JP2000139867A - Body composition estimation method, body composition estimation apparatus and recording medium recording body composition estimation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability by making the ratio of the amount of the extracellular fluid and the amount of the intracellular fluid approximately equal to a ratio advocated in physiology, etc. SOLUTION: This body composition estimation method feeds the probe current of multifrequencies to the testee's body, calculates the vital electric impedances R0 and R∞ at the time of the frequency 0 Hz and frequency infinity of the testee's body and estimates at least one of the amount of the extracellular fluid ECF or the amount of the intracellular fluid ICF by using equation (1) or equation (2). In the equations, H denotes the body height of the testee and A, B, Λ denote constants.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a body composition estimation method, a body composition estimation device, and a recording medium on which a body composition estimation program is recorded. More specifically, the present invention relates to a body water distribution ( Extracellular fluid volume,
Body composition estimating method, body composition estimating apparatus, and the like useful for estimating the amount of intracellular fluid, the amount of body water (the amount of body fluid), and the state of body fat (body fat percentage, fat weight, lean body mass, etc.) The present invention relates to a recording medium on which a body composition estimation program is recorded.

[0002]

2. Description of the Related Art In recent years, research on the electrical characteristics of living organisms has been conducted for the purpose of evaluating the body composition of humans and animals.
The electrical properties of living organisms vary significantly depending on the type of tissue or organ. For example, in the case of humans, the electrical resistivity of blood is around 150 Ωcm, whereas the electrical resistivity of bone and fat is 1 to 1. There is also 5 kΩ · cm. The electrical characteristics of the living body are determined by the bioelectric impedance (Bioelectric Impedanc
It is called e) and is measured by passing a small current between a plurality of electrodes attached to the body surface of a living body. From the bioelectrical impedance thus obtained, the body water distribution (extracellular fluid volume, intracellular fluid volume, the total body water volume (body fluid volume), etc.) of the subject and the state of body fat (body fat percentage) The method of estimating fat, fat mass, lean mass, etc. is called bioelectric impedance method ("Bioelectric impedance method as evaluation method of body composition"), Baumgartner, RN, etc.
`` Bioelectric Impedance and Its Clinical Application '', Medical Electronics and Biotechnology, Hiroshi Kanai, 20 (3) Jun 1982, `` Estimation of Body Water Distribution by Impedance Method and Its Application '', Medical Electronics and Biotechnology , Makoto Haeno, 23 (6) 19
85, “Long-term measurement of urinary bladder volume by impedance method”, Ergonomics, written by Yasuo Kuchimachi, 28 (3) 1992, etc.).

[0003] Bioelectric impedance is the resistance of a living body to the current carried by ions in the body (resistance) and the capacitive reactance associated with the various types of polarization processes created by cell membranes, tissue interfaces, or non-ionized tissue. It is composed of The capacitance (capacitance), which is the reciprocal of reactance, causes a time delay in current rather than voltage, and creates a phase shift (phase shift). This value is the arctangent of the ratio of reactance to resistance (arctangent), That is, it can be quantitatively determined as an electric phase angle. These bioelectric impedance Z and reactance X
And the electrical phase angle φ depends on the frequency. On the other hand, as shown in FIG.
Are surrounded by the cell membranes 2, 2,..., And the cell membranes 2, 2,... Can be electrically regarded as capacitors having a large capacitance (capacitance). Therefore, bioelectrical impedance, as shown in FIG. 15, the extracellular fluid resistance R _e and extracellular fluid impedance comprising only the intracellular fluid impedance comprising a series connection of the intracellular fluid resistance R _i and cell membrane capacitance C _m Can be considered as a parallel combined impedance of

By the way, in the conventional body composition estimating apparatus,
A configuration in which the bioelectric impedance of a subject is measured with the frequency of the sine wave alternating current to be passed between the surface electrodes of the limbs fixed at approximately 50 kHz, which is the frequency (characteristic frequency) at which the electrical phase angle φ is maximized. since that is the, the extracellular fluid resistance R _e, can not be determined by separating the intracellular fluid resistance R _i, based on the parallel combined impedance of extracellular fluid impedance and intracellular fluid impedance, subject Because the body water distribution and the state of body fat were estimated, the accuracy of the estimation was not very good.

[0005] Therefore, as a means for solving this drawback,
Generates a probe current of the multi-frequency, each frequency probe current generated by introducing the body of a subject by measuring the electrical impedance of the subject's body, the extracellular fluid resistance R _e
And the intracellular fluid resistance R _i are determined separately, and based on the determined extracellular fluid resistance R _e and intracellular fluid resistance R _i , the body water distribution and the state of body fat of the subject are estimated. A body composition estimating apparatus is provided (see Japanese Patent Application No. 8-176448 filed by the present applicant). Japanese Patent Application No. 8-176448
In the body composition estimation method disclosed in the above publication, the extracellular fluid volume ECF (Extracellular Fluid) [g] and the intracellular fluid volume ICF (Intracellular Fluid) [g] are determined as follows. That is, extracellular fluid volume EC
F and the intracellular fluid volume ICF are calculated based on the equivalent circuit (actually, a distributed constant circuit) shown in FIG.
7) and equation (68). Furthermore, extracellular fluid resistance R _e and the intracellular fluid resistance R _i is bioelectrical impedance R∞ by equation (69) and formula of infinite frequency when the bioelectrical impedance R0 and probe current at frequency 0Hz of probe current ( 70). The constants a and b (in units of [g · Ω / cm ² ]) in the equations (67) and (68) are obtained by calculating the lean body mass LBM from the extracellular fluid volume ECF and the intracellular fluid volume ICF. 71), the constant c of the equation (71) (unit is [g · Ω
/ Cm ² ]), a sample survey is conducted in advance on a large number of subjects by a measurement method using X-rays typified by, for example, Dual Energy X-ray Absorptiometry (DXA). The precisely measured lean body mass LBM is determined by multiple regression analysis as a dependent variable.

[0006]

ECF = aH ² / R _e (67) In equation (67), R _e [Ω] is the extracellular fluid resistance and H
[Cm] is the height of the subject, and a [g · Ω / cm ² ] is a constant.

[0007]

ICF = bH ² / R _i (68) In equation (68), R _i [Ω] is an intracellular fluid resistance, H
[Cm] is the height of the subject, and b [g · Ω / cm ² ] is a constant.

[0008]

R _e = R 0 (69)

[0009]

R _i = 1 / (1 / R∞1 / 1 / R0) (70)

[0010]

LBM = aH ² / R _e + bH ² / R _i + c (71)

[0011]

In the conventional method for estimating body composition disclosed in Japanese Patent Application No. 8-176448, the extracellular fluid ECF is calculated based on equations (67) and (68). And determine the intracellular fluid volume ICF,
The resulting ratio ECF: ICF is 1: 1 or 2: 1 on average. However, the ratio ECF: ICF conventionally proposed in physiology, anatomy, or cytology is 1:
2. Therefore, the ratio ECF: ICF obtained by the conventional body composition estimation method is significantly different from the ratio ECF: ICF in physiology, anatomy, or cytology. Therefore, the ratio is estimated based on the bioelectric impedance method. Data such as body water distribution (extracellular fluid volume, intracellular fluid volume, body water volume (body fluid volume), etc.) and body fat status (body fat percentage, fat weight, lean body mass, etc.) In the field of anatomy and cytology, there is a problem that sufficient reliability cannot be obtained.

The present invention has been made in view of the above circumstances, and the ratio between the extracellular fluid volume and the intracellular fluid volume is substantially equal to the ratio conventionally proposed in physiology, anatomy and cytology. It is an object of the present invention to provide a highly reliable body composition estimation method, a body composition estimation device, and a recording medium recording a body composition estimation program.

[0013]

In order to solve the above-mentioned problems, a body composition estimating method according to the present invention is characterized in that a multi-frequency probe current is applied to a subject's body to thereby obtain a frequency of the subject's body. Calculating the bioelectrical impedance at 0 Hz and at infinite frequency, and estimating at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body using Equation (72) or Equation (73). It is characterized by.

[0014]

[Equation 72]

[0015]

[Equation 73] ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at 0 Hz frequency RＨｚ: bioelectric impedance at infinite frequency A, B, Λ :constant

In the body composition estimating method according to the second aspect of the present invention, a multi-frequency probe current is applied to the subject's body to calculate the bioelectric impedance of the subject's body at a frequency of 0 Hz and at an infinite frequency. , Equation (74), Equation (7)
5) or the formula (75) ′ and the formulas (76) to (78) are used to estimate at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body.

[0017]

[Equation 74]

[0018]

[Equation 75]

[0019]

[Equation 76]

[0020]

ECF = AH ² / R _e (77)

[0021]

ICF = BH ² / R _i (78) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at a frequency of 0 Hz R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, Λ: constants

According to a third aspect of the present invention, there is provided the body composition estimating method according to the first or second aspect, wherein the constant Λ is calculated by the following equation (7).
It is characterized in that the calculation is performed again using 9).

[0023]

[Expression 79] In equation (79), X is a multiple regression analysis of the subject's body weight, lean body mass, extracellular fluid volume, intracellular fluid volume, or a combination thereof, obtained as a result of conducting a sample survey on a large number of subjects in advance. This is the amount required by

According to a fourth aspect of the present invention, there is provided a body composition estimating method comprising: applying a multi-frequency probe current to a subject's body to calculate a bioelectric impedance of the subject's body at a frequency of 0 Hz and at an infinite frequency. , Equations (80) to (8)
It is characterized in that the extracellular fluid volume and the intracellular fluid volume of the subject's body satisfying 2) are calculated.

[0025]

[Equation 80]

[0026]

[Equation 81]

[0027]

(Equation 82) ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C , Λ: Constant

According to a fifth aspect of the present invention, there is provided a body composition estimating method, wherein a multi-frequency probe current is applied to a subject's body to calculate a bioelectric impedance of the subject's body at a frequency of Hz and at an infinite frequency. , Expression (83), Expression (8)
4) or the formula (84) ′, and the extracellular fluid volume and intracellular fluid volume of the subject's body that satisfy the formulas (85) to (88) are characterized.

[0029]

[Equation 83]

[0030]

[Equation 84]

[0031]

[Equation 85]

[0032]

[Equation 86]

[0033]

ECF = AH ² / R _e (87)

[0034]

ICF = BH ² / R _i (88) ECF: Volume of extracellular fluid in the subject's body ICF: Volume of intracellular fluid in the subject's body H: Height of the subject R0: Bioelectric impedance at 0 Hz frequency R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, C, Λ: constants

According to a sixth aspect of the present invention, there is provided the method for estimating body composition according to any one of the first to fifth aspects, wherein the constants A, B, C and Λ are determined for each gender and / or age. It is characterized by having.

In the body composition estimating method according to the present invention, a multi-frequency probe current is applied to the subject's body to calculate the bioelectric impedance of the subject's body at a frequency of 0 Hz and at an infinite frequency. It is characterized in that the formulas (89) to (91), which are recurrence formulas, are solved by an iterative method to calculate the extracellular fluid volume and the intracellular fluid volume of the body of the subject.

[0037]

[Equation 89]

[0038]

[Equation 90]

[0039]

[Equation 91] ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C :constant

In the method of estimating body composition according to the present invention, a multi-frequency probe current is applied to the body of the subject, and the bioelectric impedance of the body of the subject at the frequency Hz and at the infinite frequency is calculated. (92), (93), (94) or (9)
4) ′, wherein equations (95) to (97) are solved by an iterative method to calculate the extracellular fluid volume and intracellular fluid volume of the subject's body.

[0041]

(Equation 92)

[0042]

[Equation 93]

[0043]

[Equation 94]

[0044]

[Equation 95]

[0045]

ECF _{n + 1} = AH ² / R _en (96)

[0046]

ICF _{n + 1} = BH ² / R _in (97) ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: at frequency of 0 Hz bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, C, Λ: constants

According to a ninth aspect of the present invention, there is provided the body composition estimating method according to any one of the first to eighth aspects, wherein the constant Λ is the thickness of the muscle fiber of the muscle of the subject or the thickness of the fascia. It has a relationship with the thickness, and is characterized in that the current flows through the intracellular fluid substantially at a saturated length.

