Obstructive Sleep Apnea is a kind of sleep syndrome, which has an adverse effect on
both the health, and quality of life of an individual. It results in severe health problems like hypertension,
stroke and many cardiovascular issues. Only a very less percentage of persons with Obstructive
Sleep Apnea are diagnosed and treated. This is due to the lack of available devices and
technology. Detection of this sleep disorder is extremely important, as negligence can prove fatal.
Hence, the critical need in healthcare is the instantaneous monitoring of this disorder. The current
approaches for detecting this disorder are very expensive, bulky and intrusive which in turn will
affect the sleep quality of patients. So there is a necessity to design less expensive, light-weight
non-intrusive systems to diagnose these sleep-related issues. In this paper, the various noninvasive
schemes using sensors and Internet-of-Things to detect Obstructive Sleep Apnea are reviewed.
Further, the open research issues and challenges in detecting Obstructive Sleep Apnea are