Figure 6.

Correlation between the internal volume of the heat and moisture exchanger and the absolute humidity delivered. The programming of the ventilator corresponds to "Setting I" (tidal volume of 500mL, respiratory frequency of 20 breaths per minute). In "B", the same analysis as in "A" was conducted, but excluding the 3 bacterial filters (Pall, Intertech HEPA, Intersurgical). Pearson's correlation coefficient was used for the statistical analysis.

Source: Based on data from the study: Branson R, Davis K Jr. Evaluation of 21 passive humidifiers according to the ISO 9360 standard: moisture output, dead space, and flow resistance. Respir Care. 1996;41:736-43.⁽¹⁸⁾