PUMP UNIT, RESPIRATORY ASSISTANCE DEVICE

摘要

A pump unit 10 includes: a housing 13 provided with an inlet 11 and an outlet 12 for a fluid; and a pump group composed of micro pumps 15 arranged in the housing 13, for allowing a fluid entering through the inlet 11 to exit from the outlet 12. The pump group includes: the micro pump 15 positioned in the most upstream (m1); the micro pump 15 positioned in the most downstream (m4); and the micro pumps 15 positioned in the middle (m2 to m3). The housing 13 includes: an inlet direct-connecting flow passage 41 directly connecting a suction port 31A of the micro pump 15 positioned in the most upstream with the inlet 11; an outlet direct-connecting flow passage 42 directly connecting a discharge port 31B of the micro pump 15 positioned in the most downstream with the outlet 12; and a flow passage forming mechanism switchable between a state in which the micro pumps 15 are connected in series and a state in which the micro pumps 15 are connected in parallel.