JP4476665B2 - Biological information measuring device - Google Patents

Description

  The present invention relates to a biological information measuring apparatus capable of measuring biological information such as a pulse rate while being worn on a wrist (arm).

  Due to the recent increase in interest in health management, various biological information measuring devices capable of measuring various biological information such as pulse rate while being worn on the wrist (arm) or the like have been provided (for example, Patent Document 1). reference).

Among this type of biological information measuring device, for example, a device that calculates a pulse rate irradiates light toward a living body while being worn on the wrist, and backscattered light from blood in a blood vessel by a pulse sensor or the like. , And a pulse signal is extracted from the backscattered light to calculate the pulse rate. In particular, since the pulse rate can be easily measured while wearing on the wrist, it is easily used by the user.
JP 2001-78973 A (paragraph numbers 0011-0031, FIG. 1 to FIG. 7)

  The biological information measuring apparatus irradiates light toward a living body from a light emitting unit such as an LED (Light Emitting Diode), and also emits backscattered light from the living body using a light receiving unit such as a PD (Photo Diode). Light is received, and biological information such as a pulse is detected based on the amount of received backscattered light.

  However, when PD receives backscattered light from a living body, there is a possibility that it directly receives part of the light emitted from the LED. Since the directly incident light does not contain any information from the living body, noise (noise) increases, resulting in a decrease in the S / N ratio and saturation of the detection voltage. For this reason, there is a possibility that biological information cannot be accurately detected.

  Even if the biological information measuring device is securely attached to the wrist, the living tissue propagates to the lower surface of the main body where the LED and PD are arranged and the biological surface under strong sunlight such as outdoors. There is a possibility that external light may be incident on the PD without being sufficiently attenuated. This external light causes a decrease in the S / N ratio, as described above.

  The present invention has been made in view of such circumstances, the purpose of which is to reduce as much as possible that light is directly incident on the light receiving unit from the external light propagating through the light irradiation unit or biological tissue, An object of the present invention is to provide a biological information measuring apparatus capable of improving the S / N ratio.

  The present invention provides the following means in order to solve the above problems.

  The biological information measuring apparatus of the present invention comprises a main body, a fixing means for fixing the main body to an arm with the lower surface of the main body facing the biological surface, and light directed toward the living body in contact with the biological surface. A light emitting unit that irradiates, and a light receiving unit that receives backscattered light from a living body among light emitted by the light emitting unit and generates a biological information signal according to the amount of received light. A biological sensor unit provided on a lower surface; and a biological information calculation unit that is provided on the main body and calculates biological information based on the biological information signal, between the light emitting unit and the light receiving unit. It is characterized in that a light shielding part for preventing light emitted from the light emitting part from directly entering the light receiving part is provided.

  In the biological information measuring apparatus according to the present invention, the fixing means irradiates light toward the living body from the light emitting unit after the main body is attached to the wrist (arm) with the lower surface of the main body facing the biological surface side. The irradiated light is absorbed and scattered by tissues and blood such as fat and muscle in the living body, and a part of the irradiated light is detected by the light receiving unit as backscattered light. The detected light varies as the blood volume changes due to pulsation. The light receiving unit receives the backscattered light and generates a pulse signal (biological information signal) corresponding to the change in the amount of received light. Then, the biological information calculation unit can perform predetermined processing on the biological information signal to detect biological information such as the pulse rate.

  When detecting the biological information, a light shielding unit is provided between the light emitting unit and the light receiving unit, so that the light emitted from the light emitting unit may be directly incident on the light receiving unit. Without irradiation, it is reliably irradiated toward the living body. Therefore, the light receiving unit can concentrate the backscattered light from the living body intensively. Therefore, S / N can be improved, and biological information can be detected more accurately.

  Further, the biological information measuring apparatus of the present invention is the biological information measuring apparatus of the present invention, wherein the biological sensor unit is disposed at a substantially center of the lower surface of the main body, and the lower surface of the main body includes the lower surface and the lower surface. A reflection groove for reflecting external light propagating through the living tissue to the living body surface from the center of the lower surface toward the outer edge of the lower surface is formed.

