PT  - JOURNAL ARTICLE
AU  - Sennhauser, F H
AU  - Sly, P D
TI  - Pressure flow characteristics of the valve in spacer devices.
AID  - 10.1136/adc.64.9.1305
DP  - 1989 Sep 01
TA  - Archives of Disease in Childhood
PG  - 1305--1307
VI  - 64
IP  - 9
4099  - http://adc.bmj.com/content/64/9/1305.short
4100  - http://adc.bmj.com/content/64/9/1305.full
SO  - Arch Dis Child1989 Sep 01; 64
AB  - The valve system in the mouth piece of two spacer devices was analysed. Pressures required to open and close the non-rebreathing valve were very low (less than 0.1 kPa). Inspiratory flow requirements were within physiological limits for infants' normal tidal breathing. Expiratory flow requirements varied significantly, and the flow required to prevent rebreathing from the chamber may exceed the physiological flow limits for normal tidal breathing.