Patent Application
20130178720
The present disclosure relates to a biorhythm estimation device, a biorhythm estimation method and a program.
Biorhythm is autonomous cyclic rhythm of an organism and adjusts changes in sleep, body temperature, blood pressure, autonomic nerves, or the like throughout the day. A deviation of biorhythm may have an influence on symptoms such as jet lag, sleep disorder, and seasonal depression, and treatment of biorhythm has attracted attention. Biorhythm may have an influence on exercise of physical ability or efficacy of a drug, and maximization of such effects has attracted attention. Accordingly, it is necessary to easily estimate biorhythm of an experimental subject.
For example, measuring a rectal temperature of an experimental subject for 24 hours or more and estimating a biorhythm curve is disclosed in the following Patent Literatures 1 and 2. Further, measuring a heart rate of an experimental subject for 24 hours or more and estimating a biorhythm curve is disclosed in the following Patent Literature 2.
However, an experimental subject should insert a measurement probe 10 cm or more into his or her anus in measurement of a rectal temperature and should attach a measurement patch to his or her chest in heart rate measurement. Further, continuously measuring biological information of an experimental subject over 24 hours or more is necessary in biorhythm estimation. Accordingly, the experimental subject experiences pain, discomfort or the like due to invasive measurement and suffers in daily life due to long-period measurement. Thus, in the related art, it is difficult to easily estimate the biorhythm of the experimental subject.
It is desirable to provide a biorhythm estimation device, a biorhythm estimation method, and a program capable of estimating biorhythm of an experimental subject based on noninvasively and easily measured biological information.
According to an aspect of the present disclosure, there is provided a biorhythm estimation device including a reference rhythm curve storage unit configured to store a reference rhythm curve based on a plurality of experimental subject samples, the reference rhythm curve being created as a biorhythm curve representing a property of intra-day fluctuation of an indicator value of biological information, a biological information measurement unit configured to noninvasively measure the biological information of an experimental subject, an indicator value calculation unit configured to calculate the indicator value from a measurement value of the biological information, an experimental-subject rhythm curve creation unit configured to fit the reference rhythm curve to the indicator value calculated from the measurement value obtained by noninvasively measuring the biological information of the experimental subject to create an experimental-subject rhythm curve whose target is the experimental subject, an experimental-subject rhythm curve storage unit configured to store the experimental-subject rhythm curve, and a biorhythm estimation unit configured to apply the indicator value calculated from the measurement value obtained by noninvasively measuring the biological information of the experimental subject to the experimental-subject rhythm curve to estimate biorhythm of the experimental subject.
The reference rhythm curve may be created from the indicator value calculated from the measurement value of the biological information measured for the plurality of experimental subject samples for 24 hours or more, the experimental-subject rhythm curve creation unit may fit the reference rhythm curve to two or more indicator values calculated from the biological information noninvasively measured for the experimental subject twice or more at a time interval, and the biorhythm estimation unit may apply the two or more indicator values calculated from the biological information noninvasively measured for the experimental subject once or more to the experimental-subject rhythm curve.
Each of the reference rhythm curve and the experimental-subject rhythm curve may have a first rhythm curve representing a property of intra-day fluctuation of a first indicator value calculated from one or more pieces of biological information and a second rhythm curve representing a property of intra-day fluctuation of a second indicator value whose type is different from the first indicator value, the indicator value calculation unit calculates the first indicator value and the second indicator value from the one or more pieces of biological information noninvasively measured for the experimental subject once, and the biorhythm estimation unit may derive times t11 and t12 (t11<t12) corresponding the first indicator value on the first rhythm curve, derives times t21 and t22 (t21<t22) corresponding to the second indicator value on the second rhythm curve, and estimate the biorhythm of the experimental subject from a time corresponding to the smaller of a period |t11-t21| and a period |t12-t22|.
The first indicator value may be a pulse rate calculated from a pulse wave, and the second indicator value may be an AI value calculated from the pulse wave.
The first indicator value may be a pulse rate or an AI value calculated from a pulse wave, and the second indicator value may be an internal temperature of a mouth or an internal temperature of an ear.
