JP2007181524A - Body composition meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a body composition meter capable of estimating the body composition of the body parts whose biological impedance cannot be measured by a conventional configuration. <P>SOLUTION: The body composition meter comprises a plurality of electrodes attached to the subject's skin, a biological impedance measuring apparatus for measuring the biological impedance of the subject's body using the plurality of electrodes for applying electricity and for detecting voltage, and a body composition calculating apparatus for calculating the body composition of the subject using the detected biological impedance. The body composition calculating apparatus estimates the body composition of parts of the subject whose biological impedance cannot be measured on the basis of the detected biological impedance of the subject. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a body composition meter. More specifically, the present invention relates to a body composition meter that estimates a body composition for each body part of a subject.

  Body fat percentage, body fat mass, lean mass, body muscle percentage, body muscle mass, bone percentage, bone mass, body moisture percentage, body moisture, basal metabolic rate, visceral fat area index, etc. A body composition meter for calculating body composition is known. In a body composition meter, generally, an electrode is brought into contact with a subject's body, and impedance (biological impedance) of a path passing through the living body is measured. Various health indexes are calculated by combining the obtained results with weight, height, and the like.

  In a general body composition meter, a health index applied to the whole body of a subject is calculated from a measurement result of bioimpedance. However, in recent years, a technique capable of calculating the body composition of each body part (arm, leg, etc.) of a subject with high accuracy has been desired in order to take into account body balance.

  As a device for obtaining a body composition for each body part of a subject, there is a body composition meter disclosed in Patent Document 1. This body composition meter touches eight electrodes, one for each of the right palm, right thumb, left palm, left thumb, right foot front, right foot rear, left foot front and left foot rear. Let The electrodes are individually selected, the bioimpedance is detected for each body part, and the body composition for each body part is estimated from the obtained result.

In this body composition meter, for example, by applying a constant current between the thumb of the right hand and the thumb of the left hand, and measuring the voltage between the right palm and the front of the right foot, ) Resistance (bioimpedance). Furthermore, the body composition of the right arm is determined based on the bioimpedance of the right arm.
Japanese National Patent Publication No. 10-510455

  In the conventional configuration, for example, when there is poor contact on the electrode of the right thumb, the bioimpedance of the right arm cannot be measured, and thus the body composition of the right arm cannot be estimated. That is, when all of the electrodes are not in a good measurement state in the conventional configuration, there is a problem that a body part where bioimpedance cannot be measured is generated, and the body composition cannot be obtained for the body part. In addition, in the configuration of four electrodes (only the foot electrode or only the hand electrode), since the bioimpedance cannot be measured for each body part, the body composition for each body part cannot be estimated.

  The present invention has been made to solve the above-described problems, and provides a body composition meter capable of estimating a body composition even for a body part in which bioimpedance cannot be measured with a conventional configuration. It is aimed.

  In order to solve the above-mentioned problems, a body composition meter according to the present invention includes a plurality of electrodes for contacting a subject's skin, and a living body of the subject's body using the plurality of electrodes for energization and voltage detection. A bioimpedance measuring device for measuring impedance; and a body composition calculating device for calculating a body composition of the subject using the detected bioimpedance, wherein the body composition calculating device includes the detected subject. Based on the biological impedance of the person, the body composition of the site where the biological impedance of the subject cannot be measured is estimated.

  In such a configuration, based on the detected bioelectrical impedance of the subject, it is possible to estimate the body composition of the site where the subject's bioimpedance cannot be measured, which could not be estimated in the conventional configuration. Therefore, for example, even in the configuration of only the foot electrode, the body composition of the arm can be estimated based on the correlation between the bioelectrical impedance of the leg and the body composition of the arm.

  In the body composition meter, the electrode and the bioimpedance measuring device are configured to be able to measure bioimpedance for a plurality of body parts in the body of the subject, and the body composition calculating device When the measurement state of the impedance is detected, and there is a body part where the measurement state does not satisfy the first condition, the measurement state of the subject is determined based on the bioimpedance of the body part that satisfies the first condition. You may estimate the body composition of a site where bioimpedance cannot be measured. Alternatively, the measurement state is the presence or absence of poor contact between the electrode and the body of the subject when measuring the bioimpedance of the body part, and the body composition calculation device includes an electrode with poor contact When doing, based on the bioimpedance measured using the electrode without a contact failure, you may estimate the body composition of a subject's bioimpedance measurement impossible part. Alternatively, the measurement state may be a contact state of an electrode used for measuring the bioimpedance of the body part.

  In such a configuration, even when there is a body part whose measurement state does not satisfy a predetermined condition due to poor contact or the like, the bioimpedance of the subject cannot be measured based on the bioimpedance of the body part that can be measured in a good measurement state. The body composition of the part can be estimated. For example, in a configuration having left and right hand electrodes and foot electrodes, if there is a contact failure in the right hand electrode, the bioimpedance of the right arm part becomes a measurement failure state, but even in such a case, the left arm part-trunk part- The body composition of the right arm can be estimated from the bioimpedance of the left leg.

  In the body composition meter, the estimation may be performed using a multiple regression equation in which a variable including bioimpedance of at least one body part is an independent variable and a body composition of a part where bioimpedance cannot be measured is a dependent variable. .

  In such a configuration, since the body composition is calculated based on the bioimpedance of the body part, the body composition of the part where the bioimpedance cannot be measured can be accurately estimated.

  In the body composition meter, a variable including at least one selected from the group consisting of age, sex, height, weight, BMI, and waist circumference may be used as the independent variable.

  In such a configuration, since the body composition can be calculated based on age, sex, height, weight, BMI, and waist circumference, the body composition of the portion where bioimpedance cannot be measured can be estimated with higher accuracy.

  The body composition meter further includes setting means for setting the use and non-use of the electrodes, the measurement state is a set state of use and non-use of the electrodes, and the body composition calculating device When there is an electrode in which the set state is not used, based on the bioimpedance detected using the electrode in which the set state is in use, Body composition may be estimated.

  In such a configuration, it is not necessary to determine the measurement state of the electrode by setting the electrode that is known in advance to have poor contact and the like so that it is not necessary to determine the measurement state of the electrode, and the bioimpedance measurement site of the subject cannot be measured quickly. Body composition can be estimated.

  The body composition meter further includes a display device for displaying the body composition of each body part of the subject, and when the body composition of a certain body part is obtained by the estimation, the body of the body part You may display that a composition was calculated | required by estimation.

  In this configuration, the user can easily determine whether the body composition of a certain body part is obtained based on the bioimpedance of the body part or the bioimpedance of another body part. Can be determined.

  In the body composition meter, as the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs corresponding to each of the right hand, the left hand, the right foot, and the left foot, and the body composition calculation device includes the right foot and the left foot. When all of the electrodes are in good contact and at least one of the right or left hand electrodes is in poor contact, based on the bioimpedance of the body part measured using at least one foot electrode, You may estimate the body composition of the right arm part, the left arm part, and the trunk part, which are parts where bioimpedance cannot be measured.

  In such a configuration, the body composition of the right arm part, the left arm part, and the trunk part can be estimated even if the hand electrode has poor contact.

  In the body composition meter, as the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs corresponding to each of the right hand, the left hand, the right foot, and the left foot, and the body composition calculation device includes the right hand and the left hand. When all of the electrodes are in good contact and at least one of the right or left foot electrodes is in poor contact, based on the bioimpedance of the body part measured using the electrode of at least one hand, You may estimate the body composition of the right leg part, the left leg part, and the trunk part which are parts where bioimpedance cannot be measured.

  With such a configuration, the body composition of the right leg, left leg, and trunk can be estimated even if the foot electrode has poor contact.

  In the body composition meter, as the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs corresponding to each of the right hand, the left hand, the right foot, and the left foot, and the body composition calculation device includes one hand and one foot. The right arm, which is a site where the bioimpedance of the subject cannot be measured, based on the bioimpedance of the body part measured using the electrode with good contact when the other electrode is in good contact and the other electrode is in poor contact The body composition of the head, left arm, right leg, left leg, and trunk may be estimated.

  In such a configuration, the body composition of the right arm part, the left arm part, the right leg part, the left leg part, and the trunk part can be estimated even if the electrodes of one hand and one leg are in poor contact.

  In the body composition meter, as the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs corresponding to each of the right hand, the left hand, the right foot, and the left foot, and the body composition calculation device includes the right foot and the left foot. When both of the electrodes of the right hand and the left hand electrodes are poorly contacted, based on the bioimpedance of both legs, the right arm part, the left arm part, which is a bioimpedance measurement part of the subject, The body composition of the right leg, the left leg, and the trunk may be estimated.

  In such a configuration, the body composition of the right arm part, the left arm part, the right leg part, the left leg part, and the trunk part can be estimated even if the electrodes of both hands are in poor contact.

  In the body composition meter, as the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs corresponding to each of the right hand, the left hand, the right foot, and the left foot, and the body composition calculation device includes the right hand and the left hand. The right arm and the left arm, which are parts where the bioimpedance of the subject cannot be measured, based on the bioimpedance of both arms when the electrodes of both are in good contact and the electrodes of the right or left foot are both in poor contact The body composition of the right leg, left leg, and trunk may be estimated.

  In such a configuration, the body composition of the right arm part, the left arm part, the right leg part, the left leg part, and the trunk part can be estimated even if the electrodes of both feet are in poor contact.

  In the body composition meter, as the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs corresponding to each of the right hand, the left hand, the right foot, and the left foot, and the body composition calculation device includes the right foot and the left foot. The bioimpedance of the subject based on the bioimpedance measured using at least one foot electrode when both of the electrodes are in good contact and either the right or left hand electrode is in poor contact Estimate the body composition of the unmeasureable right arm, left arm, and trunk, at least when the right and left hand electrodes are both in good contact and either the right or left foot electrode is in poor contact Based on the bioimpedance measured using the electrode of one hand, the body composition of the right leg, left leg, and trunk, which are the parts where the subject's bioimpedance cannot be measured, is estimated. The right arm, which is a part where the bioimpedance of the subject cannot be measured, based on the bioimpedance of the body part between the electrodes with good contact when the electrodes on one hand and one leg are in good contact and the other electrodes are in poor contact Estimate the body composition of the left arm, right leg, left leg, and trunk, and both legs when the right and left foot electrodes are both in good contact and the right or left hand electrode is in poor contact. The body composition of the right arm, left arm, right leg, left leg, and trunk is estimated based on the bioimpedance of the subject, and both right and left hand electrodes are in contact The right arm, left arm, and right leg, which are sites where bioimpedance cannot be measured, based on the bioimpedance of both arms when both the right and left foot electrodes are in poor contact Left leg, it may estimate the body composition of the trunk.

