Age

18–any

Sex

ALL

Healthy volunteers

Not accepted

1. Patient must ≥ 18 years of age
2. Patient has been diagnosed with Congestive Heart Failure, class II-IV
3. Patient is currently being admitted for decompensation related to Congestive Heart Failure
4. Subject or subject's legally authorized representative is able to give informed consent before entering the study.

1. Currently pregnant or breastfeeding
2. Clinical signs or symptoms of a respiratory infection
3. Unable to obtain a high-quality signal, as determined by variability of nPAC values throughout a single breath, within 48 hours of enrollment
4. Inability to withstand a 10 second end-inspiratory pause, in the opinion of the investigator
5. Deemed unsuitable for enrollment in study by the investigator based on subjects' history or physical examination

Comparing PA Compliance During and After Decompensation in HFP