JP2015066160A - Pulse wave detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse wave detection device reducing possibility that detection accuracy of a pulse wave deteriorates.SOLUTION: A pulse wave detection device 1 includes a translucent plate 21, a light reception part 223, and a pressure sensor 24. The translucent plate 21 has: a first face 211; and a second face 212 on a side opposite to the first face 211. The light reception part 223 is disposed on a first direction side heading for the second face 212 from the first face 211 relatively to the translucent plate 21. The pressure sensor 24 is disposed on the first direction side of the light reception part 223. The pressure sensor 24 outputs a pressure signal indicating a pressure from a second direction side heading for the first face 211 from the second face 212. A CPU of the pulse wave detection device 1 detects a pulse wave on the basis of light received by the light reception part 223. The CPU determines whether or not the pressure is within a prescribed range on the basis of the pressure signal outputted from the pressure sensor 24, and notifies a determination result.

Description

  The present invention relates to a pulse wave detection device that detects a pulse wave.

  Conventionally, a pulse wave detection device for detecting a pulse wave is known. For example, the pulse wave information measurement device described in Patent Document 1 includes a light transmitting plate, an LED, and a phototransistor. The translucent plate has an outer surface against which a user's finger is pressed. The phototransistor and the LED are arranged on the side opposite to the outer surface side of the translucent plate. If the LED emits light in a state where the user's finger is pressed against the outer surface of the translucent plate, the light reaches the blood vessel of the finger. A part of the light that reaches the blood vessel is absorbed by hemoglobin in the blood, and a part of the light is reflected or transmitted. The blood flow of the finger changes with the pulse. When the blood flow changes, the amount of hemoglobin changes, so the intensity of reflected light changes. For example, if the blood flow volume is large, hemoglobin increases, and it is considered that light absorbed by hemoglobin increases. Therefore, the intensity of the reflected light is reduced. On the other hand, it can be considered that when the blood flow is small, the amount of hemoglobin decreases and the amount of light absorbed by hemoglobin decreases. Therefore, the intensity of reflected light increases. The pulse wave information measuring device detects a change in intensity of reflected light received by a phototransistor and measures a pulse rate and the like.

JP 2004-188224 A

  However, the conventional pulse wave detection device may not be able to accurately detect the pulse wave depending on the contact state between the translucent plate and the finger. Specifically, when the finger is strongly pressed against the translucent plate, the blood vessel may be crushed and the blood flow may be reduced. For this reason, there is a possibility that the pulse wave detection device cannot accurately detect the pulse wave due to a decrease in blood flow. On the other hand, when the finger is weakly pressed by the light transmissive plate, disturbance light is likely to enter the phototransistor through the gap between the light transmissive plates where the finger does not contact. For this reason, there is a possibility that the pulse wave detection device cannot accurately detect the pulse wave due to noise based on disturbance light.

  An object of the present invention is to provide a pulse wave detection device that reduces the possibility that the detection accuracy of a pulse wave is lowered.

  The pulse wave detection device according to the present invention includes a translucent plate having a first surface and a second surface opposite to the first surface, and from the first surface to the second surface with respect to the translucent plate. A light receiving portion that is disposed on the first direction side and that receives light incident through the translucent plate from a second direction side that is a direction from the second surface toward the first surface; and the second direction side Pressure output means for outputting a pressure signal indicating the pressure applied to the translucent plate, detection means for detecting a pulse wave based on the light received by the light receiving unit, and the pressure output from the pressure output means Based on the signal, there is provided judging means for judging whether or not the pressure is within a predetermined range, and notifying means for notifying the judgment result by the judging means.

  When the user's finger is placed on the first surface side of the translucent plate, the pressure output means outputs a pressure signal indicating the pressure with which the user's finger presses the translucent plate. The determination means determines whether or not the pressure pressed by the user's finger is within a predetermined range based on the pressure signal, and the notification means notifies the determination result. Since the determination result is notified, it is easier for the user to determine whether or not the translucent plate is being pressed with a pressure within a predetermined range as compared with the case where the determination result is not notified. Therefore, the user can easily adjust the pressure for pressing the translucent plate so that the pressure falls within a predetermined range. Therefore, for example, it is possible to reduce the possibility that the finger blood vessel is crushed by pressing with a force larger than a predetermined range, the blood flow rate is lowered, and the pulse wave detection accuracy is lowered. In addition, the possibility of disturbance light entering the light receiving unit from a portion of the light transmissive plate where the finger does not contact due to the finger pressing the light transmissive plate weakly is reduced. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  In the pulse wave detection device, the pressure output unit may be provided on one surface of the substrate in the first direction, and the light receiving unit may be provided on a surface of the substrate in the second direction. In this case, since the pressure output means is disposed on the first direction side of the light receiving portion, the pressure output means does not block the light received by the light receiving portion. In addition, the pulse wave detection device can be easily manufactured by providing the light receiving unit and the pressure output unit on one substrate.

