JP2016112291A - Biological information measurement device and biological information measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biological information measurement device which can determine an abnormal state of a subject in a simple method.SOLUTION: A biological information measurement device includes: pulse wave measurement means measuring a pulse wave of a subject; amplitude strength measurement means measuring amplitude strength of the measured pulse wave; and state determination means determining an abnormal state of the subject based on a change state of the amplitude strength of the pulse wave measured by the amplitude strength measurement means.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a biological information measuring device and a biological information measuring method for measuring a biological signal such as a pulse wave.

  Due to the recent increase in interest in health management, a biological information measuring device capable of easily measuring various biological information such as pulse rate has been proposed.

  In this regard, for example, Japanese Patent Application Laid-Open No. 2011-212306 (Patent Document 1) measures physiological indices related to peripheral blood flow for risk determination such as heat stroke and hypothermia, A method for determining a risk from fluctuation of a physiological index has been proposed.

JP 2011-212306 A

  On the other hand, in the above method, a method for measuring fluctuation based on measurement of the skin temperature of the measurement subject is shown. However, since the skin temperature is easily affected by the surrounding environment, the skin temperature is measured with high accuracy. There is a problem that it is difficult to do.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a biological information measuring apparatus that can determine an abnormal state of a person to be measured by a simple method. .

  A biological information measuring device according to an aspect of the present invention is measured by a pulse wave measuring unit that measures a pulse wave of a measurement subject, an amplitude intensity measuring unit that measures the amplitude intensity of the measured pulse wave, and an amplitude intensity measuring unit. State determining means for determining an abnormal state of the person to be measured based on a change state of the amplitude intensity of the pulse wave.

  It is possible to determine the abnormal state of the person being measured by a simple method.

1 is a schematic diagram illustrating an example of an appearance of a biological information measuring apparatus (hereinafter, abbreviated as a measuring apparatus) 100 according to the present embodiment. 2 is a block diagram illustrating an example of a device configuration of a measuring device 100. FIG. It is a figure explaining the pulse wave signal detected from the detection part. It is a flowchart explaining the process of the measuring apparatus 100 based on embodiment. It is a flowchart explaining the risk determination process in the measuring apparatus 100 based on embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.
<Device configuration>
FIG. 1 is a schematic diagram illustrating an example of the appearance of a biological information measuring apparatus (hereinafter, abbreviated as a measuring apparatus) 100 according to the present embodiment.

  Referring to FIG. 1, a measuring apparatus 100 includes a main body 1 having a detection unit 2 that is a sensor for detecting a biological signal, and a belt 3 for fixing the detection unit 2 to a measurement site. .

  The detection unit 2 includes a light receiving unit 21 having a light receiving element and a light emitting unit 22 having a light emitting element (FIG. 2). The light receiving unit 21 reflects reflected light from a measurement object out of light emitted from the light emitting unit 22. Receive light. The light receiving unit 21 is a photodiode, a phototransistor, or the like. The light receiving unit 21 outputs a detection signal representing the amount of received light as a change in current value. That is, the detection unit 2 is a sensor that uses a biological phenomenon that can be measured by a change in reflectance on the skin surface as a measurement object.

  Here, the biological information refers to information representing the state of biological phenomena such as pulse, electroencephalogram, blood pressure, blood glucose level, blood oxygen concentration, and sweating.

  In this example, a case where a pulse wave signal is measured as an example of biological information will be described.

  Because hemoglobin contained in blood has light absorption characteristics (absorption characteristics), the reflected light of a living body when irradiated with light from a photoelectric sensor changes according to the amount of hemoglobin that changes with blood flow volume Therefore, it is possible to measure the pulse wave signal by changing the reflected light into an electric signal.

  The main body 1 is attached to the measurement site with a belt 3. When the biological phenomenon detected by the detection unit 2 is a pulse, the measurement site corresponds to an arteriole connected to a capillary vessel under the skin. That is, the measurement site may be any site as long as capillaries are gathered. For example, this applies to the skin directly above the artery such as the wrist, upper arm, thigh, knee, ankle, and neck. A suitable measurement site includes a fingertip in which capillaries are gathered. In order to enable measurement even while the measurement subject is operating, a wrist is a more preferable measurement site.

