JP4679993B2 - Trunk fat measurement method and apparatus - Google Patents

Description

  The present invention relates to a trunk fat measurement method and apparatus, and more particularly to a method and apparatus for measuring trunk trunk fat mass and trunk visceral fat mass.

  Body fat tissue estimation technology using bioelectrical impedance has spread to the world as a technique for measuring body fat tissue volume and body fat percentage, but in reality, it is not directly measuring fat tissue. In addition, it is an electrical measurement of lean tissue in which water other than adipose tissue is dominant. In particular, in the whole body measurement, the conventional type models one hand-one leg with a single cylinder in the supine position (one-hand-one leg guidance method). Measure between both palms to measure, guide between both legs integrated with weight scale, upper and lower limbs, upper and lower limbs and trunk, or left and right upper limbs, left and right lower limbs, trunk as 5 segments The technique of measuring the impedance by making it possible to apply a cylindrical model separately has also become apparent. In addition, a patent application has been filed for a measurement technique for estimating the visceral fat tissue volume by simplifying the impedance CT measurement technique, measuring the abdominal impedance by placing a voltage application / voltage measurement electrode in the trunk umbilical cord (See Patent Document 1 and Patent Document 2).

Japanese Patent No. 3396677 Japanese Patent No. 3396684

  However, information on body adipose tissue is particularly useful for screening lifestyle-related diseases such as diabetes, hypertension and hyperlipidemia, and in particular, visceral fat that has adhered and accumulated in the vicinity of internal organ tissues. For organizations, the importance of measurement is increasing day by day.

  Visceral adipose tissue is an adipose tissue that is concentrated in the vicinity of the abdomen of the trunk, and has been determined by the cross-sectional area of the adipose tissue using an abdominal cross-sectional image obtained by X-ray CТ or MRI. However, the apparatus is large, and in the case of X-rays, there is a problem of exposure, and there is a cost aspect, which is not suitable for measurement in the field and home. Therefore, the visceral adipose tissue is generally estimated from the correlation with the whole body adipose tissue or the correlation with the whole body lean tissue, and sufficient reliability has not been ensured even for screening.

  Recently, a method for estimating visceral adipose tissue information by placing electrodes around the umbilical girth of the trunk and measuring the internal impedance of the trunk is also under development. However, this method is based on the fact that there is a significant correlation among the skeletal muscle tissue layer, the subcutaneous fat tissue layer, and the visceral adipose tissue. It is assumed that estimation is possible. For this reason, good results can be expected for healthy subjects with high independence where a very significant correlation can exist, but subjects with different correlations between tissues, such as visceral adipose tissue, are significantly enlarged. In addition, the measurement result in the subject having a remarkably low correlation with the subcutaneous fat tissue layer or the skeletal muscle tissue layer can include a large error. In other words, even if this method is under development, if it is a subject who can live a healthy independent life, it is possible to measure somehow regardless of where the electrodes are placed around the entire umbilicus. In particular, the problem is large when measurement is performed on a bedridden patient on a bed.

  In addition, this method under development can be said to be a high technology in that the impedance value related to the internal tissue is obtained by applying current from the abdominal surface to the tissue site to be measured. The fact is that the measured impedance information itself has little useful sensitivity to visceral adipose tissue due to problems in the internal structure of the trunk, which is the part. That is, the trunk that is the measurement site is short and thick, the multiple structure, that is, the visceral fat tissue that is the measurement target is covered with a skeletal muscle tissue layer that exhibits very good conductivity together with the internal organ tissue and the spine tissue, This skeletal muscle tissue layer has a structure in which it is covered with a subcutaneous fat tissue layer having very poor conductivity. In particular, the visceral adipose tissue that is the subject of measurement is dominated by internal organ tissues that are less conductive than the skeletal muscle tissue layer and visceral adipose tissues that are attached and accumulated on this internal organ tissue and have poor conductivity. Due to the configuration, the internal conductivity is considerably inferior to that of the skeletal muscle tissue layer. For this reason, even if the current application electrode is simply arranged around the abdomen, the majority is energized through the skeletal muscle tissue layer, and the current density distribution is also a potential distribution dominant to the skeletal muscle tissue layer from the surface measurement electrode. Will be observed. Furthermore, the distribution of the applied current density is determined by the surface area of the electrode to which the current is applied or the electrode width in the abdominal circumference direction, and the current density in the subcutaneous fat tissue layer immediately below the electrode is widened, and the observation of information in the resistance region becomes dominant. End up.

  Furthermore, because the trunk, which is the measurement site, is thick and short, the sensitivity in the subcutaneous adipose tissue layer in the current density concentration (spreading resistance) region directly under the current application electrode is higher, and the skeletal muscle tissue layer is more in comparison with the adipose tissue. Therefore, most of the current that passed through the subcutaneous fat tissue layer is routed through the subcutaneous fat tissue layer to the opposing current application electrode side through the skeletal muscle tissue layer. In addition, the internal potential distribution is greatly distorted in this skeletal muscle tissue layer. Therefore, in the conventional method, most of the measured potential is information of the subcutaneous fat tissue layer, and the visceral adipose tissue to be measured, that is, the visceral adipose tissue that adheres to and accumulates in the internal organ tissue and its surroundings. It is almost impossible to energize the battery, and only information with extremely low measurement sensitivity of 10% or less of the entire impedance measurement section can be captured.

  In order to avoid these problems, a method for preventing an increase in the estimation error by incorporating an abdominal circumference that is highly correlated with the area of the subcutaneous fat tissue layer into the estimation formula has been considered. It is nothing but indirect estimation based on the correlation between the constituent tissues, and it is difficult to say that it is a measurement method that secures the necessary energization sensitivity at the center of the abdomen. In other words, individual errors that deviate from the statistical correlation design cannot be guaranteed, especially when there are many pathologically subcutaneous or visceral adipose tissues, or when there are many / small intermediate skeletal muscle tissue layers. obtain. It should be noted that the area of the subcutaneous fat tissue layer is highly correlated with the abdominal circumference, because the human trunk has a concentric tissue arrangement design, and the subcutaneous fat tissue layer is the outermost arrangement, so the outer circumference This is because the area is determined by the length and the thickness of the subcutaneous fat tissue.

  Usually, the four-electrode method is also used for the electrode arrangement on the trunk. In this method, a current is applied to the body of the subject, and a potential difference generated in the measurement region of the subject by the applied current is measured to measure the bioelectrical impedance of the measurement region. When the four-electrode method is applied to a thick and short measurement site section such as the trunk, the current density concentration at the beginning of current spreading (ie, spreading resistance region) is, for example, near the subcutaneous fat tissue layer directly under the current application electrode. A large potential difference is generated, and this potential difference occupies most of the potential difference measured between the voltage measurement electrodes. In order to reduce the influence of the spreading resistance, it is important to arrange the current application electrode and the voltage measurement electrode with a sufficient distance. Since general measurement is performed under the condition that the measurement interval is long and the distance between the voltage measurement electrodes can be sufficiently secured, so-called S / N sensitivity (N is an influence (noise) due to spreading resistance, and S is between the voltage measurement electrodes). The signal to be measured) should be sufficiently secured. However, in the case of a thick and short measurement site such as the trunk, if the voltage measurement electrode is moved away from the current application electrode in order to reduce N, the voltage measurement electrode section distance becomes smaller. As a result, S becomes smaller and eventually the S / N becomes worse. Further, the spreading resistance portion having a high current density is a subcutaneous fat tissue layer, and a thick and obese subject is generally used. Therefore, the N is considerably large, and the S / N is doubled. End up. As described above, when the four-electrode method is used for a short and short measurement site such as the trunk, a useful S / N sensitivity to visceral adipose tissue can be obtained simply by placing an electrode on the circumference of the umbilicus. It is speculated that it is quite impossible to secure. The S / N will be described in more detail in the description of the embodiments described later.

  Therefore, in the case of the induction method in which all four electrodes are arranged on the trunk to be measured, a current application electrode is arranged in the window of the aponeurosis part where the skeletal muscle tissue layer is removed, or the skeletal muscle tissue layer is used as a conductive layer. In order to use it, it is considered to limit the electrode arrangement. However, in this case, an error in the electrode arrangement is a factor that strictly affects the measurement accuracy.

  In addition, shift the electrode arrangement as much as possible to the limbs other than the abdominal part of the measurement target (by replacing the lead from the trunk by placing the electrode in a part protruding from the trunk such as the limb) Although the above restriction has been reduced, the measurement target part of the trunk abdomen cannot be freely selected due to the restriction of the limb arrangement structure protruding from the trunk. It was.

  The object of the present invention is to eliminate these problems in the prior art, eliminate the strict restrictions on electrode placement, reduce the effects of electrode placement errors on the trunk, and accumulate in the trunk. A trunk fat measurement method and apparatus capable of easily and accurately measuring information on adipose tissue, particularly visceral adipose tissue that adheres to and accumulates around internal organ tissue and subcutaneous adipose tissue layer that accumulates in the subcutaneous layer. That is.

  According to one aspect of the present invention, in a trunk fat measurement method for obtaining a trunk fat tissue mass using trunk impedance measured using a current application electrode pair and a voltage measurement electrode pair arranged on the trunk. By arranging one common electrode having a large electrode area on the trunk and sharing the common electrode as one current application electrode and one voltage measurement electrode of the current application electrode pair and the voltage measurement electrode pair, There is provided a trunk fat measurement method characterized in that the required electrode configuration is three electrodes: a current application electrode, a voltage measurement electrode, and a common electrode.

  According to one embodiment of the present invention, the common electrode is disposed on one flank of the trunk abdomen, and the current application electrode is disposed on the opposite flank.

