Inclusion Criteria:  Patients over 18 years old Patients admitted to the adult intensive care unit at Estaing Hospital, Clermont-Ferrand Patients under invasive mechanical ventilation (intubation or tracheostomy) Patients with a tidal volume greater than 10 mL.kg-1 of predicted body weight despite a minimal pressure support (< 5 cmH2O) Patients with sedation compatible with spontaneous ventilation with inspiratory support and positive end-expiratory pressure Patient calm (RASS between -2 and 0) Consent to participate in the study from the patient or authorization to carry out the research collected from the designated trusted person (failing that, a family member or a close relative who has a close and stable relationship with the patient) in accordance with the procedures described in Title II of the First Book of the Public Health Code. If no relative is present, the patient may be included on the advice of the investigator (article L. 1111-6). A consent form for the continuation of the study and the use of the data will then be signed by the patient if and when he/she is conscious and lucid again, or if the patient is unable to express his/her consent, an authorization to continue the research will be obtained from the designated trusted person Patient benefiting from a Social Security system  Exclusion Criteria:  Refusal to participate in the proposed study Protected adults  Contraindication to the placement of a nasogastric tube:  Severe uncorrected blood flow disorder Known naso-sinusal lesion Recently ligated esophageal varices (< 48h)  Contraindication to the use of the tomographic electroimpedancemetry technique  Thoracic lesions Thoracic dressings Pace-maker/implantable defibrillator Known injury to central respiratory centers, including neurocompromised patients Patients with Acute Respiratory Distress Syndrome (according to Berlin criteria)