In the biological information measuring apparatus according to the present invention, when the biological information is detected by attaching the main body to the wrist (arm), it propagates through the biological tissue under strong sunlight such as outdoors. Even if the external light becomes large, it is reflected again toward the outer edge portion on the incident side by the reflection groove. Therefore, it is possible to prevent as much as possible external light from directly entering the biosensor unit. That is, the light receiving unit can receive backscattered light from the living body in a concentrated manner without the influence of external light. Therefore, S / N can be improved, and biological information can be detected more accurately. The biological information measuring device of the present invention is the biological information measuring device of the present invention, wherein the reflection groove is the main body. It has the reflective surface where the surface inclined toward the outer edge part of the lower surface from the center of the lower surface.

  In the biological information measuring apparatus according to the present invention, the external light that has propagated through the living tissue to the lower surface of the main body and the surface of the living body is repeatedly reflected between the lower surface of the main body and the surface of the living body from the outer edge of the main body toward the center. The reflection surface reliably reflects the light toward the outer edge. Therefore, it is possible to more reliably prevent external light from directly entering the light receiving unit.

  The biological information measuring device of the present invention is the biological information measuring device of the present invention, wherein the reflection surface is formed in a circular shape centering on the biological sensor unit, and the reflection groove is centered on the biological sensor unit. And a plurality of the reflecting surfaces in the radial direction.

  In the biological information measuring apparatus according to the present invention, since a plurality of circular reflecting surfaces are formed in the radial direction with the biological sensor portion as the center, it is possible to more reliably prevent external light from entering. That is, the light incident on the outer edge is reflected to the outer edge by the reflecting surface formed on the outermost edge, and the light intensity is reduced. The light that has passed through this reflecting surface is similarly reflected to the outer edge side by the next reflecting surface, and the light intensity further decreases. As described above, the light intensity of the external light is gradually reduced toward the center of the main body, so that the external light can be more reliably prevented from entering the biosensor unit.

  The biological information measuring apparatus of the present invention is characterized in that, in the biological information measuring apparatus of the present invention, the reflecting surface is formed in a spiral shape with the biological sensor section as a center.

  In the biological information measuring apparatus according to the present invention, since the reflection surface is formed in a spiral shape with the biological sensor portion as the center, the light incident on the outer edge portion is surrounded by the reflection surface formed on the outermost edge side. Reflected by the part side, the light intensity decreases. The light that has passed through this reflecting surface is similarly reflected to the outer edge side by the next reflecting surface, and the light intensity further decreases. As described above, the light intensity of the external light is gradually reduced toward the center of the main body, so that the external light can be more reliably prevented from entering the biosensor unit. Moreover, since it is helical, it is easy to form a reflective surface.

  The biological information measuring device according to the present invention is the biological information measuring device according to any one of the present invention described above, wherein the lower surface of the main body is external light incident between the lower surface and the biological surface. Is formed of a black member that reflects the light with a reflectance of 10% or less.

  In the biological information measuring apparatus according to the present invention, the external light propagating through the biological tissue to the lower surface of the main body and the surface of the biological body, i.e., the light propagating through the biological tissue from the outer edge of the main body toward the center, The light intensity decreases each time the reflection is repeated with the surface of the living body and the light is reflected on the lower surface of the main body. Therefore, it is possible to reliably prevent the incidence of external light.

  According to the biological information measuring apparatus of the present invention, since the light shielding unit is provided between the light emitting unit and the light receiving unit when detecting biological information, the light emitted from the light emitting unit is provided. Is not directly incident on the light receiving part, but is reliably irradiated toward the living body. Therefore, since the light receiving unit can concentrate the backscattered light from the living body intensively, the S / N can be improved and the living body information can be detected more accurately.

  Hereinafter, an embodiment of a biological information measuring apparatus according to the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 to 7, the biological information measuring apparatus 1 according to the present embodiment is a wristwatch type and calculates a pulse rate that is biological information in a state of being worn on a wrist (arm) A.

