The experimental group will undergo intrapulmonary percussive therapy

The volunteers will undergo three minutes low frequency and high frequency intrapulmonary percussive treatments.

This test can assess the volunteer's lung ventilation and diffusion function.For example the max vital capacity (VCMAX),Forced vital capacity(FVC),Forced expiratory volume in one second(FEV1),functional residual capacity(FRC-SB),diffusion capacity of lung for carbon monoxide(DLCO) and so on.

EIT is a relatively advanced non-invasive monitoring technique for the lung function. This technology uses a strap attached to the chest to monitor electrical at 16 locations. The Ventilation in each area resistance of the lung is quantified according to the electrical resistance

Whether the technique has adverse reactions. How do the volunteers feel? We used a scale of 1 to 4 to show how the volunteers felt. 1 is the worst feeling. The volunteers were no longer willing to undergo the treatment. 4 means the volunteers felt better and breathed easier after the treatment. Be willing to undergo endoairway shock therapy again.