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.
BiPAP (also referred to as BPAP) stands for Bilevel Positive Airway Pressure, and is very similar in function and design to a CPAP machine (continuous positive airway pressure). Similar to a CPAP machine, A BiPAP machine is a non-invasive form of therapy for patients suffering from sleep apnea. Both machine types deliver pressurized air through a mask to the patient's airways. The air pressure keeps the throat muscles from collapsing and reducing obstructions by acting as a splint.