JP2006288884A - Trunk visceral fat measuring method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus capable of measuring visceral adipose tissue accumulated in a trunk with high accuracy.
A current is applied from a current application electrode pair to a site where the subcutaneous fat tissue layer is thin, or where the abdominal part of the skeletal muscle tissue layer is absent or thin, and a potential difference generated in the tissue energized by this current is converted into a voltage. The amount of visceral adipose tissue of the trunk is obtained by using the impedance of the trunk obtained by measuring with the measurement electrode pair and using the measured potential difference.
[Selection] Figure 10

Description

  The present invention relates to a trunk visceral fat measuring method and apparatus.

  The estimation technique of body adipose tissue using bioelectrical impedance has spread to the world as a technique for measuring body adipose tissue and body fat percentage, but in reality, it does not directly measure adipose tissue. In other words, it is an electrical measurement of lean tissue in which water other than fat 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 be measured, 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 The technique of measuring 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 that simplifies the impedance CT measurement technique, arranges a current application / voltage measurement electrode in the trunk umbilical cord, measures the impedance of the abdomen, and estimates the amount of visceral fat tissue ( (See Patent Document 1 and Patent Document 2).

Japanese Patent No. 3396677 Japanese Patent No. 3396684

  However, the body fat information is particularly useful for screening for lifestyle-related diseases such as diabetes, hypertension and hyperlipidemia. The importance of measurement is increasing day by day.

  Visceral adipose tissue is an adipose tissue that is intensively distributed in the vicinity of the abdomen of the trunk, and has been determined by the cross-sectional area of the adipose tissue in an abdominal cross-sectional image by X-ray CТ or MRI. However, the apparatus is large-scale, and in the case of X-rays, there is a problem of exposure, and there is a cost, which is not suitable for measurement in the field and home. Therefore, visceral adipose tissue is generally estimated from the correlation with whole body adipose tissue or the correlation with 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 cord of the trunk and measuring 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 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 it obtains an impedance value related to the internal tissue by applying current from the abdominal surface to the tissue site to be measured. Actually, the measured impedance information itself has little useful sensitivity to visceral adipose tissue due to problems in the internal structure of a certain trunk. 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 electrical 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 observation of information in the spreading resistance region where the current density is high in the subcutaneous fat tissue layer immediately below the electrode becomes dominant. End up.

  Furthermore, since the trunk, which is the measurement site, is thick and short, the sensitivity in the subcutaneous fat tissue layer in the current density concentration (spreading resistance) region directly under the current application electrode is high, and the skeletal muscle tissue is more in comparison with the fat tissue. Since the conductivity is considerably high, a route in which most of the current that has passed through the subcutaneous fat tissue layer returns through the subcutaneous fat tissue layer to the side of the current application electrode that opposes through the skeletal muscle tissue layer is taken. 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 fat tissue to be measured, that is, the visceral fat tissue that adheres to and accumulates in the internal organ tissue and its surroundings. It can hardly be energized, 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 subcutaneous or visceral adipose tissues pathologically or when there are many / small intermediate skeletal muscle tissue layers. . 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, 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 site section of the subject by the applied current is measured to measure the measurement site section bioelectrical impedance. When the four-electrode method is applied to a thick and short measurement site such as the trunk, the current density concentration at which the current begins to spread (ie, the spreading resistance region) is, for example, directly under the current application electrode, so that it is near the subcutaneous fat tissue layer. A large potential difference is generated and accounts for 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 have an arrangement that ensures a sufficient distance between the current application electrode and the voltage measurement electrode. In general measurement, since 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 due to spreading resistance (noise), and S is measured between the voltage electrodes). Signal) 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 portion, and is generally a subject with a tendency to obesity with a large thickness. 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.

  An object of the present invention is to eliminate these problems in the prior art, ensuring the sensitivity necessary for measurement even in areas of internal organ tissues and visceral adipose tissues with poor electrical conductivity, and fat accumulated in the trunk. It is an object of the present invention to provide a method and an apparatus capable of easily and accurately measuring adipose tissue attached and accumulated around an internal organ tissue and adipose tissue information accumulated in a subcutaneous layer.

  According to one aspect of the present invention, a current is applied from the current application electrode pair to at least one of a site where the subcutaneous fat tissue layer is thin and a muscle abdomen of the skeletal muscle tissue layer is not present or is thin, A potential difference generated in a tissue energized by the current is measured by a voltage measurement electrode pair, and a visceral fat tissue amount of the trunk is obtained using impedance of the trunk obtained using the potential difference. A method for measuring trunk visceral fat is provided.

  According to one embodiment of the present invention, the current application electrode pair is arranged in the trunk periphery direction, and the voltage measurement electrode pair is arranged at a distant position in the trunk length direction from the current application electrode pair. It is preferable to do this.

  According to another embodiment of the present invention, the voltage measurement electrode pair measures the potential difference at a site where the subcutaneous fat tissue layer is thin or a region where the skeletal muscle tissue layer is absent or thin. Is preferred.

  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 And determining the impedance of the trunk visceral fat tissue based on the determined impedance of the trunk, the impedance of the trunk skeletal muscle tissue layer and the impedance of the internal organ tissue of the trunk, Preferably, the amount of trunk visceral adipose tissue is determined based on the impedance of the trunk visceral adipose tissue and the body specifying information.

  According to yet another embodiment of the present invention, based on the impedance of the trunk, the impedance of the trunk skeletal muscle tissue layer and the impedance of the internal organ tissue of the trunk, The step of obtaining the impedance includes that the electrical equivalent circuit of the trunk has an impedance of the trunk skeletal muscle tissue layer with respect to a series circuit of the impedance of the internal organ tissue of the trunk and the impedance of the visceral fat tissue of the trunk. It is assumed that they are connected in parallel.

