Hajira Saman

Hajira Saman, Arushi Aggarwal and Kedar Harsha Seshadri
The University of Texas at Dallas
A mHealth Platform for Monitoring Heart Rate and Tracking Sleep – Combating Insomnia and Sleep Apnea
Abstract— Poor sleep quality is known to significantly affect not only one’s physical health but also one’s social well-being. Sleep is too important to ignore. It affects every organ in the human body. Diseases resulting from poor sleep such as heart disease, heart attack, heart failure, irregular heartbeat, high blood pressure, stroke, diabetes are the leading causes of mortality worldwide. More easily accessible, less laborious and more user-friendly methods of measures are needed to be able to better diagnose sleep activities and treat patients.

mHealth is an emerging research field that attracts health caregivers, researchers and application developers. mHealth solutions are based on sensors, mobile devices, and wireless networks to provide healthcare services to patients. mHealth enables professionals to make appropriate decisions and interventions, and patients can manage their daily activities independently. Sleep tracking is a very important indicator to evaluate the conditions of people for a healthy lifestyle. We present in this paper the design of our smart-phone based system to track sleep and monitor heartbeat to diagnose sleep apnea and insomnia in the patients. It constitutes an assistive mHealth solution to notify people about the current level of their health by their sleeping behavior. In addition, we briefly review known existing mHealth solutions in order to clarify the techniques used to build mHealth solutions.
Index Terms— mHealth; obstructive sleep apnea (OSA); sleep monitoring; smartphone sensing, insomnia
Introduction
It’s always been better to be smart rather being a hard worker. The word SMART symbolizes many aspects, but in today’s generation, it includes the mindset of people concerned as well. Smart is being innovative, compact, something like more work but less manpower and monitoring a vast chain of things on our fingertips is what being smart is and we have got this device called the smartphone. The smartphone is a significant measure of a mobile health ecosystem. It hosts many health-related apps and offers a convenient way to review measurements taken from different devices. Science and technology have grown up to that extent that now the mutation of both are creating wonders. It’s all the key technology to a techno hub which is well programmed and iterated for perfection. So that device is nothing but the remote to access smartness with or without profound knowledge but with better thinking which leads to a better living. Here comes the big question, how can just a wireless phone control everything in our lives? Feature phones are something which ever lasted but it was way limited usage are beyond transmitting and receiving. Today’s world is at a
the stake of our own key responsibilities. We are just at the start of this technological race. We are the key survivors for future.

We may call this a testing phase, or we may call ourselves experimental specimens but still, if we just look back in past, this race looks never ending, back in past they discovered and till date and in the future, we will keep on discovering. As a man, everybody on this planet is worried about their wellbeing. In the event that everything is picture-immaculate, and everything about will mean is seen straightforwardly, that is the thing that the humanity is sitting tight for. It’s so unverifiable however yet normal, man can assemble enormous things starting with no outside help to the sea yet all he requires is a help which makes him solid ethically. A stage towards that very stage is the mHealth administration utilizing on our own one of a kind gadget called the smartphone. With the assortment of sensors, for example, GPS, accelerometers, or a compass, it appears glaringly evident to utilize the cell phone as a detecting and tracking gadget. Truth be told, numerous applications are accessible to track a wide range of open-air sports or to utilize the smartphone as a pedometer. In fact, many apps are available to track all types of outdoor sports or to use the phone as a pedometer. In any case, such applications experience the ill effects of the way that a cell phone is intended to be utilized intelligently in the palm of the hand, not to stick on the body—a cell phone is too huge to possibly be worn the entire day. You may put it on a work area when at the workplace or bear it in a satchel as opposed to wearing. A common lame man never knew what actually an operating system is and how actually a smartphone can make wonders, forgetting the negative outcome of technological crisis let’s try looking forward in a very constructive way. Now a smartphone is not just a phone for handling calls and communications, it’s our calculator, iPod, voice assistant, personal assistant, torch, laptop, excel sheet as well a multi-purpose non-living yet a living being in its own sense.

