Body composition analyzer, body composition measurement method, and body composition measurement program

Abstract

To provide a body composition meter, a body composition measuring method, and a body composition measuring program capable of accurately measuring a body composition irrespective of a body state of a person to be measured.SOLUTION: In a body composition meter 10, a combination of electrode parts 14 arranged on a person to be measured can be changed according to a body state of the person to be measured since a plurality of the electrode parts 14 is connected to a body part 12 with a cable 16. One of a plurality of different estimation formulas is selected on the basis of the combination of the electrodes arranged on the person to be measured. A body composition of the person to be measured is calculated on the basis of the selected estimation formula and a living body impedance value acquired by applying an electric current to the electrode parts.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , , , , ,

[0001] The present invention relates to a body composition meter, a body composition measurement method, and a body composition measurement program.

Background Art

[0002] A body composition meter that calculates the body composition of a subject by measuring the bioelectrical impedance value of the subject has been widely spread. The body composition meter measures the bioelectrical impedance value with two or more electrode portions that contact the subject, and calculates the body composition by an estimation formula using the bioelectrical impedance value, height, weight, etc. as variables.

[0003] The bioelectrical impedance value is proportional to the length between the electrodes and also varies depending on the measurement posture of the subject. This is because when the subject bends a joint, for example, the current path between the electrodes and the muscle cross-sectional area change. Therefore, it is preferable for the body composition meter to measure the bioelectrical impedance value of the subject in a predetermined measurement posture.

[0004] Here, Patent Document 1 describes a bioelectrical impedance measurement device including a hand grip provided with a plurality of electrodes as a device for measuring a bioelectrical impedance value. In this bioelectrical impedance measurement device, when the subject first uses it, the accurate position of the subject's hand in the hand grip is set. Then, when the subject uses it next, it is determined whether the position of the subject's hand holding the hand grip is the accurate position, and the subject is notified.

[0005] As described above, in Patent Document 1, on the premise that the subject stands on the bioelectrical impedance measurement device to measure the bioelectrical impedance value, it is determined whether the position of the subject's hand holding the hand grip is at a predetermined position.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-534878 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, due to various physical circumstances, it may be difficult for the person being measured to assume the prescribed measurement posture, or the prescribed measurement posture may not be suitable for the usage situation. For example, the bioimpedance measuring device described in Patent Document 1 cannot be used by the person being measured who has difficulty standing.

[0008] Furthermore, in the bioimpedance measuring device described in Patent Document 1, the position of the measuring electrodes is fixed. For example, if the electrodes are fixed to the palm of the hand or the sole of the foot, it may be difficult to measure the body composition of subjects with physical conditions such as equinus deformity, missing fingers or toes, or weak grip strength.

[0009] Therefore, the present invention aims to provide a body composition analyzer, a body composition measurement method, and a body composition measurement program that can accurately measure body composition regardless of the physical condition of the person being measured. [Means for solving the problem]

[0010] A body composition analyzer according to one aspect of the present invention is a body composition analyzer in which a plurality of electrode units to be placed on a person to be measured are each connected to a main body unit via cables, comprising: an electrode placement determination means for determining a combination of the electrode units to be placed on the person to be measured from among the plurality of electrode units; an estimation formula selection means for selecting one of a plurality of different estimation formulas for calculating the body composition of the person to be measured based on the determination result of the combination by the electrode placement determination means; and a body composition calculation means for calculating the body composition based on the estimation formula selected by the estimation formula selection means and the measurement result obtained by passing an electric current through the electrode units.

[0011] In this configuration, multiple electrode units are connected to the main unit by cables, allowing the combination of electrode units placed on the subject to be changed according to the subject's physical condition. The subject's physical condition refers to the subject's posture and any missing limbs, etc. Based on the combination of electrode units placed on the subject, one of several different estimation formulas is selected. The subject's body composition is calculated based on the selected estimation formula and the measurement results obtained by passing current through the electrode units (e.g., bioimpedance values). As a result, this configuration can accurately calculate body composition regardless of the subject's physical condition.

[0012] A body composition analyzer according to one aspect of the present invention is a body composition analyzer in which a plurality of electrode units to be placed on a person to be measured are each connected to a main unit via a cable, and comprises: an electrode placement determination means for determining the combination of the electrode units to be placed on the person to be measured from among the plurality of electrode units; a body composition calculation means for calculating a body composition for each of the estimation formulas by inputting the measurement results obtained by passing an electric current through the electrode units into a plurality of different estimation formulas; and a body composition selection means for selecting one of the plurality of body compositions calculated by the body composition calculation means based on the determination result of the combination of electrode units.

[0013] In this configuration, multiple electrode units are connected to the main unit by cables, allowing the combination of electrode units placed on the subject to be changed according to the subject's physical condition. Based on the measurement results from the electrode units, body composition is calculated for each of several different estimation formulas, and one of the multiple body composition values ​​is selected based on the evaluation result of the electrode unit combination. As a result, this configuration can accurately calculate body composition regardless of the subject's physical condition.

[0014] In the above-described body composition analyzer, the body composition value may also be calculated based on the posture of the person being measured. The measurement results of a person being measured also change depending on the posture of the person being measured. Therefore, with this configuration, accurate measurement results for the person being measured can be obtained by calculating the body composition value based on the posture of the person being measured. The calculation of the body composition value with this configuration consists of a first calculation, which corrects the measurement results obtained based on the change in the posture of the person being measured, and a second calculation, which involves selecting or correcting an estimation formula for calculating body composition based on the change in the posture of the person being measured.

[0015] The above-described body composition analyzer may be equipped with a posture determination means that determines the posture of the person being measured based on the positional relationship between the position of the electrode portion placed on the person being measured and a predetermined reference. With this configuration, the posture of the person being measured can be easily determined.

[0016] In the body composition analyzer described above, the positional relationship may be the positional relationship with other electrode parts, the positional relationship with the floor surface, or the positional relationship with the main body. With this configuration, the posture of the person being measured can be easily determined.

