1、 ANSI/CTA Standard Methodology of Measurements for Features in Sleep Tracking Consumer Technology Devices and Applications ANSI/CTA/NSF-2052.2 September 2017 NOTICE Consumer Technology Association (CTA) Standards, Bulletins and other technical publications are designed to serve the public interest t
2、hrough eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence of such Standards, Bulletins and oth
3、er technical publications shall not in any respect preclude any member or nonmember of the Consumer Technology Association from manufacturing or selling products not conforming to such Standards, Bulletins or other technical publications, nor shall the existence of such Standards, Bulletins and othe
4、r technical publications preclude their voluntary use by those other than Consumer Technology Association members, whether the standard is to be used either domestically or internationally. Standards, Bulletins and other technical publications are adopted by the Consumer Technology Association in ac
5、cordance with the American National Standards Institute (ANSI) patent policy. By such action, the Consumer Technology Association does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Standard, Bulletin or other technical publication. T
6、his document does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this document to establish appropriate safety and health practices and to determine the applicability of regulatory limitations befo
7、re its use. This document is copyrighted by the Consumer Technology Association (CTA) and the National Sleep Foundation (NSF) and may not be reproduced, in whole or part, without written permission. Federal copyright law prohibits unauthorized reproduction of this document by any means. Organization
8、s may obtain permission to reproduce a limited number of copies by entering into a license agreement. Requests to reproduce text, data, charts, figures or other material should be made to the Consumer Technology Association (CTA) and the National Sleep Foundation (NSF). (Formulated under the cogniza
9、nce of the CTA R6.4 Health for example, in a chair or on a couch). 4.2.2 TATS End Time (Elemental Measure) Direct Measurement: Self-report by the subject that they are finished with their sleep period (e.g., pushing a button on the device, activating application, provide notice to test observer, or
10、adding the sleep diary entry). Inferred Measurement: Observation can be achieved by video surveillance, by a person looking at the subject and recording the start time, or with room/bed sensors (e.g., person being more active, getting out of the bed, putting lights and/or TV on). In laboratory PSG r
11、ecordings, this is recorded as “lights on” time. Remark(s): TIB is often used as a surrogate for this measurement and can be inferred from actigraphy. Actigraphy can detect a person being active (and getting up). Remarks/Caveats: TATS is differentiated from time in bed (see definition of TIB). TATS
12、is differentiated from TIB because an individual might lie down in bed without attempting to sleep. Additionally, the term addresses the issue that not all individuals sleep in bed (i.e., they can attempt to sleep in other locations; for example, in a chair or on a couch). 4.2.3 TIB Start Time (Elem
13、ental Measure) Direct Measurement: Observation can be achieved by video surveillance, by a person looking at the subject and recording the start time, or with room/bed sensors (e.g., pressure transducers in an air filled or fluid filled mattress, infrared sensors, location detector, bio-signal bed s
14、ensor). Inferred Measurement: Self-report by the subject (e.g., pushing a button on the device, activating application, or provide notice to test observer) or actigraphy that has posture sensor that estimates if the person is lying down in bed. Remarks/Caveats: TIB is differentiated from time attemp
15、ting or engaging in sleep (see definition of TATS). The term addresses the issue that not all individuals sleep in bed (i.e., they can sleep in other locations; for example, in a chair or on a couch). Additionally, TIB is differentiated from TATS because some individuals engage in other activities (
16、with minimal movement) in bed, other than attempting to sleep (e.g., reading or watching television). 4.2.4 TIB End Time (Elemental Measure) Direct Measurement: Observation can be achieved by video surveillance, by a person looking at the subject and recording the end time, or with room/bed sensors
17、(e.g., pressure transducers in an air filled or fluid filled mattress, infrared sensors, location detector, bio-signal bed sensor). Inferred Measurement: Self-report by the subject (e.g., pushing a button on the device, activating application, or providing notice to test observer) or actigraphy that