  In such a configuration, the body of the right arm part, the left arm part, the right leg part, the left leg part, and the trunk part even if the contact is poor with an electrode that contacts one or two of the right hand, left hand, right foot, and left foot. The composition can be estimated.

  The present invention has the above-described configuration and has the following effects. That is, there is an effect that it is possible to provide a body composition meter that can estimate the body composition even for a body part that cannot be estimated with the conventional configuration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
[Device configuration]
First, the configuration of the body composition meter according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a perspective view schematically showing the configuration of the body composition meter according to the first embodiment of the present invention. FIG. 2 is a plan view schematically showing a configuration of a determination display unit included in the body composition meter according to the first embodiment of the present invention. The body composition meter in the present embodiment uses the bioelectrical impedance method to determine the body composition of the subject (body fat percentage, body fat mass, lean mass, body muscle percentage, body muscle mass, bone percentage, bone mass, Body water content, body water, basal metabolic rate, visceral fat area index, etc.) and the calculation result is displayed on the display means.

  As shown in FIG. 1, the body composition meter 1 according to the present embodiment includes an installation unit 4 and a determination display unit 2 that can be attached to and detached from the installation unit 4. FIG. 1 illustrates a state where the installation unit 4 and the determination display unit 2 are isolated from each other. When the determination display unit 2 is attached to the installation unit 4, the determination display unit 2 is installed so that the attachment / detachment unit 2 a of the determination display unit 2 is located in the storage area 4 a provided in the installation unit 4. The installation unit 4 and the determination display unit 2 are electrically connected to each other by a connection cable 3. The body composition meter 1 is configured to exhibit a predetermined function as the body composition meter 1 when the installation unit 4 and the determination display unit 2 are electrically connected to each other via the connection cable 3. Yes.

  As shown in FIG. 1, the installation unit 4 has a bioimpedance measurement surface 9. On the bioimpedance measurement surface 9, electrodes E5, E6, E7, and E8 that are used when bioimpedance is measured (including simple detection, the same applies hereinafter) are disposed at predetermined positions. Here, when the subject measures his / her bioimpedance, the left foot of the subject is placed on the electrodes E5 and E6 and the right foot is placed on the electrodes E7 and E8. At this time, the electrode E5 has a front portion of the left foot sole of the subject (hereinafter referred to as a “thumbnail portion”), and the sixth electrode E6 has a heel portion of the subject's left foot, The seventh electrode 7 is in contact with the heel portion of the subject's right foot, and the eighth electrode E8 is in contact with the thumb hill portion of the subject's right foot sole. In the present embodiment, the bioimpedance measurement surface 9 of the installation unit 4 is configured to be able to measure the weight of the subject. Specifically, the installation unit 4 includes a support body 20 and a movable body 21 supported on the support body 20 via a load cell (not shown). The impedance measurement surface 9 and the storage area 4a are provided on the upper surface of the movable body 21.

  As shown in FIG. 1, the determination display unit 2 includes a display unit 5, an operation unit 6, and holding units 7a and 7b. The display unit 5 includes the height, age, sex, waist circumference (waist length), etc. of the subject input by operating the operation unit 6 described later, and the weight of the subject measured by the weight measuring unit described later. Various data such as body identification information including is displayed. Further, as shown in FIG. 2, the operation unit 6 includes a power ON / OFF key 6a, a mode switching key 6b for switching modes such as an initial setting mode, a measurement mode, and a registration mode, and a body for specifying a subject. A setting screen switching key 6c for switching a setting screen when inputting specific information and the like, a registration key 6d for storing the body specifying information and the like in a storage unit, and a numeric keypad for inputting the body specifying information and the like 6f and a measurement key 6g for measuring the bioelectrical impedance of the subject are provided. By appropriately operating these various input keys 6a to 6g, the measurement of the bioimpedance of the subject by the body composition meter 1 and the display of the body composition obtained by the measurement are performed. As shown in FIGS. 1 and 2, the determination display unit 2 is provided with holding units 7 a and 7 b that project from the main body in a plate shape. The holding parts 7a and 7b are provided with electrodes E1, E2, E3, and E4 that are used when measuring bioimpedance. When the subject holds the determination display unit 2 in order to measure his or her bioimpedance, the subject makes the left index finger contact the electrode E1 disposed on the holding unit 7a and the left hand thumb contacts the electrode E2. The determination display unit 2 is held such that the right thumb is brought into contact with the electrode E3 disposed in the holding unit 7b and the right index finger is brought into contact with the electrode E4.

  In the body composition meter 1, the electrodes E1 to E4 arranged in the determination display unit 2 and the electrodes E5 to E8 arranged in the installation unit 4 are a bioimpedance measurement circuit 8 and an electrode changeover switch 11 described later. In addition, a bioimpedance measuring means (impedance measuring device) for measuring the bioimpedance of the subject is configured. More specifically, the electrodes E1, E4, E5, and E8 are pairs of any two of these electrodes, so that the index finger of the left hand, the index finger of the right hand, and the mother of the left foot respectively. It is an electrode (current application electrode) for allowing a predetermined high-frequency current to flow through the current path having the finger hill portion and the right phalanx portion of the right foot as a measurement path end. The electrodes E2, E3, E6, and E7 are electrodes (voltage measurement) used to measure a voltage corresponding to the bioimpedance at each part of the body of the subject via any two of these electrodes. Electrode). The electrodes E <b> 1 to E <b> 4 are connected to the bioimpedance measurement circuit 8 by a predetermined wiring (not shown) inside the determination display unit 2. The electrodes E5 to E8 are connected to the bioimpedance measurement circuit 8 via the connection cable 3.

  Next, the configuration of the electric circuit of the body composition meter according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram schematically showing the configuration of the electric circuit of the body composition meter according to the first embodiment of the present invention. As shown in FIG. 3, the body composition meter 1 has a calculation processing unit 13 (body composition calculation device). The arithmetic processing unit 13 includes an arithmetic unit 15 including an arithmetic processing device such as a CPU, and a storage unit 16 including a storage device such as a memory. Here, the calculation unit 15 executes calculation and determination processing based on various data stored in the storage unit 16 and various routines. In the memory | storage part 16, various input keys 6a-6g arrange | positioned at the operation part 6 were suitably operated, and it measured via the various body specific information which identifies the subject input, and electrodes E1-E8. The bioelectrical impedance of the body part of the subject, for example, the right arm part, the left arm part, the trunk part, the right leg part, and the left leg part is stored. The storage unit 16 also stores information necessary for the body composition meter 1 to operate, various programs, and the like, such as arithmetic expressions for estimating the body composition of the body part. The storage unit 16 also stores body weight data of the subject measured by weight measuring means such as the load cell 10 described later. The calculation unit 15 and the storage unit 16 are electrically connected to each other via a bus.

  On the other hand, the biometric impedance measurement circuit 8, the various input keys 6a to 6g, the display unit 5, the load cell 10, and the clock 14 are electrically connected to the arithmetic processing unit 13 via the I / O 12. Yes.

  The bioimpedance measurement circuit 8 measures the bioimpedance for each of the body parts of the subject via the electrodes E1 to E8. More specifically, the bioelectrical impedance measurement circuit 8 includes a high-frequency current source (constant current circuit) that outputs a plurality of high-frequency currents having different frequencies, not shown here, and two different points in a current path through which the high-frequency current flows. And a voltage measuring device (not shown) for measuring the voltage difference between the two. The constant current circuit in the bioimpedance measuring circuit 8 is wired so as to be electrically connectable to the electrodes E1 to E8 via an electrode changeover switch 11 described later, whereby the left hand, left foot, and right hand of the subject's body. A high-frequency current having a predetermined frequency is caused to flow through a current path that ends at any two points on the right foot. On the other hand, the voltage measuring device in the bioimpedance measurement circuit 8 is appropriately connected to any two of the four electrodes E1 to E8 via an electrode changeover switch 11 described later, and between the two connected electrodes. Measure the voltage difference. Then, from the current value supplied from the constant current circuit and the potential difference measured by the voltage measuring device, the biological impedance of the subject is obtained for each body part. Thus, the bioimpedance of each body part of the subject is measured by using the bioimpedance measurement circuit 8, the electrode changeover switch 11, and the electrodes E1 to E8. The constant current circuit of the bioimpedance measurement circuit 8 is composed of a plurality of AC frequency current sources (for example, 20 Hz and 100 Hz), thereby obtaining the ratio of the extracellular fluid and intracellular fluid in the subject's body. It has been made possible.

  The various input keys 6a to 6g are as described above, and the operation unit 6 includes a power ON / OFF key 6a, a mode switching key 6b, a setting screen switching key 6c, a registration key 6d, a numeric key 6f, and a measurement key 6g. And.

  The display unit 5 displays various body-specific information such as the height, weight, age, and sex of the subject input by appropriately operating the various keys 6 a to 6 g of the operation unit 6, and the subject measured by the load cell 10. And the body impedance, body composition, and the like of each body part of the subject measured by the body impedance measurement circuit 8 are displayed.

  The load cell 10 constitutes a weight measuring means for measuring the body weight of the subject. The weight measuring means is configured such that when the subject is on the bioimpedance measuring surface 9 shown in FIG. 1, the weight of the subject is measured by the load cell 10. A signal related to the body weight data of the subject output from the load cell 10 is A / D converted after being amplified by an amplifier (not shown) in order to ensure measurement accuracy, and is converted into a digital signal by this A / D conversion. The data is input to the calculation unit 15 via O12. Data relating to the weight data of the subject input to the calculation unit 15 is stored in the storage unit 16 by the calculation unit 15 as one item of body identification information of the subject.

  An electrode changeover switch 11 is connected to the bioimpedance measurement circuit 8 described above. The electrodes E1 to E8 that are in contact with a predetermined part of the subject's hand or foot are connected to the electrode changeover switch 11. The electrode changeover switch 11 appropriately determines the connection state between the electrodes E1 to E8 and the bioimpedance measurement circuit 8 necessary for measuring the bioimpedance of the subject based on an instruction from the calculation unit 15 as necessary. Switch.