According to a tenth aspect of the present invention, in the body composition estimation method, a multi-frequency probe current is applied to a subject's body to calculate the bioelectric impedance of the subject's body at a frequency of 0 Hz and at a frequency of infinity. , Eqs. (98) to (102) are used to estimate at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body.

[0049]

[Equation 98]

[0050]

[Equation 99]

[0051]

[Equation 100]

[0052]

ECF = AH ² / R _e (101)

[0053]

ICF = BH ² / R _i (102) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at a frequency of 0 Hz R∞: bioelectrical impedance at infinite frequency R _e : extracellular fluid resistance R _i : intracellular fluid resistance R _m : cell membrane resistance A, B: constant

[0054] The invention of claim 11 wherein relates to body composition estimation method of claim 10, wherein the constant A, B and cell membrane resistance R _m, as characterized by being defined by different and / or age gender I have.

According to a twelfth aspect of the present invention, there is provided the body composition estimating method according to the tenth aspect, wherein the cell membrane resistance R _m is a function of the intracellular fluid resistance R _{i and} the extracellular fluid volume of the subject's body. It is characterized in that the constant of the function is determined so that the ratio ECF: ICF between the ratio and the intracellular fluid volume is 1: 2.

According to the thirteenth aspect of the present invention,
2. According to the method for estimating body composition according to any one of (2) and (13), the lean body mass LB of the subject's body is calculated by using equation (103).
M is also estimated.

[0057]

LBM = a ₁ W + ECF + ICF + d ₁ (103) LBM: lean body mass of the subject's body ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body W: subject's weight a ₁ , d ₁ : constant

According to a fourteenth aspect of the present invention, there is provided the body composition estimating apparatus according to the thirteenth aspect, wherein the lean body mass LBM given by the equation (103) is subtracted from the weight W of the subject. It is characterized in that the body fat weight FAT is also calculated.

According to the fifteenth aspect, the present invention is characterized in that
According to the body composition estimation method described in any one of (4) and (4), the body fluid amount TBW of the subject's body is also estimated using Expression (104).

[0060]

TBW = a ₃ W + ECF + ICF + d ₃ (104) TBW: body fluid volume of subject W: weight of subject a ₃ , d ₃ : constant

The body composition estimating apparatus according to the invention of claim 16 generates a multi-frequency probe current, and applies the generated probe current of each frequency to the body of the subject so that the frequency of the subject is 0 Hz and Using the bioelectric impedance measuring means for measuring the bioelectric impedance at the infinite frequency, the height input means for inputting the height H of the subject, and the body of the subject using formula (105) or (106) And estimating means for estimating at least one of the extracellular fluid amount and the intracellular fluid amount.

[0062]

[Equation 105]

[0063]

[Equation 106] ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at 0 Hz frequency RＨｚ: bioelectric impedance at infinite frequency A, B, Λ :constant

A body composition estimating apparatus according to a seventeenth aspect of the present invention generates a multi-frequency probe current, and applies the generated probe currents of each frequency to the body of the subject so that the frequency of the subject is 0 Hz. Bioelectric impedance measuring means for measuring bioelectric impedance when the frequency is infinite, height input means for inputting the height H of the subject, and formula (107), formula (108) or formula (10)
8) ′, an extracellular fluid volume / intracellular fluid volume estimating means for estimating at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body using the equations (109) to (111). It is characterized by comprising.

[0065]

[Equation 107]

[0066]

[Equation 108]

[0067]

(Equation 109)

[0068]

ECF = AH ² / R _e (110)

[0069]

ICF = BH ² / R _i (111) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at a frequency of 0 Hz R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, Λ: constants

The invention according to claim 18 relates to the body composition estimating apparatus according to claim 16 or 17, wherein the constant Λ is recalculated using the equation (112).

[0071]

[Equation 112] In the formula (112), X is a multiple regression analysis of the subject's body weight, lean body mass, extracellular fluid amount, intracellular fluid amount, or a combination thereof, which is obtained as a result of conducting a sample survey on a large number of subjects in advance. This is the amount required by

The body composition estimating apparatus according to the nineteenth aspect of the present invention generates a multi-frequency probe current, and applies the generated probe current of each frequency to the subject's body when the subject's body frequency is 0 Hz. Bioelectric impedance measuring means for measuring the bioelectric impedance at infinite frequency, height input means for inputting the height H of the subject, and the body of the subject satisfying the equations (113) to (115) An extracellular fluid volume / intracellular fluid volume estimating means for calculating the extracellular fluid volume and the intracellular fluid volume is provided.

[0073]

[Equation 113]

[0074]

[Equation 114]

[0075]

[Equation 115] ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C , Λ: Constant

According to a twentieth aspect of the present invention, the body composition estimating apparatus generates a multi-frequency probe current, and applies the generated probe currents of each frequency to the body of the subject to be used when the frequency of the body of the subject is 0 Hz. Bioelectric impedance measuring means for measuring bioelectric impedance at infinite frequency, height input means for inputting the height H of the subject, and formula (116), formula (117) or formula (11)
7) ′, an extracellular fluid volume / intracellular fluid volume estimating means for calculating the extracellular fluid volume and the intracellular fluid volume of the subject's body that satisfies the equations (118) to (121). It is characterized by.

[0077]

[Equation 116]

[0078]

[Formula 117]

[0079]

[Equation 118]

[0080]

[Equation 119]

[0081]

ECF = AH ² / R _e (120)

[0082]

ICF = BH ² / R _i (121) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at a frequency of 0 Hz R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, C, Λ: constants

According to a twenty-first aspect of the present invention, there is provided the body composition estimating apparatus according to any one of the sixteenth to twentieth aspects, wherein the constants A, B, C and Λ are determined for each gender and / or age. It is characterized by having.

The body composition estimating apparatus according to the twenty-second aspect of the present invention generates a multi-frequency probe current, and applies the generated probe current of each frequency to the subject's body when the subject's body frequency is 0 Hz. Bioelectric impedance measuring means for measuring bioelectric impedance when the frequency is infinite, and height input means for inputting the height H of the subject, and equations (122) to (12), which are recurrence equations, respectively.
It is characterized by comprising extracellular fluid volume / intracellular fluid volume estimation means for calculating the extracellular fluid volume and intracellular fluid volume of the subject's body by solving 4) by an iterative method.

[0085]

[Equation 122]

[0086]

[Equation 123]

[0087]

[Equation 124] ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C :constant

The body composition estimating apparatus according to the twenty-third aspect of the present invention generates a multi-frequency probe current, and applies the generated probe current of each frequency to the body of the subject to be used when the frequency of the body of the subject is 0 Hz and Bioelectric impedance measuring means for measuring bioelectric impedance when the frequency is infinite, height input means for inputting the height H of the subject, and recurrence formulas (125) and (12)
5), Equation (126) or Equation (126) ′, Equation (127)
(130) is characterized by an extracellular fluid / intracellular fluid estimating means for calculating the extracellular fluid volume and intracellular fluid volume of the subject's body by solving equation (130) by an iterative method.

[0089]

[Equation 125]

[0090]

[Equation 126]

[0091]

[Equation 127]

[0092]

[Equation 128]

[0093]

(129) ECF _{n + 1} = AH ² / R _en (129)

[0094]

ICF _{n + 1} = BH ² / R _in (130) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: at a frequency of 0 Hz bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, C, Λ: constants

According to a twenty-fourth aspect of the present invention, there is provided the body composition estimating apparatus according to any one of the sixteenth to twenty-third aspects, wherein the constant Λ is the thickness of the muscle fiber or the fascia of the muscle of the subject's body. It has a relationship with the thickness, and is characterized in that the current flows through the intracellular fluid substantially at a saturated length.

According to a twenty-fifth aspect of the present invention, the body composition estimating apparatus generates a multi-frequency probe current, and applies the generated probe current of each frequency to the body of the subject so that the frequency of the body of the subject is 0 Hz. Using the bioelectric impedance measuring means for measuring the bioelectric impedance at the infinite frequency, the height input means for inputting the height H of the subject, and the body of the subject using equations (131) to (135) And an extracellular fluid / intracellular fluid volume estimating means for estimating at least one of the extracellular fluid volume and the intracellular fluid volume.

[0097]

[Equation 131]

[0098]

(Equation 132)

[0099]

[Equation 133]

[0100]

ECF = AH ² / R _e (134)

[0101]

ICF = BH ² / R _i (135) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at a frequency of 0 Hz R∞: bioelectrical impedance at infinite frequency R _e : extracellular fluid resistance R _i : intracellular fluid resistance R _m : cell membrane resistance A, B: constant

[0102] The invention of claim 26 wherein relates to body composition estimating apparatus according to claim 25, wherein the constant A, B and cell membrane resistance R _m, as characterized by being defined by different and / or age gender I have.

[0103] The invention of claim 27 wherein relates to body composition estimating apparatus according to claim 25, wherein said cell membrane resistance R _m is a function of the intracellular fluid resistance R _i, extracellular fluid volume of the subject's body It is characterized in that the constant of the function is determined so that the ratio ECF: ICF between the ratio and the intracellular fluid volume is 1: 2.

According to a twenty-eighth aspect of the present invention, there is provided the body composition estimating apparatus according to any one of the sixteenth to twenty-seventh aspects, wherein a weight inputting means for inputting the weight W of the subject and a formula (136) are provided. Using the lean body mass LB of the subject's body
And a lean mass estimating means for estimating M.

[0105]

LBM = a ₁ W + ECF + ICF + d ₁ (136) LBM: lean body mass of the subject's body ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body W: subject's weight a ₁ , d ₁ : constant

According to a twenty-ninth aspect of the present invention, there is provided the body composition estimating apparatus according to the twenty-eighth aspect, wherein the lean body mass LBM given by the equation (136) is subtracted from the weight W of the subject. It is characterized by comprising a body fat weight calculating means for calculating a body fat weight FAT.

According to a thirtieth aspect of the present invention, there is provided the body composition estimating apparatus according to any one of the sixteenth to twenty-ninth aspects, wherein a weight input means for inputting the weight W of the subject and a formula (137) are provided. And a body fluid volume estimating means for estimating the body fluid volume TBW of the body of the subject.

[0108]

TBW = a ₃ W + ECF + ICF + d ₃ (137) TBW: body fluid volume of subject W: weight of subject a ₃ , d ₃ : constant

The storage medium according to claim 31 is:
A computer is stored with a body composition estimation program for realizing the function according to any one of claims 1 to 30.

[0110]

In the configuration of the present invention, a multi-frequency probe current is applied to the body of the subject to calculate the bioelectric impedance of the body of the subject at the frequency of 0 Hz and at the frequency of infinity. At least one of the extracellular fluid volume and the intracellular fluid volume of the body of the subject in consideration of Λ is estimated. Therefore, according to the configuration of the present invention, the ratio between the extracellular fluid volume and the intracellular fluid volume is determined by physiology, anatomy,
The ratio is almost equal to the ratio conventionally proposed in cytology, and the reliability is improved.

