Optalert’s Johns Drowsiness Scale (JDS) accurately quantifies impairment caused by drowsiness, surpassing competing technologies in predictive power. This post outlines how Optalert has been able to quantify the relative risk of a driver’s impairment from drowsiness with a unique biomarker. It is independent of age, gender, or ethnicity. These claims are substantiated through both internal and independent external assessments. This distinctive measure allows for intervention before a performance failure, such as drifting out of lane, occurs.
Optalert is engaged in licensing its patented algorithm into vision-based driver monitoring systems (DMSs). This involves simple integration of a proven technology. Optalert’s JDS offers the most accurate measurement of driver drowsiness. Its continuous tracking, predictive power, compliance with regulations, and seamless integration with any DMS make it the ideal solution for enhancing driver safety.
Figure 1. Relative risk of performance failure (i.e., impairment due to drowsiness) as a function of JDS score.
A DMS is only concerned with measuring the impairment caused by drowsiness. Impairment is defined as the increased likelihood of performance failure from an individual’s baseline. Optalert’s JDS uses a biomarker from eyelid movements that is the most accurate ground truth for quantifying increased risk from impairment.
Over the last 20 years, many researchers and engineering teams have attempted to find similar physical indicators that quantify impairment due to drowsiness and thus accurately predict the likelihood of a performance failure. To date, no other measure can has achieved comparable precision. All competing technologies can only detect dangerous levels of impairment far too late when the risk of an accident is imminent.
The JDS tracks driver impairment even at low levels. This allows countermeasures to be enacted far in advance of a high-risk scenario emerging. At increasing JDS scores, appropriate stimuli prolong wakefulness and reduce impairment.
It is both this continuous predictive power and the preventative capability it unlocks that is unique to the JDS. A DMS and the advanced driver assistance system (ADAS) can then adapt the response to the severity of the driver’s drowsiness
Figure 2. Examples of countermeasures to prolong wakefulness.
The easiest way to visualise the predictive power of the JDS is to see examples from Optalert’s sleep deprivation studies. Below are two examples of people who were sleep deprived and then carried out a vigilance test. Optalert has conducted hundreds of such tests.
Figure 3. In this test, we detected a dangerous level of drowsiness six minutes before the first error of omission.
Figure 4. In this test, we detected a dangerous level of drowsiness five minutes before the first error of omission.
The JDS has been endorsed as a valid alternative to the Karolinska Sleepiness Scale (KSS) by four technical services firms in Europe.
All four have reviewed the evidence and confirmed that Optalert’s JDS is a compliant measure of drowsiness under the European General Safety Regulation (GSR). Each of them operates Euro NCAP accredited testing laboratories.
Table 1. Four European technical services firms have endorsed the JDS as a valid alternative measure to KSS and more are expected to follow suit soon.
This means that an OEM can now request that the JDS be used as the ground truth when testing the drowsiness detection component of a vehicle’s DMS in order to achieve a Euro NCAP rating. Until now, the primary ground truth for testing drowsiness monitoring systems has been the KSS. This involves asking the driver how tired they are every five minutes, inadvertently rousing them and affecting the measurement. OEMs have been surprised and frustrated when their systems performed drastically differently once moving from test conditions to real world driving. Optalert’s JDS is non-invasive, thus minimising these discrepancies and making the transition seamless.
If you’re in the automotive industry, visit our Automotive page and learn about how you can integrate our drowsiness measurement technology via a software development kit (SDK) into your driver monitoring system (DMS). Together we can imptove safety on the roads and move toward vision zero.