153 preferably has a light-shielding property. Examples of the material having a light-shielding property include copper, aluminum, and gold. When the intermediate layer 153 has a light-shielding property, it is possible to reduce a possibility that light that has not passed through the measurement site passes through the substrate 15 and reaches the light receiving unit 12. Thus, the SN ratio of the output from the light receiving unit 12 can be improved.

  The other configurations and advantages in the sixth embodiment are the same as those in the first embodiment, and thus detailed description will be omitted.

(Seventh embodiment)
Next, an optical probe 1 according to a seventh embodiment of the present invention will be described with reference to FIGS. In this embodiment, the outer surface of the main body 13 is plated with chrome (the plated portions are indicated by hatching in FIGS. 21 and 22). Thus, the outer surface of the main body 13 includes the conductive material. Further, in the present embodiment, the outer surface of the protection portion 16 is also plated with chrome. Further, in this embodiment, the protection portion 16 is extended to the outside of the main body 13 (see FIGS. 21 and 22). By forming this plating, in this embodiment, the protection part 16 that covers at least partially the periphery of the light receiving part 12 includes a conductive material. In this embodiment, each chrome-plated portion is electrically grounded (see FIG. 21).

  According to the optical probe 1 of the present embodiment, the amount of electric noise received from a living body can be reduced by each chrome-plated portion. Thereby, it is possible to improve the SN ratio of the output in the light receiving unit 12. Note that a conductive material other than chromium can be used. Furthermore, as a coating method, a method other than plating (for example, vapor deposition) is also possible.

  The other configurations and advantages of the seventh embodiment are the same as those of the first embodiment, and thus detailed description will be omitted.

(Eighth embodiment)
Next, an optical probe 1 according to an eighth embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the nail attachment 30 is attached around the end 141 of the light path 14 (the bottom surface of the main body 13 in the present embodiment). The outer surface (bottom surface) 31 of the nail attachment 30 is formed in a substantially cylindrical shape (see FIG. 25).

  Further, in the present embodiment, the nail attachment 30 in the portion 32 facing the end portion 141 of the light path 14 is formed of a transparent material, and the outer portion 33 at the position facing the end portion 141 of the light path 14 and The inner portion 34 (see FIG. 25) is made of a material having a light shielding property. However, in the inner portion 34, a portion 35 corresponding to the light receiving section 12 is made of a transparent material. The hatched portions in FIGS. 23 and 24 indicate portions having a light shielding property. The nail attachment 30 having such a configuration can be formed by, for example, two-color molding. The material having a light-shielding property is, for example, a black resin.

  By providing such a nail attachment 30, it is possible to reduce the amount of disturbance light (light entering from the outside or light directly from the light emitting unit 11) received by the light receiving unit 12, and It is possible to improve the output SN ratio.

  Furthermore, in this embodiment, since the nail attachment 30 in the portion 32 facing the end portion 141 of the light path 14 is formed of a transparent material, the amount of light passing through the measurement site can be maintained. is there.

  It should be noted that a flexible material (for example, rubber) is preferable as a material forming the nail attachment 30. In this way, the adhesion between the nail and the nail attachment 30 is improved, and the intrusion of disturbance light can be effectively suppressed.

  Further, when the protection unit 16 at least partially covers the periphery of the light receiving unit 12 and furthermore, the protection unit 16 is provided with a light shielding property, so that the intrusion of disturbance light into the light receiving unit 12 can be more effectively suppressed. .

  Other configurations and advantages of the eighth embodiment are the same as those of the first embodiment, and thus detailed description is omitted.

(Ninth embodiment)
Next, an optical probe 1 according to a ninth embodiment of the present invention will be described with reference to FIGS. In this embodiment, a light-scattering medium (not shown because of its small size) is disposed inside the transparent material 142. The light scattering medium is preferably disposed inside the transparent material 142 as dispersed as possible. As the light scattering medium, it is preferable to use a white powder such as barium sulfate in order to increase light scattering.

  According to the optical probe 1 of the present embodiment, light can be scattered by the light scattering medium (see FIG. 27). The arrow in FIG. 27 schematically shows the traveling direction of the light scattered by the light scattering medium. Therefore, the light radiated from the end 141 of the light path 14 to the outside can be homogenized, and a wide range of information at the measured location can be obtained. Also, by disposing the light scattering medium as in the present embodiment, there is no need to configure the reflection section 131 as a diffuse reflection surface, and there is an advantage that the cost for configuring the reflection section 131 can be reduced.

  Other configurations and advantages in the ninth embodiment are the same as those in the first embodiment, and thus detailed description will be omitted.

