Heterogeneity of Lung Ventilation Determined by EIT During PFT in Patients With PRISM

Inclusion Criteria: Age ≥18 years old. Patients who need to complete lung function tests assessed by outpatient physicians. Patients willing to participate in the study and sign an informed consent form. Exclusion Criteria: Patients with a history of lung diseases other than COPD, previous lung surgery, or radiation therapy. Patients who cannot be evaluated for EIT or who interfere with EIT results, such as implanted pacemakers/cardioverters. Patients who cannot complete EIT or may interfere with EIT results, such as those with implanted pacemakers/defibrillators. Patients who cannot complete lung function tests, such as myocardial infarction or shock in the past 3 months; severe heart failure or angina in the past 4 weeks，uncontrolled hypertension (systolic \>200mmHg, diastolic \>100mmHg)，severe hyperthyroidism etc. Vulnerable populations, including patients with mental illnesses, cognitive impairments, critically ill patients, illiterate, pregnant women, etc.