JP2014212796A - Pulse wave measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse wave measuring device capable of shortening time to adjust a gain of a pulse wave sensor so that pulse wave amplitude falls within a proper range.SOLUTION: A CPU 5 of a pulse wave measuring device 1 calculates amplitude of a pulse wave signal detected by a pulse wave sensor 2. If the pulse wave amplitude exceeds a range (AD range) where an A/D converter 4 can perform AD conversion or is equal to or less than a predetermined standard value, the device 1 executes a first mode as a gain adjustment mode of the pulse wave sensor 2. In the first mode, the device 1 calculates an amplitude ratio of the current pulse wave amplitude to predetermined optimal amplitude, and from the amplitude ratio and a current light volume, it predicts such an optimal light volume of a light emission unit 21 that the pulse wave amplitude falls within a proper range. A light volume control unit 12 changes a light volume of the light emission unit 21 to the predicted optimal light volume at once. If the pulse wave amplitude is outside the proper range a little, the device 1 executes a second mode of gradually varying the light volume step by step with predetermined variation width until the pulse wave amplitude falls within the proper range.

Description

  The present invention relates to a pulse wave measuring device that measures a pulse wave of a human body.

  2. Description of the Related Art Conventionally, an optical pulse wave sensor that measures the pulse wave of a human body using light absorption characteristics of hemoglobin in blood is known (see, for example, Patent Document 1). This pulse wave sensor includes a light emitting element that irradiates light to the human body (user's skin) and a light receiving element that receives reflected light of the light emitted from the light emitting element, and changes in blood flow caused by blood pulsation That is, the pulse wave is detected as a change in the amount of light received by the light receiving element.

  The pulse wave measured by the pulse wave sensor is used, for example, for calculating a pulse rate or for calculating a blood pressure. In order to accurately calculate the pulse rate and blood pressure, it is necessary to measure the pulse wave so that it can be analyzed accurately. Specifically, the measured pulse wave amplitude is too small or too large. However, it is necessary to be within the proper range. On the other hand, in pulse wave measurement using an optical pulse wave sensor, the pulse wave signal measured by the pulse wave sensor depends on the environment (difference in ambient brightness, etc.) and the individual (difference in skin color, etc.). Change. Therefore, the gain of the pulse wave sensor for the pulse wave amplitude to fall within the appropriate range, specifically, the light intensity of the light emitting element of the pulse wave sensor and the amplification degree of the amplifier that amplifies the pulse wave signal received by the light receiving element. Need to be optimally adjusted according to the environment and individual.

  Therefore, conventionally, a method has been used in which the pulse wave sensor gain (the light amount and the amplification degree of the amplifier) is changed stepwise while observing the pulse wave amplitude until the pulse wave amplitude falls within an appropriate range. That is, in the conventional method, a plurality of gain stages of the pulse wave sensor are set. Then, (1) the pulse wave amplitude is calculated from the pulse wave measured by the pulse wave sensor, (2) it is determined whether or not the pulse wave amplitude is within an appropriate range, and (3) the pulse wave amplitude is appropriate. If the pulse wave sensor gain is out of the range, the gain of the pulse wave sensor is changed by one step from the current gain, and (4) the process of (1) to (4) is waited for the pulse wave signal to settle down. Is repeated until the pulse wave amplitude falls within the proper range. Patent Document 1 describes that when the measured pulse wave amplitude is out of the standard range (appropriate range), the light amount of the light emitting element and the gain of the light receiving element are adjusted.

Japanese Patent Publication No. 6-18555

  However, in the conventional gain adjustment method, since the gain of the pulse wave sensor is changed one step at a time to obtain the optimum gain, there is a problem that it takes time to obtain the optimum gain. In this respect, Patent Document 1 only describes that the gain of the pulse wave sensor is adjusted when the pulse wave amplitude is out of the standard range (appropriate range), and therefore this problem is solved. Not.

  It is an object of the present invention to provide a pulse wave measuring device capable of shortening the time until the gain of a pulse wave sensor is adjusted to an optimum gain in which the pulse wave amplitude falls within an appropriate range.

In order to solve the above-described problems, a pulse wave measuring device according to the present invention includes an irradiating unit that irradiates light on a user's skin, and a light receiving unit that receives reflected light of the light irradiated by the irradiating unit as the user's pulse wave signal. A pulse wave sensor comprising means,
Gain adjusting means for adjusting the gain of the pulse wave sensor;
Amplitude calculating means for calculating the amplitude of the pulse wave signal detected by the pulse wave sensor;
Based on the amplitude obtained by the amplitude calculating means and the current gain, gain predicting means for predicting an optimum gain that is the gain within which the amplitude of the pulse wave signal falls within a predetermined appropriate range; Prepared,
The gain adjusting means has a first mode in which the gain of the pulse wave sensor is changed at a stroke as the gain adjustment mode to the optimum gain predicted by the gain predicting means.

  According to the present invention, the optimum gain is predicted based on the pulse wave amplitude and the current gain, and the predicted optimum gain is changed at a stroke. Therefore, the optimum gain is compared with the case where the gain is changed stepwise. Time to adjust can be shortened.

It is a block diagram of a pulse wave measuring device. It is the figure which showed the 1st example of the external appearance of a pulse wave measuring device. It is the figure which showed the 2nd example of the external appearance of a pulse wave measuring device. It is a figure of the use condition of the pulse-wave measuring apparatus of FIG. It is the figure which illustrated the table of user registration information. It is the figure which showed various ranges, such as the pulse wave signal 32 and the appropriate range 63. It is a flowchart of a gain adjustment process. It is a flowchart of the process which determines a light quantity initial value. It is a flowchart of the process which calculates a pulse wave amplitude. It is a figure for demonstrating the setting method of an amplitude calculation area, and is the figure which showed the electrocardiogram signal and the pulse wave signal. It is a figure explaining the method of calculating a pulse wave amplitude, without utilizing an electrocardiogram signal. FIG. 6 is a view showing a pulse wave signal 321 within an amplitude under-range 64. It is the figure which showed the pulse wave signal 322 exceeding AD range 60. FIG. It is the figure which showed transition of the pulse-wave signal containing DC component. It is a flowchart of the process which calculates an optimal gain value in a 1st mode. It is the figure which illustrated the relationship 81 of how a pulse wave amplitude changes with respect to light quantity. It is the figure which illustrated the relationship 82 of the light quantity and the pulse wave amplitude which were calculated | required at this measurement timing. It is the figure which simplified the shape of the pulse wave signal with a triangle. The relationship 81 of how the pulse wave amplitude changes with respect to the amount of light is illustrated, and a method of calculating the amount of light L that can reduce the pulse wave amplitude to the maximum value and the minimum value of the AD range using the relationship 81 is illustrated. It is a figure explaining.

