The ventilator specifications has a 240V supply and requires 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 within hospital transfer. It also has to avoid harmful RF or EM emissions that could interfere with other critical machinery.
This is a requirement of CE marking, 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. This is a key difference with open source designs already available.
Another difference is that 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. At the same time the system has to be easy to use with minimal training.
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 large, heavy batteries.” Specifying a DC voltage (ie 12VDC) may well be the most sensible for the machine working voltage, allowing for