User manual

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Fig. 6.3: Setting up the I:E ratio.
Example: Breathing frequency f
CMV
is 15 breaths per minute. That corresponds to the
duration of the entire breathing cycle of 4 seconds. If the expiration button is set to 75
%, then the inspiration will last 25 % of the entire breathing cycle. The I:E ratio in this
case is 1:3. That means inspirium lasts for 1 second and expirium lasts for three
seconds.
• Inspiration delay time, the so called plateau time (t
plateau
) - inspiration time may be
divided into active (insufflation) and passive (plateau) parts. This so called passive
inspiration time is called the inspiration delay, or sometimes the inspiration pause.
Fig. 6.4 depicts the set-up in the I:E ratio being 1:1 (expiration time, i.e. the upper
light button, is set to 50 %). Inspiration time (lower dark button) is set to 25 %, which
creates an inspiration delay lasting for 25 % of the length of the breathing cycle
duration. If the breathing frequency in this set-up amounts to 15 breaths per minute,
then the entire breathing volume is supplied in the respiration system within 1 second.
This is followed by a one-second inspiration delay, and then by a two-second
expirium.
75