(Tenth embodiment)
Next, an optical probe 1 according to a tenth embodiment of the present invention will be described with reference to FIGS. The optical probe 1 according to this embodiment includes a heat conductor 132. In this embodiment, as in the first embodiment, the light emitting unit 11 is disposed at a position facing the reflection unit 131.

  The heat conductor 132 extends from the vicinity of the light emitting section 11 to the reflecting section 131, penetrates through the main body 13, and extends to the outside.

  The heat conductor 132 only needs to be close to the light emitting unit 11 to the extent that heat from the light emitting unit 11 can be sufficiently dissipated for practical use. Of course, the heat conductor 132 may be in contact with the light emitting unit 11 or may be connected to the substrate 15 near the light emitting unit 11. It is also possible to transfer heat by connecting the light emitting unit 11 or its vicinity and the heat conductor 132 with another member.

  The material of the heat conductor 132 is preferably a material having high thermal conductivity (eg, aluminum).

  According to the optical probe 1 of the present embodiment, since the heat dissipation efficiency of the light emitting unit 11 is increased, there is an advantage that overheating of the light emitting unit 11 and accompanying overheating of surrounding members can be suppressed.

  In each of the above embodiments, the reflecting portion 131 is a diffuse reflecting surface. However, the reflecting portion 131 may be a specular reflecting surface instead of a diffusing surface. However, in this case, it is necessary to adjust the positional relationship between the light emitting unit 11 and the light receiving unit 12 so that the light beam reaches the light receiving unit 12.

  Furthermore, in each of the above embodiments, a fingernail is illustrated as an object to which the optical probe is attached. However, the present invention is not limited to this and may be, for example, skin other than a nail. This makes it possible to measure the amount of light reflection on the skin (that is, the color of the skin). Further, foods such as fruits are not limited to living bodies such as humans and animals. This makes it possible, for example, to measure the sugar content and ripeness of the fruit. Further, the optical probe can be used for measuring the reflectance of various products other than food. Further, it is considered that this optical probe can be used not only for a pulse oximeter, but also for an optical probe for a blood glucose sensor using reflected light, for example.

  Further, in each of the above embodiments, the reflecting portion 131 has a spherical shape. However, when the inner surface of the reflecting portion 131 is a diffuse reflecting surface, the reflecting portion 131 may have any shape.

  Further, the light emitting unit in each of the above embodiments may be a light guide (a member transmitting light) such as an optical fiber. With this configuration, light from the outside of the optical probe (for example, light from a light emitter provided outside) can be used as light from the light emitting unit. Similarly, the light receiving unit in each of the above embodiments may be a light guide such as an optical fiber. With this configuration, the reflected light can be sent out of the optical probe, and photoelectric conversion and analysis can be performed outside.

  Further, a temperature sensor can be attached to the optical probe 1 of each of the above embodiments. The position of the temperature sensor is, for example, a surface (lower surface) of the substrate 15 facing the user. In this way, the temperature near the user can be measured. In addition, if the temperature sensor is arranged near the center of the main body 13, the temperature at the point where the main body 13 becomes the highest can be measured.

  However, the position of the temperature sensor may be the upper surface of the substrate 15 (the surface facing the main body 13). Further, the inner surface, the outer surface, or the inside of the main body 13 may be used. When the sensor is arranged at a position distant from the point to be measured, the temperature at the target position can be estimated by appropriately correcting the measured temperature (for example, to + 2 ° C.).

  Wiring for the temperature sensor can be performed using the substrate 15. The temperature sensor that can be used is not particularly limited. For example, a thermistor, a metal resistance thermometer, a thermocouple, or the like can be used as the temperature sensor. By monitoring the temperature of the optical probe 1 with a temperature sensor, for example, it is possible to give a warning when the temperature becomes high or to stop the light emission of the light emitting unit 11.

The description of each of the above embodiments is merely an example, and does not show a configuration essential to the present invention. The configuration of each part is not limited to the above as long as the purpose of the present invention can be achieved.
Further, the above-described functional blocks may be combined and combined into one functional block. Further, the function of one functional block may be realized by cooperation of a plurality of functional blocks.

