Non-contact registration of respiration by analysis of IR-THz human face images

Abstract

We propose a new approach to non-contact recording of respiratory function based on the analysis of a sequence of Infrared-terahertz images of the human face, allowing the processes that occur during breathing to be visualized. To obtain quantitative estimates of the respiratory function, two methods are proposed. The first one utilizes a probe which implements the function of spatial differentiation and provides high sensitivity, but requires an increased accuracy of positioning the probe at the nasal opening and scaling in accordance with the camera angle. The other one is a histogram method for obtaining quantitative estimates of the external respiratory function, which is scale invariant and does not require precise positioning, but has a lower sensitivity compared to the first one. The methods proposed have made it possible to remotely evaluate the respiratory rate, which correlates well with the data obtained by a contact method of respiratory function registration.

Keywords

• infrared imaging
• terahertz imaging
• image analysis
• instrumental non-contact diagnostics
• breathing function