Eye tracking systems can facilitate communication with critical care patients

Eye tracking systems can facilitate communication with critically ill patients in intensive care units.

Intubated, ventilated, unable to speak: Due to their condition, many critically ill patients are unable to speak. They can only communicate their wants and needs, descriptions of symptoms or pain sensations non-verbally. Eye-tracking systems can aid communication, in addition to eye-blinking, lip-reading, and similar methods. This was shown by a research group led by the Department of General and Trauma Surgery at the University Hospital BG Bergmannsheil in cooperation with the Faculty of Psychology at the FernUniversität in Hagen. Their research also provides insight into the inner lives of critically ill patients. The study, which received the 2021 International Paper Award from the American Association for the Surgery of Trauma, was published online in the Journal of Trauma and Acute Care Surgery on December 14, 2021.

Communicate without voice

Being speechless is a very frustrating experience for intensive care patients – especially when they consider themselves conscious enough to communicate with those around them. Critical care staff therefore often have to use alternative methods of non-verbal communication as part of their daily routine on the ward, to meet the needs of these patients. However, methods such as blinking, lip-reading, nodding, or using pen and paper or alphabet boards are often insufficient. In such cases, eye tracking systems could be used to overcome communication barriers.

Modern communication systems based on eye tracking have long been established in the medical-therapeutic field, for example for people with advanced neuromuscular diseases. However, their benefits as an appropriate means of communication for critically ill intensive care patients who are unable to speak have not yet been investigated. Especially for ventilated patients who, for example, cannot use their arms and hands to communicate due to quadriplegia, such technology seemed very promising.”

Dr. Christopher Ull, Department of General and Trauma Surgery, University Hospital BG Bergmannsheil in Bochum

The Surgical Intensive Care Unit research group led by Professor Christian Waydhas, Dr Uwe Hamsen and Oliver Jansen included a total of 75 patients in their study. “Our study turned out to be very informative and well-founded thanks to the interdisciplinary interaction with representatives of various professions at Bergmannsheil and our project partners Christina Weckwerth and Professor Robert Gaschler from the Faculty of Psychology in Hagen”, emphasizes Schildhauer.

How a computer learns to recognize line of sight

For their study, the research group used a commercially available eye tracking system that was mounted on a mobile stand and positioned in the patient’s line of sight. The system consists of cameras, light sources, various image processing algorithms and special software installed on a commercially available PC. The principle is as follows: the light sources emit near infrared light, which is reflected by the eyes of the person concerned. The cameras record the person’s eye and the pattern of reflection within it. Image processing algorithms find specific details of the eye and the reflection pattern. Based on the collected data, the system uses mathematical algorithms to calculate the direction the person is looking at the computer screen: in other words, the system knows where they are looking.

Prior to deployment, the system was calibrated individually for each participant. After a short training phase, the patients were then able to control the system by fixing their gaze. Established scales and scores were presented on the monitor in the standardized study protocol, allowing patients to rate their pain sensation, mood, quality of life and self-esteem.

A glimpse into the inner life of critically ill patients

The results showed that the participants were in pain and had negative moods, despite supposedly adequate pain therapy and regular psychological interventions. The state of health was generally judged to be poor. In terms of self-esteem, most patients reported feeling trapped or insecure, frustrated and misunderstood. Despite their serious illness, many patients nevertheless considered themselves to be intelligent, clear-headed, sociable and optimistic.

Open new channels of communication

“The results produced by our research group show two things: First, this eye-tracking system can enable critically ill, non-verbal, and mobility-impaired people to communicate their self-assessment and feelings to their environment in a nuanced way. using standardized scales and scores,” says Christopher Ull. “Secondly, we have identified indications for improvement measures in the delivery of critical care to patients with verbal disorders through the use of technology eye tracking. We are convinced that this technology can improve the interaction between patients and their intensive care team until they acquire an adequate capacity to communicate non-verbally or to speak. However, further research is imperative for this to occur.


Journal reference:

Ull, C., et al. (2021) The use of predefined scales and scores with eye tracking devices for symptom identification in critically ill nonverbal patients. Journal of trauma surgery and acute care. doi.org/10.1097/TA.0000000000003494.

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