  According to still another embodiment of the present invention, the site may be a section between the umbilicus and the upper edge of the iliac crest, or a connecting tendon between the rectus abdominis and the external oblique muscle.

  According to still another embodiment of the present invention, the trunk impedance may be measured near the circumference of the abdomen.

  According to still another embodiment of the present invention, any one or more of the electrodes of the current application electrode pair and the voltage measurement electrode pair may be arranged at a position shifted from the abdominal circumference. .

  According to still another embodiment of the present invention, the current application electrode pair is disposed on the abdominal circumference, and the voltage measurement electrode is formed as a pair or one of the electrodes forming the pair from the abdominal circumference. You may arrange | position in the position which remove | deviated.

  According to still another embodiment of the present invention, the current application electrode pair may be disposed between the left and right parts when viewed from the umbilicus, while the voltage measurement electrode pair includes the umbilicus. May be disposed between the left and right parts when viewed from the center.

  The voltage measurement electrode may be arranged in a trunk longitudinal direction in an abdominal region that is out of the circumference of the abdomen.

  According to another aspect of the present invention, a current applying electrode pair for applying a current to at least one of a site where the subcutaneous fat tissue layer is thin and a muscle abdomen of the skeletal muscle tissue layer is not present or thin, A voltage measuring electrode pair for measuring a potential difference generated in the tissue energized by the current, and determining the amount of visceral fat tissue of the trunk using the impedance of the trunk obtained using the potential difference A trunk visceral fat measuring device is provided.

  According to one embodiment of the present invention, the current application electrode pair may be arranged in the trunk periphery direction, and the voltage measurement electrode pair may be arranged in a distant position in the trunk length direction from the current application electrode pair. Good.

  According to another embodiment of the present invention, the voltage measurement electrode pair may measure the potential difference at a site where the subcutaneous fat tissue layer is thin or a region where the muscle abdomen of the skeletal muscle tissue layer is absent or thin. preferable.

  According to still another embodiment of the present invention, the trunk skeletal muscle tissue amount estimation means for estimating the trunk skeletal muscle tissue amount based on the body specifying information, the estimated trunk skeletal muscle tissue amount and the body The trunk skeletal muscle tissue layer impedance estimating means for estimating the impedance of the trunk skeletal muscle tissue layer based on the specified information, and the internal organ tissue amount of the trunk based on the body specified information Internal organ tissue impedance estimation means for estimating the impedance of the internal organ tissue of the trunk based on the internal organ tissue amount and body specific information of the trunk, the estimated impedance of the trunk, and the estimated Torso visceral adipose tissue I. Estimating impedance of torso visceral adipose tissue based on impedance of trunk skeletal muscle tissue layer and impedance of internal organ tissue of trunk And impedance estimating means may further include a trunk visceral fat tissue volume estimating means for estimating the trunk visceral fat tissue volume on the basis of the impedance and the body specifying information of the trunk visceral fat tissue above estimation.

  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, the impedance of the internal organ tissue of the trunk and the trunk visceral adipose tissue The estimation may be performed on the assumption that 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, the apparatus further comprises a respiratory fluctuation influence removing means for removing the influence of fluctuation due to breathing based on the impedance of the trunk measured at a sampling cycle shorter than the respiratory cycle time. There may be.

  According to still another embodiment of the present invention, there is further provided an abnormal value determination processing means for performing an abnormal value determination process by comparing the measured trunk impedance with a general value of a group. Also good.

  According to still another embodiment of the present invention, the information processing apparatus may further include a display unit that displays advice information based on a determination result by the abnormal value determination processing unit.

  According to still another embodiment of the present invention, the trunk visceral adipose tissue amount may be represented by a trunk visceral fat percentage, or a trunk visceral fat tissue cross-sectional area, It may be represented by a trunk visceral adipose tissue volume, or may be represented by a trunk visceral adipose tissue weight.

  According to the present invention, it is possible to accurately measure the trunk visceral adipose tissue by increasing the energization amount and sensitivity to the visceral organ tissue and the visceral adipose tissue. Further, the S / N characteristic can be improved by arranging the voltage measurement electrode at the position where the muscle abdominal tissue is removed from the N component due to the disturbance of the potential due to the skeletal muscle tissue layer that becomes noise.

  Further, even in a paralyzed patient and a subject who is bedridden due to care or the like, the subject can easily measure by setting the measurement part as the front surface of the abdomen excluding the back part. Furthermore, since the subject can be aware of the measurement site by attaching electrodes to the abdomen, it is beneficial to improve measurement accuracy and to ensure motivation by conscious restraint.

  In addition, the accuracy of screening information according to the required level can be made clear in the course of combining the accumulation of accumulated adipose tissue adhering to the vicinity of internal organ tissue with the conventional simple measurement method and simplicity. it can.

  Furthermore, according to the present invention, the trunk visceral adipose tissue can be accurately measured with a small and simple device, so that it can be optimized for home use. Moreover, an abdominal condition check prior to measurement, that is, early check of inflammation or pathological abnormal fluid distribution in internal organ tissues or the like is possible, and appropriate health guide advice can be given accordingly. Therefore, it is possible for the user to obtain various information useful for self-management for maintaining and promoting sustainable health by appropriately performing daily diet and exercise and maintaining motivation for it. Can be very useful.

  Before describing the embodiments and examples of the present invention in detail, the principle of measuring the visceral fat of the trunk according to the present invention will be described. The present invention basically uses the bioelectrical impedance information and body identification information, visceral fat tissue information (cross-sectional area amount, volume amount or weight) of the trunk (trunk abdomen), more specifically, the body The present invention relates to a method and the like that makes it possible to easily and accurately measure adipose tissue accumulated in a trunk, particularly adipose tissue attached and accumulated around an internal organ tissue and adipose tissue information accumulated in a subcutaneous layer.