  According to another embodiment of the present invention, the current application electrode is connected to the lateral umbilical region, the lateral abdomen, the lower scapula or the rectus abdominis and the external abdominal oblique muscle on the circumference of the umbilicus on the side facing the common electrode. Place it on the joint aponeurosis between.

  According to another embodiment of the present invention, the trunk adipose tissue mass is a trunk visceral adipose tissue mass, and the voltage measurement electrode is secured at a distance that can avoid the influence of spreading resistance due to the current application electrode. Place it at the specified position.

  According to still another embodiment of the present invention, when a current is applied between the common electrode and the current application electrode, a potential difference between the common electrode and the voltage measurement electrode is measured and applied. A trunk impedance is measured based on the current and the measured potential difference.

  According to still another embodiment of the present invention, a trunk skeletal muscle tissue amount is obtained based on body specifying information, and a trunk skeleton is obtained based on the obtained trunk skeletal muscle tissue amount and body specifying information. The impedance of the muscular tissue layer is obtained, the internal organ tissue amount of the trunk is obtained based on the body specifying information, and the internal organ tissue of the trunk is obtained based on the obtained internal organ tissue amount and the body specifying information of the trunk The impedance of the trunk visceral adipose tissue was determined based on the measured trunk impedance, the impedance of the trunk trunk skeletal muscle tissue layer and the impedance of the internal organ tissue of the trunk, Each step further includes determining the amount of trunk visceral fat tissue based on the impedance of the trunk visceral fat tissue and the body specifying information.

  According to still another embodiment of the present invention, the trunk visceral adipose tissue based on the measured trunk impedance, and the determined trunk skeletal muscle tissue layer impedance and trunk internal organ tissue impedance Determining the impedance of the torso skeletal muscle tissue layer with respect to the series circuit of the trunk internal organ tissue impedance and the trunk visceral fat tissue impedance. Are connected in parallel.

  According to still another embodiment of the present invention, the trunk adipose tissue mass is a trunk subcutaneous adipose tissue mass, and the voltage measurement electrode is dominantly influenced by the spreading resistance directly under the current application electrode. It arrange | positions in the position close to the electric current application electrode.

  According to still another embodiment of the present invention, when a current is applied between the common electrode and the current application electrode, a potential difference between the common electrode and the voltage measurement electrode is measured and applied. By measuring the trunk impedance based on the current and the measured potential difference, the subcutaneous adipose tissue layer impedance at a site close to the current application electrode is obtained.

  According to still another embodiment of the present invention, the amount of subcutaneous fat tissue of the trunk is obtained based on the obtained subcutaneous fat tissue layer impedance and body specifying information.

  According to still another embodiment of the present invention, the trunk adipose tissue volume is a trunk visceral adipose tissue volume and a trunk trunk adipose tissue volume, and the voltage measurement electrode is spread resistance by the current application electrode. And a second position close to the current application electrode where the influence of the spreading resistance directly under the current application electrode is dominant.

  According to still another embodiment of the present invention, when a current is applied between the common electrode and the current application electrode, voltage measurement is performed on the common electrode and the first position and the second position. The potential difference between the electrodes is measured, and the trunk impedance is measured based on the applied current and the measured potential difference.

  According to still another embodiment of the present invention, the step of measuring the trunk impedance measures the trunk impedance when the current application electrodes are arranged at a plurality of positions on the flank side.

  According to still another embodiment of the present invention, in the step of measuring the trunk impedance, when the trunk visceral fat tissue amount is obtained, the common electrode and the voltage measurement electrode arranged at the first position When measuring the trunk impedance based on the potential difference between and the body trunk subcutaneous fat tissue amount, the potential difference between the common electrode and the voltage measurement electrode disposed in the first position, Based on the difference between the potential difference between the common electrode and the voltage measurement electrode disposed at the second position, or the potential difference between the voltage measurement electrode disposed at the first position and the second position. Then, the trunk impedance is measured, and the subcutaneous fat tissue layer impedance at the site close to the current application electrode is obtained.

  According to still another embodiment of the present invention, when obtaining the visceral adipose tissue amount, the trunk skeletal muscle tissue amount is obtained based on the body specifying information, and the obtained trunk skeletal muscle tissue amount and The impedance of the trunk skeletal muscle tissue layer is obtained based on the body specific information, the internal organ tissue amount of the trunk is obtained based on the body specific information, and the internal organ tissue amount and body specification of the obtained trunk Based on the information, the impedance of the internal organ tissue of the trunk is determined, and the trunk is determined based on the measured trunk impedance, the impedance of the trunk skeletal muscle tissue layer and the impedance of the internal organ tissue of the trunk Each of the steps further includes obtaining the impedance of the visceral adipose tissue and obtaining the amount of the visceral adipose tissue based on the obtained impedance of the visceral adipose tissue and the body specifying information.

  According to still another embodiment of the present invention, the trunk visceral adipose tissue based on the measured trunk impedance, and the determined trunk skeletal muscle tissue layer impedance and trunk internal organ tissue impedance Determining the impedance of the torso skeletal muscle tissue layer with respect to the series circuit of the trunk internal organ tissue impedance and the trunk visceral fat tissue impedance. Are connected in parallel.

  According to still another embodiment of the present invention, when the amount of the subcutaneous adipose tissue is obtained, the subcutaneous adipose tissue layer impedance is obtained for a plurality of sites on the flank, and the obtained subcutaneous adipose tissue layer impedance of each site is obtained. And determining a subcutaneous fat tissue layer impedance of the trunk based on the above.

  According to another aspect of the present invention, in a trunk fat measurement apparatus for obtaining a trunk adipose tissue amount using trunk impedance measured using a current application electrode pair and a voltage measurement electrode pair arranged on the trunk. A common electrode having a wide electrode area configured to be used as one of the current application electrode and the voltage measurement electrode of the current application electrode pair and the voltage measurement electrode pair, thereby providing an electrode necessary for measurement. There is provided a trunk fat measuring device characterized in that the configuration of is made up of three electrodes, a current applying electrode, a voltage measuring electrode, and a common electrode.

  According to one embodiment of the present invention, the common electrode is disposed on one flank of the trunk abdomen, and the current application electrode is disposed on the opposite flank.

  According to another embodiment of the present invention, the current application electrode includes the lateral umbilical portion, the lateral abdomen, the lower scapula or the rectus abdominis and the external oblique muscle on the umbilical circumference on the side facing the common electrode. It is placed on the joint aponeurosis between.

  According to still another embodiment of the present invention, the voltage measurement electrode includes a first voltage measurement electrode disposed at a first position that secures a distance that can avoid the influence of spreading resistance due to the current application electrode, It includes a second voltage measurement electrode disposed at a second position close to the current application electrode in which the influence of the spreading resistance directly under the current application electrode is dominant.

  According to still another embodiment of the present invention, the current application electrode includes a plurality of current application electrodes arranged at a plurality of positions on the flank.

  According to still another embodiment of the present invention, a potential difference between the common electrode and the voltage measurement electrode when a current is applied between the common electrode and the current application electrode, or the voltage measurement. Means are provided for measuring a potential difference between each of the electrodes and measuring trunk impedance based on the applied current and the measured potential difference.

  According to still another embodiment of the present invention, the measurement means obtains a subcutaneous fat tissue layer impedance at a site close to the current application electrode using the measured trunk impedance.

  According to still another embodiment of the present invention, the trunk skeletal muscle tissue amount is estimated based on the body specifying information, and the trunk is based on the estimated trunk skeletal muscle tissue amount and the body specifying information. Trunk skeletal muscle tissue layer impedance estimating means for estimating impedance of skeletal muscle tissue layer, estimating internal organ tissue amount of trunk based on body specifying information, and estimating internal organ tissue amount and body of trunk Trunk internal organ tissue impedance estimating means for estimating impedance of internal organ tissue of the trunk based on the specified information, trunk impedance measured by the measuring means, and the estimated impedance of the trunk skeletal muscle tissue layer And trunk visceral adipose tissue impedance estimation means for estimating the impedance of the trunk visceral fat tissue based on the impedance of the internal organ tissue of the trunk, Further comprising a trunk visceral fat tissue volume estimating means for estimating the trunk visceral fat tissue volume on the basis of the serial estimated trunk visceral fat tissue impedance and body specifying information.

  According to still another embodiment of the present invention, the trunk visceral adipose tissue impedance estimation means includes: an electrical equivalent circuit of the trunk, wherein the impedance of the internal organ tissue of the trunk and the visceral adipose tissue of the trunk The impedance of the trunk skeletal muscle tissue layer is connected in parallel to the series circuit with the impedance.

  According to still another embodiment of the present invention, there is further provided a subcutaneous fat tissue amount estimation means for obtaining the determined subcutaneous fat tissue layer impedance and the subcutaneous fat tissue amount of the trunk based on the body specifying information.

  Therefore, according to this invention, since the electrode area of a common electrode is large, the influence by the arrangement | positioning shift to a trunk abdomen can be reduced. Strict electrode arrangement restrictions on the common electrode side are eliminated, and only electrode arrangement restrictions on the other current application electrode are provided, so that the influence on the electrode arrangement deviation can be reduced as a whole. In addition, awareness of the measurement site can be increased. Therefore, accuracy improvement by conscious restraint can also be expected. Further, by expanding the electrode area, it is possible to reduce and ignore the influence of the contact resistance with the skin and the influence of the spreading resistance directly under the current application electrode.

