Electrocardiogram (ECG) is used in order to discover

the heart disease early. Especially, R-R interval gives

an useful information for the heart condition. The purpose

of this study is the detection of an accurate R

wave position zn order to extract the R-R interval of

the ECG. Recently, a method for detecting the position

of an R wave was proposed using moving averaged

magnitude difference(MAMD). Since there is individual

difference in the ECG waveform, however, improvement

of the approach is necessary. We proposed the

R/S wave enhancement filter(RSEF) in preprocessing

and an R wave detection algorithm which adaptively

decides search region. The algorithm searches for only

the short time duration estimated from the most recent

R-wave position in order to detect the next R-wave eficiently.

We call this duration a Window. In this paper,

the comparison between the MAMD and the RSEF is

also znvestigated.