Session P81.6

Comparative Study of Approximate Entropy and Sample Entropy Performance Applied to RR Interval Records

D Cuesta-Frau, P Miro-Martinez, S Oltra Crespo, M Aboy,
D Austin, JL Rodríguez-Sotelo*

Universidad Nacional de Colombia
Manizales, Columbia

Approximate Entropy (ApEn), and Sample Entropy (SampEn) are signal regularity measures that have been widely used to discriminate a large variety of physiological signals. This paper describes a comparative study of the performance of both measures applied to RR interval records, under different parameter values and signal features.
The experiments were carried out using the records available at the CAST RR interval sub-study database. There are three groups of records in this database corresponding to three medications given to the subjects: encainide (e), flecainide (f), and moricizine (m). Pretreatment records are also available for each subject. In total, 1543 records were processed, computing their ApEn and SampEn.
An analysis of variance was used to assess any difference in record regularity. We varied parameters r (from 0.1 to 0.9 in 0.1 steps) and m, from 1 to 4. The records were partitioned in classes e, f, and m, including a further division for medication or pretreatment. The results demonstrate that it is possible to distinguish among all the different types of records clearly since p<0.001 in all cases, that is, the four individual factors: m, pretreatment or medication, r, and record class, exhibit statistically significant differences. In addition, the results also demonstrated that SampEn is more robust in general, since exhibited no interaction effect, in contrast to ApEn.

(Abstract Control Number: 173)