For this reason, the present invention makes full use of the following technique.
(1) Assume that the tissue information included in the bioelectrical impedance information of the trunk is an equivalent circuit model in which the skeletal muscle tissue layer, the internal organ tissue, and the visceral fat tissue are in series and 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 an equivalent circuit model in series-parallel in the organization.

(3) Subcutaneous fat 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 waist 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 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 replace the fluctuation of the measured impedance information of the trunk due to respiration with a constant condition value, Impedance measurement Sampling cycle is within 1/2 of general respiratory cycle, respiratory change is monitored in time series, maximum value and minimum value for each respiratory cycle are determined for each respiratory cycle, and rest breathing The median of can be supplemented.

(7) Further, it is also possible to check in advance of adverse effects caused by 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 earth's gravity, 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 fat tissue are configured in series, and the subcutaneous fat tissue layer and the skeletal muscle tissue layer are respectively parallel to the serial composite tissue. Configured. The equivalent circuit model will be described in detail in the description of the embodiment described later. According to this model, current flows predominantly through the skeletal muscle tissue layer when energized in the longitudinal direction of the trunk. Since visceral adipose tissue adheres to the gaps around the internal organ tissue, when there is no visceral adipose tissue, or when there is little visceral adipose tissue, the internal organ tissue exhibits conductivity close to that of the skeletal muscle tissue layer. Also, a current is applied. In addition, as the visceral adipose tissue increases, the energization amount to the synthetic tissue layer as a complex of the visceral 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 fat is faster than that of subcutaneous fat, it is considered that there are many blood vessels in the tissue and blood volume.

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 <FS
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 ... Equation 2
It becomes.

2. Estimation of trunk skeletal muscle tissue cross-sectional area (AMM) and trunk skeletal muscle tissue layer impedance (ZMM) (2) Visceral adipose tissue volume can be expressed in terms of cross-sectional area and volume. In the case of the cross-sectional area amount, the cross-sectional area amount by CT method (X-ray-CT, MRI) is considered as a general measurement standard in the measurement at the umbilical circumference. On the other hand, in the case of the volume amount, it can be obtained by integrating the cross-sectional area amount by the slice by the CT method with a plurality of slice information in the length direction. The amount of skeletal muscle tissue (skeletal muscle mass) is considered to have a high correlation with both the cross sectional area and volume. Here, the cross-sectional area is considered. The amount of cross-sectional area (AMM) of the skeletal muscle tissue layer can be roughly estimated by body specific information. This is because 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 non-gravity adaptors such as athletes, paralysis nurses, 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 3
Here, a, b, c, and d are constants.
(3) Trunk skeletal muscle tissue layer impedance (ZMM) can also be estimated from body specific information. For convenience, the cross sectional area (AMM) obtained above is used here. This estimation can be performed using the following equation.
ZMM = a0 * H / AMM + b0 Formula 4
Here, a0 and b0 are constants.

3. From the relational expressions of the estimation formulas 1 and 2 of the visceral fat tissue impedance (ZFV) and the visceral fat tissue amount (AFV), there can be considered a technique that enables the visceral fat tissue information to be estimated by the following two approaches.
(4) Approach 1
Since the subcutaneous adipose tissue layer has a higher volume resistivity than other constituent tissues, it is omitted from the viewpoint of the equivalent circuit of the trunk. That is, it can be considered that the information of lean tissue including visceral fat tissue excluding the subcutaneous fat tissue layer of the trunk is measured in the impedance value measured in the trunk. Therefore, this relational expression can be expressed as follows.
Ztm ≒ ZMM // (ZVM + ZFV) ... Formula 5
When formula 5 is transformed,
1 / Ztm ≒ 1 / ZMM + 1 / (ZVM + ZFV) ... Formula 6
By revealing the impedance ZMM of the skeletal muscle tissue layer and the impedance ZVM of the internal organ tissue in this formula by means described below, the impedance ZFV of the visceral fat tissue can be calculated. The visceral fat tissue amount can be estimated from the impedance information of the visceral fat tissue. When ZFV is derived from Expression 6, the following Expression 7 is obtained, and impedance information having information on visceral adipose tissue can be obtained.
ZFV = 1 / [1 / Ztm-1 / ZMM]-ZVM ... Equation 7

(5) Approach 2
In the approach 1, the subcutaneous fat tissue layer is omitted, but it can be an error factor for a subject having a large amount of subcutaneous fat tissue.
In this formula, the impedance ZMM of the skeletal muscle tissue layer and the impedance ZVM of the internal organ tissue are the same as those described above, and the impedance information for the impedance ZFS of the subcutaneous fat tissue layer is the same as that of other tissues. There is a useful relationship with the amount of tissue. Here, it is generally reported that the amount of subcutaneous adipose tissue has a very high correlation with the perimeter of the tissue surface, that is, the abdominal circumference (particularly for subjects with a lot of subcutaneous adipose tissue, Alternatively, the subcutaneous adipose tissue layer can be estimated from the abdominal circumference information. Therefore, the impedance of the subcutaneous fat tissue layer can be estimated from information on the abdominal circumference. Hereinafter, the impedance ZFV of the visceral adipose tissue can be calculated by a method similar to the above approach. The visceral fat tissue amount can be estimated from the impedance information of the visceral fat tissue.
When Equation 1 is transformed,
1 / Ztm = 1 / ZFS + 1 / ZMM + 1 / (ZVM + ZFV)
ZFV = 1 / [1 / Ztm−1 / ZMM−1 / ZFS] −ZVM ・ ・ ・ Equation 9

(6) Visceral adipose tissue volume (AFV) is treated here as the visceral adipose tissue cross-sectional area. The visceral adipose tissue volume (AFV) can be calculated from the impedance information and the height information in Equation 10,
AFV = aa * H / ZFV + bb ... Formula 10
Here, aa and bb are constants.

