JP2009201918A - Pulse wave detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulse wave detecting device capable of stably detecting a pulse wave with a simple configuration. <P>SOLUTION: The pulse wave detecting device is provided with: a light emitting part 23 for radiating light toward a finger; and a light receiving part 24 for receiving the light at a position corresponding to the side of the finger, which is reflected from the finger in the light radiated from the light emitting part. The pulse wave detecting device includes a light guide body 31 to have contact with at least the side surface of the finger by an area wider than the light emission area of the light emitting part. The light radiated from the light emitting part is radiated against the finger by way of the light guide body. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pulse wave detection device.

Conventionally, a pulse wave detection device capable of detecting and displaying pulse wave information such as a pulse wave and a pulse rate is known. In addition, a reflection type and a transmission type are generally known as pulse wave detection devices that detect a pulse wave using light. A reflection-type pulse wave detection device irradiates light toward a finger surface from a light emitting unit composed of, for example, an LED (Light Emitting Diode) or the like, while PD (Photo Diode) reflects light reflected from a finger (blood vessel). By receiving the light with a light receiving unit configured by the above, it is possible to detect a change in blood volume as a change in the amount of received light, and to detect a pulse wave or a pulse rate based on the detection result (for example, Patent Documents) 1). As shown in FIG. 7, the pulse wave measuring device (pulse wave detecting device) of Patent Document 1 is composed of a translucent plate 101 made of a glass plate in which the surface of the pulse wave detecting unit 100 is formed flat. When the LED (light emitting unit) 103 emits light toward the finger F in a state where the finger (finger belly) F is in close contact with the outer surface 102 of the optical plate 101, the phototransistor (light receiving unit) 104 is replaced by the LED 103. Of the emitted light, the light reflected from the finger F side can be received.
Further, as shown in FIG. 8, the transmission type pulse wave detection device is arranged at a position where the light emitting unit 203 and the light receiving unit 204 are opposed to each other through the finger F, and is irradiated from the light emitting unit 203 toward the finger F. Among the received light, there is one that detects a pulse wave or the like by receiving light transmitted through the finger F by the light receiving unit 204.
JP-A-9-108192

By the way, in the reflection type pulse wave detection device of Patent Document 1 described above, the light emitting unit 103 and the light receiving unit 104 are the same although the finger F can be easily measured simply by placing it on the measurement surface (translucent plate 101). There is a problem that the optical path formed between the light emitting unit 103 and the light receiving unit 104 becomes narrow, the waveform of the measured pulse wave is easily disturbed, and stable measurement cannot be performed.
On the other hand, in the transmission type pulse wave detection device, since the light emitting unit 203 and the light receiving unit 204 are linearly arranged with the finger F interposed therebetween, the light is hardly affected by reflected light noise on the skin surface. However, if the light emitting unit 203 and the light receiving unit 204 are arranged as shown in FIG. 9, there is a risk that a finger or nail may be burdened, or a clip structure for pinching the finger F There is a problem that the operability is inferior.

  Therefore, the present invention provides a pulse wave detection device capable of stably detecting a pulse wave with a simple configuration.

  In order to solve the above-described problem, a pulse wave detection device according to the present invention reflects a light emitting unit that emits light toward a finger and the light emitted from the light emitting unit from the finger side. A light-receiving unit that can receive light at a position corresponding to the abdomen of the finger, and includes a light guide that is in contact with at least the side surface of the finger in an area wider than the light-emitting area of the light-emitting unit, The light emitted from the light emitting unit is emitted to the finger through the light guide.

With this configuration, the finger is irradiated with light from the entire contact surface with the light guide, and the light reflected on the abdomen side of the finger is received by the light receiving unit. Waves can be detected. That is, the optical path formed between the light emitting part and the light receiving part can be ensured wider (more) than in the conventional reflection type, and stable pulse wave measurement can be performed.
Further, the pulse wave can be detected simply by placing the finger so that the light guide and the side surface of the finger are in contact with each other. That is, the pulse wave can be detected with a simple configuration without placing a burden on the finger or the nail unlike the conventional transmission type.

Moreover, the pulse wave detection device according to the present invention is characterized in that the light guide is formed so as to surround the light receiving portion.
By comprising in this way, the optical path formed between a light emission part and a light-receiving part can be ensured more widely (many), and more stable pulse wave measurement can be performed.

