1. contraindication to the use of poc including allergy to cannula material 2. pregnancy or planning to become pregnant during the study 3. non-covid-related cause for cognitive impairment (such as parkinson's disease, multiple sclerosis, alzheimer's disease, stroke, brain tumor, or dementia) 4. subjects with respiratory infection at screening or randomization and/or acute bronchitis requiring antibiotics at the time of randomization or expected during the treatment 5. participation in other interventional clinical trial within 30 days of randomization or expect to participate in any other investigational clinical trial during the conduct of this trial 6. subjects who should be excluded in the opinion of the investigator

1. contraindication to the use of poc including allergy to cannula material 2. pregnancy or planning to become pregnant during the study 3. non-covid-related cause for cognitive impairment (such as parkinson's disease, multiple sclerosis, alzheimer's disease, stroke, brain tumor, or dementia) 4. subjects with respiratory infection at screening or randomization and/or acute bronchitis requiring antibiotics at the time of randomization or expected during the treatment 5. participation in other interventional clinical trial within 30 days of randomization or expect to participate in any other investigational clinical trial during the conduct of this trial 6. subjects who should be excluded in the opinion of the investigator

contraindication to the use of poc including allergy to cannula material pregnancy or planning to become pregnant during the study non-covid-related cause for cognitive impairment (such as parkinson's disease, multiple sclerosis, alzheimer's disease, stroke, brain tumor, or dementia) subjects with respiratory infection at screening or randomization and/or acute bronchitis requiring antibiotics at the time of randomization or expected during the treatment participation in other interventional clinical trial within 30 days of randomization or expect to participate in any other investigational clinical trial during the conduct of this trial subjects who should be excluded in the opinion of the investigator

contraindication to the use of poc including allergy to cannula material pregnancy or planning to become pregnant during the study non-covid-related cause for cognitive impairment (such as parkinson's disease, multiple sclerosis, alzheimer's disease, stroke, brain tumor, or dementia) subjects with respiratory infection at screening or randomization and/or acute bronchitis requiring antibiotics at the time of randomization or expected during the treatment participation in other interventional clinical trial within 30 days of randomization or expect to participate in any other investigational clinical trial during the conduct of this trial subjects who should be excluded in the opinion of the investigator