  The pulse wave detection device includes a housing including a hole portion that forms a through hole penetrating in the first direction, and the hole portion is positioned on the second direction side and orthogonal to the second direction. A first hole whose length in the direction is the first length, and a second hole whose second length is located on the first direction side and whose length in the orthogonal direction is shorter than the first length. And the end of the first hole on the second direction side regulates the movement of the first surface located inside the first hole into the second hole. You may have. In this case, the end portion on the second direction side of the first hole has a shape that restricts the movement of the first surface located inside the first hole into the second hole. As a result, the possibility that the translucent plate is pressed decreases as the first surface moves into the second hole, and the possibility that the pulse wave detection accuracy decreases can be reduced.

  In the pulse wave detection device, an elastic member having an elastic force may be provided on the first direction side of the light receiving unit. The pressure when the translucent plate is pushed in the first direction by the finger varies every time the pulse wave detector is used. However, since the elastic member is provided, it is possible to reduce variation in pressure when the translucent plate is pushed in the first direction as compared to the case where the elastic member is not provided. Therefore, compared with the case where the elastic member is not provided, the pressure at which the finger and the translucent plate come into contact easily enters the predetermined range. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  In the pulse wave detection device, when the determination unit determines that the pressure is within the predetermined range, the notification unit notifies the determination result indicating that the pressure is within the predetermined range. May be. In this case, the user can easily adjust the pressure for pressing the light-transmitting plate to be within the predetermined range as compared with the case where the determination result indicating that the pressure is within the predetermined range is not notified. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  In the pulse wave detection device, the notification unit may notify the determination result indicating that the pressure is not within the predetermined range when the determination unit determines that the pressure is not within the predetermined range. Good. In this case, the user can easily adjust the pressure for pressing the light-transmitting plate to be within the predetermined range as compared with the case where the determination result indicating that the pressure is not within the predetermined range is not notified. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  In the pulse wave detection device, the detection unit may detect the pulse wave based on light received by the light receiving unit during a period when the pressure is determined to be within the predetermined range by the determination unit. Good. In this case, the detection accuracy of the pulse wave is improved as compared with the case where the pulse wave is detected in a state where the light received by the light receiving unit is included in the period in which the pressure is determined not to be within the predetermined range.

  The pulse wave detection device may include an output unit that outputs biological information based on the pulse wave detected by the detection unit. In this case, since the biological information based on the pulse wave with improved detection accuracy is output, the user can easily confirm more accurate biological information.

3 is a cross-sectional view of a main part of the pulse wave detection device 1. 2 is a block diagram showing an electrical configuration of the pulse wave detection device 1. FIG. It is a flowchart of a main process. It is sectional drawing of the principal part of the pulse wave detection apparatus 2 which concerns on 2nd embodiment of the state which the translucent board 21 and the finger | toe 51 separated. FIG. 6 is a cross-sectional view of a main part of the pulse wave detection device 2 in a state where the light transmitting plate 21 is pressed downward by a finger 51. FIG. 6 is a longitudinal sectional view of the pulse wave detection device 2 in a state in which the translucent plate 21 is pressed downward by the finger 51 more strongly than the state shown in FIG. 5.

<1. Structure of Pulse Wave Detection Device 1>
A first embodiment embodying the present invention will be described with reference to the drawings. The structure of the pulse wave detection device 1 will be described with reference to FIGS. 1 and 2. In the following description, the upper side, the lower side, the right side, the left side, the front side, and the rear side of FIG.

  As shown in FIG. 1, the pulse wave detection device 1 includes an upper housing 11 and a lower housing 12. The upper housing 11 has an upper surface 111 and a bottom surface 112. The upper surface 111 of the upper housing 11 forms the upper surface of the pulse wave detection device 1. The bottom surface 121 of the lower housing 12 forms the bottom surface of the pulse wave detection device 1. The upper housing 11 and the lower housing 12 have a plate shape extending in the front / rear / left / right direction, and are connected to each other at the front / rear / left / right end portions. For this reason, the pulse wave detection device 1 has a rectangular parallelepiped appearance that is long in the front-rear and left-right directions.