[0017] In the above-described body composition analyzer, a prediction means may be provided for predicting the convergence value of the measurement results in accordance with the changes in the posture of the person being measured, and the body composition calculation means may calculate the body composition based on the prediction results from the prediction means. Measurement results such as bioelectrical impedance values ​​change due to the effects of changes in water content and joint angles associated with changes in the posture of the person being measured. In particular, changes in measurement results due to changes in water content take time to converge. Therefore, with this configuration, since the body composition is calculated based on the prediction results of the convergence value of the measurement results, the measurement time for body composition can be shortened.

[0018] In the body composition analyzer described above, the prediction means may predict the convergence value of the measurement result based on the variation pattern of the measurement result associated with changes in the posture of the person being measured. With this configuration, the convergence value of the measurement result can be easily predicted.

[0019] In the body composition analyzer described above, the electrode section may have multiple different electrode shapes, and the electrode placement determination means may determine the combination of the electrode section and electrode shape placed on the person being measured. With this configuration, by having an electrode section of multiple shapes in the body composition analyzer, an appropriate electrode section can be selected according to the posture and physical defects of the person being measured, making it possible to measure body composition without placing a burden on the person being measured.

[0020] A body composition measurement method according to one aspect of the present invention is a body composition measurement method performed by a body composition analyzer in which a plurality of electrode units to be placed on a person to be measured are each connected to a main unit via cables, comprising: a first step in which an electrode placement determination means determines the combination of the electrode units to be placed on the person to be measured from among the plurality of electrode units; a second step in which an estimation formula selection means selects one of a plurality of different estimation formulas for calculating the body composition of the person to be measured based on the determination result of the combination by the electrode placement determination means; and a third step in which a body composition calculation means calculates the body composition based on the estimation formula selected by the estimation formula selection means and the measurement result obtained by passing an electric current through the electrode units.

[0021] A body composition measurement method according to one aspect of the present invention is a body composition measurement method in which a plurality of electrode units placed on a person to be measured are each connected to a main unit via a cable, comprising: a first step in which an electrode placement determination means determines the combination of the plurality of electrode units that are placed on the person to be measured; a second step in which a body composition calculation means calculates a body composition for each estimation formula by inputting the measurement results obtained by passing an electric current through the electrode units into a plurality of different estimation formulas; and a third step in which a body composition selection means selects one of the plurality of body compositions calculated by the body composition calculation means based on the determination result of the combination of electrode units.

[0022] A body composition measurement program according to one aspect of the present invention causes a computer included in a body composition meter, in which a plurality of electrode units arranged on a subject are each connected to a main body unit via a cable, to function as arrangement electrode determination means for determining a combination of the electrode units arranged on the subject among the plurality of electrode units, estimation formula selection means for selecting one from a plurality of different estimation formulas for calculating the body composition of the subject based on the determination result of the combination by the arrangement electrode determination means, and body composition calculation means for calculating the body composition based on the estimation formula selected by the selection means and a measurement result obtained by passing an electric current through the electrode unit.

[0023] A body composition measurement program according to one aspect of the present invention causes a computer included in a body composition meter, in which a plurality of electrode units arranged on a subject are each connected to a main body unit via a cable, to function as arrangement electrode determination means for determining a combination of the electrode units arranged on the subject among the plurality of electrode units, body composition calculation means for calculating the body composition for each estimation formula by inputting a measurement result obtained by passing an electric current through the electrode unit into a plurality of different estimation formulas, and body composition selection means for selecting one from the plurality of body compositions calculated by the body composition calculation means based on the determination result of the combination of the electrode units.

Advantages of the Invention

[0024] According to the present invention, the body composition can be accurately measured regardless of the physical condition of the subject.

Brief Description of the Drawings

[0025] [Figure 1] FIG. 1 is a schematic configuration diagram of a body composition meter according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the arrangement positions of voltage electrodes and current electrodes with respect to a subject according to the first embodiment. [Figure 3] FIG. 3 is a functional block diagram related to the body composition measurement function according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a combination of a plurality of electrode units arranged on a subject according to the first embodiment. [Figure 5] Figure 5 is a flowchart showing the flow of the body composition measurement process in the first embodiment. [Figure 6] Figure 6 is a schematic diagram showing examples of estimation formulas corresponding to combinations of electrode parts with different electrode shapes in the second embodiment. [Figure 7] Figure 7 is a functional block diagram relating to the body composition measurement function of the fourth embodiment. [Figure 8] Figure 8 is a flowchart showing the flow of the body composition measurement process in the fourth embodiment. [Modes for carrying out the invention]

[0026] Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are merely examples of how the present invention can be implemented, and the present invention is not limited to the specific configurations described below. In implementing the present invention, specific configurations may be adopted as appropriate depending on the embodiment.

[0027] (First Embodiment) Figure 1 is a schematic diagram of the body composition analyzer 10 of this embodiment. The body composition analyzer 10 is a biological information measuring device that estimates biological information, which is body composition, based on the subject's weight and bioelectrical impedance values, etc. The body composition analyzer 10 calculates body composition, including fat percentage, fat mass, lean body mass, muscle mass, visceral fat mass, visceral fat level, visceral fat area, subcutaneous fat mass, basal metabolic rate, bone mass, body water percentage, BMI, intracellular fluid volume, extracellular fluid volume, etc.

[0028] The main body 12 of the body composition analyzer 10 has multiple electrode units 14 that are placed on the person being measured, each connected via a cable 16, and calculates the person's body composition using an estimation formula.

[0029] Each of the multiple electrode sections 14 is equipped with a voltage electrode V (V1 to V4) and a current electrode A (A1 to A4), and each is electrically connected to the main body section 12 via cables 16 (16-1 to 16-4).

[0030] Figure 2 is a schematic diagram showing an example of the placement (contact position) of the electrode section 14 on the person being measured. The placement position of each of the multiple electrode sections 14 on the person being measured is predetermined. The placement position of electrode section 14A, consisting of voltage electrode V1 and current electrode A1, is on the right palm; the placement position of electrode section 14B, consisting of voltage electrode V2 and current electrode A2, is on the left palm; the placement position of electrode section 14C, consisting of voltage electrode V3 and current electrode A3, is on the top of the right foot; and the placement position of electrode section 14D, consisting of voltage electrode V4 and current electrode A4, is on the top of the left foot. In the example in Figure 2, the voltage electrode V is on the wrist side or the ankle side, but this is just an example, and the current electrode A may also be on the wrist side or the ankle side.

