摘要 |
This invention includes a pair of chambers each containing a piston which is reciprocated slowly by a computer controlled reversible fluid pressure pump between an advanced position for moving room air through a molecular sieve bed to strip nitrogen from the air and deliver oxygen enriched air to a patient, and a retracted position to back-flush the sieve bed with oxygen enriched air and exhaust the nitrogen rich air to the atmosphere. The pistons may be moved by piston rods or by a rack and pinion drive. In a third embodiment a single cylinder forms a pair of chambers separated by a central exhaust chamber, and expandable bellows in the chambers extend and retract either alternatively or simultaneously. In a fourth embodiment a single cylinder containing a single piston forms a pair of chambers one on each side of the piston and a molecular sieve bed communicates with each chamber.
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