JP2001161654A - Method and device for determining quantity of mineral in bone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To overcome the disadvantages of conventional devices for measuring the quantity of mineral in a subject's bone by using X-rays or supersonic waves with which a condition of bones of the whole body is not determined, the devices are large and of high cost, installed only in specific facilities like hospitals, and the subject cannot easily learn the condition of his own bones and take preventive measures against an osteoporosis. SOLUTION: After the body density BD of the subject is measured, the quantity of mineral in his bone BMC is found by using the following formula: BMC =0.056×BW 1-(4.570/BD-4.142)} wherein BW is the subject's weight. The quantity of mineral in his bone is displayed on a monitor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the amount of bone mineral as information for preventing osteoporosis.

[0002]

2. Description of the Related Art In recent years, osteoporosis has become a problem. Osteoporosis refers to a state in which bone quality is reduced while bone components are kept almost normal, and is asymptomatic until a fracture occurs. Osteoporosis is a disease closely related to aging, diet, and changes in diet. It is said that osteoporosis cannot be regenerated. Therefore, early detection and prevention are more important than treatment. It is desired to do. Currently,
Go to a specific facility such as a hospital, and use X such as DXA or DEXA.
Diagnosis of osteoporosis has been performed by measuring the bone density by applying a measuring device such as an X-ray system or an ultrasonic system to a required portion such as an arm, a waist, or a leg to determine the amount of X-ray transmission.

[0003]

However, in the conventional measurement using a measuring device such as an X-ray system or an ultrasonic system, for example, the bone density of the lumbar region is measured by the measuring device, and the lumbar region has a standard bone density. Even if it had, the bone density of other parts did not always reach the standard, and the state of the entire bone of the body could not be determined. In addition, conventional X-ray method,
Measuring instruments of the ultrasonic type or the like are large in scale and costly, are installed only in specific facilities such as hospitals, and cannot easily know the state of their own bones. Therefore, there has been a problem that measures for preventing osteoporosis cannot be taken in advance.

[0004] The present invention has been made in view of the above problems, and it is possible to judge the state of the entire bones of the body, to easily know the state of the own bones, and to prevent osteoporosis ( Dietary habits, etc.) in advance.

[0005]

Means for Solving the Problems Bone mineral according to the present invention
The method for measuring the amount is as follows.
The bone mineral amount BMC of the body of the person is calculated by the following equation: BMC = 0.056 · BW ｛1− (4.570 / BD−
4.142)｝ (BW is the subject's weight)
It is displayed on the indicating means. Furthermore, the body density BD
With the bioelectrical impedance R, weight BW and height H of the subject
For men, BD = 1.1554-0.0841 (BW
R) / H²  For women, BD = 1.1113-0.0556 (BW
R) / H²  Was calculated based on. Further, the bone according to the present invention
The device for measuring the amount of minerals has a bioelectrical impedance R of the subject.
Means for measuring the measured bioelectrical impedance
R and the subject based on the subject's weight BW and height H
For calculating the amount of bone mineral BMC of the elderly,
Means for displaying the amount of bone mineral BMC,
did.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the apparatus according to the present embodiment, the measurement theory of the present application will be described. The present invention
The bioimpedance method (hereinafter, referred to as BIA) is adopted. This BIA is described by Hoffer et al. In "Biological Impedance and TBW (Total Body Weight
r) Relationship "has been used since the paper was published. This BI
The theory by A models the complex structure of the body into a simple conductor cylinder. Now, assuming that the body is a cylindrical conductor having a uniform resistivity ρ, the total impedance Z (resistance) is Z = ρ · L / S (where L is the length of the conductor, and S is the break of the conductor. Area). By transforming the above equation, Z = ρ · L / S = ρ · L·L / S · L = ρ · L ² / V (where V is the volume of the conductor), and V∝L ² / Z. 1) is derived.

On the other hand, the bioimpedance Z is 1 / Z = 1 / Re + 1 / (Ri + 1) in a three-parameter equivalent circuit.
/ Cmjω). (However, Re is the resistance inside and outside the cell, Ri is the resistance inside the cell, Cm is the capacity of the cell membrane) Here, as a condition for measuring the bioelectrical impedance Z, when the frequency f = 50 Hz generally used in a body fat meter or the like, 1 /
Cmjω≪Ri, Z can be reviewed as a DC resistance component, and the above equation (1) can be expressed by V L ² / R (2). Assuming that the conductor length L is height (H) in the above equation (2), the body volume is given by V = K · H ² / R (3) (where K is a proportional constant).