  The upper housing 11 is provided with a circular hole 113 and a rectangular hole (not shown). The rectangular hole portion is provided, for example, at the front portion of the upper housing 11 and forms a through hole that vertically penetrates in a rectangular shape. A transparent resin plate is disposed inside the rectangular hole, and a display 34 shown in FIG. 2 is disposed below the resin plate. The user confirms the display on the display 34 via the resin plate. On the rear side of the display 34 in the upper housing 11, an operation unit 35 shown in FIG.

  The circular hole 113 is provided in the upper housing 11 and forms a through-hole that vertically penetrates the upper housing 11. A translucent plate 21 is disposed inside the circular hole 113. The translucent plate 21 is a plate-like member having an upper first surface 211 and a lower second surface 212 that is opposite to the first surface 211. The vertical position of the first surface 211 is substantially the same as the vertical position of the upper surface 111 of the upper housing 11. The vertical position of the second surface 212 is between the upper surface 111 and the bottom surface 112 of the upper housing 11. In the following description, a downward direction from the first surface 211 toward the second surface 212 may be referred to as a “first direction”, and an upward direction from the second surface 212 toward the first surface 211 may be referred to as a “second direction”. There is.

  A photo sensor 22 is provided on the first direction side of the translucent plate 21. The photosensor 22 is mounted on the upper surface of the electric substrate 23 disposed on the first direction side of the photosensor 22. A light emitting unit 222 and a light receiving unit 223 are provided inside the side wall 221 of the photosensor 22. That is, the light emitting unit 222 and the light receiving unit 223 are provided on one surface on the second direction side of the electric substrate 23 and are located on the first direction side of the light transmitting plate 21. The light emitting unit 222 is, for example, an LED (Light Emitting Diode). The light receiving unit 223 is, for example, a photodiode, and receives light incident from the second direction side via the translucent plate 21.

  A pressure sensor 24 is disposed on one surface of the electric substrate 23 in the first direction. That is, the pressure sensor 24 is provided on the first direction side of the light receiving unit 223. A lower housing 12 is provided on the first direction side of the pressure sensor 24. The pressure sensor 24 outputs a pressure signal indicating the pressure from the second direction side.

<2. Electrical configuration of pulse wave detection device 1>
The electrical configuration of the pulse wave detection device 1 will be described with reference to FIG. The pulse wave detection device 1 includes a CPU 31, a ROM 32, a RAM 33, a display 34, a pressure sensor 24, and an operation unit 35. The ROM 32, RAM 33, display 34, pressure sensor 24, and operation unit 35 are electrically connected to the CPU 31, respectively. The CPU 31 controls the pulse wave detection device 1. The ROM 32 stores a control program and the like for executing a main process described later shown in FIG. The RAM 33 temporarily stores various data.

  The display 34 displays an image based on the image signal output from the CPU 31. The pressure sensor 24 outputs a pressure signal to the CPU 31. The operation unit 35 outputs a signal corresponding to the operation by the user to the CPU 31. The operation unit 35 includes a power switch (not shown) for turning on / off the power of the pulse wave detection device 1.

  The pulse wave detection device 1 includes a photo sensor 22, a current-voltage conversion circuit 361, an amplification circuit 362, and an A / D conversion circuit unit 37. The light emitting unit 222 of the photosensor 22 is electrically connected to the CPU 31. The current-voltage conversion circuit 361 is electrically connected to the light receiving unit 223 and the amplifier circuit 362 of the photosensor 22. The A / D conversion circuit unit 37 is electrically connected to the amplifier circuit 362 and the CPU 31.

  The light emitting unit 222 emits light based on a control signal from the CPU 31. The light 61 emitted from the light emitting unit 222 reaches the blood vessel 52 of the finger 51 shown in FIG. A part of the light 61 that has reached the blood vessel 52 is absorbed by the hemoglobin 53 in the blood, and a part thereof is reflected or transmitted. The blood flow volume of the blood vessel 52 of the finger 51 changes according to the pulse. When the blood flow rate changes, the amount of hemoglobin 53 changes, so the intensity of the reflected light 62 changes. The light receiving unit 223 receives the reflected light 62 incident from the second direction side. The current flowing through the light receiving unit 223 changes according to the received light intensity of the reflected light 62 received by the light receiving unit 223. The current-voltage conversion circuit 361 outputs a change in current flowing through the light receiving unit 223 as a change in voltage. The amplifier circuit 362 amplifies the voltage output from the current-voltage conversion circuit 361. The A / D conversion circuit unit 37 converts the voltage output from the amplifier circuit 362 from an analog signal to a digital signal and outputs the converted signal to the CPU 31. The CPU 31 can detect the intensity of the light received by the light receiving unit 223 based on the digital signal output from the A / D conversion circuit unit 37. That is, since the intensity of the reflected light 62 received by the light receiving unit 223 changes according to the pulse wave, the CPU 31 can detect the pulse wave based on the digital signal output from the A / D conversion circuit unit 37. it can.

