April 17th

It felt like a slow week, but a lot got done.

We took delivery of the 50 Series 1 machines from Audi last Friday and started putting in the motherboards the next day.
 Thanks to Jarne, Brecht, Hendrik, Martin, Mohammed, Rupert, Rayan & Roald for the help putting the machines together over the next days.

The boards needed a couple fixes but are working. Sensor modules are working. We have about 25 machines fully built-out now.
Number 1 to 13 will stay in Belgium and will be used for tests, both in-house and at partner locations.

The other machines will be sent out early next week to other research groups in Italy, Canada, Brazil, Jordan & Spain who are interested in testing & co-developing the ventilator.

The 50-machine-run at Audi & all the component sourcing involved has proven the validity of the design approach for rapid-manufacturing.
Using their manual assembly line, Audi can output one assembled machine  frame every 2 minutes. 

Branimir & Bruno have been running the machines through the functionality tests specified in the MHRA-document, Simon has been finalizing the end-of-line tests.

The interface has come together;  Thomas, Tom, Loes, Frank & all have been bug-fixing most of the week

Sourcing the medical parts (respiratory valves, PEEP-valves) has proven troublesome. Theo and Ben have designed 3D-printable versions, and have been producing these. We are using them for on the 25  test setups for now, but may develop them for compliance with medical use.

We have been demonstrating the machine & collecting feedback. The design requirements for version 2 are taking shape.

Koen Vanden Boer, at the Flanders Make testsite in Lommel has been performing endurance tests on the Ambu bags. With the plunger from prototype 8 we had bag failure at 50’000 plunges.
We need to achieve 600’000 repetitions at full volume to safely use the machine for 2 weeks. The new plunger design has achieved 500’000 plunges and is still going. An additional 8 test stands have been installed and are pumping away to achieve more statistically valid results.

Parallel to testing version 1, Jef aims to have  a first mechanical prototype of version 2 finished by the end of the week.

However, with the pc-interface, the aluminium frame & the electronics the machine is developing into a solid, professional design. The bag has, at least in perception, become the weakest link.

  We intend to quantify & document the durability of the Ambu bag concept and fully evaluate the performance of version 1, 
but it is becoming highly likely version 2 will have a custom-built bellows, replacing the Ambu bag with a more durable solution.

The ventilator gets written about in De Standaard tomorrow:

We updated the website with pictures from this week:

Update April 10th

The 50 machines, assembled by Audi Brussels, arrived at the lab today.
With their setup, there are only 2 minutes between every finished machine rolling of the production line.

We also received the finished main PCB from Eurocircuits,
and the Arduino shield/sensor boards sponsored by Barco.

Aluminium panels were cut by Team.

We are mounting the boards in the machines this weekend and should be able to send out test machines by Tuesday.

April 9th – Demo video’s

Video illustrating test setup:

The machine is connected through a single tube to a respiratory valve (partially red) – air then goes through the pressure and flow sensor (test setup, not final sensor implementation) – then through the Fluke VT900 to an adjustable test lung. Exhalation goes back to respiratory valve and out through manually adjustable PEEP-valve (green)

( Fluke on loan from Rood, test lung on loan from Technimed)

This is still prototype 7. We will switch the test setups to Beta version 1 as soon as these arrive.

NOTE: we are aware connection between respiratory valve and patient should be as short as possible – just not very practical to do in this test setup.

Video demonstrating interface (non-touchscreen version):

Setup start at RR=20, Ppeak=30cmH20 and a PEEP setting of 10.
Video shows adjustment of RR, Ppeak, ramp settings, IE-rate, and the adjustment of the PEEP-valve.

-alarms have not been set correctly yet in this setup
-IE units should be adjusted in the interface.
IE=0.5 in this version means 50% of total time is inhalation. So IE=0.5 is 1/1, IE=0.33 is 1/2.
-Values in the teal rectangle at the right of the screen should show measured values for P, V, RR, MV – not active in this demo.

Static image, where you can read the small print
(open in new tab to enlarge)

Video demonstrating the use of breathing trigger:

Video demonstrating breathing support through pressure-trigger or flow-trigger.

April 8th Duration tests

Endurance tests on the ambu bags showed failure after 160’000 cycles. Bags were fully depressed at 1Hz. This translates to failure after 3 days of RR=35 BPM at full volume (1000 mL).

Failure mode is a tear near the hard, plastic endcap of the ambu bag.

We have updated the plunger design, to a narrower & more rounded version. This still achieves the requires Vt of 800mL , while putting less stress on the edges of the ambu bags.

The test version also did not have the silicone covers.
This updated version has been sent to the test facility.

April 6th

Documention was moved to this site.

The team is sourcing parts for the Beta1 – series.

The interface has been further developed.
There is still a lot of work to implement multiple alarms, but the PC and the Arduino can now be disconnected and reconnected without restarting.

If sensors are disconnected, the machine now goes to a safe open-loop mode and keeps running.

April 1st

The pc-interface is working.
Not the final graphical design, but we basically control the pump from a touch screen or keyboard now

This is amazing work from Thomas Van Den Dries & Tom Bruyneel, Frank Vanbever, Stein Crispel, Laurent Segers, Branimir & all 

Video: https://photos.app.goo.gl/UnNw3LmDGuY6QVMTA

Photos: https://photos.app.goo.gl/8dyWrT299qnPVCM59

Flow curve is missing on the screen, but we have the data. Flow sensor drift has been solved. User can control Vt, RR, IE, Ppeak, ramp time and can set alarm ranges on the measured values.

Computer gives alarm if microcontroller stops working and vice versa. There are no more push buttons.

It has become clear the machines will not be needed in Belgium. 
We are continuing the project, but there will not be 1000’s built in Belgium .

It also means fast-track certification in Belgium is off the table, since no need.

We have started a run of 50 with the help of Audi Brussels; we are definitely skipping a few steps and expect these beta-models to need fixes, but we will have enough to send out for testing. We expect to have those build by the end of next week
(IF the PCB’s we ordered work without dramatic mistakes,
otherwise at least one week later)

We will be putting a group on getting the documentation organised, so we can get clean files out to teams in other countries.

Ronald has set up a group in Montreal, and we also got a request to share files with Sannio University (Italy).
We also sent them the dropbox archive from the day before.

Everything is changing quickly, so we will have to reorient next weekend, but we have every intention to finish the project and get to a reliable, functional and open-source machine.

Best, Lieven