1 Introduction
2 Independent component analysis
3 Experiment
3.1 Experimental system
3.2 Procedure and condition
4 Indices for analysis
4.1 Statistical evaluation
4.2 Extraction of facial thermal images (FTIs)
4.3 Extraction of independent components
4.4 Correlation analysis
FTIs | Observed signal | Independent component | Weighting variation |
---|---|---|---|
Rest in day m | \(\mathbf{X}_{\mathrm{Rest}{} { m}}\) | \(\mathbf{S}_{\mathrm{Rest}{} { m}}\) | \(\mathbf{A}_{\mathrm{Rest}{} { m}}\) |
Task in day m | \(\mathbf{X}_{\mathrm{Task}{} { m}}\) | \(\mathbf{S}_{\mathrm{Task}{} { m}}\) | \(\mathbf{A}_{\mathrm{Task}{} { m}}\) |
Rest for 3 days | \(\mathbf{X}_{\mathrm{{Rest1-3}}}=\left[ \mathbf{X}_{\mathrm{{Rest1}}}, \mathbf{X}_{\mathrm{{Rest2}}}, \mathbf{X}_{\mathrm{{Rest3}}}\right] \) | \(\mathbf{S}_{\mathrm{{Rest1-3}}}\) | \(\mathbf{A}_{\mathrm{{Rest1-3}}}\) |
Task for 3 days | \(\mathbf{X}_{\mathrm{{Task1-3}}}=\left[ \mathbf{X}_{\mathrm{{Task1}}}, \mathbf{X}_{\mathrm{{Task2}}}, \mathbf{X}_{\mathrm{{Task3}}}\right] \) | \(\mathbf{S}_{\mathrm{{Task1-3}}}\) | \(\mathbf{A}_{\mathrm{{task1-3}}}\) |
4.5 Multiple regression analysis
5 Results and discussion
5.1 Independent component analysis to FTIs
Number of \(\mathbf{S}_{\mathrm{{ALL}}}\) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
\(s_{1}\) | \(s_{2}\) | \(s_{3}\) | \(s_{4}\) | \(s_{5}\) | \(s_{6}\) | \(s_{7}\) | \(s_{8}\) | \(s_{9}\) | \(s_{10}\) | \(s_{11}\) | \(s_{12}\) | \(s_{13}\) | |
Rest | |||||||||||||
\(\mathbf{S}_{\mathrm{{Rest1}}}\) | – | – | – | – | – | – | \(\bigcirc \) | – | \(\bigcirc \) | – | – | – | – |
\(\mathbf{S}_{\mathrm{{Rest2}}}\) | – | – | – | – | – | – | \(\bigcirc \) | \(\bigcirc \) | – | \(\bigcirc \) | \(\bigcirc \) | – | – |
\(\mathbf{S}_{\mathrm{{Rest3}}}\) | \(\bigcirc \) | – | – | \(\bigcirc \) | – | – | \(\bigcirc \) | – | – | – | \(\bigcirc \) | – | – |
\(\mathbf{S}_{\mathrm{{Rest1-3}}}\) | – | – | – | \(\bigcirc \) | \(\bigcirc \) | – | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | – | \(\bigcirc \) |
Task | |||||||||||||
\(\mathbf{S}_{\mathrm{{Task1}}}\) | – | – | – | – | – | \(\bigcirc \) | \(\bigcirc \) | – | – | – | – | – | – |
\(\mathbf{S}_{\mathrm{{Task2}}}\) | – | \(\bigcirc \) | – | – | – | \(\bigcirc \) | – | – | \(\bigcirc \) | – | \(\bigcirc \) | – | – |
\(\mathbf{S}_{\mathrm{{Task3}}}\) | – | – | – | \(\bigcirc \) | \(\bigcirc \) | – | – | – | –- | – | \(\bigcirc \) | – | – |
\(\mathbf{S}_{\mathrm{{Task1-3}}}\) | – | – | – | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | \(\bigcirc \) | – |
Cnst | Standard partial regression coefficients corresponding to \(\beta _{k}\) to \(\mathbf {A}_{\mathrm{{ALL}}}\) | \(R^{2}\) | RMSE / mmHg | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
\(\beta _{1}\) | \(\beta _{2}\) | \(\beta _{3}\) | \(\beta _{4}\) | \(\beta _{5}\) | \(\beta _{6}\) | \(\beta _{7}\) | \(\beta _{8}\) | \(\beta _{9}\) | \(\beta _{10}\) | \(\beta _{11}\) | \(\beta _{12}\) | \(\beta _{13}\) | |||
98.2 | – | – | – | 2.33 | – | – | − 2.16 | – | – | – | 3.30 | – | − 3.49 | 0.253 | 9.90 |