NoPaS - a novel patient shield for protecting health professionals and patients during aerosolgenerating procedures

ABSTRACT

Background & Aim: 'Aerosol generating procedures' (AGPs) can risk spread COVID-19 and other diseases. Suspension of routine dentistry due to COVID-19 pandemic led to increased use of antibiotics and dental extraction, reduced access to dental care, and compromised dental businesses' financial sustainability. The recommended additional personal protective equipment (PPE) for AGPs increases treatment cost, clinical waste and poses a risk to the environment. The transmission of COVID- 19 and other air-borne infections will be a risk for foreseeable future. We have developed a novel patient shield (NoPaS) to help prevent spread of COVID-19 and other air-borne viruses and bacteria during AGPs. NoPaS is a device with a hood, a suction and air curtains that prevents aerosol spread. Methods: We carried out extensive research to ensure acceptability and efficacy of NoPaS. This included market research, computational simulations. in-vitro smoke visualization and particle image velocimetry (PIV). NoPaS was then tested using dental simulation units (DSUs) with artificial salivary enzyme. Dentists carried out three AGPs (examination using air spray;ultrasonic scaling;class I cavity repair) and a non-AGP (hand-scaling) with and without NoPaS. Dentists were randomized to perform procedures with or without NoPaS first. Aerosol generation and spread were measured by counting clearance zones on starch agar plates at three distances from the dentist's working field. Results: The data obtained from lab-based studies and market research informed the final product design. Over 90% of patients and dental practitioners felt safer when using NoPaS. The mean percentage of clearance zone for AGPs with and without NoPaS were 0.9% and 75%. The patent was filed following successful test results. Conclusions: NoPaS is an effective, low-cost, and environmentallyfriendly solution for performing AGPs with no risk of virus transmission. With modifications, it can be used for medical procedures on head and neck. Further work is currently underway to take NoPaS into mass production.