Fig. 1 An infrared (IR) camera is a potential tool for detecting fever and
widely used for mass screening. However, environmental factors, such as
air conditioning, may alter the monitoring of facial skin temperature by
infrared camera.
Non-contact Measurement of Respiratory and Heart
Rates Using a CMOS Camera-equipped Infrared
Camera for Prompt Infection Screening at Airport
Quarantine Stations
Yosuke Nakayama, Guanghao Sun, Student Member, IEEE, Shigeto Abe, Takemi Matsui
Graduate School of System Design
Tokyo Metropolitan University
Tokyo, Japan
Nakayama-yosuke@ed.tmu.ac.jp
Abstract—Severe acute respiratory syndrome (SARS) was
first reported in 2003 and quickly spread around the world.
Therefore, many international airport quarantine stations
launched fever-based screening to detect infected passengers
using infrared (IR) cameras for preventing global pandemics.
However, a screening method based on fever alone can be
insufficient for detecting infected individuals because many
factors, such as antipyretics uptake, can affect it. Our previous
studies using compact radar revealed that simultaneous
measurement of facial skin temperature and respiratory and
heart rates drastically improved the sensitivity of infection
screening compared to that achieved by facial skin temperature
measurement alone. Using a CMOS camera-equipped IR camera
(CMOS-IR camera), which most Japanese International Airports
have adopted, we developed an enhanced thermal/RGB image
processing method for non-contact measurement of facial skin
temperature, and respiratory and heart rates. We conducted the
image processing on the thermal/RGB image-fusion mode in real
time; we determined the respiratory rate by thermal images of
the IR camera and the heart rate by the RGB images of the
CMOS camera. Using a CMOS-IR camera, we measured
respiratory and heart rates of ten healthy subjects (23 ± 1 years),
and compared them with those determined by a contact-type
respiratory effort belt and electrocardiograms (ECGs) as
references. The respiratory and heart rates obtained from the
CMOS-IR camera exhibited strong positive correlations with
those derived from the references, a respiratory effort belt: r =
0.99, p < 0.01; ECG: r = 0.96, p < 0.01, whereas the axillary
temperature indicated a moderate degree of correlation to
facial skin temperature (r = 0.6). Adopting this method into
conventional CMOS-IR camera image processing at international
airport quarantines will achieve higher infection screening
sensitivity.
Key words— Thermal image processing; non-contact; infection
screening; vital signs
I. INTRODUCTION
After the outbreak of SARS, many international airports
reinforced quarantine screening of infected individuals by
using thermography (Fig. 1). This non-contact method was
assumed to be essential in preventing and controlling the
transmission of infectious diseases at mass gathering places to
triage large numbers of people. However, confounding factors,
such as the ambient air or impairment by alcohol or antipyretic,
can easily influence monitoring of facial skin temperature with
thermography [1–6]. A recent study showed that the sensitivity
of fever-based screening with thermography was lower than
70.4% at Narita International Airport in Japan [7]. Considering
that the screening method has been unchanged for over a
decade and that there is a strong need for more accurate
quarantine screening, we propose a non-contact system that can
monitor infection-induced alternations of respiratory and heart
rates, as well as the facial skin temperature monitored in our
previous study [8–10]. Adding these two parameters enables
this system to achieve a higher accuracy than that with
thermography alone [11, 12].
Research supported by Tokyo Metropolitan Government Asian Human
Resources Fund and the Japan Society for the Promotion of Science Research
Fellowships for Young Scientists (13J05344).
Yosuke Nakayama, Guanghao Sun, Takemi Matsui are with the Graduate
School of System Design, Tokyo Metropolitan University, 6-6, Asahigaoka,
Hino, Tokyo, Japan (phone/fax: +81-42-585-8669)
Shigeto Abe is with the Takasaka Clinic, 172-21, Kanesaka, Uchigomiya,
Iwaki, Fukushima, Japan.
© IEEE 2015. This article is free to access and download, along with rights for full text and data mining, re-use and analysis.