
Instructions for Use Evone
58
Component
Purpose
Range
O
2
Sensor
Check the mixture for correct
amount of oxygen.
0 – 100%
Pressure Vessel Pressure Sensor
Check pressure vessel pressure.
0–5 bar
Pressure Controller
Control mixture pressure for
Jet mode.
0–6 bar
Jet Port Pressure Sensor
Check pressure on the Jet port,
this consists of two sensors of
different ranges.
+/- 1 bar
Pressure Port Sensor
Sensor for measuring the intratra-
cheal pressure.
+/- 200 mbar
Table 10.2 Components pneumatic scheme Evone
10.3 Safety Philosophy
1
Correct measurement of intratracheal pressure is essential for both prevention of barotrauma /
volutrauma and efficient oxygenation / ventilation. The Evone breathing system has two
separate lumens: a pressure lumen and a ventilation lumen. Each lumen is connected to
a dedicated reliable pressure sensor inside the Evone Control Unit enabling measuring
intratracheal pressure in two fully independent ways.
A
Both pressure sensor readings are compared at regular intervals (i.e. 10 breaths for
FCV
®
Mode and each pulse for Jet Mode). To enable optimal direct comparison, the
ventilation is shortly paused at these intervals, creating a no-flow situation through the
ventilation part.
B
If other measurements (timing, flow) indicate a potentially incorrect continuous pressure
measurement via the pressure lumen, the device pauses ventilation (no flow situation)
and directly compares the pressure reading via the pressure lumen with the independent
reading via the ventilation lumen.
Upon a significant deviation of both measurements in any of the above two situations, the
device purges the pressure lumen with air to remove any debris that may obstruct that
lumen. In case this situation is triggered during expiration, also the ventilation lumen is
purged to ensure this lumen is free of any obstructions. After the purge, the pressure
reading of the pressure lumen is again compared with the pressure reading through the
ventilation lumen. If still inconsistent, a second purge cycle is applied. When the pressure
difference still remains, an alarm (‘Pressure mismatch’) is given.