Abstract: A device for collecting exhalation gas and aiding measurement of a trace component in the exhalation gas and the usage method thereof are disclosed. The device comprises an alveolar air bag for storing alveolar air collected from the breath of a subject, a cavity channel air bag for storing cavity channel air from the subject, a three-way pipe, and a mouthpiece. The three-way pipe comprises a first branch pipe, second branch pipe, and third branch pipe communicating with each other. The first branch pipe and the second branch pipe respectively extend in opposing directions along the same axis. The third branch pipe extends along a radial direction of the first branch pipe and the second branch pipe. The mouthpiece communicates with the first branch pipe. An air hole of the cavity channel air bag communicates with the second branch pipe.

Abstract: A method and device for measuring the lifespan of a red blood cell is discussed. The method is a non-dispersive infrared spectrometry and comprises: injecting a small amount of sample at a constant speed; using an interference component absorption pack to remove interference components; measuring an alveolar gas sample and a background gas sample in pair and using a level difference-concentration difference fitting method to obtain the endogenous CO concentration in alveolar gas; using a dual-gas chamber method to measure the CO2 concentration and the CO concentration; and removing the influence of air, which is mixed into the alveolar gas when the alveolar gas is acquired, on the measured value of the endogenous CO concentration in the alveolar gas according to the obtained CO2 concentration, thereby obtaining the accurate value of the endogenous CO concentration in the alveolar gas and calculating the lifespan of the red blood cell.

Abstract: A method and apparatus for measuring endogenous CO concentration in exhaled alveolar air, comprises: proposing a method for injecting samples in small amounts, multiple times, intermittently, and establishing a CO concentration relationship between sample gas and gas in a measuring chamber; establishing a “concentration difference/electrical level difference” difference value fitting method, to obtain a fitted standard curve for a difference value between the sample gas and base gas; establishing an apparatus for measuring a CO concentration difference and a CO2 concentration difference between sample gas and base gas; proposing a method for compensating a measurement value for endogenous CO in exhaled alveolar air. The problem that the amount of sample gas in a breath test is small, and cannot completely replace the gas originally inside the measuring chamber, is solved. The effect of electrical level zero drift and residual CO of unknown concentration in cleaning gas is eliminated.