  Before describing the embodiments and examples of the present invention in detail, the principle of measuring visceral adipose tissue of the trunk according to the present invention will be described. The present invention basically uses the bioelectrical impedance information and the body specifying information, and the fat tissue information (cross-sectional area amount, volume amount or weight) of the trunk (trunk abdomen), more specifically, the trunk In particular, the present invention relates to a method for enabling easy and accurate measurement of adipose tissue accumulated in the organ, particularly visceral adipose tissue that adheres and accumulates around the internal organ tissue and subcutaneous adipose tissue layer information accumulated in the subcutaneous layer.

For this reason, the present invention makes full use of the following technique.
(1) The tissue information included in the bioelectrical impedance information of the trunk is assumed to be an equivalent circuit model in which the skeletal muscle tissue layer, the internal organ tissue, and the visceral fat tissue are serially parallel. Here, the internal organ tissue and the visceral adipose tissue are considered in series (therefore, a change in energization amount can be expected depending on the size of the visceral adipose tissue).

(2) When the abdominal circumference can be secured as body specific information, the subcutaneous fat tissue layer, the skeletal muscle tissue layer, the internal organ tissue, and the visceral fat are included as a high-accuracy model including the subcutaneous fat tissue amount in the equivalent circuit model. Assuming a series-parallel equivalent circuit model in the organization.

(3) Subcutaneous adipose tissue mass estimation is made up of multiple regression equations with the abdominal circumference in the body specifying information as the main explanatory variable. Furthermore, put the square of the abdominal circumference as the main explanatory variable.

(4) The determination of internal organ tissue information is made up of multiple regression equations with height information as the main explanatory variable in the body specific information, and is used to determine uncertain information for visceral fat tissue information estimation. .

(5) The standard measurement of the tissue used for the multiple regression analysis (calibration curve creation method) for quantifying each tissue is the tissue cross-sectional area (CSA) from the X-ray CT tomographic image at the umbilical position or the CSA by the MRI method. Tissue volume and weight using the DEXA method and MRI method (integration processing for each slice in the length direction) for the entire trunk can be calculated from the tissue density information from previous studies. ). In the DEXA method, the total adipose tissue information of the total of the abdominal visceral adipose tissue and the subcutaneous adipose tissue layer can be measured as a reference.

(6) In order to be able to capture visceral adipose tissue information with high accuracy using the method as described above, it is necessary to take a means to replace fluctuations in the measured impedance information of the trunk due to breathing or the like with a certain condition value. The impedance measurement sampling period is within 1/2 of the general respiratory cycle, the respiratory change is monitored in time series, the maximum value and the minimum value for each respiratory cycle are determined for each respiratory cycle, Capability to capture median rest breathing.

(7) Further, it is also possible to check in advance of adverse effects due to eating and drinking before the measurement and retention of bladder and urine from the measured impedance information. Generally, the information on the skeletal muscle tissue layer is dominantly reflected in the impedance value of the trunk in a general healthy subject group. In addition, the information on the skeletal muscle tissue layer of the trunk is very small as a measured value, and no great difference is recognized between individuals. The reason is that the design is highly correlated with anti-gravity muscles that support and develop their own weight under the gravity of the earth, so subjects who are specially bedridden and not affected by gravity, or athletes who are subject to several times the stress of their own weight This is because it is almost determined by body size except for special groups. Here, the influence on the impedance of the trunk other than the skeletal muscle tissue layer and the respiratory fluctuation is an adverse effect due to food and drink and urinary bladder urine storage. Therefore, when the impedance values of the trunk are collected as collective data and viewed as the mean value [mean] and deviation [SD], it can be seen that the effects of food and drink and bladder urine retention are in the range exceeding 2SD. It was. However, considering even a semi-general group such as athletes to a certain extent, 3SD can be used as a criterion to screen for this effect.

  Next, the measurement principle of the present invention based on the above-described method will be described in further detail.

1. Electrical equivalent circuit modeling of trunk tissue (1) The trunk mainly consists of subcutaneous fat tissue layer, skeletal muscle tissue layer (abdominal muscle group, back muscle group), internal organ tissue and visceral fat attached to the gap It can be thought of as an organization. The reason why the bone tissue is not listed as a constituent tissue is that the bone tissue has a very high quantitative correlation with the skeletal muscle tissue layer and can be considered as an integral tissue body. The volume resistivity is considered to have a property that is considerably good in conductivity by including bone marrow tissue and the like in a living body, and has characteristics close to those of a skeletal muscle tissue layer and internal organ tissue. Therefore, when these four tissues are represented by an electrical equivalent circuit model, the internal organ tissue and the visceral adipose tissue are configured in series, and the subcutaneous adipose tissue layer and the skeletal muscle tissue layer are respectively formed with respect to the serial composite tissue layer. Configured in parallel. This equivalent circuit model will be described in detail in the description of FIGS. According to this model, current flows predominantly through the skeletal muscle tissue layer when energized in the longitudinal direction of the trunk. The visceral adipose tissue adheres to the gap around the internal organ tissue, and when the visceral adipose tissue is absent or small, the internal organ tissue exhibits conductivity close to that of the skeletal muscle tissue layer. Also, a current is applied. Further, as the visceral adipose tissue increases, the energization amount to the composite tissue layer as a complex of the internal organ tissue and the visceral adipose tissue decreases. The model impedance when the measured impedance of the trunk and the four tissues constituting it are expressed by an equivalent circuit model can be expressed as follows.
Ztm = ZFS // ZMM // (ZVM + ZFV) Equation 1
here,
Impedance of the whole trunk: Ztm
Impedance of subcutaneous adipose tissue layer: ZFS: Volume resistivity is large.
Impedance of skeletal muscle tissue layer: ZMM: Volume resistivity is small.
Impedance of internal organ tissue: ZVM ... It is considered as volume resistivity close to the skeletal muscle tissue layer.
Impedance of visceral adipose tissue: ZFV: Volume resistivity is considered to be equal to or slightly smaller than the subcutaneous adipose tissue layer. Since the synthetic decomposition of adipose tissue is faster than that of the subcutaneous adipose tissue layer, it is considered that the blood vessels and blood volume in the tissue are large.

The electrical characteristics between tissues are determined by volume resistivity ρ [Ωm] rather than impedance. From the above relationship, the electrical characteristic values of each tissue are generally explained by the following relationship.
ρMM << ρ (VM + FV) << ρFS
ρVM << ρFV
ρMM = ρMV or ρMM <ρMV
ρFV = ρFS or ρFV <ρFS
here,
Volume resistivity of subcutaneous adipose tissue layer: ρFS
Volume resistivity of composite tissue layer of internal organ tissue and visceral adipose tissue inside skeletal muscle tissue layer: ρ (VM + FV)
Volume resistivity of skeletal muscle tissue layer: ρMM
Therefore, due to the relationship with Equation 1, the electrical property comparison relationship between the tissues is
ZFS >> (ZVM + ZFV) >> ZMM ... Formula 2
It becomes.

(2) As will be described later, according to the electrode arrangement method used with the present invention, the electrical equivalent circuit model can be expressed as shown in FIG. That is,
Ztm = 2 * ZFS + ZMM // (ZVM + ZFV) ・ ・ ・ Equation 3
Furthermore, according to the electrode arrangement method used in conjunction with the present invention, the subcutaneous fat tissue layer can be separated and removed because the effect of spreading resistance in the vicinity of the current application electrode is separated until it can be ignored. It is expressed as
Ztm = ZMM // (ZVM + ZFV) Equation 4

2. Estimating trunk skeletal muscle tissue cross-sectional area [AMM] and trunk skeletal muscle tissue layer impedance [ZMM] (3) Since skeletal muscle tissue volume is highly correlated with cross-sectional area volume and volume, here we Think by area. The cross sectional area amount AMM of the skeletal muscle tissue layer of the trunk abdomen can be roughly estimated by the body specifying information. The reason is that the developmental design of the body's skeletal muscle tissue layer is almost determined by the development and adaptation to support its own weight under the earth's gravity. Therefore, except for athletes and non-gravity adaptors such as paralyzed patients and caregivers, it is possible to estimate with body specifying information. This estimation is performed by substituting height H, weight W, and age Age into the following equations.
AMM = a * H + b * W + c * Age + d Equation 5
Here, a, b, c, and d are constants that give different values for men and women.

(4) The trunk skeletal muscle tissue layer impedance [ZMM] can be expressed by the following equation using the trunk skeletal muscle tissue cross-sectional area amount [AMM].
ZMM = a0 * H / AMM + b0 Equation 6
Here, a0 and b0 are constants.

3. Estimating internal organ tissue volume [AVM] and internal organ tissue impedance [ZVM] (5) Estimating internal organ tissue volume [AVM] of the trunk from body (individual) specific information such as height, weight, sex, and age I can do it. Among the explanatory variables, the influence of the height term is large.
Internal organ tissue volume [AVM] = a1 * Height [H] + b1 * Weight [W] + c1 * Age [Age] + d1 Equation 7
Here, a1, b1, c1, and d1 are constants that give different values for men and women.

(6) Next, the impedance ZVM of the internal organ tissue is estimated.
The internal organ tissue impedance ZVM can be estimated from body (individual) specifying information such as height, weight, sex, and age. Among the explanatory variables, the influence of the height term is large. For convenience, the internal organ tissue amount AVM obtained above is used here. This estimation can be performed using the following equation.
ZVM = a2 * H / AVM + b2 Equation 8
Here, a2 and b2 are constants.

