=Paper=
{{Paper
|id=Vol-2448/SSS19_Paper_Upload_229
|storemode=property
|title=Toward Good Circadian Rhythm through an valuate of Stress Condition
|pdfUrl=https://ceur-ws.org/Vol-2448/SSS19_Paper_Upload_229.pdf
|volume=Vol-2448
|authors=Ryo Takano,Sho Kajihara,Satoshi Hasegawa,Eiki Kitajima,Keiki Takadama,Toru Shimuta,Toru Yabe,Hideo Matsumoto
|dblpUrl=https://dblp.org/rec/conf/aaaiss/TakanoKHKTSYM19
}}
==Toward Good Circadian Rhythm through an valuate of Stress Condition==
https://ceur-ws.org/Vol-2448/SSS19_Paper_Upload_229.pdf
Toward Good Circadian Rhythm through a valuate of Stress Condition
Ryo Takano†, Sho Kajihara†, Satoshi Hasegawa†, Eiki Kitajima†, Keiki Takadama†,
Toru Shimuta‡, Toru Yabe‡ and Hideo Matsumoto‡
†Graduate School of Informatics, The University of Electro-Communications, Tokyo, Japan
‡Murata Manufacturing Company, Ltd.
takano@cas.hc.uec.ac.jp, kajihara@cas.lab.uec.ac.jp, hasegawa@cas.lab.uec.ac.jp, kitajima@cas.lab.uec.ac.jp, keiki@inf.uec.ac.jp
t-yabe@murata.com, shimuta@murata.com, hmatsumoto@murata.com
Abstract days; (2) the trends of these indices coincide details from
The final goal of this study is to implement a recommenda- the simple diary written by the subject. However, this is
tion system for promoting health which judges the degree not enough that to realize the recommendation system and
of stress and the degree of the health with less measure- further analysis is indispensable. Because these indices
ment and presents actions that will bring about appropriate representing the degree of stress and the goodness of circa-
health condition. To implement such a system, authors dian rhythm are insufficient. In this analysis, LF/HF was
tried to find the knowledge on the relationship between employed to express the degree of stress. In addition, the
circadian rhythm and stress. For this purpose, this paper standard deviation of basal body temperature was em-
proposes the method employing two indices ccvTP and ployed as an index for evaluating the goodness of the cir-
LF/HF to evaluate the degree of stress. To combine of LF / cadian rhythm. These indicators may take unexpected val-
HF and ccvTP can implement that not only the degree of ues such as noise and cannot always be evaluated appro-
stress but also the condition of stress is evaluated. In addi- priately as the degree of stress and the goodness of circadi-
tion, the index showing the goodness of the circadian an rhythm.
rhythm is employed the magnitude of the increase and de- In this paper, in order to tackle the problem, the evalua-
crease in the basal body temperature of each time zone. tion of the stress condition and the evaluation of goodness
Such an index which evaluates the totally trend for each of circadian rhythm are improved for more detailed analy-
time zone can reduce the influence of the unexpected value sis. This paper employs the autonomic nervous activity
such as noise. In order to verify the practicality of these level (ccvTP) as an additional index to evaluate the degree
indexes, this paper analyzes the data obtained by subject of stress. To combine of LF / HF and ccvTP can implement
experiments by 4 adults. As a result, by comparing two that not only the degree of stress but also the condition of
types of data of ten-odd days in parallel, we obtained the stress is evaluated. In addition, the index showing the
finding that severe stress adversely affects the circadian goodness of the circadian rhythm is employed the magni-
rhythm after a few days. tude of the increase and decrease in the basal body temper-
ature of each time zone, not the standard deviation of the
basal body temperature. Such an index which evaluates the
Introduction totally trend for each time zone can reduce the influence of
the unexpected value such as noise. Furthermore, in order
In this study, the final goal is to establish a recommen-
to verify the practicality of these indexes, this paper ana-
dation system for promoting health. In order to achieve this
lyzes the data obtained by subject experiments. This data is
goal, the authors have tried to reveal the relationship be-
consisted on numerical values (ccvTP, LF/HF and basic
tween a quality of sleep, a degree of stress, and a goodness
body temperature) and simple diaries in about 2 weeks for
of circadian rhythm [Takano, 2018]. As a result of this trial,
4 adults. The degree of stress and condition, goodness of
