Treaton MV200, Руководство пользователя

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Appendix 2.3 Mean pressure in the circuit for the respiratory cycle (Pmean)
App.2-2
t1-t2 expiraiton time,t2-t3 expiration hold (time of autoPEEP measurement)
Figure App.2.1 – Increasing of pressure in the circuit at the closed expiration valve due to pa-
tient’s end of expiration
Expiratory phase t1-t2 is carried out normally without deviations. At the time of the end of the
exhalation, inspiratory and expiratory flows are stopped, expiration valve is closed and flow ge-
nerator is also stopped. If there is an excessive pressure in the lungs, the gas flows from the
lungs to the breathing circuit. Pressure equalization occurs in the circuit-lungs system. At the
moment when the pressure change in the circuit becomes equal or less than 0.5 cmH
2
O/s, but
no earlier than 0.5 s and not later than 3 seconds, the procedure ends and inspiration begins.
autoPEEP = P(t3) – P(t2)
Expiration hold in any case can not exceed 3 seconds.
Appendix 2.3 Mean pressure in the circuit for the respiratory cycle
(Pmean)
Mean pressure for the respiratory cycle in the breathing circuit is calculated as follows:
∫
⋅ ⋅ =
T
0
dt P(t)
T
1
Pmean
,
where: Pmean – mean pressure in the circuit for the respiratory cycle,
T – period of the respiratory cycle,
P(t) – pressure in the circuit in the moment of time t.
t1 t2 t3
P(t)
autoPEEP
t4