Artificial intelligence is a boon to this mankind what we see right now on a wonderful platform called life. So, this life cycle includes everything, we are securing ourselves day by day with multiple innovations and contributions. One such contribution to this mankind we made is eHealth management. eHealth or e-health is relatively recent healthcare practice initially started in around 1999, the normal doctors started to store the health data of patients as an e-file or e-document. Later in early 2000, the actual interpretation for health management started. A technological upgrade was seen through iOS and Symbian OS phones launched in early 2004-2008.
An investigation in 2005 discovered 51 one of a kind definitions. Some contend that it is exchangeable with wellbeing informatics with a wide definition covering electronic/advanced procedures in health while others utilize it in the smaller feeling of healthcare practice by utilizing the Internet 30. Later on, one single platform many developers started thinking innovative and started developing applications on basis of the operating systems present. These applications were essentially health applications and connections on cell phones, alluded to as mHealth. Since around 2011, the expanding acknowledgment of the requirement for better digital security and direction may bring about the requirement for these specific assets to create more secure eHealth arrangements that can withstand these developing dangers
Electronic trackers or activity trackers are finely updated versions of pedometers. The basic function is to count steps but in addition to it, they use accelerometers and altimeters to calculate mileage, graph overall physical activity, calculate calorie expenditure, and in some cases also monitor and graph heart rate and sleep activity. This very basic concept led to the renaissance in the vast industry of health management. To be precise it was a big data of a particular human from head to toe in just a matter of information stored and synced in throughout his/her lifespan.

The fundamental concept of every product in the market is first creating the prototype and later digging around it for betterment and up-gradation. We are part of this every construction and destruction taking place globally, all we need is big companies, large manpower and a system to manage us (computers). We never cared about our health all time, we all are busy in making money working in some different organizations. All we need is money to spend on us without even knowing what is happening internally in our very own body.

Background and Overview
mHealth describes the use of portable electronic devices with software applications to provide healthcare services and manage patient information and is used to educate consumers about preventive health care services. Nowadays, M2M- machine to machine technology has evolved so much that it enables networked devices to exchange information and perform actions without manual assistance of humans.

Wearable health technology has become very popular these days. Wearable detection devices can track almost everything from fitness to illness, from beauty to sleep. These devices are mostly popular only among fitness fanatics. People in real need of these devices such as patients suffering from related illness are not willing to get these due to its expensive cost unless advised by the doctors. Hence it is required to make these devices at an affordable price so that it could be accessible to all the people. We need to make it cost effective as well as productive. These devices which are capable of keeping track of the health-related medical data are not yet equipped with most healthcare facilities.

The things that a wearable detection can do are but not limited to:
Activity tracking
Step count
Sleep tracking
Calories Burned
Heart rate management
Sugar level management
ECG
Distance covered on foot
Sleep disorders are an important public health problem that affects approximately 50 to 70 million people in the United States 1. Sleep disorders are defined as having abnormal sleep behaviors, including insomnia, sleep apnea, restless leg syndrome, and narcolepsy 2. Those who have chronic sleep disorders are at a greater risk for obesity, diabetes, hypertension, cardiovascular disease, stroke, and depression 3-6. Insomnia and heart-related diseases are one of the main concern that people around the globe are dealing with. Sleepless nights and restless body leads to many complications in a human’s daily life. Being a human with a brain full of convolutions and no data stored for our betterment is a very sad part.

Our bodies are supposed to go to rest when we sleep. Body signifies all the parts of our body including the heart. This is the reason why our health rate goes down during sleep. Sleep deprivation can lead to changes in the brain matter and have the adverse effect on the body such as:

Memory Issues: During sleep your brain from connections that help you process and remember new information. Alack of sleep can negatively impact both long and short-term memory.s
The trouble with thinking and concentration: Your concentration, creativity and problem-solving skills aren’t up to par when you don’t get enough sleep.

