PROBLEM TO BE SOLVED: To provide an oxygen concentrator in which a flow rate control of the oxygen enrichment gas suitable for a user is quickly made possible when a user's arterial blood oxygen saturation is placed in an excessive anoxia and hyperoxia in the oxygen concentrator for the home oxygen therapy with the SpO2 feedback function, and provide its control method.SOLUTION: A PSA-type oxygen concentrator is provided in which multiple adsorption columns are switched and used. The PSA-type oxygen concentrator includes: upper time limit control means including SpO2 feedback control means, and decreasing a supply oxygen flow rate, when the user's arterial blood oxygen saturation continuously exceeds the upper limit arterial blood oxygen saturation by the first reference number or more； and lower time limit control means for increasing the supply oxygen flow rate, when the user's arterial blood oxygen saturation is continuously lowered from the lower limit arterial blood oxygen saturation by the second reference number or more.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2019,JPO&INPIT【課題】ＳｐＯ２フィードバック機能を備える在宅酸素療法用の酸素濃縮装置において、使用者の動脈血酸素飽和度が過度な低酸素状態や高酸素状態に置かれた場合に、速やかに使用者にとって好適な酸素濃縮ガスの流量制御が可能な、酸素濃縮装置およびその制御方法を提供すること。【解決手段】複数の吸着筒を切り替えて使用するＰＳＡ式酸素濃縮装置において、ＳｐＯ２フィードバック制御手段を備え、使用者の動脈血酸素飽和度が上限動脈血酸素飽和度を第１基準回数以上連続して上回った場合に、供給酸素流量を減少させる上限時制御手段と、使用者の動脈血酸素飽和度が下限動脈血酸素飽和度を第２基準回数以上連続して下回った場合に、供給酸素流量を増加させる下限時制御手段と、を備えたＰＳＡ式酸素濃縮装置。【選択図】図１
