BODY COMPOSITION ANALYZER, BODY COMPOSITION MEASUREMENT PROGRAMM AND COMPUTER-READABLE NON-TRANSITORY STORAGE MEDIUM
20220007959 · 2022-01-13
Inventors
Cpc classification
A61B5/7221
HUMAN NECESSITIES
A61B5/0537
HUMAN NECESSITIES
International classification
Abstract
The present disclosure provides a body composition analyzer and a body composition measurement program capable of determining a measurement abnormality by analyzing a waveform of Dynamic Impedance (DI). A body composition analyzer (10) that measures body composition based on the measurement of bioelectrical impedance includes a bioelectrical impedance measuring unit (112) that acquires time-series data of the bioelectrical impedance by measurement, and a measurement abnormality determination unit (116) that determines a cause or type of an abnormality in the measurement based on the time-series data.
Claims
1. A body composition analyzer for measuring body composition based on the measurement of bioelectrical impedance, comprising: a bioelectrical impedance measuring unit configured to acquire time-series data of bioelectrical impedance by measurement, and a measurement abnormality determination unit configured to determine a cause or type of abnormality in the measurement based on the time-series data.
2. The body composition analyzer according to claim 1, wherein the measurement abnormality determining unit is configured to determine the cause or type of the abnormality of the measurement based on a trend of the time-series data.
3. The body composition analyzer according to claim 1, wherein the measurement abnormality determination unit is configured to determine the cause or type of the abnormality of the measurement based on the variation of the time-series data.
4. The body composition analyzer according to claim 2, wherein the measurement abnormality determination unit is configured to determine the cause or type of the abnormality of the measurement based on the variation of the time-series data.
5. The body composition analyzer according to claim 1, wherein the bioelectrical impedance includes resistance.
6. The body composition analyzer according to claim 2, wherein the bioelectrical impedance includes resistance.
7. The body composition analyzer according to claim 3, wherein the bioelectrical impedance includes resistance.
8. The body composition analyzer according to claim 4, wherein the bioelectrical impedance includes resistance.
9. The body composition analyzer according to claim 1, wherein the bioelectrical impedance includes reactance.
10. The body composition analyzer according to claim 2, wherein the bioelectrical impedance includes reactance.
11. The body composition analyzer according to claim 3, wherein the bioelectrical impedance includes reactance.
12. The body composition analyzer according to claim 4, wherein the bioelectrical impedance includes reactance.
13. The body composition analyzer according to claim 5, wherein the bioelectrical impedance includes reactance.
14. The body composition analyzer according to claim 6, wherein the bioelectrical impedance includes reactance.
15. The body composition analyzer according to claim 7, wherein the bioelectrical impedance includes reactance.
16. The body composition analyzer according to claim 8, wherein the bioelectrical impedance includes reactance.
17. The body composition analyzer according to claim 1, further comprising a notification unit configured to notify a remedial measure corresponding to the cause or type of the abnormality in the measurement.
18. The body composition analyzer according to claim 2, further comprising a notification unit configured to notify a remedial measure corresponding to the cause or type of the abnormality in the measurement.
19. The body composition analyzer according to claim 3, further comprising a notification unit configured to notify a remedial measure corresponding to the cause or type of the abnormality in the measurement.
20. A computer-readable non-transitory storage medium storing a body composition measurement program for controlling a body composition analyzer equipped with a computer for measuring body composition based on measurement of bioelectrical impedance, the program is configured to cause the computer to: acquire time-series data of the bioelectrical impedance by measurement; and determine a cause or type of abnormality in the measurement based on the time-series data.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] The following is a description of embodiment of the present disclosure with reference to the drawings. The embodiment described below show an example of how to implement the present disclosure, and does not limit the present disclosure to the specific configuration described below. In the implementation of the present disclosure, the specific configuration according to the embodiment may be adopted as appropriate.
First Embodiment
Configuration of the Body Composition Analyzer 10
[0042]
[0043] The main unit 20 is equipped with a load cell inside for measuring the weight, and can measure the weight of a user.