With the above configuration, the body composition meter 1 allows the subject to appropriately input the body specifying information such as the height, weight, age, and sex of the subject by appropriately operating the operation unit 6. The obtained data is input to the calculation unit 15. The body specifying information input to the calculation unit 15 is appropriately stored in the storage unit 16. Further, the subject holds the determination display unit 2 with both hands so as to come into contact with the electrodes E1 to E4 and puts both feet on the electrodes E5 to E8 of the installation unit 4 as described above. Then, the bioelectrical impedance of the subject is measured by appropriately operating the operation unit 6, and the measured bioelectrical impedance is converted into a digital signal by an A / D converter as necessary, and then appropriately stored in the storage unit. 16 is stored. Based on the information stored in the storage unit 16, the calculation unit 15 calculates a body composition (body fat percentage, etc.) for each body part of the subject and displays the calculation result on the display unit 5. With this configuration, the subject can easily know the body composition for each body part by using the body composition meter 1.
[Measure bioimpedance by body part]
FIG. 4 is a diagram schematically illustrating the position where each electrode contacts the subject and the bioimpedance of each body part of the subject. Hereinafter, a method of measuring the bioimpedance of each part of the body by the body composition meter 1 of the present embodiment will be described in detail with reference to FIG. As shown in the figure, the electrodes E1 to E8 are brought into contact with predetermined portions of the subject's limbs to measure the bioimpedance of each portion of the body. Specifically, the forefinger of the left hand is in contact with the electrode E1, the thumb of the left hand is in contact with the electrode E2, the index finger of the right hand is in contact with the electrode E4, the thumb of the right hand is in contact with the electrode E3, and the mother of the left foot By contacting the toe portion with the electrode E5, bringing the electrode E6 into contact with the heel portion of the left foot, contacting the toe portion of the right foot with the electrode E8, and contacting the electrode E7 with the heel portion of the right foot, The bioimpedance Z1 of the left arm, the bioimpedance Z2 of the right arm, the bioimpedance Z3 of the trunk, the bioimpedance Z4 of the left leg, and the bioimpedance Z5 of the right leg are measured.

In FIG. 4, symbols P1 to P6 indicate virtual measurement points used in a known bioimpedance measurement method, and are used on a current path to be described later when measuring the bioimpedance of each part of the body. In FIG. 4, the voltage is a measurement point for detecting a voltage virtually located at a position closest to the electrode for voltage measurement. This virtual measurement point is the intersection of the voltage detection line and the current path, which is the shortest path from the voltage measurement electrode to the current path, when detecting the voltage on the current path by the voltage measurement electrode not positioned on the current path. Since there is almost no current flow along the voltage detection line and almost no potential drop occurs, it is possible to measure the voltage at the virtual measurement point with the voltage measurement electrode arranged away from the current path. Become. The following description will be made on the assumption that the measurement state of all the electrodes is good.
(1) Bioimpedance measurement when a current is passed between the left hand and the left foot For example, if a known amount of a constant current I is supplied between the electrodes E1 and E5 that are electrodes for current application, In addition, a current path that passes through the left arm, trunk, and left leg is formed with the index finger of the left hand and the thumb hill portion of the left sole as ends. When the potential difference V detected by the electrodes E2 and E3, which are voltage measuring electrodes, is measured in this state, the bioimpedance Z1 of the left arm portion between P1 and P3 can be measured (calculated by an arithmetic expression Z1 = V / I). it can. When the potential difference detected by the electrodes E3 and E7 is measured, the bioimpedance Z3 of the trunk between P3 and P4 can be measured. When the potential difference detected by the electrodes E6 and E7 is measured, the bioimpedance Z4 of the left leg between P4 and P5 can be measured. When the potential difference detected by the electrodes E2 and E7 is measured, the bioimpedance Z1 + Z3 of the left arm part to the trunk part between P1 and P4 can be measured. When the potential difference detected by the electrodes E3 and E6 is measured, the bioimpedance Z3 + Z4 between the trunk and the left leg between P3 and P5 can be measured. When the potential difference detected by the electrodes E2 and E6 is measured, bioimpedance Z1 + Z3 + Z4 between the left arm part, the trunk part, and the left leg part between P1 and P5 can be measured. When a current is passed between the right hand and the right foot, the bioimpedance of the right arm, trunk, and right leg, and the bioimpedance of the body part combining them can be measured by the same method.
(2) Bioimpedance measurement when a current is passed between the left hand and the right hand By switching the electrode changeover switch 11, a known amount of constant current is supplied between the electrodes E1 and E4 that are current application electrodes. A current path is formed in the body of the subject, with the index finger of the left hand and the index finger of the right hand as ends, and passing through the left arm and the right arm (both arms). When the potential difference detected by the electrodes E2 and E3, which are voltage measuring electrodes, is measured in this state, the bioimpedance Z1 + Z2 of both arms between P1 and P3 can be measured. When the potential difference detected by the electrodes E2 and E6 (or E7) is measured, the bioimpedance Z1 of the left arm portion between P1 and P3 can be measured. When the potential difference detected by the electrodes E3 and E7 (or E6) is measured, the bioimpedance Z2 of the right arm portion between P2 and P3 can be measured.
(3) Bioimpedance measurement when a current is passed between the left foot and the right foot By switching the electrode changeover switch 11, a known amount of constant current is supplied between the electrodes E5 and E8 that are current application electrodes. A current path that passes through the left leg and the right leg (both legs) is formed in the body of the subject, with the thumb toe portion on the left foot and the thumb toe portion on the right foot as ends. In this state, when the potential difference detected by the electrodes E6 and E7 which are voltage measuring electrodes is measured, the bioimpedance Z4 + Z5 of both legs between P5 and P6 can be measured. When the potential difference detected by the electrodes E2 (or E3) and E6 is measured, the bioimpedance Z4 of the left leg between P4 and P5 can be measured. When the potential difference detected by the electrodes E3 (or E2) and E7 is measured, the bioimpedance Z5 of the right leg between P4 and P6 can be measured.
(4) Bioimpedance measurement when current is passed between left hand and right foot By switching the electrode changeover switch 11, a known amount of constant current is supplied between the electrodes E1 and E8 that are current application electrodes. A current path that passes through the left arm, trunk, and right leg is formed in the body of the subject with the index finger of the left hand and the thumb hill portion of the right foot as the ends. In this state, when the potential difference detected by the electrodes E2 and E3 which are voltage measuring electrodes is measured, the bioimpedance Z1 of the left arm portion between P1 and P3 can be measured. When the potential difference detected by the electrodes E3 and E6 is measured, the bioimpedance Z3 of the trunk between P3 and P4 can be measured. When the potential difference detected by the electrodes E6 and E7 is measured, the bioimpedance Z5 of the right leg between P4 and P6 can be measured. When the potential difference detected by the electrodes E2 and E6 is measured, the bioimpedance Z1 + Z3 of the left arm portion to the trunk portion between P1 and P4 can be measured. When the potential difference detected by the electrodes E3 and E7 is measured, the bioimpedance Z3 + Z5 of the trunk to the right leg between P3 and P6 can be measured. When the potential difference detected by the electrodes E2 and E7 is measured, bioimpedance Z1 + Z3 + Z5 between the left arm part, the trunk part, and the right leg part between P1 and P6 can be measured. When a current is passed between the right hand and the left foot, the bioimpedance of the right arm, trunk, and left leg, and the bioimpedance of the body part combining them can be measured by the same method.
(5) Others According to the bioimpedance measurement method described above, the bioimpedance can be directly measured for each of the left and right arm parts, the trunk part, the left and right leg parts, and the combined body parts. When there are multiple measurement methods according to the combination of electrodes for the bioimpedance of each body part, it is possible to improve the reliability of measurement by averaging the results obtained by different measurement methods. . When it is necessary to shorten the measurement time, only the result obtained by one typical measurement method may be used.
[Detection of electrode contact failure]
An example of detecting a contact failure (including a measurement state failure due to some cause other than a contact failure, the same applies hereinafter) in the present embodiment will be described below with reference to the drawings. For simplicity of explanation, only the hand electrode portion will be described, but contact failure can be detected by the same method when the foot electrode portion or the hand electrode and the foot electrode are combined.

  FIG. 5 is a schematic diagram showing the positional relationship between the electrode and the contact resistance when the hand electrode is brought into contact with the skin of the subject. FIG. 6 is a schematic diagram of a measurement circuit when measuring bioimpedance by the four-terminal method. In FIG. 6, AMP1 and AMP2 are differential amplifiers. The constant current I is injected into the body by flowing a constant current I between the electrodes E1 and E4 from a constant current circuit including the differential amplifier AMP1. In this case, the contact resistance between the subject's skin and the electrodes E1, E2, E3, and E4 is represented by ZE1, ZE2, ZE3, and ZE4, respectively, and the impedance of the finger joint tissue when the measurement location is a finger. Are also included in the contact resistances ZE1, ZE2, ZE3, and ZE4.

  In this measurement circuit, by passing a constant current I, a potential difference of (Z1 + Z2) I is generated between the body tissues P1 and P2. A measurement circuit including a differential amplifier AMP2 is connected between the electrodes E2 and E3, and the potential difference is read as an output voltage of the differential amplifier AMP2. If the input resistance of the measurement circuit is sufficiently higher than the contact resistances ZE2 and ZE3, no current flows through the contact resistances ZE2 and ZE3, and no potential drop occurs in the contact resistances ZE2 and ZE3. Therefore, the potential difference between P1 and P2 can be measured by the electrodes E2 and E3, and a voltage value approximately equal to the value of (Z1 + Z2) I is obtained as the output V1 of the differential amplifier AMP2. Therefore, the bioelectrical impedance Z1 + Z2 of both arms can be obtained by measuring this output voltage V1 and calculating V1 / I = Z1 + Z2 using I which is a known value in advance. Here, as specific circuit constants for determining the constant current I, for example, when the reference resistance Rs is set to 2 KΩ and the reference voltage Vc is set to 1 V, the constant current I is controlled to Vc / Rs = 0.5 mA.

  The output load of the differential amplifier AMP1 is Z1 + Z2, ZE1, ZE4, and a reference resistor Rs for a constant current circuit. If the saturation output voltage of the differential amplifier AMP1 is 3V, the constant current I = 0.5 mA, so the total output load is 6 kΩ. Since Rs = 2KΩ, if the sum of the bioresistance (Z1 + Z2) and the contact resistance (ZE1 + ZE4) exceeds 4 KΩ, the constant current I cannot be supplied, and a correct measurement value cannot be obtained.

  In this embodiment, in order to detect a contact failure of the current application electrodes (E1, E4), the voltage measurement circuit is switched, and a constant current is supplied between the current application electrodes, and at the same time, the current application electrodes. The voltage between is measured. When the sum of the contact resistance values (for example, ZE1 and ZE4) and the bioresistance value (for example, Z1 + Z2) in the measurement path exceeds a certain threshold value, it is determined that the contact is defective. Since the total resistance value is determined by the “current flowing through the living body” and the “relationship between circuit drive voltages”, the resistance value at which the circuit is saturated is set as the threshold value. In the above-described example, contact failure is determined when (contact resistance value + biological resistance value of two electrodes)> 4 kΩ. The method of determining by the total resistance value is effective when the contact area with the body differs greatly depending on the electrodes, such as a configuration in which foot electrodes and hand electrodes are used simultaneously. Further, even in a configuration in which there is only one electrode for each part (the current application electrode and the voltage measurement electrode are the same), the presence or absence of contact failure can be determined easily and quickly.