  The belt 3 is wound around the measurement site in a first circumferential direction (for example, counterclockwise) and in a second circumferential direction (for example, clockwise) opposite to the first circumferential direction. It consists of a belt 3b to be rotated. The belt 3 pulls the main body 1 in the first circumferential direction by the belt 3a and in the second circumferential direction by the belt 3b, thereby fixing the detection unit 2 to the measurement site.

  In the following description, when the main body 1 is attached to the measurement site with the belt 3, the surface facing the measurement site is the back surface of the main body 1 and the belt 3, and the surface facing the measurement site is the main body. 1 and the surface of the belt 3.

  Preferably, a display unit 13 for displaying measurement results and an operation unit 14 such as a button for instructing measurement start are arranged on the surface of the main body unit 1. Thereby, the user can operate the main body 1 with the belt 3 attached to the measurement site, or can visually check the measurement result.

  The detection unit 2 is disposed on the back surface of the main body unit 1. Thus, when the main body 1 is attached to the measurement site with the belt 3, the detection unit 2 faces the measurement site.

  As an example of the appearance, the main body 1 is circular or substantially circular, and the belt 3 a and the belt 3 b are respectively connected to both ends of the main body 1 in the diameter direction. And the detection part 2 is distribute | arranged to the center or substantially center position of the back surface of the main-body part 1. FIG. That is, the detection unit 2 is disposed at a position on the back surface of the main body unit 1 between the connection positions of the belt 3a and the belt 3b. Thereby, when the main body 1 is attached to the measurement site with the belt 3, the position of the detection unit 2 with respect to the measurement site is stabilized.

FIG. 2 is a block diagram showing an example of the device configuration of the measuring device 100.
Referring to FIG. 2, measurement apparatus 100 includes a CPU (Central Processing Unit) 10 for controlling the entire apparatus, and a ROM (Read Only Memory) 11 that is a memory for storing a program executed by CPU 10. And a RAM (Random Access Memory) 12 which is a memory for storing measurement values and serving as a work area when the CPU 10 executes a program. The CPU 10, ROM 11, and RAM 12 are built in the main body 1.

  The main body unit 1 includes a photoelectric conversion detection circuit 23 for receiving an input of a signal represented by a current value from the light receiving unit 21 included in the detection unit 2. The photoelectric conversion detection circuit 23 is a circuit that converts a current value from the light receiving unit 21 into a voltage signal that can be signal-processed.

  A photoelectric sensor is used for the detection unit 2. An LED or the like is used for light irradiation in the photoelectric sensor, and a photodiode, a phototransistor, or the like is used for receiving reflected light. A photodiode or a phototransistor is an element through which a current flows in response to received light. The current is converted into a voltage, and the voltage value is sampled by the AD converter 27 to measure the waveform of the pulse wave signal. In addition, it is not restricted to LED in particular, It can also be set as the system using a laser.

  Note that it is possible to use light having a wavelength with high absorption rate of hemoglobin in blood, and it is possible to use green light as an example.

  An AD (Analog-to-digital) converter 27 is interposed in the main body 1. The analog output signal output from the photoelectric conversion detection circuit 23 is converted into a digital signal by the AD converter 27, and the digital signal is input to the CPU 10.

  A light emission drive circuit 28 that drives the light emitting unit 22 is connected to the CPU 10. The CPU 10 reads the program stored in the ROM 11 on the RAM 12 and executes it in accordance with an operation instruction from the operation unit 14. Then, the CPU 10 controls the light emission drive circuit 28 according to the execution of the program. Further, the CPU 10 calculates biological information such as a pulse rate from the detected pulse wave signal from the photoelectric conversion detection circuit 23 input via the AD converter 27 according to the execution of the program, and uses the result as a measurement result. Processing to be displayed on the display unit 13 is executed.

