JP2021069615A - Biological information measurement device and biological information measurement program - Google Patents

Abstract

To output a warning about measurement accuracy of biological information correlated with an oxygen circulation time.SOLUTION: In the case of detecting a temperature of a measurement part of a measured person, estimating an oxygen circulation time of the measured person on the basis of variation in an oxygen saturation in blood measured at the measurement part, and measuring a cardiac output of the measured person by using the oxygen circulation time, a biological information measurement device 10 outputs warning about a measurement result of the cardiac output on the basis of the temperature of the measurement part.SELECTED DRAWING: Figure 13

Description

The present invention relates to a biological information measuring device and a biological information measuring program.

Patent Document 1 describes a signal acquisition unit that acquires an air flow signal indicating a time change of a respiratory air flow and an oxygen saturation signal indicating a time change of oxygen saturation, a first time in the air flow signal, and the first time. A circulation time measuring device having a circulation time calculation unit that measures the oxygen circulation time of blood based on the time difference from the second time in the oxygen saturation signal indicating an increase in oxygen saturation corresponding to resumption of respiration at one time. Is disclosed.

Non-Patent Document 1 discloses the relationship between the cardiac index and LFCT.

Re-table 2015-190413

Kazuya Hosokawa, Shin-ichi Ando, Takeshi Tohyama, Tomomi Kiyokawa, Yumi Tanaka, Hideki Otsubo, Ryo Nakamura, Toshiaki Kadokami, Takaya Fukuyama "Estimation of nocturnal cardiac output by automated analysis of circulation time derived from polysomnography" International Journal of Cardiology 181 ( 2015) 14-16.

The oxygen cycle time of the person to be measured may be measured, and the biological information of the person to be measured, which correlates with the oxygen cycle time, such as the cardiac output, may be estimated. However, in the conventional measurement, the oxygen cycle time may vary from measurement to measurement even for the same subject, and as a result, the measured value of the biometric information of the subject, which correlates with the oxygen cycle time, also varies. was there.

On the other hand, this time, the oxygen cycle time of the subject is affected by the temperature of the measurement site where the oxygen cycle time is measured, and as a result, the measurement accuracy of biological information that correlates with the oxygen cycle time decreases. Findings were obtained. Therefore, when measuring biological information that correlates with the oxygen cycle time, it is preferable to notify the user of the degree of measurement accuracy of the measured biological information.

An object of the present invention is to provide a biometric information measuring device and a biometric information measuring program capable of outputting a warning to a user regarding the measurement accuracy of biometric information that correlates with the oxygen cycle time.

In order to achieve the above object, the biometric information measuring device according to the first aspect includes a processor, which detects the temperature of a terminal portion which is a portion on the terminal side of the body of the person to be measured, and the terminal. Based on the change in the value representing the blood oxygen concentration of the person to be measured measured at the measurement site in the site, oxygen is taken into the body of the person to be measured and then reaches the measurement site via blood. When the oxygen circulation time indicating the time until the measurement is estimated and the pumping amount of the person to be measured is measured using the estimated oxygen circulation time, the measurement result of the pumping amount is based on the temperature of the terminal portion. Is output as a warning.

The biometric information measuring device according to the second aspect is the biometric information measuring device according to the first aspect, in which the processor outputs the warning when the temperature of the terminal portion is lower than a predetermined reference temperature.

The biometric information measuring device according to the third aspect is the biometric information measuring device according to the second aspect, when the processor outputs the warning by the time the measurement of the output amount of the person to be measured is completed, the measurer. Accepts selection information instructing whether or not to stop the measurement of the pumping amount from, and if the stop is instructed, the subsequent processing is stopped, and if the continuation is instructed, the measurement of the pumping amount is executed. To do.

The biometric information measuring device according to the fourth aspect is the biometric information measuring device according to the second aspect, in which the processor outputs the warning after stopping the measurement of the stroke amount of the person to be measured.

The biometric information measuring device according to the fifth aspect is the biometric information measuring device according to the first aspect, in which the processor outputs the warning together with the measured cardiac output of the person to be measured.

The biometric information measuring device according to the sixth aspect is the biometric information measuring device according to the fifth aspect, in which the processor notifies the content of the warning by changing the display color of the stroke amount of the person to be measured.

The biometric information measuring device according to the seventh aspect is the biometric information measuring device according to the fifth aspect, in which the processor notifies the content of the warning by changing the output sound together with the stroke amount of the person to be measured.

The biometric information measuring device according to the eighth aspect is the biometric information measuring device according to the fifth aspect, in which the processor outputs the content of the warning in characters together with the stroke amount of the person to be measured.

In the biological information measuring device according to the ninth aspect, in the biological information measuring device according to any one of the sixth to eighth aspects, the content of the warning represents the reliability of the measured stroke amount.

The biometric information measuring device according to the tenth aspect relates to a temperature sensor that detects the temperature of the terminal portion and the living body of the person to be measured in the biometric information measuring device according to any one of the first to ninth aspects. The processor includes a display device for displaying information, the processor acquires the temperature of the terminal portion of the person to be measured from the temperature sensor, and displays the measured output amount of the person to be measured and the warning to the display device. Display it.

The biological information measurement program according to the eleventh aspect detects the temperature of a terminal portion, which is a portion on the terminal side of the body of the person to be measured, on a computer, and measures the temperature at the measurement site in the terminal portion. Based on the change in the value representing the blood oxygen concentration of the measurer, the oxygen circulation time indicating the time from when oxygen is taken into the body of the person to be measured until it reaches the measurement site via blood is estimated. When measuring the pumping amount of the person to be measured using the estimated oxygen circulation time, it is a program for executing a process of outputting a warning for the measurement result of the pumping amount based on the temperature of the terminal portion. is there.

According to the first aspect and the eleventh aspect, there is an effect that a warning regarding the measurement accuracy of biometric information correlating with the oxygen cycle time can be output to the user.

According to the second aspect, it has an effect that it can be determined whether or not to output a warning by comparing the temperature of the terminal portion with the reference temperature.

According to the third aspect, there is an effect that the measurer can select whether or not to continue the measurement of the stroke amount.

According to the fourth aspect, there is an effect that it is possible to notify that the measurement of the stroke amount has been stopped.

According to the fifth aspect, there is an effect that it is possible to call attention to the handling of the measured cardiac output.

According to the sixth aspect, there is an effect that the content of the warning can be notified only by displaying the stroke amount without providing a dedicated area for expressing the content of the warning.

According to the seventh aspect, there is an effect that the content of the warning can be notified without being displayed on the screen.

According to the eighth aspect, there is an effect that the content of the warning can be notified even in an environment where it is difficult to make a sound.

According to the ninth aspect, there is an effect that it is possible to know a measure of how much the measured stroke amount can be trusted.