  Hereinafter, embodiments of a pulse wave measuring apparatus according to the present invention will be described with reference to the drawings. FIG. 1 shows a configuration diagram of a pulse wave measuring apparatus 1 of the present embodiment. The pulse wave measuring device 1 is realized as a device that measures a user's pulse rate and blood pressure, for example. The pulse wave measuring device 1 has the external appearance illustrated in FIG. 2 and FIG. 3, for example. That is, the pulse wave measuring device 1 of FIG. 2 is configured in such a manner that each configuration of FIG. 1 (a configuration other than the pulse wave sensor 2) is accommodated in a box-shaped (square) housing 14. Further, the pulse wave measuring device 1 of FIG. 3 is configured in such a manner that each component of FIG. 1 is accommodated in a spherical casing 15.

  As shown in FIG. 1, a pulse wave measuring device 1 includes a pulse wave sensor 2 that detects a user's pulse wave signal, and a processing circuit 3 that performs various processes on the pulse wave signal measured by the pulse wave sensor 2. 4 and 6. The pulse wave sensor 2 is a known optical reflective sensor that includes a light emitting unit 21 (for example, a light emitting diode) and a light receiving unit 22 (for example, a photodiode). Specifically, when light is emitted from the light emitting unit 21 toward the user's skin, part of the light is absorbed by hemoglobin in the blood flowing through small arterioles (capillaries) passing through the inside of the human body, The remaining light is reflected and scattered by small arterioles, and a part of the scattered light enters the light receiving unit 22. The amount of hemoglobin flowing through small arterioles by blood pulsation changes in a wave manner, and the light absorbed by hemoglobin also changes in the wave manner. Therefore, the amount of received light reflected by the small arteriole and detected by the light receiving unit 22 changes, and the change in the received light amount at this time is output from the pulse wave sensor 2 as a pulse wave signal (for example, a voltage signal). Is done.

  In the example of FIG. 2, the pulse wave sensor 2 is provided outside the housing 14 and is connected to a circuit in the housing 14 via a cord 24 that transmits various signals. In the example of FIG. 3, the pulse wave sensor 2 is provided so as to be exposed on the surface of the housing 15. When measuring the pulse wave, the pulse wave sensor 2 is used so as to contact the skin of the user. In the example of the pulse wave measuring device 1 of FIG. 3, as shown in FIG. 4, the casing 15 is gripped by both hands of the user, and the palm 150 of one hand contacts the pulse wave sensor 2 at that time. It has become.

  As shown in FIG. 1, the light receiving unit 22 is connected to the amplifier 3, and the pulse wave signal received by the light receiving unit 22 is input to the amplifier 3. The amplifier 3 amplifies the pulse wave signal from the pulse wave sensor 2 (light receiving unit 22). The pulse wave signal (analog signal) amplified by the amplifier 3 is input to the A / D converter 4 and converted into a digital value by the A / D converter 4. The A / D converter 4 can normally convert an analog signal within a predetermined amplitude range (hereinafter referred to as an AD range) into a digital value, whereas an analog signal whose amplitude level exceeds the AD range. Cannot be converted to a digital value for the excess part. The AD range (voltage range) is, for example, a range of 0V to 5V. The pulse wave signal converted into a digital value by the A / D converter 4 is input to a CPU 5 described later.

  The pulse wave signal detected by the pulse wave sensor 2 includes a DC component (direct current component). The DC component is caused by light reflected from the surface of the skin or ambient light, and is independent of blood pulsation. Therefore, the pulse wave measuring device 1 is provided with a filter (not shown) that removes a DC component included in the pulse wave signal. The filter is provided, for example, before the A / D converter 4 (for example, before the amplifier 3 or inside the amplifier 3 or between the amplifier 3 and the A / D converter 4).

  The pulse wave sensor 2 (light receiving unit 22) is also connected to a DC component detection circuit 6 that detects a DC component superimposed on the AC signal. The pulse wave signal detected by the pulse wave sensor 2 is input to the DC component detection circuit 6, and the DC component included in the pulse wave signal is detected by the DC component detection circuit 6. Since the method of detecting (extracting) the DC component superimposed on the AC signal is well known, the description of the principle of detecting the DC component by the DC component detection circuit 6 is omitted. The DC component detected by the DC component detection circuit 6 is input to the CPU 5 described later.

  The pulse wave measuring device 1 further includes a CPU 5, a ROM 7, a RAM 8, a display unit 9, an operation unit 10, a temperature sensor 11, a light amount control unit 12, and a gain control unit 13. The light amount control unit 12 is a circuit that adjusts the light amount of the light emitting unit 21. The gain control unit 13 is a circuit that adjusts the amplification degree (gain) of the amplifier 3.

  The CPU 5 adjusts the gain of the pulse wave sensor 2, specifically the light amount of the light emitting unit 21 and the light receiving unit 22 so that the amplitude of the pulse wave signal input from the A / D converter 4 falls within a predetermined appropriate range. Gain adjustment processing for adjusting the gain (strictly, the amplification degree of the amplifier 3) is executed. In the present embodiment, the CPU 5 adjusts the light quantity of the light emitting unit 21 while fixing the amplification degree of the amplifier 3 as the gain adjustment of the pulse wave sensor 2. The gain adjustment process executed by the CPU 5 is a feature of the present invention and will be described in detail later.

  Further, the CPU 5 calculates, for example, the pulse rate / minute, blood pressure, and the like based on the pulse wave signal whose amplitude is in an appropriate range. When the period of the pulse wave signal (time for one beat) is T, the pulse rate / minute can be obtained by 60 ÷ T. The blood pressure can be determined, for example, by the method described in Japanese Patent Application Laid-Open No. 2008-279185.

  The ROM 7 stores processing programs executed by the CPU 5, registration information of users who have performed pulse wave measurement in the past, and the like. As the ROM 7, a non-volatile memory (for example, EEPROM, flash memory) capable of writing information is used. Here, FIG. 5 illustrates a table 71 of user registration information stored in the ROM 7. The table 71 includes a user number column 711 in which a user number of each user is stored as identification information for identifying the user, and an optimum gain value (light emitting unit) obtained by gain adjustment processing when pulse wave measurement was performed in the past. 21 and a gain value column 712 in which G is stored. In addition, the table 71 is provided with information about the user (for example, a column for storing the measured pulse rate, blood pressure, etc., and a column for storing the user's age, height, weight, etc.). Each user registration information is stored in association with the user number stored in the user number column 711.