It is an explanatory view showing the state where the measurement system concerning a 1st embodiment of the present invention was attached to a subject's hand. It is the perspective view which looked at the optical probe concerning a 1st embodiment of the present invention from the bottom. FIG. 3 is an exploded view of the optical probe of FIG. 2. FIG. 3 is a bottom view of the optical probe of FIG. 2. FIG. 5 is a sectional view taken along line AA of FIG. 4. FIG. 3 is a plan view of the optical probe of FIG. 2. FIG. 5 is a side view of the optical probe of FIG. 2 when viewed from a direction B in FIG. 4. It is a principal part enlarged view of FIG. FIG. 3 is a bottom view of a substrate used for the optical probe of FIG. 2. FIG. 10 is a side view of the substrate of FIG. 9. FIG. 10 is a plan view of the substrate of FIG. 9. FIG. 2 is a block diagram illustrating a schematic configuration of an analysis unit used in the measurement system in FIG. 1. FIG. 4 is an explanatory diagram for explaining an operation of the optical probe of FIG. 2, and is an enlarged sectional view of a main part in a state where the optical probe is attached to a nail. It is explanatory drawing which shows the state which attached the measuring system which concerns on 2nd Embodiment of this invention to the hand of the subject. FIG. 15 is a block diagram illustrating a schematic configuration of an analysis unit used in the measurement system in FIG. 14. It is a schematic sectional view showing an important section of an optical probe concerning a 3rd embodiment of the present invention. It is a schematic sectional view showing an important section of an optical probe concerning a fourth embodiment of the present invention. It is a schematic sectional view showing an important section of an optical probe concerning a 5th embodiment of the present invention. It is a cross-sectional view of a substrate in an optical probe according to a sixth embodiment of the present invention. 20 is an exploded perspective view of the substrate shown in FIG. It is a bottom view of the main part of the optical probe concerning a 7th embodiment of the present invention. FIG. 22 is a right side view of FIG. 21. It is a bottom view of the main part of the optical probe concerning an 8th embodiment of the present invention. FIG. 24 is a right side view of FIG. 23. FIG. 24 is an enlarged sectional view taken along line BB in FIG. 23. It is a longitudinal section of a main part of an optical probe concerning a 9th embodiment of the present invention. FIG. 27 is a diagram corresponding to FIG. 26 and is an explanatory diagram illustrating a state of light scattering by a light-scattering medium. It is a bottom view of the optical probe concerning a 10th embodiment of the present invention. FIG. 29 is a right side view of FIG. 28. FIG. 29 is a plan view of FIG. 28. FIG. 31 is a sectional view taken along line CC in FIG. 30.

Explanation of reference numerals

Reference Signs List 1 optical probe 11 light emitting section 111 first light emitting section 112 second light emitting section 12 light receiving section 13 main body 131 reflecting section (inner surface of main body)
132 Heat conductor 14 Light path 141 End of light path 142 Transparent material filled in light path 15 Substrate 151 First substrate body 152 Second substrate body 153 Intermediate layer 16 Protector 161 Hole 162 Transparent material filled in hole 2 Analysis unit 21 Signal amplifier 22 A / D converter 23 CPU
Reference Signs List 24 interface unit 25 memory unit 26 display unit 27 operation unit 28 power supply unit 29 transmission unit 30 nail attachment 31 outer surface of nail attachment 32 transparent part of nail attachment 33 light-shielding part outside transparent part 34 inside transparent part Light shielding part 35 Transparent part at position corresponding to light receiving part 3 Wiring 4 Fixture 5 Hand 51 Finger 511 Nail 512 Tissue under nail 513 Muscle 514 Bone 6 Receiving station 7 Facility

Claims (35)