According to the tenth aspect, there is an effect that the stroke amount can be measured and the warning can be displayed only by the biological information measuring device without separately preparing the temperature sensor and the display device.

It is a schematic diagram which shows the measurement example of the blood flow information and the oxygen saturation in blood. It is a graph which shows an example of the change of the absorption amount of light absorbed by a living body. It is a graph which shows an example of the absorbance characteristic by hemoglobin. It is a schematic diagram explaining the relationship between the stroke amount and the oxygen cycle time. It is a schematic diagram explaining the measurement principle of LFCT. It is a figure which showed an example of the correspondence relation between the cardiac index and LFCT. It is a circuit block diagram which shows an example of the outline of the circuit structure in the biological information measuring apparatus. It is a figure which shows an example of arrangement of a light emitting element and a light receiving element in a biological information measuring apparatus. It is a figure which shows another example with respect to arrangement of a light emitting element and a light receiving element in a biological information measuring apparatus. It is a graph which shows an example of the sampling timing of the output voltage in a light receiving element. It is a block diagram which shows the functional structure example of the biological information measuring apparatus. It is a flowchart which shows an example of the flow of the biological information measurement processing. It is a figure which shows an example of the display screen. It is a figure which shows an example of a selection dialog. It is a flowchart which shows an example of the flow in the modification of the biological information measurement processing.

Hereinafter, an example of a mode for carrying out the present invention will be described in detail with reference to the drawings. The same components and the same processing are given the same code throughout the drawings, and duplicate description is omitted.

The biological information measuring device 10 is a device that measures biological information particularly related to the circulatory system among information (biological information) related to the living body 8. The circulatory system is a general term for a group of organs for transporting a body fluid such as blood while circulating it in the body.

There are multiple indicators of biological information about the circulatory system, and one of the indicators of the state of the heart that pumps blood into blood vessels is, for example, cardiac output (CO:), which indicates the amount of blood pumped from the heart. Cardiac Output).

When the cardiac output falls below the reference value, it is suggested that the blood volume is low, such as heart failure or dehydration of the type in which the left ventricular ejection fraction is low, and the cardiac output is various heart diseases. It is used for testing or confirming the effect of medication.

As a method for measuring cardiac output, for example, there is a method of inserting a catheter having a balloon at the tip into the pulmonary artery of a subject to be measured for cardiac output.

However, in the method for measuring cardiac output using a catheter, since it is necessary to insert the catheter into the blood vessel of the person to be measured, the invasiveness in the person to be measured is higher than that in other measurement methods.

Therefore, the cardiac output is measured using the oxygen saturation in the blood obtained from the pulse wave of the subject so that the burden on the subject is less than that of the method for measuring the cardiac output using a catheter. How to do it is being researched. Here, the oxygen saturation in blood is an example of a value indicating the oxygen concentration in blood, which is a value indicating how much hemoglobin in blood is bound to oxygen, and the oxygen saturation in blood decreases. This indicates that symptoms such as anemia are more likely to occur. Hereinafter, the oxygen saturation in blood is simply referred to as "oxygen saturation". The pulse wave is a value indicating a change in the pulsation of a blood vessel accompanying the pumping of blood by the heart.

First, with reference to FIG. 1, a method for measuring oxygen saturation among biological information will be described.

As shown in FIG. 1, the oxygen saturation is applied to the body of the person to be measured (referred to as "living body 8") by irradiating the body of the person to be measured with light from the light emitting element 1 and receiving the light by the light receiving element 3. It is measured using the intensity of light reflected or transmitted by the circulated arteries 4, veins 5, capillaries, etc., that is, the amount of reflected light or transmitted light received.

FIG. 2 is a conceptual diagram showing, for example, the amount of change in the amount of light absorbed by the living body 8. As shown in FIG. 2, the absorption amount in the living body 8 tends to fluctuate with the passage of time.

Looking at the breakdown of the fluctuation of the absorption amount in the living body 8, it can be considered that the absorption amount fluctuates mainly by the artery 4, and the absorption amount does not fluctuate in the other tissues including the vein 5 and the quiescent tissue as compared with the artery 4. It is known to be a degree of variation. This is because the arterial blood pumped from the heart moves in the blood vessel with a pulse wave, so that the artery 4 expands and contracts with time along the cross-sectional direction of the artery 4, and the thickness of the artery 4 changes. .. In FIG. 2, the range indicated by the arrow 94 indicates the amount of fluctuation in the amount of absorption corresponding to the change in the thickness of the artery 4.

In FIG. 2, if the amount of light received at _{time t a is I a} and the _{amount of light received at time t b} is I _b , the amount of change ΔA in the amount of light absorption due to the change in the thickness of the artery 4 is expressed by Eq. (1). Will be done.

(Number 1)

ΔA = ln (I _b / I _a ) ・ ・ ・ (1)

On the other hand, FIG. 3 is a diagram showing an example of the amount of light absorbed at each wavelength of hemoglobin (oxidized hemoglobin) bound to oxygen flowing through the artery 4 and hemoglobin not bound to oxygen (reduced hemoglobin). In FIG. 3, graph 96 _{represents the light absorption amount λ red} in oxidized hemoglobin, and graph 97 represents the light absorption amount λ _IR in reduced hemoglobin.

As shown in FIG. 3, oxidized hemoglobin is more likely to absorb light in the infrared (IR) region 99 having a wavelength of about 850 nm than reduced hemoglobin, and reduced hemoglobin is particularly compared to oxidized hemoglobin. It is known that light in the red region 98 having a wavelength of about 660 nm is easily absorbed.

Further, it is known that the oxygen saturation is proportional to the ratio of the amount of change ΔA in the amount of absorption at different wavelengths.

Therefore, when the living body 8 is irradiated with IR light using infrared light (IR light) and red light, which are more likely to show a difference in absorption amount between oxidized hemoglobin and reduced hemoglobin than other wavelength combinations. The oxygen saturation Sp is calculated by Eq. (2) by calculating the ratio between the amount of change ΔA _{IR and the amount of change ΔA Red in the} amount of absorption when the living body 8 is irradiated with red light. In equation (2), k is a constant of proportionality.

(Number 2)

Sp = k (ΔA _Red / ΔA _IR ) ・ ・ ・ (2)

That is, when calculating the oxygen saturation, the living body 8 is irradiated with a plurality of light emitting elements 1 that irradiate light having different wavelengths. Specifically, the light emitting element 1 that irradiates IR light and the light emitting element 1 that irradiates red light are used for the living body 8. In this case, the light emitting elements 1 that irradiate the IR light and the light emitting element 1 that irradiates the red light may overlap, but it is desirable that the light emitting periods are not overlapped. Then, the reflected light or transmitted light from each light emitting element 1 is received by the light receiving element 3, and the equations (1) and (2) or these equations are modified from the amount of light received at each light receiving time. Oxygen saturation is measured by calculating a known formula.