  Further, the ROM 7 stores an initial value of the light amount of the light emitting unit 21 according to the user attribute that is considered to affect the pulse wave. Specifically, for example, the light amount initial value corresponding to the user's sex, race, and age is stored in the ROM 7 as the user attribute. For example, when considering the gender of a user, there are more women who are cooler than men, and due to the coolness, women are more difficult to measure pulse waves than men, that is, the pulse wave amplitude tends to be smaller is there. Therefore, a light amount initial value for women and a light amount initial value for men are determined, and for example, the light amount initial value for women is made larger than the light amount initial value for men. In the pulse wave measuring device 1, the light amount of the light emitting unit 21 is adjusted in a predetermined number of stages (specifically, as the light amount adjusting mode of the light emitting unit 21 when performing pulse wave measurement until the light amount reaches an optimum light amount. Is provided with a mode (second mode) in which the level is changed step by step within a range of 9 steps, for example. Then, the light quantity initial value may be set according to which stage of the plurality of stages (9 stages). Specifically, assuming that the number of light intensity steps is nine and the light intensity increases as the numerical value of the stage increases, for example, the initial light intensity value for men is the fifth light intensity, and the initial light intensity value for women is The amount of light at the seventh stage.

  Further, for example, when considering the race of the user, the darker the color of the skin (the darker the race), the light emitted from the light emitting unit 21 is less likely to pass through the skin, and the pulse wave amplitude tends to decrease. is there. Therefore, an initial light intensity value is determined according to race (black, yellow (Asian), white), and for example, the initial light intensity is increased in the order of white, yellow (Asian), and black. When setting the light intensity initial value according to which stage of the plurality of stages (9 stages), for example, the white light intensity initial value is set to the first stage, and the yellow person initial light intensity value is set to the fifth stage. , The initial black light intensity is set at the 9th stage.

  For example, when considering the age of a user, the present inventor has the knowledge that it is difficult to measure the pulse wave of an elderly person. Therefore, for example, an initial light amount value for young users (for example, for users under 40 years old) and an initial light amount value for elderly users (for example, for users over 40 years old) are determined, and for elderly users. The light amount initial value is set larger than the light amount initial value for young users. In the case where the initial light intensity value is set according to which stage of the plurality of stages (9 stages), for example, the initial light intensity value for an elderly user is set at the seventh stage, and the initial light intensity value for a young user. Is set at the third stage.

  It is also possible to set a light intensity initial value considering all of gender, race, and age, for example, a light intensity initial value for male, black, and elderly users, and for female, yellow, and young users. An initial value of light quantity or the like may be set.

  The RAM 8 temporarily stores various types of information (for example, the amplitude value of the pulse wave signal) necessary for the CPU 5 to perform processing such as gain adjustment processing.

  The display unit 9 displays various information such as the measured pulse wave signal and the pulse rate and blood pressure calculated by the CPU 5. The display unit 9 is, for example, a liquid crystal display or an organic EL display provided on the front surfaces of the casings 14 and 15 as shown in FIGS.

  As shown in FIGS. 2 and 3, the operation unit 10 is a part that is provided on the front surface of the housings 14 and 15, for example, and is operated by a user who performs pulse wave measurement. The operation unit 10 is, for example, a push button that is pressed. As shown in FIG. 2, the operation unit 10 includes, for example, a measurement start button 101 for instructing the pulse wave measurement device 1 to start pulse wave measurement and a measurement end button 102 for instructing the end of pulse wave measurement. . Further, the operation unit 10 is assumed to be operated by a user who determines that the amplitude level of the pulse wave signal 32 (see FIG. 2) displayed on the display unit 9 is too small or too large. The gain adjustment button 103 (see FIGS. 2 and 3) for instructing the adjustment of the gain (the light amount of the light emitting unit 21) is included. In addition, the operation unit 10 includes a registration button that instructs the pulse wave measurement device 1 to register the user, information about the user (for example, information for identifying the user (user number in FIG. 5), the user's age, gender, The input button etc. which input a race etc. are included. The operation unit 10 is connected to the CPU 5, and a signal indicating that the operation unit 10 has been operated is input to the CPU 5.

  The temperature sensor 11 is a sensor that detects the temperature of the user's skin part that the pulse wave sensor 2 contacts when the pulse wave sensor 2 performs pulse wave measurement. In the example of FIG. 2, the temperature sensor 11 is provided on the skin contact surface 23 of the pulse wave sensor 2. In the example of FIG. 3, the temperature sensor 11 is close to the pulse wave sensor 2, that is, the user's hand holds the casing 15. The temperature sensor 11 is provided in a portion where the palm 150 (see FIG. 4) of the hand hits in the state. The temperature sensor 11 is connected to the CPU 5, and the temperature detected by the temperature sensor 11 is input to the CPU 5.

  The pulse wave measurement device 1 (CPU 5) is configured to acquire an electrocardiogram signal measured by an electrocardiogram measurement device 100 (see FIG. 1) that measures a user's electrocardiogram signal (electrocardiogram). The electrocardiogram measuring apparatus 100 performs various processes (noise removal, amplification, AD conversion, etc.) on the electrode that detects the electrocardiogram signal by contacting the user's skin and the electrocardiogram signal detected by the electrode. It consists of a processing circuit to perform. The electrocardiogram measurement apparatus 100 may be configured separately from the pulse wave measurement apparatus 1 or may be configured to be incorporated in the pulse wave measurement apparatus 1. In the example of FIG. 3, an example in which electrocardiographic sensors 111 and 112 as the electrocardiographic measurement device 100 are provided on the back surface of the housing 15 is shown. One electrocardiographic sensor 111 is provided at a casing part (the right end of the back surface of the casing 15) where the right finger comes into contact with the user holding the casing 15, and the other electrocardiographic sensor 112 is configured such that the left finger is It is provided in the case part (the left end of the back surface of the case 15) which contacts.

  Next, details of the gain adjustment process executed by the CPU 5 will be described. As described above, in the gain adjustment process, the light amount of the light emitting unit 21 is adjusted so that the amplitude of the measured pulse wave signal falls within a predetermined appropriate range. Here, FIG. 6 is a diagram for explaining the appropriate range and the like, and shows the pulse wave signal 32 and various ranges including the appropriate range 63. FIG. 6 illustrates an AD range 60 of the A / D converter 4 (a range between the maximum value Vmax (for example, 5 V) and the minimum value Vmin (for example, 0 V) of the AD range 60). Further, FIG. 6 illustrates a range 64 (hereinafter referred to as an amplitude under-range) that is equal to or less than the standard value V1 indicating a range in which the amplitude of the pulse wave signal is too small.