[0031] As described above, the body composition analyzer 10 of this embodiment is equipped with four electrode sections 14A to 14D as an example, but is not limited to this, and may be equipped with four or more, for example, eight electrode sections 14. That is, Figure 2 is an example of the arrangement positions of the electrode sections 14, and in addition to the arrangement positions in Figure 2, electrode sections 14 may be placed on other parts such as the shins, groin, fingers, and above the knees.

[0032] In the body composition analyzer 10 of this embodiment, it is not necessary to place all electrode units 14 on the subject in order to measure the subject's body composition; it is sufficient if at least two or more electrode units 14 are placed on the subject. Methods for fixing the electrode units 14 to the subject include, for example, fixing with a conductive adhesive, fixing with a band while the electrode units 14 are placed on the subject, or fixing by clipping the electrode units 14 to parts of the subject's limbs or other body parts.

[0033] The method for fixing the electrode unit 14 is not particularly limited, as long as the electrode unit 14 can be fixed to the person being measured regardless of the person's physical condition. The person's physical condition includes sitting in a wheelchair, lying down, missing limbs, paralysis, and unilateral diseases. The shape of each voltage electrode V and current electrode A may differ depending on the location where they are placed.

[0034] As described above, in this embodiment, the body composition analyzer 10 has multiple electrode units 14 connected to the main body 12 via a cable 16, and the electrode units 14 are placed on the person being measured. Therefore, the necessary electrodes can be placed regardless of the physical condition of the person being measured (measurement posture, limb deficiencies, etc.), and the body composition of the person being measured can be measured.

[0035] Furthermore, each electrode section 14A to 14D is equipped with a position sensor 18 (18-1 to 18-2). The position sensor 18 is placed on the person being measured together with the current electrode A and the voltage electrode V, and measures the position of the electrode section 14 (height from the floor or distance from other electrode sections 14, etc.). The position sensor 18 may be integrated with the current electrode A or the voltage electrode V. Alternatively, an electrode section 14 in which the current electrode A and the voltage electrode V are integrated, such as a clip-shaped electrode, may also be equipped with a position sensor 18.

[0036] Furthermore, in this embodiment, the body composition analyzer 10 is connected to the main body 12 by one cable 16 (16-1 to 16-2) for each electrode unit 14. However, it is not limited to this configuration, and each current electrode A, voltage electrode V, and position sensor 18 of the electrode unit 14 may be connected to the main body 12 by a cable 16, or any two of the current electrode A, voltage electrode V, and position sensor 18 may be connected to the main body 12 by a single cable 16.

[0037] The main unit 12 measures the potential difference generated in the current path between the electrode units 14 placed on the person being measured, and calculates the bioimpedance value of the person being measured as a measurement result based on this potential difference. Specifically, the body composition analyzer 10 passes a weak current of a predetermined frequency from each current electrode A to predetermined parts of the person being measured, measures the potential difference generated in the current path of the person being measured via the voltage electrode V, and calculates the bioimpedance value of the whole body and each body part of the person being measured based on these current and potential difference values.

[0038] The main unit 12 then calculates the body composition of the person being measured by applying the registered information of the person being measured (age, gender, weight, arm length, foot length, etc.) and the calculated bioelectrical impedance values ​​to an estimation formula.

[0039] The main unit 12 also includes a display unit 20 and an operation unit 22.

[0040] The display unit 20 is, for example, an LCD (Liquid Crystal Display) and displays the results of body composition measurements, etc. The operation unit 22 is used to perform various input operations on the main unit 12 and is, for example, a touch panel, keyboard, mouse, touchpad, and buttons.

[0041] Figure 3 is a functional block diagram relating to the body composition measurement function of the body composition analyzer 10 of this embodiment. The body composition analyzer 10 (main unit 12) includes a calculation unit 30 and a storage unit 32.

[0042] The arithmetic unit 30 is, for example, a CPU (Central Processing Unit) and performs various calculations.

[0043] The storage unit 32 is, for example, a non-volatile memory such as flash memory or an HDD (Hard Disk Drive), and stores various data and programs used for processing in the arithmetic unit 30. The storage unit 32 also stores multiple different estimation formulas for calculating the body composition of the person being measured, as well as the person's registration information (age, gender, weight, arm length, foot length, etc.). The registration information may be input via communication means (not shown) from another information processing device or scale, or it may be input by the operator via the operation unit 22.

[0044] The calculation unit 30 of this embodiment includes an electrode placement determination unit 40, an impedance calculation unit 42, a posture determination unit 44, an impedance correction unit 46, a convergence value prediction unit 48, an estimation formula selection unit 50, a body composition calculation unit 52, and a display control unit 54. The functions of each of these units are realized by the calculation unit 30 executing a program, but are not limited to this, and may also be realized by the body composition analyzer 10 being equipped with individual hardware such as an ASIC (Application Specific Integrated Circuit) corresponding to each function. Furthermore, the body composition analyzer 10 may be equipped with multiple calculation units 30, and each of the multiple calculation units 30 may be equipped with one or more of the above units. Moreover, the body composition analyzer 10 is not limited to the case where the main body unit 12 is equipped with the above units, but a separate housing (not shown) from the main body unit 12 may be equipped with one or more of the above units.

[0045] The electrode placement determination unit 40 determines the combination of electrode units 14 that are placed on the person being measured from among the multiple electrode units 14.

[0046] Figure 4 shows an example of a combination of multiple electrode units 14 placed on the person being measured. Figure 4 shows combinations when voltage electrodes V1 to V4 and current electrodes A1 to A4 are placed in the positions shown in Figure 2. As shown in Figure 4, there are multiple combinations (12 patterns) of voltage electrodes V and current electrodes A, so even if it is not possible to place the electrode units 14 on some of the hands or feet due to the physical condition of the person being measured, body composition can be measured by placing them in other positions.

[0047] In this embodiment, the electrode placement determination unit 40 automatically determines whether each electrode unit 14 is in contact with the human body or not after each electrode unit 14 has been placed on the person being measured and an instruction to start body composition measurement has been input via the operation unit 22. This determination method is based, for example, on whether the measurement results (bioimpedance value, reactance value, resistance value) obtained from the electrode unit 14 have human characteristics. Cases where human characteristics are present include, for example, when the low-frequency measurement value is greater than the high-frequency measurement value, when the reactance value is negative, or when 2° < |Phase Angle| < 15°.