  The biological information measuring apparatus 1 includes a housing (main body) 2 containing various electric parts and electronic parts, and fixing means for attaching the housing 2 to the wrist A with the lower surface 2a of the housing 2 facing the biological surface B side. 3 is provided.

  On the lower surface 2a of the housing 2, an LED (Light Emitting Diode) 4 that emits light toward the living body while being in contact with the surface B of the living body, and a living body of the light irradiated by the LED 4 A biological sensor unit 6 having a PD (Photo Diode) (light receiving unit) 5 that receives a backscattered light from the light source and generates a pulse signal (biological information signal) corresponding to the amount of received light is disposed. The biosensor unit 6 is disposed at the approximate center of the lower surface 2 a of the housing 2.

  The housing 2 is provided with a data processing unit (biological information calculation unit) 7 that calculates the pulse rate based on the generated pulse signal.

  As shown in FIG. 1, the housing 2 is made of a metal material such as plastic or aluminum and has a predetermined thickness, for example, a substantially rectangular shape when viewed from above. A cover glass 10 having a substantially square shape is fitted in the central portion of the upper surface 2b of the housing 2, and a display unit 11 for displaying the calculated pulse rate and other various information on the inside of the cover glass 10. Is arranged.

  Further, as shown in FIGS. 5 and 6, a main board 12 is provided in the housing 2, and the data processing section 7, the display section 11, the rechargeable battery 13, The memory 14 for recording the pulse rate, the sub-board 15 and other various electronic components are electrically connected by mounting or wiring.

  The data processing unit 7 includes an IC component such as a CPU, and after amplifying the pulse signal generated by the PD 5 with an amplifier or the like, it performs predetermined processing such as fast Fourier transform processing (FFT processing). It has a function of calculating the pulse rate by analyzing the processing result. Further, the data processing unit 7 records the calculated pulse rate in the memory 14 and causes the display unit 11 to display the pulse rate based on input from each button 20 described later. Further, the data processing unit 7 has a function of comprehensively controlling other components.

  The display unit 11 is a liquid crystal display such as an LCD (Liquid Crystal Display), for example. In addition to the above-described pulse rate, for example, a time display function for displaying a time counted by a crystal resonator (not shown) or other It has a function to display various information. For example, the time, date, day of the week, remaining power amount of the rechargeable battery 13 and the like can be displayed.

  Further, as shown in FIG. 1, the housing 2 includes a plurality of buttons 20, for example, three buttons 20 disposed on the lower surface of the display unit 11 on the upper surface 2 b of the housing 2 and the side surfaces of the housing 2. One button 20 is provided. Various operations can be performed by pressing these buttons 20. For example, operations such as starting measurement of pulse rate, stopping measurement, switching display of pulse rate and time, and transmitting pulse rate data recorded in memory 14 to an external device can be performed. Yes.

  Furthermore, an external connection terminal (charging means) 21 is provided on the side surface of the housing 2 to supply power to the rechargeable battery 13 from outside such as a charger. A cover or the like may be attached to cover the external connection terminal 21 to protect the external connection terminal 21. By doing so, it is possible to protect the external connection terminal 21 from water drops, dust, and the like, which is more preferable. Further, not only the external connection terminal 21, but also a charger and a transformer for supplying power to the housing 2 may be provided, and the rechargeable battery 13 may be charged in a non-contact state.

  Further, as shown in FIG. 6, a through hole 22 that penetrates the outside and the inside of the housing 2 is formed at the center of the lower surface 2 a of the housing 2, and the cover glass 23 covers the housing so as to close the through hole 22. 2 is fixed. The LED 4 and the PD 5 are arranged adjacent to each other in a direction perpendicular to the longitudinal direction of the housing 2 so as to contact the inside of the cover glass 23. At this time, the LED 4 and the PD 5 are mounted on one end side of the flexible substrate 24 electrically connected to the sub substrate 15 and are electrically connected to the sub substrate 15. The pulse signal generated by the PD 5 is sent to the data processing unit 7 via the flexible board 24, the sub board 15, and the main board 12.