The reference rhythm curve and the experimental-subject rhythm curve may have a rhythm curve representing a property of intra-day fluctuation of the indicator value calculated from the biological information, respectively, the indicator value calculation unit calculates a first indicator value and a second indicator value with different measurement time points from the biological information noninvasively measured for the experimental subject twice at a measurement interval within 12 hours, and the biorhythm estimation unit may derive one or more first times corresponding to the first indicator value on the experimental-subject rhythm curve, derives one or more second times corresponding to the second indicator value on the experimental-subject rhythm curve, and estimate the biorhythm of the experimental subject from the time corresponding to the closest period to the measurement interval among periods between the first times and the second times.
Each of the first and second indicator values may be a pulse rate or an AI value calculated from a pulse wave, or an internal temperature of a mouth or an internal temperature of an ear.
The reference rhythm curve and the experimental-subject rhythm curve may have a rhythm curve representing a property of intra-day fluctuation of the indicator value calculated from the biological information, respectively, the indicator value calculation unit calculates three or more indicator values with different measurement time points from the biological information noninvasively measured for the experimental subject three times or more at a time interval, and the biorhythm estimation unit may apply the three or more indicator values to the experimental-subject rhythm curve to estimate the biorhythm of the experimental subject from times corresponding to the three or more indicator values on the experimental-subject rhythm curve.
The indicator value may be a pulse rate or an AI value calculated from a pulse wave, or an internal temperature of a mouth or an internal temperature of an ear.
The reference rhythm curve may be prepared as a first rhythm curve whose target is a plurality of experimental subject samples having at least a first living-hour pattern, and a second rhythm curve whose target is a plurality of experimental subject samples having a second living-hour pattern different from the first living-hour pattern, and the experimental-subject rhythm curve creation unit may fit at least one of the first or second rhythm life that matches a living-hour pattern of the experimental subject to the indicator value to create the experimental-subject rhythm curve.
The biorhythm curve may be a single-mode function. The single-mode function may be a trigonometric function of a cycle of 24 hours.
Further, according to another aspect of the present disclosure, there is provided a biorhythm estimation method including preparing a reference rhythm curve based on a plurality of experimental subject samples as a biorhythm curve representing a property of intra-day fluctuation of an indicator value of the biological information, fitting the reference rhythm curve to the indicator value calculated from a measurement value obtained by noninvasively measuring the biological information of an experimental subject to create an experimental-subject rhythm curve whose target is the experimental subject, and applying the indicator value calculated from the measurement value obtained by noninvasively measuring the biological information of the experimental subject to the experimental-subject rhythm curve to estimate biorhythm of the experimental subject.
Further, according to another aspect of the present disclosure, there is provided a program for causing a computer to execute preparing a reference rhythm curve based on a plurality of experimental subject samples as a biorhythm curve representing a property of intra-day fluctuation of an indicator value of the biological information, fitting the reference rhythm curve to the indicator value calculated from a measurement value obtained by noninvasively measuring the biological information of an experimental subject to create an experimental-subject rhythm curve whose target is the experimental subject, and applying the indicator value calculated from the measurement value obtained by noninvasively measuring the biological information of the experimental subject to the experimental-subject rhythm curve to estimate biorhythm of the experimental subject.
As described above, according to the present disclosure, it is possible to provide a biorhythm estimation device, a biorhythm estimation method, and a program capable of estimating biorhythm of an experimental subject based on noninvasively and easily measured biological information.
Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the appended drawings. Note that, in this specification and the drawings, elements that have substantially the same function and structure are denoted with the same reference signs, and repeated explanation is omitted.
First, an overview of a biorhythm estimation method according to an embodiment of the present disclosure will be described with reference to
Here, the biological information which can be measured noninvasively and in a short time and from which the biorhythm is easily recognized, in other words, which has a goodness of fit of the biorhythm curve and the indicator value, is used in the estimation of the biorhythm. A pulse wave of an experimental subject or an experimental subject sample (hereinafter also referred to as an experimental subject or the like), an internal temperature of a mouth or an ear, or the like is used as the biological information, but the biological information is not limited thereto.