  The appropriate range 63 includes a standard value V3 (corresponding to the second standard value of the present invention) larger than the limit value V1 (standard value V1, corresponding to the fourth standard value of the present invention) of the amplitude under-range 64, and its standard. Range between standard value V2 (corresponding to the first standard value of the present invention) that is larger than value V3 and smaller than limit values Vmax and Vmin (corresponding to the third standard value of the present invention) of AD range 60 Is set to The appropriate range 63 is set to, for example, 80% to 50% of the AD range 60, that is, the standard value V2 is set to 80% of the AD range 60 (maximum value Vmax, minimum value Vmin), and the standard value V3 is set to the AD range 60. Is set to 50%. As described above, by setting the upper limit (standard value V2) of the appropriate range 63 to a value having a margin with respect to the maximum value Vmax and the minimum value Vmin of the AD range 60, the light amount of the light emitting unit 21 is set to an optimal value. After the adjustment, it is possible to prevent the pulse wave signal whose amplitude varies from moment to moment from exceeding the AD range 60. 6 shows an example in which the amplitude (maximum value and minimum value of the pulse wave signal) of the pulse wave signal 32 is within the appropriate range 63.

  FIG. 7 shows a flowchart of the gain adjustment process. 7 starts when, for example, the measurement start button 101 (see FIG. 2) is operated, and ends when the pulse rate or blood pressure can be measured or when the measurement end button 102 (see FIG. 2) is operated. .

  When the processing of FIG. 7 is started, first, an initial value of the light amount of the light emitting unit 21 is determined (S11). FIG. 8 shows a detailed flowchart of the process of S11. When the processing of FIG. 8 is performed, first, when performing pulse wave measurement of a user (user assigned a user number) registered in the table 71 of FIG. 5, a user selection operation by the user is performed ( S31). That is, the user inputs his / her user number by operating a predetermined button of the operation unit 10 (S31). In S31, the CPU 5 accepts the user number input by the user selection operation. Note that when performing pulse wave measurement for an unregistered user (a user to whom a user number is not assigned), nothing is performed in S31.

  Next, it is determined whether or not the current user is a user registered in the table 71 of FIG. 5 (S32). Specifically, when a user number is input in S31, when the user number is registered in the table 71, it is determined that the user number has been registered, while the input user number is stored in the table 71. If the user number is not registered, or if the user number is not entered in S31, it is determined that the user is an unregistered user (S32).

  In the case of a registered user (S32: Yes), the process proceeds to S33, and the gain value stored in the table 71 of FIG. 5 in association with the input user number is read as the initial value of the light amount (S33). For example, when the user number “2” is input, the gain value G2 in FIG. 5 is read. Then, the process of the flowchart of FIG. 8 is complete | finished.

  In the case of an unregistered user (S32: No), the process proceeds to S34 to register a user registration operation by the user, specifically, information related to the user (user number, sex, age, race, etc.). A user operation is performed (S34). In S <b> 34, the CPU 5 receives information related to the user input by the user registration operation. Specifically, in S <b> 34, for example, the user can perform user registration by operating a registration button (not shown) in the operation unit 10. When the registration button is operated, the CPU 5 sets a user number not registered in the table 71 as the user number of the current user. Then, information (gender, age, race, etc.) input following the operation of the registration button is stored in the table 71 in association with the set user number or stored in the RAM 8 (see FIG. 1).

  Next, it is determined whether the sex in the information registered in S34 (stored in the table 71 or stored in the RAM 8) is male or female (S35). In the case of a male, the process proceeds to S36, where the initial light quantity value for men is read from the ROM 7 (S36). In the case of a female, the process proceeds to S37, where the initial light quantity value for women is read from the ROM 7 (S37). Thereafter, the process of the flowchart of FIG.

  In S34, when the user's race or age is input instead of gender or in addition to sex, in S35 to S37, the light intensity initial value or age according to the user's race is selected. The initial light amount value may be read from the ROM 7. Alternatively, in the case where the light amount initial value considering all of gender, race, and age is stored in the ROM 7, the light amount initial value may be read. Alternatively, when the initial light intensity value according to gender, the initial light intensity value according to the race, and the initial light intensity value according to the age are individually stored in the ROM 7, in S35 to S37, the current user The light intensity initial value according to the gender, the light intensity initial value according to the race, and the light intensity initial value according to the age are all read out, and the average value of the read plural light intensity initial values is used as the final light intensity initial value. Also good.

  Returning to the processing of FIG. 7, next, the light amount control unit 12 (see FIG. 1) is instructed, and the light amount of the pulse wave sensor 2 is adjusted so that light is emitted from the light emitting unit 21 with the light amount initial value determined in S11. Then, measurement of the pulse wave signal (pulse wave sampling) is started (S12). At this time, the CPU 5 instructs the gain control unit 13 (see FIG. 1), sets the amplification degree of the amplifier 3 to a predetermined fixed value, and performs pulse wave sampling. Thereby, compared with the case where pulse wave measurement is started from a uniform light amount initial value regardless of the user's attribute, the time until the optimum light amount is obtained in the subsequent processing can be shortened. The CPU 5 may display the pulse wave signal obtained in S12 on the display unit 9.

  Next, the amplitude Ha of the pulse wave signal obtained in S12 is calculated (S13). FIG. 9 shows a detailed flowchart of S13. In S13, the pulse wave amplitude Ha is calculated by the process of the flowchart. In order to accurately calculate the pulse wave amplitude, it is necessary to accurately detect the start point (lowest point) and the end point (highest point) of the pulse wave, but noise superimposed on the pulse wave signal and the pulse wave signal Due to the influence of fluctuation or the like, it may be difficult to detect the start point and the end point. On the other hand, since a pulse is a change in pressure in an artery caused by a heartbeat, the pulse wave signal has a correlation with an electrocardiogram signal. Specifically, the pulse wave signal propagates with a delay from the electrocardiogram signal. The heartbeat signal has a clearer waveform than the pulse wave signal. Therefore, in the processing of FIG. 9, the pulse wave amplitude is calculated based on the heartbeat signal of the user.

  Specifically, when the process proceeds to the process of FIG. 9, first, an electrocardiogram signal of the user is acquired from the electrocardiograph 100 (see FIG. 1) (S41). Next, based on the electrocardiogram signal acquired in S41, a time interval (amplitude calculation interval) for calculating the amplitude from the pulse wave signal is set (S42). FIG. 10 is a diagram for explaining a setting method of the amplitude calculation section, and in detail shows the electrocardiogram signal 50 acquired in S41 and the pulse wave signal 32 obtained in S12 of FIG. The time axes of the electrocardiogram signal 50 and the pulse wave signal 32 are the same. As described above, the pulse wave signal 32 propagates with a delay with respect to the electrocardiogram signal 50 (the R wave 51 of the electrocardiogram signal 50). That is, the wave of the broken line portion 32a in the pulse wave signal 32 in FIG. 10 is a wave generated by the immediately preceding R wave 51a. Therefore, in S42, a section from time t1 of the R wave 51 of the electrocardiogram signal 50 to time t2 is set as an amplitude calculation section. Specifically, the time t2 is set so that the amplitude calculation section includes the pulse wave 32a corresponding to the R wave 51a and is shorter than the period t3 of the electrocardiogram signal 50. More specifically, a section having a predetermined ratio (for example, 70%) of the period t3 of the electrocardiogram signal 50 with the time t1 as a base point is set as the amplitude calculation section.