The light emission drive circuit 28 controls light emission of the light emitting unit 22 in accordance with an instruction from the CPU 10.
The measuring apparatus 100 further includes a communication unit 15 that executes communication processing with an external device in accordance with an instruction from the CPU 10. It is assumed that the CPU 10 is provided so as to be able to communicate with a predetermined server device via the communication unit 15.
<About pulse wave>
FIG. 3 is a diagram for explaining the pulse wave signal detected from the detection unit 2.

Referring to FIG. 3A, the amplitude waveform of the pulse wave signal is shown.
The vertical axis represents pulse wave intensity, and the horizontal axis represents time. Here, the case where it is measured as a periodic pulse wave is shown as an example.

  FIG. 3B shows a pulse wave when the subject is exercising as an example. When the subject is exercising, the heart rate increases, and a pulse wave with a relatively fast cycle is measured.

  FIG. 3C shows a pulse wave when the measurement subject is relaxed as an example. When the subject is relaxed, the heart rate is lowered, and a pulse wave with a relatively slow cycle is measured. As an example, the interval between the peaks of the pulse wave is calculated as one heartbeat.

  In FIGS. 3B and 3C, a waveform having a relatively strong intensity is measured as the amplitude intensity of the pulse wave (also referred to as pulse wave intensity), but the pulse wave intensity is affected by the change in blood flow. .

  FIG. 3D shows a pulse wave when the blood flow is small. One factor that changes the blood flow is body temperature adjustment. Body temperature adjustment is performed by a body temperature control center in the hypothalamus.

  If you want to raise your body temperature, reduce blood flow by constricting blood vessels so that your body's heat does not escape. On the other hand, when it is desired to lower the body temperature, the blood flow is increased by relaxing the blood vessels, and the heat in the body is released outside.

  When the blood flow decreases, the change in the amount of hemoglobin in the blood also decreases, so that the change in the signal intensity received from the light receiving element of the measuring apparatus 100 becomes small, and the amplitude intensity of the pulse wave becomes small.

As the blood flow increases, the change in the amount of blood hemoglobin also increases. Therefore, the change in the signal intensity received from the light receiving element of the measuring apparatus 100 increases, and the amplitude intensity of the pulse wave increases.
<Control method>
In the present embodiment, a method for determining the risk of heat stroke and hypothermia by detecting the movement of the body temperature adjustment center at an early stage based on the change in the amplitude intensity of the pulse wave will be described.

FIG. 4 is a flowchart for explaining processing of the measurement apparatus 100 based on the embodiment.
The processing is realized mainly by the CPU 10 reading a predetermined program stored in the ROM 11, and operates in cooperation with each unit.

  As shown in FIG. 4, the measuring apparatus 100 measures a heartbeat (step S2). Specifically, the heart rate is measured based on the pulse wave signal detected from the detection unit 2. For example, it is possible to calculate between the peaks of the pulse wave signal as one heartbeat. The measured pulse wave signal data is stored in the RAM 12. Note that the accumulated pulse wave signal data is set to an optimum value according to the capacity of the RAM 12 and the processing load of the CPU 10. As an example of data for determining the current situation and predicting the future situation, data for the past several days to one week may be held as an example. In this example, the case where data is stored in the RAM 12 will be described, but the present invention is not limited to the RAM 12 and may be stored in a nonvolatile memory.

  Next, the measuring apparatus 100 determines whether it is the pulse wave intensity calculation timing (step S4). As an example, whether or not it is the pulse wave intensity calculation timing can be determined as the pulse wave intensity calculation timing every predetermined period. Alternatively, the determination may be made based on the number of samples of accumulated pulse wave signal data. Alternatively, instead of calculating the pulse wave intensity at a predetermined timing, the pulse wave intensity may be calculated together with the measurement of the heartbeat.

  In step S4, when measuring device 100 determines that it is the pulse wave intensity calculation timing (YES in step S4), the process proceeds to the next process (step S6).

  On the other hand, in step S4, when measuring device 100 determines that it is not the pulse wave intensity calculation timing (NO in step S4), it returns to step S2 and repeats the measurement of the heart rate.

