JP2017148139A - Biological information measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biological information measurement device that can prevent light that should not be received from reaching a receiver to inhibit a decline in signal-to-noise ratio.SOLUTION: The biological information measurement device includes: a sensor with a first receiver capable of receiving light from an organism; and a partition material 4 for blocking light from passing that is installed so as to project in an opposite direction to an entrance direction of light from an organism from a part different from the first receiver of the sensor.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a biological information measurement apparatus.

  A reflection type sensor is used for a pulse oximeter for measuring the oxygen saturation (SpO2) of a pulse wave or arterial blood. The reflection type sensor performs measurement by reflecting light from an LED as a light source by a living body and receiving the reflected light by a detector (Photo Detector: PD).

  The sensor module equipped with the LED and the PD has a window covering the LED and the PD, thereby improving the strength of the device and avoiding contact with the skin. However, when a window made of acrylic or silicone is simply attached, stray light generated by the reflection of the window reaches the PD, causing a decrease in signal-to-noise ratio (Signal-Noise ratio: S / N). .

JP 2007-185348 A

  An embodiment of the present invention aims to prevent light that should not be received from reaching a light receiving unit and to suppress a decrease in signal to noise ratio.

  The measuring apparatus as one aspect of the present invention includes a sensor having a first light receiving unit capable of receiving light from a living body, and a direction in which light from the living body enters from a location different from the first light receiving unit of the sensor. And a partition member provided so as to protrude in the opposite direction and blocking passage of light.

The figure which shows an example of the cross section of the sensor part of the measuring apparatus which concerns on 1st Embodiment. The perspective view which shows an example of a partition material. The figure which shows an example at the time of the measurement of the measuring apparatus which concerns on 1st Embodiment. The figure which shows another example of the cross section of the sensor part of the measuring apparatus which concerns on 1st Embodiment. The figure which shows an example at the time of the measurement of the measuring apparatus which concerns on 2nd Embodiment. The figure which shows another example at the time of the measurement of the measuring apparatus which concerns on 2nd Embodiment. The figure which shows an example at the time of the measurement of the measuring apparatus which concerns on 3rd Embodiment. The figure which shows another example at the time of the measurement of the measuring apparatus which concerns on 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a cross section of a sensor portion of the measuring apparatus according to the first embodiment. In FIG. 1, the sensor 1, the board | substrate 2, the contact part 3, and the partition material 4 are shown. Here, it is assumed that the positive direction of the Z-axis shown in the figure is on the top, and that a living body exists on the sensor 1 at the time of measurement. Further, it is assumed that light (reflected light) from the living body due to reflection inside the living body or on the surface enters the sensor 1. With respect to the light entering direction from the living body, the component in the Z-axis direction is from the positive direction to the negative direction, that is, from top to bottom. The light entering direction may have a direction component other than the Z axis. That is, the light entering direction from the living body may not be perpendicular to the upper surface of the sensor 1.

  The sensor 1 detects light from a living body in order to measure biological information such as a pulse wave of the living body, oxygen saturation of arterial blood, blood pressure, blood total hemoglobin amount, blood carbon monoxide concentration.

  The sensor 1 includes a light receiving unit 11 that receives light and changes the light into an electrical signal. The light receiving unit 11 acquires light (reflected light) from a living body, but also acquires other light.

  Moreover, the sensor 1 may be provided with the light emission part 12 which emits light by LED etc. Note that the wavelength of the light emitted from the light emitting unit 12 may be appropriately changed according to the biological information that is the measurement target.

  In the description of the present embodiment, the sensor 1 is described as including one light emitting unit 12 and one light receiving unit 11, but the configuration is not limited to this. For example, the sensor 1 may include only the light receiving unit 11. Moreover, the light-emitting part 12 or the light-receiving part 11 with which the sensor 1 is provided may be one or more.

  It is assumed that the light receiving unit 11 and the light emitting unit 12 are arranged separately. As shown in FIG. 1, the light receiving unit 11 or the light emitting unit 12 may be disposed inside the sensor 1 and may be partitioned by a non-transmissive material 13 that does not transmit light. In another example, the light receiving unit 11 or the light emitting unit 12 may be formed on the upper surface of the sensor 1. It may be arranged. In FIG. 1, the transmission material 14 that transmits light is disposed on the light receiving unit 11 or the light emitting unit 12, but this may be hollow.

  The sensor 1 is attached to the substrate 2 and is supplied with power from the substrate 2.