<3. Example of processing of pulse wave detection device 1>
The main process will be described with reference to FIG. When a power switch (not shown) of the operation unit 35 is turned on, the CPU 31 starts operating. The CPU 31 reads out a control program stored in the ROM 32, develops it in the RAM 33, and executes main processing.

  As shown in FIG. 3, the CPU 31 determines whether or not the pressure is within a predetermined range based on the output signal of the pressure sensor 24 (S1). The predetermined range is, for example, a range of 50 gf or more and 500 gf or less. Note that the pressure signal output from the pressure sensor 24 varies depending on the pressure with which the user's finger 51 placed on the first surface 211 side of the translucent plate 21 pushes the translucent plate 21 in the first direction. When the pressure is not within the predetermined range (S1: NO), the CPU 31 notifies the display 34 of a determination result indicating that the pressure is not within the predetermined range (S2). In S <b> 2, the CPU 31 outputs a signal that informs the display 34 of a determination result indicating that the pressure is not within the predetermined range. The display 34 to which this signal is input displays a determination result indicating that the pressure is not within the predetermined range. For example, characters such as “the pressure pressed by the finger is not in the proper range” are displayed on the display 34 as the determination result.

  When the pressure is within the appropriate range (S1: YES), the CPU 31 notifies the display 34 of a determination result indicating that the pressure is within the predetermined range (S3). In S <b> 3, the CPU 31 outputs a signal that informs the display 34 of a determination result indicating that the pressure is within a predetermined range. The display 34 to which this signal is input displays a determination result indicating that the pressure is not within the predetermined range. For example, characters such as “the pressure pressed with a finger is in an appropriate range” are displayed on the display 34 as a determination result. Next, the CPU 31 measures the intensity of light including the reflected light 62 received by the light receiving unit 223 and the pressure based on the output signal of the pressure sensor 24 for a predetermined time (S4). The predetermined time is, for example, 10 seconds. The CPU 31 stores light intensity data and pressure data measured at predetermined intervals within the predetermined time in the RAM 33 in association with each other. The predetermined interval is, for example, 1 second.

  Next, the CPU 31 refers to the light intensity data and pressure data measured in S4 for a predetermined time, and based on the light received by the light receiving unit 223 during the period when the pressure is determined to be within the predetermined range, the pulse wave Is detected (S5). In S5, the CPU 31 determines whether or not the pressure data of the predetermined time measured in S4 is a pressure within a predetermined range. The CPU 31 specifies the light intensity during the period when the pressure is determined to be within the predetermined range. The CPU 31 detects a pulse wave based on the specified light intensity.

  Next, the CPU 31 generates biological information based on the pulse wave detected in S5 (S6). The biological information is, for example, a pulse wave waveform, a blood pressure value, a pulse rate, an evaluation of whether the pulse is arrhythmia, a blood vessel age characteristic, or the like. The blood vessel age characteristic is a state of the blood vessel 52 that changes according to the age, for example, the hardness of the blood vessel 52. CPU31 produces | generates biological information from a pulse wave by a well-known calculation method. The biometric information to be generated may be plural types or one type.

  Next, the CPU 31 outputs the biological information generated in S6 (S7). In the present embodiment, the CPU 31 outputs the generation information generated in S6 by displaying it on the display 34. Next, the CPU 31 ends the main process.

<4. Main actions and effects of first embodiment>
As described above, the main process in the present embodiment is executed. The pressure output from the pressure sensor 24 varies depending on the pressure with which the user's finger 51 placed on the first surface 211 side of the translucent plate 21 pushes the translucent plate 21 in the first direction. The CPU 31 determines whether the pressure is within a predetermined range based on the output signal of the pressure sensor 24 (S1), and notifies the determination result (S2 and S3). Since the determination result is notified, the user can easily determine whether or not the translucent plate 21 is being pressed with a pressure within a predetermined range as compared with the case where the determination result is not notified. Therefore, the user can easily adjust the pressure for pressing the translucent plate 21 so that the pressure falls within a predetermined range. Therefore, for example, it is possible to reduce the possibility that the blood vessel of the finger 51 is crushed by pressing with a force larger than a predetermined range, the blood flow rate is lowered, and the pulse wave detection accuracy is lowered. Further, it is possible to reduce the possibility that disturbance light is incident on the light receiving unit from a portion of the light transmissive plate where the finger 51 does not contact when the finger 51 presses the light transmissive plate weakly. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  Since the pressure sensor 24 is disposed on the first direction side of the light receiving unit 223, the pressure sensor 24 does not block the light received by the light receiving unit 223. In addition, since the light receiving unit 223 and the pressure sensor 24 are provided on one electric substrate 23, the pulse wave detection device 1 can be easily manufactured as compared with the case where they are provided separately.