4). Estimating internal organ tissue volume [AVM] and internal organ tissue impedance [ZVM] (7) Estimating internal organ tissue volume [VM] 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 11
Here, a1, b1, c1, and d1 are constants that give different values for men and women.
The reference amount of visceral adipose tissue volume VM used in this calibration curve (regression equation) is obtained by integrating the CSA (tissue cross-sectional area) for each slice obtained by MRI method or X-ray CТ method in the length direction. The calculated tissue volume or CSA from one slice such as the umbilical position. The tissue volume can be converted into a tissue amount by converting the tissue density information known in prior research papers into weight.

(8) 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 volume [AVM] obtained above is used here. This estimation can be performed using the following equation.
ZVM = a2 * H / AVM + b2 Equation 12
Here, a2 and b2 are constants.

5. Estimation of subcutaneous fat tissue volume [AFS] (9) The subcutaneous fat tissue volume [AFS] of the trunk can be estimated from the abdominal circumference [Lw] ² . Furthermore, accuracy improvement can be expected by adding other body specific information as an explanatory variable to obtain a multiple regression equation.
For men: Subcutaneous adipose tissue volume [AFS] = a10 * abdominal circumference [Lw] ² + b10 * height [H] + c10 * body weight [W]
+ d10 * Age [Age] + e10 ... Formula 13
For women: Subcutaneous fat tissue mass [AFS] = a11 * abdominal circumference [Lw] ² + b11 * height [H] + c11 * body weight [W]
+ d11 * Age [Age] + e11 ... Formula 14
Here, a10, a11, b10, b11, c10, c11, d10, d11, e10, e11 are regression coefficients and constants.
The standard amount of subcutaneous fat tissue volume FS used in this calibration curve (regression equation) is measured by integrating the CSA (tissue cross-sectional area) for each slice obtained by the MRI method or X-ray CТ method in the length direction. The calculated tissue volume or CSA from one slice such as the umbilical position. The tissue volume can be converted into a tissue amount by converting the tissue density information known in prior research papers into weight.

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 equations 13 and 14 and the viscera from equation 10 It can be obtained from the amount of adipose tissue [AFV].
V / S = AFV / AFS Equation 15

7. Concept of internal organ tissue abnormality judgment by trunk (middle) impedance (11) Trunk impedance Ztm necessary for visceral adipose tissue mass estimation is also a part that varies greatly due to breathing and eating and drinking, stability and Measurement of highly reliable information is required. Therefore, highly reliable impedance information of the trunk can be secured by applying the following processing. Further, it is possible to determine a tissue abnormality of the trunk from the viewpoint as information relating to the disturbance of the body fluid distribution in the partial 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 respiratory rate for each respiratory cycle enters a stable range within the prescribed number of times, it is determined that the median respiratory rate is confirmed, and the determined median impedance value is registered as the impedance value of the trunk. 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 development of the skeletal muscle tissue layer and internal organ tissue is different from the standard size without actually having these effects, the measurement should be continued.
(D) Further, as a method of increasing the determination sensitivity, the specified values are subdivided according to sex, weight, and height. Alternatively, the specified value is defined as a value per unit by dividing by weight or by height.

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

  FIG. 1 is a schematic perspective view showing an appearance of an embodiment of a trunk visceral fat measuring apparatus according to the present invention, FIG. 2 is a usage diagram thereof, and FIG. 3 is included in the trunk visceral fat measuring apparatus according to the present invention. Each block diagram of the main body is shown.

  The trunk visceral fat measuring device 1 of the present invention includes a main body part 11 and two grip electrode parts 130 and 140 connected to the main body part 11 via electric wires 120L and 120R. The grip electrode portions 130 and 140 may be of a handy type as shown in FIG. The grip electrode portions 130 and 140 are held in each hand, and they are used by being pressed against the measurement site of the subject, for example, the abdomen.

  An operation display panel 5 having an operation / input unit 51 and a display unit 52 and an alarm buzzer 22 are provided on the front surface of the main body 11, and, as is apparent from FIG. 3, for example, the calculation / control unit 21. In addition, a power supply unit 18, a storage unit (memory) 4, a printing unit 21a, an impedance measuring unit, and the like are provided.

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

  The calculation / control unit 21 determines the body skeletal muscle tissue cross-sectional area amount, the body based on the body identification information (weight, etc.) input from the operation / input unit 51, the measured impedance, Formulas 1 to 15, and the like. Calculates 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. Performs effects removal processing, internal organ tissue abnormality determination, and other various input / output, measurement, calculation, and the like.

  The power supply unit 18 supplies power to each part of the electrical system of the present apparatus.

  The storage unit 4 stores body specifying information such as height, trunk manager, trunk manager, etc., and the above formulas 1 to 15 and the like, as well as appropriate messages for health guide advice as described later, etc. Remember.

  The printing unit 21a prints various results displayed on the display unit 52, advice information, and the like.

  The impedance measurement unit includes current application electrodes 13L and 13R that apply current to the measurement site of the subject, voltage measurement electrodes 14L and 14R that measure a potential difference at the measurement site of the test subject, a current source 12 that supplies current to the current application electrode 13, An electrode selector 20 for selecting an electrode (not shown) when there are three or more voltage measuring electrodes 14, a differential amplifier 23 for amplifying the measured potential difference, a bandpass filter 24 for filtering, A detection unit 25, an amplifier 26, an A / D converter 27, and the like are included.

  On the contact surfaces of the grip electrode portions 130 and 140, for example, current application electrodes 13R and 13L are provided in the lower stage, and voltage measurement electrodes 14R and 14L are provided in the upper stage, respectively.

