Swiss Researchers Develop Saliva Test to Detect Driver Fatigue

Swiss scientists have developed a promising new method that could one day detect fatigue in drivers using a simple saliva test, potentially improving road safety and workplace security.

Researchers at the University of Zurich (UZH) have identified a metabolic “fingerprint” in saliva that can reliably indicate acute sleep deprivation. The findings suggest that fatigue affects measurable biological changes in the body that can be detected through advanced analysis techniques.

Study Shows Clear Biological Markers of Fatigue

The research team, led by scientists at the Institute of Forensic Medicine at UZH, conducted controlled sleep experiments involving twenty young male participants. Their saliva samples were collected under three conditions: after a sleepless night, after four nights of restricted sleep (six hours per night), and after a full eight-hour sleep.

Using high-resolution mass spectrometry combined with machine learning, the researchers analyzed tens of thousands of molecules to identify patterns linked to sleep deprivation.

Ten Biomarkers Identified

The study found that severe fatigue affects around 10% of all biomolecules present in saliva. After filtering complex molecular data, the team successfully identified ten specific biomarkers that consistently indicate acute sleep deprivation.

Lead researcher Michael Scholz explained that the main challenge was isolating reliable indicators from a vast number of molecular signals. The results demonstrate that fatigue leaves a detectable biological signature in saliva.

Potential Applications in Road Safety and Forensics

The researchers believe the discovery could have major practical applications in improving road safety, particularly by identifying tired drivers before accidents occur. It may also support workplace safety in high-risk professions where alertness is critical.

Thomas Krämer from UZH described the study as a “milestone for forensic research,” noting its potential use in accident investigations and legal assessments involving fatigue.

Toward a Rapid On-Site Test

The long-term goal is to develop a quick and practical test that could be used directly at roadside checks or in workplace safety controls. However, researchers emphasize that the current findings are still part of basic research.

Further studies involving larger and more diverse population groups will be required before the method can be applied in real-world settings.

If successful, the innovation could become a key tool in reducing fatigue-related accidents and enhancing public safety.