The<unk>  on a General Electric Datex-Ohmeda Aisys anaesthetic machine, with<unk>  gradations shown in centimetres of water. An<unk>  (commonly abbreviated to APL<unk> , and also referred to as an expiratory<unk> , relief<unk>  or spill<unk>  is a type of flow control<unk>  used in anaesthesiology as part of a breathing system. It allows excess fresh gas flow and exhaled gases to leave the system while preventing ambient air from entering.
Adjustable pressure-limiting valve
Articulatory technique
Artificial heart valve
Artificial cardiac pacemaker
Tissue engineering of heart valves
Minimally invasive cardiac surgery
Minimally invasive direct coronary artery bypass surgery
Cardiac pacemaker