  The current application electrodes 13R and 13L and the voltage measurement electrodes 14R and 14L 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, for example, in low-frequency treatment devices and electrocardiogram electrodes, etc., when it is removed and discarded after measurement, and when the pad surface becomes dirty and adhesion decreases or moisture evaporates There is a form in which it is stored in a cover sheet or the like until it is discarded and replaced.

  In order to explain the principle of the present invention, an electrical equivalent circuit model is introduced here. FIG. 4 schematically shows 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. 5 is a diagram in which the schematic diagram of the trunk shown in FIG. 4 is modeled by 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. 6 shows the schematic diagram shown in FIG. 5 as an electrical equivalent circuit. For example, when the current (I) is applied by the current application electrodes 13L and 13R and the potential difference (V) is measured by the voltage measurement electrodes 14L and 14R, the electrical resistance in this equivalent circuit is mainly around the umbilicus. Impedance of the subcutaneous fat tissue layer (ZFS1, ZFS2), Impedance of the subcutaneous fat tissue layer around the abdomen (ZFS0), Impedance of the skeletal muscle tissue layers on the left and right sides of the navel (ZMM1, ZMM2), Visible as visceral fat tissue impedance (ZFV1, ZFV2), and further as internal organ tissue impedance near the trunk center (ZVM).

  FIG. 7 shows a circuit obtained by further simplifying FIG. Since ZFS1 and ZFS2 are considered to have substantially the same size, they are represented as ZFS having the same value, 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. 8 shows the relationship between the distance between the electrodes and the spreading resistance. In the drawing, a portion 30 surrounded by a round dotted line indicates 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, so in these regions The current density is 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 voltage 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 the above-described formula 2, the impedance (ZFS) of the subcutaneous fat tissue layer near the umbilicus, the impedance (ZFS0) of the subcutaneous fat tissue layer around the abdomen, the impedance (ZMM) of the skeletal muscle tissue layer, viscera Between the impedance of the fat tissue (ZFV) and the impedance of the internal organ tissue near the center of the trunk (ZVM),
ZFS >> (ZVM + ZFV) >> ZMM
There is a relationship.
Therefore, the voltage 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 voltage measurement impedance ΣZ2 in the case where the distance between the IV electrodes is secured to about 10 cm is arranged as follows:
ΣZ2≈2 * ZFS + ZMM // (ZVM + ZFV)
It is. As is apparent, the influence of the spreading resistance is somewhat reduced by increasing the distance between the I and V electrodes. However, the ZFS information is still dominant only by being separated by this degree.

In order to examine the influence of the spreading resistance in detail, as shown in FIG. 9, the distance between the IV electrodes and the VV electrodes in the electrodes 13L, 14Lb, 14Rb, and 13R is about 1/3 each. Consider a case where about 10 cm is secured and arranged. However, the electrodes 14La and 14Ra are arranged close to each other with almost no distance between the IV electrodes. The voltage 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
The variation of 1-2 of S and 10-20 of N in the above formula is 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 currents are predominantly energized in the skeletal muscle tissue layer, it is not possible to ensure sufficient energization sensitivity to the mixed 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. .

  FIG. 10 shows an example of an electrode arrangement method according to the present invention in the same manner as in FIG. In order to secure the optimum S / N condition, here, the amount of current applied from the current application electrodes 13L and 13R in the internal organ tissue and the visceral fat tissue inside the skeletal muscle tissue layer is increased, and the measurement sensitivity to the measurement target tissue is increased. Secure. Furthermore, by applying a current from a thin site of the subcutaneous fat tissue layer, in other words, a site where the impedance (ZFS) of the subcutaneous fat tissue layer is small, the influence of spreading resistance is minimized, and internal organ tissue and Improves energization sensitivity to visceral adipose tissue. In order to reduce the influence of spreading resistance, the measurement of the potential difference by the voltage measuring electrodes 14L and 14R is also applied to the thin part of the subcutaneous fat tissue layer that is less affected by the subcutaneous fat tissue layer, in other words, the impedance (ZFS) of the subcutaneous fat tissue layer. Is preferably carried out at a small site. In the case where the abdominal circumference cross-sectional area is used as a measurement standard, the portion to which current is applied from the current application electrodes 13L and 13R is the portion where the subcutaneous fat tissue layer is deposited most thinly or the muscle of the skeletal muscle tissue layer having good conductivity. There is no abdomen or a thin skeletal muscle connection region, for example, tendon part (tendon drawing, aponeurosis, etc.) 15, more specifically, a section between the umbilicus and the upper edge of the iliac crest, rectus abdominis muscle and outer abdomen It becomes the connecting tendon between the oblique muscles.

  Furthermore, in order to ensure the optimum S / N condition, in the present invention, all four electrodes are not aligned on the abdominal circumference, but at least one electrode is arranged at a position shifted from the abdominal circumference. By taking the arrangement away from the umbilical circumference, the best distance condition can be secured, and the impedance (ZFS) of the subcutaneous fat tissue layer can be separated and removed as a measurement of the original four-electrode method. .

  As such an arrangement method, for example, the current application electrode pair is arranged on the abdominal (umbilical) circumference, and only one of the voltage forming electrodes is paired or one of the electrodes forming the pair is located at a position off the circumference. A method of arranging can be considered. One of the current application electrode pairs may be arranged on the circumference and the other may be arranged at a position off the circumference. The current application electrode pair or the voltage measurement electrode pair may be disposed between the left and right parts when viewed from the navel A of the subject, that is, in a thin part of the subcutaneous fat tissue layer. However, the voltage measuring electrode is, for example, in the longitudinal direction of the trunk in the abdominal region deviated from the abdominal (umbilical) circumference.

