An investigation of pupil-based cognitive load measurement with low cost infrared webcam under light reflex interference

A new global and comprehensive model for ICU ventilator performances evaluation

Background

This study aimed to provide a new global and comprehensive evaluation of recent ICU ventilators taking into account both technical performances and ergonomics.

Methods

Six recent ICU ventilators were evaluated. Technical performances were assessed under two FIO₂ levels (100%, 50%), three respiratory mechanics combinations (Normal: compliance [C] = 70 mL cmH₂O⁻¹/resistance [R] = 5 cmH₂O L⁻¹ s⁻¹; Restrictive: C = 30/R = 10; Obstructive: C = 120/R = 20), four exponential levels of leaks (from 0 to 12.5 L min⁻¹) and three levels of inspiratory effort (P0.1 = 2, 4 and 8 cmH₂O), using an automated test lung. Ergonomics were evaluated by 20 ICU physicians using a global and comprehensive model involving physiological response to stress measurements (heart rate, respiratory rate, tidal volume variability and eye tracking), psycho-cognitive scales (SUS and NASA-TLX) and objective tasks completion.

Results

Few differences in terms of technical performance were observed between devices. Non-invasive ventilation modes had a huge influence on asynchrony occurrence. Using our global model, either objective tasks completion, psycho-cognitive scales and/or physiological measurements were able to depict significant differences in terms of devices’ usability. The level of failure that was observed with some devices depicted the lack of adaptation of device’s development to end users’ requests.

Conclusions

Despite similar technical performance, some ICU ventilators exhibit low ergonomics performance and a high risk of misusage.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0285-2) contains supplementary material, which is available to authorized users.