the relationship between these data is becoming some ap-
circadian rhythm is evaluated from these data and are ana-
parent as the follows: (1) Three indices (the degree of
lyzed these two relationships. Finally, the analysis
stress, the quality of sleep, and the goodness of circadian
rhythm) have been moving with a similar trend in units of
14
12
10
LF/HF
8
6
4
2
0
10/7 03:00
10/7 06:00
10/7 09:00
10/7 12:00
10/7 15:00
10/7 18:00
10/7 21:00
10/8 00:00
10/8 03:00
10/8 06:00
10/8 09:00
10/8 12:00
10/8 15:00
10/8 18:00
10/8 21:00
10/9 00:00
10/9 03:00
(a) LF/HF
6
5
4
ccvTP
3 (a) Circadian rhythm in two days
2 2
1
Increase / decrease
0 1
10/7 03:00
10/7 06:00
10/7 09:00
10/7 12:00
10/7 15:00
10/7 18:00
10/7 21:00
10/8 00:00
10/8 03:00
10/8 06:00
10/8 09:00
10/8 12:00
10/8 15:00
10/8 18:00
10/8 21:00
10/9 00:00
10/9 03:00
0
value
-1
-2 up zone down zone (inverse)
9/25-26
9/26-27
9/27-28
9/28-29
9/29-30
9/30-10/1
10/1-2
10/2-3
10/3-4
10/4-5
10/5-6
10/6-7
10/7-8
10/8-9
10/9-10
(b) ccvTP
Figure.1 The transition stress in two days
results are checked whether it is consistent with the fact (b) Indies for circadian rhythm in two weeks
obtained from diaries.
The remaining of this paper is organized as follows. Figure.2 Index of goodness of circadian rhythm
First, second section will explain the indices for expressing the example. When the value of LF / HF is smaller than 2,
the degree of stress and the goodness of circadian rhythm. the stress is small. On the other hand, when it is 2 or more,
Next, third section will describe the comprehensive analy- it indicates that the stress is high. Figure 1 (a) shows that
sis to interpret these indices. Fourth section shows the sub- the subject was relatively higher stressed and especially
ject experiment and its result. Finally, the conclusion of noticeably high in the evening on October 7. On the other
this paper is given in the final section. hand, it shows that October 8 is the day the subject did not
feel relatively stress. In addition, Figure 1 (b) shows that
Analytical method ccvTP continues to maintain a value of 2 to 3 over 2 days.
This fact can be interpreted that the subject did not feel a
In this chapter, we explain how to calculate the indexes fatigue or stress which impairs the activities of autonomic
the degree of a stress and the goodness of a circadian nerves. The average per day of these values are employed
rhythm. In this paper, the basal body temperature and the in order to analyze the stress of daily.
two types of values about the autonomic nervous system
are employed to calculate these indices. These three values Index of the goodness of the circadian rhythm
are measured every several hours in daytime.
As an index showing "the goodness of a circadian
rhythm", we employed the s transition of basal body tem-
Indies of the degree of the stress perature. It is known that basal body temperature goes up
To evaluate the condition of stress, we employed "LF / and down according to circadian rhythm and a basal body
HF" and “ccvTP”. First, "LF / HF" is the index showing temperature rises from 3 a.m. to 3 p.m. due to the influence
the balance between the sympathetic nerve (LF) and the of circadian rhythm and falls from 3 pm to 3 am. Based on
para-sympathetic nerve (HF), which means that the higher this knowledge, this paper sets that these time zones are Up
the value show that a person gets the higher the stress. zone and Down zone (blue and orange in Figure 2 (a)),
Next, "ccvTP" is an index showing the magnitude of the respectively. In these zones, the sum from each previous
entire autonomic nerve activity. The low value of ccvTP value is calculated as an index showing "goodness of cir-
shows that autonomic nervousness is impaired due to fa- cadian rhythm". These calculation results are shown in
tigue and stress. Figure 2 (a-b) shows the transition of LF / Figure 2 (b). Figure 2 (b) is calculated from the basal body
HF and ccvTP measured every few hours for two days as temperature measured for the same timing as in Figure 1.
Furthermore, in order to improve visibility, the numerical
value of down zone is inverse. In addition, the numerical
standardization is carried out in order to improve the ease
of visual analysis. The numerical standardization is calcu-
lated as that the values subtracted each numerical value by
the own average and divided by the own standard deviation.
