基於脈搏傳輸時間和希爾伯特-黃轉換的生醫訊號處理及其盤腿現象之應用

Pulse Transit Time and Hilbert-Huang Transform Based Biosignal Analysis and Application on Leg-Crossing

張耕銘(Keng-Ming Chang)

指導教授 ： 張剛鳴

亞洲大學/資訊學院/電腦與通訊學系碩士班/碩士(2009年)

摘要

心電圖在測量的過程中經常容易被許多的雜訊干擾，而這些雜訊往往會影響心電圖的判斷或造成特徵萃取的困難。因此我們在研究中以希爾伯特-黃轉換(HHT)的第一部份，也就是經驗模組分解(EMD)來進行濾波處理。在濾波的過程中，發現EMD的濾波方法會犧牲掉心電圖一部份的低頻成份。因此，我們試著使用總體經驗模組分解(EEMD)的方法來做心電圖的濾波。並以Signal-to-Error Ratio (SER)來做誤差估測，結果EEMD方法的效果的確較優於EMD方法的濾波器也較傳統Butterworth濾波器要好。在完成心電圖的濾波處理後我們將脈搏傳輸時間(PTT)計算出來。從PTT再發展出一些新的PTT衍生參數，將參數應用在盤腿實驗當中。比較心率變異(HRV)參數與PTT衍生參數，發現PTT衍生參數比起HRV參數在盤腿坐姿的改變上有更多的差異性。當坐姿改變時，HRV參數只有RRI有差異(P<0.05)，而PTT衍生參數中PTT、PTT_SDNN、PTT_SD2、PTT_HF…等參數皆有明顯的差異(P<0.05)。這個結果顯示PTT比HRV更適合於姿勢變化的研究。在日後的研究中可以將PTT衍生參數應用到更廣的研究範圍，相信定能獲得令人新奇的發現。

關鍵字

心電圖 ； 希爾伯特-黃轉換 ； 經驗模組分解 ； 總體經驗模組分解 ； 脈搏傳輸時間 ； 心率變異 ； 盤腿坐姿

並列摘要

Electrocardiogram in survey process frequently easily by many noise disturbances, and these noise will often affect the electrocardiogram the diagnosis or let the feature extract have a difficulty. Therefore we using the first part of Hilbert - Huang transform (HHT), the empirical mode decomposition (EMD) to filter the noise. In the process, we discovered that the filter of EMD method will sacrifice a part of the low frequency ingredient. So, we try to use the ensemble empirical mode decomposition (EEMD) to as the filter. And makes the error by Signal-to-Error Ratio (SER) to estimate, finally the effect of EEMD method indeed surpasses the EMD method and also better than traditional Butterworth filter. After completing the electrocardiogram filter processing we calculate pulse transit time (PTT). We try to develop some new PTT derivation parameter from PTT, applying the parameter in the experiment of Leg-Crossing. Compared with the HRV parameter and the PTT derivation parameter, discovered that the PTT derivation parameter to have more differences than the HRV parameter in posture change. When posture change, the HRV parameter only the RRI has difference (P<0.05), But in PTT derivation parameter PTT, PTT_SDNN, PTT_SD2, PTT_HF all have the obvious difference (P<0.05). This result showed that PTT more suitable to HRV in the posture change research. In future may apply the PTT derivation parameter to the broader range of study, we believed that can obtain more interesting discoveries surely.

並列關鍵字

Electrocardiogram(ECG) ； Hilbert-Huang transform(HHT) ； Empirical mode decomposition(EMD) ； Ensemble empirical mode decomposition(EEMD) ； pulse transit time(PTT) ； HRV ； Leg-Crossing

參考文獻

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