Raissa Malu

The race for "made in DRC" ventilators

The COVID-19 outbreak put the spotlight on ventilators. Several initiatives to produce them have emerged in the DRC.

The worldwide, African and especially Congolese craze for mechanical ventilators will not have escaped you. Let me tell you this story.

Europe in the 19th century

The history of mechanical ventilation begins in 1876 with the Spirophore by Eugène Woillez (1811-1882), a French physician. It was the first ventilator by external application of a pressure variation.

In 1906 the Pulmotor by Henrich Dräger (1847-1917) was introduced. Just for pleasure, I am transcribing here the little story that can be read on the official website of the Dräger company he founded and which still exists today: "Johann Heinrich Dräger witnesses how a young man is saved from the River Thames in London and resuscitated. The event inspired him to further develop a groundbreaking idea: On-site mechanical ventilation to resuscitate people who have lost consciousness through oxygen deficiency. Back in Lübeck, Johann Heinrich Dräger begins work on the Pulmotor, the first series-produced emergency respirator in the world". 😊

Iron lungs

In 1928, people began to call iron lungs the first long-term mechanical ventilators used during polio epidemics. It was not until 1954 that the first modern, electric ventilator appeared, the Engström 150, which made the development of resuscitation possible. Without going into the technical details of improvement, the progress that followed mainly concerned the ergonomics of the ventilators and the understanding of the physiopathology of mechanical ventilation and its undesirable effects.

But what is a ventilator? An artificial respirator, or ventilator, is a medical device for respiratory assistance, which allows artificial ventilation of the lungs suffering from respiratory insufficiency or during surgery. The device ensures the functions of the injured lungs by transporting oxygen in the blood. It thus helps you to breathe if you can no longer breathe on your own.

The respiratory cycle

The important concept to master for its development is the physiological respiratory cycle that the machine must reproduce or not hinder. It has four phases:

  1. inspiration, which is active;
  2. the transition between inhalation and exhalation;
  3. exhalation, which is passive;
  4. the transition between exhalation and inhalation.

Crucial parameters

In so-called transport or emergency fans (which we are all currently working on developing 😊), a minimum of four parameters must be monitored on the screen :

  • respiratory rate (the number of breaths per minute);
  • I/E ratio (ratio of inspiration time to expiration time);
  • tidal volume (actually the ventilatory flow, i.e. the volume of air pushed into the lungs per unit of time);
  • FIO2 (the inspired fraction of oxygen, i.e. the fraction or percentage of oxygen present in the gas mixture that a person breathes).

(If you're not familiar with all these concepts of volume, pressure and flow, subscribe now to the "Learn at Home with Science and Technology Week" program, we'll talk more about it at 😉.)

An advantage in Europe and the United States

I'm not going to pretend I master the topic. This is all very technical. I'm only touching things so that we all have a minimum of vocabulary to impress people at the next Sultani Makutano for example 😉. So, how are the engineers going to develop this machine that will help your lungs in case of respiratory distress?

If you're at the Massachusetts Institute of Technology (MIT) in the USA, the Université Catholique de Louvain (UCL) in Belgium or the Mercedes-Benz F1 team, and you decide to go ahead with the development of an emergency ventilator to deal with the COVID-19 pandemic, you clearly have an advantage. Not so much in terms of skills, but because in these countries there is an industrial fabric that produces all the components needed for their developments. You will understand.

Mechanical and electrical

To develop an emergency respirator, we start with the mechanical part with the choice of the mode of actuation and of the motor to compress the Ambu bag (an insufflation bag). The power of the motor must be adapted to the pathology. Indeed, the theoretical power required is determined using the medical parameters I mentioned before. For COVID-19 disease, for example, a motor power of about 25 watts would be required.

To operate the mechanical part, you need an electrical part with a microcontroller. Today, specialists in the field are advising the Arduino. The Arduino is a printed circuit board made of free material on which a microcontroller can be programmed. It is a "magic card". Fortunately in Kinshasa we have a good programmer. I will come back to him later. 😊

Testing robustness

When these parts are working, the patient must be connected to the ventilator. This is the plumbing part with the circuit for the air-oxygen mixture and the circuit for carbon dioxide. These are two different circuits. We also have the valves, the mask, the HEPA filter (this is a high efficiency air filter to avoid contamination), etc.

