March 25, 2021

Management of Sleep and Fatigue Using the SleepTank™ Smartwatch App

The Institutes for Behavior Resources, Inc. (IBR) has developed a Fitbit-smartwatch app, an iOS mobile app, and a web-based dashboard that provides sleep feedback using SleepTank™.

Maintaining vigilance in the military operational environment and in civilian 24/7 operations requires sleep planning and management. Service members and operators need to be able to answer important questions about sleep based on concrete and objective sleep data such as: Have I had enough sleep? Am I carrying an excessive sleep debt? How long can I go without additional sleep? When should I take a nap (and for how long) to supplement my main sleep period? These are all critical questions that impact performance and the ability to successfully perform the mission.

The advent of inexpensive off-the-shelf accelerometers in a variety of devices (cell phones, remote controls, tables, etc.) has spawned an explosion of wrist-worn activity monitors for tracking sleep and exercise. This technology offers an indirect way to monitor excessive fatigue in the form of inadequate sleep and accumulated sleep debt.

With support from USAMRDC’s Military Operational Medicine Research Program (MOMRP) and MTEC, IBR has developed SleepTank™, a proprietary sleep debt algorithm that provides the wearer with long-term sleep health information and actionable recommendations for additional sleep, optimizing sleep opportunities and increasing overall sleep duration. The algorithm is calibrated to an individual’s sleep goal and uses time asleep and time awake to calculate the percent fill of the user’s SleepTank™. The available watch and mobile apps use this data to provide warnings for low SleepTank™ levels, guidance on how naps will affect their SleepTank™, and a visual representation of the user’s SleepTank™ history.

IBR has the Fitbit smartwatch and iOS mobile SleepTank™ apps available for beta testing.  SleepTank™ applications for other smartwatch consumer sleep devices and android platforms are under development. Moreover, the efficacy of SleepTank™ for improving sleep hygiene and reducing fatigue in operations are being investigated in populations of shift-working nurses, helicopter emergency medical services pilot-technicians, and U.S Air Force Service members. The SleepTank™ app can be found for Fitbit devices through the Apple app store. For more information, visit ,, or

This project was funded through MTEC’s Multi-Topic Request for Proposals (Solicitation #17-08-Multi-Topic).

About the Institutes for Behavior Resources (IBR):
The Institutes for Behavior Resources, Inc. (IBR) is an independent nonprofit research, services, and educational organization headquartered in Baltimore, Maryland. IBR’s mission is to enhance the growth of the behavioral sciences and their application to human affairs through our Research, Clinical Services, and Consulting & Education initiatives. IBR offers research expertise and state-of-the-art research techniques, including biomathematical modelling, actigraphy and wearables to measure sleep quality and quantity, and schedule assessment to support fatigue research and risk management in a diverse range of operational environments such as aviation, health care and emergency services, rail, military, trucking, and energy, among others. IBR’s team is led by Dr. Steven R. Hursh, a technical leader in biomathematical modeling of sleep deprivation and performance with 23 years of experience as a US Army scientist. His patented biomathematical model – the Sleep, Activity, Fatigue, and Task Effectiveness, or SAFTE™, model – has been accepted by the US Department of Defense as the standard warfighter fatigue model.