4). Estimation of visceral adipose tissue impedance [ZFV] and visceral adipose tissue volume [AFV] (7) Next, the impedance ZFV of the visceral adipose tissue is estimated.
When Equation 4 is transformed,
1 / Ztm = 1 / ZMM + 1 / (ZVM + ZFV) (9)
When ZFV is derived from Equation 9, the following is obtained, and impedance information having information on visceral adipose tissue can be obtained.
ZFV = 1 / [1 / Ztm-1 / ZMM]-ZVM ... Equation 10
In this equation, Ztm is an actual measurement value. Further, since the trunk skeletal muscle tissue layer impedance ZMM and the internal organ tissue impedance ZVM can be estimated from the body specifying information as described above, ZFV can be extracted by substituting the estimated values. That is, it can be calculated by substituting Equation 6 and Equation 8 into Equation 10.

(8) Visceral adipose tissue volume AFV is treated here as the cross-sectional area of visceral adipose tissue. Visceral adipose tissue amount AFV can be calculated from the above impedance information and height information,
AFV = aa * H / ZFV + bb ... Formula 11
Here, aa and bb are constants.

5. Estimation of subcutaneous fat tissue volume [AFS] (9) The subcutaneous fat tissue volume AFS of the trunk can be estimated from impedance information ZFS of the subcutaneous fat tissue layer and abdominal circumference Lw.
Subcutaneous fat tissue volume [AFS] = aa0 * ZFS * Lw + bb0
Here, aa0 and bb0 are constants.

6). Estimating the trunk visceral fat / subcutaneous fat ratio [V / S] (10) The visceral fat / subcutaneous fat ratio [V / S] is calculated based on the amount of subcutaneous fat tissue [AFS] from Equation 12 and the visceral fat tissue from Equation 11 It can be obtained from the quantity [AFV].
V / S = AFV / AFS Equation 13

7). Body impedance due splanchnic organ tissue abnormality determination concept executive (11) impedance Ztm of the trunk needed to visceral fat tissue volume estimating, since the fluctuation is also a major site by respiration and food, etc., the stability and reliability High information measurement is required. Therefore, highly reliable impedance information of the trunk can be secured by applying the following processing. In addition, it is possible to determine a tissue abnormality of the trunk from the viewpoint as information related to the disturbance of the body fluid distribution of the trunk.

(12) Removal of influence of fluctuation due to respiration (a) The impedance of the trunk is measured at a sampling cycle shorter than 1/2 of a general respiration cycle time.
(B) A smoothing process such as moving average is performed on the measurement data for each sampling.
(C) From the time series data after processing, the periodicity of respiration and the maximum and minimum values for each cycle are detected.
(D) A maximum value and a minimum value for each period are averaged separately.
(E) The average value of the maximum value and the minimum value is averaged, and the median value of respiration is calculated.
(F) When the median respiration for each respiratory cycle enters a stable range within the specified number of times, it is determined that the median respiration is confirmed, and the determined impedance value is registered as the impedance value of the trunk. And complete the measurement.

(13) Abnormal value determination processing due to eating and drinking and water retention (such as urine) in the bladder (a) As for the impedance of the trunk, 26.7 ± 4.8Ω (mean ± SD) is a general value of the group.
(B) On the other hand, the value at the time of constipation and urinary bladder retention and fullness of food and drink in the stomach exceeds the range of mean ± 3SD.
(C) Therefore, when a measured value exceeding 3SD is obtained, the subject is informed of the possibility of effects such as eating and drinking and bladder and urine, and is encouraged to hope for the measurement in the best environment. However, in a subject whose skeletal muscle tissue layer development and internal organ tissue are different from the standard size without actually having these effects, proceed so that the measurement can be continued.
(D) Further, as a method for increasing the measurement sensitivity, the specified values are subdivided according to sex, weight, and height. Alternatively, the specified value is defined as a unit-specific value divided by weight or divided by height.

  Next, based on the measurement principle of the present invention as described above, embodiments of the trunk fat measurement method and apparatus according to the present invention will be described.

  FIG. 1 is a schematic perspective view showing an appearance of an embodiment of a trunk fat measuring device according to the present invention, and FIG. 2 shows trunk fat, that is, trunk visceral fat and trunk subcutaneous fat using the device of FIG. It is the schematic for demonstrating the usage pattern in the case of measuring. 3 and 4 are block diagrams showing a main configuration (excluding electrodes) of the apparatus of FIG. Incidentally, in the apparatus of FIG. 1, three current application electrodes 13 and three voltage measurement electrodes 14 are provided, whereas in the block diagram of FIG. 3, one current application electrode 13 and one voltage measurement electrode 14 are provided. In the block diagram of FIG. 4, two current application electrodes 13 and two voltage measurement electrodes 14 are provided.

  The trunk fat measuring device 1 of the present invention includes a main body 11 and left and right grips 130 and 140. The grip portions 130 and 140 and the main body portion 11 are connected to each other via a flexible joint material so that the grip portion 130 and 140 and the main body portion 11 can be in close contact with the trunk abdomen. As shown in FIG. 2, the grip portions 130 and 140 are used by holding the grip G in each hand and pressing them against the measurement site of the subject, for example, the abdomen.

  On the front surface of the main body 11, an operation display panel 5 having an operation unit 51 and a display unit 52, an alarm buzzer 22, and the like are provided. As is apparent from FIGS. 3 and 4, for example, The calculation / control unit 21, the power supply unit 18, the storage unit 4, and the impedance measurement unit 6 are provided. As shown in FIG. 1, one common electrode C, a plurality of current application electrodes 13, and a plurality of voltage measurement electrodes 14 are provided on the rear surfaces of the grip portions 130 and 140, that is, the surfaces pressed against the abdomen. The current application electrode 13 is an electrode for applying a current to the measurement site of the subject, and the voltage measurement electrode 14 is an electrode for measuring a potential difference at the measurement site of the test subject.

  In the embodiment shown in FIG. 1, the common electrode C is provided on the left grip 130, but may be provided on the right grip 140. Further, as long as the current application electrode 13 and the voltage measurement electrode 14 are provided on the side facing the common electrode C, the current application electrode 13 and the voltage measurement electrode 14 may be provided on the left grip 130 on the opposite side to the illustrated one. Furthermore, the current application electrode and the voltage measurement electrode may be provided not only on the left and right grip portions 130 and 140 but also on the rear side of the main body portion as shown in the figure. In addition, as long as no electrode is provided on the rear surface side, the main body portion may be movable so that it can be turned upside down. That is, the display panel 5 may be arranged on the rear side instead of the front side of the main body.

  The operation unit 51 can be used for inputting body specifying information including height, weight, and the like, and the operation display panel 5 displays various results, advice information, and the like through the display unit 52. The operation display panel 5 may be formed as a touch panel type liquid crystal display in which the operation unit 51 and the display unit 52 are integrated.

  The computation and control unit 21 is based on the body identification information (weight, etc.) input from the operation unit 51, the measured impedance, and the skeletal muscle tissue cross-sectional area amount of the trunk, Calculate trunk trunk skeletal muscle tissue layer impedance, visceral fat tissue impedance, visceral fat tissue volume, internal organ tissue volume, internal organ tissue impedance, subcutaneous fat tissue volume, trunk visceral fat / subcutaneous fat ratio, etc. The process of removing the influence of the above, processing of internal organ tissue abnormality determination, and other various input / output, measurement, calculation and the like are performed.

  The power supply unit 18 supplies power to each part of the electrical system of the present apparatus. The storage unit 4 stores body identification information such as height, trunk length, and abdominal circumference, the above formulas 1 to 13, and the like, as well as appropriate messages for health guide advice as described later. To do.

  The impedance measurement unit 6 includes a current source 12 that supplies current to the current application electrode 13, a current application electrode selection unit 20 a for selecting the current application electrode 13, and a voltage measurement electrode selection unit for selecting the voltage measurement electrode 14. 20b, a differential amplifier 23 that amplifies the potential difference measured by the voltage measurement electrode 14, a band-pass filter (BPF) 24 for filtering, a detector 25, an amplifier 26, an A / D converter 27, and the like. .

  The current application electrode 13 and the voltage measurement electrode 14 may be realized by performing metal plating on the surface of the SUS material and the resin material. This type of electrode is used by coating a water-retaining polymer film on the surface of a metal electrode to wipe off moisture before measurement or wet it with water. By soaking in water, the stability of the electrical contact with the skin can be ensured. Further, although not particularly shown, it is possible to use an adhesive-attached electrode. This is a type in which a replaceable adhesive pad is attached to the base electrode surface of each electrode to ensure contact stability with the skin. This type is often used in, for example, low-frequency treatment devices and electrocardiogram electrodes, etc., and a disposable form that is removed and discarded after measurement, and the pad surface is dirty, resulting in decreased adhesion and moisture evaporation In some cases, the waste is replaced only when it is stored, and is stored in a cover sheet or the like until it is discarded. A structure that can be attached and detached for long-term storage of the electrode part, replenishment of moisture, removal of dirt, and the like can also be employed. As the detachable structure, a hook type frequently used for an electrocardiogram electrode, a connector for a flexible substrate, or the like can be considered.

  In order to explain the principle of the present invention, an electrical equivalent circuit model is introduced. FIG. 5 is a diagram schematically showing the structure of the trunk abdomen that is the basis of this equivalent circuit. From the viewpoint of electrical characteristics, the trunk is composed of subcutaneous fat tissue layer (FS), skeletal muscle tissue layer (MM), internal organ tissue (VM), and visceral adipose tissue (FV) adhering to the gap. Can be divided into

  FIG. 6 is a diagram in which the schematic diagram of the trunk shown in FIG. 5 is modeled in the abdominal circumference cross section at the umbilical height. As shown in this figure, the trunk cross section includes the outermost subcutaneous adipose tissue layer (FS), the skeletal muscle tissue layer (MM) just inside, and the inner organ tissue (VM) inside. It includes visceral adipose tissue (FV) surrounding it.

