GE MOA 280i, Руководство по эксплуатации и обслуживанию

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GE Analytical Instruments ©2006
7-1
DML 14291 Rev. A
7.
ON-LINE EXHALED NITRIC OXIDE
On-line measurement of exhaled NO is performed by having the subject exhale
orally at a constant flow rate through a restriction to elevate the soft pallet and
eliminate nasal contamination. With the NOA 280i, this is performed using the
patented Accurate NO breath kit
†
†, the exhalation pressure transducer in the NOA
and the NOAnalysis REB program. Exhalation flow rate can also be directly
measured using a thermal mass flowmeter.
The American Thoracic Society has published “Recommendations for Standardized
Procedures for the Online and Offline Measurement of Exhaled Lower Respiratory
Nitric Oxide and Nasal Nitric Oxide in Adults and Children-1999” (Am J Respir Crit
Care Med Vol 160. pp 2104–2117, 1999). The recommended flow rate for on-line
measurements is 0.05 L/s (±10%) at Body Temperature and Pressure, Saturated
with water vapor (BTPS). For adults, the duration of exhalation should be at least
6 seconds in order to obtain a stable NO value for 3 seconds. Repeated,
reproducible exhalations are performed until three NO values are obtained that
agree within 10% of the mean value. Exhaled NO (F
E
NO 0.05
) is the mean of these
three values. Instantaneous flow should not be < 0.045 L/s or > 0.055 L/s at any
time during the exhalation. If it is not possible for the subject to keep within these
values, the results should still be recorded and the failure to achieve this flow
criterion noted in the record.
For children < 12 years old, the duration of exhalation should be at least 4 seconds
in order to obtain a stable NO value for 2 seconds. Repeated exhalations are
performed until three measurements are obtained that agree within 10% of the
mean value or two measurements agree within 5% of the mean.
†
U.S. Patent Nos 5,795,787 and 6,010,459.Under license from Aperon Biosystems,
Inc.