  Moreover, CPU31 alert | reports the judgment result which shows that a pressure is in a predetermined range (S3). For this reason, the user can recognize that the translucent plate 21 is pressed with a pressure within a predetermined range. Therefore, the user can easily adjust the pressure to press the translucent plate 21 to be within the predetermined range as compared with the case where the determination result indicating that the pressure is within the predetermined range is not notified. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  Moreover, CPU31 alert | reports the judgment result which shows that a pressure is not in a predetermined range (S2). For this reason, the user can recognize that the translucent plate 21 is not pressed with a pressure within a predetermined range. Therefore, the user can easily adjust the pressure for pressing the translucent plate 21 to be within the predetermined range as compared with the case where the determination result indicating that the pressure is not within the predetermined range is not notified. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  Further, the CPU 31 detects a pulse wave based on the light received by the light receiving unit 223 during the period when the pressure is determined to be within the predetermined range (S5). For this reason, the detection accuracy of the pulse wave is improved as compared with the case where the pulse wave is detected in a state in which the light received by the light receiving unit 223 is included in the period in which the pressure is determined not to be within the predetermined range. In addition, even if the pressure with which the translucent plate 21 is pressed by the finger 51 changes during the predetermined time during which the measurement is performed in S4, the pulse wave during the period in which the pressure is determined to be within the predetermined range is automatically detected. The Therefore, for example, the convenience for the user is improved as compared with the case where the measurement is stopped when the pressure is out of the predetermined range.

  Further, the CPU 31 outputs biological information (S7). Since the biological information based on the pulse wave with improved detection accuracy is output, the user can easily confirm more accurate biological information. In the present embodiment, the CPU 301 detects the pulse wave based on the light received by the light receiving unit 223 during the period when the pressure is determined to be within the predetermined range, and generates biological information (S5 and S6). Biometric information is output (S7). Therefore, the pulse wave detection device 1 is more accurate than the case where the pulse wave is detected in a state in which the light received by the light receiving unit 223 is included in a period in which the pressure is determined not to be within the predetermined range. Information can be output.

  In the above embodiment, the pressure sensor 24 is an example of the “pressure output means” in the present invention. The electric substrate 23 is an example of the “substrate” in the present invention. The CPU 21 that performs the process of S1 and the CPU 21 that performs the process of determining whether or not the pressure for a predetermined time in S5 is within a predetermined range are examples of the “determination means” of the present invention. The CPU 21 that performs the process of detecting the pulse wave based on the light intensity during the period when the pressure is determined to be within the predetermined range in S5 is an example of the “detecting means” in the present invention. The CPU 21 that performs the processes of S2 and S3 is an example of the “notification unit” in the present invention. The CPU 21 that performs the process of S7 is an example of the “output unit” in the present invention.

  In addition, this invention is not limited to said embodiment, A various change is possible. For example, the CPU 31 refers to the light intensity data and pressure data measured in S4 for a predetermined time, and based on the light received by the light receiving unit 223 during the period when the pressure is determined to be within the predetermined range, the pulse wave Is detected (S5). However, it is not necessary to determine whether or not the pressure is within a predetermined range in S5. Even in this case, when it is determined in S1 that the pressure is within the predetermined range (S1: YES), since the measurement is performed (S4), the pressure is within the predetermined range as compared with the case where S1 is not executed. There is a high possibility. For this reason, it is not determined whether or not the pressure is within a predetermined range in S5, and if S1 is not executed even if a pulse wave is detected with reference to all the light intensities measured in S4 for a predetermined time. In comparison, the possibility that the detection accuracy of the pulse wave is lowered can be reduced. In this case, the pressure may not be measured in S4.

