For the first time: tracking through closed eyes could be used to detect arousal, awareness, and pain during sleep
A new development by Tel Aviv University will allow, for the first time in the world, monitoring of changes in pupil size and gaze direction through closed eyes, by monitoring using infrared imaging. In the future, monitoring the pupils in this way will be able to identify states of arousal during sleep, anesthesia and intensive care, thereby diagnosing the depth of anesthesia, detecting nightmares and convulsions during sleep, and even identifying pain or reactivity in patients in intensive care and trauma wards." The researchers estimate that the technology has the potential to become an important tool in clinical care.
The development was carried out by a team of researchers from Tel Aviv University led by Omer Ben Barak Dror, under the joint guidance of Prof. Yuval Nir from the Department of Physiology in the Faculty of Medical and Health Sciences, Sagol School of Neuroscience, and the Department of Biomedical Engineering and Prof. Israel Ganot from the Department of Bio-Engineering medically, and the other members of the research group Dr. Michal Teper, Dr. Barak Haddad, Dr. Hani Braum and David Hajj. The study was published in the journal Communications Medicine
Prof. Nir explains "it is customary to say that "the eyes are a window to the soul". Indeed, the size of the pupil changes frequently, expanding or contracting in order to regulate the intensity of light entering through it, thus providing clinically significant information. It is known that our pupils contract in bright light conditions and dilate when the environment is dark. But this is only one reason for the change in pupil size. The pupils also dilate in situations where we are aroused, for example when we react to a surprising event or when we experience pain. In such cases the autonomic nervous system alerts and prepares us for action. Tracking changes in pupil size and monitoring eye movements can be clinical indicators in a variety of situations. Despite this, currently the ability to follow these indicators is limited only to situations where the eyes are open. In fact, until now there was no method that allowed measuring these changes continuously, without contact and under conditions where the eyes were closed, therefore measurements of this type were not possible in the fields of sleep medicine, anesthesia and intensive care.
The new study describes an innovative technology that combines imaging in the short wave infrared radiation (SWIR-short wave infrared) together with deep learning methods and thus allows monitoring changes in the size and position of the pupil even when the eyes are closed.
Omer Ben Barak-Dror: "In order to establish and validate our technology, we focused on reflexive changes in response to a flash of light, so the pupils quickly shrink and gradually return to their original size. In healthy people, this basic reflex is characterized by a symmetrical response of both eyes. Based on this assumption, we planned experiments that test our new technology on a closed eye, while comparing the results to the open eye for the same subject."
Prof. Nir and Prof. Ganot add that "the method makes it possible to track in real time the changes in pupil size in response to light stimulation when the eyes are closed, so that the reaction can be identified each and every time the reflex occurs. It is also possible to estimate the direction of his gaze up to a level of accuracy of a few degrees and with a resolution of fractions of a second. The system operates in a range of wavelengths that allows maximum penetration into the depth of the biological tissue, and the analysis of the information using algorithmic methods of deep learning, allowed us to identify changes that cannot be detected by common methods of imaging in the field close to visible light."
Dr. Teper adds that the information that will be collected through continuous and non-contact monitoring is a critical part of the patient's electronic medical records. and will help in making informed decisions regarding the continuation of medical treatment until the patient's recovery.
Ramot, Tel Aviv University's technology commercialization company, filed a patent and is currently working to commercialize this groundbreaking technology. "We believe in the potential of this technology to revolutionize the diagnosis and treatment of neurological disorders," said Dr. Ronan Kraizman, CEO of Ramot. "This collaboration reflects Ramot's vision to connect academia and industry, and to promote innovation that will face critical medical challenges."
The researchers conclude: "The technology we are developing, which is backed by the process of obtaining a patent, paves the way for the development of equipment with clinical and commercial applications in various fields of sleep medicine, for monitoring the depth of anesthesia and awareness during surgery, and for detecting pain or reactivity in unresponsive patients in intensive care and trauma wards. ".
The research was initially funded by the Zimin Foundation, Tel-Aviv University, and now by the Ministry of Science and Technology (the Science Advances Program for Breakthrough Technologies).
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