Evaluation of heepSync, a Novel Algorithm for Transcutaneous Electrical Stimulation of Respiratory Muscles in Mechanically Ventilated Patients.

Inclusion Criteria: Patient population 1 * Adult patients with acute hypoxemic respiratory failure who have been under controlled mechanical ventilation for at least 24 hours prior to enrollment. * Clinically stable: oxygen saturation \> 90% with a fractional inspired oxygen ≤ 0.50, eternal PEEP ≤ 10 cm H2O, temperature ranging from 35.5 to 38.5 ºC, no intravenous administration of vasoactive agents. Patient population 2 * Adult patients with acute hypoxemic respiratory failure who have been under pressure support mechanical ventilation for at least 24 hours prior to enrollment. * Clinically stable: oxygen saturation \> 90% with a fractional inspired oxygen ≤ 0.50, eternal PEEP ≤ 10 cm H2O, temperature ranging from 35.5 to 38.5 ºC, no intravenous administration of vasoactive agents. Exclusion Criteria: * Patients treated with neuromuscular blocking agents * Patients with neuromuscular disease * Patients with a pacemaker or past history of arrhythmia * Patients with physical obstacles that prevent thoracic or abdominal electrostimulation (e.g., abdominal trauma, recent abdominal surgery, polytrauma, broken or irritated skin) * BMI \> 40 kg/m2 * Hemodynamically unstable (noradrenaline \>0.1 microgram/kg/min) * Pregnancy * Patients under the age of 18 * The formalized ethical decision to withhold or withdraw life support * Patient under guardianship * Patients deprived of liberties * Patients already enrolled in the present study, in a previous episode of acute respiratory failure. * The patient who does not consent.