JPH06114023A - Body fat measuring device - Google Patents

Abstract

PURPOSE:To accurately measure a body fat ratio using an impedance value, the distance value between electrodes and the cross-sectional area due to the peripheral length of an area to be measured as input items by accurately calculating the crosssectional area due to the peripheral length of the area of a human body around which a winding band is wound and the distance between electrodes. CONSTITUTION:A body fat measuring device is constituted of a winding band 1, the impedance electrodes 2 provided to the inside 10 of the band 1 and an operation part 3. A graduation part 4 is formed on the outside surface of the winding band 1 in the longitudinal direction of the peripheral direction thereof and a pair of two-in-a-set electrodes are provided to the inside surface of the end part of the inwardly wound band 1 so as to provide a distance therebetween. Therefore, the distance between the electrodes becomes a constant value. When the graduations of the position where the end edges 121 of the end part of the winding band 1 becoming outside coincides with the graduation part 4 of the inside winding band when the winding band 1 is wound around an upper arm are visually confirmed, the peripheral length of the area to be measured of the upper arm can be calculated. In the operation part 3, a body fat ratio is estimated from the crosssectional area of the band wound area to be measured, an impedance value and the distance value between the electrodes 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention makes it possible to easily measure the body fat percentage by measuring the impedance of a part of the human body. The body fat percentage can be used to determine body fat mass, lean body mass, body water mass, etc. The present invention relates to a body fat measuring device for easy measurement.

[0002]

2. Description of the Related Art Conventionally, various means for obtaining body fat have been considered, such as an underwater weight method, a heavy water dilution method, and a caliper (skin thickness gauge) method.

In the underwater weight method, the body density is obtained from the weight when diving underwater in the state of maximum exhalation and the weight in the air,
The body fat percentage is estimated based on the so-called Archimedes principle. The formula for obtaining the body fat percentage from the body density is Br
ozek. According to J et al., Body fat percentage (%) = (4.570 / body density-4.142)
× 100 is widely used. The underwater weight method is the most commonly used method for accurately determining the body fat percentage.

The heavy water dilution method is a method of obtaining the body water content and the body fat percentage by utilizing the fact that the ratio of the body water content to the fat free mass of the body is substantially constant. In the heavy water dilution method,
Using heavy water (D ₂ O) as a tracer, 1 g of heavy water per 1 kg of body weight diluted to 20% or less with drinking water was orally administered, and the body water content was calculated from the heavy water concentration in urine several hours after the administration. It is an estimate. The body fat percentage can be calculated from the formula of body fat percentage (%) = 100−water content (%) / 0.732 using the percentage (%) of water content in the body weight. Similar to the underwater weight method, the heavy water dilution method is generally used as a method for accurately obtaining the body fat percentage.

The caliper (skin thickness meter) method measures several subcutaneous fat thicknesses with calipers to estimate the amount of body fat, and the Eiken caliper is widely used in Japan.

An impedance method is a method that has been receiving attention in recent years. In this method, an electrode is attached to a body limb and electricity is applied, and the body fat mass is estimated from the measured impedance value of the human body. This utilizes that the electric conductivity of the fat component in the body composition component is smaller than that of other components. FIG. 5 shows a conventional body fat measuring device using an impedance method, in which four electrodes 2 are attached to the right hand and the right foot, and the impedance between them is measured. The body fat amount is estimated by the calculation unit 3 based on the measured impedance value and the height and weight input by the key. For example, it is described in JP-A-62-169023.

[0007]

Among the conventional body fat mass measuring methods as described above, the impedance type body fat measuring device is good in terms of its simple operability and accuracy. Impedance type body fat measurement uses a 4-electrode type electrode, and an electrode that applies a current and an electrode that measures the potential difference are attached to the back of the right hand and the back of the right foot, and a constant current is applied at a frequency of 50 KHz or 100 KHz. The body fat percentage is estimated based on the impedance value applied to the human body and measured.

Since the above-mentioned measurement regards the human body as a kind of resistor and measures the impedance, the impedance value of the human body is influenced by the body composition, and the distance between the electrodes measured and the cross-sectional area of the current-carrying part are measured. It is strongly influenced.

In this conventional impedance-type body fat measuring device, important items such as the distance between electrodes and the cross-sectional area are substituted by items such as height and weight, and the body fat mass is estimated from the measured impedance value, height and weight. Is what you are doing. This is thought to be because it is troublesome to quantify the distance between the electrodes because the electrodes were attached to the right hand and right foot, but the effect of the limbs with large electrical resistance on the measured impedance value In consideration of the size of the body fat, there was a problem that the estimation error of the body fat amount becomes large by not considering the body limb length which has a large individual difference.