[0048] Thus, the body composition analyzer 10 of this embodiment automatically determines the electrode units 14 placed on the person being measured, making operation simpler and reducing errors compared to when the operator manually inputs the electrodes to be used.

[0049] The impedance calculation unit 42 calculates the bioimpedance value of the person being measured as a measurement result obtained by passing current through the electrode unit 14.

[0050] The posture determination unit 44 determines the posture of the person being measured. Details of the posture determination will be described later.

[0051] The body composition analyzer 10 of this embodiment calculates body composition values ​​based on the posture of the person being measured. The calculation of body composition values ​​according to this embodiment is performed by correcting the measurement results obtained based on changes in the posture of the person being measured (first calculation). Therefore, the impedance correction unit 46 corrects the bioimpedance value of the person being measured based on the posture of the person being measured as the first calculation. The bioimpedance value changes depending on the distance between the electrodes being measured and the muscle cross-sectional area. Specifically, it is proportional to the distance over which the current flows between the electrodes (hereinafter referred to as "current path length") and inversely proportional to the muscle cross-sectional area. For this reason, the bioimpedance value of the person being measured also changes depending on the posture of the person being measured. Therefore, by correcting the bioimpedance value calculated based on the posture of the person being measured, the impedance correction unit 46 can reduce the phenomenon in which the bioimpedance value changes due to changes in the posture of the person being measured, and as a result, the body composition calculated changes.

[0052] The convergence value prediction unit 48 predicts the convergence value of the bioimpedance values ​​measured by the multiple electrode units 14 in accordance with the changes in the posture of the person being measured. Details of the convergence value prediction will be described later.

[0053] The estimation formula selection unit 50 selects one of several different estimation formulas for calculating the body composition of the person being measured, based on the combination determination result by the electrode placement determination unit 40. For this reason, the storage unit 32 stores multiple estimation formulas for each combination of voltage electrodes V and current electrodes A placed on the person being measured. The estimation formula selection unit 50 then selects an estimation formula corresponding to the combination of electrode units 14 determined by the electrode placement determination unit 40.

[0054] If there are multiple candidate estimation formulas, the display unit 20 may display all of the selected candidates, allowing the operator to select the one deemed appropriate from among the candidates. The operator selects the estimation formula via the control unit 22. Furthermore, when displaying multiple estimation formulas on the display unit 20, a priority order for the candidate estimation formulas may be determined, and the formulas may be displayed on the display unit 20 according to this priority order. Note that the operator of the body composition analyzer 10 is not limited to the person being measured; it may also be someone other than the person being measured, such as an assistant to the person being measured.

[0055] The body composition calculation unit 52 calculates body composition based on the estimation formula selected by the estimation formula selection unit 50 and the measurement results (bioelectrical impedance values) obtained by passing current through the electrode unit 14.

[0056] Body composition may be calculated using the measurement results of one combination (single) of the electrode units 14, or it may be calculated based on the measurement results of multiple combinations of the electrode units 14. In this configuration, the memory unit 32 stores estimation formulas corresponding to a single combination and estimation formulas corresponding to multiple combinations, and the estimation formula selection unit 50 selects an estimation formula as appropriate, either automatically or based on selection by the operator.

[0057] The display control unit 54 controls the display unit 20 to display various information such as the body composition measurement results and candidate estimation formulas.

[0058] Next, we will explain how the subject's posture is determined. The body composition analyzer 10 of this embodiment can measure body composition regardless of the subject's physical condition. However, even for the same body part, the bioelectrical impedance values ​​will differ if the subject's posture is different. Therefore, the body composition analyzer 10 of this embodiment corrects the measured bioelectrical impedance values ​​based on the subject's posture.

[0059] As described above, the placement position of each electrode unit 14 on the body of the person being measured is predetermined. Each electrode unit 14 is equipped with a position sensor 18, and the main unit 12 stores the person's race, lower leg length based on height, leg length, etc.

[0060] The posture determination unit 44 in this embodiment determines the posture of the person being measured based on the positional relationship between the positions of the electrode units 14 placed on the person being measured and a predetermined reference. This positional relationship is the positional relationship with other electrode units 14 (the distance between the electrode units 14 placed on the person being measured), the positional relationship with the floor surface, or the positional relationship with the main body 12. Therefore, the predetermined reference is the position of the other electrode units 14, the position of the floor surface, or the position of the main body 12. In other words, the posture determination unit 44 determines the posture of the person being measured based on the absolute or relative value of the electrode units 14 placed on the person being measured and the predetermined reference.

[0061] The position sensor 18 is a height sensor that detects the distance between the electrode unit 14 and the floor, a distance sensor that detects the distance between the electrode unit 14 and other electrode units 14, or the positional relationship between the electrode unit 14 and the main unit 12. When detecting the distance between the electrode unit 14 and other electrode units 14, for example, the distance between an electrode unit 14 placed on the same side foot and an electrode unit 14 placed on the hand is detected.

[0062] For example, if the electrode 14 placed on the foot and the electrode 14 placed on the hand are at the same height, the subject's posture is determined to be supine. Also, if the distance between the electrode 14 placed on the foot and the electrode 14 placed on the hand is equal to the length of the subject's lower leg, the subject's posture is determined to be seated. Furthermore, if the distance between the electrode 14 placed on the foot and the electrode 14 placed on the hand is equal to the length of the subject's leg, the subject's posture is determined to be standing.

[0063] If the position sensor 18 is a sensor that detects the distance from the floor, the position sensor 18 may be provided only on the electrode unit 14 placed on the hand. This is because even if the position sensor 18 is provided on the electrode unit 14 placed on the foot, the detection result will be almost constant (a few centimeters) regardless of the physical condition of the person being measured.

[0064] Furthermore, if the distance from the floor is within 10 cm, meaning the subject is almost in contact with the floor, the subject's posture is determined to be supine. Also, if the distance from the floor is equal to the length of the lower leg, the subject's posture is determined to be seated. And if the distance from the floor is equal to the length of the leg, the subject's posture is determined to be standing.