Accordingly, the experimental-subject rhythm curve EC can be created from measurement values measured twice or more at a time interval without continuously measuring the biological information for 24 hours, and the biorhythm can be estimated from measurement values of one time or more. The reference rhythm curve RC and the experimental-subject rhythm curve EC are created, for example, as a single-mode function such as a trigonometric function of a cycle of 24 hours.
Accordingly, the experimental subject does not experience pain, discomfort or the like due to invasive measurement and does not suffer in daily life due to long-period measurement, unlike a biorhythm estimation method of the related art. Thus, it is possible to estimate the biorhythm of the experimental subject based on the noninvasively and easily measured biological information.
Next, a primary functional configuration of a biorhythm estimation device 1 according to an embodiment of the present disclosure will be described with reference to
In the biorhythm estimation device 1 illustrated in
The biological information measurement sensor 11 is a sensor for measuring biological information such as a pulse wave of an experimental subject or the like, an internal temperature of a mouth or an ear, or the like. The pulse wave is measured as a photoelectric pulse wave or a pressure pulse wave from a fingertip or the like of the experimental subject or the like, and the internal temperature of the mouth or the ear is measured as a body temperature of the experimental subject or the like. The measurement value of the biological information is stored in the measurement value storage unit 14 for a subsequent process.
The disturbance information measurement sensor 12 is a sensor for measuring disturbance information generated at the time of measurement of the biological information due to a motion or the like of the experimental subject or the like (e.g., an acceleration due to an action of the experimental subject or the like). The measurement value of the disturbance information is also stored in the measurement value storage unit 14 for a subsequent process.
The measurement timer 13 supplies timing information indicating a predetermined measurement timing to the biological information measurement sensor 11 and the disturbance information measurement sensor 12.
The indicator value calculation unit 15 calculates an indicator value from the biological information based on the measurement values of the biological information of the experimental subject or the like and the disturbance information. The indicator value is an average pulse rate calculated from the pulse wave, an average AI (Augmentation Index) value, an average internal temperature of the mouth or the ear, or the like, but is not limited thereto.
The measurement values of the biological information and the disturbance information are read from the measurement value storage unit 14 in order to calculate the indicator value. The indicator value of the experimental subject sample is supplied to the reference rhythm curve creation unit 16. Further, the indicator value of the experimental subject is supplied to the experimental-subject rhythm curve creation unit 18 and used for creation of an experimental-subject rhythm curve EC and/or supplied to the biorhythm estimation unit 20 and used for estimation of the biorhythm.
The reference rhythm curve creation unit 16 creates the reference rhythm curve RC from the indicator value that is calculated from the measurement value of the biological information measured for 24 hours or more for a plurality of experimental subject samples. The reference rhythm curve RC is a curve representing an average property of intra-day fluctuation of the indicator value whose target is a plurality of experimental subject samples. The created reference rhythm curve RC is stored in the reference rhythm curve storage unit 17.
The experimental-subject rhythm curve creation unit 18 fits the reference rhythm curve RC to two or more indicator values C calculated from the biological information noninvasively measured for the experimental subject twice or more at a time interval to create the experimental-subject rhythm curve EC. The experimental-subject rhythm curve EC is a curve representing a property of intra-day fluctuation of the indicator value whose target is the experimental subject. The indicator value C from the indicator value calculation unit 15 and the reference rhythm curve RC from the reference rhythm curve storage unit 17 are supplied to the experimental-subject rhythm curve creation unit 18. The created experimental-subject rhythm curve EC is stored in the experimental-subject rhythm curve storage unit 19.
The biorhythm estimation unit 20 applies two or more indicator values C′ calculated from the biological information noninvasively measured one time or more to the experimental-subject rhythm curve EC to estimate the biorhythm of the experimental subject. The indicator values C′ of the experimental subject from the indicator value calculation unit 15 and the experimental-subject rhythm curve EC from the experimental-subject rhythm curve storage unit 19 are supplied to the biorhythm estimation unit 20. The estimation value of the biorhythm is supplied to the biorhythm output unit 21.