Mood Changes: Sleep deprivation can make you moody, emotional and quick-tempered. Chronics sleep deprivation can affect your mood and lead to anxiety or depression, which may escalate.

Accidents: Being drowsy during the day can increase the risk of car accidents and injuries from other causes.
Weakened Immunity: Too little sleep weakens your immune system’s defenses against viruses like those that cause the common cold and flu. You’re more like to get sick when you get exposed to these germs.

High Blood Pressure: Sleep less than 5 hours a night highly increases the risk of blood pressure.

Risk of Diabetes: Lack of sleep affects the body’s release of insulin, a blood sugar-lowering hormone. Less sleep leads to high blood sugar level and an increased risk of type 2 diabetes.

Risk of Heart Disease: Lack of sleep may lead to higher levels of chemicals linked to inflammation which plays a great role in heart diseases.

Poor balance: Absence of sleep can influence your balance and coordination, making you more inclined to falls and other physical mishaps.

Weight gain: With sleep deprivation, The chemicals that signal your brain that you are full are a low off balance. As a result, you’re more likely to overindulge even when you’ve had enough to eat. Also, it leads to a serious problem called sleep apnea which produces more sleep deprivation. It is a disorder in which a person pauses in breathing during sleep. Sleep apnea can also transform the stages of neurotransmitters in the brain.
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Figure 1. Difference between normal breathing and OSA.

There are mainly 2 types of Sleep apnea:
OSA- Obstructive Sleep Apnea
CSA- Central Sleep Apnea
Sleep is a five stages phenomenon, yet these are regularly arranged by customer level gadgets into a few phases: light sleep, profound deep, and rapid eye-development sleep. Recognizing rapid eye-development sleep with a wearable device or application is for all intents and purposes unimaginable without polysomnography, a test that records your mind waves, blood oxygen levels, heart rate, breathing, and also eye and leg developments amid the examination. It requires the position of Table 1. The above table shows different wearable detection devices, their functions, and their pricing.

electrodes on your head and is generally performed in a center for one night. The polysomnogram has for some time been the best quality level for estimating sleep physiology in fitness and illness. The PSG has demonstrated most helpful for the finding and treatment of obstructive sleep apnea (OSA), albeit less regular issue is additionally promptly distinguished by research center PSG, including narcolepsy, rapid eye-development sleep conduct issue, non- rapid eye-development parasomnias, and occasional appendage developments of sleep. The indicative criteria for certain sleep issue, for example, restless legs disorder and sleep deprivation, are absolutely clinical. For sleep deprivation specifically, restrictive dependence on self-revealed dissensions presents two vital difficulties in understanding this basic issue. To begin with, it isn’t phenomenal to watch a befuddle between the subjective report of sleep-wake lengths and the target discoveries of the polysomnogram. Second, the absence of target information obliges the ability to phenotype sleep deprivation patients, an impediment that has suggestions running from the study of disease transmission concentrates to the improvement of remedial techniques24.
With the fact the utility of polysomnogram in clinical sleep medication is clear, polysomnography is costly and inconvenient, more straightforward, more moderate, and longer-term alternatives for individuals can be obtained from personal activity trackers which are quite affordable. They are regularly put on the bed or worn on your wrist, and utilize accelerometer sensors (to recognize your development), in some cases along with a microphone to detect noise. But here we will discuss the wearable health rate monitoring devices.

