經驗模態分解法 ( Empirical Mode Decomposition, EMD )，近幾年來被廣泛的應用在訊號解析上面。這是由於我們可以藉由訊號內部變化的時間尺度來將該訊號的能量和頻率直接析出，並且將該訊號分解成數個本質模態函數 ( Intrinsic Mode Function, IMF )。每個本質模態函數皆含有該訊號中各不同尺度的特性，用以表達訊號中的物理特性。 心電訊號 ( Electrocardiogram, ECG ) 是用來判讀心臟是否有相關的心臟疾病的一個重要方法之ㄧ。但是在量測心電訊號時，會因為受測者的呼吸或者是身體的移動，造成量測到的心電訊號產生基線游移 ( Baseline wander ) 現象。而量測環境周遭所使用的儀器設備，也會產生電源線 60 Hz 的電源干擾 ( Power-line interference )，使量測到的心電訊號含有 60 Hz 雜訊。以上這些影響皆會使得心電訊號失真，降低醫師判讀訊號的精確性。 因此，本研究將使用德州儀器公司所生產的數位訊號處理器：TMS320 C6713 DSK 實現經驗模態分解法。製作出一套獨立且無須電腦的心電訊號去基線游移與電源雜訊處理系統。 The empirical mode decomposition (EMD), Recently, has been used extensively to the analysis of the signal. EMD, which use yardstick change of time within signals to resolve signals into the combination of several intrinsic mode functions (IMFs). IMFs contain different characteristics of signals and can express the physical characteristics in signals. The Electrocardiogram (ECG) is one of the import methods for diagnosis of heart diseases. But the ECG recordings are often corrupted by baseline wander and power line interference. Baseline wander is mainly caused by subjects breathing and movement. The power line interference also corrupt the ECG signals, which come from power lines to the measurement equipments. These interferences may cause the ECG distortion and lead to wrong diagnosis. This study proposed DSP implementation of the EMD algorithm and develop a complete system for signal processing without computer.
