High Flow Nasal Oxygen (HFNO) medical devices are utilised to non-invasively oxygenate Coronavirus disease 2019 (COVID-19) and acute respiratory distress syndrome (ARDS) patients with mechanisms of clinical benefit. Most recently, HFNO has proven to be effective against hypoxemic symptoms by providing a range of oxygen concentration levels (FiO2) and aims to improve patient compliance and comfort with heating and humidification of inspiratory gases. HFNO has been shown in studies to be feasible in resource-constrained settings, relying on an affordable solution to drive an increased number of supplied devices to healthcare facilities to effectively treat patients independently of intensive care units (ICU). Therefore, a Proof of Concept was developed under an iterative design approach. A full cost summary of materials was R8 100, compared to at least R45 000 for current South African market competitors. Additionally, the solution was functionally tested to determine levels of verification in technical specifications and validation in addressing clinician and patient needs. The solution achieved associated 10 - 60 l/min flow rates; stable FiO2 from 50 - 100% (with a minimum of 40%); and inspiratory gas temperatures and humidity of up to 40 oC and 90% relative humidity (RH). Further design and development need to be conducted to output a high-performing and safe medical device as guided by ISO 80601-2-90.