How wearable health rate monitor helps us sleep? How long should our heart rate go low? How low does it have to go? A healthy person has a heartbeat between 60-100 bpm when resting. The lower the resting heart rate the more fit a person is. There is a device called Holter monitor to monitor ECG heart rate for 24-48 hours. This device has electrodes attached to the chest through which the data is collected.
Wearable detection can also help us in detecting arrhythmia. It is a condition where the heartbeat is irregular, i.e. it is either too fast or too slow. It is also called as cardiac dysrhythmia. One of the main reasons/factors of arrhythmia is OSA (Obstructive sleep apnea). It is a sleep disorder in which a person’s breathing repeatedly discontinues during sleep. It is caused by a narrowing of throat tissue during sleep. It has been reported that there are more than 3 million cases of OSA every year in the United States. The symptom of OSA syndrome in adults is excessive daytime sleepiness. This conduct might be very sensational, now and then happening amid discussions with others at get-togethers.The hypoxia (absence of oxygen supply) related to OSA may cause changes in the neurons. Research utilizing neuro-imaging uncovered confirmation of hippocampal decay in individuals experiencing OSA.They found that in more than 25% of the OSA cases, this problem results in irreversible problems in mentally manipulating non-verbal information and in executive functions and working memory, despite years of optimal continuous positive airway pressure (CPAP) treatment. Untreated sleep apnea leads to serious complications like heart disease and depression. It can also lead to complications in pregnancy, car wreck caused by falling asleep while driving, stroke, high blood pressure, and brain damage. The symptoms include snoring and feeling tired among many others. Treatment includes weight loss and use of breathing assistance device at night, such as CPAP (Continuous Positive Airway Pressure) machine. The use of this can be monitored with the help of a heart rate tracker. The damage caused to the brain can be reversed by CPAP therapy machine. Polysomnography is a type of sleep study which is used as a diagnostic tool in sleep medicine. It records the biophysiological changes that occur during sleep. It is used to diagnose many types of disorders by recording brain waves, the oxygen level in our blood, heart rate and breathing, as well as eye and leg movements. In addition, polysomnography may be used to help adjust your treatment plan if a person has already been diagnosed with a sleep disorder. It monitors sleep stages to identify when the sleep patterns are disrupted and why.
sleep is best monitored through polysomnography, however, these gadgets offer considerably more open and advantageous alternatives for easygoing individuals to track their movement and take in more about their propensities during both night and day. These gadgets offer some great information and powerful data tracking tools.

Previous Study/ Related work
In 2016, the Centers for Disease Control and Prevention published findings that a third of adults weren’t getting enough sleep. And these sleep-deprived people are costing the country over 400 billion of dollars each year. According to a report by Rand Europe, some 1.2 million working days are lost in the US every year due to tired employees. This is in addition to the costs to our individual health with the long and short-term impact sleep deprivation has on our brains and bodies. The growing body of research and increased public awareness around sleep has put sleep at the forefront of everyone’s minds. 
The American Academy of Sleep Medicine reported that even though the sleep-tracking devices and mobile apps can help engage users in improving sleep health none of the consumer technologies has been proven accurate or validated to screen for sleep disorders 28.

Despite its booming popularity in 2018, sleep technology is not a new invention. One of the early pioneers was Zeo, a company established in 2003 to monitor sleep (Franceschetti). Their signature product was a headband that measures brain waves to accurately detect sleep phases. Zeo, unfortunately, shut down operations in 2013, likely because consumers weren’t yet ready to embrace sleep technology at the time. Fast forward to now, and sleep is finally ready for disruption. Innovative sleep tech is flooding the market and showing no sign of snoozing. Globally, the market for these products is expected to reach over $76 billion in 2019. 

Figure 2. Body track device
As people’s sleep quality improves, energy, productivity, health and overall happiness will rise 17. Zeo was a sleep monitor that included a wireless-enabled, sensor-equipped headband that users wore at night and a bedside display alarm clock that captured the data transmitted from the headband. The idea was for an alarm clock that could wake you up at just the right moment in your sleep cycle, during the right sleep stage, so that you would awake to feel refreshed29. Zeo’s alarm clock had this functionality built right in when it launched in 2009 (“Exclusive: Sleep Coach Company Zeo Is Shutting Down”). Before that launch, however, the startup discovered in early product tests that users wanted a device that could do more than just wake them up better, they wanted to know how well they were sleeping, too (“Thread: Sensosr for Detecting REM Sleep”).

Figure 3. A sleep monitor: (a) the headband of the Zeo sleep monitor and (b) the monitor in use.

