Millimeter-wave imaging and near-field spectroscopy for burn wound assessment

Diagnostic applications for skin in the microwave range have developed significantly in recent years, due the non-invasiveness of these applications and their ability to assess tissue water content. Despite their capabilities, however, there is still no appropriate clinically applicable microwave tool for the assessment of burn wounds. A common practice is the visual inspection and evaluation of burns by the doctor, which is a challenging task even for experienced medical professionals. An incorrect assessment can have far-reaching consequences, such as unnecessary surgery or surgery that is necessary but omitted. In this paper, two different approaches of millimeter-wave burn wound assessment are presented: millimeter-wave imaging and near-field spectroscopy. For imaging, a MIMO sparse array was used to assess ex vivo burns on porcine skin in the frequency range of 70–80 GHz. With a resonant millimeter-wave near-field probe, reflective spectroscopy at individual sites of an ex vivo burn on porcine skin in the frequency range of 75–110 GHz was performed. The results showed individual advantages and drawbacks for both approaches, with surprising benefits of the spectroscopic method. Nevertheless, both approaches were shown to be suitable for clinical usage in diagnosing burns.