# A Novel mHealth Approach for the Monitoring and Assisted Therapeutics of Obstructive Sleep Apnea
## 1 Introduction  
We live in a society in constant motion, in which time is increasingly finite and valuable, and, often, the 24 h of the day are insufficient to fulfill our obligations; consequently, we end up forgetting the importance of sleep. Sleep is a vital tool for good health and well-being in adults, adolescents, and children alike [1, 2]. Sleep is vital to the human body and necessary for life, having many functions of enormous importance, as follows: it promotes growth, learning, and cognitive development; it is important at metabolic and cognitive, cardiovascular, and cerebrovascular levels; and it is also a major contributor to good mental health and good mood. The quality and quantity of sleep that a person has also plays an important role in reducing injuries caused by traffic and work accidents, which can result from fatigue and sleepiness [3, 4]. For a healthy sleep, we must have the following factors in place: adequate time and duration, regularity, good quality, and an absence of disturbances. Although the individual needs of each person may fluctuate, the National Sleep Foundation (NSF) states that, for adults and young adults, the ideal amount of sleep is between seven and nine hours a night; however, for older people this ideal amount is reduced to seven to eight hours [5]. Many factors are responsible for a bad night's sleep, such as environmental or behavioral factors (for example, brightness, room temperature, noise, sedentary lifestyle, poor eating habits, and alcohol consumption, among others), as well as sleep disorders such as insomnia, restless leg syndrome, insufficient sleep syndrome, and obstructive sleep apnea (OSA). Sleep apnea is termed \"central\" or \"non-obstructive\" when no breathing effort is present and \"obstructive\" when breathing effort is present. Obstructive sleep apnea is a breathing disorder that, as the name implies, occurs during sleep, but has implications that go far beyond sleep disruption. The clinical disease is characterized by recurrent episodes of the partial cessation of oro-nasal airflow (hypopneas) or the sudden complete cessation of airflow (appeas), followed by a collapse of the upper airway during sleep. Upper airway obstruction during sleep lasting at least 10 s defines an apnea resulting in increased airflow resistance, which compromises and reduces blood oxygen saturation [6]. The apnea-hypopnea index (AHI) refers to the total amount of apnea and hypopnea episodes that occur during sleep, fractionalized by the hours of sleep. It is commonly used as a measure to describe these breathing disorders, resulting in a scale of disease severity [7]. OSA can be classified as follows:  
* Mild--when it presents an AHI that ranges between 5 and 15;
* Moderate--when the AHI is between 15 and 30;
* Severe--when the AHI value exceeds 30. The clinical presentation of OSA includes signs of upper airway obstruction, daytime hypersomnia, and insomnia. Before it is detected, the symptoms of this disease usually show up silently and can take the form of snoring, panting breath, or asphyxia. However, until the appearance of more flagrant daytime symptoms, patients tend to underestimate and ignore these signs, thus leading to a delay in diagnosis. In the early stages of the disease, the patient may easily fall asleep during more sedentary daily activities, such as watching television (which can often be mistaken for tiredness or fatigue). As the disorder worsens, drowsiness invades daily activities and can become dangerous and disabling, with work and traffic accidents increasingly being identified as an inherent risk of this disease. It is estimated that the monetary value of road accidents associated with OSA is so high that the diagnosis and treatment of all drivers with this condition in the USA would result in savings, and in a decrease in the costs of the damages caused to society because of this disease [8].