The main objective of this study is to evaluate the usability of a system to assist verbal communication based on BCI system using the P300 wave in patients with tetraplegia who can no longer communicate because of severe engine damage (tetraplegia) and respiratory damage requiring invasive mechanical ventilation (intubation or tracheostomy) preventing verbal communication.

Inclusion Criteria:

• Admitted in the ICU
• Quadriplegic and requiring mechanical ventilation (tracheostomy) 24/24h

Exclusion Criteria:

• Acute respiratory failure.
• Visual disorder
• Cognitive disorder
• Illiterate patient
• Mother tongue other than french

Quadriplegia, also known as tetraplegia, is paralysis caused by illness or injury to a human that results in the partial or total loss of use of all of their limbs and torso; paraplegia is similar but does not affect the arms. The loss is usually sensory and motor, which means both sensation and control are lost.