Correlations Among Functional Performance, Muscle Strength and Weaning Rate in Mechanically Ventilated Patients

To assess the correlations among the physical functional performance, muscle strength, respiratory muscle strength and the ventilator weaning rate. Investigators use the DEMMI and FSS-ICU to evaluation the physical functional performance. And MRC score and hand dynamometer to record the muscle strength. The weaning parameters include Pi, PE, RSI,minute ventilation, tidal volume and cuff leak will be recorded. After the participant enters the Respiration Care Center, Doctor and physical therapist evaluate the consciousness and meet the inclusion criteria and the participant will received the first evaluation. The second evaluation will be held before the ventilator weaning timing.