  On the other hand, on the voltage measurement circuit side, if the contact state of the subject at the electrodes E2 and E3 is not appropriate, the contact resistances ZE2 and ZE3 become extremely large values, and the input resistance portion of the differential amplifier AMP2 receives inductive noise and outputs it. The voltage V1 takes an arbitrary value depending on the magnitude of the noise signal and the magnitudes of the contact resistances ZE2 and ZE3.

  In this embodiment, in order to detect a contact failure of the voltage measurement electrodes (E2, E3), the voltage measurement circuit is switched, and a constant current is supplied between the current application electrodes, and at the same time, the voltage measurement electrode The potential difference between is measured. If a contact failure occurs in the voltage measuring electrode, even if the current applying electrode is in proper contact, the measured impedance value varies greatly and is not stable. Therefore, contact failure of the voltage measuring electrode is detected using the amount of change in impedance and the time during which the fluctuation continues. For example, the value of the bioelectrical impedance is about 500Ω, and it is determined that there is a contact failure in the voltage measurement electrode when the fluctuation exceeding ± 5Ω (or 10Ω) continues for 10 seconds (or 15 seconds).

  The detection of contact failure is not limited to the above-described method, and any method may be used. For example, when a known constant current is supplied between the two electrodes of the left hand and the voltage between the two electrodes is measured, the sum of the contact resistance values (ZE1 + ZE2) at the two electrodes of the left hand can be obtained. When the obtained contact resistance value exceeds a predetermined threshold value, it is determined that the contact is defective. The same determination can be made for the right hand, left foot, and right foot. In the case of directly measuring the contact resistance value, it is possible to detect a contact failure with higher accuracy.

  The contact failure of the current application electrodes (E1, E4) may be detected based on whether or not the SIN waveform of the output voltage is in a saturated state. When the top of the peak or the bottom of the valley of the SIN waveform is flat, the resistance value is too high, so that the voltage applied by the constant current circuit reaches the limit and the current does not rise above a certain value. Presumed. In such a case, it is determined that a contact failure has occurred in the current application electrode. Since the area of the SIN waveform increases as the resistance increases, it may be determined that a contact failure has occurred when the value obtained by integrating the absolute value of the voltage exceeds a predetermined threshold.

  In the present embodiment, when a contact failure is detected in one of the current application electrode and the voltage measurement electrode (hereinafter referred to as a pair of electrodes) that is in contact with any one of the right hand, left hand, right foot, and left foot. In this case, the measurement state of the electrode of the hand or foot is regarded as defective. For example, bioimpedance measurement using the left hand, left foot, and right foot electrodes can be performed as usual, but if the right hand electrode is used as one end of the path, the total resistance exceeds the threshold value (current contact electrode contact failure) ) When the measured impedance value is not stable (the contact failure of the voltage measurement electrode), it is determined that the measurement state of the right-hand electrode is defective.

However, even if contact failure is detected in either one of the paired electrodes (current application electrode or voltage measurement electrode), if the other contact state is good, both are less than contact failure More body parts can be measured for bioimpedance. For example, even when a contact failure occurs in the current application electrode for the right hand, if the contact state of the voltage measurement electrode for the right hand is good, a constant current is supplied between the left hand and the left foot, and the right hand and the right foot By measuring the voltage between the two, the bioimpedance of the trunk can be measured. In this way, even if contact failure is detected on one of the paired electrodes, it is not always necessary to use both electrodes, and bioimpedance is measured using the other electrode in a good measurement state. May be.
[Parts where bioimpedance cannot be measured when contact failure occurs]
In this embodiment, the body parts that can measure bioimpedance are the right arm, left arm, trunk, right leg, left leg, right arm to trunk, left arm to trunk, trunk to right leg. , Trunk-left leg, right arm-trunk-left leg, right arm-trunk-right leg, left arm-trunk-right leg, left arm-trunk-left leg. However, there is a case where the bioelectrical impedance cannot be stably measured for a certain body part due to poor contact or the like (when the measurement state does not satisfy the first condition). Hereinafter, such a part is referred to as a “bioimpedance measurement impossible part”. Hereinafter, an example of a site where bioimpedance cannot be measured when contact failure or the like occurs in a specific electrode will be described.

  When the electrodes on both legs are in poor contact (for example, when wearing socks or stockings), the bioimpedance (Z1 + Z2) of both arms can be measured, but the other body parts are parts where bioimpedance cannot be measured. . In this case, in the present embodiment, the body composition of the right arm part, the left arm part, the trunk part, the right leg part, and the left leg part is estimated among the parts where bioimpedance cannot be measured.

  When the electrodes of both hands are in poor contact (for example, when the hand electrodes are not used), the bioimpedance (Z4 + Z5) of both legs can be measured, but the other body parts are parts where bioimpedance cannot be measured. In such a case, in the present embodiment, the body composition of the right arm part, the left arm part, the trunk part, the right leg part, and the left leg part among the parts where bioimpedance cannot be measured is estimated.

  When the right hand electrode and the right foot electrode have poor contact, etc., the bioimpedance (Z1 + Z3 + Z4) from the left arm part to the trunk part to the left leg part can be measured, but the other body parts are parts where bioimpedance cannot be measured. In this case, in this embodiment, the body composition of the left arm part, the right arm part, the trunk part, the left leg part, and the right leg part among the parts where bioimpedance cannot be measured is estimated.

  When the right hand electrode and the left foot electrode have poor contact, etc., the bioimpedance (Z1 + Z3 + Z5) from the left arm part to the trunk part to the right leg part can be measured, but the other body parts are parts where bioimpedance cannot be measured. In this case, in this embodiment, the body composition of the left arm part, the right arm part, the trunk part, the left leg part, and the right leg part among the parts where bioimpedance cannot be measured is estimated.

  When the right hand electrode has poor contact or the like, left leg (Z4), right leg (Z5), both legs (Z4 + Z5), left arm to trunk (Z1 + Z3), left arm to trunk to left leg ( Z1 + Z3 + Z4), bioimpedance from the left arm to the trunk to the right leg (Z1 + Z3 + Z5) can be measured, but the other body parts cannot be measured. In this case, in this embodiment, the body composition of the left arm part, the right arm part, and the trunk part among the parts where bioimpedance cannot be measured is estimated.

  When the right foot electrode has poor contact or the like, left arm (Z1), right arm (Z2), both arms (Z1 + Z2), trunk to left leg (Z3 + Z4), left arm to trunk to left leg ( Z1 + Z3 + Z4), the bioimpedance of the right arm part to the trunk part to the left leg part (Z2 + Z3 + Z4) can be measured, but the other body parts are parts where the bioimpedance cannot be measured. In this case, in this embodiment, the body composition of the trunk, the left leg, and the right leg is estimated among the parts where bioimpedance cannot be measured.

In addition, when a specific electrode has poor contact or the like, a part of the body part is similarly a part where bioimpedance cannot be measured.
[Estimation of fat percentage by region]
The feature of the body composition meter of the present embodiment is that the body fat percentage of each body part can be estimated even when an electrode having a poor measurement state due to poor contact or the like is generated. Hereinafter, a method for estimating the body fat percentage of each body part when a specific electrode has poor contact will be described. Needless to say, the variables and coefficients are merely examples, and various changes can be made. In this embodiment, when all eight electrodes are in a good measurement state, the body fat percentage of each body part is calculated using a known method (see Example 8). Omitted.
(1) In the case where the electrodes of both legs are in poor contact, etc. In this embodiment, when the electrodes in both legs are in poor contact, for example, based on the bioimpedance measurement values of both arms, The fat percentage is estimated (see Example 1).

Whole body fat percentage = 29.9089-49.5131x1-7.3673x2 + 0.0876x3 + 1.0294x4-37.2041x5 + 0.1595x6
The variables x1 to x6 in the formula are as follows.

x1 = height (cm) ² / bioimpedance measurement value of both arms at a frequency of 100 Hz (Ω) / weight (kg)
x2 = Gender (Male: 1, Female: 2)
x3 = age x4 = BMI (weight (kg) ÷ height (m) ² )
x5 = (weight (kg) / height (cm)) ²
x6 = waist circumference (cm)
Next, based on the body fat percentage of the whole body, for example, the body fat percentage of each body part is estimated by the following formula.

Body fat percentage of right arm = a1 × body fat percentage of whole body + b1
Body fat percentage of left arm = a2 × body fat percentage of whole body + b2
Body fat percentage of trunk = a3 × body fat percentage of whole body + b3
Body fat percentage of right leg = a4 × body fat percentage of whole body + b4
Body fat percentage of left leg = a5 × body fat percentage of whole body + b5
a1 to a5 and b1 to b5 are statistical processes (single regression analysis) of the body fat percentage of the whole body obtained based on the measured bioimpedance values of both arms and the body fat percentage for each body part obtained by the DXA method. (See Example 8).
(2) When the electrodes of both hands are poorly contacted In the present embodiment, when the electrodes of both hands are poorly contacted, for example, based on the measured bioimpedance values of both legs, Estimate the rate (see Example 2).

Total body fat percentage = 124.52611-27.4878x1-91.3493x2-10.3371x3 + 1.4976x4-38.4846x5 + 0.1135x6
The variables x1 to x6 in the formula are as follows.

x1 = height (cm) ² / bioimpedance measurement value (Ω) / weight (kg) of both legs at a frequency of 100 Hz
x2 = Measurement value of bioimpedance of both legs at a frequency of 20 Hz (Ω) / Measurement value of bioimpedance of both legs at a frequency of 100 Hz (Ω)
x3 = Gender (Male: 1, Female: 2)
x4 = BMI (weight (kg) ÷ height (m) ² )
x5 = (weight (kg) / height (cm)) ²
x6 = waist circumference (cm)
Next, based on the body fat percentage of the whole body, for example, the body fat percentage of each body part is estimated by the following formula.

Body fat percentage in right arm = a6 x whole body fat percentage + b6
Body fat percentage of left arm = a7 × body fat percentage of whole body + b7
Body fat percentage of trunk = a8 × body fat percentage of whole body + b8
Body fat percentage of right leg = a9 x whole body fat percentage + b9
Body fat percentage of left leg = a10 × body fat percentage of whole body + b10
a6 to a10 and b6 to b10 perform statistical processing (single regression analysis) on the body fat percentage of the whole body obtained based on the bioimpedance measurement values of both legs and the body fat percentage for each body part obtained by the DXA method (See Example 8).
(3) When left-hand and left-foot or right-hand and right-foot electrodes have poor contact, etc. In the present embodiment, when the left-hand and left-foot electrodes have poor contact, etc., for example, the right arm, trunk, and right leg Based on the measured impedance value, the body fat percentage of the whole body is estimated by the following formula (see Example 3).