  Next, the minimum value P1 and the maximum value P2 of the pulse wave signal 32 are detected in the amplitude calculation section set in S42, and the difference Ha between the minimum value P1 and the maximum value P2 is calculated as the pulse wave amplitude (S43). ). Thereafter, the processing of the flowchart of FIG. 9 ends.

  In S42, a plurality of amplitude calculation sections are set. In S43, the pulse wave amplitude is calculated for each amplitude calculation section, and the final pulse wave amplitude is calculated based on the obtained plurality of pulse wave amplitudes. Also good. Specifically, for example, an average value or median value of a plurality of pulse wave amplitudes is set as a final pulse wave amplitude. Thereby, it is possible to obtain a highly accurate pulse wave amplitude with reduced influences such as noise and fluctuation of the pulse wave signal.

  Note that the pulse wave amplitude can be calculated without using an electrocardiogram signal. In this case, for example, as shown in FIG. 11, the pulse wave signal is divided for each predetermined time interval (amplitude calculation interval), and the pulse wave amplitudes H1, H2, H3, H4,. .. Is calculated, and the average value or median value of the obtained pulse wave amplitudes is set as the final pulse wave amplitude. However, in the method that does not use an electrocardiogram signal, the amplitude calculation section is inaccurate compared to the method of FIG. 9, that is, an amplitude calculation section that is less than one pulse wave is set, or two beats are set. In some cases, an amplitude calculation section including more than a minute pulse wave may be set, and in order to ensure the calculation accuracy of the pulse wave amplitude, it is necessary to set a large number of amplitude calculation sections. As a result, it takes time until the final pulse wave amplitude is obtained. On the other hand, in the technique using an electrocardiogram signal, an accurate amplitude calculation section can be set, so that the number of set amplitude calculation sections can be suppressed, and the pulse wave amplitude calculation time can be shortened.

  Returning to the description of the processing in FIG. In the present embodiment, in addition to the second mode, there is a first mode in which the gain of the pulse wave sensor 2 (light quantity of the light emitting unit 21) is changed to an optimal value at once (without performing stepwise light quantity adjustment). Is provided. Therefore, after S13, it is determined whether or not gain adjustment is performed in the first mode (S14). Specifically, in the present embodiment, there are four determination methods as the method of determining in S14, and whether or not the first mode is performed based on the pulse wave amplitude obtained in S13 as the first determination method. Determine whether. More specifically, the pulse wave amplitude Ha obtained in S13 exceeds the amplitude underrange 64 (in the case of the standard value V1 or less) in FIG. 6 or exceeds the AD range 60 (maximum value Vmax, minimum value Vmin). If it is determined that the gain adjustment is performed in the first mode.

  FIG. 12 shows a case where the amplitude Ha of the pulse wave signal 321 is within the amplitude under-range 64. In this case, the amplitude Ha of the pulse wave signal 321 is too small, and it is difficult to obtain the pulse rate, blood pressure, and the like from the pulse wave signal 321, and therefore, the light amount of the light emitting unit 21 is adjusted by performing gain adjustment in the first mode. Need to be larger.

  FIG. 13 shows a case where the amplitude of the pulse wave signal 322 (pulse wave signal after AD converted by the A / D converter 4) exceeds the AD range 60 (maximum value Vmax in FIG. 13). In this case, the portion 322a of the pulse wave signal 322 exceeding the AD range 60 is saturated at the maximum value Vmax, and has a shape different from the shape of the actual pulse wave signal (pulse wave signal before AD conversion). A pulse wave signal 322 is obtained. If the pulse rate, blood pressure, and the like are obtained based on the pulse wave signal 322, the accuracy thereof decreases. Therefore, it is necessary to perform gain adjustment in the first mode to reduce the light amount of the light emitting unit 21.

  Next, the second determination method will be described. It is determined whether or not to perform the first mode based on the DC component detected by the DC component detection circuit 6 (see FIG. 1). Here, FIG. 14 shows the transition of the pulse wave signal including the DC component (pulse wave signal before the DC component is removed by the filter). In FIG. 14, the current pulse wave signal is denoted by “312”, the pulse wave signal immediately before, in other words, the pulse wave signal obtained by the pulse wave sampling of S12 one time before or the pulse wave obtained before a predetermined time. The wave signal is illustrated by reference numeral “311”.

  The fact that the DC component of the pulse wave signal has changed significantly means that the surrounding environment (brightness) is present, for example, when a user who is measuring pulse waves with the portable pulse wave measuring device 1 moves from a dark place to a bright place. It can be considered that the conditions of pulse wave measurement have changed, such as when the contact state between the pulse wave sensor 2 and the skin has changed, or when the user has changed. In this case, it is necessary to readjust the light amount according to the current measurement conditions. Therefore, in S14, it is determined that the first mode is performed when the DC component detected by the DC component detection circuit 6 changes by a predetermined threshold value or more. That is, in the example of FIG. 14, it is determined that the first mode is performed when the difference ΔDC between the DC component 312a of the current pulse wave signal 312 and the DC component 311a of the immediately preceding pulse wave signal 311 is equal to or greater than a predetermined threshold. .

  Next, a third determination method will be described. The gain adjustment button 103 (FIGS. 2 and 3) is displayed by the user who has determined that the gain of the pulse wave sensor 2 is insufficient or excessive by looking at the pulse wave signal displayed on the display unit 9. When (see) is operated, it is determined that the first mode is performed.

  Next, a fourth determination method will be described. When the temperature of the skin part where the pulse wave measurement is performed is reduced, the amplitude of the pulse wave signal tends to decrease due to a decrease in blood flow. Therefore, in S14, it is determined that the first mode is performed when the temperature detected by the temperature sensor 11 (see FIG. 1) is equal to or lower than a predetermined temperature (for example, 20 ° C.).

  As described above, in S14, when at least one of the first mode execution conditions of the first to fourth determination methods is satisfied, it is determined that the gain adjustment is performed in the first mode, and when none is satisfied, Determines that no gain adjustment is performed in the first mode.

  In S14, when it is determined that the gain adjustment is performed in the first mode (S14: Yes), the process proceeds to S15 to execute the first mode. Specifically, the amplitude of the pulse wave signal is within the appropriate range 63 (FIG. 6). The gain value G of the pulse wave sensor 2 entering (see) is determined (S15). FIG. 15 shows a detailed flowchart of S15. In S15, the optimum gain value G is determined by the processing of the flowchart.