As a known formula obtained by modifying the above formula (1), for example, the formula (1) may be developed and the amount of change ΔA in the amount of light absorption may be expressed as the formula (3).

(Number 3)

ΔA = lnI _b −lnI _a ··· (3)

Further, the equation (1) can be modified as the equation (4).

(Number 4)

ΔA = ln (I _b / I _a ) = ln (1 + (I _b -I _a ) / I _a ) ... (4)

Usually, because it is _{(I b -I a) «I a} , ln order to _{(I b / I a) ≒} (I b -I a) / I a is satisfied, instead of equation (1), light Equation (5) may be used as the amount of change in the amount of absorption ΔA.

(Number 5)

ΔA ≒ (I _b -I _a ) / I _a ... (5)

Hereinafter, when distinguishing between the light emitting element 1 that irradiates IR light and the light emitting element 1 that irradiates red light, the light emitting element 1 that irradiates IR light is referred to as "light emitting element 1A", and the light emitting element that irradiates red light. Let 1 be referred to as "light emitting element 1B".

According to such a measurement method, the oxygen saturation is measured by bringing the light emitting element 1 and the light receiving element 3 close to the body surface of the person to be measured, so that the oxygen saturation is measured rather than inserting a catheter into a blood vessel. The burden on the measurer is reduced.

The oxygen saturation is measured at the terminal sites on the terminal side of the body of the person to be measured, for example, the head, arms, and legs. Among these terminal portions, the portion where IR light and red light are irradiated from the light emitting element 1 and the oxygen saturation is to be measured is particularly referred to as a “measurement portion”.

Next, with reference to FIG. 4, the oxygen cycle time, which is an example of an index having a correlation with the stroke amount of blood from the heart, will be described.

The oxygen cycle time refers to the time from when oxygen is taken into the body of the person to be measured to when the person to be measured reaches the measurement site of oxygen saturation via blood when the person to be measured breathes. Further, the stroke volume referred to here includes not only the above-mentioned cardiac output but also a stroke volume, a cardiac index, and the like. The cardiac output is defined as the amount of blood pumped into an artery by contraction of the heart per unit time (for example, 1 minute). Single stroke is defined as the volume of blood pumped into an artery by a single contraction of the heart. The cardiac index is defined as the cardiac output divided by the body surface area of the subject in order to correct the difference in physique of each subject.

Of the oxygen cycle time, the time required for oxygen to reach the fingertips of the hand from the lungs of the subject is particularly called LFCT (Lung to Finger Circulation Time). In order to measure LFCT, the fingertip of the subject's hand is used as the oxygen saturation measurement site. Hereinafter, when the term "fingertip" is simply used, it means the fingertip of the subject's hand.

The measurement site for measuring the oxygen cycle time may be any terminal site of the person to be measured, but hereinafter, an example of measuring LFCT, which is an example of the oxygen cycle time, from the oxygen saturation at the fingertip of the person to be measured will be described. I will do it.

Further, as shown in FIG. 4, there is a correlation between the stroke output and the LFCT. For example, when the cardiac output, which is an example of the cardiac output, is CO, the cardiac output CO is calculated by the following equation (6) as an example.

(Number 6)

CO = (a ₀ x S) / LFCT ... (6)

Here, a ₀ is a predetermined constant, S is the body surface area (m ² ) of the subject, and the unit of LFCT is seconds. The LFCT that correlates with the stroke amount in this way is measured from the above-mentioned change in oxygen saturation.

FIG. 5 is a diagram showing the measurement principle of LFCT. In FIG. 5, the vertical axis represents the reciprocal of oxygen saturation, and the horizontal axis represents time. As shown in FIG. 5, LFCT is obtained by measuring the time from the time when respiration is resumed after stopping respiration for a certain period of time to the inflection point indicating that oxygen saturation has begun to recover. The time when breathing is resumed is a time within a predetermined period including the time when breathing is resumed, and the time when breathing is resumed has a time range.

Non-Patent Document 1 shows that an inverse proportional relationship is established between the LFCT measured in this way and the cardiac index (CI).

On the other hand, FIG. 6 is a diagram showing an example of the correspondence between the cardiac index and the LFCT when each LFCT in a plurality of subjects is actually measured. The horizontal axis of FIG. 6 represents LFCT, and the vertical axis represents cardiac index. The curve shown by the dotted line in FIG. 6 is an estimated curve 95 representing the correspondence between the theoretical cardiac index and LFCT obtained from Non-Patent Document 1.

At each point in FIG. 6, the LFCT of the person to be measured was measured under the premise that the true value of the cardiac index of each person to be measured was known in advance, and the LFCT measured as the true value of the cardiac index of the person to be measured was measured. It is a measurement point showing the correspondence between. Each measurement point in FIG. 6 shows the measurement result of the subject to be measured.

The closer the measurement point is to the estimation curve 95, the more accurately the LFCT measurement is performed. However, in reality, there are some subjects whose measurement points deviate from the estimation curve 95.

In order to examine this situation, the inventor classifies the subjects to be measured into two groups, paying attention to whether or not the temperature of the fingertip, which is the measurement site of LFCT, is lower _{than the reference temperature T d at each measurement point.} I tried it. In FIG. 6, the measurement point 92 shown by the triangle _{represents the measurement point of the person to be measured whose fingertip temperature is lower} than the reference temperature T d, and the measurement point 93 indicated by the square is the fingertip temperature of the reference temperature T. _It represents the measurement point of the person to be measured who was d or more.

As a result, the inventor has determined that the measurement points 93 of the group of subjects (referred to as group A) whose _{fingertip temperature is equal to or higher than the reference temperature T d are distributed along the estimation curve 95, while the fingertip temperature is the reference.} It was found that the measurement points 92 of the subject group (referred to as group B) having a temperature lower than _{T d tend to be distributed out of the estimation curve 95 than the measurement points 93 of the subjects belonging to group A.} It was.

Furthermore, the inventor examined the temperature of the fingertips of the subject belonging to group B and the distribution of the measurement points 92. As a result _{, the lower the fingertip temperature was lower than the reference temperature Td, the} more the measured LFCT was true of the cardiac coefficient. By making it longer than the theoretical LFCT of the person to be measured obtained from the value, the deviation between the theoretical LFCT and the LFCT actually measured by the person to be measured becomes large, and the degree to which the measurement point 92 deviates from the estimation curve 95 is measured. It was found that the temperature was higher than point 93.

This is because when the temperature of the terminal site of the person to be measured including the measurement site is low, the peripheral blood vessels at the terminal site contract, making it difficult for blood to flow through the peripheral blood vessels, while the temperature of the terminal site of the person to be measured is low. It is presumed that this is because the peripheral blood vessels at the terminal site expand as the temperature increases, making it easier for blood to flow through the peripheral blood vessels. Therefore, it is considered that the time required for oxygen to reach from the lung to the fingertip of the subject, that is, the LFCT tends to increase as the temperature of the terminal portion of the subject decreases.

