Infrared Systems Focus on CoronaVirus


Researchers on the coronavirus front line have used infrared-based systems to detect viruses with success. Current virus diagnosis times with blood samples are reported to take less than an hour.

Systems are based on Attenuated Total Refraction Fourier Transform Infrared, also known as ATR-FTI. Although a technically complex name, infrared systems work in a fairly straight forward way. Light of different wavelengths are applied to an object and the light energy transmitted through the object for each wavelength is measured. This is called the spectral response.



A simplified system is shown above. It includes an infrared light source, a heat sensor and several low-noise Junction Field Effect Transistors (JFETS). Heat is converted to an electrical signal by the heat sensor which a JFET amplifies. The next JFET in the signal chain is used to modulate the LED current. The LED in response produces a light signal whose intensity is proportional to the modulated JFET current. The light, in this case, is focused on a virus or associated viral protein. A light sensor samples the light wave that penetrates the viral protein and produces a current that the third JFET amplifies

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