Body track platform 10 utilizes real-time data analytics and machine learning to automate health & safety and performance
monitoring. Body tracking is a unique wearable and vital signs meter. It measures biometric information from your ear. Its device measures body temperature, heart rate, speed, distance continuously – and all in real-time. Moreover, since it fits nicely into your ear, you can listen to music and make telephone calls as well.

Figure 4. Body track functions
Action trackers like Fitbits measure rest by following times of latency related to sleep, alongside heart-rate designs that connect to resting. While quite a bit of that information isn’t clinically approved, it gives medicinal services suppliers a stage on which to recognize patterns. All the more essential, scientists say, it gives them a chance to team up with patients who may somehow, or another not know how to depict their rest issues to specialists.
As people age into their 60s and beyond, sleep can turn into a nightly disappointment 11. What once was peaceful repose becomes fragmented, unsatisfying, or simply evasive. For some, the cause is a chronic illness or the medications they take to treat it. Also, some disorders, such as sleep apnea and restless leg syndrome, often worsen in old age. So, with a big chunk of the U.S. population entering its senior years, there’s a need to more clearly comprehend the correlation between sleep and physical and mental illness. And, a key is finding more efficient and less invasive ways to monitor older adults hoping to stay in their own homes. A professor of electrical engineering and computer science at MIT is helping to make that happen., she and her team have developed a device that uses radio waves to track how well people are—or aren’t—sleeping. Specifically, it can measure when and for how long a person is spending in different stages of sleep. And, unlike more conventional sleep tracking, this innovative approach is built around a box that can sit, barely noticeable, in a home, not unlike a Wi-Fi router.
Sleep Cycle alarm clock wakes utilizes the accelerometer in the phone to track sleep patterns and wakes users up in the lightest sleep phase – it feels like waking up without an alarm clock so that you feel relaxed and calm when you wake up (“Snore No More”).

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Figure 5. Sleep Cycle Alarm Application
2breathe uses smart, connected technology to deliver sleep-inducing breathing exercises. A sensor worn around the torso picks up the user’s inhale and exhale movements sending it to an iOS app via low energy Bluetooth. The app transforms, in real-time, the breathing into tones that gradually guide the user to prolonged exhalation and slow breathing. The process continues until the user falls asleep. Once the app detects that the user is asleep, 2breathe automatically shuts off and generates a report showing the falling asleep process.

Sleep Minder is a contact-less and convenient measurement of sleep and breathing in the home. It is a radiofrequency monitoring device that uses 5.8?GHz frequencies to detect body movements 23. The SleepMinder was contemplated by putting the sensor above and sidelong to the bed, for example, on a bedside table. It was most precise when setting within 0.5 meters of the bed, with the greatest separation of 2.5 meters. Recognizing sleep and wake indicated 78% precision in a populace of 153 subjects who experienced PSG observing for suspected sleep apnea 24. Add up to rest time was overestimated, which is normally the case with development discovery by wearable actigraphy devices 24. The device execution was less precise in recognizing wake, REM, and stage N1 sleep however detailed 96% exactness in arranging moderate wave rest 24. In a different investigation of 176 patients who experienced medium-term PSG checking for suspected sleep apnea, the gadget could group subjects with versus without sleep apnea 24.

Figure 6. Sleep minder
Objective
The objective of this paper is to conduct a sleep intervention study: using mHealth technology (e.g., a mobile device or app) to learn the daily activity and sleep patterns of the patients and to design a smartphone application along with a device to track and monitor sleep and heart functioning. Patients here refer to people having shown symptoms of sleep apnea and heart-related ailments or anyone else in general concerned about their health. People with sleep apnea may not be aware of their condition at all. Hence our sleep and heart rate monitoring device can keep track of the heart rate and prevent any other ailments.