The pulse wave detection device according to the present invention is characterized in that a surface other than a contact surface with the finger in the light guide is subjected to a reflective surface processing.
By comprising in this way, the light irradiated from the light emission part is reflected in surfaces other than a contact surface, and the light is irradiated toward a finger from the substantially whole surface of a contact surface with the finger in a light guide. Can do. That is, light is irradiated to the finger from a plurality of locations, and a plurality of optical paths are formed between the light receiving unit and the pulse wave can be detected stably. Moreover, all the light irradiated from the light emission part is irradiated to a finger | toe from a contact surface, and the utilization efficiency of light can be improved.

Further, in the pulse wave detection device according to the present invention, the contact surface of the light guide is tapered so that a region where the finger is placed narrows toward a side where the light receiving unit is disposed. It is characterized by being formed.
By comprising in this way, the adhesiveness of a light guide and a finger can be improved when a finger is mounted. In other words, when the light emitted from the light emitting unit is received by the light receiving unit via the light guide and the pulse wave is detected, the influence of noise such as external light can be reduced, and the pulse wave can be accurately detected. Can be detected.

  Furthermore, the pulse wave detection device according to the present invention includes a light emitting unit that emits light toward a finger, and a light receiving unit that can receive light reflected from the finger side out of light emitted from the light emitting unit. And a plurality of the light emitting portions are provided at positions corresponding to the side surfaces of the finger, and the reflected light of the light is reflected by the light receiving portion provided at a position corresponding to the abdomen of the finger. It is configured to be capable of receiving light.

With this configuration, a plurality of optical paths formed between the light emitting unit and the light receiving unit can be reliably ensured. Accordingly, since more optical paths can be secured than in the conventional reflection type, stable pulse wave measurement can be performed.
Further, the pulse wave can be detected simply by placing the finger so that the side surface and the abdomen of the finger are brought into contact with the place where the light emitting unit and the light receiving unit are arranged. That is, the pulse wave can be detected with a simple configuration without placing a burden on the finger or the nail unlike the conventional transmission type.

According to the pulse wave detection device of the present invention, the finger is irradiated with light from the entire contact surface with the light guide, and the light reflected from the abdomen side of the finger is received by the light receiving unit. By doing so, the pulse wave can be detected. That is, the optical path formed between the light emitting unit and the light receiving unit can be secured wider (more) than the conventional reflective type, and there is an effect that stable pulse wave measurement can be performed.
Further, the pulse wave can be detected simply by placing the finger so that the light guide and the side surface of the finger are in contact with each other. That is, there is an effect that a pulse wave can be detected with a simple configuration without placing a burden on a finger or a nail unlike a conventional transmission type.

(First embodiment)
Next, a first embodiment of a pulse wave detection device according to the present invention will be described with reference to FIGS.

(Pulse wave detector)
FIG. 1 is a schematic block diagram of the pulse wave detection device.
As shown in FIG. 1, the pulse wave detection device 10 irradiates light on the finger F, receives the reflected light, and converts the detection result into a signal from the pulse wave detection unit 11 and the pulse wave detection unit 11. CPU 12 for receiving various signals and performing various calculations, a display unit 13 for displaying the waveform of a pulse wave from the calculation result by CPU 12, an input unit 14 for giving various setting conditions to CPU 12, A storage unit 15 including a RAM that stores pulse wave data converted into a digital signal and the like, and an oscillation unit 16 that supplies a clock to the CPU 12 are provided.

  In addition, each part which comprises other than the pulse wave detection part 11 is comprised with a personal computer, for example, the input part 14 respond | corresponds to a keyboard and the display part 13 corresponds to a display, respectively. Further, a part other than the pulse wave detection unit 11 may be constituted by a wristwatch type device, or the result may be displayed on the television based on the information from the pulse wave detection unit 11.

(Pulse wave detector)
FIG. 2 is a perspective view of the pulse wave detection unit 11.
As shown in FIG. 2, the pulse wave detection unit 11 includes a box-shaped sensor case 21, a light emitting unit 23 made of, for example, an LED placed on the upper surface 21 a of the sensor case 21, and the upper surface of the sensor case 21. A light guide 31 that is placed and connected to the light emitting unit 23 and a light receiving unit 24 that is disposed in a component storage space 22 that is configured inside the sensor case 21 and is made of, for example, a PD. Note that the length along the longitudinal direction of the finger F in the sensor case 21 is formed to be approximately the same length as the first joint of the finger F.

  Further, a translucent plate 29 made of a translucent glass plate is attached to the upper surface 21 a of the sensor case 21, and the abdomen of the finger F is brought into close contact with the translucent plate 29. Further, the light receiving unit 24 is disposed on the component housing space 22 side of the translucent plate 29 so that the finger F is directed. The light emitting unit 23 and the light receiving unit 24 are connected to a circuit board (not shown) arranged in the component storage space 22. The circuit 12 is configured to be communicable with the CPU 12 so that the detection result of the light receiving unit 24 can be calculated and a pulse wave or the like can be displayed.