  The contact part 3 assumes that the upper surface contacts a living body, and prevents the sensor 1 positioned below the upper surface (contact surface) from directly contacting the living body. The contact part 3 may be, for example, an outer wall of the measuring device itself, or may be a table for fixing a finger or the like. In FIG. 1, the upper surface of the contact part 3 is provided higher (upper side) than the upper surface of the sensor 1 so that the living body does not touch the sensor 1 when the contact part 3 comes into contact with the living body. In FIG. 1, the cross section of the contact portion 3 is rectangular and has an upper surface, but may be a polygon other than a rectangle, and the upper end of the contact portion 3 only needs to be higher than the upper surface of the sensor 1. In addition, the contact part 3 may be isolate | separated and one housing | casing may be sufficient. For example, as the contact portion 3, a single housing having an opening on the upper surface may be used, and the sensor 1 may be disposed in a recessed portion of the opening. A wall higher than the sensor 1 surrounds the periphery of the sensor 1, and when a living body comes into contact with the opening so as to cover it, light from the outside can be prevented from entering the sensor 1 at the time of measurement. .

  The partition member 4 is a partition that is provided so as to protrude in a direction opposite to the light entering direction from the living body from a place different from the place where the light receiving unit 11 of the sensor 1 exists, and that blocks passage of light. . When the light receiving unit 11 receives light from inside the living body, the partition member 4 prevents light other than light from inside the living body, for example, reflected light from the surface of the living body.

  The structure of the partition member 4 will be described. FIG. 2 is a perspective view showing an example of the partition member 4. The partition member 4 includes a sensor contact surface 411 having a region in contact with the upper surface of the sensor 1, a biological contact surface 412 that comes into contact with a living body at the time of measurement, and a light shielding surface 413 that blocks passage of light.

  In FIG. 2, the partition member 4 is shown as a rectangular parallelepiped, but the partition member 4 is not limited to this structure. For example, each side of the partition member 4 may be a curve. The partition member 4 may be a polyhedron other than a rectangular parallelepiped. The living body contact surface 412, the sensor contact surface 411, or the light shielding surface 413 may not be a rectangle but may be a polygon or a circle other than a rectangle.

  As shown in FIG. 2, the upper surface of the sensor 1 is divided into a first planar region 15 and a second planar region 16 by the contact region where the sensor contact surface 411 and the upper surface of the sensor 1 are in contact. Yes. Thus, the sensor contact surface 411 separates the upper surface of the sensor 1 into two or more regions. Here, among the separated regions, the region where the light receiving unit 11 or the transmission material 14 existing on the light receiving unit 11 is present is defined as the first planar region 15, and the other region is distinguished from the second planar region 16.

  The sensor contact surface 411 only needs to be able to separate the first planar region 15 and the second planar region 16, and the position, size, etc. may be arbitrarily determined. For example, as shown in FIG. 2, a part of the sensor contact surface 411 may protrude from the upper surface of the sensor 1. The sensor contact surface 411 may have the same length as the sensor 1 in the Y-axis direction without protruding from the upper surface of the sensor 1. Thus, if the length of the sensor contact surface 411 in the Y-axis direction is equal to or longer than the length of the upper surface of the sensor 1 in the Y-axis direction, light in the X-axis direction can be blocked. Further, the sensor contact surface 411 may exist not near the center in the X-axis direction of the sensor but near the end in the X-axis direction. However, when there is the light emitting part 12, the light emitting part 12 or the transmissive material 14 existing on the light emitting part 12 is made to exist in the second plane region 16. That is, when the light emitting unit 12 is present, the sensor contact surface 411 is located between the light receiving unit 11 and the light emitting unit 12.

  In addition, when part or all of the sensor contact surface 411 is arranged on the upper surface of the light receiving unit 11 or in the sky, the light from the living body to be acquired by the light receiving unit 11 is blocked by the partition material 4. It is desirable that 4 is not disposed on the upper surface or in the sky of the light receiving unit 11. In addition, when a part or all of the sensor contact surface 411 is disposed on the upper surface of the light emitting unit 12 or in the sky, the light from the light emitting unit 12 does not reach the living body and is blocked by the partition material 4. It is desirable that 4 is not disposed on the upper surface or the sky of the light emitting unit 11.

  The living body contact surface 412 is assumed to be in contact with the living body at the time of measurement. In FIG. 2, although it is a surface facing the sensor contact surface 411, it is not limited to the facing surface, and changes depending on the structure of the partition member 4.

