Sleep: something that many entrepreneurs don't get enough of each night. Science has shown that it's just as important as nutrition and exercise when it comes to long-term health, happiness, and day-to-day productivity. But recently reported research has shown that rampant insomnia is cutting America's bottom line—something that a slew of start-ups is trying to change with technology. 

Based on survey of 7,428 employees, researchers at Harvard Medical School found that the average U.S. worker loses 11.3 days of productivity a year due to exhaustion. The study estimates that this loss of productivity costs American corporations roughly $63.2 billion a year.

But these three start-ups are using advances in consumer-level sensor technology and wireless smart-device integration to give people the means to a good night's sleep. 

Lark Technologies. Founded in 2012 and based in Mountain View, California, Lark Technologies makes wrist-watch type device called the lark pro that you wear while you sleep. Using an accelerometer, the lark pro tracks micro-movements to assess your sleep patterns, which it summarizes on your mobile device or on lark's website. Like most of its competitors, it visualizes your sleep habits over time and boasts a silent vibrating alarm clock feature. The lark pro costs $159 and comes with the sleep sensor, a wristband, and a charging dock that can charge your sensor and iPhone.

Rest Devices. Based out of Boston, Rest Devices was started by four MIT graduates in 2011. The young tech company sells the SleepShirt, a machine washable shirt with two sensors that monitor movement and respiratory activity. It takes that data and uploads Rest Device's servers where it's analyzed to track sleep behavior and determine with 94 percent accuracy whether or not a SleepShirt user has sleep apnea. Sleep apnea—a condition that affects roughly 7 percent of Americans and can result in day-time fatigue and long-term brain damage—often requires a sleep study to diagnose.  

GEAR4. Rebranded from Podgear in 2006, GEAR4 is the UK-based Disruptive Limited's iPod and iPhone accessory brand. They make the Renew SleepClock, a bedside iPad, iPhone, and iPod dock with a large speaker that can track your sleeping habits by measuring your breathing and movements, which it reports to its Renew app. The fact that you don't have to wear a wristband or headband while you sleep is what distinguishes the SleepClock from its competitors. The device can lull you to sleep and wake you up at the ideal moment in your sleep cycle with music, and costs $129.95.