Starting in the 1990’s, recognition of carbon dioxide rebreathing as a potential hazard to sleeping infants led to the introduction of test methods to evaluate infant bedding materials. Carleton et. al developed and published a mechanical breathing model in 1997.
The Carleton model made use of a manikin to simulate the infant’s face, breathing through the nose. At the time, CO2 analyzers did not measure beyond 20%, so Carleton used dilution of the sample to extend the range of measurement.
Leshner introduced several advancements to the test method, including:
· Direct measurement of the sample without dilution
· The manikin was replaced by an anthropomorphic probe designed to model an infant’s face
· A weight of 10 newtons on the probe simulates the weight of an infant’s head
The breathing rate, tidal volume, residual volume and airway resistance are consistent with those used by Carleton and the results are consistent as well.