  The light shielding surface 413 is a surface in contact with the sensor contact surface 411 and the biological contact surface 412. Thereby, at the time of measurement, the light shielding surface 413 is interposed in the gap between the living body and the sensor 1. Therefore, it is possible to prevent light from entering and leaking from the second spatial region on the second planar region 16 to the first spatial region on the first planar region 15.

  For example, when measuring the pulse wave of a living body or the oxygen saturation (SpO2) of arterial blood, it is necessary to allow light from the light emitting unit 12 to enter the living body and receive reflected light from the inside of the living body. In this case, it is desirable that light other than the reflected light from inside the living body, for example, reflected light on the surface of the living body, does not reach the light receiving unit 11. Therefore, the partition material 4 prevents the direct light from the light emitting unit 12 or the reflected light from the surface of the living body from entering, thereby increasing the measurement accuracy.

  When the partition member 4 is a rectangular parallelepiped as shown in FIG. 2, there are two surfaces in contact with the sensor contact surface 411 and the biological contact surface 412, but both may be the light shielding surface 413 or the first planar region 15. The surface on the near side may be the light shielding surface 413. For example, by using the partition member 4 made of a non-permeable member, both surfaces facing the first planar region 15 and the second planar region 16 become the light shielding surfaces 413. Or you may affix a light shielding sheet etc. on the surface near the 1st plane area | region 15 among the surfaces which contact the sensor contact surface 411 and the biological body contact surface 412. FIG.

  FIG. 3 is a diagram illustrating an example of measurement by the measurement apparatus according to the first embodiment. At the time of measurement, the living body 5 shown in the figure comes into contact with the contact portion 3 and the partition member 4, and becomes as shown in FIG. The light from the light emitting unit 12 that has entered the inside of the living body 5 and the reflected light from the inside of the living body 5 are indicated by solid arrows. Further, light from the light emitting unit 12 that does not enter the living body 5 is indicated by a dashed arrow. Further, the reflected light from the surface of the living body 5 is indicated by a dotted arrow. Since the partition member 4 is interposed between the sensor 1 and the living body 5, the partition member 4 receives light from the light emitting unit 12 that does not enter the living body 5 and reflected light from the surface of the living body 5 enters the light receiving unit 11. On the other hand, the reflected light from the inside of the living body 5 can reach the light receiving unit 11 beyond the partition member 4.

  In addition, the living body 5 is in contact with the contact portion 3 and the partition member 4. As described above, for example, if the contact portion 3 is a housing having an opening surrounding the sensor 1, it is possible to prevent light from the outside from entering during measurement.

  As described above, the measuring apparatus according to the present embodiment can receive the reflected light from inside the living body while eliminating the light unnecessary for the measurement from reaching the light receiving unit 11.

  In FIG. 3, since the upper end of the partition member 4 is located higher than the contact portion 3, when the living body 5 comes into contact with the partition member 4 and the contact portion 3, the partition member 4 contacts the living body 5 as shown in the figure. It becomes a form to bite. In order to prevent this, the height of the partition member 4 may be adjusted. For example, an elastic body such as a spring may be provided inside the partition member 4 so that the living body 5 can push in the partition member 4 so that the position of the upper end of the partition member 4 can be lowered.

  In addition, a coating material that reflects light is applied to the side of the partition member 4 that has the light emitting portion 12, that is, the light shielding surface 413 on the second planar region 16 side, and the state after application is more than the state before application. , More light may be reflected. Thereby, the light from the light emission part 12 is spread | diffused more, and the ratio of the light which reaches | attains a biological body may increase.

  The partition member 4 may be bonded to the sensor 1, or may be bonded or bonded to the substrate 2 or the contact portion 3. FIG. 4 is a diagram illustrating another example of the cross section of the sensor portion of the measuring apparatus according to the first embodiment. The cross section of FIG. 4 is a direction orthogonal to the cross sectional direction of FIG. In FIG. 4, the partition member 4 includes a surface 414 that contacts the substrate 2 in addition to the sensor contact surface 411. The partition member 4 may be bonded to the substrate 2 on the surface 414 that contacts the substrate 2. Moreover, a groove | channel may be provided in the contact part 3, and the partition material 4 may be supported by inserting the partition material 4 in the said groove | channel. By eliminating the gap as much as possible as shown in FIG. 4, it is also possible to prevent light that travels from the second spatial region on the second planar region 16 side to the first spatial region on the first planar region 15 side.