[0044] The main body 20 is equipped with a current-carrying electrode 22L and a measuring electrode 24L on the left side of the top surface, and a current carrying electrode 22R and a measuring electrode 24R on the right side of the top surface. The user stands upright with bare feet on top of the main unit 20 to take biometric measurements. At this time, the base of the left toe comes in contact with the current-carrying electrode 22L, the heel of the left foot comes in contact with the measuring electrode 24L, the base of the right toe comes in contact with the current-carrying electrode 22R, and the heel of the right foot comes in contact with the measuring electrode 24R.
[0045] The input unit 102 is an input means for inputting data into the body composition analyzer 10. The method of inputting information by the input unit 102 may be, for example, a manual method, a method via a recording medium, a method via wired communication, a method via wireless communication, or any other method.
[0046] The manual input method may be, for example, a button type, a dial type, or a touch sensor type. The recording medium of the method via a recording medium may be, for example, flash memory, CD-ROM, or DVD-ROM. The wireless communication of the method via wireless communication may be, for example, the Internet, a wireless LAN such as Wi-Fi (registered trademark), or a short-range wireless communication such as Bluetooth (registered trademark) or NFC (Near Field Communication). In this embodiment, the input unit 102 is a manual input method and is a button type.
[0047] The user operates the input unit 102 to input data such as the user's height, age, and gender to the body composition analyzer 10. The body composition analyzer 10 calculates the body composition data by combining this data with the body weight and the bioelectrical impedance. The body composition data includes, for example, body fat percentage, body fat mass, muscle mass, abdominal/back muscle ratio, body water content, bone mass, visceral fat area, and basal metabolism.
[0048] The output unit 106 is an output means for outputting the measurement results of the body composition analyzer 10. The measurement results are, for example, body weight, body composition data, and the like. The output unit 106 is, for example, a display panel equipped with an LCD (Liquid Crystal Display) or an OLED (Organic Light Emitting Diode). The output unit 106 may be integrated with the body composition analyzer 10, or may not be integrated with the body composition analyzer 10, such as a smartphone or tablet. In the present embodiment, the output unit 106 is a display panel equipped with an LCD integrated with the body composition analyzer 10.
[0049] The output unit 106 may, for example, display numerical values reflecting the results of the user's measurement, text, a diagram of the user's standing position at the time of measurement, or the like, or may output the data in audio or other formats. The output unit 106 may also display remedial measures corresponding to the cause or type of measurement abnormality reported to the user by a notification unit 118 described below.
Functional Configuration of Body Composition Analyzer 10
[0050]
[0051] The memory unit 104 is a memory that can store data. The memory can be, for example, volatile memory (e.g., RAM (Random Access Memory)), non-volatile memory (e.g., ROM (Read Only Memory)), etc. The memory unit 104 may be built into the body composition analyzer 10 or may be provided outside the body composition analyzer 10, such as an external hard disk drive as shown in
[0052] The memory unit 104 stores a program executed by the control unit 108, data input to the body composition analyzer 10 by a user operating the input unit 102, statistical data for calculating body composition data by the body composition analyzer 10, body composition data calculated by the body composition analyzer 10, and the like. The program may be provided to the body composition analyzer 10 by the body composition analyzer 10 by downloading it from a communication network, or may be provided to the body composition analyzer 10 via a non-transitory storage medium.
[0053] The control unit 108 is a control device that controls the input unit 102, the memory unit 104, the output unit 106, the weight measuring unit 110, the bioelectrical impedance measuring unit 112, the parameter value generation unit 114, the measurement abnormality determination unit 116, the notification unit 118, and the body composition data acquisition unit 120. The control unit 108 is equipped with a central processing unit (CPU). The control unit 108 is connected to each unit via electric communications. The control unit 108 realizes the functions of each unit by executing a program stored in the memory unit 104.
[0054] The weight measuring unit 110 is a weight measuring means for measuring the weight of a user. The weight measuring unit 110 measures the weight using the load cell described above. Specifically, the load cell consists of a straining body of a metal member that deforms in response to a load, and a strain gauge that is affixed to the straining body. When a user rides on top of the body composition analyzer 10, the load of the user causes the load cell's straining body to bend and the strain gauge to expand or contract. The resistance value (output value) of the strain gauge changes in accordance with the expansion or contraction. The weight measuring unit 110 calculates the weight from the difference between the output value of the load cell when no load is applied (zero point) and the output value when a load is applied. The weight measuring unit 110 calculates the body weight from the difference between the output value of the load cell when no load is applied (zero point) and the output value when a load is applied. The same configuration for measuring the body weight using the load cell as that of general scales can be used.
