Heyer Modular+, Service Manual

Page: 14 / 114

Repair Information
14
2.5.1 P
max
limiting on alarm violation
Exceeding the P
max
alarm limit automatically halts the inspiratory phase preventing airway pressure
from exceeding the high alarm setting. In the CMV mode, the setting of the P
max
peak pressure
provides pressure limitation. When reaching this pressure limit, a warning (alarm) “Peak greater than
P
max
” is displayed, and the inspiration is discontinued. The next inspiration is at a regular time interval,
the time control of the respiratory unit does not increase the respiratory rate. The result is a decrease
of the tidal volume “V
T
” and minute volume “M Vol.”. The respirator responses to pressure limitation
through displaying the P
max
alarm constantly.
2.6 Fresh Gas Decoupling
The tidal volume (V
T
) is adjusted independently of the adjusted fresh gas flow. This is achieved by
fresh gas decoupling. In inspiratory procedure the fresh gas flow is uncoupled by the decoupling and
expiratory diaphragm valves from the internal subsystem of the patient module. Fresh gas either is
filling the manual respiration bag (reservoir) or is led into the scavenging through the airway pressure
relief valve.
2.7 Compliance compensation
The tidal volume (V
T
) is automatically corrected in response to the compliance of the patient module
and patient tubes. Volume reduction due to system compliance is compensated as a result of this.