What is a Thermal Scanner?
A
thermal scanner is a device that detects infrared radiation (heat) emitted by objects and converts it into a temperature reading. These devices are often used for
fever screening in public places such as airports, hospitals, and workplaces to identify individuals with elevated body temperatures, which may indicate an infection.
How Do Thermal Scanners Work?
Thermal scanners use
infrared technology to measure the surface temperature of the skin, typically the forehead. The device captures infrared radiation and converts it into an electrical signal, which is then displayed as a temperature reading. Although they can quickly screen large numbers of people, they do not directly measure core body temperature.
Applications in Epidemiology
In the context of
epidemiology, thermal scanners are used for early detection and
surveillance of infectious diseases that cause fever, such as
COVID-19, influenza, and Ebola. By identifying potentially infected individuals, thermal scanners help in implementing
quarantine and isolation measures, thus preventing the spread of disease.
Advantages of Thermal Scanners
Non-invasive: Thermal scanners do not require direct contact, reducing the risk of cross-infection.
Rapid Screening: They allow for the quick screening of large groups of people, making them ideal for high-traffic areas.
Remote Monitoring: Some thermal scanners can be integrated with software for remote monitoring and data analysis.
Limitations and Challenges
Despite their benefits, thermal scanners have several limitations: False Positives: Elevated skin temperature can result from factors other than infection, such as physical activity or environmental conditions.
False Negatives: Asymptomatic individuals or those in the early stages of infection may not have a fever, leading to undetected cases.
Accuracy Issues: External factors like wind, sunlight, and ambient temperature can affect the accuracy of readings.
Effectiveness During the COVID-19 Pandemic
During the
COVID-19 pandemic, thermal scanners became widely used for preliminary screening. While they helped to identify individuals with fever, their effectiveness in controlling the spread of the virus was limited due to the high number of asymptomatic cases and the reliance on fever as the primary symptom.
Recommendations for Use
For optimal use in epidemiological settings, thermal scanners should be part of a comprehensive screening protocol that includes
questionnaires,
clinical assessment, and confirmatory
diagnostic tests. They should be calibrated regularly and used in controlled environments to enhance accuracy.