  In step S6, the measuring apparatus 100 calculates the pulse wave intensity. Specifically, the CPU 10 acquires pulse wave signal data stored in the RAM 12, and calculates the difference between the maximum value and the minimum value of the pulse wave signal in one heartbeat as the pulse wave intensity. Then, the CPU 10 calculates an average value of the calculated plurality of pulse wave intensities. In addition, although the case where an average value is calculated for an abnormal value and noise removal is demonstrated, it is not restricted to an average value in particular, The center value of a population may be sufficient. The standard deviation σ may be calculated in order to grasp the variation in pulse wave intensity.

  Then, the measuring apparatus 100 stores the calculated pulse wave intensity (Step S10). Specifically, the CPU 10 stores the calculated pulse wave intensity in the RAM 12.

  Next, the measuring apparatus 100 determines whether it is a body temperature adjustment determination timing (step S12). As an example, whether or not it is the body temperature adjustment determination timing can be determined as the body temperature adjustment determination timing every predetermined period. Alternatively, the determination may be made based on the number of samples of accumulated pulse wave intensity data. Alternatively, the pulse wave intensity calculation timing and the body temperature adjustment determination timing may be the same timing.

  In step S12, when measuring device 100 determines that it is the body temperature adjustment determination timing (YES in step S12), it calculates the absolute value of the difference between the pulse wave intensity and the reference value (step S14). The reference value is data stored in the ROM 11 in advance, and can be set to the pulse wave intensity detected from the measurement subject in a normal state that is not an abnormal state. In addition, although the case where the difference with the fixed reference value is calculated as an example is described, the reference value does not have to be fixed in particular, and may be changed according to the person to be measured. For example, the average value may be set as the reference value based on the past pulse wave intensity data, or the center value of the population may be set as the reference value.

  Next, the measuring apparatus 100 determines whether or not a predetermined condition is satisfied (step S16). Specifically, the CPU 10 determines whether or not the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value. The predetermined value is data stored in the ROM 11 in advance, and can be set as appropriate if it is a person skilled in the art in terms of determining whether or not it is a risk state.

  In this example, the case where it is determined whether or not the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value with respect to whether or not the predetermined condition is satisfied is not limited to this method. For example, it may be determined that the predetermined condition is satisfied when the calculated latest pulse wave intensity is at least three times the standard deviation σ from the center value of the past pulse wave intensity.

  Further, regarding whether or not the predetermined condition is satisfied, it is possible to further set conditions for time and number of times. Specifically, it may be further determined whether or not the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value for a predetermined period, or a predetermined number of times between the pulse wave intensity and the reference value. It may be determined whether or not the absolute value of the difference exceeds a predetermined value.

  In step S16, when measuring device 100 determines that the predetermined condition is satisfied (YES in step S16), it performs risk determination processing (step S18). Specifically, when the CPU 10 determines that the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value, the CPU 10 executes a risk determination process. Details of the risk determination process will be described later.

Next, it returns to step S2 and performs a normal heartbeat measurement.
In step S16, when measuring device 100 determines that the predetermined condition is not satisfied (NO in step S16), it skips step S18 and returns to step S2. Specifically, when the CPU 10 determines that the absolute value of the difference between the pulse wave intensity and the reference value does not exceed a predetermined value, the CPU 10 determines that no risk has occurred and skips the risk determination process.

  FIG. 5 is a flowchart for explaining risk determination processing in the measurement apparatus 100 based on the embodiment.

  As shown in FIG. 5, the measuring apparatus 100 determines whether or not the pulse wave intensity tends to increase (step S20). Specifically, the CPU 10 analyzes the tendency of the pulse wave intensity stored in the RAM 12 and determines whether or not the pulse wave intensity tends to increase in time series.

  When measuring device 100 determines that the pulse wave intensity tends to increase (YES in step S20), it determines that the heat stroke risk is high (step S22). Specifically, the CPU 10 determines that the risk of heat stroke is high when the pulse wave intensity tends to increase and the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value. The pulse wave intensity tends to increase means that the absolute value of the difference between the pulse wave intensity and the reference value tends to increase.

