Clinical Research Directory

Inclusion Criteria: 1. Age 18 years or older. 2. Admitted to an intensive care unit or postoperative monitoring unit after major thoracic or upper-abdominal surgery; tracheal tube removed; spontaneously breathing; and clinically stable. 3. Alert and able to understand and follow incentive-spirometry and EIT instructions. 4. Bedside lung ultrasound shows atelectasis or markedly reduced aeration in dorsal or posterolateral lung regions, with the lung-ultrasound assessment recorded. 5. Baseline EIT during quiet breathing in a semi-recumbent position shows insufficient dorsal ventilation with potential for improvement; dorsal ventilation fraction below 50%. 6. Written informed consent provided by the participant or legally authorized representative according to the ethics-approved process, with participant re-consent when decision-making capacity returns. Exclusion Criteria: 1. Ongoing invasive mechanical ventilation or noninvasive ventilation, or high-flow nasal oxygen when study conditions cannot be maintained stably. 2. Hemodynamic instability or inability to tolerate a semi-recumbent position. 3. Inability to cooperate with training or impaired consciousness. 4. Unsuitable for EIT monitoring, including an implanted pacemaker or defibrillator incompatible with the device, severe skin disease at the electrode-belt site, or known relevant allergy. 5. Severe underlying pulmonary disease likely to substantially affect ventilation distribution and obscure the intervention effect. 6. Chest-wall deformity or severe scoliosis affecting EIT image quality. 7. Body mass index greater than 35 kg/m2. 8. Pregnancy or breastfeeding. 9. Current participation in another interventional clinical trial that could interfere with study outcomes. 10. Any other condition that, in the investigator's judgment, makes participation inappropriate.