Infrared thermal imaging as a physiological access pathway: a study of the baseline characteristics of facial skin temperatures

Abstract

In this study we examine the baseline characteristics of facial skin temperature, as measured by dynamic infrared thermal imaging, to gauge its potential as a physiological access pathway for non-verbal individuals with severe motor impairments. Frontal facial recordings were obtained from 12 asymptomatic adults in a resting state with a high-end infrared thermal imaging system. From the infrared thermal recordings, mean skin temperature time series were generated for regions of interest encompassing the nasal, periorbital and supraorbital areas. A 90% bandwidth for all regions of interest was found to be in the 1 Hz range. Over 70% of the time series were identified as nonstationary (p<0.05), with the nonstationary mean as the greatest contributing source. Correlation coefficients between regions were significant (p<0.05) and ranged from values of 0.30 (between periorbital and supraorbital regions) to 0.75 (between contralateral supraorbital regions). Using information measures, we concluded that the greatest degree of information existed in the nasal and periorbital regions. Mutual information existed across all regions but was especially prominent between the nasal and periorbital regions. Results from this study provide insight into appropriate analysis methods and potential discriminating features for the application of facial skin temperature as a physiological access pathway.

Thermal Imaging of the Periorbital Regions during the Presentation of an Auditory Startle Stimulus

“…This corroborates previous work that characterized the skin temperature of the periorbital regions (among others on the face) as being largely non-stationary in nature [14].…”

“…The objective of the present study was to further investigate the feasibility of access technology based on infrared thermal imaging by determining if there is a detectable change in the temperature of the inner canthi of the periorbital regions of the face (previously identified as among the most useful regions of the face for thermography-based access [14]) in response to the presentation of an unexpected auditory stimulus. If such a change does exist, any thermography-based access technology would have to include measures to distinguish these startle-induced changes from changes attributable to the user's intent.…”

The effect of treadmill walking on the stride interval dynamics of children

“…The RAT is often used to evaluate the weak stationarity of physiological and biomedical signals (Alves and Chau, 2008;Chau et al, 2005;Nhan and Chau, 2009;Harris et al, 1993;Hampson et al, 2005;Bilodeau et al, 1997;Novak et al, 1996).…”

Non-intrusive car driver's emotion recognition using thermal camera

“…RELATED WORK Study of facial skin temperature measurement techniques and baseline characteristics of facial skin temperature has led to better understanding of the facial skin regions [31][32][33]. Several attempts were made to implement FER [28], [29], [24].…”