Estimating breathing movements of the chest and abdominal wall using a simple, newly developed breathing movement-measuring device.

BACKGROUND The 3-dimensional (3D) distances of specific points on the chest and abdominal wall are useful for assessing the characteristics of breathing movement. This study aimed to determine whether the 3D distances on the chest and abdominal wall during deep breathing (DB) could be estimated using a newly developed breathing movement-measuring device (BMMD). METHODS Breathing movement distances on the chest (bilateral third and eighth ribs) and abdomen (upper abdomen) of 10 healthy young males were measured using a pen-sized mechanical BMMD and a 3D motion analysis system during DB. DB was controlled and based on the distances targeted by the BMMD (ie, 1, 2, and 3 cm), which was placed on the observation points and fixed on a tripod. Simultaneously, the 3D distances of reflective markers on the observation points were measured. The obtained data were statistically analyzed using a paired t test, repeated measures analysis of variance with multiple comparisons tests, and linear regression with mixed effects. RESULTS All the BMMD distances were less than the 3D distances. The differences between the 3D and BMMD distances on the chest and abdomen, except for the left lower chest (eighth rib), were significantly greater at a target distance of 3 cm than that of 1 cm. The coefficients of determination ranged from 0.98 to 0.99. CONCLUSIONS Linear regression equations provided adequate estimates of the 3D distances of markers on the chest and abdominal wall during DB. The results suggest that this BMMD is useful for quantitatively assessing DB movement of the chest and abdominal wall in healthy young males.