  The light guide 31 is formed in a substantially U shape in plan view, and is disposed on the upper surface 21 a of the sensor case 21 so as to surround the light receiving unit 24. The finger F can be placed on the U-shaped inner region. The light guide 31 is formed in a three-dimensional shape having a substantially U-shaped horizontal cross section, and the contact surface 32 with the finger F is formed of a light-transmitting surface capable of transmitting light from the light emitting unit 23. The contact surface 32 has an area larger than the light emitting area of the light emitting unit 23, and the finger F is configured to contact the contact surface 32 having an area larger than the light emitting area of the light emitting unit 23.

The contact surface 32 is formed in a tapered shape inclined inwardly (toward the light receiving unit 24) so that a region where the finger F is placed narrows toward the side where the light receiving unit 24 is disposed. Further, the surface 34 other than the contact surface 32 in the light guide 31 is subjected to mirror processing (reflection surface processing) so that light can be reflected.
The light emitting unit 23 is connected to the U-shaped top side surface 33 of the light guide 31, and the light emitted from the light emitting unit 23 travels while reflecting inside the light guide 31, and from the contact surface 32. Irradiation is directed toward the finger F.

(Function)
Next, an operation of detecting a pulse wave by placing the finger F on the pulse wave detection unit 11 will be described.
3 is a perspective view when the finger F is placed on the pulse wave detector 11, and FIG. 4 is a cross-sectional view (partially front view) along the line AA in FIG.
As shown in FIGS. 3 and 4, the finger F is brought into close contact with the upper surface 21 a of the sensor case 21 of the pulse wave detection unit 11. At this time, the fingertip is placed so as to abut on the top side of the light guide 31. Then, the abdomen 35 of the finger F is disposed so as to contact the translucent plate 29, and the side surfaces 36, 36 of the finger F are disposed so as to contact the contact surface 32 of the light guide 31.

  In this state, the light is emitted from the light emitting unit 23 with the finger F placed on the pulse wave detecting unit 11. The light emitted from the light emitting unit 23 is irradiated to the inside of the light guide 31, and the light is reflected by the surface 34 other than the contact surface 32 and spreads over substantially the entire inside of the light guide 31. Then, the light is applied to the side surfaces 36 and 36 of the finger F from the translucent contact surface 32.

  Then, the irradiated light is absorbed, diffused, and reflected by tissues such as blood vessels (blood), fats and muscles inside the finger F, and a part of the irradiated light passes through the abdomen 35 of the finger F and below it. Is detected by the light receiving unit 24 arranged in the. The light detected by the light receiving unit 24 fluctuates with a change in blood volume due to blood vessel pulsation. The light receiving unit 24 receives light, generates a pulse wave signal corresponding to a change in the amount of received light, and outputs the pulse wave signal to the CPU 12.

  That is, since the amount of reflected light of the light emitted from the light emitting unit 23 varies according to the blood flow variation of the capillary blood vessel inside the finger F, the light receiving unit 24 reflects the pulsation of the capillary blood vessel, that is, the reflection according to the pulse wave. Light can be received. Thereby, the light receiving unit 24 can generate a pulse wave signal.

  Here, since light is emitted from a plurality of locations using the light guide 31 to the finger F, a plurality of optical paths formed between the light emitting unit 23 and the light receiving unit 24 can be secured, For example, even when pressure is applied to a location where the finger F is present and blood flow in that portion stops, blood flow in other locations can be detected, and pulse waves can be detected stably. .

  According to the present embodiment, the light guide 31 includes the light guide 31 that has the contact surface 32 formed in a larger area than the light emission area of the light emitting unit 23 and is configured to contact the side surface 36 of the finger F. The irradiated light is applied to the finger F through the light guide 31, and the reflected light can be received by the light receiving unit 24 provided at a position corresponding to the abdomen 35 of the finger F. Accordingly, the finger F is irradiated with light from the entire contact surface 32 of the light guide 31, and the light reflected by the abdomen 35 side of the finger F among the light is received by the light receiving unit 24, thereby the pulse wave. Can be detected. That is, the optical path formed between the light emitting unit 23 and the light receiving unit 24 can be widened (larger) than the conventional reflection type, and stable pulse wave measurement can be performed.

  Further, the pulse wave can be detected simply by placing the finger so that the light guide 31 and the side surface 36 of the finger F are brought into contact with each other. That is, the pulse wave can be detected with a simple configuration without placing a burden on the finger or the nail unlike the conventional transmission type.