As a result, the average value and the standard deviation of
the data set is 0 and 1, respectively. And the closer the val-
ue in the data is 0, the closer it is to the mean value.
Comprehensive analysis (a) transition of stress in two weeks
Estimating the condition of the stress
In this paper, we assumed that "LF / HF" responded to
mental stress and "ccvTP" responded to body fatigue, and
classified the stress condition into 4 types using these two
indicators. First type of them is "LF / HF" is small and
"ccvTP" is large. this indicates the state without mental
stress and body fatigue. Second type of them is "LF / HF"
is large and "ccvTP" is small. This indicates the state that a
subject has mental stress and body fatigue. Third type of
them is "LF / HF" is large and "ccvTP" is large. This indi-
(b) transition of circadian rhythm in two weeks
cates the state that a subject gets only mental stress, and
body condition is fine. Fourth type of them is "LF / HF" is Figure.3 Analysis result (of Subject 1)
small and "ccvTP" is small. This indicates the state that a
chapter, the data every two days in each time zone are
subject gets only body fatigue, and mental condition is fine.
standardized for 2 weeks. Next, this data is classified
In this paper, we evaluate the stress condition from the
whether both up zone and down zone are minus values or
above types and the numerical values of "LF / HF"
not, and the day which the values is minus is colored in red
"ccvTP".
as shown in Fig. 3 (b). This day which the values is a day
Figure 3 (a) shows the transition of LF / HF and ccvTP
when the circadian rhythm is damaged. The colorized fig-
measured every few hours for two weeks as the example.
ure as shown in Fig. 3 (a - b) enables to judge which a
The numerical standardization is calculated as that the val-
condition of the four types of stresses are disturbing the
ues in per 1 day subtracted each value by the own average
circadian rhythm.
and divided by the own standard deviation. As a result, the
average value and the standard deviation of the data set is 0
and 1, respectively. And the closer the value in the data is 0, Human subject experiment
the closer it is to the mean value. On the other hand, large
value in the data is as characteristic data. The coloring of This chapter investigates the practicality of the analysis
four colors shows each of the four types of stress condi- described in the previous section, using data obtained by
tions in Figure 3. subject experiments by four adults.
Analysis between the stress and circadian rhythm Details of usage data
In this section, we describe the comprehensive analysis In this human subject experiment, the stress measure-
using two type of data. In order to understand each cause ment sensor was employed VM 302 of Fatigue Science
and effect relation, two types of data are classified accord- Laboratory Inc. for measuring LF / HF and ccvTP. On the
ing to good or bad, respectively. Regarding the index of the other hand, the commercially available basic thermometer
degree of the stress, as described in the previous section, was employed for measurement of basal body temperature.
standardized values for LF / HF and ccvTP are calculated LF/HF, ccvTP and basal body temperature were measured
from the average value per 1 day for 2 weeks. Further, the every few hours in a day. After the end of the measurement,
data is classified according to the above-mentioned four the value of each indexes is calculated according to the
conditions. On the other hand, as the index of the goodness method described in the previous chapter. Four subjects
of the circadian rhythm, as described in the previous carried out measurements every three to four hours for
Table.1 Short diary by the subject1 Table.3 Short diary by the subject3
9/25 No description 9/15 Oversleep
Business meeting 9/16 Especially nothing
9/26
Exercise at the gym
[Holiday] Taking care of the neph-
9/27 Not have lunch 9/17
ew
9/28 Leave the office regularly
[Holiday] Taking care of the neph-
Business seminar 9/18
9/29 ew
Drinking party
[Holiday] Immerse in making pierc-
Business trip 9/19
9/30 ings
Important negotiation
9/20 Getting a strained back
10/1 [Holiday] Wander around Kanazawa
9/21 Low back pain
10/2 [Holiday] Chat with a friend
[Holiday] Low back pain
10/3 Desk work in all day 9/22
Going to a concert with a friend
Long meeting
10/4 9/23 Low back pain
Exercise at the gym
9/24 [Holiday] Dinner with friends
10/5 Go home early
[Holiday] Taking care of the neph-
10/6 Exercise at the gym 9/25
ew
10/7 Busy day
9/26 Always feeling sick
10/8 [Holiday] Relaxing at home
9/27 Low back pain
10/9 [Holiday] Shopping
9/28 Feeling dullness
9/29 Irritating at work
Table.2 Short diary by the subject2