  11 to 13 show examples of actual electrode arrangement. FIG. 11 shows the voltage measurement electrode arranged above the umbilical girth, FIG. 12 shows the voltage measurement electrode arranged below the umbilical girth, and FIG. Although it is an upper part, it arrange | positions in the aponeurosis position of the tendon drawing position a little above the navel A of a rectus abdominis muscle.

  Next, with reference to the basic flowchart shown in FIG. 14 and the subroutine flowcharts shown in FIGS. 15 to 20, the operation and operation of the trunk visceral fat measuring device in the embodiment of the present invention shown in FIGS. 1 and 2 will be described. To do.

  In the basic flowchart shown in FIG. 14, first, when a power switch (not shown) in the operation / input unit 51 is turned on, power is supplied from the power supply unit 18 to each part of the electrical system, and the height and the like are displayed by the display unit 52. A screen for inputting body specifying information (height, weight, sex, age, etc.) including is displayed (step S1).

  Subsequently, according to this screen, the user inputs height, weight, sex, age, and the like from the operation / input unit 51 (step S2). In this case, the weight may be input from the operation / input unit 51, but the data measured by the weight measuring device (not shown) connected to the main body unit 11 is automatically input to perform calculation. The body part specifying information (weight) may be calculated by the control 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 trunk length and abdominal circumference are input from the operation / input 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 calculation / control unit 21 estimates the trunk length, the 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 S6, the trunk impedance measurement process is performed by the impedance measurement unit. 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 3 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 unit 21 performs trunk skeletal muscle tissue layer impedance (ZMM) estimation processing. This ZMM is performed based on the above-described equation 4 using the height H stored in the storage unit 4 and the AMM obtained in step S7.

  Next, in step 9, the calculation / control unit 21 performs an estimation process of subcutaneous fat tissue mass (AFS). Step 9 will be described in detail later with reference to a subroutine flowchart shown in FIG.

  In step S10, the calculation / control unit 21 performs an estimation process of the internal organ tissue volume (AVM) and the visceral adipose tissue impedance (ZVM). Step 10 will be described in detail later with reference to a subroutine flowchart shown in FIG.

  In step S11, the calculation / control section 21 performs a visceral fat tissue impedance (ZFV) and visceral fat tissue volume (AFV) estimation process. Step 11 will be described in detail later with reference to a subroutine flowchart shown in FIG.

  Next, in step S12, the calculation / control unit 21 performs a calculation process of the visceral fat / subcutaneous fat ratio (V / S). This process is performed according to the above-described equation 15 stored in the storage unit 4.

Next, in step S <b> 13, the calculation / control unit 21 performs a physique index (BMI) calculation 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

Furthermore, in step S14, the calculation / control unit 21 performs a calculation process of the trunk body fat percentage (% Fatt). This calculation processing is performed from the subcutaneous fat tissue volume (AFS), visceral fat tissue volume (AFV), trunk skeletal muscle cross-sectional area volume (AMM), and internal organ tissue volume (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 unit 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 / control unit 21 calculates 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 in step S18 using the numerical values stored in the storage unit 4 and the aforementioned equations 13 and 14.

  Next, the internal organ tissue amount (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 11 in step S19, and the numerical values stored in the storage unit 4 in step S20. And using equation 12 above.

  Next, the visceral adipose tissue impedance (ZFV) and visceral adipose tissue mass (AFV) estimation processing in step S11 will be described in detail with reference to the subroutine flowchart of FIG. In this estimation process, in step S21, the visceral fat tissue impedance (ZFV) is calculated using the numerical values stored in the storage unit 4 and the above-described equation 7, and the height H stored in the storage unit 4 is calculated in step S22. Then, the visceral fat tissue impedance (ZFV) and the above-described equation 10 are used to calculate the visceral fat tissue mass (AFV).

  Next, the trunk impedance measurement process in step S6 will be described in detail with reference to the subroutine flowchart of FIG. 18 showing the first embodiment. In this first embodiment, the preceding item 7. As described in (12) and (13), the “removal effect removal processing due to respiration” and the “abnormal value determination processing due to food and drink and water retention (urine etc.) in the bladder” are performed. First, in step S23, the calculation / control unit 21 performs the initial setting of the number of samples of the measurement data of the impedance Ztm of the initial setting trunk such as a counter and the flag F based on an instruction from the operation / input unit 51 or the like. . F is a flag of “1” and “0”.

Subsequently, in step S24, the calculation / control unit 21 determines whether or not it is a measurement timing. If the measurement timing is determined, in step S25, the calculation / control unit 21 performs a trunk impedance (Ztm) measurement electrode arrangement setting process, and performs a trunk impedance (Ztm _x ) measurement process.

  Next, when it is determined in step S24 that it is not the measurement timing, the process proceeds to step S26, and measurement impedance (Zx) data smoothing processing (moving average processing or the like) is performed. Then, in step 27, trunk impedance measurement data breathing fluctuation correction processing is performed. This correction processing will be described later with reference to the subroutine flowchart of FIG.

Subsequently, in step S28, the calculation / control unit 21 performs time-series stability confirmation processing of the measurement 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, the measured Ztm _x it is judged whether or not 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 this step S29 that the stability condition has been satisfied, the process proceeds to step S30, where the determined median impedance value is the trunk impedance value, and the final stable condition determination value is the measured value result. The value is registered in the storage unit 4 as a value. 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 such as eating and drinking and urinary bladder retention, and in step S32, the notification buzzer 22 indicates the completion of the measurement (see FIG. 2). Using a buzzer or the like to notify the user, the measurement is completed. The abnormal value determination process in step 31 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 unit 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. 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. If it is not the maximum value, the minimum value determination data moving averaging process is performed in step S36 using the following equation stored in the storage unit 4.
[Ztm] min _x ← ([Ztm] min _x-1 + [Ztm] min _x ) / 2

If the maximum value is determined in step S35, the maximum value determination data moving average process is performed in step S37 according to 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 calculation / control unit 21 checks whether the trunk impedance (Ztm) is within the normal allowable range using the following equation stored in the storage unit 4.
Mean-3SD ≦ Ztm ≦ Mean + 3SD
Here, 26.7 ± 4.8 (Mean ± 3SD) can be considered as an example of the allowable value.