In other words, if the LFCT is corrected according to the temperature of the terminal part so that the measured LFCT of the person to be measured approaches the theoretical LFCT, the LFCT measured using the measured LFCT without considering the temperature of the terminal part is used. Compared with the case of measuring the stroke amount of the measurer, the measurement accuracy of the stroke amount is improved.

Here, as an example, the correspondence between the true value of the cardiac index of the subject based on the temperature of the measurement site and the measured LFCT has been described, but the cardiac output is the value obtained by multiplying the cardiac output by the body surface area of the subject. Since the stroke volume is the value obtained by dividing the cardiac output by the heart rate, the correspondence between the true value of the cardiac output based on the temperature of the measurement site and the measured LFCT, and the measurement site Similar findings can be obtained for the correspondence between the true value of stroke volume based on temperature and the measured LFCT. Further, since LFCT is an example of oxygen cycle time, LFCT in the above description may be read as oxygen cycle time measured at a terminal site other than the fingertip.

FIG. 7 is a circuit block diagram showing an example of an outline of a circuit configuration in the biological information measuring device 10 that corrects the LFCT measured according to the temperature of the terminal portion.

As shown in FIG. 7, the biological information measuring device 10 includes a light emitting element 1A, a light emitting element 1B, a light receiving element 3, a light emitting control unit 12, a drive circuit 14, an amplifier circuit 16, and an A / D (Analog / Digital) conversion circuit 18. The temperature sensor 19, the control unit 20, and the display unit 22 are included.

Of these, the light emitting element 1A, the light emitting element 1B, the light receiving element 3, the amplifier circuit 16, and the temperature sensor 19 are incorporated in the sensor unit 9 of the biological information measuring device 10 and are attached to the measurement site of the person to be measured. Further, the light emission control unit 12, the drive circuit 14, the A / D conversion circuit 18, the control unit 20, and the display unit 22 are incorporated in the main body 2 of the biological information measuring device 10. The sensor unit 9 and the main body 2 of the biological information measuring device 10 are connected by a wired or wireless communication line, and communicate with each other to measure the stroke amount of the person to be measured.

The method of dividing the circuit blocks included in the sensor unit 9 and the main body 2 of the biological information measuring device 10 is an example. For example, the amplifier circuit 16 may be included in the main body 2 of the biological information measuring device 10.

The sensor unit 9 of the biological information measuring device 10 is attached so as to be in close contact with the terminal portion of the person to be measured so that external light is not input. The sensor unit 9 according to the present embodiment is attached to the fingertip of the person to be measured as an example, but may be attached to another terminal part of the person to be measured such as the tip of a toe or an earlobe. The sensor unit 9 and the main body 2 of the biological information measuring device 10 may not be separated and may be integrally configured in the same housing.

The light emission control unit 12 outputs a control signal for controlling the light emission cycle and the light emission period of the light emitting element 1A and the light emitting element 1B to the drive circuit 14 including the power supply circuit for supplying the drive power to the light emitting element 1A and the light emitting element 1B. .. The light emission control unit 12 may be realized as a part of the control unit 20.

When the drive circuit 14 receives the control signal from the light emission control unit 12, it supplies drive power to the light emitting element 1A and the light emitting element 1B according to the light emitting cycle and the light emitting period instructed by the control signal, and the light emitting element 1A and the light emitting element Drive 1B.

The light receiving element 3 outputs a light receiving signal corresponding to the IR light received from the light emitting element 1A and a light receiving signal corresponding to the red light received from the light emitting element 1B.

The amplifier circuit 16 amplifies the light receiving signal corresponding to the intensity of each light output by the light receiving element 3 to a voltage level defined as an input voltage range of the A / D conversion circuit 18.

The A / D conversion circuit 18 takes the voltage amplified by the amplifier circuit 16 as an input, and quantifies and outputs the amount of light received by the light receiving element 3 represented by the magnitude of the voltage.

The control unit 20 is a CPU (Central Processing Unit) 20A, which is an example of a processor that has each function related to the biometric information measuring device 10, and a ROM (Read Only) that stores a biometric information measuring program that causes the computer to function as the biometric information measuring device 10. It includes a Memory) 20B and a RAM (Random Access Memory) 20C used as a temporary work area of the CPU 20A.

The display unit 22 is an example of a display device that displays information processed by the CPU 20A, specifically, biological information of the person to be measured such as a change in oxygen saturation of the person to be measured, LFCT, and cardiac output. For the display unit 22, for example, a liquid crystal display (LCD), an organic EL (Electro Luminescence) display, or the like is used.

An input device such as a button is arranged in the main body 2 of the biological information measuring device 10, and a touch panel is attached to the display unit 22, but the touch panel does not necessarily have to be attached to the display unit 22. Absent. The CPU 20A grasps the user's instruction from the pressing status of the button or the like, and controls the biological information measuring device 10 based on the user's instruction. The user is a measurer who measures the biological information measuring device 10, and includes, for example, a person to be measured and a medical worker.

FIG. 8 is a diagram showing an arrangement example of the light emitting element 1A, the light emitting element 1B, the light receiving element 3, and the temperature sensor 19 in the sensor unit 9 of the biological information measuring device 10.

As shown in FIG. 8, the light emitting element 1A, the light emitting element 1B, the light receiving element 3, and the temperature sensor 19 are arranged side by side toward one surface of the living body 8 (in this case, the fingertip of the person to be measured). In this case, the light receiving element 3 receives the light of the light emitting element 1A and the light emitting element 1B reflected by the capillaries 6.

The arrangement of the light emitting element 1A, the light emitting element 1B, and the light receiving element 3 is not limited to the arrangement example of FIG. For example, as shown in FIG. 9, the light emitting element 1A, the light emitting element 1B, and the light receiving element 3 may be arranged at positions facing each other with the living body 8 of the person to be measured interposed therebetween. In this case, the light receiving element 3 receives the light of the light emitting element 1A and the light emitting element 1B that have passed through the living body 8.

Although a surface emitting laser element is used for the light emitting element 1A and the light emitting element 1B, an end surface emitting laser element may be used. Further, the light emitted from each of the light emitting element 1A and the light emitting element 1B does not have to be laser light. For example, a light-emitting diode (LED) or an organic light-emitting diode (OLED) may be used for the light-emitting element 1A and the light-emitting element 1B.

FIG. 10 is a graph showing an example of sampling timing of the output voltage output by the light receiving element 3. In FIG. 10, the positions marked with circles represent the sampling timing, the vertical axis of FIG. 10 represents the output voltage of the light receiving element 3, and the horizontal axis represents time.

