Portable oxygen concentrator with upstream filter unit

A portable oxygen supply device for supplying a patient, comprising:

• an oxygen concentrator;
• at least one air inlet through which ambient air is transported into the oxygen supply device;
• an intake nozzle fluidically connected to the at least one air inlet through which the ambient air is sucked into the oxygen supply device;
• at least one oxygen outlet through which enriched oxygen is transported from the oxygen supply device;
• at least one exhaust air outlet through which exhaust air is transported from the oxygen supply device;
• a gas line system which is fluidically connected to the at least one air inlet, the outlet and the oxygen concentrator;
• a power source;
• at least one pump;
• a housing, wherein all components of the oxygen supply device are arranged in or on the housing;
• and
• a filter unit, the filter unit is either fastened directly to the intake nozzle or fastened to the intake nozzle with an adapter upstream of the air inlet, and the filter unit is selected from an NBC filter, combination filter and particle filter.