[0065] The posture of the person being measured may be input to the main unit 12 via the operation unit 22 by the operator, rather than being determined by the posture determination unit 44 as described above.

[0066] The impedance correction unit 46 performs correction by multiplying the bioimpedance value by a coefficient corresponding to the determined posture, as an example, but is not limited to this, and may also perform correction of the bioimpedance value using a function corresponding to the posture.

[0067] Next, we will explain how to predict the converged value of bioimpedance.

[0068] When the subject changes their posture while the electrodes 14 are placed on them, the posture change is detected by the posture determination described above. At the same time, the body composition analyzer 10 also captures the change in bioelectrical impedance value associated with the subject's change in posture.

[0069] Bioelectrical impedance values ​​change due to changes in the subject's posture, as well as changes in joint angles. In particular, changes in bioelectrical impedance values ​​due to changes in body moisture take time to converge. For this reason, body composition measurements must be performed with the subject in a resting state without changing their posture. However, while keeping the subject in a resting state is necessary from the standpoint of measurement efficiency, it is not necessarily desirable from the standpoint of the physical burden on the subject due to immobility. Therefore, in this embodiment, the measurement time is shortened by predicting the convergence value of the bioelectrical impedance values ​​even if the subject's posture changes.

[0070] The convergence value prediction unit 48 of this embodiment predicts the convergence value of the measured values ​​based on the fluctuation pattern of the measured values ​​associated with changes in the posture of the person being measured.

[0071] Therefore, the memory unit 32 stores multiple fluctuation patterns of measured values ​​associated with each posture change. The fluctuation pattern indicates the rate of change or amount of change of human body parts, frequency, impedance value, resistance value, and reactance value. The fluctuation pattern is represented by, for example, a cubic function, but is not limited to this, and may be represented by other functions such as a logarithmic function.

[0072] Furthermore, the system may determine the change in the subject's posture based on fluctuations in bioimpedance values, not only for changes in posture while the electrode unit 14 is placed on the subject, but also for changes in posture before the electrode unit 14 is placed on the subject, and predict the convergence value. This allows the system to detect changes in the subject's posture and predict the convergence value based on fluctuations in bioimpedance values ​​after the electrode unit 14 is placed and measurement begins, even if the subject's posture changes immediately before the electrode unit 14 is placed.

[0073] The convergence value prediction unit 48 then selects the variation pattern that best fits the variation in multiple measurement results within a predetermined time from the start of measurement of the bioimpedance value. The convergence value prediction unit 48 then acquires the measurement result after a sufficient time has elapsed, as predicted from the selected variation pattern, as the convergence value.

[0074] Figure 5 is a flowchart showing the flow of the body composition measurement process performed by the body composition analyzer 10. The body composition measurement process begins when, after multiple electrode units 14 have been placed on the person being measured, an operation to start measuring body composition is performed on the operation unit 22.

[0075] First, in step S100, the electrode placement determination unit 40 determines the combination of electrode units 14 placed on the person being measured.

[0076] In the next step, S102, the posture determination unit 44 determines the posture of the person being measured.

[0077] In the next step, S104, the impedance calculation unit 42 applies current to multiple electrode units 14 and calculates the bioimpedance value of the person being measured based on the potential difference between the electrodes. The calculation of the bioimpedance value is performed multiple times within a predetermined measurement time.

[0078] In the next step, S106, the convergence value prediction unit 48 determines whether or not there is a change of a predetermined value or more in the bioimpedance value within a predetermined measurement time. If the determination is positive, the process proceeds to step S108; if the determination is negative, the process proceeds to step S110.

[0079] In step S108, the convergence value prediction unit 48 predicts the convergence value of the bioimpedance value. If the process does not proceed to step S108, there is no change in the bioimpedance value, and therefore, the convergence value is not predicted.

[0080] In the next step S110, the impedance correction unit 46 corrects the bioimpedance value of the person being measured based on the person's posture. If a converged value of the bioimpedance value was predicted in step S108, the predicted converged value is used for the correction.

[0081] In the next step S112, the estimation formula selection unit 50 selects an estimation formula from several different estimation formulas to calculate the body composition of the person being measured, based on the result of the combination determination in step S100.

[0082] In the next step, S114, the body composition calculation unit 52 calculates the body composition based on the selected estimation formula and bioelectrical impedance value, and the main body composition measurement process ends. The calculated body composition is displayed on the display unit 20 and stored in the storage unit 32. Alternatively, the body composition may be transmitted to a predetermined server and stored on that server.

[0083] As described above, in this embodiment, the body composition analyzer 10 has multiple electrode units 14 connected to the main body 12 by cables 16, so the combination of electrode units 14 placed on the subject can be changed according to the subject's physical condition. Based on the combination of electrode units 14 placed on the subject, one of several different estimation formulas is selected. Based on the selected estimation formula and the bioimpedance value obtained by passing current through the electrode units 14, the subject's body composition is calculated. As a result, the body composition analyzer 10 in this embodiment can accurately calculate body composition regardless of the subject's physical condition.

[0084] (Second Embodiment) The following describes a second embodiment of this model. The body composition analyzer 10 of this model has multiple electrode sections 14 with different electrode shapes, such as an electrode section 14 for measuring when the subject is lying down and an electrode section 14 for measuring when the subject is standing. Examples of these electrode shapes include a grip shape that can be held in the hand, a clip shape that clamps onto the wrist or ankle, a band shape that wraps around the wrist or ankle, and a flat plate shape that is positioned on the sole of the foot when the subject is standing.

[0085] The calculation of body composition values ​​in this embodiment (second calculation) involves selecting or correcting an estimation formula for calculating body composition based on changes in the subject's posture. Therefore, the electrode placement determination unit 40 in this embodiment determines the combination of electrode units 14 and electrode shapes placed on the subject from among a plurality of electrode units 14. Then, the estimation formula selection unit 50, as the second calculation, selects an estimation formula associated with the combination of electrode units 14 based on the determination result by the electrode placement determination unit 40. In other words, this determination result corresponds to determining the subject's posture, and the body composition analyzer 10 stores estimation formulas (e.g., estimation formula for lying down, estimation formula for standing) corresponding to the subject's posture.