The object of the present invention has been made in view of the above-mentioned points, and by changing the part for measuring the impedance value and the measuring method, the impedance value, the inter-electrode distance value, and the circumference of the measurement part are changed. A body fat measuring device capable of accurately measuring a body fat percentage using a cross-sectional area as an input item.

[0011]

According to a first aspect of the present invention, a winding band is wound around a part of a human body and a winding circumference of the part is measured, and the inner surface of the winding body is mounted at a distance. The electrode for impedance measurement, the cross-sectional area of the wound portion calculated by the measured circumference, the measured impedance value,
A calculation unit configured to calculate the body fat percentage based on the inter-electrode distance value.

The invention according to claim 2 is such that the measurement site of the human body on which the winding band is wound is measured by the upper arm.

[0013]

According to the constitution of the body fat measuring instrument of the present invention, the cross-sectional area due to the circumferential length of the part of the human body wrapped by the winding band can be accurately measured, and the distance value between the electrodes can be accurately obtained. The body fat percentage can be accurately measured by the calculation unit based on the cross-sectional area of the wound portion calculated by the measured circumference, the measured impedance value, and the interelectrode distance value.

[0014]

EXAMPLES First, the measurement of the impedance value will be described.
The 4-electrode method is used to measure the impedance value of the human body. This four-electrode method uses four electrodes, and two electrodes, a constant current applying electrode and a voltage detecting electrode, form a set, and the impedance is measured on both sides of the human body part. Attach with the electrodes inside. Next, apply a high frequency of about 50 KHz to the constant current applying electrode for 500 times.
An impedance value is obtained by applying a constant current of about μA and detecting the potential difference from the voltage detection electrode. If the input impedance of the amplifier when measuring the potential difference is made sufficiently large, the impedance value at the measurement site of the human body can be measured accurately.

The principle of estimating the body fat percentage from the impedance value will be described. Since the impedance is proportional to the length of the conductor and inversely proportional to the cross-sectional area of the conductor, the following equation (1)
Can be expressed as

Z = ρL / a (1) where Z is the impedance (Ω), ρ is the electrical conductivity (Ωcm), L is the conductor length (cm), and a is the cross-sectional area (cm ² ). According to 1), ρ = aZ / L (2), and in this equation (2), ρ is determined by the composition of the site to be measured, and thus has a strong correlation with the water content or fat content of the measurement site. Therefore, if a body, an upper arm, or a foot, which has a high correlation with the fat mass of the human body, is selected and measured for impedance measurement, there is a strong correlation between aZ / L and the body fat mass or the body water mass. The body fat percentage can be estimated.

Taking the upper arm as an example, the estimation formula for measuring the body fat percentage is created by using the impedance value Z measured on the upper arm and the cross-sectional area a and the inter-electrode distance obtained from the circumference or diameter of the upper arm. Conductivity ρ obtained from the value L is plotted on the horizontal axis, body fat percentage obtained by the standard underwater weight method or heavy water dilution method is plotted on the vertical axis, and the measured data is plotted to find the regression line of each point. be able to. The body fat percentage can be estimated by substituting Z, a, and L into this regression line for calculation.

In the calculation unit, based on this body fat percentage,
Body fat mass, lean body mass, body water content, nutritional status of each person,
A more useful body fat measuring device can be obtained by calculating obesity determination, weight loss target, exercise menu for weight loss, and the like.

Further, the body fat percentage can be estimated in the same manner for the parts of the human body other than the upper arm by using the same estimation formula as in the above method.