18、 has a posture sensor that estimates if the person is lying down in bed. ANSI/CTA/NSF-2052.2 5Remarks/Caveats: When using an instrumented approach (e.g., a bed sensor), the specific parameters concerning weight, duration of detected entitys presence on the beds surface, and possibly the presence of
19、a confirmatory biological signal (e.g., heartbeat) will vary from device to device. TIB is differentiated from time attempting or engaging in sleep (see definition of TATS). The term addresses the issue that not all individuals sleep in bed (i.e., they can sleep in other locations; for example, in a
20、 chair or on a couch). Additionally, TIB is differentiated from TATS because an individual might lie down in bed without attempting to sleep 4.3 General Terms Describing Basic Features of Wakefulness and Sleep 4.3.1 Awake (Elemental Measure) Direct Measurement: Purposeful motoric and coherent verbal
21、 activity occurs in association with wakefulness. When either of these are present, wakefulness is present (except under extraordinary circumstances). The amount of activity can range along a spectrum. This spectrum varies from quiescent wakefulness to active wakefulness. Active wakefulness can be d
22、etermined directly (a) By observing purposeful behavior, (b) By observing coherent verbalizations, and/or (c) From self-report momentary assessment. Quiescent wakefulness can be more difficult to determine when observable purposeful behaviors are not present. It can be determined directly by self-re
23、port by not necessarily with observation. Inferential Measurement: Wakefulness can be inferred from (a) Measurements made using movement sensors placed in the bedroom or the bed indicating activity persisting over a sustained period of time, (b) Actigraphic measures indicating movement over a sustai
24、ned period of time, (c) Changes in autonomic activity (e.g., faster heart rate and/or respiration, higher and varying blood pressure), and/or (d) Sustained high body temperature. Remarks/Caveats: Some of the inferential measures rely on relative quantity. For example, activity measures may decline b
25、ut not cease when a person is still awake. Thus, cutoff values must be determined for a specific device because different devices with different sensitivities and values will differ. Similarly, many ANS measures decline at sleep onset. Such measures include heart rate, respiration, and blood pressur
26、e. When at high levels one may infer that the individual is awake, unless they have a particular pathophysiology that alters this pattern. By contrast, electrodermal activity remains at a low level during REM, N1, and N2 sleep. Most of its activity occurs during wakefulness and during N3 sleep; thus
27、, if heart rate and respiration are high and electrodermal activity is also high, one may infer that the individual is awake (unless they routinely suffer with sleep terrors). Often times Sleep Onset, even in the laboratory, is determined as much but a change in bioelectric patterns as it is by dete
28、cting an absolute level of activity. Therefore, relying on relative measures may not be able to differentiate awake from sleep at a particular point in time but rather can provide useful ancillary data. For example, body temperature declines and reaches its nadir during sleep and this information ca
29、n be paired with actigraphy to help identify awake periods. In sleep medicine, determining when an individual is awake relies on polysomnography, however, polysomnography works best when a person has well defined, clear EEG alpha activity. Wakefulness is scored when half, or more, of a 30-second epo
30、ch (time domain) has EEG alpha activity when a persons eyes are closed and they are not engaging in strenuous mental activity (e.g., counting backwards by 7s). Opening ones eyes or engaging in strenuous mental activity blocks EEG alpha activity and can masquerade as sleep if background EEG does not
31、also show an increase in high-frequency activity. Additionally, about 10% of normal individuals have poorly formed or absent EEG alpha activity. Finally, severely sleep deprived individuals may emit alpha activity when awake with eyes open. See Note 1. ANSI/CTA/NSF-2052.2 64.3.2 Asleep (Elemental Me
32、asure) Direct Measurement: There are no direct measures of sleep. A person in a quiescent state may be either in quiescent wakefulness or asleep. Under normal circumstances, a person cannot by self-report say that they are asleep while they are asleep, however, they may indicate having been asleep w
33、hen questioned immediately post hoc during wakefulness. In general, individuals are less responsive to most environmental stimuli when sleeping than during wakefulness, however, the arousal threshold varies greatly between individuals, as a function of the environmental stimuluss salience, and the u
34、nderlying sleep process ongoing at the time the stimulus occurs. Inferential Measurement: asleep can be inferred from (a) Measurements made using movement sensors placed in the bedroom or the bed indicating sustained episodes without movement, (b) Actigraphic measures showing sustained1periods with