The biorhythm output unit 21 outputs the biorhythm estimation value. The biorhythm estimation value is supplied or output to the inside of the biorhythm estimation device 1 or to an external display device, an external printing device or an external storage device (all not shown). As the biorhythm, a time corresponding to the measurement value on the experimental-subject rhythm curve EC may be output or a difference (a biorhythm deviation) between a time corresponding to the measurement value on the experimental-subject rhythm curve EC and an actual measurement time may be output.
Here, in the above functional configuration, the indicator value calculation unit 15, the reference rhythm curve creation unit 16, the experimental-subject rhythm curve creation unit 18, the biorhythm estimation unit 20, and the biorhythm output unit 21 are configured of an arithmetic processing device such as a CPU or a DSP (digital signal processing device). The measurement value storage unit 14, the reference rhythm curve storage unit 17, and the experimental-subject rhythm curve storage unit 19 are configured of an internal storage device such as a flash memory, a hard disk drive, or an external storage device such as Blu-ray disc drive. Also, the CPU develops and executes, on a RAM, a program read from a ROM or the like to realize a biorhythm estimation method. Further, at least a part of the above functional configuration may be configured as hardware such as a dedicated logic.
Next, operation of the biorhythm estimation device 1 according to the embodiment of the present disclosure will be described with reference to
As illustrated in
Then, the biological information of the experimental subject is noninvasively measured (step S12), and the reference rhythm curve RC is fitted to an indicator value C calculated from the measurement value (step S13) to create an experimental-subject rhythm curve EC (step S14). The experimental-subject rhythm curve EC is a biorhythm curve representing a property of intra-day fluctuation of the indicator value whose target is the experimental subject.
Then, the biological information of the experimental subject is noninvasively measured (step S15) and an indicator value C′ calculated from a measurement value is applied to the experimental-subject rhythm curve EC (step S16) to estimate the biorhythm of the experimental subject (step S17). Further, some of the indicator values C of step S13 may be used as the indicator value C′ of step S16.
Here, biological information which can be measured noninvasively and in a short time and from which the biorhythm is easily recognized, in other words, which has a goodness of fit of the biorhythm curve and the indicator value calculated from the measurement value, is used in the estimation of the biorhythm. Such biological information includes a photoelectric pulse wave or a pressure pulse wave of a fingertip or the like of the experimental subject or the like, an internal temperature of a mouth or an ear, or the like, but is not limited thereto.
Hereinafter, a case in which a pulse wave is measured as the biological information, and a pulse rate and an AI value are calculated as indicator values from a measurement value of the pulse wave will be described. Here, the pulse wave is a pressure wave generated in a vessel when blood is sent from a heart. As illustrated in
A method of creating the reference rhythm curve RC is illustrated in
In the reference rhythm curve creation unit 16, the reference rhythm curve RC is created from the indicator value calculated from the measurement value of the biological information measurement sensor 11, and the created reference rhythm curve RC is stored in the reference rhythm curve storage unit 17. In the creation of the reference rhythm curve RC, the measurement value of the biological information may be measured as a continuous measurement value, but a case in which the measurement value of the biological information is measured as a discontinuous measurement value will be described hereinafter.
First, a pulse wave for each of experimental subject samples of N persons (i=1 to N) (hereinafter referred to as samples) is measured for 24 hours or more (step S21). As illustrated in
Then, an average indicator value Xi,t (e.g., an average pulse rate or an average AI value) is calculated from the pulse wave of the measurement period of time y at every time t for each sample i (step S22). In the indicator value calculation unit 15, an indicator value Xi,t at every time t is calculated from the measurement values of the biological information and the disturbance information. Further, a procedure of calculating the indicator value Xi,t will be described with reference to
In the calculation of the indicator value Xi,t, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
After the indicator value Xi,t is calculated, the process returns to the procedure of creating the reference rhythm curve RC illustrated in
Then, an abnormal value included in the indicator value Xi,t is rejected (step S24). For example, if a difference value between indicator values in tandem (e.g., indicator values Xi,t and Xi,t+Δt) or indicator values within a predetermined time (e.g., indicator values Xi,t, Xi,t+Δt and Xi,t+2Δt) exceeds a predetermined threshold value, an unstable state of the sample is confirmed from the measurement value of the biological information or the disturbance information, and the indicator value is rejected as an abnormal value. Further, when the number of abnormal values exceeds a predetermined threshold value, the experimental subject or the like is requested to perform re-measurement of the pulse wave via a notification unit (not shown) or the like.
