This type of coma is usually reversible once the blood sugar is corrected. Oxygen deprivation: Oxygen is essential for brain function. Cardiac arrest causes a sudden cutoff of blood flow and oxygen to the brain, called hypoxia or anoxia.
The external power supply is the AC power adapter that converts household AC electricity voltages to the much lower DC voltages needed to charge a mobile phone's internal battery.
According to the European Commission, a common external power supply / charger standard is desirable because, Incompatibility of chargers for mobile phones is a major environmental problem and an inconvenience for users across the EU. Currently specific chargers are sold together with specific mobile phones.