摘要 |
A one-way air flow valve includes one-way inspiration and expiration valve assemblies which have a same structure, are connected to each other in parallel, and are arranged opposite to each other, so that valve plates provided in the one-way inspiration and expiration valve assemblies, respectively, are open in directions opposite to each other, and a connection part including a mouthpiece provided at one side of the inspiration and expiration valve assemblies to allow an examinee to inhale or exhale air. One end of the inspiration valve assembly is connected with a gas tank, one end of the expiration valve assembly is connected with a gas density analyzer, and the inspiration and expiration valve assemblies include a valve and suction and discharging tubes coupled with one side and an opposite side of the valve, respectively. |