Next, as illustrated in
Next, as illustrated in
RC(t)=Atmpsin(wt+Btmp), w=2π/24 hours (1)
In the measurement of the pulse wave, each experimental subject sample may go to bed or wake up according to his or her living-hour pattern or may go to bed or wake up at a time defined as a measurement condition. Here, a plurality of experimental subject samples and experimental subjects are considered as belonging to various living-hour pattern types (e.g., a morning type, an evening type, and an intermediate type). Accordingly, the living-hour patterns of the experimental subject samples are specified and then one or more reference rhythm curves (e.g., a morning type rhythm curve or an evening type rhythm curve) corresponding to the various living-hour patterns may be created.
Further, a difference between biorhythm curves according to the living-hour patterns is described in, for example, “E. K. Baehr et al., Individual differences in the phase and amplitude of the human circadian temperature rhythm: with an emphasis on morningness-eveningness, J. Sleep Res, 2000, 9, 117-127.” Further, when the biorhythm curve according to the living-hour pattern is created, the living-hour pattern of an experimental subject or the like may be identified using, for example, morning-type and evening-type questionnaire (“Morningness Eveningness Questionnaire, Home and Ostberg 1976.).”
A method of creating the experimental-subject rhythm curve EC is illustrated in
In the experimental-subject rhythm curve creation unit 18, the reference rhythm curve RC is fitted to the indicator value C calculated from the measurement value of the biological information measurement sensor 11 to create the experimental-subject rhythm curve EC, and the created experimental-subject rhythm curve EC is stored in the experimental-subject rhythm curve storage unit 19. In the creation of the experimental-subject rhythm curve EC, the measurement value of the biological information is measured as a discontinuous measurement value. Further, the experimental-subject rhythm curve EC is created for each indicator (e.g., an average pulse rate or an average AI value).
The experimental-subject rhythm curve EC is created using measurement values of two times or measurement values of three times. Hereinafter, a case in which measurement is performed three times at any time t0, after 6 hours from the time t0, and after 12 hours from the time t0 will be mainly described.
First, a case in which measurement values of three times are used will be described with reference to
The indicator values C(t0), C(t0+6 h) and C(t0+12 h) corresponding to the measurement values of three times can be applied to a single-mode function similar to Equation (1), which represents the reference rhythm curve RC, as shown in Equation (2). Here, an unknown number m corresponding to a difference between a change center of the indicator value and a baseline (amplitude center) of the trigonometric function, an unknown number A corresponding to the amplitude of the trigonometric function, and an unknown number B corresponding to a phase of the trigonometric function are estimated in the above application.
Here, the experimental-subject rhythm curve EC is created by adjusting the baseline using the unknown number m, the amplitude using the unknown number A, and the phase using the unknown number B with respect to the reference rhythm curve RC.
EC(t)=m+A sin(Z), Z=wt+B, w=2π/24 hours (2)
The indicator values C(t0), C(t0+6 h) and C(t0+12 h) are represented as Equations (3), (4) and (5).
C(t0)=m+A sin(Z) (3)
C(t0+6 h)=m+A cos(Z) (4)
C(t0+12 h)=m−A sin(Z) (5)
The unknown number m is then estimated as Equation (6) using the indicator values C(t0) and C(t0+12 h) (step S43). Similarly, the unknown number A is estimated as Equation (7) using the indicator values C(t0) and C(t0+6 h) or the indicator values C(t0+6 h) and C(t0+12 h) (step S44). Further, since the value w and the value t are known, the unknown number B is estimated using the indicator values C(t0) and C(t0+6 h) or the indicator values C(t0+6 h) and C(t0+12 h) (step S45). Also, the estimation values m, A and B are applied to Equation (2) (step S46) to create the experimental-subject rhythm curve EC (step S47).
m=(C(t0)+C(t0+12 h))/2 (6)
A=√((C(t0)−m)2+(C(t0+6 h)−m)2) (7)
Next, a case in which measurement is performed three times at any time t0, after 3 hours from the time t0, and after 6 hours from the time t0 will be briefly described. In this case, indicator values C(t0), C(t0+3 h), and C(t0+6 h) are represented as Equations (8), (9) and (10).
