Using electroencephalogram to continuously discriminate feelings of personal thermal comfort between uncomfortably hot and comfortable environments

Abstract

Thermal comfort is an important factor for the design of buildings. Although it has been well recognized that many physiological parameters are linked to the state of thermal comfort or discomfort of humans, how to use physiological signal to judge the state of thermal comfort has not been well studied. In this paper, the feasibility of continuously determining feelings of personal thermal comfort was discussed by using electroencephalogram (EEG) signals in private space. In the study, 22 subjects were exposed to thermally comfortable and uncomfortably hot environments, and their EEG signals were recorded. Spectral power features of the EEG signals were extracted, and an ensemble learning method using linear discriminant analysis or support vector machine as a sub-classifier was used to build the discriminant model. The results show that an average discriminate accuracy of 87.9% can be obtained within a detection window of 60 seconds. This study indicates that it is feasible to distinguish whether a person feels comfortable or too hot in their private space by multi-channel EEG signals without interruption and suggests possibility for further applications in neuroergonomics. K E Y W O R D S EEG-based individual thermal comfort model, electroencephalogram, linear discriminant analysis, power spectral density, support vector machine, thermal comfort How to cite this article: Wu M, Li H, Qi H. Using electroencephalogram to continuously discriminate feelings of personal thermal comfort between uncomfortably hot and comfortable environments. Indoor Air. 2020;30:534-543.

Assessment of Personal Relaxation in Indoor-Air Environments: Study in Real Full-Scale Laboratory Houses

“…Temperature changes also affect concentration, work performance, comfort, and relaxation, and thermal effects can increase or decrease the theta power of brainwaves [17,37]. In both cases, a decrease in low-frequency energy and increase in high-frequency energy indicates a sense of comfort and relaxation [38]. These findings were replicated in the present study.…”

Investigating the relation between electroencephalogram, thermal comfort, and cognitive performance in neutral to hot indoor environment

“…Wu et al used an eight‐channel wireless EEG recorder to record EEG signals and tried to continuously discriminate feelings of personal thermal comfort between uncomfortably hot and comfortable environments. When the temperature of the two rooms was 35℃ and 26℃, and the relative humidity is 30%–60%, the accuracy of discrimination between thermal discomfort and thermal comfort can reach almost 90% 17 . All the above studies have shown that using EEG to quantify the thermal comfort of the occupants is a promising method 18,19 …”

“…When the temperature of the two rooms was 35℃ and 26℃, and the relative humidity is 30%-60%, the accuracy of discrimination between thermal discomfort and thermal comfort can reach almost 90%. 17 All the above studies have shown that using EEG to quantify the thermal comfort of the occupants is a promising method. 18,19 Unlike thermal comfort, there are few physiological parameters that can be used to reflect cognitive performance, and EEG is the more used one.…”

Influencing factors on thermal comfort and biosignals of occupant-a review

“…Accordingly, it was reported that the indoor thermal environment significantly affected the emotions, health, and productivity of tenants. Wu et al [124] investigated the possibility of continuously mediating the thermal comfort of an individual by using EEG signals in the personal space. The spectral power of the EEG signals of 22 subjects was obtained, and a discriminant model was developed using a linear discriminant analysis or an ensemble learning method with a support vector machine as a sub-classification.…”