  The current COVID-19 pandemic has highlighted the need for cheap reusable
personal protective equipment. The disinfection properties of Ultraviolet (UV)
radiation in the 200-300 nm have been long known and documented. Many solutions
using UV radiation, such as cavity disinfection and whole room decontamination
between uses, are in use in various industries, including healthcare. Here we
propose a portable wearable device which can safely, efficiently and
economically, continuously disinfect inhaled/exhaled air using UV radiation
with possible 99.99% virus elimination. We utilize UV radiation in the 260 nm
range where no ozone is produced, and because of the self-contained UV chamber,
there would be no UV exposure to the user. We have optimized the cavity design
such that an amplification of 10-50 times the irradiated UV power may be
obtained. This is crucial in ensuring enough UV dosage is delivered to the air
flow during breathing. Further, due to the turbulent nature of airflow, a
series of cavities is proposed to ensure efficient actual disinfection. The
Personal Ultraviolet Respiratory Germ Eliminating Machine (PUR$\diamond$GEM)
can be worn by people or attached to devices such as ventilator
exhausts/intakes, or be used free-standing as a portable local air disinfection
unit, offering modularity with multiple avenues of usage. Patent pending.
