“…Microwave and Doppler radars measure HR and respiration rate by sensing movement of the chest during inspiration and expiration (Droitcour et al, 2001 ; Lohman et al, 2002 ; Uenoyama et al, 2006 ; Fletcher and Han, 2009 ; Li et al, 2009 ; Suzuki et al, 2009 ; Gu et al, 2010 ; Kao et al, 2013 ; Lim et al, 2015 ). Thermal imaging uses temperature variations in the wrist, face (nasal), and neck (carotid artery and jugular vein) caused by blood flow moving from the heart to the brain to monitor HR (Chekmenev et al, 2005 , 2009 ; Sun et al, 2006 ; Garbey et al, 2007 ; Gault et al, 2010 ) and respiration rate (Chekmenev et al, 2005 ; Murthy and Pavlidis, 2005 ; Murthy et al, 2009 ; Fei and Pavlidis, 2010 ; Abbas et al, 2011 ). Web-cams detect color variations in the face, and micro-movements in the head and chest caused by blood flow and expiration-inspiration, and extract information related to cardiac activity and respiration from these factors (Poh et al, 2011 ; Balakrishnan et al, 2013 ; Holton et al, 2013 ; Janssen et al, 2015 ).…”