Hereinafter, description will be given with reference to the drawings shown as the embodiments of the present invention. FIG. 1 shows an embodiment of the present invention, in which a body fat measuring instrument 1 is composed of a winding band 1, an impedance measuring electrode 2 mounted on an inner side 10 of the winding band 1, and a computing unit 3. Has been done. A scale portion 4 is formed on the outer side surface of the winding strip 1 in the longitudinal direction in the circumferential direction. The scale portion 4 is formed on the inner side surface of the end portion 11 of the winding strip 1 wound inward, and at both ends in the width direction of the winding strip 1. Two pairs of electrodes 2 are mounted in the vicinity in a state of being separated by a pair. This impedance measuring electrode 2
Has a constant current applying electrode 21 on the outer side and a voltage detecting electrode 22 on the inner side, and these constitute one set and are composed of four electrodes. In practice, the electrodes 2 need to be separated by about 3 cm or more. In this case, the distance value L between the electrodes 2 is a fixed value because it is attached to the winding band 3, and is in a fixed state. Then, as shown in FIG. 2, when the winding band 1 is wound around the upper arm 6, the edge 1 of the end portion 12 of the winding band 1 which is on the outer side of the winding.
The circumference at the measurement site can be determined by visually observing the scale at a position that coincides with the scale portion 4 formed on the outer peripheral surface of the winding band 1 on the inner side of which 21 is wound. Then, this circumference is input to the arithmetic unit 3. One sheet-shaped fastener 110 is formed at the edge of the outer peripheral surface of the winding band 1, and the other sheet-shaped fastener is engaged inside the end portion 12 wound on the outside of the winding band 1. 120 is formed. The sheet-shaped fasteners 110 and 120 are engaged so as to maintain the wound state when the winding band 1 is wound around the part of the human body (here, the upper arm 6) as shown in FIG. As other means to maintain the winding state,
It may be fastened with a string or the like.

The calculation unit 3 includes a display unit 31 and a power source operation unit 32.
And the circumference input section 33, and the constant current applying electrode 2
1, a high frequency of 50 KHz and 500 μA is applied, the potential difference is obtained by the voltage detection electrode 22, and the impedance is measured. Then, the body fat percentage is calculated by the above-described estimation formula from the cross-sectional area a of the wound portion calculated by inputting the measured circumference, the impedance value Z measured by the electrode 2, and the distance value L between the electrodes 2. To estimate. In this embodiment, the measurement can be performed only by winding the winding band 1, and the measurement is easy without any complication.

Although the perimeter of the above-mentioned measurement portion was visually determined and input, the electrical resistance portion of the linear resistor was provided at the position of the scale portion 4 of the winding strip 1 to provide the outside of the winding strip 1. End 12 that is wound toward
An electric terminal portion for contacting the electric resistance portion and measuring the resistance value thereof is provided on the inner side of the edge of the, and the winding band 1 is wound around the human body part, and at the same time, the electric resistance portion and the electric terminal portion are in contact with each other. The resistance value may be automatically measured, and the measured value may be input to the arithmetic unit 3 and arithmetically operated by the arithmetic unit 3 to automatically calculate the perimeter and cross-sectional area a of the measurement site. .

FIG. 3 shows a second embodiment, in which the tape portion 5 is pulled out from the winding band 1 in the width direction, and the electrode 2 is mounted inside the tip portion thereof. When the tape portion 5 is extended, the distance value L between the electrodes 2 is constant. In this embodiment, the width of the winding band 1 can be narrowed, the winding can be easily performed, and the measurement site can be easily attached.

Alternatively, one electrode 2 may be fixed to the winding band 1 and the other electrode may be attached to the extended tape portion 5.

FIG. 4 shows another embodiment, in which the winding band 1 is arranged so that the positions between the electrodes 2 are diagonal to the measurement site of the human body.
The electrode 2 is attached to the inside of the
In this case, it becomes possible to measure the body fat more accurately by passing through the inside of the human body by the electrodes 2 in the diagonal position.

[0026]

EFFECTS OF THE INVENTION The body fat measuring device of the present invention is different from the conventional measuring method and can be operated in a state in which the distance between electrodes at the measurement site of the human body and the cross-sectional area of the site are taken into consideration, and the body fat can be measured accurately The quantity can be measured. The operability is simple and the measurement is easy.

By setting the measurement site on the upper arm, which has a high correlation with the body fat percentage, the band can be easily attached to the measurement site and the operability is good.

[Brief description of drawings]

FIG. 1 is a perspective view showing a body fat measuring device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which the winding band of the body fat measuring device according to one embodiment is wound around the upper arm.

FIG. 3 is a perspective view showing a state in which the second embodiment is wound around an upper arm.

FIG. 4 is a perspective view showing a state in which another embodiment is wound around an upper arm.

FIG. 5 is a perspective view showing a conventional impedance measurement state.

[Explanation of symbols]

 1 winding band 2 electrode 3 arithmetic unit 4 scale unit 5 tape unit

Claims (2)

[Claims] 1. A winding band wound around a part of a human body to measure a winding circumference of the part, an impedance measuring electrode attached to the winding body at a distance, and calculation based on the measured circumference. A body fat measuring device, comprising: a calculation unit configured to calculate a body fat percentage based on the cross-sectional area of the wound portion, the measured impedance value, and the inter-electrode distance value. 2. The body fat measuring device according to claim 1, wherein the measurement site of the human body around which the winding band is wound is measured by the upper arm.