  When the process proceeds to the process of FIG. 15, first, it is determined whether or not the amplitude of the pulse wave signal exceeds the AD range 60 (see FIG. 6) (S51). Specifically, when the maximum value or minimum value of the pulse wave signal obtained in S12 reaches the maximum value Vmax or minimum value Vmin of the AD range 60, the amplitude of the pulse wave signal exceeds the AD range 60. If the maximum value Vmax or the minimum value Vmin has not been reached, it is determined that the amplitude of the pulse wave signal is within the AD range 60.

  When the amplitude of the pulse wave signal is within the AD range 60 (S51: No), the process proceeds to S52. In this case, as shown in FIG. 12, the case where the amplitude Ha of the pulse wave signal 321 is equal to or less than the standard value V1 (when the first mode is determined to be performed by the first determination method in S14 of FIG. 7). Assumed.

  In S52, an amplitude ratio between the optimum amplitude Hb stored in advance in the ROM 7 or the like as the pulse wave amplitude that falls within the appropriate range 63 (see FIG. 6) and the pulse wave amplitude Ha calculated in S13 of FIG. 7 is calculated (S52). . In the present embodiment, the ratio of the optimum amplitude Hb to the pulse wave amplitude Ha (= Hb / Ha) is calculated as the amplitude ratio.

  Next, based on the amplitude ratio Hb / Ha calculated in S52 and the current light amount La of the light emitting unit 21, the optimum light amount Lb, which is the light amount of the light emitting unit 21 from which the optimum amplitude Hb is obtained, is set as the optimum gain value G. Calculate (S53). Specifically, for example, assuming that the light amount and the pulse wave amplitude are proportional, the optimum light amount Lb is a light amount obtained by multiplying the current light amount La by an amplitude ratio Hb / Ha, that is, Lb = La × (Hb / Ha). Become.

  Since the light amount and the pulse wave amplitude are not strictly proportional, in S53, for example, as shown in FIG. 16, the relationship 81 of how the pulse wave amplitude changes with respect to the light amount is examined in advance. The relationship 81 is stored in the ROM 7 (see FIG. 1). In S53, the optimum light amount Lb may be calculated using the relationship 81 stored in the ROM 7. At this time, even if the light quantity is the same, the pulse wave amplitude changes when the measurement conditions such as the individual and the environment change, and therefore the light quantity L2 corresponding to the optimum amplitude Hb cannot be used in the relationship 81 as it is. Therefore, the light amount L1 corresponding to the pulse wave amplitude Ha calculated in S13 and the light amount L2 corresponding to the optimum amplitude Hb are obtained from the relationship 81. A light amount obtained by multiplying the current light amount La by a ratio (= L2 / L1) of the light amount L2 and the light amount L1 is set as an optimum light amount Lb. That is, Lb = La × (L2 / L1). Thereby, even when the light quantity and the pulse wave amplitude are not in a proportional relationship, the optimum light quantity Lb with high accuracy can be obtained.

  In order to obtain a more accurate optimum light amount Lb, the relationship between the light amount and the pulse wave amplitude may be obtained at the timing of measuring the pulse wave. Specifically, as shown in FIG. 17, the pulse wave amplitudes H31, H32, H33... At each light amount L31, L32, L33. Ask for. Then, in the coordinate system determined by the pulse wave amplitude and the light quantity, the approximate line 82 for the point (H31, L31), the point (H32, L32), the point (H33, L33),... Obtained as the relationship of wave amplitude. The timing for obtaining the relationship 82 may be any time during the current measurement, for example, the relationship 82 may be obtained during the processing of S34, or the relationship 82 may be obtained at a timing before S34. . In S53, the optimum light quantity Lb is calculated by the same method as described with reference to FIG. Thereby, the highly accurate optimum light quantity Lb reflecting the current measurement conditions can be obtained. After S53, the process of the flowchart of FIG.

  On the other hand, in S51, as shown in FIG. 13, when the amplitude of the pulse wave signal 322 exceeds the AD range 60 (S51: Yes), the process proceeds to S54. In this case, since an accurate pulse wave amplitude cannot be obtained in the previous S13, the optimum light amount is obtained without using the pulse wave amplitude in and after S54.

  The processing after S54 will be described with reference to FIG. 13. In S54, a saturation interval length Ta, which is a time width in the portion 322a of the pulse wave signal 322 exceeding the AD range 60, is calculated. Specifically, the length of the portion of the pulse wave signal 322 that has the same value as the maximum value Vmax or the minimum value Vmin of the AD range 60 (the length of the portion that has reached the maximum value Vmax in the example of FIG. 13). ) Is calculated as the saturation interval length Ta.

  Next, a pulse wavelength Tb, which is a time width (pulse wave cycle) of one pulse of the pulse wave signal 322, is calculated (S55). Specifically, when a highly accurate pulse wave signal, that is, a pulse wave signal capable of calculating the pulse rate, has been obtained in S12 up to the previous time, in S55, for example, the pulse rate is calculated from the pulse wave signal. The pulse wavelength Tb obtained in the calculation process is acquired. Alternatively, the pulse wavelength Tb may be obtained from the current pulse wave signal 322 (see FIG. 13). Specifically, the first inflection point 322c (the lowest point in the case of FIG. 13) is detected from the left end 322b of the saturation section in a direction reverse to the time. In addition, the first inflection point 322e (the lowest point in the case of FIG. 13) is detected from the right end 322d of the saturation section in the direction forward in time. Then, the length Tb between the detected inflection points 322c and 322e is calculated as the pulse wavelength.

  Here, FIG. 18 is a diagram schematically showing the pulse wave signal 322 and the portion 322a exceeding the AD range 60 in FIG. 13, and in detail, the shape of the pulse wave signal 322 and the portion 322a is simplified by a triangle. FIG. A solid line portion 323 in FIG. 18 corresponds to the pulse wave signal 322 in FIG. 13, and a broken line portion 323a corresponds to the broken line portion 322a in FIG. Here, by adjusting the amount of light, the triangle (height = H11 + H12) defined by the solid line portion 323 and the broken line portion 323a is changed to a triangle 324 (one-dot chain line portion) of the AD range height H12 (height of the solid line portion 323). ) At this time, assuming that the relationship between the light amount of the light emitting unit 21 and the pulse wave amplitude is a proportional relationship, the current light amount La is calculated from the relationship between the pulse wavelength Tb, the saturation interval length Ta, and the heights H11 and H12 in FIG. It can be seen that the pulse wave amplitude can be reduced to the height H12 of the triangle 324 by multiplying by (1-Ta / Tb).

