JPH11253413A - Bioimpedance measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproducibly and accurately measure the body fat ratio and body water content ratio by bringing application electrodes into contact with on the part closer to the finger tips and the part closer to the body relative to the wrist joint. SOLUTION: In measurement of a bioimpedance measurement apparatus, a user holds a grip part 1 and a grip part 2 with his/her right and left hands respectively, with the upper surfaces of the hands facing upward, brings an electrode 3 and a detection electrode 4 into contact with the right hand and a portion nearer to the user's body side than the right wrist, respectively, and also brings an application electrode 5 and a detection electrodes 6 into contact with the left hand and a portion inner than the left wrist, respectively. Then, through the application electrodes 3, 5 a minute a.c. current (e.g.500 A, 50 kHz) is made to pass through the inside of user's body for measuring a voltage between both the detection electrodes 4, 6, thereby obtaining a bioimpedance. According to the bioimpedance measurement, the body fat ratio, the body weight with the fat, the body weight without the fat, the moisture content in the body, etc., can be calculated by use of a body fat ratio estimation formula on relation based on the submerged body weight measuring method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bioelectrical impedance measuring device.

[0002]

2. Description of the Related Art In recent years, adult diseases and lifestyle diseases caused by unnatural lifestyles and lack of exercise have attracted attention as modern diseases. For these modern diseases, it is required to proactively prevent them by devising to maintain a good lifestyle, rather than treating by administering drugs.

[0003] For these purposes, advice on health management guidelines has recently been given, and especially for the prevention of adult diseases, body composition such as body fat percentage and body water percentage is measured to prevent obesity. Attempts to help improve have become active.

There is a bioimpedance measuring device as a device for easily and reproducibly measuring a body fat percentage, a body moisture percentage, and the like. The bioimpedance measurement device measures the impedance (electric resistance value) through a weak current by bringing the application electrode and the detection electrode into contact with the living body, and uses a previously created calibration curve or the like to calculate the body fat percentage or the like from the measured impedance value Is to find out.

When such a bioimpedance measuring device is used, the positions of the application electrode and the detection electrode are as follows.
Conventionally, various devices have been devised. For example, when the whole body is to be measured, the application electrodes are placed on the hands, the detection electrodes are placed on the feet, and when the legs are measured, the application electrodes and the detection electrodes are placed on both feet, When the upper body is to be measured, the application electrode and the detection electrode are arranged on both hands.

However, for example, when the application electrode is placed on the hand and the detection electrode is placed on the foot,
Although it almost reflects the whole body, there is a problem in that it lacks convenience such as the necessity of taking off the stocking or the like when wearing a stocking and the necessity of lying down at the time of measurement.

[0007] In general, the measurement of bioelectrical impedance by the commonly used caliper method reflects the condition of the back of the upper arm (triceps) and the lower part of the scapula.
A device that places the application and detection electrodes in both hands is preferred.

Japanese Patent Application Laid-Open No. 8-150130 discloses a method for measuring bioimpedance in which an applying electrode and a detecting electrode are arranged on both palms. An apparatus for arranging an applying electrode and a detecting electrode on both backs of the hand is also disclosed. Has been put to practical use.
However, these devices have a problem in that the measurement results vary widely, and it is difficult to accurately measure the body fat percentage, the body moisture percentage, and the like.

[0009]

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide an impedance measuring apparatus capable of accurately and accurately measuring a body fat percentage, a body moisture percentage, and the like. .

[0010]

SUMMARY OF THE INVENTION The present invention is a bioimpedance measuring apparatus for measuring an impedance through a weak current by bringing an applying electrode and a detecting electrode into contact with a living body, wherein the applying electrode is connected to a wrist joint. The bioimpedance measuring device is characterized in that the probe electrode is also brought into contact with the hand side, and the detection electrode is brought into contact with the body side with respect to the wrist joint.

[0011] The bioimpedance measuring apparatus of the present invention comprises:
The application electrode is brought into contact with the wrist joint more easily than the wrist joint, and the detection electrode is brought into contact with the body side than the wrist joint.Therefore, the wrist joint portion that is likely to cause an error is removed from the measurement target. , Body fat percentage, body moisture percentage, etc. can be measured accurately and with good reproducibility.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the bioimpedance measuring device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view schematically showing an example of a bioimpedance measuring apparatus of the present invention for measuring bioimpedance by a four-electrode method. In FIG. 1, reference numerals 1 and 2 denote grip portions, reference numerals 3 and 5 denote application electrodes, and reference numerals 4 and 6 denote detection electrodes.

When measuring with this bioimpedance measuring device, the grip part 1 is gripped by the right hand, the grip part 2 is gripped by the left hand, and the back of the hand is directed upward.
The detection electrode 4 is brought into contact with a part closer to the body than the right wrist,
The application electrode 5 is brought into contact with the palm of the left hand, and the detection electrode 6 is brought into contact with the portion inside the left wrist. Next, a weak alternating current (for example, 500 μA, 50 kHz) is applied to the body through the application electrodes 3 and 5.
Through z), the impedance can be determined by measuring the voltage between the detection electrodes 4 and 6.

