How long can a patient with a 2-month ventilator take oxygen on his own

The patient has been using the ventilator for 2 months how long can he breathe oxygen on his own. During the use of the ventilator, the patient received effective treatment, the condition has been improved, resulting in a gradual recovery of respiratory function, in this case, the patient's lungs have recovered enough function on their own to breathe and inhale oxygen on their own, so the patient used 2 months ventilator a month to be able to inhale oxygen on their own. A ventilator is a medical device used to assist or replace the patient's respiratory function, and its main role is to support the patient's respiratory system by delivering respiratory airflow to help the patient inhale and exhale sufficiently to maintain a suitable supply of oxygen and carbon dioxide excretion.