A couple of weeks ago I was lucky enough to interview Professor Tim Baker of UCL about the phenomenal engineering achievement by his team during the Covid-19 pandemic in response to the UK Government ventilator challenge. 

This was one of the best online events I've ever seen.  The audience were gripped in the twists and turns of how the project timeline unfolded and the insight in to how Tim's little black book of contacts brought together a team able to deliver the first prototype device to clinical trial in 100 hours, then go on to manufacture 10,000 devices in just 4 weeks!

You can watch the recording of the event below to see for yourself.  E&T Magazine also did a great 'tear down' article on the design if you're interested in how it works in detail.

I've hosted a few of these events now, but as the host it's always difficult to imagine what the audience are thinking.  During Tim's talk, there were no audience questions at all and I feared the worst, but as soon as Tim stopped speaking, the avalanche of questions came.  Unfortunately too many to answer in the time available, so Tim has kindly provided some follow-up answers that you can read below.

Q. What if anything has the existing NHS supply chain learned from your experience? Can they ever be made to be slicker or are they optimal for normal NHS activities?

Tim: "There are always lessons that can be learned. From what I know, their understanding of ‘just in time’ logistics has been tainted by poor experience with the wrong suppliers involved. Engineering can teach them a lot. If parts don’t appear on a production line in time, then all hell breaks loose. I wouldn’t say it goes to the same level but there are improvements that could be made."

Q. Riveting - thank you! The images appear to show a team with high morale - despite the hard work and pressure. Please would you comment?

Tim: "Morale was very high. Genuinely never a single argument and we were lucky not to have any large egos or anyone trying to dominate things. We have created bonds that will last a lifetime too."

Q. Are they a once only use or can it be decontaminated?

Tim: "The devices are protected with an in-line filter so the devices can be reused time and again after nothing more than a wipe down. There was some testing in the Covid ward during the first peak to check for airborne infection and contaminated surfaces as a precaution. Nothing was found."

Q. This is an amazing human and technical story. True dedication from such an extensive team of people to get the job done. Are there any plans to bring the story into the general press? It is important that the lessons are learnt.

Tim: "We are in discussions about getting the book written. We would love to tell the whole story."

Q. Can you elaborate on the warnings you received about people being hostile to your work?

Tim: "We had everything from threats to reputation and not receiving any funding unless we agreed to partner with third parties to ‘manage’ the project for us. We went our own way and succeeded when others didn’t."

Q. This is indeed an excellent integration of existing “micro-pneumatic” systems used in automobile industries. How was the process of getting the dimensional adjustments of the tubes and valves? Did you do a lot of CFD-analysis in parallel to your tests with “patients” at UCL?

Tim: "We moved very quickly to identify how to eliminate the losses in the system. This was driven by common-sense engineering, so finding the largest-area filter available and smooth-bore tubing. Not having the oxygen sensor sticking almost two-thirds of the way into the pipe! Real basics that are accepted practice. We bench tested every single item – pipes, filters, valves, masks, T-pieces – and measured the backflow for each design. Fortunately the supplier we struck up the relationship with had the best components to optimise the breathing circuit for the Ventura device. We also did a lot of CFD with Mercedes to gain a better understanding of the dynamics of the device. Plus hours and hours of testing on healthy volunteers. That is quite a task because they are so variable! Although you want to be able to cope with different physiologies, it is not very useful when trying to characterise improvements in a system!"

Q. You mentioned seeing things at the hospital meeting that came out 12 months later and were denied. What were they?

Tim: "When it’s all finally over I would be comfortable saying more. I hope that an official enquiry will bring these issues to light. It really affected us – I can’t imagine what it must have been like being on the front line in hospital."

Q. Now emotionally proud to be an engineer, but as a scuba diver what is the percentage band of oxygen enrichment please - given there is a need for a 'good flow' through the venturi?

Tim: "The Ventura uses oxygen to energise the venturi. It is possible to go from just above ambient concentration right the way up to 100% pure oxygen. But because the oxygen drives the system it wastes a lot. That’s also why we worked on reducing the back pressure as that dropped the oxygen requirement. Also, at low concentrations, oxygen was lost straight out of the air entrainment port if the back pressure was too high."

Q. How did you keep the team Covid-free before testing was rolled out? I see there weren't any masks in your group photos...

Tim: "At first the suspicion was that it was surface contact. We didn’t wear masks throughout the whole time as we lived and worked in a bubble. We were in the hospital continually, but we limited that to just two or three of us because that was the highest risk. Apart from Ben Hodgkinson, nobody in the core team caught Covid."

Q. Presumably the manufacturing tolerances of the original venturi devices were quite tight, did any considerations have to be made when opening the patent for local production around the world?

Tim: "At the beginning we hadn’t even thought of releasing the designs. We made an exact replica of what we had in front of us. When we started working with countries around the world we soon realised that it is not only healthcare that is different. Even though we designed everything so that it could be machined without the need for full CNC facilities, many faced real challenges. For them, we helped to source a cost-effective supply of the parts they had difficulty making but they still did the bulk of the manufacture and assembly themselves."

Q. You mentioned that the Ventura name came from your pyjama tops, is it just a coincidence that your young team member bought tops with a word so close to Venturi?

Tim: "Absolute coincidence as it was all they had but it was meant to be!"

And that's just a flavour of the conversation that Tim, Paul and myself had around the topic of Tim's gripping story, that we're sure will one day be made in to a feature film.  But who did we cast as George Clooney and who as Steve Coogan?  Watch the replay to discover...

"COVID Breathing Aid - UCL Ventura, from zero to 10,000 devices in 4 weeks!" is one of a series of online events presented by the IET's local Network in Surrey, UK.  Many of these are available to view on-demand.