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European Journal of Applied Sciences – Vol. 10, No. 1
Publication Date: February 25, 2022
DOI:10.14738/aivp.101.11534. Takeyama, Y., & Fujii, K. (2022). Construction of Health Care Indicators for Elderly Males Based on Phase Angle. European Journal
of Applied Sciences, 10(1). 57-67.
Services for Science and Education – United Kingdom
Construction of Health Care Indicators for Elderly Males Based on
Phase Angle
Yuki Takeyama
Graduate School of Business Administration and Computer Science
Aichi Institute of Technology, Toyota-city, Japan
Katsunori Fujii
Graduate School of Business Administration and Computer Science
Aichi Institute of Technology, Toyota-city, Japan
ABSTRACT
In Japan, preventing the need for care is central to the aim of extending healthy life
expectancy in elderly people, and many days care service and other facilities have
been built. However, health indicators for people at the time they move into
residential care facilities have not been established. In a previous study, we
surveyed phase angle in general elderly women and evaluated the phase angle of
those who require care by constructing a reference chart for its evaluation. From
the results, it was shown that the range of −1.0 SD the level of general elderly women
was a standard for care need level. However, since there are obviously sex
differences between men and women in phase angle, constructing separate
evaluation indicators for men and women is an urgent task. In this study, we
analyzed the changes in phase angle with age in general elderly men, and
constructed a span evaluation chart based on those changes with age. The phase
angle of men who require care was applied to the constructed span evaluation chart,
and standards for care need level were sought. The results showed a trend for the
phase angle in people who require care to be distributed at below 5.5° for the whole
body and 4.0° for the legs. Thus, the phase angle of people who require care was
revealed to be distributed in the range of −1.0 ± 1.0 SD that of general elderly men.
Using the phase angle aging span evaluation chart, a standard for care need level
was presented and its validity as a health care indicator in the elderly is thought to
have been shown.
Keywords: Text classification; Semantic Web with weighted idf feature; Expanded query;
Fuzzy Semantic Web; Fuzzy Ranking Algorithm.
INTRODUCTION
Advances in medical technology and the rise in health awareness in Japan have been striking in
recent years. It is one of the nations with the highest longevity in the world. According to a 2020
report by the Ministry of Health, Labor and Welfare [1], the average life expectancy of Japanese
is 87.74 years for women and 81.64 years for men. While reaching new record highs it
continues to be among the highest in the world. Together with aging, however, the serious
combination of an aging population and fewer children is a cause for concern for the future.
According to a 2021 Cabinet Office white paper on the aging society [2], the elderly population
of people ≥65 years old is 36.19 million people, accounting for 28.8% of the total population
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Takeyama, Y., & Fujii, K. (2022). Construction of Health Care Indicators for Elderly Males Based on Phase Angle. European Journal of Applied
Sciences, 10(1). 57-67.
URL: http://dx.doi.org/10.14738/aivp.101.11534
Silva et al. [13] reported racial and sex differences in phase angle. Thus, much remains unknown
about the changes in phase angle with age in the different sexes.
In this study, we calculated phase angle based on BIA and investigated the changes with age in
elderly men from age 60 to 90. Next, using the wavelet interpolation model, we constructed an
aging span standardization chart for phase angle and attempted to standardize the changes
with age in phase angle in elderly men. We then applied the phase angle values for elderly men
who require care to the constructed aging span standardization chart. Here, we propose a
health indicator for care prevention care based on phase angle.
METHODS
Subjects and methods
The subjects of this study were 61 healthy, general elderly men who participated in a care
prevention class put on by a local municipality and 5 care-requiring elderly men who used a
certain day service facility. A breakdown of the subjects is shown in Table 1. The content of the
survey and measurements were explained to the subjects in advance, and their informed
consent was obtained.
Physical composition measurements
Height was measured using a digital height rod (Tanita). Weight and resistance (R), reactance
(Xc), and impedance (Z) were measured using a Tanita MC-780 body composition analyzer that
employs bioelectrical impedance analysis (BIA).
BIA is a method in which impedance (Z) is measured when a weak electrical current is passed
through the body and the physical composition of the body is estimated. By likening the body’s
cell membranes to a condenser and body fluid components to a conductor, the cell membranes
and body fluid components (intracellular fluid, extracellular fluid) are thought to be a combined
electrical circuit. Impedance (Z) is a vector value expressed by the square root of the square of
resistance (R), which is the resistance of body water with intra- and extracellular fluids as the
conductor, and the square of reactance (Xc), the electrical capacitance resistance of the cell
membrane. Therefore, impedance (Z) is calculated using the formula below (1).
�! = �! + ��! (1)
Phase angle is the arc tangent value when reactance (Xc) is divided by resistance (R). Therefore,
phase angle is calculated using the formula below (2).
�h��� ����� = −���������� × ��
�5 × 180°
�5 (2)
The measurement principle of the phase angle expresses the phase difference of the electrical
current and voltage when alternating current is flowed in the condenser, or cell membrane.
With this alternating current, differences are produced in a pathway where current flows
depending on the frequency. Alternating currents with low frequency pass through the
extracellular fluid, and as the frequency increases the current starts to pass through cell
membranes and the reactance (Xc) becomes higher. An arc is drawn when the reactance (Xc)
and resistance (R) are plotted while the frequency is changed. Therefore, the phase difference
can be measured as an angle, and that angle is the phase angle. Phase angles have values from
a minimum of 0° to a maximum of 90°. When reactance (Xc) is increased the phase angle