This study is aimed at patients who have been admitted to the respiratory care center of this hospital who meet the PMV conditions (defined as continuous use of the ventilator for at least ten days) who are about to receive the ventilator out of training. After obtaining the explanatory consent, they will undergo continuous complete Before and after spontaneous breathing training, collect various relevant physiological data of lung volume and ventilation perfusion distribution, and analyze and predict the correlation of ventilator detachment.

Inclusion Criteria:

• Be at least 20 years old, have undergone tracheotomy, have been using a ventilator for at least 10 days, and have stable vital signs.

Exclusion Criteria:

• Age <20 years
• The oxygen concentration (FiO2) provided by the respirator exceeds 60%
• pregnant
• Blood pressure-systolic blood pressure below 70 mmHg
• Heartbeat is lower than 50/min or higher than 160/min
• Respiration rate is higher than 50/min
• Lack of voluntary breathing

Patients who were transferred to RCC and tried to get out of the ventilator after tracheotomy