Intelligent Eye Tracker Integrated with Cylindrical Capacitive Sensors for Chronic Fatigue Assessment

Abstract:

Fatigue negatively impacts health, safety, and productivity, yet current monitoring methods are often subjective, labor-intensive, and inaccurate. To address these challenges, this study presents a capacitive sensor-based eye tracker leveraging cylindrical carbon nanotube-paper composite (CCPC) sensors for chronic fatigue (CF) assessment.

Fabricated by novel wet-fracture and paper-rolling methods, CCPC sensors demonstrate superior proximity sensitivity with a small form factor. These one-dimensional sensors are seamlessly integrated into an eyeglass frame for noncontact monitoring of blink rates and eye closures. A 15-minute testing protocol, combining cognitive tasks and noise exposure, is designed to induce acute fatigue and identify CF. By analyzing changes in the digital markers against established fatigue indicators, CF is assessed with the aid of machine learning models for the evaluation of accuracy, sensitivity, and specificity.

This real-time, wearable monitoring platform provides an objective, effortless, and noncontact approach to fatigue assessment. With further testing and optimization, it holds the potential for user-friendly evaluation of acute fatigue or fatigue-associated diseases, such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Source: Li T, Park SH, Lee C, Kim S, Kwon Y, Kim H, Chung JH. Intelligent Eye Tracker Integrated with Cylindrical Capacitive Sensors for Chronic Fatigue Assessment. Adv Sens Res. 2025 Jul;4(7):e00027. doi: 10.1002/adsr.202500027. Epub 2025 May 22. PMID: 40662140; PMCID: PMC12259227. https://pmc.ncbi.nlm.nih.gov/articles/PMC12259227/ (Full text)

Impaired associative learning in chronic fatigue syndrome

Abstract:

Patients with chronic fatigue syndrome (CFS) report cognitive difficulties (impaired attention, memory and reasoning). Neuropsychological tests have failed to consistently find cognitive impairments to the degree reported by CFS patients.

We tested patients with CFS and sedentary controls in protocols designed to measure sensory reactivity and acquisition of the classically conditioned eyeblink response. Patients with CFS exhibited normal sensitivity and responsivity to acoustic stimuli.

However, CFS patients displayed impaired acquisition of the eyeblink response using a delayed-type conditioning paradigm. Sensitivity and responsivity to the airpuff stimulus were normal.

In the absence of sensory/motor abnormalities, impaired acquisition of the classically conditioned eyeblink response indicates an associative deficit. These data suggest organic brain dysfunction within a defined neural substrate in CFS patients.

 

Source: Servatius RJ, Tapp WN, Bergen MT, Pollet CA, Drastal SD, Tiersky LA, Desai P, Natelson BH. Impaired associative learning in chronic fatigue syndrome. Neuroreport. 1998 Apr 20;9(6):1153-7. http://www.ncbi.nlm.nih.gov/pubmed/9601685