1/16 Participate in the training at library
Table.4 Short diary by the subject4
1/17 Working at midnight (11-12 p.m.) [Holiday] Spending one day with
8/16
1/18 Especially nothing daughter
1/19 Especially nothing Working outdoors and getting an-
8/17
1/20 Especially nothing noyed
[Holiday] 8/18 Busy day
1/21 8/19 Drinking party
Watching the son's kendo match
[Holiday] Lunch party preparation 8/20 [Holiday] Getting hangover
1/22
at my son's school [Holiday]
1/23 Taking daughter to the hospital 8/21 Playing with the children in the
Returning home temporarily park
1/24
due to my daughter's nursing 8/22 Working overtime
1/25 Working overtime until 7 p.m. Surgery with dentistry and feeling
8/23
Stopping by to the library during uncomfortable with anesthesia
1/26
the return home Progressing work well
8/24
Son did not go home late Getting to snooze at evening
1/27
and staying up late 8/25 Working overtime
1/28 [Holiday] Taking naps 8/26 Getting to snooze at evening
[Holiday] Going to bed twice after [Holiday] Getting hangover
1/29 8/27
breakfast and shopping and snooze at afternoon
1/16 Participate in the training at library [Holiday] Playing with the children
8/28
in the outdoor
about 2 weeks in 2016 or 2017. Also, they wrote the sim- 8/29 Progressing work well
ple diary every day for verification of analysis. Four sub- 8/30 Busy day
jects live as usual except for regular measurements. Their
measurement period is as follows: The measurement peri- is from September 15 to September 29 in 2016; The meas-
od of Subject 1 is from September 25 to October 9 in 2016; urement period of Subject 4 is from August 16 to August
The measurement period of Subject 2 is from January 16 to 28 in 2016. In addition, the summary of the contents of the
January 16 in 2017; The measurement period of Subject 3 diaries is shown in Table 1-4.
Result of measurement
First, the measurement results of each subject are shown in
Figures 3 to 6. In these figures, (a) in the upper row shows
the result of the index of the degree of stress, (b) in the
lower row shows the index of goodness of the circadian
rhythm. In these figures, the color coding of stress is as
follows. Blue area indicates the state without mental stress
and body fatigue ("LF / HF" is smaller than 0 and "ccvTP"
is larger than 0). Red area indicates the state that a subject
has mental stress and body fatigue (“LF / HF" is larger
than 0 and "ccvTP" is smaller than 0). Yellow area indi-
cates the state that a subject gets only mental stress, and
(a) transition of stress in two weeks
body condition is fine (“LF / HF" is larger than 0 and
"ccvTP" is larger than 0). Purple area indicates the state
that a subject gets only body fatigue, and mental condition
is fine ("LF / HF" is smaller than 0 and "ccvTP" is smaller
than 0). On the other hand, regarding the indicator of the
goodness of the circadian rhythm, the days when both up
zone and down zone are negative are colored in red.
Analysis
In this section, as described in the previous chapter, we
analyze the relationship stress and circadian rhythm to
judge which a condition of four types of stresses are dis- (b) transition of circadian rhythm in two weeks
turbing the circadian rhythm. First, as a first step in the
Figure.5 Analysis result of Subject 3
analysis, a common trend from the data of four subjects is
found. This common tend is that the circadian rhythm
(a) transition of stress in two weeks (a) transition of stress in two weeks
(b) transition of circadian rhythm in two weeks (b) transition of circadian rhythm in two weeks
Figure.4 Analysis result of Subject 2 Figure.6 Analysis result of Subject 4
in the lower row as Figure (b) is worse 2 to 4 days after the tained the following findings: (1) when the subject receives
stress condition shown in the upper part Figure (a) become stress both mentally and physically, it turns out that the
red. In other words, if the subject suffers from bad stress, circadian rhythm will be affected several days later; (2)
the adverse effect on circadian rhythm occurs several days those trends coincide details from the simple diary written
later. Next, there was a statement in the diaries that the by the subject. As a result, by comparing two types of data
subjects got bad stresses in their bodies or minds when of 2 weeks in parallel, these data were related to each other.
subjects suffer bad stress presented in the red area in most As a future task, we try to analyze the impact on stress
of days. From these results of analysis, when the subject conditions not analyzed still yet.
receives stress both mentally and physically, it turns out
that the circadian rhythm will be affected several days later.
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