[0055] The bioelectrical impedance measuring unit 112 is a measurement means to acquire time-series data of bioelectrical impedance by measurement. Bioelectrical impedance is an electrical resistance value obtained by passing a weak electric current through the body and measuring the ease with which this current flows. The bioelectrical impedance measuring unit 112 passes a weak electric current through the body and measures it via the current-carrying electrode 22L and measuring electrode 24L shown in
[0056] The bioelectrical impedance is obtained from the measured current and voltage. The bioelectrical impedance includes a resistance component (resistance: R), which is mainly derived electrically from the extracellular fluid, and a capacitance component (reactance: X), which is mainly derived electrically from the intracellular fluid and cell membrane. By examining the time-series data of R and X, it is possible to determine whether the measurement is normal or abnormal, and if the measurement is abnormal, the cause or type of the abnormality. The R and X used for this determination can be R and X obtained by applying a current of a certain frequency, or the R and X obtained by applying a current of multiple frequencies. In this embodiment, R and X are R and X obtained by passing a current of a certain frequency.
[0057] In particular, when determining the cause or type of measurement abnormality by considering the reactance X, a current with a lower frequency may be used as compared to a current with a higher frequency. Among them, especially when the cause is when the electrode is not in contact and when it is dry, a current with a lower frequency may be used compared to a current with a higher frequency. The reason for this is that the lower the frequency of the current, the greater the effect of the electrical capacitance of the capacitor (the smaller the ω in X=1/jωC, the greater the effect of C on the size of X). A current with a low frequency is, for example, a current with a frequency of 50 kHz or lower.
[0058] First, the time-series data of R and X when the measurement is normal will be explained.
[0059] As shown in
[0060] Next, the time-series data of R and X when the measurement is abnormal will be explained. A situation of abnormal measurement includes, for example, a situation in which the electrodes and the body are not in proper contact as shown in
[0061] In the situation of electrode non-contact, the time-series data is as shown in
[0062] In the situation of electrode non-contact, the current and voltage values are undefined. Therefore, compared to the normal measurement in
[0063] Next, the time-series data between R and X in the situation of drying becomes the time-series data as shown in
[0064] In the situation of drying, the air layer between the living body and the electrodes is increased compared to the normal measurement in
[0065] In particular, in the situation of drying, the thickness of the air layer between the living body and the electrodes is thick, so the contact resistance between the skin and the electrodes is large and the electric capacitance of the capacitor is small. As time passes, the thickness of the air layer becomes thinner, the contact resistance between the skin and the electrodes becomes smaller, and the electrical capacitance of the capacitor becomes larger. As the electrical capacitance of the capacitor increases, the reactance (X) increases. In other words, as the user rides the body composition analyzer 10 and time passes, the electrical capacitance of the capacitor gradually increases and the reactance (X) gradually increases.
[0066] Therefore, as shown in
[0067] Next, the time-series data of R and X in the situation of body movement will be explained.
[0068] In the situation of body movement, the muscle cross-sectional area and muscle length of the measurement site change. Since muscle cross-sectional area is related to resistance (R) and muscle length is related to reactance (X), when the muscle cross-sectional area and muscle length of the measurement site change, both resistance (R) and reactance (X) change. However, the changes are smaller than when the electrodes are not in contact.
[0069] Therefore, as shown in
[0070] Return to
[0071]
[0072] First of all, in the situation of electrode non-contact, the variation in the value of R is larger than that of normal measurement. Therefore, whether or not the electrode and the living body are in correct contact is evaluated by a parameter that reflects the variation in the value of R. This parameter is, for example, the standard deviation, variance, and unbiased variance. This parameter can be, for example, a parameter based on the data obtained by offsetting the time-series data of R with an approximation function to be described later. In this embodiment, this parameter is the standard deviation (R.sub.SD) based on the data obtained by offsetting the time-series data of R with the approximation function described below.
