IR THERMOGRAPHY AND IMAGE PHOTOPLETHYSMOGRAPHY : NON-CONTACT MEDICAL COUNTER MEASURES FOR INFECTION SCREENING

Abstract

Screening based on non-contact infrared thermometers (NCITs) and

IRTGs shows promising results for mass fever screening. IRTGs were found to

be powerful, quick and non-invasive methods to detect elevated temperatures. In

the case of temperature measurement using IRTGs, regions medically adjacent to

inner canthi are preferred sites for fever screening (IEC 80601-2-59:2008), which

show good stability and correlation with body temperature. However, detection of

canthi in thermal images is challenging due to the absence of features unlike visible

images, which have sharp features that can be used for eye corner detection. We

use registration of thermal images with visible light images (also called white-light

images) to localize canthi regions in thermal images. We study the accuracy of such

multi-modal image registration in the context of canthi detection and measure the

feasibility of automatic canthi based temperature measurement as an alternative to

manual measurement.

The second part of thesis refers to the study of image photoplethysmography

(IPPG), a cost-effective and flexible method for heart rate monitoring using

videos recorded in ambient light. We use low-cost commercial grade video recording

equipment (mobile camera/Digital camera) with an ambient light source. The

study includes information about signal processing algorithms for estimating heart

rate, relevant parameters, and comparison with standard techniques. Such low-cost,

multi-purpose solutions for quick screening of subjects provides us with sensible and

useful information on elevated body temperature and heart rate. Hence, these methods

show promising results that enable mass fever screening as a possibility through

temperature and heart rate monitoring, where low cost of installation and flexibility

are important.