  Moreover, although the judgment result whether a pressure is a predetermined range is alert | reported (S2 and S3), the aspect to alert | report is not limited. For example, the displayed message may change depending on the pressure. For example, if the pressure is the minimum value, “Please place your finger on the translucent plate” may be displayed. (S2). Further, if the pressure is smaller than the predetermined range, “Please press a little harder” may be displayed (S2). Further, if the pressure is larger than the predetermined range, “Please weaken the pressing force” may be displayed (S2). If the pressure is within a predetermined range, “Pressure is appropriate” or “Start measurement” may be displayed (S3). In addition, instead of displaying on the display 34, an LED that emits light is provided in the upper housing 11, and if the pressure is within a predetermined range, the CPU 31 causes the LED to emit blue light (S3). May be caused to emit light (S2). Further, for example, a buzzer may be provided in the pulse wave detection device 1, and the CPU 31 may notify whether or not it is within a predetermined range due to a difference in buzzer sound (S2 and S3). Moreover, the vibration motor which generate | occur | produces a vibration is provided in the pulse-wave detection apparatus 1, and CPU31 may alert | report whether it is in a predetermined range by the difference in the interval which vibrates a vibration motor (S2 and S3). Further, only one of S2 and S3 may be executed.

  Further, the CPU 31 outputs the generated information generated in S6 by displaying it on the display 34 (S7), but it may be output by other methods. For example, when it is an evaluation of whether or not the biological information is an arrhythmia, the CPU 31 emits a red LED when it is an arrhythmia, and emits a blue LED when it is not an arrhythmia, thereby obtaining the biological information. It may be output. Moreover, biometric information does not need to be output in S7. In this case, for example, the CPU 31 may transfer the pulse wave detected in S5 or the biological information generated in S6 to another device. Further, the position of the light emitting unit 222 is not limited. The light emission part 222 should just be able to irradiate light to the finger | toe 51, for example, may exist in the right side or the left side of the translucent board 21. FIG. Moreover, the pressure sensor 24 should just be provided so that the pressure concerning the translucent board 21 can be detected from the 2nd direction side, and a position is not limited. For example, a pressure sensor may be disposed on the first direction side of the bottom surface 112 so that the pressure with which the light transmitting plate 21 is pressed is transmitted to the pressure sensor. Further, each process in the main process is not limited to the example executed by the CPU 31, and may be executed by another electronic component.

<5. Structure of Pulse Wave Detection Device 2 According to Second Embodiment>
Further, the structure of the pulse wave detection device 1 is not limited to the first embodiment. Hereinafter, the pulse wave detection device 2 according to the second embodiment will be described. In the following description, the upper side, the lower side, the right side, the left side, the front side, and the rear side of FIG. The same components as those of the pulse wave detection device 1 are denoted by the same reference numerals, and detailed description thereof is omitted. Moreover, since the structure of parts other than the principal part of the pulse wave detection apparatus 2 shown in FIG. 4 is the same as that of the pulse wave detection apparatus 1, description is abbreviate | omitted. In the following description, a direction orthogonal to the second direction may be referred to as an “orthogonal direction”.

  As shown in FIG. 4, the pulse wave detection device 2 includes an upper housing 41 and a lower housing 12. The upper surface 411 of the upper housing 41 forms the upper surface of the pulse wave detection device 2. The upper housing 41 is provided with a circular hole 413.

  The circular hole portion 413 is provided in the rear portion of the upper housing 41, and forms a through hole that penetrates the upper housing 41 in a circular shape in the first direction. The circular hole 413 includes a first hole 413A located on the second direction side and a second hole 413B located on the first direction side. The side surface of the first hole portion 413A is formed in a tapered shape in which the length in the orthogonal direction becomes longer toward the second direction. The second hole 413B extends in the vertical direction. The center in the orthogonal direction of the first hole 413A and the center in the orthogonal direction of the second hole 413B coincide with each other when viewed from above.

  The translucent plate 21 is disposed inside the first hole 413A in the circular hole 413. The first surface 211 of the translucent plate 21 is located inside the first hole 413A. In the present embodiment, the vertical position of the first surface 211 is closer to the first direction than the vertical position of the upper surface 411 of the upper housing 41. The end portion 414 on the second direction side of the first hole 413A has a shape that restricts the movement of the first surface 211 into the second hole 413B. In the present embodiment, the first length L <b> 1 in the orthogonal direction of the end 414 on the second direction side of the first hole 413 </ b> A is shorter than the width of the finger 51. When the finger 51 comes into contact with the end 414 having the first length L1, the first surface 211 is restricted from moving into the second hole 413B. For example, the first length L1 specifies an average value of the widths of the fingers 51 of a plurality of people and is set to be shorter than the average value. The average value of the multiple fingers 51 is, for example, 14.9 mm.