As shown in FIG. 10, when the output voltage corresponding to the light received from the light emitting element 1A by the light receiving element 3 is IR ₁ , IR ₂ , ..., IR _n , IR (t) is obtained as time series data. = IR ₁ , IR ₂ , ..., IR _n can be obtained. Similarly, when the output voltage corresponding to the light received by the light receiving element 3 from the light emitting element 1B is Red ₁ , Red ₂ , ..., Red _n , the time series data is Red (t) = Red ₁ , Red ₂ , ..., Red _n are obtained. At this time, both the light emitting element 1A and the light emitting element 1B may be provided with a period during which no light is emitted to obtain _{outputs Dark 1} , Dark ₂ , ..., Dark _{n in a dark state.} In this case, IR (t) may be IR _1- Dark ₁ , IR _2- Dark ₂ , ..., IR _n- Dark _n . Similarly, Red (t) may be Red _1- Dark ₁ , Red _2- Dark ₂ , ..., Red _n- Dark _n . It is desirable to sample these data in a state where the output is stable near the end of the light emission period.

FIG. 11 is a block diagram showing a functional configuration example of the biological information measuring device 10. As shown in FIG. 11, the biological information measuring device 10 includes a temperature detecting unit 30, a pulse wave processing unit 32, an oxygen saturation measuring unit 34, an oxygen circulation time measuring unit 36, a cardiac output measuring unit 38, and an output unit 40. including.

The temperature detection unit 30 detects the temperature of the terminal portion of the person to be measured, specifically the temperature of the measurement portion, by using the temperature sensor 19 incorporated in the sensor unit 9.

The pulse wave processing unit 32 uses the received amount of each of the IR light and the red light received from the sensor unit 9 of the biological information measuring device 10, and the pulse wave signal representing the pulse wave of the person to be measured obtained from the IR light. And generate a pulse wave signal representing the pulse wave of the subject obtained from infrared light.

When the oxygen saturation measuring unit 34 receives the pulse wave signal from the pulse wave processing unit 32, the oxygen saturation measuring unit 34 measures the oxygen saturation of the person to be measured from the received pulse wave signal. Specifically, the oxygen saturation measuring unit 34 uses a pulse wave signal to determine the amount of change in the absorption amount of IR light ΔA _IR due to the change in the thickness of the artery 4 and the amount of change in the amount of absorption of red light ΔA _Red . Each is calculated according to Eq. (1). Then, the oxygen saturation measuring unit 34 measures the oxygen saturation of the person to be measured from the equation (2), for example, using _{the calculated change amount ΔA IR} and the change amount ΔA _{Red, and circulates the measured oxygen saturation.} Notify the time measuring unit 36.

Hereinafter, an example in which the oxygen saturation measuring unit 34 measures the oxygen saturation of the person to be measured will be described as an example, but the oxygen saturation measuring unit 34 is a value indicating a time change of the oxygen saturation of the person to be measured. If there is, any value may be measured. For example, the oxygen saturation measuring unit 34 may measure a value that correlates with the time change of the oxygen saturation, such as _{the reciprocal of the oxygen saturation or the ratio of the change amount ΔA Red} and the change amount ΔA _IR.

The oxygen circulation time measuring unit 36 notifies that the person to be measured who has stopped breathing for measuring LFCT has resumed breathing by, for example, pressing a button attached to the main body 2 of the biological information measuring device 10. When the resumption notification is received, the time when the resumption of respiration is received is stored as _{time t 1.} Then, the oxygen cycle time measuring unit 36 monitors the change in the oxygen saturation measured by the oxygen saturation measuring unit 34, and detects the inflection point of the oxygen saturation. The oxygen circulation time measuring unit 36 stores the time when the inflection point of the oxygen saturation is detected as the time t ₂ , and measures the time represented by the difference between the time t ₁ and the time t _{2 as the LFCT.} The term "detecting an inflection point" includes a case where a position slightly deviated from the inflection point is detected within a range that does not substantially affect the measurement of the oxygen cycle time.

Then, the oxygen cycle time measuring unit 36 notifies the cardiac output measuring unit 38 of the measured oxygen cycle time.

The cardiac output measuring unit 38 measures the cardiac output of the person to be measured by using the LFCT received from the oxygen cycle time measuring unit 36. The cardiac output is calculated by the above-mentioned equation (6). In addition to the cardiac output, the cardiac output measuring unit 38 may measure values representing cardiac functions obtained from LFCT, such as a cardiac index and a stroke volume, but here, the cardiac output is measured. It is assumed that the cardiac output, which is an example, is measured.

The output unit 40 outputs the cardiac output of the person to be measured measured by the cardiac output measuring unit 38 together with the reliability indicating the measurement accuracy of the cardiac output, and notifies the user of the measurement result. The reliability output method will be described in detail later.

Next, the operation of the biological information measuring device 10 will be described with reference to FIG.

FIG. 12 shows a case where the person to be measured receives a measurement instruction of the heart rate output from the user of the biological information measuring device 10 in a state where the sensor unit 9 of the biological information measuring device 10 is attached to a fingertip which is an example of the measurement site. It is a flowchart which shows an example of the flow of the biological information measurement processing executed by the CPU 20A.

The biometric information measurement program that defines the biometric information measurement process is stored in advance in, for example, the ROM 20B of the biometric information measuring device 10. The CPU 20A of the biometric information measuring device 10 reads the biometric information measuring program stored in the ROM 20B and executes the biometric information measuring process.

In step S10, the CPU 20A acquires the temperature of the fingertip of the person to be measured detected by the temperature sensor 19. As the temperature sensor 19, for example, a thermistor, a thermocouple, a resistance temperature detector (RTD), an IC temperature sensor, or the like is used.

In step S20, the CPU 20A determines whether or not the temperature of the fingertip of the person to be measured acquired in step S10 is equal to _{or higher than the reference temperature T d.} When the temperature of the fingertip of the person to be measured _{is equal to or higher than the reference temperature T d} , the person to be measured is a person to be measured who belongs to group A. In the case of the subject belonging to Group A, as shown in FIG. 6, the deviation between the true value of the LFCT of the subject and the measured value of the LFCT of the subject obtained from the measurement is within the permissible range of error. Since it shows a tendency to fit in, a highly reliable LFCT will be measured.

Therefore, in step S30, the CPU 20A controls the sensor unit 9 to start measuring the oxygen saturation at the fingertip of the person to be measured.

The part for measuring the temperature of the person to be measured may be any part within the range of the terminal part including the measurement part to which the sensor unit 9 of the biological information measuring device 10 is attached, and is not necessarily the measurement part. It doesn't have to be. For example, when the object of oxygen saturation is the fingertip of the hand, the temperature of the back of the hand, the temperature of the palm, the temperature of the wrist, the temperature of the forearm, or the temperature of the upper arm may be measured, but the measurement site (in this case, in this case). A part close to the fingertip of the hand), in which the measured temperature correlates with the temperature of the measurement part, is preferable.