C(t0)=m+A sin(Z) (8)
C(t0+3 h)=m+A(sin Z+cos Z)/√2 (9)
C(t0+6 h)=m+A cos Z (10)
where Z=wt0+B.
The unknown numbers m and A are estimated as Equations (11) and (12) from Equations (8) to (10).
m=C{C(t0)+C(t0+6 h)−√2·C(t0+3h)}/(2−√2) (11)
A=·{(C(t0)−m)2+(C(t0+6 h)−m)2} (12)
An unknown number A is estimated by assigning Equation (11) to Equation (12).
An unknown number Z is estimated by assigning estimation values m and A to Equations (8) and (10). Here, since the value w and the value t are known, the unknown number B is obtained. Also, as the estimation values m, A and B are assigned to Equation (2), the experimental-subject rhythm curve EC is created.
Next, a case in which measurement is performed two times at any times t1 and t2 will be briefly described. In this case, indicator values C(t1) and C(t2) are represented as Equations (13) and (14).
C(t1)=m+A sin(Z+t1) (13)
C(t2)=m+A sin(Z+t2) (14)
where Z=wt+B.
Unknown numbers m and A are estimated as Equations (15) and (16) by solving a simultaneous equation of Equations (13) and (14).
m={C(t1)sin(Z+t2)−C(t2)sin(Z+t1)}/{sin(Z+t2)−sin(Z+t1)} (15)
A={C(t2)−C(t1)}/{sin(Z+t2)−sin(Z+t1)} (16)
Further, an estimation value Btmp used for creation of the reference rhythm curve RC is applied as the unknown number B. Since the estimation value Btmp is estimated from an average value <Xt> of N samples and has higher accuracy than the unknown number B, the estimation value is treated as a constant number. Also, the estimation values m, A and B (=Btmp) are assigned to Equation (2) to create the experimental-subject rhythm curve EC.
A method of estimating biorhythm of an experimental subject is shown in
In the biorhythm estimation unit 20, two or more indicator values C′ calculated from the biological information measured noninvasively one time or more for an experimental subject are applied to the experimental-subject rhythm curve EC to estimate the biorhythm of the experimental subject, and the biorhythm estimation value is supplied to the biorhythm output unit 21. Here, when the living-hour pattern of the experimental subject is considered, the biorhythm of the experimental subject is estimated by applying two or more indicator values C′ calculated from the measurement value of the biological information of one time or more to the experimental-subject rhythm curve EC in which the living-hour pattern of the experimental subject is considered.
(Biorhythm Estimation Based on 1-point Method)
In the 1-point method, first and second reference rhythm curves RC1 and RC2 and first and second experimental-subject rhythm curves EC1 and EC2 are used. The first reference rhythm curve RC1 and the first experimental-subject rhythm curve EC1 are curves representing a property of intra-day fluctuation of the first indicator value C1′. The second reference rhythm curve RC2 and the second experimental-subject rhythm curve EC2 are curves representing a property of intra-day fluctuation of a second indicator value C2′ different from the first indicator value C1′.
In the indicator value calculation unit 15, the first and second indicator values C1′ and C2′ are calculated from one or more pieces of biological information noninvasively measured for the experimental subject once. Further, in the biorhythm estimation unit 20, times t12 and t22 (t11<t12) corresponding to the first indicator value C1′ on the first rhythm curve EC1 are derived and times t21 and t22 (t21<t22) corresponding to the second indicator value C2′ on the second rhythm curve EC2 are derived. Also, the biorhythm of the experimental subject is estimated from a time corresponding to a smaller of a period d1 (=|t11−t21|) and a period d2 (=|t12−t22|).