[0086] Thus, by having multiple electrode sections 14 of different shapes, the body composition analyzer 10 can select the appropriate electrode section 14 according to the subject's posture and physical defects, enabling body composition measurement without placing any burden on the subject.

[0087] Furthermore, in this embodiment, the electrode shape of the electrode section 14 may be replaceable by attachment depending on the person being measured. For example, for a person who can grip the electrode, a grip-shaped electrode may be attached to the electrode section 14 so that they can grasp the electrode with their hand. On the other hand, for a person who cannot grip the electrode, a clip-shaped or band-shaped electrode may be attached to the electrode section 14. In this way, the tip of the electrode section 14 that comes into contact with the person being measured may be replaceable with an electrode shape suitable for the person being measured as an attachment. The replaced electrode shape can be recognized by the electrode placement determination unit 40.

[0088] As an example, the grip-shaped electrode portion 14 is placed on the palm of the person being measured, and the clip-shaped electrode portion 14 is placed on the wrist of the person being measured. Therefore, the current path length differs because the contact position with the person being measured is different for the grip-shaped and clip-shaped electrodes (palm vs. wrist). Thus, an estimation formula corresponding to the current path length according to the electrode shape of the electrode portion 14 placed on the person being measured may be selected. Figure 6 is a schematic diagram showing an example of an estimation formula corresponding to a combination of different electrode shapes.

[0089] Specifically, the clip-shaped electrode portion 14 placed on the wrist tends to have a shorter current path length and a lower bioimpedance value compared to the case where a grip-shaped electrode portion 14 is used. For this reason, the estimation formula used with the clip-shaped electrode portion 14 is selected to include a conversion unit that increases the measured impedance value (hereinafter referred to as the "reference formula").

[0090] As for the calculation of body composition (second calculation), in addition to selecting one estimation formula from the multiple estimation formulas described above, it also includes a form in which a conversion formula is selected to convert the base formula, or a form in which a coefficient is selected to multiply or divide the base formula and correct the base formula. That is, it may include a form in which one is selected from multiple conversion formulas or a form in which one is selected from multiple coefficients based on the determination result of the combination of electrode units 14. Then, the base formula is corrected by inputting the conversion formula or coefficient into the base formula conversion unit, and this becomes an estimation formula for calculating body composition.

[0091] The reference formula, as an example, is an estimation formula that estimates the bioimpedance value for each frequency and body part when the subject is in an upright position. In addition to bioimpedance values, estimation formulas that estimate resistance values, reactance values, etc., are also subject to conversion.

[0092] For example, if the subject is sitting, the reference formula is modified so that a higher bioimpedance value is calculated for the lower body. This is because, when sitting, the leg joints are bent, shortening the current path length compared to standing, resulting in a lower bioimpedance value. On the other hand, no modification is made to the estimation formula corresponding to the upper body.

[0093] Furthermore, if the subject is lying down, the reference formula is modified so that the bioelectrical impedance value for the lower body is calculated to be lower. This is because, when lying down, the amount of water in the lower body is lower compared to standing, resulting in a higher bioelectrical impedance value. Conversely, the reference formula is modified so that the bioelectrical impedance value for the upper body is calculated to be higher. This is because, when lying down, the amount of water in the upper body is higher compared to standing, resulting in a lower bioelectrical impedance value.

[0094] (Third embodiment) A third embodiment of this model will be described below. In this embodiment, an estimation formula is selected based on the number and placement of the electrode units 14 used on the person being measured.

[0095] In this embodiment, for example, when all electrode units 14-1 to 14-4 are used, that is, when electrode units 14 are placed on both hands and both feet of the person being measured, five different estimation formulas can be selected to estimate the whole body, corresponding to different parts of the body with different current paths: (1) left and right halves, (2) right half, (3) left half, (4) between both feet, and (5) between both hands.

[0096] Furthermore, methods for obtaining the body composition of a subject from the estimation formulas for each body part described in (1) to (5) above include, for example, the following methods A to C.

[0097] ·Method A One of the available estimation formulas from (1) to (5) is selected, and the subject's body composition is calculated based on the selected formula. In this case, the priority order of the selected estimation formulas is predetermined. For example, the priority order is set according to the subject's physical defects and posture.

[0098] ·Method B The subject's body composition is calculated using all available estimation formulas, and the average value is used as the measurement result.

[0099] ·Method C The subject's body composition is calculated using all available estimation formulas, and the median value is used as the measurement result.

[0100] For example, in order to use Method A, the priority order must be determined in advance, but depending on the placement of the electrode section 14, the priority order may not have been determined. In such cases, Method B or Method C may be selected.

[0101] In the above example, when electrodes 14 are placed on both hands and both feet of the person being measured, five different estimation formulas can be selected for each body part: (1) left and right halves of the body, (2) right half of the body, (3) left half of the body, (4) between both feet, and (5) between both hands. However, this is just one example, and other options may be available, such as (6) between the right hand and left foot, (7) between the left hand and right foot, or (8) calculating and summing by body part.

[0102] As an example, let's consider the case where options (1) to (8) above are available, and electrode units 14 are placed in three locations: the left hand, right hand, and right foot. We will explain the selection of estimation formulas for each body part. When the electrode placement determination unit 40 determines that electrode units 14 are to be used on the left hand, right hand, and right foot, three estimation formulas are available to estimate the whole body: (2) right half of the body, (5) between both hands, and (7) between the left hand and right foot. If the priority order is set as (2), (5), and (7), then the estimation formula for the right half of the body (2) is selected. On the other hand, if no priority order is set, body composition is calculated using method B.

[0103] (Fourth Embodiment) A fourth embodiment of the present invention will be described below. The body composition analyzer 10 of this embodiment calculates multiple body compositions using multiple different estimation formulas from the measured bioelectrical impedance values, and selects one of the multiple body compositions as an appropriate value based on the determination result of the combination of electrode units 14.

[0104] Figure 7 is a functional block diagram relating to the body composition measurement function of this embodiment. Parts of the configuration shown in Figure 7 that are the same as those shown in Figure 3 are denoted by the same reference numerals, and their descriptions are omitted.