In step S40, the CPU 20A instructs the subject to stop breathing, for example, through the display unit 22 in order to measure the LFCT of the subject. The instruction to stop breathing to the subject may be instructed not by visual instruction by characters or images, but by, for example, voice or vibration. Further, the CPU 20A activates a timer in order to measure the elapsed time since the person to be measured stops breathing. As the timer, for example, a timer function built in the CPU 20A is used.

On the other hand, the biological information measuring device 10 measures the LFCT so that the subject does not stop breathing more than necessary or resume breathing before the oxygen saturation begins to decrease. A predetermined time indicating the optimum breathing stop time is set in advance. Therefore, in step S50, the CPU 20A determines whether or not the elapsed time since the subject stopped breathing in step S40 has reached the predetermined time. The CPU 20A repeatedly executes the determination process of step S50 until the elapsed time from the time when the subject stops breathing reaches a predetermined time, and monitors the period of breathing stop in the person to be measured.

On the other hand, when the elapsed time from the time when the subject stops breathing reaches the specified time, the process proceeds to step S60.

In step S60, the CPU 20A instructs the subject to resume breathing, for example through the display unit 22. As with the instruction to stop breathing, the instruction to resume breathing to the subject may be instructed not by visual instruction by characters or images, but by, for example, voice or vibration. Further, the CPU 20A restarts the timer after stopping the timer started in step S40 in order to measure the elapsed time since the person to be measured resumes breathing.

When the subject resumes breathing, as described with reference to FIG. 5, the inflection point at which the oxygen saturation of the subject measured by the sensor unit 9 of the biological information measuring device 10 changes from decreasing to increasing. In step S70, the CPU 20A measures the change in oxygen saturation and detects the inflection point. The CPU 20A stores the change in oxygen saturation in a storage medium such as the ROM 20B.

In step S80, the CPU 20A acquires the elapsed time at the time when the inflection point is detected from the timer. The acquired elapsed time represents LFCT because it is the elapsed time from when the subject resumes breathing until the inflection point of oxygen saturation appears. As a result, the estimation of the LFCT of the person to be measured is completed, and the CPU 20A stops the timer.

In step S90, the CPU 20A substitutes the LFCT estimated in step S80 into, for example, the calculation formula of the cardiac output shown in the equation (6) to calculate the cardiac output of the person to be measured. Dividing the calculated cardiac output by the body surface area of the person being measured estimates the cardiac index of the person being measured, and dividing the calculated cardiac output by the heart rate of the person being measured is one time for the person being measured. The stroke volume is estimated.

In step S100, the CPU 20A outputs the biological information of the person to be measured including the cardiac output calculated in step S90 together with the reliability. As described above, the LFCT measured when the temperature of the fingertip of the person to be measured is equal to _{or higher than the reference temperature T d} shows a tendency that the measurement error is within the permissible range. The reliability of the measured output is high. Therefore, as shown in FIG. 13, the CPU 20A controls to display the measurement value of the cardiac output and the display screen 42 in which the reliability of the measured cardiac output is set to “high” on the display unit 22 as the measurement result. Is performed, and the biological information measurement process shown in FIG. 12 is completed.

Here, as an example, the CPU 20A outputs the measurement result by displaying the cardiac output and the reliability on the display unit 22, but there is no restriction on the output form of the measurement result, for example, the measurement result is notified by voice. Alternatively, the measurement result may be printed on paper by an image forming unit (not shown). Further, a form in which the CPU 20A stores the measurement result in a memory of an external device (not shown) through a communication line (not shown) is also included in the output form of the measurement result.

On the other hand, if it is determined in the determination process of step S20 that the temperature of the fingertip of the person to be measured is lower _{than the reference temperature T d} , the process proceeds to step S22.

In this case, the person to be measured is a person to be measured belonging to Group B. In the case of the subject belonging to Group B, as shown in FIG. 6, the difference between the true value of the LFCT of the subject and the measured value of the LFCT of the subject obtained by the measurement is within the permissible range of error. Since the fingertip temperature tends to exceed the reference temperature T _d or higher, the LFCT and the heart rate output tend to be less reliable than the LFCT and the heart rate output measured when the temperature of the fingertip is T d or higher.

Therefore, the process proceeds to step S22, and the CPU 20A outputs a warning that calls attention to the user regarding the handling of the measured value. For example, the CPU 20A notifies the user that there are points to be noted when continuing the measurement as it is, such as "Because the temperature of the measurement site is low, the reliability of the measurement result may be low." .. There are no restrictions on the method of notifying this warning, and the CPU 20A may display the warning on the display unit 22 or notify it by voice. Further, the temperature of the fingertip acquired in step S10 may be output. In particular, when the warning is notified by voice, it is not always necessary to notify by words, and the warning may be notified by a sound such as a buzzer sound.

After outputting the warning, in step S24, the CPU 20A displays the selection dialog 44 on the display unit 22.

FIG. 14 is a diagram showing an example of the selection dialog 44. In the selection dialog 44, a message asking the user whether to continue the subsequent measurement is described, for example, "Do you want to continue the measurement or stop the measurement?". When displaying the warning in characters, the CPU 20A may generate a selection dialog 44 including a warning text to be displayed in step S22, and display the warning together with the selection dialog 44 in step S24.

The user presses the "continue" button of the selection dialog 44, for example, via the touch panel when continuing the measurement, and presses the "stop" button when stopping the measurement.

When the "continue" button is pressed, the CPU 20A is notified of the selection information instructing "continue", and when the "stop" button is pressed, the CPU 20A is notified of the selection information instructing "stop". Will be done.

Therefore, in step S26, the CPU 20A determines whether or not the selection information instructing whether or not to stop the measurement of the stroke amount has been received from the user. When the selection information is accepted, the process proceeds to step S28, and when the selection information is not accepted, the determination process of step S26 is repeatedly executed until the selection information is accepted, and the acceptance status of the selection information is monitored.

In step S28, the CPU 20A determines whether or not the received selection information is selection information instructing to stop the measurement. In the case of the selection information instructing to stop the measurement, the CPU 20A stops the subsequent processing and ends the biological information measurement process shown in FIG. That is, the CPU 20A does not measure the LFCT and the cardiac output of the person to be measured.

On the other hand, in the case of the selection information instructing the continuation of the measurement, the CPU 20A proceeds to step S30 and continues the measurement of the LFCT and the cardiac output of the person to be measured according to the process already described.

