Apple has added yet another person working in digital health to its iWatch team, according to a report in 9to5Mac. The company recently hired Roy J.E.M. Raymann from Philips Research, where he led various sleep-related studies. Raymann was a senior scientist at Philips Research who founded the Philips Sleep Experience Laboratory, a non-clinical sleep research lab. He also led projects related to sleep and activity monitoring as part of Philips' Consumer Lifestyle Sleep Research Program and Philips' Brain, Body, and Behavior group.

According to the report, Raymann has studied ways to monitor and change sleep patterns by using non-medical methods like "mild skin warming" which could alter sleep-pressure, sleep quality, and alertness. He has also worked on miniaturizing sensors that help track sleep and alertness.

Apple is also looking to hire an “user studies exercise physiologist,” according to a recent job posting that 9to5Mac also found. The person would help Apple "design and run user studies related to cardiovascular fitness [and] energy expenditure, including calories burned, metabolic rate, aerobic fitness level measurement [or] tracking and other key physiological measurements.” More from the job description here.

MobiHealthNews recently broke the news that Apple had hired former Masimo Chief Medical Officer Mike O'Reilly and that another one of its recent hires -- Nancy Dougherty -- was an alum of Proteus Digital Health. (For a recap of a half dozen of the more recent health-related hires at Apple, check out this previous post.)

Early last year when high-profile sleep tracking company Zeo went out of business, the direct-to-consumer sleep monitoring field opened up. Since then an increasing number of smartphone-enabled activity tracker device companies have added some kind of sleep tracking feature to their wares. At the big Consumer Electronics Show (CES) just a few weeks ago, Withings unveiled a sleep tracking device as part of its portfolio of trackers and Basis added sophisticated sleep tracking to its heart-rate sensing, wristworn tracker.