  FIG. 7 shows the schematic diagram shown in FIG. 6 as an electrical equivalent circuit. Here, as an example, current (I) is applied by the current application electrode 13 in the vicinity of the front and back of the navel, and the potential difference (V) is measured by the voltage measurement electrode 14 disposed in the vicinity thereof. In the case of an equivalent circuit, the electrical resistance is mainly determined by the impedance of the subcutaneous fat tissue layers around the umbilicus (ZFS1, ZFS2), the impedance of the subcutaneous fat tissue layers around the abdomen (ZFS0), and the skeleton on the left and right sides of the navel It appears as the impedance of the muscle tissue layer (ZMM1, ZMM2), the impedance of the visceral adipose tissue near the umbilicus (ZFV1, ZFV2), and the impedance of the internal organ tissue (ZVM) near the center of the trunk.

  FIG. 8 shows a circuit obtained by further simplifying FIG. Since ZFS1 and ZFS2 are considered to have substantially the same size, they are collectively represented as ZFS here, and ZMM1 and ZMM2 or ZFV1 and ZFV2 are represented as ZMM and ZFV, respectively. In addition, ZFS0, which is considered to be significantly lower in conductivity than other regions, is omitted. The point where this can be omitted will be apparent from the description in the previous section “1. Modeling an electrical equivalent circuit of the trunk tissue” (1).

  Next, the relationship between the interelectrode distance and the spreading resistance in the four-electrode method will be described with reference to FIG. FIG. 9 shows the relationship between the distance between the electrodes and the spreading resistance. In the figure, a portion 30 surrounded by a round dotted line is a spreading resistance region. The current from the current application electrode gradually spreads in the subject's body after application, but in the region immediately after application, that is, in the spreading resistance region, it does not spread so much. The density will be very high compared to other areas. Therefore, when the current application electrode 13 and the voltage measurement electrode 14 are arranged too close to each other, the potential difference measured at the voltage measurement electrode 14 spreads and is greatly affected by the current in the resistance region.

For example, as is apparent from Equation 2 described above, the impedance of the subcutaneous fat tissue layer (ZFS) near the umbilicus, the impedance of the skeletal muscle tissue layer (ZMM), the impedance of the visceral fat tissue (ZFV), and the center of the trunk Between the impedance (ZVM) of nearby internal organ tissues,
ZFS >> (ZVM + ZFV) >> ZMM ... Formula 2
There is a relationship.
Therefore, the potential difference measurement impedance ΣZ1 when arranged close to each other with almost no distance between the IV electrodes is as follows:
ΣZ1 = 2 * ZFS + ZMM // (ZVM + ZFV) ≈2 * ZFS
It becomes. As is clear from this, ZFS is amplified several times under the influence of spreading resistance, and information by ZFS is dominant here.

In order to reduce the influence of the spreading resistance, it is necessary to increase the distance between the current application electrode and the voltage measurement electrode. For example, the potential difference measurement impedance ΣZ2 when the distance between the IV electrodes is secured to about 10 cm is
ΣZ2≈2 * ZFS + ZMM // (ZVM + ZFV)
It becomes. By increasing the distance between the IV electrodes, the influence of the spreading resistance is somewhat reduced. However, the ZFS information is still dominant only by separating the distance.

In order to further reduce the influence of spreading resistance, as shown in FIG. 10, a case is considered in which about 10 cm is secured and arranged so that the distance between the IV electrodes and the VV electrodes is about 1/3 each. . The potential difference measurement impedance ΣZ3 in this case is
ΣZ3≈2 * ZFS + ZMM // (ZVM + ZFV).
At this time, the relationship of the voltage drop measured between the electrodes is approximately as follows.
V1 = I * ZMM // (ZVM + ZFV)
V2 = V3 = I * 2 * ZFS
V1: (V2 + V3) ≈1-2: 10-20 = S: N
Here, S 1-2 and N 10-20 variation are due to individual differences in the thickness of the subcutaneous fat tissue layer and the development of the skeletal muscle tissue layer. As can be seen from this result, it is difficult to say that a sufficient S / N can be secured even if the distance between the electrodes is adjusted.

In addition, since most of the current is predominantly energized in the skeletal muscle tissue layer, it is not possible to sufficiently secure energization sensitivity to the composite tissue layer of internal organ tissue and visceral adipose tissue. That is, if the current flowing in the skeletal muscle tissue layer is I1, and the current flowing in the internal organ tissue and visceral fat tissue to be measured is I2,
V1 = I * ZMM // (ZVM + ZFV) = I1 * ZMM = I2 * (ZVM + ZFV)
I = I1 + I2
And therefore
ZMM: (ZVM + ZFV) = I2: I1≈1: 2-5
It becomes. As is clear from this, even if the influence of spreading resistance can be eliminated, the current flowing through the skeletal muscle tissue layer reaches 2-5 times the current flowing through the internal organ tissue and visceral adipose tissue. The S / N characteristic is further deteriorated. In this way, in a thick and short measurement site such as the trunk, even if the inter-electrode distance is adjusted, the upper limit is determined by the distance between the current electrodes, so there is a limit to the improvement of the S / N characteristics. .

  The present invention employs a three-electrode method in which, among the four electrodes in the four-electrode method, the current application electrode and the voltage measurement electrode on one end side of the abdomen can be shared by one electrode having a wide electrode area. This shareable electrode is referred to as the common electrode C as described above. By expanding the electrode area, the influence of the contact area resistance with the skin and the influence of the spreading resistance directly under the current application electrode can be reduced and ignored.

According to one embodiment of the present invention, the limiting conditions for the electrode area for the common electrode C are as follows. That is, the electrode area is 36cm ² or more (ordinary electrode size 2.0 * 2.0 = 4.0cm ² or more nine times), the electrode width of the abdominal circumferential direction, from about 1/10 of abdominal circumference More than that, the electrode length in the trunk length direction is 3 cm or more and up to about 1/10 of the trunk length. Further, the current application electrode 13 and the voltage measurement electrode 14 other than the common electrode C have a general electrode size of 2.0 * 2.0 = 4.0 cm ² .

  FIGS. 11 to 21 show electrode arrangement examples in the trunk fat measurement method of the present invention. 11 to 21 show cross sections of the trunk abdomen, a common electrode C is disposed on the left flank with respect to the umbilicus A, and current application electrodes 13a to 13e and voltage measurement electrodes are disposed on the right flank. 14c-14e are arranged.

  FIGS. 11-14 has shown the example of electrode arrangement | positioning for measuring a subcutaneous fat tissue among trunk adipose tissues. In FIGS. 11 to 14, current application electrodes 13 a, 13 c, 13 d, and 13 e are disposed on the lateral umbilicus, the lower scapula, the flank, and the aponeurosis, respectively. These are arranged at positions close to the current application electrode where the influence of the spreading resistance directly under these current application electrodes is dominant.

  In the electrode arrangement example of FIG. 11, by measuring the potential difference V1 between the common electrode C and the voltage measurement electrode 14a when the current I1 is applied between the common electrode C and the current application electrode 13a, Subcutaneous adipose tissue layer impedance is obtained.

  Similarly, in the electrode arrangement example of FIG. 12, by measuring the potential difference V3 between the common electrode C and the voltage measurement electrode 14c when the current I3 is applied between the common electrode C and the current application electrode 13c, Subcutaneous adipose tissue layer impedance in the lower scapula is obtained.

  Similarly, in the electrode arrangement example of FIG. 13, by measuring the potential difference V4 between the common electrode C and the voltage measurement electrode 14d when the current I4 is applied between the common electrode C and the current application electrode 13d, Subcutaneous adipose tissue layer impedance in the abdomen is obtained.

  Similarly, in the electrode arrangement example of FIG. 14, by measuring the potential difference V5 between the common electrode C and the voltage measurement electrode 14e when the current I5 is applied between the common electrode C and the current application electrode 13e, Subcutaneous adipose tissue layer impedance at the membrane is obtained.

  15 to 18 show electrode arrangement examples for measuring visceral adipose tissue among trunk adipose tissue. 15 to 18, the current application electrodes 13 a and 13 c are arranged on the lateral umbilicus and the lower part of the scapula, respectively, and the voltage measurement electrodes 14 a, 14 b and 14 c avoid the influence of spreading resistance caused by these current application electrodes. It is arranged at a position where a possible distance is secured.

  In the electrode arrangement example of FIG. 15, the amount of visceral fat tissue is measured by measuring the potential difference V2 between the common electrode C and the voltage measurement electrode 14b when the current I1 is applied between the common electrode C and the current application electrode 13a. Torso impedance for obtaining.

  Similarly, in the electrode arrangement example of FIG. 16, by measuring the potential difference V3 between the common electrode C and the voltage measurement electrode 14c when the current I1 is applied between the common electrode C and the current application electrode 13a, the internal organs are obtained. Trunk impedance for determining the amount of adipose tissue is obtained.

  Similarly, in the electrode arrangement example of FIG. 17, by measuring the potential difference V2 between the common electrode C and the voltage measurement electrode 14b when the current I3 is applied between the common electrode C and the current application electrode 13c, the internal organs are obtained. Trunk impedance for determining the amount of adipose tissue is obtained.

  Similarly, in the electrode arrangement example of FIG. 18, by measuring the potential difference V1 between the common electrode C and the voltage measurement electrode 14a when the current I3 is applied between the common electrode C and the current application electrode 13c, the internal organs are obtained. Trunk impedance for determining the amount of adipose tissue is obtained.