  Also, as shown in FIGS. 2 and 6, a light shielding plate (light shielding portion) 27 is provided between the LED and the PD to prevent light emitted from the LED from directly entering the PD. Yes. The light shielding plate 27 is formed in a plate shape with a metal such as plastic or aluminum, and is provided on the flexible substrate 24 so as to be in contact with the cover glass 23. The light shielding plate 27 may be provided on the inner surface of the cover glass 23 so as to be in contact with the flexible substrate 24.

  Moreover, the biosensor unit 6 of the present embodiment includes a contact detection unit 30 that detects whether or not the LED 4 and the PD 5 are in contact with the living body surface B, as shown in FIGS. 2, 5, and 6. Yes.

  The contact detection means 30 has a pair of electrodes 30a and 30b, and the pair of electrodes 30a and 30b are arranged on the lower surface 2a of the housing 2 with the LED 4 and the PD 5 interposed therebetween. That is, the pair of electrodes 30 a and 30 b, the LED 4 and the PD 5 are arranged in a line in a direction orthogonal to the longitudinal direction of the housing 2. The pair of electrodes 30 a and 30 b are provided so that the distal ends thereof slightly protrude from the lower surface 2 a of the housing 2, and the base end side is provided so as to be electrically connected to the sub-substrate 15.

  The pair of electrodes 30a and 30b has a function of detecting whether or not the living body surface B is in contact based on a potential difference between the electrodes. The data processing unit 7 is set to control the operation of the LED 4 so as to irradiate light from the LED 4 when, for example, it is detected that it is in contact with the living body surface B in response to the detection result. . In addition to this case, for example, when it is detected that the living body surface B is not touched, the FFT processing may be set not to be performed.

  Further, the lower surface 2a of the housing 2 is incident between the lower surface 2a and the living body surface B when the housing 2 is attached to the wrist A as shown in FIGS. A reflection groove 35 is formed that reflects the incoming external light from the center of the lower surface 2a toward the outer edge 2c. The reflection groove 35 is formed in a circular shape centered on the biosensor unit 6 and a reflection surface 36 formed so that the surface is inclined from the lower surface 2a of the housing 2 toward the outer edge portion 2c is directed in the radial direction. Have more than one.

  As shown in FIG. 1, the fixing means 3 has a first band 40 and a second band 41 that are attached to the wrist A with the proximal end attached to the housing 2. The first band 40 and the second band 41 are provided in the longitudinal direction of the housing 2 so as to face each other with the housing 2 interposed therebetween.

  A buckle 40a and a tongue 40b are attached to the tip of the first band 40. The second band 41 has a plurality of insertion holes 41 a into which the tongue 40 b is inserted along the longitudinal direction of the second band 41. Thereby, the lengths of the first band 40 and the second band 41 can be adjusted according to the thickness of the wrist A of the user.

  A case will be described in which the pulse rate is calculated with the biological information measuring apparatus 1 configured as described above attached to the wrist A.

  First, as shown in FIGS. 3 and 4, the bands 40 and 41 are wound so as to wind the wrist A of the user, and the tongue 40b of the first band 40 is set to the second according to the size of the wrist A. The housing 2 is attached to the wrist A by being inserted into the insertion hole 41 a of the band 41. When the housing 2 is attached to the wrist A, the living body surface B and the lower surface 2a of the housing 2 are in close contact with each other.

  When the biological surface B comes into contact with the lower surface 2a of the housing 2, the pair of electrodes 30a and 30b come into contact with the biological surface B. In particular, the pair of electrodes 30 a and 30 b are arranged so as to protrude slightly from the lower surface 2 a of the housing 2, so that they easily come into contact with the biological surface B. When the pair of electrodes 30a and 30b come into contact with the living body surface B, discharge is performed through the living body surface B, and the voltage between both electrodes decreases. In response to this voltage drop (for example, lower than a certain threshold), the data processing unit 7 detects that the pair of electrodes 30a and 30b are in contact with the biological surface B reliably. That is, it is detected that the biological sensor unit 6 including the LED 4 and the PD 5 is in contact with the biological surface B reliably.

