Here is the design of a clinical trial:

Official Title: Study on the Effectiveness and Feasibility of Prone Position Ventilation Technique for Postoperative Acute Lung Injury in Infants With Congenital Heart Disease

Included conditions:
- Investigative Techniques

Study Armgroups:
- {'label': 'Prone position ventilation technique', 'type': 'EXPERIMENTAL', 'description': 'Prone position ventilation for children with congenital heart disease after surgery', 'interventionNames': ['Behavioral: Prone position ventilation technique']}
- {'label': 'Control group', 'type': 'NO_INTERVENTION', 'description': 'conventional postoperative position, no prone position ventilation'}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Prone position ventilation technique', 'description': '1. Inform the children\'s family members of the purpose and method of prone position ventilation\n2. Assess the fixation of various catheters\n3. Suspend feeding before placing prone position\n4. Confirm the time to start prone position ventilation under the joint assessment of medical staff\n5. Place the child in a prone position with the participation of researchers, doctors and nursing staff, with the child\'s head tilted to one side to avoid damage to the eyes and nose due to compression, and the arms are bent upward to form a "W" . Bend both lower limbs downward to form an "M" shape, and use a soft pillow cushion to measure the knee joints to avoid compression\n6. The whole process ensures the smooth fixation of tracheal intubation and various catheters\n7. Proper sedation during prone position ventilation to achieve good human-machine synchronization\n8. At least 6-8 hours in prone position every day', 'armGroupLabels': ['Prone position ventilation technique']}

Primary Outcomes:
- {'measure': 'Oxygenation index', 'description': 'Oxygenation index refers to a goal in respiratory therapy,OI(mmHg)=PaO2/FiO2 It is a continuous variable.', 'timeFrame': 'at 6th hours after enrollment'}

Please estimate the sample size based on the assumption: 
Significance level (α) is 0.05, power (β) is 0.2, and an attrition rate of 10% is considered.
Sample size/power calculation
        According to pre-experimental investigations, the average oxygenation index required by the experimental group of children is 276, with a standard deviation of 68, and the control group has an average oxygenation index of 228, with a standard deviation of 67. Comparing the two independent sample means, Î± = 0.05, Î² = 0.2, the Gpower sample calculation software showed an effect size of 0.71. The ratio of the test group and the control group is 1:1. An attrition rate of 10% has been factored in the sample size calculation. The calculated sample size is 34 patients per group and total sample size is 68 patients.