As described above, according to the present embodiment, stray light from the light emitting unit 12, reflected light from the surface of the living body, and the like are prevented from directly reaching the light receiving unit 11, and the signal to noise ratio (S / N) is increased. be able to.
(Second Embodiment)
The measuring apparatus according to the second embodiment includes a cover 6 that covers the sensor 1 and whose upper surface transmits light in order to protect the sensor 1 and improve the durability of the measuring apparatus. FIG. 5 is a diagram illustrating an example of a cross section of a sensor portion of the measuring apparatus according to the second embodiment. Description of the same points as in the first embodiment will be omitted.

  The cover 6 shown in FIG. 5 has a rectangular parallelepiped shape in which the bottom surface on the substrate 2 side is opened, and the overall cross-sectional shape is a reverse concave (reverse U-shaped) structure. Here, this cover is referred to as a rectangular parallelepiped cover. As shown in FIG. 5, the rectangular parallelepiped cover 6 is attached so as to cover the sensor 1 with the open part facing down. Although the living body side of the partition member 4 in the first embodiment is the contact surface 412, the cover 6 is interposed between the partition member 4 and the living body 5 in the second embodiment. In that case, it is desirable to make the partial area | region of the cover 6 between the partition material 4 and the biological body 5 light-impermeable. By doing so, it can be expected that stray light due to the partial region of the cover 6 is prevented. Alternatively, it is also possible to configure such that the partition member 4 is directly exposed to the contact surface of the living body 5 without interposing a part of the cover 6 between the partition member 4 and the living body 5. In this case, it is necessary to provide an opening in a part of the cover 6 corresponding to the exposed portion of the partition member 4. This structure can also be expected to prevent stray light.

  As shown in FIG. 5, the partition member 4 can prevent light reflected from the surface of the living body 5 or the upper surface inside the cover 6 from entering the light receiving unit 11. On the other hand, the light that enters the living body 5 and is reflected by the inside of the living body 5 can reach the light receiving unit 11 through the partition material 4. Thereby, it is possible to exclude light unnecessary for measurement reaching the light receiving unit 11.

  FIG. 6 is a diagram illustrating another example of the cross section of the sensor portion of the measuring apparatus according to the second embodiment. FIG. 6 shows a case where a cover 6 (convex lens structure) having a circular arc cross section is provided. Here, this cover is referred to as a hemispherical cover.

  Even when the hemispherical cover 6 is provided, the partition material 4 prevents the reflected light from the surface of the living body 5 or the upper surface inside the cover 6 from entering the light receiving unit 11, as in the case of providing the cuboid cover 6. it can. On the other hand, the light that enters the living body 5 and is reflected by the inside of the living body 5 can reach the light receiving unit 11. Further, since the arc-shaped cover 6 is curved, it is easier to be in close contact with the living body 5 than the rectangular parallelepiped cover 6, and as a result, it is easier to prevent the intrusion of external light. Thereby, the light from the light emitting unit 12 easily enters the living body 5, and the reflected light from the inside of the living body easily reaches the light receiving unit 11. Therefore, the signal-to-noise ratio (S / N) can be increased when the hemispherical cover 6 is provided than when the hemispherical cover 6 is provided.

  Regardless of the structure of the cover 6, the inside of the cover 6 may be filled with a transmission material or may be hollow. As shown in FIG. 6, the diffusion material 7 may be included in the space inside the cover 6 on the second planar region 16 side. Due to the diffusion material, the light from the light emitting unit 12 is further diffused, and the ratio of the light reaching the living body is increased. Further, as described in the first embodiment, a coating material that reflects light may be applied to the light shielding surface 413 on the second planar region 16 side.

  As described above, according to the present embodiment, the durability of the measuring apparatus can be improved by providing the cover 6. Further, by using the cover 6 having a circular section, the reflected light on the upper surface inside the cover 6 can be suppressed. Moreover, the ratio of the light reaching the living body can be increased by using the diffusion material in the spatial region including the light emitting unit 12 of the sensor by the cover 6.

(Third embodiment)
In the embodiments so far, it is assumed that the sensor 1 includes one light receiving unit 11. The third embodiment assumes a case where the sensor 1 has a plurality of light receiving units 11 and light emitting units 12.

  FIG. 7 is a diagram illustrating an example of measurement by the measurement apparatus according to the third embodiment. The sensor 1 of the present embodiment includes a first light receiving unit 111, a second light receiving unit 112, and a light emitting unit 12. Moreover, the 1st partition material 41 and the 2nd partition material 42 are provided. Others are the same as those in the first or second embodiment. A description of the same points as in the first or second embodiment will be omitted. In FIG. 7, the cover 6 is provided as in the second embodiment, but may be omitted.