[0073] Therefore, the parameter value generation unit 114 generates the value of RSD from the time-series data of R. The measurement abnormality determination unit 116 determines that the situation corresponds to “R.sub.SD>γ” in the table 200 and the electrode and the living body are not in correct contact when the value of RSD generated by the parameter value generation unit 114 is greater than γ (hereinafter, this determination is also referred to as “electrode non-contact”).
[0074] In the situation of drying, the value of R gradually stabilizes as time passes, compared to normal measurement. Therefore, whether the skin is dry or not, or whether the person is wearing socks or not, is evaluated by a parameter that reflects the trend (trend variation) of the value of R. This parameter may be obtained, for example, from an approximation function of the time-series data of R. The approximation method to obtain the approximation function is, for example, the maximum likelihood estimation method, the least-squares method, etc. In the case where the approximate function is obtained by the least-squares method, this parameter may be, for example, the absolute value of the slope of the linear function when the linear function is approximated, or the coefficient of the variable when the exponential function is approximated. In this embodiment, this parameter is the absolute value (|R.sub.SL|) of the slope of the linear function when the time-series data of R is approximated by the linear function based on the least-squares method.
[0075] Therefore, the parameter value generation unit 114 generates the value of “|R.sub.SL|” from the time-series data of R. The measurement abnormality determination unit 116 determines that the situation corresponds to “|R.sub.SL>α” in the table 200 and the skin is dry or the use is wearing socks when the value of “|R.sub.SL|” generated by the parameter value generation unit 114 is greater than α (hereinafter, this determination is also referred to as “drying”).
[0076] In the situation of body movement, there is a variation in the value of R compared to normal measurement. Therefore, as in the situation of electrode non-contact, whether there is body movement or not is evaluated by the standard deviation. However, the variation in the value of R in the situation of body movement is smaller than that in the situation of electrode non-contact.
[0077] Therefore, the parameter value generation unit 114 generates the value of R.sub.SD from the time-series data of R. When the value of R.sub.SD generated by the parameter value generation unit 114 is smaller than γ but larger than β, the measurement abnormality determination unit 116 determines that the situation corresponds to “γ>R.sub.SL>β” in the table 200 and there is body movement (hereinafter, this determination is also referred to as “body movement”).
[0078] When multiple types of abnormality are determined, the type of abnormality may be determined according to the priority order of “electrode non-contact,” “drying,” and “body movement.” For example, when “|R.sub.SL|>α” and “R.sub.SD>γ”, “non-contact electrode” may be determined as shown in
[0079] Returning to
[0080] The “type” of the measurement abnormality is expressed as a combination of the parameters and determination results shown in
[0081]
[0082] In addition, the notification unit 118 may notify the user of remedial measures according to the cause or type of the measurement abnormality. As shown in 304 in
[0083] Returning to
Operation Flow of the Body Composition Analyzer 10
[0084] The following describes a flow for realizing the operation of the body composition analyzer 10 of the first embodiment by the above-described configuration of the body composition analyzer 10.
[0085] First, the body composition analyzer 10 acquires the waveform of resistance (R) of an arbitrary section (step S102).
[0086] When the body composition analyzer 10 acquires the waveform of R of an arbitrary section, it generates the values of |R.sub.SL| and R.sub.SD (Step S104). Then, the body composition analyzer 10 determines whether these values are “|R.sub.SL|>α” (Step S106), “γ>R.sub.SD>β” (Step S110), and “R.sub.SD>γ” (Step S114), respectively.
[0087] First, when it is determined that the value of “|R.sub.SL|” is “|R.sub.SL|>α” and “drying” (Step S106: Yes, S108) or not “|R.sub.SL|>α” (Step S106: No), it proceeds to the step of determining whether “γ>R.sub.SD>β” or not.
[0088] Next, if it is determined that the value of R.sub.SD is “γy>R.sub.SD>β” and there is “body movement” (Step S110: Yes, S112), or if it is determined that the value of R.sub.SD is not “γ>R.sub.SD>β” (Step S110: No), it proceeds to the step of determining whether or not “R.sub.SD>γ”.