35、minimal or no movement, (c) Detection of snoring or changes in breathing sounds (due to airway resistance when asleep vs. awake), (d) Changes in autonomic activity (e.g., slowing of averaged heart rate, stabilization of respiratory rate, decreased of respiratory tidal volume, and/or decreased blood
36、pressure. It should be noted that there may be transient changes in the opposite direction at the moment of sleep onset or when certain events occur during sleep e.g., changes in sleep position), (e) Decreased damping of evoked potentials later components (e.g., very large N2 amplitudes to sounds; t
37、hat is, the “evoked” K-complex), (f) Sustained low body temperature. Remarks/Caveats: Some of the inferential measures rely on relative quantities. For example, activity measures may decline when a person is asleep. Thus, some cutoff value must be determined for a particular device because different
38、 devices have different sensitivities. Similarly, ANS measures (e.g., heart rate, respiration, and blood pressure) decline as sleep begins. When at low levels one can infer the individual is asleep, unless they have a particular pathophysiology that alters this pattern. By contrast, electrodermal ac
39、tivity remains at a low level during REM, N1, and N2 sleep. Most electrodermal activity occurs during wakefulness and during N3 sleep; thus, if heart rate and respiration are high and electrodermal activity is also high, one may infer that the individual is awake (unless they routinely suffer with s
40、leep terrors). Although, some relativistic measures cannot differentiate awake from sleep at a particular moment in time, they can provide useful ancillary data. For example, body temperature declines and reaches its nadir during sleep and this information can be paired with actigraphy to help ident
41、ify asleep periods. In sleep medicine, determination when an individual is asleep relies on polysomnography. However, polysomnography works best when a person has well defined, clear EEG alpha activity. Sleep is scored when half, or more, of a 30-second epoch (time domain) has either a low voltage,
42、mixed frequency EEG alpha activity; when sleep spindles or K-complexes are present; or when EEG slow wave activity is present. It should be noted that even with full polysomnography, precise differentiation between wakefulness and stage N1 sleep can be difficult and inter-scorer reliability is low.
43、See Note 1. 4.3.3 Awakening from Sleep (Elemental Measure) Direct Measurement: The one direct measure of an awakening from sleep is if a person reports having just awakened. Assuming the individual is not in a fugue state or having a parasomnia episode, behaviors indicating Awakening from Sleep incl
44、ude an individual opening their eyes, sitting up, getting out of bed, and/or beginning to engage in a purposeful activity (e.g., answering their cell phone or reading), after having been asleep. By definition, in order to “awaken from sleep” the individual must have been sleeping when this event occ
45、urs; therefore, measurement of “Awake” by observation must be preceded by a period of time determined to be sleep. ANSI/CTA/NSF-2052.2 7Inferential Measurement: Wakefulness (i.e., being awake) can be inferred from (a) Measurements made using movement sensors placed on the individual, in the bedroom,
46、 or the bed indicating a transition from a sustained period without movement to significant activity. For example: (a) purposeful movement continuing for more than 15 seconds in duration or (b) movement with intensity exceeding some magnitude threshold. (b) Changes in respiratory sounds, (c) Changes
47、 in autonomic activity (e.g., sudden increased heart rate and/or respiration, increased blood pressure), Remarks/Caveats: Some of the inferential measures rely on relative quantity (see discussion above concerning Awake and Asleep Methods and Measures). Although, some relativistic measures cannot di
48、fferentiate awake from sleep at a particular moment in time, they can provide useful ancillary data. In sleep medicine, determination when an individual is asleep relies on polysomnography. However, polysomnography works best when a person has well defined, clear EEG alpha activity. Wakefulness is s
49、cored when half, or more, of a 30-second epoch (time domain) has EEG alpha activity. See Note 1. 4.3.4 Brief Awakening (Elemental Measure) Direct Measurement: There are no direct measures for brief awakenings. Self-report conflicts with one of the characteristics of brief awakening which is non-awareness. Nonetheless, observation as described in “Awake” in combination with self-report (“I did not awake”) would be possible. Inferential Measurement: A brief awakening can be inferred from: (a) Measurements made using movement sensors placed in the bedroom or the bed indicating a t