[0111]

Embodiments of the present invention will be described below with reference to the drawings. The description will be specifically made using an embodiment. A. First Embodiment << Description of Premises In this embodiment, various body composition estimation formulas described later are used. Therefore, first, the process of deriving these estimation formulas will be described. First, we describe a method of deriving the estimation formulas of the extracellular fluid resistance R _e and the intracellular fluid resistance R _i. In this embodiment, as shown in FIG.
c and Hp are applied to the back Ha of the subject E by two surface electrodes L
p and Lc were adhered to the instep part Le on the same side of the subject E via conductive cream (at this time, the surface electrode H
c, Lc are attached to a portion farther from the center of the human body than the surface electrodes Hp, Lp), and then a multi-frequency current Ib is passed from the body composition estimation device 4 to the body E of the subject as a measurement signal, and the detected multi-frequency current Based on Ib and the voltage Vp between the limbs of the subject, the body water distribution (extracellular fluid volume, intracellular fluid volume, body fluid volume, etc.) and the state of body fat (body fat percentage, fat weight, lean body mass) of the subject E Etc.). In this case, since the multi-frequency current Ib mainly flows through the limbs of the subject's body E, the multi-frequency current Ib has a large effect on the various data values of the limb muscles of the subject's body E. The cells of the muscles of the limbs are not round, but long in the direction of the muscle fibers, and have a so-called cable-like shape. Therefore, in this embodiment, the change in the membrane potential applied to one point of the nerve fiber is caused by the change in the potential (electrotonic spread) in the electrotonic spread which spreads on both sides along the nerve fiber according to the electrical properties of the membrane. Electrotonic potenti
al) is similar to the nature of the potential change applied to one point of the submarine cable, so the nerve fiber structure is made of a tube made of a membrane with relatively low electrical conductivity (cell membrane: insulating coating)
Is filled with a liquid with relatively good electrical conductivity (intracellular protoplasm: copper wire), and is immersed in an electrolyte (extracellular fluid: seawater). We will apply the cable theory, which focuses on the similarity between the shape of the cells of the muscles of the limbs and the shape of the nerve fibers. For details of the cable theory, see “Physiology” (Hidenobu Majima, Bunkodo, pp. 34-
See 41).

When this cable theory is applied to a body composition estimating method, an equivalent circuit of a limb muscle cell is shown in FIG.
In FIG. 3, I is the total current flowing through the muscle cells of the limbs,
V is the voltage applied to all cells of the limb muscle of length L,
r _e is the extracellular fluid resistance per unit length, r _i is the unit intracellular fluid resistance per length, r _m is the cell membrane resistance per unit length, c _m is the cell membrane capacitance per unit length, i ( x) is the current flowing in the extracellular fluid at a distance x from the midpoint x = 0 of the limb muscle cell, and V _e (x) is the extracellular current at a position x away from the midpoint x = 0. The potential of the fluid (V _e (0) = 0) and V _i (x) are the potentials of the intracellular fluid (V
_i (0) = 0). According to such an equivalent circuit,
The differential equations shown in Expressions (138) to (140), that is,
A differential equation relating to the voltage drop in the extracellular fluid (formula (1)
38)), a differential equation relating to the voltage drop in the intracellular fluid (Equation 139) and a differential equation relating to the current flowing from the extracellular fluid through the cell membrane to the intracellular fluid (Equation (140))
Holds.

[0113]

138

[0114]

139

[0115]

[Equation 140] In the equation (140), g _m is the cell membrane admittance per unit length, and is represented by the equation (141).

[0116]

[Equation 141]

From equations (138) and (139), equation (142) is obtained.

[0118]

[Equation 142] In equation (142), it is assumed that 2i (x) is replaced by the total current I.

On the other hand, when formula (140) is transformed, formula (1)
43) is obtained.

[0120]

[Equation 143]

Therefore, when equation (142) is substituted for the result of differentiating equation (143) with respect to x, equation (144) is obtained.

[0122]

[Equation 144]

By solving equation (144), equation (145) is obtained. In Expression (145), λ is represented by Expression (146). Further, in equation (145), C ₁ and C ₂ are integration constants.

[0124]

[Equation 145]

[0125]

[Equation 146]

Here, since I is represented by equation (147), equation (145) becomes equation (148) in consideration of the symmetry at x = 0.

[0127]

147

[0128]

[Equation 148]

As described above, the potential V _e (± L / 2) of the extracellular fluid at both ends of the limb muscle cells, ie, at x = −L / 2 and x = L / 2, is from x = 0 to x = This is obtained by multiplying the integral of the current i (x) flowing through the extracellular fluid up to ± L / 2 by the intracellular resistance per unit length _re, and is therefore expressed by equation (149).

[0130]

149

Thus, the voltage V applied to all the cells of the muscles of the limbs having the length L can be obtained by the equation (150).

[0132]

[Equation 150]

Therefore, the bioelectrical impedance Z of the whole muscle cell of the limb of length L can be obtained by equation (151).

[0134]

[Equation 151]

Here, λ is a function λ (ω) of the angular frequency, and the limit values when ω = 0 and ω = ∞ are expressed by the equations (152) and (153), respectively. The bioelectrical impedance R0 of the multi-frequency current Ib at the frequency of 0 Hz and the bioelectrical impedance R∞ of the multifrequency current Ib at the infinite frequency are expressed by the following equation (151).
2) and Equation (153) are substituted into Equation (15).
4) and equation (156).

[0136]

[Equation 152] In Expression (152), the limit value of λ (ω) when ω = 0 is λ ₀ . Since λ ₀ corresponds to the length constant of the cell membrane in the cable theory, it will be referred to as a length constant hereinafter. Here, in the cable theory, the length constant is a constant that defines the extent to which the change in the membrane potential in the electrotonic propagation propagates.
On the other hand, in the present invention, the length constant λ ₀ is related to the thickness of the muscle fibers of the muscles of the limbs of the subject's body E, the thickness of the fascia, and the like, and the length at which the current flowing through the intracellular fluid is almost saturated. It is considered.

[0137]

[Equation 153]

[0138]

[Equation 154] In Expression (154), ξ is expressed by Expression (155).

[0139]

[Equation 155]

[0140]

[Equation 156]

[0141] Here, when the height of the subject and H [cm], the entire length of the cell limbs muscle L, extracellular fluid resistance R _e
And the intracellular fluid resistance R _i are represented by equations (157) to (159), respectively. In Equations (157) to (159), k is the same constant. Because, if the height H of the subject is k times the total length L of the muscle of one limb muscle of the subject, the extracellular fluid resistance _Re and the intracellular fluid resistance _Ri are also unit lengths. This is because it can be regarded as a k multiple of the extracellular fluid resistance r _e and intracellular fluid resistance r _i per.

[0142]

[Equation 157]

[0143]

[Equation 158]

[0144]

[Equation 159]

Here, when the formulas (157) to (159) are modified and substituted into the formulas (154) and (156), the bioelectrical impedance R0 and the multifrequency current Ib at the frequency 0 Hz of the multifrequency current Ib are obtained. The bioelectrical impedance R∞ at the frequency infinity is given by the equation (16)
0) and equation (161).

[0146]

[Equation 160]

[0147]

[Equation 161]

[0148] Next, the equation (160) and (161) solved for the extracellular fluid resistance R _e, the equation (162).
Therefore, in the equation (162), the values other than the intracellular fluid resistance R _i are set as the intermediate variable α, that is, the intermediate variable α is calculated by the equation (163).
Represents, when substituted into equation (161) solved for intracellular fluid resistance R _i, intracellular fluid resistance R _i is represented by the formula (164).

[0149]

[Equation 162]

[0150]

[Equation 163]

[0151]

[Equation 164]

[0152] Substituting the formula (162) by modifying the R _e = [alpha] R _i obtained by replacing the non-intracellular fluid resistance R _i to the intermediate variable α formula (161), the extracellular fluid resistance R _e,
It is represented by equation (165).

[0153]

[Equation 165]

Expression (155) and expression (15) are added to expression (163).
Substituting 7), the intermediate variable α is expressed by Expression (166). In the equation (166), a length constant λ ₀ described later is used.
(K / 2) is also included in the constant C of the calculation formula (182).

[0155]

166

As described above, the extracellular fluid resistance R _e and the intracellular fluid resistance R _i are obtained by applying the cable theory.
Are obtained, and these are expressed by Expression (167) and Expression (16).
By substituting into 8), the extracellular fluid volume ECF and the intracellular fluid volume ICF can be obtained. Equations (167) and (168) are calculated using the body composition estimation equations disclosed in Japanese Patent Application No. 8-176448 (the above equations (67) and (68)).
Reference). In addition, the intracellular fluid resistance R _i may be obtained from the equation (164) ′ obtained by solving the equation (161) for the intracellular fluid resistance R _i .

[0157]

ECF = AH ² / R _e (167) In equation (167), R _e [Ω] is the extracellular fluid resistance and H
[Cm] is the height of the subject, and A [g · Ω / cm ² ] is a constant.

[0158]

ICF = BH ² / R _i (168) In equation (168), R _i [Ω] is the intracellular fluid resistance, and H
[Cm] is the height of the subject, and B [g · Ω / cm ² ] is a constant.

Here, by substituting the equations (164) to (166) into the equations (167) and (168), the extracellular fluid amount ECF and the intracellular fluid amount ICF can be obtained by the equation (169)
And equation (170).

[0160]

169

[0161]

[Equation 170]

Next, how to determine the length constant λ ₀ will be described. Now, let us compare the cells of the muscles of the limbs of the subject to the columns shown in FIG. In FIG. 4, a column having a diameter of 2A is an intracellular fluid, and a portion obtained by removing the intracellular fluid from a column having a diameter of 2B is an extracellular fluid. Here, the resistivity of the subject's intracellular fluid is ρ
_i [Ω · cm], the resistivity of the extracellular fluid of the subject ρ _e [Ω ·
and cm], for simplicity of description, assuming that they are equal, the unit intracellular fluid resistance r _i and extracellular fluid resistance r _e of the per unit length, respectively formula (171) and (17
It is represented by 2).

[0163]

[Equation 171]

[0164]

[Equation 172]

Here, the cell membrane resistance per unit area is represented by r
When _ma, cell membrane resistance r _m per unit length is expressed by the formula (173).

[0166]

173

Therefore, the length constant λ ₀ is given by the equation (15)
When Expressions (171) to (173) are substituted into 2), Expression (174) is obtained.

[0168]

[Equation 174]

By the way, as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-176448, the whole human body is disclosed as a column.
In cells of the muscle limb of the subject shown in the cross-sectional area [pi (B ² occupied by the extracellular fluid volume ECF _m and extracellular fluid volume ECF _m -
A ₂ ) and the cell length L, and the cross-sectional area πA ₂ occupied by the intracellular fluid volume ICF _m and the intracellular fluid volume ICF _m and the cell length L
Have the relationships shown in equations (175) and (176), respectively.

[0170]

[Equation 175]

[0171]

176

Further, the body fluid volume TBW (To
tal Body Water) _m is the sum of the extracellular fluid volume ECF _m and intracellular fluid volume ICF _m, body fluid volume TBW _m and body fluid volume TB
There is a relationship shown in equation (177) between the cross-sectional area πB ₂ occupied by W _m and the length L of the cell.

[0173]

177

Therefore, Expressions (175) to (177)
Is substituted into equation (174), the length constant λ
₀ is represented by equation (178).

[0175]

178

Here, physiology, anatomy, or cytology
Extracellular fluid volume ECF proposed in the past_mAnd intracellular
Liquid volume ICF_mIs 1: 2, so the extracellular fluid volume
ECF _mAnd intracellular fluid volume ICF_mAre, respectively, the equations (17)
9) and equation (180).

[0177]

179

[0178]

[Equation 180]

Therefore, equation (179) is replaced by equation (179).
And the equation (180), the length constant λ ₀ is represented by the equation (181).

[0180]

[Equation 181]

Considering equation (181) for the entire human body of the subject, the length constant λ ₀ is expressed by equation (182).

[0182]

[Equation 182] In Expression (182), C is a constant including the constant (k / 2) in Expression (166) described above.

The other formulas for estimating body composition are the same as those disclosed in Japanese Patent Application No. 10-076004 filed by the applicant of the present invention, which are obtained by using the above formulas (167) and (16).
8) or substitute the extracellular fluid volume ECF and intracellular fluid volume ICF determined by equations (169) and (170). For example, equation (183) is used for the body composition estimation formula for estimating the lean body mass LBM of the subject, and equation (184) is used for the body composition estimation equation for estimating the body fluid volume TBW of the subject. For details on the derivation of these body composition estimation formulas, refer to Japanese Patent Application No. 10-076004. However, in the Patent above Japanese Patent Application 10-076004, extracellular fluid resistance R _e and the intracellular fluid resistance R _i is
The respective reciprocals 1 / Y _e and 1 / Y _i are used.

