ALTERNATIVE METHOD FOR PAIN ASSESSMENT USING EMG AND GSR

Most of the existing pain estimation techniques depend on the response of the subject through verbal or nonverbal communication which does not suit infants, senseless and injured persons, and subjects with cognitive impairment. To bridge this gap, researchers have explored the potential of facial video- and image-based pain recognition methods. However, it provides limited classification performance with complex computation and costly frameworks including a large storage capacity. The dependence of autonomic nervous system (ANS) activities on stimulus like pain provides an alternative pathway to assess pain subjected to external stimuli through ANS-related biosignals. In this article, processing and analysis technique of electromyogram and galvanic skin response signals for assessment of pain for noncooperative subjects are presented and validated against BioVid heat pain database. Different intensities of pain are considered and characterized with the statistical features extracted from the said biosignals. It is noticed that the accuracy level of pain estimation increases with the rise in pain intensity. For highest pain level, 80% detection accuracy is achieved which outperforms the performances of facial expression-based pain assessment techniques.

SEMI-ANALYTICAL SOLUTION OF BIO-HEAT CONDUCTION FOR MULTI-LAYERS SKIN SUBJECTED TO LASER HEATING AND FLUID COOLING

A semi-analytical solution of bio-heat conduction on the three-layer skin is presented. The performance of the typical heat treatment (heating by laser and cooling by fluid at skin surface) is studied. The transient temperature field and thermal damage of skin are investigated. Effects of several parameters on temperature variation and thermal damage are discussed. The results of the paper will be useful for heat therapy in clinics. In addition, the presented result is very consistent to that by the finite element method. The semi-analytical method can be easily applied for solving the general problem of heat conduction in any multilayer structure.

ANALYTICAL SOLUTIONS OF BIO-HEAT CONDUCTION ON SKIN IN FOURIER AND NON-FOURIER MODELS

In general, the transport of thermal energy in living tissue is a complex process. The analysis of the heat conduction of skin tissue is helpful for understanding of the bio-thermo-mechanical behavior of skin tissue. So far, three kinds of conduction law — (1) the Fourier model, (2) the C-V model and (3) dual-phase-lag (DPL) model — are often investigated in bio-thermal transfer process. In this study, the mathematical model of heat conduction of the skin tissue subjected to a general transient heating at the skin surface was established. The analytical solutions of these three conduction models are presented. In addition, the measure of thermal injury of the skin tissue subjected to a harmonic heating was investigated. It was found that the phenomenon of Fourier model is greatly different to those of the C-V and DPL models. Moreover, the effects of the phase lags, the heating frequency, and the heat quantity on the temperature variation and the index of thermal injury were significant. In sum, the analytical method can be used to solve the conduction problem of any one-layer tissue.