I may give the impression that this part is less important, but it's actually the most critical part of the device. Finally, we have safety management, which is just as critical. Doctors must indeed be immediately and clearly informed in the event of a machine malfunction, so that they can take action.

A prototype intended for the hospital environment must therefore have tested the robustness of all these parts. To do this, it is essential that engineers have the best possible understanding of the management of patients with acute respiratory distress syndrome (ARDS). At the beginning of the last century, many patients died because of poor control of ventilation parameters and this is probably still the case today.

The situation in the DRC

I am not going to go back over the general context of the Democratic Republic of Congo quite well described by Prof Kazadi Tshikolu Romain, Dean of the Faculty of Engineering ULC Icam, Loyola University of Congo, in his article Should respirators be manufactured in the DRC for COVID-19? published at www.respirateur-rdc.org. We have several teams in the DRC that have embarked on the production of mechanical emergency respirators in response to the global appeal. This call was notably relayed by Prof. Dr. Ir Sandrine Mubenga Ngalula.

In the academic world, we have the prototype developed by the Polytechnic Faculty of the University of Kinshasa (UNIKIN), the prototype developed by the Official University of Bukavu (UOB) and the Loyola University of Congo (ULC) which has developed a functional prototype according to their designers.

Professional and associative world

In the professional world, we have in particular the prototype developed by Women's Technology of Ir Thérèse Kirongozi, well known for her Robot Rollers. Her prototype, which was presented to nine doctors in a major hospital in the capital, is currently being perfected.

In the associative world, there is the prototype developed by Investing In People (IIP) ASBL.😊

Healthy competition

Already, having different teams developing prototypes in parallel is excellent. This is healthy competition that stimulates creativity and productivity locally.

For the IIP ASBL prototype, we called on one of the most gifted inventors of his generation, Ferawi Mabla. Ferawi holds a degree in computer science from the University of Kinshasa, Faculty of Sciences, Department of Mathematics and Computer Science, option Computer Engineering. He is the local gem in programming on Arduino! 😉

Dealing with local hardware

Under my supervision, Ferawi and his team carried out the mechanical part, programmed the electrical part and imagined a first design. We used the MIT open source project as a basis, but we had to deal with the hardware available locally. It was not possible to reproduce the design of the MIT model. We did some recuperation and fortunately, Ferawi is good at programming.

The prototype of IIP ASBL currently weighs 3 kilograms. It is equipped with a NEMA 23 stepper motor, a TB6600 stepper motor controller, an LCD screen and an ATMel a328p Arduino Nano microcontroller. It works with a 12 volt battery. We are still working on the design and we are developing the monitoring of the parameters and the security management. We are also collaborating with the Women's Technology team and other teams will integrate the project.

For scientific presentations

When it is complete, the prototype mechanical respirator developed by Investing In People ASBL will be used for the scientific presentations during the next editions of the Science and Technology Week. We have called it the Respirator of Hope. The experience acquired will be put at the service of professionals and investors in order to develop mass production if necessary.

Respirateur de lespoir

Developing a mechanical ventilator for medical use is not a simple matter. This device can save lives, but it can also take lives if it is poorly designed, poorly adjusted, poorly used, poorly maintained.

That's probably why it can take up to two years to get a respirator approved! In my opinion, the information that should be retained from this adventure is that we do have in DRC and in Africa, scientific and technical skills which, if they are associated with investors (and meet a favorable economic and legal framework), can (re)develop locally the industrial fabric.

Repairing and training

For the current COVID-19 pandemic, the urgency would be to repair the professional medical respirators already present in our hospitals, as is being done by INPP, to ensure urgent training of medical personnel, to provide them with masks, protective face screens and all the necessary equipment to safely manage patients, and to continue to remind the population to follow the barrier moves scrupulously.

#StopCoronavirus

Science is fun, join us ! 😉

This post has first been published on LinkedIn. It has been translated in English by Afriscitech.

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