Total body fat percentage = 132.991-50.3900x1-81.3857x2-5.8404x3 + 0.0593x4 + 1.3178x5-32.4248x6
The variables x1 to x6 in the formula are as follows.

x1 = height (cm) ² / bioimpedance measurement value (Ω) / weight (kg) of right arm to trunk to right leg at frequency of 100 Hz
x2 = Measured value of bioimpedance from right arm to trunk to right leg at frequency 20 Hz (Ω) / Measured bioimpedance from right arm to trunk to right leg at frequency 100 Hz (Ω)
x3 = Gender (Male: 1, Female: 2)
x4 = age x5 = BMI (weight (kg) ÷ height (m) ² )
x6 = (weight (kg) / height (cm)) ²
Next, based on the body fat percentage of the whole body, for example, the body fat percentage of each body part is estimated by the following formula.

Body fat percentage of right arm = a11 × body fat percentage of whole body + b11
Body fat percentage of left arm = a12 × body fat percentage of whole body + b12
Body fat percentage of trunk = a13 × body fat percentage of whole body + b13
Body fat percentage of right leg = a14 × body fat percentage of whole body + b14
Body fat percentage of left leg = a15 × body fat percentage of whole body + b15
a11 to a15 and b11 to b15 are statistics of the body fat percentage of the whole body obtained based on the bioimpedance measurement values of the right arm part, the trunk part, and the right leg part, and the body fat percentage for each body part obtained by the DXA method. It is obtained by processing (single regression analysis) (see Example 8).

When the electrodes of the right hand and the right foot are in poor contact, for example, the body fat percentage of each body part is estimated using a similar expression based on bioimpedance measurement values of the left arm part, the trunk part, and the left leg part.
(4) When left hand and right foot or right hand and left foot electrodes have poor contact, etc. In the present embodiment, when the left hand and right foot electrodes have poor contact, etc., for example, living body of right arm, trunk, left leg Based on the measured impedance value, the body fat percentage of the whole body is estimated by the following formula (see Example 4).

Total body fat percentage = 109.7669-51.1006 x 1-59.3823 x 2-6.7979 x 3 + 0.0717 x 4 + 1.1734 x 5-22.805 x 6
The variables x1 to x6 in the formula are as follows.

x1 = height (cm) ² / bioimpedance measurement (Ω) / weight (kg) of right arm to trunk to left leg at frequency of 100 Hz
x2 = Measured value of bioimpedance from right arm to trunk to left leg at a frequency of 20 Hz (Ω) / Measured value of bioimpedance from right arm to trunk to left leg at a frequency of 100 Hz (Ω)
x3 = Gender (Male: 1, Female: 2)
x4 = age x5 = BMI (weight (kg) ÷ height (m) ² )
x6 = (weight (kg) / height (cm)) ²
Next, based on the whole body fat percentage, for example, the whole body fat percentage is estimated by the following equation.

Body fat percentage of right arm = a16 × body fat percentage of whole body + b16
Body fat percentage of left arm = a17 × body fat percentage of whole body + b17
Body fat percentage of trunk = a18 × body fat percentage of whole body + b18
Body fat percentage of right leg = a19 × body fat percentage of whole body + b19
Body fat percentage of left leg = a20 × body fat percentage of whole body + b20
a16 to a20 and b16 to b20 are statistics of the body fat percentage of the whole body obtained based on the bioimpedance measurement values of the right arm part, the trunk part, and the left leg part, and the body fat percentage for each body part obtained by the DXA method. It is obtained by processing (single regression analysis) (see Example 8).

When the electrodes of the right hand and the left foot have poor contact, for example, the body fat percentage of each body part is estimated using a similar formula based on bioimpedance measurement values of the left arm part, the trunk part, and the right leg part.
(5) In the case where the electrode of one hand has poor contact, etc. In this embodiment, when the electrode of the left hand has poor contact, etc., for example, the bioimpedance measurement values of the right arm part to the trunk part and the bioimpedance measurement values of both leg parts Based on the bioimpedance measurement value of the left leg, the body fat percentage of the whole body is estimated by the following formula (see Example 5).

Total body fat percentage = 84.5938-30.2623x1-14.522x2-30.0465x3-7.3327x4 + 0.0696x5 + 1.1121x6-35.1018x7 + 0.0852x8
The variables x1 to x8 in the equation are as follows.

x1 = height (cm) ² / measured value of bioimpedance (Ω) / weight (kg) of right arm to trunk at a frequency of 100 Hz
x2 = Measured value of bioimpedance of right arm to trunk at a frequency of 20 Hz (Ω) / Measured value of bioimpedance of both legs at a frequency of 100 Hz (Ω)
x3 = Measurement value of bioimpedance of the left leg at a frequency of 20 Hz (Ω) / Measurement value of bioimpedance of the left leg at a frequency of 100 Hz (Ω)
x4 = Gender (Male: 1, Female: 2)
x5 = age x6 = BMI (weight (kg) ÷ height (m) ² )
x7 = (weight (kg) / height (cm)) ²
x8 = waist circumference (cm)
Here, when a contact failure is seen only in the electrode of one hand, the bioimpedance of each of the left leg part and the right leg part can be measured. Therefore, the body fat percentage of each of the left leg and the right leg is calculated by a known method based on the bioimpedance of each of the left leg and the right leg (see Example 8). Next, based on the body fat percentage of the whole body, for example, the body fat percentage of other body parts is estimated by the following formula.

Body fat percentage of right arm = a21 × body fat percentage of whole body + b21
Body fat percentage of left arm = a22 × body fat percentage of whole body + b22
Body fat percentage of trunk = a23 × body fat percentage of whole body + b23
a21 to a23 and b21 to b23 are the body fat percentage of the whole body obtained based on the bioimpedance measurement values of the right arm part to the trunk part, the bioimpedance measurement values of both legs, and the bioimpedance measurement value of the left leg. The body fat percentage for each body part obtained by the DXA method is obtained by statistical processing (single regression analysis) (see Example 8).

When the right hand electrode has poor contact, etc., for example, a similar formula based on the bioimpedance measurement value of the left arm to the trunk, the bioimpedance measurement value of both legs, and the bioimpedance measurement value of the right leg To estimate the body fat percentage of each body part.
(6) In the case where the electrode of one leg has poor contact, etc. In this embodiment, when the electrode of the left foot has poor contact, etc., for example, the bioimpedance measurement values of the trunk to the right leg and the bioimpedance of both arms Based on the measured value, the body fat percentage of the whole body is estimated by the following formula (see Example 6).

Total body fat percentage = 95.9590-22.212x1 + 8.0554x2-68.582x3-6.6556x4 + 0.0392x5 + 1.21011x6-34.9103x7 + 0.0719x8
The variables x1 to x8 in the equation are as follows.

x1 = height (cm) ² / measured value of bioimpedance (Ω) / weight (kg) of trunk to right leg at a frequency of 100 Hz
x2 = Measurement value of bioimpedance of both arms at a frequency of 20 Hz (Ω) / Measurement value of bioimpedance from the trunk to the right leg at a frequency of 100 Hz (Ω)
x3 = trunk-right leg bioimpedance measurement value (Ω) at a frequency of 20 Hz / trunk-right leg bioimpedance measurement value (Ω) at a frequency of 100 Hz
x4 = Gender (Male: 1, Female: 2)
x5 = age x6 = BMI (weight (kg) ÷ height (m) ² )
x7 = (weight (kg) / height (cm)) ²
x8 = waist circumference (cm)
Here, when poor contact is observed only in the electrode on one leg, the bioimpedances of the left arm part and the right arm part can be measured. Therefore, based on the bioimpedance of each of the left arm part and the right arm part, the body fat percentage of each of the left arm part and the right arm part is calculated by a known method (see Example 8). Next, based on the body fat percentage of the whole body, for example, the body fat percentage of other body parts is estimated by the following formula.

Body fat percentage of trunk = a26 × body fat percentage of whole body + b26
Body fat percentage of right leg = a27 × body fat percentage of whole body + b27
Body fat percentage of left leg = a28 × body fat percentage of whole body + b28
a26 to a28 and b26 to b28 are body fat percentages of the whole body obtained based on the bioimpedance measurement values of the trunk to the right leg and the bioimpedance measurements of both arms, and the body obtained by the DXA method. It can be obtained by performing statistical processing (single regression analysis) on the body fat percentage by region (see Example 8).

When the right foot electrode has poor contact, for example, the body of each body part is calculated using a similar formula based on the bioimpedance measurement values of the trunk to the left leg and the bioimpedance measurement values of both arms. Estimate fat percentage.
[Operation]
FIG. 7 (a), FIG. 7 (b), and FIG. 7 (c) are flowcharts showing an example of the operation of the body composition monitor 1 of the present embodiment. FIGS. 7A to 7C are a series of flowcharts, but are divided because of drawing. Hereinafter, operation | movement of the body composition meter 1 of this embodiment is demonstrated, referring a figure.

  When the body composition analyzer 1 is turned on, the operation starts (start). First, body specific information is acquired. That is, body weight measurement (including clothing correction) is performed (step S101), input of personal data (height, age, sex, waist circumference, etc.) is received and the input result is stored (step S102). If measurement is performed periodically, the body identification information is stored together with the memory number and name, and part or all of the body identification information is recalled based on the memory number and name when the power is turned on. May be.

  When the body identification information is acquired, first, a current is applied between the right hand and the left hand, and at the same time, a voltage between the right hand and the right foot is measured (step S103), and whether there is an electrode contact failure (error) or not. Is determined (step S104). If it is determined in step S104 that there is no error, there is no contact failure in any of the right hand, left hand, and right foot electrodes. In this case, the voltage between the left hand and the left foot is measured without changing the portion to which the current is applied (step S105), and it is determined whether there is an error (step S106). If it is determined in step S106 that there is no error, there is no contact failure on the left foot. Therefore, it is stored that the measurement state of all the electrodes is good (step S107), the bioimpedance is measured for each body part (steps S108 to S112), and the body of the part is based on the bioimpedance of each body part. The fat percentage is calculated (steps S113 to S117). Since a well-known method (refer to Example 8) can be used as the calculation method and calculation formula, detailed description will be omitted. Finally, the calculation result is displayed on the display unit 5 (step S118), and the operation of the body composition monitor 1 ends (END).

