著者

Hiroki Ito Shizuka Bando Kosuke Oiwa Akio Nozawa

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.138, no.7, pp.812-821, 2018-07-01 (Released:2018-07-01)

参考文献数

39

被引用文献数

1

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An imbalance of the circadian rhythm due to an irregular lifestyle leads to autonomic dystonia. The long-hour variations of the physiological indices such as core temperature and heart rate variability, associated with the autonomic nervous activity, have been focused. Additionally, the relationships between these physiological indices and facial skin temperature have been reported. The objective of this study is to identify the day-long variable components of facial thermal images (FTIs) to evaluate the corresponding variations of autonomic nervous activity by non-contact measurement. In this study, the measured FTIs were subjected to independent component analysis (ICA). Additionally, multiple regression analysis was performed to estimate the relationships between independent components, extracted from FTIs, and other psychophysiological indices, associated with autonomic nervous activity. As a result, the facial day-long variable components, representing the reproducible rhythm through multiple days, were identified by applying ICA to several different combinations of FTIs. Moreover, these components were associated with the axillary temperature. Therefore, the long-period variations, associated with autonomic nervous activity, could be evaluated from the facial skin temperature.

著者

Kosuke Oiwa Shizuka Bando Akio Nozawa

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.138, no.7, pp.783-789, 2018-07-01 (Released:2018-07-01)

参考文献数

36

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Hypertension is one of the leading risk factors for cerebrovascular, cardiovascular, and chronic kidney diseases. Regular measurement and monitoring of blood pressure is important to decrease or prevent pathogenesis of diseases. Contactless measurement of blood pressure using a smartphone application, can enable regular monitoring. The objective of this study is to construct a system which can monitor blood pressure anytime and anywhere. In this study, contactless blood pressure assessment was attempted, using facial visible image analysis and created individual models for blood pressure estimation. Variation in brightness of the skin color was obtained from facial visible images and applied to independent component analysis, which is one of the blind source separation methods to extract the facial photoplethysmogram (PPG) component using a proposed system. Amplitude and phase of facial PPG component were used as indices for blood pressure. A correlation analysis between facial PPG component and blood pressure was performed and created individual models for blood pressure estimation.

著者

Rikito Okamoto Shizuka Bando Akio Nozawa

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.136, no.8, pp.1142-1148, 2016-08-01 (Released:2016-08-01)

参考文献数

40

被引用文献数

2

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There have been a number of investigations into image recognition and the assessment of human physiological states using infrared thermography. Assessing a human's physiological state by infrared thermography typically exploits the skin temperature of the nasal region and forehead, whereas other parts of the face are less frequently used. The present study has developed a method of analyzing facial thermal images (FTIs) by independent component analysis (ICA), a type of blind signal processing (BSP). ICA is a well-known statistical analysis tool that estimates the original source signal from observed mixture signals. When applied to thermal images, ICA is predicted to extract blind signals such as those from other parts of the face. In this study, the authors use ICA to conduct BSP on a series of FTIs. The extracted independent components are shown to represent temperature fluctuations from the opening and closing of the eyes, respiration, truncal sites such as the cheeks and forehead, and possibility of sympathetic nervous system activity. The FTIs reconstructed after the removal of artifacts indicate the local features that the blind signal cannot extract from the original FTIs.