Hereinafter, a case in which the first indicator value C1′ is a pulse rate of the experimental subject or the like and the second indicator value C2′ is an AI value of the experimental subject or the like will be described. However, a combination of the first indicator value C1′ and the second indicator value C2′ may be a combination of the pulse rate or the AI value and an internal temperature of an ear or a mouth or may be a combination of other indicator values. Hereinafter, a biorhythm estimation procedure based on a 1-point method will be described with reference to
As illustrated in
The pulse wave is then measured in a measurement period of time y seconds at any time t, and an average pulse rate C1′(t) and an average AI value C2′(t) at the time t are calculated in the procedure described with reference to
Next, as illustrated in
An abnormal value is then rejected from the calculated times t11, t12, t21, and t22 (step S56). Here, for example, if a difference value between the time t11 and the time t21 or a difference value between the time t21 and the time t22 exceeds a predetermined threshold value, the abnormal value is rejected from the calculated times when the average pulse rate C1′(t) and the average AI value C2′(t) are both located above or both located below the baseline of the rhythm curve. When the abnormal value is rejected, the experimental subject is requested to perform re-measurement of the pulse wave.
Next, as illustrated in
(Biorhythm Estimation Based on 2-point Method)
In the 2-point method, a reference rhythm curve RC and an experimental-subject rhythm curve EC representing a property of intra-day fluctuation of the indicator value C′ are used. In the indicator value calculation unit 15, two indicator values C′(t1) and C′(t2) having different measurement time points are calculated from the biological information noninvasively measured for the experimental subject twice at a measurement interval Δt within 12 hours.
Also, in the biorhythm estimation unit 20, one or more times t11 corresponding to the indicator value C′(t1) are derived on the experimental-subject rhythm curve EC and one or more times t21 and t22 corresponding to the indicator value C′(t2) are derived on the experimental-subject rhythm curve EC. Also, the biorhythm of the experimental subject is estimated from a time corresponding to the closest period to the measurement interval Δt among periods d between the time t11 and the times t21 and t22.
Hereinafter, a case in which the indicator value C′ is the pulse rate of the experimental subject or the like will be described. However, the indicator value C′ may be an AI value, an internal temperature of the ear or the mouth, or the like or may be another indicator value. Hereinafter, a biorhythm estimation procedure based on a 2-point method will be described with reference to
As illustrated in
First, the pulse wave is measured in a measurement period of time y seconds at any time t, and an indicator value C′(t1) at a time t=t1 is calculated in the procedure described with reference to
A positional relationship between the indicator values C′(t1) and C′(t2) is then estimated on the experimental-subject rhythm curve EC (step S64). As illustrated in
state 1: C′(t1) and C′(t2) are not located across a lower convex portion of the curve EC or a peak of the curve EC.
state 2: C′(t1) and C′(t2) are located across a lower convex portion of the curve EC and a peak of the curve EC.
state 3: C′(t1) and C′(t2) are not located across an upper convex portion of the curve EC or a peak of the curve EC.
state 4: C′(t1) and C′(t2) are located across an upper convex portion of the curve EC and a peak of the curve EC.
A size relationship between the indicator values C′(t1) and C′(t2) and the baseline m of the curve EC is then confirmed (step S65). Accordingly, a determination is made as to whether the indicator values C′(t1) and C′(t2) are located in the upper convex portion or the lower convex portion of the curve EC. For example, when the indicator values C′(t1) and C′(t2) are greater than the baseline m as illustrated in
Next, as illustrated in
Further, as illustrated in
In the 2-point method, the 1-point method described above may be performed twice within 12 hours. Accordingly, when the first and second indicator values C1′(t) and C2′(t) can be calculated, the 2-point method may be applied to the first and second indicator values C1′(t) and C2′(t) to calculate the first and second estimation values. Also, when an error between the first and second estimation values is small, any one of the estimation values may be adopted or an average value of the two estimation values may be adopted. On the other hand, when the error between the first and second estimation values is great, the estimation is determined to fail and the experimental subject may be requested to perform re-measurement. Further, when one of the first and second indicator values C1′(t) and C2′(t) cannot be calculated for any reason, the 2-point method may be applied to the calculated indicator value to estimate the biorhythm.