  If it is determined in step S106 that there is an error, the right hand, left hand, and right foot electrodes are not abnormal, but the left foot electrode is added and an error occurs. Therefore, the measurement state of only the left foot electrode is poor. It can be determined that there is. Therefore, the fact that the measurement state of the left foot electrode is defective is stored (step S119). The body composition meter of the present embodiment can calculate the body composition of each body part even when the measurement state of the left foot electrode is poor (see (6) of estimating the fat percentage for each part). First, the bioimpedance of a body part (for example, the trunk to the right leg and both arms) required when the left foot electrode is not used is measured (steps S120 to S123), and the whole body is measured using the obtained measurement values. The body fat percentage is calculated (step S124). For the right arm and the left arm, the body composition is calculated based on the measured value of the bioelectrical impedance (steps S125 to S126). Further, the body fat percentage of other body parts is calculated based on the whole body fat percentage (steps S127 to S129). As the calculation method and the calculation formula, for example, the one shown in (6) of estimating the fat percentage for each part can be used. Finally, the calculation result is displayed on the display unit 5 (step S130), and the operation of the body composition monitor 1 is completed (end).

  If it is determined in step S104 that there is an error, it can be determined that there is an abnormality in at least one of the right hand, left hand, and right foot electrodes. Therefore, the voltage between the right hand and the left foot is measured without changing the portion to which the current is applied (step S131), and it is determined whether or not there is an error (step S132). If it is determined in step S132 that there is no error, there is no abnormality in the electrodes on the right hand, left hand, and left foot, so it can be determined that the measurement state of only the right foot electrode is defective. The body composition meter of the present embodiment can calculate the body composition of each body part even when the measurement state of the right foot electrode is poor (see (6) of estimating the fat percentage for each part). Therefore, the fact that the measurement state of the right foot electrode is bad is stored (step S133), and the bioimpedance of the necessary body part (for example, the trunk to the left leg and both arms) is measured (steps S134 to S137). The body fat percentage of the whole body and each body part is calculated (steps S138 to S143). As the calculation method and the calculation formula, for example, the same calculation method and calculation formula as those shown in (6) of estimating the fat percentage for each part can be used. Finally, the calculation result is displayed on the display unit 5 (step S144), and the operation of the body composition monitor 1 is finished (END).

  If it is determined in step S132 that there is an error, the voltage between the right hand and left hand is measured without changing the portion to which the current is applied (step S145), and it is determined whether there is an error (step S146). ). If it is determined in step S146 that there is no error, there is no abnormality in the electrodes of the right hand and the left hand, so it can be determined that the measurement state of both the electrodes of both feet is bad. The body composition meter of the present embodiment can calculate the body composition of each body part even when both the electrodes on both feet are in a poor measurement state (see (1) of estimating the fat percentage for each part). Therefore, the fact that the measurement state of the electrodes on both feet is bad is stored (step S147), the bioimpedance of both arms is measured (step S148), and the body fat percentage of the whole body and each body part is calculated (step S148). S149 to S154). As the calculation method and calculation formula, for example, the same calculation method and calculation formula as those shown in (1) of estimating the fat percentage for each part can be used. Finally, the calculation result is displayed on the display unit 5 (step S155), and the operation of the body composition monitor 1 ends (END).

  If it is determined in step S146 that there is an error, current is applied between the right foot and the left foot, and at the same time the voltages of the right hand and right foot are measured (step S156), and it is determined whether or not there is an error (step S156). Step S157). If it is determined in step S157 that there is no error, there is no abnormality in the electrodes of the right hand, right foot, and left foot, so it can be determined that the measurement state of only the left hand electrode is defective. The body composition meter of the present embodiment can calculate the body composition of each body part even when only the left-hand electrode is in a poor measurement state (see (5) in estimating the fat percentage for each part). Therefore, the fact that the measurement state of the left hand electrode is bad is stored (step S158), and the bioimpedance of a necessary body part (for example, the right arm part to the trunk part and both leg parts) is measured (steps S159 to S162). The body fat percentage of each body part is calculated (steps S163 to S168). As the calculation method and the calculation formula, for example, the same calculation method and calculation formula as those shown in (5) of estimating the fat percentage for each part can be used. Finally, the calculation result is displayed on the display unit 5 (step S169), and the operation of the body composition monitor 1 ends (END).

  Similarly, when the measurement state of the right hand electrode is poor (steps S170 to S183), when the measurement condition of the left hand electrode and the left foot electrode is poor (steps S184 to S194), when the measurement state of the right foot electrode of the right hand electrode is bad (steps S195 to S195). S205) When the measurement state of the right hand electrode and the left foot electrode is poor (Steps S206 to S216), When the measurement state of the left hand electrode and the right foot electrode is bad (Steps S217 to S227), When the measurement state of the electrodes of both hands is bad (Steps S228 to S238) ), The bioimpedance is measured and the body fat percentage for each body part is calculated and displayed, and the operation of the body composition meter 1 ends (END). If the bioelectrical impedance cannot be measured for any body part, an error is displayed indicating that measurement is impossible (step S239), and the operation of the body composition meter 1 ends (END).

In this embodiment, when the body composition meter 1 displays the body fat percentage of each body part, the bioimpedance of the body part cannot be measured, and the body fat of the body part is based on the bioimpedance of the other body part. If the rate is estimated, a message to that effect is displayed. That is, for example, when the measurement condition of the left foot electrode is poor and the bioimpedance of the left leg cannot be measured, the body fat percentage of the left leg is estimated based on the body fat percentage of the whole body. The display of body fat percentage is blinking or a special symbol is added. As seen in Example 8 to be described later, the accuracy based on the bioimpedance of other body parts is slightly inaccurate, but in such a configuration, the user can easily grasp the difference in accuracy with respect to the obtained result. Convenient.
[effect]
According to the body composition meter of this embodiment, even when the bioimpedance of a certain body part cannot be measured, the body composition of the body part is estimated using the measurement result of the bioimpedance of another body part. be able to. Therefore, even when an electrode that cannot be used for measurement occurs due to poor contact or the like, the body composition of each body part can be estimated. Even when only the hand electrode or the foot electrode is provided, the body composition of each body part can be estimated. That is, it is possible to estimate the body composition of a body part for which bioimpedance cannot be measured with the conventional configuration.
[Modification]
In this embodiment, when any of the electrodes of both hands and both feet has poor contact, this is detected, and the body composition of each body part is estimated from the bioimpedance value measured using the remaining electrodes. However, it is not always necessary to detect a contact failure. For example, the electrodes to be used may be switched manually. For example, if the use of the foot electrode is stopped, the body composition of each body part can be quickly estimated without having to detect a poor contact when riding on a body composition meter while wearing socks. In this case, for example, when the user operates the operation unit 6, the fact that the foot electrode is not used is input, and the arithmetic processing unit 13 receives the input and measures the bioimpedance without using the foot electrode. The body composition of the part is calculated.

  Although the present embodiment is configured to have electrodes for both hands and electrodes for both feet, a configuration having only electrodes for both hands or electrodes for both feet may be used. In a body composition meter having only electrodes of both hands, since there are no electrodes of both feet, conventionally, it was impossible to estimate the body composition of the trunk and legs. According to the body composition meter of the present invention, the body composition of the trunk and each leg can be accurately estimated based on the bioimpedance measurement values of both arms even in the configuration having only the electrodes of both hands. . Even with the configuration of only the electrodes on both legs, the body composition of the trunk and each arm can be accurately estimated based on the bioimpedance measurement values of both legs.

  In the present embodiment, the body composition of each body part is estimated from the body composition of the whole body based on the results of single regression analysis of the body composition of the whole body and the body composition of each body part. However, the method for estimating the body composition of each body part from the body composition of the whole body is not particularly limited, and estimation may be performed by incorporating other parameters, and the form of the expression is not limited to a linear expression. A multi-order equation or the like may be used.

In the above description, the case of estimating the body fat percentage was given as an example of the body composition, but the body composition (body fat percentage, body fat mass, lean body mass, body muscle percentage, body body, which can be estimated based on the bioelectrical impedance. As long as the muscle mass, bone percentage, bone mass, body moisture percentage, body moisture, basal metabolic rate, visceral fat area index, etc.), the estimation target may be any parameter. For example, since the lean body ratio (100% -body fat ratio) has a high correlation with the muscle ratio, the lean body ratio or the muscle mass may be obtained by calculating the lean body mass from the estimated body fat percentage. Alternatively, it is said that 73.2% of the lean mass is water (Michiko Koda, Mitsumasa Miyashita. Body moisture method. Obesity, Japanese clinical, pp170-173, 1995). The water content or the water content may be obtained from the estimated value of the rate. In general, the biggest factor affecting basal metabolism is muscle (Hosoya Norimasa, why energy metabolism now. First publication, pp97-109). It may be estimated. Since visceral fat has a high correlation with the waist (waist circumference), the visceral fat ratio or the visceral fat mass may be estimated using the waist circumference that is input by operating the operation unit 6. Alternatively, fat in both arms is said to be related to abdominal obesity (visceral fat obesity) (Vague J. The degree of masculine differentiation of obesities: a factor determining predisposition to diabetes, atherosclrosis, gout, and uric Calculous disease. Am J Clin Nutr 4, pp20-34, 1956.)
(Example 1: Estimation of body fat percentage of whole body from bioimpedance of both arms)
In Example 1, it was examined how accurately the body fat percentage of the whole body can be estimated from the bioelectrical impedance of a specific body part. For the data, we used bioimpedance measurements and body fat percentages determined by the DXA method, with 122 males and 120 females in the Kansai Hyogo / Osaka area, mainly from 20 years old to under 60 years old. It was. Measurements were taken at Ejiri Hospital in Himeji City. The subjects were “healthy Japanese”, and data that found swelling in the body such as heart disease and kidney disease were deleted from the population. For the measurement of bioimpedance, the bioimpedance measurement device described in the first embodiment was used for testing. The body fat percentage was measured by the DXA method using a QDR-2000 bone density measuring device manufactured by HOLOGIC.

FIG. 8 is a table showing the results of multiple regression analysis when the body fat percentage (%) of the whole body is used as a dependent variable for six independent variables including variables using bioimpedance (Z1 + Z2) of both arms. And a graph (scatter diagram). The first independent variable (x1) was the measured value of bioimpedance (Ω) / weight (kg) of both arms at height (cm) ² / frequency 100 Hz. The second independent variable (x2) was gender (male: 1, female: 2). The third independent variable (x3) was age. The fourth independent variable (x4) was BMI (weight (kg) ÷ height (m) ² ). The fifth independent variable (x5) was (weight (kg) / height (cm)) ² . The sixth independent variable (x6) was the waist circumference (cm). As can be seen from FIG. 8, based on the bioimpedance (Z1 + Z2) of both arms, it was found that the body fat percentage (%) of the whole body can be accurately estimated (R ² = 0.8909). These bioimpedances are obtained without using the electrodes on both legs.
(Example 2: Estimation of body fat percentage of whole body from bioimpedance of both legs)
In Example 2, using the data obtained by the same method as in Example 1, it was examined how accurately the body fat percentage of the whole body can be estimated from the bioimpedance of both legs.

