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CNRS StopSleep study


StopSleep has been the subject of a detailed scientific study undertaken by the National Scientific Research Centre (CNRS) in France. The results of this study have proved the effectiveness of StopSleep in alerting at two levels: initial signs of drowsiness (progressive decline in concentration and awareness) and sleepiness (significant drop in concentration and awareness).

Summary of the experimental evaluation of the device StopSleep

Drowsiness has been found to be a significant factor in a large number of vehicle accidents. Driving whilst over-tired is a major social issue and public health problem. The latest epidemiological studies rank hypo vigilance among the top risk factors involved in road traffic accidents. Many people are unaware of the risks associated with driving when tired and the accidents this can cause. This has led to the development of reliable detection and prevention tools, allowing both the detection of changes in concentration and awareness and providing an efficient alert well in advance of danger so that individuals can take the necessary preventative action required. The StopSleep device has been developed to address these issues. StopSleep is a double ring placed on two fingers of either hand which alerts users through a combination of vibration and audible beeps.

StopSleep has been the subject of an experimental study undertaken by CLLE-LTDC which focussed on the reliability of the device to detect negative changes in attention levels and to alert the driver to these changes. Two experimental studies were conducted.

The first study was designed to test the detection functions of reduced attention levels and the warning given by the StopSleep device to decrease in concentration. Twenty participants were subjected to a sustained attention task. Their task was to identify as quickly as possible the audible difference between a bass sound and a treble sound.

About the Test

The participants begin the experiment at 22.00 hours when they were in a state of lower concentration and awareness. Each participant was equipped with an encephalogram, which records brain activity, an eye tracker to measure eye positions and movements, and a StopSleep device for each hand. The participants then had to listen to random sounds at the rate of one per second over a 30 minute period and correctly identify whether they are treble or bass sounds. As soon as the participant heard a sound they had to click a mouse in order to measure their performance and reaction time.



An EEG measures brain activity.



An eye tracker measures the frequency and amplitude of the beats of the individuals eyelid and the position of the gaze.

Electrodermal Activity measures

Electrodermal Activity

A probe EDA measuring electrodermal activity.



Monitors StopSleep alerts.



An EEG measures brain activity.



An eye tracker measures the frequency and amplitude of each beat of the participant's eyelids, along with the position of their gaze.

A second study was to test the ability of the StopSleep system to avoid triggering false alerts when individuals were in their correct attentional state. Ten participants were subjected to a sustained attention task in order to maintain a satisfactory attentional state.

Test result CNRS

Firstly, at a relatively general level, the comparison between the two studies (Standby vs Sleep) clearly indicated that the device emits alerts when participants are in a degraded state of concentration and awareness, than when participants are in a proper attentional state, which validates the targets set by the StopSleep system.

However, we would like to remind users that the StopSleep device is designed to detect variations in alertness and concentration, and is not a cure for driving whilst over-tired. The purpose of the device is that it can alert the user to negative changes and reductions to their concentration and awareness. Further to our study, as soon as StopSleep alerts, we recommend that driver's should immediately assess their current level of fatigue and concentration. If they recognise that they are starting to feel drowsy and their awareness has decreased they should take the most appropriate action immediately: stop driving.


There have been a large number of studies on driver fatigue, the effect that driver fatigue can have and what other factors can lead to a drop in concentration and awareness when driving. The results vary from simple factors, such as the individual already being tired before driving due to a lack of sleep. However the time of day is also a significant contributing factor. Attention and concentration changes throughout the day, often dropping to a minimum in the early afternoon after lunch and then again later at night.

These decreases in attention and concentration have serious implication to the rate of road accidents, especially as they are often completely ignored or underestimated by drivers. Sometimes these feelings of tiredness and drops in concentration are imperceptible to the driver and so they do not take appropriate action. This is especially noticeable in non-professional and inexperienced drivers. Decreases in concentration and awareness are also accentuated by the monotonous nature of driving long distances on long straight roads such as motorways creating a similar effect to a lack of sleep and general fatigue. In addition these factors have a negative effect on one another, where a long monotonous journey accentuates the driver's tiredness increasing the chance and frequency of a drop in concentration and awareness leading to an increase in accidents.

Driving a vehicle is an activity that requires sustained attention. Drivers are required to focus their attention on monitoring road situations for varying lengths of time in order in order to adapt to ever-changing road conditions. A recent accident study in the USA estimated that a lack of attention is the cause of about a quarter of all traffic accidents. Moreover, a recent major study which continuously recorded the performance of 100 drivers over a 12 month period showed that a lack of attention was the leading contributor to accidents, accounting for 78% of all accidents where there was driver inattention within three seconds before the event.

Therefore. identifying the change from an attentive state to a state of inattention is essential for the safety of drivers and other road users. The ability to identify this transition allows us to offer an effective warning system such as StopSleep. The principle is based on the detection of critical attentional profiles. The StopSleep device is in the form of a double ring that the user wears on the middle and ring fingers of either hand. The ring continuously measures the conductance response (RED) of the individual, and based on set parameters was proven to alert the user to a drop in concentration and awareness with a beep and a vibration, thus warning them they are at risk and should stop driving immediately.

Partners of StopSleep's test study

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