微循環、光容積變化圖與心電圖之相關性研究及生理訊號分析平台實現

Abstract

光容積變化圖是皮膚表層內各組織對不同波長光線進行吸收與反射結果，再結合微血管內之血液與血球的流動，進而產生之波形訊號。因此，光容積變化圖與皮膚表層微循環系統有著密不可分之關聯性。再加上人體各部位之血液循環系統皆源自心臟，傳統式觀測心臟與自主神經系統活性的方式為心電圖，及其分析所得之結果－心率變異性，但傳統心電圖量測方式需使用導電膠電極，並貼附於受測者，此量測方式將帶給使用者相當程度的不適感與不方便。綜合以上所述，本研究為探討心電圖與光容積變化圖之關聯性，建立一高效能之生理訊號分析平台，透過紅外線來進行手指光容積變化圖量測，並分析兩者分析所得之心率變異性，探討其間的異同，藉以得知光容積變化圖取代心電圖做心率變異性分析的可行性。

此外，本研究提出一套新穎的光容積陣列系統，在成本效益與方便性的考量下，透過光容積陣列所得之三維光容積訊號圖，針對皮膚真皮層與皮下組織進行微循環檢測，並藉由不同三維光容積變化圖的振幅，可推知越差的膚質，其振幅標準差越大。

在未來，期望能將光容積陣列系統微小化，並實現光容積陣列面膜，能即時針對使用者的膚質進行診斷，並透過不同能量與波長之光線，進行膚質改善與美容之功效。

Photoplethysmography (PPG) is the combinational results that the surface of skin reflects and absorbs the light with different wavelengths, and it also associated with the pulsatile of blood in the blood capillaries. As the results, the signals of PPG are generated. According to above, there must be some intimate relationship between PPG and the microcirculation system of derma. Otherwise, all of the circulator systems in body are coming from a heart, and the conventional observation method to hearts and autonomic nerves system is heart rate variability (HRV) of electrocardiogram (ECG). The conventional measurement of ECG must use gel electrodes attached to subjects. This will cause the subjects discomfort and inconvenient. Therefore, the relationship between ECG and PPG is discussed and researched in this study. According to the measurement of PPG by infrared LED, the HRV of those two signals will be derived, and then the similarities and dissimilarities are compared. Based on the result of analysis, this study wishes to replace the conventional ECG by PPG. Furthermore, a novel PPG array system is proposed in this study. In consideration of cost efficiency and convenience, the dermis and subcutis could be examined simply by the 3D PPG graph derived from the proposed PPG array system. According to the amplitude of 3D PPG waveforms, the situation of skin could be evaluated that the worse skin processes the larger standard deviation of amplitude. In the future, PPG array system will be improved and a PPG lotion mask will be expected to implement. The novel mask could do skin diagnosis to subjects. Otherwise, based on the novel mask the quality of skin will be promoted with different wavelengths and power of lights.