Description: NASA has a critical requirement for a wearable device that can provide objective measures of sleep and activity for its crew during long duration spaceflight. In the proposed program, we will develop an unobtrusive wrist worn monitor that places minimum burden on the crew in operating the device. The device, once worn, requires no action from the crew and automatically records and analyzes actigraphy and sleep data. The device will have battery life of about one year and wireless data transfer so the crew will not be burdened with recharging the device and downloading data from the device. The monitoring device will provide real-time feedback on the level of activity and duration and quality of sleep. The proposed device is based on an existing sleep and activity monitor which we will modify and enhance to make it suitable for use in spaceflight environments. Data format, including epoch length and sleep statistics provided by the proposed system will conform to formats currently used in sleep research. In Phase 1, we will deliver a set of fully functional devices that can be deployed in spaceflight analogs. We will also perform feasibility studies of a Phase 2 unit, which will measure, in addition to sleep, activity and heart rate, other physiological parameters such as heart rate variability, blood pressure, vasoconstriction, pulsewave velocity, and electrodermal activity. Since the work is based on an existing sleep and activity monitoring platform, we expect that the Technology Readiness Level (TRL) of the Phase 1 unit to be at 7, and the Phase 2 unit to be at 8.

Benefits: The technology proposed under the program will provide an unobtrusive and objective measure of sleep and activity cycles during long duration missions. The data obtained from the wrist worn device can be used to optimize work-rest-sleep schedules. Information provided by the proposed device will allow the crew to effectively adapt to the spaceflight environment and manage fatigue resulting from lack of sleep or work overload. The proposed monitor to be delivered in Phase 2 will allow the monitoring of key physiological parameters such as heart rate, heart rate variability, trends in blood pressure, vasoconstriction and electrodermal activity. The measurement of the physiological parameters, in addition to activity and sleep, can be used to monitor levels of stress as well as the general psychological health of the crew during exploration missions. We will work closely with NASA researchers to incorporate the requirements for a spaceflight capable sleep and activity monitor. The proposed device will conform to the requirements for data recording (including epoch length), dynamic wearability, and spaceflight use cases. We will also conform to representation of data currently used in sleep research.

The technologies developed in the proposed program can be readily applied to the development of consumer activity and fitness tracking devices. There is a clear market need for a compact and easy to use sleep and activity monitor that is based on science and sleep research. The key criteria for success of the NASA monitor also applies to consumer devices: functionality, accuracy and wearability. Activity and fitness monitoring is a fast growing consumer electronics segment, spanning sleep and activity monitoring, sports and fitness monitoring, chronic disease management and corporate wellness programs. Global shipments of activity and fitness monitors are set to total more than 250 million units during the next five years combined. We will introduce the consumer-grade monitors based on technologies developed under the proposed program through distribution channels already available to Linea through Linea's parent company, Salutron, Inc. Linea/Salutron's own brand, LifeTrak, is currently available in over 30,000 store locations. Retailers for the brand include Walgreen's, CVS, Walmart, Target, Fry's and B&H.