Extracting features similar to QT interval from second derivatives of photoplethysmography: A feasibility study

Electrocardiography (ECG) is the most reliable tool to measure the heart electrical activity. It is noted that the setting and measurement procedure of ECG are always complex and time consuming. This complexity has motivated us to extract the important ECG features using photoplethysmography (PPG). The aim of this paper is to study the feasibility of extracting feature similar to ECG QT interval using second derivatives PPG (SDPPG). A pilot study has been conducted using simultaneous data acquisition system to acquire PPG and ECG signals. Five healthy subjects have been participated in this study. A signal processing algorithm has been developed to extract the feature that is similar to ECG QT interval. In this work, the feature refers to AB index, which is the interval of the SDPPG that has been illustrated in Figure 6. The paired T-test shows that there is no significant difference between QT interval using ECG and AB index extracted from second derivatives PPG (p<;0.05).