  When it is detected that the LED 4 and the PD 5 are in contact with the living body surface B, the data processing unit 7 irradiates light from the LED 4 toward the living body. At this time, since the shielding plate 27 is disposed between the LED 4 and the PD 5, a part of the irradiated light does not enter the PD 5. That is, the irradiated light is reliably irradiated toward the living body.

  The irradiated light is absorbed and scattered by tissues and blood such as fat and muscle in the living body, and a part of the irradiated light is detected by the PD 5 as backscattered light. The detected light varies as the blood volume changes due to pulsation. The PD 5 receives the backscattered light, generates a pulse signal (biological information signal) corresponding to the change in the amount of received light, and outputs the pulse signal to the data processing unit 7. That is, since the amount of backscattered light of the light emitted from the LED 4 varies according to the blood flow variation in the artery and arteriole in the wrist A (living body), the PD 5 is a pulse of the artery, that is, a pulse wave. The backscattered light can be received according to. Thereby, PD5 can generate a pulse signal.

  At this time, as described above, the light emitted from the LED 4 does not directly enter the PD 5 and is surely emitted toward the living body, so that the PD 5 concentrates the backscattered light from the living body intensively. Shine. Therefore, noise and the like can be suppressed, and the S / N ratio can be improved.

  The data processing unit 7 amplifies the transmitted pulse signal, performs predetermined processing such as FFT processing, and then performs analysis to calculate the pulse rate. As described above, the calculated pulse rate is calculated based on the pulse signal in which the influence of noise or the like is reduced, and thus becomes a more accurate value. Then, the data processing unit 7 records the calculated pulse rate in the memory 14 and displays it on the display unit 11 based on the operation of each button 20.

  Since the user can confirm the pulse rate easily calculated by displaying the calculated pulse rate on the display unit 11 by pressing each button 20 when necessary, it is easy to use. In addition, the user can easily check other information other than the pulse rate, for example, the time and the remaining power of the rechargeable battery 13 by the operation of each button 20.

  Also, when used outdoors, etc., and exposed to strong direct sunlight on the surface of the living body, it is difficult to obtain a sufficient amount of attenuation only by propagation in the skin surface of the wrist A or in the living tissue. Although going toward the biosensor unit 6, as shown in FIG. 7, external light can be prevented from entering the biosensor unit 6 by the reflection groove 35 formed on the lower surface 2 b of the housing 2.

  That is, the light that has propagated through the living tissue and entered from the outer edge 2c is first reflected toward the outer edge 2c again by the reflecting surface 36 formed on the outermost edge 2c side, so that the light intensity decreases. . The light that has passed through the first reflecting surface 36 is similarly reflected toward the outer edge portion 2 c by the next reflecting surface 36. Thus, since the reflective surface 36 is formed in multiple numbers centering on the biosensor part 6, the light intensity of external light falls stepwise from the outer edge part 2c toward the center. Therefore, it is possible to prevent external light from directly entering the biosensor unit 6 as much as possible. That is, it is possible to prevent external light from directly entering the PD 5 as much as possible.

  Therefore, the influence of external light can be eliminated, the S / N ratio can be improved, and the pulse rate can be calculated with high accuracy.

  In addition, when charging the rechargeable battery 13, for example, charging can be performed by connecting a charging cord or the like connected to a charger to the external connection terminal 21, and a normal battery is separately prepared. do not have to. Therefore, the maintenance cost can be reduced. It should be noted that a sound output means such as a buzzer for outputting sound is provided in the housing 2, and when the charge amount of the rechargeable battery 13 decreases to near “0”, the sound is output and the charging time (charging timing) is reached. You may comprise so that it may notify.

