How Stressed Are You?
Selina Zhou
Collingwood School
Floor Location : S 001 N

The idea of personalized biofeedback devices came into view as more people started paying attention to their long-term physical and mental wellness. The Apple Watch integrated many sensors to monitor fitness along with its health apps, but according to people involved with the project, when they tried to look for a sensor that could monitor stress, they were not able to find any. They tried to put in an electrodermal activity sensor, but, according to the team, the results were inaccurate depending on how tight the watch is put on and the skin condition of the user. Therefore, while heart rate and motion sensors can already provide information on the health conditions of users backed up by extensive studies, the field of personalized mental health monitoring is still very limited for people who cannot afford professional clinical devices at home. In late 2016, a study (HJ, M. et al., 2016, pp. 1) suggested a link between skin volatile organic compound (VOC) emission and psychological stress, strengthening the likelihood of using VOC emission as a real-time mental stress biofeedback device.
This research evaluates the effectiveness of gas sensor skin VOC detection. A wearable VOC detector prototype will be developed and tested with reference to galvanic skin response, heart rate variability, and a self-reported stress level. Other physical states will be recorded, including age, gender, hours of rest during the previous night, and alcohol consumption. Volunteers will be asked to perform two activities, one with relatively low psychological stress, the other with higher psychological stress. They will be asked to first meditate for 3 minutes, then write a short version of the Mensa IQ test. A study in 1998 stimulated the central nervous system of volunteers with caffeine and observed increased sweat secretions in human palm and forehead (Kameia et al, 1998). Since volatile organic compounds emitted from skin mainly come from glands, and there is a concentration of sebaceous glands on the forehead (M. et al, 2016), while volunteers’ hand are occupied in taking the test, the forehead is the most reasonable measurement location. The gas sensor will be attached to volunteers’ forehead as a light headband. After the test, volunteers will be asked to self-report how stressed they felt while meditating and while taking the test, on a scale of 1 to 10. This provides a more subjective feedback of the volunteers on the effectiveness of the stress simulating method. After all the data are collected, values across individuals will be normalized to the mean, and comparison will be made to the standard deviations and variances. Ideally, results of this quantitative analysis will provide insight into the possibility of establishing a safer and more efficient method of monitoring stress for clinical and personal uses. A sample size of 20 is expected. Measured trends in skin VOC emission will be compared to trends in galvanic skin response and heart rate through statistical and graphical analysis.
There is no reliable result yet at the time of writing, but correlations are expected.