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FAQ for Clinics

How accurate is Belun Ring as compared to polysomnography?

The accuracy, sensitivity, specificity, and Kappa in categorizing AHI ≥ 15 were 0.89, 0.91, 0.88, and 0.79, respectively when compared to in-lab polysomnography.

The accuracy was 0.88 in detecting wake, 0.82 in detecting NREM, and 0.90 in detecting REM sleep, when compared to in-lab polysomnography.

Reference:

  • Strumpf Z, Gu W, Tsai CW, et al. Belun Ring (Belun Sleep System BLS-100): Deep learning-facilitated wearable enables obstructive sleep apnea detection, apnea severity categorization, and sleep stage classification in patients suspected of obstructive sleep apnea. Sleep Health. 2023;S2352-7218(23)00090-6.

Is polysomnography necessary after Belun Ring sleep test?

American Academy of Sleep Medicine (AASM) recommends home sleep test (HST) for symptomatic and uncomplicated population.

If a patient has a high pre-test probability of OSA, and HST gives AHI > 15, consider for treatment options; If a patient has a high pre-test probability of OSA, and HST gives AHI < 5, consider for further investigation.

Belun Sleep System has been cleared by U.S. FDA as a diagnostic aid for moderate to severe OSA.  Belun Ring offers a convenient but accurate HST for diagnosis and longitudinal management.

Reference:

  • Kapur VK, Auckley DH, Chowdhuri S, et al. Clinical Practice Guideline for Diagnostic Testing for Adult Obstructive Sleep Apnea: An American Academy of Sleep Medicine Clinical Practice Guideline. J Clin Sleep Med. 2017;13(3):479-504.

How can Belun Ring determine apnea/hypopnea without respiratory channels (e.g. airflow and effort to breathe)?

Belun’s AI algorithm was trained with >8000 PSG data. The algorithm determines apnea/hypopnea events from the patient’s pattern of SpO2, pulse rate, pulse rate variability and actigraphy.

How can Belun Ring determine sleep stage and total sleep time without EEG?

Belun’s AI algorithm was trained with >8000 PSG data. The algorithm determines sleep stages and total sleep time from the patient’s pattern of SpO2, pulse rate, pulse rate variability and actigraphy.

How does Belun Ring determine Autonomic Nervous System (ANS) balance?

Stress becomes visible through increased activation levels of the body. Activation levels are governed by the autonomic nervous system (ANS) which regulates gastrointestinal, endocrine, cardiovascular and pulmonary systems to facilitate the demands of daily life. The two divisions of the ANS are the sympathetic and parasympathetic divisions.

Parasympathetic nervous system (PNS) restores and maintains the body’s resting condition. Recovery means reduced activation levels in the body in the absence of internal and external stress factors. During recovery, parasympathetic (vagal) activations dominate the ANS and psychophysiological resources are restored. Indicators of recovery include low heart rate (HR) and high heart rate variability (HRV).

Sympathetic nervous system (SNS) prepares the body to meet challenges. Sympathetic nervous activity accelerates bodily functions (i.e., physiological stress reaction). The stress response results in increased activation of stress-hormone secretions (cortisol, catecholamines), increased blood pressure and HR and decreased HRV.

ANS balance can be assessed noninvasively using HR and HRV.

What is the difference between Belun Ring and overnight pulse oximeter?

Belun Ring has additional channels including actigraphy and heart rate variability for determining the total sleep time instead of using recording time for calculating ODI and AHI.

Standard oximeters cannot determine sleep time and hence underestimate the number of desaturation events per hour of sleep.

What is the difference between Belun Ring and consumer wristbands/smartwatches?

Belun Ring is U.S. FDA cleared medical device. Accuracy and reliability has been demonstrated to the regulatory body, and also proven in clinical studies.

Most of the wristbands and smartwatches on the market do not pass the requirements on accuracy. The data given by these consumer gadgets cannot be used for clinical applications.

References:

  • Gu W, Leung L, Kwok KC, Wu IC, Folz RJ, Chiang AA. Belun Ring Platform: a novel home sleep apnea testing system for assessment of obstructive sleep apnea. J Clin Sleep Med. 2020;16(9):1611-1617.
  • Yeh E, Wong E, Tsai CW, et al. Detection of obstructive sleep apnea using Belun Sleep Platform wearable with neural network-based algorithm and its combined use with STOP-Bang questionnaire. PLoS One. 2021;16(10):e0258040.
  • Ou YH, Ong J, Thant AT, et al. The Belun sleep platform to diagnose obstructive sleep apnea in patients with hypertension and high cardiovascular risk. J Hypertens. 2023;41(6):1011-1017.
  • Tsai CW, et al. Correlation of Pulse Rate Variability (PRV) and Heart Rate Variability (HRV) Metrics During Sleep in Subjects Suspected of OSA, Sleep, 2023;46(S1):A420-A421.
  • Strumpf Z, Gu W, Tsai CW, et al. Belun Ring (Belun Sleep System BLS-100): Deep learning-facilitated wearable enables obstructive sleep apnea detection, apnea severity categorization, and sleep stage classification in patients suspected of obstructive sleep apnea. Sleep Health. 2023;S2352-7218(23)00090-6.