[0184]

LBM = a ₁ W + ECF + ICF + d ₁ (183) LBM: lean body mass of subject W: subject weight a ₁ , d ₁ : constant

[0185]

TBW = a ₃ W + ECF + ICF + d ₃ (184) TBW: body fluid volume of subject W: body weight of subject a ₃ , d ₃ : constant

FIG. 1 is a block diagram showing an electrical configuration of a body composition estimating apparatus according to a first embodiment of the present invention, and FIG.
FIG. 5 is a schematic diagram schematically illustrating a use state of the device, FIG. 5 is a diagram illustrating an impedance locus of a human body, FIG. 6 is a flowchart illustrating an operation processing procedure of the device, and FIG. 7 is a diagram illustrating the same operation. 8 is a timing chart, and FIG. 8 is a diagram showing another display example of the display device in the same device. The body composition estimating device 4 of this example relates to a device that measures the extracellular fluid volume ECF, the intracellular fluid volume ICF, the body fluid volume TBW, the lean body mass LBM, the fat mass FAT, and the like, and displays the measurement result. As shown in FIGS. 1 and 2, a signal output circuit 5 for flowing a multi-frequency current Ib as a measurement signal to the body E of the subject, and a current detection circuit for detecting the multi-frequency current Ib flowing through the body E of the subject 6, a voltage detection circuit 7 for detecting a voltage Vp between the limbs of the subject, a keyboard 8 as an input device, and a display 9 as an output device.
CPU that controls each part of the device and performs various arithmetic processing
(Central processing unit) 10, ROM 11 for storing a processing program of CPU 10, RAM for setting a data area for temporarily storing various data and a work area for CPU 10
12 and four surface electrodes H that are conductively attached to the skin surface of the subject's back part Ha and foot part Le during measurement.
It is roughly composed of p, Hc, Lp, and Lc.

First, the keyboard 8 includes a numeric keypad and function keys for inputting the height, weight, and gender of the subject, a mode selection key for selecting one of the body fluid measurement mode and the body fat measurement mode, and an operator (or (A subject) has a start / end switch for instructing measurement start / measurement end and the like. Operation data and data such as height, weight, and gender supplied from the keyboard 8 are converted into key codes by a key code generation circuit (not shown), and
Supplied to The CPU 10 temporarily stores in the data area of the RAM 12 various operation signals and various data such as height, which have been input with a code. In this example, in the body fat measurement mode, the entire measurement period Tf and the number of sweeps N of the measurement signal Ia described later are input. In the body fluid volume measurement mode, the total measurement time Tw, the measurement interval t, and the number of sweeps N are input, and the total measurement time Tw is, for example, 4 in consideration of a time sufficient for monitoring the artificial dialysis. .5 hours, 5.5 hours, 5.5 hours, 6 hours, 6.5 hours, and 7 hours, and the measurement interval t can be arbitrarily selected from 10 minutes, 20 minutes, and 30 minutes. Has become. This allows
During the entire measurement time Tw, the temporal change of the body fluid volume TBW of the subject is measured. As described above, the operator may be allowed to freely set the time Tw, t using the keyboard 8 instead of selecting from several given times.

The signal output circuit 5 includes a PIO (parallel interface) 51, a measurement signal generator 52, and an output buffer 53. Measurement signal generator 52
Is the CPU 10 via the PIO 51 at a predetermined sweep cycle.
When the signal generation instruction signal SG is supplied from the
For example, in the range of 1 kHz to 400 kHz and 15 kHz
Measurement signal (current) Ia that changes stepwise at a frequency interval of Hz
Are repeatedly generated over a predetermined number of sweeps N and input to the output buffer 53. The output buffer 53 sends the input measurement signal Ia to the surface electrode Hc as a multi-frequency current Ib while keeping the input measurement signal Ia in a constant current state. This surface electrode Hc is conductively attached to the back Ha of the subject at the time of measurement, so that a multi-frequency current Ib in the range of 500 to 800 μA flows through the body E of the subject. In the body fluid measurement mode, the supply cycle of the signal generation instruction signal SG is determined by the operator using the keyboard 8.
Coincides with the measurement interval t set using

The current detection circuit 6 includes an I / V converter (current / voltage converter) 61, a BPF (bandpass filter)
62, an A / D converter 63 and a sampling memory 64. The I / V converter 61 flows between the body electrode Ec of the subject, that is, between the surface electrode Hc affixed to the back Ha of the subject (FIG. 2) and the surface electrode Lc affixed to the instep Le. The multi-frequency current Ib is detected and converted into a voltage Vb, and the voltage Vb obtained by the conversion is
Supply to F62. The BPF 62 receives the input voltage Vb
Of these, the voltage is supplied to the A / D converter 63 only through a voltage signal in a band of approximately 1 kHz to 400 kHz. The A / D converter 63 converts the analog input voltage Vb to a digital voltage signal Vb according to a digital conversion instruction issued by the CPU 10.
After the conversion, the digitized voltage signal Vb is used as the current data Vb and the measurement signal Ia
Is stored in the sampling memory 64 for each frequency of. Further, the sampling memory 64 is constituted by an SRAM, and outputs a digital voltage signal Vb temporarily stored for each frequency of the measurement signal Ia to the CPU 10 in response to a request from the CPU 10.
Send to 10.

The voltage detection circuit 7 includes a differential amplifier 71, a BP
An F (band pass filter) 72, an A / D converter 73, and a sampling memory 74 are provided. The differential amplifier 71 detects a voltage (potential difference) between the surface electrode Hp attached to the body E of the subject, that is, the surface electrode Hp attached to the back of the subject Ha and the surface electrode Lp attached to the instep Le. .
The BPF 72 has a frequency of approximately 1 kHz of the input voltage Vp.
A / D through only the voltage signal in the band of ~ 400 kHz
It is supplied to the converter 73. The A / D converter 73 is a CPU 1
After converting the analog input voltage Vp into a digital voltage signal Vp in accordance with a digital conversion instruction issued by a digital signal 0, the digitized voltage signal Vp is used as voltage data Vp.
The data is stored in the sampling memory 74 for each sampling period and for each frequency of the measurement signal Ia. The sampling memory 74 is composed of an SRAM, and stores a digital voltage signal Vp temporarily stored for each frequency of the measurement signal Ia into a CP.
It is sent to the CPU 10 in response to the request of U10. In addition,
The CPU 10 issues a digital conversion instruction to the two A / D converters 63 and 73 at the same timing.

The ROM 11 includes, as processing programs for the CPU 10, a main program, a bioelectric impedance calculating subprogram, an impedance locus calculating subprogram, a frequency 0 Hz impedance determining subprogram, a frequency infinity impedance determining subprogram, and an intermediate program. Variable calculation subprogram, extracellular fluid resistance calculation subprogram, intracellular fluid resistance calculation subprogram, extracellular fluid volume estimation subprogram, intracellular fluid volume estimation subprogram, length constant calculation subprogram, lean body mass estimation subprogram , A body fat weight estimation subprogram, a body fat percentage estimation subprogram, a body fluid amount estimation subprogram, a body fluid amount-fat free weight ratio calculation subprogram, a body fluid amount deviation calculation subprogram, and the like. Also, RO
In M11, the body fluid volume TBWS _S in a normal state of the body of a normal healthy person, which has been statistically processed in advance, is represented by the lean body mass LBM _S.
Numerical data obtained by dividing by the normal body fluid amount-fat free weight ratio (T
BW _S / LBM _S ) is registered in advance. Various programs are read into the CPU 10 from the ROM 11 and control the operation of the CPU 10. The recording medium for recording these subprograms is not limited to a semiconductor memory such as the ROM 11, but may be an FD (floppy disk) or an HD.
It may be recorded on a magnetic disk such as a (hard disk) or an optical disk such as a CD-ROM.

Here, the bioelectrical impedance calculation subprogram stores the sampling memory 6 in the CPU 10.
The processing procedure for sequentially reading out the current data and the voltage data for each frequency stored in the storage devices 4 and 74 and calculating the bioelectric impedance of the subject for each frequency is written. As described in the “Prior Art” section, the cell membranes 2, 2,... Can be regarded as large-capacity capacitors. Therefore, when the externally applied current is low in frequency, the solid lines A, As shown by A,..., Only the extracellular fluid 3 flows. However, as the frequency increases, the current flowing through the cell membranes 2, 2,... Increases, and when the frequency becomes very high, as shown by broken lines B, B,. To flow through. The impedance locus calculation subprogram includes the CPU 10
A processing procedure for calculating an impedance locus from a frequency of 0 Hz to a frequency infinity in accordance with the least squares method based on the subject's bioelectric impedance for each frequency obtained by running the bioelectric impedance calculation subprogram Is written. In the column of "Prior Art", cells in a human body tissue are represented by a simple electrical equivalent circuit (FIG. 15), but in an actual human body tissue, cells of various sizes are irregularly arranged. Therefore, the actual impedance trajectory of the human body is an arc whose center is higher than the real axis (X axis) as shown by the solid line D in FIG.

The impedance determination subprogram at the frequency of 0 Hz and the impedance determination subprogram at the infinite frequency are respectively provided to the CPU 10 based on the impedance locus obtained by the operation of the impedance locus calculation subprogram.
The procedure for determining the bioelectrical impedances R0 and R∞ at Hz and at infinity is written. In the intermediate variable calculation subprogram, the bioelectrical impedances R0 and R∞ obtained by the operation of the impedance determination subprogram at the frequency of 0 Hz and the impedance determination subprogram at the infinite frequency are input to the CPU 10 via the keyboard 8. A calculation formula (34) for calculating the intermediate variable α based on the height data H of the subject is described. In equation (34), the length constant λ ₀ is previously determined statistically for each gender,
11 and the RAM 12. For example, the length constant λ ₀ is 46.3 ± 2.0 for males,
For women, it is assumed to be 21.8 ± 1.0. The extracellular fluid resistance calculation subprogram includes an extracellular fluid resistance based on the bioelectrical impedance R∞ and the intermediate variable α obtained by operating the frequency infinity impedance determination subprogram and the intermediate variable calculation subprogram. calculation formula for calculating the R _e (165) is described. The intracellular fluid resistance calculation subprogram includes a CPU 10
A calculation formula (164) for calculating the intracellular fluid resistance R _i based on the intermediate variable α and the bioelectrical impedance R∞ obtained by the operation of the intermediate variable calculation subprogram and the frequency infinity impedance determination subprogram is executed. It has been described. The intracellular fluid resistance calculation subprogram includes, in the CPU 10, a bioelectrical impedance R obtained by running the infinite frequency impedance determination subprogram and the extracellular fluid resistance calculation subprogram.
内 and the extracellular fluid resistance R _e , based on the intracellular fluid resistance R _i
May be described.

The extracellular fluid volume estimation subprogram includes CP
To U10, and extracellular fluid resistance R _e which is obtained by operation of the extracellular fluid resistance calculation subprograms, based on the height data H of the subject input via the keyboard 8, the extracellular fluid volume ECF subjects Estimation formula (16
7) is described. Here, the equation (167) is a regression equation of the extracellular fluid volume ECF obtained as a result of performing a sample survey in advance on a large number of subjects, and the constant A is the extracellular fluid volume ECF by H ² / in one explanatory variable of R _e are those which are derived from a regression analysis. Constant A
Is, for example, in the case of a male, the central value is 356.5, the range 13
5-577, for women, median 475.5, range 28
6 to 686. The intracellular fluid volume estimation subprogram, the CPU 10, the basis of the intracellular fluid resistance R _i obtained by operation of the intracellular fluid resistance calculation subprograms, in the height data H of the subject inputted through the keyboard 8 Thus, an estimation formula (168) for estimating the intracellular fluid volume ICF of the subject is described. Here, equation (16)
8) is a regression formula of the intracellular fluid volume ICF obtained as a result of conducting a sample survey in advance on a large number of subjects, and the constant B
Is determined by regression analysis of the intracellular fluid volume ICF for each gender using one explanatory variable of H ² / R _i . The constant B is, for example, a center value 427 and a range 356 to 497 for men, a center value 354 and a range 3 for women.
11 to 396.

