Here is the design of a clinical trial:

Official Title: PRessure suppOrT vEntilation + Sigh in aCuTe hypoxemIc respiratOry Failure patieNts (PROTECTION): a Pilot Randomized Controlled Trial

Included conditions:
- Respiratory Failure
- Acute Respiratory Distress Syndrome
- Ventilator Lung

Study Armgroups:
- {'label': 'PSV group', 'type': 'ACTIVE_COMPARATOR', 'description': 'Will be treated by standard of care for patients undergoing assisted mechanical ventilation (e.g., protective PSV settings, protocolized weaning, etc.).', 'interventionNames': ['Procedure: Standard of care']}
- {'label': 'PSV+Sigh group', 'type': 'EXPERIMENTAL', 'description': 'Will be treated by standard of care for patients undergoing assisted mechanical ventilation (e.g., protective PSV settings, protocolized weaning, etc.) + Sigh (short cyclic recruitment breath once every minute) until death or spontaneous breathing trial and extubation.', 'interventionNames': ['Procedure: Sigh']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Sigh', 'description': 'Application of cyclic pressure control breath delivered at 30 cmH2O for 3 seconds once per minute in patients undergoing pressure support ventilation', 'armGroupLabels': ['PSV+Sigh group'], 'otherNames': ['Short cyclic recruitment breath']}
- {'type': 'PROCEDURE', 'name': 'Standard of care', 'description': 'Standard of care', 'armGroupLabels': ['PSV group']}

Primary Outcomes:
- {'measure': 'Clinical feasibility of PSV+Sigh vs. standard of carde (PSV)', 'description': 'Feasibility will be assessed by measuring the number of patients in each group experiencing at least one of the following failure criteria:\n\n* switch to controlled ventilation following presence of predefined criteria;\n* use of PEEP ≥15 cmH2O, prone positioning, inhaled nitric oxide, extracorporeal membrane oxygenation;\n* re-intubation within 48 hours from extubation following predefined criteria.\n\nBased on previous data, the expected rate of failure in patients undergoing PSV will be 22% and we hypothesize a rate of 15% for patients in the PSV+Sigh group. Furthermore, we assume a non-inferiority of the treatment with PSV+Sigh, with a tolerance of 5%. Thus, a sample size of 258 patients (with 129 patients per study arm) will be sufficient to assess feasibility of the PSV+Sigh strategy in this pilot phase with power of 0.8 and alpha 0.05.', 'timeFrame': '2 years'}

Please estimate the sample size based on the assumption: 
Non-inferiority tolerance of 5%, power of 0.8, and alpha of 0.05.
Sample size
        The sample size was computed based on the hypothesis that PSVâ+âsigh might decrease the rate of failure of assisted ventilation compared to standard PSV. Based on previous data [21], the expected proportion of failure in patients undergoing PSV will be 22% and we hypothesized a proportion of 15% for patients in the PSVâ+âsigh group. Assuming non-inferiority of PSVâ+âsigh treatment, with a tolerance of 5% we estimated that a sample size of 258 patients (with 129 patients per study arm) will be sufficient to assess feasibility of the PSVâ+âsigh strategy in this pilot phase with power of 0.8 and alpha 0.05.