However, the measurement accuracy of the heart rate measured by the instruction to continue the measurement in the selection dialog 44 is the heart rate measured when the temperature of the fingertip of the person to be measured is equal to or higher than the _{reference temperature T d.} It will be lower than the measurement accuracy of. Therefore, in this case, for example, on the display screen 42 shown in FIG. 13, the CPU 20A sets the reliability to be output together with the cardiac output in step S100 to, for example, "low", and the measured cardiac output is a reference value. Notify the user that

In the example of the biological information measurement process shown in FIG. 12, a warning was output during the period from the acquisition of the temperature of the measurement site to the start of the oxygen saturation measurement, but there is no restriction on the warning output timing, and the measurement is performed. When the temperature of the fingertip of the person is _{less than the reference temperature T d} , for example, a warning may be output between step S70 and step S80 in FIG. 12 to display the selection dialog 44. That is, immediately before estimating the LFCT of the person to be measured, the user may be asked whether to continue the subsequent processing. In this case, since at least the change in oxygen saturation can be obtained, it is possible to cope with the case where the LFCT of the person to be measured becomes necessary later.

Incidentally, as the temperature of the fingertip is lower than the reference temperature T _d, from the measured LFCT to exhibit a tendency to be longer than the true value, CPU 20A, the temperature of the obtained finger is lower than the reference temperature T _d in step S10 As a result, the reliability may be set so that the reliability of the measured cardiac output becomes lower. For example, when a _{temperature T e} lower than the _{reference temperature T d} is set, and the temperature range W ₁ below the reference temperature T _{d and above the temperature T e} includes the temperature of the fingertip measured in step S10, CPU 20A sets the reliability of the measured cardiac output to "medium", if the temperature of the fingertip were determined in step S10 is lower than the temperature T _e, CPU 20A is measured cardiac output reliability May be set to "Low". Here, an example of classifying the measured cardiac output reliability categories into three categories of "high", "medium", and "low" has been described, but there is no limitation on the number of reliability categories, and 4 It may be divided into one or more divisions.

The reliability of cardiac output may be expressed numerically. For example, the lowest reliability is set to "1", and as the reliability increases, "2", "3", ... "N". It may be set as ". Here, "N" is a positive integer. Further, the highest reliability may be set to "100%", and the reliability of cardiac output may be set so that the reliability approaches 0% as the reliability decreases.

In this way, the reliability indicating the degree of measurement accuracy of the biological information measured by the biological information measuring device 10 warns the user regarding the handling of the measured value of the biological information that correlates with the oxygen circulation time such as the cardiac output. This is an example of a warning to arouse.

The CPU 20A does not necessarily have to display the reliability of the cardiac output separately from the measured value of the cardiac output. For example, when the reliability of the cardiac output is "high", the cardiac output does not have to be displayed. By changing the display color of the cardiac output of the subject, such as green for the text color, yellow for "medium", and red for "low", the measured cardiac output The reliability may be notified to the user. Further, the CPU 20A associates different sounds for each reliability category divided into, for example, "high", "medium", and "low", and outputs a sound according to the measured reliability of the cardiac output. By changing it, the reliability of the cardiac output may be notified to the user. If only one type of sound is produced and it is difficult to change the output sound according to the reliability of the measured cardiac output, the volume of the sound output according to the reliability of the measured cardiac output. The reliability of cardiac output may be notified to the user by changing.

As described above, according to the biological information measuring device 10 according to the present embodiment, the measurement accuracy of the biological information having a correlation with the oxygen circulation time is estimated according to the temperature of the measurement site, and the estimated measurement accuracy is the measured value. By outputting with, attention is given to the handling of the measured biometric information.

<Modification example>
In the above-described embodiment, when the temperature of the fingertip of the person to be measured _{is lower than the reference temperature Td} , an example of causing the user to determine whether or not to continue the subsequent measurement has been described, but the CPU 20A performs the subsequent measurement. It may be possible to autonomously determine whether or not to continue.

FIG. 15 shows a case where the person to be measured receives a measurement instruction of the heart rate output from the user of the biological information measuring device 10 in a state where the sensor unit 9 of the biological information measuring device 10 is attached to a fingertip which is an example of the measurement site. It is a flowchart which shows the modification of the biological information measurement processing executed by the CPU 20A.

The difference between the flowchart shown in FIG. 15 and the flowchart of the biological information measurement process shown in FIG. 12 is that it is executed when the temperature of the fingertip of the person to be measured is determined to be less than the _{reference temperature Td in the determination process of step S20.} The processing to be performed is changed to steps S21, S23, S25, and S27. Here, a process changed from the biological information measurement process shown in FIG. 12 will be described.

When it is determined in the determination process of step S20 that the temperature of the fingertip of the person to be measured _{is less than the reference temperature T d} , the process proceeds to step S21.

In step S21, the CPU 20A acquires, for example, the continuation setting stored in the ROM 20B. The continuation setting is a preset value set in advance as to whether or not to continue the subsequent measurement when the temperature of the fingertip of the person to be measured is _{lower than the reference temperature T d, and is set by the user.}

In step S23, the CPU 20A determines whether or not the continuation setting acquired in step S21 is set to a set value instructing continuation. If the continuation setting is set to the set value instructing continuation, the process proceeds to step S25.

In step S25, the CPU 20A outputs a warning notifying the user that the temperature of the fingertip of the person to be measured is lower _{than the reference temperature Td} but continues the subsequent processing, and proceeds to step S30 to determine the oxygen saturation. Start measurement.

On the other hand, in the determination process of step S23, when the continuation setting is set to the set value instructing the cancellation, the process proceeds to step S27.

In step S27, the CPU 20A outputs a warning notifying the user that the subsequent processing is stopped because the temperature of the fingertip of the person to be measured is lower _{than the reference temperature Td, and performs the biometric information measurement processing shown in FIG.} finish.

Ie, CPU20A, when the temperature of the fingertip of the subject is lower than the reference temperature T _d, without waiting for selection information reported from the user, depending on the setting of the continuous setting, to continue the subsequent measurements Whether or not it is determined autonomously. When the measurement is continued, in step S100, the biological information of the person to be measured including the cardiac output calculated in step S90 is output together with the reliability.

The warning to notify the user that the process is to be continued, which is output in step S25, does not necessarily have to be output before starting the measurement of oxygen saturation, from the execution of step S30 to the start of step S100. It should be output in the meantime.

If a patient with sleep apnea syndrome, who temporarily stops breathing during sleep, is allowed to sleep with the biological information measuring device 10 according to the present embodiment attached, oxygen during sleep occurs at the timing when breathing is resumed. Changes in saturation are measured. Therefore, by storing the changes in the temperature and oxygen saturation of the measurement site in the ROM 20B together with the time information, biological information such as the LFCT and cardiac output of the sleeping patient can be obtained later with reliability.

In this case, the timing of stopping and resuming respiration in the subject is specified, for example, by detecting changes in airflow or temperature with an airflow sensor provided near the mouth or nose of the subject. Further, the timing of stopping and resuming respiration in the subject may be specified by using the respiration waveform obtained from the pulse wave signal generated by the pulse wave processing unit 30. The respiratory waveform is a waveform of a signal indicating the respiratory state of the living body 8, and is a waveform of a time-series signal indicating a time change of exhalation and inspiration.