  As described above, according to the biological information measuring apparatus 1 of the present embodiment, the light shielding plate 27 is provided between the LED 4 and the PD 5 when calculating the pulse rate. Is not directly incident on the PD 5 and is reliably irradiated toward the living body. Accordingly, the PD 5 can intensively receive the backscattered light from the living body, so that the S / N can be improved and the pulse rate can be calculated more accurately.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the reflection groove is configured to have a plurality of reflection surfaces formed in a circular shape around the biosensor unit in the radial direction, but may be one instead of a plurality. Moreover, although the reflective surface was formed in the circular shape centering on a biosensor part, it is not restricted to a circular shape. For example, the reflection surface may be formed in a spiral shape with the biosensor portion as the center. In this case, it is easy to form a reflection groove on the lower surface of the housing in addition to the effects similar to the above embodiment.

  The lower surface of the housing may be formed of a black member that reflects external light incident between the lower surface and the living body surface with a reflectance of 10% or less. In this case, each time the external light is reflected by the lower surface of the housing, the light intensity decreases, so it is possible to prevent the external light from directly entering the biosensor unit more reliably by combining with the reflection groove, Is preferred.

  Moreover, in the said embodiment, although demonstrated using the pulse rate as an example as biometric information, not only a pulse rate but biometric information may be sufficient.

  Moreover, you may add functions, such as a radio | wireless communication means which can be communicated by radio | wireless with another electronic device, to a housing. In this way, the pulse rate recorded in the memory can be transmitted to an external electronic device or various information can be obtained in the memory by wireless communication such as Bluetooth.

It is a front view which shows one Embodiment of the biological information measuring device which concerns on this invention. It is a rear view of the biological information measuring device shown in FIG. It is a side view which shows the state which mounted | wore the wrist with the biological information measuring device shown in FIG. It is a side view which shows the state with which the biological information measuring device shown in FIG. 1 was mounted | worn with the wrist, and the figure seen from the reverse direction to the direction shown in FIG. It is a cross-sectional arrow CC figure of the biological information measuring device shown in FIG. It is a cross-sectional arrow DD figure of the biological information measuring device shown in FIG. It is an expanded sectional view of the reflective groove formed in the biological information measuring device shown in FIG.

Explanation of symbols

B Biological surface 1 Biological information measuring device 2 Housing (main body)
2a Lower surface of main body 2c Outer edge part 3 Fixing means 4 LED (light emitting part)
5 PD (light receiving part)
6 Biosensor unit 7 Data processing unit (Biological information calculation unit)
27 Light shielding part 35 Reflecting groove 36 Reflecting surface

Claims (5)

The body,
Fixing means for fixing the main body to the arm in a state where the lower surface of the main body faces the biological surface side;
A light emitting unit that emits light toward the living body in contact with the surface of the living body, and a biological information signal that receives backscattered light from the living body out of the light emitted by the light emitting unit and that corresponds to the amount of light received A biosensor unit provided on the lower surface of the main body with a light receiving unit for generating
A biological information calculation unit that is provided in the main body and calculates biological information based on the biological information signal;
Between the light emitting unit and the light receiving unit is provided a light shielding unit for preventing light emitted from the light emitting unit from directly entering the light receiving unit ,
The biological sensor unit is arranged at the approximate center of the lower surface of the main body,
The lower surface of the main body is formed with a reflection groove that reflects external light propagating through the living tissue to the lower surface and the biological surface from the center of the lower surface toward the outer edge of the lower surface. Biological information measuring device. The biological information measuring apparatus according to claim 1 ,
The biological information measuring device, wherein the reflection groove has a reflection surface whose surface is inclined from the center of the lower surface of the main body toward an outer edge portion of the lower surface. The biological information measuring apparatus according to claim 2 ,
The reflective surface is formed in a circular shape centered on the biosensor unit,
The biological information measuring device, wherein the reflection groove has a plurality of reflection surfaces in the radial direction with the biological sensor portion as a center. The biological information measuring apparatus according to claim 2 ,
The biological information measuring apparatus, wherein the reflecting surface is formed in a spiral shape with the biological sensor portion as a center. The biological information measuring device according to any one of claims 1 to 4 ,
The biological information measuring device, wherein the lower surface of the main body is formed of a black member that reflects external light propagating through the biological tissue to the lower surface and the biological surface with a reflectance of 10% or less.

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