  In addition, since the light guide 31 is formed in a substantially U shape in plan view so as to surround the light receiving unit 24, it is possible to secure a wider (more) optical path formed between the light emitting unit 23 and the light receiving unit 24. And more stable pulse wave measurement.

  Further, since the surface 34 other than the contact surface 32 with the finger F in the light guide 31 is mirrored, the light emitted from the light emitting unit 23 is reflected inside the light guide 31 and the light is reflected in the light guide 31. Light can be irradiated toward the finger F from substantially the entire contact surface 32 with the finger F. That is, light is irradiated to the finger F from a plurality of locations, and a plurality of optical paths are formed between the light receiving unit 24 and the pulse wave can be detected stably.

  Furthermore, since the contact surface 32 of the light guide 31 is formed in a tapered shape inclined inward so that the region where the finger F is placed narrows toward the side where the light receiving unit 24 is disposed, when the finger F is placed In addition, the adhesion between the light guide 31 and the finger F can be improved. That is, when the light emitted from the light emitting unit 23 is received by the light receiving unit 24 via the light guide 31 and the pulse wave is detected, the influence of noise such as external light can be reduced. The N ratio can be improved, and the pulse wave can be detected with high accuracy.

(Second embodiment)
Next, a second embodiment of the pulse wave detection device according to the present invention will be described with reference to FIG. In addition, since this embodiment differs from 1st embodiment only in the structure of a light emission part, and it is substantially the same about other structures, the same code | symbol is attached | subjected to the same location and detailed description is abbreviate | omitted.

(Pulse wave detector)
FIG. 5 is a perspective view of the pulse wave detection unit 111.
As shown in FIG. 5, the pulse wave detection unit 111 includes a box-shaped sensor case 121, a plurality of light emitting units 123 (three in the present embodiment) placed on the upper surface 121 a of the sensor case 121, and a sensor And a light receiving unit 24 disposed in a component storage space 122 configured inside the case 121. Note that the length along the longitudinal direction of the finger F in the sensor case 121 is formed to be approximately the same length as the first joint of the finger F.

  In addition, a translucent plate 29 made of a translucent glass plate is attached to the upper surface 121 a of the sensor case 121 so that the abdomen of the finger F is in close contact with the translucent plate 29. Further, the light receiving unit 24 is disposed on the component housing space 22 side of the translucent plate 29 so that the finger F is directed. The light emitting unit 123 and the light receiving unit 24 are connected to a circuit board (not shown) arranged in the component storage space 122. The circuit 12 is configured to be communicable with the CPU 12 so that the detection result of the light receiving unit 24 can be calculated and a pulse wave or the like can be displayed.

  The three light emitting units 123 are arranged on the upper surface 121 a of the sensor case 121 so as to surround the light receiving unit 24. The light emitting unit 123 is provided with a light emitting surface 123 a that can irradiate light on the side where the light receiving unit 24 is disposed, and a finger F can be placed in an area surrounded by the three light emitting units 123. .

(Function)
Next, the operation of placing the finger F on the pulse wave detector 111 and detecting the pulse wave will be described.
FIG. 6 is a front view (partially sectional view) when the finger F is placed on the pulse wave detector 111.
As shown in FIG. 6, the finger F is brought into close contact with the upper surface 121 a of the sensor case 121 of the pulse wave detection unit 111. At this time, the side surface 36 of the finger F is placed so as to contact the light emitting surfaces 123 a of the three light emitting units 123. That is, the abdomen 35 of the finger F is disposed so as to contact the translucent plate 29, and the side surfaces 36, 36 of the finger F are disposed so as to contact the light emitting surface 123 a of the light emitting unit 123.

  With the finger F placed on the pulse wave detection unit 111 in this way, light is emitted from each of the three light emitting units 123. That is, the light emitted from the light emitting unit 123 is applied to the side surface 36 of the finger F.

  Then, the irradiated light is absorbed, diffused, and reflected by tissues such as blood vessels (blood), fats and muscles inside the finger F, and a part of the irradiated light passes through the abdomen 35 of the finger F and below it. Is detected by the light receiving unit 24 arranged in the. The light detected by the light receiving unit 24 fluctuates with a change in blood volume due to blood vessel pulsation. The light receiving unit 24 receives light, generates a pulse wave signal corresponding to a change in the amount of received light, and outputs the pulse wave signal to the CPU 12.