The length constant calculation subprogram includes a CPU
10 shows the extracellular fluid volume E obtained by running the extracellular fluid volume estimation subprogram and the intracellular fluid volume estimation subprogram.
An estimation formula (182) for estimating the length constant λ ₀ based on the CF and the intracellular fluid volume ICF and the height data H of the subject inputted via the keyboard 8 is described. Here, equation (182) is a regression equation of length constant lambda ₀ which is obtained in advance results of sample survey was conducted for a number of subjects, the constant C is the gender, the length constant lambda ₀ (E
(CF + ICF / H) determined by regression analysis with one explanatory variable of ^0.25 . The constant C is, for example, 11 ± 50% for a male and 5.5 ± for a female.
Assume that it is 50%. As described above, this length constant calculation subprogram uses the length constant λ ₀ to calculate the lean body mass LBM and the like estimated using the length constant λ ₀ , although the length constant λ ₀ has been previously calculated statistically. This is a subprogram for accurate estimation. Therefore, when very little precision is required, it may be omitted. The lean mass weight estimation subprogram is transmitted to the CPU 10 via the keyboard 8 via the extracellular fluid volume ECF and intracellular fluid volume ICF obtained by the operation of the extracellular fluid volume estimation subprogram and the intracellular fluid volume estimation subprogram. An estimation formula (183) for estimating the lean body mass LBM of the subject based on the subject's weight data W input as described above is described. Here, equation (1)
83) is a multiple regression equation of lean body mass LBM obtained as a result of conducting a sample survey in advance on a large number of subjects, and constants a ₁ and d ₁ are the lean body mass LBM measured by DXA as W, ECF, It was obtained by performing multiple regression analysis with three explanatory variables of ICF.

The body fat weight estimation subprogram is executed by the CPU.
10, subtracting the lean body mass LBM obtained by the operation of the lean body mass estimation subprogram from the subject's body weight W input via the keyboard 8 to calculate the body fat mass FAT of the subject. The procedure is described. . The body fat percentage estimation subprogram includes CP
A procedure (formula) for causing U10 to calculate the body fat percentage% FAT of the subject based on the lean body mass LBM and the body fat mass FAT obtained by operating the lean body mass estimation subprogram and the body fat mass estimation subprogram. (185))
Is described.

[0197]

% FAT = 100 FAT / (FAT + LBM) (185)

The body fluid volume estimation subprogram includes a CPU 1
0, the extracellular fluid volume EC obtained by running the extracellular fluid volume estimation subprogram and the intracellular fluid volume estimation subprogram
An estimation formula (184) for estimating the body fluid volume TBW of the subject based on F and the intracellular fluid volume ICF and the subject's body weight data W input via the keyboard 8 is described. Here, equation (184) is equivalent to the body fluid volume TB obtained as a result of conducting a sample survey on a large number of subjects in advance.
W is a multiple regression equation, and the constants a ₃ and d ₃ are obtained by performing multiple regression analysis on the body fluid volume TBW measured by DXA with three explanatory variables of W, ECF, and ICF.

The body fluid amount-fat free weight ratio calculation subprogram includes, in the CPU 10, the body fluid amount TBW obtained by running the body fluid volume estimation subprogram and the lean body mass obtained by running the lean body mass estimation subprogram. Based on the LBM, the subject's body fluid-lean mass ratio (TBW / LB)
The procedure for calculating M) is described. Further, the body fluid amount deviation calculation subprogram includes a body fluid amount-fat free weight ratio (TBW / LBM) obtained by operating the body fluid amount-fat free weight ratio calculation subprogram, and a normal set and registered in the ROM 11 in advance. Body fluid volume-lean mass ratio (TBW _S / L
BM _S ), the body fluid amount-fat-free weight ratio deviation Δ (TBW / LBM), which is the difference between the two, is calculated, and further divided into this body fluid amount-lean weight ratio deviation Δ (TBW / LBM). Fluid volume deviation Δ given by multiplying fat weight LBM
A procedure (equation (186)) for calculating TBW is described.

[0200]

ΔTBW = LBM ＝ (TBW / LBM) − (TBW _S / LBM _S )｝ (186)

The data area of the RAM 12 includes, for example, a bioelectric impedance storage area for storing the bioelectric impedance of the subject obtained by the bioelectric impedance calculation subprogram for each frequency, and a keyboard 8.
Height, weight, gender data storage area for storing the height, weight, gender data, etc. of the subject input through the body, and body fat storage for storing numerical values, such as the body fat percentage obtained by the body fat percentage estimation subprogram An area or the like is set.

The CPU 10 controls the various processing programs stored in the ROM 11 and uses the RAM 12
Subject's lean mass LBM, fat weight FAT, body fluid volume T
Processes for estimating BW and the like are sequentially executed. The display 9 includes, for example, a liquid crystal display panel capable of color display, and includes input data from the keyboard 8, calculation results of the CPU 10,
For example, a trend graph relating to a body fluid amount-fat free weight ratio, a body fluid amount deviation, a body fat percentage, an impedance locus (FIG. 8)
(A), (b)), extracellular fluid resistance, intracellular fluid resistance,
The height and weight of the subject are displayed.

Next, the operation of this example will be described. First, prior to the measurement, as shown in FIG. 2, the two surface electrodes Hc and Hp were electrically connected to the back part Ha of the subject, and the two surface electrodes Lp and Lc were connected to the instep part Le on the same side of the subject. Paste via cream (at this time, surface electrode H
c, Lc are attached to a portion farther from the center of the human body than the surface electrodes Hp, Lp). Body composition estimation device 4 having the above configuration
Is used as a monitor during dialysis, for example, the operator (or the subject himself) operates the keyboard 8 of the body composition estimating apparatus 4, operates the mode setting key, and sets the body fluid measurement mode. And the height H and weight W of the subject
And the gender, the total measurement time Tw from the start of measurement to the end of measurement, the measurement interval t (FIG. 7), the number of sweeps N
Set. In this example, it is assumed that the total measurement time Tw is selected to be 7 hours in consideration of a time sufficient to monitor dialysis, and that the measurement interval t is selected to be 30 minutes.
Data and setting values such as height H, weight W, and gender input from the keyboard 8 are stored in the RAM 12.

Next, when the operator (or the subject himself / herself) turns on the start / end switch of the keyboard 8 at the time of the start of dialysis, the CPU 10 operates according to the processing flow shown in FIG. To start. First, in step SP1, the CPU 10 supplies a signal generation instruction signal SG to the measurement signal generator 52 of the signal output circuit 5 via the PIO 51. The measurement signal generator 52 includes a CPU 1
When the signal generation instruction signal SG is received from 0, the driving is started and the frequency is in the range of 1 kHz to 400 kHz and 15 kHz in the predetermined sweep period during the entire measurement time Tw.
The measurement signal Ia which changes stepwise at the frequency interval of z is repeatedly generated and input to the output buffer 53. The output buffer 53 converts the input measurement signal Ia into a constant current state (500
The current is sent to the surface electrode Hc as the multi-frequency current Ib while maintaining the current at a constant value within a range of about 800 μA). Thereby, the multifrequency current Ib of the constant current flows through the body E of the subject from the surface electrode Hc, and the measurement is started.

When the multi-frequency current Ib is supplied to the subject's body E, the multi-frequency current Ib flowing between the limbs to which the surface electrodes Hc and Lc are attached is generated in the I / V converter 61 of the current detection circuit 6. After being detected and converted into an analog voltage signal Vb, it is supplied to the BPF 62. BP
In F62, 1 kHz is selected from the input voltage signal Vb.
Only the voltage signal components in the band of 400 kHz are allowed to pass and supplied to the A / D converter 63. A / D converter 6
In 3, the supplied analog voltage signal Vb is converted into a digital voltage signal Vb, and as current data Vb,
It is stored in the sampling memory 64 for each predetermined sampling period and for each frequency of the measurement signal Ia. In the sampling memory 64, the stored digital voltage signal Vb is
The data is sent to the CPU 10 in response to the request from the PU 10. On the other hand, in the differential amplifier 71 of the voltage detection circuit 7, the voltage Vp generated between the limbs to which the surface electrodes Hp and Lp are attached
Is detected and supplied to the BPF 72. In the BPF 72, a frequency of 1 kHz to 400
Only the voltage signal component in the kHz band is allowed to pass, and A
/ D converter 73. In the A / D converter 73,
The supplied analog voltage signal Vp is converted into a digital voltage signal Vp, and is stored as voltage data Vp in the sampling memory 74 for each predetermined sampling period and for each frequency of the measurement signal Ia. Sampling memory 74
Then, the stored digital voltage signal Vp is
Is sent to the CPU 10 in response to the request. CPU10
Indicates that the number of sweeps of the measurement signal Ia is equal to the specified number of sweeps N
Repeat the above processing until.

When the number of sweeps reaches the designated number N, the CPU 10 performs control to stop the measurement, and then proceeds to step SP2. The current data and the voltage data for each frequency stored in the sampling memories 64 and 74 are sequentially read, and the bioelectric impedance (average value of N times of the number of sweeps) of the subject for each frequency is calculated. The calculation of the bioelectric impedance includes the calculation of its components (resistance and reactance). Next, the CPU 10 activates the impedance locus calculation subprogram, and based on the subject's bioelectric impedance and its components (resistance and reactance) for each frequency obtained by the bioelectric impedance calculation subprogram, uses the least squares method. Is calculated from the frequency 0 Hz to the frequency infinity in accordance with the curve fitting method using. The impedance locus calculated in this way is shown in FIG.
As shown in (b), the center is an arc that is higher than the real axis (X axis).

Next, under the control of the impedance determination subprogram at the frequency of 0 Hz and the impedance determination subprogram at the infinity of the frequency, the CPU 10 determines the frequency at the frequency of 0 Hz and the impedance at the frequency of 0 Hz, respectively, based on the impedance locus obtained by the impedance locus calculation subprogram. The bioelectric impedances R0 and R∞ of the subject at infinity are obtained. In other words, the arc of the impedance locus is
8A and 8B, the points intersecting the X axis are the bioelectrical impedances R0 and R∞ at the frequency of 0 Hz and the infinity, respectively. Then, the CPU 10 stores the calculated bioelectric impedances R0 and R # in the data area of the RAM 12. Next, under the control of the intermediate variable calculation subprogram, the CPU 10 executes the process of calculating the intermediate variable α by using the expression (166), and then controls the expression (165) by the control of the extracellular fluid resistance calculation subprogram. Using,
Processing for calculating the extracellular fluid resistance R _e, and the control of the intracellular fluid resistance calculation subprograms, using equation (164) or formula (164) ', and performs the process of calculating the intracellular fluid resistance R _i . Then, CPU 10 stores the calculated intermediate variable alpha, the extracellular fluid resistance R _e and the intracellular fluid resistance R _i RAM 12
In the data area. Further, the CPU 10 controls the equation (167) by controlling the extracellular fluid volume estimation subprogram.
Is used to calculate the extracellular fluid volume ECF of the subject, and then, by controlling the intracellular fluid volume estimation subprogram, the expression of the subject intracellular fluid volume ICF
Is executed. Further, the CPU 10 controls the expression (182) by controlling the length constant calculation subprogram.
Is used to calculate the length constant λ ₀ .

