3D-printed breathing machine
UJ team of engineers design a mechanical ventilator that can support multiple Covid-19 patients in distress
WITH hospitals near capacity as the number of Covid-19 cases spike, the country is expected to face a shortage of lifesaving ventilators.
In an effort to minimise shortages, a team of University of Johannesburg (UJ) engineers have designed portable three-dimensional-printed mechanical ventilators that have a customisable base plate to treat multiple patients.
The ventilator, named Aura Imprimere,, meaning a breeze of air provided by printing, is portable and allows off-grid operations for up to one-and-a-half hours.
Professor Tien-Chien Jen, head of UJ’s Department of Mechanical Engineering Science and project team leader, said the ventilators were safe to operate. “These unique 3D printable ventilators use a micro-controller to control the two motors. By adjusting the speed and direction of rotation of the motors, it is possible to obtain a pressure-time profile that is suitable for respiratory assistance of patients.”
The device has a battery system that will ensure normal functioning while demand for electricity exceeds available supply, said Jen.
“Its components are designed in such a way that it can be easily assembled on site in cities, rural areas or remote areas. The micro-controller monitors the pressure inside the Ambu bag by using a pressure sensor.
The UJ-led team plans to distribute the active breathing circuit system on an “open-source” basis, making the software and designs freely available and can be produced anywhere in the world with a 3D printer.
Aura Imprimere is based on a reciprocating engine piston and crank design. The motors were extracted from electric screwdrivers.
The ventilator allows for electronic components, such as a control resistor, variable resistor, and a small programmable computer to be used. These electronic components can customise the pulse needed for a patient.
The crank design provides a linear motion for the slider relative to the slider base. Here the “fingers” are integrated so they can manipulate the Ambu bag and allow it to deflate.
Jen explained the Ambu bag was placed at the centre component and secured with clamps. “The Ambu bag comes in different sizes, and the invention can be custom-changed with ease, on site, according to the patient’s age, condition and breathing necessity.
“This is due to the meshed base plates that allow the clamps, mechanism, electrical housing, etc, to be reoriented and placed as the user pleases – inspired by LEGO-type designs.”