According to Hoffer et al., Γ = 0.0 between the parameter H ² / R in the above equation (3) and the above TBW.
It is reported that there is a correlation of 92 to 0.93. Also, by Lukaski et al., Segal et al.
TBW, FFM (Fat Free Mass), FA
It is known to estimate a body composition such as (FAT) and BD (Body Density). By the way, the body constituents can be divided by water (TBW) fat (FA) protein (P) mineral (M) according to the chemical evaluation, and the total weight BW is BW = TBW + FA + P + M (4) FFM (fat free) = TBW + P + M (5) According to Brozek et al., Water, protein, and mineral components in FFM are 7
3.8%, protein 19.4%, bone mineral 5.
It is reported that 6% and other minerals are 1.2%. From the above, it can be understood that the amount of bone mineral in the body can be estimated by measuring the bioelectrical impedance R.

[0009] Typical examples methods for estimating body composition by BIA, ^H by Lukaski like 2 /
A method of estimating FFM from R, and B
The body density BD is estimated from W · R / ^{H 2,} the Broze
There is a method of estimating FA and FFM using an expression such as k. In the latter method, that is, in the equation of Segal et al., The body density BD is male; BD = 1.154-0.0841 (BW · R) / H ² (6) female; BD = 1.113-0. 0556 (BW · R) / H ² (7), and the fat percentage (% BF) is calculated from the equation of Brozek or the like as follows:% BF = (4.570 / BD-4.142) · 100 (8) ). The lean tissue ratio (% FFM) is given by the following equation (8):% FFM = 100−% BF (9) Therefore, FFM = BW · (1-BF) = BW · {1− (4.570 / BD-4.142)} (10) From this, the amount of bone mineral of the body (hereinafter referred to as BMC) is According to Brozek et al., BMC = 0.056 · FFM = 0.056 · BW · {1- (4.570 / BD-4.142)} (11)

In the BMC measurement method according to the embodiment of the present invention, after detecting the body density BD of the subject, the above equation (11)
Thus, the BMC of the body is calculated and displayed on the display device. Further, the body density BD of the subject is calculated based on the bioelectrical impedance R, the weight BW, and the height H of the subject, using the above formula (6) for a male and the above formula (7) for a female.

Hereinafter, a BMC measuring apparatus according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a BMC measuring device 1 according to an embodiment of the present invention
A measuring instrument 2 by BIA for measuring the bioimpedance R of the subject X, an input device 3 for inputting the age, sex, height, weight, etc. of the subject X, an average value of BMC data classified by sex and age, A ROM 4 as storage means for storing statistical data such as the standard deviation SD of the BMC data and the above formulas (11), (6) and (7) as regression data of the BMC; a display device 5; a CPU 6; A non-volatile memory 7 for storing personal information such as name, gender, birthday, height, weight, password, and the like, as well as past BMC values of the individual and personal history information that is a five-level evaluation result along with the personal information; It consists of. This memory 7
For example, the past BMC value and the data of the five-level evaluation result for the past 12 months are stored.

FIG. 2 shows a specific example of the present apparatus. The subject X who has not yet experienced measurement has first entered a name input key 31, an age input key 32, a height input key 33, and a weight input key 34.
Is turned on, and personal information such as a name, an age, a height, a weight, a password, and a birthday is input to the CPU 6 using the numeric keypad and character input key 30. Gender key 3
Operate 5 to enter gender. These keys constitute the input device 3. Next, when a hand is placed on the electrode hand mold 20 (which may be an electrode finger or an electrode foot) which is a measurement part of the measuring instrument 2, a weak current flows between both hands via the electrode hand mold 20,
The biological impedance R of the subject X is measured,
Is input to The CPU 6 reads the above formula (11), (6) or (7) as the regression data from the ROM 4 and substitutes the height H, the weight BW and the bioelectrical impedance R into the formula (6) or (7) to obtain the BD. After the calculation, the BMC is calculated by substituting the BD value into Equation (11), and the calculated BMC value 60 and a five-level evaluation result 61 that is an evaluation for age and gender are displayed on the screen 50 of the display device 5. (See FIG. 3), and together with the personal information, the BMC value 6
0 and the five-level evaluation result 61 are stored in the memory 7. The five-step evaluation result 61 is, for example, a measured BMC value 60
Is the same gender and same age BMC stored in ROM4
The deviation from the average value of the data is determined.
D (good), + SD to -SD (normal), -SD to -2SD (small), -2
If it is less than or equal to SD, (very small) is displayed. That is, the above B
The standard deviation SD of the MC data is used as a criterion for judging osteoporosis. For example, in the case of a young adult woman, if the 5-level evaluation result 61 is -2SD or less (minimum), the criterion that osteoporosis treatment is necessary Becomes So, for example,
If an evaluation result of (small) is obtained, it is possible to take measures to prevent osteoporosis in advance by improving the eating habits based on the evaluation result, and to contribute to the prevention of osteoporosis.

