AI Temperature Detection Solution
Coronavirus disease (covid-19) is a global pandemic, and every country is actively fighting against the virus. It is an effective way to prevent the spread of the virus in finding the person with abnormal temperature promptly in order to perform further medical observation.
However, the traditional method of temperature measurement has low efficiency and accuracy. Additionally, a major challenge is how to efficiently detect high body temperatures without close physical contact. As an AI technology to provide new solutions.
For the past few months securing resources from COVID-19 has become a tough row to hoe for the ecosystem. With the sky-high technological demands to detect symptomatic individuals, elevated body temperature measurement is a key topic in the current pandemic situation. Thermal Camera- is one such solution which is widely being used to measure fever-like symptoms. Many OEMs have launched their solutions however evidence suggests that the ACCURACY of the cameras in temperature measurement is still an area of grave concern. To provide our society with a more reliable Thermal Camera Solution, OEMs need an AI-enabled camera design with a strong design architecture refined with accurate calibration. Let’s understand how these technologies work in the concept of Thermal Camera.
Thermal Camera Principle
Unlike CMOS/CCD cameras, thermal cameras have a microbolometer that is operated in infrared regions to capture the IR intensity of each of its pixels. The key to thermal imaging is that a hot surface emits more IR than the cold surface. A special optics focus all the heat radiations of a scene to its sensor array. All the pixel values can be then converted to respective temperature values, and the same can be represented as respective color codes (e.g, cold surfaces can be represented with blue color and hot surfaces with red color).
Calibration for High Accuracy
During this pandemic situation, the deployment of thermal cameras at various places for the measurement of body temperature demands high accuracy that can be maintained with the periodic calibration of the cameras. Having the shortest normal body temperature range (36.5C to 37.5C) with respect to the human body temperature range (35C to 40C) indicates the need for accurate measurement which can be fulfilled up to a certain level with the help of calibration. However, if we go without calibration that will lead to uncertain results with floating accuracy and thermal imaging cameras can provide low accuracy temperature values & relative temperature changes on the surface.
A calibrator device sits in the thermal camera FoV with a constant temperature as a reference to the estimate of all other pixel temperature.
Accuracy up to 0.3C can be achieved by using an external calibrator.
Flat plate IR & Black body calibrators are commonly available calibration devices.
Other Parameters that Impact Thermal Camera Accuracy are:
Emissivity – It is the measure of object ability to emits IR energy
Atmospheric temperature – Cold, Wind, Heat, etc, all play an important role
Reflected Temperature – Thermal radiations come from other sources/objects that reflect the target we are measuring
How AI, Deep Learning and Thermal Camera work together?
The onset of the pandemic has accelerated AI-infused technologies to mitigate the spread of the virus. Thermal cameras have to be repurposed to enable them to accurately identify elevated body temperature. AI and Deep Learning technologies are our best bet. Thermal Cameras, when enabled with AI, helps its accuracy by
Boosting hardware claimed accuracy with AI analytics
AI-Based precise targeting of the region of interest which is the forehead of the person
The combination of running AI on a CMOS camera with a thermal imaging camera enables the automated temperature screening by detecting a person’s forehead. This helps in avoiding many false triggering events in normal thermal cameras, e.g A person holding a hot cup of coffee will trigger false measurement without AI. Image processing, analyzing techniques, and AI & Deep Learning algorithms are often used to negate false triggering.
Automatic measurement without close physical contact High temperature screening capability, 3-4 people/second
Accuracy levels of ±0.3℃ (0.5℉) >95% mask-wearing detection accuracy Accurately detect body temperature with a distance greater than 9 feet
High temperature alert Automatic access or denial of access
< 1 hour rapid deployment Easy installation based on product manual and simple online video guide