[0089] Next, when it is determined that the value of R.sub.SD is “R.sub.SD>γ” and “electrode non-contact” (Step S114: Yes, S116) or not “R.sub.SD>γ” (Step S114: No), it proceeds to the step of determining whether it is “measurement abnormality” or not.
[0090] Finally, when the body composition analyzer 10 determines that is not “dry,” “body movement,” or “electrode non-contact” and therefore is not “measurement abnormal” (step S118: No), the weight and body composition data are acquired and displayed (step S120), and the flow ends. On the other hand, when the body composition analyzer 10 determines that is at least one of “dry,” “body movement,” and “electrode non-contact” (Step S118: Yes), the cause of the abnormality and remedial measures are notified (Step S122), and the flow returns to Step S102.
[0091] Thus, according to the first embodiment, the cause or type of abnormality of the measurement can be determined based on the time-series change of the measured bioelectrical impedance. Therefore, measurement abnormality can be determined without having to provide a circuit for detecting measurement abnormality separately from the circuit for measuring bioelectrical impedance.
[0092] According to the first embodiment, measurement abnormalities can be determined with high accuracy by using trends (trend variation) such as the slope of a linear function when time-series data is approximated by a linear function, and variations such as the standard deviation, variance, and unbiased variance of time-series data.
[0093] Furthermore, according to the first embodiment, the user can know the cause or type of measurement abnormality, and can know improvement measures for normal measurement corresponding to the cause or type of measurement abnormality.
Second Embodiment
[0094] The body composition analyzer 10 of the second embodiment has the same basic configuration as the body composition analyzer 10 of the first embodiment. The difference is that in the first embodiment, the body composition analyzer 10 determines whether or not there is a measurement abnormality based on the parameter pertaining to the resistance (R), whereas in the second embodiment, the body composition analyzer 10 determines whether or not there is a measurement abnormality based on the parameter pertaining to the resistance (R) and the inductance (X). In the following, this difference and the operation flow of the body composition analyzer will be explained.
Composition of Body Composition Analyzer 10
[0095] As shown in
[0096] The table 400 has three sub-tables. Of these, the sub-table 402 is the same as the table 200 of the first embodiment, and the sub-table 404 is a table in which the |R.sub.SL|>α, β<R.sub.SD<γ, and R.sub.SD>γ of the table 200 are changed to |X.sub.SL|>α, β<X.sub.SD<γ, and X.sub.SD>γ, respectively, and thus is not described.
[0097] The sub-table 406 is a table indicating that when “R.sub.SD>γ” or “X.sub.SD>γ”, it is determined that the electrode and the living body are not in correct contact compared to the normal measurement. When “|R.sub.SL|>α” or “|X.sub.SL|>α” is selected, the table indicates that the skin is dry or socks are worn, compared to normal measurement. The table also indicates that when “β<R.sub.SD<γ” or “β<X.sub.SD<γ”, compared to the normal measurement, it is determined that there is body movement.
[0098] The measurement abnormality determination unit 116 refers to this table 400 and determines whether the measurement is abnormal or not and the type of abnormality when the measurement is abnormal based on the value of the parameter |R.sub.SL|, the value of R.sub.SD, the value of |X.sub.SL|, and the value of X.sub.SD generated by the parameter value generating unit 114.
Operation Flow of the Body Composition Analyzer 10
[0099] The following describes a flow for realizing the operation of the body composition analyzer 10 of the second embodiment by the above-described configuration of the body composition analyzer 10.
[0100] First, the body composition analyzer 10 acquires the waveform of R and X in an arbitrary section (step S202).
[0101] When the body composition analyzer 10 acquires the waveform of R and X in an arbitrary section, it generates the value of |R.sub.SL|, the value of R.sub.SD, the value of |X.sub.SL|, and the value of X.sub.SD (Step S204). Then, the body composition analyzer 10 determines whether these values are “|R.sub.SL|>α or |X.sub.SL|>α” (Step S206), “γ>R.sub.SD>β or γ>X.sub.SD>β” (Step S210), and “R.sub.SD>γ or X.sub.SD>γ” (Step S214), respectively.