In the second and subsequent measurements, the measured (calculated) BMC value, the five-step evaluation result 61 for the measured BMC value, the measured BMC value and the memory 7
Is displayed on the screen 50 with the five-step evaluation result value 62 that is compared with the latest BMC value of the past BMC values stored in the table 50 (see FIG. 3). This five-step evaluation result value 62 is
For example, the degree of increase / decrease of the current BCM value with respect to the past BCM value is (increase), (slight increase), (invariant), (slight decrease), (decrease).
Are determined and displayed in the five stages of Therefore, for example, if an evaluation result of (slight decrease) is obtained, it is possible to take measures to prevent osteoporosis in advance by improving the eating habits based on the evaluation result and contribute to the prevention of osteoporosis. .

The screen 50 may display the past BMC value and the five-level evaluation result value compared with each other, the inspection date (both past and present), and other information. The five-level evaluation result 61 may be configured to display a result of comparison with an arbitrary BMC value among past BMC values.

That is, the CPU 6 calculates the bioelectrical impedance R of the subject X measured by the measuring device 2, the weight BW and the height H of the subject X, and the equations (6) and (6) as the regression data stored in the ROM 4. 7) According to (11), B
The MC value is calculated, and the calculated BMC value and this BM
The five-level evaluation result 61 for the sex age of the C value and the five-level evaluation result value 62 for the BMC value measured in the past are displayed on the screen 50 of the display device 5.

Incidentally, 47 healthy adult men and women (22 men,
After confirming the data by 25 to 58 years old, female: 25 people, 20 to 63 years old), the difference between BMC measured (estimated) by the apparatus of the present application and bone density measured by DEXA was γ in men. = 0.67 and γ = 0.51 in women. That is, there is a correlation between BMC and bone density, and from this, BM measured by the device according to the first embodiment.
C gave a result that was very effective in knowing the condition of the subject's bone in the same manner as the bone density measured by the conventional DEXA.

According to the BMC measuring method in the present embodiment, after calculating the BD by the equation (6) or (7), the BMC is calculated by the equation (11) and displayed on the display device 5. The displayed BMC makes it possible to judge the state of the entire bones of the body, and to take measures to prevent osteoporosis in advance. Further, since the BMC corresponding to each of the male and female can be calculated and displayed, it is possible to make a determination corresponding to male and female. In addition, according to the BMC measuring device according to the present embodiment, it becomes possible to measure BMC at home every day with the same feeling as measuring weight, so that it is easy to know the state of one's own bones every day. Since the change in the state of the entire bone of the body can be determined in detail, it is possible to take measures to prevent osteoporosis in advance. In addition, since the BMC corresponding to each man and woman is calculated and compared with the average value corresponding to each age and gender, the determination result can be displayed, so that the determination corresponding to each age and gender can be performed. In addition, since the five-level judgment evaluation result is displayed, it is possible to take a proactive measure according to the situation at that time. Further, since the result of comparison with the past BMC is displayed, the user's own history can be grasped, and measures can be taken in accordance with the situation.

According to the embodiment, the body density BD of the subject is calculated based on the bioelectrical impedance R, the weight BW, and the height H of the subject according to the above formula (6), and the female is determined according to the above formula (7). ), The body density BD is detected by a measuring device having the function of a body fat meter, and the expression (1) is used.
The BMC value may be calculated according to 1).

Further, the device may be provided with a function of a weight scale, and the weight may be automatically inputted at the time when the weight is measured.

[0020]

As described above, according to the bone mineral measuring method of the present invention, it is possible to determine the state of the entire bone of the body, and to take measures to prevent osteoporosis in advance. Become like Further, since the BMC corresponding to each of the male and female can be calculated and displayed, it is possible to make a determination corresponding to male and female. In addition, according to the bone mineral measurement device according to the present invention, since it becomes possible to measure BMC at home every day with the same feeling as weight measurement, it is possible to know the state of own bones every day, Since the change in the state of the entire bone of the body can be determined in detail, it is possible to take measures in advance to prevent osteoporosis. Therefore, a device that can contribute to the prevention of osteoporosis can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a block configuration of a bone mineral amount measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a specific example of a bone mineral amount measuring device according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a display screen.

[Explanation of symbols]

1 BMC measuring device, 2 measuring device, 3 input device, 4
ROM, 5 display device, 6 CPU.

Claims (4)

[Claims] After detecting the body density BD of a subject, the bone mineral amount BMC of the subject's body is calculated by the following equation: BMC = 0.056 · BW ｛1− (4.570 / BD−
4.142)｝ (where BW is the weight of the subject) and the result is displayed on the display means. 2. The method according to claim 1, wherein the body density BD is calculated based on the bioelectrical impedance R, the weight BW, and the height H of the subject. 3. The body density BD is determined in advance for males and females.
The following equation is set: Male; BD = 1.154-0.0841 (BW · R)
/ H²  Female; BD = 1.1113-0.0556 (BW · R)
/ H²  The calculation according to claim 2, wherein
A method for measuring the amount of bone mineral. 4. A means for measuring the bioelectrical impedance R of the subject, a means for calculating the bone mineral amount BMC of the subject based on the measured bioimpedance R, the weight BW and the height H of the subject, Means for displaying the calculated amount of bone mineral BMC.