Novel System Objectively Determines Physicians’ Fatigue Level

A new study reveals that the speed of saccadic eye movements is an excellent index to objectively measure the level of fatigue in the healthcare professionals.

Researchers at the University of Granada (UGR, Spain) evaluated the performance of doctors from the traumatology service at St Joseph’s Hospital and Medical Center (Phoenix, AZ, USA). All participants had the speed of their saccadic eye movements measured both before and after their 24-hour shift. The participants also performed simulated laparoscopic tests while having their saccadic movements measured.


The results proved that after long hours, the speed of saccadic movements effectively diminished, while the doctor’s subjective perception of fatigue increased. However, in simulated laparoscopic tests after the shift, execution was not affected in any significant way by their fatigue. Accordingly, the researchers concluded that previous work hours did not have a negative impact on their surgery practice, supporting the hypothesis that fatigue is not the only source of errors in medical professionals.

The researchers suggest that the results of the study also open to debate the number of hours that doctors can work without affecting patient safety. For instance, residents in the United States work almost twice as their Spanish or French counterparts (80 hours a week versus 40). And although shifts involve restless work, there is a complex relationship between continuous care, patient safety, economic factors, and the level of fatigue in doctors themselves. The study was published in the April 2014 issue of Annals of Surgery.

“Saccadic velocity is a reliable indicator of the subjective fatigue of health care professionals during prolonged time-on-duty,” concluded lead author Leandro Luigi Di Stasi, PhD, and colleagues. “These findings have potential impacts for the development of neuro-ergonomic tools to detect fatigue among health professionals, and in the specifications of future guidelines regarding residents' duty hours.”

Saccades are quick, simultaneous movements of both eyes in the same direction, serving as a mechanism for fixation, rapid eye movement (REM), and the fast phase of optokinetic nystagmus (involuntary eye movements). They are initiated cortically by the frontal eye fields, or subcortically by the superior colliculus.

Related Links:
University of Granada
St Joseph’s Hospital and Medical Center