Brazilian researchers design low-cost mechanical ventilators

A group of researchers at the University of São Paulo's Engineering School (POLI-USP) in Brazil have developed a mechanical ventilator that costs only approximately 7% as much as a conventional ventilator. Called Inspire, it has an open patent allowing royalty-free manufacturing, although as a life support device, its distribution is controlled.

A pilot batch will be produced by the Brazilian Navy for use in clinical trials. Twenty companies are interested in making the ventilator, which has already been tested in animals and humans.

Ventilators are essential for the treatment of patients with acute respiratory syndrome, one of the most severe outcomes of COVID-19.

Our ventilator is designed to be used in emergencies where there's a shortage of ICU [intensive care unit] ventilators, which are more monitored, but it has all the functionality required by a severe patient. It also has the advantage of not depending on a compressed air line, as conventional ventilators do. It only needs an electric power outlet and piped oxygen [O2] from the hospital or even bottled O2."

Raul Gonzalez Lima, professor at POLI-USP and principal investigator for the project

Lima has been working for approximately 20 years, with São Paulo Research Foundation - FAPESP's support (id_pesquisador_exact%3A86942)%20AND%20(*:*)), on the development of electrical impedance tomography (EIT) technology to monitor and optimize mechanical ventilation in ICUs. Monitoring these patients can mitigate side effects, shorten the weaning process and minimize the duration of mechanical ventilation.

From Lima's group came some of the researchers who founded Timpel, a manufacturer of tomographs used by hospitals in Brazil and abroad. The startup was supported by FAPESP via its Innovative Research in Small Business (PIPE) program (read more at: agencia.fapesp.br/33000).

Inputs and raw materials for Inspire are easily acquired in Brazil. The device takes no more than two hours to produce, for a cost of BRL 1,000 (currently approximately USD 170), compared with an average cost of BRL 15,000 for conventional ventilators.

Collaborations

Marcelo Knorich Zuffo, a professor at POLI-USP, is also collaborating on the project. Other professors at POLI-USP and at the same university's Medical School (FM-USP) and School of Veterinary Medicine and Animal Science (FMVZ-USP) are collaborating with Lima and Zuffo to perform the different tests required for product development and approval.

In developing the ventilator, the researchers needed to analyze the range of oxygen flow rates and levels it could offer patients. For this purpose, they simulated the various breathing frequencies of human lungs using a gas analyzer and gas flow meter at the Advanced Combustion Diagnostics Laboratory run by the FAPESP-Shell Research Center for Gas Innovation (RCGI). The RCGI is hosted by POLI-USP under FAPESP's Engineering Research Center (ERC) program. The head of the laboratory is Guenther Carlos Krieger Filho, also a professor at POLI-USP.

"This kind of equipment has to deliver an air-oxygen mixture to the patient's lungs, so we designed a test to measure the ratio between the time the oxygen line is open and the percentage of oxygen mixed with air," Lima said.

The instrument available at the RCGI, however, was developed to measure fuel combustion and can detect up to 30% of oxygen in air. A ventilator must deliver close to 100%. The researchers therefore calculated the mixture indirectly by measuring other gases and inferring the level of oxygen, which they found to be adequate.

Animal tests were conducted under the coordination of Denise Tabacchi Fantoni and Aline Ambrósio, both of whom are professors at FMVZ-USP.

The tests were performed at FM-USP's anesthesiology laboratory (LIM08) under the supervision of Professor José Otávio Costa Auler Junior, in collaboration with Denise Aya Otsuki, a researcher in LIM08.

The first human trials involved four patients undergoing treatment at FM-USP's Heart Institute (INCOR). They were led by Auler Junior, with the collaboration of Filomena Regina Barbosa Gomes Galas, the supervisor at INCOR's surgical ICU, nurse Suely Pereira Zeferino, and physical therapist Alcino Costa Leme. Zeferino and Leme are also researchers at INCOR. No complications were reported in the patients intubated with Inspire ventilators.

The researchers are now preparing a clinical trial with a larger number of patients. This will be one of the last steps before production of the ventilator is approved by ANVISA, Brazil's national health surveillance authority.