Microwave Imaging for Lung Covid-19 Infection Detection through Huygens Principle

This paper aims to show the capability of the Huygens Principle-based microwave imaging for use in Lung COVID-19 infection detection. Frequency-domain measurements have been performed in an anechoic chamber using two Microstrip antennas operating at frequency range of 1 to 5 GHz, in a multi-bistatic fashion, employing dedicated phantoms that mimic the dimensions and the dielectric properties of a human torso, containing a target mimicking an infection. A Multi-layered elliptically-shaped torso-mimicking phantom having the circumference of 82 cm has been constructed; the external layer mimics the dielectric properties of a combination of muscle, fat and rib bone tissues, the inner layer mimics the dielectric properties of lung (inflated). A cylindrically-shaped tube of water has been positioned inside the inner layer to dielectrically mimic the infection. The S21 signals have been used for image reconstruction (after removing artefacts), obtaining detection with a signal to clutter ratio of 7 dB. Our results confirm that Huygens based technique can be successfully used for lung infection detection even if antennas and phantom are in free space, i.e., no coupling liquid is required.