  On the other hand, the measuring apparatus 100 determines whether or not the pulse wave intensity tends to decrease (step S26). Specifically, the CPU 10 analyzes the tendency of the pulse wave intensity stored in the RAM 12 and determines whether or not the pulse wave intensity tends to decrease in time series.

  If measuring device 100 determines that the pulse wave intensity is decreasing (YES in step S26), it determines that the risk of hypothermia is high (step S28). Specifically, the CPU 10 determines that the risk of hypothermia is high when the pulse wave intensity tends to decrease and the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value. The pulse wave intensity tends to decrease means that the absolute value of the difference between the pulse wave intensity and the reference value tends to increase.

  On the other hand, when it is difficult to determine whether the pulse wave intensity tends to increase or decrease (NO in step S26), the measuring apparatus ends the process (return). Specifically, the CPU 10 analyzes the tendency of the pulse wave intensity, and when it cannot be determined whether the trend is increasing or decreasing, the CPU 10 terminates the process with no particular abnormality.

  When the measuring apparatus 100 determines that the risk of heat stroke is high or the risk of hypothermia is high, the measuring apparatus 100 notifies the state (step S24). Specifically, the CPU 10 displays that the heat stroke risk or the hypothermia risk is high on the display unit 13. For example, in this regard, if the risk of heat stroke is high, a message prompting to supply water may be displayed, and if the risk of hypothermia is high, a message prompting to warm the body is displayed. You may let them.

  In this example, the CPU 10 will explain the case where the display unit 13 is used to display that the heat stroke risk or hypothermia risk is high. However, the present invention is not limited to this, and the heat stroke risk or hypothermia risk. Any means may be used as long as it can be notified that the value is high. For example, the information may be notified using a speaker (not shown), or an alarm sound may be notified.

  Next, the measuring apparatus 100 determines whether or not the state continues for a predetermined period. When the state is resolved, the risk is resolved and the initial state is restored. On the other hand, if the state continues for a predetermined period, the communication unit executes a predetermined process assuming that the abnormality continues.

  In step S30, the measuring apparatus 100 measures a heart rate. Specifically, the heart rate is measured based on the pulse wave signal detected from the detection unit 2. For example, it is possible to calculate between the peaks of the pulse wave signal as one heartbeat.

  The measuring apparatus 100 calculates the pulse wave intensity (step S32). Specifically, the CPU 10 acquires pulse wave signal data stored in the RAM 12, and calculates the difference between the maximum value and the minimum value of the pulse wave signal in one heartbeat as the pulse wave intensity. Then, the CPU 10 calculates an average value of the calculated plurality of pulse wave intensities.

  The measuring apparatus 100 calculates the absolute value of the difference between the pulse wave intensity and the reference value (step S36). The reference value is data stored in the ROM 11 in advance, and can be set to the pulse wave intensity detected from the measurement subject in a normal state that is not an abnormal state.

  Next, the measuring apparatus 100 determines whether or not a predetermined condition is satisfied (step S38). Specifically, the CPU 10 determines whether or not the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value. As an example, the predetermined value is data stored in the ROM 11 in advance, and can be set as appropriate if it is a person skilled in the art from the viewpoint of determining whether or not the risk state.

  In this example, the case where it is determined whether or not the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value with respect to whether or not the predetermined condition is satisfied is not limited to this method. For example, it may be determined that the predetermined condition is satisfied when the calculated latest pulse wave intensity is more than twice the standard deviation σ from the center value of the past pulse wave intensity.

  If it is determined in step S38 that the predetermined condition is satisfied (YES in step S38), the measuring apparatus 100 determines whether or not the state continues for a predetermined period (step S40). Specifically, the CPU 10 determines whether or not the abnormal state continues for a predetermined period. The predetermined period is data stored in the ROM 11 in advance, and can be set as appropriate by those skilled in the art according to the risk state.