[0105] The calculation unit 30 of this embodiment includes a body composition calculation unit 60 and a body composition selection unit 62, along with an electrode placement determination unit 40, an impedance calculation unit 42, a posture determination unit 44, an impedance correction unit 46, a convergence value prediction unit 48, and a display control unit 54. The functions of each of these units are realized by the calculation unit 30 executing a program, but the body composition analyzer 10 may also be realized by providing individual hardware such as an ASIC (Application Specific Integrated Circuit) corresponding to each function. Furthermore, the body composition analyzer 10 may have multiple calculation units 30, and each of the multiple calculation units 30 may include one or more of the above-mentioned units. Moreover, the body composition analyzer 10 is not limited to the case where the main body unit 12 includes the above-mentioned units, but a separate housing (not shown) may include one or more of the above-mentioned units.

[0106] The body composition calculation unit 60 calculates body composition for each estimation formula by inputting the measurement results (bioelectrical impedance values) obtained by passing an electric current through the electrode unit 14 into several different estimation formulas. In other words, the body composition calculation unit 60 calculates multiple body compositions by substituting the bioelectrical impedance values ​​and the registered information of the person being measured into several different estimation formulas stored in the memory unit 32.

[0107] The body composition selection unit 62 selects one of several body compositions calculated by the body composition calculation unit 60 based on the determination result of the electrode placement determination unit 40 regarding the combination of electrode units 14. In other words, although the body composition calculation unit 60 calculates multiple body compositions, the body composition selection unit 62 selects the body composition deemed appropriate based on the combination of electrode units 14 placed on the person being measured.

[0108] For example, the selection of body composition may be based on pre-set criteria, and one body composition may be selected by the body composition selection unit 62 based on these criteria. However, it is not limited to this; for example, the average value of the calculation results from multiple estimation formulas may be selected as one body composition, or the median value of the calculation results from multiple estimation formulas may be selected as one body composition. Alternatively, an appropriate body composition may be selected based on the electrode shape of the electrode unit 14.

[0109] The memory unit 32 stores a range of body composition deemed appropriate based on the combination of electrodes 14 and the subject's registered information (height, weight, arm length, foot length, etc.) (hereinafter referred to as the "appropriate range"). The body composition selection unit 62 then selects a body composition that falls within the appropriate range from among the multiple body compositions calculated by the body composition calculation unit 60. In this selection, the subject's past body composition may be referenced, and a body composition that falls within a predetermined range relative to past body compositions may be selected as the appropriate body composition.

[0110] If there are multiple suitable body composition candidates, the display unit 20 may display multiple body composition candidates, and the operator may select the body composition deemed appropriate from these candidates. The operator's selection of body composition is made via the control unit 22. Alternatively, when multiple body composition candidates are displayed on the display unit 20, the body composition selection unit 62 may determine the priority order, and the body compositions may be displayed on the display unit 20 according to this priority order.

[0111] Figure 8 is a flowchart showing the flow of the body composition measurement process in this embodiment. Steps in Figure 8 that are the same as those shown in Figure 5 are denoted by the same reference numerals, and their descriptions are omitted.

[0112] In step S200, which follows from step S110, the body composition calculation unit 60 calculates multiple body compositions based on bioelectrical impedance values ​​and multiple different estimation formulas.

[0113] In the next step, S202, the body composition selection unit 62 selects one of several body compositions calculated based on the determination result of the combination of electrodes 14, and the main body composition measurement process ends. The selected body composition is displayed on the display unit 20 and stored in the storage unit 32. Alternatively, the body composition may be transmitted to a predetermined server and stored on that server.

[0114] As described above, in this embodiment, the body composition analyzer 10 has multiple electrode units 14 connected to the main body 12 by cables 16, so the combination of electrode units 14 placed on the person being measured can be changed according to the person's physical condition. The body composition analyzer 10 then calculates body composition for each of several different estimation formulas based on the measurement results from the electrode units 14, and selects one of the multiple body compositions based on the determination result of the combination of electrode units 14. As a result, the body composition analyzer 10 in this embodiment can accurately calculate body composition regardless of the person's physical condition.

[0115] Although the present invention has been described above using the embodiments described above, the technical scope of the present invention is not limited to the scope described in the embodiments above. Various modifications or improvements can be made to the embodiments above without departing from the spirit of the invention, and such modified or improved forms are also included in the technical scope of the present invention.

[0116] In the above embodiment, a configuration was described in which the weight of the person being measured, etc., measured by another measuring device, is input to the body composition analyzer 10. However, the present invention is not limited to this. For example, the body composition analyzer 10 may be provided with other functions, such as a function to measure the weight of the person being measured. Furthermore, the body composition analyzer 10 may be capable of transmitting and receiving data with other devices such as a weighing scale via wired or wireless connection, and may also incorporate data acquired by other devices.

[0117] Furthermore, if the subject has a disease (such as paralysis or unilateral edema), the body composition can be measured in the affected area and compared to the healthy area of ​​the subject to obtain an indication of the severity of the disease. [Explanation of Symbols]

[0118] 10 Body composition monitor 12 Main body 14 Electrode part 16 Cables 40 Placed electrode determination unit (placed electrode determination means) 44 Attitude determination unit (attitude determination means) 46 Impedance correction unit (correction means) 48. Convergence Value Prediction Unit (Prediction Means) 50 Estimation formula selection unit (estimation formula selection means) 52 Body composition calculation unit (body composition calculation means) 60 Body composition calculation unit (body composition calculation means) 62 Body composition selection unit (body composition selection means)

Claims

1. A body composition analyzer in which multiple electrode units placed on the person being measured are each connected to the main unit via cables, Each of the electrode sections is equipped with a position sensor, and its placement on the body of the person being measured is defined. An electrode placement determination means for determining the combination of the electrode portions that are placed on the person being measured from among the plurality of electrode portions, Based on the combination determination result by the electrode placement determination means, an estimation formula selection means selects one of several different estimation formulas for calculating the body composition of the person being measured, A body composition calculation means calculates the body composition based on the estimation formula selected by the estimation formula selection means and the measurement results obtained by passing an electric current through the electrode portion. A posture determination means that determines whether the posture of the person being measured is lying down, sitting, or standing, based on the positional relationship between the position of the electrode placed on the person being measured and a predetermined reference, Equipped with, The positional relationship refers to the positional relationship between the electrode portions placed on the person being measured, the positional relationship with the floor surface, or the positional relationship with the main body. The body composition is calculated based on the estimation formula selected by the estimation formula selection means, the measurement result obtained by passing current through the electrode portion, and the posture of the person being measured determined by the posture determination means. Body composition meter.