The distance between the application electrodes 3 and 5 and the detection electrodes 4 and 6 is about 100 mm, respectively, and is arranged at a position about 50 mm from an average human wrist joint. The material of the electrode is not particularly limited. For example, JIS G
Austinite stainless steel according to 4304, S
US304 (Cr: 19%, Ni: 8%, Fe: 73
%), And those obtained by plating gold, nickel, or chromium on copper or ABS resin. In the bioimpedance measuring device of the present invention, it is preferable to apply a conductive cream to an electrode contact site in order to improve conductivity.

The bioimpedance measuring device of the present invention comprises:
By measuring the bioelectrical impedance, using the body fat percentage estimation formula based on the underwater weight measurement method, the body fat percentage,
Fat weight, lean body mass, body water content, and the like can be calculated. Further, the bioimpedance measuring device of the present invention,
It has grips 1 and 2 and the detection electrodes 4 and 6 are arranged so as to be in contact with the body side of the wrist joint. Further, the application electrodes 3 and 5 and the detection electrodes 4 and 6 are always at the same position.
Can be brought into contact. Therefore, the measurement result can be satisfactorily reproduced, and the body fat percentage and the like can be accurately measured.

FIG. 2 is a perspective view schematically showing another embodiment of the bioimpedance measuring device of the present invention. FIG.
The bioimpedance measuring device of the present invention differs from the bioimpedance measuring device of FIG. FIG.
1 can be measured in the same manner as the bioimpedance measuring apparatus of FIG.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Using a body fat percentage measuring device (Fat Par Center Model S-201) manufactured by Sekisui Chemical Co., Ltd., as an electrode to be applied to the body, a sticking electrode (Care Electrode CA- 301), and
Height 170cm, weight 63kg, distance between both wrists 13
As a test subject, a male with a medium thickness of 4 cm was measured, and the impedance value of the living body was measured.

As a measuring method, an applied electrode is attached to the center of the palm (50 mm closer to the hand than the wrist joint).
Move the detection electrode 10m to the position 10-80mm from the wrist joint
m, and the impedance between the detection electrodes was measured. The measurement results are shown in Table 1 below. FIG. 3 is a graph showing the measurement results, in which the vertical axis represents the impedance, and the horizontal axis represents the distance from the wrist joint.

[0021]

[Table 1]

As is clear from Table 1 and FIG. 3, when the detection electrode is arranged at a position about 50 mm from the wrist joint, the amount of change in impedance per unit distance is relatively large.
Comparing the amount of impedance change per 10 mm,
The amount of change when the detection electrode is set up to 50 mm from the wrist joint is about twice the amount of change when the detection electrode is set at a position exceeding 50 mm from the wrist joint. Therefore, in order to reduce the error due to the variation in the measured impedance value, it is preferable that the detection electrode is brought into contact with the body at a distance of 30 mm or more from the wrist joint so as to be less affected by the variation.

Example 2 and Comparative Example 1 Bioimpedance was measured using seven women as subjects using the same impedance measuring apparatus as in Example 1. The measurement was performed when the application electrode and the detection electrode were attached to the palm (Comparative Example 1), and when the application electrode was attached to the palm and the detection electrode was attached to a position 50 mm away from the wrist joint on the body side (Example 2). And went for.

The measured values of the impedance, the difference between the measured values of the age, height, and weight of each subject (−
) And the wrist impedance ratio are shown in Table 2. Note that the wrist impedance ratio is (−) × 100
Means /.

[0025]

[Table 2]

As is clear from the results shown in Table 2, 7
The difference (-) between the impedance measurements of the names is 2 on average.
31Ω, wrist impedance ratio is 2 on average
8.7%. The wrist joint portion is a portion where there is almost no fat or muscle, and the position 50 mm from the palm to the body side from the wrist joint is a distance of almost 100 mm.
Is less than 10% of the distance between the palms.

However, as described above, the ratio of the impedance in this portion is close to 30%, and-
Is as high as 88.1Ω (subject number 2−subject number 1 = 261.3-173.2), which is about 11% in terms of body fat percentage in the conventional measurement method. Therefore, when the bioelectrical impedance is measured including the wrist joint, an error is caused when calculating the body fat percentage or the like.

As is clear from the above Examples and Comparative Examples, the body fat percentage, body moisture percentage, etc. can be measured with good reproducibility and accurately by excluding the wrist joint, which is likely to cause an error, from the measurement object. It turns out that you can.

[0029]

Since the bioimpedance measuring apparatus of the present invention is as described above, the body fat percentage, the body moisture percentage and the like can be measured with good reproducibility and accurately.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a bioimpedance measuring apparatus according to the present invention.

FIG. 2 is a perspective view showing another embodiment of the bioimpedance measuring device of the present invention.

FIG. 3 is a graph showing measurement results in Example 1 of the present invention.

[Explanation of symbols]

 1, 2 grip 3, 5 applied electrode 4, 6 detection electrode

Claims (2)

[Claims] 1. A bioimpedance measuring apparatus for measuring an impedance through a weak current by bringing an application electrode and a detection electrode into contact with a living body, wherein the application electrode is brought into contact with a hand side of a wrist joint, and A bioimpedance measuring device, wherein the detection electrode is brought into contact with the body side of the wrist joint. 2. The detecting electrode is located on the body side of the wrist joint.
The bioimpedance measuring device according to claim 1, wherein the bioimpedance measuring device is brought into contact at a position separated by 0 mm or more.