|
Brief Summary
|
Obstructive Sleep Apnea (OSA) is
a condition where the upper airway muscles relax resulting in airflow
obstruction. Central Sleep Apnea is a condition where there is no evidence of complete
obstruction but associated with reduced airflow and respiratory effort. Complex
sleep apnea syndrome is a combination of both obstructive and central sleep apnea
[1]. According to AASM manual apnea and hypopnea are defined as follows: Apnea
is flow limitation of more than or equal to 90% for atleast 10 seconds whereas
hypopnea is fall in signal excursion for more than or equal to 30% with 3% drop
in saturation or 4% desaturation with an arousal.[2].
Polysomnography (PSG) is the gold
standard for detecting and assessing sleep apnea. It is performed overnight on
subjects in a resource-intensive specialised sleep centre, with the subjects
wearing encephalography (EEG) electrodes, oronasal airflow sensors, thoracic
and abdominal respiratory inductive plethysmography (RIP) belts,
electrocardiography (ECG) sensors, an oxygen saturation finger-clip sensor, a
body position sensor. This arrangement is very distracting to the individual
and interferes with a decent night’s sleep. Furthermore, the PSG approach
necessitates the use of well-trained personnel and is a costly procedure [3]. Because
PSG is such a resource-intensive process, researchers are constantly looking
for a simpler, less demanding, and intrusive way to screen for sleep apnea
first, and then propose PSG based on the severity of the screening test.
Ballistocardiography (BCG) is a
promising approach that uses a non-invasive way to quantify the body motion
caused by blood ejection during each cardiac cycle [8]. BCG can be used to measure
the micro body motions produced during each cardiac contraction [9], as well as
detect breathing, snoring, and limb movements [4,5], and it can also be made
to work in a contact-free and non-wearable manner. Thus, BCG can be utilised to
overcome the PSG system’s problems in a non-invasive way.
Dozee, developed by Turtle Shell
Technologies employs the concept of BCG. Dozee which is placed beneath the
mattress, detects micro-vibrations, from which proprietary algorithms derive
parameters such as heart rate, respiration, stress levels, restlessness, and sleep
quality. It has been validated for heart rate (HR), respiration rate (RR), and
movement measurement. Contact accessories such as SpO2 are also included. When
compared to the PSG, Dozee is far more user-friendly and comfortable for the
subjects. Since BCG is contactless there is very little risk to the patients. 1. Jayaraj R, Mohan J, Kanagasabai
A. A Review on Detection and Treatment Methods of Sleep Apnea. J Clin Diagn
Res. 2017;11(3):VE01â€VE03.
2. Gould GA, Whyte KF, Rhind GB, et
al. The sleep hypopnea syndrome. Am Rev Respir Dis. 1988;137(4):895â€898.
doi:10.1164/ajrccm/137.4.895.
3. Wang, Z., Zhou, X., Zhao, W.,
Liu, F., Ni, H., & Yu, Z. (2017). Assessing the severity of sleep apnea
syndrome based on ballistocardiogram. PLOS ONE, 12(4), e0175351. doi:10.1371/journal.pone.0175351
4. V. Saran, G. Kumar, U. Dhawan and
G. Parchani, "Unsupervised Identification of Cardiac Contraction through
Ballistocardiography," 2018 IEEE-EMBS Conference on Biomedical Engineering
and Sciences (IECBES), Sarawak, Malaysia, 2018, pp. 42-47, doi: 10.1109/IECBES.2018.8626652.
5. Saran V., Kumar G., Parchani G.
(2019) Unsupervised Extraction of Respiration Cycles Through
Ballistocardiography. In: Luhach A., Jat D., Hawari K., Gao XZ., Lingras P.
(eds) Advanced Informatics for Computing Research. ICAICR 2019. Communications
in Computer and Information Science, vol 1075. Springer, Singapore. https://doi.org/10.1007/978-981-15-0108-1_14
|