  The second length L2 in the orthogonal direction in the second hole portion 413B is shorter than the first length L1. A flat surface 49 is provided at the end of the first hole portion 413A on the first direction side. The plane 49 is a plane connecting the first hole 413A and the second hole 413B having different lengths in the orthogonal direction and is a surface facing the second direction.

  Similar to the pulse wave detection device 1 shown in FIG. 1, a photo sensor 22, an electric substrate 23, and a pressure sensor 24 are provided on the first direction side of the translucent plate 21. 4 is longer than the length of the photo sensor 22 in FIG. 1 in the vertical direction, it may be the same length. In FIG. 4, the light receiving portion 223 in the photosensor 22 is located on the rear side of the light emitting portion 222.

  An elastic member 57 having a vertical elastic force is provided on the first direction side of the pressure sensor 24. The elastic member 57 is, for example, a synthetic resin or a spring. A lower housing 12 is provided on the first direction side of the elastic member 57.

  When the finger 51 is not placed on the first surface 211 of the translucent plate 21, or when the finger 51 is placed and the translucent plate 21 is not pushed in the first direction, as shown in FIG. 57 is the state which is not compressed. In this case, the pressure indicated by the pressure signal output from the pressure sensor 24 is a pressure that is not within the predetermined range. As shown in FIG. 3, the CPU 31 determines that the pressure is not within the predetermined range based on the output signal of the pressure sensor 24 (S1: NO), and notifies that the pressure is not within the predetermined range (S2).

  When the translucent plate 21 is pressed by the finger 51, the elastic member 57 is compressed and the translucent plate 21 moves in the first direction as shown in FIG. The end 414 on the second direction side of the first hole portion 413A abuts on the finger 51, and the vertical position of the first surface 211 of the translucent plate 21 is a position along the contour of the finger 51. In this case, the pressure indicated by the pressure signal output from the pressure sensor 24 is a pressure within a predetermined range. As shown in FIG. 3, the CPU 31 determines that the pressure is within a predetermined range based on the output signal of the pressure sensor 24 (S1: YES), and executes the processes of S3 to S7.

  When the translucent plate 21 is pushed downward with a stronger force, the elastic member 57 is further compressed and the translucent plate 21 moves in the first direction as shown in FIG. Since the first length L1 of the end 414 on the second direction side of the first hole 413A is smaller than the width of the finger 51, the movement of the finger 51 in the first direction is restricted, and the first surface 211 is the second hole. Movement to the inside of the portion 413B is restricted. In the case illustrated in FIG. 6, the finger 51 is deformed along the shape of the first hole 413A. In this case, the pressure indicated by the pressure signal output from the pressure sensor 24 is a pressure that is not within the predetermined range. As shown in FIG. 3, the CPU 31 determines that the pressure is not within the predetermined range based on the output signal of the pressure sensor 24 (S1: NO), and notifies that the pressure is not within the predetermined range (S2).

<6. Main functions and effects of the second embodiment>
As described above, the pulse wave detection device 2 in the present embodiment is formed. The pressure when the translucent plate 21 is pushed in the first direction by the finger 51 varies every time the pulse wave detector 2 is used. However, since the elastic member 57 is provided, it is possible to reduce variations in pressure when the translucent plate 21 is pushed in the first direction as compared with the case where the elastic member 57 is not provided. Therefore, compared with the case where the elastic member 57 is not provided, the pressure at which the finger 51 and the translucent plate 21 come into contact easily falls within a predetermined range. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  Since the end portion 414 on the second direction side of the first hole portion 413A restricts the movement of the first surface 211 into the second hole portion 413B, the first surface 211 is placed inside the second hole portion 413B. As it moves, the possibility that the translucent plate 21 is pressed can be reduced. Therefore, for example, it is possible to reduce the possibility that the blood vessel of the finger 51 is crushed by pressing with a force larger than a predetermined range, the blood flow rate is lowered, and the pulse wave detection accuracy is lowered.

  Further, in the present embodiment, a flat surface 49 is provided, and as shown in FIG. 6, the flat surface 49 contacts the finger 51 and restricts the movement of the first surface 211 in the first direction. Therefore, the possibility that the translucent plate 21 is pressed can be further reduced as the first surface 211 moves into the second hole 413B.

  When the user pushes the translucent plate 21 in the first direction to the position shown in FIG. 5, the end portion 414 on the second direction side of the first hole 413A and the translucent plate 21 follow the outline of the finger 51. The state of the finger 51 is stabilized. Since the position of the finger 51 is stabilized, it is possible to reduce the possibility that the user further pushes the translucent plate 21 in the first direction. Therefore, the possibility that the detection accuracy of the pulse wave is lowered can be reduced.