  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 / 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” may 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 message notification processing 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 condition of trunk” is conceivable.

  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 processing 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 embodiments, the trunk visceral adipose tissue information is obtained as the fat percentage. However, the present invention is not limited to this, and by using an appropriate conversion equation or the like, the cross-sectional area amount or the volume amount is obtained. Or weight.

  FIG. 21 shows an external perspective view of a measuring apparatus according to another embodiment of the present invention. In addition, the same number shall be attached | subjected to the member similar to the above embodiment. The apparatus 1 ′ includes a main body 60 that is slightly curved so as to conform to the shape of the abdomen of the subject, and each of the left and right sides of the main body 60 so as to be able to bend slightly with respect to the main body 60. And electrode support portions 62R and 62L provided in a movable state on the side. As shown in the figure, the device 1 may be of a handy type. For example, the device 1 can be used by pressing each side of the electrode support portions 62R and 62L with the left and right hands against the abdomen of the subject. . Since the electrode support portions 62R and 62L are provided so as to be movable with respect to the main body portion 60, the apparatus 1 'fits perfectly around the abdomen of the subject.

  A liquid crystal display section 64 and various switches 66 are provided on the ventral side surface of the main body section 60. These parts are placed on the subject's ventral side during measurement. Therefore, the subject cannot see the display of the main body 60 during the measurement, but can see it by pulling away from the abdomen after the measurement.

The electrode support portion 62 includes support frames 70R and 70L provided with a hole in the center, two parallel slide rods 74R and 74L spanning the holes 72R and 72L of the support frames 70R and 70L on the left and right sides, and slides thereof. The slide supports 76R and 76L are slidable along the rods 74R and 74L. On the upper surfaces of the slide supports 76R and 76L, various electrodes arranged on the subject's abdomen, that is, the current application electrode 13L ₁ , the voltage measurement electrodes 14L ₁ and 14L ₂ , the current application electrode 13R ₁ , the voltage measurement electrode 14R ₁ , 14R ₂ is provided.

  The number and position of the electrodes 13 and 14 are determined according to a usage mode. In the example of FIG. 25, the arrangement is the same as that of FIG. As is clear from the above-described configuration, according to the measuring apparatus 1 ′ according to the present embodiment, the slide supports 76R and 76L are slid in the directions indicated by the arrows A on the left and right sides of the apparatus. The electrodes 13 and 14 can be easily set to various widths according to the size of the body of the subject.

It is a schematic perspective view which shows the external appearance of one Example of the trunk visceral fat measuring device by this invention. FIG. 2 is a diagram illustrating how the apparatus of FIG. 1 is used. It is a block diagram of the main-body part of the trunk visceral fat measuring device by this invention. It is a figure which shows typically the structure of a trunk trunk abdomen. It is the figure which modeled the schematic diagram of the trunk shown in FIG. 4 in the abdominal circumference cross section in umbilical height. It is the figure which represented the model figure of FIG. 5 as an electrical equivalent circuit. FIG. 7 is a simplified diagram of the circuit of FIG. 6. 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 figure which shows typically an example of electrode arrangement | positioning by this invention with the structure of a trunk abdomen. It is a figure which shows an example of electrode arrangement | positioning. It is a figure which shows an example of electrode arrangement | positioning. It is a figure which shows an example of electrode arrangement | positioning. It is a figure which shows the basic flowchart for trunk visceral 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. FIG. 15 is a diagram illustrating an internal organ tissue amount and internal organ tissue impedance estimation processing flow as a subroutine of the basic flow of FIG. 14. 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 process flow as a subroutine of the basic flow of FIG. FIG. 19 is a diagram showing a trunk core impedance measurement data respiration variation correction process flow as a subroutine of the trunk impedance measurement process flow of FIG. 18. It is a figure which shows the abnormal value determination processing flow by eating and drinking, urinary bladder urine storage, etc. as a subroutine of the trunk | body impedance measurement processing flow of FIG. It is a figure which shows the external appearance perspective view of the measuring apparatus by other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fat measuring device 5 Operation display panel 11 Main body part 13 Current application electrode 14 Voltage measurement electrode 21 Calculation / control part 51 Operation / input part 52 Display part 120L Electric wire 120R Electric wire 130 Grip electrode part 140 Grip electrode part A Umbilical

Claims (24)

