Determination of stress obtained from sensor-based wearable measurements using VGG16 deep learning model

Abstract

<p>There are many researches carried out for different purposes on human-computer interactions. One of them is related to stress-related activity detection. Today, in people with disorders whose activity is not understood or misunderstood, the correct detection of the relevant movement can be vital in some cases. It may be more advantageous to use physiological signals in the body in determining the type of activity. Due to these important situations, two different research applications were carried out within the scope of this study in order to automatically detect four different types of stress, namely Neutral, Emotional, Mental, and Physical. For both applications, the data was first converted to images as a preprocessing. In the first stage of the research, the images of the standard dataset were presented to the VGG16 deep learning model. As a result, the highest accuracy rate was obtained as 67% for class 1 Neutral activation. In the second part of the study, an application was performed using the Isolation Forest Algorithm on the existing image data to remove outliers. The new dataset obtained were presented to the same model and detailed analyses were made. Accordingly, the maximum accuracy value was 97% in Physical activity. In the same application, the average rate for all activities was 82.5%. Briefly, the research contributes to the literature by demonstrating the significant impact of outliers on system performance through image transformations of existing time series physiological signals.</p>