2. A body composition analyzer in which multiple electrode units placed on the person being measured are each connected to the main unit via cables, Each of the electrode sections is equipped with a position sensor, and its placement on the body of the person being measured is defined. An electrode placement determination means for determining the combination of the electrode portions that are placed on the person being measured from among the plurality of electrode portions, A body composition calculation means that calculates body composition for each estimation formula by inputting the measurement results obtained by passing an electric current through the electrode into a plurality of different estimation formulas, A body composition selection means that selects one of the multiple body compositions calculated by the body composition calculation means based on the determination result of the combination of the electrode parts, A posture determination means that determines whether the posture of the person being measured is lying down, sitting, or standing, based on the positional relationship between the position of the electrode placed on the person being measured and a predetermined reference, Equipped with, The positional relationship refers to the positional relationship between the electrode portions placed on the person being measured, the positional relationship with the floor surface, or the positional relationship with the main body. The body composition is calculated based on the estimation formula, the measurement result obtained by passing an electric current through the electrode, and the posture of the person being measured determined by the posture determination means. Body composition meter.

3. The system includes a prediction means for predicting the convergence value of the measurement results in accordance with the changes in the posture of the person being measured. The body composition analyzer according to claim 1 or claim 2, wherein the body composition calculation means calculates the body composition based on the prediction result by the prediction means.

4. The body composition analyzer according to claim 3, wherein the prediction means predicts the convergence value of the measurement result based on the variation pattern of the measurement result associated with the change in the posture of the person being measured.

5. The electrode portion has multiple different electrode shapes, The body composition analyzer according to any one of claims 1 to 4, wherein the electrode placement determination means determines the combination of the electrode portion and the electrode shape placed on the person being measured.

6. A body composition measurement method performed by a body composition analyzer in which multiple electrode units to be placed on a person to be measured are each connected to a main unit via a cable, each electrode unit is equipped with a position sensor, and the placement position on the person to be measured is defined, The first step involves the electrode placement determination means determining the combination of the electrode parts from the plurality of electrode parts that are placed on the person being measured, A second step in which, based on the combination determination result by the electrode placement determination means, the estimation formula selection means selects one of several different estimation formulas for calculating the body composition of the person being measured. A third step in which the body composition calculation means calculates the body composition based on the estimation formula selected by the estimation formula selection means and the measurement results obtained by passing current through the electrode part, It has, Based on the positional relationship between the position of the electrode placed on the person being measured and a predetermined reference, the posture determination means determines that the person being measured is lying down, sitting, or standing. The positional relationship refers to the positional relationship between the electrode portions placed on the person being measured, the positional relationship with the floor surface, or the positional relationship with the main body. The body composition is calculated based on the estimation formula selected by the estimation formula selection means, the measurement result obtained by passing current through the electrode portion, and the posture of the person being measured determined by the posture determination means. Body composition measurement method.

7. A body composition measurement method in which multiple electrode units to be placed on a person to be measured are each connected to a main unit via a cable, each electrode unit is equipped with a position sensor, and the placement position on the person to be measured is defined, The first step involves the electrode placement determination means determining the combination of the electrode parts from the plurality of electrode parts that are placed on the person being measured, The second step involves inputting the measurement results obtained by passing an electric current through the electrode into a plurality of different estimation formulas, thereby enabling the body composition calculation means to calculate the body composition for each estimation formula. A third step in which, based on the determination result of the combination of the electrode parts, the body composition selection means selects one of the multiple body compositions calculated by the body composition calculation means, It has, Based on the positional relationship between the position of the electrode placed on the person being measured and a predetermined reference, the posture determination means determines that the person being measured is lying down, sitting, or standing. The positional relationship refers to the positional relationship between the electrode portions placed on the person being measured, the positional relationship with the floor surface, or the positional relationship with the main body. The body composition is calculated based on the estimation formula, the measurement result obtained by passing an electric current through the electrode, and the posture of the person being measured determined by the posture determination means. Body composition measurement method.

8. Multiple electrode units, each placed on the person being measured, are connected to the main unit via cables, and each electrode unit is equipped with a position sensor and a computer in the body composition analyzer that defines the placement position on the person being measured, An electrode placement determination means for determining the combination of the electrode portions that are placed on the person being measured from among the plurality of electrode portions, Based on the combination determination result by the electrode placement determination means, an estimation formula selection means selects one of several different estimation formulas for calculating the body composition of the person being measured, A body composition calculation means calculates the body composition based on the estimation formula selected by the estimation formula selection means and the measurement results obtained by passing an electric current through the electrode portion. A posture determination means that determines whether the posture of the person being measured is lying down, sitting, or standing, based on the positional relationship between the position of the electrode placed on the person being measured and a predetermined reference, and make it work The positional relationship refers to the positional relationship between the electrode portions placed on the person being measured, the positional relationship with the floor surface, or the positional relationship with the main body. The body composition is calculated based on the posture of the person being measured, as determined by the posture determination means. Body composition measurement program.

9. Multiple electrode units, each placed on the person being measured, are connected to the main unit via cables, and each electrode unit is equipped with a position sensor and a computer in the body composition analyzer that defines the placement position on the person being measured, An electrode placement determination means for determining the combination of the electrode portions that are placed on the person being measured from among the plurality of electrode portions, A body composition calculation means that calculates body composition for each estimation formula by inputting the measurement results obtained by passing an electric current through the electrode into a plurality of different estimation formulas, A body composition selection means that selects one of the multiple body compositions calculated by the body composition calculation means based on the determination result of the combination of the electrode parts, A posture determination means that determines whether the posture of the person being measured is lying down, sitting, or standing, based on the positional relationship between the position of the electrode placed on the person being measured and a predetermined reference, and make it work The positional relationship refers to the positional relationship between the electrode portions placed on the person being measured, the positional relationship with the floor surface, or the positional relationship with the main body. The body composition is calculated based on the posture of the person being measured, as determined by the posture determination means. Body composition measurement program.

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