  A current was applied from a current application electrode pair to a site where the subcutaneous fat tissue layer was thin and at least one of the skeletal muscle tissue layer where the muscle abdomen was not present or was thin. A trunk visceral fat measurement method, wherein a potential difference is measured by a voltage measurement electrode pair, and a visceral fat tissue amount of the trunk is obtained using impedance of the trunk obtained using the potential difference.   The trunk visceral fat measuring method according to claim 1, wherein the current application electrode pair is arranged in the trunk periphery direction, and the voltage measurement electrode pair is arranged at a position far from the current application electrode pair in the trunk length direction. .   3. The trunk visceral fat measurement method according to claim 1, wherein the voltage measurement electrode pair measures the potential difference at a site where the subcutaneous fat tissue layer is thin, or a region where the skeletal muscle tissue layer does not have or is thin. .   The trunk skeletal muscle tissue amount is obtained based on the body specific information, the impedance of the trunk skeletal muscle tissue layer is obtained based on the obtained trunk skeletal muscle tissue amount and the body specific information, and the body specific information is obtained. Based on the internal organ tissue amount of the trunk and the body specific information, the impedance of the internal organ tissue of the trunk is determined based on the determined internal organ tissue amount of the trunk, Then, the impedance of the trunk visceral adipose tissue is obtained based on the obtained impedance of the trunk skeletal muscle tissue layer and the impedance of the internal organ tissue of the trunk, and the obtained impedance of the trunk visceral fat tissue and body specifying information The trunk visceral fat measuring method according to any one of claims 1 to 3, wherein the trunk visceral fat tissue amount is obtained based on the above.   The step of obtaining the impedance of the trunk visceral adipose tissue based on the impedance of the trunk and the obtained impedance of the trunk skeletal muscle tissue layer and the impedance of the internal organ tissue of the trunk comprises an electrical equivalent circuit of the trunk 5. The impedance of the trunk skeletal muscle tissue layer is connected in parallel to a series circuit of the impedance of the internal organ tissue of the trunk and the impedance of the trunk visceral fat tissue. Torso visceral fat measurement method.   The trunk visceral fat measurement according to any one of claims 1 to 5, wherein the part is a section between the umbilicus and the upper edge of the iliac crest, or a connecting tendon between the rectus abdominis and the external oblique muscle. Method.   The trunk trunk visceral fat measurement method according to any one of claims 1 to 6, wherein the measurement of the impedance of the trunk is performed near the circumference of the abdomen.   The trunk part according to any one of claims 1 to 7, wherein any one or more of the electrodes of the current application electrode pair and the electrodes of the voltage measurement electrode pair are arranged at positions shifted from the abdominal circumference. Visceral fat measurement method.   The current application electrode pair is disposed on the circumference of the abdominal circumference, and the voltage measurement electrode is disposed as a pair or at a position where one of the electrodes forming the pair is out of the circumference of the abdominal circumference. The trunk visceral fat measuring method according to claim 1.   10. The trunk visceral fat measurement method according to claim 1, wherein the current application electrode pair is disposed between the left and right parts when viewed from the umbilicus. 10.   The trunk voltage visceral fat measurement method according to any one of claims 1 to 9, wherein the voltage measurement electrode pair is disposed between the left and right parts when viewed from the umbilicus.   10. The trunk visceral fat measuring method according to claim 1, wherein the voltage measurement electrode pair is arranged in a longitudinal direction of a trunk in an abdominal region deviated from the circumference of the abdomen.   A current applying electrode pair that applies a current to at least one of a site where the subcutaneous fat tissue layer is thin and a muscle abdominal part of the skeletal muscle tissue layer is not present or thin, and a tissue energized by the current A trunk visceral fat measuring device comprising a voltage measuring electrode pair for measuring a potential difference, and determining the visceral fat tissue amount of the trunk using the impedance of the trunk obtained using the potential difference.   The trunk visceral fat measuring device according to claim 13, wherein the current application electrode pair is arranged in a trunk periphery direction, and the voltage measurement electrode pair is arranged in a position far from the current application electrode pair in a trunk length direction.   The trunk visceral fat measuring device according to claim 13 or 14, wherein the voltage measurement electrode pair measures the potential difference at a site where the subcutaneous fat tissue layer is thin, or a region where the abdominal part of the skeletal muscle tissue layer is absent or thin.   Trunk skeletal muscle tissue amount estimation means for estimating trunk skeletal muscle tissue amount based on body specific information, and trunk skeletal muscle tissue layer based on the estimated trunk skeletal muscle tissue amount and body specific information Body skeletal muscle tissue layer impedance estimation means for estimating the impedance of the torso, estimating the internal organ tissue amount of the trunk based on the body specifying information, and the estimated internal organ tissue amount and body specifying information of the trunk The internal organ tissue impedance estimating means for estimating the impedance of the internal organ tissue of the trunk based on the above, the estimated impedance of the trunk, the impedance of the estimated trunk skeletal muscle tissue layer and the inside of the trunk Trunk visceral adipose tissue impedance estimation means for estimating impedance of trunk visceral adipose tissue based on impedance of organ tissue, and the estimated body The body according to any one of claims 13 to 15, further comprising a trunk visceral fat tissue amount estimation unit that estimates a trunk visceral fat tissue amount based on the impedance of the visceral fat tissue and the body specifying information. Executive visceral fat measuring device.   The trunk visceral adipose tissue impedance estimator is configured such that an electrical equivalent circuit of the trunk has the trunk skeletal muscle 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 visceral fat measuring apparatus according to claim 16, wherein the estimation is performed on the assumption that the impedance of the tissue layer is connected in parallel.   The trunk part according to any one of claims 13 to 17, further comprising a breathing fluctuation effect removing unit for removing the influence of fluctuation due to breathing based on impedance of the trunk part measured at a sampling cycle shorter than a breathing cycle time. Visceral fat measuring device.   The trunk visceral fat according to any one of claims 13 to 18, further comprising an abnormal value determination processing unit that performs an abnormal value determination process by comparing the measured impedance of the trunk with a general value of a group. measuring device.   The trunk visceral fat measuring device according to claim 19, further comprising display means for displaying advice information based on a determination result by the abnormal value determination processing means.   21. The trunk visceral fat measuring device according to claim 16, wherein the trunk visceral fat tissue amount is represented by a trunk visceral fat rate.   21. The trunk visceral fat measurement device according to claim 16, wherein the trunk visceral fat tissue amount is expressed by a trunk visceral fat tissue cross-sectional area.   21. The trunk visceral fat measuring device according to claim 16, wherein the trunk visceral fat tissue amount is expressed by a trunk visceral fat tissue volume amount.   21. The trunk visceral fat measurement device according to claim 16, wherein the trunk visceral fat tissue amount is expressed by a trunk visceral fat tissue weight.

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