In this list you will find our published research articles that discuss Somnofy.
Validation of Somnofy against PSG
Somnofy is a new, contactless night sleep assistant that monitors vital functions fully automatically during sleep. Somnofy achieves significant agreement with PSG in staging sleep (Cohen's κ = .63). Somnofy can thus be considered a valid tool to advance the field of sleep in specific research questions and areas that were previously impractical to study.
Ståle Toften, Ståle Pallesen, Maria Hrozanova, Frode Moen, Janne Grønli: "Validation of sleep stage classification using non-contact radar technology and machine learning (Somnofy®)", available online March 6, 2020, epub ahead of print, Sleep Medicine. DOI: 10.1016/j.sleep.2020.02.022
Validation of non-contact longitudinal respiratory rate measurement with Somnofy
We argue for respiratory rate as the most important vital sign to detect clinical deterioration. The measurements from the radar-based sleep monitor Somnofy are compared with respiratory inductance plethysmography (RIP). Respiratory rate deviations from individual baselines can be easily identified with Somnofy.
Toften S, Kjellstadli J, Thu O, Ellingsen O. Noncontact Longitudinal Respiratory Rate Measurements in Healthy Adults Using Radar-Based Sleep Monitor (Somnofy): Validation Study. JMIR Biomed Eng 2022;7(2):e36618. DOI: 10.2196/36618
Detecting sleep apnea events using touchlessradar technology,pulse oximetry and machine learning
The pilot study included 14 participants and resulted in a Cohen's kappa for a second-by-second event/no-event classification of .81 or near-perfect agreement. For classification of no event/hypopnea/apnea and no event/hypopnea/obstructive apnea/central apnea/mixed apnea, Cohen's kappa was 0.43 (moderate agreement) and 0.36 (reasonable agreement), respectively. All participants were correctly classified in relation to the severity of sleep apnea. The results indicate that radar technology and pulse oximetry can reliably provide second-by-second no-event/event information that may be valuable for treating sleep apnea.
Ståle Toften, Jonas T. Kjellstadli, Stig S. Tyvold, Mads HS Moxness, “A Pilot Study of Detecting Individual Sleep Apnea Events Using Noncontact Radar Technology, Pulse Oximetry, and Machine Learning”, Journal of Sensors, vol. 2021, Article ID 2998202, 9 pages, 2021. https://doi.org/10.1155/2021/2998202
Associating sleep in junior endurance athletes with mental strain and training strain using a prospective, observational design
Non-intrusive, objective sleep measurements using new radar technology were obtained, and subjective daily reports of mental strain and exercise strain were collected. The role of subjective sleep quality was examined to identify whether the reciprocal associations between sleep, mental load and exercise load depended on being a good versus poor sleeper.
Hrozanova, Maria & Klöckner, Christian & Sandbakk, Oyvind & Pallesen, Ståle & Moen, Frode (2020). Reciprocal associations between sleep, mental load, and training load in junior endurance athletes and the role of poor subjective sleep quality. Frontiers in psychology. 11. 1-14. 10.3389/fpsyg.2020.545581.
Chess players at elite level show high emotional and cognitive stress related to performance development
Sleep is an important recovery strategy, previously implicated in athletic performance. The main purpose of the current study was to investigate relationships between performance development and objectively measured sleep in a sample of 14 Norwegian chess players over a period of 120 consecutive days. The sleep pattern of the chess players with positive performance development was different from the players with negative development.
Moen, Frode & Olsen, Maja & Hrozanova, Maria (2020). Associations between sleep patterns and performance development among Norwegian chess players. Frontiers in psychology. 11. 1855. 10.3389/fpsyg.2020.01855.
The influence of the menstrual cycle on women's sleep has been investigated in junior endurance athletes
The authors assessed subjective sleep quality, as well as objective sleep parameters, mental load, training load and menstrual cycle in junior endurance athletes over 61 consecutive days. The main objective was to investigate gender differences in objective sleep parameters, including sleep stage distributions, in junior endurance athletes, considering the possible confounding roles of mental load, training load and subjective sleep quality. The secondary aim was to compare objectively measured sleep during menstrual bleeding and in the different phases of the menstrual cycle in naturally menstruating female endurance athletes.
Hrozanova M, Klöckner CA, Sandbakk Ø, Pallesen S, Moen F (2021). Gender differences in sleep and the influence of the menstrual cycle on women's sleep in junior endurance athletes. PLoS ONE 16(6): e0253376. https://doi.org/10.1371/journal.pone.0253376
The study examined the associations between elite female soccer players' perceived fatigue and their sleep, and the associations between the players' sleep and soccer matches
Sleep was monitored with a non-intrusive impulse radio ultra-wideband Doppler radar (Somnofy). Perceived fatigue was based on a self-report mobile phone application that detected daily perceived fatigue. Deep and REM sleep, and respiratory rate in non-REM sleep, are key indicators of perceived fatigue in female elite soccer players. Sleep is disturbed during the night, probably due to the high physical and mental stress experienced during football matches. Sleep normalizes during the first and second night after soccer matches, which likely prevents further negative performance-related consequences.
Moen, F., Olsen, M., Halmøy, G., & Hrozanova, M. (2021). Variations in elite female soccer players' sleep, and associations with perceived fatigue and soccer play. Frontiers in Sports and Active Living, 3. DOI:10.3389/fspor.2021.694537
A study investigated changes in blood serum proteomes after 6 hours of sleep deprivation in healthy women
A study investigated changes in blood serum proteomes after 6 hours of sleep deprivation in healthy women. Of a total of 725 proteins identified in human blood serum, 34 proteins were significantly differentially expressed after 6 hours of sleep deprivation at night. Acute sleep deprivation (in women) affects several known biological processes and molecular functional categories that are similarly altered through oxidative stress, immune suppression, neurodegenerative disorders and cancer.
Bjørkum, AA, Carrasco Duran, A., Frode, B. et al. Human blood serum proteome changes after 6 hours of nocturnal sleep deprivation. Sleep Science Practice 5, 14 (2021). https://doi.org/10.1186/s41606-021-00066-2
An observational study of sleep characteristics in elite endurance athletes during an altitude training camp at 1800 m found changes in the form of reduced total sleep time, but certainly increased deep sleep and respiratory rate during NREM sleep.
It is hypothesized that, despite overall small changes in sleep parameters at altitude compared to near sea level, the accumulated reduction in sleep duration and quality may affect recovery in elite athletes.
Hrozanova, M., Talsnes, RK, Karlsson, Ø., McGawley, K., & Moen, F. (2021). An observational study of sleep characteristics in elite endurance athletes during an altitude training camp at 1800 m. Sleep health.