  A light-emitting unit, a light-receiving unit, a reflection unit, and a light path; and the light-receiving unit receives light emitted from the light-emitting unit and passing through the light path and the outside. The part reflects the light that has entered the light path from the light emitting part and returns the light to the inside of the light path, and the light path reflects the light emitted from the light emitting part through the reflecting part or the outside. An optical probe, which is sent to the light receiving unit via the optical probe.   The optical probe according to claim 1, wherein the light emitting unit emits light toward the reflection unit or the light path.   The optical probe according to claim 1, wherein the light emitting unit emits light toward the outside.   The optical probe according to claim 1, wherein the light emitting unit emits light of at least two types of wavelengths.   The optical probe according to claim 1, wherein the light emitting unit includes a light emitting LED or a laser diode.   The light emitting unit includes a first light emitting unit and a second light emitting unit, the first light emitting unit includes an LED or a laser diode that emits light of a first wavelength, and the second light emitting unit includes The optical probe according to any one of claims 1 to 4, further comprising an LED or a laser diode that emits light of a second wavelength.   The optical probe according to claim 1, wherein the light receiving unit includes a photodiode that detects the received light.   The optical probe according to claim 1, wherein the reflection unit is a diffuse reflection surface.   The optical probe according to any one of claims 1 to 8, wherein the reflector is formed in a spherical shape.   The body according to any one of claims 1 to 9, further comprising a main body, wherein the reflection portion is formed on an inner surface of the main body, and the main body is deformable. Optical probe.   The optical probe according to claim 1, wherein the optical path includes an end disposed around the light emitting unit or the light receiving unit.   The optical probe according to claim 1, wherein a transparent material is filled in the optical path.   13. The optical probe according to claim 12, wherein all or a part of the transparent material is an epoxy resin.   13. The optical probe according to claim 12, wherein all or a part of the transparent material is a silicone resin.   The optical probe according to any one of claims 1 to 14, wherein the light receiving unit or the light emitting unit is disposed on a substrate, and the substrate is deformable.   16. The light emitting unit according to claim 1, wherein the light emitting unit is disposed on a substrate, and the substrate has a heat conductivity for guiding heat generated in the light emitting unit to the outside. Optical probe.   The optical probe according to claim 1, wherein the light emitting unit includes a light guide.   The optical probe according to claim 1, wherein the light receiving unit includes a light guide.   A light emitting unit, a light receiving unit, a reflecting unit, and an optical path are provided, the light emitting unit emits light toward the reflecting unit, and the reflecting unit faces the light emitting unit, and The light emitted from the light emitting unit is returned to the light path, the light path is disposed between the light emitting unit and the reflecting unit, and further, the light path is from the light emitting unit Emitted, and sends out the light reflected by the reflecting portion to the outside, the light receiving portion receives light emitted from the light emitting portion, and passed through the light path and the outside An optical probe, characterized in that:   A light emitting unit, a light receiving unit, a reflecting unit, and a light path, wherein the light emitting unit emits light to the outside, and the light path is emitted from the light emitting unit, and passes through the outside. Taking in the reflected light, and guiding the light to the reflecting section. The reflecting section reflects the light taken in the light path and sends the light to the light receiving section through the light path. The optical probe, wherein the unit receives light transmitted through the optical path.   21. The optical probe according to claim 19, wherein the light emitting unit is arranged on one surface of the substrate, and the light receiving unit is arranged on another surface of the substrate.   A measurement system comprising: the optical probe according to claim 1; and an analysis unit configured to analyze characteristics of light received by the optical probe. A method for detecting reflected light, comprising the following steps:
(1) emitting the light emitted from the light emitting unit to the outside from around the light receiving unit;
(2) receiving a part of the light emitted to the outside and passing through the outside by the light receiving section;   The detection method according to claim 23, wherein in the step (1), the light emitted from the light emitting unit is diffused and reflected, and then the emission is performed. A method for detecting reflected light, comprising the following steps:
(1) emitting light from the light emitting unit to the outside;
(2) capturing a part of the light emitted toward the outside and passing through the outside into the light path from around the light emitting unit;
(3) receiving the light taken in the light path by the light receiving section;   26. The detection method according to claim 25, wherein, in the step (3), the light taken in the light path is diffusely reflected and then received by the light receiving unit.   The substrate includes a first substrate body, a second substrate body, and an intermediate layer, the first substrate body is disposed on one surface side of the substrate, and the second substrate body is provided on the substrate. The intermediate layer is disposed on the other surface side, the intermediate layer is disposed between the first substrate body and the second substrate body, and the intermediate layer has conductivity. Item 22. An optical probe according to item 21.   The substrate includes a first substrate body, a second substrate body, and an intermediate layer, the first substrate body is disposed on one surface side of the substrate, and the second substrate body is provided on the substrate. The intermediate layer is disposed on the other surface side, the intermediate layer is disposed between the first substrate body and the second substrate body, and the intermediate layer has a light shielding property. Item 22. An optical probe according to item 21.   The body according to claim 1, further comprising a main body, wherein the reflection portion is formed on an inner surface of the main body, and an outer surface of the main body is provided with a conductive material. The optical probe according to claim 1.   22. The optical probe according to claim 21, further comprising a protection unit that at least partially covers a periphery of the light receiving unit disposed on the substrate, wherein the protection unit includes a conductive material.   22. A nail attachment is attached around an end of the light path, and an outer surface of the nail attachment is formed in a substantially cylindrical shape. Item 2. The optical probe according to item 1.   The optical probe according to claim 31, wherein the nail attachment has a light shielding property outside a position facing an end of the light path.   22. The optical probe according to claim 21, further comprising a protection unit that at least partially covers a periphery of the light receiving unit disposed on the substrate, wherein the protection unit has a light shielding property.   The optical probe according to any one of claims 12 to 14, wherein a light scattering medium is disposed inside the transparent material. The light emitting unit further includes a heat conductor, the light emitting unit is disposed at a position facing the reflection unit, and the heat conductor extends from the vicinity of the light emission unit to the reflection unit or outside thereof. The optical probe according to claim 21.

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