More than 90 percent of the patients in ICU
need respiratory protection by mechanical
ventilator [7]. The advent of mechanical
ventilators for supporting oxygenation and
ventilation in patients that cannot continue
natural breathing could save many patients’ life
[8]. Although mechanical ventilation is mostly
lifesaving, it can have some life threatening
complications too [9].The important stage in
ICU procedure is patient’s weaning from
mechanical ventilator; it can take forty percent
of the mechanical ventilation duration [10].