Reespirator aims to contribute to solving the lack of mechanical ventilation devices in emergency situations. In recent days, many countries in Europe were faced with a difficult health situation due to the high and timely demand for technical resources caused by the CoVid-19 pandemic. The situation is gradually returning to normal, but at present it is uncertain how long and how many waves this virus will eventually produce, and whether emergency devices such as the REESPIRATOR2020 ventilator will ever be needed.

The pandemic has become a global problem, with great uncertainty about the current and future impact on different countries depending on their climate, living habits, health resources, economic situation,… It is easy to understand that emergency devices, even if they are not certified medical equipment, can help to lessen the effects of this disease, as support or main ventilation devices.

On the other hand, many countries and communities have a structural lack of technical health resources that makes it difficult or impossible to treat adequately diseases that would be much more advantageously treated in Europe. This situation predates CoVid-19 and is likely to continue after the pandemic is brought under control. Although emergency teams may not be needed in Europe, they can always be useful in countries and communities with weak health systems.

Reespirator is an Open Source emergency ventilator. The aim of the project is to collect and publish all the necessary information so that a device to help in specific or permanent emergency situations can be built with few resources. The documentation will be released under a creative commons license in order to make its access as free as possible, and at the same time allowing that the improvements or adaptations made will result in better information for those who are encouraged to build one of these devices.

<note warning>Reespirator is not a medical device It is currently not medically certified and is not expected to become so. The responsibility for the use of the device must be assumed by whoever decides to build and use it.</note>

At this document there is a basic introduction to the main functions of today's mechanical fans, and in particular to the functions we expect the Reespirator2020 to have. Initially we are implementing the pressure control mode completely and safely, both in the Arduino based version and the PLC based version. We are working on the electronics, pneumatics, mechanics and control displays simultaneously. This stage is what we call Release 1.

Repository of the original project Respirator23 Includes a basic description of the hardware and equipment needed to buildt the respirator. It includes a software to work with arduino and an advanced display around a Beagle Bone.

This model has been validated with artificial lung and animal model. However, it is possible that any change in the configuration or the control system will require a new validation process.

Repository of the Respirator2020 It is a branch of the original project. In the folder Respirator2020 there is a complete description of the current state of the project, with building plans for laser/CNC cutting, principle diagrams, electrical and pneumatic diagrams, software and list of materials.

There are two major implementations, and some other variants under study. One is based on an industrial PLC from SIEMENS, which is a little more advanced, and the other one is based on arduino MEGA or a similar architecture. The first one uses a proprietary touch screen, while for the second one a communication protocol and a control program in LINUX has been developed. This programa can be executed in a Beagle Bone, Raspberry or any laptop with Linux. The functions of the touch screen are the same in any case, and include control menus, parameter setting and operating modes, graphics, alarm management, etc.. The version with arduino also includes a basic low cost control around a 4×20 character LCD display that allows to manage all the functions of the equipment, but not to see graphics.

There is still a lack of information in the communications sections, electronic board, diagram, and others that are being developed. Also missing is a complete list of materials needed to build the Respirator2020, and some of the elements are still in the testing and development phase.

There are several working groups that are coordinated through telegram lists:

• ARDUINO: focused on the programming of the Arduino MEGA or similar system. Among other aspects it includes: development of the main program, control loops, fault and emergency situation management, system modelling, definition of communications with the advanced display, operation of the basic LCD display… The idea is that the program is easily transportable between different platforms, so that if it is necessary to migrate to a more powwrful board or microprocessor can be carried as much as possible of the code.

• ELECTRONICS: takes care of the design of a control board for the system that can withstand the electromagnetic immunity tests required to avoid interference.

• SENSORS: currently the main uncertainty is how to monitor the inspired and expired airflow. Commercial flowmeters are in high demand, and we consider that it would be very interesting to have a low cost alternative that allows the flowmeter to be considered as a disposable element. The group is studying the use of a throttle in the tube to generate a pressure difference related to the flow rate.

• PROTOTYPES: the team is starting to build functional prototypes in order to test the real operation of all the elements. They will also serve to initiate the tests that can be made depending on the resources available at each location.

During the weekend of April 24-26, 2020, the prototype bricolabs-rees-2020 will participate in the European-wide hackaton EUvsVirus.

These days we were updating the documentation of the equipment, looking for materials to complete it and advancing in the programming of the control loops with the intention of having a functional equipment in a term inferiors to one week. Specifically:

• Mechanical adjustments to the prototype
• Connector design for patient side tubing
• Selection of the expiration zone solenoid valve and Jackson Rees device elements
• Advances on the LCD-based low cost control panel
• Discussion of the implementation of control loops.
• Exchange of ideas and proposals with other teams that are developing their own mechanical fans