(A) Body Fluid Volume Measurement Mode Next, the process proceeds to step SP3, where the CPU 10 looks at a mode setting flag (not shown) and determines whether the current mode is the body fluid volume measurement mode or the body fat measurement mode. Find out. Now, since the body fluid measurement mode is set by the operator (or the subject himself), the CPU 10 proceeds to step S
Proceeding to P4, first, a process of estimating the body fluid volume TBW of the subject using the equation (184) is executed under the control of the body fluid volume estimation subprogram. Next, the CPU 10 estimates the lean mass LBM of the subject by using the equation (183) under the control of the lean mass estimation subprogram, and thereafter,
Under the control of the body fluid amount-fat free weight ratio calculation subprogram, the body fluid amount-lean fat weight ratio (TBW / LBM) is calculated. Finally, under the control of the body fluid amount deviation calculation subprogram, the equation (186) is used. Then, the current body fluid deviation ΔTBW of the subject is calculated.

When the above series of calculation processing is completed, the CP
U10 is the calculated extracellular fluid volume ECF, intracellular fluid volume ICF, body fluid volume TBW, lean body mass LBM, body fluid amount-lean body mass ratio (TBW / LBM), body fluid deviation Δ
The RAM 12 stores the TBW and the like
And proceeds to step SP5 to display the trend graph (the elapsed time from the start of dialysis on the horizontal axis as the horizontal axis, the body fluid amount-fat free weight ratio (TBW / LB)
M) is plotted on a line graph with the vertical axis representing M), and the value of the body fluid-lean weight ratio (TBW / LBM) is plotted, and the extracellular fluid volume ECF, the intracellular fluid volume ICF, the body fluid volume TBW, the lean mass The weight LBM and the body fluid amount deviation ΔTBW are displayed on the screen as current data.

Thereafter, the flow advances to step SP6 where the CPU 1
A value of 0 determines whether the entire measurement time Tw (FIG. 7) has elapsed. In this determination, if it is determined that the total measurement time Tw (7 hours in this example) has elapsed, the subsequent measurement processing is terminated. However, since the first measurement has just been completed, the total measurement time has been reached. It is determined that Tw has not yet elapsed, the process proceeds to step SP7, and waits for the elapse of time t (FIG. 6) corresponding to the measurement interval. During this waiting time, the trend graph screen of the display 9 is displayed. Then, when the time t (30 minutes in this example) corresponding to the measurement interval has elapsed, the process returns to step SP1 and returns to step SP1.
Start the second measurement. Then, the above-described processing is repeated until the entire measurement time Tw elapses, that is, until the end of the dialysis.

(B) At the time of body fat measurement mode On the other hand, when the subject is lean body mass LBM, body fat mass FAT,
If you want to measure body fat percentage% FAT,
Prior to the measurement, the operator (or the subject himself / herself) operates the keyboard 8 of the body composition estimation device 4, operates the mode setting key to set the body fat measurement mode, and furthermore, the height H and weight W of the subject. And sex, and the total measurement time Tf and the number of sweeps N are set. Next, when the start / end switch of the keyboard 8 is pressed, C
The PU 10 executes the above-described measurement calculation processing (Step SP1 and Step SP2). And step SP
Proceeding to 3, the CPU 10 checks the mode setting flag and checks whether the current mode is the body fluid measurement mode or the body fat measurement mode. This time, since the body fat measurement mode has been selected, the process proceeds to step SP8, and the CPU 10
Estimates the lean mass LBM of the subject using the equation (183) under the control of the lean mass estimation subprogram. Next, the CPU 10 estimates the fat weight FAT of the subject under the control of the body fat weight estimation subprogram,
Next, under the control of the body fat percentage estimation subprogram, the body fat percentage% FAT is calculated using equation (185).

When the above-described series of calculation processing is completed, the CP
U10 stores the calculated lean body mass LBM, the body fat weight FAT, the body fat percentage% FAT, etc. of the subject in the RAM 12, and in step SP9, as shown in FIG. The display unit 9 displays the fat locus FAT, the body fat percentage FAT, the impedance locus, the extracellular fluid resistance, the height and weight of the subject, and the like. Then, the series of processing ends.

[0213] Here, in FIG. 9, the configuration at the request extracellular fluid volume ECF, divided by the square of H ² height intracellular fluid volume ICF and body fluid volume TBW subject, ECF / H ^2, IC
The F / H ² and TBW / H ² shows a diagram plotting each age. FIG. 9 (a) shows a case of a man and FIG. 9 (b) shows a case of a woman.
² , black □ indicates ICF / H ² value, Δ indicates TBW /
This is the value of H ² . From FIG. 9 it can be seen that the ratio ECF: ICF is approximately equal to the ratio 1: 2 conventionally proposed in physiology, anatomy or cytology. Here, extracellular fluid volume E
The CF, the intracellular fluid volume ICF and the body fluid volume TBW divided by the square of the height of the subject, H ² , are used as an index BMI (Body Mass Index) representing the physique used to determine the presence or absence of obesity.
Divides the subject's weight by the square of his height, H ² , by analogy therewith.

As described above, according to the above configuration, by introducing the length constant λ ₀ by applying the cable theory, the extracellular fluid volume ECF and the intracellular fluid volume IC determined by the above configuration are obtained.
The F ratio ECF: ICF is approximately equal to the ratio 1: 2 conventionally proposed in physiology, anatomy or cytology.
Therefore, reliability is improved.

B. Second Embodiment Next, a second embodiment of the present invention will be described. The configuration of the second embodiment is significantly different from that of the first embodiment in that the intracellular fluid resistance R _i and the extracellular fluid in the processing of step SP2 shown in FIG. The resistance R _e , the intermediate variable α, the extracellular fluid volume ECF, the intracellular fluid volume ICF, and the length constant λ ₀ are calculated by using the formula (164) or (164) ′, the formula (165), the formula (166), and the formula, respectively. (167), the numerical values are substituted into the expressions (168) and (182), and the calculation is performed. In the second embodiment, the above-mentioned six equations are satisfied in the process of step SP2 shown in FIG. Extracellular fluid volume ECF and intracellular fluid volume ICF
Or the following six equations (187) to (192) are solved using an iterative method to calculate the extracellular fluid amount ECF and the intracellular fluid amount ICF. Here, the iterative method refers to a method of obtaining a solution of an equation by repeating a predetermined method one after another, and is repeated until the solution converges to an appropriate initial value for practical use.

[0216]

187

[0219]

188

[0218]

189

[0219]

[Equation 190]

[0220]

[Equation 191]

[0221]

[Equation 192]

In this case, for the constant A [g · Ω / cm ² ], the center value is 500.2961, and the range is 300 to 900.
It is assumed that the constant B [g · Ω / cm ² ] is in the range of 400 to 510 at the center value of 468.1615, and the constant C is in the range of 7 to 9 at the center value of 8.15. . Accordingly, the ROM 11 stores the above-described intermediate variable calculation subprogram, extracellular fluid resistance calculation subprogram, intracellular fluid resistance calculation subprogram, extracellular fluid volume estimation subprogram, and intracellular fluid volume estimation subprogram. And the length constant calculation subprogram, the formula (164) or the formula (164) ′, the formula (165), the formula (1)
66), Expression (167), Expression (168), and Expression (182)
Or a subprogram for calculating the extracellular fluid volume ECF and the intracellular fluid volume ICF by the above-described iterative method. In step SP2 shown in FIG. 6, the CPU 10 calculates the extracellular fluid amount ECF and the intracellular fluid amount ICF under the control of any of the above subprograms. In other respects, the configuration (FIG. 1) and operation (FIG. 6) are substantially the same as those of the first embodiment, and therefore, description thereof will be omitted.

Here, FIG. 10 shows that, in the above configuration, the initial value was (ECF ₀ + ICF ₀ = 0.6 W), the extracellular fluid volume ECF and the intracellular fluid volume ICF were determined by the above iterative method with n = 3. And the body fluid volume TBW is the square of the height of the subject, H ²
Divided by ECF / H ² , ICF / H ² and TBW / H
^The figure which plotted ² for every age is shown. If FIG. 10 (a) is a male, and FIG. 10 (b) is shows the case of women, in each figure, black ◇ mark of ECF / H ² values, black □
Mark value of ICF / H ^2, a △ mark in TBW / H ² value.
From FIG. 10, it can be seen that the ratio ECF: ICF is approximately equal to the ratio 1: 2 conventionally proposed in physiology, anatomy or cytology. Here, the initial value is (ECF ₀ + ICF ₀₎
= 0.6 W) because the body water content TBW (= E
(CF + ICF) is said to be on average 0.6 of body weight W. The reason why n = 3 is that this value is sufficient for practical accuracy.

As described above, according to the above configuration, the length constant λ ₀ need not be determined in advance as in the first embodiment.
Since the extracellular fluid volume ECF and the like can be obtained and the solution can be obtained at one time, substantially the same effects as described in the first embodiment can be obtained, and the processing time can be further reduced. .

C. Third Embodiment Next, a third embodiment of the present invention will be described. The configuration of the third embodiment is significantly different from that of the above-described first and second embodiments. In the first and second embodiments, an electric equivalent circuit of cells in a tissue is shown in FIG. is a and despite being in, but contains the cell membrane resistance r _ma per unit in the formula (182) area about (length constant lambda ₀ not particularly taken into consideration for the effect of cell membrane resistance R _m, constant are to be included in the C) is, in the third embodiment, the electrical equivalent circuit of the tissue cells and is as shown in FIG. 11, and is a point to consider also the influence of cell membrane resistance R _m . Therefore, first, as described above, the ratio ECF between the extracellular fluid volume ECF and the intracellular fluid volume ICF:
Since the ratio of ICF is 1: 2 conventionally proposed in physiology, anatomy, or cytology, the ratio ECF: ICF is also assumed to be 1: 2 in this example. Next, assume that the cell membrane resistance R _m assumes that there is no individual difference, and is a fixed value. Then, in the equivalent circuit diagram shown in FIG. 11, bioelectrical impedance R0 measured at frequency 0Hz, since good ignoring the cell membrane capacitance C _m, the reciprocal is represented by the formula (193). At the infinite frequency, the cell membrane loses its capacitive capacity, and the reciprocal of the measured bioelectrical impedance R∞ is expressed by equation (194).

[0226]

193

[0227]

[Equation 194]

Therefore, equations (193) and (19)
4) and solving for the intracellular fluid resistance R _i, intracellular fluid resistance R _i is represented by the formula (195).

[0229]

[Equation 195] In Expression (195), β is an intermediate variable, and Expression (19)
6).

[0230]

[Equation 196]

[0231] On the other hand, extracellular fluid resistance R _e of the formula (194)
Is transformed into a formula (197).

[0232]

[Equation 197]

The extracellular fluid volume ECF and intracellular fluid volume IC
F, the lean body mass LBM, and the body fluid amount TBW are determined by equations (167), (168), (183), and (184), respectively, as in the first and second embodiments. However, Expression (167) and Expression (168)
, The constants A and B, as described later,
This is different from the first and second embodiments.

Along with this, the ROM 11 stores the above-mentioned intermediate variable calculation subprogram, extracellular fluid resistance calculation subprogram, intracellular fluid resistance calculation subprogram, extracellular fluid volume estimation subprogram, and intracellular fluid volume. In place of the estimation subprogram and length constant calculation subprogram, a new intermediate variable calculation subprogram, extracellular fluid resistance calculation subprogram, intracellular fluid resistance calculation subprogram, extracellular fluid volume estimation subprogram, and intracellular fluid The quantity estimation subprogram is stored. The new intermediate variable calculation sub-program, the CPU 10, the bioelectrical impedance R0 and R∞ obtained by operation frequency 0Hz when the impedance determined subprograms and frequency infinitely Daitoki impedance determination subprogram, in the cell membrane resistance R _m A calculation formula (196) for calculating the intermediate variable β is described based on this. In the equation (196), the cell membrane resistance R _m is previously determined statistically for each gender,
11 and the RAM 12. For example, the cell membrane resistance R _m is 600 ± 20% for males,
In the case of women, it is assumed to be 400 ± 20%. Calculating the new intracellular fluid resistance calculation subprogram, the CPU 10, the intermediate variable β obtained by the operation of the intermediate variable calculation sub-program, which based on the cell membrane resistance R _m, is calculated intracellular fluid resistance R _i Equation (195) is described. The new extracellular fluid resistance calculation subprogram includes:
Bioelectric impedance R∞ and intracellular fluid resistance R obtained by running the impedance determination subprogram at infinite frequency and the new intracellular fluid resistance subprogram
Based on the _i, the calculation formula to calculate the extracellular fluid resistance R _e (1
97) is described.