  The vertical position of the first surface 211 is on the first direction side of the vertical position of the upper surface 411 of the upper housing 41. For this reason, for example, when the top surface 411 side of the upper housing 41 is placed on the desk in contact with the desk, the first surface 211 of the translucent plate 21 does not contact the desk. Therefore, it is possible to prevent the translucent plate 21 from being damaged. Further, compared to the case where the vertical position of the first surface 211 is closer to the second direction than the vertical position of the upper surface 411, for example, when the user carries the pulse wave detection device 1, other objects may transmit light. It is difficult to contact the plate 21. Therefore, it is possible to reduce the possibility of malfunction caused by another object coming into contact with the light transmitting plate 21.

  In the present embodiment, the upper casing 41 is an example of the “casing” in the present invention. The circular hole 413 is an example of the “hole” in the present invention. In addition, this invention is not limited to said 2nd embodiment, A various change is possible. For example, the elastic member 57 may be on the first direction side from the light receiving unit 223. For example, in FIG. 4, the positions of the elastic member 57 and the pressure sensor 24 may be interchanged. In this case, the elastic member 57 is located between the electric board 23 and the pressure sensor 24. An electric board for mounting the pressure sensor 24 may be provided between the pressure sensor 24 and the lower housing 12.

  Moreover, although the elastic member 57 was provided, it does not need to be provided. The shape of the end portion 414 on the second direction side of the first hole portion 413A is desirably a shape that restricts the movement of the first surface 211 into the second hole portion 413B. For example, the end portion 414 on the second direction side of the first hole portion 413A may be made larger than the width of the finger 51, and only a part may protrude inside the first hole portion 413A so as to contact the finger 51. .

  Further, the vertical position of the first surface 211 is closer to the first direction than the vertical position of the upper surface 411 of the upper casing 41, but is the same as the vertical position of the upper surface 411 of the upper casing 41. Alternatively, it may be on the second direction side from the vertical position of the upper surface 411 of the upper housing 41.

1, 2 Pulse wave detection devices 11, 41 Upper housing 21 Translucent plate 24 Pressure sensor 57 Elastic member 211 First surface 212 Second surface 223 Light receiving unit 223 Electric substrate 413 Circular hole 413A First hole 413B Second hole Part

Claims (8)

A translucent plate having a first surface and a second surface opposite the first surface;
The translucent plate is disposed on the first direction side from the first surface toward the second surface with respect to the translucent plate, and the translucent plate from the second direction side that is the direction from the second surface toward the first surface. A light receiving portion for receiving light incident through
Pressure output means for outputting a pressure signal indicating the pressure applied to the translucent plate from the second direction side;
Detecting means for detecting a pulse wave based on the light received by the light receiving unit;
Determination means for determining whether or not the pressure is within a predetermined range based on the pressure signal output from the pressure output means;
A pulse wave detection apparatus comprising: an informing means for informing a judgment result by the judging means. The pressure output means is provided on one surface of the substrate in the first direction,
The pulse wave detection device according to claim 1, wherein the light receiving unit is provided on one surface of the substrate in the second direction. A housing having a hole that forms a through hole penetrating in the first direction;
The hole is
A first hole portion located on the second direction side and having a length in the orthogonal direction perpendicular to the second direction being a first length;
A second hole located on the first direction side and having a second length shorter than the first length in the orthogonal direction;
The end portion on the second direction side of the first hole portion has a shape that restricts the movement of the first surface located inside the first hole portion into the second hole portion. The pulse wave detection device according to claim 1 or 2, characterized by the above.   The pulse wave detection device according to claim 1, wherein an elastic member having an elastic force is provided on the first direction side of the light receiving unit.   The notification means notifies the determination result indicating that the pressure is in the predetermined range when the determination means determines that the pressure is within the predetermined range. The pulse wave detection device according to any one of 1 to 4.   2. The notification unit, when the determination unit determines that the pressure is not within the predetermined range, notifies the determination result indicating that the pressure is not within the predetermined range. The pulse wave detection device according to any one of 5.   The detection unit detects the pulse wave based on light received by the light receiving unit during a period when the determination unit determines that the pressure is within the predetermined range. 6. The pulse wave detection device according to any one of 6 above.   The pulse wave detection device according to claim 1, further comprising an output unit that outputs biological information based on the pulse wave detected by the detection unit.

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