Figure 6. Functions of the proposed system
Architecture and System Description

Figure 7. Functions of proposed sleep tracking system

Figure 8. Proposed System Functioning Flow
The proposed architecture includes a sleep tracking device and a smartphone through which the data collected is conveyed to the person wearing the device. It would be a simple package especially for the aged with a straightforward set-up process that includes better indicators for opening the package and removing the device as well as more detailed, step-by-step instructions for syncing 27. The tracking device monitors heart rate for arrhythmia and sends data to the smartphone, monitors sleep apnea, tracks noise level in the room and tracks the amount of sleep. The tracker must give users a view of progress that is up to date. Noise recording allows you to record significant noises during your sleep. You may reveal that you are sleep talking, sleep laughing, snore or even have a more serious issue (such as obstructive sleep apnea OSA).

Conclusion
The present attention on mHealth in the United States is mostly on smartphone applications, by means of a promptly growing interest in embedded wireless devices, for instance those for in-home patient observation. However in the rest of the world, products and services depends profoundly over voice and text messaging. The previous five years in the United States have perceived a fast acceptance of text messaging. According to Nielsen, people under the age of 18 send or receive an average of 2,779 texts per month. On the other end of the spectrum, those over age 65 exchange 32 texts per month, still many more messages than in past years. These figures propose a prospect for text messaging results. In addition, voice communications have been used for significant health hotlines in Mexico and India, and collaborative voice-recognition arrangements have maintained community health workers in Pakistan. Even though smartphone solicitations might signify the exploiting advantage, simple text and voice signify influential tools with nearly omnipresent reach 14.
Economical customer specific sleep tools will undoubtedly have an imperative part to show in the future. Nevertheless, they haven’t been scrupulously verified for precision in contradiction of the specialized apparatus in sleep clinics, and they can’t change a medicinal assessment 28. Since many devices and applications are peddled in the standard of living/entertainment group, they don’t entail supervisory consent or omission. The tools assert to roadway and describe sleep-related metrics such as a number of hours asleep, along with movement and restiveness overnight. But clinicians cannot ractually practice this statistics as the technologies haven’t been corroborated. Also, the information isn’t consistent from one device or applicatio to the other and aren’t presented for doctors to examine directly. Furthermore, sleep applications don’t have a tendency to practice the latest study or national guidelines to support their recommendations. Sooner or later, sleep devices and applications will provide long-term statistics for sleep study, permit doctors to evaluate patients’ sleep data tenuously between office visits and turn into a part of electronic medical archives, the statement facts out 28. Carrying innovation into the rooms is something that can honestly transform the sleep involvement. Innovation has advanced moderately every fragment of our lives as of today. From air travel to robots that clean our home to entreating sustenance with a tap of our fingers, we can do as such significantly further because of innovation (Editor). The future of sleep involves technology, there’s simply no way around it.

APPENDIX
Table 2 shows the number of studies based on study design and sleep measurement tools conducted by people at University of Illinois- Urbana Champaign. Several questionnaires were used to evaluate various aspects of sleep quality and quantity.

References
Altevogt B, Colten H. Sleep Disorders, and Sleep Deprivation: An Unmet Public Health Problem. Washington, DC: National Academies Press; 2006.

Cleveland Clinic. 2013. 2017-02-18. Common sleep disordershttps://my.clevelandclinic.org/health/articles/common-sleep-disorders.