[0235] The new extracellular fluid volume estimation subprogram, the CPU 10, and the extracellular fluid resistance R _e which is obtained by operation of the extracellular fluid resistance calculation subprogram, a keyboard 8
An estimation formula (167) for estimating the extracellular fluid amount ECF of the subject based on the height data H of the subject input via the is described. Here, equation (167)
Is a regression equation of the extracellular fluid volume ECF obtained as a result of conducting a sample survey in advance for many subjects, and the constant A is
By gender, in which the extracellular fluid volume ECF was determined by regression analysis with one explanatory variable of H ² / R _e.
The constant A is, for example, 342.81 ± 20 for a male.
% For women and 371.16 ± 20%.
The new intracellular fluid volume estimation subprogram includes CPU 10
Then, the intracellular fluid volume ICF of the subject is estimated based on the intracellular fluid resistance R _i obtained by running the intracellular fluid resistance calculation subprogram and the subject's height data H input via the keyboard 8. The estimation formula (168) for making the calculation is described. Here, the equation (168) is a regression equation of the intracellular fluid amount ICF obtained as a result of conducting a sample survey in advance on a large number of subjects, and the constant B is expressed by dividing the intracellular fluid amount ICF by H ² / It is obtained by performing regression analysis on one explanatory variable of R _i . The constant B is, for example, 44.733 ± 20% for a man, and
364.36 ± 20%.

The CPU 10 proceeds to step SP2 shown in FIG.
In the above, the expression (1)
95) to Expression (197), Expression (167), and Expression (168)
Is used to calculate the intracellular fluid resistance R _i , the extracellular fluid resistance R _e , the intermediate variable β, the extracellular fluid volume ECF, and the intracellular fluid volume ICF. In other respects, the configuration (FIG. 1) and operation (FIG. 6) are substantially the same as those of the first embodiment, and therefore, description thereof will be omitted.

Here, FIGS. 12 and 13 show values obtained by dividing the extracellular fluid volume ECF and the intracellular fluid volume ICF obtained in the above configuration by the lean tissue mass FFM (Fat-free Mass).
The figure which plotted CF / FFM and ICF / FFM according to age is shown. FIG. 12 shows the case of a man and FIG. 13 shows the case of a woman.
FM values and black squares indicate ICF / FFM values. From FIGS. 12 and 13, the ratio ECF: ICF is 1: 2, which has been conventionally proposed in physiology, anatomy, or cytology.
It turns out that it is almost equal to.

As described above, according to the above configuration, substantially the same effects as described in the first embodiment can be obtained.

The embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and the design may be changed without departing from the scope of the present invention. Even if there is, it is included in the present invention. For example, in the first embodiment, the intermediate variable α, the extracellular fluid resistance R are controlled by controlling the intermediate variable computation subprogram, the extracellular fluid resistance computation subprogram, and the intracellular fluid resistance computation subprogram.
an example of calculation of _e and intracellular fluid resistance R _i, but is not limited thereto. For example, equations (169) and (170)
The intermediate variable α, the extracellular fluid resistance _Re and the intracellular fluid resistance R _i
Without calculating the bioelectrical impedance R0 and R- [infinity], by substituting the body height H, length constant lambda ₀ of the subject, can estimate the extracellular fluid volume ECF and intracellular fluid volume ICF. Therefore, instead of the intermediate variable calculation subprogram, extracellular fluid resistance calculation subprogram, intracellular fluid resistance calculation subprogram, extracellular fluid volume estimation subprogram, and intracellular fluid volume estimation subprogram, extracellular A new extracellular fluid volume estimation subprogram for estimating the fluid volume ECF and a new intracellular fluid volume estimation subprogram for estimating the intracellular fluid volume ICF by equation (170) may be stored in the ROM 11. good. Similarly, also in the above-described second embodiment, Expression (164) or Expression (164) ′, Expression (165), Expression (166), Expression (167), Expression (16)
8) and the formula (182), the extracellular fluid volume ECF and the intracellular fluid volume ICF are calculated.
Rather than solving the equations (88) to (192) using an iterative method, in the former, the extracellular fluid volume ECF and the intracellular fluid volume ICF satisfying the equations (169), (170) and (182) In the latter case, it is configured to solve the three equations, which are obtained by transforming equations (169) and (170) into a recurrence equation and equation (192), using an iterative method. May be.

In the first and second embodiments described above, the length constant λ ₀ is, as shown in equation (182), the sum of the extracellular fluid amount ECF and the intracellular fluid amount ICF (ECF + IC
Although the example represented by the formula for F) is shown, the present invention is not limited to this. Since the relationship between the length constant λ ₀ and (ECF + ICF) is only a statistical one, it is not limited to (ECF + ICF) and the subject's weight W, lean body mass LBM, extracellular fluid amount ECF alone or intracellularly Any liquid amount, such as ICF alone or a combination thereof, may be used as long as it can be an index of the physique of the subject. The length constant λ ₀ is calculated by the equation (19)
8), and X is the weight W, the lean mass L obtained as a result of conducting a sample survey in advance on many subjects.
The BM, the extracellular fluid volume ECF, the intracellular fluid volume ICF, or a combination thereof may be determined by multiple regression analysis.

[0241]

[Equation 198]

Further, in each of the above-described embodiments, the length constant λ ₀ , the constants A, B, C, and the cell membrane resistance R _m have been described as being determined for men and women, but are not limited thereto. It may be configured for each age, or for both genders and ages, and may be configured to have an age input function for inputting an age on the keyboard 8. Since it is considered that the composition of the human body changes according to gender and age, measurement accuracy is further improved by setting constants for each gender and age as described above. Further, in the third embodiment described above, an example for determining the cell membrane resistance R _m as a fixed value, but is not limited thereto. Since the cell membrane is believed to be related to intracellular fluid, assuming the cell membrane resistance R _m is as a function of the intracellular fluid resistance R _i, a ratio ECF: ICF is 1:
The constant of the function may be determined so as to be 2.

Further, in each of the above embodiments, two of the four surface electrodes Hc, Hp, Lc and Lp are used.
c and Hp were attached to the back Ha of the subject E, and the remaining two surface electrodes Lc and Lp were attached to the instep Le of the subject E. However, the present invention is not limited to this. You may make it attach. Also, the measurement signal (current) I
The frequency range of a is not limited to 1 kHz to 400 kHz. Similarly, the number of frequencies is arbitrary as long as it is plural. Also, instead of calculating the bioelectrical impedance, a bioelectrical admittance may be calculated, and accordingly, an admittance locus may be calculated instead of calculating an impedance locus.
Further, in each of the above-described embodiments, the bioelectrical impedance at the frequency of 0 Hz and at the time of infinity was obtained by using a curve fitting method by the least square method.
However, the present invention is not limited to this. If the influence of stray capacitance or external noise can be avoided by other means, for example, two frequencies (5 kHz)
A low frequency below z and a high frequency above 200 kHz) are generated and applied to the subject, and the bioelectric impedance at low frequency of the subject's body is regarded as the bioelectric impedance at frequency 0 Hz, and the subject's body is The bioelectric impedance at high frequency may be regarded as the bioelectric impedance at infinite frequency. Further, the trend graph of the display 9 may be a bar graph instead of the line graph. Further, the output device is not limited to the display device, and a printer may be used.

[0244]

As described above, according to the structure of the present invention, the ratio of the extracellular fluid volume to the intracellular fluid volume is 1: 2 which has been conventionally proposed in physiology, anatomy and cytology. And the reliability is improved. Further, according to another configuration of the present invention, the processing time can be reduced. further,
According to another configuration of the present invention, detailed measurement can be performed according to the difference in the composition of the human body based on the gender and age of the subject, so that the measurement accuracy is further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of a body composition estimation device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram schematically showing a use state of the body composition estimation device.

FIG. 3 is an electrical equivalent circuit diagram of limb muscle cells according to the cable theory applied to the present invention.

FIG. 4 is an explanatory diagram for explaining how to obtain a length constant.

FIG. 5 is a diagram showing an impedance locus of a human body.

FIG. 6 is a flowchart showing an operation processing procedure of the body composition estimation device.

FIG. 7 is a timing chart for explaining the operation of the body composition estimation device.

FIG. 8 is a diagram showing a display example of a display device in the body composition estimation device.

FIG. 9 Extracellular data obtained by the body composition estimation device
Test fluid volume ECF, intracellular fluid volume ICF and body fluid volume TBW
Of the height of the elderly H^TwoECF / H divided by^Two, ICF / H
^TwoAnd TBW / H^TwoDiagram showing an example in which is plotted for each age
It is.

FIG. 10 shows a value obtained by dividing the extracellular fluid volume ECF, intracellular fluid volume ICF, and body fluid volume TBW obtained by the body composition estimating apparatus according to the second embodiment of the present invention by the square H ² of the height of the subject. the ^{ECF / H 2, ICF / H} 2 and TBW / H ² is a diagram showing an example of plotting for each age.

FIG. 11 is an electrical equivalent circuit diagram of cells in a tissue employed in the body composition estimating apparatus according to the third embodiment of the present invention.

FIG. 12 shows values ECF / FFM and ICF / FFM obtained by dividing a male extracellular fluid volume ECF and an intracellular fluid volume ICF obtained by the body composition estimating apparatus by a lean tissue mass FFM.
Is a diagram showing an example in which is plotted for each age.

FIG. 13 shows values ECF / FFM and ICF / FFM obtained by dividing the extracellular fluid volume ECF and intracellular fluid volume ICF of a woman obtained by the body composition estimation device by the lean tissue mass FFM.
Is a diagram showing an example in which is plotted for each age.

FIG. 14 is a schematic diagram schematically showing cells in a tissue of a human body.

FIG. 15 is an electrical equivalent circuit diagram of cells in a tissue.

[Explanation of symbols]

4 Body Composition Estimation Device 5 Signal Output Circuit (Part of Bioelectric Impedance Calculation Means) 6 Current Detection Circuit (Part of Bioelectric Impedance Calculation Means) 7 Voltage Detection Circuit (Part of Bioelectric Impedance Calculation Means) 8 Keyboard 10 CPU (bioelectric impedance calculating means) 11 ROM 12 RAM 52 measurement signal generator 53 output buffer 61 I / V converter 62, 72 BPF 63, 73 A / D converter 64, 74 sampling memory 71 differential amplifier Hc, Hp , Lc, Lp Surface electrode E Subject's body Ha Subject's back part Le Subject's instep part Ia Measurement signal Ib Multi-frequency current (multi-frequency probe current) Vp Voltage between subject's limbs

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4C027 AA06 CC00 EE05 FF01 FF02 GG00 GG13 HH02 HH11 KK00 KK03 KK05 4C038 VA20 VB01 VC20

Claims (31)

