GE MOA 280i, Руководство по эксплуатации и обслуживанию

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GE Analytical Instruments ©2006
7-5
DML 14291 Rev. A
-10
0
10
20
30
40
50
60
0 5 10 15 20 25 30
Time (sec)
[NO] ppb
Flow (mL/s BTPS)
Figure 7-2: Plateau with Low
Inspired NO.
-10
0
10
20
30
40
50
60
0 5 10 15 20 25 30
Time (sec)
[NO] ppb
Flow (mL/s)
Figure 7-4: Plateau with High
Inspired NO and Filter.
-10
0
10
20
30
40
50
60
0 5 10 15 20 25 30
Time (sec)
[NO] (ppb)
Flow (mL/s BTPS)
Figure 7-3: Plateau with High
Inspired NO.
Performing the Maneuver
On-line measurements of exhaled NO are best performed using the NOAnalysis REB
program. Consult the NOAnalysis manual for program instructions. The maneuver
consists of having the subject inhale to total lung capacity (TLC) and immediately
exhale while maintaining the targeted exhalation pressure or exhalation flow rate
for the required duration (6 seconds of adults, 4 seconds for children. For 50 mL/s
at 760torr, the target pressure is 16 cm H
2
O.
It is usually necessary to have the subject
practice a few times before good exhalations
can be achieved. Subjects that are used to
spirometry usually will exhale at too high of
flow rate as the on-line measurement uses a
very slow exhalation. When a subject exhale
too fast, there is a tendency to stop exhaling
rather than continuing to exhale, but at a lower
flow rate.
While the subject is exhaling, monitor the NO
signal and have the subject continue exhaling
until the NO signal is stable for the required
duration (3 seconds for adults, 2 seconds for
children). Figure 7-2 shows a typical exhalation when inspiratory NO is low. The
NO signal slowly increases, then reaches a plateau after a ~10 seconds. Figure 7-
shows a typical exhalation when ambient NO is
high. NO levels start at ambient levels, and
then slowly decrease until a stable NO plateau
is obtained (~ 20 seconds after start of
exhalation). Figure 7-4 shows an exhalation
with high ambient NO, but using the inspiratory