Inclusion Criteria:  Within three months of onset Age≥18 years old GCS≥8 Clinical stability( defined as the absence of fever, sepsis, or active infection and hemodynamic stability) Without massive pooling or silent aspiration of saliva, more than one efficient swallow per minute, adequate cough reflex were tested by gently touching the aryepiglottic region with the tip of the endoscope. Passing a tracheostomy-tube de-cuff test(de-cuff the tube for 3 days without pulmonary complications. Without significant airway stenosis.  Exclusion Criteria:  Patients with pending diagnostic or therapeutic procedures and were considered by the clinicians to be at risk for neurologic deterioration Medical history of severe respiratory system or heart disease Neuromuscular disease other than ICU-acquired weakness, or tracheostomy for airway control Don't get informed consent from patient or guardian