  FIG. 19 to FIG. 21 show examples of electrode arrangement for measuring the trunk adipose tissue, that is, both the subcutaneous fat tissue layer and the visceral adipose tissue. In FIGS. 19-21, the current application electrodes 13a and 13c are arranged on the lateral umbilicus and the lower part of the scapula, respectively, and the voltage measurement electrodes 14a and 14c have spreading resistances just below the current application electrodes 13a and 13c, respectively. It is arranged at a position close to the current application electrodes 13a and 13c where the influence is dominant. On the other hand, the voltage measurement electrode 14b is disposed at a position that secures a distance that can avoid the influence of spreading resistance caused by the current application electrodes 13a and 13c.

In the electrode arrangement example of FIG. 19, the potential difference V1 between the common electrode C and the voltage measurement electrode 14a, the common electrode C, and the voltage measurement electrode 14b when the current I1 is applied between the common electrode C and the current application electrode 13a. The potential difference V2 is measured. Then, by obtaining ΔV = V1−V2 obtained by subtracting the potential difference V2 from the potential difference V1, the subcutaneous fat tissue layer impedance in the lateral portion of the umbilicus is obtained. ΔV can also be obtained by directly measuring the potential difference V _1-2 between the voltage measuring electrodes 14a and 14b. Further, the trunk impedance for obtaining the visceral fat tissue amount is obtained from the potential difference V2.

As described with reference to FIG. 10, the potential difference measurement impedance when the electrodes are arranged close to each other with little distance between the IV electrodes is as follows.
ΣZ3≈2 * ZFS + ZMM // (ZVM + ZFV). Therefore, applying this to V1 and V2 above,
V1 = I1 * ΣZ3≈I * 2 * ZFS + I * ZMM // (ZVM + ZFV)
V2 = I * ZMM // (ZVM + ZFV)
It becomes. Accordingly, by obtaining ΔV = V1−V2 = I * 2 * ZFS, it is possible to obtain a subcutaneous fat tissue layer impedance with higher accuracy than using only V1 in the arrangement examples of FIGS.

Similarly, in the electrode arrangement example of FIG. 20, when the current I3 is applied between the common electrode C and the current application electrode 13c, the potential difference V3 between the common electrode C and the voltage measurement electrode 14c, the common electrode C, and the voltage. The potential difference V2 between the measurement electrodes 14b is measured. Then, by obtaining a difference ΔV = V3−V2 obtained by subtracting the potential difference V2 from the potential difference V3, the subcutaneous fat tissue layer impedance in the lower scapula is obtained. ΔV can also be obtained by directly measuring the potential difference V _3-2 between the voltage measuring electrodes 14c and 14b. Further, the trunk impedance for obtaining the visceral fat tissue amount is obtained from the potential difference V2.

  In the electrode arrangement example of FIG. 21, two current application electrodes and two voltage measurement electrodes are arranged. In this electrode arrangement example, the potential difference V1 (I1) between the common electrode C and the voltage measurement electrode 14a, the common electrode C, and the voltage measurement electrode when the current I1 is applied between the common electrode C and the current application electrode 13a. The potential difference V3 (I1) between 14c is measured. Then, by obtaining a difference ΔV = V3 (I1) −V2 (I1) obtained by subtracting the potential difference V2 (I1) from the potential difference V3 (I1), the subcutaneous fat tissue layer impedance in the lateral portion of the umbilicus is obtained. ΔV can also be obtained by directly measuring the potential difference ΔV (I1) between the voltage measuring electrodes 14a and 14c. Further, the trunk impedance for obtaining the visceral fat tissue amount is obtained from the potential difference V3 (I1).

  Furthermore, in the electrode arrangement example of FIG. 21, the potential difference V3 (I3) between the common electrode C and the voltage measurement electrode 14c and the common electrode C when the current I3 is applied between the common electrode C and the current application electrode 13c. And the voltage difference V1 (I3) between the voltage measuring electrode 14a is measured. Then, by obtaining a difference ΔV = V3 (I3) −V1 (I3) obtained by subtracting the potential difference V1 (I3) from the potential difference V3 (I3), the subcutaneous fat tissue layer impedance in the lower scapula is obtained. ΔV can also be obtained by directly measuring the potential difference ΔV (I3) between the voltage measuring electrodes 14a and 14c. Further, the trunk impedance for obtaining the amount of visceral fat tissue is obtained from the potential differences V3 (I1) and V1 (I3).

  Next, with reference to the basic flowchart shown in FIG. 22 and the subroutine flowcharts shown in FIGS. 23 to 28, the trunk visceral fat measuring device in the embodiment of the present invention shown in FIGS. 1 to 4 and FIGS. The operation and operation will be described.

  In the basic flowchart shown in FIG. 22, first, when a power switch (not shown) in the operation unit 51 is turned on, power is supplied from the power supply unit 18 to each part of the electrical system, and the display unit 52 includes the height and the like. A screen for inputting body specifying information (height, weight, sex, age, etc.) is displayed (step S1).

  Subsequently, according to this screen, the user inputs height, weight, sex, age, and the like from the operation unit 51 (step S2). In this case, the body weight may be input from the operation unit 51. However, data measured by a body weight measuring device (not shown) connected to the main body unit 11 is automatically input to perform calculation and control. The body eye identification information (weight) may be calculated by the unit 21. These input values are stored in the storage unit 4.

  Next, in step S3, it is determined whether or not morphometric measurement actual values such as trunk length and abdominal circumference length are input. If these morphometric measurement actual values are input, morphometric measurement is performed in step S4. The actual values such as the trunk length and the waist circumference are input from the operation unit 51, and the process proceeds to step S6. If it is determined in step S3 that the morphometric measurement actual value is not input, the process proceeds to step S5. These input values are also stored in the storage unit 4. Similarly, numerical information obtained in the following processing is stored in the storage unit 4.

  In step S5, the computation / control unit 21 estimates the trunk length, abdominal circumference, and the like from the body specifying information such as height, weight, sex, and age stored in the storage unit 4 (for example, , Use calibration curve created from human body information database).

  Subsequently, in step S <b> 6, trunk impedance (Zx) measurement processing is performed by the impedance measurement unit 6. The trunk impedance measurement process will be described later with reference to a subroutine flowchart shown in FIG.

  Next, in step S7, the calculation / control unit 21 performs a trunk skeletal muscle tissue cross-sectional area amount (AMM) estimation process. This calculation process is performed based on the above-described Expression 5 using, for example, the height H, the weight W, and the age Age stored in the storage unit 4.

  Next, in step S8, the calculation / control section 21 performs a trunk skeletal muscle tissue layer impedance (ZMM) estimation process. This ZMM is performed based on the above-described equation 6 using the height H stored in the storage unit 4 and the AMM obtained in step S7.

  Next, in step S9, the computation and control unit 21 performs an estimation process of the subcutaneous fat tissue mass (AFS). Step S9 will be described in detail later with reference to a subroutine flowchart shown in FIG.

  In step S10, the calculation / control section 21 performs an internal organ tissue amount (AVM) and internal organ tissue impedance (ZVM) estimation process. Step S10 will be described in detail later with reference to a subroutine flowchart shown in FIG.

  In step S11, the calculation / control unit 21 performs a visceral fat tissue impedance (ZFV) and visceral fat tissue amount (AFV) estimation process. Step S11 will be described in detail later with reference to a subroutine flowchart shown in FIG.

  Next, in step S12, the calculation / control section 21 performs a calculation process of the visceral fat / subcutaneous fat ratio (V / S). This process is performed according to the above-described equation 13 stored in the storage unit 4.

Next, in step S <b> 13, the computation / control section 21 performs a physique index (BMI) computation process. This calculation process can be calculated from the weight W and the height H stored in the storage unit 4 by the following formula.
BMI = W / H ²

Further, in step S14, the calculation / control section 21 performs a calculation process of the trunk body fat percentage (% Fatt). This calculation process is based on the amount of subcutaneous fat tissue (AFS), visceral fat tissue (AFV), trunk skeletal muscle tissue cross-sectional area (AMM), and internal organ tissue (AVM) stored in the storage unit 4. It is calculated by the following formula.
% Fatt = (AFS + AFV) / [(AFS + AFV) + AMM + AVM] * 100

Next, in step S15, the calculation / control section 21 performs a calculation process of the visceral fat rate (% VFat). This process is performed by the following formula from the trunk body fat percentage (% Fatt) and the visceral fat / subcutaneous fat ratio (V / S) calculated by the above-described calculation process and stored in the storage unit 4.
% VFat =% Fatt * (V / S) / [(V / S) +1]

  Finally, in step S16, the calculation and control unit 21 determines the visceral fat tissue information (AFV,% VFat), body composition information (% Fatt, AMM, AFS, AVM) obtained by the calculation process as described above, A display process is performed to display a physique index (BMI), advice guidelines obtained by a process described later, and the like on the display unit 52. Thereby, a series of processes is completed (step S17).

Next, the subcutaneous fat tissue mass (AFS) estimation process in step S9 will be described in detail with reference to the subroutine flowchart of FIG. This estimation process is performed using various values stored in the storage unit 4 in step S18. In the present invention, first, the subcutaneous fat tissue layer impedance ZFS is calculated by the following equation.
ZFS = aa1 * ZFS1 + bb1 * ZFS2 + cc1
Here, aa1, bb1, and cc1 are constants, and different values are given for men and women. Then, the subcutaneous fat tissue amount AFS is calculated based on the above-described Expression 12.

  Next, the internal organ tissue quantity (AVM) and internal organ tissue impedance (ZVM) estimation processing in step S10 will be described in detail with reference to the subroutine flowchart of FIG. In this estimation process, the internal organ tissue amount (AVM) is calculated using the numerical values stored in the storage unit 4 and the above-described equation 7 in step S19, and the numerical values stored in the storage unit 4 in step S20. And using Equation 8 above.

