Article
Effect of a Recliner Chair with Rocking Motions on Sleep
Efficiency
Suwhan Baek
1,†
, Hyunsoo Yu
1,†
, Jongryun Roh
2
, Jungnyun Lee
2
, Illsoo Sohn
3
, Sayup Kim
2,
*
and Cheolsoo Park
1,
*
Citation: Suwhan, B.; Hyunsoo, Y.;
Jongryun, R.; Jungnyun, L. ; Illsoo, S.;
Cheolsoo , P. Effect of a Recliner Chair
with Rocking Motions on Sleep
Efficiency. Sensors 2021, 21, 8214.
https://doi.org/10.3390/s21248214
Academic Editor: YangQuan Chen;
Subhas Mukhopadhyay; Nunzio
Cennamo; M. Jamal Deen; Junseop
Lee; Simone Morais
Received: 14 October 2021
Accepted: 30 November 2021
Published: 8 December 2021
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4.0/).
1
Department of Computer engineering, Kwangwoon University, Seoul 01897, Korea; zhsjzhsj@gmail.com
(S.B.); byeng3@kw.ac.kr (H.Y.)
2
Digital Transformation RnD Department, Korea Institute of Industrial Technology, Ansan 15588, Korea;
ssaccn@kitech.re.kr (J.R.); blueleen2@kitech.re.kr (J.L.)
3
Department of Computer Science and Engineering, Seoul National University of Science and Technology,
Seoul 01811, Korea; isohn@seoultech.ac.kr
* Correspondence: sayub@kitech.re.kr (S.K.); parkcheolsoo@kw.ac.kr (C.P.)
† These authors contributed equally to this work.
Abstract:
In this study, we analyze the effect of a recliner chair with rocking motions on sleep
quality of naps using automated sleep scoring and spindle detection models. The quality of sleep
corresponding to the two rocking motions was measured quantitatively and qualitatively. For the
quantitative evaluation, we conducted a sleep parameter analysis based on the results of the estimated
sleep stages obtained on the brainwave and spindle estimation, and a sleep survey assessment from
the participants was analyzed for the qualitative evaluation. The analysis showed that sleep in the
recliner chair with rocking motions positively increased the duration of the spindles and deep sleep
stage, resulting in improved sleep quality.
Keywords:
rocking motion; sleep quality; sleep staging; spindle; real world data; deep
neural networks
1. Introduction
Sleep plays a major role in maintaining an individual’s physical health, owing to its
involvement in several physiological processes such as tissue healing and repair [
1
–
3
].
Moreover, several studies claimed that sleep could critically affect physical and cognitive
performances, thereby encouraging researchers to investigate how to achieve effective rest
and improved sleep quality in a limited amount of time. Improved sleep quality could
result in having a healthier condition and better quality of life [
4
–
6
]. Specifically, good
sleep quality would relieve the risk of acquiring insomnia [
7
–
10
], which could critically
impair the immune function [
11
] and cause neurodegenerative disorders and cardiac
diseases [
12
]. On the other hand, poor sleep quality is associated to coronary artery
diseases in adults such as myocardial infarction [
13
–
16
] and affective states like depression
and anxiety [
17
,
18
], which may affect an individual’s work productivity, social functioning,
and safety. These results suggest that the sleep quality is as crucial as sleep quantity in
ensuring life satisfaction [19], which is one of the core indicators of a healthy lifestyle.
The benefits of sleep on angle-adjustable recliner chairs have been reported several
times. It has been reported that sleep in an angle-adjustable chair, such as a recliner,
improved the sleep quality through the sleep at a higher angle of posture or the
neck [20–22]
.
In particular, it has been proven that some sleep disorders could be medically improved
in patients with sleep apnea [22–25] and nocturnal gastroesophageal reflux through sleep
in a recliner [
26
]. In this paper, we propose an additional way to further improve the
quality of sleep with providing a rocking motion to the recliner. This study introduces a
new swinging mechanism with rocking motions, which improves the quality of a day-time
sleep in a recliner. Therefore, a new swinging recliner chair is proposed to improve the nap
environment with controlling the rocking and reclining functions.
Sensors 2021, 21, 8214. https://doi.org/10.3390/s21248214 https://www.mdpi.com/journal/sensors