  That is, since the amount of reflected light of the light emitted from the light emitting unit 123 varies according to the blood flow variation of the capillary blood vessel inside the finger F, the light receiving unit 24 reflects the pulsation of the capillary blood vessel, that is, the reflection according to the pulse wave. Light can be received. Thereby, the light receiving unit 24 can generate a pulse wave signal.

  Here, since the plurality of light emitting units 123 are arranged so that the finger F is irradiated with light from a plurality of locations, a plurality of optical paths formed between the light emitting unit 123 and the light receiving unit 24 are ensured. For example, even when pressure is applied to a location where the finger F is present and blood flow in that portion stops, blood flow in other locations can be detected, and pulse waves can be detected stably. be able to.

  The light emitting surface 123a of the light emitting unit 123 may be curved so as to follow the side surface 36 of the finger F. In this way, when the finger F is placed on the pulse wave detection device 111, the adhesion between the light emitting surface 123a and the finger F can be improved. That is, when the light emitted from the light emitting unit 123 is received by the light receiving unit 24 and a pulse wave is detected, the influence of noise such as external light can be reduced, and the S / N ratio can be improved. The pulse wave can be detected with high accuracy.

  According to the present embodiment, a plurality of light emitting units 123 are provided at positions corresponding to the side surfaces 36 of the finger F, and reflected light can be received by the light receiving unit 24 provided at a position corresponding to the abdomen 36 of the finger F. A plurality of optical paths formed between the light emitting unit 123 and the light receiving unit 24 can be ensured reliably. Accordingly, since more optical paths can be secured than in the conventional reflection type, stable pulse wave measurement can be performed.

  Further, the pulse wave can be detected simply by placing the finger F so that the side surface 36 and the abdomen 35 of the finger F are brought into contact with the place where the light emitting unit 123 and the light receiving unit 24 are arranged. That is, the pulse wave can be detected with a simple configuration without damaging the nail as in the conventional transmission type.

  The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. That is, the specific shape, configuration, and the like given in the present embodiment are merely examples, and can be changed as appropriate.

For example, although the case where the contact surface of the light guide is formed in a tapered shape has been described in the present embodiment, a curved surface shape that matches the shape of the finger may be used.
Moreover, although this embodiment demonstrated the case where one light emission part was attached with respect to the light guide, you may connect a some light emission part to a light guide.

It is a schematic block diagram of a pulse wave detection device in an embodiment of the present invention. It is a perspective view of the pulse wave detection part in a first embodiment of the present invention. It is a perspective view when a finger | toe is arrange | positioned at the pulse-wave detection part in 1st embodiment of this invention. It is sectional drawing (a part, front view) in alignment with the AA of FIG. It is a perspective view of the pulse wave detection part in a second embodiment of the present invention. It is sectional drawing when a finger is arrange | positioned at the pulse-wave detection part in 2nd embodiment of this invention (a part, front view). It is explanatory drawing when a finger | toe is arrange | positioned to the conventional reflection type pulse wave detection part. It is explanatory drawing when a finger | toe is arrange | positioned to the conventional transmission type pulse wave detection part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Pulse wave detection apparatus 11 ... Pulse wave detection part 23 ... Light emission part 24 ... Light reception part 31 ... Light guide 32 ... Contact surface 35 ... Abdominal part of a finger | toe 36 ... Side surface of a finger 111 ... Pulse wave detection part 123 ... Light emission part F …finger

Claims (5)

A light emitting unit that emits light toward the finger;
In the pulse wave detection device comprising: a light receiving unit capable of receiving light reflected from the finger side of light emitted from the light emitting unit at a position corresponding to the abdomen of the finger;
A light guide that is in contact with at least a side surface of the finger in an area wider than a light emitting area of the light emitting unit;
The pulse wave detection device, wherein the light irradiated from the light emitting unit is irradiated to the finger through the light guide.   The pulse wave detection device according to claim 1, wherein the light guide is formed so as to surround the light receiving unit.   The pulse wave detection device according to claim 1, wherein a surface other than a contact surface with the finger in the light guide is subjected to a reflection surface processing.   The contact surface of the light guide is formed in a tapered shape inclined inward so that a region on which the finger is placed narrows toward a side where the light receiving unit is disposed. 3. The pulse wave detection device according to 1 or 2. A light emitting unit that emits light toward the finger;
In the pulse wave detection device comprising: a light receiving unit capable of receiving light reflected from the finger side of the light emitted from the light emitting unit;
A plurality of the light emitting portions are provided at positions corresponding to the side surfaces of the fingers;
The pulse wave detection device, wherein the light receiving unit provided at a position corresponding to the abdomen of the finger is configured to receive the reflected light of the light.

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