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Chapter 5 – Development of innovative instruments for acquisition of respiratory variables
simulator a mechanical resistance of 0 cm H2O/(L/sec) and a compliance of 20 ml/cm H2O
was fixed. The acquired data was digitally filtered with a low-pass third order Butterworth IIR
filter with a cut-off frequency of 400 Hz.
The laboratory measurement system of respiratory parameters supplies directly the
measured volume. The volume measured by the new instrument was calculated integrating
the flow curves.
The acquired values of flow (Fig. 5.4), pressure (Fig. 5.5) and computed volume (Fig. 5.6),
were evaluated considering a single respiratory act.
Flow (lpm)
50
0
-50
Fleisch
VT+
Flow (lpm)
12 12.5 13 13.5 14 14.5 15 15.5 16
Time(s)
Fleisch
VT+
50
0
-50
13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9
Time(s)
Figure 5.4 Flow behaviour along a single respiratory act (top) and a particular (bottom), acquired by means of
our device (Fleisch) and the VT+ Gas Flow Analyzer.
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