[Claims] 1. A multi-frequency probe current is applied to a subject's body to calculate the bioelectric impedance of the subject's body at a frequency of 0 Hz and at a frequency of infinity, and the equation (1) or (2) is used. And estimating at least one of an extracellular fluid volume and an intracellular fluid volume of the subject's body. (Equation 1) (Equation 2) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at 0 Hz frequency RＨｚ: bioelectric impedance at infinite frequency A, B, Λ :constant 2. A multi-frequency probe current is applied to a subject's body to calculate the bioelectric impedance of the subject's body at a frequency of 0 Hz and at a frequency of infinity.
Estimating at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body using Equation (4) or Equation (4) ′ and Equations (5) to (7). Body composition estimation method. (Equation 3) (Equation 4) (Equation 5) (6) ECF = AH ² / R _e (6) ICF = BH ² / R _i (7) ECF: extracellular fluid volume of the subject's body ICF: intracellular volume of the subject's body liquid volume H: height of the subject R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, Λ: constants 3. The body composition estimating method according to claim 1, wherein the constant 算出 is recalculated using Expression (8). (Equation 8) In the formula (8), X is a multiple regression analysis of a subject's body weight, lean body mass, extracellular fluid volume, intracellular fluid volume, or a combination thereof, which is obtained as a result of conducting a sample survey in advance on many subjects. This is the amount required by 4. A multi-frequency probe current is applied to a subject's body to calculate the bioelectric impedance of the subject's body at a frequency of 0 Hz and at a frequency of infinity.
A body composition estimating method, comprising calculating an extracellular fluid amount and an intracellular fluid volume of the subject's body satisfying Expression (11). (Equation 9) (Equation 10) [Equation 11] ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C , Λ: Constant 5. A multi-frequency probe current is applied to a subject's body to calculate a bioelectrical impedance of the subject's body at a frequency of Hz and at a frequency of infinity.
Expression (13) or Expression (13) ′, Expression (14) to Expression (17)
Calculating an extracellular fluid volume and an intracellular fluid volume of the subject's body that satisfies the following. (Equation 12) (Equation 13) [Equation 14] (Equation 15) (16) ECF = AH ² / R _e (16) ICF = BH ² / R _i (17) ECF: extracellular fluid volume of subject's body ICF: intracellular volume of subject's body liquid volume H: height of the subject R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, C, Λ: constants 6. The body composition estimation method according to claim 1, wherein the constants A, B, C, and Λ are determined for each gender and / or age. 7. A multi-frequency probe current is applied to a subject's body to calculate the bioelectric impedance of the subject's body at a frequency of 0 Hz and at a frequency of infinity. A body composition estimating method, wherein equation (20) is solved by an iterative method to calculate an extracellular fluid volume and an intracellular fluid volume of the subject's body. (Equation 18) [Equation 19] (Equation 20) ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C :constant 8. A multi-frequency probe current is applied to the subject's body to calculate the bioelectrical impedance of the subject's body at a frequency of Hz and at a frequency of infinity. Solving the equation (22), the equation (23) or the equation (23) ′, and the equations (24) to (26) by an iterative method to calculate the extracellular fluid volume and the intracellular fluid volume of the body of the subject. Characteristic body composition estimation method. (Equation 21) (Equation 22) (Equation 23) (Equation 24) (25) ECF _{n + 1} = AH ² / R _en (25) ICF _{n + 1} = BH ² / R _in (26) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid of the subject's body H: height of the subject R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B , C, Λ: constant 9. The constant Λ is related to the thickness of the muscle fiber of the body muscle of the subject or the thickness of the fascia, and is substantially equal to the length at which the current flowing through the intracellular fluid is saturated. The body composition estimation method according to any one of claims 1 to 8. 10. A multi-frequency probe current is applied to a subject's body to calculate a bioelectric impedance of the subject's body at a frequency of 0 Hz and at a frequency of infinity.
7) A method of estimating body composition, comprising estimating at least one of the extracellular fluid amount or the intracellular fluid volume of the subject's body using Equation (31). [Equation 27] [Equation 28] (Equation 29) (30) ECF = AH ² / R _e (30) ICF = BH ² / R _i (31) ECF: extracellular fluid volume of subject's body ICF: intracellular volume of subject's body liquid volume H: subject's height R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance R _m: the cell membrane resistance a, B: constant 11. The constants A and B and the cell membrane resistance R.
The body composition estimation method according to claim 10, wherein _m is determined for each gender and / or age. 12. The cell membrane resistance R _m is a function of the intracellular fluid resistance R _i , such that the ratio ECF: ICF between the extracellular fluid volume and the intracellular fluid volume of the subject's body is 1: 2. 11. The body composition estimation method according to claim 10, wherein a constant of the function is determined. 13. The body composition estimating method according to claim 1, wherein the lean body mass LBM of the subject is also estimated using the equation (32). LBM = a ₁ W + ECF + ICF + d ₁ (32) LBM: lean body mass of subject body ECF: extracellular fluid volume of subject body ICF: intracellular fluid volume of subject body W: subject weight a ₁ , d ₁ : constant 14. The body fat weight FAT of the subject is also calculated by subtracting the lean body mass LBM given by equation (32) from the body weight W of the subject. Body composition estimation device. 15. The body fluid volume TBW of the subject is also estimated using equation (33).
15. The body composition estimating method according to any one of claims 14 to 14. (33) TBW = a ₃ W + ECF + ICF + d ₃ (33) TBW: body fluid volume of subject W: weight of subject a ₃ , d ₃ : constant 16. Generating a multi-frequency probe current,
Bioelectric impedance measuring means for inputting the generated probe current of each frequency to the body of the subject to measure the bioelectric impedance of the subject at a frequency of 0 Hz and at an infinite frequency, and inputting the height H of the subject Extracellular fluid volume / intracellular fluid volume for estimating at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body using the height input means for formula (34) or (35) A body composition estimating device comprising: an estimating means. (Equation 34) (Equation 35) ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body H: height of the subject R0: bioelectric impedance at 0 Hz frequency RＨｚ: bioelectric impedance at infinite frequency A, B, Λ :constant 17. Generating a multi-frequency probe current,
Bioelectric impedance measuring means for inputting the generated probe current of each frequency to the body of the subject to measure the bioelectric impedance of the subject at a frequency of 0 Hz and at an infinite frequency, and inputting the height H of the subject (36), (37) or (37) ', (38)
-Extracellular fluid volume estimating at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body using equation (40)
An apparatus for estimating a body composition, comprising: means for estimating an intracellular fluid volume. [Equation 36] (37) (38) (39) ECF = AH ² / R _e (39) ICF = BH ² / R _i (40) ECF: extracellular fluid volume of subject's body ICF: intracellular volume of subject's body liquid volume H: height of the subject R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, Λ: constants 18. The body composition estimating apparatus according to claim 16, wherein the constant 直 す is recalculated using Expression (41). [Equation 41] In the equation (41), X is a multiple regression analysis of the subject's body weight, lean body mass, extracellular fluid volume, intracellular fluid volume, or a combination thereof, which is obtained as a result of conducting a sample survey on a large number of subjects in advance. This is the amount required by 19. Producing a multi-frequency probe current,
Bioelectric impedance measuring means for inputting the generated probe current of each frequency to the body of the subject to measure the bioelectric impedance of the subject at a frequency of 0 Hz and at an infinite frequency, and inputting the height H of the subject Height input means for calculating the extracellular fluid quantity and intracellular fluid quantity estimating means for calculating the extracellular fluid quantity and the intracellular fluid quantity of the body of the subject satisfying the equations (42) to (44). An apparatus for estimating body composition, comprising: (Equation 42) [Equation 43] [Equation 44] ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C , Λ: Constant 20. Generating a multi-frequency probe current,
Bioelectric impedance measuring means for inputting the generated probe current of each frequency to the body of the subject to measure the bioelectric impedance of the subject at a frequency of 0 Hz and at an infinite frequency, and inputting the height H of the subject (45), (46) or (46) ', (47)
A body composition estimating device comprising: an extracellular fluid volume / intracellular fluid volume estimating means for calculating an extracellular fluid volume and an intracellular fluid volume of the body of the subject satisfying formula (50). . [Equation 45] [Equation 46] [Equation 47] [Equation 48] ECF = AH ² / R _e (49) ICF = BH ² / R _i (50) ECF: extracellular fluid volume of the subject's body ICF: intracellular volume of the subject's body liquid volume H: height of the subject R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B, C, Λ: constants 21. The body composition estimation device according to claim 16, wherein the constants A, B, C, and Λ are determined for each gender and / or age. 22. Generating a multi-frequency probe current,
Bioelectric impedance measuring means for inputting the generated probe current of each frequency to the body of the subject to measure the bioelectric impedance of the subject at a frequency of 0 Hz and at an infinite frequency, and inputting the height H of the subject Height input means for calculating the extracellular fluid volume and intracellular fluid volume of the subject's body by solving equations (51) to (53), which are recurrence formulas, by an iterative method. An apparatus for estimating a body composition, comprising: means for estimating an intracellular fluid volume. (Equation 51) (Equation 52) (Equation 53) ECF: extracellular fluid volume of subject's body ICF: intracellular fluid volume of subject's body H: height of subject R0: bioelectric impedance at frequency 0 Hz R∞: bioelectric impedance at infinite frequency A, B, C :constant 23. Generating a multi-frequency probe current,
Bioelectric impedance measuring means for inputting the generated probe current of each frequency to the body of the subject to measure the bioelectric impedance of the subject at a frequency of 0 Hz and at an infinite frequency, and inputting the height H of the subject Height input means, and equations (54), (55), and (5)
6) or formula (56) ′, formula (57) to formula (59) are solved by an iterative method to calculate the volume of extracellular fluid and the volume of intracellular fluid in the body of the subject. A body composition estimating device comprising: an estimating means. (Equation 54) [Equation 55] [Equation 56] [Equation 57] (58) ECF _{n + 1} = AH ² / R _en (58) ICF _{n + 1} = BH ² / R _in (59) ECF: Extracellular fluid volume of the subject's body ICF: intracellular fluid of the subject's body H: height of the subject R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance a, B , C, Λ: constant 24. The constant Λ is related to the thickness of muscle fibers or fascia of the body muscles of the subject, and is substantially equal to the length at which the current flowing through the intracellular fluid is saturated. The body composition estimation device according to any one of claims 16 to 23. 25. Generating a multi-frequency probe current,
Bioelectric impedance measuring means for inputting the generated probe current of each frequency to the body of the subject to measure the bioelectric impedance of the subject at a frequency of 0 Hz and at an infinite frequency, and inputting the height H of the subject Extracellular fluid volume / intracellular fluid volume for estimating at least one of the extracellular fluid volume or the intracellular fluid volume of the subject's body using height input means for calculating the following formulas (60) to (64): A body composition estimating device comprising: an estimating means. [Equation 60] [Equation 61] (Equation 62) (63) ECF = AH ² / R _e (63) ICF = BH ² / R _i (64) ECF: extracellular fluid volume of subject's body ICF: intracellular volume of subject's body liquid volume H: subject's height R0: frequency 0Hz when bioelectrical impedance R- [infinity]: infinite frequency when the bioelectrical impedance R _e: extracellular fluid resistance R _i: intracellular fluid resistance R _m: the cell membrane resistance a, B: constant 26. The constants A and B and the cell membrane resistance R
The body composition estimation device according to claim 25, wherein _m is determined for each gender and / or age. 27. The cell membrane resistance R _m is a function of the intracellular fluid resistance R _i , such that the ratio ECF: ICF between the extracellular fluid volume and the intracellular fluid volume of the subject's body is 1: 2. 26. The body composition estimating apparatus according to claim 25, wherein a constant of the function is determined. 28. A body weight input unit for inputting the weight W of the subject, and a lean body mass estimating unit for estimating the lean body mass LBM of the body of the subject using equation (65). The body composition estimating apparatus according to any one of claims 16 to 27, characterized in that: LBM = a ₁ W + ECF + ICF + d ₁ (65) LBM: lean body mass of the subject's body ECF: extracellular fluid volume of the subject's body ICF: intracellular fluid volume of the subject's body W: subject's weight a ₁ , d ₁ : constant 29. A body fat weight calculating means for calculating the body fat weight FAT of the subject by subtracting the lean body mass LBM given by the equation (65) from the weight W of the subject. Claim 2
8. The body composition estimation device according to 8. 30. A body weight input unit for inputting the weight W of the subject, and a body fluid volume estimating unit for estimating a body fluid volume TBW of the body of the subject using equation (66). The body composition estimating device according to any one of claims 16 to 29, characterized in that: (66) TBW = a ₃ W + ECF + ICF + d ₃ (66) TBW: body fluid volume of subject W: weight of subject a ₃ , d ₃ : constant 31. A storage medium storing a body composition estimating program for causing a computer to realize the function according to claim 1. Description: