A ventilator specification released by the UK government recommends contacting an electronic engineer to tackle the battery issues of the design.
“[You] need the advice of an electronic engineer with military/resource limited experience before specifying anything here. It needs to be got right first time,” it says.
While the ventilator will use a 240V supply, it will also need a battery back-up to provide 20 minutes of operation. There is an option for hot swappable batteries so that it can be run on battery supply for an extended period, for example, two hours for movement within a hospital. It also has to avoid harmful RF or EMI emissions that could interfere with other critical machinery.
This of course is a requirement of CE marking for equipment, and the specification also points to the BS EN 794-3:1998 +A2:2009 standard on emergency and transport ventilators, as well as ISO 10651-3:1997, BS ISO 80601-2-84:2018 on the safety of medical electrical equipment and BS ISO 19223:2019. The UK’s MHRA medical hardware regulation agency will lead an exercise to define which can be ‘safely’ relaxed to speed up the roll out of the equipment.
Components used in a design also have to be available in volume in the UK, which could be a challenge for sourcing the batteries and for the electronics for controlling and monitoring the equipment.
Companies such as Airbus, Jaguar Land Rover, Meggit, as well as vacuum cleaner designers Dyson and Gtech, have been connected to projects aiming to develop and build ventilators for the UK, many using 3D printing capacity. University College London and the University of Cambridge have also been leading ventilator design projects. Many of these projects have been collated by the UK's Institute of Manufacturing.
Designing in the battery backup is needs very careful thought to balance the risks, says the specification. “Including this in the spec means instantly trying to source 30,000