The victim was bound upon this wheel, on his knees, with his hands behind his back.
A continuous positive airway pressure (CPAP) machine was initially used mainly by patients for the treatment of sleep apnea at home, but now is in widespread use across intensive care units as a form of ventilation.
CPAP is the most effective treatment for obstructive sleep apnea, in which the mild pressure from CPAP prevents the airway from collapsing or becoming blocked. Although delivery of CPAP through nasal mask is the most common modality of treatment, other systems exist for interfacing with adults and children.