Israeli researchers have developed a novel method to track clinical responses of people unresponsive but breathing, such as those in sleep, anesthesia or intensive care, Tel Aviv University (TAU) said in a statement on Sunday.

This new closed-eye imaging technology, described in Communications Medicine, can monitor awareness and pain in conditions of unresponsive wakefulness.

TAU noted that the method allows for the first time to monitor changes in pupil size and gaze direction behind closed eyes using touchless infrared imaging.

It added the method will help detect seizures, nightmares and the depth of sedation as well as recognize pain and responsiveness that may occur after trauma or in intensive care units, expecting this technology to be applied for clinical care.

Pupil size, which constantly changes to regulate light entering the eye, also dilates in response to stimuli, such as sudden events or pain, as part of the autonomic nervous system's alarm response, preparing the body for action.

According to the research team, the new method can successfully track the precise dynamics of the pupillary light reflex in closed-eye conditions, reveal changes in pupil size after each light flash in individual subjects, and accurately estimate eye gaze direction.

The researchers concluded that this technology, backed by a patent application, paves the way for developing devices with wide-ranging clinical and commercial applications.