  Next, the visceral adipose tissue impedance (ZFV) and visceral adipose tissue volume (AFV) estimation processing in step S11 will be described in detail with reference to the subroutine flowchart of FIG. In this estimation process, the visceral fat tissue impedance (ZFV) is calculated using the numerical values stored in the storage unit 4 and the above-described equation 10 in step S21, and the height H stored in the storage unit 4 in step S22. And the visceral fat tissue amount (AFV) is calculated using the calculated visceral fat tissue impedance (ZFV) and the above-described equation 11.

  Next, the trunk impedance (Zx) measurement process in step S6 will be described in detail with reference to the subroutine flowchart of FIG. 26 showing the first embodiment. In the first embodiment, the preceding section 7. As described in (12) and (13), the “removal effect removal process due to respiration” and the “abnormal value determination process due to eating and drinking and water retention (urine etc.) in the bladder” are performed. First, in step S23, the arithmetic and control unit 21 performs initial setting of a counter and the like, for example, initial setting of the number of samples of measurement data of the trunk impedance Ztm, based on an instruction from the operation unit 51 or the like.

Subsequently, in step S24, the calculation / control section 21 determines whether or not it is a measurement timing. If the measurement timing is determined, in step S25a, the computation / control unit 21 performs a trunk impedance (Ztm) measurement electrode arrangement setting process, and performs a trunk impedance (Ztm _x ) measurement process. Further, in step S25b, subcutaneous fat tissue layer impedance (ZFS1) measurement electrode arrangement setting processing is performed, and subcutaneous fat tissue layer impedance (ZFS1 _x ) measurement processing is performed. In step S25c, a subcutaneous fat tissue layer impedance (ZFS2) measurement electrode arrangement setting process is performed, and a subcutaneous fat tissue layer impedance (ZFS2 _x ) measurement process is performed.

On the other hand, if it is determined in step S24 that it is not the measurement timing, the process proceeds to step S26, where the measured impedance (ZFS1 _x , ZFS2 _x ) is measured impedance (Ztmx _x ) and subcutaneous fat tissue layer impedance (ZFS1 _x , ZFS2 _x ). Zx) Data smoothing processing (moving average processing or the like), that is, Z _x = (Z _x-1 + Z _x ) / 2 is performed. Then, in step S27, trunk impedance measurement data respiration variation correction processing is performed. This correction processing will be described later with reference to the subroutine flowchart of FIG. Note that the subcutaneous fat tissue layer impedance (ZFS1 _x , ZFS2 _x ) is not affected by respiratory fluctuations, and thus correction processing such as trunk impedance is not performed.

  Subsequently, in step S28, the computation / control section 21 performs time-series stability confirmation processing of the measured impedance for each part. This is performed by determining whether or not each value after the trunk impedance measurement data breathing fluctuation correction process in step S27 has converged to a value within a predetermined fluctuation a predetermined number of times.

In step S29, the arithmetic and control unit 21, measured Ztm _x and ZFS _x is to determine whether to satisfy the stability condition. This determination is such that it is determined that the respiration median value is determined when the respiration median value for each respiration cycle enters a stable range within the specified number of times. If it is determined in step S29 that the stability condition has been satisfied, the process proceeds to step S30, where the determined median impedance value is used as the trunk impedance value or the subcutaneous fat tissue layer impedance to determine the final stable condition. The value is registered in the storage unit 4 as a measurement result value. In other words, it satisfies the stability condition, the Ztm _x as Ztm, as ZFS1 the ZFS1 _x, as ZFS2 the ZFS2 _x, respectively registers. On the other hand, if it is determined in step S29 that the stability condition is not satisfied, the process returns to step S24 and the same processing is repeated.

  Subsequent to step S30, in step S31, the calculation / control unit 21 performs an abnormal value determination process by eating and drinking and urinary bladder retention, and in step S32, the notification buzzer 22 indicates the completion of the measurement (see FIG. 3). Using a buzzer or the like to notify the user, the measurement is completed. The abnormal value determination process in step S31 will be described later with reference to the subroutine flowchart of FIG.

Next, the trunk impedance measurement data respiration variation correction process in step S27 will be described in detail with reference to the subroutine flowchart of FIG. First, in step S33, the calculation / control section 21 performs an inflection point detection process from the time series data processed in step S27. In step S34, it is determined whether or not it is an inflection point. This is performed by detecting data of polarity change positions of the front and rear derivatives or difference values. If it is determined in step S34 that the point is not an inflection point, this respiration variation correction process ends. On the other hand, when it is determined in step S34 that the point is an inflection point, the process proceeds to step S35, and it is determined whether or not the maximum value is reached. This is a step of distributing the maximum value and the minimum value. When it is not the maximum value, the minimum value determination data moving average process is performed by the following equation stored in the storage unit 4 in step S36.
[Ztm] min _x ← ([Ztm] min _x-1 + [Ztm] min _x ) / 2

When it is determined in step S35 that the maximum value is obtained, in step S37, the maximum value determination data moving averaging process is performed using the following equation stored in the storage unit 4.
[Ztm] max _x ← ([Ztm] max _x-1 + [Ztm] max _x ) / 2

Subsequently, in step S38, it is determined whether the maximum value and minimum value data for one breathing cycle have been secured. If it is determined in step S38 that the data has been secured, in step S39, the respiration fluctuation median value calculation process (average value of maximum value and minimum value data) is calculated using the following formula stored in the storage unit 4. Operation).
Ztm _x ← ([Ztm] max _x + [Ztm] min _x ) / 2

Next, the abnormal value determination processing based on eating and drinking and urinary bladder retention in step S31 will be described in detail with reference to the subroutine flowchart of FIG. First, in step S40, the arithmetic and control unit 21 checks whether the trunk impedance (Ztm) is within the normal allowable range using the following formula stored in the storage unit 4.
Mean-3SD ≦ Ztm ≦ Mean + 3SD
Here, as an allowable value example, ± 3SD is conceivable with respect to 26.7 ± 4.8 (Mean ± SD).

  In step S41, it is determined whether the trunk impedance is within an allowable range. When it is determined that the value is not within the allowable range, the process proceeds to step S42, where the arithmetic and control unit 21 performs message notification processing regarding a trunk (abdomen) condition abnormality, and displays appropriate advice on the display unit 52. Etc. are made. As this advice, for example, a notification such as “performing a preparation process such as defecation and urination for abnormal trunk condition” can be considered. Further, when the same determination result is obtained after the preparation process, the measurement can be completed using the abnormal value, and the measurement can be stopped.

  When it is determined within the allowable range in step S41, in step S43, the calculation / control unit 21 performs a message notification process regarding normal condition of the trunk (abdomen) condition, and displays appropriate advice on the display unit 52. Made. As this advice, for example, notification such as “normal trunk condition” can be considered.

  With such operations and operations, according to the present invention, visceral adipose tissue information of the trunk (trunk abdomen) can be obtained, and furthermore, the influence removal process of fluctuation due to breathing, and the moisture in the bladder and the like It is possible to perform abnormality determination processing due to storage (such as urine) and provide advice information accordingly. In the above-described embodiment, the fat percentage is obtained as the trunk visceral adipose tissue information. However, the present invention is not limited to this, and by using an appropriate conversion equation, the cross-sectional area amount and the volume amount are obtained. Or weight.

It is a schematic perspective view which shows the external appearance of one Example of the trunk visceral fat measuring device by this invention. It is the schematic for demonstrating the usage aspect in the case of measuring trunk visceral fat using the apparatus of FIG. It is a block diagram which shows the structure of one Example of the trunk visceral fat measuring device by this invention. It is a block diagram which shows the structure of another Example of the trunk visceral fat measuring device by this invention. It is a figure which shows typically the structure of a trunk abdomen. It is the figure which modeled the schematic diagram of the trunk abdominal part shown by FIG. 5 in the abdominal circumference cross section in umbilical height. It is the figure which represented the model figure of FIG. 6 as an electrical equivalent circuit. It is the figure which simplified and showed the circuit of FIG. It is a figure explaining the relationship between the distance between electrodes, and spreading resistance. It is a figure explaining the relationship between the distance between electrodes, and spreading resistance. It is a cross-sectional view of a trunk abdomen showing an example of electrode arrangement for subcutaneous adipose tissue measurement. It is a cross-sectional view of a trunk abdomen showing another example of electrode arrangement for subcutaneous adipose tissue measurement. It is a cross-sectional view of the trunk abdomen showing still another example of electrode arrangement for measuring subcutaneous fat tissue. It is a cross-sectional view of the trunk abdomen showing still another example of electrode arrangement for measuring subcutaneous fat tissue. It is a cross-sectional view of a trunk abdomen showing an example of electrode arrangement for visceral adipose tissue measurement. It is a cross-sectional view of the trunk abdomen showing another example of electrode arrangement for visceral adipose tissue measurement. It is a cross-sectional view of the trunk abdomen showing still another example of electrode arrangement for visceral adipose tissue measurement. It is a cross-sectional view of the trunk abdomen showing still another example of electrode arrangement for visceral adipose tissue measurement. It is a cross-sectional view of the trunk abdomen showing an example of electrode arrangement for subcutaneous fat tissue measurement and visceral fat tissue measurement. It is a cross-sectional view of the trunk abdomen showing another example of electrode arrangement for subcutaneous fat tissue measurement and visceral fat tissue measurement. It is a cross-sectional view of the trunk abdomen showing still another example of electrode arrangement for subcutaneous fat tissue measurement and visceral fat tissue measurement. It is a figure which shows the basic flowchart for trunk fat measurement by one Example of this invention. It is a figure which shows the estimation processing flow of the amount of subcutaneous fat tissues as a subroutine of the basic flow of FIG. It is a figure which shows the estimation processing flow of the internal organ tissue quantity and internal organ tissue impedance as a subroutine of the basic flow of FIG. It is a figure which shows the estimation processing flow of the visceral fat tissue impedance and visceral fat tissue amount as a subroutine of the basic flow of FIG. It is a figure which shows the trunk | body impedance measurement processing flow as a subroutine of the basic flow of FIG. FIG. 27 is a diagram showing a trunk impedance measurement data respiration variation correction process flow as a subroutine of the trunk impedance measurement process flow of FIG. 26. It is a figure which shows the abnormal value determination processing flow by eating and drinking, bladder urine retention, etc. as a subroutine of the trunk | body trunk impedance measurement processing flow of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Trunk visceral fat measuring device 4 Memory | storage part 5 Operation display panel 6 Impedance measuring part 11 Main body part 12 Current source 13, 13a, 13b, 13c, 13d, 13e Current application electrode 14, 14a, 14b, 14c, 14d, 14e Voltage Measurement electrode 20a Current application electrode selection unit 20b Voltage measurement electrode selection unit 21 Operation / control unit 23 Differential amplifier 24 Bandpass filter 25 Detection unit 26 Amplifier 27 A / D converter 30 Spreading resistance region 51 Operation unit 52 Display unit 130 Grip Part 140 Grip part C Common electrode G Grip A Navel