  In step S40, when measuring apparatus 100 determines that the state continues for a predetermined period (YES in step S40), it performs communication processing (step S42). Specifically, the CPU 10 transmits information indicating that the abnormal state continues to a predetermined server device via the communication unit 15. Various information such as time and position information may be transmitted as the information. And it returns to step S30 again. Risk notification because the measurement subject may not be able to receive notification that the measurement subject is at risk, or the measurement subject may not be able to take action to avoid the risk, such as when the measurement subject himself / herself is unaware. Execute processing to expand the range.

  As an example, when a predetermined server device receives the information, it may be determined as an emergency and notify the administrator, or information indicating that there is an abnormality in a predetermined mail address may be transmitted. Also good. Further, a predetermined server device may execute a predetermined process corresponding to an emergency in cooperation with a device provided in a medical institution.

  On the other hand, in step S40, when measuring device 100 determines that the state has not continued for the predetermined period (NO in step S40), it skips step S42 and returns to step S30. It is determined whether or not the state is recovered until a predetermined period has elapsed.

  If the measurement apparatus 100 determines in step S38 that the predetermined condition is not satisfied (NO in step S38), the process ends (return). Specifically, the CPU 10 determines whether or not the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value, and determines that the state has been improved when it is determined that the absolute value does not exceed the predetermined value. Is possible.

  In this example, the case where it is determined whether or not the absolute value of the difference between the pulse wave intensity and the reference value exceeds a predetermined value with respect to whether or not the predetermined condition is satisfied is not limited to this method. For example, it is possible to determine that the state has been improved when the calculated latest pulse wave intensity is within twice the standard deviation σ from the center value of the past pulse wave intensity.

  Further, regarding whether or not the predetermined condition is satisfied, it is possible to further set conditions for time and number of times. Specifically, it may be determined that the state has been improved when the absolute value of the difference between the pulse wave intensity and the reference value does not exceed the predetermined value for a predetermined period or a predetermined number of times.

  If the state recovers before the predetermined period elapses, the risk determination process is terminated and the process returns to the normal process.

  If the absolute value of the difference between the pulse wave intensity and the reference value is greater than or equal to the predetermined value and the absolute value of the difference tends to increase due to the above processing, the abnormality is high at the risk of heat stroke or hypothermia. Since the state is determined, it is possible to determine the abnormal state of the measurement subject at an early stage by a simple method.

[Other embodiments]
It is also possible to provide a program that causes a computer to function and execute control as described in the above flowchart. The program may be a program module provided as part of an operating system (OS) of a computer, in which necessary modules are called at a predetermined timing and executed at a predetermined timing.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Main part, 2 Detection part, 3, 3a, 3b Belt, 11 ROM, 12 RAM, 13 Display part, 14 Operation part, 15 Communication part, 21 Light receiving part, 22 Light emission part, 23 Photoelectric conversion detection circuit, 27 AD converter 28 Light emission drive circuit, 100 Biological information measuring device.

Claims (5)

A pulse wave measuring means for measuring the pulse wave of the measurement subject;
Amplitude intensity measuring means for measuring the amplitude intensity of the measured pulse wave;
A biological information measuring apparatus comprising: state determining means for determining an abnormal state of the measurement subject based on a change state of amplitude intensity of the pulse wave measured by the amplitude intensity measuring means.   The biological information measuring device according to claim 1, further comprising a notification unit that notifies when the state determination unit determines that the state is abnormal.   When the absolute value of the difference between the amplitude intensity of the pulse wave measured by the amplitude intensity measuring means and a reference value is equal to or greater than a predetermined value, and the absolute value of the difference tends to increase The biological information measuring device according to claim 1, wherein the biological information measuring device determines that the subject is in an abnormal state.   4. The communication device according to claim 1, further comprising a communication unit that notifies the outside of the abnormal state when the determination state of the abnormal state of the measurement subject by the state determination unit continues for a predetermined period or longer. The biological information measuring device according to item. Measuring the pulse wave of the subject;
Measuring the amplitude intensity of the measured pulse wave;
And a step of determining an abnormal state of the person to be measured based on a change state of the amplitude intensity of the measured pulse wave.

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