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Chapter 6 – High Frequency Percussive Ventilator characterization
Fig. 6.5
Servo-I : R mean, E mean
Table 6.2 presents the reference values of resistance (R FLUKE) and elastance (E FLUKE)
for the VDR-4 test, with the corresponding resistance (R mean ± 1SD) and elastance (E mean
± 1SD) estimated values together with their % relative estimation errors (∆R% and ∆E%) and
the normalized mean square error between measured and estimated pressure (NMSE). The
percussive frequency was fixed to 450 cycles/minute.
Table 6.2 Resistance and compliance estimated during inflation by the VDR-4 percussive
ventilator. Measures were carried out for 60 seconds, setting up on the VDR-4 a
respiratory frequency of 15 breaths per minute with I/E 1:1 and a percussive frequency of
450 cycles per minute with work pressure of 20 cm H 2 O and free expiratory flow.
R FLUKE
cm
H 2 O/(l/sec)
E FLUKE
cm H 2 O/l
R
mean±1SD
cm
H 2 O/(l/sec)
∆R%
E
mean±1SD
cm H 2 O/l
∆E%
NMSE
5 20 4.9±0.16 -1.3% 21.9±0.19 9.4% 2.8
20 20 13.7±0.16 -31.7% 23.6±0.51 18.0% 4.7
50 20 37.2±0.56 -25.7% 31.7±1.42 58.6% 22.9
5 50 5.0±0.07 -0.70% 54.8±1.66 9.6% 5.9
20 50 14.7±0.26 -26.4% 52.1±0.78 4.2% 10.0
50 50 42.2±0.70 -15.6% 62.1±1.45 24.1% 37.8
5 100 4.9±0.06 -1.4% 116.4±5.37 16.4% 5.3
20 100 13.2±0.15 -33.7% 116.9±4.27 16.9% 9.9
50 100 41.2±0.63 -17.6% 109.8±1.84 9.8% 36.5
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