Frequently Asked Questions

The SAFTE™ Fatigue Model

What is the SAFTE Fatigue Model?

The SAFTE Fatigue Model is a biomathematical analytical model. When the SAFTE Fatigue Model is given accurate sleep data, it can measure, quantify and predict human fatigue impairment. It was developed by the Walter Reed Army Institute of Research at the U.S. Army Medical Research Development Command, and stands for: Sleep, Activity, Fatigue and Task Effectiveness. Learn more about the science of sleep here.

How has the SAFTE Fatigue Model been validated and proven in real-world applications?

The SAFTE Fatigue Model has been extensively validated and used by various departments of the US military and government. It has also undergone several clinical trials. Research validating the SAFTE Fatigue Model can be found here.

How does the SAFTE Fatigue Model reveal who is most fatigued?

The SAFTE Fatigue Model comes to life in the Fatigue Science web app, an easy-to-use, at-a-glance secure web application that graphically shows authorized risk managers and coaches who is currently fatigue-impaired, as well as who will become fatigue-impaired over the hours of the upcoming day ahead. With the Fatigue Science Predictive Fatigue Management Solution, managers can also view historical sleep and fatigue trend data for filtered groups or selected individuals, or in aggregate across their workforce.

SAFTE score | Frequently Asked Questions | Fatigue Science

Does the SAFTE Fatigue Model consider napping?

Yes, all periods detected as sleep periods are factored into the SAFTE Fatigue Model’s sleep algorithm, and will have a corresponding effect on a person’s SAFTE Alertness Score.

Can the SAFTE Fatigue Model identify sleep disorders such as sleep apnea?

The Fatigue Science Predictive Fatigue Management Solution is not intended to provide a formal medical diagnosis of sleep disorders such as sleep apnea. However, insights from our platform can provide a useful “pre-screening” function to many organizations, helping to provide insight not only into the most chronically fatigued individuals among a larger population, but possible indicators of likely sleep abnormalities (such as high sleep latency or heavily interrupted sleep).

With this information, our platform makes it easy for organizations not only to help steer their most chronically fatigued workers to treatment and guidance, but also to monitor for improvements and degradations in conditions over time.

What is FAST?

FAST, or the Fatigue Avoidance Scheduling Tool, is a desktop software application that helps risk managers plan out schedules based on the sleep opportunity that they afford — using the SAFTE Fatigue Model to simulate the likely impact of these schedules on fatigue exposure, and determining optimal timing and conditions for work and rest.

FAST is used extensively by the US military, global aviation firms, and many other industrial organizations. Learn more here.

ReadiBand™ Wearable Device

What is the ReadiBand?

Readiband Wearable Device frequently asked questions | Fatigue ScienceThe ReadiBand is a small, wrist-worn wearable device that measures sleep via actigraphy — high-frequency accelerometry sampling of the movement of the wrist.

It has been validated against clinical sleep labs (polysomnography) at 92% accuracy for sleep/wake detection — far exceeding the measurement accuracy available from a consumer-grade device.

The ReadiBand uses Bluetooth to transmit collected sleep data to authorized mobile devices, which pass this data to the SAFTE Fatigue Model for analysis in our secure cloud platform. Learn more about the validation behind the ReadiBand here.

What does the ReadiBand track?

The ReadiBand only tracks actigraphy — body motion — to determine the quantity and quality of a person’s sleep. For data privacy reasons, the ReadiBand intentionally does not track a person’s location (no GPS), or other biometrics such as heart rate, stress or temperature.

How does the ReadiBand differ from consumer fitness trackers?

Consumer-grade fitness trackers provide some insight into fitness metrics like GPS location, steps, and distance walked, and in some cases sleep. However, consumer grade devices are not validated in their accuracy of sleep capture, and often miss or under-estimate critical nuances such as acute wake episodes, which have a material impact on one’s fatigue.

The ReadiBand has been validated against clinical sleep labs (polysomnography) at 92% accuracy for sleep/wake detection — far exceeding anything available from a consumer device.

More importantly, accurate sleep data collection is only half the equation. The other critical question is: is one’s pattern of sleep truly restorative, or is an individual facing reduced performance due to fatigue? Only with the SAFTE Fatigue Model paired with the ReadiBand are these insights available from sleep data.

Does a ReadiBand have to be worn continuously?

For the most accurate results, the ReadiBand should be worn continuously, in order to ensure capturing of any periods such as naps. However, brief periods of non-use (such as an hour or two) will not affect the ReadiBand’s overall accuracy unless a period of sleep is missed during that period. For instance, athletes will often remove their ReadiBands during training or game time.

How is the ReadiBand charged?

When it needs to be recharged, the ReadiBand can simply be plugged into a computer’s USB port, or using a standard USB wall charger.

Fatigue Science in use

What sleep data is collected?

The ReadiBand only tracks actigraphy — body motion — to determine the quantity and quality of a person’s sleep. For data privacy purposes, the ReadiBand intentionally does not track a person’s location (no GPS), or other biometrics such as heart rate, stress or temperature.

Who can see personal sleep data?

Only managers / coaches expressly authorized by the organization are able to see individual sleep data.

Can ReadiBand wearers see their own sleep data?

Readiband Sleep Data frequently asked questions | Fatigue ScienceYes, we believe that for sleep, fatigue and performance management to be successful, ReadiBand wearers should be involved in monitoring their own sleep health.

With our ReadiBand app, users can easily see their current and predicted SAFTE Alertness Scores, their most recent sleep, and their sleep over the last 7 days.

Can managers or coaches see sleep data remotely?

Only if a company or team’s Readiband program has been configured to permit access.

Many programs are implemented for purely “self-management,” i.e. with no access provided to coaches or management, while other programs use certain management tools to provide closer assistance to players and workers. You will know when your program is launched if your organization’s personnel have been provisioned access to your data.

How is personal sleep data kept secure?

Our data centers are secured and monitored 24/7/365, with interior/exterior surveillance and access limited to authorized personnel.  Web and API traffic is transmitted over HTTPS (TLS 1.2). Sensitive data is stored behind a DMZ, and all passwords are encrypted using industry best practices.


How do I get started?

You can find all you need to get started online at Fatigue Science Help.

What additional support is available from Fatigue Science?

We want to ensure that you succeed in your sleep and fatigue management goals. Depending on your requirements, we’ll assign a dedicated account manager, provide virtual and on-site training, as well as comprehensive documentation and guides.

Who do I contact with technical issues?

Please call or email us with any questions or concerns.

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