  Therefore, in the next S56, the ratio Ta / Tb of the saturation section length Ta to the pulse wavelength Tb is calculated. Next, based on the ratio Ta / Tb and the current light amount La, the light amount (optimum light amount Lb) of the light-emitting unit 21 from which a pulse wave signal whose pulse wave amplitude falls within the appropriate range 63 (see FIG. 6) is obtained is optimal. The gain value G is calculated (S57). Specifically, as described above, the pulse wave amplitude can theoretically be reduced to the maximum value Vmax and the minimum value Vmin of the AD range 60 by multiplying the current light amount La by (1−Ta / Tb) times. . Further, when the pulse wave amplitude is lowered to within the appropriate range 63, it corresponds to the difference between the upper limit value V2 (see FIG. 6) of the appropriate range 63 and the maximum value Vmax and minimum value Vmin of the AD range 60. You only need to reduce the amount of light. That is, in S57, Lb = La × (1−Ta / Tb) × k may be calculated. Note that k is a coefficient of 1 or less corresponding to the difference between the upper limit value V2, the maximum value Vmax, and the minimum value Vmin.

  As in S53, since the light quantity and the pulse wave amplitude are not strictly proportional, in S57, for example, as shown in FIG. 19, how the pulse wave amplitude changes with respect to the light quantity. 81 is examined in advance, and the relationship 81 is stored in the ROM 7 (see FIG. 1). And in S57, you may calculate the optimal light quantity Lb using the relationship 81 memorize | stored in ROM7. Specifically, the pulse wave amplitude Hc corresponding to the current light amount La is obtained from the relationship 81. Then, the light quantity L corresponding to the pulse wave amplitude (= Hc × (1-Ta / Tb)) obtained by multiplying the pulse wave amplitude Hc by (1−Ta / Tb) is obtained from the relationship 81. Thereby, even when the light amount and the pulse wave amplitude are not in a proportional relationship, the light amount L that can reduce the pulse wave amplitude to the maximum value Vmax and the minimum value Vmin of the AD range 60 is obtained. Further, by multiplying the light quantity L by the coefficient k, the optimum light quantity Lb in which the pulse wave amplitude falls within the appropriate range 63 can be obtained.

  As in S53, the relationship 82 between the light amount and the pulse wave amplitude (see FIG. 17) may be obtained at the timing of measuring the pulse wave, and the optimum light amount Lb may be calculated using the relationship 82 in S57. As a result, it is possible to obtain the optimum light quantity Lb with higher accuracy. After S57, the process of the flowchart of FIG.

  Returning to the processing of FIG. 7, after calculating the optimum gain value G (optimum light amount Lb) in S15, the process proceeds to S20, and the light amount control unit 12 adjusts the light amount of the light emitting unit 21 so that the gain value G is obtained. . That is, the light amount of the light emitting unit 21 is changed at a stroke from the current light amount La to the optimum light amount Lb obtained in S15 (S20). Accordingly, in the example of FIG. 12, the pulse wave signal 321 of the solid line can be changed at a stroke from the pulse wave signal 33 of the broken line, and in the example of FIG. 13, the pulse wave signal 322 of the solid line is changed to the pulse wave signal 33 of the broken line. It can be changed at once. That is, the pulse wave amplitude can be changed at a stretch to within the appropriate range 63. Therefore, the time for adjusting the light amount can be shortened. After S20, the process returns to S12, and the pulse wave signal at the next time is measured (S12).

  On the other hand, if it is determined in S14 that the gain adjustment is not performed in the first mode (S14: No), the process proceeds to S16 to determine whether the gain adjustment is performed in the second mode in which the light amount is changed step by step. Judgment is made (S16). Specifically, the pulse wave amplitude Ha calculated in S13 (strictly, the highest point and the lowest point of the pulse wave amplitude Ha) is a range between the standard value V2 and the maximum value Vmax or the minimum value Vmin shown in FIG. 66, or whether or not the gain adjustment is performed in the second mode is determined based on whether or not it is within the range 65 between the standard value V1 and the standard value V3.

  When the pulse wave amplitude Ha falls within the ranges 65 and 66 in FIG. 6 (S16: Yes), the second mode is executed and the process proceeds to S17. In S17, it is determined whether the pulse wave amplitude Ha is too small or too large based on whether the pulse wave amplitude Ha is in the range 65 or 66 in FIG. 6 (S17). If the pulse wave amplitude Ha is in the range 65, it is determined that the amplitude Ha is too small, and the process proceeds to S18, where the gain value G (light quantity of the light emitting unit 21) is increased by one step from the current gain value (light quantity). (S18). Thereafter, the process proceeds to S20, and the light amount control unit 12 adjusts the light amount of the light emitting unit 21 so that the gain value G determined in S18 is obtained. As a result, the pulse wave amplitude can be increased by an amount corresponding to an increase in the amount of light by one step.

  Thereafter, returning to S12, pulse wave sampling at the next time point is performed, and when the amplitude Ha of the pulse wave signal obtained by the pulse wave sampling is still too small (S17: small amplitude), the gain value G is further increased by 1. Increase the level (S18, S20). After that, in S16, if the pulse wave amplitude Ha does not enter either of the ranges 65 and 66 in FIG. 6 (S16: No), that is, if the pulse wave amplitude Ha is in the appropriate range 63, the process proceeds to S21. The current gain value G is recorded in the table 71 (see FIG. 5) in association with the current user number (S21). The gain value G recorded in S21 is used as the light quantity initial value determined in S11 in the next and subsequent pulse wave measurements. The gain value (optimum light quantity Lb) determined in the first mode is adjusted when the pulse wave amplitude Ha is within the appropriate range 63, that is, the gain is adjusted in the first mode by S15 → S20. After performing, when returning to S12 and determining that S14: No → S16: No, it is recorded in the table 71 (S21).

  On the other hand, if the pulse wave amplitude Ha is in the range 66 (see FIG. 6) in S17, it is determined that the amplitude Ha is too large, and the process proceeds to S19, where the gain value G (light quantity of the light emitting unit 21) is set to the current value. The gain value (light quantity) is decreased by one step (S19). Thereafter, the process proceeds to S20, and the light amount control unit 12 is caused to adjust the light amount of the light emitting unit 21 so that the gain value determined in S19 is obtained. As a result, the pulse wave amplitude can be reduced by an amount corresponding to a one-step decrease in the amount of light.

  Thereafter, returning to S12, pulse wave sampling at the next time point is performed, and if the pulse wave amplitude Ha of the pulse wave signal obtained by the pulse wave sampling is still too large (S17: large amplitude), the gain value G is set to Further, it is decreased by one step (S19, S20). After that, in S16, if the pulse wave amplitude Ha does not enter either of the ranges 65 and 66 in FIG. 6 (S16: No), that is, if the pulse wave amplitude Ha is in the appropriate range 63, the process proceeds to S21. The current gain value G is recorded in the table 71 (see FIG. 5) in association with the current user number (S21). Thereafter, the CPU 5 calculates the pulse rate, blood pressure, and the like based on the pulse wave signal within the appropriate range, and displays the calculated pulse rate, blood pressure, and the like on the display unit 9.