Gottlieb DJ, Yenokyan G, Newman AB, O’Connor GT, Punjabi NM, Quan SF, Redline S, Resnick HE, Tong EK, Diener-West M, Shahar E. Prospective study of obstructive sleep apnea and incident coronary heart disease and heart failure: the sleep heart health study. Circulation. 2010 Jul 27;122(4):352–360. doi: 10.1161/CIRCULATIONAHA.109.901801. http://circ .ahajournals.org/CGI/pmidlookup?view=long&pmid=20625114Cappuccio FP, Taggart FM, Kandala N, Currie A, Peile E, Stranges S, Miller MA. Meta-analysis of short sleep duration and obesity in children and adults. Sleep. 2008 May;31(5):619–626.http://europepmc.org/abstract/MED/18517032. 
Gangwisch JE, Heymsfield SB, Boden-Albala B, Buijs RM, Kreier F, Pickering TG, Rundle AG, Zammit GK, Malaspina D. Sleep duration as a risk factor for diabetes incidence in a large U.S. sample. Sleep. 2007 Dec;30(12):1667–1673. http://europepmc.org/abstract/MED/18246976. 
Macey PM, Woo MA, Kumar R, Cross RL, Harper RM. The relationship between obstructive sleep apnea severity and sleep, depression and anxiety symptoms in newly-diagnosed patients. PLoS One. 2010 Apr 16;5(4):e10211. doi: 10.1371/journal.pone.0010211. http://dx.plos.org/10.1371/journal.pone.0010211. 
Digital Health Devices for Everyone- https:// ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6818515
https://www.aarp.org/content/dam/aarp/home-and-family/ personal-technology/2015-07/innovation-50-project-catalyst-tracker-study-AARP.pdf
Bodytrak platform: http://www.bodytrak.co/
https://www.smithsonianmag.com/innovation/device-uses-radio-waves-track-how-youre-sleeping-180964713/Smart-Phone based System to Monitor Walking Activity: mHealth Solution:https://ieeexplore.ieee.org/stamp/stamp.jsp? tp=&arnumber=8371021
http://www.mobihealthnews.com/20772/exclusive-sleep-coach-company-zeo-is-shutting-downhttps://ssir.org/articles/entry/opportunities_in_mobile_ healthJ. Sarasohn-Kahn, “How Smartphones Are Changing Health Care for Consumers and Providers,” California HealthCare Foundation report, April 2010.

Why is a technology the future of sleep? https://www.forbes.com/sites/forbestechcouncil/2018/02/06/why-technology-is-the-future-of-sleep/#365d27bf1f32https://www.mensjournal.com/gear/10-best-mobile-apps-track-your-sleep/https://en.wikipedia.org/wiki/Obstructive_sleep_apneaGale SD, Hopkins RO (2004). “Effects of hypoxia on the brain: neuroimaging and neuropsychological findings following carbon monoxide poisoning and obstructive sleep apnea”. J Int Neuropsychol Soc. 10 (1): 60–71. doi:10.1017/S1355617704101082.

Henry, D; Rosenthal, L (Feb 2013). “Listening for his breath:” the significance of gender and partner reporting on the diagnosis, management, and treatment of obstructive sleep apnea”. Social Science & Medicine. 79: 48–56. doi:10.1016/j.socscimed.2012.05.021. .

https://arstechnica.com/gadgets/2017/05/sleep-it-off-how-and-how-well-wearables-can-track-sleep/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5608984 /# ref
De Chazal P, Fox N, O’Hare E, et al. Sleep/wake measurement using a non-contact biomotion sensor. Journal of Sleep Research. 2011;20(2):356–366. 
The Platform Online, theplatformonline.com/2018/02/07/why-technology-is-the-future-of-sleep/.

International Scholarly Research Notices, Hindawi, 14 Oct. 2012, www.hindawi.com/journals/isrn/2012/768794/.

Leonardosanchezdelerin, leonardosanchezdelerin.wordpress.com/tag/innovation/.

LinkBack URL, www.dreamviews.com/research/145941-sensosr-detecting-rem-sleep.html.

Longevity Network. LinkedIn SlideShare, 9 Jan. 2017, www.slideshare.net/TheLongevityNetwork/building-a-better-tracker-older-consumers-weigh-in-on-activity-and-sleep-monitoring-devices.

WSAU, WSAU News/Talk 550 AM · 99.9 FM | Wausau, Stevens Point, 24 May 2018, wsau.com/news/articles/2018/may/24/sleep-tracking-wearables-and-apps-no-substitute-for-sleep-tests/.

Sleep Cycle Alarm Clock, 19 Apr. 2018, www.sleepcycle.com/news/snore-no-more/.

Acchi Khabar, Acchi Khabar, www.mahamrityunjayamantra.co.in/ehealth/.