[0102] First of all, when it is determined that the value of “|R.sub.SL|” and the value of “|X.sub.SL|” are “|R.sub.SL|>α or |X.sub.SL|>α” and “drying” (Step S206: Yes, S208), or when it is determined that it is not “|R.sub.SL|>α or |X.sub.SL|>α” (Step S206: No), it proceeds to the step of determining whether “γ>R.sub.SD>β or γ>X.sub.SD>β”.
[0103] Next, when it is determined that the value of R.sub.SD and the value of X.sub.SD are “γ>R.sub.SD>β or γ>X.sub.SD>β” and there is “body movement” (Step S210: Yes, S212), when it is determined that it is not “γ>R.sub.SD>β or γ>X.sub.SD>β” (Step S210: No), it proceeds to the step of determining whether “R.sub.SD>γ or X.sub.SD>γ”.
[0104] Next, when it is determined that the value of R.sub.SD and the value of X.sub.SD are “R.sub.SD>γ or X.sub.SD>γ” and “electrode non-contact” (Step S214: Yes, S216) or not “R.sub.SD>γ or X.sub.SD>γ” (Step S214: No), it proceeds to the step of determining whether or not it is “measurement abnormality”.
[0105] Finally, when the body composition analyzer 10 determines that it is not “drying,” “with body movement,” or “without electrode contact” and therefore is not a “measurement abnormality” (Step S218: No), the weight and body composition data are acquired and displayed (Step S220), and the flow ends. On the other hand, when the body composition analyzer 10 determines that is at least one of “drying,” “body movement,” and “electrode non-contact” (Step S218: Yes), the cause of the abnormality and remedial measures are notified (Step S222), and the flow returns to Step S202.
[0106] Thus, according to the second embodiment, the measurement abnormality can be determined more accurately based on the resistance (R), which is mainly derived electrically from the extracellular fluid, and the reactance (X), which is mainly derived electrically from the intracellular fluid and the cell membrane.
Variant 1
[0107] In the first embodiment, the body composition analyzer 10 determines a measurement abnormality using a parameter pertaining to R. However, a measurement abnormality may be determined using a parameter pertaining to X. That is, the sub-table 404 may be used to determine the measurement abnormality.
Variant 2
[0108] In the second embodiment, for example, “|R.sub.SL|>α or |X.sub.SL|>α” is used to determine “drying” if at least one of “|R.sub.SL|>α” or “|X.sub.SL|>α” is satisfied, but “drying” may be determined if both “|R.sub.SL|>α” and “|X.sub.SL|>α” are satisfied. In other words, it may be determined as “drying” when “|R.sub.SL|>α and |X.sub.SL|>α” is satisfied. Similarly, it may be determined as “body movement” when “γ>R.sub.SD>β and γ>X.sub.SD>β” is satisfied, and it may be may be as “electrode non-contact” when “R.sub.SD>γ and X.sub.SD>γ” is satisfied.
Variant 3
[0109] In the second embodiment, for example, the same threshold value α was used as “|R.sub.SL|>α or |X.sub.SL|>α”, but a different threshold value α and δ may be used as “|R.sub.SL|>α or |X.sub.SL|>δ”. Similarly, different threshold values β and ε, γ and ζ can be used to make “γ>R.sub.SD>β or ζ>X.sub.SD>ε” or “R.sub.SD>γ or X.sub.SD>ζ”.
Variant 4
[0110] When the process of notifying the cause of abnormality and remedial measures in
DESCRIPTION OF THE CODE
[0111] 10 Body composition analyzer
[0112] 20 Main unit
[0113] 22L, R Current-carrying electrode
[0114] 24L, R Measuring electrode
[0115] 102 Input unit
[0116] 104 Memory unit
[0117] 106 Output unit
[0118] 108 Control unit
[0119] 110 Measuring unit
[0120] 112 Bioelectrical impedance measuring unit
[0121] 114 Parameter value generation unit
[0122] 116 Measurement abnormality determination unit
[0123] 118 Notification unit
[0124] 120 Body composition data acquisition unit
[0125] 200 Table
[0126] 400 Table