1. Introduction
Both the morbidity and mortality of respiratory diseases in children
occupy the first place among all systemic diseases in pediatrics. Lung
function is an important respiratory physiological index of the human
body, which is closely related to the evaluation of children’s growth,
development, and motor ability of respiratory diseases, and plays an
important role in the diagnosis and efficacy evaluation of respiratory
diseases. The measurement of respiratory function has a key role in
diagnosing and monitoring respiratory diseases. However, lung function
testing is limited in the preschool population because of the poor
performance and lack of cooperation by children. The impulse
oscillometry system (IOS) is a simple and noninvasive technique for
measuring lung mechanics during tidal breathing. It requires no special
cooperation from patients and features simple, non-invasive, repeatable,
and comprehensive analysis. It can provide a variety of respiratory
physiological parameters and is suitable for people aged 3 years and
above, especially the elderly and children. How to accurately assess the
outcome of lung function is related to the diagnosis and treatment of
the disease by clinicians. American Thoracic Society (ATS) and the
European Respiratory Society (ERS) are made clear, pulmonary function
should be evaluated using the reference from the same ethnicity, living
environment and age, and estimated value according to the improper can
lead to differences of lung disease assessment results[1,2]. Children’s lung function testing at present
in China using the reference from the foreign children, due to
differences in race, and so obviously affected the accuracy of the
assessment. Therefore, Shanghai Children’s Medical Center was taken as
the lead unit, and the pediatrics department of twenty specialized or
general hospitals in China were combined to conduct the measurement of
IOS lung function in 6284 healthy children from May 2017 to May 2019,
aiming to establish the normal reference value of IOS in China, to
facilitate the clinical application and research of IOS.