Cerebra Health Inc. (“Cerebra”), a digital health-tech company focused on the diagnosis of sleep disorders, is pleased to announce the issuance of U.S. Patent No. 9,763,589 titled “Method and Software to Determine Probability of Sleep/Wake States and Quality of Sleep and Wakefulness from an Electroencephalogram.”  The patent relates to an objective, continuous index of sleep depth, referred to as the Odds-Ratio-Product (ORP), or SLEEP DEPTH SCALETM, which can be obtained from brain activity as measured by EEG. The ORP is one of a number of digital sleep analysis features of the MICHELE SLEEP SCORING system (MICHELE), Cerebra’s polysomnography software system for sleep lab and sleep research organizations.  


Understanding the SLEEP DEPTH SCALE

The SLEEP DEPTH SCALE (referred to in scientific literature as the Odds-Ratio-Product or ORP) is an invention of Dr. Magdy Younes, a world-renowned respirologist and sleep physician. 

To understand the SLEEP DEPTH SCALE, one needs to begin with a discussion of sleep itself.  Sleep is not an all-or-none phenomenon that could be understood adequately as being either awake or asleep. Rather, sleep is a dynamic state that progresses gradually from wakefulness to light sleep (where one is still highly arousable), to progressively deeper states. Some people spend most of sleep time in a light state (light sleepers) while others are deep sleepers. It is very likely that sleep depth is important in determining susceptibility to sleep disorders, as well as the restorative function of sleep.

In the clinical setting, sleep depth is currently measured using a manually scored, 3-step scale, progressing from N1 (light sleep), to N2 (moderately deep sleep) and finally to N3 (deep sleep).  This scale, known as the Rechtschaffen and Kales (R&K) rules, was proposed in 1968 when sleep signals were recorded with ink pens writing on paper and microprocessors had not yet been invented. While the scale was useful for characterizing sleep based on distinct EEG landmarks that could be seen with the human eye, the system has many known limitations including the time consuming nature and cost of manual scoring, the high degree of variability in scoring between different scorers, inability to measure EEG features that are not readily visible, and, perhaps most importantly, the reality that sleep depth does not progress in a stepwise fashion.

ORP’s ability to objectively determine sleep depth is based on classifying EEG patterns into 10,000 possible digital “fingerprints”, each of which is then assessed a probability of occurring when a person is awake, as determined by visual scoring of data from multiple sleep studies.   The probabilities range from 100% (EEG pattern only occurs when a person is awake, which is associated with a maximal ORP of 2.5) to 0% (EEG pattern only occurs when a person is asleep, which is associated with a minimal ORP of 0.0).  

The ability of the SLEEP DEPTH SCALE to accurately reflect sleep depth has been validated1-4 in a number of peer reviewed publications.  For detailed references and more information visit www.cerebrahealth.com/article.  

The ability to distinguish between sleep depths without relying on current, sleep stage based scoring has potential to greatly impact the understanding, classification, diagnosis and treatment of a variety of sleep disorders, as well as for personal sleep optimization.  Under the leadership of Dr. Younes, Chief Scientific Officer, Cerebra is now engaged in a number of collaborative research projects that are exploring clinical applications of ORP. 

Sleep analysis using the SLEEP DEPTH SCALE can be accessed through the Michele software, and is also available in Canada through Cerebra’s in-home, sleep diagnostic service.

In addition to the patent issuance by the United States Patent and Trademark Office (USPTO), ORP patent applications have also been filed and are pending in multiple other countries.



The MICHELE system is medical device software that has received US-FDA clearance and approval by Health Canada, European Union (CE Mark) and other national regulatory bodies for use in assisting the diagnosis of sleep disorders.   MICHELE is a polysomnography (PSG) software scoring system for sleep laboratories and sleep research organizations.  

The system’s digital sleep analytics include the SLEEP DEPTH SCALE (Odds Ratio Product) as well as other tools to assist in diagnosis and in the understanding of sleep dynamics.  MICHELE also provides conventional PSG software functionality, as well as fully-automated or digitally-assisted sleep scoring, which greatly reduces the time and effort required to score a sleep study with a high level of accuracy.   Agreement between the sleep scoring results of MICHELE and that of highly-experienced academic sleep technologists was shown to be similar to, if not better than, agreement between individual scorers in an arms-length, multicenter study5.

MICHELE and ORP (SLEEP DEPTH SCALETM) are provided by Cerebra and its subsidiary, Younes Medical Technologies Ltd. (YMT), under a worldwide, exclusive license from Younes Respiratory Technologies Ltd. (YRT). For more information on MICHELE visit www.michelesleepscoring.com.


About Cerebra Health Inc.

Cerebra Health is a Manitoba based, digital health-tech company focused on improving access to advanced, diagnostic technology for the assessment of sleep and the diagnosis of sleep disorders. Cerebra was founded and initially funded by Rana Respiratory Care Group, a sleep and respiratory care provider that has been operating in Western Canada for 25 years. Cerebra provides in-home sleep study services for dental and home-care companies that offer treatments for sleep apnea and other sleep disorders in the Canadian market. The Company’s digital service platform provides unmatched capabilities for in-home sleep analysis, with a focus on improved user experience, state-of-the-art diagnosis, and increased operational efficiency.  Cerebra is also working in partnership with leading sleep scientists and researchers to revolutionize clinical sleep medicine by leveraging its core capabilities in digital sleep analysis.  

For more information on Cerebra Health please visit www.cerebrahealth.com



Cerebra Health Inc.

 Dawson Reimer


5-55 Henlow Bay, Winnipeg, MB, Canada


 204-928-8040 (FAX)





MICHELE is a Class II medical device and is restricted to sale by or on the order of a physician.  Refer to product labeling for specific information and directions regarding product purpose, use, warnings and cautions.


Regulatory Statement

YMT operates a Quality Management System that complies with the requirements of ISO 13485:2003 and holds Certificate Number FM 551942 issued by the British Standards Institute (BSI). This certification includes the Standards Council of Canada (SCC) endorsement under the Canadian Medical Device Conformity Assessment System (CMDCAS) scheme.

YMT is also in conformance with the provisions of Annex V/Annex VII and of the Essential Requirements of Annex I of the European Medical Devices Directive 93/42/EEC as amended by Directive 2007/47/EC. As well, YMT’s Quality Management System incorporates all requirements of the US FDA Quality System Regulations, as per Part 820 of Title 21 of the Code of Federal Regulations (CFR).

Younes Medical Technologies is committed to continual improvement of its product and Quality Management System.



  1. Younes M, Ostrowski M, Soiferman M, Younes H, Younes M, Raneri J, Hanly P. Odds ratio product of sleep EEG as a continuous measure of sleep state (2015) Sleep 38:641-654. 
  2. Younes M, Hanly PJ. Immediate postarousal sleep dynamics: an important determinant of sleep stability in obstructive sleep apnea (2016) J Appl Physiol 120:801-8. 
  3. Meza-Vargas S, Giannouli E, Younes M. Enhancements to the multiple sleep latency test (2016) Nat Sci Sleep 8:145-58.
  4. Qanash S, Giannouli E, Younes M. Assessment of Intervention-Related Changes in Non-REM Sleep Depth: Importance of Sleep Depth Changes within Stage 2. Sleep Medicine. In Press.
  5. Malhotra A, Younes M, Kuna ST, Benca R, Kushida CA, Walsh J, Hanlon A, Staley B, Pack AI, Pien GW. Performance of an automated polysomnography scoring system versus computer-assisted manual scoring (2013) Sleep 36:573-82.