  As shown in FIG. 7, the first partition member 41 and the second partition member 42 are provided so as to protrude in the direction opposite to the light entering direction from the living body, similarly to the partition member 4 of the first embodiment. It has been. Further, the contact area between the first partition member 41 and the sensor 1 is located between the first light receiving unit 111 and the light emitting unit 12. The second light receiving unit 112 is disposed in a direction opposite to the direction from the first light receiving unit 111 toward the first partition member 41. The contact area between the second partition member 42 and the sensor 1 is located between the first light receiving unit 111 and the second light receiving unit 112.

  As shown in FIG. 7, consider a case where light that has entered the living body 5 is reflected by a shallow portion and a deep portion inside the living body 5. The first light receiving unit 111 receives light reflected from the shallow portion, and the second light receiving unit 112 receives light reflected from the deep portion. The light reflected by the shallow portion may reach not only the first light receiving unit 111 but also the second light receiving unit 112, but is blocked by the second partition member 42. As described above, the second partition member 42 can prevent light that does not need to be received from entering the second light receiving unit 112.

  FIG. 8 is a diagram illustrating another example at the time of measurement by the measurement apparatus according to the third embodiment. Although FIG. 7 shows the case where there is one light emitting unit 12, in FIG. 8, the light emitting unit 12 of the sensor 1 is assumed to be the first light emitting unit 121 and the second light emitting unit 122. The first light emitting unit 121 and the second light emitting unit 122 may be configured to emit light having different wavelengths. For example, for the calculation of Sp02, the first light emitting unit 121 may emit red light, and the second light emitting unit 122 may emit infrared light.

  It is assumed that the light emitted from the first light emitting unit 121 is reflected by a shallow portion inside the living body 5 after entering the living body 5. On the other hand, it is assumed that the light emitted from the second light emitting unit 122 is reflected by a deep portion inside the living body 5 after entering the living body 5. The light reflected by the shallow portion may reach not only the first light receiving unit 111 but also the second light receiving unit 112, but is blocked by the second partition member 42. As described above, the second partition member 42 can prevent light that does not need to be received from entering the second light receiving unit 112. A partition material may also be provided between the first light emitting unit 121 and the second light emitting unit 122.

  As described above, according to the present embodiment, even when a plurality of light receiving units or light emitting units are provided, arrival of light that does not need to be received can be prevented, and Sp02 and the like can be easily measured.

  Although one embodiment of the present invention has been described above, these embodiment are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Sensor part 11 Light-receiving part 111 1st light-receiving part 112 2nd light-receiving part 12 Light-emitting part 13 Non-transmissive material 14 Transparent material 15 1st plane area 16 2nd plane area 2 Board | substrate 3 Contact part (housing | casing)
4 partition material 41 first partition material 411 sensor contact surface 412 biological contact surface 413 partition surface 414 surface in contact with substrate 42 second partition material 5 biological body 6 cover 7 diffusion material

Claims (8)

A sensor having a first light receiving portion capable of receiving light from a living body;
A partition material that is provided so as to protrude in a direction opposite to the light entering direction from the living body from a location different from the first light receiving portion of the sensor;
A biological information measuring device comprising: The sensor further includes a light emitting unit,
The biological information measuring device according to claim 1, wherein a region where the partition member and the sensor are in contact is located between the light emitting unit and the first light receiving unit. The biological information measuring device according to claim 1, further comprising a contact portion that surrounds the sensor and has an upper end at a position higher than an upper surface of the sensor irradiated with light from the living body. A cover that includes the sensor and the partition material on the inner side, and whose upper surface transmits light;
The biological information measuring device according to any one of claims 1 to 3, wherein the partition member is interposed between the cover and the sensor. The biological information measuring device according to claim 4, wherein a cross section of the cover has an arc shape. 6. The biological information measurement according to claim 4, wherein a diffusion material is included in a three-dimensional region on the side where the first light receiving unit does not exist, among the three-dimensional regions partitioned by the partition material inside the cover. apparatus. The biological information measuring device according to any one of claims 1 to 6, wherein a side surface of the partition member opposite to the first light receiving unit has a light reflectance higher than that of the side surface on the first light receiving unit side. . The sensor further includes a second light receiving unit capable of receiving light from a living body in a direction opposite to the direction from the first light receiving unit toward the partition member,
A second partition member that is provided so as to protrude in a direction opposite to the light entering direction from the living body from between the first light receiving unit and the second light receiving unit of the sensor; The biological information measuring device according to any one of claims 1 to 7, further comprising: