Table 4.

Ventilatory variables measured with the non-contact vibrometer using airborne ultrasound during synchronous pneumotachograph-SONAR recordings (PNT-SONAR) and with the SONAR only (SONAR-only).

SONAR signal	BF (breath min-1)	TT S	TI S	TE S	Displacement cm
In SONAR-PNT condition	13.1 (11.2–17.6)	4.6 (3.6–5.5)	1.9 (1.6–2.4)	2.7 (2.0–3.1)	3.0 (2.3–5.3)
In SONAR-only condition	15.7 (13.3–17.4)	4.0 (3.5–4.7)	1.7 (1.4–2.2)	2.1 (1.9–2.8)	2.4 (2.3–2.5)
p-Value	0.12	0.07	0.13	0.06	0.10

Data are presented as median (Q1–Q3). BF, breathing frequency; TT, breathing cycle period; TI, inspiratory time; TE, expiratory time; s, second.