关键词: 肺疾病, 呼吸系统, 压差式-肺量计, 标准模拟器, 准确性, 重复性, 线性

Abstract: Background　As an appropriate approach facilitating the diagnosis and treatment of respiratory disease，one of the four major diseases in China，pulmonary function test has been included in the national health plan and the long-term plan for the prevention and treatment of chronic diseases. A variety of domestically-made portable spirometers have been widely used in primary healthcare，but their performance needs to be scientifically verified. Objective　To assess the performance of spirometer PF680，a new domestically-made spirometer based on differential pressure sensing. Methods　This study was conducted from September to October 2020. A comparative analysis was performed between spirometer PF680 （produced by e-Link Care Meditech Co.，Ltd.，Zhejiang，China，n=2，experimental group） and Master Screen Pneumo spirometer（produced by Jaeger，Germany，n=2，control group） in terms of performance indicators〔forced vital capacity （FVC），forced expiratory volume in one second （FEV1），peak expiratory flow （PEF），maximal mid-expiratory flow （MMEF），forced expiratory flow at 50% of vital capacity （FEF50%），forced expiratory flow at 75% of vital capacity（FEF75%）〕 generated by the standard flow/volume simulator，which was applied according to 13 standard waveforms （C1-C13） in the ISO 26782：2009. Results　As for accuracy，in the experimental group，except for FVC of the C12 waveform measured by No. 2 spirometer，the errors of the FVC of the other 25 waveforms and the FEV1 of the 26 waveforms measured by two spirometers were all ≤±0.05 L or ±3%. In terms of repeatabilities，the maximal differences between the values of FVC and FEV1measured for three times by the two spirometers in the experimental group were <0.05 L and <3% of the average value. With regard to linearity，in the experimental group，except for the C5 waveform FVC of the No. 2 spirometerand the C5 waveform FVC and FEV1 of the No. 1 spirometer，the waveform linearity errors of the remaining FVC and FEV1 measured by the two spirometers were within a permissible range. The impedance for all respiratory airflow waveforms was <0.15 kPa•L-1•s-1. Compared with the single waveform of the control group，the FVC of C5，C7-C8 and C11-C12 waveforms demonstrated significantly differences between the two groups（P<0.05）. The FEV1 of C3，C5-C6，C8-C9 and C11-C12 waveforms differed significantly between the two groups （P<0.05）. The PEF of C1-C10 waveforms was significantly different between the two groups（P<0.05）. The PEF of C13 waveform was significantly different between the two groups（P<0.05）. The difference of C1-C11 and C13 waveform MMEF between the two groups was statistically significant（P<0.05）. The FEF50% of C1，C3-C11 and C13 waveforms between the two groups showed statistically significant differences （P<0.05）. The difference of C1-C12 waveform FEF75% between the two groups was statistically significant（P<0.05）. There were statistically significant differences in MMEF，FEF50% and FEF75% of the overall 13 waveforms between the two groups （P<0.05）. The Bland-Altman chart showed that FVC，FEV1，PEF，and FEF50% had 12 values （92.31%） and MMEF，and FEF75%had all values（100.00%）within the 95% confidence interval. The maximum absolute error for FVC，FEV1，PEF and FEF50% was 0.193 L，0.108 L，0.364 L/s，and 0.387 L/s，respectively. Conclusion　The spirometer PF680 has proved to be eligible for measuring pulmonary functions，and has good consistency with the German Jaeger spirometer，so it can be used for collectingreliable data clinically.

Key words: Lung diseases, Respiratory system, Differential pressure-spirometer, Standard simulator, Accuracy, Repeatability, Linearity