Air Liquide OSIRIS 2 Manual De Uso página 35

EN
Expiratory trigger
The expiratory demand is based on the detection of pressure variations during the inspiratory phase.
At the beginning of insufflation, OSIRIS 2 has a refractory period, during which the expiratory trigger may not be triggered.
The duration of this refractory period varies according to the duration of the inspiratory time: it is equal to half of the
inspiratory time setting, with a minimum limit of 300 ms and a maximum limit of 1000 ms.
To limit any incompatibility between patient and machine, the minimum frequency setting should be slightly less than
that of the patient (approximately 20% less), which will give the best possible adjustment of the refractory period.
This refractory period, moreover, has the advantage of ensuring at least a certain minimum inspiratory time, and there-
fore at least a certain minimum tidal volume for any patient who might tend to cut his or her inspiratory time too short.
If the practitioner wishes to place top priority on this safety feature, note that the refractory period may be deliberately
extended (although only up to one second) by lowering the frequency setting or by increasing the value of the I/E ratio.
This safety feature is useful in an emergency and transport ventilator, where monitoring is bound to be more limited
than on a resuscitation ventilator.
As an indication: on OSIRIS 2, this refractory period is at its maximum (1000 ms) for any frequency setting less than or
equal to 10 bpm (case I/E = 1/2), and for any frequency setting less than or equal to 15 bpm (case I/E=1/1).
 Each time the device is powered up, the default settings are used: TRIG = -1 cmH O, I/E = ½, Fmax = 40 bpm,
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Pmin = 5 cmH O for software versions V1.020 or earlier, and 10 cmH O for software versions V1.021 or later.
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III. 4. Display of frequency and I/E ratio measured by OSIRIS 2
OSIRIS 2 displays measured values of the I/E ratio and respiratory frequency du patient when the button is pressed
successively. . Parameters are displayed in the upper part of the screen for 5 seconds.
 The respiratory frequency measured by OSIRIS 2 can, in certain cases (respiratory cycles started by the
patient), be greater than the frequency set on the unit.
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YL024400 - V 2.1 - 10/2012