Abstract
An annotated photoplethysmogram (PPG) is required when evaluating PPG algorithms that have been developed to detect the onset and systolic peaks of PPG waveforms. However, few publicly accessible PPG datasets exist in which the onset and systolic peaks of the waveforms are annotated. Therefore, this study developed a MATLAB toolbox that stitches predetermined annotated PPGs in a random manner to generate a long, annotated PPG signal. With this toolbox, any combination of four annotated PPG templates that represent regular, irregular, fast rhythm, and noisy PPG waveforms can be stitched together to generate a long, annotated PPG. Furthermore, this toolbox can simulate real-life PPG signals by introducing different noise levels and PPG waveforms. The toolbox can implement two stitching methods: one based on the systolic peak and the other on the onset. Additionally, cubic spline interpolation is used to smooth the waveform around the stitching point, and a skewness index is used as a signal quality index to select the final signal output based on the stitching method used. The developed toolbox is free and open-source software, and a graphical user interface is provided. The method of synthesizing by stitching introduced in this paper is a data augmentation strategy that can help researchers significantly increase the size and diversity of annotated PPG signals available for training and testing different feature extraction algorithms.
Highlights
To evaluate the performance of PPGTempStitch when stitching different PPG types together, four types of normalized PPG templates were used for testing: regular PPG, irregular PPG, fast-rhythm PPG, and noisy PPG
Four types of PPG templates were supported in the graphical user interface (GUI)
The PPG signal needed be longer than five seconds, the length of all the PPG templates, and so the stitched PPG was resampled to the required sampling rate when the needed sampling frequency was not 125 Hz
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Photoplethysmography is a technology that optically detects changes in the blood volume of microvascular tissue beds. This technology, which can obtain a wealth of information about the cardiovascular system, has received extensive attention from scientists with different backgrounds, as it is non-invasive and can be continuously monitored. It is used in devices like smartphones and wearable devices for health monitoring and primary health checks [1,2]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
