Vibration response imaging: a novel noninvasive tool for evaluating the initial therapeutic effect of noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease

Table 1 Experiment flow chart

Time Points	Procedure	Healthy volunteers	Patients with AECOPD	NPPV settings
Before NPPV Treatment (T1)	Recruitment, informed consent	√	√	S/T Mode, Inspiratory pressure 10 cmH₂O
	Baseline Assessment (Medical History, Check-up)	√	√	Expiratory pressure 5 cmH₂O
	Pulmonary function	√		Backup rate 10 times/min
	First VRI examination	√	√
	Vital signs		√
	Clinical score		√
	Blood gas analysis		√
at 15 min of NPPV treatment (T2)	Vital signs		√
	Clinical score		√
	VRI examination	√	√
at 2 hours of NPPV treatment (T3)	Vital signs		√	Increase the pressure level in the principle of “the highest inspiratory pressure that a patient can endure”
	Clinical score		√
	Blood gas analysis		√
at 15 min after the end of NPPV treatment (T4)	Vital signs		√
	Clinical score		√
	VRI examination		√

ISSN: 1465-993X