FIG. 9 is a table showing results of multiple regression analysis when the body fat percentage (%) of the whole body is used as a dependent variable for six independent variables including a variable using bioimpedance (Z4 + Z5) of both legs, It is a graph (scatter diagram). The first independent variable (x1) was defined as the measured bioimpedance (Ω) / weight (kg) of both legs at height (cm) ² / frequency 100 Hz. The second independent variable (x2) was the bioimpedance measurement value (Ω) of both legs at a frequency of 20 Hz / the bioimpedance measurement value (Ω) of both legs at a frequency of 100 Hz. The third independent variable (x3) was gender (male: 1, female: 2). The fourth independent variable (x4) was BMI (weight (kg) ÷ height (m) ² ). The fifth independent variable (x5) was (weight (kg) / height (cm)) ² . The sixth independent variable (x6) was the waist circumference (cm). As can be seen from FIG. 8, based on the bioimpedance (Z4 + Z5) of both legs, it was found that the body fat percentage (%) of the whole body can be accurately estimated (R ² = 0.8807). These bioimpedances are obtained without using both-hand electrodes.
(Example 3: Estimation of whole body fat percentage from bioimpedance of right arm part-trunk part-right leg part)
In Example 3, using the data obtained by the same method as in Example 1, it is examined to what degree of accuracy the body fat percentage of the whole body can be estimated from the bioimpedance of the right arm part, the trunk part, and the right leg part. It was.

FIG. 10 shows multiple regressions when the body fat percentage (%) of the whole body is used as a dependent variable for six independent variables including variables using bioimpedance (Z2 + Z3 + Z5) of the right arm, trunk, and right leg. It is the table | surface and graph (scattering chart) which show the result of an analysis. The first independent variable (x1) was the measured value of bioimpedance (Ω) / weight (kg) of the right arm, trunk, and right leg at height (cm) ² / frequency of 100 Hz. The second independent variable (x2) is the measured bioimpedance (Ω) from the right arm to the trunk to the right leg at a frequency of 20 Hz / the measured bioimpedance from the right arm to the trunk to the right leg at a frequency of 100 Hz. Value (Ω). The third independent variable (x3) was gender (male: 1, female: 2). The fourth independent variable (x4) was age. The fifth independent variable (x5) was BMI (weight (kg) ÷ height (m) ² ). The sixth independent variable (x6) was (weight (kg) / height (cm)) ² . As can be seen from FIG. 10, based on the bioimpedance (Z4 + Z5) of the right arm part, the trunk part, and the right leg part, the body fat percentage (%) of the whole body can be accurately estimated (R ² = 0.9127). found. These bioimpedances are obtained without using the left hand and left foot electrodes.
(Example 4: Estimation of body fat percentage of whole body from bioimpedance of right arm part-trunk part-left leg part)
In Example 4, by using the data obtained by the same method as in Example 1, it is examined to what degree of accuracy the body fat percentage of the whole body can be estimated from the bioimpedance of the right arm part, the trunk part, and the left leg part. It was.

FIG. 11 shows multiple regressions with the body fat percentage (%) of the whole body as a dependent variable for six independent variables including variables using the bioimpedance (Z2 + Z3 + Z4) of the right arm, trunk, and left leg. It is the table | surface and graph (scattering chart) which show the result of an analysis. The first independent variable (x1) was the measured value of bioimpedance (Ω) / weight (kg) of the right arm, trunk, and left leg at height (cm) ² / frequency of 100 Hz. The second independent variable (x2) is the measurement value of bioimpedance (Ω) of right arm to trunk to left leg at a frequency of 20 Hz / measurement of bioimpedance of right arm to trunk to left leg at a frequency of 100 Hz. Value (Ω). The third independent variable (x3) was gender (male: 1, female: 2). The fourth independent variable (x4) was age. The fifth independent variable (x5) was BMI (weight (kg) ÷ height (m) ² ). The sixth independent variable (x6) was (weight (kg) / height (cm)) ² . As can be seen from FIG. 11, based on the bioimpedance (Z2 + Z3 + Z4) of the right arm part, the trunk part, and the left leg part, the body fat percentage (%) of the whole body can be accurately estimated (R ² = 0.9071). found. These bioimpedances are obtained without using the left hand and right foot electrodes.
(Example 5: Estimation of whole body fat percentage from bioimpedance obtained without using left hand electrode)
In Example 5, using the data obtained by the same method as in Example 1, it was examined how accurately the body fat percentage of the whole body can be estimated from the bioimpedance obtained without using the left hand electrode.

FIG. 12 shows the relationship between eight independent variables including variables using the right arm to trunk bioimpedance (Z2 + Z3), the bioimpedance of both legs (Z4 + Z5), and the bioimpedance (Z4) of the left leg. It is the table | surface and graph (scattering chart) which show the result of the multiple regression analysis at the time of making body fat percentage (%) into a dependent variable. The first independent variable (x1) was the height (cm) ² / bioimpedance measurement value (Ω) / weight (kg) of the right arm to the trunk at a frequency of 100 Hz. The second independent variable (x2) was a measured value of bioimpedance (Ω) of the right arm to the trunk at a frequency of 20 Hz / measured value of bioimpedance (Ω) of both legs at a frequency of 100 Hz. The third independent variable (x3) was the left leg bioimpedance measurement value (Ω) at a frequency of 20 Hz / the left leg bioimpedance measurement value (Ω) at a frequency of 100 Hz. The fourth independent variable (x4) was gender (male: 1, female: 2). The fifth independent variable (x5) was age. The sixth independent variable (x6) was BMI (weight (kg) ÷ height (m) ² ). The seventh independent variable (x7) was (weight (kg) / height (cm)) ² . The eighth variable (x8) was the waist circumference (cm). As can be seen from FIG. 12, based on the bioimpedance (Z2 + Z3) of the right arm to the trunk, the bioimpedance (Z4 + Z5) of both legs, and the bioimpedance (Z4) of the left leg, the body fat percentage of the whole body is accurate. It was found that it can be estimated well (R ² = 0.9067). These bioimpedances are obtained without using the left-hand electrode. In addition, based on the bioelectrical impedance obtained without using the right-hand electrode, the body fat percentage (%) of the whole body could be accurately estimated with the same accuracy.
(Example 6: Estimation of whole body fat percentage from bioimpedance obtained without using left foot electrode)
In Example 6, using data obtained by the same method as in Example 1, it was examined how accurately the body fat percentage of the whole body can be estimated from the bioimpedance obtained without using the left foot electrode.

FIG. 13 shows that the body fat percentage (%) of the whole body is dependent on 8 independent variables including the bioimpedance (Z3 + Z5) of the trunk to the right leg and the bioimpedance (Z1 + Z2) of both arms. It is the table | surface and graph (scattering chart) which show the result of the multiple regression analysis at the time of setting it as a variable. The first independent variable (x1) was defined as the measured body impedance (Ω) / weight (kg) of the trunk to the right leg at height (cm) ² / frequency 100 Hz. The second independent variable (x2) was a bioimpedance measurement value (Ω) of both arms at a frequency of 20 Hz / a bioimpedance measurement value (Ω) of the trunk to the right leg at a frequency of 100 Hz. The third independent variable (x3) was the trunk-right leg bioimpedance measurement value (Ω) at a frequency of 20 Hz / the trunk-right leg bioimpedance measurement value (Ω) at a frequency of 100 Hz. . The fourth independent variable (x4) was gender (male: 1, female: 2). The fifth independent variable (x5) was age. The sixth independent variable (x6) was BMI (weight (kg) ÷ height (m) ² ). The seventh independent variable (x7) was (weight (kg) / height (cm)) ² . The eighth variable (x8) was the waist circumference (cm). As can be seen from FIG. 13, based on the bioimpedance (Z3 + Z5) of the trunk to the right leg and the bioimpedance (Z1 + Z2) of both arms, the body fat percentage of the whole body is accurately determined (R ² = 0.9170). ) It turned out that it can be estimated. These bioimpedances are obtained without using the left foot electrode. Note that the body fat percentage (%) of the whole body could be accurately estimated with the same accuracy even based on the bioelectrical impedance obtained without using the right foot electrode.
(Example 7: Estimation of whole body fat percentage from bioimpedance obtained using all electrodes)
In Example 7, using the data obtained by the same method as in Example 1, it was examined how accurately the body fat percentage of the whole body can be estimated from the bioimpedance obtained using all electrodes.

FIG. 14 shows the body fat percentage of the whole body for eight independent variables including the bioimpedance (Z4 + Z5) of both legs, the bioimpedance (Z3) of the trunk, and the bioimpedance (Z1 + Z2) of both arms. It is the table | surface and graph (scattering chart) which show the result of the multiple regression analysis when (%) is made into the dependent variable. The first independent variable (x1) was gender (male: 1, female: 2). The second independent variable (x2) was BMI (weight (kg) ÷ height (m) ² ). The third independent variable (x3) was (weight (kg) / height (cm)) ² . The fourth independent variable (x4) was defined as the measured bioimpedance (Ω) / weight (kg) of both legs at height (cm) ² / frequency 100 Hz. The fifth independent variable (x5) was defined as the measured bioimpedance (Ω) / weight (kg) of the trunk at height (cm) ² / frequency 100 Hz. The sixth independent variable (x6) was the bioimpedance measurement value (Ω) of both arms at a frequency of 100 Hz / the bioimpedance measurement value (Ω) of both legs at a frequency of 100 Hz. The seventh independent variable (x7) was the bioimpedance measurement value (Ω) of both legs at a frequency of 20 Hz / the bioimpedance measurement value (Ω) of both legs at a frequency of 100 Hz. The eighth variable (x8) was the waist circumference (cm). As can be seen from FIG. 14, based on the bioimpedance (Z4 + Z5) of both legs, the bioimpedance (Z3) of the trunk, and the bioimpedance (Z1 + Z2) of both arms, the body fat percentage of the whole body is accurately (R ² = 0.9410) It was found that it can be estimated.

In this example, there is no restriction on the electrode to be used, but in such a case, the accuracy (R ² value) was the highest. However, it was found that the body fat percentage (%) of the whole body can be estimated with sufficiently high accuracy even in other cases (Examples 1 to 6).
(Example 8: Estimation of body fat percentage at a site where bioimpedance cannot be measured)
In Example 8, the correlation between the body fat percentage estimated in Examples 1 to 7 and the body fat percentage of each body part obtained by the DXA method was examined. For Example 1 to Example 6, the body fat percentage (%) of the whole body obtained by estimation, the body fat percentage (%) of the right arm part, and the body fat percentage of the left arm part obtained by the DXA method ( %), Body fat percentage (%) of the trunk, body fat percentage (%) of the right leg, and body fat percentage (%) of the left leg. About Example 7, the estimation precision of the body fat rate (%) of each body part based on the bioimpedance of the same body part is shown. That is, for a plurality of independent variables including variables using the bioimpedance of each part (variables obtained by combining height, weight, waist circumference with the bioimpedance of each part), the body fat percentage (%) of the part The correlation coefficient was obtained by multiple regression analysis with the dependent variable.

