Standards Development

Scope

This standard defines terms used to describe sleep and indicates, where appropriate, the functionality necessary in a consumer sleep measuring device to measure those characteristics. This standard provides definitions of sleep features terminology recommended for wearable sleep monitoring consumer products. This standard does not provide operational definitions for terminology used for medical devices. Furthermore, it is acknowledged that not all compliant products will include features to meet every use case, but the ones that it does claim such will meet the respective requirements.

This standard address performance criteria and testing protocols for features in sleep tracking consumer technology devices and applications. The criteria and testing protocols are intentionally limited to “elemental” measures as defined in this standard. Other measures are derived from these measures and will reflect accuracy or inaccuracy of the elemental measures; therefore, attention centers on precision and quantitative correctness of elemental parameters. The relevant measures are:

• Time Attempting to Sleep (TATS) Start Time,

• TATS End Time, Time in Bed (TIB) Start Time,

• TIB End Time, Awake, Asleep,

• Awakening from Sleep,

• Brief Awakening,

• Initial Sleep Onset Time,

• Final Awakening Time,

• Brief Moment of Sleep (Dozing),

• REM Sleep,

• N1 Sleep,

• N2 Sleep,

• N3 Sleep,

• CNS Arousal,

• Dream Sleep,

• Core Sleep,

• Restless Sleep,

• Sound Sleep,

• Circadian Amplitude,

• Circadian Period Length (tau), and

• Circadian Phase.

Purpose

The purpose of this standard is to define terminology used to describe events once there is an intention to sleep. Some of the terms have both general and laboratory definitions. Terms such as “sleep” existed long before polysomnographic procedures were applied to investigate the neurophysiology, psychophysiology, and general physiology of sleep. These terms include (but are not limited to): Awake, asleep, and awakening from sleep. Additionally, other sleep measures can be derived from these parameters (e.g., total sleep time and number of awakenings). Therefore, defining the terminology and definitions are a key step to improving performance of measurements.

The measures fall into three main groupings with respect to the type of parameter they represent. This is important because different types of parameters require different evaluation metrics. The approach to determining accuracy for a specific event (e.g., the time at which something occurred) differs from verifying that an ongoing process within a specific time domain is occurring concomitantly. Furthermore, methods will also differ when attempting to compare patterns recorded by two different measuring in struments over even longer time periods. The following generalizations apply in this regard:

Events are evaluated in terms of their variance from the measurement considered as a “standard”. In some cases, the standard may be measured directly (e.g., observing a video in showing a person getting in bed). However, sometimes measures should only be evaluated indirectly by correlative methods (e.g., using concurrent PSG to determine if REM sleep is present).

The need and justification for developing this standard was agreed to when PWI 124 -11 was accepted. There are many devices used by consumers and sold by manufacturers, and a standard to help improve the accuracy of reporting will serve this market