An open access database for the evaluation of respiratory sound classification algorithms.

OBJECTIVE: Over the last few decades, there has been significant interest in the automatic analysis of respiratory sounds. However, currently there are no publicly available large databases with which new algorithms can be evaluated and compared. Further developments in the field are dependent on the creation of such databases. APPROACH: This paper describes a public respiratory sound database, which was compiled for an international competition, the first scientific challenge of the IFMBE's International Conference on Biomedical and Health Informatics. The database includes 920 recordings acquired from 126 participants and two sets of annotations. One set contains 6898 annotated respiratory cycles, some including crackles, wheezes, or a combination of both, and some with no adventitious respiratory sounds. In the other set, precise locations of 10 775 events of crackles and wheezes were annotated. MAIN RESULTS: The best system that participated in the challenge achieved an average score of 52.5% with the respiratory cycle annotations and an average score of 91.2% with the event annotations. SIGNIFICANCE: The creation and public release of this database will be useful to the research community and could bring attention to the respiratory sound classification problem.

External cardioversion of atrial fibrillation: the role of electrode position on cardioversion success.

The optimal method to perform external electrical cardioversion of atrial fibrillation has not been fully determined yet. In order to define the effects of different pad positions on cardioversion success rates, shock energy requirements and serum myocardial proteins levels we studied 62 patients with persistent atrial fibrillation who underwent elective external electrical cardioversion using a standardized step-up protocol of increasing energy levels. Electrode positions were randomly assigned as anterolateral (Group A) or anteroposterior (Group B). After all shocks were delivered there was no difference in the cardioversion success rate between the two groups. However, a significantly greater proportion of patients in group B were restored to sinus rhythm after the second shock of 300 J was delivered (p=0.005). Mean shock energy requirements and peak serum creatine kinase levels were lower for group B than for group A (p=0.049 and p=0.021 respectively). Troponin T serum levels were not increased after the cardioversion attempts in either group. We conclude that an anteroposterior electrode position is more effective in achieving restoration of sinus rhythm in lower energy shock levels compared to the anterolateral position.