Measurement of the Diaphragm Loading During the Training With a IMT Device

This study has a quasi-experimental design. The investigators will recruit ten healthy adult volunteers without anticoagulation or esophageal lesions, after signing a consent form. After checking the appropriate correct position of each catheter, each subject will use the IMT device throughout different randomized loads (percentages of the maximal inspiratory pressure, counting by tens from 10% to 100%). FluxMed® GrT MBMed respiratory mechanic monitor will be used. Each percentage of resistive load will be maintained for 5 inspirations. Meanwhile, an operator will register the esophageal pressure,the gastric pressure and the transdiaphragmatic pressure. Diaphragm collaboration in each percentage of resistive load will be determine by calculating the relation between the gastric pressure and the transdiaphragmatic pressure (∆Pgas/∆Pdi).