Measuring Emotional Arousal for Online Applications: Evaluation of Ultra-short Term Heart Rate Variability Measures

Abstract

The objective of this paper is to examine the possibilities and limitations of heart rate variability (HRV) as an indicator of emotional arousal for mobile applications which require online biofeedback. In contrast to offline classification, feature extraction for online applications sets other requirements to the window size in which data is analyzed as the delay between a change of a person's arousal level and the reaction of an application should be as short as possible. For this purpose we compare various HRV features in order to evaluate how far window size can be decreased to enable online arousal recognition. Using data from a study where high and low arousal were induced in a game scenario, HRV features are analyzed for their discriminatory power depending on the window size using Fisher's discriminant analysis. Moreover, we use these features to train an SVM based classifier. Results indicate that for some features it is possible to use ultra-short term window sizes, i.e. window sizes shorter than the 5 minute window which has traditionally been used for short term HRV analysis.

Estimation of Mental Distress from Photoplethysmography

“…Just as in our approach, the authors state that it can be efficiently implemented on mobile devices, since the proposed method only uses time-domain features. In the same line, the arousal level has been assessed on patients, reporting that temporal parameters RMSSD, PNN12 and PNN20 showed statistical significance on ultra-short temporal series of 15 s length [48]. No global precision was reported in this study.…”

Student’s Attention Improvement Supported by Physiological Measurements Analysis

“…Because of that, biosignals, such as electrocardiogram (ECG), electromyogram (EMG), electroencephalogram (EEG), galvanic skin response (GSR), blood volume pressure (BVP), heart rate (HR) or heart rate variability (HRV), temperature (T), respiration rate (RR), become the most important vital signals of the human body for an emotional assessment. Although the majority of the studies use different biosignals in conjunction with ECG in order to detect the emotional states [16,17,18], there are studies focused only in relating ECG with the expression of human emotions [19,3].…”

“…Both systems interact antagonistically causing the variations in interbeat intervals of consecutive heart beats [22]. Parasympathetic nervous system is more active in calm periods decreasing heart rate (HR) [17,23]. However sympathetic activity is predominant when arousal increases conducting to the acceleration of HR [17,23].…”

“…Parasympathetic nervous system is more active in calm periods decreasing heart rate (HR) [17,23]. However sympathetic activity is predominant when arousal increases conducting to the acceleration of HR [17,23].…”

Emopad: An Affective Gamepad

“…Schaaf and Adam [19] have used an HRV sensor as indicator of emotional arousal for mobile games. For some features, it is possible to use ultra-short term window sizes (shorter than 5 minutes) for short term HRV analysis.…”