(Biorhythm Estimation Based on Domain Method)
In the domain method, a reference rhythm curve RC and an experimental-subject rhythm curve EC representing a property of intra-day fluctuation of an indicator value are used. In the indicator value calculation unit 15, three or more indicator values C′(t1), C′(t2), C′(t3), . . . with different measurement time points are calculated from the biological information noninvasively measured for the experimental subject three times or more.
Also, in the biorhythm estimation unit 20, three or more indicator values C′(t1), C′(t2), C′(t3), . . . are applied to the experimental-subject rhythm curve EC to estimate the biorhythm of the experimental subject from times corresponding to the three or more indicator values on the experimental-subject rhythm curve EC.
Hereinafter, a case in which the indicator value C′ is the pulse rate of the experimental subject or the like will be described. However, the indicator value C′ may be an AI value, an internal temperature of the ear or mouth, or the like or may be another indicator value. Hereinafter, a biorhythm estimation procedure based on the domain method will be described with reference to
As illustrated in
A pulse wave is then measured in a measurement period of time y seconds at any three or more times t=t1, t2, t3, . . . (step S72), and indicator values C′(t1), C′(t2), C′(t3), . . . at a time t which is t1, t2, t3, . . . are calculated in the procedure described with reference to
Here, the pulse wave may be measured as a continuous measurement value during sleep or while awake. In this case, the measured pulse wave is separated at certain time intervals such as 0.5 hours, 1 hour or the like, and indicator values C′(t1), C′(t2), C′(t3), . . . are calculated in each section in the procedure described with reference to
Next, as illustrated in
Also, at least one of the times t11, t12, t13, . . . corresponding to the indicator values C′(t1), C′(t2), C′(t3), . . . on the experimental-subject rhythm curve EC is estimated as the biorhythm of the experimental subject (step S75). For example, in an example illustrated in
Even in the domain method, the 1-point method described above may be performed three times or more. Accordingly, when the first and second indicator values C1′(t) and C2′(t) can be calculated, the domain method can be applied to the first and second indicator values C1′(t) and C2′(t) to calculate the first and second estimation values. Also, when the error between the first and second estimation values is small, any one of the estimation values may be adopted or an average value of two estimation values may be adopted. On the other hand, when the error between the first and second estimation values is great, the estimation is determined to have failed and the experimental subject may be requested to perform re-measurement. Further, even when one of the first and second indicator values C1′(t) and C2′(t) cannot be calculated for any reason, the domain method may be applied to the calculated indicator value to estimate the biorhythm.
As described above, according to the biorhythm estimation method in the embodiment of the present disclosure, the biological information which can be measured noninvasively and in a short time and from which the biorhythm is easily recognized, in other words, which has a goodness of fit of the biorhythm curve and the indicator value, is used in the estimation of the biorhythm.
Accordingly, the experimental subject does not experience pain, discomfort or the like due to invasive measurement and does not suffer in daily life due to long-period measurement, unlike a biorhythm estimation method of the related art. Thus, it is possible to estimate the biorhythm of the experimental subject based on the noninvasively and easily measured biological information.
The preferred embodiments of the present disclosure have been described above with reference to the accompanying drawings, whilst the present invention is not limited to the above examples, of course. A person skilled in the art may find various alternations and modifications within the scope of the appended claims, and it should be understood that they will naturally come under the technical scope of the present invention.
For example, in the above description, the case in which the pulse wave is used as the biological information has been mainly described. However, the biological information is not limited to the pulse wave, and other biological information which can be measured noninvasively and in a short time and from which the biorhythm is easily recognized, in other words, which has a goodness of fit of the biorhythm curve and the indicator value may be used.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-165786 | Jul 2010 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP11/62095 | 5/26/2011 | WO | 00 | 3/27/2013 |
