OXYGEN CONCENTRATION APPARATUS

摘要

The present invention provides a gas supply apparatus (400) comprising: means (414) for detecting a user's respiration; a product gas flow path on-off valve (412) having a function to start and stop output of the product gas in synchronization with the user's respiration; and an ultrasonic type gas concentration and flow rate measuring means (410) having two ultrasonic transducers (420) disposed in an opposed manner in the line (422) through which the product gas flows, wherein a concentration value measured when said product gas output is stopped is determined to be a product gas concentration. As the oxygen concentration is measured while the output of the product gas flow is stopped in synchronization with the user's respiration, even in the respiratory synchronous type gas supply apparatus, the ultrasonic type gas concentration and flow rate measuring means can measure the oxygen concentration of the product gas accurately.