In this study, we propose a method for classifying echocardiograms into different tissue types on the basis of brightness. In general, the echo level between different electrocardiograms changes because the doctor or clinical examiner has to make adjustments according to the imaging conditions. It is therefore difficult to obtain the same echo level (i.e., brightness value) for the same tissue across images. In order to reliably identify tissue types, classification algorithms need to be

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... dent of changes in the echo level. We here propose a system in which tissue can be correctly classified, independent of the overall echo level, using self-organizing maps [1]- [3] .