  FIG. 15 is a table showing the correlation between the body fat percentage (%) of the whole body estimated in each example and the body fat percentage (%) of each body part obtained by the DXA method. For reference, correlations are also shown for age, height, weight, BMI, and waist circumference. As can be seen from the figure, for any of the examples, the body fat percentage of the whole body obtained and the body fat percentage of each body part obtained by the DXA method are all in good correlation (correlation coefficient> 0.827, Significance probability <0.001). From this, it became clear that the body fat percentage of each body part can be accurately estimated even when a specific electrode cannot be used. That is, the body fat percentage of each body part can be accurately estimated by, for example, a linear expression of the whole body fat percentage. Therefore, it has been clarified that the body fat percentage can be estimated even at a site where bioimpedance cannot be measured.

  In addition, the correlation is highest for Example 7, and it can be seen that the estimation accuracy is the best when the bioelectrical impedance of the part is used. As a method for obtaining the body composition of a part based on the bioimpedance of a part, for example, a plurality of independent variables including variables using the bioimpedance of each part (height, weight, body Multiple correlation using variables) can be used.

  The body composition meter according to the present invention is useful as a body composition meter capable of estimating a body composition even for a body part for which bioimpedance cannot be measured with a conventional configuration.

It is a perspective view which shows typically the structure of the body composition meter of 1st Embodiment of this invention. It is a top view which shows typically the structure of the determination display part which the body composition meter of 1st Embodiment of this invention has. It is a block diagram which shows typically the structure of the electric circuit of the body composition meter of 1st Embodiment of this invention. It is a figure which shows typically the position which each electrode contacts with respect to a subject, and the bioimpedance of each body part of a subject. It is a schematic diagram which shows positional relationship, such as an electrode and contact resistance, when a hand electrode is made to contact a subject's skin. It is the schematic of the measurement circuit in the case of measuring bioimpedance by a 4 terminal method. It is a flowchart which shows an example of operation | movement of the body composition meter 1 of this embodiment. It is a flowchart (continuation of Fig.7 (a)) which shows an example of operation | movement of the body composition meter 1 of this embodiment. It is a flowchart (continuation of FIG.7 (b)) which shows an example of operation | movement of the body composition meter 1 of this embodiment. Tables and graphs (scatter plots) showing the results of multiple regression analysis with the body fat percentage (%) as the dependent variable for six independent variables including variables using bioimpedance of both arms is there. It is the table | surface and graph (scattering chart) which show the result of the multiple regression analysis when the body fat percentage (%) of the whole body is made into a dependent variable with respect to six independent variables including the variable using the bioimpedance of both legs. . A table showing the results of multiple regression analysis when the body fat percentage (%) of the whole body is used as a dependent variable for six independent variables including variables using the bioimpedance of the right arm, trunk, and right leg, and It is a graph (scatter diagram). A table showing the results of multiple regression analysis when the body fat percentage (%) of the whole body is used as a dependent variable for six independent variables including variables using the bioimpedance of the right arm, trunk, and left leg, and It is a graph (scatter diagram). When the body fat percentage (%) of the whole body is used as a dependent variable for eight independent variables including the bioimpedance of the right arm to trunk, the bioimpedance of both legs, and the bioimpedance of the left leg. It is the table | surface and graph (scattering chart) which show the result of multiple regression analysis. Results of multiple regression analysis with the body fat percentage (%) as the dependent variable for 8 independent variables including bioimpedance from the trunk to right leg and bioimpedance of both arms It is the table | surface and graph (scattering chart) which show. Multiple regression analysis with the body fat percentage (%) as the dependent variable for 8 independent variables including the bioimpedance of both legs, the bioimpedance of the trunk, and the bioimpedance of both arms It is the table | surface and graph (scattering chart) which show the result of. It is a table | surface which shows the correlation of the body fat percentage (%) of the whole body estimated in each Example, and the body fat percentage (%) of each body part obtained by DXA method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body composition meter 2 Judgment display part 3 Connection cable 4 Installation part 5 Display part 6 Operation part 6a Power ON / OFF key 6b Mode switching key 6c Setting screen switching key 6d Registration key 6f Numeric keypad 6g Measurement key 7a Holding part 7b Holding part 8 Bioimpedance measurement circuit 9 Bioimpedance measurement surface 10 Load cell 11 Electrode changeover switch 12 I / O
13 Calculation processing unit 14 Calculation unit 15 Storage unit E1, E2, E3, E4, E5, E6, E7, E8 Electrode

Claims (14)

A plurality of electrodes for contacting the subject's skin;
A bioimpedance measuring device that measures bioimpedance of the body of the subject using the plurality of electrodes for energization and voltage detection; and
A body composition calculation device that calculates the body composition of the subject using the detected bioelectrical impedance,
The said body composition calculating apparatus is a body composition meter which estimates the body composition of the part which cannot measure a bioimpedance of a subject based on the detected bioimpedance of the subject. The electrode and the bioimpedance measurement device are configured to be able to measure bioimpedance for a plurality of body parts in the body of the subject,
The body composition calculation device detects a measurement state of bioimpedance for the plurality of body parts,
When there is a body part whose measurement state does not satisfy the first condition,
The body composition meter according to claim 1, wherein the body composition of the site where the bioimpedance cannot be measured of the subject is estimated based on the bioimpedance of the body part whose measurement state satisfies the first condition.   2. The body composition according to claim 1, wherein the estimation is performed using a multiple regression equation in which a variable including bioimpedance of at least one body part is an independent variable and a body composition of a part where bioimpedance cannot be measured is a dependent variable. Total.   The body composition meter according to claim 3, wherein a variable including at least one selected from the group consisting of age, sex, height, weight, BMI, and waist circumference is used as the independent variable. The measurement state is the presence or absence of poor contact between the electrode and the body of the subject when measuring the bioimpedance of the body part,
When the body composition calculating device has an electrode with poor contact,
The body composition meter according to claim 2, wherein the body composition of the site where the bioimpedance cannot be measured of the subject is estimated based on the bioimpedance measured using an electrode having no poor contact.   The body composition meter according to claim 2, wherein the measurement state is a contact state of an electrode used for measuring a bioimpedance of the body part. Furthermore, a setting means for setting use and non-use of the electrode is provided,
The measurement state is a set state of use and non-use of the electrode,
When the body composition calculating device has an electrode in which the setting state is not used,
The body composition meter according to claim 2, wherein the body composition of the site where the bioimpedance cannot be measured of the subject is estimated based on the bioimpedance detected using the electrode in which the set state is in use. In addition, a display device that displays the body composition of each body part of the subject,
The body composition meter according to claim 1, wherein when the body composition of a certain body part is obtained by the estimation, it is displayed that the body composition of the body part is obtained by estimation. As the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs, corresponding to each of the right hand, left hand, right foot, and left foot,
The body composition calculation device is configured to detect a body part measured using at least one foot electrode when both the right and left foot electrodes are in good contact and at least one of the right or left hand electrodes is in poor contact. The body composition meter according to claim 6, wherein body composition of a right arm part, a left arm part, and a trunk part, which are sites where the bioimpedance cannot be measured, is estimated based on the bioimpedance. As the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs, corresponding to each of the right hand, left hand, right foot, and left foot,
The body composition calculation device is configured to detect a body part measured using at least one hand electrode when both the right and left hand electrodes are in good contact and at least one of the right or left foot electrodes is in poor contact. The body composition meter according to claim 6, wherein the body composition of the right leg, the left leg, and the trunk is estimated based on the bioimpedance, which is a part where the bioimpedance cannot be measured. As the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs, corresponding to each of the right hand, left hand, right foot, and left foot,
The body composition calculation device is based on the bioimpedance of a body part measured using an electrode with good contact when the electrodes on one hand and one foot are in good contact and the other electrodes are in poor contact. The body composition meter according to claim 6, wherein body composition of a right arm part, a left arm part, a right leg part, a left leg part, and a trunk part, which are sites where a person's bioimpedance cannot be measured, is estimated. As the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs, corresponding to each of the right hand, left hand, right foot, and left foot,
The body composition calculation device measures the bioimpedance of a subject based on the bioimpedance of both legs when both the right and left foot electrodes are in good contact and the right or left hand electrode is in poor contact. The body composition meter according to claim 6, wherein the body composition of the right arm part, left arm part, right leg part, left leg part, and trunk part, which are impossible parts, is estimated. As the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs, corresponding to each of the right hand, left hand, right foot, and left foot,
The body composition calculation device uses the bioimpedance of the subject based on the bioimpedance of both arms when both the right hand and left hand electrodes are in good contact and the right or left foot electrode is in poor contact. The body composition meter according to claim 6, wherein the body composition of the right arm part, the left arm part, the right leg part, the left leg part, and the trunk part, which are unmeasurable parts, is estimated. As the electrodes, a current application electrode and a voltage measurement electrode are provided in pairs, corresponding to each of the right hand, left hand, right foot, and left foot,
The body composition calculation device is a bioimpedance measured using at least one foot electrode when both the right and left foot electrodes are in good contact and either the right or left hand electrode is in poor contact. Based on the estimation of the body composition of the right arm, left arm, trunk, which is a site where the subject's bioimpedance cannot be measured,
Based on the bioimpedance measured using at least one hand electrode when both the right and left hand electrodes are in good contact and either the right or left foot electrode is in poor contact Estimating the body composition of the right leg, left leg, and trunk, which are sites where bioimpedance cannot be measured,
The right arm, which is a part where the bioimpedance of the subject cannot be measured, based on the bioimpedance of the body part between the electrodes with good contact when the electrodes on one hand and one leg are in good contact and the other electrodes are in poor contact Estimate the body composition of the left arm, right leg, left leg, and trunk,
When both the right and left foot electrodes are in good contact and both the right and left hand electrodes are in poor contact, based on the bioimpedance of both legs, the right arm part that is a bioimpedance measurement site of the subject, Estimate the body composition of the left arm, right leg, left leg, and trunk,
When both the right and left hand electrodes are in good contact and both the right and left foot electrodes are in poor contact, the right arm part, which is a part where the bioimpedance of the subject cannot be measured, based on the bioimpedance of both arms The body composition meter according to claim 6, wherein the body composition of the left arm, right leg, left leg, and trunk is estimated.

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