Abstract:
The paper proposes the concept of a simplified ventilation device that meets the requirements for the
South African Health Products Regulatory Authority (SAHPRA) approval and may be manufactured in
large numbers at moderate cost to meet the requirements of the current or future pneumonic type
pandemics. The paper further describes the development of such a device and presents descriptions
of the final prototype.
The philosophy behind the design was to take an engineering view of the problem of safe ventilation,
which also meets World Health Organisation (WHO) guideline ‘Technical specifications for invasive
and non-invasive ventilators for COVID-19’ (2020), whilst using the human biological responses to
control the aspiration boundaries, thereby avoiding the very complex processes which simulate the
breathing mechanism.
The methodology employed was a conceptual design phase followed by an engineering design
phase, prototyping, testing, and further developments. The concept was based on guidelines from
WHO, 2020: Technical specifications for invasive and non-invasive ventilators for COVID-19: Interim
guidance: paragraphs 2.1.2 and 2.2.2.(2020) and measured against the UK standard of the Medicines
and Healthcare Products Regulatory Agency (MHPRA) ‘Rapidly manufactured ventilator system’
(2020). Each component of the conceptual design was developed in this way and a final prototype
was assembled for independent evaluation and eventual SAHPRA evaluation.
The finished prototype meets WHO guidelines for a Bi-level Positive Airway Pressure (BiPAP) system
and also meets the guideline requirements for portability. The prototype also meets the initial intent
regarding simplicity, functionality and cost. The further developments to mass production will reduce
the part count and assembly processes, with some components to be reconfigured as disposable
items, not for sterilisation or re-use. The project has shown that specialised equipment may be viewed
pragmatically according to the requirement — to treat all breathing difficulties with a full specification
ventilator is not possible or necessary; to assist the majority of ostensibly minor cases with a Bi-PAP
system is both practical and more affordable. The intent is not to compete with the high technology
commercially sourced equipment, or even the rapidly prototyped re-purposed industrial efforts
worldwide, but rather to initiate some progress in the Republic of South Africa to quickly produce an
abundance of these machines, to cope with the possible deficit of medical ventilators expected in
future.
The solution lies in a simple but failsafe device that provides assisted breathing with the option of
oxygen enrichment. It is intended to be locally manufactured with the minimum of skills and is easily
maintained and sterilised.