利用PPG分析自然心律變異

Analysis natural heart rate variability using photoplethysmography

張肇峰(Chao-Feng Chang)

指導教授 ： 胡威志

中原大學/工學院/生物醫學工程學系/碩士(2008年)

https://doi.org/10.6840/cycu200900347

摘要

心率變異度的高低可以反應一個人的自律神經是否失調，可以反應心臟功能的健康，其低變異度代表著高心臟病危險性。本研究利用光體積變化描記法量測生理訊號，發展出可長期監控使用者之心率變異之心率監控系統，本研究之特徵在於耳戴式之PPG量測裝置及其訊號分析系統，加上同時播放音樂能消除使用者情緒的影響而取得自然心率及心率變異。
本系統的核心使用簡單可解調MP3資料之系統單晶片，能同時處理音訊播放和生理訊號之擷取與分析。生理資訊可以在系統裝置中儲存和即時顯示，也可以透過USB通訊傳輸介面把生理資訊傳至電腦，所得之時序脈搏資料及分析後之心率變異資料可經由Borland C++ Builder編輯視窗化軟體使用者介面程式，顯示系統平台的分析結果及儲存。
在實驗分析的辯證流程中，本研究分為無聽音樂ECG、無聽音樂PPG、有聽音樂ECG和有聽音樂PPG這四種類型，利用T-TEST分析四種類型的HRV參數，可以證明音樂和不同的量測方式對使用者是有影響的。把每種類型的時頻域頻譜做成圖像以影像處理之方法利用自相關分析，做交叉比對，分析統計量測心電圖與量測PPG方式之差異，辯證於耳機內裝設PPG量測系統，在受測者聆聽音樂時不自覺之狀況下使用PPG量測方式，可取得長期的自然心率變異資訊。

關鍵字

心電圖 ； 光體積變化描記圖 ； 心率變異度

並列摘要

This innovation is related to measuring the heart rate under unawareness of subject to extract the true nature heart rate variability. The Heart Rate Variability (HRV) is an important index that could be used for long term monitor of cardiac function. The low variability of heart rate indicates that the cardiac rhythm could not be regulated by autonomic nerve system. It is not a healthy condition for regular daily activities. This innovation has devised a portable photo-plethysmo-graphy (PPG) through an ear plug appliance.
The PPG signal was acquired and analyzed using a simple microcontroller with a MP3 data decoder. In this way, the user of MP3 player could has option of monitoring and recording his or her heart rate and heart rate variability regularly and unaware. The prototype system was also including functions of data display with color LCD, data storage with CF card, data communication with USB. An off-line PC window program was also provided for reviewing the recorded PPG and analyzed HRV.
The system was used to assess the psychophysic effect of heart beat monitoring over four circumstances. That were the situation of monitoring the ECG without listening to music, assessing the PPG without listening to music, listening to music with monitoring the ECG, and listening to music with the assessment of PPG. Four types of HRV parameters were analysed among named four circumstances using Student’s T-TEST. It were to examine the impact of heart beat monitoring methods on users. While examining the HRV frequency spectrum against each testing situation, the parasympathetic tone was found activated much earlier using PPG to assessing heart beat than the using ECG. This result demonstrated that the subjects’s heat rate and their natural heart rate variability could be monitored unconsciously using PPG while listening to music.

並列關鍵字

heart rate variability ； electrocardiogram ； photo-plethysmo-graphy

參考文獻

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