Claims (10)

In the trunk fat measurement method for determining the amount of trunk fat tissue using the trunk impedance measured using the current application electrode pair and the voltage measurement electrode pair arranged in the trunk,
Necessary for measurement by arranging one common electrode having a large electrode area on the trunk and sharing the common electrode as one of the current application electrode and the voltage measurement electrode pair. The configuration of each of the three electrodes is a current application electrode, a voltage measurement electrode, and a common electrode.
Placing the common electrode on one side of the trunk abdomen,
The current application electrode is disposed on the lateral umbilical region on the umbilical circumference on the side facing the common electrode, the lateral abdomen, the lower scapula or the joint aponeurosis between the rectus abdominis and the external oblique muscle,
The trunk adipose tissue mass is a trunk visceral adipose tissue mass, and the voltage measurement electrode is disposed at a position that secures a distance that can avoid the influence of spreading resistance due to the current application electrode ,
The electrode area of the common electrode is 36 cm ² or more, the electrode width in the abdominal circumference direction is about 1/10 or more of the abdominal circumference, and the electrode length in the trunk length direction is 3 cm. This is up to about 1/10 of the trunk length,
The position of the voltage measurement electrode is at a position about 10 cm or more away from the current application electrode so that the distance between the current application electrode and the voltage measurement electrode and the distance between the voltage measurement electrodes are about 1/3 of the distance between the current application electrodes A method for measuring trunk fat, comprising: In the trunk fat measurement method for determining the amount of trunk fat tissue using the trunk impedance measured using the current application electrode pair and the voltage measurement electrode pair arranged in the trunk,
Necessary for measurement by arranging one common electrode having a large electrode area on the trunk and sharing the common electrode as one of the current application electrode and the voltage measurement electrode pair. The configuration of each of the three electrodes is a current application electrode, a voltage measurement electrode, and a common electrode.
Placing the common electrode on one side of the trunk abdomen,
The current application electrode is disposed on the lateral umbilical region on the umbilical circumference on the side facing the common electrode, the lateral abdomen, the lower scapula or the joint aponeurosis between the rectus abdominis and the external oblique muscle,
The trunk adipose tissue mass is a trunk subcutaneous adipose tissue mass, and the voltage measurement electrode is arranged at a position close to the current application electrode where the influence of the spreading resistance just under the current application electrode is dominant ,
The electrode area of the common electrode is 36 cm ² or more, the electrode width in the abdominal circumference direction is about 1/10 or more of the abdominal circumference, and the electrode length in the trunk length direction is 3 cm. This is up to about 1/10 of the trunk length,
The trunk fat measurement method , wherein the position of the voltage measurement electrode is less than 10 cm from the current application electrode . In the trunk fat measurement method for determining the amount of trunk fat tissue using the trunk impedance measured using the current application electrode pair and the voltage measurement electrode pair arranged in the trunk,
Necessary for measurement by arranging one common electrode having a large electrode area on the trunk and sharing the common electrode as one of the current application electrode and the voltage measurement electrode pair. The configuration of each of the three electrodes is a current application electrode, a voltage measurement electrode, and a common electrode.
Placing the common electrode on one side of the trunk abdomen,
The current application electrode is disposed on the lateral umbilical region on the umbilical circumference on the side facing the common electrode, the lateral abdomen, the lower scapula or the joint aponeurosis between the rectus abdominis and the external oblique muscle,
The trunk adipose tissue mass is a trunk visceral adipose tissue mass and a trunk subcutaneous adipose tissue mass, and the voltage measurement electrode has a first position that secures a distance that can avoid the influence of spreading resistance due to the current application electrode; And a second position adjacent to the current application electrode where the influence of the spreading resistance directly under the current application electrode is dominant ,
The electrode area of the common electrode is 36 cm ² or more, the electrode width in the abdominal circumference direction is about 1/10 or more of the abdominal circumference, and the electrode length in the trunk length direction is 3 cm. This is up to about 1/10 of the trunk length,
The first position of the voltage measurement electrode is separated from the current application electrode by about 10 cm or more so that the distance between the current application electrode and the voltage measurement electrode and the distance between the voltage measurement electrodes are about 1/3 of the distance between the current application electrodes. Position,
The trunk fat measurement method , wherein the second position of the voltage measurement electrode is a position less than 10 cm from the current application electrode . In the trunk fat measurement apparatus for obtaining a trunk fat tissue amount using trunk impedance measured using a current application electrode pair and a voltage measurement electrode pair arranged on the trunk, the current application electrode pair and the voltage measurement One common electrode having a large electrode area is provided so as to be used as one of the current application electrode and the voltage measurement electrode of the electrode pair, so that the configuration of the electrodes necessary for the measurement is the current application electrode and the voltage measurement electrode. And three common electrodes,
The electrode area of the common electrode is 36 cm ² or more, the electrode width in the abdominal circumference direction is about 1/10 or more of the abdominal circumference, and the electrode length in the trunk length direction is 3 cm. This is up to about 1/10 of the trunk length,
The common electrode is disposed on one flank of the trunk abdomen,
The current application electrode is disposed on the lateral umbilical region on the circumference of the umbilicus on the side facing the common electrode, the flank, the lower scapula or the joint aponeurosis between the rectus abdominis and the external oblique muscle,
The voltage measurement electrode is dominantly influenced by the first voltage measurement electrode disposed at a first position that secures a distance that can avoid the influence of the spreading resistance due to the current application electrode, and the spreading resistance immediately below the current application electrode. a second voltage measuring electrodes disposed in the second position close to the current applying electrodes seen including,
The electrode area of the common electrode is 36 cm ² or more, the electrode width in the abdominal circumference direction is about 1/10 or more of the abdominal circumference, and the electrode length in the trunk length direction is 3 cm. This is up to about 1/10 of the trunk length,
The first position of the voltage measurement electrode is separated from the current application electrode by about 10 cm or more so that the distance between the current application electrode and the voltage measurement electrode and the distance between the voltage measurement electrodes are about 1/3 of the distance between the current application electrodes. Position,
The trunk fat measuring device , wherein the second position of the voltage measuring electrode is a position less than 10 cm from the current application electrode . The trunk fat measuring device according to claim 4 , wherein the current application electrode includes a plurality of current application electrodes arranged at a plurality of positions on the flank. Measure and apply a potential difference between the common electrode and the voltage measurement electrode when a current is applied between the common electrode and the current application electrode, or a potential difference between each of the voltage measurement electrodes. The trunk fat measuring device according to any one of claims 4 to 5 , further comprising means for measuring trunk impedance based on the measured current and the measured potential difference. The trunk fat measurement device according to claim 6 , wherein the measuring unit obtains a subcutaneous fat tissue layer impedance at a site close to the current application electrode using the measured trunk impedance. Trunk skeletal muscle that estimates the amount of trunk skeletal muscle tissue based on the body specific information and estimates the impedance of the trunk skeletal muscle tissue layer based on the estimated trunk skeletal muscle tissue amount and the body specific information Tissue layer impedance estimating means, estimating internal organ tissue amount of trunk based on body identification information, and internal organ tissue of trunk based on estimated internal organ volume of body trunk and body identification information a trunk organ tissue impedance estimating means for estimating the impedance, and body trunk impedance measured by the measuring means, the body based on the impedance of the splanchnic organ tissue impedance and trunk of the estimated trunk skeletal muscle tissue layer A trunk visceral adipose tissue impedance estimating means for estimating the impedance of the trunk visceral adipose tissue, and an impedance of the estimated trunk visceral adipose tissue Trunk fat measuring apparatus according to claim 6, further comprising a trunk visceral fat tissue volume estimating means for estimating the trunk visceral fat tissue volume based on the dance and body specifying information. The trunk visceral adipose tissue impedance estimator means that the trunk's skeletal muscle has an electrical equivalent circuit for the trunk with respect to a series circuit of the impedance of the internal organ tissue of the trunk and the impedance of the trunk visceral fat tissue. The trunk fat measuring device according to claim 8 , wherein the impedance of the tissue layer is connected in parallel. The trunk fat measurement apparatus according to claim 7 , further comprising a subcutaneous fat tissue amount estimation unit that calculates a subcutaneous fat tissue amount of the trunk based on the determined subcutaneous fat tissue layer impedance and body specifying information.

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