In order to obtain the respiratory waveform of the subject, the CPU 20A extracts peak inflection points and bottom inflection points from either pulse wave signal obtained from IR light or red light, and between peak inflection points and between peak inflection points. The peak waveform and the bottom waveform generated by interpolating between the bottom inflection points by a known interpolation method such as spline interpolation are generated. The "peak inflection point" is the point where the pulse wave value changes from rising to falling, and the "bottom inflection point" is the point where the pulse wave value changes from falling to rising.

Then, the CPU 20A generates a difference waveform between the peak waveform and the bottom waveform, performs a fast Fourier transform on the generated difference waveform, and calculates a frequency component included in the difference waveform. Further, the CPU 20A obtains the maximum frequency component from the calculated frequency component, sets the frequencies of the components before and after the obtained maximum frequency component as the cutoff frequency, and then uses, for example, a bandpass filter to set the respective cutoff frequencies. The respiratory waveform is extracted by leaving only the frequency components included in the interval and removing the other frequency components.

Although the present invention has been described above using the embodiments, the present invention is not limited to the scope described in the embodiments. Various changes or improvements can be made to the embodiments without departing from the gist of the present invention, and the modified or improved forms are also included in the technical scope of the present invention. For example, the order of processing may be changed without departing from the gist of the present invention. Specifically, after starting to measure the change in oxygen saturation in step S70 of FIGS. 12 and 15, the temperature of the measurement site is acquired, and it is determined whether or not _{the acquired temperature is less than the reference temperature T d.} You may decide whether to continue the subsequent measurements.

Further, in the embodiment, a mode in which the biometric information measurement processing is realized by software has been described as an example, but the same processing as the flowcharts shown in FIGS. 12 and 15 can be performed by, for example, ASIC (Application Specific Integrated Circuit), FPGA ( It may be implemented in a Field Programmable Gate Array) or PLD (Programmable Logic Device) and processed by hardware. In this case, the speed of the processing can be increased as compared with the case where the biological information measurement processing is realized by software.

In this way, the CPU 20A may be replaced with a dedicated processor specialized for a specific process such as an ASIC, FPGA, PLD, GPU (Graphics Processing Unit), and FPU (Floating Point Unit).

The operation of the CPU 20A in the embodiment may be realized by a plurality of CPUs 20A in addition to the form realized by one CPU 20A. Further, the operation of the CPU 20A in the embodiment may be realized by the cooperation of the CPU 20A in a computer located at a physically separated position.

Further, in the above-described embodiment, the embodiment in which the biometric information measurement program is installed in the ROM 20B has been described, but the present invention is not limited to this. The biological information measurement program according to the present invention can also be provided in a form recorded on a computer-readable storage medium. For example, the biometric information measurement program may be provided in the form of being recorded on an optical disk such as a CD (Compact Disc) -ROM or a DVD (Digital Versatile Disc) -ROM. Further, the biometric information measurement program according to the present invention may be provided in the form of being recorded in a portable semiconductor memory such as a USB (Universal Serial Bus) memory or a memory card.

Further, the biometric information measuring device 10 may acquire the biometric information measuring program according to the present invention from an external device (not shown) connected to a communication line (not shown).

1 (1A, 1B) light emitting element, 2 main body, 3 light receiving element, 4 arteries, 5 veins, 6 capillaries, 8 living organisms, 9 sensor units, 10 biological information measuring devices, 12 light emitting control units, 14 drive circuits, 16 Amplifier circuit, 18 A / D conversion circuit, 19 temperature sensor, 20 control unit, 20A CPU, 20B ROM, 20C RAM, 22 display unit, 30 temperature detection unit, 32 pulse wave processing unit, 34 oxygen saturation measurement unit, 36 Oxygen circulation time measurement unit, 38 heart rate output measurement unit, 40 output unit, 42 display screen, 44 selection dialog, 92 (93) measurement point, 94 arrow, 95 estimation curve, 96 (97) graph, 98 red region, 99 Infrared region

Claims (11)

Equipped with a processor
The processor
Detects the temperature of the terminal part, which is the part on the terminal side of the body of the person to be measured,
Based on the change in the value representing the blood oxygen concentration of the person to be measured measured at the measurement site in the terminal site, oxygen is taken into the body of the person to be measured and then the measurement site is passed through the blood. Estimate the oxygen circulation time, which indicates the time to reach
A biological information measuring device that outputs a warning for the measurement result of the stroke amount based on the temperature of the terminal portion when measuring the stroke amount of the person to be measured using the estimated oxygen cycle time. The biometric information measuring device according to claim 1, wherein the processor outputs the warning when the temperature of the terminal portion is lower than a predetermined reference temperature. If the processor outputs the warning before the measurement of the stroke amount of the person to be measured is completed, the processor receives selection information from the measurer instructing whether or not to stop the measurement of the stroke amount, and the stop is performed. The biometric information measuring device according to claim 2, wherein the subsequent processing is stopped when instructed, and the stroke amount is measured when the continuation is instructed. The biometric information measuring device according to claim 2, wherein the processor outputs the warning after stopping the measurement of the stroke amount of the person to be measured. The biometric information measuring device according to claim 1, wherein the processor outputs the warning together with the measured cardiac output of the person to be measured. The biometric information measuring device according to claim 5, wherein the processor notifies the content of the warning by changing the display color of the stroke amount of the person to be measured. The biometric information measuring device according to claim 5, wherein the processor notifies the content of the warning by changing the output sound together with the stroke amount of the person to be measured. The biometric information measuring device according to claim 5, wherein the processor outputs the content of the warning in characters together with the stroke amount of the person to be measured. The biometric information measuring device according to any one of claims 6 to 8, wherein the content of the warning represents the reliability of the measured cardiac output. A temperature sensor for detecting the temperature of the terminal portion and a display device for displaying information on the living body of the person to be measured are provided.
The processor obtains the temperature of the terminal portion of the person to be measured from the temperature sensor, and causes the display device to display the measured pumping amount of the person to be measured and the warning. The biometric information measuring device according to any one of the above items. On the computer
Detects the temperature of the terminal part, which is the part on the terminal side of the body of the person to be measured,
Based on the change in the value representing the blood oxygen concentration of the person to be measured measured at the measurement site in the terminal site, oxygen is taken into the body of the person to be measured and then the measurement site is passed through the blood. Estimate the oxygen circulation time, which indicates the time to reach
When measuring the cardiac output of the person to be measured using the estimated oxygen cycle time,
A biological information measurement program for executing a process of outputting a warning for the measurement result of the stroke amount based on the temperature of the terminal portion.

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