  As described above, according to the present embodiment, when the pulse wave amplitude is significantly out of the appropriate range, or when the measurement condition is changed (when the DC component is greatly changed, or when the gain adjustment button is operated). When the skin temperature decreases), the first mode is executed to change the light amount at a stretch, so that the light amount adjustment time can be shortened. In addition, when the pulse wave amplitude is slightly outside the appropriate range, the second mode is executed and the amount of light is changed step by step until the pulse wave amplitude enters the appropriate range. Can be put inside.

  In addition, this invention is not limited to the said embodiment, A various change is possible to the limit which does not deviate from description of a claim. For example, in the above-described embodiment, an example in which the light amount adjustment of the light emitting unit is performed as the gain adjustment of the pulse wave sensor, but the amplification degree of the amplifier 3 (see FIG. 1) is adjusted instead of or in addition to the light amount. You may do it. In the above embodiment, the first mode is executed when the pulse wave amplitude exceeds the AD range, or when the pulse wave amplitude is within the amplitude under-range, but the pulse wave amplitude is within the AD range and outside the amplitude under-range. Even in such a case, the first mode may be executed in place of the second mode when it is out of the proper range.

DESCRIPTION OF SYMBOLS 1 Pulse wave measuring device 2 Pulse wave sensor 21 Light emission part 22 Light reception part 5 CPU
12 Light quantity control unit 13 Gain control unit

Claims (14)

A pulse wave sensor (2) comprising an irradiating means (21) for irradiating light on the user's skin and a light receiving means (22) for receiving reflected light of the light irradiated by the irradiating means as the pulse wave signal of the user; ,
Gain adjusting means (12, 13, 5, S20) for adjusting the gain of the pulse wave sensor;
Amplitude calculating means (S13) for calculating the amplitude of the pulse wave signal detected by the pulse wave sensor;
Based on the amplitude obtained by the amplitude calculating means and the current gain, gain predicting means for predicting the optimum gain that is the gain within which the amplitude of the pulse wave signal falls within a predetermined appropriate range (63). (S15)
The gain adjusting unit has a first mode in which the gain of the pulse wave sensor is changed at a stroke to the optimum gain predicted by the gain predicting unit as the gain adjusting mode. .   The gain adjusting means (S18, S19) changes the gain stepwise in a predetermined range until the amplitude calculated by the amplitude calculating means falls within the appropriate range as the gain adjustment mode. It has a 2nd mode, The pulse wave measuring device of Claim 1 characterized by the above-mentioned.   The gain predicting means (S52, S53) includes an amplitude ratio between a current amplitude of the pulse wave signal obtained by the amplitude calculating means and an optimum amplitude predetermined as the amplitude falling within the appropriate range; The pulse wave measuring device according to claim 1, wherein the optimum gain is predicted based on the gain of the pulse wave. An A / D converter (4) for converting the pulse wave signal received by the light receiving means into a digital value;
A pulse wavelength calculating means (S55) for calculating a pulse wavelength which is a time width of one pulse of the pulse wave signal;
When the amplitude of the pulse wave signal before conversion into a digital value by the A / D converter exceeds the amplitude range (60) of the analog signal that can be converted into a digital value by the A / D converter, the pulse Saturation section calculation means (S54) for calculating a saturation section length that is a time width in a portion of the wave signal that exceeds the amplitude range;
The amplitude calculation means calculates the amplitude of the pulse wave signal based on the pulse wave signal converted into a digital value by the A / D converter,
When the amplitude of the pulse wave signal exceeds the amplitude range, the gain predicting means (S56, S57) uses the ratio of the saturation interval length and the pulse wavelength instead of the amplitude ratio, and the ratio The pulse wave measuring device according to claim 3, wherein the optimum gain is predicted based on the current gain and the current gain. The appropriate range is set to a range not less than a first standard value (V2) and not less than a second standard value (V3) smaller than the first standard value,
The gain adjusting means (S14), when the amplitude of the pulse wave signal exceeds a third standard value (Vmax, Vmin) set in a direction in which the amplitude is larger than the first standard value, Alternatively, the first mode is executed when the amplitude falls below a fourth standard value (V1) set in a direction in which the amplitude is smaller than the second standard value. The pulse wave measuring device according to claim 1.   The said gain adjustment means (S14) performs the said 1st mode, when the direct current | flow component of the said pulse wave signal changes more than a predetermined threshold value, The 1st mode of Claim 1 characterized by the above-mentioned. Pulse wave measuring device. Display means (9) for displaying the pulse wave signal;
An operation unit (103) operated by a user who determines that the gain adjustment is necessary,
The pulse wave measuring device according to any one of claims 1 to 6, wherein the gain adjusting means (S14) executes the first mode when the operation unit is operated. A temperature sensor (11) for detecting the temperature of the user's skin part where the pulse wave signal is detected by the pulse wave sensor;
The pulse wave according to any one of claims 1 to 7, wherein the gain adjusting means (S14) executes the first mode when the temperature detected by the temperature sensor is equal to or lower than a predetermined temperature. Measuring device.   The gain adjusting means (S16) is configured such that the amplitude of the pulse wave signal is not less than the first standard value and not greater than the third standard value, or not greater than the second standard value, and The pulse wave measuring device according to claim 5, wherein the second mode is executed when the value is equal to or greater than a fourth standard value. Comprising an electrocardiogram signal acquisition means (S41) for acquiring a user's electrocardiogram signal;
The amplitude calculation means (S42, S43) sets a time interval for calculating the amplitude from the pulse wave signal based on the electrocardiogram signal acquired by the electrocardiogram signal acquisition means, and the pulse in the time interval is set. The pulse wave measuring device according to claim 1, wherein the difference between the minimum value and the maximum value of the wave signal is calculated as the amplitude of the pulse wave signal. Gain storage means (7, 71) for storing the optimum gain adjusted by the gain adjustment means in association with specific information for specifying a user;
User information acquisition means (S31, 10) for acquiring the specific information of the user this time;
Initial value setting means (S33) for setting the optimum gain stored in the gain storage means in association with the specific information acquired by the user information acquisition means as an initial value of the gain in the current pulse wave measurement; The pulse wave measuring device according to claim 1, comprising: Attribute acquisition means (S34, 10) for acquiring user attributes;
The pulse according to any one of claims 1 to 10, further comprising initial value setting means (S35 to S37) for setting an initial value of the gain according to the attribute acquired by the attribute acquisition means. Wave measuring device.   The pulse wave measuring apparatus according to claim 12, wherein the attribute acquisition unit acquires the gender, race, or age of the user as the attribute.   The pulse wave measuring device according to claim 1, wherein the gain is a light amount of the irradiation unit.

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