Measuring acute stress response through physiological signals: towards a quantitative assessment of stress

Abstract

Social and medical problems associated with stress are increasing globally and seriously affect mental health and well-being. However, an effective stress-level monitoring method is still not available. This paper presents a quantitative method for monitoring acute stress levels in healthy young people using biomarkers from physiological signals that can be unobtrusively monitored. Two states were induced to 40 volunteers, a basal state generated with a relaxation task and an acute stress state generated by applying a standard stress test that includes five different tasks. Standard psychological questionnaires and biochemical markers were utilized as ground truth of stress levels. A multivariable approach to comprehensively measure the physiological stress response is proposed using stress biomarkers derived from skin temperature, heart rate, and pulse wave signals. Acute physiological stress levels (total-range 0-100 au) were continuously estimated every 1 min showing medians of 29.06 au in the relaxation tasks, while rising from 34.58 to 47.55 au in the stress tasks. Moreover, using the proposed method, five statistically different stress levels induced by the performed tasks were also measured. Results obtained show that, in these experimental conditions, stress can be monitored from unobtrusive biomarkers. Thus, a more general stress monitoring method could be derived based on this approach. Graphical abstract Stress measurements of different healthy young people throughout a Stress Session that includes a pre-relax stage (BL), memory test (ST and MT), stress anticipation time (SA), video display (VD) and arithmetic task.

Phase Space Reconstruction from a Biological Time Series: A Photoplethysmographic Signal Case Study

“…With the aim of examining the PPG signal dynamics, we use the PPG signals (to show in this paper only five individuals chosen randomly) from a total of 40 students, between 18 and 30 years old and a non-regular consumers of psychotropic substances, alcohol or tobacco, selected to participate in a national research study 34,35 ; the five PPG signals show in this paper are the same as those used in previous research that confirms its predominantly quasi-periodic behavior for small timescales in healthy young people with the 0-1 test 36 . To show more than five subjects will not clarify the proposed method.…”

Photoplethysmographic Waveform Analysis for Autonomic Reactivity Assessment in Depression

“…The experimental protocol had a duration of about 2 hours (starting time between 09:00 a.m. and 11:00 a.m. to avoid circadian rhythm changes) and it consists of three stages. The first stage consists in a basal condition (B), where the subjects were filling psychometric tests including state-trait anxiety inventory test, scale of stress symptoms, perceived stress scale, and visual analogue stress scale [22]. Then, in the second stage, stress was induced to participants by applying two cognitive tasks widely-used in the neuropsychological field for assessing executive function: first the trail making test (S T ) followed by the stroop color task (S C ), consisting in a non-verbal and verbal stressor, respectively [23], [24].…”

Self-Aware Machine Learning for Multimodal Workload Monitoring during Manual Labor on Edge Wearable Sensors

“…Then, in the prepossessing, each signal is filtered and different biomarkers are extracted. Figure 1 shows the main biomarkers obtained from each time series and are computed as in [9] and [12]. Next, from those biomarkers, several features in time and frequency domain are extracted, as described in our previous work [12].…”

“…Stress and cognitive workload are by nature multimodal and a single biomarker cannot comprehensively evaluate their response [9]. In general, workload triggers alterations in the sympathetic and parasympathetic balance, provoke hormonal responses, behavioral changes and/or decrease cognitive skills [10].…”