SLE 2000 - PTV Mode

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9.1.5 PTV Mode
Another main feature of the ventilator is its patient trigger system. This functions
without any transducer in the patient circuit, on the principle of monitoring the rate
of change of pressure during the onset of inspiratory effort. In fact it measures
inspiratory flow by this means and not a pressure plateau.
The BPM control no longer functions in this mode. The last
BPM setting in CMV, prior to switching to PTV will be the
back-up rate. (Setting a time window for Apnoea). Additionally
the PTV sensitivity control is activated, all inspiratory efforts at
chosen sensitivity should trigger the ventilator.
However, if the sensitivity is set too low, or the patient fails to
make an inspiratory effort during the back-up time window, the
ventilator will deliver a back-up breath and indicate this by the TRIGGER BACK UP
LED. If the sensitivity is set too high the ventilator could auto trigger at a high rate.
After 60 seconds with an update every 60 seconds, the BPM LED display will
indicate the number of patient initiated breaths that were delivered in the preceding
minute.
In this mode inspiratory times of less than 0.4 seconds are recommended.
• In PTV mode the BPM display will show only patient initiated breaths. To check
back up rate it is necessary to change the mode switch temporarily to CMV.
• To enable an audible back-up bleep, hold the Reset button in during the automatic
test mode on power up.
Note: PTV has a default of 12 breaths per minute, if the mode switch is turned
straight to PTV mode with out stopping on CMV mode to set the back up breath
rate.
This is also the case if there is an interruption to the power supply, the
ventilator will also default to this setting. It will be necessary to change the
mode switch temporarily to CMV to reset the required BPM.
9.1.6 SIMV Mode.
This mode enables BPM control to select and display the maximum number of
breaths, triggered or untriggered, to be delivered by the ventilator.
If the patient fails to trigger the ventilator during the first half of the SIMV time
window, the ventilator will immediately deliver a mandatory breath and indicate this
with an audible bleep. Any additional spontaneous breaths by the patient will be
unsupported by the ventilator.
• To enable an audible back-up bleep, hold the Reset button in during the automatic
test mode on power up.